mbox series

[V11,00/12] Add Tegra194 PCIe support

Message ID 20190624091505.1711-1-vidyas@nvidia.com
Headers show
Series Add Tegra194 PCIe support | expand

Message

Vidya Sagar June 24, 2019, 9:14 a.m. UTC
Tegra194 has six PCIe controllers based on Synopsys DesignWare core.
There are two Universal PHY (UPHY) blocks with each supporting 12(HSIO:
Hisg Speed IO) and 8(NVHS: NVIDIA High Speed) lanes respectively.
Controllers:0~4 use UPHY lanes from HSIO brick whereas Controller:5 uses
UPHY lanes from NVHS brick. Lane mapping in HSIO UPHY brick to each PCIe
controller (0~4) is controlled in XBAR module by BPMP-FW. Since PCIe
core has PIPE interface, a glue module called PIPE-to-UPHY (P2U) is used
to connect each UPHY lane (applicable to both HSIO and NVHS UPHY bricks)
to PCIe controller
This patch series
- Adds support for P2U PHY driver
- Adds support for PCIe host controller
- Adds device tree nodes each PCIe controllers
- Enables nodes applicable to p2972-0000 platform
- Adds helper APIs in Designware core driver to get capability regs offset
- Adds defines for new feature registers of PCIe spec revision 4
- Makes changes in DesignWare core driver to get Tegra194 PCIe working

Testing done on P2972-0000 platform
- Able to get PCIe link up with on-board Marvel eSATA controller
- Able to get PCIe link up with NVMe cards connected to M.2 Key-M slot
- Able to do data transfers with both SATA drives and NVMe cards

Note
- Enabling x8 slot on P2972-0000 platform requires pinmux driver for Tegra194.
  It is being worked on currently and hence Controller:5 (i.e. x8 slot) is
  disabled in this patch series. A future patch series would enable this.
- This series is based on top of the following series
  Jisheng's patches to add support to .remove() in Designware sub-system
  https://patchwork.kernel.org/project/linux-pci/list/?series=98559
  (Jisheng's patches are now accepted and applied for v5.2)
  My patches made on top of Jisheng's patches to export various symbols
  http://patchwork.ozlabs.org/project/linux-pci/list/?series=115671

Changes since [v10]:
* Removed device-tree patches from the series as they are applied to relevant
  Tegra specific trees by Thierry Reding.
* Included older Tegra chips to extend quirk that disables MSI interrupt being
  used for Tegra PCIe root ports.
* Addressed review comments in P2U driver file.

Changes since [v9]:
* Used _relaxed() versions of readl() & writel()

Changes since [v8]:
* Made the drivers dependent on ARCH_TEGRA_194_SOC directly
* Addressed review comments from Dmitry

Changes since [v7]:
* Changed P2U driver file name from pcie-p2u-tegra194.c to phy-tegra194-p2u.c
* Addressed review comments from Thierry and Rob

Changes since [v6]:
* Took care of review comments from Rob
* Added a quirk to disable MSI for root ports
* Removed using pcie_pme_disable_msi() API in host controller driver

Changes since [v5]:
* Removed patch that exports pcie_bus_config symbol
* Took care of review comments from Thierry and Rob

Changes since [v4]:
* Removed redundant APIs in pcie-designware-ep.c file after moving them
  to pcie-designware.c file based on Bjorn's review comments

Changes since [v3]:
* Rebased on top of linux-next top of the tree
* Addressed Gustavo's comments and added his Ack for some of the changes.

Changes since [v2]:
* Addressed review comments from Thierry

Changes since [v1]:
* Addressed review comments from Bjorn, Thierry, Jonathan, Rob & Kishon
* Added more patches in v2 series

Vidya Sagar (12):
  PCI: Add #defines for some of PCIe spec r4.0 features
  PCI: Disable MSI for Tegra root ports
  PCI: dwc: Perform dbi regs write lock towards the end
  PCI: dwc: Move config space capability search API
  PCI: dwc: Add ext config space capability search API
  dt-bindings: PCI: designware: Add binding for CDM register check
  PCI: dwc: Add support to enable CDM register check
  dt-bindings: Add PCIe supports-clkreq property
  dt-bindings: PCI: tegra: Add device tree support for Tegra194
  dt-bindings: PHY: P2U: Add Tegra194 P2U block
  phy: tegra: Add PCIe PIPE2UPHY support
  PCI: tegra: Add Tegra194 PCIe support

