Merge branch 'topic-pci' into leg-kernel

31 files changed, 1421 insertions, 462 deletions

diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig
index 46779e39e35e..edb0f9795d0e 100644
--- a/arch/arm64/Kconfig
+++ b/arch/arm64/Kconfig
@@ -2,6 +2,7 @@ config ARM64
 	def_bool y
 	select ACPI_CCA_REQUIRED if ACPI
 	select ACPI_GENERIC_GSI if ACPI
+	select ACPI_PCI_HOST_GENERIC if ACPI
 	select ACPI_REDUCED_HARDWARE_ONLY if ACPI
 	select ACPI_SPCR_TABLE if ACPI
 	select ARCH_HAS_DEVMEM_IS_ALLOWED
diff --git a/arch/arm64/kernel/pci.c b/arch/arm64/kernel/pci.c
index c72de668e1d4..e484c9177456 100644
--- a/arch/arm64/kernel/pci.c
+++ b/arch/arm64/kernel/pci.c
@@ -17,6 +17,7 @@
 #include <linux/mm.h>
 #include <linux/of_pci.h>
 #include <linux/of_platform.h>
+#include <linux/pci-acpi.h>
 #include <linux/slab.h>
 
 /*
@@ -50,35 +51,26 @@ int pcibios_enable_device(struct pci_dev *dev, int mask)
 }
 
 /*
- * Try to assign the IRQ number from DT when adding a new device
+ * Try to assign the IRQ number when probing a new device
  */
-int pcibios_add_device(struct pci_dev *dev)
+int pcibios_alloc_irq(struct pci_dev *dev)
 {
-	dev->irq = of_irq_parse_and_map_pci(dev, 0, 0);
+	if (acpi_disabled)
+		dev->irq = of_irq_parse_and_map_pci(dev, 0, 0);
+#ifdef CONFIG_ACPI
+	else
+		return acpi_pci_irq_enable(dev);
+#endif
 
 	return 0;
 }
 
-/*
- * raw_pci_read/write - Platform-specific PCI config space access.
- */
-int raw_pci_read(unsigned int domain, unsigned int bus,
-		  unsigned int devfn, int reg, int len, u32 *val)
+void pcibios_add_bus(struct pci_bus *bus)
 {
-	return -ENXIO;
+	acpi_pci_add_bus(bus);
 }
 
-int raw_pci_write(unsigned int domain, unsigned int bus,
-		unsigned int devfn, int reg, int len, u32 val)
+void pcibios_remove_bus(struct pci_bus *bus)
 {
-	return -ENXIO;
+	acpi_pci_remove_bus(bus);
 }
-
-#ifdef CONFIG_ACPI
-/* Root bridge scanning */
-struct pci_bus *pci_acpi_scan_root(struct acpi_pci_root *root)
-{
-	/* TODO: Should be revisited when implementing PCI on ACPI */
-	return NULL;
-}
-#endif
diff --git a/drivers/acpi/Kconfig b/drivers/acpi/Kconfig
index ed3208fc9f9b..f8ee2f2658df 100644
--- a/drivers/acpi/Kconfig
+++ b/drivers/acpi/Kconfig
@@ -57,6 +57,9 @@ config ACPI_SYSTEM_POWER_STATES_SUPPORT
 config ACPI_CCA_REQUIRED
 	bool
 
+config IORT_TABLE
+	bool
+
 config ACPI_DEBUGGER
 	bool "AML debugger interface"
 	select ACPI_DEBUG
@@ -346,6 +349,14 @@ 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_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 948c5e6f2d8b..42723f0306c6 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-$(CONFIG_ACPI_PCI_HOST_GENERIC)	+= pci_root_generic.o pci_mcfg.o
 acpi-y				+= acpi_lpss.o acpi_apd.o
 acpi-y				+= acpi_platform.o
 acpi-y				+= acpi_pnp.o
@@ -82,6 +83,7 @@ obj-$(CONFIG_ACPI_BGRT)		+= bgrt.o
 obj-$(CONFIG_ACPI_CPPC_LIB)	+= cppc_acpi.o
 obj-$(CONFIG_ACPI_SPCR_TABLE)	+= spcr.o
 obj-$(CONFIG_ACPI_DEBUGGER_USER) += acpi_dbg.o
+obj-$(CONFIG_IORT_TABLE) 	+= iort.o
 
