diff --git a/drivers/acpi/mmconfig.c b/drivers/acpi/mmconfig.c
new file mode 100644
index 0000000..d62dccda
--- /dev/null
+++ b/drivers/acpi/mmconfig.c

@@ -0,0 +1,242 @@
+/*
+ * Arch agnostic low-level direct PCI config space access via MMCONFIG
+ *
+ * Per-architecture code takes care of the mappings, region validation and
+ * accesses themselves.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ */
+
+#include <linux/mutex.h>
+#include <linux/rculist.h>
+#include <linux/mmconfig.h>
+
+#define PREFIX "PCI: "
+
+static DEFINE_MUTEX(pci_mmcfg_lock);
+
+LIST_HEAD(pci_mmcfg_list);
+
+static void __init pci_mmconfig_remove(struct pci_mmcfg_region *cfg)
+{
+	if (cfg->res.parent)
+		release_resource(&cfg->res);
+	list_del(&cfg->list);
+	kfree(cfg);
+}
+
+void __init free_all_mmcfg(void)
+{
+	struct pci_mmcfg_region *cfg, *tmp;
+
+	pci_mmcfg_arch_free();
+	list_for_each_entry_safe(cfg, tmp, &pci_mmcfg_list, list)
+		pci_mmconfig_remove(cfg);
+}
+
+void list_add_sorted(struct pci_mmcfg_region *new)
+{
+	struct pci_mmcfg_region *cfg;
+
+	/* keep list sorted by segment and starting bus number */
+	list_for_each_entry_rcu(cfg, &pci_mmcfg_list, list) {
+		if (cfg->segment > new->segment ||
+		    (cfg->segment == new->segment &&
+		     cfg->start_bus >= new->start_bus)) {
+			list_add_tail_rcu(&new->list, &cfg->list);
+			return;
+		}
+	}
+	list_add_tail_rcu(&new->list, &pci_mmcfg_list);
+}
+
+struct pci_mmcfg_region *pci_mmconfig_alloc(int segment, int start,
+					    int end, u64 addr)
+{
+	struct pci_mmcfg_region *new;
+	struct resource *res;
+
+	if (addr == 0)
+		return NULL;
+
+	new = kzalloc(sizeof(*new), GFP_KERNEL);
+	if (!new)
+		return NULL;
+
+	new->address = addr;
+	new->segment = segment;
+	new->start_bus = start;
+	new->end_bus = end;
+
+	res = &new->res;
+	res->start = addr + PCI_MMCFG_BUS_OFFSET(start);
+	res->end = addr + PCI_MMCFG_BUS_OFFSET(end + 1) - 1;
+	res->flags = IORESOURCE_MEM | IORESOURCE_BUSY;
+	snprintf(new->name, PCI_MMCFG_RESOURCE_NAME_LEN,
+		 "PCI MMCONFIG %04x [bus %02x-%02x]", segment, start, end);
+	res->name = new->name;
+
+	return new;
+}
+
+struct pci_mmcfg_region *pci_mmconfig_add(int segment, int start,
+					  int end, u64 addr)
+{
+	struct pci_mmcfg_region *new;
+
+	new = pci_mmconfig_alloc(segment, start, end, addr);
+	if (new) {
+		mutex_lock(&pci_mmcfg_lock);
+		list_add_sorted(new);
+		mutex_unlock(&pci_mmcfg_lock);
+
+		pr_info(PREFIX
+		       "MMCONFIG for domain %04x [bus %02x-%02x] at %pR "
+		       "(base %#lx)\n",
+		       segment, start, end, &new->res, (unsigned long)addr);
+	}
+
+	return new;
+}
+
+int __init pci_mmconfig_inject(struct pci_mmcfg_region *cfg)
+{
+	struct pci_mmcfg_region *cfg_conflict;
+	int err = 0;
+
+	mutex_lock(&pci_mmcfg_lock);
+	cfg_conflict = pci_mmconfig_lookup(cfg->segment, cfg->start_bus);
+	if (cfg_conflict) {
+		if (cfg_conflict->end_bus < cfg->end_bus)
+			pr_info(FW_INFO "MMCONFIG for "
+				"domain %04x [bus %02x-%02x] "
+				"only partially covers this bridge\n",