 .../bindings/pci/designware-pcie.txt          |    5 +
 .../bindings/pci/nvidia,tegra194-pcie.txt     |  155 ++
 Documentation/devicetree/bindings/pci/pci.txt |    5 +
 .../bindings/phy/phy-tegra194-p2u.txt         |   28 +
 drivers/pci/controller/dwc/Kconfig            |   10 +
 drivers/pci/controller/dwc/Makefile           |    1 +
 .../pci/controller/dwc/pcie-designware-ep.c   |   37 +-
 .../pci/controller/dwc/pcie-designware-host.c |   14 +-
 drivers/pci/controller/dwc/pcie-designware.c  |   87 +
 drivers/pci/controller/dwc/pcie-designware.h  |   12 +
 drivers/pci/controller/dwc/pcie-tegra194.c    | 1635 +++++++++++++++++
 drivers/pci/quirks.c                          |   53 +
 drivers/phy/tegra/Kconfig                     |    7 +
 drivers/phy/tegra/Makefile                    |    1 +
 drivers/phy/tegra/phy-tegra194-p2u.c          |  120 ++
 include/uapi/linux/pci_regs.h                 |   22 +-
 16 files changed, 2150 insertions(+), 42 deletions(-)
 create mode 100644 Documentation/devicetree/bindings/pci/nvidia,tegra194-pcie.txt
 create mode 100644 Documentation/devicetree/bindings/phy/phy-tegra194-p2u.txt
 create mode 100644 drivers/pci/controller/dwc/pcie-tegra194.c
 create mode 100644 drivers/phy/tegra/phy-tegra194-p2u.c

Comments

Lorenzo Pieralisi June 27, 2019, 2:38 p.m. UTC | #1
On Mon, Jun 24, 2019 at 02:44:54PM +0530, Vidya Sagar wrote:
> Add #defines only for the Data Link Feature and Physical Layer 16.0 GT/s
> features.
> 
> Signed-off-by: Vidya Sagar <vidyas@nvidia.com>
> Reviewed-by: Thierry Reding <treding@nvidia.com>
> ---
> Changes since [v10]:
> * None
> 
> Changes since [v9]:
> * None
> 
> Changes since [v8]:
> * None
> 
> Changes since [v7]:
> * None
> 
> Changes since [v6]:
> * None
> 
> Changes since [v5]:
> * None
> 
> Changes since [v4]:
> * None
> 
> Changes since [v3]:
> * None
> 
> Changes since [v2]:
> * Updated commit message and description to explicitly mention that defines are
>   added only for some of the features and not all.
> 
> Changes since [v1]:
> * None
> 
>  include/uapi/linux/pci_regs.h | 22 +++++++++++++++++++++-
>  1 file changed, 21 insertions(+), 1 deletion(-)

I need Bjorn's ACK to merge this patch.

Lorenzo

> diff --git a/include/uapi/linux/pci_regs.h b/include/uapi/linux/pci_regs.h
> index f28e562d7ca8..1c79f6a097d2 100644
> --- a/include/uapi/linux/pci_regs.h
