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/drivers/firewire/core-device.c

https://bitbucket.org/ndreys/linux-sunxi
C | 1292 lines | 879 code | 213 blank | 200 comment | 171 complexity | 1b150ae1b0eb01f50d072fd6633211ba MD5 | raw file
Possible License(s): GPL-2.0, LGPL-2.0, AGPL-1.0
   1/*
   2 * Device probing and sysfs code.
   3 *
   4 * Copyright (C) 2005-2006  Kristian Hoegsberg <krh@bitplanet.net>
   5 *
   6 * This program is free software; you can redistribute it and/or modify
   7 * it under the terms of the GNU General Public License as published by
   8 * the Free Software Foundation; either version 2 of the License, or
   9 * (at your option) any later version.
  10 *
  11 * This program is distributed in the hope that it will be useful,
  12 * but WITHOUT ANY WARRANTY; without even the implied warranty of
  13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14 * GNU General Public License for more details.
  15 *
  16 * You should have received a copy of the GNU General Public License
  17 * along with this program; if not, write to the Free Software Foundation,
  18 * Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
  19 */
  20
  21#include <linux/bug.h>
  22#include <linux/ctype.h>
  23#include <linux/delay.h>
  24#include <linux/device.h>
  25#include <linux/errno.h>
  26#include <linux/firewire.h>
  27#include <linux/firewire-constants.h>
  28#include <linux/idr.h>
  29#include <linux/jiffies.h>
  30#include <linux/kobject.h>
  31#include <linux/list.h>
  32#include <linux/mod_devicetable.h>
  33#include <linux/module.h>
  34#include <linux/mutex.h>
  35#include <linux/rwsem.h>
  36#include <linux/slab.h>
  37#include <linux/spinlock.h>
  38#include <linux/string.h>
  39#include <linux/workqueue.h>
  40
  41#include <asm/atomic.h>
  42#include <asm/byteorder.h>
  43#include <asm/system.h>
  44
  45#include "core.h"
  46
  47void fw_csr_iterator_init(struct fw_csr_iterator *ci, const u32 *p)
  48{
  49	ci->p = p + 1;
  50	ci->end = ci->p + (p[0] >> 16);
  51}
  52EXPORT_SYMBOL(fw_csr_iterator_init);
  53
  54int fw_csr_iterator_next(struct fw_csr_iterator *ci, int *key, int *value)
  55{
  56	*key = *ci->p >> 24;
  57	*value = *ci->p & 0xffffff;
  58
  59	return ci->p++ < ci->end;
  60}
  61EXPORT_SYMBOL(fw_csr_iterator_next);
  62
  63static const u32 *search_leaf(const u32 *directory, int search_key)
  64{
  65	struct fw_csr_iterator ci;
  66	int last_key = 0, key, value;
  67
  68	fw_csr_iterator_init(&ci, directory);
  69	while (fw_csr_iterator_next(&ci, &key, &value)) {
  70		if (last_key == search_key &&
  71		    key == (CSR_DESCRIPTOR | CSR_LEAF))
  72			return ci.p - 1 + value;
  73
  74		last_key = key;
  75	}
  76
  77	return NULL;
  78}
  79
  80static int textual_leaf_to_string(const u32 *block, char *buf, size_t size)
  81{
  82	unsigned int quadlets, i;
  83	char c;
  84
  85	if (!size || !buf)
  86		return -EINVAL;
  87
  88	quadlets = min(block[0] >> 16, 256U);
  89	if (quadlets < 2)
  90		return -ENODATA;
  91
  92	if (block[1] != 0 || block[2] != 0)
  93		/* unknown language/character set */
  94		return -ENODATA;
  95
  96	block += 3;
  97	quadlets -= 2;
  98	for (i = 0; i < quadlets * 4 && i < size - 1; i++) {
  99		c = block[i / 4] >> (24 - 8 * (i % 4));
 100		if (c == '\0')
 101			break;
 102		buf[i] = c;
 103	}
 104	buf[i] = '\0';
 105
 106	return i;
 107}
 108
 109/**
 110 * fw_csr_string() - reads a string from the configuration ROM
 111 * @directory:	e.g. root directory or unit directory
 112 * @key:	the key of the preceding directory entry
 113 * @buf:	where to put the string
 114 * @size:	size of @buf, in bytes
 115 *
 116 * The string is taken from a minimal ASCII text descriptor leaf after
 117 * the immediate entry with @key.  The string is zero-terminated.
 118 * Returns strlen(buf) or a negative error code.
