[0/7] TI K3 R5F remoteproc support

Hi All,

The following series adds a new K3 R5F remoteproc driver for all the R5F
processor clusters/subsystems on TI AM65x and J721E SoCs. The AM65x has a
single R5FSS cluster, while J721E has three R5FSS clusters. All clusters
are capable of supporting either LockStep (safety compliant providing
fault tolerance) or Split (performance mode) mode. The modes themselves
are limited on some SoC variants through an eFUSE setting. The IP version
and SoC integration is slightly different between AM65x and J721E SoC
families leading to couple of functional behavior differences.

The R5Fs are designed to boot out of TCMs with the initial boot-up code
on the R5Fs configure the Memory Protection Unit (MPU) to run code from
DDR. IPC is through the virtio-rpmsg transport. There is no error recovery
or Power Management support at present. The J721E 

The patches are on top of the current rproc-next branch, and uses one
patch from the OMAP remoteproc series [1]. It also leverages the fixed
memory carveout fixes series [2].  

The following is the patch summary:
 - Patch 1 is an old patch [3] from Loic posted previously to the upstream
   lists and allows the driver to perform the necessary sequencing
   w.r.t IP power-on and local resets and provide a balanced state
   machine across sysfs start/stop, and bind/unbind or module removal.
 - Patch 2 is a minor enhancement in remoteproc core to allow dynamically
   created platform devices to be registered with remoteproc core.
 - Patches 3 and 5 add the base binding and the the driver respectively.
 - Patch 4 is a common helper that will also be used by a TI K3 DSP 
   remoteproc driver (to be posted in the near future) providing the
   interface to the System Controller software over TI-SCI for performing
   device-specific operations.
 - Patches 6 and 7 are couple of incremental features to the R5F driver.

regards
Suman

[1] https://patchwork.kernel.org/patch/11455135/
[2] https://patchwork.kernel.org/cover/11447649/
[3] https://patchwork.kernel.org/patch/10251897/

Loic Pallardy (1):
  remoteproc: add prepare and unprepare ops

Suman Anna (6):
  remoteproc: use a local copy for the name field
  dt-bindings: remoteproc: Add bindings for R5F subsystem on TI K3 SoCs
  remoteproc/k3-r5: Add TI-SCI processor control helper functions
  remoteproc/k3-r5: Add a remoteproc driver for R5F subsystem
  remoteproc/k3-r5: Initialize TCM memories for ECC
  remoteproc/k3-r5: Add loading support for on-chip SRAM regions

 .../bindings/remoteproc/ti,k3-r5f-rproc.yaml  |  338 ++++
 drivers/remoteproc/Kconfig                    |   16 +
 drivers/remoteproc/Makefile                   |    1 +
 drivers/remoteproc/remoteproc_core.c          |   29 +-
 drivers/remoteproc/ti_k3_r5_remoteproc.c      | 1461 +++++++++++++++++
 drivers/remoteproc/ti_sci_proc.h              |  102 ++
 include/linux/remoteproc.h                    |    6 +-
 7 files changed, 1950 insertions(+), 3 deletions(-)
 create mode 100644 Documentation/devicetree/bindings/remoteproc/ti,k3-r5f-rproc.yaml
 create mode 100644 drivers/remoteproc/ti_k3_r5_remoteproc.c
 create mode 100644 drivers/remoteproc/ti_sci_proc.h

On Tue 24 Mar 13:18 PDT 2020, Suman Anna wrote:

> The current name field used in the remoteproc structure is simply
> a pointer to a name field supplied during the rproc_alloc() call.
> The pointer passed in by remoteproc drivers during registration is
> typically a dev_name pointer, but it is possible that the pointer
> will no longer remain valid if the devices themselves were created
> at runtime like in the case of of_platform_populate(), and were
> deleted upon any failures within the respective remoteproc driver
> probe function.
> 
> So, allocate and maintain a local copy for this name field to
> keep it agnostic of the logic used in the remoteproc drivers.
> 
> Signed-off-by: Suman Anna <s-anna@ti.com>
> ---
>  drivers/remoteproc/remoteproc_core.c | 9 ++++++++-
>  include/linux/remoteproc.h           | 2 +-
>  2 files changed, 9 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/remoteproc/remoteproc_core.c b/drivers/remoteproc/remoteproc_core.c
> index aca6d022901a..6e0b91fa6f11 100644
> --- a/drivers/remoteproc/remoteproc_core.c
> +++ b/drivers/remoteproc/remoteproc_core.c
> @@ -1989,6 +1989,7 @@ static void rproc_type_release(struct device *dev)
>  
>  	kfree(rproc->firmware);
>  	kfree(rproc->ops);
> +	kfree(rproc->name);
>  	kfree(rproc);
>  }
>  
> @@ -2061,7 +2062,13 @@ struct rproc *rproc_alloc(struct device *dev, const char *name,
>  	}
>  
>  	rproc->firmware = p;
> -	rproc->name = name;
> +	rproc->name = kstrdup(name, GFP_KERNEL);

Let's use kstrdup_const() instead here (and kfree_const() instead of
kfree()), so that the cases where we are passed a constant we won't
create a duplicate on the heap.

And the "name" in struct rproc can remain const.

> +	if (!rproc->name) {
> +		kfree(p);
> +		kfree(rproc->ops);
> +		kfree(rproc);
> +		return NULL;

Perhaps we can rearrange the hunks here slightly and get to a point
where we can rely on the release function earlier?

Regards,
Bjorn

> +	}
>  	rproc->priv = &rproc[1];
>  	rproc->auto_boot = true;
>  	rproc->elf_class = ELFCLASS32;
> diff --git a/include/linux/remoteproc.h b/include/linux/remoteproc.h
> index ddce7a7775d1..77788a4bb94e 100644
> --- a/include/linux/remoteproc.h
> +++ b/include/linux/remoteproc.h
> @@ -490,7 +490,7 @@ struct rproc_dump_segment {
>  struct rproc {
>  	struct list_head node;
>  	struct iommu_domain *domain;
> -	const char *name;
> +	char *name;
>  	char *firmware;
>  	void *priv;
>  	struct rproc_ops *ops;
> -- 
> 2.23.0
>

Hi Bjorn,

On 3/26/20 12:42 AM, Bjorn Andersson wrote:
> On Tue 24 Mar 13:18 PDT 2020, Suman Anna wrote:
> 
>> The current name field used in the remoteproc structure is simply
>> a pointer to a name field supplied during the rproc_alloc() call.
>> The pointer passed in by remoteproc drivers during registration is
>> typically a dev_name pointer, but it is possible that the pointer
>> will no longer remain valid if the devices themselves were created
>> at runtime like in the case of of_platform_populate(), and were
>> deleted upon any failures within the respective remoteproc driver
>> probe function.
>>
>> So, allocate and maintain a local copy for this name field to
>> keep it agnostic of the logic used in the remoteproc drivers.
>>
>> Signed-off-by: Suman Anna <s-anna@ti.com>
>> ---
>>  drivers/remoteproc/remoteproc_core.c | 9 ++++++++-
>>  include/linux/remoteproc.h           | 2 +-
>>  2 files changed, 9 insertions(+), 2 deletions(-)
>>
>> diff --git a/drivers/remoteproc/remoteproc_core.c b/drivers/remoteproc/remoteproc_core.c
>> index aca6d022901a..6e0b91fa6f11 100644
>> --- a/drivers/remoteproc/remoteproc_core.c
>> +++ b/drivers/remoteproc/remoteproc_core.c
>> @@ -1989,6 +1989,7 @@ static void rproc_type_release(struct device *dev)
>>  
>>  	kfree(rproc->firmware);
>>  	kfree(rproc->ops);
>> +	kfree(rproc->name);
>>  	kfree(rproc);
>>  }
>>  
>> @@ -2061,7 +2062,13 @@ struct rproc *rproc_alloc(struct device *dev, const char *name,
>>  	}
>>  
>>  	rproc->firmware = p;
>> -	rproc->name = name;
>> +	rproc->name = kstrdup(name, GFP_KERNEL);
> 
> Let's use kstrdup_const() instead here (and kfree_const() instead of
> kfree()), so that the cases where we are passed a constant we won't
> create a duplicate on the heap.
> 
> And the "name" in struct rproc can remain const.

Agreed, that's better functions to use for this.

> 
>> +	if (!rproc->name) {
>> +		kfree(p);
>> +		kfree(rproc->ops);
>> +		kfree(rproc);
>> +		return NULL;
> 
> Perhaps we can rearrange the hunks here slightly and get to a point
> where we can rely on the release function earlier?

Not sure I understand. I don't see any release function, all failure
paths in rproc_alloc() directly unwind the previous operations. You mean
move this to before the alloc for rproc structure, something similar to
what we are doing with firmware?

regards
Suman


> 
> Regards,
> Bjorn
> 
>> +	}
>>  	rproc->priv = &rproc[1];
>>  	rproc->auto_boot = true;
>>  	rproc->elf_class = ELFCLASS32;
>> diff --git a/include/linux/remoteproc.h b/include/linux/remoteproc.h
>> index ddce7a7775d1..77788a4bb94e 100644
>> --- a/include/linux/remoteproc.h
>> +++ b/include/linux/remoteproc.h
>> @@ -490,7 +490,7 @@ struct rproc_dump_segment {
>>  struct rproc {
>>  	struct list_head node;
>>  	struct iommu_domain *domain;
>> -	const char *name;
>> +	char *name;
>>  	char *firmware;
>>  	void *priv;
>>  	struct rproc_ops *ops;
>> -- 
>> 2.23.0
>>

On Thu 26 Mar 07:01 PDT 2020, Suman Anna wrote:

> Hi Bjorn,
> 
> On 3/26/20 12:42 AM, Bjorn Andersson wrote:
> > On Tue 24 Mar 13:18 PDT 2020, Suman Anna wrote:
> > 
> >> The current name field used in the remoteproc structure is simply
> >> a pointer to a name field supplied during the rproc_alloc() call.
> >> The pointer passed in by remoteproc drivers during registration is
> >> typically a dev_name pointer, but it is possible that the pointer
> >> will no longer remain valid if the devices themselves were created
> >> at runtime like in the case of of_platform_populate(), and were
> >> deleted upon any failures within the respective remoteproc driver
> >> probe function.
> >>
> >> So, allocate and maintain a local copy for this name field to
> >> keep it agnostic of the logic used in the remoteproc drivers.
> >>
> >> Signed-off-by: Suman Anna <s-anna@ti.com>
> >> ---
> >>  drivers/remoteproc/remoteproc_core.c | 9 ++++++++-
> >>  include/linux/remoteproc.h           | 2 +-
> >>  2 files changed, 9 insertions(+), 2 deletions(-)
> >>
> >> diff --git a/drivers/remoteproc/remoteproc_core.c b/drivers/remoteproc/remoteproc_core.c
> >> index aca6d022901a..6e0b91fa6f11 100644
> >> --- a/drivers/remoteproc/remoteproc_core.c
> >> +++ b/drivers/remoteproc/remoteproc_core.c
> >> @@ -1989,6 +1989,7 @@ static void rproc_type_release(struct device *dev)
> >>  
> >>  	kfree(rproc->firmware);
> >>  	kfree(rproc->ops);
> >> +	kfree(rproc->name);
> >>  	kfree(rproc);
> >>  }
> >>  
> >> @@ -2061,7 +2062,13 @@ struct rproc *rproc_alloc(struct device *dev, const char *name,
> >>  	}
> >>  
> >>  	rproc->firmware = p;
> >> -	rproc->name = name;
> >> +	rproc->name = kstrdup(name, GFP_KERNEL);
> > 
> > Let's use kstrdup_const() instead here (and kfree_const() instead of
> > kfree()), so that the cases where we are passed a constant we won't
> > create a duplicate on the heap.
> > 
> > And the "name" in struct rproc can remain const.
> 
> Agreed, that's better functions to use for this.
> 
> > 
> >> +	if (!rproc->name) {
> >> +		kfree(p);
> >> +		kfree(rproc->ops);
> >> +		kfree(rproc);
> >> +		return NULL;
> > 
> > Perhaps we can rearrange the hunks here slightly and get to a point
> > where we can rely on the release function earlier?
> 
> Not sure I understand. I don't see any release function, all failure
> paths in rproc_alloc() directly unwind the previous operations. You mean
> move this to before the alloc for rproc structure, something similar to
> what we are doing with firmware?
> 

Look at the failure for ida_simple_get(), there we're past the setup of
rproc->dev.type, so the rproc_type->release function will be invoked as
we call put_device().

So if you move the initialization of rproc->dev up right after the
allocation of rproc we should be able to rely on that to clean up all
these for us.

Regards,
Bjorn

> regards
> Suman
> 
> 
> > 
> > Regards,
> > Bjorn
> > 
> >> +	}
> >>  	rproc->priv = &rproc[1];
> >>  	rproc->auto_boot = true;
> >>  	rproc->elf_class = ELFCLASS32;
> >> diff --git a/include/linux/remoteproc.h b/include/linux/remoteproc.h
> >> index ddce7a7775d1..77788a4bb94e 100644
> >> --- a/include/linux/remoteproc.h
> >> +++ b/include/linux/remoteproc.h
> >> @@ -490,7 +490,7 @@ struct rproc_dump_segment {
> >>  struct rproc {
> >>  	struct list_head node;
> >>  	struct iommu_domain *domain;
> >> -	const char *name;
> >> +	char *name;
> >>  	char *firmware;
> >>  	void *priv;
> >>  	struct rproc_ops *ops;
> >> -- 
> >> 2.23.0
> >>
>

On Tue 24 Mar 13:18 PDT 2020, Suman Anna wrote:

> From: Loic Pallardy <loic.pallardy@st.com>
> 
> On some SoC architecture, it is needed to enable HW like
> clock, bus, regulator, memory region... before loading
> co-processor firmware.
> 
> This patch introduces prepare and unprepare ops to execute
> platform specific function before firmware loading and after
> stop execution.
> 

Reviewed-by: Bjorn Andersson <bjorn.andersson@linaro.org>

> Signed-off-by: Loic Pallardy <loic.pallardy@st.com>
> Signed-off-by: Suman Anna <s-anna@ti.com>
> ---
>  drivers/remoteproc/remoteproc_core.c | 20 +++++++++++++++++++-
>  include/linux/remoteproc.h           |  4 ++++
>  2 files changed, 23 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/remoteproc/remoteproc_core.c b/drivers/remoteproc/remoteproc_core.c
> index 26f6947267d2..aca6d022901a 100644
> --- a/drivers/remoteproc/remoteproc_core.c
> +++ b/drivers/remoteproc/remoteproc_core.c
> @@ -1394,12 +1394,22 @@ static int rproc_fw_boot(struct rproc *rproc, const struct firmware *fw)
>  		return ret;
>  	}
>  
> +	/* Prepare rproc for firmware loading if needed */
> +	if (rproc->ops->prepare) {
> +		ret = rproc->ops->prepare(rproc);
> +		if (ret) {
> +			dev_err(dev, "can't prepare rproc %s: %d\n",
> +				rproc->name, ret);
> +			goto disable_iommu;
> +		}
> +	}
> +
>  	rproc->bootaddr = rproc_get_boot_addr(rproc, fw);
>  
>  	/* Load resource table, core dump segment list etc from the firmware */
>  	ret = rproc_parse_fw(rproc, fw);
>  	if (ret)
> -		goto disable_iommu;
> +		goto unprepare_rproc;
>  
>  	/* reset max_notifyid */
>  	rproc->max_notifyid = -1;
> @@ -1433,6 +1443,10 @@ static int rproc_fw_boot(struct rproc *rproc, const struct firmware *fw)
>  	kfree(rproc->cached_table);
>  	rproc->cached_table = NULL;
>  	rproc->table_ptr = NULL;
> +unprepare_rproc:
> +	/* release HW resources if needed */
> +	if (rproc->ops->unprepare)
> +		rproc->ops->unprepare(rproc);
>  disable_iommu:
>  	rproc_disable_iommu(rproc);
>  	return ret;
> @@ -1838,6 +1852,10 @@ void rproc_shutdown(struct rproc *rproc)
>  	/* clean up all acquired resources */
>  	rproc_resource_cleanup(rproc);
>  
> +	/* release HW resources if needed */
> +	if (rproc->ops->unprepare)
> +		rproc->ops->unprepare(rproc);
> +
>  	rproc_disable_iommu(rproc);
>  
>  	/* Free the copy of the resource table */
> diff --git a/include/linux/remoteproc.h b/include/linux/remoteproc.h
> index 07bd73a6d72a..ddce7a7775d1 100644
> --- a/include/linux/remoteproc.h
> +++ b/include/linux/remoteproc.h
> @@ -355,6 +355,8 @@ enum rsc_handling_status {
>  
>  /**
>   * struct rproc_ops - platform-specific device handlers
> + * @prepare:	prepare device for code loading
> + * @unprepare:	unprepare device after stop
>   * @start:	power on the device and boot it
>   * @stop:	power off the device
>   * @kick:	kick a virtqueue (virtqueue id given as a parameter)
> @@ -371,6 +373,8 @@ enum rsc_handling_status {
>   * @get_boot_addr:	get boot address to entry point specified in firmware
>   */
>  struct rproc_ops {
> +	int (*prepare)(struct rproc *rproc);
> +	int (*unprepare)(struct rproc *rproc);
>  	int (*start)(struct rproc *rproc);
>  	int (*stop)(struct rproc *rproc);
>  	void (*kick)(struct rproc *rproc, int vqid);
> -- 
> 2.23.0
>

On 3/26/20 2:43 PM, Bjorn Andersson wrote:
> On Thu 26 Mar 07:01 PDT 2020, Suman Anna wrote:
> 
>> Hi Bjorn,
>>
>> On 3/26/20 12:42 AM, Bjorn Andersson wrote:
>>> On Tue 24 Mar 13:18 PDT 2020, Suman Anna wrote:
>>>
>>>> The current name field used in the remoteproc structure is simply
>>>> a pointer to a name field supplied during the rproc_alloc() call.
>>>> The pointer passed in by remoteproc drivers during registration is
>>>> typically a dev_name pointer, but it is possible that the pointer
>>>> will no longer remain valid if the devices themselves were created
>>>> at runtime like in the case of of_platform_populate(), and were
>>>> deleted upon any failures within the respective remoteproc driver
>>>> probe function.
>>>>
>>>> So, allocate and maintain a local copy for this name field to
>>>> keep it agnostic of the logic used in the remoteproc drivers.
>>>>
>>>> Signed-off-by: Suman Anna <s-anna@ti.com>
>>>> ---
>>>>  drivers/remoteproc/remoteproc_core.c | 9 ++++++++-
>>>>  include/linux/remoteproc.h           | 2 +-
>>>>  2 files changed, 9 insertions(+), 2 deletions(-)
>>>>
>>>> diff --git a/drivers/remoteproc/remoteproc_core.c b/drivers/remoteproc/remoteproc_core.c
>>>> index aca6d022901a..6e0b91fa6f11 100644
>>>> --- a/drivers/remoteproc/remoteproc_core.c
>>>> +++ b/drivers/remoteproc/remoteproc_core.c
>>>> @@ -1989,6 +1989,7 @@ static void rproc_type_release(struct device *dev)
>>>>  
>>>>  	kfree(rproc->firmware);
>>>>  	kfree(rproc->ops);
>>>> +	kfree(rproc->name);
>>>>  	kfree(rproc);
>>>>  }
>>>>  
>>>> @@ -2061,7 +2062,13 @@ struct rproc *rproc_alloc(struct device *dev, const char *name,
>>>>  	}
>>>>  
>>>>  	rproc->firmware = p;
>>>> -	rproc->name = name;
>>>> +	rproc->name = kstrdup(name, GFP_KERNEL);
>>>
>>> Let's use kstrdup_const() instead here (and kfree_const() instead of
>>> kfree()), so that the cases where we are passed a constant we won't
>>> create a duplicate on the heap.
>>>
>>> And the "name" in struct rproc can remain const.
>>
>> Agreed, that's better functions to use for this.
>>
>>>
>>>> +	if (!rproc->name) {
>>>> +		kfree(p);
>>>> +		kfree(rproc->ops);
>>>> +		kfree(rproc);
>>>> +		return NULL;
>>>
>>> Perhaps we can rearrange the hunks here slightly and get to a point
>>> where we can rely on the release function earlier?
>>
>> Not sure I understand. I don't see any release function, all failure
>> paths in rproc_alloc() directly unwind the previous operations. You mean
>> move this to before the alloc for rproc structure, something similar to
>> what we are doing with firmware?
>>
> 
> Look at the failure for ida_simple_get(), there we're past the setup of
> rproc->dev.type, so the rproc_type->release function will be invoked as
> we call put_device().
> 
> So if you move the initialization of rproc->dev up right after the
> allocation of rproc we should be able to rely on that to clean up all
> these for us.

Yeah ok. That's cleanup though, and probably a patch of its own, and not
directly related to the subject of this patch. Yeah, I can rework this
patch to sit on top of that cleanup patch.

regards
Suman

> 
> Regards,
> Bjorn
> 
>> regards
>> Suman
>>
>>
>>>
>>> Regards,
>>> Bjorn
>>>
>>>> +	}
>>>>  	rproc->priv = &rproc[1];
>>>>  	rproc->auto_boot = true;
>>>>  	rproc->elf_class = ELFCLASS32;
>>>> diff --git a/include/linux/remoteproc.h b/include/linux/remoteproc.h
>>>> index ddce7a7775d1..77788a4bb94e 100644
>>>> --- a/include/linux/remoteproc.h
>>>> +++ b/include/linux/remoteproc.h
>>>> @@ -490,7 +490,7 @@ struct rproc_dump_segment {
>>>>  struct rproc {
>>>>  	struct list_head node;
>>>>  	struct iommu_domain *domain;
>>>> -	const char *name;
>>>> +	char *name;
>>>>  	char *firmware;
>>>>  	void *priv;
>>>>  	struct rproc_ops *ops;
>>>> -- 
>>>> 2.23.0
>>>>
>>

Good morning Suman,

I have started to work on this set - comments will come in over the next few
days...

On Tue, Mar 24, 2020 at 03:18:13PM -0500, Suman Anna wrote:
> From: Loic Pallardy <loic.pallardy@st.com>
> 
> On some SoC architecture, it is needed to enable HW like
> clock, bus, regulator, memory region... before loading
> co-processor firmware.
> 
> This patch introduces prepare and unprepare ops to execute
> platform specific function before firmware loading and after
> stop execution.
> 
> Signed-off-by: Loic Pallardy <loic.pallardy@st.com>
> Signed-off-by: Suman Anna <s-anna@ti.com>
> ---
>  drivers/remoteproc/remoteproc_core.c | 20 +++++++++++++++++++-
>  include/linux/remoteproc.h           |  4 ++++
>  2 files changed, 23 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/remoteproc/remoteproc_core.c b/drivers/remoteproc/remoteproc_core.c
> index 26f6947267d2..aca6d022901a 100644
> --- a/drivers/remoteproc/remoteproc_core.c
> +++ b/drivers/remoteproc/remoteproc_core.c
> @@ -1394,12 +1394,22 @@ static int rproc_fw_boot(struct rproc *rproc, const struct firmware *fw)
>  		return ret;
>  	}
>  
> +	/* Prepare rproc for firmware loading if needed */
> +	if (rproc->ops->prepare) {
> +		ret = rproc->ops->prepare(rproc);

In my patchset on MCU synchronisation I have moved ops->{start/stop} to
remoteproc_internal.h and called them rproc_start/stop_device() (after Loic's
suggestion).  In order to be consistent and remove boiler plate code in the core
we could do the same, i.e have rproc_prepare/unprepare_device() in
remoteproc_internal.h .

With the above:
Reviewed-by: Mathieu Poirier <mathieu.poirier@linaro.org>

Thanks,
Mathieu

> +		if (ret) {
> +			dev_err(dev, "can't prepare rproc %s: %d\n",
> +				rproc->name, ret);
> +			goto disable_iommu;
> +		}
> +	}
> +
>  	rproc->bootaddr = rproc_get_boot_addr(rproc, fw);
>  
>  	/* Load resource table, core dump segment list etc from the firmware */
>  	ret = rproc_parse_fw(rproc, fw);
>  	if (ret)
> -		goto disable_iommu;
> +		goto unprepare_rproc;
>  
>  	/* reset max_notifyid */
>  	rproc->max_notifyid = -1;
> @@ -1433,6 +1443,10 @@ static int rproc_fw_boot(struct rproc *rproc, const struct firmware *fw)
>  	kfree(rproc->cached_table);
>  	rproc->cached_table = NULL;
>  	rproc->table_ptr = NULL;
> +unprepare_rproc:
> +	/* release HW resources if needed */
> +	if (rproc->ops->unprepare)
> +		rproc->ops->unprepare(rproc);
>  disable_iommu:
>  	rproc_disable_iommu(rproc);
>  	return ret;
> @@ -1838,6 +1852,10 @@ void rproc_shutdown(struct rproc *rproc)
>  	/* clean up all acquired resources */
>  	rproc_resource_cleanup(rproc);
>  
> +	/* release HW resources if needed */
> +	if (rproc->ops->unprepare)
> +		rproc->ops->unprepare(rproc);
> +
>  	rproc_disable_iommu(rproc);
>  
>  	/* Free the copy of the resource table */
> diff --git a/include/linux/remoteproc.h b/include/linux/remoteproc.h
> index 07bd73a6d72a..ddce7a7775d1 100644
> --- a/include/linux/remoteproc.h
> +++ b/include/linux/remoteproc.h
> @@ -355,6 +355,8 @@ enum rsc_handling_status {
>  
>  /**
>   * struct rproc_ops - platform-specific device handlers
> + * @prepare:	prepare device for code loading
> + * @unprepare:	unprepare device after stop
>   * @start:	power on the device and boot it
>   * @stop:	power off the device
>   * @kick:	kick a virtqueue (virtqueue id given as a parameter)
> @@ -371,6 +373,8 @@ enum rsc_handling_status {
>   * @get_boot_addr:	get boot address to entry point specified in firmware
>   */
>  struct rproc_ops {
> +	int (*prepare)(struct rproc *rproc);
> +	int (*unprepare)(struct rproc *rproc);
>  	int (*start)(struct rproc *rproc);
>  	int (*stop)(struct rproc *rproc);
>  	void (*kick)(struct rproc *rproc, int vqid);
> -- 
> 2.23.0
>

On Tue, Mar 24, 2020 at 03:18:17PM -0500, Suman Anna wrote:
> The TI K3 family of SoCs typically have one or more dual-core Arm Cortex
> R5F processor clusters/subsystems (R5FSS). This R5F subsystem/cluster
> can be configured at boot time to be either run in a LockStep mode or in
> an Asymmetric Multi Processing (AMP) fashion in Split-mode. This subsystem
> has 64 KB each Tightly-Coupled Memory (TCM) internal memories for each
> core split between two banks - TCMA and TCMB (further interleaved into
> two banks). The subsystem does not have an MMU, but has a Region Address
> Translater (RAT) module that is accessible only from the R5Fs for providing
> translations between 32-bit CPU addresses into larger system bus addresses.
> 
> Add a remoteproc driver to support this subsystem to be able to load and
> boot the R5F cores primarily in LockStep mode. The code also includes the
> base support for Split mode. Error Recovery and Power Management features
> are not currently supported. Loading support includes the internal TCMs
> and DDR. RAT support is left for a future patch, and as such the reserved
> memory carveout regions are all expected to be using memory regions within
> the first 2 GB.
> 
> The R5F remote processors do not have an MMU, and so require fixed memory
> carveout regions matching the firmware image addresses. Support for this
> is provided by mandating multiple memory regions to be attached to the
> remoteproc device. The first memory region will be used to serve as the
> DMA pool for all dynamic allocations like the vrings and vring buffers.
> The remaining memory regions are mapped into the kernel at device probe
> time, and are used to provide address translations for firmware image
> segments without the need for any RSC_CARVEOUT entries. Any firmware
> image using memory outside of the supplied reserved memory carveout
> regions will be errored out.
> 
> The R5F processors on TI K3 SoCs require a specific sequence for booting
> and shutting down the processors. This sequence is also dependent on the
> mode (LockStep or Split) the R5F cluster is configured for. The R5F cores
> have a Memory Protection Unit (MPU) that has a default configuration that
> does not allow the cores to run out of DDR out of reset. This is resolved
> by using the TCMs for boot-strapping code that applies the appropriate
> executable permissions on desired DDR memory. The loading into the TCMs
> requires that the resets be released first with the cores in halted state.
> The Power Sleep Controller (PSC) module on K3 SoCs requires that the cores
> be in WFI/WFE states with no active bus transactions before the cores can
> be put back into reset. Support for this is provided by using the newly
> introduced .prepare() and .unprepare() ops in the remoteproc core. The
> .prepare() ops is invoked before any loading, and the .unprepare() ops
> is invoked after the remoteproc resource cleanup. The R5F core resets
> are deasserted in .prepare() and asserted in .unprepare(), and the cores
> themselves are started and halted in .start() and .stop() ops. This
> ensures symmetric usage and allows the R5F cores state machine to be
> maintained properly between using the sysfs 'state' variable, bind/unbind
> and regular module load/unload flows.
> 
> The subsystem is represented as a single remoteproc in LockStep mode, and
> as two remoteprocs in Split mode.

Thank you for the detailed explanation, it really helps understand what is going
on.  From the above the assumption I made in the previous patch about lockstep
and split mode is wrong.  On the flip side it does highlight the need to add
more details to the bindings.

> The driver uses various TI-SCI interfaces
> to talk to the System Controller (DMSC) for managing configuration, power
> and reset management of these cores. IPC between the A53 cores and the R5
> cores is supported through the virtio rpmsg stack using shared memory and
> OMAP Mailboxes.
> 
> The AM65x SoCs typically have a single R5FSS in the MCU voltage domain. The
> J721E SoCs uses a slightly revised IP and typically have three R5FSSs, with
> one cluster present within the MCU voltage domain (MCU_R5FSS0), and the
> remaining two clusters present in the MAIN voltage domain (MAIN_R5FSS0 and
> MAIN_R5FSS1). The integration of these clusters on J721E SoC is also
> slightly different in that these IPs do support an actual local reset line,
> while they are a no-op on AM65x SoCs.
> 
> Signed-off-by: Suman Anna <s-anna@ti.com>
> ---
>  drivers/remoteproc/Kconfig               |   16 +
>  drivers/remoteproc/Makefile              |    1 +
>  drivers/remoteproc/ti_k3_r5_remoteproc.c | 1346 ++++++++++++++++++++++
>  3 files changed, 1363 insertions(+)
>  create mode 100644 drivers/remoteproc/ti_k3_r5_remoteproc.c
> 
> diff --git a/drivers/remoteproc/Kconfig b/drivers/remoteproc/Kconfig
> index de3862c15fcc..073048b4c0fb 100644
> --- a/drivers/remoteproc/Kconfig
> +++ b/drivers/remoteproc/Kconfig
> @@ -224,6 +224,22 @@ config STM32_RPROC
>  
>  	  This can be either built-in or a loadable module.
>  
> +config TI_K3_R5_REMOTEPROC
> +	tristate "TI K3 R5 remoteproc support"
> +	depends on ARCH_K3
> +	select MAILBOX
> +	select OMAP2PLUS_MBOX
> +	help
> +	  Say y here to support TI's R5F remote processor subsystems
> +	  on various TI K3 family of SoCs through the remote processor
> +	  framework.
> +
> +	  You want to say y here in order to offload some processing
> +	  tasks to these processors
> +
> +	  It's safe to say N here if you're not interested in utilizing
> +	  a slave processor
> +
>  endif # REMOTEPROC
>  
>  endmenu
> diff --git a/drivers/remoteproc/Makefile b/drivers/remoteproc/Makefile
> index e30a1b15fbac..00ba826818af 100644
> --- a/drivers/remoteproc/Makefile
> +++ b/drivers/remoteproc/Makefile
> @@ -28,3 +28,4 @@ qcom_wcnss_pil-y			+= qcom_wcnss_iris.o
>  obj-$(CONFIG_ST_REMOTEPROC)		+= st_remoteproc.o
>  obj-$(CONFIG_ST_SLIM_REMOTEPROC)	+= st_slim_rproc.o
>  obj-$(CONFIG_STM32_RPROC)		+= stm32_rproc.o
> +obj-$(CONFIG_TI_K3_R5_REMOTEPROC)	+= ti_k3_r5_remoteproc.o
> diff --git a/drivers/remoteproc/ti_k3_r5_remoteproc.c b/drivers/remoteproc/ti_k3_r5_remoteproc.c
> new file mode 100644
> index 000000000000..655f8f14c37d
> --- /dev/null
> +++ b/drivers/remoteproc/ti_k3_r5_remoteproc.c
> @@ -0,0 +1,1346 @@
> +// SPDX-License-Identifier: GPL-2.0-only
> +/*
> + * TI K3 R5F (MCU) Remote Processor driver
> + *
> + * Copyright (C) 2017-2020 Texas Instruments Incorporated - http://www.ti.com/
> + *	Suman Anna <s-anna@ti.com>
> + */
> +
> +#include <linux/dma-mapping.h>
> +#include <linux/err.h>
> +#include <linux/interrupt.h>
> +#include <linux/kernel.h>
> +#include <linux/mailbox_client.h>
> +#include <linux/module.h>
> +#include <linux/of_device.h>
> +#include <linux/of_address.h>
> +#include <linux/of_reserved_mem.h>
> +#include <linux/platform_device.h>
> +#include <linux/pm_runtime.h>
> +#include <linux/remoteproc.h>
> +#include <linux/omap-mailbox.h>

