[PATCH v4 02/29] PCI: Add pci_dev_resource_n()

[Yinghai Lu <yinghai@kernel.org>]

Now pci device resource iteration is done via "for (i=0...)" open code.
That make code hard to read esp when only bridge or sriov resources
are involved.

We want to replace those open code with for_each_pci_resource().
Also want to add addon_resource handling, and need to make addon resource
to be treated as normal PCI resources during iteration.

Add pci_device_resource_n() instead of using dev->resources[n].
Use it with for_each_pci_resource macro and addon_resource support.

-v2: Add EXPORT_SYMBOL to find building error found by Gary Hade

Signed-off-by: Yinghai Lu <yinghai@kernel.org>
---
 drivers/pci/probe.c | 9 +++++++++
 include/linux/pci.h | 2 ++
 2 files changed, 11 insertions(+)

diff --git a/drivers/pci/probe.c b/drivers/pci/probe.c
index b494066..9cb3eb3 100644
--- a/drivers/pci/probe.c
+++ b/drivers/pci/probe.c
@@ -105,6 +105,15 @@ static int __init pcibus_class_init(void)
 }
 postcore_initcall(pcibus_class_init);
 
+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;
+}
+EXPORT_SYMBOL(pci_dev_resource_n);
+
 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 bcd9769..ffff013 100644
--- a/include/linux/pci.h
+++ b/include/linux/pci.h
@@ -353,6 +353,8 @@ struct pci_dev {
 	size_t romlen; /* Length of ROM if it's not from the BAR */
 };
 
+struct resource *pci_dev_resource_n(struct pci_dev *dev, int n);
+
 static inline struct pci_dev *pci_physfn(struct pci_dev *dev)
 {
 #ifdef CONFIG_PCI_IOV
-- 
1.8.1.4