1 files changed, 37 insertions, 15 deletions

diff --git a/arch/x86/pci/mmconfig_64.c b/arch/x86/pci/mmconfig_64.c
index 915a493502cb..d4ebd07c306d 100644
--- a/arch/x86/pci/mmconfig_64.c
+++ b/arch/x86/pci/mmconfig_64.c
@@ -9,6 +9,7 @@
 #include <linux/init.h>
 #include <linux/acpi.h>
 #include <linux/bitmap.h>
+#include <linux/rcupdate.h>
 #include <asm/e820.h>
 #include <asm/pci_x86.h>
 
@@ -34,9 +35,12 @@ err:		*value = -1;
                 return -EINVAL;
         }
 
+        rcu_read_lock();
         addr = pci_dev_base(seg, bus, devfn);
-        if (!addr)
+        if (!addr) {
+                rcu_read_unlock();
                 goto err;
+        }
 
         switch (len) {
         case 1:
@@ -49,6 +53,7 @@ err:		*value = -1;
                 *value = mmio_config_readl(addr + reg);
                 break;
         }
+        rcu_read_unlock();
 
         return 0;
 }
@@ -62,9 +67,12 @@ static int pci_mmcfg_write(unsigned int seg, unsigned int bus,
         if (unlikely((bus > 255) || (devfn > 255) || (reg > 4095)))
                 return -EINVAL;
 
+        rcu_read_lock();
         addr = pci_dev_base(seg, bus, devfn);
-        if (!addr)
+        if (!addr) {
+                rcu_read_unlock();
                 return -EINVAL;
+        }
 
         switch (len) {
         case 1:
@@ -77,16 +85,17 @@ static int pci_mmcfg_write(unsigned int seg, unsigned int bus,
                 mmio_config_writel(addr + reg, value);
                 break;
         }
+        rcu_read_unlock();
 
         return 0;
 }
 
-static const struct pci_raw_ops pci_mmcfg = {
+const struct pci_raw_ops pci_mmcfg = {
         .read =         pci_mmcfg_read,
         .write =        pci_mmcfg_write,
 };
 
-static void __iomem * __init mcfg_ioremap(struct pci_mmcfg_region *cfg)
+static void __iomem * __devinit mcfg_ioremap(struct pci_mmcfg_region *cfg)
 {
         void __iomem *addr;
         u64 start, size;
@@ -105,16 +114,14 @@ int __init pci_mmcfg_arch_init(void)
 {
         struct pci_mmcfg_region *cfg;
 
-        list_for_each_entry(cfg, &pci_mmcfg_list, list) {
-                cfg->virt = mcfg_ioremap(cfg);
-                if (!cfg->virt) {
-                        printk(KERN_ERR PREFIX "can't map MMCONFIG at %pR\n",
-                               &cfg->res);
+        list_for_each_entry(cfg, &pci_mmcfg_list, list)
+                if (pci_mmcfg_arch_map(cfg)) {
                         pci_mmcfg_arch_free();
                         return 0;
                 }
-        }
+
         raw_pci_ext_ops = &pci_mmcfg;
+
         return 1;
 }
 
@@ -122,10 +129,25 @@ void __init pci_mmcfg_arch_free(void)
 {
         struct pci_mmcfg_region *cfg;
 
-        list_for_each_entry(cfg, &pci_mmcfg_list, list) {
-                if (cfg->virt) {
-                        iounmap(cfg->virt + PCI_MMCFG_BUS_OFFSET(cfg->start_bus));
-                        cfg->virt = NULL;
-                }
+        list_for_each_entry(cfg, &pci_mmcfg_list, list)
+                pci_mmcfg_arch_unmap(cfg);
+}
+
+int __devinit pci_mmcfg_arch_map(struct pci_mmcfg_region *cfg)
+{
+        cfg->virt = mcfg_ioremap(cfg);
+        if (!cfg->virt) {
+                pr_err(PREFIX "can't map MMCONFIG at %pR\n", &cfg->res);
+                return -ENOMEM;
+        }
+
+        return 0;
+}
+
+void pci_mmcfg_arch_unmap(struct pci_mmcfg_region *cfg)
+{
+        if (cfg && cfg->virt) {
+                iounmap(cfg->virt + PCI_MMCFG_BUS_OFFSET(cfg->start_bus));
+                cfg->virt = NULL;
         }
 }