diff mbox

[RFC,5/6] ACPI: arm: Support for IORT

Message ID 1496950247-8755-6-git-send-email-sgoel@codeaurora.org (mailing list archive)
State New, archived
Headers show

Commit Message

Goel, Sameer June 8, 2017, 7:30 p.m. UTC
Verbatim files from Linux kernel.
iort.c: commit ca78d3173cff:Merge tag 'arm64-upstream'
acpi_iort.h: commit 18b709beb503:ACPI/IORT: Make dma masks set-up IORT
specific

Signed-off-by: Sameer Goel <sgoel@codeaurora.org>
---
 xen/drivers/acpi/arm/iort.c  | 961 +++++++++++++++++++++++++++++++++++++++++++
 xen/include/acpi/acpi_iort.h |  58 +++
 2 files changed, 1019 insertions(+)
 create mode 100644 xen/drivers/acpi/arm/iort.c
 create mode 100644 xen/include/acpi/acpi_iort.h

Comments

Jan Beulich July 14, 2017, 3:36 p.m. UTC | #1
>>> On 08.06.17 at 21:30, <sgoel@codeaurora.org> wrote:
> Verbatim files from Linux kernel.

This is pretty odd - they won't even come close to compile in that
shape. But if the ARM folks are happy with it to be done this way,
so be it.

> iort.c: commit ca78d3173cff:Merge tag 'arm64-upstream'

Please don't name merge commits - there must be a real one (or
perhaps it's more than one, but anyway).

Jan
diff mbox

Patch

diff --git a/xen/drivers/acpi/arm/iort.c b/xen/drivers/acpi/arm/iort.c
new file mode 100644
index 0000000..4a5bb96
--- /dev/null
+++ b/xen/drivers/acpi/arm/iort.c
@@ -0,0 +1,961 @@ 
+/*
+ * 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/acpi_iort.h>
+#include <linux/iommu.h>
+#include <linux/kernel.h>
+#include <linux/list.h>
+#include <linux/pci.h>
+#include <linux/platform_device.h>
+#include <linux/slab.h>
+
+#define IORT_TYPE_MASK(type)	(1 << (type))
+#define IORT_MSI_TYPE		(1 << ACPI_IORT_NODE_ITS_GROUP)
+#define IORT_IOMMU_TYPE		((1 << ACPI_IORT_NODE_SMMU) |	\
+				(1 << ACPI_IORT_NODE_SMMU_V3))
+
+struct iort_its_msi_chip {
+	struct list_head	list;
+	struct fwnode_handle	*fw_node;
+	u32			translation_id;
+};
+
+struct iort_fwnode {
+	struct list_head list;
+	struct acpi_iort_node *iort_node;
+	struct fwnode_handle *fwnode;
+};
+static LIST_HEAD(iort_fwnode_list);
+static DEFINE_SPINLOCK(iort_fwnode_lock);
+
+/**
+ * iort_set_fwnode() - Create iort_fwnode and use it to register
+ *		       iommu data in the iort_fwnode_list
+ *
+ * @node: IORT table node associated with the IOMMU
+ * @fwnode: fwnode associated with the IORT node
+ *
+ * Returns: 0 on success
+ *          <0 on failure
+ */
+static inline int iort_set_fwnode(struct acpi_iort_node *iort_node,
+				  struct fwnode_handle *fwnode)
+{
+	struct iort_fwnode *np;
+
+	np = kzalloc(sizeof(struct iort_fwnode), GFP_ATOMIC);
+
+	if (WARN_ON(!np))
+		return -ENOMEM;
+
+	INIT_LIST_HEAD(&np->list);
+	np->iort_node = iort_node;
+	np->fwnode = fwnode;
+
+	spin_lock(&iort_fwnode_lock);
+	list_add_tail(&np->list, &iort_fwnode_list);
+	spin_unlock(&iort_fwnode_lock);
+
+	return 0;
+}
+
+/**
+ * iort_get_fwnode() - Retrieve fwnode associated with an IORT node
+ *
+ * @node: IORT table node to be looked-up
+ *
+ * Returns: fwnode_handle pointer on success, NULL on failure
+ */
+static inline
+struct fwnode_handle *iort_get_fwnode(struct acpi_iort_node *node)
+{
+	struct iort_fwnode *curr;
+	struct fwnode_handle *fwnode = NULL;
+
+	spin_lock(&iort_fwnode_lock);
+	list_for_each_entry(curr, &iort_fwnode_list, list) {
+		if (curr->iort_node == node) {
+			fwnode = curr->fwnode;
+			break;
+		}
+	}
+	spin_unlock(&iort_fwnode_lock);
+
