linux/drivers/firewire/fw-card.c
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   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/completion.h>
  20#include <linux/crc-itu-t.h>
  21#include <linux/delay.h>
  22#include <linux/device.h>
  23#include <linux/errno.h>
  24#include <linux/kref.h>
  25#include <linux/module.h>
  26#include <linux/mutex.h>
  27
  28#include "fw-transaction.h"
  29#include "fw-topology.h"
  30#include "fw-device.h"
  31
  32int fw_compute_block_crc(u32 *block)
  33{
  34        __be32 be32_block[256];
  35        int i, length;
  36
  37        length = (*block >> 16) & 0xff;
  38        for (i = 0; i < length; i++)
  39                be32_block[i] = cpu_to_be32(block[i + 1]);
  40        *block |= crc_itu_t(0, (u8 *) be32_block, length * 4);
  41
  42        return length;
  43}
  44
  45static DEFINE_MUTEX(card_mutex);
  46static LIST_HEAD(card_list);
  47
  48static LIST_HEAD(descriptor_list);
  49static int descriptor_count;
  50
  51#define BIB_CRC(v)              ((v) <<  0)
  52#define BIB_CRC_LENGTH(v)       ((v) << 16)
  53#define BIB_INFO_LENGTH(v)      ((v) << 24)
  54
  55#define BIB_LINK_SPEED(v)       ((v) <<  0)
  56#define BIB_GENERATION(v)       ((v) <<  4)
  57#define BIB_MAX_ROM(v)          ((v) <<  8)
  58#define BIB_MAX_RECEIVE(v)      ((v) << 12)
  59#define BIB_CYC_CLK_ACC(v)      ((v) << 16)
  60#define BIB_PMC                 ((1) << 27)
  61#define BIB_BMC                 ((1) << 28)
  62#define BIB_ISC                 ((1) << 29)
  63#define BIB_CMC                 ((1) << 30)
  64#define BIB_IMC                 ((1) << 31)
  65
  66static u32 *
  67generate_config_rom(struct fw_card *card, size_t *config_rom_length)
  68{
  69        struct fw_descriptor *desc;
  70        static u32 config_rom[256];
  71        int i, j, length;
  72
  73        /*
  74         * Initialize contents of config rom buffer.  On the OHCI
  75         * controller, block reads to the config rom accesses the host
  76         * memory, but quadlet read access the hardware bus info block
  77         * registers.  That's just crack, but it means we should make
  78         * sure the contents of bus info block in host memory mathces
  79         * the version stored in the OHCI registers.
  80         */
  81
  82        memset(config_rom, 0, sizeof(config_rom));
  83        config_rom[0] = BIB_CRC_LENGTH(4) | BIB_INFO_LENGTH(4) | BIB_CRC(0);
  84        config_rom[1] = 0x31333934;
  85
  86        config_rom[2] =
  87                BIB_LINK_SPEED(card->link_speed) |
  88                BIB_GENERATION(card->config_rom_generation++ % 14 + 2) |
  89                BIB_MAX_ROM(2) |
  90                BIB_MAX_RECEIVE(card->max_receive) |
  91                BIB_BMC | BIB_ISC | BIB_CMC | BIB_IMC;
  92        config_rom[3] = card->guid >> 32;
  93        config_rom[4] = card->guid;
  94
  95        /* Generate root directory. */
  96        i = 5;
  97        config_rom[i++] = 0;
  98        config_rom[i++] = 0x0c0083c0; /* node capabilities */
  99        j = i + descriptor_count;
 100
 101        /* Generate root directory entries for descriptors. */
 102        list_for_each_entry (desc, &descriptor_list, link) {
 103                if (desc->immediate > 0)
 104                        config_rom[i++] = desc->immediate;
 105                config_rom[i] = desc->key | (j - i);
 106                i++;
 107                j += desc->length;
 108        }
 109
 110        /* Update root directory length. */
 111        config_rom[5] = (i - 5 - 1) << 16;
 112
 113        /* End of root directory, now copy in descriptors. */
 114        list_for_each_entry (desc, &descriptor_list, link) {
 115                memcpy(&config_rom[i], desc->data, desc->length * 4);
 116                i += desc->length;
 117        }
 118
 119        /* Calculate CRCs for all blocks in the config rom.  This
 120         * assumes that CRC length and info length are identical for
 121         * the bus info block, which is always the case for this
 122         * implementation. */
 123        for (i = 0; i < j; i += length + 1)
 124                length = fw_compute_block_crc(config_rom + i);
 125
 126        *config_rom_length = j;
 127
 128        return config_rom;
 129}
 130
 131static void
 132update_config_roms(void)
 133{
 134        struct fw_card *card;
 135        u32 *config_rom;
 136        size_t length;
 137
 138        list_for_each_entry (card, &card_list, link) {
 139                config_rom = generate_config_rom(card, &length);
 140                card->driver->set_config_rom(card, config_rom, length);
 141        }
 142}
 143
 144int
 145fw_core_add_descriptor(struct fw_descriptor *desc)
 146{
 147        size_t i;
 148
 149        /*
 150         * Check descriptor is valid; the length of all blocks in the
 151         * descriptor has to add up to exactly the length of the
 152         * block.
