diff --git a/arch/x86/include/asm/pci_x86.h b/arch/x86/include/asm/pci_x86.h
index eddf8f0..f7f3b6a 100644
--- a/arch/x86/include/asm/pci_x86.h
+++ b/arch/x86/include/asm/pci_x86.h
@@ -139,6 +139,11 @@ struct pci_mmcfg_region {
 	char name[PCI_MMCFG_RESOURCE_NAME_LEN];
 };
 
+struct pci_mmcfg_mmio_ops {
+	u32 (*read)(int len, void __iomem *addr);
+	void (*write)(int len, void __iomem *addr, u32 value);
+};
+
 extern int __init pci_mmcfg_arch_init(void);
 extern void __init pci_mmcfg_arch_free(void);
 extern int pci_mmcfg_arch_map(struct pci_mmcfg_region *cfg);
@@ -147,6 +152,9 @@ extern int pci_mmconfig_insert(struct device *dev, u16 seg, u8 start, u8 end,
 			       phys_addr_t addr);
 extern int pci_mmconfig_delete(u16 seg, u8 start, u8 end);
 extern struct pci_mmcfg_region *pci_mmconfig_lookup(int segment, int bus);
+extern u32 pci_mmio_read(int len, void __iomem *addr);
+extern void pci_mmio_write(int len, void __iomem *addr, u32 value);
+extern void pci_mmconfig_register_mmio(struct pci_mmcfg_mmio_ops *ops);
 
 extern struct list_head pci_mmcfg_list;
 
diff --git a/arch/x86/pci/mmconfig-shared.c b/arch/x86/pci/mmconfig-shared.c
index 326198a..1fe9d0d 100644
--- a/arch/x86/pci/mmconfig-shared.c
+++ b/arch/x86/pci/mmconfig-shared.c
@@ -31,6 +31,118 @@ static DEFINE_MUTEX(pci_mmcfg_lock);
 
 LIST_HEAD(pci_mmcfg_list);
 
+static u32
+pci_mmconfig_generic_read(int len, void __iomem *addr)
+{
+	u32 data = 0;
+
+	switch (len) {
+	case 1:
+		data = readb(addr);
+		break;
+	case 2:
+		data = readw(addr);
+		break;
+	case 4:
+		data = readl(addr);
+		break;
+	}
+
+	return data;
+}
+
+static void
+pci_mmconfig_generic_write(int len, void __iomem *addr, u32 value)
+{
+	switch (len) {
+	case 1:
+		writeb(value, addr);
+		break;
+	case 2:
+		writew(value, addr);
+		break;
+	case 4:
+		writel(value, addr);
+		break;
+	}
+}
+
+static struct pci_mmcfg_mmio_ops pci_mmcfg_mmio_default = {
+	.read = pci_mmconfig_generic_read,
+	.write = pci_mmconfig_generic_write,
+};
+
+static struct pci_mmcfg_mmio_ops *pci_mmcfg_mmio = &pci_mmcfg_mmio_default;
+
+static u32
+pci_mmconfig_amd_read(int len, void __iomem *addr)
+{
+	u32 data = 0;
+
+	switch (len) {
+	case 1:
+		data = mmio_config_readb(addr);
+		break;
+	case 2:
+		data = mmio_config_readw(addr);
+		break;
+	case 4:
+		data = mmio_config_readl(addr);
+		break;
+	}
+
+	return data;
+}
+
+static void
+pci_mmconfig_amd_write(int len, void __iomem *addr, u32 value)
+{
+	switch (len) {
+	case 1:
+		mmio_config_writeb(addr, value);
+		break;
+	case 2:
+		mmio_config_writew(addr, value);
+		break;
+	case 4:
+		mmio_config_writel(addr, value);
+		break;
+	}
+}
+
+static struct pci_mmcfg_mmio_ops pci_mmcfg_mmio_amd_fam10h = {
+	.read = pci_mmconfig_amd_read,
+	.write = pci_mmconfig_amd_write,
+};
+
+void
+pci_mmconfig_register_mmio(struct pci_mmcfg_mmio_ops *ops)
+{
+	pci_mmcfg_mmio = ops;
+}
+
+u32
+pci_mmio_read(int len, void __iomem *addr)
+{
+	if (!pci_mmcfg_mmio) {
+		pr_err("PCI config space has no accessors !");
+		return 0;
+	}
+
+	return pci_mmcfg_mmio->read(len, addr);
+}
+
+void
+pci_mmio_write(int len, void __iomem *addr, u32 value)
+{
+	if (!pci_mmcfg_mmio) {
+		pr_err("PCI config space has no accessors !");
+		return;
+	}
+
+	pci_mmcfg_mmio->write(len, addr, value);
+}
+
 static void __init pci_mmconfig_remove(struct pci_mmcfg_region *cfg)
 {
 	if (cfg->res.parent)
@@ -231,6 +343,8 @@ static const char *__init pci_mmcfg_amd_fam10h(void)
 			return NULL;
 		}
 