+	return fwnode;
+}
+
+/**
+ * iort_delete_fwnode() - Delete fwnode associated with an IORT node
+ *
+ * @node: IORT table node associated with fwnode to delete
+ */
+static inline void iort_delete_fwnode(struct acpi_iort_node *node)
+{
+	struct iort_fwnode *curr, *tmp;
+
+	spin_lock(&iort_fwnode_lock);
+	list_for_each_entry_safe(curr, tmp, &iort_fwnode_list, list) {
+		if (curr->iort_node == node) {
+			list_del(&curr->list);
+			kfree(curr);
+			break;
+		}
+	}
+	spin_unlock(&iort_fwnode_lock);
+}
+
+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);
+static DEFINE_SPINLOCK(iort_msi_chip_lock);
+
+/**
+ * iort_register_domain_token() - register domain token and related ITS ID
+ * to the list from where we can get it back later on.
+ * @trans_id: ITS ID.
+ * @fw_node: Domain token.
+ *
+ * Returns: 0 on success, -ENOMEM if no 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;
+
+	spin_lock(&iort_msi_chip_lock);
+	list_add(&its_msi_chip->list, &iort_msi_chip_list);
+	spin_unlock(&iort_msi_chip_lock);
+
+	return 0;
+}
+
+/**
+ * iort_deregister_domain_token() - Deregister domain token based on ITS ID
+ * @trans_id: ITS ID.
+ *
+ * Returns: none.
+ */
+void iort_deregister_domain_token(int trans_id)
+{
+	struct iort_its_msi_chip *its_msi_chip, *t;
+
+	spin_lock(&iort_msi_chip_lock);
+	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;
+		}
+	}
+	spin_unlock(&iort_msi_chip_lock);
+}
+
+/**
+ * iort_find_domain_token() - Find domain token based on given ITS ID
+ * @trans_id: ITS ID.
+ *
+ * Returns: domain token when find on the list, NULL otherwise
+ */
+struct fwnode_handle *iort_find_domain_token(int trans_id)
+{
+	struct fwnode_handle *fw_node = NULL;
+	struct iort_its_msi_chip *its_msi_chip;
+
+	spin_lock(&iort_msi_chip_lock);
+	list_for_each_entry(its_msi_chip, &iort_msi_chip_list, list) {
+		if (its_msi_chip->translation_id == trans_id) {
+			fw_node = its_msi_chip->fw_node;
+			break;
+		}
+	}
+	spin_unlock(&iort_msi_chip_lock);
+
+	return fw_node;
+}
+
+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;
+
+	/* Get the first IORT node */
+	iort = (struct acpi_table_iort *)iort_table;
+	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 (WARN_TAINT(iort_node >= iort_end, TAINT_FIRMWARE_WORKAROUND,
+			       "IORT node pointer overflows, bad table!\n"))
+			return NULL;
+
+		if (iort_node->type == type &&
+		    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_match_type_callback(struct acpi_iort_node *node, void *context)
+{
+	return AE_OK;
+}
+
+bool iort_node_match(u8 type)
+{
+	struct acpi_iort_node *node;
+
+	node = iort_scan_node(type, iort_match_type_callback, NULL);
+
+	return node != NULL;
+}
+
+static acpi_status iort_match_node_callback(struct acpi_iort_node *node,
+					    void *context)
+{
+	struct device *dev = context;
+	acpi_status status;
+
+	if (node->type == ACPI_IORT_NODE_NAMED_COMPONENT) {
+		struct acpi_buffer buf = { ACPI_ALLOCATE_BUFFER, NULL };
+		struct acpi_device *adev = to_acpi_device_node(dev->fwnode);
+		struct acpi_iort_named_component *ncomp;
+
+		if (!adev) {
+			status = AE_NOT_FOUND;
+			goto out;
+		}
+
+		status = acpi_get_name(adev->handle, ACPI_FULL_PATHNAME, &buf);
+		if (ACPI_FAILURE(status)) {
+			dev_warn(dev, "Can't get device full path name\n");
+			goto out;
+		}
+
+		ncomp = (struct acpi_iort_named_component *)node->node_data;
+		status = !strcmp(ncomp->device_name, buf.pointer) ?
