core-device.c

   1// SPDX-License-Identifier: GPL-2.0-or-later
   2/*
   3 * Device probing and sysfs code.
   4 *
   5 * Copyright (C) 2005-2006  Kristian Hoegsberg <krh@bitplanet.net>
   6 */
   7
   8#include <linux/bug.h>
   9#include <linux/ctype.h>
  10#include <linux/delay.h>
  11#include <linux/device.h>
  12#include <linux/errno.h>
  13#include <linux/firewire.h>
  14#include <linux/firewire-constants.h>
  15#include <linux/jiffies.h>
  16#include <linux/kobject.h>
  17#include <linux/list.h>
  18#include <linux/mod_devicetable.h>
  19#include <linux/module.h>
  20#include <linux/mutex.h>
  21#include <linux/random.h>
  22#include <linux/rwsem.h>
  23#include <linux/slab.h>
  24#include <linux/spinlock.h>
  25#include <linux/string.h>
  26#include <linux/workqueue.h>
  27
  28#include <linux/atomic.h>
  29#include <asm/byteorder.h>
  30
  31#include "core.h"
  32
  33#define ROOT_DIR_OFFSET	5
  34
  35void fw_csr_iterator_init(struct fw_csr_iterator *ci, const u32 *p)
  36{
  37	ci->p = p + 1;
  38	ci->end = ci->p + (p[0] >> 16);
  39}
  40EXPORT_SYMBOL(fw_csr_iterator_init);
  41
  42int fw_csr_iterator_next(struct fw_csr_iterator *ci, int *key, int *value)
  43{
  44	*key = *ci->p >> 24;
  45	*value = *ci->p & 0xffffff;
  46
  47	return ci->p++ < ci->end;
  48}
  49EXPORT_SYMBOL(fw_csr_iterator_next);
  50
  51static const u32 *search_directory(const u32 *directory, int search_key)
  52{
  53	struct fw_csr_iterator ci;
  54	int key, value;
  55
  56	search_key |= CSR_DIRECTORY;
  57
  58	fw_csr_iterator_init(&ci, directory);
  59	while (fw_csr_iterator_next(&ci, &key, &value)) {
  60		if (key == search_key)
  61			return ci.p - 1 + value;
  62	}
  63
  64	return NULL;
  65}
  66
  67static const u32 *search_leaf(const u32 *directory, int search_key)
  68{
  69	struct fw_csr_iterator ci;
  70	int last_key = 0, key, value;
  71
  72	fw_csr_iterator_init(&ci, directory);
  73	while (fw_csr_iterator_next(&ci, &key, &value)) {
  74		if (last_key == search_key &&
  75		    key == (CSR_DESCRIPTOR | CSR_LEAF))
  76			return ci.p - 1 + value;
  77
  78		last_key = key;
  79	}
  80
  81	return NULL;
  82}
  83
  84static int textual_leaf_to_string(const u32 *block, char *buf, size_t size)
  85{
  86	unsigned int quadlets, i;
  87	char c;
  88
  89	if (!size || !buf)
  90		return -EINVAL;
  91
  92	quadlets = min(block[0] >> 16, 256U);
  93	if (quadlets < 2)
  94		return -ENODATA;
  95
  96	if (block[1] != 0 || block[2] != 0)
  97		/* unknown language/character set */
  98		return -ENODATA;
  99
 100	block += 3;
 101	quadlets -= 2;
 102	for (i = 0; i < quadlets * 4 && i < size - 1; i++) {
 103		c = block[i / 4] >> (24 - 8 * (i % 4));
 104		if (c == '\0')
 105			break;
 106		buf[i] = c;
 107	}
 108	buf[i] = '\0';
 109
 110	return i;
 111}
 112
 113/**
 114 * fw_csr_string() - reads a string from the configuration ROM
 115 * @directory:	e.g. root directory or unit directory
 116 * @key:	the key of the preceding directory entry
 117 * @buf:	where to put the string
 118 * @size:	size of @buf, in bytes
 119 *
 120 * The string is taken from a minimal ASCII text descriptor leaf just after the entry with the
 121 * @key. The string is zero-terminated. An overlong string is silently truncated such that it
 122 * and the zero byte fit into @size.
 123 *
 124 * Returns strlen(buf) or a negative error code.
 125 */
 126int fw_csr_string(const u32 *directory, int key, char *buf, size_t size)
 127{
 128	const u32 *leaf = search_leaf(directory, key);
 129	if (!leaf)
 130		return -ENOENT;
 131
 132	return textual_leaf_to_string(leaf, buf, size);
 133}
 134EXPORT_SYMBOL(fw_csr_string);
 135
 136static void get_ids(const u32 *directory, int *id)
 137{
 138	struct fw_csr_iterator ci;
 139	int key, value;
 140
 141	fw_csr_iterator_init(&ci, directory);
 142	while (fw_csr_iterator_next(&ci, &key, &value)) {
 143		switch (key) {
 144		case CSR_VENDOR:	id[0] = value; break;
 145		case CSR_MODEL:		id[1] = value; break;
 146		case CSR_SPECIFIER_ID:	id[2] = value; break;
 147		case CSR_VERSION:	id[3] = value; break;
 148		}
 149	}
 150}
 151
 152static void get_modalias_ids(const struct fw_unit *unit, int *id)
 153{
 154	const u32 *root_directory = &fw_parent_device(unit)->config_rom[ROOT_DIR_OFFSET];
 155	const u32 *directories[] = {NULL, NULL, NULL};
 156	const u32 *vendor_directory;
 157	int i;
 158
 159	directories[0] = root_directory;
 160
 161	// Legacy layout of configuration ROM described in Annex 1 of 'Configuration ROM for AV/C
 162	// Devices 1.0 (December 12, 2000, 1394 Trading Association, TA Document 1999027)'.
