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1// SPDX-License-Identifier: GPL-2.0-or-later2/*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 534 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 ROM115 * @directory: e.g. root directory or unit directory116 * @key: the key of the preceding directory entry117 * @buf: where to put the string118 * @size: size of @buf, in bytes119 *120 * The string is taken from a minimal ASCII text descriptor leaf just after the entry with the121 * @key. The string is zero-terminated. An overlong string is silently truncated such that it122 * 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/C162 // 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 of302 // 'Configuration ROM for AV/C Devices 1.0 (December 12, 2000, 1394 Trading303 // 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 of351 // 'Configuration ROM for AV/C Devices 1.0 (December 12, 2000, 1394352 // 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 entry373 // in the root directory follows to the directory entry for vendor ID374 // 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 545static int read_rom(struct fw_device *device,546 int generation, int index, u32 *data)547{548 u64 offset = (CSR_REGISTER_BASE | CSR_CONFIG_ROM) + index * 4;549 int i, rcode;550 551 /* device->node_id, accessed below, must not be older than generation */552 smp_rmb();553 554 for (i = 10; i < 100; i += 10) {555 rcode = fw_run_transaction(device->card,556 TCODE_READ_QUADLET_REQUEST, device->node_id,557 generation, device->max_speed, offset, data, 4);558 if (rcode != RCODE_BUSY)559 break;560 msleep(i);561 }562 be32_to_cpus(data);563 564 return rcode;565}566 567// By quadlet unit.568#define MAX_CONFIG_ROM_SIZE ((CSR_CONFIG_ROM_END - CSR_CONFIG_ROM) / sizeof(u32))569 570/*571 * Read the bus info block, perform a speed probe, and read all of the rest of572 * the config ROM. We do all this with a cached bus generation. If the bus573 * generation changes under us, read_config_rom will fail and get retried.574 * It's better to start all over in this case because the node from which we575 * are reading the ROM may have changed the ROM during the reset.576 * Returns either a result code or a negative error code.577 */578static int read_config_rom(struct fw_device *device, int generation)579{580 struct fw_card *card = device->card;581 const u32 *old_rom, *new_rom;582 u32 *rom, *stack;583 u32 sp, key;584 int i, end, length, ret;585 586 rom = kmalloc(sizeof(*rom) * MAX_CONFIG_ROM_SIZE +587 sizeof(*stack) * MAX_CONFIG_ROM_SIZE, GFP_KERNEL);588 if (rom == NULL)589 return -ENOMEM;590 591 stack = &rom[MAX_CONFIG_ROM_SIZE];592 memset(rom, 0, sizeof(*rom) * MAX_CONFIG_ROM_SIZE);593 594 device->max_speed = SCODE_100;595 596 /* First read the bus info block. */597 for (i = 0; i < 5; i++) {598 ret = read_rom(device, generation, i, &rom[i]);599 if (ret != RCODE_COMPLETE)600 goto out;601 /*602 * As per IEEE1212 7.2, during initialization, devices can603 * reply with a 0 for the first quadlet of the config604 * rom to indicate that they are booting (for example,605 * if the firmware is on the disk of a external606 * harddisk). In that case we just fail, and the607 * retry mechanism will try again later.608 */609 if (i == 0 && rom[i] == 0) {610 ret = RCODE_BUSY;611 goto out;612 }613 }614 615 device->max_speed = device->node->max_speed;616 617 /*618 * Determine the speed of619 * - devices with link speed less than PHY speed,620 * - devices with 1394b PHY (unless only connected to 1394a PHYs),621 * - all devices if there are 1394b repeaters.622 * Note, we cannot use the bus info block's link_spd