 # processor has its own "processor." module_param namespace
 processor-y			:= processor_driver.o
diff --git a/drivers/acpi/iort.c b/drivers/acpi/iort.c
new file mode 100644
index 000000000000..226eb6d6f92b
--- /dev/null
+++ b/drivers/acpi/iort.c
@@ -0,0 +1,344 @@
+/*
+ * Copyright (C) 2016, Semihalf
+ *	Author: Tomasz Nowicki <tn@semihalf.com>
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms and conditions of the GNU General Public License,
+ * version 2, as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope 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 for
+ * more details.
+ *
+ * This file implements early detection/parsing of I/O mapping
+ * reported to OS through firmware via I/O Remapping Table (IORT)
+ * IORT document number: ARM DEN 0049A
+ */
+
+#define pr_fmt(fmt)	"ACPI: IORT: " fmt
+
+#include <linux/export.h>
+#include <linux/iort.h>
+#include <linux/irqdomain.h>
+#include <linux/kernel.h>
+#include <linux/pci.h>
+
+struct iort_its_msi_chip {
+	struct list_head	list;
+	struct fwnode_handle	*fw_node;
+	u32			translation_id;
+};
+
+typedef acpi_status (*iort_find_node_callback)
+	(struct acpi_iort_node *node, void *context);
+
+/* Root pointer to the mapped IORT table */
+static struct acpi_table_header *iort_table;
+
+static LIST_HEAD(iort_msi_chip_list);
+
+/**
+ * iort_register_domain_token() - register domain token and related ITS ID
+ * 				  to the list from where we can get it back
+ * 				  later on.
+ * @translation_id: ITS ID
+ * @token: domain token
+ *
+ * Returns: 0 on success, -ENOMEM if not memory when allocating list element.
+ */
+int iort_register_domain_token(int trans_id, struct fwnode_handle *fw_node)
+{
+	struct iort_its_msi_chip *its_msi_chip;
+
+	its_msi_chip = kzalloc(sizeof(*its_msi_chip), GFP_KERNEL);
+	if (!its_msi_chip)
+		return -ENOMEM;
+
+	its_msi_chip->fw_node = fw_node;
+	its_msi_chip->translation_id = trans_id;
+
+	list_add(&its_msi_chip->list, &iort_msi_chip_list);
+	return 0;
+}
+
+/**
+ * iort_unregister_domain_token() - unregister domain token based on ITS ID.
+ * @translation_id: ITS ID
+ *
+ * Returns: none.
+ */
+void iort_deregister_domain_token(int trans_id)
+{
+	struct iort_its_msi_chip *its_msi_chip, *t;
+
+	list_for_each_entry_safe(its_msi_chip, t, &iort_msi_chip_list, list) {
+		if (its_msi_chip->translation_id == trans_id) {
+			list_del(&its_msi_chip->list);
+			kfree(its_msi_chip);
+			break;
+		}
+	}
+}
+
+/**
+ * iort_find_its_domain_token() - find domain token based on given ITS ID.
+ * @translation_id: ITS ID
+ *
+ * Returns: domain token when find on the list, NULL otherwise.
+ */
+struct fwnode_handle *iort_its_find_domain_token(int trans_id)
+{
+	struct iort_its_msi_chip *its_msi_chip;
+
+	list_for_each_entry(its_msi_chip, &iort_msi_chip_list, list) {
+		if (its_msi_chip->translation_id == trans_id)
+			return its_msi_chip->fw_node;
+	}
+
+	return NULL;
+}
+
+static struct acpi_iort_node *
+iort_scan_node(enum acpi_iort_node_type type,
+	       iort_find_node_callback callback, void *context)
+{
+	struct acpi_iort_node *iort_node, *iort_end;
+	struct acpi_table_iort *iort;
+	int i;
+
+	if (!iort_table)
+		return NULL;
+
+	/*
+	 * iort_table and iort both point to the start of IORT table, but
+	 * have different struct types
+	 */
+	iort = (struct acpi_table_iort *)iort_table;
+
+	/* Get the first IORT node */
+	iort_node = ACPI_ADD_PTR(struct acpi_iort_node, iort,
+				 iort->node_offset);
+	iort_end = ACPI_ADD_PTR(struct acpi_iort_node, iort_table,
+				iort_table->length);
+
+	for (i = 0; i < iort->node_count; i++) {
+		if (iort_node >= iort_end) {
+			pr_err("iort node pointer overflows, bad table\n");
+			return NULL;
+		}
+
+		if (iort_node->type == type) {
+			if (ACPI_SUCCESS(callback(iort_node, context)))
+				return iort_node;
+		}
+
+		iort_node = ACPI_ADD_PTR(struct acpi_iort_node, iort_node,
+					 iort_node->length);
+	}
+
+	return NULL;
+}
+
+static acpi_status
+iort_find_dev_callback(struct acpi_iort_node *node, void *context)
+{
+	struct acpi_iort_root_complex *pci_rc;
+	struct device *dev = context;
+	struct pci_bus *bus;
+
+	switch (node->type) {
+	case ACPI_IORT_NODE_PCI_ROOT_COMPLEX:
+		bus = to_pci_bus(dev);
+		pci_rc = (struct acpi_iort_root_complex *)node->node_data;
+
+		/*
+		 * It is assumed that PCI segment numbers maps one-to-one
+		 * with root complexes. Each segment number can represent only
+		 * one root complex.
+		 */
+		if (pci_rc->pci_segment_number == pci_domain_nr(bus))
+			return AE_OK;
+
+		break;
+	}
+
+	return AE_NOT_FOUND;
+}
+
+static struct acpi_iort_node *
+iort_dev_map_rid(struct acpi_iort_node *node, u32 rid_in,
+			    u32 *rid_out)
+{
+
+	if (!node)
+		goto out;
+
+	/* Go upstream */
+	while (node->type != ACPI_IORT_NODE_ITS_GROUP) {
+		struct acpi_iort_id_mapping *id;
+		int i, found = 0;
+
+		/* Exit when no mapping array */
+		if (!node->mapping_offset || !node->mapping_count)
+			return NULL;
+
+		id = ACPI_ADD_PTR(struct acpi_iort_id_mapping, node,
+				  node->mapping_offset);
+
+		for (i = 0, found = 0; i < node->mapping_count; i++, id++) {
+			/*
+			 * Single mapping is not translation rule,
+			 * lets move on for this case
+			 */
+			if (id->flags & ACPI_IORT_ID_SINGLE_MAPPING) {
+				if (node->type != ACPI_IORT_NODE_SMMU) {
+					rid_in = id->output_base;
+					found = 1;
+					break;
+				}
+
+				pr_warn(FW_BUG "[node %p type %d] SINGLE MAPPING flag not allowed for SMMU node, skipping ID map\n",
+					node, node->type);
+				continue;
+			}
+
+			if (rid_in < id->input_base ||
+			    (rid_in > id->input_base + id->id_count))
+				continue;
+
+			rid_in = id->output_base + (rid_in - id->input_base);
+			found = 1;
+			break;
+		}
+
+		if (!found)
+			return NULL;
+
+		/* Firmware bug! */
+		if (!id->output_reference) {
+			pr_err(FW_BUG "[node %p type %d] ID map has NULL parent reference\n",
+			       node, node->type);
+			return NULL;
+		}
+
+		node = ACPI_ADD_PTR(struct acpi_iort_node, iort_table,
+				    id->output_reference);
+	}
+
+out:
+	if (rid_out)
+		*rid_out = rid_in;
+	return node;
+}
+
+static struct acpi_iort_node *
+iort_its_find_node_and_map_rid(struct pci_dev *pdev, u32 req_id, u32 *dev_id)
+{
+	struct pci_bus *pbus = pdev->bus;
+	struct acpi_iort_node *node;
+
+	/* Find a PCI root bus */
+	while (!pci_is_root_bus(pbus))
+		pbus = pbus->parent;
+
+
+	node = iort_scan_node(ACPI_IORT_NODE_PCI_ROOT_COMPLEX,
+			      iort_find_dev_callback, &pbus->dev);
+	if (!node) {
+		dev_err(&pdev->dev, "can't find related IORT node\n");
+		return NULL;
+	}
+
+	return iort_dev_map_rid(node, req_id, dev_id);
+}
+
+/**
+ * iort_pci_domain_get_msi_rid() - find MSI RID based on PCI device ID
+ * @pdev: The PCI device
+ * @req_id: The PCI device requester ID
+ *
+ * Returns: MSI RID on success, input requester ID otherwise
+ */
+u32 iort_pci_get_msi_rid(struct pci_dev *pdev, u32 req_id)
+{
+	u32 dev_id;
+
+	if (!iort_its_find_node_and_map_rid(pdev, req_id, &dev_id))
+		return req_id;
+
+	return dev_id;
+}
+
+/**
+ * iort_pci_find_its_id() - find the ITS identifier based on specified device.
+ * @pdev: The PCI device
+ * @idx: Index of the ITS identifier list
+ * @its_id: ITS identifier
+ *
+ * Returns: 0 on success, appropriate error value otherwise
+ */
+static int
+iort_pci_find_its_id(struct pci_dev *pdev, u32 req_id, unsigned int idx,
+		     int *its_id)
+{
+	struct acpi_iort_its_group *its;
+	struct acpi_iort_node *node;
+
+	node = iort_its_find_node_and_map_rid(pdev, req_id, NULL);
+	if (!node)
+		return -ENXIO;
+
+	/* Move to ITS specific data */
+	its = (struct acpi_iort_its_group *)node->node_data;
+	if (idx > its->its_count) {
+		dev_err(&pdev->dev, "requested ITS ID index [%d] is greater than available[%d]\n",
+			idx, its->its_count);
+		return -ENXIO;
+	}
+
+	*its_id = its->identifiers[idx];
+	return 0;
+}
+
+/**
+ * iort_pci_get_msi_domain_handle() - find registered domain token related to
+ *                                    PCI device
+ * @pdev:    The PCI device
+ * @req_id:  The PCI device requester ID
+ *
+ * Returns: the MSI domain for this device, NULL otherwise
+ */
+struct irq_domain *
+iort_pci_get_domain(struct pci_dev *pdev, u32 req_id)
+{
+	static struct fwnode_handle *handle;
+	int its_id;
+
+	if (iort_pci_find_its_id(pdev, req_id, 0, &its_id))
+		return NULL;
+
+	handle = iort_its_find_domain_token(its_id);
+	if (!handle)
+		return NULL;
+
+	return irq_find_matching_fwnode(handle, DOMAIN_BUS_PCI_MSI);
+}
+
+static int __init iort_table_detect(void)
+{
+	acpi_status status;
+
+	if (acpi_disabled)
+		return -ENODEV;
+
+	status = acpi_get_table(ACPI_SIG_IORT, 0, &iort_table);
+	if (ACPI_FAILURE(status)) {
+		const char *msg = acpi_format_exception(status);
+		pr_err("Failed to get table, %s\n", msg);
+		return -EINVAL;
+	}
+
+	return 0;
+}
+arch_initcall(iort_table_detect);
diff --git a/drivers/acpi/pci_mcfg.c b/drivers/acpi/pci_mcfg.c
new file mode 100644
index 000000000000..373d07954bc7
--- /dev/null
+++ b/drivers/acpi/pci_mcfg.c
@@ -0,0 +1,97 @@
+/*
+ * Copyright (C) 2016 Broadcom
+ *	Author: Jayachandran C <jchandra@broadcom.com>
+ * Copyright (C) 2016 Semihalf
+ * 	Author: Tomasz Nowicki <tn@semihalf.com>
+ *
+ * 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>
+
+#define PREFIX	"ACPI: "
+
+/* Root pointer to the mapped MCFG table */
+static struct acpi_table_mcfg *mcfg_table;
+
+#define MCFG_ENTRIES(mcfg_ptr)	(((mcfg_ptr)->header.length -		\
+				sizeof(struct acpi_table_mcfg)) /	\
+				sizeof(struct acpi_mcfg_allocation))
+
+static phys_addr_t pci_mcfg_lookup_static(u16 seg, u8 bus_start, u8 bus_end)
+{
+	struct acpi_mcfg_allocation *mptr;
+	int i;
+
+	if (!mcfg_table) {
+		pr_err(PREFIX "MCFG table not available, lookup failed\n");
+		return -ENXIO;
+	}
+
+	mptr = (struct acpi_mcfg_allocation *) &mcfg_table[1];
+
+	/*
+	 * We expect exact match, unless MCFG entry end bus covers more than
+	 * specified by caller.
+	 */
+	for (i = 0; i < MCFG_ENTRIES(mcfg_table); i++, mptr++) {
+		if (mptr->pci_segment == seg &&
+		    mptr->start_bus_number == bus_start &&
+		    mptr->end_bus_number >= bus_end) {
+			return mptr->address;
+		}
+	}
+
+	return -ENXIO;
+}
+
+phys_addr_t pci_mcfg_lookup(struct acpi_device *device, u16 seg,
+			    struct resource *bus_res)
+{
+	phys_addr_t addr;
+
+	addr = acpi_pci_root_get_mcfg_addr(device->handle);
+	if (addr)
+		return addr;
+
+	return pci_mcfg_lookup_static(seg, bus_res->start, bus_res->end);
+}
+
+static __init int pci_mcfg_parse(struct acpi_table_header *header)
+{
+	struct acpi_table_mcfg *mcfg;
+	int n;
+
+	if (!header)
+		return -EINVAL;
+
+	mcfg = (struct acpi_table_mcfg *)header;
+	n = MCFG_ENTRIES(mcfg);
+	if (n <= 0 || n > 255) {
+		pr_err(PREFIX "MCFG has incorrect entries (%d).\n", n);
+		return -EINVAL;
+	}
+
+	mcfg_table = mcfg;
+	pr_info(PREFIX "MCFG table loaded, %d entries detected\n", n);
+	return 0;
+}
+
+/* Interface called by ACPI - parse and save MCFG table */
+void __init pci_mmcfg_late_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);
+}
diff --git a/drivers/acpi/pci_root.c b/drivers/acpi/pci_root.c
index ae3fe4e64203..cb3071dcc166 100644
--- a/drivers/acpi/pci_root.c
+++ b/drivers/acpi/pci_root.c
@@ -719,6 +719,34 @@ next:
 			resource_list_add_tail(entry, resources);
 	}
 }
+static void acpi_pci_root_remap_iospace(struct resource_entry *entry)
+{
+#ifdef PCI_IOBASE
+	struct resource *res = entry->res;
+	resource_size_t cpu_addr = res->start;
+	resource_size_t pci_addr = cpu_addr - entry->offset;
+	resource_size_t length = resource_size(res);
+	unsigned long port;
+
+	if (pci_register_io_range(cpu_addr, length))
+		goto err;
+
+	port = pci_address_to_pio(cpu_addr);
+	if (port == (unsigned long)-1)
+		goto err;
+
+	res->start = port;
+	res->end = port + length - 1;
+	entry->offset = port - pci_addr;
+
+	if (pci_remap_iospace(res, cpu_addr) < 0)
+		goto err;
+	pr_info("Remapped I/O %pa to %pR\n", &cpu_addr, res);
+	return;
+err:
+	res->flags |= IORESOURCE_DISABLED;
+#endif
+}
 
 int acpi_pci_probe_root_resources(struct acpi_pci_root_info *info)
 {
@@ -740,6 +768,9 @@ int acpi_pci_probe_root_resources(struct acpi_pci_root_info *info)
 			"no IO and memory resources present in _CRS\n");
 	else {
 		resource_list_for_each_entry_safe(entry, tmp, list) {
+			if (entry->res->flags & IORESOURCE_IO)
+				acpi_pci_root_remap_iospace(entry);
+
 			if (entry->res->flags & IORESOURCE_DISABLED)
 				resource_list_destroy_entry(entry);
 			else
@@ -811,6 +842,8 @@ static void acpi_pci_root_release_info(struct pci_host_bridge *bridge)
 
 	resource_list_for_each_entry(entry, &bridge->windows) {
 		res = entry->res;
+		if (res->flags & IORESOURCE_IO)
+			pci_unmap_iospace(res);
 		if (res->parent &&
 		    (res->flags & (IORESOURCE_MEM | IORESOURCE_IO)))
 			release_resource(res);
diff --git a/drivers/acpi/pci_root_generic.c b/drivers/acpi/pci_root_generic.c
new file mode 100644
index 000000000000..6f4940a7262d
--- /dev/null
+++ b/drivers/acpi/pci_root_generic.c
@@ -0,0 +1,149 @@
+/*
+ * Copyright (C) 2016 Broadcom
+ *	Author: Jayachandran C <jchandra@broadcom.com>
+ * Copyright (C) 2016 Semihalf
+ * 	Author: Tomasz Nowicki <tn@semihalf.com>
+ *
+ * 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/slab.h>
+
+#include "../pci/ecam.h"
+
+#define PREFIX	"ACPI PCI: "
+
+/* 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 */
+};
+
+void acpi_pci_set_companion(struct pci_host_bridge *bridge)
+{
+	struct pci_config_window *cfg = bridge->bus->sysdata;
+
+	ACPI_COMPANION_SET(&bridge->dev, cfg->companion);
+}
+
+int acpi_pci_bus_domain_nr(struct pci_bus *bus)
+{
+	struct pci_config_window *cfg = bus->sysdata;
+
+	return cfg->domain;
+}
+
+/*
+ * 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)
+{
+	struct resource *bus_res = &root->secondary;
+	u16 seg = root->segment;
+	struct pci_config_window *cfg;
+	struct resource cfgres;
+	unsigned int bsz;
+	phys_addr_t addr;
+
+	addr = pci_mcfg_lookup(root->device, seg, bus_res);
+	if (IS_ERR_VALUE(addr)) {
+		pr_err(PREFIX"%04x:%pR MCFG region not found\n", seg, bus_res);
+		return addr;
+	}
+
+	bsz = 1 << pci_generic_ecam_ops.bus_shift;
+	cfgres.start = addr + bus_res->start * bsz;
+	cfgres.end = addr + (bus_res->end + 1) * bsz - 1;
+	cfgres.flags = IORESOURCE_MEM;
+	cfg = pci_ecam_create(&root->device->dev, &cfgres, bus_res,
+						  &pci_generic_ecam_ops);
+	if (IS_ERR(cfg)) {
+		pr_err("%04x:%pR error %ld mapping CAM\n", seg, bus_res,
+		       PTR_ERR(cfg));
+		return PTR_ERR(cfg);
+	}
+
+	cfg->domain = seg;
+	cfg->companion = root->device;
+	ri->cfg = cfg;
+	return 0;
+}
+
+/* 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_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;
+}
+
+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/drivers/irqchip/Kconfig b/drivers/irqchip/Kconfig
index 3e124793e224..f582e0d19df7 100644
--- a/drivers/irqchip/Kconfig
+++ b/drivers/irqchip/Kconfig
@@ -31,6 +31,7 @@ config ARM_GIC_V3
 config ARM_GIC_V3_ITS
 	bool
 	select PCI_MSI_IRQ_DOMAIN
+	select IORT_TABLE if ACPI
 
 config ARM_NVIC
 	bool
diff --git a/drivers/irqchip/irq-gic-v3-its-pci-msi.c b/drivers/irqchip/irq-gic-v3-its-pci-msi.c
index aee60ed025dc..eb29b217feb7 100644
--- a/drivers/irqchip/irq-gic-v3-its-pci-msi.c
+++ b/drivers/irqchip/irq-gic-v3-its-pci-msi.c
@@ -15,6 +15,7 @@
  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  */
 
