1 // SPDX-License-Identifier: GPL-2.0-only
3 * Copyright (C) 2016, Semihalf
4 * Author: Tomasz Nowicki <tn@semihalf.com>
6 * This file implements early detection/parsing of I/O mapping
7 * reported to OS through firmware via I/O Remapping Table (IORT)
8 * IORT document number: ARM DEN 0049A
11 #define pr_fmt(fmt) "ACPI: IORT: " fmt
13 #include <linux/acpi_iort.h>
14 #include <linux/bitfield.h>
15 #include <linux/iommu.h>
16 #include <linux/kernel.h>
17 #include <linux/list.h>
18 #include <linux/pci.h>
19 #include <linux/platform_device.h>
20 #include <linux/slab.h>
21 #include <linux/dma-map-ops.h>
23 #define IORT_TYPE_MASK(type) (1 << (type))
24 #define IORT_MSI_TYPE (1 << ACPI_IORT_NODE_ITS_GROUP)
25 #define IORT_IOMMU_TYPE ((1 << ACPI_IORT_NODE_SMMU) | \
26 (1 << ACPI_IORT_NODE_SMMU_V3))
28 struct iort_its_msi_chip {
29 struct list_head list;
30 struct fwnode_handle *fw_node;
31 phys_addr_t base_addr;
36 struct list_head list;
37 struct acpi_iort_node *iort_node;
38 struct fwnode_handle *fwnode;
40 static LIST_HEAD(iort_fwnode_list);
41 static DEFINE_SPINLOCK(iort_fwnode_lock);
44 * iort_set_fwnode() - Create iort_fwnode and use it to register
45 * iommu data in the iort_fwnode_list
47 * @node: IORT table node associated with the IOMMU
48 * @fwnode: fwnode associated with the IORT node
50 * Returns: 0 on success
53 static inline int iort_set_fwnode(struct acpi_iort_node *iort_node,
54 struct fwnode_handle *fwnode)
56 struct iort_fwnode *np;
58 np = kzalloc(sizeof(struct iort_fwnode), GFP_ATOMIC);
63 INIT_LIST_HEAD(&np->list);
64 np->iort_node = iort_node;
67 spin_lock(&iort_fwnode_lock);
68 list_add_tail(&np->list, &iort_fwnode_list);
69 spin_unlock(&iort_fwnode_lock);
75 * iort_get_fwnode() - Retrieve fwnode associated with an IORT node
77 * @node: IORT table node to be looked-up
79 * Returns: fwnode_handle pointer on success, NULL on failure
81 static inline struct fwnode_handle *iort_get_fwnode(
82 struct acpi_iort_node *node)
84 struct iort_fwnode *curr;
85 struct fwnode_handle *fwnode = NULL;
87 spin_lock(&iort_fwnode_lock);
88 list_for_each_entry(curr, &iort_fwnode_list, list) {
89 if (curr->iort_node == node) {
90 fwnode = curr->fwnode;
94 spin_unlock(&iort_fwnode_lock);
100 * iort_delete_fwnode() - Delete fwnode associated with an IORT node
102 * @node: IORT table node associated with fwnode to delete
104 static inline void iort_delete_fwnode(struct acpi_iort_node *node)
106 struct iort_fwnode *curr, *tmp;
108 spin_lock(&iort_fwnode_lock);
109 list_for_each_entry_safe(curr, tmp, &iort_fwnode_list, list) {
110 if (curr->iort_node == node) {
111 list_del(&curr->list);
116 spin_unlock(&iort_fwnode_lock);
120 * iort_get_iort_node() - Retrieve iort_node associated with an fwnode
122 * @fwnode: fwnode associated with device to be looked-up
124 * Returns: iort_node pointer on success, NULL on failure
126 static inline struct acpi_iort_node *iort_get_iort_node(
127 struct fwnode_handle *fwnode)
129 struct iort_fwnode *curr;
130 struct acpi_iort_node *iort_node = NULL;
132 spin_lock(&iort_fwnode_lock);
133 list_for_each_entry(curr, &iort_fwnode_list, list) {
134 if (curr->fwnode == fwnode) {
135 iort_node = curr->iort_node;
139 spin_unlock(&iort_fwnode_lock);
144 typedef acpi_status (*iort_find_node_callback)
145 (struct acpi_iort_node *node, void *context);
147 /* Root pointer to the mapped IORT table */
148 static struct acpi_table_header *iort_table;
150 static LIST_HEAD(iort_msi_chip_list);
151 static DEFINE_SPINLOCK(iort_msi_chip_lock);
154 * iort_register_domain_token() - register domain token along with related
155 * ITS ID and base address to the list from where we can get it back later on.
157 * @base: ITS base address.
158 * @fw_node: Domain token.
