drivers/firewire/core-card.c

   1 /*
   2  * Copyright (C) 2005-2007  Kristian Hoegsberg <krh@bitplanet.net>
   3  *
   4  * This program is free software; you can redistribute it and/or modify
   5  * it under the terms of the GNU General Public License as published by
   6  * the Free Software Foundation; either version 2 of the License, or
   7  * (at your option) any later version.
   8  *
   9  * This program is distributed in the hope that it will be useful,
  10  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  12  * GNU General Public License for more details.
  13  *
  14  * You should have received a copy of the GNU General Public License
  15  * along with this program; if not, write to the Free Software Foundation,
  16  * Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
  17  */
  18
  19 #include <linux/bug.h>
  20 #include <linux/completion.h>
  21 #include <linux/crc-itu-t.h>
  22 #include <linux/device.h>
  23 #include <linux/errno.h>
  24 #include <linux/firewire.h>
  25 #include <linux/firewire-constants.h>
  26 #include <linux/jiffies.h>
  27 #include <linux/kernel.h>
  28 #include <linux/kref.h>
  29 #include <linux/list.h>
  30 #include <linux/module.h>
  31 #include <linux/mutex.h>
  32 #include <linux/spinlock.h>
  33 #include <linux/timer.h>
  34 #include <linux/workqueue.h>
  35
  36 #include <asm/atomic.h>
  37 #include <asm/byteorder.h>
  38
  39 #include "core.h"
  40
  41 int fw_compute_block_crc(__be32 *block)
  42 {
  43         int length;
  44         u16 crc;
  45
  46         length = (be32_to_cpu(block[0]) >> 16) & 0xff;
  47         crc = crc_itu_t(0, (u8 *)&block[1], length * 4);
  48         *block |= cpu_to_be32(crc);
  49
  50         return length;
  51 }
  52
  53 static DEFINE_MUTEX(card_mutex);
  54 static LIST_HEAD(card_list);
  55
  56 static LIST_HEAD(descriptor_list);
  57 static int descriptor_count;
  58
  59 static __be32 tmp_config_rom[256];
  60 /* ROM header, bus info block, root dir header, capabilities = 7 quadlets */
  61 static size_t config_rom_length = 1 + 4 + 1 + 1;
  62
  63 #define BIB_CRC(v)              ((v) <<  0)
  64 #define BIB_CRC_LENGTH(v)       ((v) << 16)
  65 #define BIB_INFO_LENGTH(v)      ((v) << 24)
  66
  67 #define BIB_LINK_SPEED(v)       ((v) <<  0)
  68 #define BIB_GENERATION(v)       ((v) <<  4)
  69 #define BIB_MAX_ROM(v)          ((v) <<  8)
  70 #define BIB_MAX_RECEIVE(v)      ((v) << 12)
  71 #define BIB_CYC_CLK_ACC(v)      ((v) << 16)
  72 #define BIB_PMC                 ((1) << 27)
  73 #define BIB_BMC                 ((1) << 28)
  74 #define BIB_ISC                 ((1) << 29)
  75 #define BIB_CMC                 ((1) << 30)
  76 #define BIB_IMC                 ((1) << 31)
  77
  78 #define CANON_OUI               0x000085
  79
  80 static void generate_config_rom(struct fw_card *card, __be32 *config_rom)
  81 {
  82         struct fw_descriptor *desc;
  83         int i, j, k, length;
  84
  85         /*
  86          * Initialize contents of config rom buffer.  On the OHCI
  87          * controller, block reads to the config rom accesses the host
  88          * memory, but quadlet read access the hardware bus info block
  89          * registers.  That's just crack, but it means we should make
  90          * sure the contents of bus info block in host memory matches
  91          * the version stored in the OHCI registers.
