diff mbox

[v2,1/8] device core: Introduce per-device MSI domain pointer

Message ID 1420736772-11088-2-git-send-email-marc.zyngier@arm.com
State Not Applicable
Headers show

Commit Message

Marc Zyngier Jan. 8, 2015, 5:06 p.m. UTC
As MSI-type features are creeping into non-PCI devices, it is
starting to make sense to give our struct device some form of
support for this, by allowing a pointer to an MSI irq domain to
be set/retrieved.

Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
---
 include/linux/device.h | 20 ++++++++++++++++++++
 1 file changed, 20 insertions(+)

Comments

Stuart Yoder Jan. 15, 2015, 8:35 p.m. UTC | #1
On Thu, Jan 8, 2015 at 11:06 AM, Marc Zyngier <marc.zyngier@arm.com> wrote:
> As MSI-type features are creeping into non-PCI devices, it is
> starting to make sense to give our struct device some form of
> support for this, by allowing a pointer to an MSI irq domain to
> be set/retrieved.
>
> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
> ---
>  include/linux/device.h | 20 ++++++++++++++++++++
>  1 file changed, 20 insertions(+)
>
> diff --git a/include/linux/device.h b/include/linux/device.h
> index fb50673..ec4cee5 100644
> --- a/include/linux/device.h
> +++ b/include/linux/device.h
> @@ -690,6 +690,7 @@ struct acpi_dev_node {
>   *             along with subsystem-level and driver-level callbacks.
>   * @pins:      For device pin management.
>   *             See Documentation/pinctrl.txt for details.
> + * @msi_domain: The generic MSI domain this device is using.
>   * @numa_node: NUMA node this device is close to.
>   * @dma_mask:  Dma mask (if dma'ble device).
>   * @coherent_dma_mask: Like dma_mask, but for alloc_coherent mapping as not all
> @@ -750,6 +751,9 @@ struct device {
>         struct dev_pm_info      power;
>         struct dev_pm_domain    *pm_domain;
>
> +#ifdef CONFIG_GENERIC_MSI_IRQ_DOMAIN
> +       struct irq_domain       *msi_domain; /* MSI domain device uses */
> +#endif

This is not a comment on this patch specifically, but a question about other
MSI specific fields that might be needed in struct device.

Currently the generic MSI domain handling has hardcoded assumptions
that devices are PCI-- see the for_each_msi_entry() iterator in msi.h:

  #define dev_to_msi_list(dev)            (&to_pci_dev((dev))->msi_list)

  #define for_each_msi_entry(desc, dev)   \
        list_for_each_entry((desc), dev_to_msi_list((dev)), list)

One approach would be to move the msi_list out of pci_dev and put
it in struct device, so all devices can have an msi_list.

The other approach would be to keep msi_list in a bus specific
device struct, and then dev_to_msi_list() would need to be
implemented as a bus specific callback of some kind.

The above hardcoded PCI assumption isn't going to work.   Wanted to
see if there is any advice in which direction to go.

Thanks,
Stuart Yoder
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Marc Zyngier Jan. 16, 2015, 7:10 p.m. UTC | #2
Hi Stuart,

On 15/01/15 20:35, Stuart Yoder wrote:
> On Thu, Jan 8, 2015 at 11:06 AM, Marc Zyngier <marc.zyngier@arm.com> wrote:
>> As MSI-type features are creeping into non-PCI devices, it is
>> starting to make sense to give our struct device some form of
>> support for this, by allowing a pointer to an MSI irq domain to
>> be set/retrieved.
>>
>> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
>> ---
>>  include/linux/device.h | 20 ++++++++++++++++++++
>>  1 file changed, 20 insertions(+)
>>
>> diff --git a/include/linux/device.h b/include/linux/device.h
>> index fb50673..ec4cee5 100644
>> --- a/include/linux/device.h
>> +++ b/include/linux/device.h
>> @@ -690,6 +690,7 @@ struct acpi_dev_node {
>>   *             along with subsystem-level and driver-level callbacks.
>>   * @pins:      For device pin management.
>>   *             See Documentation/pinctrl.txt for details.
>> + * @msi_domain: The generic MSI domain this device is using.
>>   * @numa_node: NUMA node this device is close to.
>>   * @dma_mask:  Dma mask (if dma'ble device).
>>   * @coherent_dma_mask: Like dma_mask, but for alloc_coherent mapping as not all
>> @@ -750,6 +751,9 @@ struct device {
>>         struct dev_pm_info      power;
>>         struct dev_pm_domain    *pm_domain;
>>
>> +#ifdef CONFIG_GENERIC_MSI_IRQ_DOMAIN
>> +       struct irq_domain       *msi_domain; /* MSI domain device uses */
>> +#endif
> 
> This is not a comment on this patch specifically, but a question about other
> MSI specific fields that might be needed in struct device.
> 
> Currently the generic MSI domain handling has hardcoded assumptions
> that devices are PCI-- see the for_each_msi_entry() iterator in msi.h:
> 
>   #define dev_to_msi_list(dev)            (&to_pci_dev((dev))->msi_list)
> 
>   #define for_each_msi_entry(desc, dev)   \
>         list_for_each_entry((desc), dev_to_msi_list((dev)), list)
> 
> One approach would be to move the msi_list out of pci_dev and put
> it in struct device, so all devices can have an msi_list.
> 
> The other approach would be to keep msi_list in a bus specific
> device struct, and then dev_to_msi_list() would need to be
> implemented as a bus specific callback of some kind.
> 
> The above hardcoded PCI assumption isn't going to work.   Wanted to
> see if there is any advice in which direction to go.