+#include <linux/iort.h>
 #include <linux/msi.h>
 #include <linux/of.h>
 #include <linux/of_irq.h>
@@ -106,34 +107,87 @@ static struct of_device_id its_device_id[] = {
 	{},
 };
 
-static int __init its_pci_msi_init(void)
+static int __init its_pci_msi_init_one(struct fwnode_handle *handle,
+				       const char *name)
 {
-	struct device_node *np;
 	struct irq_domain *parent;
 
+	parent = irq_find_matching_fwnode(handle, DOMAIN_BUS_NEXUS);
+	if (!parent || !msi_get_domain_info(parent)) {
+		pr_err("%s: Unable to locate ITS domain\n", name);
+		return -ENXIO;
+	}
+
+	if (!pci_msi_create_irq_domain(handle, &its_pci_msi_domain_info,
+				       parent)) {
+		pr_err("%s: Unable to create PCI domain\n", name);
+		return -ENOMEM;
+	}
+
+	return 0;
+}
+
+static int __init its_pci_of_msi_init(void)
+{
+	struct device_node *np;
+
 	for (np = of_find_matching_node(NULL, its_device_id); np;
 	     np = of_find_matching_node(np, its_device_id)) {
 		if (!of_property_read_bool(np, "msi-controller"))
 			continue;
 
-		parent = irq_find_matching_host(np, DOMAIN_BUS_NEXUS);
-		if (!parent || !msi_get_domain_info(parent)) {
-			pr_err("%s: unable to locate ITS domain\n",
-			       np->full_name);
-			continue;
-		}
-
-		if (!pci_msi_create_irq_domain(of_node_to_fwnode(np),
-					       &its_pci_msi_domain_info,
-					       parent)) {
-			pr_err("%s: unable to create PCI domain\n",
-			       np->full_name);
+		if (its_pci_msi_init_one(of_node_to_fwnode(np), np->full_name))
 			continue;
-		}
 
 		pr_info("PCI/MSI: %s domain created\n", np->full_name);
 	}
 
 	return 0;
 }
+
+#ifdef CONFIG_ACPI
+
+static int __init
+its_pci_msi_parse_madt(struct acpi_subtable_header *header,
+		       const unsigned long end)
+{
+	struct acpi_madt_generic_translator *its_entry;
+	struct fwnode_handle *domain_handle;
+	char node_name[6 + 16 + 1];
+
+	its_entry = (struct acpi_madt_generic_translator *)header;
+	snprintf(node_name, 23, "ITS@0x%lx", (long)its_entry->base_address);
+	domain_handle = iort_its_find_domain_token(its_entry->translation_id);
+	if (!domain_handle) {
+		pr_err("%s: Unable to locate ITS domain handle\n", node_name);
+		return 0;
+	}
+
+	if (its_pci_msi_init_one(domain_handle, node_name))
+		return 0;
+
+	pr_info("PCI/MSI: %s domain created\n", node_name);
+	return 0;
+}
+
+static int __init its_pci_acpi_msi_init(void)
+{
+	acpi_table_parse_madt(ACPI_MADT_TYPE_GENERIC_TRANSLATOR,
+			      its_pci_msi_parse_madt, 0);
+	return 0;
+}
+#else
+inline static int __init its_pci_acpi_msi_init(void)
+{
+	return 0;
+}
+#endif
+
+static int __init its_pci_msi_init(void)
+{
+	its_pci_of_msi_init();
+	its_pci_acpi_msi_init();
+
+	return 0;
+}
 early_initcall(its_pci_msi_init);
diff --git a/drivers/irqchip/irq-gic-v3-its.c b/drivers/irqchip/irq-gic-v3-its.c
index 39261798c59f..f403d8b05d9d 100644
--- a/drivers/irqchip/irq-gic-v3-its.c
+++ b/drivers/irqchip/irq-gic-v3-its.c
@@ -15,10 +15,13 @@
  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  */
 
+#include <linux/acpi.h>
 #include <linux/bitmap.h>
 #include <linux/cpu.h>
 #include <linux/delay.h>
 #include <linux/interrupt.h>
+#include <linux/irqdomain.h>
+#include <linux/iort.h>
 #include <linux/log2.h>
 #include <linux/mm.h>
 #include <linux/msi.h>
@@ -63,7 +66,7 @@ struct its_node {
 	raw_spinlock_t		lock;
 	struct list_head	entry;
 	void __iomem		*base;
-	unsigned long		phys_base;
+	phys_addr_t		phys_base;
 	struct its_cmd_block	*cmd_base;
 	struct its_cmd_block	*cmd_write;
 	struct {
@@ -104,6 +107,7 @@ struct its_device {
 static LIST_HEAD(its_nodes);
 static DEFINE_SPINLOCK(its_lock);
 static struct rdists *gic_rdists;
+static struct irq_domain *its_parent;
 
 #define gic_data_rdist()		(raw_cpu_ptr(gic_rdists->rdist))
 #define gic_data_rdist_rd_base()	(gic_data_rdist()->rd_base)
@@ -815,7 +819,7 @@ static void its_free_tables(struct its_node *its)
 	}
 }
 
-static int its_alloc_tables(const char *node_name, struct its_node *its)
+static int its_alloc_tables(struct its_node *its)
 {
 	int err;
 	int i;
@@ -869,8 +873,8 @@ static int its_alloc_tables(const char *node_name, struct its_node *its)
 				    order);
 			if (order >= MAX_ORDER) {
 				order = MAX_ORDER - 1;
-				pr_warn("%s: Device Table too large, reduce its page order to %u\n",
-					node_name, order);
+				pr_warn("ITS@%pa: Device Table too large, reduce its page order to %u\n",
+					&its->phys_base, order);
 			}
 		}
 
@@ -879,8 +883,8 @@ retry_alloc_baser:
 		if (alloc_pages > GITS_BASER_PAGES_MAX) {
 			alloc_pages = GITS_BASER_PAGES_MAX;
 			order = get_order(GITS_BASER_PAGES_MAX * psz);
-			pr_warn("%s: Device Table too large, reduce its page order to %u (%u pages)\n",
-				node_name, order, alloc_pages);
+			pr_warn("ITS@%pa: Device Table too large, reduce its page order to %u (%u pages)\n",
+				&its->phys_base, order, alloc_pages);
 		}
 
 		base = (void *)__get_free_pages(GFP_KERNEL | __GFP_ZERO, order);
@@ -953,8 +957,8 @@ retry_baser:
 		}
 
 		if (val != tmp) {
-			pr_err("ITS: %s: GITS_BASER%d doesn't stick: %lx %lx\n",
-			       node_name, i,
+			pr_err("ITS@%pa: GITS_BASER%d doesn't stick: %lx %lx\n",
+			       &its->phys_base, i,
 			       (unsigned long) val, (unsigned long) tmp);
 			err = -ENXIO;
 			goto out_free;
@@ -1277,6 +1281,11 @@ static int its_irq_gic_domain_alloc(struct irq_domain *domain,
 		fwspec.param[0] = GIC_IRQ_TYPE_LPI;
 		fwspec.param[1] = hwirq;
 		fwspec.param[2] = IRQ_TYPE_EDGE_RISING;
+	} else if (is_fwnode_irqchip(domain->parent->fwnode)) {
+		fwspec.fwnode = domain->parent->fwnode;
+		fwspec.param_count = 2;
+		fwspec.param[0] = hwirq;
+		fwspec.param[1] = IRQ_TYPE_EDGE_RISING;
 	} else {
 		return -EINVAL;
 	}
@@ -1429,44 +1438,59 @@ static void its_enable_quirks(struct its_node *its)
 	gic_enable_quirks(iidr, its_quirks, its);
 }
 
-static int __init its_probe(struct device_node *node,
-			    struct irq_domain *parent)
+static int its_init_domain(struct fwnode_handle *handle, struct its_node *its)
+{
+	struct irq_domain *inner_domain;
+	struct msi_domain_info *info;
+
+	info = kzalloc(sizeof(*info), GFP_KERNEL);
+	if (!info)
+		return -ENOMEM;
+
+	inner_domain = irq_domain_create_tree(handle, &its_domain_ops, its);
+	if (!inner_domain) {
+		kfree(info);
+		return -ENOMEM;
+	}
+
+	inner_domain->parent = its_parent;
+	inner_domain->bus_token = DOMAIN_BUS_NEXUS;
+	info->ops = &its_msi_domain_ops;
+	info->data = its;
+	inner_domain->host_data = info;
+
+	return 0;
+}
+
+static int __init its_probe_one(struct resource *res,
+				struct fwnode_handle *handle)
 {
-	struct resource res;
 	struct its_node *its;
 	void __iomem *its_base;
-	struct irq_domain *inner_domain;
 	u32 val;
 	u64 baser, tmp;
 	int err;
 
-	err = of_address_to_resource(node, 0, &res);
-	if (err) {
-		pr_warn("%s: no regs?\n", node->full_name);
-		return -ENXIO;
-	}
-
-	its_base = ioremap(res.start, resource_size(&res));
+	its_base = ioremap(res->start, resource_size(res));
 	if (!its_base) {
-		pr_warn("%s: unable to map registers\n", node->full_name);
+		pr_warn("ITS@%pa: Unable to map ITS registers\n", &res->start);
 		return -ENOMEM;
 	}
 
 	val = readl_relaxed(its_base + GITS_PIDR2) & GIC_PIDR2_ARCH_MASK;
 	if (val != 0x30 && val != 0x40) {
-		pr_warn("%s: no ITS detected, giving up\n", node->full_name);
+		pr_warn("ITS@%pa: No ITS detected, giving up\n", &res->start);
 		err = -ENODEV;
 		goto out_unmap;
 	}
 
 	err = its_force_quiescent(its_base);
 	if (err) {
-		pr_warn("%s: failed to quiesce, giving up\n",
-			node->full_name);
+		pr_warn("ITS@%pa: Failed to quiesce, giving up\n", &res->start);
 		goto out_unmap;
 	}
 
-	pr_info("ITS: %s\n", node->full_name);
+	pr_info("ITS@%pa\n", &res->start);
 
 	its = kzalloc(sizeof(*its), GFP_KERNEL);
 	if (!its) {
@@ -1478,7 +1502,7 @@ static int __init its_probe(struct device_node *node,
 	INIT_LIST_HEAD(&its->entry);
 	INIT_LIST_HEAD(&its->its_device_list);
 	its->base = its_base;
-	its->phys_base = res.start;
+	its->phys_base = res->start;
 	its->ite_size = ((readl_relaxed(its_base + GITS_TYPER) >> 4) & 0xf) + 1;
 
 	its->cmd_base = kzalloc(ITS_CMD_QUEUE_SZ, GFP_KERNEL);
@@ -1490,7 +1514,7 @@ static int __init its_probe(struct device_node *node,
 
 	its_enable_quirks(its);
 
