diff options
Diffstat (limited to 'drivers/pci/pci.c')
-rw-r--r-- | drivers/pci/pci.c | 57 |
1 files changed, 57 insertions, 0 deletions
diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c index d828ca835a98..86821313c007 100644 --- a/drivers/pci/pci.c +++ b/drivers/pci/pci.c @@ -173,6 +173,29 @@ unsigned char pci_bus_max_busnr(struct pci_bus *bus) } EXPORT_SYMBOL_GPL(pci_bus_max_busnr); +/** + * pci_status_get_and_clear_errors - return and clear error bits in PCI_STATUS + * @pdev: the PCI device + * + * Returns error bits set in PCI_STATUS and clears them. + */ +int pci_status_get_and_clear_errors(struct pci_dev *pdev) +{ + u16 status; + int ret; + + ret = pci_read_config_word(pdev, PCI_STATUS, &status); + if (ret != PCIBIOS_SUCCESSFUL) + return -EIO; + + status &= PCI_STATUS_ERROR_BITS; + if (status) + pci_write_config_word(pdev, PCI_STATUS, status); + + return status; +} +EXPORT_SYMBOL_GPL(pci_status_get_and_clear_errors); + #ifdef CONFIG_HAS_IOMEM void __iomem *pci_ioremap_bar(struct pci_dev *pdev, int bar) { @@ -557,6 +580,40 @@ int pci_find_ext_capability(struct pci_dev *dev, int cap) } EXPORT_SYMBOL_GPL(pci_find_ext_capability); +/** + * pci_get_dsn - Read and return the 8-byte Device Serial Number + * @dev: PCI device to query + * + * Looks up the PCI_EXT_CAP_ID_DSN and reads the 8 bytes of the Device Serial + * Number. + * + * Returns the DSN, or zero if the capability does not exist. + */ +u64 pci_get_dsn(struct pci_dev *dev) +{ + u32 dword; + u64 dsn; + int pos; + + pos = pci_find_ext_capability(dev, PCI_EXT_CAP_ID_DSN); + if (!pos) + return 0; + + /* + * The Device Serial Number is two dwords offset 4 bytes from the + * capability position. The specification says that the first dword is + * the lower half, and the second dword is the upper half. + */ + pos += 4; + pci_read_config_dword(dev, pos, &dword); + dsn = (u64)dword; + pci_read_config_dword(dev, pos + 4, &dword); + dsn |= ((u64)dword) << 32; + + return dsn; +} +EXPORT_SYMBOL_GPL(pci_get_dsn); + static int __pci_find_next_ht_cap(struct pci_dev *dev, int pos, int ht_cap) { int rc, ttl = PCI_FIND_CAP_TTL; |