+				cfg_conflict->segment, cfg_conflict->start_bus,
+				cfg_conflict->end_bus);
+		err = -EEXIST;
+		goto out;
+	}
+
+	if (pci_mmcfg_arch_map(cfg)) {
+		pr_warn("fail to map MMCONFIG %pR.\n", &cfg->res);
+		err = -ENOMEM;
+		goto out;
+	} else {
+		list_add_sorted(cfg);
+		pr_info("MMCONFIG at %pR (base %#lx)\n",
+			&cfg->res, (unsigned long)cfg->address);
+
+	}
+out:
+	mutex_unlock(&pci_mmcfg_lock);
+	return err;
+}
+
+struct pci_mmcfg_region *pci_mmconfig_lookup(int segment, int bus)
+{
+	struct pci_mmcfg_region *cfg;
+
+	list_for_each_entry_rcu(cfg, &pci_mmcfg_list, list)
+		if (cfg->segment == segment &&
+		    cfg->start_bus <= bus && bus <= cfg->end_bus)
+			return cfg;
+
+	return NULL;
+}
+
+int __init __weak acpi_mcfg_check_entry(struct acpi_table_mcfg *mcfg,
+					struct acpi_mcfg_allocation *cfg)
+{
+	return 0;
+}
+
+int __init pci_parse_mcfg(struct acpi_table_header *header)
+{
+	struct acpi_table_mcfg *mcfg;
+	struct acpi_mcfg_allocation *cfg_table, *cfg;
+	unsigned long i;
+	int entries;
+
+	if (!header)
+		return -EINVAL;
+
+	mcfg = (struct acpi_table_mcfg *)header;
+
+	/* how many config structures do we have */
+	free_all_mmcfg();
+	entries = 0;
+	i = header->length - sizeof(struct acpi_table_mcfg);
+	while (i >= sizeof(struct acpi_mcfg_allocation)) {
+		entries++;
+		i -= sizeof(struct acpi_mcfg_allocation);
+	}
+	if (entries == 0) {
+		pr_err(PREFIX "MMCONFIG has no entries\n");
+		return -ENODEV;
+	}
+
+	cfg_table = (struct acpi_mcfg_allocation *) &mcfg[1];
+	for (i = 0; i < entries; i++) {
+		cfg = &cfg_table[i];
+		if (acpi_mcfg_check_entry(mcfg, cfg)) {
+			free_all_mmcfg();
+			return -ENODEV;
+		}
+
+		if (pci_mmconfig_add(cfg->pci_segment, cfg->start_bus_number,
+				   cfg->end_bus_number, cfg->address) == NULL) {
+			pr_warn(PREFIX "no memory for MCFG entries\n");
+			free_all_mmcfg();
+			return -ENOMEM;
+		}
+	}
+
+	return 0;
+}
+
+/* Delete MMCFG information for host bridges */
+int pci_mmconfig_delete(u16 seg, u8 start, u8 end)
+{
+	struct pci_mmcfg_region *cfg;
+
+	mutex_lock(&pci_mmcfg_lock);
+	list_for_each_entry_rcu(cfg, &pci_mmcfg_list, list)
+		if (cfg->segment == seg && cfg->start_bus == start &&
+		    cfg->end_bus == end) {
+			list_del_rcu(&cfg->list);
+			synchronize_rcu();
+			pci_mmcfg_arch_unmap(cfg);
+			if (cfg->res.parent)
+				release_resource(&cfg->res);
+			mutex_unlock(&pci_mmcfg_lock);
+			kfree(cfg);
+			return 0;
+		}
+	mutex_unlock(&pci_mmcfg_lock);
+
+	return -ENOENT;
+}
+
+void __init __weak pci_mmcfg_early_init(void)
+{
+
+}
+
+void __init __weak pci_mmcfg_late_init(void)
+{
+	struct pci_mmcfg_region *cfg;
+
+	acpi_table_parse(ACPI_SIG_MCFG, pci_parse_mcfg);
+
+	if (list_empty(&pci_mmcfg_list))
+		return;
+
+	if (!pci_mmcfg_arch_init())
+		free_all_mmcfg();
+
+	list_for_each_entry(cfg, &pci_mmcfg_list, list)
+		insert_resource(&iomem_resource, &cfg->res);
+}

diff --git a/include/linux/mmconfig.h b/include/linux/mmconfig.h
new file mode 100644
index 0000000..6ccd1ee
--- /dev/null
+++ b/include/linux/mmconfig.h