-	err = its_alloc_tables(node->full_name, its);
+	err = its_alloc_tables(its);
 	if (err)
 		goto out_free_cmd;
 
@@ -1526,28 +1550,9 @@ static int __init its_probe(struct device_node *node,
 	writeq_relaxed(0, its->base + GITS_CWRITER);
 	writel_relaxed(GITS_CTLR_ENABLE, its->base + GITS_CTLR);
 
-	if (of_property_read_bool(node, "msi-controller")) {
-		struct msi_domain_info *info;
-
-		info = kzalloc(sizeof(*info), GFP_KERNEL);
-		if (!info) {
-			err = -ENOMEM;
-			goto out_free_tables;
-		}
-
-		inner_domain = irq_domain_add_tree(node, &its_domain_ops, its);
-		if (!inner_domain) {
-			err = -ENOMEM;
-			kfree(info);
-			goto out_free_tables;
-		}
-
-		inner_domain->parent = parent;
-		inner_domain->bus_token = DOMAIN_BUS_NEXUS;
-		info->ops = &its_msi_domain_ops;
-		info->data = its;
-		inner_domain->host_data = info;
-	}
+	err = its_init_domain(handle, its);
+	if (err)
+		goto out_free_tables;
 
 	spin_lock(&its_lock);
 	list_add(&its->entry, &its_nodes);
@@ -1563,7 +1568,7 @@ out_free_its:
 	kfree(its);
 out_unmap:
 	iounmap(its_base);
-	pr_err("ITS: failed probing %s (%d)\n", node->full_name, err);
+	pr_err("ITS@%pa: failed probing (%d)\n", &res->start, err);
 	return err;
 }
 
@@ -1591,15 +1596,88 @@ static struct of_device_id its_device_id[] = {
 	{},
 };
 
-int __init its_init(struct device_node *node, struct rdists *rdists,
-	     struct irq_domain *parent_domain)
+static int __init
+its_of_probe(struct device_node *node)
 {
 	struct device_node *np;
+	struct resource res;
 
 	for (np = of_find_matching_node(node, its_device_id); np;
 	     np = of_find_matching_node(np, its_device_id)) {
-		its_probe(np, parent_domain);
+		if (!of_property_read_bool(np, "msi-controller")) {
+			pr_warn("%s: no msi-controller property, ITS ignored\n",
+				np->full_name);
+			continue;
+		}
+
+		if (of_address_to_resource(np, 0, &res)) {
+			pr_warn("%s: no regs?\n", np->full_name);
+			continue;
+		}
+
+		its_probe_one(&res, &np->fwnode);
+	}
+	return 0;
+}
+
+#ifdef CONFIG_ACPI
+
+#define ACPI_GICV3_ITS_MEM_SIZE (2 * SZ_64K)
+
+static int __init
+gic_acpi_parse_madt_its(struct acpi_subtable_header *header,
+			const unsigned long end)
+{
+	struct acpi_madt_generic_translator *its_entry;
+	struct fwnode_handle *domain_handle;
+	struct resource res;
+	int err;
+
+	its_entry = (struct acpi_madt_generic_translator *)header;
+	domain_handle = irq_domain_alloc_fwnode((void *)its_entry->base_address);
+	if (!domain_handle) {
+		pr_err("Unable to allocate GICv3 ITS domain token\n");
+		return -ENOMEM;
+	}
+
+	err = iort_register_domain_token(its_entry->translation_id, domain_handle);
+	if (err) {
+		irq_domain_free_fwnode(domain_handle);
+		goto out;
+	}
+
+	res.start = its_entry->base_address;
+	res.end = its_entry->base_address + ACPI_GICV3_ITS_MEM_SIZE - 1;
+	err = its_probe_one(&res, domain_handle);
+	if (err) {
+		iort_deregister_domain_token(its_entry->translation_id);
+		irq_domain_free_fwnode(domain_handle);
 	}
+out:
+	return err;
+}
+
+void __init its_acpi_probe(void)
+{
+	if (acpi_table_parse_madt(ACPI_MADT_TYPE_GENERIC_TRANSLATOR,
+				  gic_acpi_parse_madt_its, 0) <= 0)
+		pr_info("No valid GIC ITS entries exist\n");
+}
+#else
+static inline void __init its_acpi_probe(struct irq_domain *parent_domain) { }
+#endif
+
+int __init its_init(struct fwnode_handle *handle, struct rdists *rdists,
+		    struct irq_domain *parent_domain)
+{
+	struct device_node *of_node;
+
+	its_parent = parent_domain;
+	of_node = to_of_node(handle);
+	if (of_node)
+		its_of_probe(of_node);
+	else
+		its_acpi_probe();
 
 	if (list_empty(&its_nodes)) {
 		pr_warn("ITS: No ITS available, not enabling LPIs\n");
diff --git a/drivers/irqchip/irq-gic-v3.c b/drivers/irqchip/irq-gic-v3.c
index 5b7d3c2129d8..77089412eb34 100644
--- a/drivers/irqchip/irq-gic-v3.c
+++ b/drivers/irqchip/irq-gic-v3.c
@@ -832,7 +832,6 @@ static int __init gic_init_bases(void __iomem *dist_base,
 				 u64 redist_stride,
 				 struct fwnode_handle *handle)
 {
-	struct device_node *node;
 	u32 typer;
 	int gic_irqs;
 	int err;
@@ -872,10 +871,8 @@ static int __init gic_init_bases(void __iomem *dist_base,
 
 	set_handle_irq(gic_handle_irq);
 
-	node = to_of_node(handle);
-	if (IS_ENABLED(CONFIG_ARM_GIC_V3_ITS) && gic_dist_supports_lpis() &&
-	    node) /* Temp hack to prevent ITS init for ACPI */
-		its_init(node, &gic_data.rdists, gic_data.domain);
+	if (IS_ENABLED(CONFIG_ARM_GIC_V3_ITS) && gic_dist_supports_lpis())
+		its_init(handle, &gic_data.rdists, gic_data.domain);
 
 	gic_smp_init();
 	gic_dist_init();
diff --git a/drivers/of/address.c b/drivers/of/address.c
index 91a469d55b8f..0a553c084a81 100644
--- a/drivers/of/address.c
+++ b/drivers/of/address.c
@@ -4,6 +4,7 @@
 #include <linux/ioport.h>
 #include <linux/module.h>
 #include <linux/of_address.h>
+#include <linux/pci.h>
 #include <linux/pci_regs.h>
 #include <linux/sizes.h>
 #include <linux/slab.h>
@@ -673,121 +674,6 @@ const __be32 *of_get_address(struct device_node *dev, int index, u64 *size,
 }
 EXPORT_SYMBOL(of_get_address);
 
-#ifdef PCI_IOBASE
-struct io_range {
-	struct list_head list;
-	phys_addr_t start;
-	resource_size_t size;
-};
-
-static LIST_HEAD(io_range_list);
-static DEFINE_SPINLOCK(io_range_lock);
-#endif
-
-/*
- * Record the PCI IO range (expressed as CPU physical address + size).
- * Return a negative value if an error has occured, zero otherwise
- */
-int __weak pci_register_io_range(phys_addr_t addr, resource_size_t size)
-{
-	int err = 0;
-
-#ifdef PCI_IOBASE
-	struct io_range *range;
-	resource_size_t allocated_size = 0;
-
-	/* check if the range hasn't been previously recorded */
-	spin_lock(&io_range_lock);
-	list_for_each_entry(range, &io_range_list, list) {
-		if (addr >= range->start && addr + size <= range->start + size) {
-			/* range already registered, bail out */
-			goto end_register;
-		}
-		allocated_size += range->size;
-	}
-
-	/* range not registed yet, check for available space */
-	if (allocated_size + size - 1 > IO_SPACE_LIMIT) {
-		/* if it's too big check if 64K space can be reserved */
-		if (allocated_size + SZ_64K - 1 > IO_SPACE_LIMIT) {
-			err = -E2BIG;
-			goto end_register;
-		}
-
-		size = SZ_64K;
-		pr_warn("Requested IO range too big, new size set to 64K\n");
-	}
-
-	/* add the range to the list */
-	range = kzalloc(sizeof(*range), GFP_ATOMIC);
-	if (!range) {
-		err = -ENOMEM;
-		goto end_register;
-	}
-
-	range->start = addr;
-	range->size = size;
-
-	list_add_tail(&range->list, &io_range_list);
-
-end_register:
-	spin_unlock(&io_range_lock);
-#endif
-
-	return err;
-}
-
-phys_addr_t pci_pio_to_address(unsigned long pio)
-{
-	phys_addr_t address = (phys_addr_t)OF_BAD_ADDR;
-
-#ifdef PCI_IOBASE
-	struct io_range *range;
-	resource_size_t allocated_size = 0;
-
-	if (pio > IO_SPACE_LIMIT)
-		return address;
-
-	spin_lock(&io_range_lock);
-	list_for_each_entry(range, &io_range_list, list) {
-		if (pio >= allocated_size && pio < allocated_size + range->size) {
-			address = range->start + pio - allocated_size;
-			break;
-		}
-		allocated_size += range->size;
-	}
-	spin_unlock(&io_range_lock);
-#endif
-
-	return address;
-}
-
-unsigned long __weak pci_address_to_pio(phys_addr_t address)
-{
-#ifdef PCI_IOBASE
-	struct io_range *res;
-	resource_size_t offset = 0;
-	unsigned long addr = -1;
-
-	spin_lock(&io_range_lock);
-	list_for_each_entry(res, &io_range_list, list) {
-		if (address >= res->start && address < res->start + res->size) {
-			addr = address - res->start + offset;
-			break;
-		}
-		offset += res->size;
-	}
-	spin_unlock(&io_range_lock);
-
-	return addr;
-#else
-	if (address > IO_SPACE_LIMIT)
-		return (unsigned long)-1;
-
-	return (unsigned long) address;
-#endif
-}
-
 static int __of_address_to_resource(struct device_node *dev,
 		const __be32 *addrp, u64 size, unsigned int flags,
 		const char *name, struct resource *r)
diff --git a/drivers/pci/Kconfig b/drivers/pci/Kconfig
index 209292e067d2..56389be5d08b 100644
--- a/drivers/pci/Kconfig
+++ b/drivers/pci/Kconfig
@@ -83,6 +83,9 @@ config HT_IRQ
 config PCI_ATS
 	bool
 