+							AE_OK : AE_NOT_FOUND;
+		acpi_os_free(buf.pointer);
+	} else if (node->type == ACPI_IORT_NODE_PCI_ROOT_COMPLEX) {
+		struct acpi_iort_root_complex *pci_rc;
+		struct pci_bus *bus;
+
+		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.
+		 */
+		status = pci_rc->pci_segment_number == pci_domain_nr(bus) ?
+							AE_OK : AE_NOT_FOUND;
+	} else {
+		status = AE_NOT_FOUND;
+	}
+out:
+	return status;
+}
+
+static int iort_id_map(struct acpi_iort_id_mapping *map, u8 type, u32 rid_in,
+		       u32 *rid_out)
+{
+	/* Single mapping does not care for input id */
+	if (map->flags & ACPI_IORT_ID_SINGLE_MAPPING) {
+		if (type == ACPI_IORT_NODE_NAMED_COMPONENT ||
+		    type == ACPI_IORT_NODE_PCI_ROOT_COMPLEX) {
+			*rid_out = map->output_base;
+			return 0;
+		}
+
+		pr_warn(FW_BUG "[map %p] SINGLE MAPPING flag not allowed for node type %d, skipping ID map\n",
+			map, type);
+		return -ENXIO;
+	}
+
+	if (rid_in < map->input_base ||
+	    (rid_in >= map->input_base + map->id_count))
+		return -ENXIO;
+
+	*rid_out = map->output_base + (rid_in - map->input_base);
+	return 0;
+}
+
+static
+struct acpi_iort_node *iort_node_get_id(struct acpi_iort_node *node,
+					u32 *id_out, u8 type_mask,
+					int index)
+{
+	struct acpi_iort_node *parent;
+	struct acpi_iort_id_mapping *map;
+
+	if (!node->mapping_offset || !node->mapping_count ||
+				     index >= node->mapping_count)
+		return NULL;
+
+	map = ACPI_ADD_PTR(struct acpi_iort_id_mapping, node,
+			   node->mapping_offset + index * sizeof(*map));
+
+	/* Firmware bug! */
+	if (!map->output_reference) {
+		pr_err(FW_BUG "[node %p type %d] ID map has NULL parent reference\n",
+		       node, node->type);
+		return NULL;
+	}
+
+	parent = ACPI_ADD_PTR(struct acpi_iort_node, iort_table,
+			       map->output_reference);
+
+	if (!(IORT_TYPE_MASK(parent->type) & type_mask))
+		return NULL;
+
+	if (map->flags & ACPI_IORT_ID_SINGLE_MAPPING) {
+		if (node->type == ACPI_IORT_NODE_NAMED_COMPONENT ||
+		    node->type == ACPI_IORT_NODE_PCI_ROOT_COMPLEX) {
+			*id_out = map->output_base;
+			return parent;
+		}
+	}
+
+	return NULL;
+}
+
+static struct acpi_iort_node *iort_node_map_rid(struct acpi_iort_node *node,
+						u32 rid_in, u32 *rid_out,
+						u8 type_mask)
+{
+	u32 rid = rid_in;
+
+	/* Parse the ID mapping tree to find specified node type */
+	while (node) {
+		struct acpi_iort_id_mapping *map;
+		int i;
+
+		if (IORT_TYPE_MASK(node->type) & type_mask) {
+			if (rid_out)
+				*rid_out = rid;
+			return node;
+		}
+
+		if (!node->mapping_offset || !node->mapping_count)
+			goto fail_map;
+
+		map = ACPI_ADD_PTR(struct acpi_iort_id_mapping, node,
+				   node->mapping_offset);
+
+		/* Firmware bug! */
+		if (!map->output_reference) {
+			pr_err(FW_BUG "[node %p type %d] ID map has NULL parent reference\n",
+			       node, node->type);
+			goto fail_map;
+		}
+
+		/* Do the RID translation */
+		for (i = 0; i < node->mapping_count; i++, map++) {
+			if (!iort_id_map(map, node->type, rid, &rid))
+				break;
+		}
+
+		if (i == node->mapping_count)
+			goto fail_map;
+
+		node = ACPI_ADD_PTR(struct acpi_iort_node, iort_table,
+				    map->output_reference);
+	}
+
+fail_map:
+	/* Map input RID to output RID unchanged on mapping failure*/
+	if (rid_out)
+		*rid_out = rid_in;
+
+	return NULL;
+}
+
+static struct acpi_iort_node *iort_find_dev_node(struct device *dev)
+{
+	struct pci_bus *pbus;
+
+	if (!dev_is_pci(dev))
+		return iort_scan_node(ACPI_IORT_NODE_NAMED_COMPONENT,
+				      iort_match_node_callback, dev);
+
+	/* Find a PCI root bus */
+	pbus = to_pci_dev(dev)->bus;
+	while (!pci_is_root_bus(pbus))
+		pbus = pbus->parent;
+
+	return iort_scan_node(ACPI_IORT_NODE_PCI_ROOT_COMPLEX,
+			      iort_match_node_callback, &pbus->dev);
+}
+
+/**
+ * iort_msi_map_rid() - Map a MSI requester ID for a device
+ * @dev: The device for which the mapping is to be done.
+ * @req_id: The device requester ID.
+ *
+ * Returns: mapped MSI RID on success, input requester ID otherwise
+ */
+u32 iort_msi_map_rid(struct device *dev, u32 req_id)
+{
+	struct acpi_iort_node *node;
+	u32 dev_id;
+
+	node = iort_find_dev_node(dev);
+	if (!node)
+		return req_id;
+
+	iort_node_map_rid(node, req_id, &dev_id, IORT_MSI_TYPE);
+	return dev_id;
+}
+
+/**
+ * iort_dev_find_its_id() - Find the ITS identifier for a device
+ * @dev: The device.
+ * @idx: Index of the ITS identifier list.
+ * @its_id: ITS identifier.
+ *
+ * Returns: 0 on success, appropriate error value otherwise
+ */
+static int iort_dev_find_its_id(struct device *dev, u32 req_id,
+				unsigned int idx, int *its_id)
+{
+	struct acpi_iort_its_group *its;
+	struct acpi_iort_node *node;
+
+	node = iort_find_dev_node(dev);
+	if (!node)
+		return -ENXIO;
+
+	node = iort_node_map_rid(node, req_id, NULL, IORT_MSI_TYPE);
+	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(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_get_device_domain() - Find MSI domain related to a device
+ * @dev: The device.
+ * @req_id: Requester ID for the device.
+ *
+ * Returns: the MSI domain for this device, NULL otherwise
+ */
+struct irq_domain *iort_get_device_domain(struct device *dev, u32 req_id)
+{
+	struct fwnode_handle *handle;
+	int its_id;
+
+	if (iort_dev_find_its_id(dev, req_id, 0, &its_id))
+		return NULL;
+
+	handle = iort_find_domain_token(its_id);
+	if (!handle)
+		return NULL;
+
+	return irq_find_matching_fwnode(handle, DOMAIN_BUS_PCI_MSI);
+}
+
+static int __get_pci_rid(struct pci_dev *pdev, u16 alias, void *data)
+{
+	u32 *rid = data;
+
+	*rid = alias;
+	return 0;
+}
+
+static int arm_smmu_iort_xlate(struct device *dev, u32 streamid,
+			       struct fwnode_handle *fwnode,
+			       const struct iommu_ops *ops)
+{
+	int ret = iommu_fwspec_init(dev, fwnode, ops);
+
+	if (!ret)
+		ret = iommu_fwspec_add_ids(dev, &streamid, 1);
+
+	return ret;
+}
+
+static const struct iommu_ops *iort_iommu_xlate(struct device *dev,
+					struct acpi_iort_node *node,
+					u32 streamid)
+{
+	const struct iommu_ops *ops = NULL;
+	int ret = -ENODEV;
+	struct fwnode_handle *iort_fwnode;
+
+	if (node) {
+		iort_fwnode = iort_get_fwnode(node);
+		if (!iort_fwnode)
+			return NULL;
+
+		ops = iommu_ops_from_fwnode(iort_fwnode);
+		if (!ops)
+			return NULL;
+
+		ret = arm_smmu_iort_xlate(dev, streamid, iort_fwnode, ops);
+	}
+
+	return ret ? NULL : ops;
+}
+
+/**
+ * iort_set_dma_mask - Set-up dma mask for a device.