160 * Returns: 0 on success, -ENOMEM if no memory when allocating list element
162 int iort_register_domain_token(int trans_id, phys_addr_t base,
163 struct fwnode_handle *fw_node)
165 struct iort_its_msi_chip *its_msi_chip;
167 its_msi_chip = kzalloc(sizeof(*its_msi_chip), GFP_KERNEL);
171 its_msi_chip->fw_node = fw_node;
172 its_msi_chip->translation_id = trans_id;
173 its_msi_chip->base_addr = base;
175 spin_lock(&iort_msi_chip_lock);
176 list_add(&its_msi_chip->list, &iort_msi_chip_list);
177 spin_unlock(&iort_msi_chip_lock);
183 * iort_deregister_domain_token() - Deregister domain token based on ITS ID
188 void iort_deregister_domain_token(int trans_id)
190 struct iort_its_msi_chip *its_msi_chip, *t;
192 spin_lock(&iort_msi_chip_lock);
193 list_for_each_entry_safe(its_msi_chip, t, &iort_msi_chip_list, list) {
194 if (its_msi_chip->translation_id == trans_id) {
195 list_del(&its_msi_chip->list);
200 spin_unlock(&iort_msi_chip_lock);
204 * iort_find_domain_token() - Find domain token based on given ITS ID
207 * Returns: domain token when find on the list, NULL otherwise
209 struct fwnode_handle *iort_find_domain_token(int trans_id)
211 struct fwnode_handle *fw_node = NULL;
212 struct iort_its_msi_chip *its_msi_chip;
214 spin_lock(&iort_msi_chip_lock);
215 list_for_each_entry(its_msi_chip, &iort_msi_chip_list, list) {
216 if (its_msi_chip->translation_id == trans_id) {
217 fw_node = its_msi_chip->fw_node;
221 spin_unlock(&iort_msi_chip_lock);
226 static struct acpi_iort_node *iort_scan_node(enum acpi_iort_node_type type,
227 iort_find_node_callback callback,
230 struct acpi_iort_node *iort_node, *iort_end;
231 struct acpi_table_iort *iort;
237 /* Get the first IORT node */
238 iort = (struct acpi_table_iort *)iort_table;
239 iort_node = ACPI_ADD_PTR(struct acpi_iort_node, iort,
241 iort_end = ACPI_ADD_PTR(struct acpi_iort_node, iort_table,
244 for (i = 0; i < iort->node_count; i++) {
245 if (WARN_TAINT(iort_node >= iort_end, TAINT_FIRMWARE_WORKAROUND,
246 "IORT node pointer overflows, bad table!\n"))
249 if (iort_node->type == type &&
250 ACPI_SUCCESS(callback(iort_node, context)))
253 iort_node = ACPI_ADD_PTR(struct acpi_iort_node, iort_node,
260 static acpi_status iort_match_node_callback(struct acpi_iort_node *node,
263 struct device *dev = context;
264 acpi_status status = AE_NOT_FOUND;
266 if (node->type == ACPI_IORT_NODE_NAMED_COMPONENT) {
267 struct acpi_buffer buf = { ACPI_ALLOCATE_BUFFER, NULL };
268 struct acpi_device *adev;
269 struct acpi_iort_named_component *ncomp;
270 struct device *nc_dev = dev;
273 * Walk the device tree to find a device with an
274 * ACPI companion; there is no point in scanning
275 * IORT for a device matching a named component if
276 * the device does not have an ACPI companion to
280 adev = ACPI_COMPANION(nc_dev);
284 nc_dev = nc_dev->parent;
290 status = acpi_get_name(adev->handle, ACPI_FULL_PATHNAME, &buf);
291 if (ACPI_FAILURE(status)) {
292 dev_warn(nc_dev, "Can't get device full path name\n");
296 ncomp = (struct acpi_iort_named_component *)node->node_data;
297 status = !strcmp(ncomp->device_name, buf.pointer) ?
298 AE_OK : AE_NOT_FOUND;
299 acpi_os_free(buf.pointer);
300 } else if (node->type == ACPI_IORT_NODE_PCI_ROOT_COMPLEX) {
301 struct acpi_iort_root_complex *pci_rc;
304 bus = to_pci_bus(dev);
305 pci_rc = (struct acpi_iort_root_complex *)node->node_data;
308 * It is assumed that PCI segment numbers maps one-to-one
309 * with root complexes. Each segment number can represent only
312 status = pci_rc->pci_segment_number == pci_domain_nr(bus) ?
313 AE_OK : AE_NOT_FOUND;
319 static int iort_id_map(struct acpi_iort_id_mapping *map, u8 type, u32 rid_in,
320 u32 *rid_out, bool check_overlap)
322 /* Single mapping does not care for input id */
323 if (map->flags & ACPI_IORT_ID_SINGLE_MAPPING) {
324 if (type == ACPI_IORT_NODE_NAMED_COMPONENT ||
325 type == ACPI_IORT_NODE_PCI_ROOT_COMPLEX) {
326 *rid_out = map->output_base;
330 pr_warn(FW_BUG "[map %p] SINGLE MAPPING flag not allowed for node type %d, skipping ID map\n",
335 if (rid_in < map->input_base ||
336 (rid_in > map->input_base + map->id_count))
341 * We already found a mapping for this input ID at the end of
342 * another region. If it coincides with the start of this
343 * region, we assume the prior match was due to the off-by-1
344 * issue mentioned below, and allow it to be superseded.
345 * Otherwise, things are *really* broken, and we just disregard
346 * duplicate matches entirely to retain compatibility.
348 pr_err(FW_BUG "[map %p] conflicting mapping for input ID 0x%x\n",
350 if (rid_in != map->input_base)
353 pr_err(FW_BUG "applying workaround.\n");
356 *rid_out = map->output_base + (rid_in - map->input_base);
359 * Due to confusion regarding the meaning of the id_count field (which
360 * carries the number of IDs *minus 1*), we may have to disregard this
361 * match if it is at the end of the range, and overlaps with the start
364 if (map->id_count > 0 && rid_in == map->input_base + map->id_count)
369 static struct acpi_iort_node *iort_node_get_id(struct acpi_iort_node *node,
370 u32 *id_out, int index)
372 struct acpi_iort_node *parent;
373 struct acpi_iort_id_mapping *map;
375 if (!node->mapping_offset || !node->mapping_count ||
376 index >= node->mapping_count)
379 map = ACPI_ADD_PTR(struct acpi_iort_id_mapping, node,
380 node->mapping_offset + index * sizeof(*map));
383 if (!map->output_reference) {
384 pr_err(FW_BUG "[node %p type %d] ID map has NULL parent reference\n",
389 parent = ACPI_ADD_PTR(struct acpi_iort_node, iort_table,
390 map->output_reference);
392 if (map->flags & ACPI_IORT_ID_SINGLE_MAPPING) {
393 if (node->type == ACPI_IORT_NODE_NAMED_COMPONENT ||
394 node->type == ACPI_IORT_NODE_PCI_ROOT_COMPLEX ||
395 node->type == ACPI_IORT_NODE_SMMU_V3 ||
396 node->type == ACPI_IORT_NODE_PMCG) {
397 *id_out = map->output_base;
405 static int iort_get_id_mapping_index(struct acpi_iort_node *node)
407 struct acpi_iort_smmu_v3 *smmu;
408 struct acpi_iort_pmcg *pmcg;
410 switch (node->type) {
411 case ACPI_IORT_NODE_SMMU_V3:
413 * SMMUv3 dev ID mapping index was introduced in revision 1
414 * table, not available in revision 0
416 if (node->revision < 1)
419 smmu = (struct acpi_iort_smmu_v3 *)node->node_data;
421 * ID mapping index is only ignored if all interrupts are
424 if (smmu->event_gsiv && smmu->pri_gsiv && smmu->gerr_gsiv
428 if (smmu->id_mapping_index >= node->mapping_count) {
429 pr_err(FW_BUG "[node %p type %d] ID mapping index overflows valid mappings\n",
434 return smmu->id_mapping_index;
435 case ACPI_IORT_NODE_PMCG:
436 pmcg = (struct acpi_iort_pmcg *)node->node_data;
437 if (pmcg->overflow_gsiv || node->mapping_count == 0)
446 static struct acpi_iort_node *iort_node_map_id(struct acpi_iort_node *node,
447 u32 id_in, u32 *id_out,
452 /* Parse the ID mapping tree to find specified node type */
454 struct acpi_iort_id_mapping *map;
455 int i, index, rc = 0;
456 u32 out_ref = 0, map_id = id;
458 if (IORT_TYPE_MASK(node->type) & type_mask) {
464 if (!node->mapping_offset || !node->mapping_count)
467 map = ACPI_ADD_PTR(struct acpi_iort_id_mapping, node,
468 node->mapping_offset);
471 if (!map->output_reference) {
472 pr_err(FW_BUG "[node %p type %d] ID map has NULL parent reference\n",
478 * Get the special ID mapping index (if any) and skip its
479 * associated ID map to prevent erroneous multi-stage
480 * IORT ID translations.