+config PCI_ECAM
+	bool
+
 config PCI_IOV
 	bool "PCI IOV support"
 	depends on PCI
diff --git a/drivers/pci/Makefile b/drivers/pci/Makefile
index 2154092ddee8..1fa6925733d3 100644
--- a/drivers/pci/Makefile
+++ b/drivers/pci/Makefile
@@ -55,6 +55,8 @@ obj-$(CONFIG_PCI_SYSCALL) += syscall.o
 
 obj-$(CONFIG_PCI_STUB) += pci-stub.o
 
+obj-$(CONFIG_PCI_ECAM) += ecam.o
+
 obj-$(CONFIG_XEN_PCIDEV_FRONTEND) += xen-pcifront.o
 
 obj-$(CONFIG_OF) += of.o
diff --git a/drivers/pci/ecam.c b/drivers/pci/ecam.c
new file mode 100644
index 000000000000..3d52005c09f8
--- /dev/null
+++ b/drivers/pci/ecam.c
@@ -0,0 +1,161 @@
+/*
+ * Copyright 2016 Broadcom
+ *
+ * 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/device.h>
+#include <linux/io.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/pci.h>
+#include <linux/slab.h>
+
+#include "ecam.h"
+
+/*
+ * On 64 bit systems, we do a single ioremap for the whole config space
+ * since we have enough virtual address range available. On 32 bit, do an
+ * ioremap per bus.
+ */
+static const bool per_bus_mapping = !config_enabled(CONFIG_64BIT);
+
+/*
+ * Create a PCI config space window
+ *  - reserve mem region
+ *  - alloc struct pci_config_window with space for all mappings
+ *  - ioremap the config space
+ */
+struct pci_config_window *pci_ecam_create(struct device *dev,
+		struct resource *cfgres, struct resource *busr,
+		struct pci_ecam_ops *ops)
+{
+	struct pci_config_window *cfg;
+	unsigned int bus_range, bus_range_max, bsz;
+	int i, err;
+
+	if (busr->start > busr->end)
+		return ERR_PTR(-EINVAL);
+
+	cfg = kzalloc(sizeof(*cfg), GFP_KERNEL);
+	if (!cfg)
+		return ERR_PTR(-ENOMEM);
+
+	cfg->ops = ops;
+	cfg->busr.start = busr->start;
+	cfg->busr.end = busr->end;
+	cfg->busr.flags = IORESOURCE_BUS;
+	bus_range = resource_size(&cfg->busr);
+	bus_range_max = resource_size(cfgres) >> ops->bus_shift;
+	if (bus_range > bus_range_max) {
+		dev_warn(dev, "bus max %#x reduced to %#x",
+					bus_range, bus_range_max);
+		bus_range = bus_range_max;
+		cfg->busr.end = busr->start + bus_range - 1;
+	}
+	bsz = 1 << ops->bus_shift;
+
+	cfg->res.start = cfgres->start;
+	cfg->res.end = cfgres->end;
+	cfg->res.flags = IORESOURCE_MEM | IORESOURCE_BUSY;
+	cfg->res.name = "PCI ECAM";
+
+	err = request_resource(&iomem_resource, &cfg->res);
+	if (err) {
+		dev_err(dev, "request ECAM res %pR failed\n", &cfg->res);
+		goto err_exit;
+	}
+
+	if (per_bus_mapping) {
+		cfg->winp = kcalloc(bus_range, sizeof(*cfg->winp), GFP_KERNEL);
+		if (!cfg->winp)
+			goto err_exit_malloc;
+		for (i = 0; i < bus_range; i++) {
+			cfg->winp[i] = ioremap(cfgres->start + i * bsz, bsz);
+			if (!cfg->winp[i])
+				goto err_exit_iomap;
+		}
+	} else {
+		cfg->win = ioremap(cfgres->start, bus_range * bsz);
+		if (!cfg->win)
+			goto err_exit_iomap;
+	}
+
+	if (ops->init) {
+		err = ops->init(dev, cfg);
+		if (err)
+			goto err_exit;
+	}
+	dev_info(dev, "ECAM at %pR for %pR\n", &cfg->res, &cfg->busr);
+	return cfg;
+
+err_exit_iomap:
+	dev_err(dev, "ECAM ioremap failed\n");
+err_exit_malloc:
+	err = -ENOMEM;
+err_exit:
+	pci_ecam_free(cfg);
+	return ERR_PTR(err);
+}
+
+void pci_ecam_free(struct pci_config_window *cfg)
+{
+	int i;
+
+	if (per_bus_mapping) {
+		if (cfg->winp) {
+			for (i = 0; i < resource_size(&cfg->busr); i++)
+				if (cfg->winp[i])
+					iounmap(cfg->winp[i]);
+			kfree(cfg->winp);
+		}
+	} else {
+		if (cfg->win)
+			iounmap(cfg->win);
+	}
+	if (cfg->res.parent)
+		release_resource(&cfg->res);
+	kfree(cfg);
+}
+
+/*
+ * Function to implement the pci_ops ->map_bus method
+ */
+void __iomem *pci_ecam_map_bus(struct pci_bus *bus, unsigned int devfn,
+			       int where)
+{
+	struct pci_config_window *cfg = bus->sysdata;
+	unsigned int devfn_shift = cfg->ops->bus_shift - 8;
+	unsigned int busn = bus->number;
+	void __iomem *base;
+
+	if (busn < cfg->busr.start || busn > cfg->busr.end)
+		return NULL;
+
+	busn -= cfg->busr.start;
+	if (per_bus_mapping)
+		base = cfg->winp[busn];
+	else
+		base = cfg->win + (busn << cfg->ops->bus_shift);
+	return base + (devfn << devfn_shift) + where;
+}
+
+/* ECAM ops */
+struct pci_ecam_ops pci_generic_ecam_ops = {
+	.bus_shift	= 20,
+	.pci_ops	= {
+		.map_bus	= pci_ecam_map_bus,
+		.read		= pci_generic_config_read,
+		.write		= pci_generic_config_write,
+	}
+};
diff --git a/drivers/pci/ecam.h b/drivers/pci/ecam.h
new file mode 100644
index 000000000000..1cccf575ba7c
--- /dev/null
+++ b/drivers/pci/ecam.h
@@ -0,0 +1,72 @@
+/*
+ * Copyright 2016 Broadcom
+ *
+ * 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.
+ */
+#ifndef DRIVERS_PCI_ECAM_H
+#define DRIVERS_PCI_ECAM_H
+
+#include <linux/kernel.h>
+#include <linux/platform_device.h>
+
+/*
+ * struct to hold pci ops and bus shift of the config window
+ * for a PCI controller.
+ */
+struct pci_config_window;
+struct pci_ecam_ops {
+	unsigned int			bus_shift;
+	struct pci_ops			pci_ops;
+	int				(*init)(struct device *,
+						struct pci_config_window *);
+};
+
+/*
+ * struct to hold the mappings of a config space window. This
+ * is expected to be used as sysdata for PCI controlllers which
+ * use ECAM.
+ */
+struct pci_config_window {
+	struct resource			res;
+	struct resource			busr;
+	void				*priv;
+	struct pci_ecam_ops		*ops;
+	union {
+		void __iomem		*win;	/* 64-bit single mapping */
+		void __iomem		**winp; /* 32-bit per bus mapping */
+	};
+#ifdef CONFIG_ACPI_PCI_HOST_GENERIC
+	struct acpi_device		*companion; /* ACPI companion device */
+#endif
+	int				domain;
+
+};
+
+/* create and free for pci_config_window */
+struct pci_config_window *pci_ecam_create(struct device *dev,
+		struct resource *cfgres, struct resource *busr,
+		struct pci_ecam_ops *ops);
+void pci_ecam_free(struct pci_config_window *cfg);
+
+/* map_bus when ->sysdata is an instance of pci_config_window */
+void __iomem *pci_ecam_map_bus(struct pci_bus *bus, unsigned int devfn,
+			       int where);
+/* default ECAM ops, bus shift 20, generic read and write */
+extern struct pci_ecam_ops pci_generic_ecam_ops;
+
+#ifdef CONFIG_PCI_HOST_GENERIC
+/* for DT based pci controllers that support ECAM */
+int pci_host_common_probe(struct platform_device *pdev,
+			  struct pci_ecam_ops *ops);
+#endif
+#endif
diff --git a/drivers/pci/host/Kconfig b/drivers/pci/host/Kconfig
index 7a0780d56d2d..963300dffcba 100644
--- a/drivers/pci/host/Kconfig
+++ b/drivers/pci/host/Kconfig
@@ -77,6 +77,7 @@ config PCI_RCAR_GEN2_PCIE
 
 config PCI_HOST_COMMON
 	bool
+	select PCI_ECAM
 
 config PCI_HOST_GENERIC
 	bool "Generic PCI host controller"
diff --git a/drivers/pci/host/pci-host-common.c b/drivers/pci/host/pci-host-common.c
index e9f850f07968..8cba7ab73df9 100644
--- a/drivers/pci/host/pci-host-common.c
+++ b/drivers/pci/host/pci-host-common.c
@@ -22,27 +22,21 @@
 #include <linux/of_pci.h>
 #include <linux/platform_device.h>
 
-#include "pci-host-common.h"
+#include "../ecam.h"
 
-static void gen_pci_release_of_pci_ranges(struct gen_pci *pci)
-{
-	pci_free_resource_list(&pci->resources);
-}
-
-static int gen_pci_parse_request_of_pci_ranges(struct gen_pci *pci)
+static int gen_pci_parse_request_of_pci_ranges(struct device *dev,
+		       struct list_head *resources, struct resource **bus_range)
 {
 	int err, res_valid = 0;
-	struct device *dev = pci->host.dev.parent;
 	struct device_node *np = dev->of_node;
 	resource_size_t iobase;
 	struct resource_entry *win;
 
-	err = of_pci_get_host_bridge_resources(np, 0, 0xff, &pci->resources,
-					       &iobase);
+	err = of_pci_get_host_bridge_resources(np, 0, 0xff, resources, &iobase);
 	if (err)
 		return err;
 
-	resource_list_for_each_entry(win, &pci->resources) {
+	resource_list_for_each_entry(win, resources) {
 		struct resource *parent, *res = win->res;
 
 		switch (resource_type(res)) {
@@ -60,7 +54,7 @@ static int gen_pci_parse_request_of_pci_ranges(struct gen_pci *pci)
 			res_valid |= !(res->flags & IORESOURCE_PREFETCH);
 			break;
 		case IORESOURCE_BUS:
-			pci->cfg.bus_range = res;
+			*bus_range = res;
 		default:
 			continue;
 		}
@@ -79,65 +73,60 @@ static int gen_pci_parse_request_of_pci_ranges(struct gen_pci *pci)
 	return 0;
 
 out_release_res:
-	gen_pci_release_of_pci_ranges(pci);
 	return err;
 }
 
-static int gen_pci_parse_map_cfg_windows(struct gen_pci *pci)
+static void gen_pci_unmap_cfg(void *ptr)
+{
+	pci_ecam_free((struct pci_config_window *)ptr);
+}
+
+static struct pci_config_window *gen_pci_init(struct device *dev,
+		struct list_head *resources, struct pci_ecam_ops *ops)
 {
 	int err;
-	u8 bus_max;
-	resource_size_t busn;
-	struct resource *bus_range;
-	struct device *dev = pci->host.dev.parent;
-	struct device_node *np = dev->of_node;
-	u32 sz = 1 << pci->cfg.ops->bus_shift;
+	struct resource cfgres;
+	struct resource *bus_range = NULL;
+	struct pci_config_window *cfg;
 
-	err = of_address_to_resource(np, 0, &pci->cfg.res);
+	/* Parse our PCI ranges and request their resources */
+	err = gen_pci_parse_request_of_pci_ranges(dev, resources, &bus_range);
+	if (err)
+		goto err_out;
+
+	err = of_address_to_resource(dev->of_node, 0, &cfgres);
 	if (err) {
 		dev_err(dev, "missing \"reg\" property\n");
-		return err;
+		goto err_out;
 	}
 