  92          */
  93
  94         config_rom[0] = cpu_to_be32(
  95                 BIB_CRC_LENGTH(4) | BIB_INFO_LENGTH(4) | BIB_CRC(0));
  96         config_rom[1] = cpu_to_be32(0x31333934);
  97         config_rom[2] = cpu_to_be32(
  98                 BIB_LINK_SPEED(card->link_speed) |
  99                 BIB_GENERATION(card->config_rom_generation++ % 14 + 2) |
 100                 BIB_MAX_ROM(2) |
 101                 BIB_MAX_RECEIVE(card->max_receive) |
 102                 BIB_BMC | BIB_ISC | BIB_CMC | BIB_IMC);
 103         config_rom[3] = cpu_to_be32(card->guid >> 32);
 104         config_rom[4] = cpu_to_be32(card->guid);
 105
 106         /* Generate root directory. */
 107         config_rom[6] = cpu_to_be32(0x0c0083c0); /* node capabilities */
 108         i = 7;
 109         j = 7 + descriptor_count;
 110
 111         /* Generate root directory entries for descriptors. */
 112         list_for_each_entry (desc, &descriptor_list, link) {
 113                 if (desc->immediate > 0)
 114                         config_rom[i++] = cpu_to_be32(desc->immediate);
 115                 config_rom[i] = cpu_to_be32(desc->key | (j - i));
 116                 i++;
 117                 j += desc->length;
 118         }
 119
 120         /* Update root directory length. */
 121         config_rom[5] = cpu_to_be32((i - 5 - 1) << 16);
 122
 123         /* End of root directory, now copy in descriptors. */
 124         list_for_each_entry (desc, &descriptor_list, link) {
 125                 for (k = 0; k < desc->length; k++)
 126                         config_rom[i + k] = cpu_to_be32(desc->data[k]);
 127                 i += desc->length;
 128         }
 129
 130         /* Calculate CRCs for all blocks in the config rom.  This
 131          * assumes that CRC length and info length are identical for
 132          * the bus info block, which is always the case for this
 133          * implementation. */
 134         for (i = 0; i < j; i += length + 1)
 135                 length = fw_compute_block_crc(config_rom + i);
 136
 137         WARN_ON(j != config_rom_length);
 138 }
 139
 140 static void update_config_roms(void)
 141 {
 142         struct fw_card *card;
 143
 144         list_for_each_entry (card, &card_list, link) {
 145                 generate_config_rom(card, tmp_config_rom);
 146                 card->driver->set_config_rom(card, tmp_config_rom,
 147                                              config_rom_length);
 148         }
 149 }
 150
 151 static size_t required_space(struct fw_descriptor *desc)
 152 {
 153         /* descriptor + entry into root dir + optional immediate entry */
 154         return desc->length + 1 + (desc->immediate > 0 ? 1 : 0);
 155 }
 156
 157 int fw_core_add_descriptor(struct fw_descriptor *desc)
 158 {
 159         size_t i;
 160         int ret;
 161
 162         /*
 163          * Check descriptor is valid; the length of all blocks in the
 164          * descriptor has to add up to exactly the length of the
 165          * block.
 166          */
 167         i = 0;
 168         while (i < desc->length)
 169                 i += (desc->data[i] >> 16) + 1;
 170
 171         if (i != desc->length)
 172                 return -EINVAL;
 173
 174         mutex_lock(&card_mutex);
 175
 176         if (config_rom_length + required_space(desc) > 256) {
 177                 ret = -EBUSY;
 178         } else {
 179                 list_add_tail(&desc->link, &descriptor_list);
 180                 config_rom_length += required_space(desc);
 181                 descriptor_count++;
 182                 if (desc->immediate > 0)
 183                         descriptor_count++;
 184                 update_config_roms();
 185                 ret = 0;
 186         }
 187
 188         mutex_unlock(&card_mutex);
 189
 190         return ret;
 191 }
 192 EXPORT_SYMBOL(fw_core_add_descriptor);
 193
 194 void fw_core_remove_descriptor(struct fw_descriptor *desc)
 195 {
 196         mutex_lock(&card_mutex);
 197
 198         list_del(&desc->link);
 199         config_rom_length -= required_space(desc);
 200         descriptor_count--;
 201         if (desc->immediate > 0)
 202                 descriptor_count--;
 203         update_config_roms();
 204
 205         mutex_unlock(&card_mutex);
 206 }
 207 EXPORT_SYMBOL(fw_core_remove_descriptor);
 208
 209 static void allocate_broadcast_channel(struct fw_card *card, int generation)
 210 {
 211         int channel, bandwidth = 0;
 212
 213         fw_iso_resource_manage(card, generation, 1ULL << 31, &channel,
 214                                &bandwidth, true, card->bm_transaction_data);
 215         if (channel == 31) {
 216                 card->broadcast_channel_allocated = true;
 217                 device_for_each_child(card->device, (void *)(long)generation,
 218                                       fw_device_set_broadcast_channel);
 219         }
 220 }
 221
 222 static const char gap_count_table[] = {
 223         63, 5, 7, 8, 10, 13, 16, 18, 21, 24, 26, 29, 32, 35, 37, 40
 224 };
 225
 226 void fw_schedule_bm_work(struct fw_card *card, unsigned long delay)
 227 {
