diff options
| author | Bjorn Helgaas <bhelgaas@google.com> | 2012-07-13 14:24:59 -0600 |
|---|---|---|
| committer | Bjorn Helgaas <bhelgaas@google.com> | 2012-08-22 13:47:27 -0600 |
| commit | 44a9a36f6be43636ac2342c06d9feb60db77826a (patch) | |
| tree | 3ff1b3d23d6416454599aa5712a081fdbe5aaaa0 /drivers | |
| parent | 0d7614f09c1ebdbaa1599a5aba7593f147bf96ee (diff) | |
PCI: Add pci_find_next_ext_capability()
Some extended capabilities, e.g., the vendor-specific capability, can
occur several times. The existing pci_find_ext_capability() only finds
the first occurrence. This adds pci_find_next_ext_capability(), which
can iterate through all of them.
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Diffstat (limited to 'drivers')
| -rw-r--r-- | drivers/pci/pci.c | 40 |
1 files changed, 30 insertions, 10 deletions
diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c index f3ea977a5b1b..d34415ba0f64 100644 --- a/drivers/pci/pci.c +++ b/drivers/pci/pci.c @@ -286,20 +286,17 @@ static int pci_pcie_cap2(struct pci_dev *dev) } /** - * pci_find_ext_capability - Find an extended capability + * pci_find_next_ext_capability - Find an extended capability * @dev: PCI device to query + * @start: address at which to start looking (0 to start at beginning of list) * @cap: capability code * - * Returns the address of the requested extended capability structure + * Returns the address of the next matching extended capability structure * within the device's PCI configuration space or 0 if the device does - * not support it. Possible values for @cap: - * - * %PCI_EXT_CAP_ID_ERR Advanced Error Reporting - * %PCI_EXT_CAP_ID_VC Virtual Channel - * %PCI_EXT_CAP_ID_DSN Device Serial Number - * %PCI_EXT_CAP_ID_PWR Power Budgeting + * not support it. Some capabilities can occur several times, e.g., the + * vendor-specific capability, and this provides a way to find them all. */ -int pci_find_ext_capability(struct pci_dev *dev, int cap) +int pci_find_next_ext_capability(struct pci_dev *dev, int start, int cap) { u32 header; int ttl; @@ -311,6 +308,9 @@ int pci_find_ext_capability(struct pci_dev *dev, int cap) if (dev->cfg_size <= PCI_CFG_SPACE_SIZE) return 0; + if (start) + pos = start; + if (pci_read_config_dword(dev, pos, &header) != PCIBIOS_SUCCESSFUL) return 0; @@ -322,7 +322,7 @@ int pci_find_ext_capability(struct pci_dev *dev, int cap) return 0; while (ttl-- > 0) { - if (PCI_EXT_CAP_ID(header) == cap) + if (PCI_EXT_CAP_ID(header) == cap && pos != start) return pos; pos = PCI_EXT_CAP_NEXT(header); @@ -335,6 +335,26 @@ int pci_find_ext_capability(struct pci_dev *dev, int cap) return 0; } +EXPORT_SYMBOL_GPL(pci_find_next_ext_capability); + +/** + * pci_find_ext_capability - Find an extended capability + * @dev: PCI device to query + * @cap: capability code + * + * Returns the address of the requested extended capability structure + * within the device's PCI configuration space or 0 if the device does + * not support it. Possible values for @cap: + * + * %PCI_EXT_CAP_ID_ERR Advanced Error Reporting + * %PCI_EXT_CAP_ID_VC Virtual Channel + * %PCI_EXT_CAP_ID_DSN Device Serial Number + * %PCI_EXT_CAP_ID_PWR Power Budgeting + */ +int pci_find_ext_capability(struct pci_dev *dev, int cap) +{ + return pci_find_next_ext_capability(dev, 0, cap); +} EXPORT_SYMBOL_GPL(pci_find_ext_capability); static int __pci_find_next_ht_cap(struct pci_dev *dev, int pos, int ht_cap) |