diff options
Diffstat (limited to 'drivers/pci')
| -rw-r--r-- | drivers/pci/pci.c | 30 |
1 files changed, 30 insertions, 0 deletions
diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c index f4c26e6118ea..1027f180792c 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 |