@@ -0,0 +1,58 @@
+#ifndef __MMCONFIG_H
+#define __MMCONFIG_H
+#ifdef __KERNEL__
+
+#include <linux/types.h>
+#include <linux/acpi.h>
+
+#ifdef CONFIG_PCI_MMCONFIG
+/* "PCI MMCONFIG %04x [bus %02x-%02x]" */
+#define PCI_MMCFG_RESOURCE_NAME_LEN (22 + 4 + 2 + 2)
+
+struct pci_mmcfg_region {
+	struct list_head list;
+	struct resource res;
+	u64 address;
+	char __iomem *virt;
+	u16 segment;
+	u8 start_bus;
+	u8 end_bus;
+	char name[PCI_MMCFG_RESOURCE_NAME_LEN];
+};
+
+void pci_mmcfg_early_init(void);
+void pci_mmcfg_late_init(void);
+struct pci_mmcfg_region *pci_mmconfig_lookup(int segment, int bus);
+
+int pci_parse_mcfg(struct acpi_table_header *header);
+struct pci_mmcfg_region *pci_mmconfig_alloc(int segment, int start,
+						   int end, u64 addr);
+int pci_mmconfig_inject(struct pci_mmcfg_region *cfg);
+struct pci_mmcfg_region *pci_mmconfig_add(int segment, int start,
+						 int end, u64 addr);
+void list_add_sorted(struct pci_mmcfg_region *new);
+int acpi_mcfg_check_entry(struct acpi_table_mcfg *mcfg,
+			  struct acpi_mcfg_allocation *cfg);
+void free_all_mmcfg(void);
+int pci_mmconfig_insert(struct device *dev, u16 seg, u8 start, u8 end,
+		       phys_addr_t addr);
+int pci_mmconfig_delete(u16 seg, u8 start, u8 end);
+
+/* Arch specific calls */
+int pci_mmcfg_arch_init(void);
+void pci_mmcfg_arch_free(void);
+int pci_mmcfg_arch_map(struct pci_mmcfg_region *cfg);
+void pci_mmcfg_arch_unmap(struct pci_mmcfg_region *cfg);
+
+extern struct list_head pci_mmcfg_list;
+
+#define PCI_MMCFG_BUS_OFFSET(bus)      ((bus) << 20)
+#else /* CONFIG_PCI_MMCONFIG */
+static inline void pci_mmcfg_late_init(void) { }
+static inline void pci_mmcfg_early_init(void) { }
+static inline void *pci_mmconfig_lookup(int segment, int bus)
+{ return NULL; }
+#endif /* CONFIG_PCI_MMCONFIG */
+
+#endif  /* __KERNEL__ */
+#endif  /* __MMCONFIG_H */

diff --git a/include/linux/pci.h b/include/linux/pci.h
index 6afba72..0a8b82e 100644
--- a/include/linux/pci.h
+++ b/include/linux/pci.h

@@ -1658,14 +1658,6 @@ void pcibios_release_device(struct pci_dev *dev);
 extern struct dev_pm_ops pcibios_pm_ops;
 #endif
 
-#ifdef CONFIG_PCI_MMCONFIG
-void __init pci_mmcfg_early_init(void);
-void __init pci_mmcfg_late_init(void);
-#else
-static inline void pci_mmcfg_early_init(void) { }
-static inline void pci_mmcfg_late_init(void) { }
-#endif
-
 int pci_ext_cfg_avail(void);
 
 void __iomem *pci_ioremap_bar(struct pci_dev *pdev, int bar);

-- 
1.9.1