 119 */
 120int fw_csr_string(const u32 *directory, int key, char *buf, size_t size)
 121{
 122	const u32 *leaf = search_leaf(directory, key);
 123	if (!leaf)
 124		return -ENOENT;
 125
 126	return textual_leaf_to_string(leaf, buf, size);
 127}
 128EXPORT_SYMBOL(fw_csr_string);
 129
 130static void get_ids(const u32 *directory, int *id)
 131{
 132	struct fw_csr_iterator ci;
 133	int key, value;
 134
 135	fw_csr_iterator_init(&ci, directory);
 136	while (fw_csr_iterator_next(&ci, &key, &value)) {
 137		switch (key) {
 138		case CSR_VENDOR:	id[0] = value; break;
 139		case CSR_MODEL:		id[1] = value; break;
 140		case CSR_SPECIFIER_ID:	id[2] = value; break;
 141		case CSR_VERSION:	id[3] = value; break;
 142		}
 143	}
 144}
 145
 146static void get_modalias_ids(struct fw_unit *unit, int *id)
 147{
 148	get_ids(&fw_parent_device(unit)->config_rom[5], id);
 149	get_ids(unit->directory, id);
 150}
 151
 152static bool match_ids(const struct ieee1394_device_id *id_table, int *id)
 153{
 154	int match = 0;
 155
 156	if (id[0] == id_table->vendor_id)
 157		match |= IEEE1394_MATCH_VENDOR_ID;
 158	if (id[1] == id_table->model_id)
 159		match |= IEEE1394_MATCH_MODEL_ID;
 160	if (id[2] == id_table->specifier_id)
 161		match |= IEEE1394_MATCH_SPECIFIER_ID;
 162	if (id[3] == id_table->version)
 163		match |= IEEE1394_MATCH_VERSION;
 164
 165	return (match & id_table->match_flags) == id_table->match_flags;
 166}
 167
 168static bool is_fw_unit(struct device *dev);
 169
 170static int fw_unit_match(struct device *dev, struct device_driver *drv)
 171{
 172	const struct ieee1394_device_id *id_table =
 173			container_of(drv, struct fw_driver, driver)->id_table;
 174	int id[] = {0, 0, 0, 0};
 175
 176	/* We only allow binding to fw_units. */
 177	if (!is_fw_unit(dev))
 178		return 0;
 179
 180	get_modalias_ids(fw_unit(dev), id);
 181
 182	for (; id_table->match_flags != 0; id_table++)
 183		if (match_ids(id_table, id))
 184			return 1;
 185
 186	return 0;
 187}
 188
 189static int get_modalias(struct fw_unit *unit, char *buffer, size_t buffer_size)
 190{
 191	int id[] = {0, 0, 0, 0};
 192
 193	get_modalias_ids(unit, id);
 194
 195	return snprintf(buffer, buffer_size,
 196			"ieee1394:ven%08Xmo%08Xsp%08Xver%08X",
 197			id[0], id[1], id[2], id[3]);
 198}
 199
 200static int fw_unit_uevent(struct device *dev, struct kobj_uevent_env *env)
 201{
 202	struct fw_unit *unit = fw_unit(dev);
 203	char modalias[64];
 204
 205	get_modalias(unit, modalias, sizeof(modalias));
 206
 207	if (add_uevent_var(env, "MODALIAS=%s", modalias))
 208		return -ENOMEM;
 209
 210	return 0;
 211}
 212
 213struct bus_type fw_bus_type = {
 214	.name = "firewire",
 215	.match = fw_unit_match,
 216};
 217EXPORT_SYMBOL(fw_bus_type);
 218
 219int fw_device_enable_phys_dma(struct fw_device *device)
 220{
 221	int generation = device->generation;
 222
 223	/* device->node_id, accessed below, must not be older than generation */
 224	smp_rmb();
 225
 226	return device->card->driver->enable_phys_dma(device->card,
 227						     device->node_id,
 228						     generation);
 229}
 230EXPORT_SYMBOL(fw_device_enable_phys_dma);
 231
 232struct config_rom_attribute {
 233	struct device_attribute attr;
 234	u32 key;
 235};
 236
 237static ssize_t show_immediate(struct device *dev,
 238			      struct device_attribute *dattr, char *buf)
 239{
 240	struct config_rom_attribute *attr =
 241		container_of(dattr, struct config_rom_attribute, attr);
 242	struct fw_csr_iterator ci;
 243	const u32 *dir;
 244	int key, value, ret = -ENOENT;
 245
 246	down_read(&fw_device_rwsem);
 247
 248	if (is_fw_unit(dev))
 249		dir = fw_unit(dev)->directory;
 250	else
 251		dir = fw_device(dev)->config_rom + 5;
 252
 253	fw_csr_iterator_init(&ci, dir);
 254	while (fw_csr_iterator_next(&ci, &key, &value))
 255		if (attr->key == key) {
 256			ret = snprintf(buf, buf ? PAGE_SIZE : 0,
 257				       "0x%06x\n", value);
 258			break;
 259		}
 260
 261	up_read(&fw_device_rwsem);
 262
 263	return ret;
 264}
 265
 266#define IMMEDIATE_ATTR(name, key)				\
 267	{ __ATTR(name, S_IRUGO, show_immediate, NULL), key }
 268
 269static ssize_t show_text_leaf(struct device *dev,
 270			      struct device_attribute *dattr, char *buf)
 271{
 272	struct config_rom_attribute *attr =
 273		container_of(dattr, struct config_rom_attribute, attr);
 274	const u32 *dir;
 275	size_t bufsize;
 276	char dummy_buf[2];
 277	int ret;
 278
 279	down_read(&fw_device_rwsem);
 280
 281	if (is_fw_unit(dev))
 282		dir = fw_unit(dev)->directory;
 283	else
 284		dir = fw_device(dev)->config_rom + 5;
 285
 286	if (buf) {
 287		bufsize = PAGE_SIZE - 1;
 288	} else {
 289		buf = dummy_buf;
 290		bufsize = 1;
 291	}
 292
 293	ret = fw_csr_string(dir, attr->key, buf, bufsize);
 294
 295	if (ret >= 0) {
 296		/* Strip trailing whitespace and add newline. */
 297		while (ret > 0 && isspace(buf[ret - 1]))
 298			ret--;
 299		strcpy(buf + ret, "\n");
 300		ret++;
 301	}
 302
 303	up_read(&fw_device_rwsem);
 304
 305	return ret;
 306}
 307
 308#define TEXT_LEAF_ATTR(name, key)				\
 309	{ __ATTR(name, S_IRUGO, show_text_leaf, NULL), key }
 310