> +++ b/include/uapi/linux/pci_regs.h
> @@ -713,7 +713,9 @@
>  #define PCI_EXT_CAP_ID_DPC	0x1D	/* Downstream Port Containment */
>  #define PCI_EXT_CAP_ID_L1SS	0x1E	/* L1 PM Substates */
>  #define PCI_EXT_CAP_ID_PTM	0x1F	/* Precision Time Measurement */
> -#define PCI_EXT_CAP_ID_MAX	PCI_EXT_CAP_ID_PTM
> +#define PCI_EXT_CAP_ID_DLF	0x25	/* Data Link Feature */
> +#define PCI_EXT_CAP_ID_PL	0x26	/* Physical Layer 16.0 GT/s */
> +#define PCI_EXT_CAP_ID_MAX	PCI_EXT_CAP_ID_PL
>  
>  #define PCI_EXT_CAP_DSN_SIZEOF	12
>  #define PCI_EXT_CAP_MCAST_ENDPOINT_SIZEOF 40
> @@ -1053,4 +1055,22 @@
>  #define  PCI_L1SS_CTL1_LTR_L12_TH_SCALE	0xe0000000  /* LTR_L1.2_THRESHOLD_Scale */
>  #define PCI_L1SS_CTL2		0x0c	/* Control 2 Register */
>  
> +/* Data Link Feature */
> +#define PCI_DLF_CAP		0x04	/* Capabilities Register */
> +#define  PCI_DLF_LOCAL_DLF_SUP_MASK	0x007fffff  /* Local Data Link Feature Supported */
> +#define  PCI_DLF_EXCHANGE_ENABLE	0x80000000  /* Data Link Feature Exchange Enable */
> +#define PCI_DLF_STS		0x08	/* Status Register */
> +#define  PCI_DLF_REMOTE_DLF_SUP_MASK	0x007fffff  /* Remote Data Link Feature Supported */
> +#define  PCI_DLF_REMOTE_DLF_SUP_VALID	0x80000000  /* Remote Data Link Feature Support Valid */
> +
> +/* Physical Layer 16.0 GT/s */
> +#define PCI_PL_16GT_CAP		0x04	/* Capabilities Register */
> +#define PCI_PL_16GT_CTRL	0x08	/* Control Register */
> +#define PCI_PL_16GT_STS		0x0c	/* Status Register */
> +#define PCI_PL_16GT_LDPM_STS	0x10	/* Local Data Parity Mismatch Status Register */
> +#define PCI_PL_16GT_FRDPM_STS	0x14	/* First Retimer Data Parity Mismatch Status Register */
> +#define PCI_PL_16GT_SRDPM_STS	0x18	/* Second Retimer Data Parity Mismatch Status Register */
> +#define PCI_PL_16GT_RSVD	0x1C	/* Reserved */
> +#define PCI_PL_16GT_LE_CTRL	0x20	/* Lane Equalization Control Register */
> +
>  #endif /* LINUX_PCI_REGS_H */
> -- 
> 2.17.1
>
Lorenzo Pieralisi June 27, 2019, 2:58 p.m. UTC | #2
On Mon, Jun 24, 2019 at 02:44:56PM +0530, Vidya Sagar wrote:
> Remove multiple write enable and disable sequences of dbi registers as
> Tegra194 implements writes to BAR-0 register (offset: 0x10) controlled by
> DBI write-lock enable bit thereby not allowing any further writes to BAR-0
> register in config space to take place. Hence enabling write permission at
> the start of function and disabling the same only towards the end.