482 index = iort_get_id_mapping_index(node);
484 /* Do the ID translation */
485 for (i = 0; i < node->mapping_count; i++, map++) {
486 /* if it is special mapping index, skip it */
490 rc = iort_id_map(map, node->type, map_id, &id, out_ref);
494 out_ref = map->output_reference;
497 if (i == node->mapping_count && !out_ref)
500 node = ACPI_ADD_PTR(struct acpi_iort_node, iort_table,
501 rc ? out_ref : map->output_reference);
505 /* Map input ID to output ID unchanged on mapping failure */
512 static struct acpi_iort_node *iort_node_map_platform_id(
513 struct acpi_iort_node *node, u32 *id_out, u8 type_mask,
516 struct acpi_iort_node *parent;
519 /* step 1: retrieve the initial dev id */
520 parent = iort_node_get_id(node, &id, index);
525 * optional step 2: map the initial dev id if its parent is not
526 * the target type we want, map it again for the use cases such
527 * as NC (named component) -> SMMU -> ITS. If the type is matched,
528 * return the initial dev id and its parent pointer directly.
530 if (!(IORT_TYPE_MASK(parent->type) & type_mask))
531 parent = iort_node_map_id(parent, id, id_out, type_mask);
539 static struct acpi_iort_node *iort_find_dev_node(struct device *dev)
541 struct pci_bus *pbus;
543 if (!dev_is_pci(dev)) {
544 struct acpi_iort_node *node;
546 * scan iort_fwnode_list to see if it's an iort platform
547 * device (such as SMMU, PMCG),its iort node already cached
548 * and associated with fwnode when iort platform devices
551 node = iort_get_iort_node(dev->fwnode);
555 * if not, then it should be a platform device defined in
556 * DSDT/SSDT (with Named Component node in IORT)
558 return iort_scan_node(ACPI_IORT_NODE_NAMED_COMPONENT,
559 iort_match_node_callback, dev);
562 pbus = to_pci_dev(dev)->bus;
564 return iort_scan_node(ACPI_IORT_NODE_PCI_ROOT_COMPLEX,
565 iort_match_node_callback, &pbus->dev);
569 * iort_msi_map_id() - Map a MSI input ID for a device
570 * @dev: The device for which the mapping is to be done.
571 * @input_id: The device input ID.
573 * Returns: mapped MSI ID on success, input ID otherwise
575 u32 iort_msi_map_id(struct device *dev, u32 input_id)
577 struct acpi_iort_node *node;
580 node = iort_find_dev_node(dev);
584 iort_node_map_id(node, input_id, &dev_id, IORT_MSI_TYPE);
589 * iort_pmsi_get_dev_id() - Get the device id for a device
590 * @dev: The device for which the mapping is to be done.
591 * @dev_id: The device ID found.
593 * Returns: 0 for successful find a dev id, -ENODEV on error
595 int iort_pmsi_get_dev_id(struct device *dev, u32 *dev_id)
598 struct acpi_iort_node *node;
600 node = iort_find_dev_node(dev);
604 index = iort_get_id_mapping_index(node);
605 /* if there is a valid index, go get the dev_id directly */
607 if (iort_node_get_id(node, dev_id, index))
610 for (i = 0; i < node->mapping_count; i++) {
611 if (iort_node_map_platform_id(node, dev_id,
620 static int __maybe_unused iort_find_its_base(u32 its_id, phys_addr_t *base)
622 struct iort_its_msi_chip *its_msi_chip;
625 spin_lock(&iort_msi_chip_lock);
626 list_for_each_entry(its_msi_chip, &iort_msi_chip_list, list) {
627 if (its_msi_chip->translation_id == its_id) {
628 *base = its_msi_chip->base_addr;
633 spin_unlock(&iort_msi_chip_lock);
639 * iort_dev_find_its_id() - Find the ITS identifier for a device
642 * @idx: Index of the ITS identifier list.
643 * @its_id: ITS identifier.
645 * Returns: 0 on success, appropriate error value otherwise
647 static int iort_dev_find_its_id(struct device *dev, u32 id,
648 unsigned int idx, int *its_id)
650 struct acpi_iort_its_group *its;
651 struct acpi_iort_node *node;
653 node = iort_find_dev_node(dev);
657 node = iort_node_map_id(node, id, NULL, IORT_MSI_TYPE);
661 /* Move to ITS specific data */
662 its = (struct acpi_iort_its_group *)node->node_data;
663 if (idx >= its->its_count) {
664 dev_err(dev, "requested ITS ID index [%d] overruns ITS entries [%d]\n",
665 idx, its->its_count);
669 *its_id = its->identifiers[idx];
674 * iort_get_device_domain() - Find MSI domain related to a device
676 * @req_id: Requester ID for the device.
