x86/PCI: MMCONFIG: add lookup function

This patch factors out the search for an MMCONFIG region, which was
previously implemented in both mmconfig_32 and mmconfig_64.  No functional
change.

Reviewed-by: Yinghai Lu <yinghai@kernel.org>
Signed-off-by: Bjorn Helgaas <bjorn.helgaas@hp.com>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
diff --git a/arch/x86/include/asm/pci_x86.h b/arch/x86/include/asm/pci_x86.h
index 0b7c316..b4bf9a9 100644
--- a/arch/x86/include/asm/pci_x86.h
+++ b/arch/x86/include/asm/pci_x86.h
@@ -134,6 +134,7 @@
 
 extern int __init pci_mmcfg_arch_init(void);
 extern void __init pci_mmcfg_arch_free(void);
+extern struct pci_mmcfg_region *pci_mmconfig_lookup(int segment, int bus);
 
 extern struct list_head pci_mmcfg_list;
 
diff --git a/arch/x86/pci/mmconfig-shared.c b/arch/x86/pci/mmconfig-shared.c
index 71d69b8..b19d1e5 100644
--- a/arch/x86/pci/mmconfig-shared.c
+++ b/arch/x86/pci/mmconfig-shared.c
@@ -97,6 +97,18 @@
 	return new;
 }
 
+struct pci_mmcfg_region *pci_mmconfig_lookup(int segment, int bus)
+{
+	struct pci_mmcfg_region *cfg;
+
+	list_for_each_entry(cfg, &pci_mmcfg_list, list)
+		if (cfg->segment == segment &&
+		    cfg->start_bus <= bus && bus <= cfg->end_bus)
+			return cfg;
+
+	return NULL;
+}
+
 static const char __init *pci_mmcfg_e7520(void)
 {
 	u32 win;
diff --git a/arch/x86/pci/mmconfig_32.c b/arch/x86/pci/mmconfig_32.c
index c04523e..90d5fd47 100644
--- a/arch/x86/pci/mmconfig_32.c
+++ b/arch/x86/pci/mmconfig_32.c
@@ -27,15 +27,10 @@
  */
 static u32 get_base_addr(unsigned int seg, int bus, unsigned devfn)
 {
-	struct pci_mmcfg_region *cfg;
+	struct pci_mmcfg_region *cfg = pci_mmconfig_lookup(seg, bus);
 
-	list_for_each_entry(cfg, &pci_mmcfg_list, list)
-		if (cfg->segment == seg &&
-		    (cfg->start_bus <= bus) &&
-		    (cfg->end_bus >= bus))
-			return cfg->address;
-
-	/* Fall back to type 0 */
+	if (cfg)
+		return cfg->address;
 	return 0;
 }
 
diff --git a/arch/x86/pci/mmconfig_64.c b/arch/x86/pci/mmconfig_64.c
index cfa6cdb..e783841 100644
--- a/arch/x86/pci/mmconfig_64.c
+++ b/arch/x86/pci/mmconfig_64.c
@@ -14,28 +14,13 @@
 
 #define PREFIX "PCI: "
 
-static char __iomem *get_virt(unsigned int seg, unsigned bus)
-{
-	struct pci_mmcfg_region *cfg;
-
-	list_for_each_entry(cfg, &pci_mmcfg_list, list)
-		if (cfg->segment == seg &&
-		    (cfg->start_bus <= bus) &&
-		    (cfg->end_bus >= bus))
-			return cfg->virt;
-
-	/* Fall back to type 0 */
-	return NULL;
-}
-
 static char __iomem *pci_dev_base(unsigned int seg, unsigned int bus, unsigned int devfn)
 {
-	char __iomem *addr;
+	struct pci_mmcfg_region *cfg = pci_mmconfig_lookup(seg, bus);
 
-	addr = get_virt(seg, bus);
-	if (!addr)
-		return NULL;
-	return addr + (PCI_MMCFG_BUS_OFFSET(bus) | (devfn << 12));
+	if (cfg && cfg->virt)
+		return cfg->virt + (PCI_MMCFG_BUS_OFFSET(bus) | (devfn << 12));
+	return NULL;
 }
 
 static int pci_mmcfg_read(unsigned int seg, unsigned int bus,