 228         fw_card_get(card);
 229         if (!schedule_delayed_work(&card->work, delay))
 230                 fw_card_put(card);
 231 }
 232
 233 static void fw_card_bm_work(struct work_struct *work)
 234 {
 235         struct fw_card *card = container_of(work, struct fw_card, work.work);
 236         struct fw_device *root_device, *irm_device;
 237         struct fw_node *root_node;
 238         unsigned long flags;
 239         int root_id, new_root_id, irm_id, local_id;
 240         int gap_count, generation, grace, rcode;
 241         bool do_reset = false;
 242         bool root_device_is_running;
 243         bool root_device_is_cmc;
 244         bool irm_is_1394_1995_only;
 245         bool keep_this_irm;
 246
 247         spin_lock_irqsave(&card->lock, flags);
 248
 249         if (card->local_node == NULL) {
 250                 spin_unlock_irqrestore(&card->lock, flags);
 251                 goto out_put_card;
 252         }
 253
 254         generation = card->generation;
 255
 256         root_node = card->root_node;
 257         fw_node_get(root_node);
 258         root_device = root_node->data;
 259         root_device_is_running = root_device &&
 260                         atomic_read(&root_device->state) == FW_DEVICE_RUNNING;
 261         root_device_is_cmc = root_device && root_device->cmc;
 262
 263         irm_device = card->irm_node->data;
 264         irm_is_1394_1995_only = irm_device && irm_device->config_rom &&
 265                         (irm_device->config_rom[2] & 0x000000f0) == 0;
 266
 267         /* Canon MV5i works unreliably if it is not root node. */
 268         keep_this_irm = irm_device && irm_device->config_rom &&
 269                         irm_device->config_rom[3] >> 8 == CANON_OUI;
 270
 271         root_id  = root_node->node_id;
 272         irm_id   = card->irm_node->node_id;
 273         local_id = card->local_node->node_id;
 274
 275         grace = time_after(jiffies, card->reset_jiffies + DIV_ROUND_UP(HZ, 8));
 276
 277         if (is_next_generation(generation, card->bm_generation) ||
 278             (card->bm_generation != generation && grace)) {
 279                 /*
 280                  * This first step is to figure out who is IRM and
 281                  * then try to become bus manager.  If the IRM is not
 282                  * well defined (e.g. does not have an active link
 283                  * layer or does not responds to our lock request, we
 284                  * will have to do a little vigilante bus management.
 285                  * In that case, we do a goto into the gap count logic
 286                  * so that when we do the reset, we still optimize the
 287                  * gap count.  That could well save a reset in the
 288                  * next generation.
 289                  */
 290
 291                 if (!card->irm_node->link_on) {
 292                         new_root_id = local_id;
 293                         fw_notify("%s, making local node (%02x) root.\n",
 294                                   "IRM has link off", new_root_id);
 295                         goto pick_me;
 296                 }
 297
 298                 if (irm_is_1394_1995_only && !keep_this_irm) {
 299                         new_root_id = local_id;
 300                         fw_notify("%s, making local node (%02x) root.\n",
 301                                   "IRM is not 1394a compliant", new_root_id);
 302                         goto pick_me;
 303                 }
 304
 305                 card->bm_transaction_data[0] = cpu_to_be32(0x3f);
 306                 card->bm_transaction_data[1] = cpu_to_be32(local_id);
 307
 308                 spin_unlock_irqrestore(&card->lock, flags);
 309
 310                 rcode = fw_run_transaction(card, TCODE_LOCK_COMPARE_SWAP,
 311                                 irm_id, generation, SCODE_100,
 312                                 CSR_REGISTER_BASE + CSR_BUS_MANAGER_ID,
 313                                 card->bm_transaction_data,
 314                                 sizeof(card->bm_transaction_data));
 315
 316                 if (rcode == RCODE_GENERATION)
 317                         /* Another bus reset, BM work has been rescheduled. */
 318                         goto out;
 319
 320                 if (rcode == RCODE_COMPLETE &&
 321                     card->bm_transaction_data[0] != cpu_to_be32(0x3f)) {
 322
 323                         /* Somebody else is BM.  Only act as IRM. */
 324                         if (local_id == irm_id)
 325                                 allocate_broadcast_channel(card, generation);
 326
 327                         goto out;
 328                 }
 329
 330                 spin_lock_irqsave(&card->lock, flags);
 331
 332                 if (rcode != RCODE_COMPLETE && !keep_this_irm) {
 333                         /*
 334                          * The lock request failed, maybe the IRM
 335                          * isn't really IRM capable after all. Let's
 336                          * do a bus reset and pick the local node as
 337                          * root, and thus, IRM.