as starting point623 * because some buggy firmwares set it lower than necessary and because624 * 1394-1995 nodes do not have the field.625 */626 if ((rom[2] & 0x7) < device->max_speed ||627 device->max_speed == SCODE_BETA ||628 card->beta_repeaters_present) {629 u32 dummy;630 631 /* for S1600 and S3200 */632 if (device->max_speed == SCODE_BETA)633 device->max_speed = card->link_speed;634 635 while (device->max_speed > SCODE_100) {636 if (read_rom(device, generation, 0, &dummy) ==637 RCODE_COMPLETE)638 break;639 device->max_speed--;640 }641 }642 643 /*644 * Now parse the config rom. The config rom is a recursive645 * directory structure so we parse it using a stack of646 * references to the blocks that make up the structure. We647 * push a reference to the root directory on the stack to648 * start things off.649 */650 length = i;651 sp = 0;652 stack[sp++] = 0xc0000005;653 while (sp > 0) {654 /*655 * Pop the next block reference of the stack. The656 * lower 24 bits is the offset into the config rom,657 * the upper 8 bits are the type of the reference the658 * block.659 */660 key = stack[--sp];661 i = key & 0xffffff;662 if (WARN_ON(i >= MAX_CONFIG_ROM_SIZE)) {663 ret = -ENXIO;664 goto out;665 }666 667 /* Read header quadlet for the block to get the length. */668 ret = read_rom(device, generation, i, &rom[i]);669 if (ret != RCODE_COMPLETE)670 goto out;671 end = i + (rom[i] >> 16) + 1;672 if (end > MAX_CONFIG_ROM_SIZE) {673 /*674 * This block extends outside the config ROM which is675 * a firmware bug. Ignore this whole block, i.e.676 * simply set a fake block length of 0.677 */678 fw_err(card, "skipped invalid ROM block %x at %llx\n",679 rom[i],680 i * 4 | CSR_REGISTER_BASE | CSR_CONFIG_ROM);681 rom[i] = 0;682 end = i;683 }684 i++;685 686 /*687 * Now read in the block. If this is a directory688 * block, check the entries as we read them to see if689 * it references another block, and push it in that case.690 */691 for (; i < end; i++) {692 ret = read_rom(device, generation, i, &rom[i]);693 if (ret != RCODE_COMPLETE)694 goto out;695 696 if ((key >> 30) != 3 || (rom[i] >> 30) < 2)697 continue;698 /*699 * Offset points outside the ROM. May be a firmware700 * bug or an Extended ROM entry (IEEE 1212-2001 clause701 * 7.7.18). Simply overwrite this pointer here by a702 * fake immediate entry so that later iterators over703 * the ROM don't have to check offsets all the time.704 */705 if (i + (rom[i] & 0xffffff) >= MAX_CONFIG_ROM_SIZE) {706 fw_err(card,707 "skipped unsupported ROM entry %x at %llx\n",708 rom[i],709 i * 4 | CSR_REGISTER_BASE | CSR_CONFIG_ROM);710 rom[i] = 0;711 continue;712 }713 stack[sp++] = i + rom[i];714 }715 if (length < i)716 length = i;717 }718 719 old_rom = device->config_rom;720 new_rom = kmemdup(rom, length * 4, GFP_KERNEL);721 if (new_rom == NULL) {722 ret = -ENOMEM;723 goto out;724 }725 726 scoped_guard(rwsem_write, &fw_device_rwsem) {727 device->config_rom = new_rom;728 device->config_rom_length = length;729 }730 731 kfree(old_rom);732 ret = RCODE_COMPLETE;733 device->max_rec = rom[2] >> 12 & 0xf;734 device->cmc = rom[2] >> 30 & 1;735 device->irmc = rom[2] >> 31 & 1;736 out:737 kfree(rom);738 739 return ret;740}741 742static void fw_unit_release(struct device *dev)743{744 struct fw_unit *unit = fw_unit(dev);745 746 fw_device_put(fw_parent_device(unit));747 kfree(unit);748}749 750static struct device_type fw_unit_type = {751 .uevent = fw_unit_uevent,752 .release = fw_unit_release,753};754 755static bool is_fw_unit(const struct device *dev)756{757 return dev->type == &fw_unit_type;758}759 760static void create_units(struct fw_device *device)761{762 struct