PCI: pci resource iterator
Currently pci_dev structure holds an array of 17 PCI resources; six
base BARs, one ROM BAR, four BRIDGE BARs, six sriov BARs. This is
wasteful. A bridge device just needs the 4 bridge resources. A
non-bridge device just needs the six base resources and one ROM
resource. The sriov resources are needed only if the device has
SRIOV capability.
The pci_dev structure needs to be re-organized to avoid unnecessary
bloating. However too much code outside the pci-bus driver, assumes
the internal details of the pci_dev structure, thus making it hard
to re-organize the datastructure.
As a first step this patch provides generic methods to access the
resource structure of the pci_dev.
Next step, change the code in all the drivers that access the
resource structure to use the new iterator.
Finally we can re-organize the resource structure in the pci_dev
structure and correspondingly update the methods.
This patch is compile tested only.
Changelog v2:
Consolidated iterator interface as per Bjorn's suggestion.
Changelog v3:
ability to get index of the returned resource. Suggested by Yinghai.
Incorporates Yinghai's code snippets.
<TODO get Yinghai's SOB>
Signed-off-by: Ram Pai <linuxram@xxxxxxxxxx>
diff --git a/include/linux/pci.h b/include/linux/pci.h
index e444f5b..7101da2 100644
--- a/include/linux/pci.h
+++ b/include/linux/pci.h
@@ -1351,6 +1351,48 @@ static inline int pci_domain_nr(struct pci_bus *bus)
(pci_resource_end((dev), (bar)) - \
pci_resource_start((dev), (bar)) + 1))
+#define PCI_STD_RES (1<<0)
+#define PCI_ROM_RES (1<<1)
+#define PCI_BRIDGE_RES (1<<2)
+#define PCI_IOV_RES (1<<3)
+#define PCI_ALL_RES (PCI_STD_RES|PCI_ROM_RES|PCI_BRIDGE_RES|PCI_IOV_RES)
+#define PCI_NOSTD_RES (PCI_ALL_RES & ~PCI_STD_RES)
+#define PCI_NOIOV_RES (PCI_ALL_RES & ~PCI_IOV_RES)
+#define PCI_NOROM_RES (PCI_ALL_RES & ~PCI_ROM_RES)
+#define PCI_NOBRIDGE_RES (PCI_ALL_RES & ~PCI_BRIDGE_RES)
+#define PCI_STD_ROM_RES (PCI_STD_RES | PCI_ROM_RES)
+#define PCI_STD_IOV_RES (PCI_STD_RES | PCI_IOV_RES)
+#define PCI_STD_ROM_IOV_RES (PCI_NOBRIDGE_RES)
+
+static inline struct resource *pci_dev_resource_n(struct pci_dev *dev, int n)
+{
+ if (n >= 0 && n < PCI_NUM_RESOURCES)
+ return &dev->resource[n];
+
+ return NULL;
+}
+
+static inline int pci_next_resource_idx(int i, int flag)
+{
+ while (++i < PCI_NUM_RESOURCES) {
+ if ((i >= 0 && i < PCI_ROM_RESOURCE && (flag & PCI_STD_RES)) ||
+ (i == PCI_ROM_RESOURCE && (flag & PCI_ROM_RES)) ||
+#ifdef CONFIG_PCI_IOV
+ (i <= PCI_IOV_RESOURCE_END && (flag & PCI_IOV_RES)) ||
+#endif
+ (i <= PCI_BRIDGE_RESOURCE_END && (flag & PCI_BRIDGE_RES)))
+ return i;
+ }
+ return -1;
+}
+
+#define for_each_pci_resource(dev, res, flag) \
+ for (i = pci_next_resource_idx(-1, flag), \
+ res = pci_dev_resource_n(dev, i); \
+ res; \
+ i = pci_next_resource_idx(i, flag), \
+ res = pci_dev_resource_n(dev, i))
+
/* Similar to the helpers above, these manipulate per-pci_dev
* driver-specific data. They are really just a wrapper around
* the generic device structure functions of these calls.
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