+	pci_mmconfig_register_mmio(&pci_mmcfg_mmio_amd_fam10h);
+
 	return "AMD Family 10h NB";
 }
 
diff --git a/arch/x86/pci/mmconfig_32.c b/arch/x86/pci/mmconfig_32.c
index 43984bc..4b3d025 100644
--- a/arch/x86/pci/mmconfig_32.c
+++ b/arch/x86/pci/mmconfig_32.c
@@ -71,17 +71,7 @@ err:		*value = -1;
 
 	pci_exp_set_dev_base(base, bus, devfn);
 
-	switch (len) {
-	case 1:
-		*value = mmio_config_readb(mmcfg_virt_addr + reg);
-		break;
-	case 2:
-		*value = mmio_config_readw(mmcfg_virt_addr + reg);
-		break;
-	case 4:
-		*value = mmio_config_readl(mmcfg_virt_addr + reg);
-		break;
-	}
+	*value = pci_mmio_read(len, mmcfg_virt_addr + reg);
 	raw_spin_unlock_irqrestore(&pci_config_lock, flags);
 	rcu_read_unlock();
 
@@ -108,17 +98,7 @@ static int pci_mmcfg_write(unsigned int seg, unsigned int bus,
 
 	pci_exp_set_dev_base(base, bus, devfn);
 
-	switch (len) {
-	case 1:
-		mmio_config_writeb(mmcfg_virt_addr + reg, value);
-		break;
-	case 2:
-		mmio_config_writew(mmcfg_virt_addr + reg, value);
-		break;
-	case 4:
-		mmio_config_writel(mmcfg_virt_addr + reg, value);
-		break;
-	}
+	pci_mmio_write(len, mmcfg_virt_addr + reg, value);
 	raw_spin_unlock_irqrestore(&pci_config_lock, flags);
 	rcu_read_unlock();
 
diff --git a/arch/x86/pci/mmconfig_64.c b/arch/x86/pci/mmconfig_64.c
index bea5249..032593d 100644
--- a/arch/x86/pci/mmconfig_64.c
+++ b/arch/x86/pci/mmconfig_64.c
@@ -42,17 +42,7 @@ err:		*value = -1;
 		goto err;
 	}
 
-	switch (len) {
-	case 1:
-		*value = mmio_config_readb(addr + reg);
-		break;
-	case 2:
-		*value = mmio_config_readw(addr + reg);
-		break;
-	case 4:
-		*value = mmio_config_readl(addr + reg);
-		break;
-	}
+	*value = pci_mmio_read(len, addr + reg);
 	rcu_read_unlock();
 
 	return 0;
@@ -74,17 +64,7 @@ static int pci_mmcfg_write(unsigned int seg, unsigned int bus,
 		return -EINVAL;
 	}
 
-	switch (len) {
-	case 1:
-		mmio_config_writeb(addr + reg, value);
-		break;
-	case 2:
-		mmio_config_writew(addr + reg, value);
-		break;
-	case 4:
-		mmio_config_writel(addr + reg, value);
-		break;
-	}
+	pci_mmio_write(len, addr + reg, value);
 	rcu_read_unlock();
 
 	return 0;
diff --git a/arch/x86/pci/numachip.c b/arch/x86/pci/numachip.c
index 2e565e6..5047e9b 100644
--- a/arch/x86/pci/numachip.c
+++ b/arch/x86/pci/numachip.c
@@ -51,17 +51,7 @@ err:		*value = -1;
 		goto err;
 	}
 
-	switch (len) {
-	case 1:
-		*value = mmio_config_readb(addr + reg);
-		break;
-	case 2:
-		*value = mmio_config_readw(addr + reg);
-		break;
-	case 4:
-		*value = mmio_config_readl(addr + reg);
-		break;
-	}
+	*value = pci_mmio_read(len, addr + reg);
 	rcu_read_unlock();
 
 	return 0;
@@ -87,17 +77,7 @@ static int pci_mmcfg_write_numachip(unsigned int seg, unsigned int bus,
 		return -EINVAL;
 	}
 
-	switch (len) {
-	case 1:
-		mmio_config_writeb(addr + reg, value);
-		break;
-	case 2:
-		mmio_config_writew(addr + reg, value);
-		break;
-	case 4:
-		mmio_config_writel(addr + reg, value);
-		break;
-	}
+	pci_mmio_write(len, addr + reg, value);
 	rcu_read_unlock();
 
 	return 0;