I do not understand what this patch does, I would like to rephrase
the commit log in a way that is easier to parse.

In particular I do not get what you mean in relation to BAR-0, I am
confused, please clarify.

Lorenzo

> Signed-off-by: Vidya Sagar <vidyas@nvidia.com>
> Reviewed-by: Thierry Reding <treding@nvidia.com>
> Acked-by: Jingoo Han <jingoohan1@gmail.com>
> ---
> Changes since [v10]:
> * None
> 
> Changes since [v9]:
> * None
> 
> Changes since [v8]:
> * None
> 
> Changes since [v7]:
> * None
> 
> Changes since [v6]:
> * None
> 
> Changes since [v5]:
> * Moved write enable to the beginning of the API and write disable to the end
> 
> Changes since [v4]:
> * None
> 
> Changes since [v3]:
> * None
> 
> Changes since [v2]:
> * None
> 
> Changes since [v1]:
> * None
> 
>  drivers/pci/controller/dwc/pcie-designware-host.c | 14 ++++++++------
>  1 file changed, 8 insertions(+), 6 deletions(-)
> 
> diff --git a/drivers/pci/controller/dwc/pcie-designware-host.c b/drivers/pci/controller/dwc/pcie-designware-host.c
> index f93252d0da5b..d3156446ff27 100644
> --- a/drivers/pci/controller/dwc/pcie-designware-host.c
> +++ b/drivers/pci/controller/dwc/pcie-designware-host.c
> @@ -628,6 +628,12 @@ void dw_pcie_setup_rc(struct pcie_port *pp)
>  	u32 val, ctrl, num_ctrls;
>  	struct dw_pcie *pci = to_dw_pcie_from_pp(pp);
>  
> +	/*
> +	 * Enable DBI read-only registers for writing/updating configuration.
> +	 * Write permission gets disabled towards the end of this function.
> +	 */
> +	dw_pcie_dbi_ro_wr_en(pci);
> +
>  	dw_pcie_setup(pci);
>  
>  	if (!pp->ops->msi_host_init) {
> @@ -650,12 +656,10 @@ void dw_pcie_setup_rc(struct pcie_port *pp)
>  	dw_pcie_writel_dbi(pci, PCI_BASE_ADDRESS_1, 0x00000000);
>  
>  	/* Setup interrupt pins */
> -	dw_pcie_dbi_ro_wr_en(pci);
>  	val = dw_pcie_readl_dbi(pci, PCI_INTERRUPT_LINE);
>  	val &= 0xffff00ff;
>  	val |= 0x00000100;
>  	dw_pcie_writel_dbi(pci, PCI_INTERRUPT_LINE, val);
> -	dw_pcie_dbi_ro_wr_dis(pci);
>  
>  	/* Setup bus numbers */
>  	val = dw_pcie_readl_dbi(pci, PCI_PRIMARY_BUS);
> @@ -687,15 +691,13 @@ void dw_pcie_setup_rc(struct pcie_port *pp)
>  
>  	dw_pcie_wr_own_conf(pp, PCI_BASE_ADDRESS_0, 4, 0);
>  
> -	/* Enable write permission for the DBI read-only register */
> -	dw_pcie_dbi_ro_wr_en(pci);
>  	/* Program correct class for RC */
>  	dw_pcie_wr_own_conf(pp, PCI_CLASS_DEVICE, 2, PCI_CLASS_BRIDGE_PCI);
> -	/* Better disable write permission right after the update */
> -	dw_pcie_dbi_ro_wr_dis(pci);
>  
>  	dw_pcie_rd_own_conf(pp, PCIE_LINK_WIDTH_SPEED_CONTROL, 4, &val);
>  	val |= PORT_LOGIC_SPEED_CHANGE;
>  	dw_pcie_wr_own_conf(pp, PCIE_LINK_WIDTH_SPEED_CONTROL, 4, val);
> +
> +	dw_pcie_dbi_ro_wr_dis(pci);
>  }
>  EXPORT_SYMBOL_GPL(dw_pcie_setup_rc);
> -- 
> 2.17.1
>
Vidya Sagar June 27, 2019, 3:33 p.m. UTC | #3
On 6/27/2019 8:28 PM, Lorenzo Pieralisi wrote:
> On Mon, Jun 24, 2019 at 02:44:56PM +0530, Vidya Sagar wrote:
>> Remove multiple write enable and disable sequences of dbi registers as
>> Tegra194 implements writes to BAR-0 register (offset: 0x10) controlled by
>> DBI write-lock enable bit thereby not allowing any further writes to BAR-0
>> register in config space to take place. Hence enabling write permission at
>> the start of function and disabling the same only towards the end.
> 
> I do not understand what this patch does, I would like to rephrase
> the commit log in a way that is easier to parse.
> 
> In particular I do not get what you mean in relation to BAR-0, I am
> confused, please clarify.
> 
> Lorenzo
Well, some of the Synopsys DesignWare core's DBI registers are protected with a lock
without which, they are read-only by default. Existing code in dw_pcie_setup_rc() API
tries to unlock and lock multiple times whenever it wants to update those write-protected
registers. This patch attempts to unlock all such write-protected registers for writing
once in the beginning of the function and lock them back towards the end.
As far as BAR-0 register (which is at offset 0x10 in DBI space... nothing but the
config space) in Tegra194 is concerned, it is one of those registers to which
writes are protected. I could have added unlock/lock pair around accessing this register,
but that would bloat this API with one more pair of unlock/lock, instead I chose to remove
unlock/lock pairs for all protected registers and have unlock in the beginning and lock
towards the end.