+ *
+ * @dev: device to configure
+ */
+void iort_set_dma_mask(struct device *dev)
+{
+	/*
+	 * Set default coherent_dma_mask to 32 bit.  Drivers are expected to
+	 * setup the correct supported mask.
+	 */
+	if (!dev->coherent_dma_mask)
+		dev->coherent_dma_mask = DMA_BIT_MASK(32);
+
+	/*
+	 * Set it to coherent_dma_mask by default if the architecture
+	 * code has not set it.
+	 */
+	if (!dev->dma_mask)
+		dev->dma_mask = &dev->coherent_dma_mask;
+}
+
+/**
+ * iort_iommu_configure - Set-up IOMMU configuration for a device.
+ *
+ * @dev: device to configure
+ *
+ * Returns: iommu_ops pointer on configuration success
+ *          NULL on configuration failure
+ */
+const struct iommu_ops *iort_iommu_configure(struct device *dev)
+{
+	struct acpi_iort_node *node, *parent;
+	const struct iommu_ops *ops = NULL;
+	u32 streamid = 0;
+
+	if (dev_is_pci(dev)) {
+		struct pci_bus *bus = to_pci_dev(dev)->bus;
+		u32 rid;
+
+		pci_for_each_dma_alias(to_pci_dev(dev), __get_pci_rid,
+				       &rid);
+
+		node = iort_scan_node(ACPI_IORT_NODE_PCI_ROOT_COMPLEX,
+				      iort_match_node_callback, &bus->dev);
+		if (!node)
+			return NULL;
+
+		parent = iort_node_map_rid(node, rid, &streamid,
+					   IORT_IOMMU_TYPE);
+
+		ops = iort_iommu_xlate(dev, parent, streamid);
+
+	} else {
+		int i = 0;
+
+		node = iort_scan_node(ACPI_IORT_NODE_NAMED_COMPONENT,
+				      iort_match_node_callback, dev);
+		if (!node)
+			return NULL;
+
+		parent = iort_node_get_id(node, &streamid,
+					  IORT_IOMMU_TYPE, i++);
+
+		while (parent) {
+			ops = iort_iommu_xlate(dev, parent, streamid);
+
+			parent = iort_node_get_id(node, &streamid,
+						  IORT_IOMMU_TYPE, i++);
+		}
+	}
+
+	return ops;
+}
+
+static void __init acpi_iort_register_irq(int hwirq, const char *name,
+					  int trigger,
+					  struct resource *res)
+{
+	int irq = acpi_register_gsi(NULL, hwirq, trigger,
+				    ACPI_ACTIVE_HIGH);
+
+	if (irq <= 0) {
+		pr_err("could not register gsi hwirq %d name [%s]\n", hwirq,
+								      name);
+		return;
+	}
+
+	res->start = irq;
+	res->end = irq;
+	res->flags = IORESOURCE_IRQ;
+	res->name = name;
+}
+
+static int __init arm_smmu_v3_count_resources(struct acpi_iort_node *node)
+{
+	struct acpi_iort_smmu_v3 *smmu;
+	/* Always present mem resource */
+	int num_res = 1;
+
+	/* Retrieve SMMUv3 specific data */
+	smmu = (struct acpi_iort_smmu_v3 *)node->node_data;
+
+	if (smmu->event_gsiv)
+		num_res++;
+
+	if (smmu->pri_gsiv)
+		num_res++;
+
+	if (smmu->gerr_gsiv)
+		num_res++;
+
+	if (smmu->sync_gsiv)
+		num_res++;
+
+	return num_res;
+}
+
+static void __init arm_smmu_v3_init_resources(struct resource *res,
+					      struct acpi_iort_node *node)
+{
+	struct acpi_iort_smmu_v3 *smmu;
+	int num_res = 0;
+