fw_csr_iterator ci;763 struct fw_unit *unit;764 int key, value, i;765 766 i = 0;767 fw_csr_iterator_init(&ci, &device->config_rom[ROOT_DIR_OFFSET]);768 while (fw_csr_iterator_next(&ci, &key, &value)) {769 if (key != (CSR_UNIT | CSR_DIRECTORY))770 continue;771 772 /*773 * Get the address of the unit directory and try to774 * match the drivers id_tables against it.775 */776 unit = kzalloc(sizeof(*unit), GFP_KERNEL);777 if (unit == NULL)778 continue;779 780 unit->directory = ci.p + value - 1;781 unit->device.bus = &fw_bus_type;782 unit->device.type = &fw_unit_type;783 unit->device.parent = &device->device;784 dev_set_name(&unit->device, "%s.%d", dev_name(&device->device), i++);785 786 BUILD_BUG_ON(ARRAY_SIZE(unit->attribute_group.attrs) <787 ARRAY_SIZE(fw_unit_attributes) +788 ARRAY_SIZE(config_rom_attributes));789 init_fw_attribute_group(&unit->device,790 fw_unit_attributes,791 &unit->attribute_group);792 793 fw_device_get(device);794 if (device_register(&unit->device) < 0) {795 put_device(&unit->device);796 continue;797 }798 }799}800 801static int shutdown_unit(struct device *device, void *data)802{803 device_unregister(device);804 805 return 0;806}807 808/*809 * fw_device_rwsem acts as dual purpose mutex:810 * - serializes accesses to fw_device.config_rom/.config_rom_length and811 * fw_unit.directory, unless those accesses happen at safe occasions812 */813DECLARE_RWSEM(fw_device_rwsem);814 815DEFINE_XARRAY_ALLOC(fw_device_xa);816int fw_cdev_major;817 818struct fw_device *fw_device_get_by_devt(dev_t devt)819{820 struct fw_device *device;821 822 device = xa_load(&fw_device_xa, MINOR(devt));823 if (device)824 fw_device_get(device);825 826 return device;827}828 829struct workqueue_struct *fw_workqueue;830EXPORT_SYMBOL(fw_workqueue);831 832static void fw_schedule_device_work(struct fw_device *device,833 unsigned long delay)834{835 queue_delayed_work(fw_workqueue, &device->work, delay);836}837 838/*839 * These defines control the retry behavior for reading the config840 * rom. It shouldn't be necessary to tweak these; if the device841 * doesn't respond to a config rom read within 10 seconds, it's not842 * going to respond at all. As for the initial delay, a lot of843 * devices will be able to respond within half a second after bus844 * reset. On the other hand, it's not really worth being more845 * aggressive than that, since it scales pretty well; if 10 devices846 * are plugged in, they're all getting read within one second.847 */848 849#define MAX_RETRIES 10850#define RETRY_DELAY (3 * HZ)851#define INITIAL_DELAY (HZ / 2)852#define SHUTDOWN_DELAY (2 * HZ)853 854static void fw_device_shutdown(struct work_struct *work)855{856 struct fw_device *device =857 container_of(work, struct fw_device, work.work);858 859 if (time_before64(get_jiffies_64(),860 device->card->reset_jiffies + SHUTDOWN_DELAY)861 && !list_empty(&device->card->link)) {862 fw_schedule_device_work(device, SHUTDOWN_DELAY);863 return;864 }865 866 if (atomic_cmpxchg(&device->state,867 FW_DEVICE_GONE,868 FW_DEVICE_SHUTDOWN) != FW_DEVICE_GONE)869 return;870 871 fw_device_cdev_remove(device);872 device_for_each_child(&device->device, NULL, shutdown_unit);873 device_unregister(&device->device);874 875 xa_erase(&fw_device_xa, MINOR(device->device.devt));876 877 fw_device_put(device);878}879 880static void fw_device_release(struct device *dev)881{882 struct fw_device *device = fw_device(dev);883 struct fw_card *card = device->card;884 885 /*886 * Take the card lock so we don't set this to NULL while a887 * FW_NODE_UPDATED callback is being handled or while the888 * bus manager work looks at this node.889 */890 