diff --git a/drivers/acpi/Kconfig b/drivers/acpi/Kconfig
index 183ffa3..70272c5 100644
--- a/drivers/acpi/Kconfig
+++ b/drivers/acpi/Kconfig
@@ -346,6 +346,14 @@ config ACPI_PCI_SLOT
 	  i.e., segment/bus/device/function tuples, with physical slots in
 	  the system.  If you are unsure, say N.
 
+config ACPI_PCI_HOST_GENERIC
+	bool
+	select PCI_GENERIC_ECAM
+	help
+	  Select this config option from the architecture Kconfig,
+	  if it is preferred to enable ACPI PCI host controller driver which
+	  has no arch-specific assumptions.
+
 config X86_PM_TIMER
 	bool "Power Management Timer Support" if EXPERT
 	depends on X86
diff --git a/drivers/acpi/Makefile b/drivers/acpi/Makefile
index 81e5cbc..b12fa64 100644
--- a/drivers/acpi/Makefile
+++ b/drivers/acpi/Makefile
@@ -40,6 +40,7 @@ acpi-$(CONFIG_ARCH_MIGHT_HAVE_ACPI_PDC) += processor_pdc.o
 acpi-y				+= ec.o
 acpi-$(CONFIG_ACPI_DOCK)	+= dock.o
 acpi-y				+= pci_root.o pci_link.o pci_irq.o
+obj-$(CONFIG_ACPI_PCI_HOST_GENERIC)	+= pci_gen_host.o
 acpi-y				+= acpi_lpss.o acpi_apd.o
 acpi-y				+= acpi_platform.o
 acpi-y				+= acpi_pnp.o
diff --git a/drivers/acpi/bus.c b/drivers/acpi/bus.c
index c068c82..803a1d7 100644
--- a/drivers/acpi/bus.c
+++ b/drivers/acpi/bus.c
@@ -1107,6 +1107,7 @@ static int __init acpi_init(void)
 	}
 