-Vidya Sagar

> 
>> Signed-off-by: Vidya Sagar <vidyas@nvidia.com>
>> Reviewed-by: Thierry Reding <treding@nvidia.com>
>> Acked-by: Jingoo Han <jingoohan1@gmail.com>
>> ---
>> Changes since [v10]:
>> * None
>>
>> Changes since [v9]:
>> * None
>>
>> Changes since [v8]:
>> * None
>>
>> Changes since [v7]:
>> * None
>>
>> Changes since [v6]:
>> * None
>>
>> Changes since [v5]:
>> * Moved write enable to the beginning of the API and write disable to the end
>>
>> Changes since [v4]:
>> * None
>>
>> Changes since [v3]:
>> * None
>>
>> Changes since [v2]:
>> * None
>>
>> Changes since [v1]:
>> * None
>>
>>   drivers/pci/controller/dwc/pcie-designware-host.c | 14 ++++++++------
>>   1 file changed, 8 insertions(+), 6 deletions(-)
>>
>> diff --git a/drivers/pci/controller/dwc/pcie-designware-host.c b/drivers/pci/controller/dwc/pcie-designware-host.c
>> index f93252d0da5b..d3156446ff27 100644
>> --- a/drivers/pci/controller/dwc/pcie-designware-host.c
>> +++ b/drivers/pci/controller/dwc/pcie-designware-host.c
>> @@ -628,6 +628,12 @@ void dw_pcie_setup_rc(struct pcie_port *pp)
>>   	u32 val, ctrl, num_ctrls;
>>   	struct dw_pcie *pci = to_dw_pcie_from_pp(pp);
>>   
>> +	/*
>> +	 * Enable DBI read-only registers for writing/updating configuration.
>> +	 * Write permission gets disabled towards the end of this function.
>> +	 */
>> +	dw_pcie_dbi_ro_wr_en(pci);
>> +
>>   	dw_pcie_setup(pci);
>>   
>>   	if (!pp->ops->msi_host_init) {
>> @@ -650,12 +656,10 @@ void dw_pcie_setup_rc(struct pcie_port *pp)
>>   	dw_pcie_writel_dbi(pci, PCI_BASE_ADDRESS_1, 0x00000000);
>>   
>>   	/* Setup interrupt pins */
>> -	dw_pcie_dbi_ro_wr_en(pci);
>>   	val = dw_pcie_readl_dbi(pci, PCI_INTERRUPT_LINE);
>>   	val &= 0xffff00ff;
>>   	val |= 0x00000100;
>>   	dw_pcie_writel_dbi(pci, PCI_INTERRUPT_LINE, val);
>> -	dw_pcie_dbi_ro_wr_dis(pci);
>>   
>>   	/* Setup bus numbers */
>>   	val = dw_pcie_readl_dbi(pci, PCI_PRIMARY_BUS);
>> @@ -687,15 +691,13 @@ void dw_pcie_setup_rc(struct pcie_port *pp)
>>   
>>   	dw_pcie_wr_own_conf(pp, PCI_BASE_ADDRESS_0, 4, 0);
>>   
>> -	/* Enable write permission for the DBI read-only register */
>> -	dw_pcie_dbi_ro_wr_en(pci);
>>   	/* Program correct class for RC */
>>   	dw_pcie_wr_own_conf(pp, PCI_CLASS_DEVICE, 2, PCI_CLASS_BRIDGE_PCI);
>> -	/* Better disable write permission right after the update */
>> -	dw_pcie_dbi_ro_wr_dis(pci);
>>   
>>   	dw_pcie_rd_own_conf(pp, PCIE_LINK_WIDTH_SPEED_CONTROL, 4, &val);
>>   	val |= PORT_LOGIC_SPEED_CHANGE;
>>   	dw_pcie_wr_own_conf(pp, PCIE_LINK_WIDTH_SPEED_CONTROL, 4, val);
>> +
>> +	dw_pcie_dbi_ro_wr_dis(pci);
>>   }
>>   EXPORT_SYMBOL_GPL(dw_pcie_setup_rc);
>> -- 
>> 2.17.1
>>
Lorenzo Pieralisi June 27, 2019, 3:50 p.m. UTC | #4
On Thu, Jun 27, 2019 at 09:03:08PM +0530, Vidya Sagar wrote:
> On 6/27/2019 8:28 PM, Lorenzo Pieralisi wrote:
> > On Mon, Jun 24, 2019 at 02:44:56PM +0530, Vidya Sagar wrote:
> > > Remove multiple write enable and disable sequences of dbi registers as
> > > Tegra194 implements writes to BAR-0 register (offset: 0x10) controlled by
> > > DBI write-lock enable bit thereby not allowing any further writes to BAR-0
> > > register in config space to take place. Hence enabling write permission at
> > > the start of function and disabling the same only towards the end.
> > 
> > I do not understand what this patch does, I would like to rephrase
> > the commit log in a way that is easier to parse.
> > 
> > In particular I do not get what you mean in relation to BAR-0, I am
> > confused, please clarify.
> > 
> > Lorenzo
> Well, some of the Synopsys DesignWare core's DBI registers are
> protected with a lock without which, they are read-only by default.
> Existing code in dw_pcie_setup_rc() API tries to unlock and lock
> multiple times whenever it wants to update those write-protected
> registers. This patch attempts to unlock all such write-protected
> registers for writing once in the beginning of the function and lock
> them back towards the end.  As far as BAR-0 register (which is at
> offset 0x10 in DBI space... nothing but the config space) in Tegra194
> is concerned, it is one of those registers to which writes are
> protected. I could have added unlock/lock pair around accessing this
> register, but that would bloat this API with one more pair of
> unlock/lock, instead I chose to remove unlock/lock pairs for all
> protected registers and have unlock in the beginning and lock towards
> the end.

Ok, so DBI space registers that require write permissions are per-IP.
This is clearer so the commit log must be rewritten, it is not clear at
all in this respect at least not as-is, if you read it you will
notice ;-)