Please move this up after of_reserved_mem.h

> +#include <linux/reset.h>
> +#include <linux/soc/ti/ti_sci_protocol.h>
> +
> +#include "omap_remoteproc.h"
> +#include "remoteproc_internal.h"
> +#include "ti_sci_proc.h"
> +
> +/* This address can either be for ATCM or BTCM with the other at address 0x0 */
> +#define K3_R5_TCM_DEV_ADDR	0x41010000
> +
> +/* R5 TI-SCI Processor Configuration Flags */
> +#define PROC_BOOT_CFG_FLAG_R5_DBG_EN			0x00000001
> +#define PROC_BOOT_CFG_FLAG_R5_DBG_NIDEN			0x00000002
> +#define PROC_BOOT_CFG_FLAG_R5_LOCKSTEP			0x00000100
> +#define PROC_BOOT_CFG_FLAG_R5_TEINIT			0x00000200
> +#define PROC_BOOT_CFG_FLAG_R5_NMFI_EN			0x00000400
> +#define PROC_BOOT_CFG_FLAG_R5_TCM_RSTBASE		0x00000800
> +#define PROC_BOOT_CFG_FLAG_R5_BTCM_EN			0x00001000
> +#define PROC_BOOT_CFG_FLAG_R5_ATCM_EN			0x00002000
> +
> +/* R5 TI-SCI Processor Control Flags */
> +#define PROC_BOOT_CTRL_FLAG_R5_CORE_HALT		0x00000001
> +
> +/* R5 TI-SCI Processor Status Flags */
> +#define PROC_BOOT_STATUS_FLAG_R5_WFE			0x00000001
> +#define PROC_BOOT_STATUS_FLAG_R5_WFI			0x00000002
> +#define PROC_BOOT_STATUS_FLAG_R5_CLK_GATED		0x00000004
> +#define PROC_BOOT_STATUS_FLAG_R5_LOCKSTEP_PERMITTED	0x00000100
> +
> +/**
> + * struct k3_r5_mem - internal memory structure
> + * @cpu_addr: MPU virtual address of the memory region
> + * @bus_addr: Bus address used to access the memory region
> + * @dev_addr: Device address from remoteproc view
> + * @size: Size of the memory region
> + */
> +struct k3_r5_mem {
> +	void __iomem *cpu_addr;
> +	phys_addr_t bus_addr;
> +	u32 dev_addr;
> +	size_t size;
> +};
> +
> +enum cluster_mode {
> +	CLUSTER_MODE_SPLIT = 0,
> +	CLUSTER_MODE_LOCKSTEP,
> +};
> +
> +/**
> + * struct k3_r5_cluster - K3 R5F Cluster structure
> + * @dev: cached device pointer
> + * @mode: Mode to configure the Cluster - Split or LockStep
> + * @cores: list of R5 cores within the cluster
> + */
> +struct k3_r5_cluster {
> +	struct device *dev;
> +	enum cluster_mode mode;
> +	struct list_head cores;
> +};
> +
> +/**
> + * struct k3_r5_core - K3 R5 core structure
> + * @elem: linked list item
> + * @dev: cached device pointer
> + * @rproc: rproc handle representing this core
> + * @mem: internal memory regions data
> + * @num_mems: number of internal memory regions
> + * @reset: reset control handle
> + * @tsp: TI-SCI processor control handle
> + * @ti_sci: TI-SCI handle
> + * @ti_sci_id: TI-SCI device identifier
> + * @atcm_enable: flag to control ATCM enablement
> + * @btcm_enable: flag to control BTCM enablement
> + * @loczrama: flag to dictate which TCM is at device address 0x0
> + */
> +struct k3_r5_core {
> +	struct list_head elem;
> +	struct device *dev;
> +	struct rproc *rproc;
> +	struct k3_r5_mem *mem;
> +	int num_mems;
> +	struct reset_control *reset;
> +	struct ti_sci_proc *tsp;
> +	const struct ti_sci_handle *ti_sci;
> +	u32 ti_sci_id;
> +	u32 atcm_enable;
> +	u32 btcm_enable;
> +	u32 loczrama;
> +};
> +
> +/**
> + * struct k3_r5_rproc - K3 remote processor state
> + * @dev: cached device pointer
> + * @cluster: cached pointer to parent cluster structure
> + * @mbox: mailbox channel handle
> + * @client: mailbox client to request the mailbox channel
> + * @rproc: rproc handle
> + * @core: cached pointer to r5 core structure being used
> + * @rmem: reserved memory regions data
> + * @num_rmems: number of reserved memory regions
> + */
> +struct k3_r5_rproc {
> +	struct device *dev;
> +	struct k3_r5_cluster *cluster;
> +	struct mbox_chan *mbox;
> +	struct mbox_client client;
> +	struct rproc *rproc;
> +	struct k3_r5_core *core;
> +	struct k3_r5_mem *rmem;
> +	int num_rmems;
> +};
> +
> +/**
> + * k3_r5_rproc_mbox_callback() - inbound mailbox message handler
> + * @client: mailbox client pointer used for requesting the mailbox channel
> + * @data: mailbox payload
> + *
> + * This handler is invoked by the OMAP mailbox driver whenever a mailbox
> + * message is received. Usually, the mailbox payload simply contains
> + * the index of the virtqueue that is kicked by the remote processor,
> + * and we let remoteproc core handle it.
> + *
> + * In addition to virtqueue indices, we also have some out-of-band values
> + * that indicate different events. Those values are deliberately very
> + * large so they don't coincide with virtqueue indices.
> + */
> +static void k3_r5_rproc_mbox_callback(struct mbox_client *client, void *data)
> +{
> +	struct k3_r5_rproc *kproc = container_of(client, struct k3_r5_rproc,
> +						client);
> +	struct device *dev = kproc->rproc->dev.parent;
> +	const char *name = kproc->rproc->name;
> +	u32 msg = omap_mbox_message(data);
> +
> +	dev_dbg(dev, "mbox msg: 0x%x\n", msg);
> +
> +	switch (msg) {
> +	case RP_MBOX_CRASH:
> +		/*
> +		 * remoteproc detected an exception, but error recovery is not
> +		 * supported. So, just log this for now
> +		 */
> +		dev_err(dev, "K3 R5F rproc %s crashed\n", name);
> +		break;
> +	case RP_MBOX_ECHO_REPLY:
> +		dev_info(dev, "received echo reply from %s\n", name);
> +		break;
> +	default:
> +		/* silently handle all other valid messages */
> +		if (msg >= RP_MBOX_READY && msg < RP_MBOX_END_MSG)
> +			return;
> +		if (msg > kproc->rproc->max_notifyid) {
> +			dev_dbg(dev, "dropping unknown message 0x%x", msg);
> +			return;
> +		}
> +		/* msg contains the index of the triggered vring */
> +		if (rproc_vq_interrupt(kproc->rproc, msg) == IRQ_NONE)
> +			dev_dbg(dev, "no message was found in vqid %d\n", msg);
> +	}
> +}
> +
> +/* kick a virtqueue */
> +static void k3_r5_rproc_kick(struct rproc *rproc, int vqid)
> +{
> +	struct k3_r5_rproc *kproc = rproc->priv;
> +	struct device *dev = rproc->dev.parent;
> +	mbox_msg_t msg = (mbox_msg_t)vqid;
> +	int ret;
> +
> +	/* send the index of the triggered virtqueue in the mailbox payload */
> +	ret = mbox_send_message(kproc->mbox, (void *)msg);
> +	if (ret < 0)
> +		dev_err(dev, "failed to send mailbox message, status = %d\n",
> +			ret);
> +}
> +
> +static int k3_r5_split_reset(struct k3_r5_core *core)
> +{
> +	int ret;
> +
> +	ret = reset_control_assert(core->reset);
> +	if (ret) {
> +		dev_err(core->dev, "local-reset assert failed, ret = %d\n",
> +			ret);
> +		return ret;
> +	}
> +
> +	ret = core->ti_sci->ops.dev_ops.put_device(core->ti_sci,
> +						   core->ti_sci_id);
> +	if (ret) {
> +		dev_err(core->dev, "module-reset assert failed, ret = %d\n",
> +			ret);
> +		if (reset_control_deassert(core->reset))
> +			dev_warn(core->dev, "local-reset deassert back failed\n");
> +	}
> +
> +	return ret;
> +}
> +
> +static int k3_r5_split_release(struct k3_r5_core *core)
> +{
> +	int ret;
> +
> +	ret = core->ti_sci->ops.dev_ops.get_device(core->ti_sci,
> +						   core->ti_sci_id);
> +	if (ret) {
> +		dev_err(core->dev, "module-reset deassert failed, ret = %d\n",
> +			ret);
> +		return ret;
> +	}
> +
> +	ret = reset_control_deassert(core->reset);
> +	if (ret) {
> +		dev_err(core->dev, "local-reset deassert failed, ret = %d\n",
> +			ret);
> +		if (core->ti_sci->ops.dev_ops.put_device(core->ti_sci,
> +							 core->ti_sci_id))
> +			dev_warn(core->dev, "module-reset assert back failed\n");
> +	}
> +
> +	return ret;
> +}
> +
> +static int k3_r5_lockstep_reset(struct k3_r5_cluster *cluster)
> +{
> +	struct k3_r5_core *core;
> +	int ret;
> +
> +	/* assert local reset on all applicable cores */
> +	list_for_each_entry(core, &cluster->cores, elem) {
> +		ret = reset_control_assert(core->reset);
> +		if (ret) {
> +			dev_err(core->dev, "local-reset assert failed, ret = %d\n",
> +				ret);
> +			core = list_prev_entry(core, elem);
> +			goto unroll_local_reset;
> +		}
> +	}
> +
> +	/* disable PSC modules on all applicable cores */
> +	list_for_each_entry(core, &cluster->cores, elem) {
> +		ret = core->ti_sci->ops.dev_ops.put_device(core->ti_sci,
> +							   core->ti_sci_id);
> +		if (ret) {
> +			dev_err(core->dev, "module-reset assert failed, ret = %d\n",
> +				ret);
> +			goto unroll_module_reset;
> +		}
> +	}
> +
> +	return 0;
> +
> +unroll_module_reset:
> +	list_for_each_entry_continue_reverse(core, &cluster->cores, elem) {
> +		if (core->ti_sci->ops.dev_ops.put_device(core->ti_sci,
> +							 core->ti_sci_id))
> +			dev_warn(core->dev, "module-reset assert back failed\n");
> +	}
> +	core = list_last_entry(&cluster->cores, struct k3_r5_core, elem);
> +unroll_local_reset:
> +	list_for_each_entry_from_reverse(core, &cluster->cores, elem) {
> +		if (reset_control_deassert(core->reset))
> +			dev_warn(core->dev, "local-reset deassert back failed\n");
> +	}
> +
> +	return ret;
> +}
> +
> +static int k3_r5_lockstep_release(struct k3_r5_cluster *cluster)
> +{
> +	struct k3_r5_core *core;
> +	int ret;
> +
> +	/* enable PSC modules on all applicable cores */
> +	list_for_each_entry_reverse(core, &cluster->cores, elem) {
> +		ret = core->ti_sci->ops.dev_ops.get_device(core->ti_sci,
> +							   core->ti_sci_id);
> +		if (ret) {
> +			dev_err(core->dev, "module-reset deassert failed, ret = %d\n",
> +				ret);
> +			core = list_next_entry(core, elem);
> +			goto unroll_module_reset;
> +		}
> +	}
> +
> +	/* deassert local reset on all applicable cores */
> +	list_for_each_entry_reverse(core, &cluster->cores, elem) {
> +		ret = reset_control_deassert(core->reset);
> +		if (ret) {
> +			dev_err(core->dev, "module-reset deassert failed, ret = %d\n",
> +				ret);
> +			goto unroll_local_reset;
> +		}
> +	}
> +
> +	return 0;
> +
> +unroll_local_reset:
> +	list_for_each_entry_continue(core, &cluster->cores, elem) {
> +		if (reset_control_assert(core->reset))
> +			dev_warn(core->dev, "local-reset assert back failed\n");
> +	}
> +	core = list_first_entry(&cluster->cores, struct k3_r5_core, elem);
> +unroll_module_reset:
> +	list_for_each_entry_from(core, &cluster->cores, elem) {
> +		if (core->ti_sci->ops.dev_ops.put_device(core->ti_sci,
> +							 core->ti_sci_id))
> +			dev_warn(core->dev, "module-reset assert back failed\n");
> +	}
> +
> +	return ret;
> +}
> +
> +static inline int k3_r5_core_halt(struct k3_r5_core *core)
> +{
> +	return ti_sci_proc_set_control(core->tsp,
> +				       PROC_BOOT_CTRL_FLAG_R5_CORE_HALT, 0);
> +}
> +
> +static inline int k3_r5_core_run(struct k3_r5_core *core)
> +{
> +	return ti_sci_proc_set_control(core->tsp,
> +				       0, PROC_BOOT_CTRL_FLAG_R5_CORE_HALT);
> +}
> +
> +/*
> + * The R5F cores have controls for both a reset and a halt/run. The code
> + * execution from DDR requires the initial boot-strapping code to be run
> + * from the internal TCMs. This function is used to release the resets on
> + * applicable cores to allow loading into the TCMs. The .prepare() ops is
> + * invoked by remoteproc core before any firmware loading, and is followed
> + * by the .start() ops after loading to actually let the R5 cores run.
> + */
> +static int k3_r5_rproc_prepare(struct rproc *rproc)
> +{
> +	struct k3_r5_rproc *kproc = rproc->priv;
> +	struct k3_r5_cluster *cluster = kproc->cluster;
> +	struct k3_r5_core *core = kproc->core;
> +	struct device *dev = kproc->dev;
> +	int ret;
> +
> +	ret = cluster->mode ? k3_r5_lockstep_release(cluster) :
> +			      k3_r5_split_release(core);
> +	if (ret)
> +		dev_err(dev, "unable to enable cores for TCM loading, ret = %d\n",
> +			ret);
> +
> +	return ret;
> +}
> +
> +/*
> + * This function implements the .unprepare() ops and performs the complimentary
> + * operations to that of the .prepare() ops. The function is used to assert the
> + * resets on all applicable cores for the rproc device (depending on LockStep
> + * or Split mode). This completes the second portion of powering down the R5F
> + * cores. The cores themselves are only halted in the .stop() ops, and the
> + * .unprepare() ops is invoked by the remoteproc core after the remoteproc is
> + * stopped.
> + */
> +static int k3_r5_rproc_unprepare(struct rproc *rproc)
> +{
> +	struct k3_r5_rproc *kproc = rproc->priv;
> +	struct k3_r5_cluster *cluster = kproc->cluster;
> +	struct k3_r5_core *core = kproc->core;
> +	struct device *dev = kproc->dev;
> +	int ret;
> +
> +	ret = cluster->mode ? k3_r5_lockstep_reset(cluster) :
> +			      k3_r5_split_reset(core);
> +	if (ret)
> +		dev_err(dev, "unable to disable cores, ret = %d\n", ret);
> +
> +	return ret;
> +}
> +
> +/*
> + * The R5F start sequence includes two different operations
> + * 1. Configure the boot vector for R5F core(s)
> + * 2. Unhalt/Run the R5F core(s)
> + *
> + * The sequence is different between LockStep and Split modes. The LockStep
> + * mode requires the boot vector to be configured only for Core0, and then
> + * unhalt both the cores to start the execution - Core1 needs to be unhalted
> + * first followed by Core0. The Split-mode requires that Core0 to be maintained
> + * always in a higher power state that Core1 (implying Core1 needs to be started
> + * always only after Core0 is started).
> + */
> +static int k3_r5_rproc_start(struct rproc *rproc)
> +{
> +	struct k3_r5_rproc *kproc = rproc->priv;
> +	struct k3_r5_cluster *cluster = kproc->cluster;
> +	struct mbox_client *client = &kproc->client;
> +	struct device *dev = kproc->dev;
> +	struct k3_r5_core *core;
> +	u32 boot_addr;
> +	int ret;
> +
> +	client->dev = dev;
> +	client->tx_done = NULL;
> +	client->rx_callback = k3_r5_rproc_mbox_callback;
> +	client->tx_block = false;
> +	client->knows_txdone = false;
> +
> +	kproc->mbox = mbox_request_channel(client, 0);
> +	if (IS_ERR(kproc->mbox)) {
> +		ret = -EBUSY;
> +		dev_err(dev, "mbox_request_channel failed: %ld\n",
> +			PTR_ERR(kproc->mbox));
> +		return ret;
> +	}
> +
> +	/*
> +	 * Ping the remote processor, this is only for sanity-sake for now;
> +	 * there is no functional effect whatsoever.
> +	 *
> +	 * Note that the reply will _not_ arrive immediately: this message
> +	 * will wait in the mailbox fifo until the remote processor is booted.
> +	 */
> +	ret = mbox_send_message(kproc->mbox, (void *)RP_MBOX_ECHO_REQUEST);
> +	if (ret < 0) {
> +		dev_err(dev, "mbox_send_message failed: %d\n", ret);
> +		goto put_mbox;
> +	}
> +
> +	boot_addr = rproc->bootaddr;
> +	/* TODO: add boot_addr sanity checking */
> +	dev_err(dev, "booting R5F core using boot addr = 0x%x\n", boot_addr);
> +
> +	/* boot vector need not be programmed for Core1 in LockStep mode */
> +	core = kproc->core;
> +	ret = ti_sci_proc_set_config(core->tsp, boot_addr, 0, 0);
> +	if (ret)
> +		goto put_mbox;
> +
> +	/* unhalt/run all applicable cores */
> +	if (cluster->mode) {
> +		list_for_each_entry_reverse(core, &cluster->cores, elem) {
> +			ret = k3_r5_core_run(core);
> +			if (ret)
> +				goto unroll_core_run;
> +		}
> +	} else {
> +		ret = k3_r5_core_run(core);
> +		if (ret)
> +			goto put_mbox;
> +	}
> +
> +	return 0;
> +
> +unroll_core_run:
> +	list_for_each_entry_continue(core, &cluster->cores, elem) {
> +		if (k3_r5_core_halt(core))
> +			dev_warn(core->dev, "core halt back failed\n");
> +	}
> +put_mbox:
> +	mbox_free_channel(kproc->mbox);
> +	return ret;
> +}
> +
> +/*
> + * The R5F stop function includes the following operations
> + * 1. Halt R5F core(s)
> + *
> + * The sequence is different between LockStep and Split modes, and the order
> + * of cores the operations are performed are also in general reverse to that
> + * of the start function. The LockStep mode requires each operation to be
> + * performed first on Core0 followed by Core1. The Split-mode requires that
> + * Core0 to be maintained always in a higher power state that Core1 (implying
> + * Core1 needs to be stopped first before Core0).
> + *
> + * Note that the R5F halt operation in general is not effective when the R5F
> + * core is running, but is needed to make sure the core won't run after
> + * deasserting the reset the subsequent time. The asserting of reset can
> + * be done here, but is preferred to be done in the .unprepare() ops - this
> + * maintains the symmetric behavior between the .start(), .stop(), .prepare()
> + * and .unprepare() ops, and also balances them well between sysfs 'state'
> + * flow and device bind/unbind or module removal.
> + */
> +static int k3_r5_rproc_stop(struct rproc *rproc)
> +{
> +	struct k3_r5_rproc *kproc = rproc->priv;
> +	struct k3_r5_cluster *cluster = kproc->cluster;
> +	struct k3_r5_core *core = kproc->core;
> +	int ret;
> +
> +	/* halt all applicable cores */
> +	if (cluster->mode) {
> +		list_for_each_entry(core, &cluster->cores, elem) {
> +			ret = k3_r5_core_halt(core);
> +			if (ret) {
> +				core = list_prev_entry(core, elem);
> +				goto unroll_core_halt;
> +			}
> +		}
> +	} else {
> +		ret = k3_r5_core_halt(core);
> +		if (ret)
> +			goto out;
> +	}
> +
> +	mbox_free_channel(kproc->mbox);
> +
> +	return 0;
> +
> +unroll_core_halt:
> +	list_for_each_entry_from_reverse(core, &cluster->cores, elem) {
> +		if (k3_r5_core_run(core))
> +			dev_warn(core->dev, "core run back failed\n");
> +	}
> +out:
> +	return ret;
> +}
> +
> +/*
> + * Internal Memory translation helper
> + *
> + * Custom function implementing the rproc .da_to_va ops to provide address
> + * translation (device address to kernel virtual address) for internal RAMs
> + * present in a DSP or IPU device). The translated addresses can be used
> + * either by the remoteproc core for loading, or by any rpmsg bus drivers.
> + */
> +static void *k3_r5_rproc_da_to_va(struct rproc *rproc, u64 da, size_t len)
> +{
> +	struct k3_r5_rproc *kproc = rproc->priv;
> +	struct k3_r5_core *core = kproc->core;
> +	void __iomem *va = NULL;
> +	phys_addr_t bus_addr;
> +	u32 dev_addr, offset;
> +	size_t size;
> +	int i;
> +
> +	if (len == 0)
> +		return NULL;
> +
> +	/* handle both R5 and SoC views of ATCM and BTCM */
> +	for (i = 0; i < core->num_mems; i++) {
> +		bus_addr = core->mem[i].bus_addr;
> +		dev_addr = core->mem[i].dev_addr;
> +		size = core->mem[i].size;
> +
> +		/* handle R5-view addresses of TCMs */
> +		if (da >= dev_addr && ((da + len) <= (dev_addr + size))) {
> +			offset = da - dev_addr;
> +			va = core->mem[i].cpu_addr + offset;
> +			return (__force void *)va;
> +		}
> +
> +		/* handle SoC-view addresses of TCMs */
> +		if (da >= bus_addr && ((da + len) <= (bus_addr + size))) {
> +			offset = da - bus_addr;
> +			va = core->mem[i].cpu_addr + offset;
> +			return (__force void *)va;
> +		}
> +	}
> +
> +	/* handle static DDR reserved memory regions */
> +	for (i = 0; i < kproc->num_rmems; i++) {
> +		dev_addr = kproc->rmem[i].dev_addr;
> +		size = kproc->rmem[i].size;
> +
> +		if (da >= dev_addr && ((da + len) <= (dev_addr + size))) {
> +			offset = da - dev_addr;
> +			va = kproc->rmem[i].cpu_addr + offset;
> +			return (__force void *)va;
> +		}
> +	}
> +
> +	return NULL;
> +}
> +
> +static const struct rproc_ops k3_r5_rproc_ops = {
> +	.prepare	= k3_r5_rproc_prepare,
> +	.unprepare	= k3_r5_rproc_unprepare,
> +	.start		= k3_r5_rproc_start,
> +	.stop		= k3_r5_rproc_stop,
> +	.kick		= k3_r5_rproc_kick,
> +	.da_to_va	= k3_r5_rproc_da_to_va,
> +};
> +
> +static const char *k3_r5_rproc_get_firmware(struct device *dev)
> +{
> +	const char *fw_name;
> +	int ret;
> +
> +	ret = of_property_read_string(dev->of_node, "firmware-name",
> +				      &fw_name);
> +	if (ret) {
> +		dev_err(dev, "failed to parse firmware-name property, ret = %d\n",
> +			ret);
> +		return ERR_PTR(ret);
> +	}
> +
> +	return fw_name;
> +}
> +
> +static int k3_r5_rproc_configure(struct k3_r5_rproc *kproc)
> +{
> +	struct k3_r5_cluster *cluster = kproc->cluster;
> +	struct device *dev = kproc->dev;
> +	struct k3_r5_core *core0, *core, *temp;
> +	u32 ctrl = 0, cfg = 0, stat = 0;
> +	u32 set_cfg = 0, clr_cfg = 0;
> +	u64 boot_vec = 0;
> +	bool lockstep_en;
> +	int ret;
> +
> +	core0 = list_first_entry(&cluster->cores, struct k3_r5_core, elem);
> +	core = cluster->mode ? core0 : kproc->core;
> +
> +	ret = ti_sci_proc_get_status(core->tsp, &boot_vec, &cfg, &ctrl,
> +				     &stat);
> +	if (ret < 0)
> +		return ret;
> +
> +	dev_dbg(dev, "boot_vector = 0x%llx, cfg = 0x%x ctrl = 0x%x stat = 0x%x\n",
> +		boot_vec, cfg, ctrl, stat);
> +
> +	lockstep_en = !!(stat & PROC_BOOT_STATUS_FLAG_R5_LOCKSTEP_PERMITTED);
> +	if (!lockstep_en && cluster->mode) {
> +		dev_err(cluster->dev, "lockstep mode not permitted, force configuring for split-mode\n");
> +		cluster->mode = 0;
> +	}
> +
> +	/* always enable ARM mode and set boot vector to 0 */
> +	boot_vec = 0x0;
> +	if (core == core0) {
> +		clr_cfg = PROC_BOOT_CFG_FLAG_R5_TEINIT;
> +		/*
> +		 * LockStep configuration bit is Read-only on Split-mode _only_
> +		 * devices and system firmware will NACK any requests with the
> +		 * bit configured, so program it only on permitted devices
> +		 */
> +		if (lockstep_en)
> +			clr_cfg |= PROC_BOOT_CFG_FLAG_R5_LOCKSTEP;
> +	}
> +
> +	if (core->atcm_enable)
> +		set_cfg |= PROC_BOOT_CFG_FLAG_R5_ATCM_EN;
> +	else
> +		clr_cfg |= PROC_BOOT_CFG_FLAG_R5_ATCM_EN;
> +
> +	if (core->btcm_enable)
> +		set_cfg |= PROC_BOOT_CFG_FLAG_R5_BTCM_EN;
> +	else
> +		clr_cfg |= PROC_BOOT_CFG_FLAG_R5_BTCM_EN;
> +
> +	if (core->loczrama)
> +		set_cfg |= PROC_BOOT_CFG_FLAG_R5_TCM_RSTBASE;
> +	else
> +		clr_cfg |= PROC_BOOT_CFG_FLAG_R5_TCM_RSTBASE;
> +
> +	if (cluster->mode) {
> +		/*
> +		 * work around system firmware limitations to make sure both
> +		 * cores are programmed symmetrically in LockStep. LockStep
> +		 * and TEINIT config is only allowed with Core0.
> +		 */
> +		list_for_each_entry(temp, &cluster->cores, elem) {
> +			ret = k3_r5_core_halt(core);
> +			if (ret)
> +				goto out;
> +
> +			if (temp != core) {
> +				clr_cfg &= ~PROC_BOOT_CFG_FLAG_R5_LOCKSTEP;
> +				clr_cfg &= ~PROC_BOOT_CFG_FLAG_R5_TEINIT;
> +			}
> +			ret = ti_sci_proc_set_config(temp->tsp, boot_vec,
> +						     set_cfg, clr_cfg);
> +			if (ret)
> +				goto out;
> +		}
> +
> +		set_cfg = PROC_BOOT_CFG_FLAG_R5_LOCKSTEP;
> +		clr_cfg = 0;
> +		ret = ti_sci_proc_set_config(core->tsp, boot_vec,
> +					     set_cfg, clr_cfg);
> +	} else {
> +		ret = k3_r5_core_halt(core);
> +		if (ret)
> +			goto out;
> +
> +		ret = ti_sci_proc_set_config(core->tsp, boot_vec,
> +					     set_cfg, clr_cfg);
> +	}
> +
> +out:
> +	return ret;
> +}
> +
> +static int k3_r5_reserved_mem_init(struct k3_r5_rproc *kproc)
> +{
> +	struct device *dev = kproc->dev;
> +	struct device_node *np = dev->of_node;
> +	struct device_node *rmem_np;
> +	struct reserved_mem *rmem;
> +	int num_rmems;
> +	int ret, i;
> +
> +	num_rmems = of_property_count_elems_of_size(np, "memory-region",
> +						    sizeof(phandle));
> +	if (num_rmems <= 0) {
> +		dev_err(dev, "device does not have reserved memory regions, ret = %d\n",
> +			num_rmems);
> +		return -EINVAL;
> +	}
> +	if (num_rmems < 2) {
> +		dev_err(dev, "device needs atleast two memory regions to be defined, num = %d\n",
> +			num_rmems);
> +		return -EINVAL;
> +	}
> +
> +	/* use reserved memory region 0 for vring DMA allocations */
> +	ret = of_reserved_mem_device_init_by_idx(dev, np, 0);
> +	if (ret) {
> +		dev_err(dev, "device cannot initialize DMA pool, ret = %d\n",
> +			ret);
> +		return ret;
> +	}
> +
> +	num_rmems--;
> +	kproc->rmem = kcalloc(num_rmems, sizeof(*kproc->rmem), GFP_KERNEL);
> +	if (!kproc->rmem) {
> +		ret = -ENOMEM;
> +		goto release_rmem;
> +	}
> +
> +	/* use remaining reserved memory regions for static carveouts */
> +	for (i = 0; i < num_rmems; i++) {
> +		rmem_np = of_parse_phandle(np, "memory-region", i + 1);
> +		if (!rmem_np) {
> +			ret = -EINVAL;
> +			goto unmap_rmem;
> +		}
> +
> +		rmem = of_reserved_mem_lookup(rmem_np);
> +		if (!rmem) {
> +			of_node_put(rmem_np);
> +			ret = -EINVAL;
> +			goto unmap_rmem;
> +		}
> +		of_node_put(rmem_np);
> +
> +		kproc->rmem[i].bus_addr = rmem->base;
> +		/* 64-bit address regions currently not supported */
> +		kproc->rmem[i].dev_addr = (u32)rmem->base;
> +		kproc->rmem[i].size = rmem->size;
> +		kproc->rmem[i].cpu_addr = ioremap_wc(rmem->base, rmem->size);
> +		if (!kproc->rmem[i].cpu_addr) {
> +			dev_err(dev, "failed to map reserved memory#%d at %pa of size %pa\n",
> +				i + 1, &rmem->base, &rmem->size);
> +			ret = -ENOMEM;
> +			goto unmap_rmem;
> +		}
> +
> +		dev_dbg(dev, "reserved memory%d: bus addr %pa size 0x%zx va %pK da 0x%x\n",
> +			i + 1, &kproc->rmem[i].bus_addr,
> +			kproc->rmem[i].size, kproc->rmem[i].cpu_addr,
> +			kproc->rmem[i].dev_addr);
> +	}
> +	kproc->num_rmems = num_rmems;
> +
> +	return 0;
> +
> +unmap_rmem:
> +	for (i--; i >= 0; i--) {
> +		if (kproc->rmem[i].cpu_addr)
> +			iounmap(kproc->rmem[i].cpu_addr);
> +	}
> +	kfree(kproc->rmem);
> +release_rmem:
> +	of_reserved_mem_device_release(dev);
> +	return ret;
> +}
> +
> +static void k3_r5_reserved_mem_exit(struct k3_r5_rproc *kproc)
> +{
> +	int i;
> +
> +	for (i = 0; i < kproc->num_rmems; i++)
> +		iounmap(kproc->rmem[i].cpu_addr);
> +	kfree(kproc->rmem);
> +
> +	of_reserved_mem_device_release(kproc->dev);
> +}
> +
> +static int k3_r5_cluster_rproc_init(struct platform_device *pdev)
> +{
> +	struct k3_r5_cluster *cluster = platform_get_drvdata(pdev);
> +	struct device *dev = &pdev->dev;
> +	struct k3_r5_rproc *kproc;
> +	struct k3_r5_core *core, *core1;
> +	struct device *cdev;
> +	const char *fw_name;
> +	struct rproc *rproc;
> +	int ret;
> +
> +	core1 = list_last_entry(&cluster->cores, struct k3_r5_core, elem);
> +	list_for_each_entry(core, &cluster->cores, elem) {
> +		cdev = core->dev;
> +		fw_name = k3_r5_rproc_get_firmware(cdev);
> +		if (IS_ERR(fw_name)) {
> +			ret = PTR_ERR(fw_name);
> +			goto out;
> +		}
> +
> +		rproc = rproc_alloc(cdev, dev_name(cdev), &k3_r5_rproc_ops,
> +				    fw_name, sizeof(*kproc));
> +		if (!rproc) {
> +			ret = -ENOMEM;
> +			goto out;
> +		}
> +
> +		/* K3 R5s have a Region Address Translator (RAT) but no MMU */
> +		rproc->has_iommu = false;
> +		/* error recovery is not supported at present */
> +		rproc->recovery_disabled = true;
> +
> +		kproc = rproc->priv;
> +		kproc->cluster = cluster;
> +		kproc->core = core;
> +		kproc->dev = cdev;
> +		kproc->rproc = rproc;
> +		core->rproc = rproc;
> +
> +		ret = k3_r5_rproc_configure(kproc);
> +		if (ret) {
> +			dev_err(dev, "initial configure failed, ret = %d\n",
> +				ret);
> +			goto err_config;
> +		}
> +
> +		ret = k3_r5_reserved_mem_init(kproc);
> +		if (ret) {
> +			dev_err(dev, "reserved memory init failed, ret = %d\n",
> +				ret);
> +			goto err_config;
> +		}
> +
> +		ret = rproc_add(rproc);
> +		if (ret) {
> +			dev_err(dev, "rproc_add failed, ret = %d\n", ret);
> +			goto err_add;
> +		}
> +
> +		/* create only one rproc in lockstep mode */
> +		if (cluster->mode)
> +			break;
> +	}
> +
> +	return 0;
> +
> +err_split:
> +	rproc_del(rproc);
> +err_add:
> +	k3_r5_reserved_mem_exit(kproc);
> +err_config:
> +	rproc_free(rproc);
> +	core->rproc = NULL;
> +out:
> +	/* undo core0 upon any failures on core1 in split-mode */
> +	if (!cluster->mode && core == core1) {
> +		core = list_prev_entry(core, elem);
> +		rproc = core->rproc;
> +		kproc = rproc->priv;
> +		goto err_split;
> +	}
> +	return ret;
> +}
> +
> +static int k3_r5_cluster_rproc_exit(struct platform_device *pdev)
> +{
> +	struct k3_r5_cluster *cluster = platform_get_drvdata(pdev);
> +	struct k3_r5_rproc *kproc;
> +	struct k3_r5_core *core;
> +	struct rproc *rproc;
> +
> +	/*
> +	 * lockstep mode has only one rproc associated with first core, whereas
> +	 * split-mode has two rprocs associated with each core, and requires
> +	 * that core1 be powered down first
> +	 */
> +	core = cluster->mode ?
> +		list_first_entry(&cluster->cores, struct k3_r5_core, elem) :
> +		list_last_entry(&cluster->cores, struct k3_r5_core, elem);
> +
> +	list_for_each_entry_from_reverse(core, &cluster->cores, elem) {
> +		rproc = core->rproc;
> +		kproc = rproc->priv;
> +
> +		rproc_del(rproc);
> +
> +		k3_r5_reserved_mem_exit(kproc);
> +
> +		rproc_free(rproc);
> +		core->rproc = NULL;
> +	}
> +
> +	return 0;
> +}
> +
> +static int k3_r5_core_of_get_internal_memories(struct platform_device *pdev,
> +					       struct k3_r5_core *core)
> +{
> +	static const char * const mem_names[] = {"atcm", "btcm"};
> +	struct device *dev = &pdev->dev;
> +	struct resource *res;
> +	int num_mems;
> +	int i, ret;
> +
> +	num_mems = ARRAY_SIZE(mem_names);
> +	core->mem = devm_kcalloc(dev, num_mems, sizeof(*core->mem), GFP_KERNEL);
> +	if (!core->mem)
> +		return -ENOMEM;
> +
> +	for (i = 0; i < num_mems; i++) {
> +		res = platform_get_resource_byname(pdev, IORESOURCE_MEM,
> +						   mem_names[i]);
> +		if (!res) {
> +			dev_err(dev, "found no memory resource for %s\n",
> +				mem_names[i]);
> +			ret = -EINVAL;
> +			goto fail;
> +		}
> +		if (!devm_request_mem_region(dev, res->start,
> +					     resource_size(res),
> +					     dev_name(dev))) {
> +			dev_err(dev, "could not request %s region for resource\n",
> +				mem_names[i]);
> +			ret = -EBUSY;
> +			goto fail;
> +		}
> +
> +		/*
> +		 * TCMs are designed in general to support RAM-like backing
> +		 * memories. So, map these as Normal Non-Cached memories. This
> +		 * also avoids/fixes any potential alignment faults due to
> +		 * unaligned data accesses when using memcpy() or memset()
> +		 * functions (normally seen with device type memory).
> +		 */
> +		core->mem[i].cpu_addr = devm_ioremap_wc(dev, res->start,
> +							resource_size(res));
> +		if (IS_ERR(core->mem[i].cpu_addr)) {
> +			dev_err(dev, "failed to map %s memory\n", mem_names[i]);
> +			ret = PTR_ERR(core->mem[i].cpu_addr);
> +			devm_release_mem_region(dev, res->start,
> +						resource_size(res));
> +			goto fail;
> +		}
> +		core->mem[i].bus_addr = res->start;
> +
> +		/*
> +		 * TODO:
> +		 * The R5F cores can place ATCM & BTCM anywhere in its address
> +		 * based on the corresponding Region Registers in the System
> +		 * Control coprocessor. For now, place ATCM and BTCM at
> +		 * addresses 0 and 0x41010000 (same as the bus address on AM65x
> +		 * SoCs) based on loczrama setting
> +		 */
> +		if (!strcmp(mem_names[i], "atcm")) {
> +			core->mem[i].dev_addr = core->loczrama ?
> +							0 : K3_R5_TCM_DEV_ADDR;
> +		} else {
> +			core->mem[i].dev_addr = core->loczrama ?
> +							K3_R5_TCM_DEV_ADDR : 0;
> +		}
> +		core->mem[i].size = resource_size(res);
> +
> +		dev_dbg(dev, "memory %8s: bus addr %pa size 0x%zx va %pK da 0x%x\n",
> +			mem_names[i], &core->mem[i].bus_addr,
> +			core->mem[i].size, core->mem[i].cpu_addr,
> +			core->mem[i].dev_addr);
> +	}
> +	core->num_mems = num_mems;
> +
> +	return 0;
> +
> +fail:
> +	for (i--; i >= 0; i--) {
> +		devm_iounmap(dev, core->mem[i].cpu_addr);
> +		devm_release_mem_region(dev, core->mem[i].bus_addr,
> +					core->mem[i].size);
> +	}
> +	if (core->mem)
> +		devm_kfree(dev, core->mem);
> +	return ret;
> +}
> +
> +static
> +struct ti_sci_proc *k3_r5_core_of_get_tsp(struct device *dev,
> +					  const struct ti_sci_handle *sci)
> +{
> +	struct ti_sci_proc *tsp;
> +	u32 temp[2];
> +	int ret;
> +
> +	ret = of_property_read_u32_array(dev->of_node, "ti,sci-proc-ids",
> +					 temp, 2);
> +	if (ret < 0)
> +		return ERR_PTR(ret);
> +
> +	tsp = kzalloc(sizeof(*tsp), GFP_KERNEL);
> +	if (!tsp)
> +		return ERR_PTR(-ENOMEM);
> +
> +	tsp->dev = dev;
> +	tsp->sci = sci;
> +	tsp->ops = &sci->ops.proc_ops;
> +	tsp->proc_id = temp[0];
> +	tsp->host_id = temp[1];
> +
> +	return tsp;
> +}
> +
> +static int k3_r5_core_of_init(struct platform_device *pdev)
> +{
> +	struct device *dev = &pdev->dev;
> +	struct device_node *np = dev->of_node;
> +	struct k3_r5_core *core;
> +	int ret, ret1;
> +
> +	core = devm_kzalloc(dev, sizeof(*core), GFP_KERNEL);
> +	if (!core)
> +		return -ENOMEM;
> +
> +	core->dev = dev;
> +	core->atcm_enable = 0;
> +	core->btcm_enable = 1;
> +	core->loczrama = 1;
> +
> +	ret = of_property_read_u32(np, "atcm-enable", &core->atcm_enable);
> +	if (ret < 0 && ret != -EINVAL) {
> +		dev_err(dev, "invalid format for atcm-enable, ret = %d\n", ret);
> +		goto err_of;
> +	}
> +
> +	ret = of_property_read_u32(np, "btcm-enable", &core->btcm_enable);
> +	if (ret < 0 && ret != -EINVAL) {
> +		dev_err(dev, "invalid format for btcm-enable, ret = %d\n", ret);
> +		goto err_of;
> +	}
> +
> +	ret = of_property_read_u32(np, "loczrama", &core->loczrama);
> +	if (ret < 0 && ret != -EINVAL) {
> +		dev_err(dev, "invalid format for loczrama, ret = %d\n", ret);
> +		goto err_of;
> +	}
> +
> +	core->ti_sci = ti_sci_get_by_phandle(np, "ti,sci");
> +	if (IS_ERR(core->ti_sci)) {
> +		ret = PTR_ERR(core->ti_sci);
> +		if (ret != -EPROBE_DEFER) {
> +			dev_err(dev, "failed to get ti-sci handle, ret = %d\n",
> +				ret);
> +		}
> +		core->ti_sci = NULL;
> +		goto err_of;
> +	}
> +
> +	ret = of_property_read_u32(np, "ti,sci-dev-id", &core->ti_sci_id);
> +	if (ret) {
> +		dev_err(dev, "missing 'ti,sci-dev-id' property\n");
> +		goto err_sci_id;
> +	}
> +
> +	core->reset = reset_control_get_exclusive(dev, NULL);
> +	if (IS_ERR(core->reset)) {
> +		ret = PTR_ERR(core->reset);
> +		if (ret != -EPROBE_DEFER) {
> +			dev_err(dev, "failed to get reset handle, ret = %d\n",
> +				ret);
> +		}
> +		goto err_sci_id;
> +	}
> +
> +	core->tsp = k3_r5_core_of_get_tsp(dev, core->ti_sci);
> +	if (IS_ERR(core->tsp)) {
> +		dev_err(dev, "failed to construct ti-sci proc control, ret = %d\n",
> +			ret);
> +		ret = PTR_ERR(core->tsp);
> +		goto err_sci_proc;

Why not calling the label "err_reset"?  I don't see what how "err_sci_proc"
relates to what the code is doing... 

I'll continue reviewing this patch tomorrow.

Thanks,
Mathieu

> +	}
> +
> +	ret = ti_sci_proc_request(core->tsp);
> +	if (ret < 0) {
> +		dev_err(dev, "ti_sci_proc_request failed, ret = %d\n", ret);
> +		goto err_proc;
> +	}
> +
> +	ret = k3_r5_core_of_get_internal_memories(pdev, core);
> +	if (ret) {
> +		dev_err(dev, "failed to get internal memories, ret = %d\n",
> +			ret);
> +		goto err_intmem;
> +	}
> +
> +	platform_set_drvdata(pdev, core);
> +
> +	return 0;
> +
> +err_intmem:
> +	ret1 = ti_sci_proc_release(core->tsp);
> +	if (ret1)
> +		dev_err(dev, "failed to release proc, ret1 = %d\n", ret1);
> +err_proc:
> +	kfree(core->tsp);
> +err_sci_proc:
> +	reset_control_put(core->reset);
> +err_sci_id:
> +	ret1 = ti_sci_put_handle(core->ti_sci);
> +	if (ret1)
> +		dev_err(dev, "failed to put ti_sci handle, ret = %d\n", ret1);
> +err_of:
> +	devm_kfree(dev, core);
> +	return ret;
> +}
> +
> +/*
> + * free the resources explicitly since driver model is not being used
> + * for the child R5F devices
> + */
> +static int k3_r5_core_of_exit(struct platform_device *pdev)
> +{
> +	struct k3_r5_core *core = platform_get_drvdata(pdev);
> +	struct device *dev = &pdev->dev;
> +	int i, ret;
> +
> +	for (i = 0; i < core->num_mems; i++) {
> +		devm_release_mem_region(dev, core->mem[i].bus_addr,
> +					core->mem[i].size);
> +		devm_iounmap(dev, core->mem[i].cpu_addr);
> +	}
> +	if (core->mem)
> +		devm_kfree(dev, core->mem);
> +
> +	ret = ti_sci_proc_release(core->tsp);
> +	if (ret)
> +		dev_err(dev, "failed to release proc, ret = %d\n", ret);
> +
> +	kfree(core->tsp);
> +	reset_control_put(core->reset);
> +
> +	ret = ti_sci_put_handle(core->ti_sci);
> +	if (ret)
> +		dev_err(dev, "failed to put ti_sci handle, ret = %d\n", ret);
> +
> +	platform_set_drvdata(pdev, NULL);
> +	devm_kfree(dev, core);
> +
> +	return ret;
> +}
> +
> +static int k3_r5_cluster_of_init(struct platform_device *pdev)
> +{
> +	struct k3_r5_cluster *cluster = platform_get_drvdata(pdev);
> +	struct device *dev = &pdev->dev;
> +	struct device_node *np = dev->of_node;
> +	struct platform_device *cpdev;
> +	struct device_node *child;
> +	struct k3_r5_core *core, *temp;
> +	int ret;
> +
> +	for_each_available_child_of_node(np, child) {
> +		cpdev = of_find_device_by_node(child);
> +		if (!cpdev) {
> +			ret = -ENODEV;
> +			dev_err(dev, "could not get R5 core platform device\n");
> +			goto fail;
> +		}
> +
> +		ret = k3_r5_core_of_init(cpdev);
> +		if (ret) {
> +			dev_err(dev, "k3_r5_core_of_init failed, ret = %d\n",
> +				ret);
> +			put_device(&cpdev->dev);
> +			goto fail;
> +		}
> +
> +		core = platform_get_drvdata(cpdev);
> +		put_device(&cpdev->dev);
> +		list_add_tail(&core->elem, &cluster->cores);
> +	}
> +
> +	return 0;
> +
> +fail:
> +	list_for_each_entry_safe_reverse(core, temp, &cluster->cores, elem) {
> +		list_del(&core->elem);
> +		cpdev = to_platform_device(core->dev);
> +		if (k3_r5_core_of_exit(cpdev))
> +			dev_err(dev, "k3_r5_core_of_exit cleanup failed\n");

I would move k3_r5_cluster_of_exit() just above k3_r5_cluster_of_init() and
reuse the former here instead of repeating the same code.

> +	}
> +	return ret;
> +}
> +
> +static int k3_r5_cluster_of_exit(struct platform_device *pdev)
> +{
> +	struct k3_r5_cluster *cluster = platform_get_drvdata(pdev);
> +	struct device *dev = &pdev->dev;
> +	struct platform_device *cpdev;
> +	struct k3_r5_core *core, *temp;
> +	int ret;
> +
> +	list_for_each_entry_safe_reverse(core, temp, &cluster->cores, elem) {
> +		list_del(&core->elem);
> +		cpdev = to_platform_device(core->dev);
> +		ret = k3_r5_core_of_exit(cpdev);
> +		if (ret) {
> +			dev_err(dev, "k3_r5_core_of_exit failed, ret = %d\n",
> +				ret);
> +			break;

So why stopping when encountering an error?  Since this is the exit path I think
it is better to call k3_r5_core_of_exit() on as many core as possible.