scoped_guard(spinlock_irqsave, &card->lock)891 device->node->data = NULL;892 893 fw_node_put(device->node);894 kfree(device->config_rom);895 kfree(device);896 fw_card_put(card);897}898 899static struct device_type fw_device_type = {900 .release = fw_device_release,901};902 903static bool is_fw_device(const struct device *dev)904{905 return dev->type == &fw_device_type;906}907 908static int update_unit(struct device *dev, void *data)909{910 struct fw_unit *unit = fw_unit(dev);911 struct fw_driver *driver = (struct fw_driver *)dev->driver;912 913 if (is_fw_unit(dev) && driver != NULL && driver->update != NULL) {914 device_lock(dev);915 driver->update(unit);916 device_unlock(dev);917 }918 919 return 0;920}921 922static void fw_device_update(struct work_struct *work)923{924 struct fw_device *device =925 container_of(work, struct fw_device, work.work);926 927 fw_device_cdev_update(device);928 device_for_each_child(&device->device, NULL, update_unit);929}930 931enum { BC_UNKNOWN = 0, BC_UNIMPLEMENTED, BC_IMPLEMENTED, };932 933static void set_broadcast_channel(struct fw_device *device, int generation)934{935 struct fw_card *card = device->card;936 __be32 data;937 int rcode;938 939 if (!card->broadcast_channel_allocated)940 return;941 942 /*943 * The Broadcast_Channel Valid bit is required by nodes which want to944 * transmit on this channel. Such transmissions are practically945 * exclusive to IP over 1394 (RFC 2734). IP capable nodes are required946 * to be IRM capable and have a max_rec of 8 or more. We use this fact947 * to narrow down to which nodes we send Broadcast_Channel updates.948 */949 if (!device->irmc || device->max_rec < 8)950 return;951 952 /*953 * Some 1394-1995 nodes crash if this 1394a-2000 register is written.954 * Perform a read test first.955 */956 if (device->bc_implemented == BC_UNKNOWN) {957 rcode = fw_run_transaction(card, TCODE_READ_QUADLET_REQUEST,958 device->node_id, generation, device->max_speed,959 CSR_REGISTER_BASE + CSR_BROADCAST_CHANNEL,960 &data, 4);961 switch (rcode) {962 case RCODE_COMPLETE:963 if (data & cpu_to_be32(1 << 31)) {964 device->bc_implemented = BC_IMPLEMENTED;965 break;966 }967 fallthrough; /* to case address error */968 case RCODE_ADDRESS_ERROR:969 device->bc_implemented = BC_UNIMPLEMENTED;970 }971 }972 973 if (device->bc_implemented == BC_IMPLEMENTED) {974 data = cpu_to_be32(BROADCAST_CHANNEL_INITIAL |975 BROADCAST_CHANNEL_VALID);976 fw_run_transaction(card, TCODE_WRITE_QUADLET_REQUEST,977 device->node_id, generation, device->max_speed,978 CSR_REGISTER_BASE + CSR_BROADCAST_CHANNEL,979 &data, 4);980 }981}982 983int fw_device_set_broadcast_channel(struct device *dev, void *gen)984{985 if (is_fw_device(dev))986 set_broadcast_channel(fw_device(dev), (long)gen);987 988 return 0;989}990 991static int compare_configuration_rom(struct device *dev, void *data)992{993 const struct fw_device *old = fw_device(dev);994 const u32 *config_rom = data;995 996 if (!is_fw_device(dev))997 return 0;998 999 // Compare the bus information block and root_length/root_crc.1000 return !memcmp(old->config_rom, config_rom, 6 * 4);1001}1002 1003static void fw_device_init(struct work_struct *work)1004{1005 struct fw_device *device =1006 container_of(work, struct fw_device, work.work);1007 struct fw_card *card = device->card;1008 struct device *found;1009 u32 minor;1010 int ret;1011 1012 /*1013 * All failure paths here set node->data to NULL, so that we1014 * don't try to do device_for_each_child() on a kfree()'d1015 * device.1016 */1017 1018 ret = read_config_rom(device, device->generation);1019 if (ret != RCODE_COMPLETE) {1020 if (device->config_rom_retries < MAX_RETRIES &&1021 