Lorenzo

> 
> -Vidya Sagar
> 
> > 
> > > Signed-off-by: Vidya Sagar <vidyas@nvidia.com>
> > > Reviewed-by: Thierry Reding <treding@nvidia.com>
> > > Acked-by: Jingoo Han <jingoohan1@gmail.com>
> > > ---
> > > Changes since [v10]:
> > > * None
> > > 
> > > Changes since [v9]:
> > > * None
> > > 
> > > Changes since [v8]:
> > > * None
> > > 
> > > Changes since [v7]:
> > > * None
> > > 
> > > Changes since [v6]:
> > > * None
> > > 
> > > Changes since [v5]:
> > > * Moved write enable to the beginning of the API and write disable to the end
> > > 
> > > Changes since [v4]:
> > > * None
> > > 
> > > Changes since [v3]:
> > > * None
> > > 
> > > Changes since [v2]:
> > > * None
> > > 
> > > Changes since [v1]:
> > > * None
> > > 
> > >   drivers/pci/controller/dwc/pcie-designware-host.c | 14 ++++++++------
> > >   1 file changed, 8 insertions(+), 6 deletions(-)
> > > 
> > > diff --git a/drivers/pci/controller/dwc/pcie-designware-host.c b/drivers/pci/controller/dwc/pcie-designware-host.c
> > > index f93252d0da5b..d3156446ff27 100644
> > > --- a/drivers/pci/controller/dwc/pcie-designware-host.c
> > > +++ b/drivers/pci/controller/dwc/pcie-designware-host.c
> > > @@ -628,6 +628,12 @@ void dw_pcie_setup_rc(struct pcie_port *pp)
> > >   	u32 val, ctrl, num_ctrls;
> > >   	struct dw_pcie *pci = to_dw_pcie_from_pp(pp);
> > > +	/*
> > > +	 * Enable DBI read-only registers for writing/updating configuration.
> > > +	 * Write permission gets disabled towards the end of this function.
> > > +	 */
> > > +	dw_pcie_dbi_ro_wr_en(pci);
> > > +
> > >   	dw_pcie_setup(pci);
> > >   	if (!pp->ops->msi_host_init) {
> > > @@ -650,12 +656,10 @@ void dw_pcie_setup_rc(struct pcie_port *pp)
> > >   	dw_pcie_writel_dbi(pci, PCI_BASE_ADDRESS_1, 0x00000000);
> > >   	/* Setup interrupt pins */
> > > -	dw_pcie_dbi_ro_wr_en(pci);
> > >   	val = dw_pcie_readl_dbi(pci, PCI_INTERRUPT_LINE);
> > >   	val &= 0xffff00ff;
> > >   	val |= 0x00000100;
> > >   	dw_pcie_writel_dbi(pci, PCI_INTERRUPT_LINE, val);
> > > -	dw_pcie_dbi_ro_wr_dis(pci);
> > >   	/* Setup bus numbers */
> > >   	val = dw_pcie_readl_dbi(pci, PCI_PRIMARY_BUS);
> > > @@ -687,15 +691,13 @@ void dw_pcie_setup_rc(struct pcie_port *pp)
> > >   	dw_pcie_wr_own_conf(pp, PCI_BASE_ADDRESS_0, 4, 0);
> > > -	/* Enable write permission for the DBI read-only register */
> > > -	dw_pcie_dbi_ro_wr_en(pci);
> > >   	/* Program correct class for RC */
> > >   	dw_pcie_wr_own_conf(pp, PCI_CLASS_DEVICE, 2, PCI_CLASS_BRIDGE_PCI);
> > > -	/* Better disable write permission right after the update */
> > > -	dw_pcie_dbi_ro_wr_dis(pci);
> > >   	dw_pcie_rd_own_conf(pp, PCIE_LINK_WIDTH_SPEED_CONTROL, 4, &val);
> > >   	val |= PORT_LOGIC_SPEED_CHANGE;
> > >   	dw_pcie_wr_own_conf(pp, PCIE_LINK_WIDTH_SPEED_CONTROL, 4, val);
> > > +
> > > +	dw_pcie_dbi_ro_wr_dis(pci);
> > >   }
> > >   EXPORT_SYMBOL_GPL(dw_pcie_setup_rc);
> > > -- 
> > > 2.17.1
> > > 
>
Vidya Sagar June 27, 2019, 4:52 p.m. UTC | #5
On 6/27/2019 9:20 PM, Lorenzo Pieralisi wrote:
> On Thu, Jun 27, 2019 at 09:03:08PM +0530, Vidya Sagar wrote:
>> On 6/27/2019 8:28 PM, Lorenzo Pieralisi wrote:
>>> On Mon, Jun 24, 2019 at 02:44:56PM +0530, Vidya Sagar wrote:
>>>> Remove multiple write enable and disable sequences of dbi registers as
>>>> Tegra194 implements writes to BAR-0 register (offset: 0x10) controlled by
>>>> DBI write-lock enable bit thereby not allowing any further writes to BAR-0
>>>> register in config space to take place. Hence enabling write permission at
>>>> the start of function and disabling the same only towards the end.
>>>
>>> I do not understand what this patch does, I would like to rephrase
>>> the commit log in a way that is easier to parse.
>>>
>>> In particular I do not get what you mean in relation to BAR-0, I am
>>> confused, please clarify.
>>>
>>> Lorenzo
>> Well, some of the Synopsys DesignWare core's DBI registers are
>> protected with a lock without which, they are read-only by default.
>> Existing code in dw_pcie_setup_rc() API tries to unlock and lock
>> multiple times whenever it wants to update those write-protected
>> registers. This patch attempts to unlock all such write-protected
>> registers for writing once in the beginning of the function and lock
>> them back towards the end.  As far as BAR-0 register (which is at
>> offset 0x10 in DBI space... nothing but the config space) in Tegra194
>> is concerned, it is one of those registers to which writes are
>> protected. I could have added unlock/lock pair around accessing this
>> register, but that would bloat this API with one more pair of
>> unlock/lock, instead I chose to remove unlock/lock pairs for all
>> protected registers and have unlock in the beginning and lock towards
>> the end.
> 
> Ok, so DBI space registers that require write permissions are per-IP.
> This is clearer so the commit log must be rewritten, it is not clear at
> all in this respect at least not as-is, if you read it you will
> notice ;-)
Ok. I'll update commit message in next patch series.