678 * Returns: the MSI domain for this device, NULL otherwise
680 struct irq_domain *iort_get_device_domain(struct device *dev, u32 id,
681 enum irq_domain_bus_token bus_token)
683 struct fwnode_handle *handle;
686 if (iort_dev_find_its_id(dev, id, 0, &its_id))
689 handle = iort_find_domain_token(its_id);
693 return irq_find_matching_fwnode(handle, bus_token);
696 static void iort_set_device_domain(struct device *dev,
697 struct acpi_iort_node *node)
699 struct acpi_iort_its_group *its;
700 struct acpi_iort_node *msi_parent;
701 struct acpi_iort_id_mapping *map;
702 struct fwnode_handle *iort_fwnode;
703 struct irq_domain *domain;
706 index = iort_get_id_mapping_index(node);
710 map = ACPI_ADD_PTR(struct acpi_iort_id_mapping, node,
711 node->mapping_offset + index * sizeof(*map));
714 if (!map->output_reference ||
715 !(map->flags & ACPI_IORT_ID_SINGLE_MAPPING)) {
716 pr_err(FW_BUG "[node %p type %d] Invalid MSI mapping\n",
721 msi_parent = ACPI_ADD_PTR(struct acpi_iort_node, iort_table,
722 map->output_reference);
724 if (!msi_parent || msi_parent->type != ACPI_IORT_NODE_ITS_GROUP)
727 /* Move to ITS specific data */
728 its = (struct acpi_iort_its_group *)msi_parent->node_data;
730 iort_fwnode = iort_find_domain_token(its->identifiers[0]);
734 domain = irq_find_matching_fwnode(iort_fwnode, DOMAIN_BUS_PLATFORM_MSI);
736 dev_set_msi_domain(dev, domain);
740 * iort_get_platform_device_domain() - Find MSI domain related to a
742 * @dev: the dev pointer associated with the platform device
744 * Returns: the MSI domain for this device, NULL otherwise
746 static struct irq_domain *iort_get_platform_device_domain(struct device *dev)
748 struct acpi_iort_node *node, *msi_parent = NULL;
749 struct fwnode_handle *iort_fwnode;
750 struct acpi_iort_its_group *its;
753 /* find its associated iort node */
754 node = iort_scan_node(ACPI_IORT_NODE_NAMED_COMPONENT,
755 iort_match_node_callback, dev);
759 /* then find its msi parent node */
760 for (i = 0; i < node->mapping_count; i++) {
761 msi_parent = iort_node_map_platform_id(node, NULL,
770 /* Move to ITS specific data */
771 its = (struct acpi_iort_its_group *)msi_parent->node_data;
773 iort_fwnode = iort_find_domain_token(its->identifiers[0]);
777 return irq_find_matching_fwnode(iort_fwnode, DOMAIN_BUS_PLATFORM_MSI);
780 void acpi_configure_pmsi_domain(struct device *dev)
782 struct irq_domain *msi_domain;
784 msi_domain = iort_get_platform_device_domain(dev);
786 dev_set_msi_domain(dev, msi_domain);
789 #ifdef CONFIG_IOMMU_API
790 static struct acpi_iort_node *iort_get_msi_resv_iommu(struct device *dev)
792 struct acpi_iort_node *iommu;
793 struct iommu_fwspec *fwspec = dev_iommu_fwspec_get(dev);
795 iommu = iort_get_iort_node(fwspec->iommu_fwnode);
797 if (iommu && (iommu->type == ACPI_IORT_NODE_SMMU_V3)) {
798 struct acpi_iort_smmu_v3 *smmu;
800 smmu = (struct acpi_iort_smmu_v3 *)iommu->node_data;
801 if (smmu->model == ACPI_IORT_SMMU_V3_HISILICON_HI161X)
808 static inline const struct iommu_ops *iort_fwspec_iommu_ops(struct device *dev)
810 struct iommu_fwspec *fwspec = dev_iommu_fwspec_get(dev);
812 return (fwspec && fwspec->ops) ? fwspec->ops : NULL;
815 static inline int iort_add_device_replay(struct device *dev)
819 if (dev->bus && !device_iommu_mapped(dev))
820 err = iommu_probe_device(dev);
826 * iort_iommu_msi_get_resv_regions - Reserved region driver helper
827 * @dev: Device from iommu_get_resv_regions()
828 * @head: Reserved region list from iommu_get_resv_regions()
830 * Returns: Number of msi reserved regions on success (0 if platform
831 * doesn't require the reservation or no associated msi regions),
832 * appropriate error value otherwise. The ITS interrupt translation
833 * spaces (ITS_base + SZ_64K, SZ_64K) associated with the device
834 * are the msi reserved regions.
836 int iort_iommu_msi_get_resv_regions(struct device *dev, struct list_head *head)
838 struct iommu_fwspec *fwspec = dev_iommu_fwspec_get(dev);
839 struct acpi_iort_its_group *its;
840 struct acpi_iort_node *iommu_node, *its_node = NULL;
843 iommu_node = iort_get_msi_resv_iommu(dev);
848 * Current logic to reserve ITS regions relies on HW topologies
849 * where a given PCI or named component maps its IDs to only one
850 * ITS group; if a PCI or named component can map its IDs to
851 * different ITS groups through IORT mappings this function has
852 * to be reworked to ensure we reserve regions for all ITS groups
853 * a given PCI or named component may map IDs to.
856 for (i = 0; i < fwspec->num_ids; i++) {
857 its_node = iort_node_map_id(iommu_node,
859 NULL, IORT_MSI_TYPE);
867 /* Move to ITS specific data */
868 its = (struct acpi_iort_its_group *)its_node->node_data;
870 for (i = 0; i < its->its_count; i++) {
873 if (!iort_find_its_base(its->identifiers[i], &base)) {
874 int prot = IOMMU_WRITE | IOMMU_NOEXEC | IOMMU_MMIO;
875 struct iommu_resv_region *region;
877 region = iommu_alloc_resv_region(base + SZ_64K, SZ_64K,
878 prot, IOMMU_RESV_MSI);
880 list_add_tail(®ion->list, head);
886 return (resv == its->its_count) ? resv : -ENODEV;
889 static inline bool iort_iommu_driver_enabled(u8 type)
892 case ACPI_IORT_NODE_SMMU_V3:
893 return IS_ENABLED(CONFIG_ARM_SMMU_V3);
894 case ACPI_IORT_NODE_SMMU:
895 return IS_ENABLED(CONFIG_ARM_SMMU);
897 pr_warn("IORT node type %u does not describe an SMMU\n", type);
902 static int arm_smmu_iort_xlate(struct device *dev, u32 streamid,
903 struct fwnode_handle *fwnode,
904 const struct iommu_ops *ops)
906 int ret = iommu_fwspec_init(dev, fwnode, ops);
909 ret = iommu_fwspec_add_ids(dev, &streamid, 1);
914 static bool iort_pci_rc_supports_ats(struct acpi_iort_node *node)
916 struct acpi_iort_root_complex *pci_rc;
918 pci_rc = (struct acpi_iort_root_complex *)node->node_data;
919 return pci_rc->ats_attribute & ACPI_IORT_ATS_SUPPORTED;
922 static int iort_iommu_xlate(struct device *dev, struct acpi_iort_node *node,
925 const struct iommu_ops *ops;
926 struct fwnode_handle *iort_fwnode;
931 iort_fwnode = iort_get_fwnode(node);
936 * If the ops look-up fails, this means that either
937 * the SMMU drivers have not been probed yet or that
938 * the SMMU drivers are not built in the kernel;
939 * Depending on whether the SMMU drivers are built-in
940 * in the kernel or not, defer the IOMMU configuration
943 ops = iommu_ops_from_fwnode(iort_fwnode);
945 return iort_iommu_driver_enabled(node->type) ?