 311static struct config_rom_attribute config_rom_attributes[] = {
 312	IMMEDIATE_ATTR(vendor, CSR_VENDOR),
 313	IMMEDIATE_ATTR(hardware_version, CSR_HARDWARE_VERSION),
 314	IMMEDIATE_ATTR(specifier_id, CSR_SPECIFIER_ID),
 315	IMMEDIATE_ATTR(version, CSR_VERSION),
 316	IMMEDIATE_ATTR(model, CSR_MODEL),
 317	TEXT_LEAF_ATTR(vendor_name, CSR_VENDOR),
 318	TEXT_LEAF_ATTR(model_name, CSR_MODEL),
 319	TEXT_LEAF_ATTR(hardware_version_name, CSR_HARDWARE_VERSION),
 320};
 321
 322static void init_fw_attribute_group(struct device *dev,
 323				    struct device_attribute *attrs,
 324				    struct fw_attribute_group *group)
 325{
 326	struct device_attribute *attr;
 327	int i, j;
 328
 329	for (j = 0; attrs[j].attr.name != NULL; j++)
 330		group->attrs[j] = &attrs[j].attr;
 331
 332	for (i = 0; i < ARRAY_SIZE(config_rom_attributes); i++) {
 333		attr = &config_rom_attributes[i].attr;
 334		if (attr->show(dev, attr, NULL) < 0)
 335			continue;
 336		group->attrs[j++] = &attr->attr;
 337	}
 338
 339	group->attrs[j] = NULL;
 340	group->groups[0] = &group->group;
 341	group->groups[1] = NULL;
 342	group->group.attrs = group->attrs;
 343	dev->groups = (const struct attribute_group **) group->groups;
 344}
 345
 346static ssize_t modalias_show(struct device *dev,
 347			     struct device_attribute *attr, char *buf)
 348{
 349	struct fw_unit *unit = fw_unit(dev);
 350	int length;
 351
 352	length = get_modalias(unit, buf, PAGE_SIZE);
 353	strcpy(buf + length, "\n");
 354
 355	return length + 1;
 356}
 357
 358static ssize_t rom_index_show(struct device *dev,
 359			      struct device_attribute *attr, char *buf)
 360{
 361	struct fw_device *device = fw_device(dev->parent);
 362	struct fw_unit *unit = fw_unit(dev);
 363
 364	return snprintf(buf, PAGE_SIZE, "%d\n",
 365			(int)(unit->directory - device->config_rom));
 366}
 367
 368static struct device_attribute fw_unit_attributes[] = {
 369	__ATTR_RO(modalias),
 370	__ATTR_RO(rom_index),
 371	__ATTR_NULL,
 372};
 373
 374static ssize_t config_rom_show(struct device *dev,
 375			       struct device_attribute *attr, char *buf)
 376{
 377	struct fw_device *device = fw_device(dev);
 378	size_t length;
 379
 380	down_read(&fw_device_rwsem);
 381	length = device->config_rom_length * 4;
 382	memcpy(buf, device->config_rom, length);
 383	up_read(&fw_device_rwsem);
 384
 385	return length;
 386}
 387
 388static ssize_t guid_show(struct device *dev,
 389			 struct device_attribute *attr, char *buf)
 390{
 391	struct fw_device *device = fw_device(dev);
 392	int ret;
 393
 394	down_read(&fw_device_rwsem);
 395	ret = snprintf(buf, PAGE_SIZE, "0x%08x%08x\n",
 396		       device->config_rom[3], device->config_rom[4]);
 397	up_read(&fw_device_rwsem);
 398
 399	return ret;
 400}
 401
 402static int units_sprintf(char *buf, const u32 *directory)
 403{
 404	struct fw_csr_iterator ci;
 405	int key, value;
 406	int specifier_id = 0;
 407	int version = 0;
 408
 409	fw_csr_iterator_init(&ci, directory);
 410	while (fw_csr_iterator_next(&ci, &key, &value)) {
 411		switch (key) {
 412		case CSR_SPECIFIER_ID:
 413			specifier_id = value;
 414			break;
 415		case CSR_VERSION:
 416			version = value;
 417			break;
 418		}
 419	}
 420
 421	return sprintf(buf, "0x%06x:0x%06x ", specifier_id, version);
 422}
 423
 424static ssize_t units_show(struct device *dev,
 425			  struct device_attribute *attr, char *buf)
 426{
 427	struct fw_device *device = fw_device(dev);
 428	struct fw_csr_iterator ci;
 429	int key, value, i = 0;
 430
 431	down_read(&fw_device_rwsem);
 432	fw_csr_iterator_init(&ci, &device->config_rom[5]);
 433	while (fw_csr_iterator_next(&ci, &key, &value)) {
 434		if (key != (CSR_UNIT | CSR_DIRECTORY))
 435			continue;
 436		i += units_sprintf(&buf[i], ci.p + value - 1);
 437		if (i >= PAGE_SIZE - (8 + 1 + 8 + 1))
 438			break;
 439	}
 440	up_read(&fw_device_rwsem);
 441
 442	if (i)
 443		buf[i - 1] = '\n';
 444
 445	return i;
 446}
 447
 448static struct device_attribute fw_device_attributes[] = {
 449	__ATTR_RO(config_rom),
 450	__ATTR_RO(guid),
 451	__ATTR_RO(units),
 452	__ATTR_NULL,
 453};
 454
 455static int read_rom(struct fw_device *device,
 456		    int generation, int index, u32 *data)
 457{
 458	u64 offset = (CSR_REGISTER_BASE | CSR_CONFIG_ROM) + index * 4;
 459	int i, rcode;
 460
 461	/* device->node_id, accessed below, must not be older than generation */
 462	smp_rmb();
 463
 464	for (i = 10; i < 100; i += 10) {
 465		rcode = fw_run_transaction(device->card,
 466				TCODE_READ_QUADLET_REQUEST, device->node_id,
 467				generation, device->max_speed, offset, data, 4);
 468		if (rcode != RCODE_BUSY)
 469			break;
 470		msleep(i);
 471	}
 472	be32_to_cpus(data);
 473
 474	return rcode;
 475}
 476
 477#define MAX_CONFIG_ROM_SIZE 256
 478
 479/*
 480 * Read the bus info block, perform a speed probe, and read all of the rest of
 481 * the config ROM.  We do all this with a cached bus generation.  If the bus
 482 * generation changes under us, read_config_rom will fail and get retried.
 483 * It's better to start all over in this case because the node from which we
 484 * are reading the ROM may have changed the ROM during the reset.
