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