> +		}
> +	}
> +
> +	return ret;
> +}
> +
> +static int k3_r5_probe(struct platform_device *pdev)
> +{
> +	struct device *dev = &pdev->dev;
> +	struct device_node *np = dev->of_node;
> +	struct k3_r5_cluster *cluster;
> +	int ret, ret1;
> +	int num_cores;
> +
> +	cluster = devm_kzalloc(dev, sizeof(*cluster), GFP_KERNEL);
> +	if (!cluster)
> +		return -ENOMEM;
> +
> +	cluster->dev = dev;
> +	cluster->mode = CLUSTER_MODE_LOCKSTEP;
> +	INIT_LIST_HEAD(&cluster->cores);
> +
> +	ret = of_property_read_u32(np, "lockstep-mode", &cluster->mode);
> +	if (ret < 0 && ret != -EINVAL) {
> +		dev_err(dev, "invalid format for lockstep-mode, ret = %d\n",
> +			ret);
> +		return ret;
> +	}
> +
> +	num_cores = of_get_available_child_count(np);
> +	if (num_cores != 2) {
> +		dev_err(dev, "MCU cluster requires both R5F cores to be enabled, num_cores = %d\n",
> +			num_cores);
> +		return -ENODEV;
> +	}
> +
> +	platform_set_drvdata(pdev, cluster);
> +
> +	dev_dbg(dev, "creating child devices for R5F cores\n");
> +	ret = of_platform_populate(np, NULL, NULL, dev);
> +	if (ret) {
> +		dev_err(dev, "of_platform_populate failed, ret = %d\n", ret);
> +		return ret;
> +	}
> +
> +	ret = k3_r5_cluster_of_init(pdev);
> +	if (ret) {
> +		dev_err(dev, "k3_r5_cluster_of_init failed, ret = %d\n", ret);
> +		goto fail_of;
> +	}
> +
> +	ret = k3_r5_cluster_rproc_init(pdev);
> +	if (ret) {
> +		dev_err(dev, "k3_r5_cluster_rproc_init failed, ret = %d\n",
> +			ret);
> +		goto fail_rproc;
> +	}
> +
> +	return 0;
> +
> +fail_rproc:
> +	ret1 = k3_r5_cluster_of_exit(pdev);
> +	if (ret1)
> +		dev_err(dev, "k3_r5_cluster_of_exit failed, ret = %d\n", ret1);
> +fail_of:
> +	of_platform_depopulate(dev);
> +	return ret;
> +}
> +
> +static int k3_r5_remove(struct platform_device *pdev)
> +{
> +	struct device *dev = &pdev->dev;
> +	int ret;
> +
> +	ret = k3_r5_cluster_rproc_exit(pdev);
> +	if (ret) {
> +		dev_err(dev, "k3_r5_cluster_rproc_exit failed, ret = %d\n",
> +			ret);
> +		goto fail;
> +	}
> +
> +	ret = k3_r5_cluster_of_exit(pdev);
> +	if (ret) {
> +		dev_err(dev, "k3_r5_cluster_of_exit failed, ret = %d\n", ret);
> +		goto fail;
> +	}
> +
> +	dev_dbg(dev, "removing child devices for R5F cores\n");
> +	of_platform_depopulate(dev);
> +
> +fail:
> +	return ret;
> +}
> +
> +static const struct of_device_id k3_r5_of_match[] = {
> +	{ .compatible = "ti,am654-r5fss", },
> +	{ .compatible = "ti,j721e-r5fss", },
> +	{ /* sentinel */ },
> +};
> +MODULE_DEVICE_TABLE(of, k3_r5_of_match);
> +
> +static struct platform_driver k3_r5_rproc_driver = {
> +	.probe = k3_r5_probe,
> +	.remove = k3_r5_remove,
> +	.driver = {
> +		.name = "k3_r5_rproc",
> +		.of_match_table = k3_r5_of_match,
> +	},
> +};
> +
> +module_platform_driver(k3_r5_rproc_driver);
> +
> +MODULE_LICENSE("GPL v2");
> +MODULE_DESCRIPTION("TI K3 R5F remote processor driver");
> +MODULE_AUTHOR("Suman Anna <s-anna@ti.com>");
> -- 
> 2.23.0
>

On Tue, Mar 24, 2020 at 03:18:17PM -0500, Suman Anna wrote:
> The TI K3 family of SoCs typically have one or more dual-core Arm Cortex
> R5F processor clusters/subsystems (R5FSS). This R5F subsystem/cluster
> can be configured at boot time to be either run in a LockStep mode or in
> an Asymmetric Multi Processing (AMP) fashion in Split-mode. This subsystem
> has 64 KB each Tightly-Coupled Memory (TCM) internal memories for each
> core split between two banks - TCMA and TCMB (further interleaved into
> two banks). The subsystem does not have an MMU, but has a Region Address
> Translater (RAT) module that is accessible only from the R5Fs for providing
> translations between 32-bit CPU addresses into larger system bus addresses.
> 
> Add a remoteproc driver to support this subsystem to be able to load and
> boot the R5F cores primarily in LockStep mode. The code also includes the
> base support for Split mode. Error Recovery and Power Management features
> are not currently supported. Loading support includes the internal TCMs
> and DDR. RAT support is left for a future patch, and as such the reserved
> memory carveout regions are all expected to be using memory regions within
> the first 2 GB.
> 
> The R5F remote processors do not have an MMU, and so require fixed memory
> carveout regions matching the firmware image addresses. Support for this
> is provided by mandating multiple memory regions to be attached to the
> remoteproc device. The first memory region will be used to serve as the
> DMA pool for all dynamic allocations like the vrings and vring buffers.
> The remaining memory regions are mapped into the kernel at device probe
> time, and are used to provide address translations for firmware image
> segments without the need for any RSC_CARVEOUT entries. Any firmware
> image using memory outside of the supplied reserved memory carveout
> regions will be errored out.
> 
> The R5F processors on TI K3 SoCs require a specific sequence for booting
> and shutting down the processors. This sequence is also dependent on the
> mode (LockStep or Split) the R5F cluster is configured for. The R5F cores
> have a Memory Protection Unit (MPU) that has a default configuration that
> does not allow the cores to run out of DDR out of reset. This is resolved
> by using the TCMs for boot-strapping code that applies the appropriate
> executable permissions on desired DDR memory. The loading into the TCMs
> requires that the resets be released first with the cores in halted state.
> The Power Sleep Controller (PSC) module on K3 SoCs requires that the cores
> be in WFI/WFE states with no active bus transactions before the cores can
> be put back into reset. Support for this is provided by using the newly
> introduced .prepare() and .unprepare() ops in the remoteproc core. The
> .prepare() ops is invoked before any loading, and the .unprepare() ops
> is invoked after the remoteproc resource cleanup. The R5F core resets
> are deasserted in .prepare() and asserted in .unprepare(), and the cores
> themselves are started and halted in .start() and .stop() ops. This
> ensures symmetric usage and allows the R5F cores state machine to be
> maintained properly between using the sysfs 'state' variable, bind/unbind
> and regular module load/unload flows.
> 
> The subsystem is represented as a single remoteproc in LockStep mode, and
> as two remoteprocs in Split mode. The driver uses various TI-SCI interfaces
> to talk to the System Controller (DMSC) for managing configuration, power
> and reset management of these cores. IPC between the A53 cores and the R5
> cores is supported through the virtio rpmsg stack using shared memory and
> OMAP Mailboxes.
> 
> The AM65x SoCs typically have a single R5FSS in the MCU voltage domain. The
> J721E SoCs uses a slightly revised IP and typically have three R5FSSs, with
> one cluster present within the MCU voltage domain (MCU_R5FSS0), and the
> remaining two clusters present in the MAIN voltage domain (MAIN_R5FSS0 and
> MAIN_R5FSS1). The integration of these clusters on J721E SoC is also
> slightly different in that these IPs do support an actual local reset line,
> while they are a no-op on AM65x SoCs.
> 
> Signed-off-by: Suman Anna <s-anna@ti.com>
> ---
>  drivers/remoteproc/Kconfig               |   16 +
>  drivers/remoteproc/Makefile              |    1 +
>  drivers/remoteproc/ti_k3_r5_remoteproc.c | 1346 ++++++++++++++++++++++
>  3 files changed, 1363 insertions(+)
>  create mode 100644 drivers/remoteproc/ti_k3_r5_remoteproc.c
> 
> diff --git a/drivers/remoteproc/Kconfig b/drivers/remoteproc/Kconfig
> index de3862c15fcc..073048b4c0fb 100644
> --- a/drivers/remoteproc/Kconfig
> +++ b/drivers/remoteproc/Kconfig
> @@ -224,6 +224,22 @@ config STM32_RPROC
>  
>  	  This can be either built-in or a loadable module.
>  
> +config TI_K3_R5_REMOTEPROC
> +	tristate "TI K3 R5 remoteproc support"
> +	depends on ARCH_K3
> +	select MAILBOX
> +	select OMAP2PLUS_MBOX
> +	help
> +	  Say y here to support TI's R5F remote processor subsystems
> +	  on various TI K3 family of SoCs through the remote processor
> +	  framework.
> +
> +	  You want to say y here in order to offload some processing
> +	  tasks to these processors
> +
> +	  It's safe to say N here if you're not interested in utilizing
> +	  a slave processor
> +
>  endif # REMOTEPROC
>  
>  endmenu
> diff --git a/drivers/remoteproc/Makefile b/drivers/remoteproc/Makefile
> index e30a1b15fbac..00ba826818af 100644
> --- a/drivers/remoteproc/Makefile
> +++ b/drivers/remoteproc/Makefile
> @@ -28,3 +28,4 @@ qcom_wcnss_pil-y			+= qcom_wcnss_iris.o
>  obj-$(CONFIG_ST_REMOTEPROC)		+= st_remoteproc.o
>  obj-$(CONFIG_ST_SLIM_REMOTEPROC)	+= st_slim_rproc.o
>  obj-$(CONFIG_STM32_RPROC)		+= stm32_rproc.o
> +obj-$(CONFIG_TI_K3_R5_REMOTEPROC)	+= ti_k3_r5_remoteproc.o
> diff --git a/drivers/remoteproc/ti_k3_r5_remoteproc.c b/drivers/remoteproc/ti_k3_r5_remoteproc.c
> new file mode 100644
> index 000000000000..655f8f14c37d
> --- /dev/null
> +++ b/drivers/remoteproc/ti_k3_r5_remoteproc.c
> @@ -0,0 +1,1346 @@
> +// SPDX-License-Identifier: GPL-2.0-only
> +/*
> + * TI K3 R5F (MCU) Remote Processor driver
> + *
> + * Copyright (C) 2017-2020 Texas Instruments Incorporated - http://www.ti.com/
> + *	Suman Anna <s-anna@ti.com>
> + */
> +
> +#include <linux/dma-mapping.h>
> +#include <linux/err.h>
> +#include <linux/interrupt.h>
> +#include <linux/kernel.h>
> +#include <linux/mailbox_client.h>
> +#include <linux/module.h>
> +#include <linux/of_device.h>
> +#include <linux/of_address.h>
> +#include <linux/of_reserved_mem.h>
> +#include <linux/platform_device.h>
> +#include <linux/pm_runtime.h>
> +#include <linux/remoteproc.h>
> +#include <linux/omap-mailbox.h>
> +#include <linux/reset.h>
> +#include <linux/soc/ti/ti_sci_protocol.h>
> +
> +#include "omap_remoteproc.h"
> +#include "remoteproc_internal.h"
> +#include "ti_sci_proc.h"
> +
> +/* This address can either be for ATCM or BTCM with the other at address 0x0 */
> +#define K3_R5_TCM_DEV_ADDR	0x41010000
> +
> +/* R5 TI-SCI Processor Configuration Flags */
> +#define PROC_BOOT_CFG_FLAG_R5_DBG_EN			0x00000001
> +#define PROC_BOOT_CFG_FLAG_R5_DBG_NIDEN			0x00000002
> +#define PROC_BOOT_CFG_FLAG_R5_LOCKSTEP			0x00000100
> +#define PROC_BOOT_CFG_FLAG_R5_TEINIT			0x00000200
> +#define PROC_BOOT_CFG_FLAG_R5_NMFI_EN			0x00000400
> +#define PROC_BOOT_CFG_FLAG_R5_TCM_RSTBASE		0x00000800
> +#define PROC_BOOT_CFG_FLAG_R5_BTCM_EN			0x00001000
> +#define PROC_BOOT_CFG_FLAG_R5_ATCM_EN			0x00002000
> +
> +/* R5 TI-SCI Processor Control Flags */
> +#define PROC_BOOT_CTRL_FLAG_R5_CORE_HALT		0x00000001
> +
> +/* R5 TI-SCI Processor Status Flags */
> +#define PROC_BOOT_STATUS_FLAG_R5_WFE			0x00000001
> +#define PROC_BOOT_STATUS_FLAG_R5_WFI			0x00000002
> +#define PROC_BOOT_STATUS_FLAG_R5_CLK_GATED		0x00000004
> +#define PROC_BOOT_STATUS_FLAG_R5_LOCKSTEP_PERMITTED	0x00000100
> +
> +/**
> + * struct k3_r5_mem - internal memory structure
> + * @cpu_addr: MPU virtual address of the memory region
> + * @bus_addr: Bus address used to access the memory region
> + * @dev_addr: Device address from remoteproc view
> + * @size: Size of the memory region
> + */
> +struct k3_r5_mem {
> +	void __iomem *cpu_addr;
> +	phys_addr_t bus_addr;
> +	u32 dev_addr;
> +	size_t size;
> +};
> +
> +enum cluster_mode {
> +	CLUSTER_MODE_SPLIT = 0,
> +	CLUSTER_MODE_LOCKSTEP,
> +};
> +
> +/**
> + * struct k3_r5_cluster - K3 R5F Cluster structure
> + * @dev: cached device pointer
> + * @mode: Mode to configure the Cluster - Split or LockStep
> + * @cores: list of R5 cores within the cluster
> + */
> +struct k3_r5_cluster {
> +	struct device *dev;
> +	enum cluster_mode mode;
> +	struct list_head cores;
> +};
> +
> +/**
> + * struct k3_r5_core - K3 R5 core structure
> + * @elem: linked list item
> + * @dev: cached device pointer
> + * @rproc: rproc handle representing this core
> + * @mem: internal memory regions data
> + * @num_mems: number of internal memory regions
> + * @reset: reset control handle
> + * @tsp: TI-SCI processor control handle
> + * @ti_sci: TI-SCI handle
> + * @ti_sci_id: TI-SCI device identifier
> + * @atcm_enable: flag to control ATCM enablement
> + * @btcm_enable: flag to control BTCM enablement
> + * @loczrama: flag to dictate which TCM is at device address 0x0
> + */
> +struct k3_r5_core {
> +	struct list_head elem;
> +	struct device *dev;
> +	struct rproc *rproc;
> +	struct k3_r5_mem *mem;
> +	int num_mems;
> +	struct reset_control *reset;
> +	struct ti_sci_proc *tsp;
> +	const struct ti_sci_handle *ti_sci;
> +	u32 ti_sci_id;
> +	u32 atcm_enable;
> +	u32 btcm_enable;
> +	u32 loczrama;
> +};
> +
> +/**
> + * struct k3_r5_rproc - K3 remote processor state
> + * @dev: cached device pointer
> + * @cluster: cached pointer to parent cluster structure
> + * @mbox: mailbox channel handle
> + * @client: mailbox client to request the mailbox channel
> + * @rproc: rproc handle
> + * @core: cached pointer to r5 core structure being used
> + * @rmem: reserved memory regions data
> + * @num_rmems: number of reserved memory regions
> + */
> +struct k3_r5_rproc {
> +	struct device *dev;
> +	struct k3_r5_cluster *cluster;
> +	struct mbox_chan *mbox;
> +	struct mbox_client client;
> +	struct rproc *rproc;
> +	struct k3_r5_core *core;
> +	struct k3_r5_mem *rmem;
> +	int num_rmems;
> +};
> +
> +/**
> + * k3_r5_rproc_mbox_callback() - inbound mailbox message handler
> + * @client: mailbox client pointer used for requesting the mailbox channel
> + * @data: mailbox payload
> + *
> + * This handler is invoked by the OMAP mailbox driver whenever a mailbox
> + * message is received. Usually, the mailbox payload simply contains
> + * the index of the virtqueue that is kicked by the remote processor,
> + * and we let remoteproc core handle it.
> + *
> + * In addition to virtqueue indices, we also have some out-of-band values
> + * that indicate different events. Those values are deliberately very
> + * large so they don't coincide with virtqueue indices.
> + */
> +static void k3_r5_rproc_mbox_callback(struct mbox_client *client, void *data)
> +{
> +	struct k3_r5_rproc *kproc = container_of(client, struct k3_r5_rproc,
> +						client);
> +	struct device *dev = kproc->rproc->dev.parent;
> +	const char *name = kproc->rproc->name;
> +	u32 msg = omap_mbox_message(data);
> +
> +	dev_dbg(dev, "mbox msg: 0x%x\n", msg);
> +
> +	switch (msg) {
> +	case RP_MBOX_CRASH:
> +		/*
> +		 * remoteproc detected an exception, but error recovery is not
> +		 * supported. So, just log this for now
> +		 */
> +		dev_err(dev, "K3 R5F rproc %s crashed\n", name);
> +		break;
> +	case RP_MBOX_ECHO_REPLY:
> +		dev_info(dev, "received echo reply from %s\n", name);
> +		break;
> +	default:
> +		/* silently handle all other valid messages */
> +		if (msg >= RP_MBOX_READY && msg < RP_MBOX_END_MSG)
> +			return;
> +		if (msg > kproc->rproc->max_notifyid) {
> +			dev_dbg(dev, "dropping unknown message 0x%x", msg);
> +			return;
> +		}
> +		/* msg contains the index of the triggered vring */
> +		if (rproc_vq_interrupt(kproc->rproc, msg) == IRQ_NONE)
> +			dev_dbg(dev, "no message was found in vqid %d\n", msg);
> +	}
> +}
> +
> +/* kick a virtqueue */
> +static void k3_r5_rproc_kick(struct rproc *rproc, int vqid)
> +{
> +	struct k3_r5_rproc *kproc = rproc->priv;
> +	struct device *dev = rproc->dev.parent;
> +	mbox_msg_t msg = (mbox_msg_t)vqid;
> +	int ret;
> +
> +	/* send the index of the triggered virtqueue in the mailbox payload */
> +	ret = mbox_send_message(kproc->mbox, (void *)msg);
> +	if (ret < 0)
> +		dev_err(dev, "failed to send mailbox message, status = %d\n",
> +			ret);
> +}
> +
> +static int k3_r5_split_reset(struct k3_r5_core *core)
> +{
> +	int ret;
> +
> +	ret = reset_control_assert(core->reset);
> +	if (ret) {
> +		dev_err(core->dev, "local-reset assert failed, ret = %d\n",
> +			ret);
> +		return ret;
> +	}
> +
> +	ret = core->ti_sci->ops.dev_ops.put_device(core->ti_sci,
> +						   core->ti_sci_id);
> +	if (ret) {
> +		dev_err(core->dev, "module-reset assert failed, ret = %d\n",
> +			ret);
> +		if (reset_control_deassert(core->reset))
> +			dev_warn(core->dev, "local-reset deassert back failed\n");
> +	}
> +
> +	return ret;
> +}
> +
> +static int k3_r5_split_release(struct k3_r5_core *core)
> +{
> +	int ret;
> +
> +	ret = core->ti_sci->ops.dev_ops.get_device(core->ti_sci,
> +						   core->ti_sci_id);
> +	if (ret) {
> +		dev_err(core->dev, "module-reset deassert failed, ret = %d\n",
> +			ret);
> +		return ret;
> +	}
> +
> +	ret = reset_control_deassert(core->reset);
> +	if (ret) {
> +		dev_err(core->dev, "local-reset deassert failed, ret = %d\n",
> +			ret);
> +		if (core->ti_sci->ops.dev_ops.put_device(core->ti_sci,
> +							 core->ti_sci_id))
> +			dev_warn(core->dev, "module-reset assert back failed\n");
> +	}
> +
> +	return ret;
> +}
> +
> +static int k3_r5_lockstep_reset(struct k3_r5_cluster *cluster)
> +{
> +	struct k3_r5_core *core;
> +	int ret;
> +
> +	/* assert local reset on all applicable cores */
> +	list_for_each_entry(core, &cluster->cores, elem) {
> +		ret = reset_control_assert(core->reset);
> +		if (ret) {
> +			dev_err(core->dev, "local-reset assert failed, ret = %d\n",
> +				ret);
> +			core = list_prev_entry(core, elem);
> +			goto unroll_local_reset;
> +		}
> +	}
> +
> +	/* disable PSC modules on all applicable cores */
> +	list_for_each_entry(core, &cluster->cores, elem) {
> +		ret = core->ti_sci->ops.dev_ops.put_device(core->ti_sci,
> +							   core->ti_sci_id);
> +		if (ret) {
> +			dev_err(core->dev, "module-reset assert failed, ret = %d\n",
> +				ret);
> +			goto unroll_module_reset;
> +		}
> +	}
> +
> +	return 0;
> +
> +unroll_module_reset:
> +	list_for_each_entry_continue_reverse(core, &cluster->cores, elem) {
> +		if (core->ti_sci->ops.dev_ops.put_device(core->ti_sci,
> +							 core->ti_sci_id))
> +			dev_warn(core->dev, "module-reset assert back failed\n");
> +	}
> +	core = list_last_entry(&cluster->cores, struct k3_r5_core, elem);
> +unroll_local_reset:
> +	list_for_each_entry_from_reverse(core, &cluster->cores, elem) {
> +		if (reset_control_deassert(core->reset))
> +			dev_warn(core->dev, "local-reset deassert back failed\n");
> +	}
> +
> +	return ret;
> +}
> +
> +static int k3_r5_lockstep_release(struct k3_r5_cluster *cluster)
> +{
> +	struct k3_r5_core *core;
> +	int ret;
> +
> +	/* enable PSC modules on all applicable cores */
> +	list_for_each_entry_reverse(core, &cluster->cores, elem) {
> +		ret = core->ti_sci->ops.dev_ops.get_device(core->ti_sci,
> +							   core->ti_sci_id);
> +		if (ret) {
> +			dev_err(core->dev, "module-reset deassert failed, ret = %d\n",
> +				ret);
> +			core = list_next_entry(core, elem);
> +			goto unroll_module_reset;
> +		}
> +	}
> +
> +	/* deassert local reset on all applicable cores */
> +	list_for_each_entry_reverse(core, &cluster->cores, elem) {
> +		ret = reset_control_deassert(core->reset);
> +		if (ret) {
> +			dev_err(core->dev, "module-reset deassert failed, ret = %d\n",
> +				ret);
> +			goto unroll_local_reset;
> +		}
> +	}
> +
> +	return 0;
> +
> +unroll_local_reset:
> +	list_for_each_entry_continue(core, &cluster->cores, elem) {
> +		if (reset_control_assert(core->reset))
> +			dev_warn(core->dev, "local-reset assert back failed\n");
> +	}
> +	core = list_first_entry(&cluster->cores, struct k3_r5_core, elem);
> +unroll_module_reset:
> +	list_for_each_entry_from(core, &cluster->cores, elem) {
> +		if (core->ti_sci->ops.dev_ops.put_device(core->ti_sci,
> +							 core->ti_sci_id))
> +			dev_warn(core->dev, "module-reset assert back failed\n");
> +	}
> +
> +	return ret;
> +}
> +
> +static inline int k3_r5_core_halt(struct k3_r5_core *core)
> +{
> +	return ti_sci_proc_set_control(core->tsp,
> +				       PROC_BOOT_CTRL_FLAG_R5_CORE_HALT, 0);
> +}
> +
> +static inline int k3_r5_core_run(struct k3_r5_core *core)
> +{
> +	return ti_sci_proc_set_control(core->tsp,
> +				       0, PROC_BOOT_CTRL_FLAG_R5_CORE_HALT);
> +}
> +
> +/*
> + * The R5F cores have controls for both a reset and a halt/run. The code
> + * execution from DDR requires the initial boot-strapping code to be run
> + * from the internal TCMs. This function is used to release the resets on
> + * applicable cores to allow loading into the TCMs. The .prepare() ops is
> + * invoked by remoteproc core before any firmware loading, and is followed
> + * by the .start() ops after loading to actually let the R5 cores run.
> + */
> +static int k3_r5_rproc_prepare(struct rproc *rproc)
> +{
> +	struct k3_r5_rproc *kproc = rproc->priv;
> +	struct k3_r5_cluster *cluster = kproc->cluster;
> +	struct k3_r5_core *core = kproc->core;
> +	struct device *dev = kproc->dev;
> +	int ret;
> +
> +	ret = cluster->mode ? k3_r5_lockstep_release(cluster) :
> +			      k3_r5_split_release(core);
> +	if (ret)
> +		dev_err(dev, "unable to enable cores for TCM loading, ret = %d\n",
> +			ret);
> +
> +	return ret;
> +}
> +
> +/*
> + * This function implements the .unprepare() ops and performs the complimentary
> + * operations to that of the .prepare() ops. The function is used to assert the
> + * resets on all applicable cores for the rproc device (depending on LockStep
> + * or Split mode). This completes the second portion of powering down the R5F
> + * cores. The cores themselves are only halted in the .stop() ops, and the
> + * .unprepare() ops is invoked by the remoteproc core after the remoteproc is
> + * stopped.
> + */
> +static int k3_r5_rproc_unprepare(struct rproc *rproc)
> +{
> +	struct k3_r5_rproc *kproc = rproc->priv;
> +	struct k3_r5_cluster *cluster = kproc->cluster;
> +	struct k3_r5_core *core = kproc->core;
> +	struct device *dev = kproc->dev;
> +	int ret;
> +
> +	ret = cluster->mode ? k3_r5_lockstep_reset(cluster) :
> +			      k3_r5_split_reset(core);
> +	if (ret)
> +		dev_err(dev, "unable to disable cores, ret = %d\n", ret);
> +
> +	return ret;
> +}
> +
> +/*
> + * The R5F start sequence includes two different operations
> + * 1. Configure the boot vector for R5F core(s)
> + * 2. Unhalt/Run the R5F core(s)
> + *
> + * The sequence is different between LockStep and Split modes. The LockStep
> + * mode requires the boot vector to be configured only for Core0, and then
> + * unhalt both the cores to start the execution - Core1 needs to be unhalted
> + * first followed by Core0. The Split-mode requires that Core0 to be maintained
> + * always in a higher power state that Core1 (implying Core1 needs to be started
> + * always only after Core0 is started).
> + */
> +static int k3_r5_rproc_start(struct rproc *rproc)
> +{
> +	struct k3_r5_rproc *kproc = rproc->priv;
> +	struct k3_r5_cluster *cluster = kproc->cluster;
> +	struct mbox_client *client = &kproc->client;
> +	struct device *dev = kproc->dev;
> +	struct k3_r5_core *core;
> +	u32 boot_addr;
> +	int ret;
> +
> +	client->dev = dev;
> +	client->tx_done = NULL;
> +	client->rx_callback = k3_r5_rproc_mbox_callback;
> +	client->tx_block = false;
> +	client->knows_txdone = false;
> +
> +	kproc->mbox = mbox_request_channel(client, 0);
> +	if (IS_ERR(kproc->mbox)) {
> +		ret = -EBUSY;
> +		dev_err(dev, "mbox_request_channel failed: %ld\n",
> +			PTR_ERR(kproc->mbox));
> +		return ret;
> +	}
> +
> +	/*
> +	 * Ping the remote processor, this is only for sanity-sake for now;
> +	 * there is no functional effect whatsoever.
> +	 *
> +	 * Note that the reply will _not_ arrive immediately: this message
> +	 * will wait in the mailbox fifo until the remote processor is booted.
> +	 */
> +	ret = mbox_send_message(kproc->mbox, (void *)RP_MBOX_ECHO_REQUEST);
> +	if (ret < 0) {
> +		dev_err(dev, "mbox_send_message failed: %d\n", ret);
> +		goto put_mbox;
> +	}
> +
> +	boot_addr = rproc->bootaddr;
> +	/* TODO: add boot_addr sanity checking */
> +	dev_err(dev, "booting R5F core using boot addr = 0x%x\n", boot_addr);
> +
> +	/* boot vector need not be programmed for Core1 in LockStep mode */
> +	core = kproc->core;
> +	ret = ti_sci_proc_set_config(core->tsp, boot_addr, 0, 0);
> +	if (ret)
> +		goto put_mbox;
> +
> +	/* unhalt/run all applicable cores */
> +	if (cluster->mode) {
> +		list_for_each_entry_reverse(core, &cluster->cores, elem) {
> +			ret = k3_r5_core_run(core);
> +			if (ret)
> +				goto unroll_core_run;
> +		}
> +	} else {
> +		ret = k3_r5_core_run(core);
> +		if (ret)
> +			goto put_mbox;
> +	}
> +
> +	return 0;
> +
> +unroll_core_run:
> +	list_for_each_entry_continue(core, &cluster->cores, elem) {
> +		if (k3_r5_core_halt(core))
> +			dev_warn(core->dev, "core halt back failed\n");
> +	}
> +put_mbox:
> +	mbox_free_channel(kproc->mbox);
> +	return ret;
> +}
> +
> +/*
> + * The R5F stop function includes the following operations
> + * 1. Halt R5F core(s)
> + *
> + * The sequence is different between LockStep and Split modes, and the order
> + * of cores the operations are performed are also in general reverse to that
> + * of the start function. The LockStep mode requires each operation to be
> + * performed first on Core0 followed by Core1. The Split-mode requires that
> + * Core0 to be maintained always in a higher power state that Core1 (implying
> + * Core1 needs to be stopped first before Core0).
> + *
> + * Note that the R5F halt operation in general is not effective when the R5F
> + * core is running, but is needed to make sure the core won't run after
> + * deasserting the reset the subsequent time. The asserting of reset can
> + * be done here, but is preferred to be done in the .unprepare() ops - this
> + * maintains the symmetric behavior between the .start(), .stop(), .prepare()
> + * and .unprepare() ops, and also balances them well between sysfs 'state'
> + * flow and device bind/unbind or module removal.
> + */
> +static int k3_r5_rproc_stop(struct rproc *rproc)
> +{
> +	struct k3_r5_rproc *kproc = rproc->priv;
> +	struct k3_r5_cluster *cluster = kproc->cluster;
> +	struct k3_r5_core *core = kproc->core;
> +	int ret;
> +
> +	/* halt all applicable cores */
> +	if (cluster->mode) {
> +		list_for_each_entry(core, &cluster->cores, elem) {
> +			ret = k3_r5_core_halt(core);
> +			if (ret) {
> +				core = list_prev_entry(core, elem);
> +				goto unroll_core_halt;
> +			}
> +		}
> +	} else {
> +		ret = k3_r5_core_halt(core);
> +		if (ret)
> +			goto out;
> +	}
> +
> +	mbox_free_channel(kproc->mbox);
> +
> +	return 0;
> +
> +unroll_core_halt:
> +	list_for_each_entry_from_reverse(core, &cluster->cores, elem) {
> +		if (k3_r5_core_run(core))
> +			dev_warn(core->dev, "core run back failed\n");
> +	}
> +out:
> +	return ret;
> +}
> +
> +/*
> + * Internal Memory translation helper
> + *
> + * Custom function implementing the rproc .da_to_va ops to provide address
> + * translation (device address to kernel virtual address) for internal RAMs
> + * present in a DSP or IPU device). The translated addresses can be used
> + * either by the remoteproc core for loading, or by any rpmsg bus drivers.
> + */
> +static void *k3_r5_rproc_da_to_va(struct rproc *rproc, u64 da, size_t len)
> +{
> +	struct k3_r5_rproc *kproc = rproc->priv;
> +	struct k3_r5_core *core = kproc->core;
> +	void __iomem *va = NULL;
> +	phys_addr_t bus_addr;
> +	u32 dev_addr, offset;
> +	size_t size;
> +	int i;
> +
> +	if (len == 0)
> +		return NULL;
> +
> +	/* handle both R5 and SoC views of ATCM and BTCM */
> +	for (i = 0; i < core->num_mems; i++) {
> +		bus_addr = core->mem[i].bus_addr;
> +		dev_addr = core->mem[i].dev_addr;
> +		size = core->mem[i].size;
> +
> +		/* handle R5-view addresses of TCMs */
> +		if (da >= dev_addr && ((da + len) <= (dev_addr + size))) {
> +			offset = da - dev_addr;
> +			va = core->mem[i].cpu_addr + offset;
> +			return (__force void *)va;
> +		}
> +
> +		/* handle SoC-view addresses of TCMs */
> +		if (da >= bus_addr && ((da + len) <= (bus_addr + size))) {
> +			offset = da - bus_addr;
> +			va = core->mem[i].cpu_addr + offset;
> +			return (__force void *)va;
> +		}
> +	}
> +
> +	/* handle static DDR reserved memory regions */
> +	for (i = 0; i < kproc->num_rmems; i++) {
> +		dev_addr = kproc->rmem[i].dev_addr;
> +		size = kproc->rmem[i].size;
> +
> +		if (da >= dev_addr && ((da + len) <= (dev_addr + size))) {
> +			offset = da - dev_addr;
> +			va = kproc->rmem[i].cpu_addr + offset;
> +			return (__force void *)va;
> +		}
> +	}
> +
> +	return NULL;
> +}
> +
> +static const struct rproc_ops k3_r5_rproc_ops = {
> +	.prepare	= k3_r5_rproc_prepare,
> +	.unprepare	= k3_r5_rproc_unprepare,
> +	.start		= k3_r5_rproc_start,
> +	.stop		= k3_r5_rproc_stop,
> +	.kick		= k3_r5_rproc_kick,
> +	.da_to_va	= k3_r5_rproc_da_to_va,
> +};
> +
> +static const char *k3_r5_rproc_get_firmware(struct device *dev)
> +{
> +	const char *fw_name;
> +	int ret;
> +
> +	ret = of_property_read_string(dev->of_node, "firmware-name",
> +				      &fw_name);
> +	if (ret) {
> +		dev_err(dev, "failed to parse firmware-name property, ret = %d\n",
> +			ret);
> +		return ERR_PTR(ret);
> +	}
> +
> +	return fw_name;
> +}
> +
> +static int k3_r5_rproc_configure(struct k3_r5_rproc *kproc)
> +{
> +	struct k3_r5_cluster *cluster = kproc->cluster;
> +	struct device *dev = kproc->dev;
> +	struct k3_r5_core *core0, *core, *temp;
> +	u32 ctrl = 0, cfg = 0, stat = 0;
> +	u32 set_cfg = 0, clr_cfg = 0;
> +	u64 boot_vec = 0;
> +	bool lockstep_en;
> +	int ret;
> +
> +	core0 = list_first_entry(&cluster->cores, struct k3_r5_core, elem);
> +	core = cluster->mode ? core0 : kproc->core;

The above two lines generated interesting mental gymnastic - please sprinkle
with comments in order to disambiguate what is going on.

> +
> +	ret = ti_sci_proc_get_status(core->tsp, &boot_vec, &cfg, &ctrl,
> +				     &stat);
> +	if (ret < 0)
> +		return ret;
> +
> +	dev_dbg(dev, "boot_vector = 0x%llx, cfg = 0x%x ctrl = 0x%x stat = 0x%x\n",
> +		boot_vec, cfg, ctrl, stat);
> +
> +	lockstep_en = !!(stat & PROC_BOOT_STATUS_FLAG_R5_LOCKSTEP_PERMITTED);
> +	if (!lockstep_en && cluster->mode) {
> +		dev_err(cluster->dev, "lockstep mode not permitted, force configuring for split-mode\n");
> +		cluster->mode = 0;
> +	}
> +
> +	/* always enable ARM mode and set boot vector to 0 */
> +	boot_vec = 0x0;
> +	if (core == core0) {
> +		clr_cfg = PROC_BOOT_CFG_FLAG_R5_TEINIT;
> +		/*
> +		 * LockStep configuration bit is Read-only on Split-mode _only_
> +		 * devices and system firmware will NACK any requests with the
> +		 * bit configured, so program it only on permitted devices
> +		 */
> +		if (lockstep_en)
> +			clr_cfg |= PROC_BOOT_CFG_FLAG_R5_LOCKSTEP;
> +	}
> +
> +	if (core->atcm_enable)
> +		set_cfg |= PROC_BOOT_CFG_FLAG_R5_ATCM_EN;
> +	else
> +		clr_cfg |= PROC_BOOT_CFG_FLAG_R5_ATCM_EN;
> +
> +	if (core->btcm_enable)
> +		set_cfg |= PROC_BOOT_CFG_FLAG_R5_BTCM_EN;
> +	else
> +		clr_cfg |= PROC_BOOT_CFG_FLAG_R5_BTCM_EN;
> +
> +	if (core->loczrama)
> +		set_cfg |= PROC_BOOT_CFG_FLAG_R5_TCM_RSTBASE;
> +	else
> +		clr_cfg |= PROC_BOOT_CFG_FLAG_R5_TCM_RSTBASE;
> +
> +	if (cluster->mode) {
> +		/*
> +		 * work around system firmware limitations to make sure both
> +		 * cores are programmed symmetrically in LockStep. LockStep
> +		 * and TEINIT config is only allowed with Core0.
> +		 */
> +		list_for_each_entry(temp, &cluster->cores, elem) {
> +			ret = k3_r5_core_halt(core);

When I first read this I thought this was an error and what was really needed
was k3_r5_core_halt(temp)... But no, this is correct because
k3_r5_rproc_configure() is called for each core in the cluster in function
k3_r5_cluster_rproc_init().  But then again why halting the same for each of the
cores found in the system?

So something seems wrong here.  Either call k3_r5_core_halt(temp) or move
k3_r5_core_halt(core) outside of the if (cluster->mode) to avoid more confusion.

> +			if (ret)
> +				goto out;
> +
> +			if (temp != core) {
> +				clr_cfg &= ~PROC_BOOT_CFG_FLAG_R5_LOCKSTEP;
> +				clr_cfg &= ~PROC_BOOT_CFG_FLAG_R5_TEINIT;
> +			}
> +			ret = ti_sci_proc_set_config(temp->tsp, boot_vec,
> +						     set_cfg, clr_cfg);
> +			if (ret)
> +				goto out;
> +		}
> +
> +		set_cfg = PROC_BOOT_CFG_FLAG_R5_LOCKSTEP;
> +		clr_cfg = 0;
> +		ret = ti_sci_proc_set_config(core->tsp, boot_vec,
> +					     set_cfg, clr_cfg);
> +	} else {
> +		ret = k3_r5_core_halt(core);
> +		if (ret)
> +			goto out;
> +
> +		ret = ti_sci_proc_set_config(core->tsp, boot_vec,
> +					     set_cfg, clr_cfg);
> +	}
> +
> +out:
> +	return ret;
> +}
> +
> +static int k3_r5_reserved_mem_init(struct k3_r5_rproc *kproc)
> +{
> +	struct device *dev = kproc->dev;
> +	struct device_node *np = dev->of_node;
> +	struct device_node *rmem_np;
> +	struct reserved_mem *rmem;
> +	int num_rmems;
> +	int ret, i;
> +
> +	num_rmems = of_property_count_elems_of_size(np, "memory-region",
> +						    sizeof(phandle));
> +	if (num_rmems <= 0) {
> +		dev_err(dev, "device does not have reserved memory regions, ret = %d\n",
> +			num_rmems);
> +		return -EINVAL;
> +	}
> +	if (num_rmems < 2) {
> +		dev_err(dev, "device needs atleast two memory regions to be defined, num = %d\n",
> +			num_rmems);
> +		return -EINVAL;
> +	}
> +
> +	/* use reserved memory region 0 for vring DMA allocations */
> +	ret = of_reserved_mem_device_init_by_idx(dev, np, 0);
> +	if (ret) {
> +		dev_err(dev, "device cannot initialize DMA pool, ret = %d\n",
> +			ret);
> +		return ret;
> +	}
> +
> +	num_rmems--;
> +	kproc->rmem = kcalloc(num_rmems, sizeof(*kproc->rmem), GFP_KERNEL);
> +	if (!kproc->rmem) {
> +		ret = -ENOMEM;
> +		goto release_rmem;
> +	}
> +
> +	/* use remaining reserved memory regions for static carveouts */
> +	for (i = 0; i < num_rmems; i++) {
> +		rmem_np = of_parse_phandle(np, "memory-region", i + 1);
> +		if (!rmem_np) {
> +			ret = -EINVAL;
> +			goto unmap_rmem;
> +		}
> +
> +		rmem = of_reserved_mem_lookup(rmem_np);
> +		if (!rmem) {
> +			of_node_put(rmem_np);
> +			ret = -EINVAL;
> +			goto unmap_rmem;
> +		}
> +		of_node_put(rmem_np);
> +
> +		kproc->rmem[i].bus_addr = rmem->base;
> +		/* 64-bit address regions currently not supported */
> +		kproc->rmem[i].dev_addr = (u32)rmem->base;
> +		kproc->rmem[i].size = rmem->size;
> +		kproc->rmem[i].cpu_addr = ioremap_wc(rmem->base, rmem->size);
> +		if (!kproc->rmem[i].cpu_addr) {
> +			dev_err(dev, "failed to map reserved memory#%d at %pa of size %pa\n",
> +				i + 1, &rmem->base, &rmem->size);
> +			ret = -ENOMEM;
> +			goto unmap_rmem;
> +		}
> +
> +		dev_dbg(dev, "reserved memory%d: bus addr %pa size 0x%zx va %pK da 0x%x\n",
> +			i + 1, &kproc->rmem[i].bus_addr,
> +			kproc->rmem[i].size, kproc->rmem[i].cpu_addr,
> +			kproc->rmem[i].dev_addr);
> +	}
> +	kproc->num_rmems = num_rmems;
> +
> +	return 0;
> +
> +unmap_rmem:
> +	for (i--; i >= 0; i--) {
> +		if (kproc->rmem[i].cpu_addr)
> +			iounmap(kproc->rmem[i].cpu_addr);
> +	}
> +	kfree(kproc->rmem);
> +release_rmem:
> +	of_reserved_mem_device_release(dev);
> +	return ret;
> +}
> +
> +static void k3_r5_reserved_mem_exit(struct k3_r5_rproc *kproc)
> +{
> +	int i;
> +
> +	for (i = 0; i < kproc->num_rmems; i++)
> +		iounmap(kproc->rmem[i].cpu_addr);
> +	kfree(kproc->rmem);
> +
> +	of_reserved_mem_device_release(kproc->dev);
> +}
> +
> +static int k3_r5_cluster_rproc_init(struct platform_device *pdev)
> +{
> +	struct k3_r5_cluster *cluster = platform_get_drvdata(pdev);
> +	struct device *dev = &pdev->dev;
> +	struct k3_r5_rproc *kproc;
> +	struct k3_r5_core *core, *core1;
> +	struct device *cdev;
> +	const char *fw_name;
> +	struct rproc *rproc;
> +	int ret;
> +
> +	core1 = list_last_entry(&cluster->cores, struct k3_r5_core, elem);
> +	list_for_each_entry(core, &cluster->cores, elem) {
> +		cdev = core->dev;
> +		fw_name = k3_r5_rproc_get_firmware(cdev);
> +		if (IS_ERR(fw_name)) {
> +			ret = PTR_ERR(fw_name);
> +			goto out;
> +		}
> +
> +		rproc = rproc_alloc(cdev, dev_name(cdev), &k3_r5_rproc_ops,
> +				    fw_name, sizeof(*kproc));
> +		if (!rproc) {
> +			ret = -ENOMEM;
> +			goto out;
> +		}
> +
> +		/* K3 R5s have a Region Address Translator (RAT) but no MMU */
> +		rproc->has_iommu = false;
> +		/* error recovery is not supported at present */
> +		rproc->recovery_disabled = true;
> +
> +		kproc = rproc->priv;
> +		kproc->cluster = cluster;
> +		kproc->core = core;
> +		kproc->dev = cdev;
> +		kproc->rproc = rproc;
> +		core->rproc = rproc;
> +
> +		ret = k3_r5_rproc_configure(kproc);
> +		if (ret) {
> +			dev_err(dev, "initial configure failed, ret = %d\n",
> +				ret);
> +			goto err_config;
> +		}
> +
> +		ret = k3_r5_reserved_mem_init(kproc);
> +		if (ret) {
> +			dev_err(dev, "reserved memory init failed, ret = %d\n",
> +				ret);
> +			goto err_config;
> +		}
> +
> +		ret = rproc_add(rproc);
> +		if (ret) {
> +			dev_err(dev, "rproc_add failed, ret = %d\n", ret);
> +			goto err_add;
> +		}
> +
> +		/* create only one rproc in lockstep mode */
> +		if (cluster->mode)

Here and throughout the file, please use the cluster mode enumeration in order
to improve readability, i.e 

                if (cluster->mode == CLUSTER_MODE_LOCKSTEP)

> +			break;
> +	}
> +
> +	return 0;
> +
> +err_split:
> +	rproc_del(rproc);
> +err_add:
> +	k3_r5_reserved_mem_exit(kproc);
> +err_config:
> +	rproc_free(rproc);
> +	core->rproc = NULL;
> +out:
> +	/* undo core0 upon any failures on core1 in split-mode */
> +	if (!cluster->mode && core == core1) {
> +		core = list_prev_entry(core, elem);
> +		rproc = core->rproc;
> +		kproc = rproc->priv;
> +		goto err_split;
> +	}
> +	return ret;
> +}
> +
> +static int k3_r5_cluster_rproc_exit(struct platform_device *pdev)
> +{
> +	struct k3_r5_cluster *cluster = platform_get_drvdata(pdev);
> +	struct k3_r5_rproc *kproc;
> +	struct k3_r5_core *core;
> +	struct rproc *rproc;
> +
> +	/*
> +	 * lockstep mode has only one rproc associated with first core, whereas
> +	 * split-mode has two rprocs associated with each core, and requires
> +	 * that core1 be powered down first
> +	 */
> +	core = cluster->mode ?
> +		list_first_entry(&cluster->cores, struct k3_r5_core, elem) :
> +		list_last_entry(&cluster->cores, struct k3_r5_core, elem);
> +
> +	list_for_each_entry_from_reverse(core, &cluster->cores, elem) {
> +		rproc = core->rproc;
> +		kproc = rproc->priv;
> +
> +		rproc_del(rproc);
> +
> +		k3_r5_reserved_mem_exit(kproc);
> +
> +		rproc_free(rproc);
> +		core->rproc = NULL;
> +	}
> +
> +	return 0;
> +}
> +
> +static int k3_r5_core_of_get_internal_memories(struct platform_device *pdev,
> +					       struct k3_r5_core *core)
> +{
> +	static const char * const mem_names[] = {"atcm", "btcm"};
> +	struct device *dev = &pdev->dev;
> +	struct resource *res;
> +	int num_mems;
> +	int i, ret;
> +
> +	num_mems = ARRAY_SIZE(mem_names);
> +	core->mem = devm_kcalloc(dev, num_mems, sizeof(*core->mem), GFP_KERNEL);
> +	if (!core->mem)
> +		return -ENOMEM;
> +
> +	for (i = 0; i < num_mems; i++) {
> +		res = platform_get_resource_byname(pdev, IORESOURCE_MEM,
> +						   mem_names[i]);
> +		if (!res) {
> +			dev_err(dev, "found no memory resource for %s\n",
> +				mem_names[i]);
> +			ret = -EINVAL;
> +			goto fail;
> +		}
> +		if (!devm_request_mem_region(dev, res->start,
> +					     resource_size(res),
> +					     dev_name(dev))) {
> +			dev_err(dev, "could not request %s region for resource\n",
> +				mem_names[i]);
> +			ret = -EBUSY;
> +			goto fail;
> +		}
> +
> +		/*
> +		 * TCMs are designed in general to support RAM-like backing
> +		 * memories. So, map these as Normal Non-Cached memories. This
> +		 * also avoids/fixes any potential alignment faults due to
> +		 * unaligned data accesses when using memcpy() or memset()
> +		 * functions (normally seen with device type memory).
> +		 */
> +		core->mem[i].cpu_addr = devm_ioremap_wc(dev, res->start,
> +							resource_size(res));
> +		if (IS_ERR(core->mem[i].cpu_addr)) {
> +			dev_err(dev, "failed to map %s memory\n", mem_names[i]);
> +			ret = PTR_ERR(core->mem[i].cpu_addr);
> +			devm_release_mem_region(dev, res->start,
> +						resource_size(res));
> +			goto fail;
> +		}
> +		core->mem[i].bus_addr = res->start;
> +
> +		/*
> +		 * TODO:
> +		 * The R5F cores can place ATCM & BTCM anywhere in its address
> +		 * based on the corresponding Region Registers in the System
> +		 * Control coprocessor. For now, place ATCM and BTCM at
> +		 * addresses 0 and 0x41010000 (same as the bus address on AM65x
> +		 * SoCs) based on loczrama setting
> +		 */
> +		if (!strcmp(mem_names[i], "atcm")) {
> +			core->mem[i].dev_addr = core->loczrama ?
> +							0 : K3_R5_TCM_DEV_ADDR;
> +		} else {
> +			core->mem[i].dev_addr = core->loczrama ?
> +							K3_R5_TCM_DEV_ADDR : 0;
> +		}
> +		core->mem[i].size = resource_size(res);
> +
> +		dev_dbg(dev, "memory %8s: bus addr %pa size 0x%zx va %pK da 0x%x\n",
> +			mem_names[i], &core->mem[i].bus_addr,
> +			core->mem[i].size, core->mem[i].cpu_addr,
> +			core->mem[i].dev_addr);
> +	}
> +	core->num_mems = num_mems;
> +
> +	return 0;
> +
> +fail:
> +	for (i--; i >= 0; i--) {
> +		devm_iounmap(dev, core->mem[i].cpu_addr);
> +		devm_release_mem_region(dev, core->mem[i].bus_addr,
> +					core->mem[i].size);
> +	}
> +	if (core->mem)
> +		devm_kfree(dev, core->mem);

Since the devm_ API has been used for memory allocation all this should be
called automatically when of_platform_depopulate() is called. 