 163	vendor_directory = search_directory(root_directory, CSR_VENDOR);
 164	if (!vendor_directory) {
 165		directories[1] = unit->directory;
 166	} else {
 167		directories[1] = vendor_directory;
 168		directories[2] = unit->directory;
 169	}
 170
 171	for (i = 0; i < ARRAY_SIZE(directories) && !!directories[i]; ++i)
 172		get_ids(directories[i], id);
 173}
 174
 175static bool match_ids(const struct ieee1394_device_id *id_table, int *id)
 176{
 177	int match = 0;
 178
 179	if (id[0] == id_table->vendor_id)
 180		match |= IEEE1394_MATCH_VENDOR_ID;
 181	if (id[1] == id_table->model_id)
 182		match |= IEEE1394_MATCH_MODEL_ID;
 183	if (id[2] == id_table->specifier_id)
 184		match |= IEEE1394_MATCH_SPECIFIER_ID;
 185	if (id[3] == id_table->version)
 186		match |= IEEE1394_MATCH_VERSION;
 187
 188	return (match & id_table->match_flags) == id_table->match_flags;
 189}
 190
 191static const struct ieee1394_device_id *unit_match(struct device *dev,
 192						   const struct device_driver *drv)
 193{
 194	const struct ieee1394_device_id *id_table =
 195			container_of_const(drv, struct fw_driver, driver)->id_table;
 196	int id[] = {0, 0, 0, 0};
 197
 198	get_modalias_ids(fw_unit(dev), id);
 199
 200	for (; id_table->match_flags != 0; id_table++)
 201		if (match_ids(id_table, id))
 202			return id_table;
 203
 204	return NULL;
 205}
 206
 207static bool is_fw_unit(const struct device *dev);
 208
 209static int fw_unit_match(struct device *dev, const struct device_driver *drv)
 210{
 211	/* We only allow binding to fw_units. */
 212	return is_fw_unit(dev) && unit_match(dev, drv) != NULL;
 213}
 214
 215static int fw_unit_probe(struct device *dev)
 216{
 217	struct fw_driver *driver =
 218			container_of(dev->driver, struct fw_driver, driver);
 219
 220	return driver->probe(fw_unit(dev), unit_match(dev, dev->driver));
 221}
 222
 223static void fw_unit_remove(struct device *dev)
 224{
 225	struct fw_driver *driver =
 226			container_of(dev->driver, struct fw_driver, driver);
 227
 228	driver->remove(fw_unit(dev));
 229}
 230
 231static int get_modalias(const struct fw_unit *unit, char *buffer, size_t buffer_size)
 232{
 233	int id[] = {0, 0, 0, 0};
 234
 235	get_modalias_ids(unit, id);
 236
 237	return snprintf(buffer, buffer_size,
 238			"ieee1394:ven%08Xmo%08Xsp%08Xver%08X",
 239			id[0], id[1], id[2], id[3]);
 240}
 241
 242static int fw_unit_uevent(const struct device *dev, struct kobj_uevent_env *env)
 243{
 244	const struct fw_unit *unit = fw_unit(dev);
 245	char modalias[64];
 246
 247	get_modalias(unit, modalias, sizeof(modalias));
 248
 249	if (add_uevent_var(env, "MODALIAS=%s", modalias))
 250		return -ENOMEM;
 251
 252	return 0;
 253}
 254
 255const struct bus_type fw_bus_type = {
 256	.name = "firewire",
 257	.match = fw_unit_match,
 258	.probe = fw_unit_probe,
 259	.remove = fw_unit_remove,
 260};
 261EXPORT_SYMBOL(fw_bus_type);
 262
 263int fw_device_enable_phys_dma(struct fw_device *device)
 264{
 265	int generation = device->generation;
 266
 267	/* device->node_id, accessed below, must not be older than generation */
 268	smp_rmb();
 269
 270	return device->card->driver->enable_phys_dma(device->card,
 271						     device->node_id,
 272						     generation);
 273}
 274EXPORT_SYMBOL(fw_device_enable_phys_dma);
 275
 276struct config_rom_attribute {
 277	struct device_attribute attr;
 278	u32 key;
 279};
 280
 281static ssize_t show_immediate(struct device *dev,
 282			      struct device_attribute *dattr, char *buf)
 283{
 284	struct config_rom_attribute *attr =
 285		container_of(dattr, struct config_rom_attribute, attr);
 286	struct fw_csr_iterator ci;
 287	const u32 *directories[] = {NULL, NULL};
 288	int i, value = -1;
 289
 290	guard(rwsem_read)(&fw_device_rwsem);
 291
 292	if (is_fw_unit(dev)) {
 293		directories[0] = fw_unit(dev)->directory;
 294	} else {
 295		const u32 *root_directory = fw_device(dev)->config_rom + ROOT_DIR_OFFSET;
 296		const u32 *vendor_directory = search_directory(root_directory, CSR_VENDOR);
 297
 298		if (!vendor_directory) {
 299			directories[0] = root_directory;
 300		} else {
 301			// Legacy layout of configuration ROM described in Annex 1 of
 302			// 'Configuration ROM for AV/C Devices 1.0 (December 12, 2000, 1394 Trading
 303			// Association, TA Document 1999027)'.
 304			directories[0] = vendor_directory;
 305			directories[1] = root_directory;
 306		}
 307	}
 308
 309	for (i = 0; i < ARRAY_SIZE(directories) && !!directories[i]; ++i) {
 310		int key, val;
 311
 312		fw_csr_iterator_init(&ci, directories[i]);
 313		while (fw_csr_iterator_next(&ci, &key, &val)) {
 314			if (attr->key == key)
 315				value = val;
 316		}
 317	}
 318
 319	if (value < 0)
 320		return -ENOENT;
 321
 322	// Note that this function is also called by init_fw_attribute_group() with NULL pointer.
 323	return buf ? sysfs_emit(buf, "0x%06x\n", value) : 0;
 324}
 325
 326#define IMMEDIATE_ATTR(name, key)				\
 327	{ __ATTR(name, S_IRUGO, show_immediate, NULL), key }
 328
 329static ssize_t show_text_leaf(struct device *dev,
 330			      struct device_attribute *dattr, char *buf)
 331{
 332	struct config_rom_attribute *attr =
 333		container_of(dattr, struct config_rom_attribute, attr);
 334	const u32 *directories[] = {NULL, NULL};
 335	size_t bufsize;
 336	char dummy_buf[2];
 337	int i, ret = -ENOENT;
 338
 339	guard(rwsem_read)(&fw_device_rwsem);
 340
 341	if (is_fw_unit(dev)) {
 342		directories[0] = fw_unit(dev)->directory;
 343	} else {
 344		const u32 *root_directory = fw_device(dev)->config_rom + ROOT_DIR_OFFSET;
 345		const u32 *vendor_directory = search_directory(root_directory, CSR_VENDOR);
 346
 347		if (!vendor_directory) {
 348			directories[0] = root_directory;
 349		} else {
 350			// Legacy layout of configuration ROM described in Annex 1 of
 351			// 'Configuration ROM for AV/C Devices 1.0 (December 12, 2000, 1394
 352			// Trading Association, TA Document 1999027)'.
 353			directories[0] = root_directory;
 354			directories[1] = vendor_directory;
 355		}
 356	}
 357
 358	// Note that this function is also called by init_fw_attribute_group() with NULL pointer.
 359	if (buf) {
 360		bufsize = PAGE_SIZE - 1;
 361	} else {
 362		buf = dummy_buf;
 363		bufsize = 1;
 364	}
 365
 366	for (i = 0; i < ARRAY_SIZE(directories) && !!directories[i]; ++i) {
 367		int result = fw_csr_string(directories[i], attr->key, buf, bufsize);
 368		// Detected.