946 -EPROBE_DEFER : -ENODEV;
948 return arm_smmu_iort_xlate(dev, streamid, iort_fwnode, ops);
951 struct iort_pci_alias_info {
953 struct acpi_iort_node *node;
956 static int iort_pci_iommu_init(struct pci_dev *pdev, u16 alias, void *data)
958 struct iort_pci_alias_info *info = data;
959 struct acpi_iort_node *parent;
962 parent = iort_node_map_id(info->node, alias, &streamid,
964 return iort_iommu_xlate(info->dev, parent, streamid);
967 static void iort_named_component_init(struct device *dev,
968 struct acpi_iort_node *node)
970 struct acpi_iort_named_component *nc;
971 struct iommu_fwspec *fwspec = dev_iommu_fwspec_get(dev);
976 nc = (struct acpi_iort_named_component *)node->node_data;
977 fwspec->num_pasid_bits = FIELD_GET(ACPI_IORT_NC_PASID_BITS,
981 static int iort_nc_iommu_map(struct device *dev, struct acpi_iort_node *node)
983 struct acpi_iort_node *parent;
984 int err = -ENODEV, i = 0;
989 parent = iort_node_map_platform_id(node, &streamid,
994 err = iort_iommu_xlate(dev, parent, streamid);
995 } while (parent && !err);
1000 static int iort_nc_iommu_map_id(struct device *dev,
1001 struct acpi_iort_node *node,
1004 struct acpi_iort_node *parent;
1007 parent = iort_node_map_id(node, *in_id, &streamid, IORT_IOMMU_TYPE);
1009 return iort_iommu_xlate(dev, parent, streamid);
1016 * iort_iommu_configure_id - Set-up IOMMU configuration for a device.
1018 * @dev: device to configure
1019 * @id_in: optional input id const value pointer
1021 * Returns: iommu_ops pointer on configuration success
1022 * NULL on configuration failure
1024 const struct iommu_ops *iort_iommu_configure_id(struct device *dev,
1027 struct acpi_iort_node *node;
1028 const struct iommu_ops *ops;
1032 * If we already translated the fwspec there
1033 * is nothing left to do, return the iommu_ops.
1035 ops = iort_fwspec_iommu_ops(dev);
1039 if (dev_is_pci(dev)) {
1040 struct iommu_fwspec *fwspec;
1041 struct pci_bus *bus = to_pci_dev(dev)->bus;
1042 struct iort_pci_alias_info info = { .dev = dev };
1044 node = iort_scan_node(ACPI_IORT_NODE_PCI_ROOT_COMPLEX,
1045 iort_match_node_callback, &bus->dev);
1050 err = pci_for_each_dma_alias(to_pci_dev(dev),
1051 iort_pci_iommu_init, &info);
1053 fwspec = dev_iommu_fwspec_get(dev);
1054 if (fwspec && iort_pci_rc_supports_ats(node))
1055 fwspec->flags |= IOMMU_FWSPEC_PCI_RC_ATS;
1057 node = iort_scan_node(ACPI_IORT_NODE_NAMED_COMPONENT,
1058 iort_match_node_callback, dev);
1062 err = id_in ? iort_nc_iommu_map_id(dev, node, id_in) :
1063 iort_nc_iommu_map(dev, node);
1066 iort_named_component_init(dev, node);
1070 * If we have reason to believe the IOMMU driver missed the initial
1071 * add_device callback for dev, replay it to get things in order.
1074 ops = iort_fwspec_iommu_ops(dev);
1075 err = iort_add_device_replay(dev);
1078 /* Ignore all other errors apart from EPROBE_DEFER */
1079 if (err == -EPROBE_DEFER) {
1082 dev_dbg(dev, "Adding to IOMMU failed: %d\n", err);
1090 int iort_iommu_msi_get_resv_regions(struct device *dev, struct list_head *head)
1092 const struct iommu_ops *iort_iommu_configure_id(struct device *dev,
1093 const u32 *input_id)
1097 static int nc_dma_get_range(struct device *dev, u64 *size)
1099 struct acpi_iort_node *node;
1100 struct acpi_iort_named_component *ncomp;
1102 node = iort_scan_node(ACPI_IORT_NODE_NAMED_COMPONENT,
1103 iort_match_node_callback, dev);
1107 ncomp = (struct acpi_iort_named_component *)node->node_data;
1109 *size = ncomp->memory_address_limit >= 64 ? U64_MAX :
1110 1ULL<<ncomp->memory_address_limit;
1115 static int rc_dma_get_range(struct device *dev, u64 *size)
1117 struct acpi_iort_node *node;
1118 struct acpi_iort_root_complex *rc;
1119 struct pci_bus *pbus = to_pci_dev(dev)->bus;
1121 node = iort_scan_node(ACPI_IORT_NODE_PCI_ROOT_COMPLEX,
1122 iort_match_node_callback, &pbus->dev);
1123 if (!node || node->revision < 1)
1126 rc = (struct acpi_iort_root_complex *)node->node_data;
1128 *size = rc->memory_address_limit >= 64 ? U64_MAX :
1129 1ULL<<rc->memory_address_limit;
1135 * iort_dma_setup() - Set-up device DMA parameters.
1137 * @dev: device to configure
1138 * @dma_addr: device DMA address result pointer
1139 * @size: DMA range size result pointer
1141 void iort_dma_setup(struct device *dev, u64 *dma_addr, u64 *dma_size)
1143 u64 end, mask, dmaaddr = 0, size = 0, offset = 0;
1147 * If @dev is expected to be DMA-capable then the bus code that created
1148 * it should have initialised its dma_mask pointer by this point. For
1149 * now, we'll continue the legacy behaviour of coercing it to the
1150 * coherent mask if not, but we'll no longer do so quietly.