> +	return ret;
> +}
> +
> +static
> +struct ti_sci_proc *k3_r5_core_of_get_tsp(struct device *dev,
> +					  const struct ti_sci_handle *sci)
> +{
> +	struct ti_sci_proc *tsp;
> +	u32 temp[2];
> +	int ret;
> +
> +	ret = of_property_read_u32_array(dev->of_node, "ti,sci-proc-ids",
> +					 temp, 2);
> +	if (ret < 0)
> +		return ERR_PTR(ret);
> +
> +	tsp = kzalloc(sizeof(*tsp), GFP_KERNEL);

Here @dev is available, I would just call devm_kzalloc() and get rid of the
kfree() in the error path of k3_r5_core_of_init() and k3_r5_core_of_exit().  

> +	if (!tsp)
> +		return ERR_PTR(-ENOMEM);
> +
> +	tsp->dev = dev;
> +	tsp->sci = sci;
> +	tsp->ops = &sci->ops.proc_ops;
> +	tsp->proc_id = temp[0];
> +	tsp->host_id = temp[1];
> +
> +	return tsp;
> +}
> +
> +static int k3_r5_core_of_init(struct platform_device *pdev)
> +{
> +	struct device *dev = &pdev->dev;
> +	struct device_node *np = dev->of_node;
> +	struct k3_r5_core *core;
> +	int ret, ret1;
> +
> +	core = devm_kzalloc(dev, sizeof(*core), GFP_KERNEL);
> +	if (!core)
> +		return -ENOMEM;
> +
> +	core->dev = dev;
> +	core->atcm_enable = 0;
> +	core->btcm_enable = 1;
> +	core->loczrama = 1;

Please add a comment that justifies the selection of default value.  Otherwise
this looks very esoteric. 

> +
> +	ret = of_property_read_u32(np, "atcm-enable", &core->atcm_enable);
> +	if (ret < 0 && ret != -EINVAL) {
> +		dev_err(dev, "invalid format for atcm-enable, ret = %d\n", ret);
> +		goto err_of;
> +	}
> +
> +	ret = of_property_read_u32(np, "btcm-enable", &core->btcm_enable);
> +	if (ret < 0 && ret != -EINVAL) {
> +		dev_err(dev, "invalid format for btcm-enable, ret = %d\n", ret);
> +		goto err_of;
> +	}
> +
> +	ret = of_property_read_u32(np, "loczrama", &core->loczrama);
> +	if (ret < 0 && ret != -EINVAL) {
> +		dev_err(dev, "invalid format for loczrama, ret = %d\n", ret);
> +		goto err_of;
> +	}
> +
> +	core->ti_sci = ti_sci_get_by_phandle(np, "ti,sci");
> +	if (IS_ERR(core->ti_sci)) {
> +		ret = PTR_ERR(core->ti_sci);
> +		if (ret != -EPROBE_DEFER) {
> +			dev_err(dev, "failed to get ti-sci handle, ret = %d\n",
> +				ret);
> +		}
> +		core->ti_sci = NULL;
> +		goto err_of;
> +	}
> +
> +	ret = of_property_read_u32(np, "ti,sci-dev-id", &core->ti_sci_id);
> +	if (ret) {
> +		dev_err(dev, "missing 'ti,sci-dev-id' property\n");
> +		goto err_sci_id;
> +	}
> +
> +	core->reset = reset_control_get_exclusive(dev, NULL);
> +	if (IS_ERR(core->reset)) {
> +		ret = PTR_ERR(core->reset);
> +		if (ret != -EPROBE_DEFER) {
> +			dev_err(dev, "failed to get reset handle, ret = %d\n",
> +				ret);
> +		}
> +		goto err_sci_id;
> +	}
> +
> +	core->tsp = k3_r5_core_of_get_tsp(dev, core->ti_sci);
> +	if (IS_ERR(core->tsp)) {
> +		dev_err(dev, "failed to construct ti-sci proc control, ret = %d\n",
> +			ret);
> +		ret = PTR_ERR(core->tsp);
> +		goto err_sci_proc;
> +	}
> +
> +	ret = ti_sci_proc_request(core->tsp);
> +	if (ret < 0) {
> +		dev_err(dev, "ti_sci_proc_request failed, ret = %d\n", ret);
> +		goto err_proc;
> +	}
> +
> +	ret = k3_r5_core_of_get_internal_memories(pdev, core);
> +	if (ret) {
> +		dev_err(dev, "failed to get internal memories, ret = %d\n",
> +			ret);
> +		goto err_intmem;
> +	}
> +
> +	platform_set_drvdata(pdev, core);
> +
> +	return 0;
> +
> +err_intmem:
> +	ret1 = ti_sci_proc_release(core->tsp);
> +	if (ret1)
> +		dev_err(dev, "failed to release proc, ret1 = %d\n", ret1);
> +err_proc:
> +	kfree(core->tsp);
> +err_sci_proc:
> +	reset_control_put(core->reset);
> +err_sci_id:
> +	ret1 = ti_sci_put_handle(core->ti_sci);
> +	if (ret1)
> +		dev_err(dev, "failed to put ti_sci handle, ret = %d\n", ret1);

s/"ret = %d"/"ret1 = %d"

> +err_of:
> +	devm_kfree(dev, core);

Same comment as above, this should be called automatically.

> +	return ret;
> +}
> +
> +/*
> + * free the resources explicitly since driver model is not being used
> + * for the child R5F devices
> + */
> +static int k3_r5_core_of_exit(struct platform_device *pdev)
> +{
> +	struct k3_r5_core *core = platform_get_drvdata(pdev);
> +	struct device *dev = &pdev->dev;
> +	int i, ret;
> +
> +	for (i = 0; i < core->num_mems; i++) {
> +		devm_release_mem_region(dev, core->mem[i].bus_addr,
> +					core->mem[i].size);
> +		devm_iounmap(dev, core->mem[i].cpu_addr);
> +	}
> +	if (core->mem)
> +		devm_kfree(dev, core->mem);
> +
> +	ret = ti_sci_proc_release(core->tsp);
> +	if (ret)
> +		dev_err(dev, "failed to release proc, ret = %d\n", ret);
> +
> +	kfree(core->tsp);
> +	reset_control_put(core->reset);
> +
> +	ret = ti_sci_put_handle(core->ti_sci);
> +	if (ret)
> +		dev_err(dev, "failed to put ti_sci handle, ret = %d\n", ret);
> +
> +	platform_set_drvdata(pdev, NULL);
> +	devm_kfree(dev, core);

Same comment regarding the devm_ API, this should be called automatically.

I will continue tomorrow,
Mathieu

> +
> +	return ret;
> +}
> +
> +static int k3_r5_cluster_of_init(struct platform_device *pdev)
> +{
> +	struct k3_r5_cluster *cluster = platform_get_drvdata(pdev);
> +	struct device *dev = &pdev->dev;
> +	struct device_node *np = dev->of_node;
> +	struct platform_device *cpdev;
> +	struct device_node *child;
> +	struct k3_r5_core *core, *temp;
> +	int ret;
> +
> +	for_each_available_child_of_node(np, child) {
> +		cpdev = of_find_device_by_node(child);
> +		if (!cpdev) {
> +			ret = -ENODEV;
> +			dev_err(dev, "could not get R5 core platform device\n");
> +			goto fail;
> +		}
> +
> +		ret = k3_r5_core_of_init(cpdev);
> +		if (ret) {
> +			dev_err(dev, "k3_r5_core_of_init failed, ret = %d\n",
> +				ret);
> +			put_device(&cpdev->dev);
> +			goto fail;
> +		}
> +
> +		core = platform_get_drvdata(cpdev);
> +		put_device(&cpdev->dev);
> +		list_add_tail(&core->elem, &cluster->cores);
> +	}
> +
> +	return 0;
> +
> +fail:
> +	list_for_each_entry_safe_reverse(core, temp, &cluster->cores, elem) {
> +		list_del(&core->elem);
> +		cpdev = to_platform_device(core->dev);
> +		if (k3_r5_core_of_exit(cpdev))
> +			dev_err(dev, "k3_r5_core_of_exit cleanup failed\n");
> +	}
> +	return ret;
> +}
> +
> +static int k3_r5_cluster_of_exit(struct platform_device *pdev)
> +{
> +	struct k3_r5_cluster *cluster = platform_get_drvdata(pdev);
> +	struct device *dev = &pdev->dev;
> +	struct platform_device *cpdev;
> +	struct k3_r5_core *core, *temp;
> +	int ret;
> +
> +	list_for_each_entry_safe_reverse(core, temp, &cluster->cores, elem) {
> +		list_del(&core->elem);
> +		cpdev = to_platform_device(core->dev);
> +		ret = k3_r5_core_of_exit(cpdev);
> +		if (ret) {
> +			dev_err(dev, "k3_r5_core_of_exit failed, ret = %d\n",
> +				ret);
> +			break;
> +		}
> +	}
> +
> +	return ret;
> +}
> +
> +static int k3_r5_probe(struct platform_device *pdev)
> +{
> +	struct device *dev = &pdev->dev;
> +	struct device_node *np = dev->of_node;
> +	struct k3_r5_cluster *cluster;
> +	int ret, ret1;
> +	int num_cores;
> +
> +	cluster = devm_kzalloc(dev, sizeof(*cluster), GFP_KERNEL);
> +	if (!cluster)
> +		return -ENOMEM;
> +
> +	cluster->dev = dev;
> +	cluster->mode = CLUSTER_MODE_LOCKSTEP;
> +	INIT_LIST_HEAD(&cluster->cores);
> +
> +	ret = of_property_read_u32(np, "lockstep-mode", &cluster->mode);
> +	if (ret < 0 && ret != -EINVAL) {
> +		dev_err(dev, "invalid format for lockstep-mode, ret = %d\n",
> +			ret);
> +		return ret;
> +	}
> +
> +	num_cores = of_get_available_child_count(np);
> +	if (num_cores != 2) {
> +		dev_err(dev, "MCU cluster requires both R5F cores to be enabled, num_cores = %d\n",
> +			num_cores);
> +		return -ENODEV;
> +	}
> +
> +	platform_set_drvdata(pdev, cluster);
> +
> +	dev_dbg(dev, "creating child devices for R5F cores\n");
> +	ret = of_platform_populate(np, NULL, NULL, dev);
> +	if (ret) {
> +		dev_err(dev, "of_platform_populate failed, ret = %d\n", ret);
> +		return ret;
> +	}
> +
> +	ret = k3_r5_cluster_of_init(pdev);
> +	if (ret) {
> +		dev_err(dev, "k3_r5_cluster_of_init failed, ret = %d\n", ret);
> +		goto fail_of;
> +	}
> +
> +	ret = k3_r5_cluster_rproc_init(pdev);
> +	if (ret) {
> +		dev_err(dev, "k3_r5_cluster_rproc_init failed, ret = %d\n",
> +			ret);
> +		goto fail_rproc;
> +	}
> +
> +	return 0;
> +
> +fail_rproc:
> +	ret1 = k3_r5_cluster_of_exit(pdev);
> +	if (ret1)
> +		dev_err(dev, "k3_r5_cluster_of_exit failed, ret = %d\n", ret1);
> +fail_of:
> +	of_platform_depopulate(dev);
> +	return ret;
> +}
> +
> +static int k3_r5_remove(struct platform_device *pdev)
> +{
> +	struct device *dev = &pdev->dev;
> +	int ret;
> +
> +	ret = k3_r5_cluster_rproc_exit(pdev);
> +	if (ret) {
> +		dev_err(dev, "k3_r5_cluster_rproc_exit failed, ret = %d\n",
> +			ret);
> +		goto fail;
> +	}
> +
> +	ret = k3_r5_cluster_of_exit(pdev);
> +	if (ret) {
> +		dev_err(dev, "k3_r5_cluster_of_exit failed, ret = %d\n", ret);
> +		goto fail;
> +	}
> +
> +	dev_dbg(dev, "removing child devices for R5F cores\n");
> +	of_platform_depopulate(dev);
> +
> +fail:
> +	return ret;
> +}
> +
> +static const struct of_device_id k3_r5_of_match[] = {
> +	{ .compatible = "ti,am654-r5fss", },
> +	{ .compatible = "ti,j721e-r5fss", },
> +	{ /* sentinel */ },
> +};
> +MODULE_DEVICE_TABLE(of, k3_r5_of_match);
> +
> +static struct platform_driver k3_r5_rproc_driver = {
> +	.probe = k3_r5_probe,
> +	.remove = k3_r5_remove,
> +	.driver = {
> +		.name = "k3_r5_rproc",
> +		.of_match_table = k3_r5_of_match,
> +	},
> +};
> +
> +module_platform_driver(k3_r5_rproc_driver);
> +
> +MODULE_LICENSE("GPL v2");
> +MODULE_DESCRIPTION("TI K3 R5F remote processor driver");
> +MODULE_AUTHOR("Suman Anna <s-anna@ti.com>");
> -- 
> 2.23.0
>

Hi Mathieu,

On 4/6/20 12:20 PM, Mathieu Poirier wrote:
> Good morning Suman,
> 
> I have started to work on this set - comments will come in over the next few
> days...
> 
> On Tue, Mar 24, 2020 at 03:18:13PM -0500, Suman Anna wrote:
>> From: Loic Pallardy <loic.pallardy@st.com>
>>
>> On some SoC architecture, it is needed to enable HW like
>> clock, bus, regulator, memory region... before loading
>> co-processor firmware.
>>
>> This patch introduces prepare and unprepare ops to execute
>> platform specific function before firmware loading and after
>> stop execution.
>>
>> Signed-off-by: Loic Pallardy <loic.pallardy@st.com>
>> Signed-off-by: Suman Anna <s-anna@ti.com>
>> ---
>>  drivers/remoteproc/remoteproc_core.c | 20 +++++++++++++++++++-
>>  include/linux/remoteproc.h           |  4 ++++
>>  2 files changed, 23 insertions(+), 1 deletion(-)
>>
>> diff --git a/drivers/remoteproc/remoteproc_core.c b/drivers/remoteproc/remoteproc_core.c
>> index 26f6947267d2..aca6d022901a 100644
>> --- a/drivers/remoteproc/remoteproc_core.c
>> +++ b/drivers/remoteproc/remoteproc_core.c
>> @@ -1394,12 +1394,22 @@ static int rproc_fw_boot(struct rproc *rproc, const struct firmware *fw)
>>  		return ret;
>>  	}
>>  
>> +	/* Prepare rproc for firmware loading if needed */
>> +	if (rproc->ops->prepare) {
>> +		ret = rproc->ops->prepare(rproc);
> 
> In my patchset on MCU synchronisation I have moved ops->{start/stop} to
> remoteproc_internal.h and called them rproc_start/stop_device() (after Loic's
> suggestion).  In order to be consistent and remove boiler plate code in the core
> we could do the same, i.e have rproc_prepare/unprepare_device() in
> remoteproc_internal.h .

Yes, I will update so for v2. I plan to separate out this patch and the
next patch for v2 to go alongside your cleanup and Alex's patch on the
idr_init move.

regards
Suman

> 
> With the above:
> Reviewed-by: Mathieu Poirier <mathieu.poirier@linaro.org>
> 
> Thanks,
> Mathieu
> 
>> +		if (ret) {
>> +			dev_err(dev, "can't prepare rproc %s: %d\n",
>> +				rproc->name, ret);
>> +			goto disable_iommu;
>> +		}
>> +	}
>> +
>>  	rproc->bootaddr = rproc_get_boot_addr(rproc, fw);
>>  
>>  	/* Load resource table, core dump segment list etc from the firmware */
>>  	ret = rproc_parse_fw(rproc, fw);
>>  	if (ret)
>> -		goto disable_iommu;
>> +		goto unprepare_rproc;
>>  
>>  	/* reset max_notifyid */
>>  	rproc->max_notifyid = -1;
>> @@ -1433,6 +1443,10 @@ static int rproc_fw_boot(struct rproc *rproc, const struct firmware *fw)
>>  	kfree(rproc->cached_table);
>>  	rproc->cached_table = NULL;
>>  	rproc->table_ptr = NULL;
>> +unprepare_rproc:
>> +	/* release HW resources if needed */
>> +	if (rproc->ops->unprepare)
>> +		rproc->ops->unprepare(rproc);
>>  disable_iommu:
>>  	rproc_disable_iommu(rproc);
>>  	return ret;
>> @@ -1838,6 +1852,10 @@ void rproc_shutdown(struct rproc *rproc)
>>  	/* clean up all acquired resources */
>>  	rproc_resource_cleanup(rproc);
>>  
>> +	/* release HW resources if needed */
>> +	if (rproc->ops->unprepare)
>> +		rproc->ops->unprepare(rproc);
>> +
>>  	rproc_disable_iommu(rproc);
>>  
>>  	/* Free the copy of the resource table */
>> diff --git a/include/linux/remoteproc.h b/include/linux/remoteproc.h
>> index 07bd73a6d72a..ddce7a7775d1 100644
>> --- a/include/linux/remoteproc.h
>> +++ b/include/linux/remoteproc.h
>> @@ -355,6 +355,8 @@ enum rsc_handling_status {
>>  
>>  /**
>>   * struct rproc_ops - platform-specific device handlers
>> + * @prepare:	prepare device for code loading
>> + * @unprepare:	unprepare device after stop
>>   * @start:	power on the device and boot it
>>   * @stop:	power off the device
>>   * @kick:	kick a virtqueue (virtqueue id given as a parameter)
>> @@ -371,6 +373,8 @@ enum rsc_handling_status {
>>   * @get_boot_addr:	get boot address to entry point specified in firmware
>>   */
>>  struct rproc_ops {
>> +	int (*prepare)(struct rproc *rproc);
>> +	int (*unprepare)(struct rproc *rproc);
>>  	int (*start)(struct rproc *rproc);
>>  	int (*stop)(struct rproc *rproc);
>>  	void (*kick)(struct rproc *rproc, int vqid);
>> -- 
>> 2.23.0
>>
>

On 4/7/20 1:08 PM, Mathieu Poirier wrote:
> On Tue, Mar 24, 2020 at 03:18:17PM -0500, Suman Anna wrote:
>> The TI K3 family of SoCs typically have one or more dual-core Arm Cortex
>> R5F processor clusters/subsystems (R5FSS). This R5F subsystem/cluster
>> can be configured at boot time to be either run in a LockStep mode or in
>> an Asymmetric Multi Processing (AMP) fashion in Split-mode. This subsystem
>> has 64 KB each Tightly-Coupled Memory (TCM) internal memories for each
>> core split between two banks - TCMA and TCMB (further interleaved into
>> two banks). The subsystem does not have an MMU, but has a Region Address
>> Translater (RAT) module that is accessible only from the R5Fs for providing
>> translations between 32-bit CPU addresses into larger system bus addresses.
>>
>> Add a remoteproc driver to support this subsystem to be able to load and
>> boot the R5F cores primarily in LockStep mode. The code also includes the
>> base support for Split mode. Error Recovery and Power Management features
>> are not currently supported. Loading support includes the internal TCMs
>> and DDR. RAT support is left for a future patch, and as such the reserved
>> memory carveout regions are all expected to be using memory regions within
>> the first 2 GB.
>>
>> The R5F remote processors do not have an MMU, and so require fixed memory
>> carveout regions matching the firmware image addresses. Support for this
>> is provided by mandating multiple memory regions to be attached to the
>> remoteproc device. The first memory region will be used to serve as the
>> DMA pool for all dynamic allocations like the vrings and vring buffers.
>> The remaining memory regions are mapped into the kernel at device probe
>> time, and are used to provide address translations for firmware image
>> segments without the need for any RSC_CARVEOUT entries. Any firmware
>> image using memory outside of the supplied reserved memory carveout
>> regions will be errored out.
>>
>> The R5F processors on TI K3 SoCs require a specific sequence for booting
>> and shutting down the processors. This sequence is also dependent on the
>> mode (LockStep or Split) the R5F cluster is configured for. The R5F cores
>> have a Memory Protection Unit (MPU) that has a default configuration that
>> does not allow the cores to run out of DDR out of reset. This is resolved
>> by using the TCMs for boot-strapping code that applies the appropriate
>> executable permissions on desired DDR memory. The loading into the TCMs
>> requires that the resets be released first with the cores in halted state.
>> The Power Sleep Controller (PSC) module on K3 SoCs requires that the cores
>> be in WFI/WFE states with no active bus transactions before the cores can
>> be put back into reset. Support for this is provided by using the newly
>> introduced .prepare() and .unprepare() ops in the remoteproc core. The
>> .prepare() ops is invoked before any loading, and the .unprepare() ops
>> is invoked after the remoteproc resource cleanup. The R5F core resets
>> are deasserted in .prepare() and asserted in .unprepare(), and the cores
>> themselves are started and halted in .start() and .stop() ops. This
>> ensures symmetric usage and allows the R5F cores state machine to be
>> maintained properly between using the sysfs 'state' variable, bind/unbind
>> and regular module load/unload flows.
>>
>> The subsystem is represented as a single remoteproc in LockStep mode, and
>> as two remoteprocs in Split mode.
> 
> Thank you for the detailed explanation, it really helps understand what is going
> on.  From the above the assumption I made in the previous patch about lockstep
> and split mode is wrong.  On the flip side it does highlight the need to add
> more details to the bindings.

Yeah, I usually tend to lean on the verbose-side, but some of the
details on bindings itself are deemed unnecessary.

> 
>> The driver uses various TI-SCI interfaces
>> to talk to the System Controller (DMSC) for managing configuration, power
>> and reset management of these cores. IPC between the A53 cores and the R5
>> cores is supported through the virtio rpmsg stack using shared memory and
>> OMAP Mailboxes.
>>
>> The AM65x SoCs typically have a single R5FSS in the MCU voltage domain. The
>> J721E SoCs uses a slightly revised IP and typically have three R5FSSs, with
>> one cluster present within the MCU voltage domain (MCU_R5FSS0), and the
>> remaining two clusters present in the MAIN voltage domain (MAIN_R5FSS0 and
>> MAIN_R5FSS1). The integration of these clusters on J721E SoC is also
>> slightly different in that these IPs do support an actual local reset line,
>> while they are a no-op on AM65x SoCs.
>>
>> Signed-off-by: Suman Anna <s-anna@ti.com>
>> ---
>>  drivers/remoteproc/Kconfig               |   16 +
>>  drivers/remoteproc/Makefile              |    1 +
>>  drivers/remoteproc/ti_k3_r5_remoteproc.c | 1346 ++++++++++++++++++++++
>>  3 files changed, 1363 insertions(+)
>>  create mode 100644 drivers/remoteproc/ti_k3_r5_remoteproc.c
>>
>> diff --git a/drivers/remoteproc/Kconfig b/drivers/remoteproc/Kconfig
>> index de3862c15fcc..073048b4c0fb 100644
>> --- a/drivers/remoteproc/Kconfig
>> +++ b/drivers/remoteproc/Kconfig
>> @@ -224,6 +224,22 @@ config STM32_RPROC
>>  
>>  	  This can be either built-in or a loadable module.
>>  
>> +config TI_K3_R5_REMOTEPROC
>> +	tristate "TI K3 R5 remoteproc support"
>> +	depends on ARCH_K3
>> +	select MAILBOX
>> +	select OMAP2PLUS_MBOX
>> +	help
>> +	  Say y here to support TI's R5F remote processor subsystems
>> +	  on various TI K3 family of SoCs through the remote processor
>> +	  framework.
>> +
>> +	  You want to say y here in order to offload some processing
>> +	  tasks to these processors
>> +
>> +	  It's safe to say N here if you're not interested in utilizing
>> +	  a slave processor
>> +
>>  endif # REMOTEPROC
>>  
>>  endmenu
>> diff --git a/drivers/remoteproc/Makefile b/drivers/remoteproc/Makefile
>> index e30a1b15fbac..00ba826818af 100644
>> --- a/drivers/remoteproc/Makefile
>> +++ b/drivers/remoteproc/Makefile
>> @@ -28,3 +28,4 @@ qcom_wcnss_pil-y			+= qcom_wcnss_iris.o
>>  obj-$(CONFIG_ST_REMOTEPROC)		+= st_remoteproc.o
>>  obj-$(CONFIG_ST_SLIM_REMOTEPROC)	+= st_slim_rproc.o
>>  obj-$(CONFIG_STM32_RPROC)		+= stm32_rproc.o
>> +obj-$(CONFIG_TI_K3_R5_REMOTEPROC)	+= ti_k3_r5_remoteproc.o
>> diff --git a/drivers/remoteproc/ti_k3_r5_remoteproc.c b/drivers/remoteproc/ti_k3_r5_remoteproc.c
>> new file mode 100644
>> index 000000000000..655f8f14c37d
>> --- /dev/null
>> +++ b/drivers/remoteproc/ti_k3_r5_remoteproc.c
>> @@ -0,0 +1,1346 @@
>> +// SPDX-License-Identifier: GPL-2.0-only
>> +/*
>> + * TI K3 R5F (MCU) Remote Processor driver
>> + *
>> + * Copyright (C) 2017-2020 Texas Instruments Incorporated - http://www.ti.com/
>> + *	Suman Anna <s-anna@ti.com>
>> + */
>> +
>> +#include <linux/dma-mapping.h>
>> +#include <linux/err.h>
>> +#include <linux/interrupt.h>
>> +#include <linux/kernel.h>
>> +#include <linux/mailbox_client.h>
>> +#include <linux/module.h>
>> +#include <linux/of_device.h>
>> +#include <linux/of_address.h>
>> +#include <linux/of_reserved_mem.h>
>> +#include <linux/platform_device.h>
>> +#include <linux/pm_runtime.h>
>> +#include <linux/remoteproc.h>
>> +#include <linux/omap-mailbox.h>
> 
> Please move this up after of_reserved_mem.h

Haa, I missed one after all :). Yep, will move it up.