-	/* Limit the bus-range to fit within reg */
-	bus_max = pci->cfg.bus_range->start +
-		  (resource_size(&pci->cfg.res) >> pci->cfg.ops->bus_shift) - 1;
-	pci->cfg.bus_range->end = min_t(resource_size_t,
-					pci->cfg.bus_range->end, bus_max);
-
-	pci->cfg.win = devm_kcalloc(dev, resource_size(pci->cfg.bus_range),
-				    sizeof(*pci->cfg.win), GFP_KERNEL);
-	if (!pci->cfg.win)
-		return -ENOMEM;
-
-	/* Map our Configuration Space windows */
-	if (!devm_request_mem_region(dev, pci->cfg.res.start,
-				     resource_size(&pci->cfg.res),
-				     "Configuration Space"))
-		return -ENOMEM;
-
-	bus_range = pci->cfg.bus_range;
-	for (busn = bus_range->start; busn <= bus_range->end; ++busn) {
-		u32 idx = busn - bus_range->start;
-
-		pci->cfg.win[idx] = devm_ioremap(dev,
-						 pci->cfg.res.start + idx * sz,
-						 sz);
-		if (!pci->cfg.win[idx])
-			return -ENOMEM;
+	cfg = pci_ecam_create(dev, &cfgres, bus_range, ops);
+	if (IS_ERR(cfg)) {
+		err = PTR_ERR(cfg);
+		goto err_out;
 	}
 
-	return 0;
+	err = devm_add_action(dev, gen_pci_unmap_cfg, cfg);
+	if (err) {
+		gen_pci_unmap_cfg(cfg);
+		goto err_out;
+	}
+	return cfg;
+
+err_out:
+	pci_free_resource_list(resources);
+	return ERR_PTR(err);
 }
 
 int pci_host_common_probe(struct platform_device *pdev,
-			  struct gen_pci *pci)
+			  struct pci_ecam_ops *ops)
 {
-	int err;
 	const char *type;
 	struct device *dev = &pdev->dev;
 	struct device_node *np = dev->of_node;
 	struct pci_bus *bus, *child;
+	struct pci_config_window *cfg;
+	struct list_head resources;
 
 	type = of_get_property(np, "device_type", NULL);
 	if (!type || strcmp(type, "pci")) {
@@ -147,29 +136,18 @@ int pci_host_common_probe(struct platform_device *pdev,
 
 	of_pci_check_probe_only();
 
-	pci->host.dev.parent = dev;
-	INIT_LIST_HEAD(&pci->host.windows);
-	INIT_LIST_HEAD(&pci->resources);
-
-	/* Parse our PCI ranges and request their resources */
-	err = gen_pci_parse_request_of_pci_ranges(pci);
-	if (err)
-		return err;
-
 	/* Parse and map our Configuration Space windows */
-	err = gen_pci_parse_map_cfg_windows(pci);
-	if (err) {
-		gen_pci_release_of_pci_ranges(pci);
-		return err;
-	}
+	INIT_LIST_HEAD(&resources);
+	cfg = gen_pci_init(dev, &resources, ops);
+	if (IS_ERR(cfg))
+		return PTR_ERR(cfg);
 
 	/* Do not reassign resources if probe only */
 	if (!pci_has_flag(PCI_PROBE_ONLY))
 		pci_add_flags(PCI_REASSIGN_ALL_RSRC | PCI_REASSIGN_ALL_BUS);
 
-
-	bus = pci_scan_root_bus(dev, pci->cfg.bus_range->start,
-				&pci->cfg.ops->ops, pci, &pci->resources);
+	bus = pci_scan_root_bus(dev, cfg->busr.start, &ops->pci_ops, cfg,
+				&resources);
 	if (!bus) {
 		dev_err(dev, "Scanning rootbus failed");
 		return -ENODEV;
diff --git a/drivers/pci/host/pci-host-common.h b/drivers/pci/host/pci-host-common.h
deleted file mode 100644
index 09f3fa0a55d7..000000000000
--- a/drivers/pci/host/pci-host-common.h
+++ /dev/null
@@ -1,47 +0,0 @@
-/*
- * 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.
- *
- * 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 for more details.
- *
- * You should have received a copy of the GNU General Public License
- * along with this program.  If not, see <http://www.gnu.org/licenses/>.
- *
- * Copyright (C) 2014 ARM Limited
- *
- * Author: Will Deacon <will.deacon@arm.com>
- */
-
-#ifndef _PCI_HOST_COMMON_H
-#define _PCI_HOST_COMMON_H
-
-#include <linux/kernel.h>
-#include <linux/platform_device.h>
-
-struct gen_pci_cfg_bus_ops {
-	u32 bus_shift;
-	struct pci_ops ops;
-};
-
-struct gen_pci_cfg_windows {
-	struct resource				res;
-	struct resource				*bus_range;
-	void __iomem				**win;
-
-	struct gen_pci_cfg_bus_ops		*ops;
-};
-
-struct gen_pci {
-	struct pci_host_bridge			host;
-	struct gen_pci_cfg_windows		cfg;
-	struct list_head			resources;
-};
-
-int pci_host_common_probe(struct platform_device *pdev,
-			  struct gen_pci *pci);
-
-#endif /* _PCI_HOST_COMMON_H */
diff --git a/drivers/pci/host/pci-host-generic.c b/drivers/pci/host/pci-host-generic.c
index e8aa78faa16d..6eaceab1bf04 100644
--- a/drivers/pci/host/pci-host-generic.c
+++ b/drivers/pci/host/pci-host-generic.c
@@ -25,41 +25,12 @@
 #include <linux/of_pci.h>
 #include <linux/platform_device.h>
 
-#include "pci-host-common.h"
+#include "../ecam.h"
 
-static void __iomem *gen_pci_map_cfg_bus_cam(struct pci_bus *bus,
-					     unsigned int devfn,
-					     int where)
-{
-	struct gen_pci *pci = bus->sysdata;
-	resource_size_t idx = bus->number - pci->cfg.bus_range->start;
-
-	return pci->cfg.win[idx] + ((devfn << 8) | where);
-}
-
-static struct gen_pci_cfg_bus_ops gen_pci_cfg_cam_bus_ops = {
+static struct pci_ecam_ops gen_pci_cfg_cam_bus_ops = {
 	.bus_shift	= 16,
-	.ops		= {
-		.map_bus	= gen_pci_map_cfg_bus_cam,
-		.read		= pci_generic_config_read,
-		.write		= pci_generic_config_write,
-	}
-};
-
-static void __iomem *gen_pci_map_cfg_bus_ecam(struct pci_bus *bus,
-					      unsigned int devfn,
-					      int where)
-{
-	struct gen_pci *pci = bus->sysdata;
-	resource_size_t idx = bus->number - pci->cfg.bus_range->start;
-
-	return pci->cfg.win[idx] + ((devfn << 12) | where);
-}
-
-static struct gen_pci_cfg_bus_ops gen_pci_cfg_ecam_bus_ops = {
-	.bus_shift	= 20,
-	.ops		= {
-		.map_bus	= gen_pci_map_cfg_bus_ecam,
+	.pci_ops	= {
+		.map_bus	= pci_ecam_map_bus,
 		.read		= pci_generic_config_read,
 		.write		= pci_generic_config_write,
 	}
@@ -70,25 +41,22 @@ static const struct of_device_id gen_pci_of_match[] = {
 	  .data = &gen_pci_cfg_cam_bus_ops },
 
 	{ .compatible = "pci-host-ecam-generic",
-	  .data = &gen_pci_cfg_ecam_bus_ops },
+	  .data = &pci_generic_ecam_ops },
 
 	{ },
 };
+
 MODULE_DEVICE_TABLE(of, gen_pci_of_match);
 
 static int gen_pci_probe(struct platform_device *pdev)
 {
-	struct device *dev = &pdev->dev;
 	const struct of_device_id *of_id;
-	struct gen_pci *pci = devm_kzalloc(dev, sizeof(*pci), GFP_KERNEL);
-
-	if (!pci)
-		return -ENOMEM;
+	struct pci_ecam_ops *ops;
 
-	of_id = of_match_node(gen_pci_of_match, dev->of_node);
-	pci->cfg.ops = (struct gen_pci_cfg_bus_ops *)of_id->data;
+	of_id = of_match_node(gen_pci_of_match, pdev->dev.of_node);
+	ops = (struct pci_ecam_ops *)of_id->data;
 
-	return pci_host_common_probe(pdev, pci);
+	return pci_host_common_probe(pdev, ops);
 }
 
 static struct platform_driver gen_pci_driver = {
diff --git a/drivers/pci/host/pci-thunder-ecam.c b/drivers/pci/host/pci-thunder-ecam.c
index d71935cb2678..540d030613eb 100644
--- a/drivers/pci/host/pci-thunder-ecam.c
+++ b/drivers/pci/host/pci-thunder-ecam.c
@@ -13,18 +13,7 @@
 #include <linux/of.h>
 #include <linux/platform_device.h>
 
-#include "pci-host-common.h"
-
-/* Mapping is standard ECAM */
-static void __iomem *thunder_ecam_map_bus(struct pci_bus *bus,
-					  unsigned int devfn,
-					  int where)
-{
-	struct gen_pci *pci = bus->sysdata;
-	resource_size_t idx = bus->number - pci->cfg.bus_range->start;
-
-	return pci->cfg.win[idx] + ((devfn << 12) | where);
-}
+#include "../ecam.h"
 
 static void set_val(u32 v, int where, int size, u32 *val)
 {
@@ -99,7 +88,7 @@ static int handle_ea_bar(u32 e0, int bar, struct pci_bus *bus,
 static int thunder_ecam_p2_config_read(struct pci_bus *bus, unsigned int devfn,
 				       int where, int size, u32 *val)
 {
-	struct gen_pci *pci = bus->sysdata;
+	struct pci_config_window *cfg = bus->sysdata;
 	int where_a = where & ~3;
 	void __iomem *addr;
 	u32 node_bits;
@@ -129,7 +118,7 @@ static int thunder_ecam_p2_config_read(struct pci_bus *bus, unsigned int devfn,
 	 * the config space access window.  Since we are working with
 	 * the high-order 32 bits, shift everything down by 32 bits.
 	 */
-	node_bits = (pci->cfg.res.start >> 32) & (1 << 12);
+	node_bits = (cfg->res.start >> 32) & (1 << 12);
 
 	v |= node_bits;
 	set_val(v, where, size, val);
@@ -358,36 +347,24 @@ static int thunder_ecam_config_write(struct pci_bus *bus, unsigned int devfn,
 	return pci_generic_config_write(bus, devfn, where, size, val);
 }
 
-static struct gen_pci_cfg_bus_ops thunder_ecam_bus_ops = {
+static struct pci_ecam_ops pci_thunder_ecam_ops = {
 	.bus_shift	= 20,
-	.ops		= {
-		.map_bus        = thunder_ecam_map_bus,
+	.pci_ops	= {
+		.map_bus        = pci_ecam_map_bus,
 		.read           = thunder_ecam_config_read,
 		.write          = thunder_ecam_config_write,
 	}
 };
 
 static const struct of_device_id thunder_ecam_of_match[] = {
-	{ .compatible = "cavium,pci-host-thunder-ecam",
-	  .data = &thunder_ecam_bus_ops },
-
+	{ .compatible = "cavium,pci-host-thunder-ecam" },
 	{ },
 };
 MODULE_DEVICE_TABLE(of, thunder_ecam_of_match);
 
 static int thunder_ecam_probe(struct platform_device *pdev)
 {
-	struct device *dev = &pdev->dev;
-	const struct of_device_id *of_id;
-	struct gen_pci *pci = devm_kzalloc(dev, sizeof(*pci), GFP_KERNEL);
-
-	if (!pci)
-		return -ENOMEM;
-
-	of_id = of_match_node(thunder_ecam_of_match, dev->of_node);
-	pci->cfg.ops = (struct gen_pci_cfg_bus_ops *)of_id->data;
-
-	return pci_host_common_probe(pdev, pci);
+	return pci_host_common_probe(pdev, &pci_thunder_ecam_ops);
 }
 
 static struct platform_driver thunder_ecam_driver = {
diff --git a/drivers/pci/host/pci-thunder-pem.c b/drivers/pci/host/pci-thunder-pem.c
index cabb92a514ac..a7b61ce35117 100644
--- a/drivers/pci/host/pci-thunder-pem.c
+++ b/drivers/pci/host/pci-thunder-pem.c
@@ -20,34 +20,22 @@
 #include <linux/of_pci.h>
 #include <linux/platform_device.h>
 
