[+cc Vinod, Dan, dmaengine]
On Tue, Dec 15, 2020 at 06:30:13PM +0100, Gustavo Pimentel wrote:
> Add pci_find_vsec_capability() that crawls through the device config
> space searching in all Vendor-Specific Extended Capabilities for a
> particular capability ID.
>
> Vendor-Specific Extended Capability (VSEC) is a PCIe capability (acts
> like a wrapper) specified by PCI-SIG that allows the vendor to create
> their own and specific capability in the device config space.
>
> Signed-off-by: Gustavo Pimentel <gustavo.pimentel@xxxxxxxxxxxx>
If you fix the below, feel free to add my
Acked-by: Bjorn Helgaas <bhelgaas@xxxxxxxxxx>
Otherwise, I can take it myself. But that will be an ordering issue
in the merge window if you merge the rest of the series via another
tree.
> ---
> drivers/pci/pci.c | 29 +++++++++++++++++++++++++++++
> include/linux/pci.h | 1 +
> include/uapi/linux/pci_regs.h | 5 +++++
> 3 files changed, 35 insertions(+)
>
> diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c
> index 6d4d5a2..235d0b2 100644
> --- a/drivers/pci/pci.c
> +++ b/drivers/pci/pci.c
> @@ -623,6 +623,35 @@ u64 pci_get_dsn(struct pci_dev *dev)
> }
> EXPORT_SYMBOL_GPL(pci_get_dsn);
>
> +/**
> + * pci_find_vsec_capability - Find a vendor-specific extended capability
> + * @dev: PCI device to query
> + * @cap: vendor-specific capability id code
s/id/ID/
> + *
> + * Returns the address of the vendor-specific structure that matches the
> + * requested capability id code within the device's PCI configuration space
s/id/ID/
> + * or 0 if it does not find a match.
> + */
> +int pci_find_vsec_capability(struct pci_dev *dev, int vsec_cap_id)
> +{
> + u32 header;
> + int vsec;
int vsec;
u32 header;
since that's the order they're used.
> +
> + vsec = pci_find_ext_capability(dev, PCI_EXT_CAP_ID_VNDR);
> + while (vsec) {
> + if (pci_read_config_dword(dev, vsec + 0x4,
s/0x4/PCI_VSEC_HDR/
> + &header) == PCIBIOS_SUCCESSFUL &&
> + PCI_VSEC_CAP_ID(header) == vsec_cap_id)
> + break;
return vsec;
> +
> + vsec = pci_find_next_ext_capability(dev, vsec,
> + PCI_EXT_CAP_ID_VNDR);
> + }
> +
> + return vsec;
return 0;
> +}
> +EXPORT_SYMBOL_GPL(pci_find_vsec_capability);
> +
> static int __pci_find_next_ht_cap(struct pci_dev *dev, int pos, int ht_cap)
> {
> int rc, ttl = PCI_FIND_CAP_TTL;
> diff --git a/include/linux/pci.h b/include/linux/pci.h
> index 22207a7..effecb0 100644
> --- a/include/linux/pci.h
> +++ b/include/linux/pci.h
> @@ -1067,6 +1067,7 @@ int pci_find_capability(struct pci_dev *dev, int cap);
> int pci_find_next_capability(struct pci_dev *dev, u8 pos, int cap);
> int pci_find_ext_capability(struct pci_dev *dev, int cap);
> int pci_find_next_ext_capability(struct pci_dev *dev, int pos, int cap);
> +int pci_find_vsec_capability(struct pci_dev *dev, int vsec_cap_id);
> int pci_find_ht_capability(struct pci_dev *dev, int ht_cap);
> int pci_find_next_ht_capability(struct pci_dev *dev, int pos, int ht_cap);
> struct pci_bus *pci_find_next_bus(const struct pci_bus *from);
> diff --git a/include/uapi/linux/pci_regs.h b/include/uapi/linux/pci_regs.h
> index a95d55f..f5d17be 100644
> --- a/include/uapi/linux/pci_regs.h
> +++ b/include/uapi/linux/pci_regs.h
> @@ -730,6 +730,11 @@
> #define PCI_EXT_CAP_DSN_SIZEOF 12
> #define PCI_EXT_CAP_MCAST_ENDPOINT_SIZEOF 40
>
> +/* Vendor-Specific Extended Capabilities */
> +#define PCI_VSEC_CAP_ID(header) (header & 0x0000ffff)
> +#define PCI_VSEC_CAP_REV(header) ((header >> 16) & 0xf)
> +#define PCI_VSEC_CAP_LEN(header) ((header >> 20) & 0xffc)
Please put these next to the existing PCI_VSEC_HDR.
Why does PCI_VSEC_CAP_LEN mask with 0xffc instead of 0xfff? I don't
see anything in the spec about VSEC Length having to be a multiple of
4 (PCIe r5.0, sec 7.9.5.2).
But you don't use this anyway, so I'd just drop it (and
PCI_VSEC_CAP_REV) altogether.
> /* Advanced Error Reporting */
> #define PCI_ERR_UNCOR_STATUS 4 /* Uncorrectable Error Status */
> #define PCI_ERR_UNC_UND 0x00000001 /* Undefined */
> --
> 2.7.4
>
