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: NYinghai Lu <yinghai@kernel.org>
Signed-off-by: NBjorn Helgaas <bjorn.helgaas@hp.com>
Signed-off-by: NJesse Barnes <jbarnes@virtuousgeek.org>

arch/x86/include/asm/pci_x86.h

@@ -134,6 +134,7 @@ struct pci_mmcfg_region {
 
 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;
 

arch/x86/pci/mmconfig-shared.c

@@ -97,6 +97,18 @@ static __init struct pci_mmcfg_region *pci_mmconfig_add(int segment, int start,
 	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;

arch/x86/pci/mmconfig_32.c

@@ -27,15 +27,10 @@ static int mmcfg_last_accessed_cpu;
  */
 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;
 }
 

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,