1 files changed, 27 insertions, 3 deletions

diff --git a/arch/x86/pci/mmconfig_32.c b/arch/x86/pci/mmconfig_32.c
index 5372e86834c0..db63ac23e3d9 100644
--- a/arch/x86/pci/mmconfig_32.c
+++ b/arch/x86/pci/mmconfig_32.c
@@ -11,6 +11,7 @@
 
 #include <linux/pci.h>
 #include <linux/init.h>
+#include <linux/rcupdate.h>
 #include <asm/e820.h>
 #include <asm/pci_x86.h>
 #include <acpi/acpi.h>
@@ -60,9 +61,12 @@ err:		*value = -1;
                 return -EINVAL;
         }
 
+        rcu_read_lock();
         base = get_base_addr(seg, bus, devfn);
-        if (!base)
+        if (!base) {
+                rcu_read_unlock();
                 goto err;
+        }
 
         raw_spin_lock_irqsave(&pci_config_lock, flags);
 
@@ -80,6 +84,7 @@ err:		*value = -1;
                 break;
         }
         raw_spin_unlock_irqrestore(&pci_config_lock, flags);
+        rcu_read_unlock();
 
         return 0;
 }
@@ -93,9 +98,12 @@ static int pci_mmcfg_write(unsigned int seg, unsigned int bus,
         if ((bus > 255) || (devfn > 255) || (reg > 4095))
                 return -EINVAL;
 
+        rcu_read_lock();
         base = get_base_addr(seg, bus, devfn);
-        if (!base)
+        if (!base) {
+                rcu_read_unlock();
                 return -EINVAL;
+        }
 
         raw_spin_lock_irqsave(&pci_config_lock, flags);
 
@@ -113,11 +121,12 @@ static int pci_mmcfg_write(unsigned int seg, unsigned int bus,
                 break;
         }
         raw_spin_unlock_irqrestore(&pci_config_lock, flags);
+        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,
 };
@@ -132,3 +141,18 @@ int __init pci_mmcfg_arch_init(void)
 void __init pci_mmcfg_arch_free(void)
 {
 }
+
+int __devinit pci_mmcfg_arch_map(struct pci_mmcfg_region *cfg)
+{
+        return 0;
+}
+
+void pci_mmcfg_arch_unmap(struct pci_mmcfg_region *cfg)
+{
+        unsigned long flags;
+
+        /* Invalidate the cached mmcfg map entry. */
+        raw_spin_lock_irqsave(&pci_config_lock, flags);
+        mmcfg_last_accessed_device = 0;
+        raw_spin_unlock_irqrestore(&pci_config_lock, flags);
+}