> 
>> +#include <linux/reset.h>
>> +#include <linux/soc/ti/ti_sci_protocol.h>
>> +
>> +#include "omap_remoteproc.h"
>> +#include "remoteproc_internal.h"
>> +#include "ti_sci_proc.h"
>> +
>> +/* This address can either be for ATCM or BTCM with the other at address 0x0 */
>> +#define K3_R5_TCM_DEV_ADDR	0x41010000
>> +
>> +/* R5 TI-SCI Processor Configuration Flags */
>> +#define PROC_BOOT_CFG_FLAG_R5_DBG_EN			0x00000001
>> +#define PROC_BOOT_CFG_FLAG_R5_DBG_NIDEN			0x00000002
>> +#define PROC_BOOT_CFG_FLAG_R5_LOCKSTEP			0x00000100
>> +#define PROC_BOOT_CFG_FLAG_R5_TEINIT			0x00000200
>> +#define PROC_BOOT_CFG_FLAG_R5_NMFI_EN			0x00000400
>> +#define PROC_BOOT_CFG_FLAG_R5_TCM_RSTBASE		0x00000800
>> +#define PROC_BOOT_CFG_FLAG_R5_BTCM_EN			0x00001000
>> +#define PROC_BOOT_CFG_FLAG_R5_ATCM_EN			0x00002000
>> +
>> +/* R5 TI-SCI Processor Control Flags */
>> +#define PROC_BOOT_CTRL_FLAG_R5_CORE_HALT		0x00000001
>> +
>> +/* R5 TI-SCI Processor Status Flags */
>> +#define PROC_BOOT_STATUS_FLAG_R5_WFE			0x00000001
>> +#define PROC_BOOT_STATUS_FLAG_R5_WFI			0x00000002
>> +#define PROC_BOOT_STATUS_FLAG_R5_CLK_GATED		0x00000004
>> +#define PROC_BOOT_STATUS_FLAG_R5_LOCKSTEP_PERMITTED	0x00000100
>> +
>> +/**
>> + * struct k3_r5_mem - internal memory structure
>> + * @cpu_addr: MPU virtual address of the memory region
>> + * @bus_addr: Bus address used to access the memory region
>> + * @dev_addr: Device address from remoteproc view
>> + * @size: Size of the memory region
>> + */
>> +struct k3_r5_mem {
>> +	void __iomem *cpu_addr;
>> +	phys_addr_t bus_addr;
>> +	u32 dev_addr;
>> +	size_t size;
>> +};
>> +
>> +enum cluster_mode {
>> +	CLUSTER_MODE_SPLIT = 0,
>> +	CLUSTER_MODE_LOCKSTEP,
>> +};
>> +
>> +/**
>> + * struct k3_r5_cluster - K3 R5F Cluster structure
>> + * @dev: cached device pointer
>> + * @mode: Mode to configure the Cluster - Split or LockStep
>> + * @cores: list of R5 cores within the cluster
>> + */
>> +struct k3_r5_cluster {
>> +	struct device *dev;
>> +	enum cluster_mode mode;
>> +	struct list_head cores;
>> +};
>> +
>> +/**
>> + * struct k3_r5_core - K3 R5 core structure
>> + * @elem: linked list item
>> + * @dev: cached device pointer
>> + * @rproc: rproc handle representing this core
>> + * @mem: internal memory regions data
>> + * @num_mems: number of internal memory regions
>> + * @reset: reset control handle
>> + * @tsp: TI-SCI processor control handle
>> + * @ti_sci: TI-SCI handle
>> + * @ti_sci_id: TI-SCI device identifier
>> + * @atcm_enable: flag to control ATCM enablement
>> + * @btcm_enable: flag to control BTCM enablement
>> + * @loczrama: flag to dictate which TCM is at device address 0x0
>> + */
>> +struct k3_r5_core {
>> +	struct list_head elem;
>> +	struct device *dev;
>> +	struct rproc *rproc;
>> +	struct k3_r5_mem *mem;
>> +	int num_mems;
>> +	struct reset_control *reset;
>> +	struct ti_sci_proc *tsp;
>> +	const struct ti_sci_handle *ti_sci;
>> +	u32 ti_sci_id;
>> +	u32 atcm_enable;
>> +	u32 btcm_enable;
>> +	u32 loczrama;
>> +};
>> +
>> +/**
>> + * struct k3_r5_rproc - K3 remote processor state
>> + * @dev: cached device pointer
>> + * @cluster: cached pointer to parent cluster structure
>> + * @mbox: mailbox channel handle
>> + * @client: mailbox client to request the mailbox channel
>> + * @rproc: rproc handle
>> + * @core: cached pointer to r5 core structure being used
>> + * @rmem: reserved memory regions data
>> + * @num_rmems: number of reserved memory regions
>> + */
>> +struct k3_r5_rproc {
>> +	struct device *dev;
>> +	struct k3_r5_cluster *cluster;
>> +	struct mbox_chan *mbox;
>> +	struct mbox_client client;
>> +	struct rproc *rproc;
>> +	struct k3_r5_core *core;
>> +	struct k3_r5_mem *rmem;
>> +	int num_rmems;
>> +};
>> +
>> +/**
>> + * k3_r5_rproc_mbox_callback() - inbound mailbox message handler
>> + * @client: mailbox client pointer used for requesting the mailbox channel
>> + * @data: mailbox payload
>> + *
>> + * This handler is invoked by the OMAP mailbox driver whenever a mailbox
>> + * message is received. Usually, the mailbox payload simply contains
>> + * the index of the virtqueue that is kicked by the remote processor,
>> + * and we let remoteproc core handle it.
>> + *
>> + * In addition to virtqueue indices, we also have some out-of-band values
>> + * that indicate different events. Those values are deliberately very
>> + * large so they don't coincide with virtqueue indices.
>> + */
>> +static void k3_r5_rproc_mbox_callback(struct mbox_client *client, void *data)
>> +{
>> +	struct k3_r5_rproc *kproc = container_of(client, struct k3_r5_rproc,
>> +						client);
>> +	struct device *dev = kproc->rproc->dev.parent;
>> +	const char *name = kproc->rproc->name;
>> +	u32 msg = omap_mbox_message(data);
>> +
>> +	dev_dbg(dev, "mbox msg: 0x%x\n", msg);
>> +
>> +	switch (msg) {
>> +	case RP_MBOX_CRASH:
>> +		/*
>> +		 * remoteproc detected an exception, but error recovery is not
>> +		 * supported. So, just log this for now
>> +		 */
>> +		dev_err(dev, "K3 R5F rproc %s crashed\n", name);
>> +		break;
>> +	case RP_MBOX_ECHO_REPLY:
>> +		dev_info(dev, "received echo reply from %s\n", name);
>> +		break;
>> +	default:
>> +		/* silently handle all other valid messages */
>> +		if (msg >= RP_MBOX_READY && msg < RP_MBOX_END_MSG)
>> +			return;
>> +		if (msg > kproc->rproc->max_notifyid) {
>> +			dev_dbg(dev, "dropping unknown message 0x%x", msg);
>> +			return;
>> +		}
>> +		/* msg contains the index of the triggered vring */
>> +		if (rproc_vq_interrupt(kproc->rproc, msg) == IRQ_NONE)
>> +			dev_dbg(dev, "no message was found in vqid %d\n", msg);
>> +	}
>> +}
>> +
>> +/* kick a virtqueue */
>> +static void k3_r5_rproc_kick(struct rproc *rproc, int vqid)
>> +{
>> +	struct k3_r5_rproc *kproc = rproc->priv;
>> +	struct device *dev = rproc->dev.parent;
>> +	mbox_msg_t msg = (mbox_msg_t)vqid;
>> +	int ret;
>> +
>> +	/* send the index of the triggered virtqueue in the mailbox payload */
>> +	ret = mbox_send_message(kproc->mbox, (void *)msg);
>> +	if (ret < 0)
>> +		dev_err(dev, "failed to send mailbox message, status = %d\n",
>> +			ret);
>> +}
>> +
>> +static int k3_r5_split_reset(struct k3_r5_core *core)
>> +{
>> +	int ret;
>> +
>> +	ret = reset_control_assert(core->reset);
>> +	if (ret) {
>> +		dev_err(core->dev, "local-reset assert failed, ret = %d\n",
>> +			ret);
>> +		return ret;
>> +	}
>> +
>> +	ret = core->ti_sci->ops.dev_ops.put_device(core->ti_sci,
>> +						   core->ti_sci_id);
>> +	if (ret) {
>> +		dev_err(core->dev, "module-reset assert failed, ret = %d\n",
>> +			ret);
>> +		if (reset_control_deassert(core->reset))
>> +			dev_warn(core->dev, "local-reset deassert back failed\n");
>> +	}
>> +
>> +	return ret;
>> +}
>> +
>> +static int k3_r5_split_release(struct k3_r5_core *core)
>> +{
>> +	int ret;
>> +
>> +	ret = core->ti_sci->ops.dev_ops.get_device(core->ti_sci,
>> +						   core->ti_sci_id);
>> +	if (ret) {
>> +		dev_err(core->dev, "module-reset deassert failed, ret = %d\n",
>> +			ret);
>> +		return ret;
>> +	}
>> +
>> +	ret = reset_control_deassert(core->reset);
>> +	if (ret) {
>> +		dev_err(core->dev, "local-reset deassert failed, ret = %d\n",
>> +			ret);
>> +		if (core->ti_sci->ops.dev_ops.put_device(core->ti_sci,
>> +							 core->ti_sci_id))
>> +			dev_warn(core->dev, "module-reset assert back failed\n");
>> +	}
>> +
>> +	return ret;
>> +}
>> +
>> +static int k3_r5_lockstep_reset(struct k3_r5_cluster *cluster)
>> +{
>> +	struct k3_r5_core *core;
>> +	int ret;
>> +
>> +	/* assert local reset on all applicable cores */
>> +	list_for_each_entry(core, &cluster->cores, elem) {
>> +		ret = reset_control_assert(core->reset);
>> +		if (ret) {
>> +			dev_err(core->dev, "local-reset assert failed, ret = %d\n",
>> +				ret);
>> +			core = list_prev_entry(core, elem);
>> +			goto unroll_local_reset;
>> +		}
>> +	}
>> +
>> +	/* disable PSC modules on all applicable cores */
>> +	list_for_each_entry(core, &cluster->cores, elem) {
>> +		ret = core->ti_sci->ops.dev_ops.put_device(core->ti_sci,
>> +							   core->ti_sci_id);
>> +		if (ret) {
>> +			dev_err(core->dev, "module-reset assert failed, ret = %d\n",
>> +				ret);
>> +			goto unroll_module_reset;
>> +		}
>> +	}
>> +
>> +	return 0;
>> +
>> +unroll_module_reset:
>> +	list_for_each_entry_continue_reverse(core, &cluster->cores, elem) {
>> +		if (core->ti_sci->ops.dev_ops.put_device(core->ti_sci,
>> +							 core->ti_sci_id))
>> +			dev_warn(core->dev, "module-reset assert back failed\n");
>> +	}
>> +	core = list_last_entry(&cluster->cores, struct k3_r5_core, elem);
>> +unroll_local_reset:
>> +	list_for_each_entry_from_reverse(core, &cluster->cores, elem) {
>> +		if (reset_control_deassert(core->reset))
>> +			dev_warn(core->dev, "local-reset deassert back failed\n");
>> +	}
>> +
>> +	return ret;
>> +}
>> +
>> +static int k3_r5_lockstep_release(struct k3_r5_cluster *cluster)
>> +{
>> +	struct k3_r5_core *core;
>> +	int ret;
>> +
>> +	/* enable PSC modules on all applicable cores */
>> +	list_for_each_entry_reverse(core, &cluster->cores, elem) {
>> +		ret = core->ti_sci->ops.dev_ops.get_device(core->ti_sci,
>> +							   core->ti_sci_id);
>> +		if (ret) {
>> +			dev_err(core->dev, "module-reset deassert failed, ret = %d\n",
>> +				ret);
>> +			core = list_next_entry(core, elem);
>> +			goto unroll_module_reset;
>> +		}
>> +	}
>> +
>> +	/* deassert local reset on all applicable cores */
>> +	list_for_each_entry_reverse(core, &cluster->cores, elem) {
>> +		ret = reset_control_deassert(core->reset);
>> +		if (ret) {
>> +			dev_err(core->dev, "module-reset deassert failed, ret = %d\n",
>> +				ret);
>> +			goto unroll_local_reset;
>> +		}
>> +	}
>> +
>> +	return 0;
>> +
>> +unroll_local_reset:
>> +	list_for_each_entry_continue(core, &cluster->cores, elem) {
>> +		if (reset_control_assert(core->reset))
>> +			dev_warn(core->dev, "local-reset assert back failed\n");
>> +	}
>> +	core = list_first_entry(&cluster->cores, struct k3_r5_core, elem);
>> +unroll_module_reset:
>> +	list_for_each_entry_from(core, &cluster->cores, elem) {
>> +		if (core->ti_sci->ops.dev_ops.put_device(core->ti_sci,
>> +							 core->ti_sci_id))
>> +			dev_warn(core->dev, "module-reset assert back failed\n");
>> +	}
>> +
>> +	return ret;
>> +}
>> +
>> +static inline int k3_r5_core_halt(struct k3_r5_core *core)
>> +{
>> +	return ti_sci_proc_set_control(core->tsp,
>> +				       PROC_BOOT_CTRL_FLAG_R5_CORE_HALT, 0);
>> +}
>> +
>> +static inline int k3_r5_core_run(struct k3_r5_core *core)
>> +{
>> +	return ti_sci_proc_set_control(core->tsp,
>> +				       0, PROC_BOOT_CTRL_FLAG_R5_CORE_HALT);
>> +}
>> +
>> +/*
>> + * The R5F cores have controls for both a reset and a halt/run. The code
>> + * execution from DDR requires the initial boot-strapping code to be run
>> + * from the internal TCMs. This function is used to release the resets on
>> + * applicable cores to allow loading into the TCMs. The .prepare() ops is
>> + * invoked by remoteproc core before any firmware loading, and is followed
>> + * by the .start() ops after loading to actually let the R5 cores run.
>> + */
>> +static int k3_r5_rproc_prepare(struct rproc *rproc)
>> +{
>> +	struct k3_r5_rproc *kproc = rproc->priv;
>> +	struct k3_r5_cluster *cluster = kproc->cluster;
>> +	struct k3_r5_core *core = kproc->core;
>> +	struct device *dev = kproc->dev;
>> +	int ret;
>> +
>> +	ret = cluster->mode ? k3_r5_lockstep_release(cluster) :
>> +			      k3_r5_split_release(core);
>> +	if (ret)
>> +		dev_err(dev, "unable to enable cores for TCM loading, ret = %d\n",
>> +			ret);
>> +
>> +	return ret;
>> +}
>> +
>> +/*
>> + * This function implements the .unprepare() ops and performs the complimentary
>> + * operations to that of the .prepare() ops. The function is used to assert the
>> + * resets on all applicable cores for the rproc device (depending on LockStep
>> + * or Split mode). This completes the second portion of powering down the R5F
>> + * cores. The cores themselves are only halted in the .stop() ops, and the
>> + * .unprepare() ops is invoked by the remoteproc core after the remoteproc is
>> + * stopped.
>> + */
>> +static int k3_r5_rproc_unprepare(struct rproc *rproc)
>> +{
>> +	struct k3_r5_rproc *kproc = rproc->priv;
>> +	struct k3_r5_cluster *cluster = kproc->cluster;
>> +	struct k3_r5_core *core = kproc->core;
>> +	struct device *dev = kproc->dev;
>> +	int ret;
>> +
>> +	ret = cluster->mode ? k3_r5_lockstep_reset(cluster) :
>> +			      k3_r5_split_reset(core);
>> +	if (ret)
>> +		dev_err(dev, "unable to disable cores, ret = %d\n", ret);
>> +
>> +	return ret;
>> +}
>> +
>> +/*
>> + * The R5F start sequence includes two different operations
>> + * 1. Configure the boot vector for R5F core(s)
>> + * 2. Unhalt/Run the R5F core(s)
>> + *
>> + * The sequence is different between LockStep and Split modes. The LockStep
>> + * mode requires the boot vector to be configured only for Core0, and then
>> + * unhalt both the cores to start the execution - Core1 needs to be unhalted
>> + * first followed by Core0. The Split-mode requires that Core0 to be maintained
>> + * always in a higher power state that Core1 (implying Core1 needs to be started
>> + * always only after Core0 is started).
>> + */
>> +static int k3_r5_rproc_start(struct rproc *rproc)
>> +{
>> +	struct k3_r5_rproc *kproc = rproc->priv;
>> +	struct k3_r5_cluster *cluster = kproc->cluster;
>> +	struct mbox_client *client = &kproc->client;
>> +	struct device *dev = kproc->dev;
>> +	struct k3_r5_core *core;
>> +	u32 boot_addr;
>> +	int ret;
>> +
>> +	client->dev = dev;
>> +	client->tx_done = NULL;
>> +	client->rx_callback = k3_r5_rproc_mbox_callback;
>> +	client->tx_block = false;
>> +	client->knows_txdone = false;
>> +
>> +	kproc->mbox = mbox_request_channel(client, 0);
>> +	if (IS_ERR(kproc->mbox)) {
>> +		ret = -EBUSY;
>> +		dev_err(dev, "mbox_request_channel failed: %ld\n",
>> +			PTR_ERR(kproc->mbox));
>> +		return ret;
>> +	}
>> +
>> +	/*
>> +	 * Ping the remote processor, this is only for sanity-sake for now;
>> +	 * there is no functional effect whatsoever.
>> +	 *
>> +	 * Note that the reply will _not_ arrive immediately: this message
>> +	 * will wait in the mailbox fifo until the remote processor is booted.
>> +	 */
>> +	ret = mbox_send_message(kproc->mbox, (void *)RP_MBOX_ECHO_REQUEST);
>> +	if (ret < 0) {
>> +		dev_err(dev, "mbox_send_message failed: %d\n", ret);
>> +		goto put_mbox;
>> +	}
>> +
>> +	boot_addr = rproc->bootaddr;
>> +	/* TODO: add boot_addr sanity checking */
>> +	dev_err(dev, "booting R5F core using boot addr = 0x%x\n", boot_addr);
>> +
>> +	/* boot vector need not be programmed for Core1 in LockStep mode */
>> +	core = kproc->core;
>> +	ret = ti_sci_proc_set_config(core->tsp, boot_addr, 0, 0);
>> +	if (ret)
>> +		goto put_mbox;
>> +
>> +	/* unhalt/run all applicable cores */
>> +	if (cluster->mode) {
>> +		list_for_each_entry_reverse(core, &cluster->cores, elem) {
>> +			ret = k3_r5_core_run(core);
>> +			if (ret)
>> +				goto unroll_core_run;
>> +		}
>> +	} else {
>> +		ret = k3_r5_core_run(core);
>> +		if (ret)
>> +			goto put_mbox;
>> +	}
>> +
>> +	return 0;
>> +
>> +unroll_core_run:
>> +	list_for_each_entry_continue(core, &cluster->cores, elem) {
>> +		if (k3_r5_core_halt(core))
>> +			dev_warn(core->dev, "core halt back failed\n");
>> +	}
>> +put_mbox:
>> +	mbox_free_channel(kproc->mbox);
>> +	return ret;
>> +}
>> +
>> +/*
>> + * The R5F stop function includes the following operations
>> + * 1. Halt R5F core(s)
>> + *
>> + * The sequence is different between LockStep and Split modes, and the order
>> + * of cores the operations are performed are also in general reverse to that
>> + * of the start function. The LockStep mode requires each operation to be
>> + * performed first on Core0 followed by Core1. The Split-mode requires that
>> + * Core0 to be maintained always in a higher power state that Core1 (implying
>> + * Core1 needs to be stopped first before Core0).
>> + *
>> + * Note that the R5F halt operation in general is not effective when the R5F
>> + * core is running, but is needed to make sure the core won't run after
>> + * deasserting the reset the subsequent time. The asserting of reset can
>> + * be done here, but is preferred to be done in the .unprepare() ops - this
>> + * maintains the symmetric behavior between the .start(), .stop(), .prepare()
>> + * and .unprepare() ops, and also balances them well between sysfs 'state'
>> + * flow and device bind/unbind or module removal.
>> + */
>> +static int k3_r5_rproc_stop(struct rproc *rproc)
>> +{
>> +	struct k3_r5_rproc *kproc = rproc->priv;
>> +	struct k3_r5_cluster *cluster = kproc->cluster;
>> +	struct k3_r5_core *core = kproc->core;
>> +	int ret;
>> +
>> +	/* halt all applicable cores */
>> +	if (cluster->mode) {
>> +		list_for_each_entry(core, &cluster->cores, elem) {
>> +			ret = k3_r5_core_halt(core);
>> +			if (ret) {
>> +				core = list_prev_entry(core, elem);
>> +				goto unroll_core_halt;
>> +			}
>> +		}
>> +	} else {
>> +		ret = k3_r5_core_halt(core);
>> +		if (ret)
>> +			goto out;
>> +	}
>> +
>> +	mbox_free_channel(kproc->mbox);
>> +
>> +	return 0;
>> +
>> +unroll_core_halt:
>> +	list_for_each_entry_from_reverse(core, &cluster->cores, elem) {
>> +		if (k3_r5_core_run(core))
>> +			dev_warn(core->dev, "core run back failed\n");
>> +	}
>> +out:
>> +	return ret;
>> +}
>> +
>> +/*
>> + * Internal Memory translation helper
>> + *
>> + * Custom function implementing the rproc .da_to_va ops to provide address
>> + * translation (device address to kernel virtual address) for internal RAMs
>> + * present in a DSP or IPU device). The translated addresses can be used
>> + * either by the remoteproc core for loading, or by any rpmsg bus drivers.
>> + */
>> +static void *k3_r5_rproc_da_to_va(struct rproc *rproc, u64 da, size_t len)
>> +{
>> +	struct k3_r5_rproc *kproc = rproc->priv;
>> +	struct k3_r5_core *core = kproc->core;
>> +	void __iomem *va = NULL;
>> +	phys_addr_t bus_addr;
>> +	u32 dev_addr, offset;
>> +	size_t size;
>> +	int i;
>> +
>> +	if (len == 0)
>> +		return NULL;
>> +
>> +	/* handle both R5 and SoC views of ATCM and BTCM */
>> +	for (i = 0; i < core->num_mems; i++) {
>> +		bus_addr = core->mem[i].bus_addr;
>> +		dev_addr = core->mem[i].dev_addr;
>> +		size = core->mem[i].size;
>> +
>> +		/* handle R5-view addresses of TCMs */
>> +		if (da >= dev_addr && ((da + len) <= (dev_addr + size))) {
>> +			offset = da - dev_addr;
>> +			va = core->mem[i].cpu_addr + offset;
>> +			return (__force void *)va;
>> +		}
>> +
>> +		/* handle SoC-view addresses of TCMs */
>> +		if (da >= bus_addr && ((da + len) <= (bus_addr + size))) {
>> +			offset = da - bus_addr;
>> +			va = core->mem[i].cpu_addr + offset;
>> +			return (__force void *)va;
>> +		}
>> +	}
>> +
>> +	/* handle static DDR reserved memory regions */
>> +	for (i = 0; i < kproc->num_rmems; i++) {
>> +		dev_addr = kproc->rmem[i].dev_addr;
>> +		size = kproc->rmem[i].size;
>> +
>> +		if (da >= dev_addr && ((da + len) <= (dev_addr + size))) {
>> +			offset = da - dev_addr;
>> +			va = kproc->rmem[i].cpu_addr + offset;
>> +			return (__force void *)va;
>> +		}
>> +	}
>> +
>> +	return NULL;
>> +}
>> +
>> +static const struct rproc_ops k3_r5_rproc_ops = {
>> +	.prepare	= k3_r5_rproc_prepare,
>> +	.unprepare	= k3_r5_rproc_unprepare,
>> +	.start		= k3_r5_rproc_start,
>> +	.stop		= k3_r5_rproc_stop,
>> +	.kick		= k3_r5_rproc_kick,
>> +	.da_to_va	= k3_r5_rproc_da_to_va,
>> +};
>> +
>> +static const char *k3_r5_rproc_get_firmware(struct device *dev)
>> +{
>> +	const char *fw_name;
>> +	int ret;
>> +
>> +	ret = of_property_read_string(dev->of_node, "firmware-name",
>> +				      &fw_name);
>> +	if (ret) {
>> +		dev_err(dev, "failed to parse firmware-name property, ret = %d\n",
>> +			ret);
>> +		return ERR_PTR(ret);
>> +	}
>> +
>> +	return fw_name;
>> +}
>> +
>> +static int k3_r5_rproc_configure(struct k3_r5_rproc *kproc)
>> +{
>> +	struct k3_r5_cluster *cluster = kproc->cluster;
>> +	struct device *dev = kproc->dev;
>> +	struct k3_r5_core *core0, *core, *temp;
>> +	u32 ctrl = 0, cfg = 0, stat = 0;
>> +	u32 set_cfg = 0, clr_cfg = 0;
>> +	u64 boot_vec = 0;
>> +	bool lockstep_en;
>> +	int ret;
>> +
>> +	core0 = list_first_entry(&cluster->cores, struct k3_r5_core, elem);
>> +	core = cluster->mode ? core0 : kproc->core;
>> +
>> +	ret = ti_sci_proc_get_status(core->tsp, &boot_vec, &cfg, &ctrl,
>> +				     &stat);
>> +	if (ret < 0)
>> +		return ret;
>> +
>> +	dev_dbg(dev, "boot_vector = 0x%llx, cfg = 0x%x ctrl = 0x%x stat = 0x%x\n",
>> +		boot_vec, cfg, ctrl, stat);
>> +
>> +	lockstep_en = !!(stat & PROC_BOOT_STATUS_FLAG_R5_LOCKSTEP_PERMITTED);
>> +	if (!lockstep_en && cluster->mode) {
>> +		dev_err(cluster->dev, "lockstep mode not permitted, force configuring for split-mode\n");
>> +		cluster->mode = 0;
>> +	}
>> +
>> +	/* always enable ARM mode and set boot vector to 0 */
>> +	boot_vec = 0x0;
>> +	if (core == core0) {
>> +		clr_cfg = PROC_BOOT_CFG_FLAG_R5_TEINIT;
>> +		/*
>> +		 * LockStep configuration bit is Read-only on Split-mode _only_
>> +		 * devices and system firmware will NACK any requests with the
>> +		 * bit configured, so program it only on permitted devices
>> +		 */
>> +		if (lockstep_en)
>> +			clr_cfg |= PROC_BOOT_CFG_FLAG_R5_LOCKSTEP;
>> +	}
>> +
>> +	if (core->atcm_enable)
>> +		set_cfg |= PROC_BOOT_CFG_FLAG_R5_ATCM_EN;
>> +	else
>> +		clr_cfg |= PROC_BOOT_CFG_FLAG_R5_ATCM_EN;
>> +
>> +	if (core->btcm_enable)
>> +		set_cfg |= PROC_BOOT_CFG_FLAG_R5_BTCM_EN;
>> +	else
>> +		clr_cfg |= PROC_BOOT_CFG_FLAG_R5_BTCM_EN;
>> +
>> +	if (core->loczrama)
>> +		set_cfg |= PROC_BOOT_CFG_FLAG_R5_TCM_RSTBASE;
>> +	else
>> +		clr_cfg |= PROC_BOOT_CFG_FLAG_R5_TCM_RSTBASE;
>> +
>> +	if (cluster->mode) {
>> +		/*
>> +		 * work around system firmware limitations to make sure both
>> +		 * cores are programmed symmetrically in LockStep. LockStep
>> +		 * and TEINIT config is only allowed with Core0.
>> +		 */
>> +		list_for_each_entry(temp, &cluster->cores, elem) {
>> +			ret = k3_r5_core_halt(core);
>> +			if (ret)
>> +				goto out;
>> +
>> +			if (temp != core) {
>> +				clr_cfg &= ~PROC_BOOT_CFG_FLAG_R5_LOCKSTEP;
>> +				clr_cfg &= ~PROC_BOOT_CFG_FLAG_R5_TEINIT;
>> +			}
>> +			ret = ti_sci_proc_set_config(temp->tsp, boot_vec,
>> +						     set_cfg, clr_cfg);
>> +			if (ret)
>> +				goto out;
>> +		}
>> +
>> +		set_cfg = PROC_BOOT_CFG_FLAG_R5_LOCKSTEP;
>> +		clr_cfg = 0;
>> +		ret = ti_sci_proc_set_config(core->tsp, boot_vec,
>> +					     set_cfg, clr_cfg);
>> +	} else {
>> +		ret = k3_r5_core_halt(core);
>> +		if (ret)
>> +			goto out;
>> +
>> +		ret = ti_sci_proc_set_config(core->tsp, boot_vec,
>> +					     set_cfg, clr_cfg);
>> +	}
>> +
>> +out:
>> +	return ret;
>> +}
>> +
>> +static int k3_r5_reserved_mem_init(struct k3_r5_rproc *kproc)
>> +{
>> +	struct device *dev = kproc->dev;
>> +	struct device_node *np = dev->of_node;
>> +	struct device_node *rmem_np;
>> +	struct reserved_mem *rmem;
>> +	int num_rmems;
>> +	int ret, i;
>> +
>> +	num_rmems = of_property_count_elems_of_size(np, "memory-region",
>> +						    sizeof(phandle));
>> +	if (num_rmems <= 0) {
>> +		dev_err(dev, "device does not have reserved memory regions, ret = %d\n",
>> +			num_rmems);
>> +		return -EINVAL;
>> +	}
>> +	if (num_rmems < 2) {
>> +		dev_err(dev, "device needs atleast two memory regions to be defined, num = %d\n",
>> +			num_rmems);
>> +		return -EINVAL;
>> +	}
>> +
>> +	/* use reserved memory region 0 for vring DMA allocations */
>> +	ret = of_reserved_mem_device_init_by_idx(dev, np, 0);
>> +	if (ret) {
>> +		dev_err(dev, "device cannot initialize DMA pool, ret = %d\n",
>> +			ret);
>> +		return ret;
>> +	}
>> +
>> +	num_rmems--;
>> +	kproc->rmem = kcalloc(num_rmems, sizeof(*kproc->rmem), GFP_KERNEL);
>> +	if (!kproc->rmem) {
>> +		ret = -ENOMEM;
>> +		goto release_rmem;
>> +	}
>> +
>> +	/* use remaining reserved memory regions for static carveouts */
>> +	for (i = 0; i < num_rmems; i++) {
>> +		rmem_np = of_parse_phandle(np, "memory-region", i + 1);
>> +		if (!rmem_np) {
>> +			ret = -EINVAL;
>> +			goto unmap_rmem;
>> +		}
>> +
>> +		rmem = of_reserved_mem_lookup(rmem_np);
>> +		if (!rmem) {
>> +			of_node_put(rmem_np);
>> +			ret = -EINVAL;
>> +			goto unmap_rmem;
>> +		}
>> +		of_node_put(rmem_np);
>> +
>> +		kproc->rmem[i].bus_addr = rmem->base;
>> +		/* 64-bit address regions currently not supported */
>> +		kproc->rmem[i].dev_addr = (u32)rmem->base;
>> +		kproc->rmem[i].size = rmem->size;
>> +		kproc->rmem[i].cpu_addr = ioremap_wc(rmem->base, rmem->size);
>> +		if (!kproc->rmem[i].cpu_addr) {
>> +			dev_err(dev, "failed to map reserved memory#%d at %pa of size %pa\n",
>> +				i + 1, &rmem->base, &rmem->size);
>> +			ret = -ENOMEM;
>> +			goto unmap_rmem;
>> +		}
>> +
>> +		dev_dbg(dev, "reserved memory%d: bus addr %pa size 0x%zx va %pK da 0x%x\n",
>> +			i + 1, &kproc->rmem[i].bus_addr,
>> +			kproc->rmem[i].size, kproc->rmem[i].cpu_addr,
>> +			kproc->rmem[i].dev_addr);
>> +	}
>> +	kproc->num_rmems = num_rmems;
>> +
>> +	return 0;
>> +
>> +unmap_rmem:
>> +	for (i--; i >= 0; i--) {
>> +		if (kproc->rmem[i].cpu_addr)
>> +			iounmap(kproc->rmem[i].cpu_addr);
>> +	}
>> +	kfree(kproc->rmem);
>> +release_rmem:
>> +	of_reserved_mem_device_release(dev);
>> +	return ret;
>> +}
>> +
>> +static void k3_r5_reserved_mem_exit(struct k3_r5_rproc *kproc)
>> +{
>> +	int i;
>> +
>> +	for (i = 0; i < kproc->num_rmems; i++)
>> +		iounmap(kproc->rmem[i].cpu_addr);
>> +	kfree(kproc->rmem);
>> +
>> +	of_reserved_mem_device_release(kproc->dev);
>> +}
>> +
>> +static int k3_r5_cluster_rproc_init(struct platform_device *pdev)
>> +{
>> +	struct k3_r5_cluster *cluster = platform_get_drvdata(pdev);
>> +	struct device *dev = &pdev->dev;
>> +	struct k3_r5_rproc *kproc;
>> +	struct k3_r5_core *core, *core1;
>> +	struct device *cdev;
>> +	const char *fw_name;
>> +	struct rproc *rproc;
>> +	int ret;
>> +
>> +	core1 = list_last_entry(&cluster->cores, struct k3_r5_core, elem);
>> +	list_for_each_entry(core, &cluster->cores, elem) {
>> +		cdev = core->dev;
>> +		fw_name = k3_r5_rproc_get_firmware(cdev);
>> +		if (IS_ERR(fw_name)) {
>> +			ret = PTR_ERR(fw_name);
>> +			goto out;
>> +		}
>> +
>> +		rproc = rproc_alloc(cdev, dev_name(cdev), &k3_r5_rproc_ops,
>> +				    fw_name, sizeof(*kproc));
>> +		if (!rproc) {
>> +			ret = -ENOMEM;
>> +			goto out;
>> +		}
>> +
>> +		/* K3 R5s have a Region Address Translator (RAT) but no MMU */
>> +		rproc->has_iommu = false;
>> +		/* error recovery is not supported at present */
>> +		rproc->recovery_disabled = true;
>> +
>> +		kproc = rproc->priv;
>> +		kproc->cluster = cluster;
>> +		kproc->core = core;
>> +		kproc->dev = cdev;
>> +		kproc->rproc = rproc;
>> +		core->rproc = rproc;
>> +
>> +		ret = k3_r5_rproc_configure(kproc);
>> +		if (ret) {
>> +			dev_err(dev, "initial configure failed, ret = %d\n",
>> +				ret);
>> +			goto err_config;
>> +		}
>> +
>> +		ret = k3_r5_reserved_mem_init(kproc);
>> +		if (ret) {
>> +			dev_err(dev, "reserved memory init failed, ret = %d\n",
>> +				ret);
>> +			goto err_config;
>> +		}
>> +
>> +		ret = rproc_add(rproc);
>> +		if (ret) {
>> +			dev_err(dev, "rproc_add failed, ret = %d\n", ret);
>> +			goto err_add;
>> +		}
>> +
>> +		/* create only one rproc in lockstep mode */
>> +		if (cluster->mode)
>> +			break;
>> +	}
>> +
>> +	return 0;
>> +
>> +err_split:
>> +	rproc_del(rproc);
>> +err_add:
>> +	k3_r5_reserved_mem_exit(kproc);
>> +err_config:
>> +	rproc_free(rproc);
>> +	core->rproc = NULL;
>> +out:
>> +	/* undo core0 upon any failures on core1 in split-mode */
>> +	if (!cluster->mode && core == core1) {
>> +		core = list_prev_entry(core, elem);
>> +		rproc = core->rproc;
>> +		kproc = rproc->priv;
>> +		goto err_split;
>> +	}
>> +	return ret;
>> +}
>> +
>> +static int k3_r5_cluster_rproc_exit(struct platform_device *pdev)
>> +{
>> +	struct k3_r5_cluster *cluster = platform_get_drvdata(pdev);
>> +	struct k3_r5_rproc *kproc;
>> +	struct k3_r5_core *core;
>> +	struct rproc *rproc;
>> +
>> +	/*
>> +	 * lockstep mode has only one rproc associated with first core, whereas
>> +	 * split-mode has two rprocs associated with each core, and requires
>> +	 * that core1 be powered down first
>> +	 */
>> +	core = cluster->mode ?
>> +		list_first_entry(&cluster->cores, struct k3_r5_core, elem) :
>> +		list_last_entry(&cluster->cores, struct k3_r5_core, elem);
>> +
>> +	list_for_each_entry_from_reverse(core, &cluster->cores, elem) {
>> +		rproc = core->rproc;
>> +		kproc = rproc->priv;
>> +
>> +		rproc_del(rproc);
>> +
>> +		k3_r5_reserved_mem_exit(kproc);
>> +
>> +		rproc_free(rproc);
>> +		core->rproc = NULL;
>> +	}
>> +
>> +	return 0;
>> +}
>> +
>> +static int k3_r5_core_of_get_internal_memories(struct platform_device *pdev,
>> +					       struct k3_r5_core *core)
>> +{
>> +	static const char * const mem_names[] = {"atcm", "btcm"};
>> +	struct device *dev = &pdev->dev;
>> +	struct resource *res;
>> +	int num_mems;
>> +	int i, ret;
>> +
>> +	num_mems = ARRAY_SIZE(mem_names);
>> +	core->mem = devm_kcalloc(dev, num_mems, sizeof(*core->mem), GFP_KERNEL);
>> +	if (!core->mem)
>> +		return -ENOMEM;
>> +
>> +	for (i = 0; i < num_mems; i++) {
>> +		res = platform_get_resource_byname(pdev, IORESOURCE_MEM,
>> +						   mem_names[i]);
>> +		if (!res) {
>> +			dev_err(dev, "found no memory resource for %s\n",
>> +				mem_names[i]);
>> +			ret = -EINVAL;
>> +			goto fail;
>> +		}
>> +		if (!devm_request_mem_region(dev, res->start,
>> +					     resource_size(res),
>> +					     dev_name(dev))) {
>> +			dev_err(dev, "could not request %s region for resource\n",
>> +				mem_names[i]);
>> +			ret = -EBUSY;
>> +			goto fail;
>> +		}
>> +
>> +		/*
>> +		 * TCMs are designed in general to support RAM-like backing
>> +		 * memories. So, map these as Normal Non-Cached memories. This
>> +		 * also avoids/fixes any potential alignment faults due to
>> +		 * unaligned data accesses when using memcpy() or memset()
>> +		 * functions (normally seen with device type memory).
>> +		 */
>> +		core->mem[i].cpu_addr = devm_ioremap_wc(dev, res->start,
>> +							resource_size(res));
>> +		if (IS_ERR(core->mem[i].cpu_addr)) {
>> +			dev_err(dev, "failed to map %s memory\n", mem_names[i]);
>> +			ret = PTR_ERR(core->mem[i].cpu_addr);
>> +			devm_release_mem_region(dev, res->start,
>> +						resource_size(res));
>> +			goto fail;
>> +		}
>> +		core->mem[i].bus_addr = res->start;
>> +
>> +		/*
>> +		 * TODO:
>> +		 * The R5F cores can place ATCM & BTCM anywhere in its address
>> +		 * based on the corresponding Region Registers in the System
>> +		 * Control coprocessor. For now, place ATCM and BTCM at
>> +		 * addresses 0 and 0x41010000 (same as the bus address on AM65x
>> +		 * SoCs) based on loczrama setting
>> +		 */
>> +		if (!strcmp(mem_names[i], "atcm")) {
>> +			core->mem[i].dev_addr = core->loczrama ?
>> +							0 : K3_R5_TCM_DEV_ADDR;
>> +		} else {
>> +			core->mem[i].dev_addr = core->loczrama ?
>> +							K3_R5_TCM_DEV_ADDR : 0;
>> +		}
>> +		core->mem[i].size = resource_size(res);
>> +
>> +		dev_dbg(dev, "memory %8s: bus addr %pa size 0x%zx va %pK da 0x%x\n",
>> +			mem_names[i], &core->mem[i].bus_addr,
>> +			core->mem[i].size, core->mem[i].cpu_addr,
>> +			core->mem[i].dev_addr);
>> +	}
>> +	core->num_mems = num_mems;
>> +
>> +	return 0;
>> +
>> +fail:
>> +	for (i--; i >= 0; i--) {
>> +		devm_iounmap(dev, core->mem[i].cpu_addr);
>> +		devm_release_mem_region(dev, core->mem[i].bus_addr,
>> +					core->mem[i].size);
>> +	}
>> +	if (core->mem)
>> +		devm_kfree(dev, core->mem);
>> +	return ret;
>> +}
>> +
>> +static
>> +struct ti_sci_proc *k3_r5_core_of_get_tsp(struct device *dev,
>> +					  const struct ti_sci_handle *sci)
>> +{
>> +	struct ti_sci_proc *tsp;
>> +	u32 temp[2];
>> +	int ret;
>> +
>> +	ret = of_property_read_u32_array(dev->of_node, "ti,sci-proc-ids",
>> +					 temp, 2);
>> +	if (ret < 0)
>> +		return ERR_PTR(ret);
>> +
>> +	tsp = kzalloc(sizeof(*tsp), GFP_KERNEL);
>> +	if (!tsp)
>> +		return ERR_PTR(-ENOMEM);
>> +
>> +	tsp->dev = dev;
>> +	tsp->sci = sci;
>> +	tsp->ops = &sci->ops.proc_ops;
>> +	tsp->proc_id = temp[0];
>> +	tsp->host_id = temp[1];
>> +
>> +	return tsp;
>> +}
>> +
>> +static int k3_r5_core_of_init(struct platform_device *pdev)
>> +{
>> +	struct device *dev = &pdev->dev;
>> +	struct device_node *np = dev->of_node;
>> +	struct k3_r5_core *core;
>> +	int ret, ret1;
>> +
>> +	core = devm_kzalloc(dev, sizeof(*core), GFP_KERNEL);
>> +	if (!core)
>> +		return -ENOMEM;
>> +
>> +	core->dev = dev;
>> +	core->atcm_enable = 0;
>> +	core->btcm_enable = 1;
>> +	core->loczrama = 1;
>> +
>> +	ret = of_property_read_u32(np, "atcm-enable", &core->atcm_enable);
>> +	if (ret < 0 && ret != -EINVAL) {
>> +		dev_err(dev, "invalid format for atcm-enable, ret = %d\n", ret);
>> +		goto err_of;
>> +	}
>> +
>> +	ret = of_property_read_u32(np, "btcm-enable", &core->btcm_enable);
>> +	if (ret < 0 && ret != -EINVAL) {
>> +		dev_err(dev, "invalid format for btcm-enable, ret = %d\n", ret);
>> +		goto err_of;
>> +	}
>> +
>> +	ret = of_property_read_u32(np, "loczrama", &core->loczrama);
>> +	if (ret < 0 && ret != -EINVAL) {
>> +		dev_err(dev, "invalid format for loczrama, ret = %d\n", ret);
>> +		goto err_of;
>> +	}
>> +
>> +	core->ti_sci = ti_sci_get_by_phandle(np, "ti,sci");
>> +	if (IS_ERR(core->ti_sci)) {
>> +		ret = PTR_ERR(core->ti_sci);
>> +		if (ret != -EPROBE_DEFER) {
>> +			dev_err(dev, "failed to get ti-sci handle, ret = %d\n",
>> +				ret);
>> +		}
>> +		core->ti_sci = NULL;
>> +		goto err_of;
>> +	}
>> +
>> +	ret = of_property_read_u32(np, "ti,sci-dev-id", &core->ti_sci_id);
>> +	if (ret) {
>> +		dev_err(dev, "missing 'ti,sci-dev-id' property\n");
>> +		goto err_sci_id;
>> +	}
>> +
>> +	core->reset = reset_control_get_exclusive(dev, NULL);
>> +	if (IS_ERR(core->reset)) {
>> +		ret = PTR_ERR(core->reset);
>> +		if (ret != -EPROBE_DEFER) {
>> +			dev_err(dev, "failed to get reset handle, ret = %d\n",
>> +				ret);
>> +		}
>> +		goto err_sci_id;
>> +	}
>> +
>> +	core->tsp = k3_r5_core_of_get_tsp(dev, core->ti_sci);
>> +	if (IS_ERR(core->tsp)) {
>> +		dev_err(dev, "failed to construct ti-sci proc control, ret = %d\n",
>> +			ret);
>> +		ret = PTR_ERR(core->tsp);
>> +		goto err_sci_proc;
> 
> Why not calling the label "err_reset"?  I don't see what how "err_sci_proc"
> relates to what the code is doing... 

Hmm, I have been using the err labels based on what failed, and this has
nothing to do with err_reset, which ideally would have been used above,
but I didn't need any specific cleanup on that. tsp is short for
ti_sci_proc, as I fill in all the relevant fields to talk to the
centralized System Firmware.

> 
> I'll continue reviewing this patch tomorrow.

Thanks for the reviews.

regards
Suman


> 
> Thanks,
> Mathieu
> 
>> +	}
>> +
>> +	ret = ti_sci_proc_request(core->tsp);
>> +	if (ret < 0) {
>> +		dev_err(dev, "ti_sci_proc_request failed, ret = %d\n", ret);
>> +		goto err_proc;
>> +	}
>> +
>> +	ret = k3_r5_core_of_get_internal_memories(pdev, core);
>> +	if (ret) {
>> +		dev_err(dev, "failed to get internal memories, ret = %d\n",
>> +			ret);
>> +		goto err_intmem;
>> +	}
>> +
>> +	platform_set_drvdata(pdev, core);
>> +
>> +	return 0;
>> +
>> +err_intmem:
>> +	ret1 = ti_sci_proc_release(core->tsp);
>> +	if (ret1)
>> +		dev_err(dev, "failed to release proc, ret1 = %d\n", ret1);
>> +err_proc:
>> +	kfree(core->tsp);
>> +err_sci_proc:
>> +	reset_control_put(core->reset);
>> +err_sci_id:
>> +	ret1 = ti_sci_put_handle(core->ti_sci);
>> +	if (ret1)
>> +		dev_err(dev, "failed to put ti_sci handle, ret = %d\n", ret1);
>> +err_of:
>> +	devm_kfree(dev, core);
>> +	return ret;
>> +}
>> +
>> +/*
>> + * free the resources explicitly since driver model is not being used
>> + * for the child R5F devices
>> + */
>> +static int k3_r5_core_of_exit(struct platform_device *pdev)
>> +{
>> +	struct k3_r5_core *core = platform_get_drvdata(pdev);
>> +	struct device *dev = &pdev->dev;
>> +	int i, ret;
>> +
>> +	for (i = 0; i < core->num_mems; i++) {
>> +		devm_release_mem_region(dev, core->mem[i].bus_addr,
>> +					core->mem[i].size);
>> +		devm_iounmap(dev, core->mem[i].cpu_addr);
>> +	}
>> +	if (core->mem)
>> +		devm_kfree(dev, core->mem);
>> +
>> +	ret = ti_sci_proc_release(core->tsp);
>> +	if (ret)
>> +		dev_err(dev, "failed to release proc, ret = %d\n", ret);
>> +
>> +	kfree(core->tsp);
>> +	reset_control_put(core->reset);
>> +
>> +	ret = ti_sci_put_handle(core->ti_sci);
>> +	if (ret)
>> +		dev_err(dev, "failed to put ti_sci handle, ret = %d\n", ret);
>> +
>> +	platform_set_drvdata(pdev, NULL);
>> +	devm_kfree(dev, core);
>> +
>> +	return ret;
>> +}
>> +
>> +static int k3_r5_cluster_of_init(struct platform_device *pdev)
>> +{
>> +	struct k3_r5_cluster *cluster = platform_get_drvdata(pdev);
>> +	struct device *dev = &pdev->dev;
>> +	struct device_node *np = dev->of_node;
>> +	struct platform_device *cpdev;
>> +	struct device_node *child;
>> +	struct k3_r5_core *core, *temp;
>> +	int ret;
>> +
>> +	for_each_available_child_of_node(np, child) {
>> +		cpdev = of_find_device_by_node(child);
>> +		if (!cpdev) {
>> +			ret = -ENODEV;
>> +			dev_err(dev, "could not get R5 core platform device\n");
>> +			goto fail;
>> +		}
>> +
>> +		ret = k3_r5_core_of_init(cpdev);
>> +		if (ret) {
>> +			dev_err(dev, "k3_r5_core_of_init failed, ret = %d\n",
>> +				ret);
>> +			put_device(&cpdev->dev);
>> +			goto fail;
>> +		}
>> +
>> +		core = platform_get_drvdata(cpdev);
>> +		put_device(&cpdev->dev);
>> +		list_add_tail(&core->elem, &cluster->cores);
>> +	}
>> +
>> +	return 0;
>> +
>> +fail:
>> +	list_for_each_entry_safe_reverse(core, temp, &cluster->cores, elem) {
>> +		list_del(&core->elem);
>> +		cpdev = to_platform_device(core->dev);
>> +		if (k3_r5_core_of_exit(cpdev))
>> +			dev_err(dev, "k3_r5_core_of_exit cleanup failed\n");
> 
> I would move k3_r5_cluster_of_exit() just above k3_r5_cluster_of_init() and
> reuse the former here instead of repeating the same code.
> 
>> +	}
>> +	return ret;
>> +}
>> +
>> +static int k3_r5_cluster_of_exit(struct platform_device *pdev)
>> +{
>> +	struct k3_r5_cluster *cluster = platform_get_drvdata(pdev);
>> +	struct device *dev = &pdev->dev;
>> +	struct platform_device *cpdev;
>> +	struct k3_r5_core *core, *temp;
>> +	int ret;
>> +
>> +	list_for_each_entry_safe_reverse(core, temp, &cluster->cores, elem) {
>> +		list_del(&core->elem);
>> +		cpdev = to_platform_device(core->dev);
>> +		ret = k3_r5_core_of_exit(cpdev);
>> +		if (ret) {
>> +			dev_err(dev, "k3_r5_core_of_exit failed, ret = %d\n",
>> +				ret);
>> +			break;
> 
> So why stopping when encountering an error?  Since this is the exit path I think
> it is better to call k3_r5_core_of_exit() on as many core as possible.
> 
>> +		}
>> +	}
>> +
>> +	return ret;
>> +}
>> +
>> +static int k3_r5_probe(struct platform_device *pdev)
>> +{
>> +	struct device *dev = &pdev->dev;
>> +	struct device_node *np = dev->of_node;
>> +	struct k3_r5_cluster *cluster;
>> +	int ret, ret1;
>> +	int num_cores;
>> +
>> +	cluster = devm_kzalloc(dev, sizeof(*cluster), GFP_KERNEL);
>> +	if (!cluster)
>> +		return -ENOMEM;
>> +
>> +	cluster->dev = dev;
>> +	cluster->mode = CLUSTER_MODE_LOCKSTEP;
>> +	INIT_LIST_HEAD(&cluster->cores);
>> +
>> +	ret = of_property_read_u32(np, "lockstep-mode", &cluster->mode);
>> +	if (ret < 0 && ret != -EINVAL) {
>> +		dev_err(dev, "invalid format for lockstep-mode, ret = %d\n",
>> +			ret);
>> +		return ret;
>> +	}
>> +
>> +	num_cores = of_get_available_child_count(np);
>> +	if (num_cores != 2) {
>> +		dev_err(dev, "MCU cluster requires both R5F cores to be enabled, num_cores = %d\n",
>> +			num_cores);
>> +		return -ENODEV;
>> +	}
>> +
>> +	platform_set_drvdata(pdev, cluster);
>> +
>> +	dev_dbg(dev, "creating child devices for R5F cores\n");
>> +	ret = of_platform_populate(np, NULL, NULL, dev);
>> +	if (ret) {
>> +		dev_err(dev, "of_platform_populate failed, ret = %d\n", ret);
>> +		return ret;
>> +	}
>> +
>> +	ret = k3_r5_cluster_of_init(pdev);
>> +	if (ret) {
>> +		dev_err(dev, "k3_r5_cluster_of_init failed, ret = %d\n", ret);
>> +		goto fail_of;
>> +	}
>> +
>> +	ret = k3_r5_cluster_rproc_init(pdev);
>> +	if (ret) {
>> +		dev_err(dev, "k3_r5_cluster_rproc_init failed, ret = %d\n",
>> +			ret);
>> +		goto fail_rproc;
>> +	}
>> +
>> +	return 0;
>> +
>> +fail_rproc:
>> +	ret1 = k3_r5_cluster_of_exit(pdev);
>> +	if (ret1)
>> +		dev_err(dev, "k3_r5_cluster_of_exit failed, ret = %d\n", ret1);
>> +fail_of:
>> +	of_platform_depopulate(dev);
>> +	return ret;
>> +}
>> +
>> +static int k3_r5_remove(struct platform_device *pdev)
>> +{
>> +	struct device *dev = &pdev->dev;
>> +	int ret;
>> +
>> +	ret = k3_r5_cluster_rproc_exit(pdev);
>> +	if (ret) {
>> +		dev_err(dev, "k3_r5_cluster_rproc_exit failed, ret = %d\n",
>> +			ret);
>> +		goto fail;
>> +	}
>> +
>> +	ret = k3_r5_cluster_of_exit(pdev);
>> +	if (ret) {
>> +		dev_err(dev, "k3_r5_cluster_of_exit failed, ret = %d\n", ret);
>> +		goto fail;
>> +	}
>> +
>> +	dev_dbg(dev, "removing child devices for R5F cores\n");
>> +	of_platform_depopulate(dev);
>> +
>> +fail:
>> +	return ret;
>> +}
>> +
>> +static const struct of_device_id k3_r5_of_match[] = {
>> +	{ .compatible = "ti,am654-r5fss", },
>> +	{ .compatible = "ti,j721e-r5fss", },
>> +	{ /* sentinel */ },
>> +};
>> +MODULE_DEVICE_TABLE(of, k3_r5_of_match);
>> +
>> +static struct platform_driver k3_r5_rproc_driver = {
>> +	.probe = k3_r5_probe,
>> +	.remove = k3_r5_remove,
>> +	.driver = {
>> +		.name = "k3_r5_rproc",
>> +		.of_match_table = k3_r5_of_match,
>> +	},
>> +};
>> +
>> +module_platform_driver(k3_r5_rproc_driver);
>> +
>> +MODULE_LICENSE("GPL v2");
>> +MODULE_DESCRIPTION("TI K3 R5F remote processor driver");
>> +MODULE_AUTHOR("Suman Anna <s-anna@ti.com>");
>> -- 
>> 2.23.0
>>