atomic_read(&device->state) == FW_DEVICE_INITIALIZING) {1022 device->config_rom_retries++;1023 fw_schedule_device_work(device, RETRY_DELAY);1024 } else {1025 if (device->node->link_on)1026 fw_notice(card, "giving up on node %x: reading config rom failed: %s\n",1027 device->node_id,1028 fw_rcode_string(ret));1029 if (device->node == card->root_node)1030 fw_schedule_bm_work(card, 0);1031 fw_device_release(&device->device);1032 }1033 return;1034 }1035 1036 // If a device was pending for deletion because its node went away but its bus info block1037 // and root directory header matches that of a newly discovered device, revive the1038 // existing fw_device. The newly allocated fw_device becomes obsolete instead.1039 //1040 // serialize config_rom access.1041 scoped_guard(rwsem_read, &fw_device_rwsem) {1042 found = device_find_child(card->device, (void *)device->config_rom,1043 compare_configuration_rom);1044 }1045 if (found) {1046 struct fw_device *reused = fw_device(found);1047 1048 if (atomic_cmpxchg(&reused->state,1049 FW_DEVICE_GONE,1050 FW_DEVICE_RUNNING) == FW_DEVICE_GONE) {1051 // serialize node access1052 scoped_guard(spinlock_irq, &card->lock) {1053 struct fw_node *current_node = device->node;1054 struct fw_node *obsolete_node = reused->node;1055 1056 device->node = obsolete_node;1057 device->node->data = device;1058 reused->node = current_node;1059 reused->node->data = reused;1060 1061 reused->max_speed = device->max_speed;1062 reused->node_id = current_node->node_id;1063 smp_wmb(); /* update node_id before generation */1064 reused->generation = card->generation;1065 reused->config_rom_retries = 0;1066 fw_notice(card, "rediscovered device %s\n",1067 dev_name(found));1068 1069 reused->workfn = fw_device_update;1070 fw_schedule_device_work(reused, 0);1071 1072 if (current_node == card->root_node)1073 fw_schedule_bm_work(card, 0);1074 }1075 1076 put_device(found);1077 fw_device_release(&device->device);1078 1079 return;1080 }1081 1082 put_device(found);1083 }1084 1085 device_initialize(&device->device);1086 1087 fw_device_get(device);1088 1089 // The index of allocated entry is used for minor identifier of device node.1090 ret = xa_alloc(&fw_device_xa, &minor, device, XA_LIMIT(0, MINORMASK), GFP_KERNEL);1091 if (ret < 0)1092 goto error;1093 1094 device->device.bus = &fw_bus_type;1095 device->device.type = &fw_device_type;1096 device->device.parent = card->device;1097 device->device.devt = MKDEV(fw_cdev_major, minor);1098 dev_set_name(&device->device, "fw%d", minor);1099 1100 BUILD_BUG_ON(ARRAY_SIZE(device->attribute_group.attrs) <1101 ARRAY_SIZE(fw_device_attributes) +1102 ARRAY_SIZE(config_rom_attributes));1103 init_fw_attribute_group(&device->device,1104 fw_device_attributes,1105 &device->attribute_group);1106 1107 if (device_add(&device->device)) {1108 fw_err(card, "failed to add device\n");1109 goto error_with_cdev;1110 }1111 1112 create_units(device);1113 1114 /*1115 * Transition the device to running state. If it got pulled1116 * out from under us while we did the initialization work, we1117 * have to shut down the device again here. Normally, though,1118 * fw_node_event will be responsible for shutting it down when1119 * necessary. We have to use the atomic cmpxchg here to avoid1120 * racing with the FW_NODE_DESTROYED case in1121 * fw_node_event().1122 */1123 if (atomic_cmpxchg(&device->state,1124 FW_DEVICE_INITIALIZING,1125 FW_DEVICE_RUNNING) == FW_DEVICE_GONE) {1126 device->workfn = fw_device_shutdown;1127 fw_schedule_device_work(device, SHUTDOWN_DELAY);1128 } else {1129 fw_notice(card, "created device %s: GUID %08x%08x, S%d00\n",1130 dev_name(&device->device),1131 