 	pci_mmcfg_late_init();
+	pci_mcfg_init();
 	acpi_scan_init();
 	acpi_ec_init();
 	acpi_debugfs_init();
diff --git a/drivers/acpi/pci_gen_host.c b/drivers/acpi/pci_gen_host.c
new file mode 100644
index 0000000..fd360b5
--- /dev/null
+++ b/drivers/acpi/pci_gen_host.c
@@ -0,0 +1,231 @@
+/*
+ * 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 (the "GPL").
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * General Public License version 2 (GPLv2) for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * version 2 (GPLv2) along with this source code.
+ */
+#include <linux/kernel.h>
+#include <linux/pci.h>
+#include <linux/pci-acpi.h>
+#include <linux/sfi_acpi.h>
+#include <linux/slab.h>
+
+#include "../pci/ecam.h"
+
+#define PREFIX	"ACPI: "
+
+/* Structure to hold entries from the MCFG table */
+struct mcfg_entry {
+	struct list_head	list;
+	phys_addr_t		addr;
+	u16			segment;
+	u8			bus_start;
+	u8			bus_end;
+};
+
+/* List to save mcfg entries */
+static LIST_HEAD(pci_mcfg_list);
+static DEFINE_MUTEX(pci_mcfg_lock);
+
+/* ACPI info for generic ACPI PCI controller */
+struct acpi_pci_generic_root_info {
+	struct acpi_pci_root_info	common;
+	struct pci_config_window	*cfg;	/* config space mapping */
+};
+
+/* Find the entry in mcfg list which contains range bus_start */
+static struct mcfg_entry *pci_mcfg_lookup(u16 seg, u8 bus_start)
+{
+	struct mcfg_entry *e;
+
+	list_for_each_entry(e, &pci_mcfg_list, list) {
+		if (e->segment == seg &&
+		    e->bus_start <= bus_start && bus_start <= e->bus_end)
+			return e;
+	}
+
+	return NULL;
+}
+
+
+/*
+ * Lookup the bus range for the domain in MCFG, and set up config space
+ * mapping.
+ */
+static int pci_acpi_setup_ecam_mapping(struct acpi_pci_root *root,
+				       struct acpi_pci_generic_root_info *ri)
+{
+	u16 seg = root->segment;
+	u8 bus_start = root->secondary.start;
+	u8 bus_end = root->secondary.end;
+	struct pci_config_window *cfg;
+	struct mcfg_entry *e;
+	phys_addr_t addr;
+	int err = 0;
+
+	mutex_lock(&pci_mcfg_lock);
+	e = pci_mcfg_lookup(seg, bus_start);
+	if (!e) {
+		addr = acpi_pci_root_get_mcfg_addr(root->device->handle);
+		if (addr == 0) {
+			pr_err(PREFIX"%04x:%02x-%02x bus range error\n",
+			       seg, bus_start, bus_end);
+			err = -ENOENT;
+			goto err_out;
+		}
+	} else {
+		if (bus_start != e->bus_start) {
+			pr_err("%04x:%02x-%02x bus range mismatch %02x\n",
+			       seg, bus_start, bus_end, e->bus_start);
+			err = -EINVAL;
+			goto err_out;
+		} else if (bus_end != e->bus_end) {
+			pr_warn("%04x:%02x-%02x bus end mismatch %02x\n",
+				seg, bus_start, bus_end, e->bus_end);
+			bus_end = min(bus_end, e->bus_end);
+		}
+		addr = e->addr;
+	}
+
+	cfg = pci_generic_ecam_create(&root->device->dev, addr, bus_start,
+				      bus_end, &pci_generic_ecam_default_ops);
+	if (IS_ERR(cfg)) {
+		err = PTR_ERR(cfg);
+		pr_err("%04x:%02x-%02x error %d mapping CAM\n", seg,
+			bus_start, bus_end, err);
+		goto err_out;
+	}
+
+	cfg->domain = seg;
+	ri->cfg = cfg;
+err_out:
+	mutex_unlock(&pci_mcfg_lock);
+	return err;
+}
+
+/* release_info: free resrouces allocated by init_info */
+static void pci_acpi_generic_release_info(struct acpi_pci_root_info *ci)
+{
+	struct acpi_pci_generic_root_info *ri;
+
+	ri = container_of(ci, struct acpi_pci_generic_root_info, common);
+	pci_generic_ecam_free(ri->cfg);
+	kfree(ri);
+}
+
+static struct acpi_pci_root_ops acpi_pci_root_ops = {
+	.release_info = pci_acpi_generic_release_info,
+};
+
+/* Interface called from ACPI code to setup PCI host controller */
+struct pci_bus *pci_acpi_scan_root(struct acpi_pci_root *root)
+{
+	int node = acpi_get_node(root->device->handle);
+	struct acpi_pci_generic_root_info *ri;
+	struct pci_bus *bus, *child;
+	int err;
+
+	ri = kzalloc_node(sizeof(*ri), GFP_KERNEL, node);
+	if (!ri)
+		return NULL;
+
+	err = pci_acpi_setup_ecam_mapping(root, ri);
+	if (err)
+		return NULL;
+
+	acpi_pci_root_ops.pci_ops = &ri->cfg->ops->pci_ops;
+	bus = acpi_pci_root_create(root, &acpi_pci_root_ops, &ri->common,
+				   ri->cfg);
+	if (!bus)
+		return NULL;
+
+	pci_bus_size_bridges(bus);
+	pci_bus_assign_resources(bus);
+
+	list_for_each_entry(child, &bus->children, node)
+		pcie_bus_configure_settings(child);
+
+	return bus;
+}
+
+/* handle MCFG table entries */
+static __init int pci_mcfg_parse(struct acpi_table_header *header)
+{
+	struct acpi_table_mcfg *mcfg;
+	struct acpi_mcfg_allocation *mptr;
+	struct mcfg_entry *e, *arr;
+	int i, n;
+
+	if (!header)
+		return -EINVAL;
+
+	mcfg = (struct acpi_table_mcfg *)header;
+	mptr = (struct acpi_mcfg_allocation *) &mcfg[1];
+	n = (header->length - sizeof(*mcfg)) / sizeof(*mptr);
+	if (n <= 0 || n > 255) {
+		pr_err(PREFIX " MCFG has incorrect entries (%d).\n", n);
+		return -EINVAL;
+	}
+
+	arr = kcalloc(n, sizeof(*arr), GFP_KERNEL);
+	if (!arr)
+		return -ENOMEM;
+
+	for (i = 0, e = arr; i < n; i++, mptr++, e++) {
+		e->segment = mptr->pci_segment;
+		e->addr =  mptr->address;
+		e->bus_start = mptr->start_bus_number;
+		e->bus_end = mptr->end_bus_number;
+		list_add(&e->list, &pci_mcfg_list);
+		pr_info(PREFIX
+			"MCFG entry for domain %04x [bus %02x-%02x] (base %pa)\n",
+			e->segment, e->bus_start, e->bus_end, &e->addr);
+	}
+
+	return 0;
+}
+
+/* Interface called by ACPI - parse and save MCFG table */
+void __init pci_mcfg_init(void)
+{
+	int err = acpi_table_parse(ACPI_SIG_MCFG, pci_mcfg_parse);
+	if (err)
+		pr_err(PREFIX "Failed to parse MCFG (%d)\n", err);
+	else if (list_empty(&pci_mcfg_list))
+		pr_info(PREFIX "No valid entries in MCFG table.\n");
+	else {
+		struct mcfg_entry *e;
+		int i = 0;
+		list_for_each_entry(e, &pci_mcfg_list, list)
+			i++;
+		pr_info(PREFIX "MCFG table loaded, %d entries\n", i);
+	}
+}
+
+/* Raw operations, works only for MCFG entries with an associated bus */
+int raw_pci_read(unsigned int domain, unsigned int busn, unsigned int devfn,
+		 int reg, int len, u32 *val)
+{
+	struct pci_bus *bus = pci_find_bus(domain, busn);
+
+	if (!bus)
+		return PCIBIOS_DEVICE_NOT_FOUND;
+	return bus->ops->read(bus, devfn, reg, len, val);
+}
+
+int raw_pci_write(unsigned int domain, unsigned int busn, unsigned int devfn,
+		  int reg, int len, u32 val)
+{
+	struct pci_bus *bus = pci_find_bus(domain, busn);
+
+	if (!bus)
+		return PCIBIOS_DEVICE_NOT_FOUND;
+	return bus->ops->write(bus, devfn, reg, len, val);
+}
diff --git a/include/linux/pci.h b/include/linux/pci.h
index df1f33d..c0422ea 100644
--- a/include/linux/pci.h
+++ b/include/linux/pci.h
@@ -1729,6 +1729,12 @@ static inline void pci_mmcfg_early_init(void) { }
 static inline void pci_mmcfg_late_init(void) { }
 #endif
 
+#ifdef CONFIG_ACPI_PCI_HOST_GENERIC
+void __init pci_mcfg_init(void);
+#else
+static inline void pci_mcfg_init(void) { return; }
+#endif
+
 int pci_ext_cfg_avail(void);
 
 void __iomem *pci_ioremap_bar(struct pci_dev *pdev, int bar);