 369		if (result >= 0) {
 370			ret = result;
 371		} else if (i == 0 && attr->key == CSR_VENDOR) {
 372			// Sony DVMC-DA1 has configuration ROM such that the descriptor leaf entry
 373			// in the root directory follows to the directory entry for vendor ID
 374			// instead of the immediate value for vendor ID.
 375			result = fw_csr_string(directories[i], CSR_DIRECTORY | attr->key, buf,
 376					       bufsize);
 377			if (result >= 0)
 378				ret = result;
 379		}
 380	}
 381
 382	if (ret < 0)
 383		return ret;
 384
 385	// Strip trailing whitespace and add newline.
 386	while (ret > 0 && isspace(buf[ret - 1]))
 387		ret--;
 388	strcpy(buf + ret, "\n");
 389	ret++;
 390
 391	return ret;
 392}
 393
 394#define TEXT_LEAF_ATTR(name, key)				\
 395	{ __ATTR(name, S_IRUGO, show_text_leaf, NULL), key }
 396
 397static struct config_rom_attribute config_rom_attributes[] = {
 398	IMMEDIATE_ATTR(vendor, CSR_VENDOR),
 399	IMMEDIATE_ATTR(hardware_version, CSR_HARDWARE_VERSION),
 400	IMMEDIATE_ATTR(specifier_id, CSR_SPECIFIER_ID),
 401	IMMEDIATE_ATTR(version, CSR_VERSION),
 402	IMMEDIATE_ATTR(model, CSR_MODEL),
 403	TEXT_LEAF_ATTR(vendor_name, CSR_VENDOR),
 404	TEXT_LEAF_ATTR(model_name, CSR_MODEL),
 405	TEXT_LEAF_ATTR(hardware_version_name, CSR_HARDWARE_VERSION),
 406};
 407
 408static void init_fw_attribute_group(struct device *dev,
 409				    struct device_attribute *attrs,
 410				    struct fw_attribute_group *group)
 411{
 412	struct device_attribute *attr;
 413	int i, j;
 414
 415	for (j = 0; attrs[j].attr.name != NULL; j++)
 416		group->attrs[j] = &attrs[j].attr;
 417
 418	for (i = 0; i < ARRAY_SIZE(config_rom_attributes); i++) {
 419		attr = &config_rom_attributes[i].attr;
 420		if (attr->show(dev, attr, NULL) < 0)
 421			continue;
 422		group->attrs[j++] = &attr->attr;
 423	}
 424
 425	group->attrs[j] = NULL;
 426	group->groups[0] = &group->group;
 427	group->groups[1] = NULL;
 428	group->group.attrs = group->attrs;
 429	dev->groups = (const struct attribute_group **) group->groups;
 430}
 431
 432static ssize_t modalias_show(struct device *dev,
 433			     struct device_attribute *attr, char *buf)
 434{
 435	struct fw_unit *unit = fw_unit(dev);
 436	int length;
 437
 438	length = get_modalias(unit, buf, PAGE_SIZE);
 439	strcpy(buf + length, "\n");
 440
 441	return length + 1;
 442}
 443
 444static ssize_t rom_index_show(struct device *dev,
 445			      struct device_attribute *attr, char *buf)
 446{
 447	struct fw_device *device = fw_device(dev->parent);
 448	struct fw_unit *unit = fw_unit(dev);
 449
 450	return sysfs_emit(buf, "%td\n", unit->directory - device->config_rom);
 451}
 452
 453static struct device_attribute fw_unit_attributes[] = {
 454	__ATTR_RO(modalias),
 455	__ATTR_RO(rom_index),
 456	__ATTR_NULL,
 457};
 458
 459static ssize_t config_rom_show(struct device *dev,
 460			       struct device_attribute *attr, char *buf)
 461{
 462	struct fw_device *device = fw_device(dev);
 463	size_t length;
 464
 465	guard(rwsem_read)(&fw_device_rwsem);
 466
 467	length = device->config_rom_length * 4;
 468	memcpy(buf, device->config_rom, length);
 469
 470	return length;
 471}
 472
 473static ssize_t guid_show(struct device *dev,
 474			 struct device_attribute *attr, char *buf)
 475{
 476	struct fw_device *device = fw_device(dev);
 477
 478	guard(rwsem_read)(&fw_device_rwsem);
 479
 480	return sysfs_emit(buf, "0x%08x%08x\n", device->config_rom[3], device->config_rom[4]);
 481}
 482
 483static ssize_t is_local_show(struct device *dev,
 484			     struct device_attribute *attr, char *buf)
 485{
 486	struct fw_device *device = fw_device(dev);
 487
 488	return sysfs_emit(buf, "%u\n", device->is_local);
 489}
 490
 491static int units_sprintf(char *buf, const u32 *directory)
 492{
 493	struct fw_csr_iterator ci;
 494	int key, value;
 495	int specifier_id = 0;
 496	int version = 0;
 497
 498	fw_csr_iterator_init(&ci, directory);
 499	while (fw_csr_iterator_next(&ci, &key, &value)) {
 500		switch (key) {
 501		case CSR_SPECIFIER_ID:
 502			specifier_id = value;
 503			break;
 504		case CSR_VERSION:
 505			version = value;
 506			break;
 507		}
 508	}
 509
 510	return sprintf(buf, "0x%06x:0x%06x ", specifier_id, version);
 511}
 512
 513static ssize_t units_show(struct device *dev,
 514			  struct device_attribute *attr, char *buf)
 515{
 516	struct fw_device *device = fw_device(dev);
 517	struct fw_csr_iterator ci;
 518	int key, value, i = 0;
 519
 520	guard(rwsem_read)(&fw_device_rwsem);
 521
 522	fw_csr_iterator_init(&ci, &device->config_rom[ROOT_DIR_OFFSET]);
 523	while (fw_csr_iterator_next(&ci, &key, &value)) {
 524		if (key != (CSR_UNIT | CSR_DIRECTORY))
 525			continue;
 526		i += units_sprintf(&buf[i], ci.p + value - 1);
 527		if (i >= PAGE_SIZE - (8 + 1 + 8 + 1))
 528			break;
 529	}
 530
 531	if (i)
 532		buf[i - 1] = '\n';
 533
 534	return i;
 535}
 536
 537static struct device_attribute fw_device_attributes[] = {
 538	__ATTR_RO(config_rom),
 539	__ATTR_RO(guid),
 540	__ATTR_RO(is_local),
 541	__ATTR_RO(units),
 542	__ATTR_NULL,
 543};
 544
 545#define CANON_OUI		0x000085
 546
 547static int detect_quirks_by_bus_information_block(const u32 *bus_information_block)
 548{
 549	int quirks = 0;
 550
 551	if ((bus_information_block[2] & 0x000000f0) == 0)
 552		quirks |= FW_DEVICE_QUIRK_IRM_IS_1394_1995_ONLY;
 553
 554	if ((bus_information_block[3] >> 8) == CANON_OUI)