-Vidya Sagar
> 
> Lorenzo
> 
>>
>> -Vidya Sagar
>>
>>>
>>>> Signed-off-by: Vidya Sagar <vidyas@nvidia.com>
>>>> Reviewed-by: Thierry Reding <treding@nvidia.com>
>>>> Acked-by: Jingoo Han <jingoohan1@gmail.com>
>>>> ---
>>>> Changes since [v10]:
>>>> * None
>>>>
>>>> Changes since [v9]:
>>>> * None
>>>>
>>>> Changes since [v8]:
>>>> * None
>>>>
>>>> Changes since [v7]:
>>>> * None
>>>>
>>>> Changes since [v6]:
>>>> * None
>>>>
>>>> Changes since [v5]:
>>>> * Moved write enable to the beginning of the API and write disable to the end
>>>>
>>>> Changes since [v4]:
>>>> * None
>>>>
>>>> Changes since [v3]:
>>>> * None
>>>>
>>>> Changes since [v2]:
>>>> * None
>>>>
>>>> Changes since [v1]:
>>>> * None
>>>>
>>>>    drivers/pci/controller/dwc/pcie-designware-host.c | 14 ++++++++------
>>>>    1 file changed, 8 insertions(+), 6 deletions(-)
>>>>
>>>> diff --git a/drivers/pci/controller/dwc/pcie-designware-host.c b/drivers/pci/controller/dwc/pcie-designware-host.c
>>>> index f93252d0da5b..d3156446ff27 100644
>>>> --- a/drivers/pci/controller/dwc/pcie-designware-host.c
>>>> +++ b/drivers/pci/controller/dwc/pcie-designware-host.c
>>>> @@ -628,6 +628,12 @@ void dw_pcie_setup_rc(struct pcie_port *pp)
>>>>    	u32 val, ctrl, num_ctrls;
>>>>    	struct dw_pcie *pci = to_dw_pcie_from_pp(pp);
>>>> +	/*
>>>> +	 * Enable DBI read-only registers for writing/updating configuration.
>>>> +	 * Write permission gets disabled towards the end of this function.
>>>> +	 */
>>>> +	dw_pcie_dbi_ro_wr_en(pci);
>>>> +
>>>>    	dw_pcie_setup(pci);
>>>>    	if (!pp->ops->msi_host_init) {
>>>> @@ -650,12 +656,10 @@ void dw_pcie_setup_rc(struct pcie_port *pp)
>>>>    	dw_pcie_writel_dbi(pci, PCI_BASE_ADDRESS_1, 0x00000000);
>>>>    	/* Setup interrupt pins */
>>>> -	dw_pcie_dbi_ro_wr_en(pci);
>>>>    	val = dw_pcie_readl_dbi(pci, PCI_INTERRUPT_LINE);
>>>>    	val &= 0xffff00ff;
>>>>    	val |= 0x00000100;
>>>>    	dw_pcie_writel_dbi(pci, PCI_INTERRUPT_LINE, val);
>>>> -	dw_pcie_dbi_ro_wr_dis(pci);
>>>>    	/* Setup bus numbers */
>>>>    	val = dw_pcie_readl_dbi(pci, PCI_PRIMARY_BUS);
>>>> @@ -687,15 +691,13 @@ void dw_pcie_setup_rc(struct pcie_port *pp)
>>>>    	dw_pcie_wr_own_conf(pp, PCI_BASE_ADDRESS_0, 4, 0);
>>>> -	/* Enable write permission for the DBI read-only register */
>>>> -	dw_pcie_dbi_ro_wr_en(pci);
>>>>    	/* Program correct class for RC */
>>>>    	dw_pcie_wr_own_conf(pp, PCI_CLASS_DEVICE, 2, PCI_CLASS_BRIDGE_PCI);
>>>> -	/* Better disable write permission right after the update */
>>>> -	dw_pcie_dbi_ro_wr_dis(pci);
>>>>    	dw_pcie_rd_own_conf(pp, PCIE_LINK_WIDTH_SPEED_CONTROL, 4, &val);
>>>>    	val |= PORT_LOGIC_SPEED_CHANGE;
>>>>    	dw_pcie_wr_own_conf(pp, PCIE_LINK_WIDTH_SPEED_CONTROL, 4, val);
>>>> +
>>>> +	dw_pcie_dbi_ro_wr_dis(pci);
>>>>    }
>>>>    EXPORT_SYMBOL_GPL(dw_pcie_setup_rc);
>>>> -- 
>>>> 2.17.1
>>>>
>>
Vidya Sagar July 1, 2019, 12:42 p.m. UTC | #6
On 6/27/2019 8:08 PM, Lorenzo Pieralisi wrote:
> On Mon, Jun 24, 2019 at 02:44:54PM +0530, Vidya Sagar wrote:
>> Add #defines only for the Data Link Feature and Physical Layer 16.0 GT/s
>> features.
>>
>> Signed-off-by: Vidya Sagar <vidyas@nvidia.com>
>> Reviewed-by: Thierry Reding <treding@nvidia.com>
>> ---
>> Changes since [v10]:
>> * None
>>
>> Changes since [v9]:
>> * None
>>
>> Changes since [v8]:
>> * None
>>
>> Changes since [v7]:
>> * None
>>
>> Changes since [v6]:
>> * None
>>
>> Changes since [v5]:
>> * None
>>
>> Changes since [v4]:
>> * None
>>
>> Changes since [v3]:
>> * None
>>
>> Changes since [v2]:
>> * Updated commit message and description to explicitly mention that defines are
>>    added only for some of the features and not all.
>>
>> Changes since [v1]:
>> * None
>>
>>   include/uapi/linux/pci_regs.h | 22 +++++++++++++++++++++-
>>   1 file changed, 21 insertions(+), 1 deletion(-)
> 
> I need Bjorn's ACK to merge this patch.
I sent V12 patches out for review.
Bjorn, please provide ACK for V12 version of this change.