The question is: can we define a generic msi_desc? If yes, then your
first proposal make sense. If not, then it is the second one.

My hunch is that we'll have to move to a model that would look like this:

struct mybus_msi_desc {
	struct msi_desc desc;
	struct mybus_stuff stuff;
};

and move the PCI-specific stuff out of msi_desc.

Thoughts?

	M.
Jiang Liu Jan. 19, 2015, 2:10 a.m. UTC | #3
On 2015/1/16 4:35, Stuart Yoder wrote:
> On Thu, Jan 8, 2015 at 11:06 AM, Marc Zyngier <marc.zyngier@arm.com> wrote:
>> As MSI-type features are creeping into non-PCI devices, it is
>> starting to make sense to give our struct device some form of
>> support for this, by allowing a pointer to an MSI irq domain to
>> be set/retrieved.
>>
>> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
>> ---
>>  include/linux/device.h | 20 ++++++++++++++++++++
>>  1 file changed, 20 insertions(+)
>>
>> diff --git a/include/linux/device.h b/include/linux/device.h
>> index fb50673..ec4cee5 100644
>> --- a/include/linux/device.h
>> +++ b/include/linux/device.h
>> @@ -690,6 +690,7 @@ struct acpi_dev_node {
>>   *             along with subsystem-level and driver-level callbacks.
>>   * @pins:      For device pin management.
>>   *             See Documentation/pinctrl.txt for details.
>> + * @msi_domain: The generic MSI domain this device is using.
>>   * @numa_node: NUMA node this device is close to.
>>   * @dma_mask:  Dma mask (if dma'ble device).
>>   * @coherent_dma_mask: Like dma_mask, but for alloc_coherent mapping as not all
>> @@ -750,6 +751,9 @@ struct device {
>>         struct dev_pm_info      power;
>>         struct dev_pm_domain    *pm_domain;
>>
>> +#ifdef CONFIG_GENERIC_MSI_IRQ_DOMAIN
>> +       struct irq_domain       *msi_domain; /* MSI domain device uses */
>> +#endif
> 
> This is not a comment on this patch specifically, but a question about other
> MSI specific fields that might be needed in struct device.
> 
> Currently the generic MSI domain handling has hardcoded assumptions
> that devices are PCI-- see the for_each_msi_entry() iterator in msi.h:
> 
>   #define dev_to_msi_list(dev)            (&to_pci_dev((dev))->msi_list)
> 
>   #define for_each_msi_entry(desc, dev)   \
>         list_for_each_entry((desc), dev_to_msi_list((dev)), list)
> 
> One approach would be to move the msi_list out of pci_dev and put
> it in struct device, so all devices can have an msi_list.
> 
> The other approach would be to keep msi_list in a bus specific
> device struct, and then dev_to_msi_list() would need to be
> implemented as a bus specific callback of some kind.
> 
> The above hardcoded PCI assumption isn't going to work.   Wanted to
> see if there is any advice in which direction to go.
Hi Stuart,
	I already have some a patch set to go that direction waiting
send out for review:)
Thanks!
Gerry

> 
> Thanks,
> Stuart Yoder
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> 
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Stuart Yoder Jan. 20, 2015, 5:17 p.m. UTC | #4
Gerry,

So which direction did you take in your patch set--  a) common,
generic msi_desc, or b)  bus-specific msi_desc like Marc showed
(mybus_msi_desc)?