1152 if (!dev->dma_mask) {
1153 dev_warn(dev, "DMA mask not set\n");
1154 dev->dma_mask = &dev->coherent_dma_mask;
1157 if (dev->coherent_dma_mask)
1158 size = max(dev->coherent_dma_mask, dev->coherent_dma_mask + 1);
1162 ret = acpi_dma_get_range(dev, &dmaaddr, &offset, &size);
1164 ret = dev_is_pci(dev) ? rc_dma_get_range(dev, &size)
1165 : nc_dma_get_range(dev, &size);
1169 * Limit coherent and dma mask based on size retrieved from
1172 end = dmaaddr + size - 1;
1173 mask = DMA_BIT_MASK(ilog2(end) + 1);
1174 dev->bus_dma_limit = end;
1175 dev->coherent_dma_mask = mask;
1176 *dev->dma_mask = mask;
1179 *dma_addr = dmaaddr;
1182 ret = dma_direct_set_offset(dev, dmaaddr + offset, dmaaddr, size);
1184 dev_dbg(dev, "dma_offset(%#08llx)%s\n", offset, ret ? " failed!" : "");
1187 static void __init acpi_iort_register_irq(int hwirq, const char *name,
1189 struct resource *res)
1191 int irq = acpi_register_gsi(NULL, hwirq, trigger,
1195 pr_err("could not register gsi hwirq %d name [%s]\n", hwirq,
1202 res->flags = IORESOURCE_IRQ;
1206 static int __init arm_smmu_v3_count_resources(struct acpi_iort_node *node)
1208 struct acpi_iort_smmu_v3 *smmu;
1209 /* Always present mem resource */
1212 /* Retrieve SMMUv3 specific data */
1213 smmu = (struct acpi_iort_smmu_v3 *)node->node_data;
1215 if (smmu->event_gsiv)
1221 if (smmu->gerr_gsiv)
1224 if (smmu->sync_gsiv)
1230 static bool arm_smmu_v3_is_combined_irq(struct acpi_iort_smmu_v3 *smmu)
1233 * Cavium ThunderX2 implementation doesn't not support unique
1234 * irq line. Use single irq line for all the SMMUv3 interrupts.
1236 if (smmu->model != ACPI_IORT_SMMU_V3_CAVIUM_CN99XX)
1240 * ThunderX2 doesn't support MSIs from the SMMU, so we're checking
1243 return smmu->event_gsiv == smmu->pri_gsiv &&
1244 smmu->event_gsiv == smmu->gerr_gsiv &&
1245 smmu->event_gsiv == smmu->sync_gsiv;
1248 static unsigned long arm_smmu_v3_resource_size(struct acpi_iort_smmu_v3 *smmu)
1251 * Override the size, for Cavium ThunderX2 implementation
1252 * which doesn't support the page 1 SMMU register space.
1254 if (smmu->model == ACPI_IORT_SMMU_V3_CAVIUM_CN99XX)
1260 static void __init arm_smmu_v3_init_resources(struct resource *res,
1261 struct acpi_iort_node *node)
1263 struct acpi_iort_smmu_v3 *smmu;
1266 /* Retrieve SMMUv3 specific data */
1267 smmu = (struct acpi_iort_smmu_v3 *)node->node_data;
1269 res[num_res].start = smmu->base_address;
1270 res[num_res].end = smmu->base_address +
1271 arm_smmu_v3_resource_size(smmu) - 1;
1272 res[num_res].flags = IORESOURCE_MEM;
1275 if (arm_smmu_v3_is_combined_irq(smmu)) {
1276 if (smmu->event_gsiv)
1277 acpi_iort_register_irq(smmu->event_gsiv, "combined",
1278 ACPI_EDGE_SENSITIVE,
1282 if (smmu->event_gsiv)
1283 acpi_iort_register_irq(smmu->event_gsiv, "eventq",
1284 ACPI_EDGE_SENSITIVE,
1288 acpi_iort_register_irq(smmu->pri_gsiv, "priq",
1289 ACPI_EDGE_SENSITIVE,
1292 if (smmu->gerr_gsiv)
1293 acpi_iort_register_irq(smmu->gerr_gsiv, "gerror",
1294 ACPI_EDGE_SENSITIVE,
1297 if (smmu->sync_gsiv)
1298 acpi_iort_register_irq(smmu->sync_gsiv, "cmdq-sync",
1299 ACPI_EDGE_SENSITIVE,
1304 static void __init arm_smmu_v3_dma_configure(struct device *dev,
1305 struct acpi_iort_node *node)
1307 struct acpi_iort_smmu_v3 *smmu;
1308 enum dev_dma_attr attr;
1310 /* Retrieve SMMUv3 specific data */
1311 smmu = (struct acpi_iort_smmu_v3 *)node->node_data;
1313 attr = (smmu->flags & ACPI_IORT_SMMU_V3_COHACC_OVERRIDE) ?
1314 DEV_DMA_COHERENT : DEV_DMA_NON_COHERENT;
1316 /* We expect the dma masks to be equivalent for all SMMUv3 set-ups */
1317 dev->dma_mask = &dev->coherent_dma_mask;
1319 /* Configure DMA for the page table walker */
1320 acpi_dma_configure(dev, attr);
1323 #if defined(CONFIG_ACPI_NUMA)
1325 * set numa proximity domain for smmuv3 device
1327 static int __init arm_smmu_v3_set_proximity(struct device *dev,
1328 struct acpi_iort_node *node)
1330 struct acpi_iort_smmu_v3 *smmu;
1332 smmu = (struct acpi_iort_smmu_v3 *)node->node_data;
1333 if (smmu->flags & ACPI_IORT_SMMU_V3_PXM_VALID) {
1334 int dev_node = pxm_to_node(smmu->pxm);
1336 if (dev_node != NUMA_NO_NODE && !node_online(dev_node))
1339 set_dev_node(dev, dev_node);
1340 pr_info("SMMU-v3[%llx] Mapped to Proximity domain %d\n",
1347 #define arm_smmu_v3_set_proximity NULL
1350 static int __init arm_smmu_count_resources(struct acpi_iort_node *node)
1352 struct acpi_iort_smmu *smmu;
1354 /* Retrieve SMMU specific data */
1355 smmu = (struct acpi_iort_smmu *)node->node_data;
1358 * Only consider the global fault interrupt and ignore the
1359 * configuration access interrupt.