 153         */
 154        i = 0;
 155        while (i < desc->length)
 156                i += (desc->data[i] >> 16) + 1;
 157
 158        if (i != desc->length)
 159                return -EINVAL;
 160
 161        mutex_lock(&card_mutex);
 162
 163        list_add_tail(&desc->link, &descriptor_list);
 164        descriptor_count++;
 165        if (desc->immediate > 0)
 166                descriptor_count++;
 167        update_config_roms();
 168
 169        mutex_unlock(&card_mutex);
 170
 171        return 0;
 172}
 173
 174void
 175fw_core_remove_descriptor(struct fw_descriptor *desc)
 176{
 177        mutex_lock(&card_mutex);
 178
 179        list_del(&desc->link);
 180        descriptor_count--;
 181        if (desc->immediate > 0)
 182                descriptor_count--;
 183        update_config_roms();
 184
 185        mutex_unlock(&card_mutex);
 186}
 187
 188static const char gap_count_table[] = {
 189        63, 5, 7, 8, 10, 13, 16, 18, 21, 24, 26, 29, 32, 35, 37, 40
 190};
 191
 192static void
 193fw_card_bm_work(struct work_struct *work)
 194{
 195        struct fw_card *card = container_of(work, struct fw_card, work.work);
 196        struct fw_device *root_device;
 197        struct fw_node *root_node, *local_node;
 198        unsigned long flags;
 199        int root_id, new_root_id, irm_id, gap_count, generation, grace, rcode;
 200        bool do_reset = false;
 201        __be32 lock_data[2];
 202
 203        spin_lock_irqsave(&card->lock, flags);
 204        local_node = card->local_node;
 205        root_node  = card->root_node;
 206
 207        if (local_node == NULL) {
 208                spin_unlock_irqrestore(&card->lock, flags);
 209                return;
 210        }
 211        fw_node_get(local_node);
 212        fw_node_get(root_node);
 213
 214        generation = card->generation;
 215        root_device = root_node->data;
 216        if (root_device)
 217                fw_device_get(root_device);
 218        root_id = root_node->node_id;
 219        grace = time_after(jiffies, card->reset_jiffies + DIV_ROUND_UP(HZ, 10));
 220
 221        if (card->bm_generation + 1 == generation ||
 222            (card->bm_generation != generation && grace)) {
 223                /*
 224                 * This first step is to figure out who is IRM and
 225                 * then try to become bus manager.  If the IRM is not
 226                 * well defined (e.g. does not have an active link
 227                 * layer or does not responds to our lock request, we
 228                 * will have to do a little vigilante bus management.
 229                 * In that case, we do a goto into the gap count logic
 230                 * so that when we do the reset, we still optimize the
 231                 * gap count.  That could well save a reset in the
 232                 * next generation.
 233                 */
 234
 235                irm_id = card->irm_node->node_id;
 236                if (!card->irm_node->link_on) {
 237                        new_root_id = local_node->node_id;
 238                        fw_notify("IRM has link off, making local node (%02x) root.\n",
 239                                  new_root_id);
 240                        goto pick_me;
 241                }
 242
 243                lock_data[0] = cpu_to_be32(0x3f);
 244                lock_data[1] = cpu_to_be32(local_node->node_id);
 245
 246                spin_unlock_irqrestore(&card->lock, flags);
 247
 248                rcode = fw_run_transaction(card, TCODE_LOCK_COMPARE_SWAP,
 249                                irm_id, generation, SCODE_100,
 250                                CSR_REGISTER_BASE + CSR_BUS_MANAGER_ID,
 251                                lock_data, sizeof(lock_data));
 252
 253                if (rcode == RCODE_GENERATION)
 254                        /* Another bus reset, BM work has been rescheduled. */
 255                        goto out;
 256
 257                if (rcode == RCODE_COMPLETE &&
 258                    lock_data[0] != cpu_to_be32(0x3f))
 259                        /* Somebody else is BM, let them do the work. */
 260                        goto out;
 261
 262                spin_lock_irqsave(&card->lock, flags);
 263
 264                if (rcode != RCODE_COMPLETE) {
 265                        /*
 266                         * The lock request failed, maybe the IRM
 267                         * isn't really IRM capable after all. Let's
 268                         * do a bus reset and pick the local node as
 269                         * root, and thus, IRM.