Thanks,
Stuart

On Sun, Jan 18, 2015 at 8:10 PM, Jiang Liu <jiang.liu@linux.intel.com> wrote:
>
>
> On 2015/1/16 4:35, Stuart Yoder wrote:
>> On Thu, Jan 8, 2015 at 11:06 AM, Marc Zyngier <marc.zyngier@arm.com> wrote:
>>> As MSI-type features are creeping into non-PCI devices, it is
>>> starting to make sense to give our struct device some form of
>>> support for this, by allowing a pointer to an MSI irq domain to
>>> be set/retrieved.
>>>
>>> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
>>> ---
>>>  include/linux/device.h | 20 ++++++++++++++++++++
>>>  1 file changed, 20 insertions(+)
>>>
>>> diff --git a/include/linux/device.h b/include/linux/device.h
>>> index fb50673..ec4cee5 100644
>>> --- a/include/linux/device.h
>>> +++ b/include/linux/device.h
>>> @@ -690,6 +690,7 @@ struct acpi_dev_node {
>>>   *             along with subsystem-level and driver-level callbacks.
>>>   * @pins:      For device pin management.
>>>   *             See Documentation/pinctrl.txt for details.
>>> + * @msi_domain: The generic MSI domain this device is using.
>>>   * @numa_node: NUMA node this device is close to.
>>>   * @dma_mask:  Dma mask (if dma'ble device).
>>>   * @coherent_dma_mask: Like dma_mask, but for alloc_coherent mapping as not all
>>> @@ -750,6 +751,9 @@ struct device {
>>>         struct dev_pm_info      power;
>>>         struct dev_pm_domain    *pm_domain;
>>>
>>> +#ifdef CONFIG_GENERIC_MSI_IRQ_DOMAIN
>>> +       struct irq_domain       *msi_domain; /* MSI domain device uses */
>>> +#endif
>>
>> This is not a comment on this patch specifically, but a question about other
>> MSI specific fields that might be needed in struct device.
>>
>> Currently the generic MSI domain handling has hardcoded assumptions
>> that devices are PCI-- see the for_each_msi_entry() iterator in msi.h:
>>
>>   #define dev_to_msi_list(dev)            (&to_pci_dev((dev))->msi_list)
>>
>>   #define for_each_msi_entry(desc, dev)   \
>>         list_for_each_entry((desc), dev_to_msi_list((dev)), list)
>>
>> One approach would be to move the msi_list out of pci_dev and put
>> it in struct device, so all devices can have an msi_list.
>>
>> The other approach would be to keep msi_list in a bus specific
>> device struct, and then dev_to_msi_list() would need to be
>> implemented as a bus specific callback of some kind.
>>
>> The above hardcoded PCI assumption isn't going to work.   Wanted to
>> see if there is any advice in which direction to go.
> Hi Stuart,
>         I already have some a patch set to go that direction waiting
> send out for review:)
> Thanks!
> Gerry
>
>>
>> Thanks,
>> Stuart Yoder
>> --
>> To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
>> the body of a message to majordomo@vger.kernel.org
>> More majordomo info at  http://vger.kernel.org/majordomo-info.html
>> Please read the FAQ at  http://www.tux.org/lkml/
>>
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Jiang Liu Jan. 21, 2015, 1:34 a.m. UTC | #5
On 2015/1/21 1:17, Stuart Yoder wrote:
> Gerry,
> 
> So which direction did you take in your patch set--  a) common,
> generic msi_desc, or b)  bus-specific msi_desc like Marc showed
> (mybus_msi_desc)?
Hi Stuart,
	Currently I'm trying to go the former way as below.
Regards,
Gerry
-----------------------------------------------------------------------
struct msi_desc {
        struct list_head                list;
        unsigned int                    irq;
        unsigned int                    nvec_used;      /* number of
messages */
        struct device *                 dev;
        struct msi_msg                  msg;            /* Last set MSI
message */

#ifdef CONFIG_PCI_MSI
        union {
                struct {                                /* For PCI
MSI/MSI-X */
                        u32 masked;                     /* mask bits */
                        struct {
                                __u8    is_msix : 1;
                                __u8    multiple: 3;    /* log2 num of
messages allocated */
                                __u8    multi_cap : 3;  /* log2 num of
messages supported */
                                __u8    maskbit : 1;    /* mask-pending
bit supported ? */
                                __u8    is_64   : 1;    /* Address size:
0=32bit 1=64bit */
                                __u16   entry_nr;       /* specific
enabled entry */
                                unsigned default_irq;   /* default
pre-assigned irq */
                        } msi_attrib;
                        union {
                                u8      mask_pos;
                                void __iomem *mask_base;
                        };
                };
        };
#endif /* CONFIG_PCI_MSI */
};

