[PATCH v4 04/29] PCI: Add pci_dev_resource_idx() helper

[Yinghai Lu <yinghai@kernel.org>]

Use resource pointer to get index in pci resources array/list.

-v2: export symbol for acpiphp compiling error, found by
       Steven Newbury <steve@snewbury.org.uk>

Signed-off-by: Yinghai Lu <yinghai@kernel.org>
---
 drivers/pci/probe.c | 9 +++++++++
 include/linux/pci.h | 1 +
 2 files changed, 10 insertions(+)

diff --git a/drivers/pci/probe.c b/drivers/pci/probe.c
index 9cb3eb3..1df75f7 100644
--- a/drivers/pci/probe.c
+++ b/drivers/pci/probe.c
@@ -114,6 +114,15 @@ struct resource *pci_dev_resource_n(struct pci_dev *dev, int n)
 }
 EXPORT_SYMBOL(pci_dev_resource_n);
 
+int pci_dev_resource_idx(struct pci_dev *dev, struct resource *res)
+{
+	if (res >= dev->resource &&
+	    res <= dev->resource + (PCI_NUM_RESOURCES - 1))
+		return res - dev->resource;
+
+	return -1;
+}
+
 static u64 pci_size(u64 base, u64 maxbase, u64 mask)
 {
 	u64 size = mask & maxbase;	/* Find the significant bits */
diff --git a/include/linux/pci.h b/include/linux/pci.h
index 6d450d2..f4da78d 100644
--- a/include/linux/pci.h
+++ b/include/linux/pci.h
@@ -354,6 +354,7 @@ struct pci_dev {
 };
 
 struct resource *pci_dev_resource_n(struct pci_dev *dev, int n);
+int pci_dev_resource_idx(struct pci_dev *dev, struct resource *res);
 
 static inline struct pci_dev *pci_physfn(struct pci_dev *dev)
 {
-- 
1.8.1.4