+	/* Retrieve SMMUv3 specific data */
+	smmu = (struct acpi_iort_smmu_v3 *)node->node_data;
+
+	res[num_res].start = smmu->base_address;
+	res[num_res].end = smmu->base_address + SZ_128K - 1;
+	res[num_res].flags = IORESOURCE_MEM;
+
+	num_res++;
+
+	if (smmu->event_gsiv)
+		acpi_iort_register_irq(smmu->event_gsiv, "eventq",
+				       ACPI_EDGE_SENSITIVE,
+				       &res[num_res++]);
+
+	if (smmu->pri_gsiv)
+		acpi_iort_register_irq(smmu->pri_gsiv, "priq",
+				       ACPI_EDGE_SENSITIVE,
+				       &res[num_res++]);
+
+	if (smmu->gerr_gsiv)
+		acpi_iort_register_irq(smmu->gerr_gsiv, "gerror",
+				       ACPI_EDGE_SENSITIVE,
+				       &res[num_res++]);
+
+	if (smmu->sync_gsiv)
+		acpi_iort_register_irq(smmu->sync_gsiv, "cmdq-sync",
+				       ACPI_EDGE_SENSITIVE,
+				       &res[num_res++]);
+}
+
+static bool __init arm_smmu_v3_is_coherent(struct acpi_iort_node *node)
+{
+	struct acpi_iort_smmu_v3 *smmu;
+
+	/* Retrieve SMMUv3 specific data */
+	smmu = (struct acpi_iort_smmu_v3 *)node->node_data;
+
+	return smmu->flags & ACPI_IORT_SMMU_V3_COHACC_OVERRIDE;
+}
+
+static int __init arm_smmu_count_resources(struct acpi_iort_node *node)
+{
+	struct acpi_iort_smmu *smmu;
+
+	/* Retrieve SMMU specific data */
+	smmu = (struct acpi_iort_smmu *)node->node_data;
+
+	/*
+	 * Only consider the global fault interrupt and ignore the
+	 * configuration access interrupt.
+	 *
+	 * MMIO address and global fault interrupt resources are always
+	 * present so add them to the context interrupt count as a static
+	 * value.
+	 */
+	return smmu->context_interrupt_count + 2;
+}
+
+static void __init arm_smmu_init_resources(struct resource *res,
+					   struct acpi_iort_node *node)
+{
+	struct acpi_iort_smmu *smmu;
+	int i, hw_irq, trigger, num_res = 0;
+	u64 *ctx_irq, *glb_irq;
+
+	/* Retrieve SMMU specific data */
+	smmu = (struct acpi_iort_smmu *)node->node_data;
+
+	res[num_res].start = smmu->base_address;
+	res[num_res].end = smmu->base_address + smmu->span - 1;
+	res[num_res].flags = IORESOURCE_MEM;
+	num_res++;
+
+	glb_irq = ACPI_ADD_PTR(u64, node, smmu->global_interrupt_offset);
+	/* Global IRQs */
+	hw_irq = IORT_IRQ_MASK(glb_irq[0]);
+	trigger = IORT_IRQ_TRIGGER_MASK(glb_irq[0]);
+
+	acpi_iort_register_irq(hw_irq, "arm-smmu-global", trigger,
+				     &res[num_res++]);
+
+	/* Context IRQs */
+	ctx_irq = ACPI_ADD_PTR(u64, node, smmu->context_interrupt_offset);
+	for (i = 0; i < smmu->context_interrupt_count; i++) {
+		hw_irq = IORT_IRQ_MASK(ctx_irq[i]);
+		trigger = IORT_IRQ_TRIGGER_MASK(ctx_irq[i]);
+
+		acpi_iort_register_irq(hw_irq, "arm-smmu-context", trigger,
+				       &res[num_res++]);
+	}
+}
+
+static bool __init arm_smmu_is_coherent(struct acpi_iort_node *node)
+{
+	struct acpi_iort_smmu *smmu;