> 
> Thanks,
> Stuart
> 
> On Sun, Jan 18, 2015 at 8:10 PM, Jiang Liu <jiang.liu@linux.intel.com> wrote:
>>
>>
>> On 2015/1/16 4:35, Stuart Yoder wrote:
>>> On Thu, Jan 8, 2015 at 11:06 AM, Marc Zyngier <marc.zyngier@arm.com> wrote:
>>>> As MSI-type features are creeping into non-PCI devices, it is
>>>> starting to make sense to give our struct device some form of
>>>> support for this, by allowing a pointer to an MSI irq domain to
>>>> be set/retrieved.
>>>>
>>>> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
>>>> ---
>>>>  include/linux/device.h | 20 ++++++++++++++++++++
>>>>  1 file changed, 20 insertions(+)
>>>>
>>>> diff --git a/include/linux/device.h b/include/linux/device.h
>>>> index fb50673..ec4cee5 100644
>>>> --- a/include/linux/device.h
>>>> +++ b/include/linux/device.h
>>>> @@ -690,6 +690,7 @@ struct acpi_dev_node {
>>>>   *             along with subsystem-level and driver-level callbacks.
>>>>   * @pins:      For device pin management.
>>>>   *             See Documentation/pinctrl.txt for details.
>>>> + * @msi_domain: The generic MSI domain this device is using.
>>>>   * @numa_node: NUMA node this device is close to.
>>>>   * @dma_mask:  Dma mask (if dma'ble device).
>>>>   * @coherent_dma_mask: Like dma_mask, but for alloc_coherent mapping as not all
>>>> @@ -750,6 +751,9 @@ struct device {
>>>>         struct dev_pm_info      power;
>>>>         struct dev_pm_domain    *pm_domain;
>>>>
>>>> +#ifdef CONFIG_GENERIC_MSI_IRQ_DOMAIN
>>>> +       struct irq_domain       *msi_domain; /* MSI domain device uses */
>>>> +#endif
>>>
>>> This is not a comment on this patch specifically, but a question about other
>>> MSI specific fields that might be needed in struct device.
>>>
>>> Currently the generic MSI domain handling has hardcoded assumptions
>>> that devices are PCI-- see the for_each_msi_entry() iterator in msi.h:
>>>
>>>   #define dev_to_msi_list(dev)            (&to_pci_dev((dev))->msi_list)
>>>
>>>   #define for_each_msi_entry(desc, dev)   \
>>>         list_for_each_entry((desc), dev_to_msi_list((dev)), list)
>>>
>>> One approach would be to move the msi_list out of pci_dev and put
>>> it in struct device, so all devices can have an msi_list.
>>>
>>> The other approach would be to keep msi_list in a bus specific
>>> device struct, and then dev_to_msi_list() would need to be
>>> implemented as a bus specific callback of some kind.
>>>
>>> The above hardcoded PCI assumption isn't going to work.   Wanted to
>>> see if there is any advice in which direction to go.
>> Hi Stuart,
>>         I already have some a patch set to go that direction waiting
>> send out for review:)
>> Thanks!
>> Gerry
>>
>>>
>>> Thanks,
>>> Stuart Yoder
>>> --
>>> To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
>>> the body of a message to majordomo@vger.kernel.org
>>> More majordomo info at  http://vger.kernel.org/majordomo-info.html
>>> Please read the FAQ at  http://www.tux.org/lkml/
>>>
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diff mbox

Patch

diff --git a/include/linux/device.h b/include/linux/device.h
index fb50673..ec4cee5 100644
--- a/include/linux/device.h
+++ b/include/linux/device.h
@@ -690,6 +690,7 @@  struct acpi_dev_node {
  * 		along with subsystem-level and driver-level callbacks.
  * @pins:	For device pin management.
  *		See Documentation/pinctrl.txt for details.
+ * @msi_domain: The generic MSI domain this device is using.
  * @numa_node:	NUMA node this device is close to.
  * @dma_mask:	Dma mask (if dma'ble device).
  * @coherent_dma_mask: Like dma_mask, but for alloc_coherent mapping as not all
@@ -750,6 +751,9 @@  struct device {
 	struct dev_pm_info	power;
 	struct dev_pm_domain	*pm_domain;
 
+#ifdef CONFIG_GENERIC_MSI_IRQ_DOMAIN
+	struct irq_domain	*msi_domain; /* MSI domain device uses */
+#endif
 #ifdef CONFIG_PINCTRL
 	struct dev_pin_info	*pins;
 #endif
@@ -837,6 +841,22 @@  static inline void set_dev_node(struct device *dev, int node)
 }
 #endif
 
+static inline struct irq_domain *dev_get_msi_domain(const struct device *dev)
+{
+#ifdef CONFIG_GENERIC_MSI_IRQ_DOMAIN
+	return dev->msi_domain;
+#else
+	return NULL;
+#endif
+}
+
+static inline void dev_set_msi_domain(struct device *dev, struct irq_domain *d)
+{
+#ifdef CONFIG_GENERIC_MSI_IRQ_DOMAIN
+	dev->msi_domain = d;
+#endif
+}
+
 static inline void *dev_get_drvdata(const struct device *dev)
 {
 	return dev->driver_data;