 555		quirks |= FW_DEVICE_QUIRK_IRM_IGNORES_BUS_MANAGER;
 556
 557	return quirks;
 558}
 559
 560struct entry_match {
 561	unsigned int index;
 562	u32 value;
 563};
 564
 565static const struct entry_match motu_audio_express_matches[] = {
 566	{ 1, 0x030001f2 },
 567	{ 3, 0xd1000002 },
 568	{ 4, 0x8d000005 },
 569	{ 6, 0x120001f2 },
 570	{ 7, 0x13000033 },
 571	{ 8, 0x17104800 },
 572};
 573
 574static const struct entry_match tascam_fw_series_matches[] = {
 575	{ 1, 0x0300022e },
 576	{ 3, 0x8d000006 },
 577	{ 4, 0xd1000001 },
 578	{ 6, 0x1200022e },
 579	{ 8, 0xd4000004 },
 580};
 581
 582static int detect_quirks_by_root_directory(const u32 *root_directory, unsigned int length)
 583{
 584	static const struct {
 585		enum fw_device_quirk quirk;
 586		const struct entry_match *matches;
 587		unsigned int match_count;
 588	} *entry, entries[] = {
 589		{
 590			.quirk = FW_DEVICE_QUIRK_ACK_PACKET_WITH_INVALID_PENDING_CODE,
 591			.matches = motu_audio_express_matches,
 592			.match_count = ARRAY_SIZE(motu_audio_express_matches),
 593		},
 594		{
 595			.quirk = FW_DEVICE_QUIRK_UNSTABLE_AT_S400,
 596			.matches = tascam_fw_series_matches,
 597			.match_count = ARRAY_SIZE(tascam_fw_series_matches),
 598		},
 599	};
 600	int quirks = 0;
 601	int i;
 602
 603	for (i = 0; i < ARRAY_SIZE(entries); ++i) {
 604		int j;
 605
 606		entry = entries + i;
 607		for (j = 0; j < entry->match_count; ++j) {
 608			unsigned int index = entry->matches[j].index;
 609			unsigned int value = entry->matches[j].value;
 610
 611			if ((length < index) || (root_directory[index] != value))
 612				break;
 613		}
 614		if (j == entry->match_count)
 615			quirks |= entry->quirk;
 616	}
 617
 618	return quirks;
 619}
 620
 621static int read_rom(struct fw_device *device, int generation, int speed, int index, u32 *data)
 622{
 623	u64 offset = (CSR_REGISTER_BASE | CSR_CONFIG_ROM) + index * 4;
 624	int i, rcode;
 625
 626	/* device->node_id, accessed below, must not be older than generation */
 627	smp_rmb();
 628
 629	for (i = 10; i < 100; i += 10) {
 630		rcode = fw_run_transaction(device->card,
 631				TCODE_READ_QUADLET_REQUEST, device->node_id,
 632				generation, speed, offset, data, 4);
 633		if (rcode != RCODE_BUSY)
 634			break;
 635		msleep(i);
 636	}
 637	be32_to_cpus(data);
 638
 639	return rcode;
 640}
 641
 642// By quadlet unit.
 643#define MAX_CONFIG_ROM_SIZE	((CSR_CONFIG_ROM_END - CSR_CONFIG_ROM) / sizeof(u32))
 644
 645/*
 646 * Read the bus info block, perform a speed probe, and read all of the rest of
 647 * the config ROM.  We do all this with a cached bus generation.  If the bus
 648 * generation changes under us, read_config_rom will fail and get retried.
 649 * It's better to start all over in this case because the node from which we
 650 * are reading the ROM may have changed the ROM during the reset.
 651 * Returns either a result code or a negative error code.
 652 */
 653static int read_config_rom(struct fw_device *device, int generation)
 654{
 655	struct fw_card *card = device->card;
 656	const u32 *new_rom, *old_rom __free(kfree) = NULL;
 657	u32 *stack, *rom __free(kfree) = NULL;
 658	u32 sp, key;
 659	int i, end, length, ret, speed;
 660	int quirks;
 661
 662	rom = kmalloc(sizeof(*rom) * MAX_CONFIG_ROM_SIZE +
 663		      sizeof(*stack) * MAX_CONFIG_ROM_SIZE, GFP_KERNEL);
 664	if (rom == NULL)
 665		return -ENOMEM;
 666
 667	stack = &rom[MAX_CONFIG_ROM_SIZE];
 668	memset(rom, 0, sizeof(*rom) * MAX_CONFIG_ROM_SIZE);
 669
 670	speed = SCODE_100;
 671
 672	/* First read the bus info block. */
 673	for (i = 0; i < 5; i++) {
 674		ret = read_rom(device, generation, speed, i, &rom[i]);
 675		if (ret != RCODE_COMPLETE)
 676			return ret;
 677		/*
 678		 * As per IEEE1212 7.2, during initialization, devices can
 679		 * reply with a 0 for the first quadlet of the config
 680		 * rom to indicate that they are booting (for example,
 681		 * if the firmware is on the disk of a external
 682		 * harddisk).  In that case we just fail, and the
 683		 * retry mechanism will try again later.
 684		 */
 685		if (i == 0 && rom[i] == 0)
 686			return RCODE_BUSY;
 687	}
 688
 689	quirks = detect_quirks_by_bus_information_block(rom);
 690
 691	// Just prevent from torn writing/reading.
 692	WRITE_ONCE(device->quirks, quirks);
 693
 694	/*
 695	 * Now parse the config rom.  The config rom is a recursive
 696	 * directory structure so we parse it using a stack of
 697	 * references to the blocks that make up the structure.  We
 698	 * push a reference to the root directory on the stack to
 699	 * start things off.
 700	 */
 701	length = i;
 702	sp = 0;
 703	stack[sp++] = 0xc0000005;
 704	while (sp > 0) {
 705		/*
 706		 * Pop the next block reference of the stack.  The
 707		 * lower 24 bits is the offset into the config rom,
 708		 * the upper 8 bits are the type of the reference the
 709		 * block.
 710		 */
 711		key = stack[--sp];
 712		i = key & 0xffffff;
 713		if (WARN_ON(i >= MAX_CONFIG_ROM_SIZE))
 714			return -ENXIO;
 715
 716		/* Read header quadlet for the block to get the length. */
 717		ret = read_rom(device, generation, speed, i, &rom[i]);
 718		if (ret != RCODE_COMPLETE)
 719			return ret;
 720		end = i + (rom[i] >> 16) + 1;
 721		if (end > MAX_CONFIG_ROM_SIZE) {
 722			/*
 723			 * This block extends outside the config ROM which is
 724			 * a firmware bug.  Ignore this whole block, i.e.