1361 * MMIO address and global fault interrupt resources are always
1362 * present so add them to the context interrupt count as a static
1365 return smmu->context_interrupt_count + 2;
1368 static void __init arm_smmu_init_resources(struct resource *res,
1369 struct acpi_iort_node *node)
1371 struct acpi_iort_smmu *smmu;
1372 int i, hw_irq, trigger, num_res = 0;
1373 u64 *ctx_irq, *glb_irq;
1375 /* Retrieve SMMU specific data */
1376 smmu = (struct acpi_iort_smmu *)node->node_data;
1378 res[num_res].start = smmu->base_address;
1379 res[num_res].end = smmu->base_address + smmu->span - 1;
1380 res[num_res].flags = IORESOURCE_MEM;
1383 glb_irq = ACPI_ADD_PTR(u64, node, smmu->global_interrupt_offset);
1385 hw_irq = IORT_IRQ_MASK(glb_irq[0]);
1386 trigger = IORT_IRQ_TRIGGER_MASK(glb_irq[0]);
1388 acpi_iort_register_irq(hw_irq, "arm-smmu-global", trigger,
1392 ctx_irq = ACPI_ADD_PTR(u64, node, smmu->context_interrupt_offset);
1393 for (i = 0; i < smmu->context_interrupt_count; i++) {
1394 hw_irq = IORT_IRQ_MASK(ctx_irq[i]);
1395 trigger = IORT_IRQ_TRIGGER_MASK(ctx_irq[i]);
1397 acpi_iort_register_irq(hw_irq, "arm-smmu-context", trigger,
1402 static void __init arm_smmu_dma_configure(struct device *dev,
1403 struct acpi_iort_node *node)
1405 struct acpi_iort_smmu *smmu;
1406 enum dev_dma_attr attr;
1408 /* Retrieve SMMU specific data */
1409 smmu = (struct acpi_iort_smmu *)node->node_data;
1411 attr = (smmu->flags & ACPI_IORT_SMMU_COHERENT_WALK) ?
1412 DEV_DMA_COHERENT : DEV_DMA_NON_COHERENT;
1414 /* We expect the dma masks to be equivalent for SMMU set-ups */
1415 dev->dma_mask = &dev->coherent_dma_mask;
1417 /* Configure DMA for the page table walker */
1418 acpi_dma_configure(dev, attr);
1421 static int __init arm_smmu_v3_pmcg_count_resources(struct acpi_iort_node *node)
1423 struct acpi_iort_pmcg *pmcg;
1425 /* Retrieve PMCG specific data */
1426 pmcg = (struct acpi_iort_pmcg *)node->node_data;
1429 * There are always 2 memory resources.
1430 * If the overflow_gsiv is present then add that for a total of 3.
1432 return pmcg->overflow_gsiv ? 3 : 2;
1435 static void __init arm_smmu_v3_pmcg_init_resources(struct resource *res,
1436 struct acpi_iort_node *node)
1438 struct acpi_iort_pmcg *pmcg;
1440 /* Retrieve PMCG specific data */
1441 pmcg = (struct acpi_iort_pmcg *)node->node_data;
1443 res[0].start = pmcg->page0_base_address;
1444 res[0].end = pmcg->page0_base_address + SZ_4K - 1;
1445 res[0].flags = IORESOURCE_MEM;
1446 res[1].start = pmcg->page1_base_address;
1447 res[1].end = pmcg->page1_base_address + SZ_4K - 1;
1448 res[1].flags = IORESOURCE_MEM;
1450 if (pmcg->overflow_gsiv)
1451 acpi_iort_register_irq(pmcg->overflow_gsiv, "overflow",
1452 ACPI_EDGE_SENSITIVE, &res[2]);
1455 static struct acpi_platform_list pmcg_plat_info[] __initdata = {
1456 /* HiSilicon Hip08 Platform */
1457 {"HISI ", "HIP08 ", 0, ACPI_SIG_IORT, greater_than_or_equal,
1458 "Erratum #162001800", IORT_SMMU_V3_PMCG_HISI_HIP08},
1462 static int __init arm_smmu_v3_pmcg_add_platdata(struct platform_device *pdev)
1467 idx = acpi_match_platform_list(pmcg_plat_info);
1469 model = pmcg_plat_info[idx].data;
1471 model = IORT_SMMU_V3_PMCG_GENERIC;
1473 return platform_device_add_data(pdev, &model, sizeof(model));
1476 struct iort_dev_config {
1478 int (*dev_init)(struct acpi_iort_node *node);
1479 void (*dev_dma_configure)(struct device *dev,
1480 struct acpi_iort_node *node);
1481 int (*dev_count_resources)(struct acpi_iort_node *node);
1482 void (*dev_init_resources)(struct resource *res,
1483 struct acpi_iort_node *node);
1484 int (*dev_set_proximity)(struct device *dev,
1485 struct acpi_iort_node *node);
1486 int (*dev_add_platdata)(struct platform_device *pdev);
1489 static const struct iort_dev_config iort_arm_smmu_v3_cfg __initconst = {
1490 .name = "arm-smmu-v3",
1491 .dev_dma_configure = arm_smmu_v3_dma_configure,
1492 .dev_count_resources = arm_smmu_v3_count_resources,
1493 .dev_init_resources = arm_smmu_v3_init_resources,
1494 .dev_set_proximity = arm_smmu_v3_set_proximity,
1497 static const struct iort_dev_config iort_arm_smmu_cfg __initconst = {
1499 .dev_dma_configure = arm_smmu_dma_configure,
1500 .dev_count_resources = arm_smmu_count_resources,
1501 .dev_init_resources = arm_smmu_init_resources,
1504 static const struct iort_dev_config iort_arm_smmu_v3_pmcg_cfg __initconst = {
1505 .name = "arm-smmu-v3-pmcg",
1506 .dev_count_resources = arm_smmu_v3_pmcg_count_resources,
1507 .dev_init_resources = arm_smmu_v3_pmcg_init_resources,
1508 .dev_add_platdata = arm_smmu_v3_pmcg_add_platdata,
1511 static __init const struct iort_dev_config *iort_get_dev_cfg(
1512 struct acpi_iort_node *node)
1514 switch (node->type) {
1515 case ACPI_IORT_NODE_SMMU_V3:
1516 return &iort_arm_smmu_v3_cfg;
1517 case ACPI_IORT_NODE_SMMU:
1518 return &iort_arm_smmu_cfg;
1519 case ACPI_IORT_NODE_PMCG:
1520 return &iort_arm_smmu_v3_pmcg_cfg;
1527 * iort_add_platform_device() - Allocate a platform device for IORT node
1528 * @node: Pointer to device ACPI IORT node
1530 * Returns: 0 on success, <0 failure
1532 static int __init iort_add_platform_device(struct acpi_iort_node *node,
1533 const struct iort_dev_config *ops)
1535 struct fwnode_handle *fwnode;
1536 struct platform_device *pdev;
1540 pdev = platform_device_alloc(ops->name, PLATFORM_DEVID_AUTO);
1544 if (ops->dev_set_proximity) {
1545 ret = ops->dev_set_proximity(&pdev->dev, node);
1550 count = ops->dev_count_resources(node);
1552 r = kcalloc(count, sizeof(*r), GFP_KERNEL);
1558 ops->dev_init_resources(r, node);
1560 ret = platform_device_add_resources(pdev, r, count);
1562 * Resources are duplicated in platform_device_add_resources,
1563 * free their allocated memory
1571 * Platform devices based on PMCG nodes uses platform_data to
1572 * pass the hardware model info to the driver. For others, add
1573 * a copy of IORT node pointer to platform_data to be used to
1574 * retrieve IORT data information.