 270                         */
 271                        new_root_id = local_node->node_id;
 272                        fw_notify("BM lock failed, making local node (%02x) root.\n",
 273                                  new_root_id);
 274                        goto pick_me;
 275                }
 276        } else if (card->bm_generation != generation) {
 277                /*
 278                 * OK, we weren't BM in the last generation, and it's
 279                 * less than 100ms since last bus reset. Reschedule
 280                 * this task 100ms from now.
 281                 */
 282                spin_unlock_irqrestore(&card->lock, flags);
 283                schedule_delayed_work(&card->work, DIV_ROUND_UP(HZ, 10));
 284                goto out;
 285        }
 286
 287        /*
 288         * We're bus manager for this generation, so next step is to
 289         * make sure we have an active cycle master and do gap count
 290         * optimization.
 291         */
 292        card->bm_generation = generation;
 293
 294        if (root_device == NULL) {
 295                /*
 296                 * Either link_on is false, or we failed to read the
 297                 * config rom.  In either case, pick another root.
 298                 */
 299                new_root_id = local_node->node_id;
 300        } else if (atomic_read(&root_device->state) != FW_DEVICE_RUNNING) {
 301                /*
 302                 * If we haven't probed this device yet, bail out now
 303                 * and let's try again once that's done.
 304                 */
 305                spin_unlock_irqrestore(&card->lock, flags);
 306                goto out;
 307        } else if (root_device->cmc) {
 308                /*
 309                 * FIXME: I suppose we should set the cmstr bit in the
 310                 * STATE_CLEAR register of this node, as described in
 311                 * 1394-1995, 8.4.2.6.  Also, send out a force root
 312                 * packet for this node.
 313                 */
 314                new_root_id = root_id;
 315        } else {
 316                /*
 317                 * Current root has an active link layer and we
 318                 * successfully read the config rom, but it's not
 319                 * cycle master capable.
 320                 */
 321                new_root_id = local_node->node_id;
 322        }
 323
 324 pick_me:
 325        /*
 326         * Pick a gap count from 1394a table E-1.  The table doesn't cover
 327         * the typically much larger 1394b beta repeater delays though.
 328         */
 329        if (!card->beta_repeaters_present &&
 330            root_node->max_hops < ARRAY_SIZE(gap_count_table))
 331                gap_count = gap_count_table[root_node->max_hops];
 332        else
 333                gap_count = 63;
 334
 335        /*
 336         * Finally, figure out if we should do a reset or not.  If we have
 337         * done less than 5 resets with the same physical topology and we
 338         * have either a new root or a new gap count setting, let's do it.
 339         */
 340
 341        if (card->bm_retries++ < 5 &&
 342            (card->gap_count != gap_count || new_root_id != root_id))
 343                do_reset = true;
 344
 345        spin_unlock_irqrestore(&card->lock, flags);
 346
 347        if (do_reset) {
 348                fw_notify("phy config: card %d, new root=%x, gap_count=%d\n",
 349                          card->index, new_root_id, gap_count);
 350                fw_send_phy_config(card, new_root_id, generation, gap_count);
 351                fw_core_initiate_bus_reset(card, 1);
 352        }
 353 out:
 354        if (root_device)
 355                fw_device_put(root_device);
 356        fw_node_put(root_node);
 357        fw_node_put(local_node);
 358}
 359
 360static void
 361flush_timer_callback(unsigned long data)
 362{
 363        struct fw_card *card = (struct fw_card *)data;
 364
 365        fw_flush_transactions(card);
 366}
 367
 368void
 369fw_card_initialize(struct fw_card *card, const struct fw_card_driver *driver,
 370                   struct device *device)
 371{
 372        static atomic_t index = ATOMIC_INIT(-1);
 373
 374        card->index = atomic_inc_return(&index);
 375        card->driver = driver;
 376        card->device = device;
 377        card->current_tlabel = 0;
 378        card->tlabel_mask = 0;
 379        card->color = 0;
 380        card->broadcast_channel = BROADCAST_CHANNEL_INITIAL;
 381
 382        kref_init(&card->kref);
 383        init_completion(&card->done);
 384        INIT_LIST_HEAD(&card->transaction_list);
 385        spin_lock_init(&card->lock);
 386        setup_timer(&card->flush_timer,
 387                    flush_timer_callback, (unsigned long)card);
 388
 389        card->local_node = NULL;
 390
 391        INIT_DELAYED_WORK(&card->work, fw_card_bm_work);
 392}
 393EXPORT_SYMBOL(fw_card_initialize);
 394
 395int
 396fw_card_add(struct fw_card *card,
 397            u32 max_receive, u32 link_speed, u64 guid)
 398{
 399        u32 *config_rom;
 400        size_t length;
 401
 402        card->max_receive = max_receive;
 403        card->link_speed = link_speed;
 404        card->guid = guid;
 405
 406        mutex_lock(&card_mutex);
 407        config_rom = generate_config_rom(card, &length);
 408        list_add_tail(&card->link, &card_list);
 409        mutex_unlock(&card_mutex);
 410
 411        return card->driver->enable(card, config_rom, length);
 412}
 413EXPORT_SYMBOL(fw_card_add);
 414
 415
 416/*
 417 * The next few functions implements a dummy driver that use once a
 418 * card driver shuts down an fw_card.  This allows the driver to
 419 * cleanly unload, as all IO to the card will be handled by the dummy
 420 * driver instead of calling into the (possibly) unloaded module.  The
 421 * dummy driver just fails all IO.