 725			 * simply set a fake block length of 0.
 726			 */
 727			fw_err(card, "skipped invalid ROM block %x at %llx\n",
 728			       rom[i],
 729			       i * 4 | CSR_REGISTER_BASE | CSR_CONFIG_ROM);
 730			rom[i] = 0;
 731			end = i;
 732		}
 733		i++;
 734
 735		/*
 736		 * Now read in the block.  If this is a directory
 737		 * block, check the entries as we read them to see if
 738		 * it references another block, and push it in that case.
 739		 */
 740		for (; i < end; i++) {
 741			ret = read_rom(device, generation, speed, i, &rom[i]);
 742			if (ret != RCODE_COMPLETE)
 743				return ret;
 744
 745			if ((key >> 30) != 3 || (rom[i] >> 30) < 2)
 746				continue;
 747			/*
 748			 * Offset points outside the ROM.  May be a firmware
 749			 * bug or an Extended ROM entry (IEEE 1212-2001 clause
 750			 * 7.7.18).  Simply overwrite this pointer here by a
 751			 * fake immediate entry so that later iterators over
 752			 * the ROM don't have to check offsets all the time.
 753			 */
 754			if (i + (rom[i] & 0xffffff) >= MAX_CONFIG_ROM_SIZE) {
 755				fw_err(card,
 756				       "skipped unsupported ROM entry %x at %llx\n",
 757				       rom[i],
 758				       i * 4 | CSR_REGISTER_BASE | CSR_CONFIG_ROM);
 759				rom[i] = 0;
 760				continue;
 761			}
 762			stack[sp++] = i + rom[i];
 763		}
 764		if (length < i)
 765			length = i;
 766	}
 767
 768	quirks |= detect_quirks_by_root_directory(rom + ROOT_DIR_OFFSET, length - ROOT_DIR_OFFSET);
 769
 770	// Just prevent from torn writing/reading.
 771	WRITE_ONCE(device->quirks, quirks);
 772
 773	if (unlikely(quirks & FW_DEVICE_QUIRK_UNSTABLE_AT_S400))
 774		speed = SCODE_200;
 775	else
 776		speed = device->node->max_speed;
 777
 778	// Determine the speed of
 779	//   - devices with link speed less than PHY speed,
 780	//   - devices with 1394b PHY (unless only connected to 1394a PHYs),
 781	//   - all devices if there are 1394b repeaters.
 782	// Note, we cannot use the bus info block's link_spd as starting point because some buggy
 783	// firmwares set it lower than necessary and because 1394-1995 nodes do not have the field.
 784	if ((rom[2] & 0x7) < speed || speed == SCODE_BETA || card->beta_repeaters_present) {
 785		u32 dummy;
 786
 787		// for S1600 and S3200.
 788		if (speed == SCODE_BETA)
 789			speed = card->link_speed;
 790
 791		while (speed > SCODE_100) {
 792			if (read_rom(device, generation, speed, 0, &dummy) ==
 793			    RCODE_COMPLETE)
 794				break;
 795			--speed;
 796		}
 797	}
 798
 799	device->max_speed = speed;
 800
 801	old_rom = device->config_rom;
 802	new_rom = kmemdup(rom, length * 4, GFP_KERNEL);
 803	if (new_rom == NULL)
 804		return -ENOMEM;
 805
 806	scoped_guard(rwsem_write, &fw_device_rwsem) {
 807		device->config_rom = new_rom;
 808		device->config_rom_length = length;
 809	}
 810
 811	device->max_rec	= rom[2] >> 12 & 0xf;
 812	device->cmc	= rom[2] >> 30 & 1;
 813	device->irmc	= rom[2] >> 31 & 1;
 814
 815	return RCODE_COMPLETE;
 816}
 817
 818static void fw_unit_release(struct device *dev)
 819{
 820	struct fw_unit *unit = fw_unit(dev);
 821
 822	fw_device_put(fw_parent_device(unit));
 823	kfree(unit);
 824}
 825
 826static struct device_type fw_unit_type = {
 827	.uevent		= fw_unit_uevent,
 828	.release	= fw_unit_release,
 829};
 830
 831static bool is_fw_unit(const struct device *dev)
 832{
 833	return dev->type == &fw_unit_type;
 834}
 835
 836static void create_units(struct fw_device *device)
 837{
 838	struct fw_csr_iterator ci;
 839	struct fw_unit *unit;
 840	int key, value, i;
 841
 842	i = 0;
 843	fw_csr_iterator_init(&ci, &device->config_rom[ROOT_DIR_OFFSET]);
 844	while (fw_csr_iterator_next(&ci, &key, &value)) {
 845		if (key != (CSR_UNIT | CSR_DIRECTORY))
 846			continue;
 847
 848		/*
 849		 * Get the address of the unit directory and try to
 850		 * match the drivers id_tables against it.
 851		 */
 852		unit = kzalloc(sizeof(*unit), GFP_KERNEL);
 853		if (unit == NULL)
 854			continue;
 855
 856		unit->directory = ci.p + value - 1;
 857		unit->device.bus = &fw_bus_type;
 858		unit->device.type = &fw_unit_type;
 859		unit->device.parent = &device->device;
 860		dev_set_name(&unit->device, "%s.%d", dev_name(&device->device), i++);
 861
 862		BUILD_BUG_ON(ARRAY_SIZE(unit->attribute_group.attrs) <
 863				ARRAY_SIZE(fw_unit_attributes) +
 864				ARRAY_SIZE(config_rom_attributes));
 865		init_fw_attribute_group(&unit->device,
 866					fw_unit_attributes,
 867					&unit->attribute_group);
 868
 869		fw_device_get(device);
 870		if (device_register(&unit->device) < 0) {
 871			put_device(&unit->device);
 872			continue;
 873		}
 874	}
 875}
 876
 877static int shutdown_unit(struct device *device, void *data)
 878{
 879	device_unregister(device);
 880
 881	return 0;
 882}
 883
 884/*
 885 * fw_device_rwsem acts as dual purpose mutex:
 886 *   - serializes accesses to fw_device.config_rom/.config_rom_length and
 887 *     fw_unit.directory, unless those accesses happen at safe occasions
 888 */
 889DECLARE_RWSEM(fw_device_rwsem);
 890
 891DEFINE_XARRAY_ALLOC(fw_device_xa);
 892int fw_cdev_major;
 893
 894struct fw_device *fw_device_get_by_devt(dev_t devt)
 895{
 896	struct fw_device *device;
 897
 898	device = xa_load(&fw_device_xa, MINOR(devt));
 899	if (device)
 900		fw_device_get(device);
 901
 902	return device;
 903}
 904
 905struct workqueue_struct *fw_workqueue;
 906EXPORT_SYMBOL(fw_workqueue);
 907
 908static void fw_schedule_device_work(struct fw_device *device,
 909				    unsigned long delay)
 910{
 911	queue_delayed_work(fw_workqueue, &device->work, delay);
 912}
 913
 914/*
 915 * These defines control the retry behavior for reading the config
 916 * rom.  It shouldn't be necessary to tweak these; if the device
 917 * doesn't respond to a config rom read within 10 seconds, it's not
 918 * going to respond at all.  As for the initial delay, a lot of
 919 * devices will be able to respond within half a second after bus
 920 * reset.  On the other hand, it's not really worth being more
 921 * aggressive than that, since it scales pretty well; if 10 devices
 922 * are plugged in, they're all getting read within one second.