device->config_rom[3], device->config_rom[4],1132 1 << device->max_speed);1133 device->config_rom_retries = 0;1134 1135 set_broadcast_channel(device, device->generation);1136 1137 add_device_randomness(&device->config_rom[3], 8);1138 }1139 1140 /*1141 * Reschedule the IRM work if we just finished reading the1142 * root node config rom. If this races with a bus reset we1143 * just end up running the IRM work a couple of extra times -1144 * pretty harmless.1145 */1146 if (device->node == card->root_node)1147 fw_schedule_bm_work(card, 0);1148 1149 return;1150 1151 error_with_cdev:1152 xa_erase(&fw_device_xa, minor);1153 error:1154 fw_device_put(device); // fw_device_xa's reference.1155 1156 put_device(&device->device); /* our reference */1157}1158 1159/* Reread and compare bus info block and header of root directory */1160static int reread_config_rom(struct fw_device *device, int generation,1161 bool *changed)1162{1163 u32 q;1164 int i, rcode;1165 1166 for (i = 0; i < 6; i++) {1167 rcode = read_rom(device, generation, i, &q);1168 if (rcode != RCODE_COMPLETE)1169 return rcode;1170 1171 if (i == 0 && q == 0)1172 /* inaccessible (see read_config_rom); retry later */1173 return RCODE_BUSY;1174 1175 if (q != device->config_rom[i]) {1176 *changed = true;1177 return RCODE_COMPLETE;1178 }1179 }1180 1181 *changed = false;1182 return RCODE_COMPLETE;1183}1184 1185static void fw_device_refresh(struct work_struct *work)1186{1187 struct fw_device *device =1188 container_of(work, struct fw_device, work.work);1189 struct fw_card *card = device->card;1190 int ret, node_id = device->node_id;1191 bool changed;1192 1193 ret = reread_config_rom(device, device->generation, &changed);1194 if (ret != RCODE_COMPLETE)1195 goto failed_config_rom;1196 1197 if (!changed) {1198 if (atomic_cmpxchg(&device->state,1199 FW_DEVICE_INITIALIZING,1200 FW_DEVICE_RUNNING) == FW_DEVICE_GONE)1201 goto gone;1202 1203 fw_device_update(work);1204 device->config_rom_retries = 0;1205 goto out;1206 }1207 1208 /*1209 * Something changed. We keep things simple and don't investigate1210 * further. We just destroy all previous units and create new ones.1211 */1212 device_for_each_child(&device->device, NULL, shutdown_unit);1213 1214 ret = read_config_rom(device, device->generation);1215 if (ret != RCODE_COMPLETE)1216 goto failed_config_rom;1217 1218 fw_device_cdev_update(device);1219 create_units(device);1220 1221 /* Userspace may want to re-read attributes. */1222 kobject_uevent(&device->device.kobj, KOBJ_CHANGE);1223 1224 if (atomic_cmpxchg(&device->state,1225 FW_DEVICE_INITIALIZING,1226 FW_DEVICE_RUNNING) == FW_DEVICE_GONE)1227 goto gone;1228 1229 fw_notice(card, "refreshed device %s\n", dev_name(&device->device));1230 device->config_rom_retries = 0;1231 goto out;1232 1233 failed_config_rom:1234 if (device->config_rom_retries < MAX_RETRIES &&1235 atomic_read(&device->state) == FW_DEVICE_INITIALIZING) {1236 device->config_rom_retries++;1237 fw_schedule_device_work(device, RETRY_DELAY);1238 return;1239 }1240 1241 fw_notice(card, "giving up on refresh of device %s: %s\n",1242 dev_name(&device->device), fw_rcode_string(ret));1243 gone:1244 atomic_set(&device->state, FW_DEVICE_GONE);1245 device->workfn = fw_device_shutdown;1246 fw_schedule_device_work(device, SHUTDOWN_DELAY);1247 out:1248 if (node_id == card->root_node->node_id)1249 fw_schedule_bm_work(card, 0);1250}1251 1252static void fw_device_workfn(struct work_struct *work)1253{1254 struct fw_device *device = container_of(to_delayed_work(work),1255 struct fw_device, work);1256 device->workfn(work);1257}1258 1259void fw_node_event(struct fw_card *card, struct fw_node *node, int