 485 */
 486static int read_config_rom(struct fw_device *device, int generation)
 487{
 488	const u32 *old_rom, *new_rom;
 489	u32 *rom, *stack;
 490	u32 sp, key;
 491	int i, end, length, ret = -1;
 492
 493	rom = kmalloc(sizeof(*rom) * MAX_CONFIG_ROM_SIZE +
 494		      sizeof(*stack) * MAX_CONFIG_ROM_SIZE, GFP_KERNEL);
 495	if (rom == NULL)
 496		return -ENOMEM;
 497
 498	stack = &rom[MAX_CONFIG_ROM_SIZE];
 499	memset(rom, 0, sizeof(*rom) * MAX_CONFIG_ROM_SIZE);
 500
 501	device->max_speed = SCODE_100;
 502
 503	/* First read the bus info block. */
 504	for (i = 0; i < 5; i++) {
 505		if (read_rom(device, generation, i, &rom[i]) != RCODE_COMPLETE)
 506			goto out;
 507		/*
 508		 * As per IEEE1212 7.2, during power-up, devices can
 509		 * reply with a 0 for the first quadlet of the config
 510		 * rom to indicate that they are booting (for example,
 511		 * if the firmware is on the disk of a external
 512		 * harddisk).  In that case we just fail, and the
 513		 * retry mechanism will try again later.
 514		 */
 515		if (i == 0 && rom[i] == 0)
 516			goto out;
 517	}
 518
 519	device->max_speed = device->node->max_speed;
 520
 521	/*
 522	 * Determine the speed of
 523	 *   - devices with link speed less than PHY speed,
 524	 *   - devices with 1394b PHY (unless only connected to 1394a PHYs),
 525	 *   - all devices if there are 1394b repeaters.
 526	 * Note, we cannot use the bus info block's link_spd as starting point
 527	 * because some buggy firmwares set it lower than necessary and because
 528	 * 1394-1995 nodes do not have the field.
 529	 */
 530	if ((rom[2] & 0x7) < device->max_speed ||
 531	    device->max_speed == SCODE_BETA ||
 532	    device->card->beta_repeaters_present) {
 533		u32 dummy;
 534
 535		/* for S1600 and S3200 */
 536		if (device->max_speed == SCODE_BETA)
 537			device->max_speed = device->card->link_speed;
 538
 539		while (device->max_speed > SCODE_100) {
 540			if (read_rom(device, generation, 0, &dummy) ==
 541			    RCODE_COMPLETE)
 542				break;
 543			device->max_speed--;
 544		}
 545	}
 546
 547	/*
 548	 * Now parse the config rom.  The config rom is a recursive
 549	 * directory structure so we parse it using a stack of
 550	 * references to the blocks that make up the structure.  We
 551	 * push a reference to the root directory on the stack to
 552	 * start things off.
 553	 */
 554	length = i;
 555	sp = 0;
 556	stack[sp++] = 0xc0000005;
 557	while (sp > 0) {
 558		/*
 559		 * Pop the next block reference of the stack.  The
 560		 * lower 24 bits is the offset into the config rom,
 561		 * the upper 8 bits are the type of the reference the
 562		 * block.
 563		 */
 564		key = stack[--sp];
 565		i = key & 0xffffff;
 566		if (WARN_ON(i >= MAX_CONFIG_ROM_SIZE))
 567			goto out;
 568
 569		/* Read header quadlet for the block to get the length. */
 570		if (read_rom(device, generation, i, &rom[i]) != RCODE_COMPLETE)
 571			goto out;
 572		end = i + (rom[i] >> 16) + 1;
 573		if (end > MAX_CONFIG_ROM_SIZE) {
 574			/*
 575			 * This block extends outside the config ROM which is
 576			 * a firmware bug.  Ignore this whole block, i.e.
 577			 * simply set a fake block length of 0.
 578			 */
 579			fw_error("skipped invalid ROM block %x at %llx\n",
 580				 rom[i],
 581				 i * 4 | CSR_REGISTER_BASE | CSR_CONFIG_ROM);
 582			rom[i] = 0;
 583			end = i;
 584		}
 585		i++;
 586
 587		/*
 588		 * Now read in the block.  If this is a directory
 589		 * block, check the entries as we read them to see if
 590		 * it references another block, and push it in that case.
 591		 */
 592		for (; i < end; i++) {
 593			if (read_rom(device, generation, i, &rom[i]) !=
 594			    RCODE_COMPLETE)
 595				goto out;
 596
 597			if ((key >> 30) != 3 || (rom[i] >> 30) < 2)
 598				continue;
 599			/*
 600			 * Offset points outside the ROM.  May be a firmware
 601			 * bug or an Extended ROM entry (IEEE 1212-2001 clause
 602			 * 7.7.18).  Simply overwrite this pointer here by a
 603			 * fake immediate entry so that later iterators over
 604			 * the ROM don't have to check offsets all the time.
 605			 */
 606			if (i + (rom[i] & 0xffffff) >= MAX_CONFIG_ROM_SIZE) {
 607				fw_error("skipped unsupported ROM entry %x at %llx\n",
 608					 rom[i],
 609					 i * 4 | CSR_REGISTER_BASE | CSR_CONFIG_ROM);
 610				rom[i] = 0;
 611				continue;
 612			}
 613			stack[sp++] = i + rom[i];
 614		}
 615		if (length < i)
 616			length = i;
 617	}
 618
 619	old_rom = device->config_rom;
 620	new_rom = kmemdup(rom, length * 4, GFP_KERNEL);
 621	if (new_rom == NULL)
 622		goto out;
 623
 624	down_write(&fw_device_rwsem);
 625	device->config_rom = new_rom;
 626	device->config_rom_length = length;
 627	up_write(&fw_device_rwsem);
 628
 629	kfree(old_rom);
 630	ret = 0;
 631	device->max_rec	= rom[2] >> 12 & 0xf;
 632	device->cmc	= rom[2] >> 30 & 1;
 633	device->irmc	= rom[2] >> 31 & 1;
 634 out:
 635	kfree(rom);
 636
 637	return ret;
 638}
 639
 640static void fw_unit_release(struct device *dev)
 641{
 642	struct fw_unit *unit = fw_unit(dev);
 643
 644	kfree(unit);
 645}
 646
 647static struct device_type fw_unit_type = {
 648	.uevent		= fw_unit_uevent,
 649	.release	= fw_unit_release,
 650};
 651
 652static bool is_fw_unit(struct device *dev)
 653{
 654	return dev->type == &fw_unit_type;
 655}
 656
 657static void create_units(struct fw_device *device)
 658{
 659	struct fw_csr_iterator ci;
 660	struct fw_unit *unit;
 661	int key, value, i;
 662
 663	i = 0;
 664	fw_csr_iterator_init(&ci, &device->config_rom[5]);
 665	while (fw_csr_iterator_next(&ci, &key, &value)) {
 666		if (key != (CSR_UNIT | CSR_DIRECTORY))
 667			continue;
 668
 669		/*
 670		 * Get the address of the unit directory and try to
 671		 * match the drivers id_tables against it.