+
+	/* Retrieve SMMU specific data */
+	smmu = (struct acpi_iort_smmu *)node->node_data;
+
+	return smmu->flags & ACPI_IORT_SMMU_COHERENT_WALK;
+}
+
+struct iort_iommu_config {
+	const char *name;
+	int (*iommu_init)(struct acpi_iort_node *node);
+	bool (*iommu_is_coherent)(struct acpi_iort_node *node);
+	int (*iommu_count_resources)(struct acpi_iort_node *node);
+	void (*iommu_init_resources)(struct resource *res,
+				     struct acpi_iort_node *node);
+};
+
+static const struct iort_iommu_config iort_arm_smmu_v3_cfg __initconst = {
+	.name = "arm-smmu-v3",
+	.iommu_is_coherent = arm_smmu_v3_is_coherent,
+	.iommu_count_resources = arm_smmu_v3_count_resources,
+	.iommu_init_resources = arm_smmu_v3_init_resources
+};
+
+static const struct iort_iommu_config iort_arm_smmu_cfg __initconst = {
+	.name = "arm-smmu",
+	.iommu_is_coherent = arm_smmu_is_coherent,
+	.iommu_count_resources = arm_smmu_count_resources,
+	.iommu_init_resources = arm_smmu_init_resources
+};
+
+static __init
+const struct iort_iommu_config *iort_get_iommu_cfg(struct acpi_iort_node *node)
+{
+	switch (node->type) {
+	case ACPI_IORT_NODE_SMMU_V3:
+		return &iort_arm_smmu_v3_cfg;
+	case ACPI_IORT_NODE_SMMU:
+		return &iort_arm_smmu_cfg;
+	default:
+		return NULL;
+	}
+}
+
+/**
+ * iort_add_smmu_platform_device() - Allocate a platform device for SMMU
+ * @node: Pointer to SMMU ACPI IORT node
+ *
+ * Returns: 0 on success, <0 failure
+ */
+static int __init iort_add_smmu_platform_device(struct acpi_iort_node *node)
+{
+	struct fwnode_handle *fwnode;
+	struct platform_device *pdev;
+	struct resource *r;
+	enum dev_dma_attr attr;
+	int ret, count;
+	const struct iort_iommu_config *ops = iort_get_iommu_cfg(node);
+
+	if (!ops)
+		return -ENODEV;
+
+	pdev = platform_device_alloc(ops->name, PLATFORM_DEVID_AUTO);
+	if (!pdev)
+		return -ENOMEM;
+
+	count = ops->iommu_count_resources(node);
+
+	r = kcalloc(count, sizeof(*r), GFP_KERNEL);
+	if (!r) {
+		ret = -ENOMEM;
+		goto dev_put;
+	}
+
+	ops->iommu_init_resources(r, node);
+
+	ret = platform_device_add_resources(pdev, r, count);
+	/*
+	 * Resources are duplicated in platform_device_add_resources,
+	 * free their allocated memory
+	 */
+	kfree(r);
+
+	if (ret)
+		goto dev_put;
+
+	/*
+	 * Add a copy of IORT node pointer to platform_data to
+	 * be used to retrieve IORT data information.
+	 */
+	ret = platform_device_add_data(pdev, &node, sizeof(node));
+	if (ret)
+		goto dev_put;
+
+	/*
+	 * We expect the dma masks to be equivalent for
+	 * all SMMUs set-ups
+	 */
+	pdev->dev.dma_mask = &pdev->dev.coherent_dma_mask;
+
+	fwnode = iort_get_fwnode(node);
+
+	if (!fwnode) {
+		ret = -ENODEV;
+		goto dev_put;
+	}
+
+	pdev->dev.fwnode = fwnode;
+
+	attr = ops->iommu_is_coherent(node) ?