On Tue, Mar 24, 2020 at 03:18:17PM -0500, Suman Anna wrote:
> The TI K3 family of SoCs typically have one or more dual-core Arm Cortex
> R5F processor clusters/subsystems (R5FSS). This R5F subsystem/cluster
> can be configured at boot time to be either run in a LockStep mode or in
> an Asymmetric Multi Processing (AMP) fashion in Split-mode. This subsystem
> has 64 KB each Tightly-Coupled Memory (TCM) internal memories for each
> core split between two banks - TCMA and TCMB (further interleaved into
> two banks). The subsystem does not have an MMU, but has a Region Address
> Translater (RAT) module that is accessible only from the R5Fs for providing
> translations between 32-bit CPU addresses into larger system bus addresses.
> 
> Add a remoteproc driver to support this subsystem to be able to load and
> boot the R5F cores primarily in LockStep mode. The code also includes the
> base support for Split mode. Error Recovery and Power Management features
> are not currently supported. Loading support includes the internal TCMs
> and DDR. RAT support is left for a future patch, and as such the reserved
> memory carveout regions are all expected to be using memory regions within
> the first 2 GB.
> 
> The R5F remote processors do not have an MMU, and so require fixed memory
> carveout regions matching the firmware image addresses. Support for this
> is provided by mandating multiple memory regions to be attached to the
> remoteproc device. The first memory region will be used to serve as the
> DMA pool for all dynamic allocations like the vrings and vring buffers.
> The remaining memory regions are mapped into the kernel at device probe
> time, and are used to provide address translations for firmware image
> segments without the need for any RSC_CARVEOUT entries. Any firmware
> image using memory outside of the supplied reserved memory carveout
> regions will be errored out.
> 
> The R5F processors on TI K3 SoCs require a specific sequence for booting
> and shutting down the processors. This sequence is also dependent on the
> mode (LockStep or Split) the R5F cluster is configured for. The R5F cores
> have a Memory Protection Unit (MPU) that has a default configuration that
> does not allow the cores to run out of DDR out of reset. This is resolved
> by using the TCMs for boot-strapping code that applies the appropriate
> executable permissions on desired DDR memory. The loading into the TCMs
> requires that the resets be released first with the cores in halted state.
> The Power Sleep Controller (PSC) module on K3 SoCs requires that the cores
> be in WFI/WFE states with no active bus transactions before the cores can
> be put back into reset. Support for this is provided by using the newly
> introduced .prepare() and .unprepare() ops in the remoteproc core. The
> .prepare() ops is invoked before any loading, and the .unprepare() ops
> is invoked after the remoteproc resource cleanup. The R5F core resets
> are deasserted in .prepare() and asserted in .unprepare(), and the cores
> themselves are started and halted in .start() and .stop() ops. This
> ensures symmetric usage and allows the R5F cores state machine to be
> maintained properly between using the sysfs 'state' variable, bind/unbind
> and regular module load/unload flows.
> 
> The subsystem is represented as a single remoteproc in LockStep mode, and
> as two remoteprocs in Split mode. The driver uses various TI-SCI interfaces
> to talk to the System Controller (DMSC) for managing configuration, power
> and reset management of these cores. IPC between the A53 cores and the R5
> cores is supported through the virtio rpmsg stack using shared memory and
> OMAP Mailboxes.
> 
> The AM65x SoCs typically have a single R5FSS in the MCU voltage domain. The
> J721E SoCs uses a slightly revised IP and typically have three R5FSSs, with
> one cluster present within the MCU voltage domain (MCU_R5FSS0), and the
> remaining two clusters present in the MAIN voltage domain (MAIN_R5FSS0 and
> MAIN_R5FSS1). The integration of these clusters on J721E SoC is also
> slightly different in that these IPs do support an actual local reset line,
> while they are a no-op on AM65x SoCs.
> 
> Signed-off-by: Suman Anna <s-anna@ti.com>
> ---
>  drivers/remoteproc/Kconfig               |   16 +
>  drivers/remoteproc/Makefile              |    1 +
>  drivers/remoteproc/ti_k3_r5_remoteproc.c | 1346 ++++++++++++++++++++++
>  3 files changed, 1363 insertions(+)
>  create mode 100644 drivers/remoteproc/ti_k3_r5_remoteproc.c
> 
> diff --git a/drivers/remoteproc/Kconfig b/drivers/remoteproc/Kconfig
> index de3862c15fcc..073048b4c0fb 100644
> --- a/drivers/remoteproc/Kconfig
> +++ b/drivers/remoteproc/Kconfig
> @@ -224,6 +224,22 @@ config STM32_RPROC
>  
>  	  This can be either built-in or a loadable module.
>  
> +config TI_K3_R5_REMOTEPROC
> +	tristate "TI K3 R5 remoteproc support"
> +	depends on ARCH_K3
> +	select MAILBOX
> +	select OMAP2PLUS_MBOX
> +	help
> +	  Say y here to support TI's R5F remote processor subsystems
> +	  on various TI K3 family of SoCs through the remote processor
> +	  framework.
> +
> +	  You want to say y here in order to offload some processing
> +	  tasks to these processors
> +
> +	  It's safe to say N here if you're not interested in utilizing
> +	  a slave processor
> +
>  endif # REMOTEPROC
>  
>  endmenu
> diff --git a/drivers/remoteproc/Makefile b/drivers/remoteproc/Makefile
> index e30a1b15fbac..00ba826818af 100644
> --- a/drivers/remoteproc/Makefile
> +++ b/drivers/remoteproc/Makefile
> @@ -28,3 +28,4 @@ qcom_wcnss_pil-y			+= qcom_wcnss_iris.o
>  obj-$(CONFIG_ST_REMOTEPROC)		+= st_remoteproc.o
>  obj-$(CONFIG_ST_SLIM_REMOTEPROC)	+= st_slim_rproc.o
>  obj-$(CONFIG_STM32_RPROC)		+= stm32_rproc.o
> +obj-$(CONFIG_TI_K3_R5_REMOTEPROC)	+= ti_k3_r5_remoteproc.o
> diff --git a/drivers/remoteproc/ti_k3_r5_remoteproc.c b/drivers/remoteproc/ti_k3_r5_remoteproc.c
> new file mode 100644
> index 000000000000..655f8f14c37d
> --- /dev/null
> +++ b/drivers/remoteproc/ti_k3_r5_remoteproc.c
> @@ -0,0 +1,1346 @@
> +// SPDX-License-Identifier: GPL-2.0-only
> +/*
> + * TI K3 R5F (MCU) Remote Processor driver
> + *
> + * Copyright (C) 2017-2020 Texas Instruments Incorporated - http://www.ti.com/
> + *	Suman Anna <s-anna@ti.com>
> + */
> +
> +#include <linux/dma-mapping.h>
> +#include <linux/err.h>
> +#include <linux/interrupt.h>
> +#include <linux/kernel.h>
> +#include <linux/mailbox_client.h>
> +#include <linux/module.h>
> +#include <linux/of_device.h>
> +#include <linux/of_address.h>
> +#include <linux/of_reserved_mem.h>
> +#include <linux/platform_device.h>
> +#include <linux/pm_runtime.h>
> +#include <linux/remoteproc.h>
> +#include <linux/omap-mailbox.h>
> +#include <linux/reset.h>
> +#include <linux/soc/ti/ti_sci_protocol.h>
> +
> +#include "omap_remoteproc.h"
> +#include "remoteproc_internal.h"
> +#include "ti_sci_proc.h"
> +
> +/* This address can either be for ATCM or BTCM with the other at address 0x0 */
> +#define K3_R5_TCM_DEV_ADDR	0x41010000
> +
> +/* R5 TI-SCI Processor Configuration Flags */
> +#define PROC_BOOT_CFG_FLAG_R5_DBG_EN			0x00000001
> +#define PROC_BOOT_CFG_FLAG_R5_DBG_NIDEN			0x00000002
> +#define PROC_BOOT_CFG_FLAG_R5_LOCKSTEP			0x00000100
> +#define PROC_BOOT_CFG_FLAG_R5_TEINIT			0x00000200
> +#define PROC_BOOT_CFG_FLAG_R5_NMFI_EN			0x00000400
> +#define PROC_BOOT_CFG_FLAG_R5_TCM_RSTBASE		0x00000800
> +#define PROC_BOOT_CFG_FLAG_R5_BTCM_EN			0x00001000
> +#define PROC_BOOT_CFG_FLAG_R5_ATCM_EN			0x00002000
> +
> +/* R5 TI-SCI Processor Control Flags */
> +#define PROC_BOOT_CTRL_FLAG_R5_CORE_HALT		0x00000001
> +
> +/* R5 TI-SCI Processor Status Flags */
> +#define PROC_BOOT_STATUS_FLAG_R5_WFE			0x00000001
> +#define PROC_BOOT_STATUS_FLAG_R5_WFI			0x00000002
> +#define PROC_BOOT_STATUS_FLAG_R5_CLK_GATED		0x00000004
> +#define PROC_BOOT_STATUS_FLAG_R5_LOCKSTEP_PERMITTED	0x00000100
> +
> +/**
> + * struct k3_r5_mem - internal memory structure
> + * @cpu_addr: MPU virtual address of the memory region
> + * @bus_addr: Bus address used to access the memory region
> + * @dev_addr: Device address from remoteproc view
> + * @size: Size of the memory region
> + */
> +struct k3_r5_mem {
> +	void __iomem *cpu_addr;
> +	phys_addr_t bus_addr;
> +	u32 dev_addr;
> +	size_t size;
> +};
> +
> +enum cluster_mode {
> +	CLUSTER_MODE_SPLIT = 0,
> +	CLUSTER_MODE_LOCKSTEP,
> +};
> +
> +/**
> + * struct k3_r5_cluster - K3 R5F Cluster structure
> + * @dev: cached device pointer
> + * @mode: Mode to configure the Cluster - Split or LockStep
> + * @cores: list of R5 cores within the cluster
> + */
> +struct k3_r5_cluster {
> +	struct device *dev;
> +	enum cluster_mode mode;
> +	struct list_head cores;
> +};
> +
> +/**
> + * struct k3_r5_core - K3 R5 core structure
> + * @elem: linked list item
> + * @dev: cached device pointer
> + * @rproc: rproc handle representing this core
> + * @mem: internal memory regions data
> + * @num_mems: number of internal memory regions
> + * @reset: reset control handle
> + * @tsp: TI-SCI processor control handle
> + * @ti_sci: TI-SCI handle
> + * @ti_sci_id: TI-SCI device identifier
> + * @atcm_enable: flag to control ATCM enablement
> + * @btcm_enable: flag to control BTCM enablement
> + * @loczrama: flag to dictate which TCM is at device address 0x0
> + */
> +struct k3_r5_core {
> +	struct list_head elem;
> +	struct device *dev;
> +	struct rproc *rproc;
> +	struct k3_r5_mem *mem;
> +	int num_mems;
> +	struct reset_control *reset;
> +	struct ti_sci_proc *tsp;
> +	const struct ti_sci_handle *ti_sci;
> +	u32 ti_sci_id;
> +	u32 atcm_enable;
> +	u32 btcm_enable;
> +	u32 loczrama;
> +};
> +
> +/**
> + * struct k3_r5_rproc - K3 remote processor state
> + * @dev: cached device pointer
> + * @cluster: cached pointer to parent cluster structure
> + * @mbox: mailbox channel handle
> + * @client: mailbox client to request the mailbox channel
> + * @rproc: rproc handle
> + * @core: cached pointer to r5 core structure being used
> + * @rmem: reserved memory regions data
> + * @num_rmems: number of reserved memory regions
> + */
> +struct k3_r5_rproc {
> +	struct device *dev;
> +	struct k3_r5_cluster *cluster;
> +	struct mbox_chan *mbox;
> +	struct mbox_client client;
> +	struct rproc *rproc;
> +	struct k3_r5_core *core;
> +	struct k3_r5_mem *rmem;
> +	int num_rmems;
> +};
> +
> +/**
> + * k3_r5_rproc_mbox_callback() - inbound mailbox message handler
> + * @client: mailbox client pointer used for requesting the mailbox channel
> + * @data: mailbox payload
> + *
> + * This handler is invoked by the OMAP mailbox driver whenever a mailbox
> + * message is received. Usually, the mailbox payload simply contains
> + * the index of the virtqueue that is kicked by the remote processor,
> + * and we let remoteproc core handle it.
> + *
> + * In addition to virtqueue indices, we also have some out-of-band values
> + * that indicate different events. Those values are deliberately very
> + * large so they don't coincide with virtqueue indices.
> + */
> +static void k3_r5_rproc_mbox_callback(struct mbox_client *client, void *data)
> +{
> +	struct k3_r5_rproc *kproc = container_of(client, struct k3_r5_rproc,
> +						client);
> +	struct device *dev = kproc->rproc->dev.parent;
> +	const char *name = kproc->rproc->name;
> +	u32 msg = omap_mbox_message(data);
> +
> +	dev_dbg(dev, "mbox msg: 0x%x\n", msg);
> +
> +	switch (msg) {
> +	case RP_MBOX_CRASH:
> +		/*
> +		 * remoteproc detected an exception, but error recovery is not
> +		 * supported. So, just log this for now
> +		 */
> +		dev_err(dev, "K3 R5F rproc %s crashed\n", name);
> +		break;
> +	case RP_MBOX_ECHO_REPLY:
> +		dev_info(dev, "received echo reply from %s\n", name);
> +		break;
> +	default:
> +		/* silently handle all other valid messages */
> +		if (msg >= RP_MBOX_READY && msg < RP_MBOX_END_MSG)
> +			return;
> +		if (msg > kproc->rproc->max_notifyid) {
> +			dev_dbg(dev, "dropping unknown message 0x%x", msg);
> +			return;
> +		}
> +		/* msg contains the index of the triggered vring */
> +		if (rproc_vq_interrupt(kproc->rproc, msg) == IRQ_NONE)
> +			dev_dbg(dev, "no message was found in vqid %d\n", msg);
> +	}
> +}
> +
> +/* kick a virtqueue */
> +static void k3_r5_rproc_kick(struct rproc *rproc, int vqid)
> +{
> +	struct k3_r5_rproc *kproc = rproc->priv;
> +	struct device *dev = rproc->dev.parent;
> +	mbox_msg_t msg = (mbox_msg_t)vqid;
> +	int ret;
> +
> +	/* send the index of the triggered virtqueue in the mailbox payload */
> +	ret = mbox_send_message(kproc->mbox, (void *)msg);
> +	if (ret < 0)
> +		dev_err(dev, "failed to send mailbox message, status = %d\n",
> +			ret);
> +}
> +
> +static int k3_r5_split_reset(struct k3_r5_core *core)
> +{
> +	int ret;
> +
> +	ret = reset_control_assert(core->reset);
> +	if (ret) {
> +		dev_err(core->dev, "local-reset assert failed, ret = %d\n",
> +			ret);
> +		return ret;
> +	}
> +
> +	ret = core->ti_sci->ops.dev_ops.put_device(core->ti_sci,
> +						   core->ti_sci_id);
> +	if (ret) {
> +		dev_err(core->dev, "module-reset assert failed, ret = %d\n",
> +			ret);
> +		if (reset_control_deassert(core->reset))
> +			dev_warn(core->dev, "local-reset deassert back failed\n");
> +	}
> +
> +	return ret;
> +}
> +
> +static int k3_r5_split_release(struct k3_r5_core *core)
> +{
> +	int ret;
> +
> +	ret = core->ti_sci->ops.dev_ops.get_device(core->ti_sci,
> +						   core->ti_sci_id);
> +	if (ret) {
> +		dev_err(core->dev, "module-reset deassert failed, ret = %d\n",
> +			ret);
> +		return ret;
> +	}
> +
> +	ret = reset_control_deassert(core->reset);
> +	if (ret) {
> +		dev_err(core->dev, "local-reset deassert failed, ret = %d\n",
> +			ret);
> +		if (core->ti_sci->ops.dev_ops.put_device(core->ti_sci,
> +							 core->ti_sci_id))
> +			dev_warn(core->dev, "module-reset assert back failed\n");
> +	}
> +
> +	return ret;
> +}
> +
> +static int k3_r5_lockstep_reset(struct k3_r5_cluster *cluster)
> +{
> +	struct k3_r5_core *core;
> +	int ret;
> +
> +	/* assert local reset on all applicable cores */
> +	list_for_each_entry(core, &cluster->cores, elem) {
> +		ret = reset_control_assert(core->reset);
> +		if (ret) {
> +			dev_err(core->dev, "local-reset assert failed, ret = %d\n",
> +				ret);
> +			core = list_prev_entry(core, elem);
> +			goto unroll_local_reset;
> +		}
> +	}
> +
> +	/* disable PSC modules on all applicable cores */
> +	list_for_each_entry(core, &cluster->cores, elem) {
> +		ret = core->ti_sci->ops.dev_ops.put_device(core->ti_sci,
> +							   core->ti_sci_id);
> +		if (ret) {
> +			dev_err(core->dev, "module-reset assert failed, ret = %d\n",
> +				ret);
> +			goto unroll_module_reset;
> +		}
> +	}
> +
> +	return 0;
> +
> +unroll_module_reset:
> +	list_for_each_entry_continue_reverse(core, &cluster->cores, elem) {
> +		if (core->ti_sci->ops.dev_ops.put_device(core->ti_sci,
> +							 core->ti_sci_id))
> +			dev_warn(core->dev, "module-reset assert back failed\n");
> +	}
> +	core = list_last_entry(&cluster->cores, struct k3_r5_core, elem);
> +unroll_local_reset:
> +	list_for_each_entry_from_reverse(core, &cluster->cores, elem) {
> +		if (reset_control_deassert(core->reset))
> +			dev_warn(core->dev, "local-reset deassert back failed\n");
> +	}
> +
> +	return ret;
> +}
> +
> +static int k3_r5_lockstep_release(struct k3_r5_cluster *cluster)
> +{
> +	struct k3_r5_core *core;
> +	int ret;
> +
> +	/* enable PSC modules on all applicable cores */
> +	list_for_each_entry_reverse(core, &cluster->cores, elem) {

Out of curiosity, any HW specific reason to start with the last core?

> +		ret = core->ti_sci->ops.dev_ops.get_device(core->ti_sci,
> +							   core->ti_sci_id);
> +		if (ret) {
> +			dev_err(core->dev, "module-reset deassert failed, ret = %d\n",
> +				ret);
> +			core = list_next_entry(core, elem);
> +			goto unroll_module_reset;
> +		}
> +	}
> +
> +	/* deassert local reset on all applicable cores */
> +	list_for_each_entry_reverse(core, &cluster->cores, elem) {
> +		ret = reset_control_deassert(core->reset);
> +		if (ret) {
> +			dev_err(core->dev, "module-reset deassert failed, ret = %d\n",
> +				ret);
> +			goto unroll_local_reset;
> +		}
> +	}
> +
> +	return 0;
> +
> +unroll_local_reset:
> +	list_for_each_entry_continue(core, &cluster->cores, elem) {
> +		if (reset_control_assert(core->reset))
> +			dev_warn(core->dev, "local-reset assert back failed\n");
> +	}
> +	core = list_first_entry(&cluster->cores, struct k3_r5_core, elem);
> +unroll_module_reset:
> +	list_for_each_entry_from(core, &cluster->cores, elem) {
> +		if (core->ti_sci->ops.dev_ops.put_device(core->ti_sci,
> +							 core->ti_sci_id))
> +			dev_warn(core->dev, "module-reset assert back failed\n");
> +	}
> +
> +	return ret;
> +}
> +
> +static inline int k3_r5_core_halt(struct k3_r5_core *core)
> +{
> +	return ti_sci_proc_set_control(core->tsp,
> +				       PROC_BOOT_CTRL_FLAG_R5_CORE_HALT, 0);
> +}
> +
> +static inline int k3_r5_core_run(struct k3_r5_core *core)
> +{
> +	return ti_sci_proc_set_control(core->tsp,
> +				       0, PROC_BOOT_CTRL_FLAG_R5_CORE_HALT);
> +}
> +
> +/*
> + * The R5F cores have controls for both a reset and a halt/run. The code
> + * execution from DDR requires the initial boot-strapping code to be run
> + * from the internal TCMs. This function is used to release the resets on
> + * applicable cores to allow loading into the TCMs. The .prepare() ops is
> + * invoked by remoteproc core before any firmware loading, and is followed
> + * by the .start() ops after loading to actually let the R5 cores run.
> + */
> +static int k3_r5_rproc_prepare(struct rproc *rproc)
> +{
> +	struct k3_r5_rproc *kproc = rproc->priv;
> +	struct k3_r5_cluster *cluster = kproc->cluster;
> +	struct k3_r5_core *core = kproc->core;
> +	struct device *dev = kproc->dev;
> +	int ret;
> +
> +	ret = cluster->mode ? k3_r5_lockstep_release(cluster) :
> +			      k3_r5_split_release(core);
> +	if (ret)
> +		dev_err(dev, "unable to enable cores for TCM loading, ret = %d\n",
> +			ret);
> +
> +	return ret;
> +}
> +
> +/*
> + * This function implements the .unprepare() ops and performs the complimentary
> + * operations to that of the .prepare() ops. The function is used to assert the
> + * resets on all applicable cores for the rproc device (depending on LockStep
> + * or Split mode). This completes the second portion of powering down the R5F
> + * cores. The cores themselves are only halted in the .stop() ops, and the
> + * .unprepare() ops is invoked by the remoteproc core after the remoteproc is
> + * stopped.
> + */
> +static int k3_r5_rproc_unprepare(struct rproc *rproc)
> +{
> +	struct k3_r5_rproc *kproc = rproc->priv;
> +	struct k3_r5_cluster *cluster = kproc->cluster;
> +	struct k3_r5_core *core = kproc->core;
> +	struct device *dev = kproc->dev;
> +	int ret;
> +
> +	ret = cluster->mode ? k3_r5_lockstep_reset(cluster) :
> +			      k3_r5_split_reset(core);
> +	if (ret)
> +		dev_err(dev, "unable to disable cores, ret = %d\n", ret);
> +
> +	return ret;
> +}
> +
> +/*
> + * The R5F start sequence includes two different operations
> + * 1. Configure the boot vector for R5F core(s)
> + * 2. Unhalt/Run the R5F core(s)
> + *
> + * The sequence is different between LockStep and Split modes. The LockStep
> + * mode requires the boot vector to be configured only for Core0, and then
> + * unhalt both the cores to start the execution - Core1 needs to be unhalted
> + * first followed by Core0. The Split-mode requires that Core0 to be maintained
> + * always in a higher power state that Core1 (implying Core1 needs to be started
> + * always only after Core0 is started).
> + */
> +static int k3_r5_rproc_start(struct rproc *rproc)
> +{
> +	struct k3_r5_rproc *kproc = rproc->priv;
> +	struct k3_r5_cluster *cluster = kproc->cluster;
> +	struct mbox_client *client = &kproc->client;
> +	struct device *dev = kproc->dev;
> +	struct k3_r5_core *core;
> +	u32 boot_addr;
> +	int ret;
> +
> +	client->dev = dev;
> +	client->tx_done = NULL;
> +	client->rx_callback = k3_r5_rproc_mbox_callback;
> +	client->tx_block = false;
> +	client->knows_txdone = false;
> +
> +	kproc->mbox = mbox_request_channel(client, 0);
> +	if (IS_ERR(kproc->mbox)) {
> +		ret = -EBUSY;
> +		dev_err(dev, "mbox_request_channel failed: %ld\n",
> +			PTR_ERR(kproc->mbox));
> +		return ret;
> +	}

Does this needs to be done every time a remote processor is booted or could it
be done just once in k3_r5_core_of_init()?

> +
> +	/*
> +	 * Ping the remote processor, this is only for sanity-sake for now;
> +	 * there is no functional effect whatsoever.
> +	 *
> +	 * Note that the reply will _not_ arrive immediately: this message
> +	 * will wait in the mailbox fifo until the remote processor is booted.
> +	 */
> +	ret = mbox_send_message(kproc->mbox, (void *)RP_MBOX_ECHO_REQUEST);
> +	if (ret < 0) {
> +		dev_err(dev, "mbox_send_message failed: %d\n", ret);
> +		goto put_mbox;
> +	}
> +
> +	boot_addr = rproc->bootaddr;
> +	/* TODO: add boot_addr sanity checking */
> +	dev_err(dev, "booting R5F core using boot addr = 0x%x\n", boot_addr);

s/dev_err()/dev_dbg()

> +
> +	/* boot vector need not be programmed for Core1 in LockStep mode */
> +	core = kproc->core;
> +	ret = ti_sci_proc_set_config(core->tsp, boot_addr, 0, 0);
> +	if (ret)
> +		goto put_mbox;
> +
> +	/* unhalt/run all applicable cores */
> +	if (cluster->mode) {
> +		list_for_each_entry_reverse(core, &cluster->cores, elem) {
> +			ret = k3_r5_core_run(core);
> +			if (ret)
> +				goto unroll_core_run;
> +		}
> +	} else {
> +		ret = k3_r5_core_run(core);
> +		if (ret)
> +			goto put_mbox;
> +	}
> +
> +	return 0;
> +
> +unroll_core_run:
> +	list_for_each_entry_continue(core, &cluster->cores, elem) {
> +		if (k3_r5_core_halt(core))
> +			dev_warn(core->dev, "core halt back failed\n");
> +	}
> +put_mbox:
> +	mbox_free_channel(kproc->mbox);
> +	return ret;
> +}
> +
> +/*
> + * The R5F stop function includes the following operations
> + * 1. Halt R5F core(s)
> + *
> + * The sequence is different between LockStep and Split modes, and the order
> + * of cores the operations are performed are also in general reverse to that
> + * of the start function. The LockStep mode requires each operation to be
> + * performed first on Core0 followed by Core1. The Split-mode requires that
> + * Core0 to be maintained always in a higher power state that Core1 (implying
> + * Core1 needs to be stopped first before Core0).
> + *
> + * Note that the R5F halt operation in general is not effective when the R5F
> + * core is running, but is needed to make sure the core won't run after
> + * deasserting the reset the subsequent time. The asserting of reset can
> + * be done here, but is preferred to be done in the .unprepare() ops - this
> + * maintains the symmetric behavior between the .start(), .stop(), .prepare()
> + * and .unprepare() ops, and also balances them well between sysfs 'state'
> + * flow and device bind/unbind or module removal.
> + */
> +static int k3_r5_rproc_stop(struct rproc *rproc)
> +{
> +	struct k3_r5_rproc *kproc = rproc->priv;
> +	struct k3_r5_cluster *cluster = kproc->cluster;
> +	struct k3_r5_core *core = kproc->core;
> +	int ret;
> +
> +	/* halt all applicable cores */
> +	if (cluster->mode) {
> +		list_for_each_entry(core, &cluster->cores, elem) {
> +			ret = k3_r5_core_halt(core);
> +			if (ret) {
> +				core = list_prev_entry(core, elem);
> +				goto unroll_core_halt;
> +			}
> +		}
> +	} else {
> +		ret = k3_r5_core_halt(core);
> +		if (ret)
> +			goto out;
> +	}
> +
> +	mbox_free_channel(kproc->mbox);
> +
> +	return 0;
> +
> +unroll_core_halt:
> +	list_for_each_entry_from_reverse(core, &cluster->cores, elem) {
> +		if (k3_r5_core_run(core))
> +			dev_warn(core->dev, "core run back failed\n");
> +	}
> +out:
> +	return ret;
> +}
> +
> +/*
> + * Internal Memory translation helper
> + *
> + * Custom function implementing the rproc .da_to_va ops to provide address
> + * translation (device address to kernel virtual address) for internal RAMs
> + * present in a DSP or IPU device). The translated addresses can be used
> + * either by the remoteproc core for loading, or by any rpmsg bus drivers.
> + */
> +static void *k3_r5_rproc_da_to_va(struct rproc *rproc, u64 da, size_t len)
> +{
> +	struct k3_r5_rproc *kproc = rproc->priv;
> +	struct k3_r5_core *core = kproc->core;
> +	void __iomem *va = NULL;
> +	phys_addr_t bus_addr;
> +	u32 dev_addr, offset;
> +	size_t size;
> +	int i;
> +
> +	if (len == 0)
> +		return NULL;
> +
> +	/* handle both R5 and SoC views of ATCM and BTCM */
> +	for (i = 0; i < core->num_mems; i++) {
> +		bus_addr = core->mem[i].bus_addr;
> +		dev_addr = core->mem[i].dev_addr;
> +		size = core->mem[i].size;
> +
> +		/* handle R5-view addresses of TCMs */
> +		if (da >= dev_addr && ((da + len) <= (dev_addr + size))) {
> +			offset = da - dev_addr;
> +			va = core->mem[i].cpu_addr + offset;
> +			return (__force void *)va;
> +		}
> +
> +		/* handle SoC-view addresses of TCMs */
> +		if (da >= bus_addr && ((da + len) <= (bus_addr + size))) {
> +			offset = da - bus_addr;
> +			va = core->mem[i].cpu_addr + offset;
> +			return (__force void *)va;
> +		}
> +	}
> +
> +	/* handle static DDR reserved memory regions */
> +	for (i = 0; i < kproc->num_rmems; i++) {
> +		dev_addr = kproc->rmem[i].dev_addr;
> +		size = kproc->rmem[i].size;
> +
> +		if (da >= dev_addr && ((da + len) <= (dev_addr + size))) {
> +			offset = da - dev_addr;
> +			va = kproc->rmem[i].cpu_addr + offset;
> +			return (__force void *)va;
> +		}
> +	}
> +
> +	return NULL;
> +}
> +
> +static const struct rproc_ops k3_r5_rproc_ops = {
> +	.prepare	= k3_r5_rproc_prepare,
> +	.unprepare	= k3_r5_rproc_unprepare,
> +	.start		= k3_r5_rproc_start,
> +	.stop		= k3_r5_rproc_stop,
> +	.kick		= k3_r5_rproc_kick,
> +	.da_to_va	= k3_r5_rproc_da_to_va,
> +};
> +
> +static const char *k3_r5_rproc_get_firmware(struct device *dev)
> +{
> +	const char *fw_name;
> +	int ret;
> +
> +	ret = of_property_read_string(dev->of_node, "firmware-name",
> +				      &fw_name);
> +	if (ret) {
> +		dev_err(dev, "failed to parse firmware-name property, ret = %d\n",
> +			ret);
> +		return ERR_PTR(ret);
> +	}
> +
> +	return fw_name;
> +}
> +
> +static int k3_r5_rproc_configure(struct k3_r5_rproc *kproc)
> +{
> +	struct k3_r5_cluster *cluster = kproc->cluster;
> +	struct device *dev = kproc->dev;
> +	struct k3_r5_core *core0, *core, *temp;
> +	u32 ctrl = 0, cfg = 0, stat = 0;
> +	u32 set_cfg = 0, clr_cfg = 0;
> +	u64 boot_vec = 0;
> +	bool lockstep_en;
> +	int ret;
> +
> +	core0 = list_first_entry(&cluster->cores, struct k3_r5_core, elem);
> +	core = cluster->mode ? core0 : kproc->core;
> +
> +	ret = ti_sci_proc_get_status(core->tsp, &boot_vec, &cfg, &ctrl,
> +				     &stat);
> +	if (ret < 0)
> +		return ret;
> +
> +	dev_dbg(dev, "boot_vector = 0x%llx, cfg = 0x%x ctrl = 0x%x stat = 0x%x\n",
> +		boot_vec, cfg, ctrl, stat);
> +
> +	lockstep_en = !!(stat & PROC_BOOT_STATUS_FLAG_R5_LOCKSTEP_PERMITTED);
> +	if (!lockstep_en && cluster->mode) {
> +		dev_err(cluster->dev, "lockstep mode not permitted, force configuring for split-mode\n");
> +		cluster->mode = 0;
> +	}
> +
> +	/* always enable ARM mode and set boot vector to 0 */
> +	boot_vec = 0x0;
> +	if (core == core0) {
> +		clr_cfg = PROC_BOOT_CFG_FLAG_R5_TEINIT;
> +		/*
> +		 * LockStep configuration bit is Read-only on Split-mode _only_
> +		 * devices and system firmware will NACK any requests with the
> +		 * bit configured, so program it only on permitted devices
> +		 */
> +		if (lockstep_en)
> +			clr_cfg |= PROC_BOOT_CFG_FLAG_R5_LOCKSTEP;
> +	}
> +
> +	if (core->atcm_enable)
> +		set_cfg |= PROC_BOOT_CFG_FLAG_R5_ATCM_EN;
> +	else
> +		clr_cfg |= PROC_BOOT_CFG_FLAG_R5_ATCM_EN;
> +
> +	if (core->btcm_enable)
> +		set_cfg |= PROC_BOOT_CFG_FLAG_R5_BTCM_EN;
> +	else
> +		clr_cfg |= PROC_BOOT_CFG_FLAG_R5_BTCM_EN;
> +
> +	if (core->loczrama)
> +		set_cfg |= PROC_BOOT_CFG_FLAG_R5_TCM_RSTBASE;
> +	else
> +		clr_cfg |= PROC_BOOT_CFG_FLAG_R5_TCM_RSTBASE;
> +
> +	if (cluster->mode) {
> +		/*
> +		 * work around system firmware limitations to make sure both
> +		 * cores are programmed symmetrically in LockStep. LockStep
> +		 * and TEINIT config is only allowed with Core0.
> +		 */
> +		list_for_each_entry(temp, &cluster->cores, elem) {
> +			ret = k3_r5_core_halt(core);
> +			if (ret)
> +				goto out;
> +
> +			if (temp != core) {
> +				clr_cfg &= ~PROC_BOOT_CFG_FLAG_R5_LOCKSTEP;
> +				clr_cfg &= ~PROC_BOOT_CFG_FLAG_R5_TEINIT;
> +			}
> +			ret = ti_sci_proc_set_config(temp->tsp, boot_vec,
> +						     set_cfg, clr_cfg);
> +			if (ret)
> +				goto out;
> +		}
> +
> +		set_cfg = PROC_BOOT_CFG_FLAG_R5_LOCKSTEP;
> +		clr_cfg = 0;
> +		ret = ti_sci_proc_set_config(core->tsp, boot_vec,
> +					     set_cfg, clr_cfg);
> +	} else {
> +		ret = k3_r5_core_halt(core);
> +		if (ret)
> +			goto out;
> +
> +		ret = ti_sci_proc_set_config(core->tsp, boot_vec,
> +					     set_cfg, clr_cfg);
> +	}
> +
> +out:
> +	return ret;
> +}
> +
> +static int k3_r5_reserved_mem_init(struct k3_r5_rproc *kproc)
> +{
> +	struct device *dev = kproc->dev;
> +	struct device_node *np = dev->of_node;
> +	struct device_node *rmem_np;
> +	struct reserved_mem *rmem;
> +	int num_rmems;
> +	int ret, i;
> +
> +	num_rmems = of_property_count_elems_of_size(np, "memory-region",
> +						    sizeof(phandle));
> +	if (num_rmems <= 0) {
> +		dev_err(dev, "device does not have reserved memory regions, ret = %d\n",
> +			num_rmems);
> +		return -EINVAL;
> +	}
> +	if (num_rmems < 2) {
> +		dev_err(dev, "device needs atleast two memory regions to be defined, num = %d\n",
> +			num_rmems);
> +		return -EINVAL;
> +	}
> +
> +	/* use reserved memory region 0 for vring DMA allocations */
> +	ret = of_reserved_mem_device_init_by_idx(dev, np, 0);
> +	if (ret) {
> +		dev_err(dev, "device cannot initialize DMA pool, ret = %d\n",
> +			ret);
> +		return ret;
> +	}
> +
> +	num_rmems--;
> +	kproc->rmem = kcalloc(num_rmems, sizeof(*kproc->rmem), GFP_KERNEL);
> +	if (!kproc->rmem) {
> +		ret = -ENOMEM;
> +		goto release_rmem;
> +	}
> +
> +	/* use remaining reserved memory regions for static carveouts */
> +	for (i = 0; i < num_rmems; i++) {
> +		rmem_np = of_parse_phandle(np, "memory-region", i + 1);
> +		if (!rmem_np) {
> +			ret = -EINVAL;
> +			goto unmap_rmem;
> +		}
> +
> +		rmem = of_reserved_mem_lookup(rmem_np);
> +		if (!rmem) {
> +			of_node_put(rmem_np);
> +			ret = -EINVAL;
> +			goto unmap_rmem;
> +		}
> +		of_node_put(rmem_np);
> +
> +		kproc->rmem[i].bus_addr = rmem->base;
> +		/* 64-bit address regions currently not supported */
> +		kproc->rmem[i].dev_addr = (u32)rmem->base;

Because the bus and the device addresses are the same I have to deduce the AP
and the R5 have the same view of the memory.  Please add a comment to assert
that is really the case.

> +		kproc->rmem[i].size = rmem->size;
> +		kproc->rmem[i].cpu_addr = ioremap_wc(rmem->base, rmem->size);
> +		if (!kproc->rmem[i].cpu_addr) {
> +			dev_err(dev, "failed to map reserved memory#%d at %pa of size %pa\n",
> +				i + 1, &rmem->base, &rmem->size);
> +			ret = -ENOMEM;
> +			goto unmap_rmem;
> +		}
> +
> +		dev_dbg(dev, "reserved memory%d: bus addr %pa size 0x%zx va %pK da 0x%x\n",
> +			i + 1, &kproc->rmem[i].bus_addr,
> +			kproc->rmem[i].size, kproc->rmem[i].cpu_addr,
> +			kproc->rmem[i].dev_addr);
> +	}
> +	kproc->num_rmems = num_rmems;
> +
> +	return 0;
> +
> +unmap_rmem:
> +	for (i--; i >= 0; i--) {
> +		if (kproc->rmem[i].cpu_addr)
> +			iounmap(kproc->rmem[i].cpu_addr);
> +	}
> +	kfree(kproc->rmem);
> +release_rmem:
> +	of_reserved_mem_device_release(dev);
> +	return ret;
> +}
> +
> +static void k3_r5_reserved_mem_exit(struct k3_r5_rproc *kproc)
> +{
> +	int i;
> +
> +	for (i = 0; i < kproc->num_rmems; i++)
> +		iounmap(kproc->rmem[i].cpu_addr);
> +	kfree(kproc->rmem);
> +
> +	of_reserved_mem_device_release(kproc->dev);
> +}
> +
> +static int k3_r5_cluster_rproc_init(struct platform_device *pdev)
> +{
> +	struct k3_r5_cluster *cluster = platform_get_drvdata(pdev);
> +	struct device *dev = &pdev->dev;
> +	struct k3_r5_rproc *kproc;
> +	struct k3_r5_core *core, *core1;
> +	struct device *cdev;
> +	const char *fw_name;
> +	struct rproc *rproc;
> +	int ret;
> +
> +	core1 = list_last_entry(&cluster->cores, struct k3_r5_core, elem);
> +	list_for_each_entry(core, &cluster->cores, elem) {
> +		cdev = core->dev;
> +		fw_name = k3_r5_rproc_get_firmware(cdev);
> +		if (IS_ERR(fw_name)) {
> +			ret = PTR_ERR(fw_name);
> +			goto out;
> +		}
> +
> +		rproc = rproc_alloc(cdev, dev_name(cdev), &k3_r5_rproc_ops,
> +				    fw_name, sizeof(*kproc));
> +		if (!rproc) {
> +			ret = -ENOMEM;
> +			goto out;
> +		}
> +
> +		/* K3 R5s have a Region Address Translator (RAT) but no MMU */
> +		rproc->has_iommu = false;
> +		/* error recovery is not supported at present */
> +		rproc->recovery_disabled = true;
> +
> +		kproc = rproc->priv;
> +		kproc->cluster = cluster;
> +		kproc->core = core;
> +		kproc->dev = cdev;
> +		kproc->rproc = rproc;
> +		core->rproc = rproc;
> +
> +		ret = k3_r5_rproc_configure(kproc);
> +		if (ret) {
> +			dev_err(dev, "initial configure failed, ret = %d\n",
> +				ret);
> +			goto err_config;
> +		}
> +
> +		ret = k3_r5_reserved_mem_init(kproc);
> +		if (ret) {
> +			dev_err(dev, "reserved memory init failed, ret = %d\n",
> +				ret);
> +			goto err_config;
> +		}
> +
> +		ret = rproc_add(rproc);
> +		if (ret) {
> +			dev_err(dev, "rproc_add failed, ret = %d\n", ret);
> +			goto err_add;
> +		}
> +
> +		/* create only one rproc in lockstep mode */
> +		if (cluster->mode)
> +			break;
> +	}
> +
> +	return 0;
> +
> +err_split:
> +	rproc_del(rproc);
> +err_add:
> +	k3_r5_reserved_mem_exit(kproc);
> +err_config:
> +	rproc_free(rproc);
> +	core->rproc = NULL;
> +out:
> +	/* undo core0 upon any failures on core1 in split-mode */
> +	if (!cluster->mode && core == core1) {
> +		core = list_prev_entry(core, elem);
> +		rproc = core->rproc;
> +		kproc = rproc->priv;
> +		goto err_split;
> +	}
> +	return ret;
> +}
> +
> +static int k3_r5_cluster_rproc_exit(struct platform_device *pdev)
> +{
> +	struct k3_r5_cluster *cluster = platform_get_drvdata(pdev);
> +	struct k3_r5_rproc *kproc;
> +	struct k3_r5_core *core;
> +	struct rproc *rproc;
> +
> +	/*
> +	 * lockstep mode has only one rproc associated with first core, whereas
> +	 * split-mode has two rprocs associated with each core, and requires
> +	 * that core1 be powered down first
> +	 */
> +	core = cluster->mode ?
> +		list_first_entry(&cluster->cores, struct k3_r5_core, elem) :
> +		list_last_entry(&cluster->cores, struct k3_r5_core, elem);
> +
> +	list_for_each_entry_from_reverse(core, &cluster->cores, elem) {
> +		rproc = core->rproc;
> +		kproc = rproc->priv;
> +
> +		rproc_del(rproc);
> +
> +		k3_r5_reserved_mem_exit(kproc);
> +
> +		rproc_free(rproc);
> +		core->rproc = NULL;
> +	}
> +
> +	return 0;
> +}
> +
> +static int k3_r5_core_of_get_internal_memories(struct platform_device *pdev,
> +					       struct k3_r5_core *core)
> +{
> +	static const char * const mem_names[] = {"atcm", "btcm"};
> +	struct device *dev = &pdev->dev;
> +	struct resource *res;
> +	int num_mems;
> +	int i, ret;
> +
> +	num_mems = ARRAY_SIZE(mem_names);
> +	core->mem = devm_kcalloc(dev, num_mems, sizeof(*core->mem), GFP_KERNEL);
> +	if (!core->mem)
> +		return -ENOMEM;
> +
> +	for (i = 0; i < num_mems; i++) {
> +		res = platform_get_resource_byname(pdev, IORESOURCE_MEM,
> +						   mem_names[i]);
> +		if (!res) {
> +			dev_err(dev, "found no memory resource for %s\n",
> +				mem_names[i]);
> +			ret = -EINVAL;
> +			goto fail;
> +		}
> +		if (!devm_request_mem_region(dev, res->start,
> +					     resource_size(res),
> +					     dev_name(dev))) {
> +			dev_err(dev, "could not request %s region for resource\n",
> +				mem_names[i]);
> +			ret = -EBUSY;
> +			goto fail;
> +		}
> +
> +		/*
> +		 * TCMs are designed in general to support RAM-like backing
> +		 * memories. So, map these as Normal Non-Cached memories. This
> +		 * also avoids/fixes any potential alignment faults due to
> +		 * unaligned data accesses when using memcpy() or memset()
> +		 * functions (normally seen with device type memory).
> +		 */
> +		core->mem[i].cpu_addr = devm_ioremap_wc(dev, res->start,
> +							resource_size(res));
> +		if (IS_ERR(core->mem[i].cpu_addr)) {
> +			dev_err(dev, "failed to map %s memory\n", mem_names[i]);
> +			ret = PTR_ERR(core->mem[i].cpu_addr);
> +			devm_release_mem_region(dev, res->start,
> +						resource_size(res));
> +			goto fail;
> +		}
> +		core->mem[i].bus_addr = res->start;
> +
> +		/*
> +		 * TODO:
> +		 * The R5F cores can place ATCM & BTCM anywhere in its address
> +		 * based on the corresponding Region Registers in the System
> +		 * Control coprocessor. For now, place ATCM and BTCM at
> +		 * addresses 0 and 0x41010000 (same as the bus address on AM65x
> +		 * SoCs) based on loczrama setting
> +		 */
> +		if (!strcmp(mem_names[i], "atcm")) {
> +			core->mem[i].dev_addr = core->loczrama ?
> +							0 : K3_R5_TCM_DEV_ADDR;
> +		} else {
> +			core->mem[i].dev_addr = core->loczrama ?
> +							K3_R5_TCM_DEV_ADDR : 0;
> +		}
> +		core->mem[i].size = resource_size(res);
> +
> +		dev_dbg(dev, "memory %8s: bus addr %pa size 0x%zx va %pK da 0x%x\n",
> +			mem_names[i], &core->mem[i].bus_addr,
> +			core->mem[i].size, core->mem[i].cpu_addr,
> +			core->mem[i].dev_addr);
> +	}
> +	core->num_mems = num_mems;
> +
> +	return 0;
> +
> +fail:
> +	for (i--; i >= 0; i--) {
> +		devm_iounmap(dev, core->mem[i].cpu_addr);
> +		devm_release_mem_region(dev, core->mem[i].bus_addr,
> +					core->mem[i].size);
> +	}
> +	if (core->mem)
> +		devm_kfree(dev, core->mem);
> +	return ret;
> +}
> +
> +static
> +struct ti_sci_proc *k3_r5_core_of_get_tsp(struct device *dev,
> +					  const struct ti_sci_handle *sci)
> +{
> +	struct ti_sci_proc *tsp;
> +	u32 temp[2];
> +	int ret;
> +
> +	ret = of_property_read_u32_array(dev->of_node, "ti,sci-proc-ids",
> +					 temp, 2);
> +	if (ret < 0)
> +		return ERR_PTR(ret);
> +
> +	tsp = kzalloc(sizeof(*tsp), GFP_KERNEL);
> +	if (!tsp)
> +		return ERR_PTR(-ENOMEM);
> +
> +	tsp->dev = dev;
> +	tsp->sci = sci;
> +	tsp->ops = &sci->ops.proc_ops;
> +	tsp->proc_id = temp[0];
> +	tsp->host_id = temp[1];
> +
> +	return tsp;
> +}
> +
> +static int k3_r5_core_of_init(struct platform_device *pdev)
> +{
> +	struct device *dev = &pdev->dev;
> +	struct device_node *np = dev->of_node;
> +	struct k3_r5_core *core;
> +	int ret, ret1;
> +
> +	core = devm_kzalloc(dev, sizeof(*core), GFP_KERNEL);
> +	if (!core)
> +		return -ENOMEM;
> +
> +	core->dev = dev;
> +	core->atcm_enable = 0;
> +	core->btcm_enable = 1;
> +	core->loczrama = 1;
> +
> +	ret = of_property_read_u32(np, "atcm-enable", &core->atcm_enable);
> +	if (ret < 0 && ret != -EINVAL) {
> +		dev_err(dev, "invalid format for atcm-enable, ret = %d\n", ret);
> +		goto err_of;
> +	}
> +
> +	ret = of_property_read_u32(np, "btcm-enable", &core->btcm_enable);
> +	if (ret < 0 && ret != -EINVAL) {
> +		dev_err(dev, "invalid format for btcm-enable, ret = %d\n", ret);
> +		goto err_of;
> +	}
> +
> +	ret = of_property_read_u32(np, "loczrama", &core->loczrama);
> +	if (ret < 0 && ret != -EINVAL) {
> +		dev_err(dev, "invalid format for loczrama, ret = %d\n", ret);
> +		goto err_of;
> +	}
> +
> +	core->ti_sci = ti_sci_get_by_phandle(np, "ti,sci");
> +	if (IS_ERR(core->ti_sci)) {
> +		ret = PTR_ERR(core->ti_sci);
> +		if (ret != -EPROBE_DEFER) {
> +			dev_err(dev, "failed to get ti-sci handle, ret = %d\n",
> +				ret);
> +		}
> +		core->ti_sci = NULL;
> +		goto err_of;
> +	}
> +
> +	ret = of_property_read_u32(np, "ti,sci-dev-id", &core->ti_sci_id);
> +	if (ret) {
> +		dev_err(dev, "missing 'ti,sci-dev-id' property\n");
> +		goto err_sci_id;
> +	}
> +
> +	core->reset = reset_control_get_exclusive(dev, NULL);
> +	if (IS_ERR(core->reset)) {
> +		ret = PTR_ERR(core->reset);
> +		if (ret != -EPROBE_DEFER) {
> +			dev_err(dev, "failed to get reset handle, ret = %d\n",
> +				ret);
> +		}
> +		goto err_sci_id;
> +	}
> +
> +	core->tsp = k3_r5_core_of_get_tsp(dev, core->ti_sci);
> +	if (IS_ERR(core->tsp)) {
> +		dev_err(dev, "failed to construct ti-sci proc control, ret = %d\n",
> +			ret);
> +		ret = PTR_ERR(core->tsp);
> +		goto err_sci_proc;
> +	}
> +
> +	ret = ti_sci_proc_request(core->tsp);
> +	if (ret < 0) {
> +		dev_err(dev, "ti_sci_proc_request failed, ret = %d\n", ret);
> +		goto err_proc;
> +	}
> +
> +	ret = k3_r5_core_of_get_internal_memories(pdev, core);
> +	if (ret) {
> +		dev_err(dev, "failed to get internal memories, ret = %d\n",
> +			ret);
> +		goto err_intmem;
> +	}
> +
> +	platform_set_drvdata(pdev, core);
> +
> +	return 0;
> +
> +err_intmem:
> +	ret1 = ti_sci_proc_release(core->tsp);
> +	if (ret1)
> +		dev_err(dev, "failed to release proc, ret1 = %d\n", ret1);
> +err_proc:
> +	kfree(core->tsp);
> +err_sci_proc:
> +	reset_control_put(core->reset);
> +err_sci_id:
> +	ret1 = ti_sci_put_handle(core->ti_sci);
> +	if (ret1)
> +		dev_err(dev, "failed to put ti_sci handle, ret = %d\n", ret1);
> +err_of:
> +	devm_kfree(dev, core);
> +	return ret;
> +}
> +
> +/*
> + * free the resources explicitly since driver model is not being used
> + * for the child R5F devices
> + */
> +static int k3_r5_core_of_exit(struct platform_device *pdev)
> +{
> +	struct k3_r5_core *core = platform_get_drvdata(pdev);
> +	struct device *dev = &pdev->dev;
> +	int i, ret;
> +
> +	for (i = 0; i < core->num_mems; i++) {
> +		devm_release_mem_region(dev, core->mem[i].bus_addr,
> +					core->mem[i].size);
> +		devm_iounmap(dev, core->mem[i].cpu_addr);
> +	}
> +	if (core->mem)
> +		devm_kfree(dev, core->mem);
> +
> +	ret = ti_sci_proc_release(core->tsp);
> +	if (ret)
> +		dev_err(dev, "failed to release proc, ret = %d\n", ret);
> +
> +	kfree(core->tsp);
> +	reset_control_put(core->reset);
> +
> +	ret = ti_sci_put_handle(core->ti_sci);
> +	if (ret)
> +		dev_err(dev, "failed to put ti_sci handle, ret = %d\n", ret);
> +
> +	platform_set_drvdata(pdev, NULL);
> +	devm_kfree(dev, core);
> +
> +	return ret;
> +}
> +
> +static int k3_r5_cluster_of_init(struct platform_device *pdev)
> +{
> +	struct k3_r5_cluster *cluster = platform_get_drvdata(pdev);
> +	struct device *dev = &pdev->dev;
> +	struct device_node *np = dev->of_node;
> +	struct platform_device *cpdev;
> +	struct device_node *child;
> +	struct k3_r5_core *core, *temp;
> +	int ret;
> +
> +	for_each_available_child_of_node(np, child) {
> +		cpdev = of_find_device_by_node(child);
> +		if (!cpdev) {
> +			ret = -ENODEV;
> +			dev_err(dev, "could not get R5 core platform device\n");
> +			goto fail;
> +		}
> +
> +		ret = k3_r5_core_of_init(cpdev);
> +		if (ret) {
> +			dev_err(dev, "k3_r5_core_of_init failed, ret = %d\n",
> +				ret);
> +			put_device(&cpdev->dev);
> +			goto fail;
> +		}
> +
> +		core = platform_get_drvdata(cpdev);
> +		put_device(&cpdev->dev);
> +		list_add_tail(&core->elem, &cluster->cores);
> +	}
> +
> +	return 0;
> +
> +fail:
> +	list_for_each_entry_safe_reverse(core, temp, &cluster->cores, elem) {
> +		list_del(&core->elem);
> +		cpdev = to_platform_device(core->dev);
> +		if (k3_r5_core_of_exit(cpdev))
> +			dev_err(dev, "k3_r5_core_of_exit cleanup failed\n");
> +	}
> +	return ret;
> +}
> +
> +static int k3_r5_cluster_of_exit(struct platform_device *pdev)
> +{
> +	struct k3_r5_cluster *cluster = platform_get_drvdata(pdev);
> +	struct device *dev = &pdev->dev;
> +	struct platform_device *cpdev;
> +	struct k3_r5_core *core, *temp;
> +	int ret;
> +
> +	list_for_each_entry_safe_reverse(core, temp, &cluster->cores, elem) {
> +		list_del(&core->elem);
> +		cpdev = to_platform_device(core->dev);
> +		ret = k3_r5_core_of_exit(cpdev);
> +		if (ret) {
> +			dev_err(dev, "k3_r5_core_of_exit failed, ret = %d\n",
> +				ret);
> +			break;
> +		}
> +	}
> +
> +	return ret;
> +}
> +
> +static int k3_r5_probe(struct platform_device *pdev)
> +{
> +	struct device *dev = &pdev->dev;
> +	struct device_node *np = dev->of_node;
> +	struct k3_r5_cluster *cluster;
> +	int ret, ret1;
> +	int num_cores;
> +
> +	cluster = devm_kzalloc(dev, sizeof(*cluster), GFP_KERNEL);
> +	if (!cluster)
> +		return -ENOMEM;
> +
> +	cluster->dev = dev;
> +	cluster->mode = CLUSTER_MODE_LOCKSTEP;
> +	INIT_LIST_HEAD(&cluster->cores);
> +
> +	ret = of_property_read_u32(np, "lockstep-mode", &cluster->mode);
> +	if (ret < 0 && ret != -EINVAL) {
> +		dev_err(dev, "invalid format for lockstep-mode, ret = %d\n",
> +			ret);
> +		return ret;
> +	}
> +
> +	num_cores = of_get_available_child_count(np);
> +	if (num_cores != 2) {
> +		dev_err(dev, "MCU cluster requires both R5F cores to be enabled, num_cores = %d\n",
> +			num_cores);
> +		return -ENODEV;
> +	}
> +
> +	platform_set_drvdata(pdev, cluster);
> +
> +	dev_dbg(dev, "creating child devices for R5F cores\n");
> +	ret = of_platform_populate(np, NULL, NULL, dev);
> +	if (ret) {
> +		dev_err(dev, "of_platform_populate failed, ret = %d\n", ret);
> +		return ret;
> +	}
> +
> +	ret = k3_r5_cluster_of_init(pdev);
> +	if (ret) {
> +		dev_err(dev, "k3_r5_cluster_of_init failed, ret = %d\n", ret);
> +		goto fail_of;
> +	}
> +
> +	ret = k3_r5_cluster_rproc_init(pdev);
> +	if (ret) {
> +		dev_err(dev, "k3_r5_cluster_rproc_init failed, ret = %d\n",
> +			ret);
> +		goto fail_rproc;
> +	}
> +
> +	return 0;
> +
> +fail_rproc:
> +	ret1 = k3_r5_cluster_of_exit(pdev);
> +	if (ret1)
> +		dev_err(dev, "k3_r5_cluster_of_exit failed, ret = %d\n", ret1);
> +fail_of:
> +	of_platform_depopulate(dev);
> +	return ret;
> +}
> +
> +static int k3_r5_remove(struct platform_device *pdev)
> +{
> +	struct device *dev = &pdev->dev;
> +	int ret;
> +
> +	ret = k3_r5_cluster_rproc_exit(pdev);
> +	if (ret) {
> +		dev_err(dev, "k3_r5_cluster_rproc_exit failed, ret = %d\n",
> +			ret);
> +		goto fail;
> +	}
> +
> +	ret = k3_r5_cluster_of_exit(pdev);
> +	if (ret) {
> +		dev_err(dev, "k3_r5_cluster_of_exit failed, ret = %d\n", ret);
> +		goto fail;
> +	}
> +
> +	dev_dbg(dev, "removing child devices for R5F cores\n");
> +	of_platform_depopulate(dev);
> +
> +fail:
> +	return ret;
> +}
> +
> +static const struct of_device_id k3_r5_of_match[] = {
> +	{ .compatible = "ti,am654-r5fss", },
> +	{ .compatible = "ti,j721e-r5fss", },
> +	{ /* sentinel */ },
> +};
> +MODULE_DEVICE_TABLE(of, k3_r5_of_match);
> +
> +static struct platform_driver k3_r5_rproc_driver = {
> +	.probe = k3_r5_probe,
> +	.remove = k3_r5_remove,
> +	.driver = {
> +		.name = "k3_r5_rproc",
> +		.of_match_table = k3_r5_of_match,
> +	},
> +};
> +
> +module_platform_driver(k3_r5_rproc_driver);
> +
> +MODULE_LICENSE("GPL v2");
> +MODULE_DESCRIPTION("TI K3 R5F remote processor driver");
> +MODULE_AUTHOR("Suman Anna <s-anna@ti.com>");
> -- 
> 2.23.0
>