 672		 */
 673		unit = kzalloc(sizeof(*unit), GFP_KERNEL);
 674		if (unit == NULL) {
 675			fw_error("failed to allocate memory for unit\n");
 676			continue;
 677		}
 678
 679		unit->directory = ci.p + value - 1;
 680		unit->device.bus = &fw_bus_type;
 681		unit->device.type = &fw_unit_type;
 682		unit->device.parent = &device->device;
 683		dev_set_name(&unit->device, "%s.%d", dev_name(&device->device), i++);
 684
 685		BUILD_BUG_ON(ARRAY_SIZE(unit->attribute_group.attrs) <
 686				ARRAY_SIZE(fw_unit_attributes) +
 687				ARRAY_SIZE(config_rom_attributes));
 688		init_fw_attribute_group(&unit->device,
 689					fw_unit_attributes,
 690					&unit->attribute_group);
 691
 692		if (device_register(&unit->device) < 0)
 693			goto skip_unit;
 694
 695		continue;
 696
 697	skip_unit:
 698		kfree(unit);
 699	}
 700}
 701
 702static int shutdown_unit(struct device *device, void *data)
 703{
 704	device_unregister(device);
 705
 706	return 0;
 707}
 708
 709/*
 710 * fw_device_rwsem acts as dual purpose mutex:
 711 *   - serializes accesses to fw_device_idr,
 712 *   - serializes accesses to fw_device.config_rom/.config_rom_length and
 713 *     fw_unit.directory, unless those accesses happen at safe occasions
 714 */
 715DECLARE_RWSEM(fw_device_rwsem);
 716
 717DEFINE_IDR(fw_device_idr);
 718int fw_cdev_major;
 719
 720struct fw_device *fw_device_get_by_devt(dev_t devt)
 721{
 722	struct fw_device *device;
 723
 724	down_read(&fw_device_rwsem);
 725	device = idr_find(&fw_device_idr, MINOR(devt));
 726	if (device)
 727		fw_device_get(device);
 728	up_read(&fw_device_rwsem);
 729
 730	return device;
 731}
 732
 733struct workqueue_struct *fw_workqueue;
 734EXPORT_SYMBOL(fw_workqueue);
 735
 736static void fw_schedule_device_work(struct fw_device *device,
 737				    unsigned long delay)
 738{
 739	queue_delayed_work(fw_workqueue, &device->work, delay);
 740}
 741
 742/*
 743 * These defines control the retry behavior for reading the config
 744 * rom.  It shouldn't be necessary to tweak these; if the device
 745 * doesn't respond to a config rom read within 10 seconds, it's not
 746 * going to respond at all.  As for the initial delay, a lot of
 747 * devices will be able to respond within half a second after bus
 748 * reset.  On the other hand, it's not really worth being more
 749 * aggressive than that, since it scales pretty well; if 10 devices
 750 * are plugged in, they're all getting read within one second.
 751 */
 752
 753#define MAX_RETRIES	10
 754#define RETRY_DELAY	(3 * HZ)
 755#define INITIAL_DELAY	(HZ / 2)
 756#define SHUTDOWN_DELAY	(2 * HZ)
 757
 758static void fw_device_shutdown(struct work_struct *work)
 759{
 760	struct fw_device *device =
 761		container_of(work, struct fw_device, work.work);
 762	int minor = MINOR(device->device.devt);
 763
 764	if (time_before64(get_jiffies_64(),
 765			  device->card->reset_jiffies + SHUTDOWN_DELAY)
 766	    && !list_empty(&device->card->link)) {
 767		fw_schedule_device_work(device, SHUTDOWN_DELAY);
 768		return;
 769	}
 770
 771	if (atomic_cmpxchg(&device->state,
 772			   FW_DEVICE_GONE,
 773			   FW_DEVICE_SHUTDOWN) != FW_DEVICE_GONE)
 774		return;
 775
 776	fw_device_cdev_remove(device);
 777	device_for_each_child(&device->device, NULL, shutdown_unit);
 778	device_unregister(&device->device);
 779
 780	down_write(&fw_device_rwsem);
 781	idr_remove(&fw_device_idr, minor);
 782	up_write(&fw_device_rwsem);
 783
 784	fw_device_put(device);
 785}
 786
 787static void fw_device_release(struct device *dev)
 788{
 789	struct fw_device *device = fw_device(dev);
 790	struct fw_card *card = device->card;
 791	unsigned long flags;
 792
 793	/*
 794	 * Take the card lock so we don't set this to NULL while a
 795	 * FW_NODE_UPDATED callback is being handled or while the
 796	 * bus manager work looks at this node.