 338                          */
 339                         new_root_id = local_id;
 340                         fw_notify("%s, making local node (%02x) root.\n",
 341                                   "BM lock failed", new_root_id);
 342                         goto pick_me;
 343                 }
 344         } else if (card->bm_generation != generation) {
 345                 /*
 346                  * We weren't BM in the last generation, and the last
 347                  * bus reset is less than 125ms ago.  Reschedule this job.
 348                  */
 349                 spin_unlock_irqrestore(&card->lock, flags);
 350                 fw_schedule_bm_work(card, DIV_ROUND_UP(HZ, 8));
 351                 goto out;
 352         }
 353
 354         /*
 355          * We're bus manager for this generation, so next step is to
 356          * make sure we have an active cycle master and do gap count
 357          * optimization.
 358          */
 359         card->bm_generation = generation;
 360
 361         if (root_device == NULL) {
 362                 /*
 363                  * Either link_on is false, or we failed to read the
 364                  * config rom.  In either case, pick another root.
 365                  */
 366                 new_root_id = local_id;
 367         } else if (!root_device_is_running) {
 368                 /*
 369                  * If we haven't probed this device yet, bail out now
 370                  * and let's try again once that's done.
 371                  */
 372                 spin_unlock_irqrestore(&card->lock, flags);
 373                 goto out;
 374         } else if (root_device_is_cmc) {
 375                 /*
 376                  * FIXME: I suppose we should set the cmstr bit in the
 377                  * STATE_CLEAR register of this node, as described in
 378                  * 1394-1995, 8.4.2.6.  Also, send out a force root
 379                  * packet for this node.
 380                  */
 381                 new_root_id = root_id;
 382         } else {
 383                 /*
 384                  * Current root has an active link layer and we
 385                  * successfully read the config rom, but it's not
 386                  * cycle master capable.
 387                  */
 388                 new_root_id = local_id;
 389         }
 390
 391  pick_me:
 392         /*
 393          * Pick a gap count from 1394a table E-1.  The table doesn't cover
 394          * the typically much larger 1394b beta repeater delays though.
 395          */
 396         if (!card->beta_repeaters_present &&
 397             root_node->max_hops < ARRAY_SIZE(gap_count_table))
 398                 gap_count = gap_count_table[root_node->max_hops];
 399         else
 400                 gap_count = 63;
 401
 402         /*
 403          * Finally, figure out if we should do a reset or not.  If we have
 404          * done less than 5 resets with the same physical topology and we
 405          * have either a new root or a new gap count setting, let's do it.
 406          */
 407
 408         if (card->bm_retries++ < 5 &&
 409             (card->gap_count != gap_count || new_root_id != root_id))
 410                 do_reset = true;
 411
 412         spin_unlock_irqrestore(&card->lock, flags);
 413
 414         if (do_reset) {
 415                 fw_notify("phy config: card %d, new root=%x, gap_count=%d\n",
 416                           card->index, new_root_id, gap_count);
 417                 fw_send_phy_config(card, new_root_id, generation, gap_count);
 418                 fw_core_initiate_bus_reset(card, 1);
 419                 /* Will allocate broadcast channel after the reset. */
 420         } else {
 421                 if (local_id == irm_id)
 422                         allocate_broadcast_channel(card, generation);
 423         }
 424
 425  out:
 426         fw_node_put(root_node);
 427  out_put_card:
 428         fw_card_put(card);
 429 }
 430
 431 static void flush_timer_callback(unsigned long data)
 432 {
 433         struct fw_card *card = (struct fw_card *)data;
 434
 435         fw_flush_transactions(card);
 436 }
 437
 438 void fw_card_initialize(struct fw_card *card,
 439                         const struct fw_card_driver *driver,
 440                         struct device *device)
 441 {
 442         static atomic_t index = ATOMIC_INIT(-1);
 443
 444         card->index = atomic_inc_return(&index);
 445         card->driver = driver;
 446         card->device = device;
 447         card->current_tlabel = 0;
 448         card->tlabel_mask = 0;
 449         card->color = 0;
 450         card->broadcast_channel = BROADCAST_CHANNEL_INITIAL;
 451
 452         kref_init(&card->kref);
 453         init_completion(&card->done);
 454         INIT_LIST_HEAD(&card->transaction_list);
 455         spin_lock_init(&card->lock);
 456         setup_timer(&card->flush_timer,
 457                     flush_timer_callback, (unsigned long)card);
 458
 459         card->local_node = NULL;
 460
 461         INIT_DELAYED_WORK(&card->work, fw_card_bm_work);
 462 }
 463 EXPORT_SYMBOL(fw_card_initialize);
 464
 465 int fw_card_add(struct fw_card *card,
 466                 u32 max_receive, u32 link_speed, u64 guid)
 467 {
 468         int ret;
 469
 470         card->max_receive = max_receive;
 471         card->link_speed = link_speed;
 472         card->guid = guid;
 473
 474         mutex_lock(&card_mutex);
 475
 476         generate_config_rom(card, tmp_config_rom);
 477         ret = card->driver->enable(card, tmp_config_rom, config_rom_length);
 478         if (ret == 0)
 479                 list_add_tail(&card->link, &card_list);
 480
 481         mutex_unlock(&card_mutex);
 482
 483         return ret;
 484 }
 485 EXPORT_SYMBOL(fw_card_add);
 486
 487
 488 /*
 489  * The next few functions implement a dummy driver that is used once a card
 490  * driver shuts down an fw_card.  This allows the driver to cleanly unload,
 491  * as all IO to the card will be handled (and failed) by the dummy driver
 492  * instead of calling into the module.  Only functions for iso context
 493  * shutdown still need to be provided by the card driver.
