diff options
Diffstat (limited to 'drivers/pci/pci.c')
| -rw-r--r-- | drivers/pci/pci.c | 46 |
1 files changed, 32 insertions, 14 deletions
diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c index e74d7584304..8e287a828d5 100644 --- a/drivers/pci/pci.c +++ b/drivers/pci/pci.c @@ -63,11 +63,38 @@ pci_max_busnr(void) return max; } +static int __pci_find_next_cap(struct pci_bus *bus, unsigned int devfn, u8 pos, int cap) +{ + u8 id; + int ttl = 48; + + while (ttl--) { + pci_bus_read_config_byte(bus, devfn, pos, &pos); + if (pos < 0x40) + break; + pos &= ~3; + pci_bus_read_config_byte(bus, devfn, pos + PCI_CAP_LIST_ID, + &id); + if (id == 0xff) + break; + if (id == cap) + return pos; + pos += PCI_CAP_LIST_NEXT; + } + return 0; +} + +int pci_find_next_capability(struct pci_dev *dev, u8 pos, int cap) +{ + return __pci_find_next_cap(dev->bus, dev->devfn, + pos + PCI_CAP_LIST_NEXT, cap); +} +EXPORT_SYMBOL_GPL(pci_find_next_capability); + static int __pci_bus_find_cap(struct pci_bus *bus, unsigned int devfn, u8 hdr_type, int cap) { u16 status; - u8 pos, id; - int ttl = 48; + u8 pos; pci_bus_read_config_word(bus, devfn, PCI_STATUS, &status); if (!(status & PCI_STATUS_CAP_LIST)) @@ -76,24 +103,15 @@ static int __pci_bus_find_cap(struct pci_bus *bus, unsigned int devfn, u8 hdr_ty switch (hdr_type) { case PCI_HEADER_TYPE_NORMAL: case PCI_HEADER_TYPE_BRIDGE: - pci_bus_read_config_byte(bus, devfn, PCI_CAPABILITY_LIST, &pos); + pos = PCI_CAPABILITY_LIST; break; case PCI_HEADER_TYPE_CARDBUS: - pci_bus_read_config_byte(bus, devfn, PCI_CB_CAPABILITY_LIST, &pos); + pos = PCI_CB_CAPABILITY_LIST; break; default: return 0; } - while (ttl-- && pos >= 0x40) { - pos &= ~3; - pci_bus_read_config_byte(bus, devfn, pos + PCI_CAP_LIST_ID, &id); - if (id == 0xff) - break; - if (id == cap) - return pos; - pci_bus_read_config_byte(bus, devfn, pos + PCI_CAP_LIST_NEXT, &pos); - } - return 0; + return __pci_find_next_cap(bus, devfn, pos, cap); } /** |