 923 */
 924
 925#define MAX_RETRIES	10
 926#define RETRY_DELAY	secs_to_jiffies(3)
 927#define INITIAL_DELAY	msecs_to_jiffies(500)
 928#define SHUTDOWN_DELAY	secs_to_jiffies(2)
 929
 930static void fw_device_shutdown(struct work_struct *work)
 931{
 932	struct fw_device *device = from_work(device, work, work.work);
 933
 934	if (time_is_after_jiffies64(device->card->reset_jiffies + SHUTDOWN_DELAY)
 935	    && !list_empty(&device->card->link)) {
 936		fw_schedule_device_work(device, SHUTDOWN_DELAY);
 937		return;
 938	}
 939
 940	if (atomic_cmpxchg(&device->state,
 941			   FW_DEVICE_GONE,
 942			   FW_DEVICE_SHUTDOWN) != FW_DEVICE_GONE)
 943		return;
 944
 945	fw_device_cdev_remove(device);
 946	device_for_each_child(&device->device, NULL, shutdown_unit);
 947	device_unregister(&device->device);
 948
 949	xa_erase(&fw_device_xa, MINOR(device->device.devt));
 950
 951	fw_device_put(device);
 952}
 953
 954static void fw_device_release(struct device *dev)
 955{
 956	struct fw_device *device = fw_device(dev);
 957	struct fw_card *card = device->card;
 958
 959	/*
 960	 * Take the card lock so we don't set this to NULL while a
 961	 * FW_NODE_UPDATED callback is being handled or while the
 962	 * bus manager work looks at this node.
 963	 */
 964	scoped_guard(spinlock_irqsave, &card->lock)
 965		fw_node_set_device(device->node, NULL);
 966
 967	fw_node_put(device->node);
 968	kfree(device->config_rom);
 969	kfree(device);
 970	fw_card_put(card);
 971}
 972
 973static struct device_type fw_device_type = {
 974	.release = fw_device_release,
 975};
 976
 977static bool is_fw_device(const struct device *dev)
 978{
 979	return dev->type == &fw_device_type;
 980}
 981
 982static int update_unit(struct device *dev, void *data)
 983{
 984	struct fw_unit *unit = fw_unit(dev);
 985	struct fw_driver *driver = (struct fw_driver *)dev->driver;
 986
 987	if (is_fw_unit(dev) && driver != NULL && driver->update != NULL) {
 988		device_lock(dev);
 989		driver->update(unit);
 990		device_unlock(dev);
 991	}
 992
 993	return 0;
 994}
 995
 996static void fw_device_update(struct work_struct *work)
 997{
 998	struct fw_device *device = from_work(device, work, work.work);
 999
1000	fw_device_cdev_update(device);
1001	device_for_each_child(&device->device, NULL, update_unit);
1002}
1003
1004enum { BC_UNKNOWN = 0, BC_UNIMPLEMENTED, BC_IMPLEMENTED, };
1005
1006static void set_broadcast_channel(struct fw_device *device, int generation)
1007{
1008	struct fw_card *card = device->card;
1009	__be32 data;
1010	int rcode;
1011
1012	if (!card->broadcast_channel_allocated)
1013		return;
1014
1015	/*
1016	 * The Broadcast_Channel Valid bit is required by nodes which want to
1017	 * transmit on this channel.  Such transmissions are practically
1018	 * exclusive to IP over 1394 (RFC 2734).  IP capable nodes are required
1019	 * to be IRM capable and have a max_rec of 8 or more.  We use this fact
1020	 * to narrow down to which nodes we send Broadcast_Channel updates.
1021	 */
1022	if (!device->irmc || device->max_rec < 8)
1023		return;
1024
1025	/*
1026	 * Some 1394-1995 nodes crash if this 1394a-2000 register is written.
1027	 * Perform a read test first.
1028	 */
1029	if (device->bc_implemented == BC_UNKNOWN) {
1030		rcode = fw_run_transaction(card, TCODE_READ_QUADLET_REQUEST,
1031				device->node_id, generation, device->max_speed,
1032				CSR_REGISTER_BASE + CSR_BROADCAST_CHANNEL,
1033				&data, 4);
1034		switch (rcode) {
1035		case RCODE_COMPLETE:
1036			if (data & cpu_to_be32(1 << 31)) {
1037				device->bc_implemented = BC_IMPLEMENTED;
1038				break;
1039			}
1040			fallthrough;	/* to case address error */
1041		case RCODE_ADDRESS_ERROR:
1042			device->bc_implemented = BC_UNIMPLEMENTED;
1043		}
1044	}
1045
1046	if (device->bc_implemented == BC_IMPLEMENTED) {
1047		data = cpu_to_be32(BROADCAST_CHANNEL_INITIAL |
1048				   BROADCAST_CHANNEL_VALID);
1049		fw_run_transaction(card, TCODE_WRITE_QUADLET_REQUEST,
1050				device->node_id, generation, device->max_speed,
1051				CSR_REGISTER_BASE + CSR_BROADCAST_CHANNEL,
1052				&data, 4);
1053	}
1054}
1055
1056int fw_device_set_broadcast_channel(struct device *dev, void *gen)
1057{
1058	if (is_fw_device(dev))
1059		set_broadcast_channel(fw_device(dev), (long)gen);
1060
1061	return 0;
1062}
1063
1064static int compare_configuration_rom(struct device *dev, const void *data)
1065{
1066	const struct fw_device *old = fw_device(dev);
1067	const u32 *config_rom = data;
1068
1069	if (!is_fw_device(dev))
1070		return 0;
1071
1072	// Compare the bus information block and root_length/root_crc.
1073	return !memcmp(old->config_rom, config_rom, 6 * 4);
1074}
1075
1076static void fw_device_init(struct work_struct *work)
1077{
1078	struct fw_device *device = from_work(device, work, work.work);
1079	struct fw_card *card = device->card;
1080	struct device *found;
1081	u32 minor;
1082	int ret;
1083
1084	/*
1085	 * All failure paths here call fw_node_set_device(node, NULL), so that we
1086	 * don't try to do device_for_each_child() on a kfree()'d
1087	 * device.
