iort.c 9.3 KB
Newer Older
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24
/*
 * 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/kernel.h>
#include <linux/pci.h>

25 26 27 28 29 30
struct iort_its_msi_chip {
	struct list_head	list;
	struct fwnode_handle	*fw_node;
	u32			translation_id;
};

31 32 33 34 35 36 37 38 39
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);

40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109
/**
 * 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;
}

110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282
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_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_map_rid(struct acpi_iort_node *node,
						u32 rid_in, u32 *rid_out,
						u8 type)
{
	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 (node->type == type) {
			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);
}

283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331 332 333 334 335 336 337 338 339 340 341 342 343 344 345 346 347 348 349 350 351 352 353 354 355 356 357 358
/**
 * 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, ACPI_IORT_NODE_ITS_GROUP);
	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, ACPI_IORT_NODE_ITS_GROUP);
	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);
}

359 360 361 362 363
void __init acpi_iort_init(void)
{
	acpi_status status;

	status = acpi_get_table(ACPI_SIG_IORT, 0, &iort_table);
364 365 366 367 368 369 370 371
	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;
372
	}
373 374

	acpi_probe_device_table(iort);
375
}