event)1260{1261 struct fw_device *device;1262 1263 switch (event) {1264 case FW_NODE_CREATED:1265 /*1266 * Attempt to scan the node, regardless whether its self ID has1267 * the L (link active) flag set or not. Some broken devices1268 * send L=0 but have an up-and-running link; others send L=11269 * without actually having a link.1270 */1271 create:1272 device = kzalloc(sizeof(*device), GFP_ATOMIC);1273 if (device == NULL)1274 break;1275 1276 /*1277 * Do minimal initialization of the device here, the1278 * rest will happen in fw_device_init().1279 *1280 * Attention: A lot of things, even fw_device_get(),1281 * cannot be done before fw_device_init() finished!1282 * You can basically just check device->state and1283 * schedule work until then, but only while holding1284 * card->lock.1285 */1286 atomic_set(&device->state, FW_DEVICE_INITIALIZING);1287 device->card = fw_card_get(card);1288 device->node = fw_node_get(node);1289 device->node_id = node->node_id;1290 device->generation = card->generation;1291 device->is_local = node == card->local_node;1292 mutex_init(&device->client_list_mutex);1293 INIT_LIST_HEAD(&device->client_list);1294 1295 /*1296 * Set the node data to point back to this device so1297 * FW_NODE_UPDATED callbacks can update the node_id1298 * and generation for the device.1299 */1300 node->data = device;1301 1302 /*1303 * Many devices are slow to respond after bus resets,1304 * especially if they are bus powered and go through1305 * power-up after getting plugged in. We schedule the1306 * first config rom scan half a second after bus reset.1307 */1308 device->workfn = fw_device_init;1309 INIT_DELAYED_WORK(&device->work, fw_device_workfn);1310 fw_schedule_device_work(device, INITIAL_DELAY);1311 break;1312 1313 case FW_NODE_INITIATED_RESET:1314 case FW_NODE_LINK_ON:1315 device = node->data;1316 if (device == NULL)1317 goto create;1318 1319 device->node_id = node->node_id;1320 smp_wmb(); /* update node_id before generation */1321 device->generation = card->generation;1322 if (atomic_cmpxchg(&device->state,1323 FW_DEVICE_RUNNING,1324 FW_DEVICE_INITIALIZING) == FW_DEVICE_RUNNING) {1325 device->workfn = fw_device_refresh;1326 fw_schedule_device_work(device,1327 device->is_local ? 0 : INITIAL_DELAY);1328 }1329 break;1330 1331 case FW_NODE_UPDATED:1332 device = node->data;1333 if (device == NULL)1334 break;1335 1336 device->node_id = node->node_id;1337 smp_wmb(); /* update node_id before generation */1338 device->generation = card->generation;1339 if (atomic_read(&device->state) == FW_DEVICE_RUNNING) {1340 device->workfn = fw_device_update;1341 fw_schedule_device_work(device, 0);1342 }1343 break;1344 1345 case FW_NODE_DESTROYED:1346 case FW_NODE_LINK_OFF:1347 if (!node->data)1348 break;1349 1350 /*1351 * Destroy the device associated with the node. There1352 * are two cases here: either the device is fully1353 * initialized (FW_DEVICE_RUNNING) or we're in the1354 * process of reading its config rom1355 * (FW_DEVICE_INITIALIZING). If it is fully1356 * initialized we can reuse device->work to schedule a1357 * full fw_device_shutdown(). If not, there's work1358 * scheduled to read it's config rom, and we just put1359 * the device in shutdown state to have that code fail1360 * to create the device.1361 */1362 device = node->data;1363 if (atomic_xchg(&device->state,1364 FW_DEVICE_GONE) == FW_DEVICE_RUNNING) {1365 device->workfn = fw_device_shutdown;1366 fw_schedule_device_work(device,1367 list_empty(&card->link) ? 0 : SHUTDOWN_DELAY);1368 }1369 break;1370 }1371}1372 1373#ifdef CONFIG_FIREWIRE_KUNIT_DEVICE_ATTRIBUTE_TEST1374#include "device-attribute-test.c"1375#endif1376