On Tue, Mar 24, 2020 at 03:18:18PM -0500, Suman Anna wrote:
> The R5F processors on K3 SoCs all have two TCMs (ATCM and BTCM) that
> support 32-bit ECC. The TCMs are typically loaded with some boot-up
> code to initialize the R5 MPUs to further execute code out of DDR.
> The ECC for the TCMs is enabled by default on K3 SoCs due to internal
> default tie-off values, but the TCM memories are not initialized on
> device power up. Any read access without the corresponding TCM memory
> location initialized will generate an ECC error, and any such access
> from a A72 or A53 core will trigger a SError.
> 
> So, zero initialize both the TCM memories before loading any firmware
> onto a R5F in remoteproc mode. Any R5F booted from U-Boot/SPL would
> require a similar initialization in the bootloader. Note that both
> the TCMs are initialized unconditionally as the TCM enable config bits
> only manage the access and visibility from R5. The Core1 TCMs are not
> used and accessible in LockStep mode, so they are only initialized
> in Split-mode.

Everything was going well with this changelog until the last sentence.
Intuitively one is looking for the code that avoids the initialisation for
"Core1" in the patch but it is not there, and rightly so.  In locksetup mode the
second core is not registered with the remoteproc core and as such the
associated TCMs won't be initialised.

Simply put, I would just remove the last sentence as all it does (at least for
me) is add confusion.

With that:

Acked-by: Mathieu Poirier <mathieu.poirier@linaro.org>

> 
> Signed-off-by: Suman Anna <s-anna@ti.com>
> ---
>  drivers/remoteproc/ti_k3_r5_remoteproc.c | 11 +++++++++++
>  1 file changed, 11 insertions(+)
> 
> diff --git a/drivers/remoteproc/ti_k3_r5_remoteproc.c b/drivers/remoteproc/ti_k3_r5_remoteproc.c
> index 655f8f14c37d..8c9b7ae5d8b7 100644
> --- a/drivers/remoteproc/ti_k3_r5_remoteproc.c
> +++ b/drivers/remoteproc/ti_k3_r5_remoteproc.c
> @@ -366,6 +366,17 @@ static int k3_r5_rproc_prepare(struct rproc *rproc)
>  		dev_err(dev, "unable to enable cores for TCM loading, ret = %d\n",
>  			ret);
>  
> +	/*
> +	 * Zero out both TCMs unconditionally (access from v8 Arm core is not
> +	 * affected by ATCM & BTCM enable configuration values) so that ECC
> +	 * can be effective on all TCM addresses.
> +	 */
> +	dev_dbg(dev, "zeroing out ATCM memory\n");
> +	memset(core->mem[0].cpu_addr, 0x00, core->mem[0].size);
> +
> +	dev_dbg(dev, "zeroing out BTCM memory\n");
> +	memset(core->mem[1].cpu_addr, 0x00, core->mem[1].size);
> +
>  	return ret;
>  }
>  
> -- 
> 2.23.0
>

On 4/9/20 4:36 PM, Mathieu Poirier wrote:
> On Tue, Mar 24, 2020 at 03:18:18PM -0500, Suman Anna wrote:
>> The R5F processors on K3 SoCs all have two TCMs (ATCM and BTCM) that
>> support 32-bit ECC. The TCMs are typically loaded with some boot-up
>> code to initialize the R5 MPUs to further execute code out of DDR.
>> The ECC for the TCMs is enabled by default on K3 SoCs due to internal
>> default tie-off values, but the TCM memories are not initialized on
>> device power up. Any read access without the corresponding TCM memory
>> location initialized will generate an ECC error, and any such access
>> from a A72 or A53 core will trigger a SError.
>>
>> So, zero initialize both the TCM memories before loading any firmware
>> onto a R5F in remoteproc mode. Any R5F booted from U-Boot/SPL would
>> require a similar initialization in the bootloader. Note that both
>> the TCMs are initialized unconditionally as the TCM enable config bits
>> only manage the access and visibility from R5. The Core1 TCMs are not
>> used and accessible in LockStep mode, so they are only initialized
>> in Split-mode.
> 
> Everything was going well with this changelog until the last sentence.
> Intuitively one is looking for the code that avoids the initialisation for
> "Core1" in the patch but it is not there, and rightly so.  In locksetup mode the
> second core is not registered with the remoteproc core and as such the
> associated TCMs won't be initialised.
> 
> Simply put, I would just remove the last sentence as all it does (at least for
> me) is add confusion.

Yep, that was more of a "NOTE: " type comment on overall behavior. I
will drop the sentence for v2.

regards
Suman

> 
> With that:
> 
> Acked-by: Mathieu Poirier <mathieu.poirier@linaro.org>
> 
>>
>> Signed-off-by: Suman Anna <s-anna@ti.com>
>> ---
>>  drivers/remoteproc/ti_k3_r5_remoteproc.c | 11 +++++++++++
>>  1 file changed, 11 insertions(+)
>>
>> diff --git a/drivers/remoteproc/ti_k3_r5_remoteproc.c b/drivers/remoteproc/ti_k3_r5_remoteproc.c
>> index 655f8f14c37d..8c9b7ae5d8b7 100644
>> --- a/drivers/remoteproc/ti_k3_r5_remoteproc.c
>> +++ b/drivers/remoteproc/ti_k3_r5_remoteproc.c
>> @@ -366,6 +366,17 @@ static int k3_r5_rproc_prepare(struct rproc *rproc)
>>  		dev_err(dev, "unable to enable cores for TCM loading, ret = %d\n",
>>  			ret);
>>  
>> +	/*
>> +	 * Zero out both TCMs unconditionally (access from v8 Arm core is not
>> +	 * affected by ATCM & BTCM enable configuration values) so that ECC
>> +	 * can be effective on all TCM addresses.
>> +	 */
>> +	dev_dbg(dev, "zeroing out ATCM memory\n");
>> +	memset(core->mem[0].cpu_addr, 0x00, core->mem[0].size);
>> +
>> +	dev_dbg(dev, "zeroing out BTCM memory\n");
>> +	memset(core->mem[1].cpu_addr, 0x00, core->mem[1].size);
>> +
>>  	return ret;
>>  }
>>  
>> -- 
>> 2.23.0
>>

On Tue, Mar 24, 2020 at 03:18:19PM -0500, Suman Anna wrote:
> The K3 SoCs has various internal on-chip SRAM memories like the SRAM
> within the MCU domain or the shared MSMC RAM within NavSS that can be
> used for multiple purposes. One such purpose is to have the R5F cores
> use a portion of such on-chip SRAM for fast-access data or to directly
> execute code.
> 
> Add support to the K3 R5 remoteproc driver to parse and support
> loading into such memories. The SRAM regions need to be mapped as
> normal non-cacheable memory to avoid kernel crashes when the remoteproc
> loader code uses the Arm64 memset library function (the "DC ZVA"
> instruction throws a alignment fault on device type memory).
> 
> These SRAM regions are completely optional as not all firmware images
> require these memories, and any such memory has to be reserved as such
> in the DTS files.
> 
> Signed-off-by: Suman Anna <s-anna@ti.com>
> ---
>  drivers/remoteproc/ti_k3_r5_remoteproc.c | 106 ++++++++++++++++++++++-
>  1 file changed, 105 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/remoteproc/ti_k3_r5_remoteproc.c b/drivers/remoteproc/ti_k3_r5_remoteproc.c
> index 8c9b7ae5d8b7..0ae0b66ec9eb 100644
> --- a/drivers/remoteproc/ti_k3_r5_remoteproc.c
> +++ b/drivers/remoteproc/ti_k3_r5_remoteproc.c
> @@ -85,7 +85,9 @@ struct k3_r5_cluster {
>   * @dev: cached device pointer
>   * @rproc: rproc handle representing this core
>   * @mem: internal memory regions data
> + * @sram: on-chip SRAM memory regions data
>   * @num_mems: number of internal memory regions
> + * @num_sram: number of on-chip SRAM memory regions
>   * @reset: reset control handle
>   * @tsp: TI-SCI processor control handle
>   * @ti_sci: TI-SCI handle
> @@ -99,7 +101,9 @@ struct k3_r5_core {
>  	struct device *dev;
>  	struct rproc *rproc;
>  	struct k3_r5_mem *mem;
> +	struct k3_r5_mem *sram;
>  	int num_mems;
> +	int num_sram;
>  	struct reset_control *reset;
>  	struct ti_sci_proc *tsp;
>  	const struct ti_sci_handle *ti_sci;
> @@ -585,6 +589,18 @@ static void *k3_r5_rproc_da_to_va(struct rproc *rproc, u64 da, size_t len)
>  		}
>  	}
>  
> +	/* handle any SRAM regions using SoC-view addresses */
> +	for (i = 0; i < core->num_sram; i++) {
> +		dev_addr = core->sram[i].dev_addr;
> +		size = core->sram[i].size;
> +
> +		if (da >= dev_addr && ((da + len) <= (dev_addr + size))) {
> +			offset = da - dev_addr;
> +			va = core->sram[i].cpu_addr + offset;
> +			return (__force void *)va;
> +		}
> +	}
> +
>  	/* handle static DDR reserved memory regions */
>  	for (i = 0; i < kproc->num_rmems; i++) {
>  		dev_addr = kproc->rmem[i].dev_addr;
> @@ -1017,6 +1033,77 @@ static int k3_r5_core_of_get_internal_memories(struct platform_device *pdev,
>  	return ret;
>  }
>  
> +static int k3_r5_core_of_get_sram_memories(struct platform_device *pdev,
> +					   struct k3_r5_core *core)
> +{
> +	struct device_node *np = pdev->dev.of_node;
> +	struct device *dev = &pdev->dev;
> +	struct device_node *sram_np;
> +	struct resource res;
> +	int num_sram;
> +	int i, ret;
> +
> +	num_sram = of_property_count_elems_of_size(np, "sram", sizeof(phandle));
> +	if (num_sram <= 0) {
> +		dev_dbg(dev, "device does not use reserved on-chip memories, num_sram = %d\n",
> +			num_sram);
> +		return 0;
> +	}
> +
> +	core->sram = kcalloc(num_sram, sizeof(*core->sram), GFP_KERNEL);
> +	if (!core->sram)
> +		return -ENOMEM;
> +
> +	for (i = 0; i < num_sram; i++) {
> +		sram_np = of_parse_phandle(np, "sram", i);
> +		if (!sram_np) {
> +			ret = -EINVAL;
> +			goto fail;
> +		}
> +
> +		if (!of_device_is_available(sram_np)) {
> +			of_node_put(sram_np);
> +			ret = -EINVAL;
> +			goto fail;
> +		}
> +
> +		ret = of_address_to_resource(sram_np, 0, &res);
> +		of_node_put(sram_np);
> +		if (ret) {
> +			ret = -EINVAL;
> +			goto fail;
> +		}
> +		core->sram[i].bus_addr = res.start;
> +		core->sram[i].dev_addr = res.start;
> +		core->sram[i].size = resource_size(&res);
> +		core->sram[i].cpu_addr = ioremap_wc(res.start,
> +						    resource_size(&res));
> +		if (!core->sram[i].cpu_addr) {
> +			dev_err(dev, "failed to parse and map sram%d memory at %pad\n",
> +				i, &res.start);
> +			ret = -ENOMEM;
> +			goto fail;
> +		}
> +
> +		dev_dbg(dev, "memory    sram%d: bus addr %pa size 0x%zx va %pK da 0x%x\n",

s/"memory    sram%d:..."/"memory sram%d:..."

With the above:
Acked-by: Mathieu Poirier <mathieu.poirier@linaro.org>

I am done reviewing this set.  Despite the significant amount of material to
process and the comments here and there, I haven't found anything to really
complain about.

Thanks,
Mathieu

> +			i, &core->sram[i].bus_addr,
> +			core->sram[i].size, core->sram[i].cpu_addr,
> +			core->sram[i].dev_addr);
> +	}
> +	core->num_sram = num_sram;
> +
> +	return 0;
> +
> +fail:
> +	for (i--; i >= 0; i--) {
> +		if (core->sram[i].cpu_addr)
> +			iounmap(core->sram[i].cpu_addr);
> +	}
> +	kfree(core->sram);
> +
> +	return ret;
> +}
> +
>  static
>  struct ti_sci_proc *k3_r5_core_of_get_tsp(struct device *dev,
>  					  const struct ti_sci_handle *sci)
> @@ -1048,7 +1135,7 @@ static int k3_r5_core_of_init(struct platform_device *pdev)
>  	struct device *dev = &pdev->dev;
>  	struct device_node *np = dev->of_node;
>  	struct k3_r5_core *core;
> -	int ret, ret1;
> +	int ret, ret1, i;
>  
>  	core = devm_kzalloc(dev, sizeof(*core), GFP_KERNEL);
>  	if (!core)
> @@ -1125,10 +1212,23 @@ static int k3_r5_core_of_init(struct platform_device *pdev)
>  		goto err_intmem;
>  	}
>  
> +	ret = k3_r5_core_of_get_sram_memories(pdev, core);
> +	if (ret) {
> +		dev_err(dev, "failed to get sram memories, ret = %d\n", ret);
> +		goto err_sram;
> +	}
> +
>  	platform_set_drvdata(pdev, core);
>  
>  	return 0;
>  
> +err_sram:
> +	for (i = 0; i < core->num_mems; i++) {
> +		devm_iounmap(dev, core->mem[i].cpu_addr);
> +		devm_release_mem_region(dev, core->mem[i].bus_addr,
> +					core->mem[i].size);
> +	}
> +	devm_kfree(dev, core->mem);
>  err_intmem:
>  	ret1 = ti_sci_proc_release(core->tsp);
>  	if (ret1)
> @@ -1156,6 +1256,10 @@ static int k3_r5_core_of_exit(struct platform_device *pdev)
>  	struct device *dev = &pdev->dev;
>  	int i, ret;
>  
> +	for (i = 0; i < core->num_sram; i++)
> +		iounmap(core->sram[i].cpu_addr);
> +	kfree(core->sram);
> +
>  	for (i = 0; i < core->num_mems; i++) {
>  		devm_release_mem_region(dev, core->mem[i].bus_addr,
>  					core->mem[i].size);
> -- 
> 2.23.0
>

Hi Mathieu,

On 4/8/20 2:38 PM, Mathieu Poirier wrote:
> On Tue, Mar 24, 2020 at 03:18:17PM -0500, Suman Anna wrote:
>> The TI K3 family of SoCs typically have one or more dual-core Arm Cortex
>> R5F processor clusters/subsystems (R5FSS). This R5F subsystem/cluster
>> can be configured at boot time to be either run in a LockStep mode or in
>> an Asymmetric Multi Processing (AMP) fashion in Split-mode. This subsystem
>> has 64 KB each Tightly-Coupled Memory (TCM) internal memories for each
>> core split between two banks - TCMA and TCMB (further interleaved into
>> two banks). The subsystem does not have an MMU, but has a Region Address
>> Translater (RAT) module that is accessible only from the R5Fs for providing
>> translations between 32-bit CPU addresses into larger system bus addresses.
>>
>> Add a remoteproc driver to support this subsystem to be able to load and
>> boot the R5F cores primarily in LockStep mode. The code also includes the
>> base support for Split mode. Error Recovery and Power Management features
>> are not currently supported. Loading support includes the internal TCMs
>> and DDR. RAT support is left for a future patch, and as such the reserved
>> memory carveout regions are all expected to be using memory regions within
>> the first 2 GB.
>>
>> The R5F remote processors do not have an MMU, and so require fixed memory
>> carveout regions matching the firmware image addresses. Support for this
>> is provided by mandating multiple memory regions to be attached to the
>> remoteproc device. The first memory region will be used to serve as the
>> DMA pool for all dynamic allocations like the vrings and vring buffers.
>> The remaining memory regions are mapped into the kernel at device probe
>> time, and are used to provide address translations for firmware image
>> segments without the need for any RSC_CARVEOUT entries. Any firmware
>> image using memory outside of the supplied reserved memory carveout
>> regions will be errored out.
>>
>> The R5F processors on TI K3 SoCs require a specific sequence for booting
>> and shutting down the processors. This sequence is also dependent on the
>> mode (LockStep or Split) the R5F cluster is configured for. The R5F cores
>> have a Memory Protection Unit (MPU) that has a default configuration that
>> does not allow the cores to run out of DDR out of reset. This is resolved
>> by using the TCMs for boot-strapping code that applies the appropriate
>> executable permissions on desired DDR memory. The loading into the TCMs
>> requires that the resets be released first with the cores in halted state.
>> The Power Sleep Controller (PSC) module on K3 SoCs requires that the cores
>> be in WFI/WFE states with no active bus transactions before the cores can
>> be put back into reset. Support for this is provided by using the newly
>> introduced .prepare() and .unprepare() ops in the remoteproc core. The
>> .prepare() ops is invoked before any loading, and the .unprepare() ops
>> is invoked after the remoteproc resource cleanup. The R5F core resets
>> are deasserted in .prepare() and asserted in .unprepare(), and the cores
>> themselves are started and halted in .start() and .stop() ops. This
>> ensures symmetric usage and allows the R5F cores state machine to be
>> maintained properly between using the sysfs 'state' variable, bind/unbind
>> and regular module load/unload flows.
>>
>> The subsystem is represented as a single remoteproc in LockStep mode, and
>> as two remoteprocs in Split mode. The driver uses various TI-SCI interfaces
>> to talk to the System Controller (DMSC) for managing configuration, power
>> and reset management of these cores. IPC between the A53 cores and the R5
>> cores is supported through the virtio rpmsg stack using shared memory and
>> OMAP Mailboxes.
>>
>> The AM65x SoCs typically have a single R5FSS in the MCU voltage domain. The
>> J721E SoCs uses a slightly revised IP and typically have three R5FSSs, with
>> one cluster present within the MCU voltage domain (MCU_R5FSS0), and the
>> remaining two clusters present in the MAIN voltage domain (MAIN_R5FSS0 and
>> MAIN_R5FSS1). The integration of these clusters on J721E SoC is also
>> slightly different in that these IPs do support an actual local reset line,
>> while they are a no-op on AM65x SoCs.
>>
>> Signed-off-by: Suman Anna <s-anna@ti.com>
>> ---
>>   drivers/remoteproc/Kconfig               |   16 +
>>   drivers/remoteproc/Makefile              |    1 +
>>   drivers/remoteproc/ti_k3_r5_remoteproc.c | 1346 ++++++++++++++++++++++
>>   3 files changed, 1363 insertions(+)
>>   create mode 100644 drivers/remoteproc/ti_k3_r5_remoteproc.c
>>
>> diff --git a/drivers/remoteproc/Kconfig b/drivers/remoteproc/Kconfig
>> index de3862c15fcc..073048b4c0fb 100644
>> --- a/drivers/remoteproc/Kconfig
>> +++ b/drivers/remoteproc/Kconfig
>> @@ -224,6 +224,22 @@ config STM32_RPROC
>>   
>>   	  This can be either built-in or a loadable module.
>>   
>> +config TI_K3_R5_REMOTEPROC
>> +	tristate "TI K3 R5 remoteproc support"
>> +	depends on ARCH_K3
>> +	select MAILBOX
>> +	select OMAP2PLUS_MBOX
>> +	help
>> +	  Say y here to support TI's R5F remote processor subsystems
>> +	  on various TI K3 family of SoCs through the remote processor
>> +	  framework.
>> +
>> +	  You want to say y here in order to offload some processing
>> +	  tasks to these processors
>> +
>> +	  It's safe to say N here if you're not interested in utilizing
>> +	  a slave processor
>> +
>>   endif # REMOTEPROC
>>   
>>   endmenu
>> diff --git a/drivers/remoteproc/Makefile b/drivers/remoteproc/Makefile
>> index e30a1b15fbac..00ba826818af 100644
>> --- a/drivers/remoteproc/Makefile
>> +++ b/drivers/remoteproc/Makefile
>> @@ -28,3 +28,4 @@ qcom_wcnss_pil-y			+= qcom_wcnss_iris.o
>>   obj-$(CONFIG_ST_REMOTEPROC)		+= st_remoteproc.o
>>   obj-$(CONFIG_ST_SLIM_REMOTEPROC)	+= st_slim_rproc.o
>>   obj-$(CONFIG_STM32_RPROC)		+= stm32_rproc.o
>> +obj-$(CONFIG_TI_K3_R5_REMOTEPROC)	+= ti_k3_r5_remoteproc.o
>> diff --git a/drivers/remoteproc/ti_k3_r5_remoteproc.c b/drivers/remoteproc/ti_k3_r5_remoteproc.c
>> new file mode 100644
>> index 000000000000..655f8f14c37d
>> --- /dev/null
>> +++ b/drivers/remoteproc/ti_k3_r5_remoteproc.c
>> @@ -0,0 +1,1346 @@
>> +// SPDX-License-Identifier: GPL-2.0-only
>> +/*
>> + * TI K3 R5F (MCU) Remote Processor driver
>> + *
>> + * Copyright (C) 2017-2020 Texas Instruments Incorporated - http://www.ti.com/
>> + *	Suman Anna <s-anna@ti.com>
>> + */
>> +
>> +#include <linux/dma-mapping.h>
>> +#include <linux/err.h>
>> +#include <linux/interrupt.h>
>> +#include <linux/kernel.h>
>> +#include <linux/mailbox_client.h>
>> +#include <linux/module.h>
>> +#include <linux/of_device.h>
>> +#include <linux/of_address.h>
>> +#include <linux/of_reserved_mem.h>
>> +#include <linux/platform_device.h>
>> +#include <linux/pm_runtime.h>
>> +#include <linux/remoteproc.h>
>> +#include <linux/omap-mailbox.h>
>> +#include <linux/reset.h>
>> +#include <linux/soc/ti/ti_sci_protocol.h>
>> +
>> +#include "omap_remoteproc.h"
>> +#include "remoteproc_internal.h"
>> +#include "ti_sci_proc.h"
>> +
>> +/* This address can either be for ATCM or BTCM with the other at address 0x0 */
>> +#define K3_R5_TCM_DEV_ADDR	0x41010000
>> +
>> +/* R5 TI-SCI Processor Configuration Flags */
>> +#define PROC_BOOT_CFG_FLAG_R5_DBG_EN			0x00000001
>> +#define PROC_BOOT_CFG_FLAG_R5_DBG_NIDEN			0x00000002
>> +#define PROC_BOOT_CFG_FLAG_R5_LOCKSTEP			0x00000100
>> +#define PROC_BOOT_CFG_FLAG_R5_TEINIT			0x00000200
>> +#define PROC_BOOT_CFG_FLAG_R5_NMFI_EN			0x00000400
>> +#define PROC_BOOT_CFG_FLAG_R5_TCM_RSTBASE		0x00000800
>> +#define PROC_BOOT_CFG_FLAG_R5_BTCM_EN			0x00001000
>> +#define PROC_BOOT_CFG_FLAG_R5_ATCM_EN			0x00002000
>> +
>> +/* R5 TI-SCI Processor Control Flags */
>> +#define PROC_BOOT_CTRL_FLAG_R5_CORE_HALT		0x00000001
>> +
>> +/* R5 TI-SCI Processor Status Flags */
>> +#define PROC_BOOT_STATUS_FLAG_R5_WFE			0x00000001
>> +#define PROC_BOOT_STATUS_FLAG_R5_WFI			0x00000002
>> +#define PROC_BOOT_STATUS_FLAG_R5_CLK_GATED		0x00000004
>> +#define PROC_BOOT_STATUS_FLAG_R5_LOCKSTEP_PERMITTED	0x00000100
>> +
>> +/**
>> + * struct k3_r5_mem - internal memory structure
>> + * @cpu_addr: MPU virtual address of the memory region
>> + * @bus_addr: Bus address used to access the memory region
>> + * @dev_addr: Device address from remoteproc view
>> + * @size: Size of the memory region
>> + */
>> +struct k3_r5_mem {
>> +	void __iomem *cpu_addr;
>> +	phys_addr_t bus_addr;
>> +	u32 dev_addr;
>> +	size_t size;
>> +};
>> +
>> +enum cluster_mode {
>> +	CLUSTER_MODE_SPLIT = 0,
>> +	CLUSTER_MODE_LOCKSTEP,
>> +};
>> +
>> +/**
>> + * struct k3_r5_cluster - K3 R5F Cluster structure
>> + * @dev: cached device pointer
>> + * @mode: Mode to configure the Cluster - Split or LockStep
>> + * @cores: list of R5 cores within the cluster
>> + */
>> +struct k3_r5_cluster {
>> +	struct device *dev;
>> +	enum cluster_mode mode;
>> +	struct list_head cores;
>> +};
>> +
>> +/**
>> + * struct k3_r5_core - K3 R5 core structure
>> + * @elem: linked list item
>> + * @dev: cached device pointer
>> + * @rproc: rproc handle representing this core
>> + * @mem: internal memory regions data
>> + * @num_mems: number of internal memory regions
>> + * @reset: reset control handle
>> + * @tsp: TI-SCI processor control handle
>> + * @ti_sci: TI-SCI handle
>> + * @ti_sci_id: TI-SCI device identifier
>> + * @atcm_enable: flag to control ATCM enablement
>> + * @btcm_enable: flag to control BTCM enablement
>> + * @loczrama: flag to dictate which TCM is at device address 0x0
>> + */
>> +struct k3_r5_core {
>> +	struct list_head elem;
>> +	struct device *dev;
>> +	struct rproc *rproc;
>> +	struct k3_r5_mem *mem;
>> +	int num_mems;
>> +	struct reset_control *reset;
>> +	struct ti_sci_proc *tsp;
>> +	const struct ti_sci_handle *ti_sci;
>> +	u32 ti_sci_id;
>> +	u32 atcm_enable;
>> +	u32 btcm_enable;
>> +	u32 loczrama;
>> +};
>> +
>> +/**
>> + * struct k3_r5_rproc - K3 remote processor state
>> + * @dev: cached device pointer
>> + * @cluster: cached pointer to parent cluster structure
>> + * @mbox: mailbox channel handle
>> + * @client: mailbox client to request the mailbox channel
>> + * @rproc: rproc handle
>> + * @core: cached pointer to r5 core structure being used
>> + * @rmem: reserved memory regions data
>> + * @num_rmems: number of reserved memory regions
>> + */
>> +struct k3_r5_rproc {
>> +	struct device *dev;
>> +	struct k3_r5_cluster *cluster;
>> +	struct mbox_chan *mbox;
>> +	struct mbox_client client;
>> +	struct rproc *rproc;
>> +	struct k3_r5_core *core;
>> +	struct k3_r5_mem *rmem;
>> +	int num_rmems;
>> +};
>> +
>> +/**
>> + * k3_r5_rproc_mbox_callback() - inbound mailbox message handler
>> + * @client: mailbox client pointer used for requesting the mailbox channel
>> + * @data: mailbox payload
>> + *
>> + * This handler is invoked by the OMAP mailbox driver whenever a mailbox
>> + * message is received. Usually, the mailbox payload simply contains
>> + * the index of the virtqueue that is kicked by the remote processor,
>> + * and we let remoteproc core handle it.
>> + *
>> + * In addition to virtqueue indices, we also have some out-of-band values
>> + * that indicate different events. Those values are deliberately very
>> + * large so they don't coincide with virtqueue indices.
>> + */
>> +static void k3_r5_rproc_mbox_callback(struct mbox_client *client, void *data)
>> +{
>> +	struct k3_r5_rproc *kproc = container_of(client, struct k3_r5_rproc,
>> +						client);
>> +	struct device *dev = kproc->rproc->dev.parent;
>> +	const char *name = kproc->rproc->name;
>> +	u32 msg = omap_mbox_message(data);
>> +
>> +	dev_dbg(dev, "mbox msg: 0x%x\n", msg);
>> +
>> +	switch (msg) {
>> +	case RP_MBOX_CRASH:
>> +		/*
>> +		 * remoteproc detected an exception, but error recovery is not
>> +		 * supported. So, just log this for now
>> +		 */
>> +		dev_err(dev, "K3 R5F rproc %s crashed\n", name);
>> +		break;
>> +	case RP_MBOX_ECHO_REPLY:
>> +		dev_info(dev, "received echo reply from %s\n", name);
>> +		break;
>> +	default:
>> +		/* silently handle all other valid messages */
>> +		if (msg >= RP_MBOX_READY && msg < RP_MBOX_END_MSG)
>> +			return;
>> +		if (msg > kproc->rproc->max_notifyid) {
>> +			dev_dbg(dev, "dropping unknown message 0x%x", msg);
>> +			return;
>> +		}
>> +		/* msg contains the index of the triggered vring */
>> +		if (rproc_vq_interrupt(kproc->rproc, msg) == IRQ_NONE)
>> +			dev_dbg(dev, "no message was found in vqid %d\n", msg);
>> +	}
>> +}
>> +
>> +/* kick a virtqueue */
>> +static void k3_r5_rproc_kick(struct rproc *rproc, int vqid)
>> +{
>> +	struct k3_r5_rproc *kproc = rproc->priv;
>> +	struct device *dev = rproc->dev.parent;
>> +	mbox_msg_t msg = (mbox_msg_t)vqid;
>> +	int ret;
>> +
>> +	/* send the index of the triggered virtqueue in the mailbox payload */
>> +	ret = mbox_send_message(kproc->mbox, (void *)msg);
>> +	if (ret < 0)
>> +		dev_err(dev, "failed to send mailbox message, status = %d\n",
>> +			ret);
>> +}
>> +
>> +static int k3_r5_split_reset(struct k3_r5_core *core)
>> +{
>> +	int ret;
>> +
>> +	ret = reset_control_assert(core->reset);
>> +	if (ret) {
>> +		dev_err(core->dev, "local-reset assert failed, ret = %d\n",
>> +			ret);
>> +		return ret;
>> +	}
>> +
>> +	ret = core->ti_sci->ops.dev_ops.put_device(core->ti_sci,
>> +						   core->ti_sci_id);
>> +	if (ret) {
>> +		dev_err(core->dev, "module-reset assert failed, ret = %d\n",
>> +			ret);
>> +		if (reset_control_deassert(core->reset))
>> +			dev_warn(core->dev, "local-reset deassert back failed\n");
>> +	}
>> +
>> +	return ret;
>> +}
>> +
>> +static int k3_r5_split_release(struct k3_r5_core *core)
>> +{
>> +	int ret;
>> +
>> +	ret = core->ti_sci->ops.dev_ops.get_device(core->ti_sci,
>> +						   core->ti_sci_id);
>> +	if (ret) {
>> +		dev_err(core->dev, "module-reset deassert failed, ret = %d\n",
>> +			ret);
>> +		return ret;
>> +	}
>> +
>> +	ret = reset_control_deassert(core->reset);
>> +	if (ret) {
>> +		dev_err(core->dev, "local-reset deassert failed, ret = %d\n",
>> +			ret);
>> +		if (core->ti_sci->ops.dev_ops.put_device(core->ti_sci,
>> +							 core->ti_sci_id))
>> +			dev_warn(core->dev, "module-reset assert back failed\n");
>> +	}
>> +
>> +	return ret;
>> +}
>> +
>> +static int k3_r5_lockstep_reset(struct k3_r5_cluster *cluster)
>> +{
>> +	struct k3_r5_core *core;
>> +	int ret;
>> +
>> +	/* assert local reset on all applicable cores */
>> +	list_for_each_entry(core, &cluster->cores, elem) {
>> +		ret = reset_control_assert(core->reset);
>> +		if (ret) {
>> +			dev_err(core->dev, "local-reset assert failed, ret = %d\n",
>> +				ret);
>> +			core = list_prev_entry(core, elem);
>> +			goto unroll_local_reset;
>> +		}
>> +	}
>> +
>> +	/* disable PSC modules on all applicable cores */
>> +	list_for_each_entry(core, &cluster->cores, elem) {
>> +		ret = core->ti_sci->ops.dev_ops.put_device(core->ti_sci,
>> +							   core->ti_sci_id);
>> +		if (ret) {
>> +			dev_err(core->dev, "module-reset assert failed, ret = %d\n",
>> +				ret);
>> +			goto unroll_module_reset;
>> +		}
>> +	}
>> +
>> +	return 0;
>> +
>> +unroll_module_reset:
>> +	list_for_each_entry_continue_reverse(core, &cluster->cores, elem) {
>> +		if (core->ti_sci->ops.dev_ops.put_device(core->ti_sci,
>> +							 core->ti_sci_id))
>> +			dev_warn(core->dev, "module-reset assert back failed\n");
>> +	}
>> +	core = list_last_entry(&cluster->cores, struct k3_r5_core, elem);
>> +unroll_local_reset:
>> +	list_for_each_entry_from_reverse(core, &cluster->cores, elem) {
>> +		if (reset_control_deassert(core->reset))
>> +			dev_warn(core->dev, "local-reset deassert back failed\n");
>> +	}
>> +
>> +	return ret;
>> +}
>> +
>> +static int k3_r5_lockstep_release(struct k3_r5_cluster *cluster)
>> +{
>> +	struct k3_r5_core *core;
>> +	int ret;
>> +
>> +	/* enable PSC modules on all applicable cores */
>> +	list_for_each_entry_reverse(core, &cluster->cores, elem) {
>> +		ret = core->ti_sci->ops.dev_ops.get_device(core->ti_sci,
>> +							   core->ti_sci_id);
>> +		if (ret) {
>> +			dev_err(core->dev, "module-reset deassert failed, ret = %d\n",
>> +				ret);
>> +			core = list_next_entry(core, elem);
>> +			goto unroll_module_reset;
>> +		}
>> +	}
>> +
>> +	/* deassert local reset on all applicable cores */
>> +	list_for_each_entry_reverse(core, &cluster->cores, elem) {
>> +		ret = reset_control_deassert(core->reset);
>> +		if (ret) {
>> +			dev_err(core->dev, "module-reset deassert failed, ret = %d\n",
>> +				ret);
>> +			goto unroll_local_reset;
>> +		}
>> +	}
>> +
>> +	return 0;
>> +
>> +unroll_local_reset:
>> +	list_for_each_entry_continue(core, &cluster->cores, elem) {
>> +		if (reset_control_assert(core->reset))
>> +			dev_warn(core->dev, "local-reset assert back failed\n");
>> +	}
>> +	core = list_first_entry(&cluster->cores, struct k3_r5_core, elem);
>> +unroll_module_reset:
>> +	list_for_each_entry_from(core, &cluster->cores, elem) {
>> +		if (core->ti_sci->ops.dev_ops.put_device(core->ti_sci,
>> +							 core->ti_sci_id))
>> +			dev_warn(core->dev, "module-reset assert back failed\n");
>> +	}
>> +
>> +	return ret;
>> +}
>> +
>> +static inline int k3_r5_core_halt(struct k3_r5_core *core)
>> +{
>> +	return ti_sci_proc_set_control(core->tsp,
>> +				       PROC_BOOT_CTRL_FLAG_R5_CORE_HALT, 0);
>> +}
>> +
>> +static inline int k3_r5_core_run(struct k3_r5_core *core)
>> +{
>> +	return ti_sci_proc_set_control(core->tsp,
>> +				       0, PROC_BOOT_CTRL_FLAG_R5_CORE_HALT);
>> +}
>> +
>> +/*
>> + * The R5F cores have controls for both a reset and a halt/run. The code
>> + * execution from DDR requires the initial boot-strapping code to be run
>> + * from the internal TCMs. This function is used to release the resets on
>> + * applicable cores to allow loading into the TCMs. The .prepare() ops is
>> + * invoked by remoteproc core before any firmware loading, and is followed
>> + * by the .start() ops after loading to actually let the R5 cores run.
>> + */
>> +static int k3_r5_rproc_prepare(struct rproc *rproc)
>> +{
>> +	struct k3_r5_rproc *kproc = rproc->priv;
>> +	struct k3_r5_cluster *cluster = kproc->cluster;
>> +	struct k3_r5_core *core = kproc->core;
>> +	struct device *dev = kproc->dev;
>> +	int ret;
>> +
>> +	ret = cluster->mode ? k3_r5_lockstep_release(cluster) :
>> +			      k3_r5_split_release(core);
>> +	if (ret)
>> +		dev_err(dev, "unable to enable cores for TCM loading, ret = %d\n",
>> +			ret);
>> +
>> +	return ret;
>> +}
>> +
>> +/*
>> + * This function implements the .unprepare() ops and performs the complimentary
>> + * operations to that of the .prepare() ops. The function is used to assert the
>> + * resets on all applicable cores for the rproc device (depending on LockStep
>> + * or Split mode). This completes the second portion of powering down the R5F
>> + * cores. The cores themselves are only halted in the .stop() ops, and the
>> + * .unprepare() ops is invoked by the remoteproc core after the remoteproc is
>> + * stopped.
>> + */
>> +static int k3_r5_rproc_unprepare(struct rproc *rproc)
>> +{
>> +	struct k3_r5_rproc *kproc = rproc->priv;
>> +	struct k3_r5_cluster *cluster = kproc->cluster;
>> +	struct k3_r5_core *core = kproc->core;
>> +	struct device *dev = kproc->dev;
>> +	int ret;
>> +
>> +	ret = cluster->mode ? k3_r5_lockstep_reset(cluster) :
>> +			      k3_r5_split_reset(core);
>> +	if (ret)
>> +		dev_err(dev, "unable to disable cores, ret = %d\n", ret);
>> +
>> +	return ret;
>> +}
>> +
>> +/*
>> + * The R5F start sequence includes two different operations
>> + * 1. Configure the boot vector for R5F core(s)
>> + * 2. Unhalt/Run the R5F core(s)
>> + *
>> + * The sequence is different between LockStep and Split modes. The LockStep
>> + * mode requires the boot vector to be configured only for Core0, and then
>> + * unhalt both the cores to start the execution - Core1 needs to be unhalted
>> + * first followed by Core0. The Split-mode requires that Core0 to be maintained
>> + * always in a higher power state that Core1 (implying Core1 needs to be started
>> + * always only after Core0 is started).
>> + */
>> +static int k3_r5_rproc_start(struct rproc *rproc)
>> +{
>> +	struct k3_r5_rproc *kproc = rproc->priv;
>> +	struct k3_r5_cluster *cluster = kproc->cluster;
>> +	struct mbox_client *client = &kproc->client;
>> +	struct device *dev = kproc->dev;
>> +	struct k3_r5_core *core;
>> +	u32 boot_addr;
>> +	int ret;
>> +
>> +	client->dev = dev;
>> +	client->tx_done = NULL;
>> +	client->rx_callback = k3_r5_rproc_mbox_callback;
>> +	client->tx_block = false;
>> +	client->knows_txdone = false;
>> +
>> +	kproc->mbox = mbox_request_channel(client, 0);
>> +	if (IS_ERR(kproc->mbox)) {
>> +		ret = -EBUSY;
>> +		dev_err(dev, "mbox_request_channel failed: %ld\n",
>> +			PTR_ERR(kproc->mbox));
>> +		return ret;
>> +	}
>> +
>> +	/*
>> +	 * Ping the remote processor, this is only for sanity-sake for now;
>> +	 * there is no functional effect whatsoever.
>> +	 *
>> +	 * Note that the reply will _not_ arrive immediately: this message
>> +	 * will wait in the mailbox fifo until the remote processor is booted.
>> +	 */
>> +	ret = mbox_send_message(kproc->mbox, (void *)RP_MBOX_ECHO_REQUEST);
>> +	if (ret < 0) {
>> +		dev_err(dev, "mbox_send_message failed: %d\n", ret);
>> +		goto put_mbox;
>> +	}
>> +
>> +	boot_addr = rproc->bootaddr;
>> +	/* TODO: add boot_addr sanity checking */
>> +	dev_err(dev, "booting R5F core using boot addr = 0x%x\n", boot_addr);
>> +
>> +	/* boot vector need not be programmed for Core1 in LockStep mode */
>> +	core = kproc->core;
>> +	ret = ti_sci_proc_set_config(core->tsp, boot_addr, 0, 0);
>> +	if (ret)
>> +		goto put_mbox;
>> +
>> +	/* unhalt/run all applicable cores */
>> +	if (cluster->mode) {
>> +		list_for_each_entry_reverse(core, &cluster->cores, elem) {
>> +			ret = k3_r5_core_run(core);
>> +			if (ret)
>> +				goto unroll_core_run;
>> +		}
>> +	} else {
>> +		ret = k3_r5_core_run(core);
>> +		if (ret)
>> +			goto put_mbox;
>> +	}
>> +
>> +	return 0;
>> +
>> +unroll_core_run:
>> +	list_for_each_entry_continue(core, &cluster->cores, elem) {
>> +		if (k3_r5_core_halt(core))
>> +			dev_warn(core->dev, "core halt back failed\n");
>> +	}
>> +put_mbox:
>> +	mbox_free_channel(kproc->mbox);
>> +	return ret;
>> +}
>> +
>> +/*
>> + * The R5F stop function includes the following operations
>> + * 1. Halt R5F core(s)
>> + *
>> + * The sequence is different between LockStep and Split modes, and the order
>> + * of cores the operations are performed are also in general reverse to that
>> + * of the start function. The LockStep mode requires each operation to be
>> + * performed first on Core0 followed by Core1. The Split-mode requires that
>> + * Core0 to be maintained always in a higher power state that Core1 (implying
>> + * Core1 needs to be stopped first before Core0).
>> + *
>> + * Note that the R5F halt operation in general is not effective when the R5F
>> + * core is running, but is needed to make sure the core won't run after
>> + * deasserting the reset the subsequent time. The asserting of reset can
>> + * be done here, but is preferred to be done in the .unprepare() ops - this
>> + * maintains the symmetric behavior between the .start(), .stop(), .prepare()
>> + * and .unprepare() ops, and also balances them well between sysfs 'state'
>> + * flow and device bind/unbind or module removal.
>> + */
>> +static int k3_r5_rproc_stop(struct rproc *rproc)
>> +{
>> +	struct k3_r5_rproc *kproc = rproc->priv;
>> +	struct k3_r5_cluster *cluster = kproc->cluster;
>> +	struct k3_r5_core *core = kproc->core;
>> +	int ret;
>> +
>> +	/* halt all applicable cores */
>> +	if (cluster->mode) {
>> +		list_for_each_entry(core, &cluster->cores, elem) {
>> +			ret = k3_r5_core_halt(core);
>> +			if (ret) {
>> +				core = list_prev_entry(core, elem);
>> +				goto unroll_core_halt;
>> +			}
>> +		}
>> +	} else {
>> +		ret = k3_r5_core_halt(core);
>> +		if (ret)
>> +			goto out;
>> +	}
>> +
>> +	mbox_free_channel(kproc->mbox);
>> +
>> +	return 0;
>> +
>> +unroll_core_halt:
>> +	list_for_each_entry_from_reverse(core, &cluster->cores, elem) {
>> +		if (k3_r5_core_run(core))
>> +			dev_warn(core->dev, "core run back failed\n");
>> +	}
>> +out:
>> +	return ret;
>> +}
>> +
>> +/*
>> + * Internal Memory translation helper
>> + *
>> + * Custom function implementing the rproc .da_to_va ops to provide address
>> + * translation (device address to kernel virtual address) for internal RAMs
>> + * present in a DSP or IPU device). The translated addresses can be used
>> + * either by the remoteproc core for loading, or by any rpmsg bus drivers.
>> + */
>> +static void *k3_r5_rproc_da_to_va(struct rproc *rproc, u64 da, size_t len)
>> +{
>> +	struct k3_r5_rproc *kproc = rproc->priv;
>> +	struct k3_r5_core *core = kproc->core;
>> +	void __iomem *va = NULL;
>> +	phys_addr_t bus_addr;
>> +	u32 dev_addr, offset;
>> +	size_t size;
>> +	int i;
>> +
>> +	if (len == 0)
>> +		return NULL;
>> +
>> +	/* handle both R5 and SoC views of ATCM and BTCM */
>> +	for (i = 0; i < core->num_mems; i++) {
>> +		bus_addr = core->mem[i].bus_addr;
>> +		dev_addr = core->mem[i].dev_addr;
>> +		size = core->mem[i].size;
>> +
>> +		/* handle R5-view addresses of TCMs */
>> +		if (da >= dev_addr && ((da + len) <= (dev_addr + size))) {
>> +			offset = da - dev_addr;
>> +			va = core->mem[i].cpu_addr + offset;
>> +			return (__force void *)va;
>> +		}
>> +
>> +		/* handle SoC-view addresses of TCMs */
>> +		if (da >= bus_addr && ((da + len) <= (bus_addr + size))) {
>> +			offset = da - bus_addr;
>> +			va = core->mem[i].cpu_addr + offset;
>> +			return (__force void *)va;
>> +		}
>> +	}
>> +
>> +	/* handle static DDR reserved memory regions */
>> +	for (i = 0; i < kproc->num_rmems; i++) {
>> +		dev_addr = kproc->rmem[i].dev_addr;
>> +		size = kproc->rmem[i].size;
>> +
>> +		if (da >= dev_addr && ((da + len) <= (dev_addr + size))) {
>> +			offset = da - dev_addr;
>> +			va = kproc->rmem[i].cpu_addr + offset;
>> +			return (__force void *)va;
>> +		}
>> +	}
>> +
>> +	return NULL;
>> +}
>> +
>> +static const struct rproc_ops k3_r5_rproc_ops = {
>> +	.prepare	= k3_r5_rproc_prepare,
>> +	.unprepare	= k3_r5_rproc_unprepare,
>> +	.start		= k3_r5_rproc_start,
>> +	.stop		= k3_r5_rproc_stop,
>> +	.kick		= k3_r5_rproc_kick,
>> +	.da_to_va	= k3_r5_rproc_da_to_va,
>> +};
>> +
>> +static const char *k3_r5_rproc_get_firmware(struct device *dev)
>> +{
>> +	const char *fw_name;
>> +	int ret;
>> +
>> +	ret = of_property_read_string(dev->of_node, "firmware-name",
>> +				      &fw_name);
>> +	if (ret) {
>> +		dev_err(dev, "failed to parse firmware-name property, ret = %d\n",
>> +			ret);
>> +		return ERR_PTR(ret);
>> +	}
>> +
>> +	return fw_name;
>> +}
>> +
>> +static int k3_r5_rproc_configure(struct k3_r5_rproc *kproc)
>> +{
>> +	struct k3_r5_cluster *cluster = kproc->cluster;
>> +	struct device *dev = kproc->dev;
>> +	struct k3_r5_core *core0, *core, *temp;
>> +	u32 ctrl = 0, cfg = 0, stat = 0;
>> +	u32 set_cfg = 0, clr_cfg = 0;
>> +	u64 boot_vec = 0;
>> +	bool lockstep_en;
>> +	int ret;
>> +
>> +	core0 = list_first_entry(&cluster->cores, struct k3_r5_core, elem);
>> +	core = cluster->mode ? core0 : kproc->core;
> 
> The above two lines generated interesting mental gymnastic - please sprinkle
> with comments in order to disambiguate what is going on.