-#include "pci-host-common.h"
+#include "../ecam.h"
 
 #define PEM_CFG_WR 0x28
 #define PEM_CFG_RD 0x30
 
 struct thunder_pem_pci {
-	struct gen_pci	gen_pci;
 	u32		ea_entry[3];
 	void __iomem	*pem_reg_base;
 };
 
-static void __iomem *thunder_pem_map_bus(struct pci_bus *bus,
-					 unsigned int devfn, int where)
-{
-	struct gen_pci *pci = bus->sysdata;
-	resource_size_t idx = bus->number - pci->cfg.bus_range->start;
-
-	return pci->cfg.win[idx] + ((devfn << 16) | where);
-}
-
 static int thunder_pem_bridge_read(struct pci_bus *bus, unsigned int devfn,
 				   int where, int size, u32 *val)
 {
 	u64 read_val;
-	struct thunder_pem_pci *pem_pci;
-	struct gen_pci *pci = bus->sysdata;
-
-	pem_pci = container_of(pci, struct thunder_pem_pci, gen_pci);
+	struct pci_config_window *cfg = bus->sysdata;
+	struct thunder_pem_pci *pem_pci = (struct thunder_pem_pci *)cfg->priv;
 
 	if (devfn != 0 || where >= 2048) {
 		*val = ~0;
@@ -132,17 +120,17 @@ static int thunder_pem_bridge_read(struct pci_bus *bus, unsigned int devfn,
 static int thunder_pem_config_read(struct pci_bus *bus, unsigned int devfn,
 				   int where, int size, u32 *val)
 {
-	struct gen_pci *pci = bus->sysdata;
+	struct pci_config_window *cfg = bus->sysdata;
 
-	if (bus->number < pci->cfg.bus_range->start ||
-	    bus->number > pci->cfg.bus_range->end)
+	if (bus->number < cfg->busr.start ||
+	    bus->number > cfg->busr.end)
 		return PCIBIOS_DEVICE_NOT_FOUND;
 
 	/*
 	 * The first device on the bus is the PEM PCIe bridge.
 	 * Special case its config access.
 	 */
-	if (bus->number == pci->cfg.bus_range->start)
+	if (bus->number == cfg->busr.start)
 		return thunder_pem_bridge_read(bus, devfn, where, size, val);
 
 	return pci_generic_config_read(bus, devfn, where, size, val);
@@ -187,12 +175,11 @@ static u32 thunder_pem_bridge_w1c_bits(int where)
 static int thunder_pem_bridge_write(struct pci_bus *bus, unsigned int devfn,
 				    int where, int size, u32 val)
 {
-	struct gen_pci *pci = bus->sysdata;
-	struct thunder_pem_pci *pem_pci;
+	struct pci_config_window *cfg = bus->sysdata;
+	struct thunder_pem_pci *pem_pci = (struct thunder_pem_pci *)cfg->priv;
 	u64 write_val, read_val;
 	u32 mask = 0;
 
-	pem_pci = container_of(pci, struct thunder_pem_pci, gen_pci);
 
 	if (devfn != 0 || where >= 2048)
 		return PCIBIOS_DEVICE_NOT_FOUND;
@@ -256,53 +243,38 @@ static int thunder_pem_bridge_write(struct pci_bus *bus, unsigned int devfn,
 static int thunder_pem_config_write(struct pci_bus *bus, unsigned int devfn,
 				    int where, int size, u32 val)
 {
-	struct gen_pci *pci = bus->sysdata;
+	struct pci_config_window *cfg = bus->sysdata;
 
-	if (bus->number < pci->cfg.bus_range->start ||
-	    bus->number > pci->cfg.bus_range->end)
+	if (bus->number < cfg->busr.start ||
+	    bus->number > cfg->busr.end)
 		return PCIBIOS_DEVICE_NOT_FOUND;
 	/*
 	 * The first device on the bus is the PEM PCIe bridge.
 	 * Special case its config access.
 	 */
-	if (bus->number == pci->cfg.bus_range->start)
+	if (bus->number == cfg->busr.start)
 		return thunder_pem_bridge_write(bus, devfn, where, size, val);
 
 
 	return pci_generic_config_write(bus, devfn, where, size, val);
 }
 
-static struct gen_pci_cfg_bus_ops thunder_pem_bus_ops = {
-	.bus_shift	= 24,
-	.ops		= {
-		.map_bus	= thunder_pem_map_bus,
-		.read		= thunder_pem_config_read,
-		.write		= thunder_pem_config_write,
-	}
-};
-
-static const struct of_device_id thunder_pem_of_match[] = {
-	{ .compatible = "cavium,pci-host-thunder-pem",
-	  .data = &thunder_pem_bus_ops },
-
-	{ },
-};
-MODULE_DEVICE_TABLE(of, thunder_pem_of_match);
-
-static int thunder_pem_probe(struct platform_device *pdev)
+static int thunder_pem_init(struct device *dev, struct pci_config_window *cfg)
 {
-	struct device *dev = &pdev->dev;
-	const struct of_device_id *of_id;
 	resource_size_t bar4_start;
 	struct resource *res_pem;
 	struct thunder_pem_pci *pem_pci;
+	struct platform_device *pdev;
+
+	/* Only OF support for now */
+	if (!dev->of_node)
+		return -EINVAL;
 
 	pem_pci = devm_kzalloc(dev, sizeof(*pem_pci), GFP_KERNEL);
 	if (!pem_pci)
 		return -ENOMEM;
 
-	of_id = of_match_node(thunder_pem_of_match, dev->of_node);
-	pem_pci->gen_pci.cfg.ops = (struct gen_pci_cfg_bus_ops *)of_id->data;
+	pdev = to_platform_device(dev);
 
 	/*
 	 * The second register range is the PEM bridge to the PCIe
@@ -330,7 +302,29 @@ static int thunder_pem_probe(struct platform_device *pdev)
 	pem_pci->ea_entry[1] = (u32)(res_pem->end - bar4_start) & ~3u;
 	pem_pci->ea_entry[2] = (u32)(bar4_start >> 32);
 
-	return pci_host_common_probe(pdev, &pem_pci->gen_pci);
+	cfg->priv = pem_pci;
+	return 0;
+}
+
+static struct pci_ecam_ops pci_thunder_pem_ops = {
+	.bus_shift	= 24,
+	.init		= thunder_pem_init,
+	.pci_ops	= {
+		.map_bus	= pci_ecam_map_bus,
+		.read		= thunder_pem_config_read,
+		.write		= thunder_pem_config_write,
+	}
+};
+
+static const struct of_device_id thunder_pem_of_match[] = {
+	{ .compatible = "cavium,pci-host-thunder-pem" },
+	{ },
+};
+MODULE_DEVICE_TABLE(of, thunder_pem_of_match);
+
+static int thunder_pem_probe(struct platform_device *pdev)
+{
+	return pci_host_common_probe(pdev, &pci_thunder_pem_ops);
 }
 
 static struct platform_driver thunder_pem_driver = {
diff --git a/drivers/pci/msi.c b/drivers/pci/msi.c
index a080f4496fe2..ba49df7afd6b 100644
--- a/drivers/pci/msi.c
+++ b/drivers/pci/msi.c
@@ -18,6 +18,7 @@
 #include <linux/smp.h>
 #include <linux/errno.h>
 #include <linux/io.h>
+#include <linux/iort.h>
 #include <linux/slab.h>
 #include <linux/irqdomain.h>
 #include <linux/of_irq.h>
@@ -1364,8 +1365,8 @@ u32 pci_msi_domain_get_msi_rid(struct irq_domain *domain, struct pci_dev *pdev)
 	pci_for_each_dma_alias(pdev, get_msi_id_cb, &rid);
 
 	of_node = irq_domain_get_of_node(domain);
-	if (of_node)
-		rid = of_msi_map_rid(&pdev->dev, of_node, rid);
+	rid = of_node ? of_msi_map_rid(&pdev->dev, of_node, rid) :
+			iort_pci_get_msi_rid(pdev, rid);
 
 	return rid;
 }
@@ -1381,9 +1382,13 @@ u32 pci_msi_domain_get_msi_rid(struct irq_domain *domain, struct pci_dev *pdev)
  */
 struct irq_domain *pci_msi_get_device_domain(struct pci_dev *pdev)
 {
+	struct irq_domain *dom;
 	u32 rid = 0;
 
 	pci_for_each_dma_alias(pdev, get_msi_id_cb, &rid);
-	return of_msi_map_get_device_domain(&pdev->dev, rid);
+	dom = of_msi_map_get_device_domain(&pdev->dev, rid);
+	if (!dom)
+		dom = iort_pci_get_domain(pdev, rid);
+	return dom;
 }
 #endif /* CONFIG_PCI_MSI_IRQ_DOMAIN */
diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c
index 25e0327d4429..a1d7bcfbf569 100644
--- a/drivers/pci/pci.c
+++ b/drivers/pci/pci.c
@@ -19,12 +19,14 @@
 #include <linux/spinlock.h>
 #include <linux/string.h>
 #include <linux/log2.h>
+#include <linux/pci-acpi.h>
 #include <linux/pci-aspm.h>
 #include <linux/pm_wakeup.h>
 #include <linux/interrupt.h>
 #include <linux/device.h>
 #include <linux/pm_runtime.h>
 #include <linux/pci_hotplug.h>
+#include <linux/vmalloc.h>
 #include <asm/setup.h>
 #include <linux/aer.h>
 #include "pci.h"
@@ -3021,6 +3023,121 @@ int pci_request_regions_exclusive(struct pci_dev *pdev, const char *res_name)
 }
 EXPORT_SYMBOL(pci_request_regions_exclusive);
 