1088	 */
1089
1090	ret = read_config_rom(device, device->generation);
1091	if (ret != RCODE_COMPLETE) {
1092		if (device->config_rom_retries < MAX_RETRIES &&
1093		    atomic_read(&device->state) == FW_DEVICE_INITIALIZING) {
1094			device->config_rom_retries++;
1095			fw_schedule_device_work(device, RETRY_DELAY);
1096		} else {
1097			if (device->node->link_on)
1098				fw_notice(card, "giving up on node %x: reading config rom failed: %s\n",
1099					  device->node_id,
1100					  fw_rcode_string(ret));
1101			if (device->node == card->root_node)
1102				fw_schedule_bm_work(card, 0);
1103			fw_device_release(&device->device);
1104		}
1105		return;
1106	}
1107
1108	// If a device was pending for deletion because its node went away but its bus info block
1109	// and root directory header matches that of a newly discovered device, revive the
1110	// existing fw_device. The newly allocated fw_device becomes obsolete instead.
1111	//
1112	// serialize config_rom access.
1113	scoped_guard(rwsem_read, &fw_device_rwsem) {
1114		found = device_find_child(card->device, device->config_rom,
1115					  compare_configuration_rom);
1116	}
1117	if (found) {
1118		struct fw_device *reused = fw_device(found);
1119
1120		if (atomic_cmpxchg(&reused->state,
1121				   FW_DEVICE_GONE,
1122				   FW_DEVICE_RUNNING) == FW_DEVICE_GONE) {
1123			// serialize node access
1124			scoped_guard(spinlock_irq, &card->lock) {
1125				struct fw_node *current_node = device->node;
1126				struct fw_node *obsolete_node = reused->node;
1127
1128				device->node = obsolete_node;
1129				fw_node_set_device(device->node, device);
1130				reused->node = current_node;
1131				fw_node_set_device(reused->node, reused);
1132
1133				reused->max_speed = device->max_speed;
1134				reused->node_id = current_node->node_id;
1135				smp_wmb();  /* update node_id before generation */
1136				reused->generation = card->generation;
1137				reused->config_rom_retries = 0;
1138				fw_notice(card, "rediscovered device %s\n",
1139					  dev_name(found));
1140
1141				reused->workfn = fw_device_update;
1142				fw_schedule_device_work(reused, 0);
1143
1144				if (current_node == card->root_node)
1145					fw_schedule_bm_work(card, 0);
1146			}
1147
1148			put_device(found);
1149			fw_device_release(&device->device);
1150
1151			return;
1152		}
1153
1154		put_device(found);
1155	}
1156
1157	device_initialize(&device->device);
1158
1159	fw_device_get(device);
1160
1161	// The index of allocated entry is used for minor identifier of device node.
1162	ret = xa_alloc(&fw_device_xa, &minor, device, XA_LIMIT(0, MINORMASK), GFP_KERNEL);
1163	if (ret < 0)
1164		goto error;
1165
1166	device->device.bus = &fw_bus_type;
1167	device->device.type = &fw_device_type;
1168	device->device.parent = card->device;
1169	device->device.devt = MKDEV(fw_cdev_major, minor);
1170	dev_set_name(&device->device, "fw%d", minor);
1171
1172	BUILD_BUG_ON(ARRAY_SIZE(device->attribute_group.attrs) <
1173			ARRAY_SIZE(fw_device_attributes) +
1174			ARRAY_SIZE(config_rom_attributes));
1175	init_fw_attribute_group(&device->device,
1176				fw_device_attributes,
1177				&device->attribute_group);
1178
1179	if (device_add(&device->device)) {
1180		fw_err(card, "failed to add device\n");
1181		goto error_with_cdev;
1182	}
1183
1184	create_units(device);
1185
1186	/*
1187	 * Transition the device to running state.  If it got pulled
1188	 * out from under us while we did the initialization work, we
1189	 * have to shut down the device again here.  Normally, though,
1190	 * fw_node_event will be responsible for shutting it down when
1191	 * necessary.  We have to use the atomic cmpxchg here to avoid
1192	 * racing with the FW_NODE_DESTROYED case in
1193	 * fw_node_event().
1194	 */
1195	if (atomic_cmpxchg(&device->state,
1196			   FW_DEVICE_INITIALIZING,
1197			   FW_DEVICE_RUNNING) == FW_DEVICE_GONE) {
1198		device->workfn = fw_device_shutdown;
1199		fw_schedule_device_work(device, SHUTDOWN_DELAY);
1200	} else {
1201		fw_notice(card, "created device %s: GUID %08x%08x, S%d00, quirks %08x\n",
1202			  dev_name(&device->device),
1203			  device->config_rom[3], device->config_rom[4],
1204			  1 << device->max_speed, device->quirks);
1205		device->config_rom_retries = 0;
1206
1207		set_broadcast_channel(device, device->generation);
1208
1209		add_device_randomness(&device->config_rom[3], 8);
1210	}
1211
1212	/*
1213	 * Reschedule the IRM work if we just finished reading the
1214	 * root node config rom.  If this races with a bus reset we
1215	 * just end up running the IRM work a couple of extra times -
1216	 * pretty harmless.
1217	 */
1218	if (device->node == card->root_node)
1219		fw_schedule_bm_work(card, 0);
1220
1221	return;
1222
1223 error_with_cdev:
1224	xa_erase(&fw_device_xa, minor);
1225 error:
1226	fw_device_put(device);		// fw_device_xa's reference.
1227
1228	put_device(&device->device);	/* our reference */
1229}
1230
1231/* Reread and compare bus info block and header of root directory */
1232static int reread_config_rom(struct fw_device *device, int generation,
1233			     bool *changed)
1234{
1235	u32 q;
1236	int i, rcode;
1237
1238	for (i = 0; i < 6; i++) {
1239		rcode = read_rom(device, generation, device->max_speed, i, &q);
1240		if (rcode != RCODE_COMPLETE)
1241			return rcode;
1242
1243		if (i == 0 && q == 0)
1244			/* inaccessible (see read_config_rom); retry later */
1245			return RCODE_BUSY;
1246
1247		if (q != device->config_rom[i]) {
1248			*changed = true;
1249			return RCODE_COMPLETE;
1250		}
1251	}
1252
1253	*changed = false;
1254	return RCODE_COMPLETE;
1255}
1256
1257static void fw_device_refresh(struct work_struct *work)
1258{
1259	struct fw_device *device = from_work(device, work, work.work);
1260	struct fw_card *card = device->card;
1261	int ret, node_id = device->node_id;
1262	bool changed;
1263
1264	ret = reread_config_rom(device, device->generation, &changed);
1265	if (ret != RCODE_COMPLETE)
1266		goto failed_config_rom;
1267
1268	if (!changed) {
1269		if (atomic_cmpxchg(&device->state,
1270				   FW_DEVICE_INITIALIZING,
1271				   FW_DEVICE_RUNNING) == FW_DEVICE_GONE)
1272			goto gone;
1273
1274		fw_device_update(work);
1275		device->config_rom_retries = 0;
1276		goto out;
1277	}
1278
1279	/*
1280	 * Something changed.  We keep things simple and don't investigate
1281	 * further.  We just destroy all previous units and create new ones.