 797	 */
 798	spin_lock_irqsave(&card->lock, flags);
 799	device->node->data = NULL;
 800	spin_unlock_irqrestore(&card->lock, flags);
 801
 802	fw_node_put(device->node);
 803	kfree(device->config_rom);
 804	kfree(device);
 805	fw_card_put(card);
 806}
 807
 808static struct device_type fw_device_type = {
 809	.release = fw_device_release,
 810};
 811
 812static bool is_fw_device(struct device *dev)
 813{
 814	return dev->type == &fw_device_type;
 815}
 816
 817static int update_unit(struct device *dev, void *data)
 818{
 819	struct fw_unit *unit = fw_unit(dev);
 820	struct fw_driver *driver = (struct fw_driver *)dev->driver;
 821
 822	if (is_fw_unit(dev) && driver != NULL && driver->update != NULL) {
 823		device_lock(dev);
 824		driver->update(unit);
 825		device_unlock(dev);
 826	}
 827
 828	return 0;
 829}
 830
 831static void fw_device_update(struct work_struct *work)
 832{
 833	struct fw_device *device =
 834		container_of(work, struct fw_device, work.work);
 835
 836	fw_device_cdev_update(device);
 837	device_for_each_child(&device->device, NULL, update_unit);
 838}
 839
 840/*
 841 * If a device was pending for deletion because its node went away but its
 842 * bus info block and root directory header matches that of a newly discovered
 843 * device, revive the existing fw_device.
 844 * The newly allocated fw_device becomes obsolete instead.
 845 */
 846static int lookup_existing_device(struct device *dev, void *data)
 847{
 848	struct fw_device *old = fw_device(dev);
 849	struct fw_device *new = data;
 850	struct fw_card *card = new->card;
 851	int match = 0;
 852
 853	if (!is_fw_device(dev))
 854		return 0;
 855
 856	down_read(&fw_device_rwsem); /* serialize config_rom access */
 857	spin_lock_irq(&card->lock);  /* serialize node access */
 858
 859	if (memcmp(old->config_rom, new->config_rom, 6 * 4) == 0 &&
 860	    atomic_cmpxchg(&old->state,
 861			   FW_DEVICE_GONE,
 862			   FW_DEVICE_RUNNING) == FW_DEVICE_GONE) {
 863		struct fw_node *current_node = new->node;
 864		struct fw_node *obsolete_node = old->node;
 865
 866		new->node = obsolete_node;
 867		new->node->data = new;
 868		old->node = current_node;
 869		old->node->data = old;
 870
 871		old->max_speed = new->max_speed;
 872		old->node_id = current_node->node_id;
 873		smp_wmb();  /* update node_id before generation */
 874		old->generation = card->generation;
 875		old->config_rom_retries = 0;
 876		fw_notify("rediscovered device %s\n", dev_name(dev));
 877
 878		PREPARE_DELAYED_WORK(&old->work, fw_device_update);
 879		fw_schedule_device_work(old, 0);
 880
 881		if (current_node == card->root_node)
 882			fw_schedule_bm_work(card, 0);
 883
 884		match = 1;
 885	}
 886
 887	spin_unlock_irq(&card->lock);
 888	up_read(&fw_device_rwsem);
 889
 890	return match;
 891}
 892
 893enum { BC_UNKNOWN = 0, BC_UNIMPLEMENTED, BC_IMPLEMENTED, };
 894
 895static void set_broadcast_channel(struct fw_device *device, int generation)
 896{
 897	struct fw_card *card = device->card;
 898	__be32 data;
 899	int rcode;
 900
 901	if (!card->broadcast_channel_allocated)
 902		return;
 903
 904	/*
 905	 * The Broadcast_Channel Valid bit is required by nodes which want to
 906	 * transmit on this channel.  Such transmissions are practically
 907	 * exclusive to IP over 1394 (RFC 2734).  IP capable nodes are required
 908	 * to be IRM capable and have a max_rec of 8 or more.  We use this fact
 909	 * to narrow down to which nodes we send Broadcast_Channel updates.
 910	 */
 911	if (!device->irmc || device->max_rec < 8)
 912		return;
 913
 914	/*
 915	 * Some 1394-1995 nodes crash if this 1394a-2000 register is written.
 916	 * Perform a read test first.
 917	 */
 918	if (device->bc_implemented == BC_UNKNOWN) {
 919		rcode = fw_run_transaction(card, TCODE_READ_QUADLET_REQUEST,
 920				device->node_id, generation, device->max_speed,
 921				CSR_REGISTER_BASE + CSR_BROADCAST_CHANNEL,
 922				&data, 4);
 923		switch (rcode) {
 924		case RCODE_COMPLETE:
 925			if (data & cpu_to_be32(1 << 31)) {
 926				device->bc_implemented = BC_IMPLEMENTED;
 927				break;
 928			}
 929			/* else fall through to case address error */
 930		case RCODE_ADDRESS_ERROR:
 931			device->bc_implemented = BC_UNIMPLEMENTED;
 932		}
 933	}
 934
 935	if (device->bc_implemented == BC_IMPLEMENTED) {
 936		data = cpu_to_be32(BROADCAST_CHANNEL_INITIAL |
 937				   BROADCAST_CHANNEL_VALID);
 938		fw_run_transaction(card, TCODE_WRITE_QUADLET_REQUEST,
 939				device->node_id, generation, device->max_speed,
 940				CSR_REGISTER_BASE + CSR_BROADCAST_CHANNEL,
 941				&data, 4);
 942	}
 943}
 944
 945int fw_device_set_broadcast_channel(struct device *dev, void *gen)
 946{
 947	if (is_fw_device(dev))
 948		set_broadcast_channel(fw_device(dev), (long)gen);
 949
 950	return 0;
 951}
 952
 953static void fw_device_init(struct work_struct *work)
 954{
 955	struct fw_device *device =
 956		container_of(work, struct fw_device, work.work);
 957	struct device *revived_dev;
 958	int minor, ret;
 959
 960	/*
 961	 * All failure paths here set node->data to NULL, so that we
 962	 * don't try to do device_for_each_child() on a kfree()'d
 963	 * device.
