Re: [PATCH mlx5-next 1/2] PCI/TPH: Expose pcie_tph_get_st_table_loc()

[Yishai Hadas <yishaih@nvidia.com>]

On 03/11/2025 17:43, Bjorn Helgaas wrote:
> On Mon, Oct 27, 2025 at 11:34:01AM +0200, Leon Romanovsky wrote:
>> From: Yishai Hadas <yishaih@nvidia.com>
>>
>> Expose pcie_tph_get_st_table_loc() to be used by drivers as will be done
>> in the next patch from the series.
>>
>> Signed-off-by: Yishai Hadas <yishaih@nvidia.com>
>> Signed-off-by: Edward Srouji <edwards@nvidia.com>
>> Signed-off-by: Leon Romanovsky <leonro@nvidia.com>
>> ---
>>   drivers/pci/tph.c       | 7 ++++---
>>   include/linux/pci-tph.h | 1 +
>>   2 files changed, 5 insertions(+), 3 deletions(-)
>>
>> diff --git a/drivers/pci/tph.c b/drivers/pci/tph.c
>> index cc64f93709a4..8f8457ec9adb 100644
>> --- a/drivers/pci/tph.c
>> +++ b/drivers/pci/tph.c
>> @@ -155,7 +155,7 @@ static u8 get_st_modes(struct pci_dev *pdev)
>>   	return reg;
>>   }
>>   
>> -static u32 get_st_table_loc(struct pci_dev *pdev)
>> +u32 pcie_tph_get_st_table_loc(struct pci_dev *pdev)
>>   {
>>   	u32 reg;
>>   
>> @@ -163,6 +163,7 @@ static u32 get_st_table_loc(struct pci_dev *pdev)
>>   
>>   	return FIELD_GET(PCI_TPH_CAP_LOC_MASK, reg);
>>   }
>> +EXPORT_SYMBOL(pcie_tph_get_st_table_loc);
> 
> OK by me, but I think we should add kernel-doc for the return value.
> 
> With that doc added:
> 
> Acked-by: Bjorn Helgaas <bhelgaas@google.com>

Thanks Bjorn.

We may add the below hunk.

Can that work for you ?

diff --git a/drivers/pci/tph.c b/drivers/pci/tph.c
index 8f8457ec9adb..385307a9a328 100644
--- a/drivers/pci/tph.c
+++ b/drivers/pci/tph.c
@@ -155,6 +155,12 @@ static u8 get_st_modes(struct pci_dev *pdev)
         return reg;
  }

+/**
+ * pcie_tph_get_st_table_loc - query the device for its ST table location
+ * @pdev: PCI device to query
+ *
+ * Return the location of the ST table
+ */
  u32 pcie_tph_get_st_table_loc(struct pci_dev *pdev)
  {
         u32 reg;

Yishai

> 
> 
>>   /*
>>    * Return the size of ST table. If ST table is not in TPH Requester Extended
>> @@ -174,7 +175,7 @@ u16 pcie_tph_get_st_table_size(struct pci_dev *pdev)
>>   	u32 loc;
>>   
>>   	/* Check ST table location first */
>> -	loc = get_st_table_loc(pdev);
>> +	loc = pcie_tph_get_st_table_loc(pdev);
>>   
>>   	/* Convert loc to match with PCI_TPH_LOC_* defined in pci_regs.h */
>>   	loc = FIELD_PREP(PCI_TPH_CAP_LOC_MASK, loc);
>> @@ -299,7 +300,7 @@ int pcie_tph_set_st_entry(struct pci_dev *pdev, unsigned int index, u16 tag)
>>   	 */
>>   	set_ctrl_reg_req_en(pdev, PCI_TPH_REQ_DISABLE);
>>   
>> -	loc = get_st_table_loc(pdev);
>> +	loc = pcie_tph_get_st_table_loc(pdev);
>>   	/* Convert loc to match with PCI_TPH_LOC_* */
>>   	loc = FIELD_PREP(PCI_TPH_CAP_LOC_MASK, loc);
>>   
>> diff --git a/include/linux/pci-tph.h b/include/linux/pci-tph.h
>> index 9e4e331b1603..ba28140ce670 100644
>> --- a/include/linux/pci-tph.h
>> +++ b/include/linux/pci-tph.h
>> @@ -29,6 +29,7 @@ int pcie_tph_get_cpu_st(struct pci_dev *dev,
>>   void pcie_disable_tph(struct pci_dev *pdev);
>>   int pcie_enable_tph(struct pci_dev *pdev, int mode);
>>   u16 pcie_tph_get_st_table_size(struct pci_dev *pdev);
>> +u32 pcie_tph_get_st_table_loc(struct pci_dev *pdev);
>>   #else
>>   static inline int pcie_tph_set_st_entry(struct pci_dev *pdev,
>>   					unsigned int index, u16 tag)
>>
>> -- 
>> 2.51.0
>>