Re: [PATCH v2] PCI: Remove redundant macro

[Alex Williamson <alex.williamson@redhat.com>]

On Mon, 16 Dec 2024 09:35:36 +0800
zhangdongdong@eswincomputing.com wrote:

> From: Dongdong Zhang <zhangdongdong@eswincomputing.com>
> 
> Removed the duplicate macro `PCI_VSEC_HDR` and its related macro
> `PCI_VSEC_HDR_LEN_SHIFT` from `pci_regs.h` to avoid redundancy and
> inconsistencies. Updated VFIO PCI code to use `PCI_VNDR_HEADER` and
> `PCI_VNDR_HEADER_LEN()` for consistent naming and functionality.
> 
> These changes aim to streamline header handling while minimizing
> impact, given the niche usage of these macros in userspace.
> 
> Signed-off-by: Dongdong Zhang <zhangdongdong@eswincomputing.com>
> ---
>  drivers/vfio/pci/vfio_pci_config.c | 5 +++--

Acked-by: Alex Williamson <alex.williamson@redhat.com>

Let me know if this is expected to go through the vfio tree.  Given
that vfio is just collateral to a PCI change and it's touching PCI
uapi, I'm assuming it'll go through the PCI tree.  Thanks,

Alex

>  include/uapi/linux/pci_regs.h      | 3 ---
>  2 files changed, 3 insertions(+), 5 deletions(-)
> 
> diff --git a/drivers/vfio/pci/vfio_pci_config.c b/drivers/vfio/pci/vfio_pci_config.c
> index ea2745c1ac5e..5572fd99b921 100644
> --- a/drivers/vfio/pci/vfio_pci_config.c
> +++ b/drivers/vfio/pci/vfio_pci_config.c
> @@ -1389,11 +1389,12 @@ static int vfio_ext_cap_len(struct vfio_pci_core_device *vdev, u16 ecap, u16 epo
>  
>  	switch (ecap) {
>  	case PCI_EXT_CAP_ID_VNDR:
> -		ret = pci_read_config_dword(pdev, epos + PCI_VSEC_HDR, &dword);
> +		ret = pci_read_config_dword(pdev, epos + PCI_VNDR_HEADER,
> +					    &dword);
>  		if (ret)
>  			return pcibios_err_to_errno(ret);
>  
> -		return dword >> PCI_VSEC_HDR_LEN_SHIFT;
> +		return PCI_VNDR_HEADER_LEN(dword);
>  	case PCI_EXT_CAP_ID_VC:
>  	case PCI_EXT_CAP_ID_VC9:
>  	case PCI_EXT_CAP_ID_MFVC:
> diff --git a/include/uapi/linux/pci_regs.h b/include/uapi/linux/pci_regs.h
> index 1601c7ed5fab..bcd44c7ca048 100644
> --- a/include/uapi/linux/pci_regs.h
> +++ b/include/uapi/linux/pci_regs.h
> @@ -1001,9 +1001,6 @@
>  #define PCI_ACS_CTRL		0x06	/* ACS Control Register */
>  #define PCI_ACS_EGRESS_CTL_V	0x08	/* ACS Egress Control Vector */
>  
> -#define PCI_VSEC_HDR		4	/* extended cap - vendor-specific */
> -#define  PCI_VSEC_HDR_LEN_SHIFT	20	/* shift for length field */
> -
>  /* SATA capability */
>  #define PCI_SATA_REGS		4	/* SATA REGs specifier */
>  #define  PCI_SATA_REGS_MASK	0xF	/* location - BAR#/inline */