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path: root/drivers/pci/pci.c
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Diffstat (limited to 'drivers/pci/pci.c')
-rw-r--r--drivers/pci/pci.c46
1 files changed, 32 insertions, 14 deletions
diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c
index e74d75843047..8e287a828d5d 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);
}
/**