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authorBjorn Helgaas <bhelgaas@google.com>2012-07-13 14:24:59 -0600
committerBjorn Helgaas <bhelgaas@google.com>2012-08-22 13:47:27 -0600
commit44a9a36f6be43636ac2342c06d9feb60db77826a (patch)
tree3ff1b3d23d6416454599aa5712a081fdbe5aaaa0 /drivers/pci/pci.c
parent0d7614f09c1ebdbaa1599a5aba7593f147bf96ee (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/pci/pci.c')
-rw-r--r--drivers/pci/pci.c40
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)