-Vidya Sagar

> 
> Lorenzo
> 
>> diff --git a/include/uapi/linux/pci_regs.h b/include/uapi/linux/pci_regs.h
>> index f28e562d7ca8..1c79f6a097d2 100644
>> --- a/include/uapi/linux/pci_regs.h
>> +++ b/include/uapi/linux/pci_regs.h
>> @@ -713,7 +713,9 @@
>>   #define PCI_EXT_CAP_ID_DPC	0x1D	/* Downstream Port Containment */
>>   #define PCI_EXT_CAP_ID_L1SS	0x1E	/* L1 PM Substates */
>>   #define PCI_EXT_CAP_ID_PTM	0x1F	/* Precision Time Measurement */
>> -#define PCI_EXT_CAP_ID_MAX	PCI_EXT_CAP_ID_PTM
>> +#define PCI_EXT_CAP_ID_DLF	0x25	/* Data Link Feature */
>> +#define PCI_EXT_CAP_ID_PL	0x26	/* Physical Layer 16.0 GT/s */
>> +#define PCI_EXT_CAP_ID_MAX	PCI_EXT_CAP_ID_PL
>>   
>>   #define PCI_EXT_CAP_DSN_SIZEOF	12
>>   #define PCI_EXT_CAP_MCAST_ENDPOINT_SIZEOF 40
>> @@ -1053,4 +1055,22 @@
>>   #define  PCI_L1SS_CTL1_LTR_L12_TH_SCALE	0xe0000000  /* LTR_L1.2_THRESHOLD_Scale */
>>   #define PCI_L1SS_CTL2		0x0c	/* Control 2 Register */
>>   
>> +/* Data Link Feature */
>> +#define PCI_DLF_CAP		0x04	/* Capabilities Register */
>> +#define  PCI_DLF_LOCAL_DLF_SUP_MASK	0x007fffff  /* Local Data Link Feature Supported */
>> +#define  PCI_DLF_EXCHANGE_ENABLE	0x80000000  /* Data Link Feature Exchange Enable */
>> +#define PCI_DLF_STS		0x08	/* Status Register */
>> +#define  PCI_DLF_REMOTE_DLF_SUP_MASK	0x007fffff  /* Remote Data Link Feature Supported */
>> +#define  PCI_DLF_REMOTE_DLF_SUP_VALID	0x80000000  /* Remote Data Link Feature Support Valid */
>> +
>> +/* Physical Layer 16.0 GT/s */
>> +#define PCI_PL_16GT_CAP		0x04	/* Capabilities Register */
>> +#define PCI_PL_16GT_CTRL	0x08	/* Control Register */
>> +#define PCI_PL_16GT_STS		0x0c	/* Status Register */
>> +#define PCI_PL_16GT_LDPM_STS	0x10	/* Local Data Parity Mismatch Status Register */
>> +#define PCI_PL_16GT_FRDPM_STS	0x14	/* First Retimer Data Parity Mismatch Status Register */
>> +#define PCI_PL_16GT_SRDPM_STS	0x18	/* Second Retimer Data Parity Mismatch Status Register */
>> +#define PCI_PL_16GT_RSVD	0x1C	/* Reserved */
>> +#define PCI_PL_16GT_LE_CTRL	0x20	/* Lane Equalization Control Register */
>> +
>>   #endif /* LINUX_PCI_REGS_H */
>> -- 
>> 2.17.1
>>