1282	 */
1283	device_for_each_child(&device->device, NULL, shutdown_unit);
1284
1285	ret = read_config_rom(device, device->generation);
1286	if (ret != RCODE_COMPLETE)
1287		goto failed_config_rom;
1288
1289	fw_device_cdev_update(device);
1290	create_units(device);
1291
1292	/* Userspace may want to re-read attributes. */
1293	kobject_uevent(&device->device.kobj, KOBJ_CHANGE);
1294
1295	if (atomic_cmpxchg(&device->state,
1296			   FW_DEVICE_INITIALIZING,
1297			   FW_DEVICE_RUNNING) == FW_DEVICE_GONE)
1298		goto gone;
1299
1300	fw_notice(card, "refreshed device %s\n", dev_name(&device->device));
1301	device->config_rom_retries = 0;
1302	goto out;
1303
1304 failed_config_rom:
1305	if (device->config_rom_retries < MAX_RETRIES &&
1306	    atomic_read(&device->state) == FW_DEVICE_INITIALIZING) {
1307		device->config_rom_retries++;
1308		fw_schedule_device_work(device, RETRY_DELAY);
1309		return;
1310	}
1311
1312	fw_notice(card, "giving up on refresh of device %s: %s\n",
1313		  dev_name(&device->device), fw_rcode_string(ret));
1314 gone:
1315	atomic_set(&device->state, FW_DEVICE_GONE);
1316	device->workfn = fw_device_shutdown;
1317	fw_schedule_device_work(device, SHUTDOWN_DELAY);
1318 out:
1319	if (node_id == card->root_node->node_id)
1320		fw_schedule_bm_work(card, 0);
1321}
1322
1323static void fw_device_workfn(struct work_struct *work)
1324{
1325	struct fw_device *device = from_work(device, to_delayed_work(work), work);
1326	device->workfn(work);
1327}
1328
1329void fw_node_event(struct fw_card *card, struct fw_node *node, int event)
1330{
1331	struct fw_device *device;
1332
1333	switch (event) {
1334	case FW_NODE_CREATED:
1335		/*
1336		 * Attempt to scan the node, regardless whether its self ID has
1337		 * the L (link active) flag set or not.  Some broken devices
1338		 * send L=0 but have an up-and-running link; others send L=1
1339		 * without actually having a link.
1340		 */
1341 create:
1342		device = kzalloc(sizeof(*device), GFP_ATOMIC);
1343		if (device == NULL)
1344			break;
1345
1346		/*
1347		 * Do minimal initialization of the device here, the
1348		 * rest will happen in fw_device_init().
1349		 *
1350		 * Attention:  A lot of things, even fw_device_get(),
1351		 * cannot be done before fw_device_init() finished!
1352		 * You can basically just check device->state and
1353		 * schedule work until then, but only while holding
1354		 * card->lock.
1355		 */
1356		atomic_set(&device->state, FW_DEVICE_INITIALIZING);
1357		device->card = fw_card_get(card);
1358		device->node = fw_node_get(node);
1359		device->node_id = node->node_id;
1360		device->generation = card->generation;
1361		device->is_local = node == card->local_node;
1362		mutex_init(&device->client_list_mutex);
1363		INIT_LIST_HEAD(&device->client_list);
1364
1365		/*
1366		 * Set the node data to point back to this device so
1367		 * FW_NODE_UPDATED callbacks can update the node_id
1368		 * and generation for the device.
1369		 */
1370		fw_node_set_device(node, device);
1371
1372		/*
1373		 * Many devices are slow to respond after bus resets,
1374		 * especially if they are bus powered and go through
1375		 * power-up after getting plugged in.  We schedule the
1376		 * first config rom scan half a second after bus reset.
1377		 */
1378		device->workfn = fw_device_init;
1379		INIT_DELAYED_WORK(&device->work, fw_device_workfn);
1380		fw_schedule_device_work(device, INITIAL_DELAY);
1381		break;
1382
1383	case FW_NODE_INITIATED_RESET:
1384	case FW_NODE_LINK_ON:
1385		device = fw_node_get_device(node);
1386		if (device == NULL)
1387			goto create;
1388
1389		device->node_id = node->node_id;
1390		smp_wmb();  /* update node_id before generation */
1391		device->generation = card->generation;
1392		if (atomic_cmpxchg(&device->state,
1393			    FW_DEVICE_RUNNING,
1394			    FW_DEVICE_INITIALIZING) == FW_DEVICE_RUNNING) {
1395			device->workfn = fw_device_refresh;
1396			fw_schedule_device_work(device,
1397				device->is_local ? 0 : INITIAL_DELAY);
1398		}
1399		break;
1400
1401	case FW_NODE_UPDATED:
1402		device = fw_node_get_device(node);
1403		if (device == NULL)
1404			break;
1405
1406		device->node_id = node->node_id;
1407		smp_wmb();  /* update node_id before generation */
1408		device->generation = card->generation;
1409		if (atomic_read(&device->state) == FW_DEVICE_RUNNING) {
1410			device->workfn = fw_device_update;
1411			fw_schedule_device_work(device, 0);
1412		}
1413		break;
1414
1415	case FW_NODE_DESTROYED:
1416	case FW_NODE_LINK_OFF:
1417		if (!fw_node_get_device(node))
1418			break;
1419
1420		/*
1421		 * Destroy the device associated with the node.  There
1422		 * are two cases here: either the device is fully
1423		 * initialized (FW_DEVICE_RUNNING) or we're in the
1424		 * process of reading its config rom
1425		 * (FW_DEVICE_INITIALIZING).  If it is fully
1426		 * initialized we can reuse device->work to schedule a
1427		 * full fw_device_shutdown().  If not, there's work
1428		 * scheduled to read it's config rom, and we just put
1429		 * the device in shutdown state to have that code fail
1430		 * to create the device.
1431		 */
1432		device = fw_node_get_device(node);
1433		if (atomic_xchg(&device->state,
1434				FW_DEVICE_GONE) == FW_DEVICE_RUNNING) {
1435			device->workfn = fw_device_shutdown;
1436			fw_schedule_device_work(device,
1437				list_empty(&card->link) ? 0 : SHUTDOWN_DELAY);
1438		}
1439		break;
1440	}
1441}
1442
1443#ifdef CONFIG_FIREWIRE_KUNIT_DEVICE_ATTRIBUTE_TEST
1444#include "device-attribute-test.c"
1445#endif