diff options
Diffstat (limited to 'drivers/pci')
| -rw-r--r-- | drivers/pci/pci.c | 32 |
1 files changed, 32 insertions, 0 deletions
diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c index da75c422ba85..f2cd11130737 100644 --- a/drivers/pci/pci.c +++ b/drivers/pci/pci.c @@ -733,6 +733,38 @@ u16 pci_find_vsec_capability(struct pci_dev *dev, u16 vendor, int cap) EXPORT_SYMBOL_GPL(pci_find_vsec_capability); /** + * pci_find_dvsec_capability - Find DVSEC for vendor + * @dev: PCI device to query + * @vendor: Vendor ID to match for the DVSEC + * @dvsec: Designated Vendor-specific capability ID + * + * If DVSEC has Vendor ID @vendor and DVSEC ID @dvsec return the capability + * offset in config space; otherwise return 0. + */ +u16 pci_find_dvsec_capability(struct pci_dev *dev, u16 vendor, u16 dvsec) +{ + int pos; + + pos = pci_find_ext_capability(dev, PCI_EXT_CAP_ID_DVSEC); + if (!pos) + return 0; + + while (pos) { + u16 v, id; + + pci_read_config_word(dev, pos + PCI_DVSEC_HEADER1, &v); + pci_read_config_word(dev, pos + PCI_DVSEC_HEADER2, &id); + if (vendor == v && dvsec == id) + return pos; + + pos = pci_find_next_ext_capability(dev, pos, PCI_EXT_CAP_ID_DVSEC); + } + + return 0; +} +EXPORT_SYMBOL_GPL(pci_find_dvsec_capability); + +/** * pci_find_parent_resource - return resource region of parent bus of given * region * @dev: PCI device structure contains resources to be searched |