+			     DEV_DMA_COHERENT : DEV_DMA_NON_COHERENT;
+
+	/* Configure DMA for the page table walker */
+	acpi_dma_configure(&pdev->dev, attr);
+
+	ret = platform_device_add(pdev);
+	if (ret)
+		goto dma_deconfigure;
+
+	return 0;
+
+dma_deconfigure:
+	acpi_dma_deconfigure(&pdev->dev);
+dev_put:
+	platform_device_put(pdev);
+
+	return ret;
+}
+
+static void __init iort_init_platform_devices(void)
+{
+	struct acpi_iort_node *iort_node, *iort_end;
+	struct acpi_table_iort *iort;
+	struct fwnode_handle *fwnode;
+	int i, ret;
+
+	/*
+	 * 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,
+				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;
+		}
+
+		if ((iort_node->type == ACPI_IORT_NODE_SMMU) ||
+			(iort_node->type == ACPI_IORT_NODE_SMMU_V3)) {
+
+			fwnode = acpi_alloc_fwnode_static();
+			if (!fwnode)
+				return;
+
+			iort_set_fwnode(iort_node, fwnode);
+
+			ret = iort_add_smmu_platform_device(iort_node);
+			if (ret) {
+				iort_delete_fwnode(iort_node);
+				acpi_free_fwnode_static(fwnode);
+				return;
+			}
+		}
+
+		iort_node = ACPI_ADD_PTR(struct acpi_iort_node, iort_node,
+					 iort_node->length);
+	}
+}
+
+void __init acpi_iort_init(void)
+{
+	acpi_status status;
+
+	status = acpi_get_table(ACPI_SIG_IORT, 0, &iort_table);
+	if (ACPI_FAILURE(status)) {
+		if (status != AE_NOT_FOUND) {
+			const char *msg = acpi_format_exception(status);
+
+			pr_err("Failed to get table, %s\n", msg);
+		}
+
+		return;
+	}
+
+	iort_init_platform_devices();
+
+	acpi_probe_device_table(iort);
+}
diff --git a/xen/include/acpi/acpi_iort.h b/xen/include/acpi/acpi_iort.h
new file mode 100644
index 0000000..77e0809
--- /dev/null
+++ b/xen/include/acpi/acpi_iort.h
@@ -0,0 +1,58 @@ 
+/*
+ * 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 __ACPI_IORT_H__
+#define __ACPI_IORT_H__
+
+#include <linux/acpi.h>
+#include <linux/fwnode.h>
+#include <linux/irqdomain.h>
+
+#define IORT_IRQ_MASK(irq)		(irq & 0xffffffffULL)
+#define IORT_IRQ_TRIGGER_MASK(irq)	((irq >> 32) & 0xffffffffULL)
+
+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_find_domain_token(int trans_id);
+#ifdef CONFIG_ACPI_IORT
+void acpi_iort_init(void);
+bool iort_node_match(u8 type);
+u32 iort_msi_map_rid(struct device *dev, u32 req_id);
+struct irq_domain *iort_get_device_domain(struct device *dev, u32 req_id);
+/* IOMMU interface */
+void iort_set_dma_mask(struct device *dev);
+const struct iommu_ops *iort_iommu_configure(struct device *dev);
+#else
+static inline void acpi_iort_init(void) { }
+static inline bool iort_node_match(u8 type) { return false; }
+static inline u32 iort_msi_map_rid(struct device *dev, u32 req_id)
+{ return req_id; }
+static inline struct irq_domain *iort_get_device_domain(struct device *dev,
+							u32 req_id)
+{ return NULL; }
+/* IOMMU interface */
+static inline void iort_set_dma_mask(struct device *dev) { }
+static inline
+const struct iommu_ops *iort_iommu_configure(struct device *dev)
+{ return NULL; }
+#endif
+
+#define IORT_ACPI_DECLARE(name, table_id, fn)		\
+	ACPI_DECLARE_PROBE_ENTRY(iort, name, table_id, 0, NULL, 0, fn)
+
+#endif /* __ACPI_IORT_H__ */