 494  */
 495
 496 static int dummy_enable(struct fw_card *card,
 497                         const __be32 *config_rom, size_t length)
 498 {
 499         BUG();
 500         return -1;
 501 }
 502
 503 static int dummy_update_phy_reg(struct fw_card *card, int address,
 504                                 int clear_bits, int set_bits)
 505 {
 506         return -ENODEV;
 507 }
 508
 509 static int dummy_set_config_rom(struct fw_card *card,
 510                                 const __be32 *config_rom, size_t length)
 511 {
 512         /*
 513          * We take the card out of card_list before setting the dummy
 514          * driver, so this should never get called.
 515          */
 516         BUG();
 517         return -1;
 518 }
 519
 520 static void dummy_send_request(struct fw_card *card, struct fw_packet *packet)
 521 {
 522         packet->callback(packet, card, -ENODEV);
 523 }
 524
 525 static void dummy_send_response(struct fw_card *card, struct fw_packet *packet)
 526 {
 527         packet->callback(packet, card, -ENODEV);
 528 }
 529
 530 static int dummy_cancel_packet(struct fw_card *card, struct fw_packet *packet)
 531 {
 532         return -ENOENT;
 533 }
 534
 535 static int dummy_enable_phys_dma(struct fw_card *card,
 536                                  int node_id, int generation)
 537 {
 538         return -ENODEV;
 539 }
 540
 541 static const struct fw_card_driver dummy_driver_template = {
 542         .enable          = dummy_enable,
 543         .update_phy_reg  = dummy_update_phy_reg,
 544         .set_config_rom  = dummy_set_config_rom,
 545         .send_request    = dummy_send_request,
 546         .cancel_packet   = dummy_cancel_packet,
 547         .send_response   = dummy_send_response,
 548         .enable_phys_dma = dummy_enable_phys_dma,
 549 };
 550
 551 void fw_card_release(struct kref *kref)
 552 {
 553         struct fw_card *card = container_of(kref, struct fw_card, kref);
 554
 555         complete(&card->done);
 556 }
 557
 558 void fw_core_remove_card(struct fw_card *card)
 559 {
 560         struct fw_card_driver dummy_driver = dummy_driver_template;
 561
 562         card->driver->update_phy_reg(card, 4,
 563                                      PHY_LINK_ACTIVE | PHY_CONTENDER, 0);
 564         fw_core_initiate_bus_reset(card, 1);
 565
 566         mutex_lock(&card_mutex);
 567         list_del_init(&card->link);
 568         mutex_unlock(&card_mutex);
 569
 570         /* Switch off most of the card driver interface. */
 571         dummy_driver.free_iso_context   = card->driver->free_iso_context;
 572         dummy_driver.stop_iso           = card->driver->stop_iso;
 573         card->driver = &dummy_driver;
 574
 575         fw_destroy_nodes(card);
 576
 577         /* Wait for all users, especially device workqueue jobs, to finish. */
 578         fw_card_put(card);
 579         wait_for_completion(&card->done);
 580
 581         WARN_ON(!list_empty(&card->transaction_list));
 582         del_timer_sync(&card->flush_timer);
 583 }
 584 EXPORT_SYMBOL(fw_core_remove_card);
 585
 586 int fw_core_initiate_bus_reset(struct fw_card *card, int short_reset)
 587 {
 588         int reg = short_reset ? 5 : 1;
 589         int bit = short_reset ? PHY_BUS_SHORT_RESET : PHY_BUS_RESET;
 590
 591         return card->driver->update_phy_reg(card, reg, 0, bit);
 592 }
 593 EXPORT_SYMBOL(fw_core_initiate_bus_reset);