1576 if (ops->dev_add_platdata)
1577 ret = ops->dev_add_platdata(pdev);
1579 ret = platform_device_add_data(pdev, &node, sizeof(node));
1584 fwnode = iort_get_fwnode(node);
1591 pdev->dev.fwnode = fwnode;
1593 if (ops->dev_dma_configure)
1594 ops->dev_dma_configure(&pdev->dev, node);
1596 iort_set_device_domain(&pdev->dev, node);
1598 ret = platform_device_add(pdev);
1600 goto dma_deconfigure;
1605 arch_teardown_dma_ops(&pdev->dev);
1607 platform_device_put(pdev);
1613 static void __init iort_enable_acs(struct acpi_iort_node *iort_node)
1615 static bool acs_enabled __initdata;
1620 if (iort_node->type == ACPI_IORT_NODE_PCI_ROOT_COMPLEX) {
1621 struct acpi_iort_node *parent;
1622 struct acpi_iort_id_mapping *map;
1625 map = ACPI_ADD_PTR(struct acpi_iort_id_mapping, iort_node,
1626 iort_node->mapping_offset);
1628 for (i = 0; i < iort_node->mapping_count; i++, map++) {
1629 if (!map->output_reference)
1632 parent = ACPI_ADD_PTR(struct acpi_iort_node,
1633 iort_table, map->output_reference);
1635 * If we detect a RC->SMMU mapping, make sure
1636 * we enable ACS on the system.
1638 if ((parent->type == ACPI_IORT_NODE_SMMU) ||
1639 (parent->type == ACPI_IORT_NODE_SMMU_V3)) {
1648 static inline void iort_enable_acs(struct acpi_iort_node *iort_node) { }
1651 static void __init iort_init_platform_devices(void)
1653 struct acpi_iort_node *iort_node, *iort_end;
1654 struct acpi_table_iort *iort;
1655 struct fwnode_handle *fwnode;
1657 const struct iort_dev_config *ops;
1660 * iort_table and iort both point to the start of IORT table, but
1661 * have different struct types
1663 iort = (struct acpi_table_iort *)iort_table;
1665 /* Get the first IORT node */
1666 iort_node = ACPI_ADD_PTR(struct acpi_iort_node, iort,
1668 iort_end = ACPI_ADD_PTR(struct acpi_iort_node, iort,
1669 iort_table->length);
1671 for (i = 0; i < iort->node_count; i++) {
1672 if (iort_node >= iort_end) {
1673 pr_err("iort node pointer overflows, bad table\n");
1677 iort_enable_acs(iort_node);
1679 ops = iort_get_dev_cfg(iort_node);
1681 fwnode = acpi_alloc_fwnode_static();
1685 iort_set_fwnode(iort_node, fwnode);
1687 ret = iort_add_platform_device(iort_node, ops);
1689 iort_delete_fwnode(iort_node);
1690 acpi_free_fwnode_static(fwnode);
1695 iort_node = ACPI_ADD_PTR(struct acpi_iort_node, iort_node,
1700 void __init acpi_iort_init(void)
1704 /* iort_table will be used at runtime after the iort init,
1705 * so we don't need to call acpi_put_table() to release
1706 * the IORT table mapping.
1708 status = acpi_get_table(ACPI_SIG_IORT, 0, &iort_table);
1709 if (ACPI_FAILURE(status)) {
1710 if (status != AE_NOT_FOUND) {
1711 const char *msg = acpi_format_exception(status);
1713 pr_err("Failed to get table, %s\n", msg);
1719 iort_init_platform_devices();
1722 #ifdef CONFIG_ZONE_DMA
1724 * Extract the highest CPU physical address accessible to all DMA masters in
1725 * the system. PHYS_ADDR_MAX is returned when no constrained device is found.
1727 phys_addr_t __init acpi_iort_dma_get_max_cpu_address(void)
1729 phys_addr_t limit = PHYS_ADDR_MAX;
1730 struct acpi_iort_node *node, *end;
1731 struct acpi_table_iort *iort;
1738 status = acpi_get_table(ACPI_SIG_IORT, 0,
1739 (struct acpi_table_header **)&iort);
1740 if (ACPI_FAILURE(status))
1743 node = ACPI_ADD_PTR(struct acpi_iort_node, iort, iort->node_offset);
1744 end = ACPI_ADD_PTR(struct acpi_iort_node, iort, iort->header.length);
1746 for (i = 0; i < iort->node_count; i++) {
1750 switch (node->type) {
1751 struct acpi_iort_named_component *ncomp;
1752 struct acpi_iort_root_complex *rc;
1753 phys_addr_t local_limit;
1755 case ACPI_IORT_NODE_NAMED_COMPONENT:
1756 ncomp = (struct acpi_iort_named_component *)node->node_data;
1757 local_limit = DMA_BIT_MASK(ncomp->memory_address_limit);
1758 limit = min_not_zero(limit, local_limit);
1761 case ACPI_IORT_NODE_PCI_ROOT_COMPLEX:
1762 if (node->revision < 1)
1765 rc = (struct acpi_iort_root_complex *)node->node_data;
1766 local_limit = DMA_BIT_MASK(rc->memory_address_limit);
1767 limit = min_not_zero(limit, local_limit);
1770 node = ACPI_ADD_PTR(struct acpi_iort_node, node, node->length);
1772 acpi_put_table(&iort->header);