On Thu, Feb 18, 2021 at 08:03:58PM +0100, Gustavo Pimentel wrote:
> Add pci_find_vsec_capability() to locate a Vendor-Specific Extended
> Capability with the specified VSEC ID.
>
> The Vendor-Specific Extended Capability (VSEC) allows one or more
> proprietary capabilities defined by the vendor which aren't standard
> or shared between vendors.
>
> Signed-off-by: Gustavo Pimentel <gustavo.pimentel@xxxxxxxxxxxx>
Beautiful, thanks!
Acked-by: Bjorn Helgaas <bhelgaas@xxxxxxxxxx>
> ---
> drivers/pci/pci.c | 30 ++++++++++++++++++++++++++++++
> include/linux/pci.h | 1 +
> 2 files changed, 31 insertions(+)
>
> diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c
> index b9fecc2..aef217c 100644
> --- a/drivers/pci/pci.c
> +++ b/drivers/pci/pci.c
> @@ -693,6 +693,36 @@ u8 pci_find_ht_capability(struct pci_dev *dev, int ht_cap)
> EXPORT_SYMBOL_GPL(pci_find_ht_capability);
>
> /**
> + * pci_find_vsec_capability - Find a vendor-specific extended capability
> + * @dev: PCI device to query
> + * @vendor: Vendor ID for which capability is defined
> + * @cap: Vendor-specific capability ID
> + *
> + * If @dev has Vendor ID @vendor, search for a VSEC capability with
> + * VSEC ID @cap. If found, return the capability offset in
> + * config space; otherwise return 0.
> + */
> +u16 pci_find_vsec_capability(struct pci_dev *dev, u16 vendor, int cap)
> +{
> + u16 vsec = 0;
> + u32 header;
> +
> + if (vendor != dev->vendor)
> + return 0;
> +
> + while ((vsec = pci_find_next_ext_capability(dev, vsec,
> + PCI_EXT_CAP_ID_VNDR))) {
> + if (pci_read_config_dword(dev, vsec + PCI_VNDR_HEADER,
> + &header) == PCIBIOS_SUCCESSFUL &&
> + PCI_VNDR_HEADER_ID(header) == cap)
> + return vsec;
> + }
> +
> + return 0;
> +}
> +EXPORT_SYMBOL_GPL(pci_find_vsec_capability);
> +
> +/**
> * pci_find_parent_resource - return resource region of parent bus of given
> * region
> * @dev: PCI device structure contains resources to be searched
> diff --git a/include/linux/pci.h b/include/linux/pci.h
> index b32126d..814f814 100644
> --- a/include/linux/pci.h
> +++ b/include/linux/pci.h
> @@ -1077,6 +1077,7 @@ u8 pci_find_next_ht_capability(struct pci_dev *dev, u8 pos, int ht_cap);
> u16 pci_find_ext_capability(struct pci_dev *dev, int cap);
> u16 pci_find_next_ext_capability(struct pci_dev *dev, u16 pos, int cap);
> struct pci_bus *pci_find_next_bus(const struct pci_bus *from);
> +u16 pci_find_vsec_capability(struct pci_dev *dev, u16 vendor, int cap);
If you do any updates for other reasons, slide this up one more line
so we have:
u16 pci_find_ext_capability(struct pci_dev *dev, int cap);
u16 pci_find_next_ext_capability(struct pci_dev *dev, u16 pos, int cap);
u16 pci_find_vsec_capability(struct pci_dev *dev, u16 vendor, int cap);
struct pci_bus *pci_find_next_bus(const struct pci_bus *from);
I don't know why pci_find_next_bus() got stuck with the capability
things. It doesn't have anything to do with finding capabilities. It
goes more with pci_get_device(), etc.
But don't roll the series just for that.
> u64 pci_get_dsn(struct pci_dev *dev);
>
> --
> 2.7.4
>