 964	 */
 965
 966	if (read_config_rom(device, device->generation) < 0) {
 967		if (device->config_rom_retries < MAX_RETRIES &&
 968		    atomic_read(&device->state) == FW_DEVICE_INITIALIZING) {
 969			device->config_rom_retries++;
 970			fw_schedule_device_work(device, RETRY_DELAY);
 971		} else {
 972			if (device->node->link_on)
 973				fw_notify("giving up on config rom for node id %x\n",
 974					  device->node_id);
 975			if (device->node == device->card->root_node)
 976				fw_schedule_bm_work(device->card, 0);
 977			fw_device_release(&device->device);
 978		}
 979		return;
 980	}
 981
 982	revived_dev = device_find_child(device->card->device,
 983					device, lookup_existing_device);
 984	if (revived_dev) {
 985		put_device(revived_dev);
 986		fw_device_release(&device->device);
 987
 988		return;
 989	}
 990
 991	device_initialize(&device->device);
 992
 993	fw_device_get(device);
 994	down_write(&fw_device_rwsem);
 995	ret = idr_pre_get(&fw_device_idr, GFP_KERNEL) ?
 996	      idr_get_new(&fw_device_idr, device, &minor) :
 997	      -ENOMEM;
 998	up_write(&fw_device_rwsem);
 999
1000	if (ret < 0)
1001		goto error;
1002
1003	device->device.bus = &fw_bus_type;
1004	device->device.type = &fw_device_type;
1005	device->device.parent = device->card->device;
1006	device->device.devt = MKDEV(fw_cdev_major, minor);
1007	dev_set_name(&device->device, "fw%d", minor);
1008
1009	BUILD_BUG_ON(ARRAY_SIZE(device->attribute_group.attrs) <
1010			ARRAY_SIZE(fw_device_attributes) +
1011			ARRAY_SIZE(config_rom_attributes));
1012	init_fw_attribute_group(&device->device,
1013				fw_device_attributes,
1014				&device->attribute_group);
1015
1016	if (device_add(&device->device)) {
1017		fw_error("Failed to add device.\n");
1018		goto error_with_cdev;
1019	}
1020
1021	create_units(device);
1022
1023	/*
1024	 * Transition the device to running state.  If it got pulled
1025	 * out from under us while we did the intialization work, we
1026	 * have to shut down the device again here.  Normally, though,
1027	 * fw_node_event will be responsible for shutting it down when
1028	 * necessary.  We have to use the atomic cmpxchg here to avoid
1029	 * racing with the FW_NODE_DESTROYED case in
1030	 * fw_node_event().
1031	 */
1032	if (atomic_cmpxchg(&device->state,
1033			   FW_DEVICE_INITIALIZING,
1034			   FW_DEVICE_RUNNING) == FW_DEVICE_GONE) {
1035		PREPARE_DELAYED_WORK(&device->work, fw_device_shutdown);
1036		fw_schedule_device_work(device, SHUTDOWN_DELAY);
1037	} else {
1038		if (device->config_rom_retries)
1039			fw_notify("created device %s: GUID %08x%08x, S%d00, "
1040				  "%d config ROM retries\n",
1041				  dev_name(&device->device),
1042				  device->config_rom[3], device->config_rom[4],
1043				  1 << device->max_speed,
1044				  device->config_rom_retries);
1045		else
1046			fw_notify("created device %s: GUID %08x%08x, S%d00\n",
1047				  dev_name(&device->device),
1048				  device->config_rom[3], device->config_rom[4],
1049				  1 << device->max_speed);
1050		device->config_rom_retries = 0;
1051
1052		set_broadcast_channel(device, device->generation);
1053	}
1054
1055	/*
1056	 * Reschedule the IRM work if we just finished reading the
1057	 * root node config rom.  If this races with a bus reset we
1058	 * just end up running the IRM work a couple of extra times -
1059	 * pretty harmless.
1060	 */
1061	if (device->node == device->card->root_node)
1062		fw_schedule_bm_work(device->card, 0);
1063
1064	return;
1065
1066 error_with_cdev:
1067	down_write(&fw_device_rwsem);
1068	idr_remove(&fw_device_idr, minor);
1069	up_write(&fw_device_rwsem);
1070 error:
1071	fw_device_put(device);		/* fw_device_idr's reference */
1072
1073	put_device(&device->device);	/* our reference */
1074}
1075
1076enum {
1077	REREAD_BIB_ERROR,
1078	REREAD_BIB_GONE,
1079	REREAD_BIB_UNCHANGED,
1080	REREAD_BIB_CHANGED,
1081};
1082
1083/* Reread and compare bus info block and header of root directory */
1084static int reread_config_rom(struct fw_device *device, int generation)
1085{
1086	u32 q;
1087	int i;
1088
1089	for (i = 0; i < 6; i++) {
1090		if (read_rom(device, generation, i, &q) != RCODE_COMPLETE)
1091			return REREAD_BIB_ERROR;
1092
1093		if (i == 0 && q == 0)
1094			return REREAD_BIB_GONE;
1095
1096		if (q != device->config_rom[i])
1097			return REREAD_BIB_CHANGED;
1098	}
1099
1100	return REREAD_BIB_UNCHANGED;
1101}
1102
1103static void fw_device_refresh(struct work_struct *work)
1104{
1105	struct fw_device *device =
1106		container_of(work, struct fw_device, work.work);
1107	struct fw_card *card = device->card;
1108	int node_id = device->node_id;
1109
1110	switch (reread_config_rom(device, device->generation)) {
1111	case REREAD_BIB_ERROR:
1112		if (device->config_rom_retries < MAX_RETRIES / 2 &&
1113		    atomic_read(&device->state) == FW_DEVICE_INITIALIZING) {
1114			device->config_rom_retries++;
1115			fw_schedule_device_work(device, RETRY_DELAY / 2);
1116
1117			return;
1118		}
1119		goto give_up;
1120
1121	case REREAD_BIB_GONE:
1122		goto gone;
1123
1124	case REREAD_BIB_UNCHANGED:
1125		if (atomic_cmpxchg(&device->state,
1126				   FW_DEVICE_INITIALIZING,
1127				   FW_DEVICE_RUNNING) == FW_DEVICE_GONE)
1128			goto gone;
1129
1130		fw_device_update(work);
1131		device->config_rom_retries = 0;
1132		goto out;
1133
1134	case REREAD_BIB_CHANGED:
1135		break;
1136	}
1137
1138	/*
1139	 * Something changed.  We keep things simple and don't investigate
1140	 * further.  We just destroy all previous units and create new ones.