 422 */
 423
 424static int
 425dummy_enable(struct fw_card *card, u32 *config_rom, size_t length)
 426{
 427        BUG();
 428        return -1;
 429}
 430
 431static int
 432dummy_update_phy_reg(struct fw_card *card, int address,
 433                     int clear_bits, int set_bits)
 434{
 435        return -ENODEV;
 436}
 437
 438static int
 439dummy_set_config_rom(struct fw_card *card,
 440                     u32 *config_rom, size_t length)
 441{
 442        /*
 443         * We take the card out of card_list before setting the dummy
 444         * driver, so this should never get called.
 445         */
 446        BUG();
 447        return -1;
 448}
 449
 450static void
 451dummy_send_request(struct fw_card *card, struct fw_packet *packet)
 452{
 453        packet->callback(packet, card, -ENODEV);
 454}
 455
 456static void
 457dummy_send_response(struct fw_card *card, struct fw_packet *packet)
 458{
 459        packet->callback(packet, card, -ENODEV);
 460}
 461
 462static int
 463dummy_cancel_packet(struct fw_card *card, struct fw_packet *packet)
 464{
 465        return -ENOENT;
 466}
 467
 468static int
 469dummy_enable_phys_dma(struct fw_card *card,
 470                      int node_id, int generation)
 471{
 472        return -ENODEV;
 473}
 474
 475static struct fw_card_driver dummy_driver = {
 476        .enable          = dummy_enable,
 477        .update_phy_reg  = dummy_update_phy_reg,
 478        .set_config_rom  = dummy_set_config_rom,
 479        .send_request    = dummy_send_request,
 480        .cancel_packet   = dummy_cancel_packet,
 481        .send_response   = dummy_send_response,
 482        .enable_phys_dma = dummy_enable_phys_dma,
 483};
 484
 485void
 486fw_card_release(struct kref *kref)
 487{
 488        struct fw_card *card = container_of(kref, struct fw_card, kref);
 489
 490        complete(&card->done);
 491}
 492
 493void
 494fw_core_remove_card(struct fw_card *card)
 495{
 496        card->driver->update_phy_reg(card, 4,
 497                                     PHY_LINK_ACTIVE | PHY_CONTENDER, 0);
 498        fw_core_initiate_bus_reset(card, 1);
 499
 500        mutex_lock(&card_mutex);
 501        list_del(&card->link);
 502        mutex_unlock(&card_mutex);
 503
 504        /* Set up the dummy driver. */
 505        card->driver = &dummy_driver;
 506
 507        fw_destroy_nodes(card);
 508
 509        /* Wait for all users, especially device workqueue jobs, to finish. */
 510        fw_card_put(card);
 511        wait_for_completion(&card->done);
 512
 513        cancel_delayed_work_sync(&card->work);
 514        WARN_ON(!list_empty(&card->transaction_list));
 515        del_timer_sync(&card->flush_timer);
 516}
 517EXPORT_SYMBOL(fw_core_remove_card);
 518
 519int
 520fw_core_initiate_bus_reset(struct fw_card *card, int short_reset)
 521{
 522        int reg = short_reset ? 5 : 1;
 523        int bit = short_reset ? PHY_BUS_SHORT_RESET : PHY_BUS_RESET;
 524
 525        return card->driver->update_phy_reg(card, reg, 0, bit);
 526}
 527EXPORT_SYMBOL(fw_core_initiate_bus_reset);
 528