Yeah, I will add some comments or add some top-level description above 
the function for v2.

> 
>> +
>> +	ret = ti_sci_proc_get_status(core->tsp, &boot_vec, &cfg, &ctrl,
>> +				     &stat);
>> +	if (ret < 0)
>> +		return ret;
>> +
>> +	dev_dbg(dev, "boot_vector = 0x%llx, cfg = 0x%x ctrl = 0x%x stat = 0x%x\n",
>> +		boot_vec, cfg, ctrl, stat);
>> +
>> +	lockstep_en = !!(stat & PROC_BOOT_STATUS_FLAG_R5_LOCKSTEP_PERMITTED);
>> +	if (!lockstep_en && cluster->mode) {
>> +		dev_err(cluster->dev, "lockstep mode not permitted, force configuring for split-mode\n");
>> +		cluster->mode = 0;
>> +	}
>> +
>> +	/* always enable ARM mode and set boot vector to 0 */
>> +	boot_vec = 0x0;
>> +	if (core == core0) {
>> +		clr_cfg = PROC_BOOT_CFG_FLAG_R5_TEINIT;
>> +		/*
>> +		 * LockStep configuration bit is Read-only on Split-mode _only_
>> +		 * devices and system firmware will NACK any requests with the
>> +		 * bit configured, so program it only on permitted devices
>> +		 */
>> +		if (lockstep_en)
>> +			clr_cfg |= PROC_BOOT_CFG_FLAG_R5_LOCKSTEP;
>> +	}
>> +
>> +	if (core->atcm_enable)
>> +		set_cfg |= PROC_BOOT_CFG_FLAG_R5_ATCM_EN;
>> +	else
>> +		clr_cfg |= PROC_BOOT_CFG_FLAG_R5_ATCM_EN;
>> +
>> +	if (core->btcm_enable)
>> +		set_cfg |= PROC_BOOT_CFG_FLAG_R5_BTCM_EN;
>> +	else
>> +		clr_cfg |= PROC_BOOT_CFG_FLAG_R5_BTCM_EN;
>> +
>> +	if (core->loczrama)
>> +		set_cfg |= PROC_BOOT_CFG_FLAG_R5_TCM_RSTBASE;
>> +	else
>> +		clr_cfg |= PROC_BOOT_CFG_FLAG_R5_TCM_RSTBASE;
>> +
>> +	if (cluster->mode) {
>> +		/*
>> +		 * work around system firmware limitations to make sure both
>> +		 * cores are programmed symmetrically in LockStep. LockStep
>> +		 * and TEINIT config is only allowed with Core0.
>> +		 */
>> +		list_for_each_entry(temp, &cluster->cores, elem) {
>> +			ret = k3_r5_core_halt(core);
> 
> When I first read this I thought this was an error and what was really needed
> was k3_r5_core_halt(temp)... But no, this is correct because
> k3_r5_rproc_configure() is called for each core in the cluster in function
> k3_r5_cluster_rproc_init().  But then again why halting the same for each of the
> cores found in the system?
> 
> So something seems wrong here.  Either call k3_r5_core_halt(temp) or move
> k3_r5_core_halt(core) outside of the if (cluster->mode) to avoid more confusion.

LockStep-mode in general still requires operating/managing both the 
cores. Let me double-check this again, the halt should be done on both 
the cores for sure, so it does appear that I should be using 
k3_r5_core_halt(temp) indeed.

This function is not called a second time if the cluster is in LockStep 
mode. I break out of the loop at the end in k3_r5_cluster_rproc_init()
if the cluster is in LockStep mode.

> 
>> +			if (ret)
>> +				goto out;
>> +
>> +			if (temp != core) {
>> +				clr_cfg &= ~PROC_BOOT_CFG_FLAG_R5_LOCKSTEP;
>> +				clr_cfg &= ~PROC_BOOT_CFG_FLAG_R5_TEINIT;
>> +			}
>> +			ret = ti_sci_proc_set_config(temp->tsp, boot_vec,
>> +						     set_cfg, clr_cfg);
>> +			if (ret)
>> +				goto out;
>> +		}
>> +
>> +		set_cfg = PROC_BOOT_CFG_FLAG_R5_LOCKSTEP;
>> +		clr_cfg = 0;
>> +		ret = ti_sci_proc_set_config(core->tsp, boot_vec,
>> +					     set_cfg, clr_cfg);
>> +	} else {
>> +		ret = k3_r5_core_halt(core);
>> +		if (ret)
>> +			goto out;
>> +
>> +		ret = ti_sci_proc_set_config(core->tsp, boot_vec,
>> +					     set_cfg, clr_cfg);
>> +	}
>> +
>> +out:
>> +	return ret;
>> +}
>> +
>> +static int k3_r5_reserved_mem_init(struct k3_r5_rproc *kproc)
>> +{
>> +	struct device *dev = kproc->dev;
>> +	struct device_node *np = dev->of_node;
>> +	struct device_node *rmem_np;
>> +	struct reserved_mem *rmem;
>> +	int num_rmems;
>> +	int ret, i;
>> +
>> +	num_rmems = of_property_count_elems_of_size(np, "memory-region",
>> +						    sizeof(phandle));
>> +	if (num_rmems <= 0) {
>> +		dev_err(dev, "device does not have reserved memory regions, ret = %d\n",
>> +			num_rmems);
>> +		return -EINVAL;
>> +	}
>> +	if (num_rmems < 2) {
>> +		dev_err(dev, "device needs atleast two memory regions to be defined, num = %d\n",
>> +			num_rmems);
>> +		return -EINVAL;
>> +	}
>> +
>> +	/* use reserved memory region 0 for vring DMA allocations */
>> +	ret = of_reserved_mem_device_init_by_idx(dev, np, 0);
>> +	if (ret) {
>> +		dev_err(dev, "device cannot initialize DMA pool, ret = %d\n",
>> +			ret);
>> +		return ret;
>> +	}
>> +
>> +	num_rmems--;
>> +	kproc->rmem = kcalloc(num_rmems, sizeof(*kproc->rmem), GFP_KERNEL);
>> +	if (!kproc->rmem) {
>> +		ret = -ENOMEM;
>> +		goto release_rmem;
>> +	}
>> +
>> +	/* use remaining reserved memory regions for static carveouts */
>> +	for (i = 0; i < num_rmems; i++) {
>> +		rmem_np = of_parse_phandle(np, "memory-region", i + 1);
>> +		if (!rmem_np) {
>> +			ret = -EINVAL;
>> +			goto unmap_rmem;
>> +		}
>> +
>> +		rmem = of_reserved_mem_lookup(rmem_np);
>> +		if (!rmem) {
>> +			of_node_put(rmem_np);
>> +			ret = -EINVAL;
>> +			goto unmap_rmem;
>> +		}
>> +		of_node_put(rmem_np);
>> +
>> +		kproc->rmem[i].bus_addr = rmem->base;
>> +		/* 64-bit address regions currently not supported */
>> +		kproc->rmem[i].dev_addr = (u32)rmem->base;
>> +		kproc->rmem[i].size = rmem->size;
>> +		kproc->rmem[i].cpu_addr = ioremap_wc(rmem->base, rmem->size);
>> +		if (!kproc->rmem[i].cpu_addr) {
>> +			dev_err(dev, "failed to map reserved memory#%d at %pa of size %pa\n",
>> +				i + 1, &rmem->base, &rmem->size);
>> +			ret = -ENOMEM;
>> +			goto unmap_rmem;
>> +		}
>> +
>> +		dev_dbg(dev, "reserved memory%d: bus addr %pa size 0x%zx va %pK da 0x%x\n",
>> +			i + 1, &kproc->rmem[i].bus_addr,
>> +			kproc->rmem[i].size, kproc->rmem[i].cpu_addr,
>> +			kproc->rmem[i].dev_addr);
>> +	}
>> +	kproc->num_rmems = num_rmems;
>> +
>> +	return 0;
>> +
>> +unmap_rmem:
>> +	for (i--; i >= 0; i--) {
>> +		if (kproc->rmem[i].cpu_addr)
>> +			iounmap(kproc->rmem[i].cpu_addr);
>> +	}
>> +	kfree(kproc->rmem);
>> +release_rmem:
>> +	of_reserved_mem_device_release(dev);
>> +	return ret;
>> +}
>> +
>> +static void k3_r5_reserved_mem_exit(struct k3_r5_rproc *kproc)
>> +{
>> +	int i;
>> +
>> +	for (i = 0; i < kproc->num_rmems; i++)
>> +		iounmap(kproc->rmem[i].cpu_addr);
>> +	kfree(kproc->rmem);
>> +
>> +	of_reserved_mem_device_release(kproc->dev);
>> +}
>> +
>> +static int k3_r5_cluster_rproc_init(struct platform_device *pdev)
>> +{
>> +	struct k3_r5_cluster *cluster = platform_get_drvdata(pdev);
>> +	struct device *dev = &pdev->dev;
>> +	struct k3_r5_rproc *kproc;
>> +	struct k3_r5_core *core, *core1;
>> +	struct device *cdev;
>> +	const char *fw_name;
>> +	struct rproc *rproc;
>> +	int ret;
>> +
>> +	core1 = list_last_entry(&cluster->cores, struct k3_r5_core, elem);
>> +	list_for_each_entry(core, &cluster->cores, elem) {
>> +		cdev = core->dev;
>> +		fw_name = k3_r5_rproc_get_firmware(cdev);
>> +		if (IS_ERR(fw_name)) {
>> +			ret = PTR_ERR(fw_name);
>> +			goto out;
>> +		}
>> +
>> +		rproc = rproc_alloc(cdev, dev_name(cdev), &k3_r5_rproc_ops,
>> +				    fw_name, sizeof(*kproc));
>> +		if (!rproc) {
>> +			ret = -ENOMEM;
>> +			goto out;
>> +		}
>> +
>> +		/* K3 R5s have a Region Address Translator (RAT) but no MMU */
>> +		rproc->has_iommu = false;
>> +		/* error recovery is not supported at present */
>> +		rproc->recovery_disabled = true;
>> +
>> +		kproc = rproc->priv;
>> +		kproc->cluster = cluster;
>> +		kproc->core = core;
>> +		kproc->dev = cdev;
>> +		kproc->rproc = rproc;
>> +		core->rproc = rproc;
>> +
>> +		ret = k3_r5_rproc_configure(kproc);
>> +		if (ret) {
>> +			dev_err(dev, "initial configure failed, ret = %d\n",
>> +				ret);
>> +			goto err_config;
>> +		}
>> +
>> +		ret = k3_r5_reserved_mem_init(kproc);
>> +		if (ret) {
>> +			dev_err(dev, "reserved memory init failed, ret = %d\n",
>> +				ret);
>> +			goto err_config;
>> +		}
>> +
>> +		ret = rproc_add(rproc);
>> +		if (ret) {
>> +			dev_err(dev, "rproc_add failed, ret = %d\n", ret);
>> +			goto err_add;
>> +		}
>> +
>> +		/* create only one rproc in lockstep mode */
>> +		if (cluster->mode)
> 
> Here and throughout the file, please use the cluster mode enumeration in order
> to improve readability, i.e
> 
>                  if (cluster->mode == CLUSTER_MODE_LOCKSTEP)

OK.

> 
>> +			break;
>> +	}
>> +
>> +	return 0;
>> +
>> +err_split:
>> +	rproc_del(rproc);
>> +err_add:
>> +	k3_r5_reserved_mem_exit(kproc);
>> +err_config:
>> +	rproc_free(rproc);
>> +	core->rproc = NULL;
>> +out:
>> +	/* undo core0 upon any failures on core1 in split-mode */
>> +	if (!cluster->mode && core == core1) {
>> +		core = list_prev_entry(core, elem);
>> +		rproc = core->rproc;
>> +		kproc = rproc->priv;
>> +		goto err_split;
>> +	}
>> +	return ret;
>> +}
>> +
>> +static int k3_r5_cluster_rproc_exit(struct platform_device *pdev)
>> +{
>> +	struct k3_r5_cluster *cluster = platform_get_drvdata(pdev);
>> +	struct k3_r5_rproc *kproc;
>> +	struct k3_r5_core *core;
>> +	struct rproc *rproc;
>> +
>> +	/*
>> +	 * lockstep mode has only one rproc associated with first core, whereas
>> +	 * split-mode has two rprocs associated with each core, and requires
>> +	 * that core1 be powered down first
>> +	 */
>> +	core = cluster->mode ?
>> +		list_first_entry(&cluster->cores, struct k3_r5_core, elem) :
>> +		list_last_entry(&cluster->cores, struct k3_r5_core, elem);
>> +
>> +	list_for_each_entry_from_reverse(core, &cluster->cores, elem) {
>> +		rproc = core->rproc;
>> +		kproc = rproc->priv;
>> +
>> +		rproc_del(rproc);
>> +
>> +		k3_r5_reserved_mem_exit(kproc);
>> +
>> +		rproc_free(rproc);
>> +		core->rproc = NULL;
>> +	}
>> +
>> +	return 0;
>> +}
>> +
>> +static int k3_r5_core_of_get_internal_memories(struct platform_device *pdev,
>> +					       struct k3_r5_core *core)
>> +{
>> +	static const char * const mem_names[] = {"atcm", "btcm"};
>> +	struct device *dev = &pdev->dev;
>> +	struct resource *res;
>> +	int num_mems;
>> +	int i, ret;
>> +
>> +	num_mems = ARRAY_SIZE(mem_names);
>> +	core->mem = devm_kcalloc(dev, num_mems, sizeof(*core->mem), GFP_KERNEL);
>> +	if (!core->mem)
>> +		return -ENOMEM;
>> +
>> +	for (i = 0; i < num_mems; i++) {
>> +		res = platform_get_resource_byname(pdev, IORESOURCE_MEM,
>> +						   mem_names[i]);
>> +		if (!res) {
>> +			dev_err(dev, "found no memory resource for %s\n",
>> +				mem_names[i]);
>> +			ret = -EINVAL;
>> +			goto fail;
>> +		}
>> +		if (!devm_request_mem_region(dev, res->start,
>> +					     resource_size(res),
>> +					     dev_name(dev))) {
>> +			dev_err(dev, "could not request %s region for resource\n",
>> +				mem_names[i]);
>> +			ret = -EBUSY;
>> +			goto fail;
>> +		}
>> +
>> +		/*
>> +		 * TCMs are designed in general to support RAM-like backing
>> +		 * memories. So, map these as Normal Non-Cached memories. This
>> +		 * also avoids/fixes any potential alignment faults due to
>> +		 * unaligned data accesses when using memcpy() or memset()
>> +		 * functions (normally seen with device type memory).
>> +		 */
>> +		core->mem[i].cpu_addr = devm_ioremap_wc(dev, res->start,
>> +							resource_size(res));
>> +		if (IS_ERR(core->mem[i].cpu_addr)) {
>> +			dev_err(dev, "failed to map %s memory\n", mem_names[i]);
>> +			ret = PTR_ERR(core->mem[i].cpu_addr);
>> +			devm_release_mem_region(dev, res->start,
>> +						resource_size(res));
>> +			goto fail;
>> +		}
>> +		core->mem[i].bus_addr = res->start;
>> +
>> +		/*
>> +		 * TODO:
>> +		 * The R5F cores can place ATCM & BTCM anywhere in its address
>> +		 * based on the corresponding Region Registers in the System
>> +		 * Control coprocessor. For now, place ATCM and BTCM at
>> +		 * addresses 0 and 0x41010000 (same as the bus address on AM65x
>> +		 * SoCs) based on loczrama setting
>> +		 */
>> +		if (!strcmp(mem_names[i], "atcm")) {
>> +			core->mem[i].dev_addr = core->loczrama ?
>> +							0 : K3_R5_TCM_DEV_ADDR;
>> +		} else {
>> +			core->mem[i].dev_addr = core->loczrama ?
>> +							K3_R5_TCM_DEV_ADDR : 0;
>> +		}
>> +		core->mem[i].size = resource_size(res);
>> +
>> +		dev_dbg(dev, "memory %8s: bus addr %pa size 0x%zx va %pK da 0x%x\n",
>> +			mem_names[i], &core->mem[i].bus_addr,
>> +			core->mem[i].size, core->mem[i].cpu_addr,
>> +			core->mem[i].dev_addr);
>> +	}
>> +	core->num_mems = num_mems;
>> +
>> +	return 0;
>> +
>> +fail:
>> +	for (i--; i >= 0; i--) {
>> +		devm_iounmap(dev, core->mem[i].cpu_addr);
>> +		devm_release_mem_region(dev, core->mem[i].bus_addr,
>> +					core->mem[i].size);
>> +	}
>> +	if (core->mem)
>> +		devm_kfree(dev, core->mem);
> 
> Since the devm_ API has been used for memory allocation all this should be
> called automatically when of_platform_depopulate() is called.

The per-core platform devices do not use a dedicated platform driver 
associated with them, so there were no probe/remove functions associated 
with them. I added these since some of them do not have devm_ 
equivalents, and it was easier to balance everything. Let me retest 
these and get back to you, if of_platform_depopulate() takes care 
automatically and without any ordering issues.

> 
>> +	return ret;
>> +}
>> +
>> +static
>> +struct ti_sci_proc *k3_r5_core_of_get_tsp(struct device *dev,
>> +					  const struct ti_sci_handle *sci)
>> +{
>> +	struct ti_sci_proc *tsp;
>> +	u32 temp[2];
>> +	int ret;
>> +
>> +	ret = of_property_read_u32_array(dev->of_node, "ti,sci-proc-ids",
>> +					 temp, 2);
>> +	if (ret < 0)
>> +		return ERR_PTR(ret);
>> +
>> +	tsp = kzalloc(sizeof(*tsp), GFP_KERNEL);
> 
> Here @dev is available, I would just call devm_kzalloc() and get rid of the
> kfree() in the error path of k3_r5_core_of_init() and k3_r5_core_of_exit().
> 
>> +	if (!tsp)
>> +		return ERR_PTR(-ENOMEM);
>> +
>> +	tsp->dev = dev;
>> +	tsp->sci = sci;
>> +	tsp->ops = &sci->ops.proc_ops;
>> +	tsp->proc_id = temp[0];
>> +	tsp->host_id = temp[1];
>> +
>> +	return tsp;
>> +}
>> +
>> +static int k3_r5_core_of_init(struct platform_device *pdev)
>> +{
>> +	struct device *dev = &pdev->dev;
>> +	struct device_node *np = dev->of_node;
>> +	struct k3_r5_core *core;
>> +	int ret, ret1;
>> +
>> +	core = devm_kzalloc(dev, sizeof(*core), GFP_KERNEL);
>> +	if (!core)
>> +		return -ENOMEM;
>> +
>> +	core->dev = dev;
>> +	core->atcm_enable = 0;
>> +	core->btcm_enable = 1;
>> +	core->loczrama = 1;
> 
> Please add a comment that justifies the selection of default value.  Otherwise
> this looks very esoteric.

Yeah sure. These are default values on the SoC.

> 
>> +
>> +	ret = of_property_read_u32(np, "atcm-enable", &core->atcm_enable);
>> +	if (ret < 0 && ret != -EINVAL) {
>> +		dev_err(dev, "invalid format for atcm-enable, ret = %d\n", ret);
>> +		goto err_of;
>> +	}
>> +
>> +	ret = of_property_read_u32(np, "btcm-enable", &core->btcm_enable);
>> +	if (ret < 0 && ret != -EINVAL) {
>> +		dev_err(dev, "invalid format for btcm-enable, ret = %d\n", ret);
>> +		goto err_of;
>> +	}
>> +
>> +	ret = of_property_read_u32(np, "loczrama", &core->loczrama);
>> +	if (ret < 0 && ret != -EINVAL) {
>> +		dev_err(dev, "invalid format for loczrama, ret = %d\n", ret);
>> +		goto err_of;
>> +	}
>> +
>> +	core->ti_sci = ti_sci_get_by_phandle(np, "ti,sci");
>> +	if (IS_ERR(core->ti_sci)) {
>> +		ret = PTR_ERR(core->ti_sci);
>> +		if (ret != -EPROBE_DEFER) {
>> +			dev_err(dev, "failed to get ti-sci handle, ret = %d\n",
>> +				ret);
>> +		}
>> +		core->ti_sci = NULL;
>> +		goto err_of;
>> +	}
>> +
>> +	ret = of_property_read_u32(np, "ti,sci-dev-id", &core->ti_sci_id);
>> +	if (ret) {
>> +		dev_err(dev, "missing 'ti,sci-dev-id' property\n");
>> +		goto err_sci_id;
>> +	}
>> +
>> +	core->reset = reset_control_get_exclusive(dev, NULL);
>> +	if (IS_ERR(core->reset)) {
>> +		ret = PTR_ERR(core->reset);
>> +		if (ret != -EPROBE_DEFER) {
>> +			dev_err(dev, "failed to get reset handle, ret = %d\n",
>> +				ret);
>> +		}
>> +		goto err_sci_id;
>> +	}
>> +
>> +	core->tsp = k3_r5_core_of_get_tsp(dev, core->ti_sci);
>> +	if (IS_ERR(core->tsp)) {
>> +		dev_err(dev, "failed to construct ti-sci proc control, ret = %d\n",
>> +			ret);
>> +		ret = PTR_ERR(core->tsp);
>> +		goto err_sci_proc;
>> +	}
>> +
>> +	ret = ti_sci_proc_request(core->tsp);
>> +	if (ret < 0) {
>> +		dev_err(dev, "ti_sci_proc_request failed, ret = %d\n", ret);
>> +		goto err_proc;
>> +	}
>> +
>> +	ret = k3_r5_core_of_get_internal_memories(pdev, core);
>> +	if (ret) {
>> +		dev_err(dev, "failed to get internal memories, ret = %d\n",
>> +			ret);
>> +		goto err_intmem;
>> +	}
>> +
>> +	platform_set_drvdata(pdev, core);
>> +
>> +	return 0;
>> +
>> +err_intmem:
>> +	ret1 = ti_sci_proc_release(core->tsp);
>> +	if (ret1)
>> +		dev_err(dev, "failed to release proc, ret1 = %d\n", ret1);
>> +err_proc:
>> +	kfree(core->tsp);
>> +err_sci_proc:
>> +	reset_control_put(core->reset);
>> +err_sci_id:
>> +	ret1 = ti_sci_put_handle(core->ti_sci);
>> +	if (ret1)
>> +		dev_err(dev, "failed to put ti_sci handle, ret = %d\n", ret1);
> 
> s/"ret = %d"/"ret1 = %d"

OK

> 
>> +err_of:
>> +	devm_kfree(dev, core);
> 
> Same comment as above, this should be called automatically.
> 
>> +	return ret;
>> +}
>> +
>> +/*
>> + * free the resources explicitly since driver model is not being used
>> + * for the child R5F devices
>> + */
>> +static int k3_r5_core_of_exit(struct platform_device *pdev)
>> +{
>> +	struct k3_r5_core *core = platform_get_drvdata(pdev);
>> +	struct device *dev = &pdev->dev;
>> +	int i, ret;
>> +
>> +	for (i = 0; i < core->num_mems; i++) {
>> +		devm_release_mem_region(dev, core->mem[i].bus_addr,
>> +					core->mem[i].size);
>> +		devm_iounmap(dev, core->mem[i].cpu_addr);
>> +	}
>> +	if (core->mem)
>> +		devm_kfree(dev, core->mem);
>> +
>> +	ret = ti_sci_proc_release(core->tsp);
>> +	if (ret)
>> +		dev_err(dev, "failed to release proc, ret = %d\n", ret);
>> +
>> +	kfree(core->tsp);
>> +	reset_control_put(core->reset);
>> +
>> +	ret = ti_sci_put_handle(core->ti_sci);
>> +	if (ret)
>> +		dev_err(dev, "failed to put ti_sci handle, ret = %d\n", ret);
>> +
>> +	platform_set_drvdata(pdev, NULL);
>> +	devm_kfree(dev, core);
> 
> Same comment regarding the devm_ API, this should be called automatically.

Yeah, will relook at the devm_ usage at all places.

Thanks for the review.

regards,
Suman

> 
> I will continue tomorrow,
> Mathieu
> 
>> +
>> +	return ret;
>> +}
>> +
>> +static int k3_r5_cluster_of_init(struct platform_device *pdev)
>> +{
>> +	struct k3_r5_cluster *cluster = platform_get_drvdata(pdev);
>> +	struct device *dev = &pdev->dev;
>> +	struct device_node *np = dev->of_node;
>> +	struct platform_device *cpdev;
>> +	struct device_node *child;
>> +	struct k3_r5_core *core, *temp;
>> +	int ret;
>> +
>> +	for_each_available_child_of_node(np, child) {
>> +		cpdev = of_find_device_by_node(child);
>> +		if (!cpdev) {
>> +			ret = -ENODEV;
>> +			dev_err(dev, "could not get R5 core platform device\n");
>> +			goto fail;
>> +		}
>> +
>> +		ret = k3_r5_core_of_init(cpdev);
>> +		if (ret) {
>> +			dev_err(dev, "k3_r5_core_of_init failed, ret = %d\n",
>> +				ret);
>> +			put_device(&cpdev->dev);
>> +			goto fail;
>> +		}
>> +
>> +		core = platform_get_drvdata(cpdev);
>> +		put_device(&cpdev->dev);
>> +		list_add_tail(&core->elem, &cluster->cores);
>> +	}
>> +
>> +	return 0;
>> +
>> +fail:
>> +	list_for_each_entry_safe_reverse(core, temp, &cluster->cores, elem) {
>> +		list_del(&core->elem);
>> +		cpdev = to_platform_device(core->dev);
>> +		if (k3_r5_core_of_exit(cpdev))
>> +			dev_err(dev, "k3_r5_core_of_exit cleanup failed\n");
>> +	}
>> +	return ret;
>> +}
>> +
>> +static int k3_r5_cluster_of_exit(struct platform_device *pdev)
>> +{
>> +	struct k3_r5_cluster *cluster = platform_get_drvdata(pdev);
>> +	struct device *dev = &pdev->dev;
>> +	struct platform_device *cpdev;
>> +	struct k3_r5_core *core, *temp;
>> +	int ret;
>> +
>> +	list_for_each_entry_safe_reverse(core, temp, &cluster->cores, elem) {
>> +		list_del(&core->elem);
>> +		cpdev = to_platform_device(core->dev);
>> +		ret = k3_r5_core_of_exit(cpdev);
>> +		if (ret) {
>> +			dev_err(dev, "k3_r5_core_of_exit failed, ret = %d\n",
>> +				ret);
>> +			break;
>> +		}
>> +	}
>> +
>> +	return ret;
>> +}
>> +
>> +static int k3_r5_probe(struct platform_device *pdev)
>> +{
>> +	struct device *dev = &pdev->dev;
>> +	struct device_node *np = dev->of_node;
>> +	struct k3_r5_cluster *cluster;
>> +	int ret, ret1;
>> +	int num_cores;
>> +
>> +	cluster = devm_kzalloc(dev, sizeof(*cluster), GFP_KERNEL);
>> +	if (!cluster)
>> +		return -ENOMEM;
>> +
>> +	cluster->dev = dev;
>> +	cluster->mode = CLUSTER_MODE_LOCKSTEP;
>> +	INIT_LIST_HEAD(&cluster->cores);
>> +
>> +	ret = of_property_read_u32(np, "lockstep-mode", &cluster->mode);
>> +	if (ret < 0 && ret != -EINVAL) {
>> +		dev_err(dev, "invalid format for lockstep-mode, ret = %d\n",
>> +			ret);
>> +		return ret;
>> +	}
>> +
>> +	num_cores = of_get_available_child_count(np);
>> +	if (num_cores != 2) {
>> +		dev_err(dev, "MCU cluster requires both R5F cores to be enabled, num_cores = %d\n",
>> +			num_cores);
>> +		return -ENODEV;
>> +	}
>> +
>> +	platform_set_drvdata(pdev, cluster);
>> +
>> +	dev_dbg(dev, "creating child devices for R5F cores\n");
>> +	ret = of_platform_populate(np, NULL, NULL, dev);
>> +	if (ret) {
>> +		dev_err(dev, "of_platform_populate failed, ret = %d\n", ret);
>> +		return ret;
>> +	}
>> +
>> +	ret = k3_r5_cluster_of_init(pdev);
>> +	if (ret) {
>> +		dev_err(dev, "k3_r5_cluster_of_init failed, ret = %d\n", ret);
>> +		goto fail_of;
>> +	}
>> +
>> +	ret = k3_r5_cluster_rproc_init(pdev);
>> +	if (ret) {
>> +		dev_err(dev, "k3_r5_cluster_rproc_init failed, ret = %d\n",
>> +			ret);
>> +		goto fail_rproc;
>> +	}
>> +
>> +	return 0;
>> +
>> +fail_rproc:
>> +	ret1 = k3_r5_cluster_of_exit(pdev);
>> +	if (ret1)
>> +		dev_err(dev, "k3_r5_cluster_of_exit failed, ret = %d\n", ret1);
>> +fail_of:
>> +	of_platform_depopulate(dev);
>> +	return ret;
>> +}
>> +
>> +static int k3_r5_remove(struct platform_device *pdev)
>> +{
>> +	struct device *dev = &pdev->dev;
>> +	int ret;
>> +
>> +	ret = k3_r5_cluster_rproc_exit(pdev);
>> +	if (ret) {
>> +		dev_err(dev, "k3_r5_cluster_rproc_exit failed, ret = %d\n",
>> +			ret);
>> +		goto fail;
>> +	}
>> +
>> +	ret = k3_r5_cluster_of_exit(pdev);
>> +	if (ret) {
>> +		dev_err(dev, "k3_r5_cluster_of_exit failed, ret = %d\n", ret);
>> +		goto fail;
>> +	}
>> +
>> +	dev_dbg(dev, "removing child devices for R5F cores\n");
>> +	of_platform_depopulate(dev);
>> +
>> +fail:
>> +	return ret;
>> +}
>> +
>> +static const struct of_device_id k3_r5_of_match[] = {
>> +	{ .compatible = "ti,am654-r5fss", },
>> +	{ .compatible = "ti,j721e-r5fss", },
>> +	{ /* sentinel */ },
>> +};
>> +MODULE_DEVICE_TABLE(of, k3_r5_of_match);
>> +
>> +static struct platform_driver k3_r5_rproc_driver = {
>> +	.probe = k3_r5_probe,
>> +	.remove = k3_r5_remove,
>> +	.driver = {
>> +		.name = "k3_r5_rproc",
>> +		.of_match_table = k3_r5_of_match,
>> +	},
>> +};
>> +
>> +module_platform_driver(k3_r5_rproc_driver);
>> +
>> +MODULE_LICENSE("GPL v2");
>> +MODULE_DESCRIPTION("TI K3 R5F remote processor driver");
>> +MODULE_AUTHOR("Suman Anna <s-anna@ti.com>");
>> -- 
>> 2.23.0
>>