1141	 */
1142	device_for_each_child(&device->device, NULL, shutdown_unit);
1143
1144	if (read_config_rom(device, device->generation) < 0) {
1145		if (device->config_rom_retries < MAX_RETRIES &&
1146		    atomic_read(&device->state) == FW_DEVICE_INITIALIZING) {
1147			device->config_rom_retries++;
1148			fw_schedule_device_work(device, RETRY_DELAY);
1149
1150			return;
1151		}
1152		goto give_up;
1153	}
1154
1155	fw_device_cdev_update(device);
1156	create_units(device);
1157
1158	/* Userspace may want to re-read attributes. */
1159	kobject_uevent(&device->device.kobj, KOBJ_CHANGE);
1160
1161	if (atomic_cmpxchg(&device->state,
1162			   FW_DEVICE_INITIALIZING,
1163			   FW_DEVICE_RUNNING) == FW_DEVICE_GONE)
1164		goto gone;
1165
1166	fw_notify("refreshed device %s\n", dev_name(&device->device));
1167	device->config_rom_retries = 0;
1168	goto out;
1169
1170 give_up:
1171	fw_notify("giving up on refresh of device %s\n", dev_name(&device->device));
1172 gone:
1173	atomic_set(&device->state, FW_DEVICE_GONE);
1174	PREPARE_DELAYED_WORK(&device->work, fw_device_shutdown);
1175	fw_schedule_device_work(device, SHUTDOWN_DELAY);
1176 out:
1177	if (node_id == card->root_node->node_id)
1178		fw_schedule_bm_work(card, 0);
1179}
1180
1181void fw_node_event(struct fw_card *card, struct fw_node *node, int event)
1182{
1183	struct fw_device *device;
1184
1185	switch (event) {
1186	case FW_NODE_CREATED:
1187		/*
1188		 * Attempt to scan the node, regardless whether its self ID has
1189		 * the L (link active) flag set or not.  Some broken devices
1190		 * send L=0 but have an up-and-running link; others send L=1
1191		 * without actually having a link.
1192		 */
1193 create:
1194		device = kzalloc(sizeof(*device), GFP_ATOMIC);
1195		if (device == NULL)
1196			break;
1197
1198		/*
1199		 * Do minimal intialization of the device here, the
1200		 * rest will happen in fw_device_init().
1201		 *
1202		 * Attention:  A lot of things, even fw_device_get(),
1203		 * cannot be done before fw_device_init() finished!
1204		 * You can basically just check device->state and
1205		 * schedule work until then, but only while holding
1206		 * card->lock.
1207		 */
1208		atomic_set(&device->state, FW_DEVICE_INITIALIZING);
1209		device->card = fw_card_get(card);
1210		device->node = fw_node_get(node);
1211		device->node_id = node->node_id;
1212		device->generation = card->generation;
1213		device->is_local = node == card->local_node;
1214		mutex_init(&device->client_list_mutex);
1215		INIT_LIST_HEAD(&device->client_list);
1216
1217		/*
1218		 * Set the node data to point back to this device so
1219		 * FW_NODE_UPDATED callbacks can update the node_id
1220		 * and generation for the device.
1221		 */
1222		node->data = device;
1223
1224		/*
1225		 * Many devices are slow to respond after bus resets,
1226		 * especially if they are bus powered and go through
1227		 * power-up after getting plugged in.  We schedule the
1228		 * first config rom scan half a second after bus reset.
1229		 */
1230		INIT_DELAYED_WORK(&device->work, fw_device_init);
1231		fw_schedule_device_work(device, INITIAL_DELAY);
1232		break;
1233
1234	case FW_NODE_INITIATED_RESET:
1235	case FW_NODE_LINK_ON:
1236		device = node->data;
1237		if (device == NULL)
1238			goto create;
1239
1240		device->node_id = node->node_id;
1241		smp_wmb();  /* update node_id before generation */
1242		device->generation = card->generation;
1243		if (atomic_cmpxchg(&device->state,
1244			    FW_DEVICE_RUNNING,
1245			    FW_DEVICE_INITIALIZING) == FW_DEVICE_RUNNING) {
1246			PREPARE_DELAYED_WORK(&device->work, fw_device_refresh);
1247			fw_schedule_device_work(device,
1248				device->is_local ? 0 : INITIAL_DELAY);
1249		}
1250		break;
1251
1252	case FW_NODE_UPDATED:
1253		device = node->data;
1254		if (device == NULL)
1255			break;
1256
1257		device->node_id = node->node_id;
1258		smp_wmb();  /* update node_id before generation */
1259		device->generation = card->generation;
1260		if (atomic_read(&device->state) == FW_DEVICE_RUNNING) {
1261			PREPARE_DELAYED_WORK(&device->work, fw_device_update);
1262			fw_schedule_device_work(device, 0);
1263		}
1264		break;
1265
1266	case FW_NODE_DESTROYED:
1267	case FW_NODE_LINK_OFF:
1268		if (!node->data)
1269			break;
1270
1271		/*
1272		 * Destroy the device associated with the node.  There
1273		 * are two cases here: either the device is fully
1274		 * initialized (FW_DEVICE_RUNNING) or we're in the
1275		 * process of reading its config rom
1276		 * (FW_DEVICE_INITIALIZING).  If it is fully
1277		 * initialized we can reuse device->work to schedule a
1278		 * full fw_device_shutdown().  If not, there's work
1279		 * scheduled to read it's config rom, and we just put
1280		 * the device in shutdown state to have that code fail
1281		 * to create the device.
1282		 */
1283		device = node->data;
1284		if (atomic_xchg(&device->state,
1285				FW_DEVICE_GONE) == FW_DEVICE_RUNNING) {
1286			PREPARE_DELAYED_WORK(&device->work, fw_device_shutdown);
1287			fw_schedule_device_work(device,
1288				list_empty(&card->link) ? 0 : SHUTDOWN_DELAY);
1289		}
1290		break;
1291	}
1292}