+#ifdef PCI_IOBASE
+struct io_range {
+	struct list_head list;
+	phys_addr_t start;
+	resource_size_t size;
+};
+
+static LIST_HEAD(io_range_list);
+static DEFINE_SPINLOCK(io_range_lock);
+#endif
+
+/*
+ * Record the PCI IO range (expressed as CPU physical address + size).
+ * Return a negative value if an error has occured, zero otherwise
+ */
+int __weak pci_register_io_range(phys_addr_t addr, resource_size_t size)
+{
+	int err = 0;
+
+#ifdef PCI_IOBASE
+	struct io_range *range;
+	resource_size_t allocated_size = 0;
+
+	/* check if the range hasn't been previously recorded */
+	spin_lock(&io_range_lock);
+	list_for_each_entry(range, &io_range_list, list) {
+		if (addr >= range->start && addr + size <= range->start + size) {
+			/* range already registered, bail out */
+			goto end_register;
+		}
+		allocated_size += range->size;
+	}
+
+	/* range not registed yet, check for available space */
+	if (allocated_size + size - 1 > IO_SPACE_LIMIT) {
+		/* if it's too big check if 64K space can be reserved */
+		if (allocated_size + SZ_64K - 1 > IO_SPACE_LIMIT) {
+			err = -E2BIG;
+			goto end_register;
+		}
+
+		size = SZ_64K;
+		pr_warn("Requested IO range too big, new size set to 64K\n");
+	}
+
+	/* add the range to the list */
+	range = kzalloc(sizeof(*range), GFP_ATOMIC);
+	if (!range) {
+		err = -ENOMEM;
+		goto end_register;
+	}
+
+	range->start = addr;
+	range->size = size;
+
+	list_add_tail(&range->list, &io_range_list);
+
+end_register:
+	spin_unlock(&io_range_lock);
+#endif
+
+	return err;
+}
+
+phys_addr_t pci_pio_to_address(unsigned long pio)
+{
+	phys_addr_t address = (phys_addr_t)OF_BAD_ADDR;
+
+#ifdef PCI_IOBASE
+	struct io_range *range;
+	resource_size_t allocated_size = 0;
+
+	if (pio > IO_SPACE_LIMIT)
+		return address;
+
+	spin_lock(&io_range_lock);
+	list_for_each_entry(range, &io_range_list, list) {
+		if (pio >= allocated_size && pio < allocated_size + range->size) {
+			address = range->start + pio - allocated_size;
+			break;
+		}
+		allocated_size += range->size;
+	}
+	spin_unlock(&io_range_lock);
+#endif
+
+	return address;
+}
+
+unsigned long __weak pci_address_to_pio(phys_addr_t address)
+{
+#ifdef PCI_IOBASE
+	struct io_range *res;
+	resource_size_t offset = 0;
+	unsigned long addr = -1;
+
+	spin_lock(&io_range_lock);
+	list_for_each_entry(res, &io_range_list, list) {
+		if (address >= res->start && address < res->start + res->size) {
+			addr = address - res->start + offset;
+			break;
+		}
+		offset += res->size;
+	}
+	spin_unlock(&io_range_lock);
+
+	return addr;
+#else
+	if (address > IO_SPACE_LIMIT)
+		return (unsigned long)-1;
+
+	return (unsigned long) address;
+#endif
+}
+
 /**
  *	pci_remap_iospace - Remap the memory mapped I/O space
  *	@res: Resource describing the I/O space
@@ -3052,6 +3169,29 @@ int __weak pci_remap_iospace(const struct resource *res, phys_addr_t phys_addr)
 #endif
 }
 
+/**
+ *	pci_unmap_iospace - Unmap the memory mapped I/O space
+ *	@res: resource to be unmapped
+ *
+ *	Unmap the CPU virtual address @res from virtual address space.
+ *	Only architectures that have memory mapped IO functions defined
+ *	(and the PCI_IOBASE value defined) should call this function.
+ */
+void  pci_unmap_iospace(struct resource *res)
+{
+#if defined(PCI_IOBASE) && defined(CONFIG_MMU)
+	unsigned long vaddr = (unsigned long)PCI_IOBASE + res->start;
+
+	unmap_kernel_range(vaddr, resource_size(res));
+#else
+	/*
+	 * This architecture does not have memory mapped I/O space,
+	 * so this function should never be called.
+	 */
+	WARN_ONCE(1, "This architecture does not support memory mapped I/O\n");
+#endif
+}
+
 static void __pci_set_master(struct pci_dev *dev, bool enable)
 {
 	u16 old_cmd, cmd;
@@ -4779,7 +4919,7 @@ int pci_get_new_domain_nr(void)
 }
 
 #ifdef CONFIG_PCI_DOMAINS_GENERIC
-void pci_bus_assign_domain_nr(struct pci_bus *bus, struct device *parent)
+static int of_pci_bus_domain_nr(struct device *parent)
 {
 	static int use_dt_domains = -1;
 	int domain = -1;
@@ -4823,7 +4963,13 @@ void pci_bus_assign_domain_nr(struct pci_bus *bus, struct device *parent)
 		domain = -1;
 	}
 
-	bus->domain_nr = domain;
+	return domain;
+}
+
+void pci_bus_assign_domain_nr(struct pci_bus *bus, struct device *parent)
+{
+	bus->domain_nr = acpi_disabled ? of_pci_bus_domain_nr(parent) :
+					 acpi_pci_bus_domain_nr(bus);
 }
 #endif
 #endif
diff --git a/drivers/pci/probe.c b/drivers/pci/probe.c
index 8004f67c57ec..fb0b75219e02 100644
--- a/drivers/pci/probe.c
+++ b/drivers/pci/probe.c
@@ -12,6 +12,7 @@
 #include <linux/slab.h>
 #include <linux/module.h>
 #include <linux/cpumask.h>
+#include <linux/pci-acpi.h>
 #include <linux/pci-aspm.h>
 #include <linux/aer.h>
 #include <linux/acpi.h>
@@ -2141,6 +2142,7 @@ struct pci_bus *pci_create_root_bus(struct device *parent, int bus,
 	bridge->dev.parent = parent;
 	bridge->dev.release = pci_release_host_bridge_dev;
 	dev_set_name(&bridge->dev, "pci%04x:%02x", pci_domain_nr(b), bus);
+	acpi_pci_set_companion(bridge);
 	error = pcibios_root_bridge_prepare(bridge);
 	if (error) {
 		kfree(bridge);
diff --git a/include/linux/iort.h b/include/linux/iort.h
new file mode 100644
index 000000000000..490ff4de2eec
--- /dev/null
+++ b/include/linux/iort.h
@@ -0,0 +1,38 @@
+/*
+ * Copyright (C) 2016, Semihalf
+ *	Author: Tomasz Nowicki <tn@semihalf.com>
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms and conditions of the GNU General Public License,
+ * version 2, as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope 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 for
+ * more details.
+ *
+ * You should have received a copy of the GNU General Public License along with
+ * this program; if not, write to the Free Software Foundation, Inc., 59 Temple
+ * Place - Suite 330, Boston, MA 02111-1307 USA.
+ */
+
+#ifndef __IORT_H__
+#define __IORT_H__
+
+#include <linux/acpi.h>
+
+struct fwnode_handle;
+int iort_register_domain_token(int trans_id, struct fwnode_handle *fw_node);
+void iort_deregister_domain_token(int trans_id);
+struct fwnode_handle *iort_its_find_domain_token(int trans_id);
+#ifdef CONFIG_IORT_TABLE
+u32 iort_pci_get_msi_rid(struct pci_dev *pdev, u32 req_id);
+struct irq_domain *iort_pci_get_domain(struct pci_dev *pdev, u32 req_id);
+#else
+static inline u32 iort_pci_get_msi_rid(struct pci_dev *pdev, u32 req_id)
+{ return req_id; }
+static inline struct irq_domain *
+iort_pci_get_domain(struct pci_dev *pdev, u32 req_id) { return NULL; }
+#endif
+
+#endif /* __IORT_H__ */
diff --git a/include/linux/irqchip/arm-gic-v3.h b/include/linux/irqchip/arm-gic-v3.h
index d5d798b35c1f..589ddcd1ef43 100644
--- a/include/linux/irqchip/arm-gic-v3.h
+++ b/include/linux/irqchip/arm-gic-v3.h
@@ -330,9 +330,9 @@ struct rdists {
 };
 
 struct irq_domain;
-struct device_node;
+struct fwnode_handle;
 int its_cpu_init(void);
-int its_init(struct device_node *node, struct rdists *rdists,
+int its_init(struct fwnode_handle *handle, struct rdists *rdists,
 	     struct irq_domain *domain);
 
 static inline bool gic_enable_sre(void)
diff --git a/include/linux/of_address.h b/include/linux/of_address.h
index 01c0a556448b..37864734ca50 100644
--- a/include/linux/of_address.h
+++ b/include/linux/of_address.h
@@ -47,10 +47,6 @@ void __iomem *of_io_request_and_map(struct device_node *device,
 extern const __be32 *of_get_address(struct device_node *dev, int index,
 			   u64 *size, unsigned int *flags);
 
-extern int pci_register_io_range(phys_addr_t addr, resource_size_t size);
-extern unsigned long pci_address_to_pio(phys_addr_t addr);
-extern phys_addr_t pci_pio_to_address(unsigned long pio);
-
 extern int of_pci_range_parser_init(struct of_pci_range_parser *parser,
 			struct device_node *node);
 extern struct of_pci_range *of_pci_range_parser_one(
@@ -86,11 +82,6 @@ static inline const __be32 *of_get_address(struct device_node *dev, int index,
 	return NULL;
 }
 
-static inline phys_addr_t pci_pio_to_address(unsigned long pio)
-{
-	return 0;
-}
-
 static inline int of_pci_range_parser_init(struct of_pci_range_parser *parser,
 			struct device_node *node)
 {
diff --git a/include/linux/pci-acpi.h b/include/linux/pci-acpi.h
index 89ab0572dbc6..42ff844bfff2 100644
--- a/include/linux/pci-acpi.h
+++ b/include/linux/pci-acpi.h
@@ -111,6 +111,20 @@ static inline void acpi_pci_add_bus(struct pci_bus *bus) { }
 static inline void acpi_pci_remove_bus(struct pci_bus *bus) { }
 #endif	/* CONFIG_ACPI */
 
+#ifdef CONFIG_ACPI_PCI_HOST_GENERIC
+void acpi_pci_set_companion(struct pci_host_bridge *bridge);
+int acpi_pci_bus_domain_nr(struct pci_bus *bus);
+#else
+static inline void acpi_pci_set_companion(struct pci_host_bridge *bridge)
+{
+}
+
+static inline int acpi_pci_bus_domain_nr(struct pci_bus *bus)
+{
+	return 0;
+}
+#endif
+
 #ifdef CONFIG_ACPI_APEI
 extern bool aer_acpi_firmware_first(void);
 #else
diff --git a/include/linux/pci.h b/include/linux/pci.h
index 932ec74909c6..b2e88860c083 100644
--- a/include/linux/pci.h
+++ b/include/linux/pci.h
@@ -1165,7 +1165,11 @@ int __must_check pci_bus_alloc_resource(struct pci_bus *bus,
 			void *alignf_data);
 
 
+int pci_register_io_range(phys_addr_t addr, resource_size_t size);
+unsigned long pci_address_to_pio(phys_addr_t addr);
+phys_addr_t pci_pio_to_address(unsigned long pio);
 int pci_remap_iospace(const struct resource *res, phys_addr_t phys_addr);
+void pci_unmap_iospace(struct resource *res);
 
 static inline pci_bus_addr_t pci_bus_address(struct pci_dev *pdev, int bar)
 {
@@ -1481,6 +1485,8 @@ static inline int pci_request_regions(struct pci_dev *dev, const char *res_name)
 { return -EIO; }
 static inline void pci_release_regions(struct pci_dev *dev) { }
 
+static inline unsigned long pci_address_to_pio(phys_addr_t addr) { return -1; }
+
 static inline void pci_block_cfg_access(struct pci_dev *dev) { }
 static inline int pci_block_cfg_access_in_atomic(struct pci_dev *dev)
 { return 0; }
@@ -1716,7 +1722,10 @@ void pcibios_free_irq(struct pci_dev *dev);
 extern struct dev_pm_ops pcibios_pm_ops;
 #endif
 
-#ifdef CONFIG_PCI_MMCONFIG
+#if defined(CONFIG_PCI_MMCONFIG) || defined(CONFIG_ACPI_PCI_HOST_GENERIC)
+struct acpi_device;
+phys_addr_t pci_mcfg_lookup(struct acpi_device *device, u16 seg,
+			    struct resource *bus_res);
 void __init pci_mmcfg_early_init(void);
 void __init pci_mmcfg_late_init(void);
 #else