drivers/firewire/fw-sbp2.c

   1 /*
   2  * SBP2 driver (SCSI over IEEE1394)
   3  *
   4  * Copyright (C) 2005-2007  Kristian Hoegsberg <krh@bitplanet.net>
   5  *
   6  * This program is free software; you can redistribute it and/or modify
   7  * it under the terms of the GNU General Public License as published by
   8  * the Free Software Foundation; either version 2 of the License, or
   9  * (at your option) any later version.
  10  *
  11  * This program is distributed in the hope that it will be useful,
  12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14  * GNU General Public License for more details.
  15  *
  16  * You should have received a copy of the GNU General Public License
  17  * along with this program; if not, write to the Free Software Foundation,
  18  * Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
  19  */
  20
  21 /*
  22  * The basic structure of this driver is based on the old storage driver,
  23  * drivers/ieee1394/sbp2.c, originally written by
  24  *     James Goodwin <jamesg@filanet.com>
  25  * with later contributions and ongoing maintenance from
  26  *     Ben Collins <bcollins@debian.org>,
  27  *     Stefan Richter <stefanr@s5r6.in-berlin.de>
  28  * and many others.
  29  */
  30
  31 #include <linux/blkdev.h>
  32 #include <linux/delay.h>
  33 #include <linux/device.h>
  34 #include <linux/dma-mapping.h>
  35 #include <linux/kernel.h>
  36 #include <linux/mod_devicetable.h>
  37 #include <linux/module.h>
  38 #include <linux/moduleparam.h>
  39 #include <linux/scatterlist.h>
  40 #include <linux/string.h>
  41 #include <linux/stringify.h>
  42 #include <linux/timer.h>
  43 #include <linux/workqueue.h>
  44 #include <asm/system.h>
  45
  46 #include <scsi/scsi.h>
  47 #include <scsi/scsi_cmnd.h>
  48 #include <scsi/scsi_device.h>
  49 #include <scsi/scsi_host.h>
  50
  51 #include "fw-device.h"
  52 #include "fw-topology.h"
  53 #include "fw-transaction.h"
  54
  55 /*
  56  * So far only bridges from Oxford Semiconductor are known to support
  57  * concurrent logins. Depending on firmware, four or two concurrent logins
  58  * are possible on OXFW911 and newer Oxsemi bridges.
  59  *
  60  * Concurrent logins are useful together with cluster filesystems.
  61  */
  62 static int sbp2_param_exclusive_login = 1;
  63 module_param_named(exclusive_login, sbp2_param_exclusive_login, bool, 0644);
  64 MODULE_PARM_DESC(exclusive_login, "Exclusive login to sbp2 device "
  65                  "(default = Y, use N for concurrent initiators)");
  66
  67 /*
  68  * Flags for firmware oddities
  69  *
  70  * - 128kB max transfer
  71  *   Limit transfer size. Necessary for some old bridges.
  72  *
  73  * - 36 byte inquiry
  74  *   When scsi_mod probes the device, let the inquiry command look like that
  75  *   from MS Windows.
  76  *
  77  * - skip mode page 8
  78  *   Suppress sending of mode_sense for mode page 8 if the device pretends to
  79  *   support the SCSI Primary Block commands instead of Reduced Block Commands.
  80  *
  81  * - fix capacity
  82  *   Tell sd_mod to correct the last sector number reported by read_capacity.
  83  *   Avoids access beyond actual disk limits on devices with an off-by-one bug.
  84  *   Don't use this with devices which don't have this bug.
  85  *
  86  * - delay inquiry
  87  *   Wait extra SBP2_INQUIRY_DELAY seconds after login before SCSI inquiry.
  88  *
  89  * - power condition
  90  *   Set the power condition field in the START STOP UNIT commands sent by
  91  *   sd_mod on suspend, resume, and shutdown (if manage_start_stop is on).
  92  *   Some disks need this to spin down or to resume properly.
  93  *
  94  * - override internal blacklist
  95  *   Instead of adding to the built-in blacklist, use only the workarounds
  96  *   specified in the module load parameter.
  97  *   Useful if a blacklist entry interfered with a non-broken device.
  98  */
  99 #define SBP2_WORKAROUND_128K_MAX_TRANS  0x1
 100 #define SBP2_WORKAROUND_INQUIRY_36      0x2
 101 #define SBP2_WORKAROUND_MODE_SENSE_8    0x4
 102 #define SBP2_WORKAROUND_FIX_CAPACITY    0x8
 103 #define SBP2_WORKAROUND_DELAY_INQUIRY   0x10
 104 #define SBP2_INQUIRY_DELAY              12
 105 #define SBP2_WORKAROUND_POWER_CONDITION 0x20
 106 #define SBP2_WORKAROUND_OVERRIDE        0x100
 107
 108 static int sbp2_param_workarounds;
 109 module_param_named(workarounds, sbp2_param_workarounds, int, 0644);
 110 MODULE_PARM_DESC(workarounds, "Work around device bugs (default = 0"
 111         ", 128kB max transfer = " __stringify(SBP2_WORKAROUND_128K_MAX_TRANS)
 112         ", 36 byte inquiry = "    __stringify(SBP2_WORKAROUND_INQUIRY_36)
 113         ", skip mode page 8 = "   __stringify(SBP2_WORKAROUND_MODE_SENSE_8)
 114         ", fix capacity = "       __stringify(SBP2_WORKAROUND_FIX_CAPACITY)
 115         ", delay inquiry = "      __stringify(SBP2_WORKAROUND_DELAY_INQUIRY)
 116         ", set power condition in start stop unit = "
 117                                   __stringify(SBP2_WORKAROUND_POWER_CONDITION)
 118         ", override internal blacklist = " __stringify(SBP2_WORKAROUND_OVERRIDE)
 119         ", or a combination)");
 120
 121 /* I don't know why the SCSI stack doesn't define something like this... */
 122 typedef void (*scsi_done_fn_t)(struct scsi_cmnd *);
 123
 124 static const char sbp2_driver_name[] = "sbp2";
 125
 126 /*
 127  * We create one struct sbp2_logical_unit per SBP-2 Logical Unit Number Entry
 128  * and one struct scsi_device per sbp2_logical_unit.
 129  */
 130 struct sbp2_logical_unit {
 131         struct sbp2_target *tgt;
 132         struct list_head link;
 133         struct fw_address_handler address_handler;
 134         struct list_head orb_list;
 135
 136         u64 command_block_agent_address;
 137         u16 lun;
 138         int login_id;
 139
 140         /*
 141          * The generation is updated once we've logged in or reconnected
 142          * to the logical unit.  Thus, I/O to the device will automatically
 143          * fail and get retried if it happens in a window where the device
 144          * is not ready, e.g. after a bus reset but before we reconnect.
 145          */
 146         int generation;
 147         int retries;
 148         struct delayed_work work;
 149         bool has_sdev;
 150         bool blocked;
 151 };
 152
 153 /*
 154  * We create one struct sbp2_target per IEEE 1212 Unit Directory
 155  * and one struct Scsi_Host per sbp2_target.
 156  */
 157 struct sbp2_target {
 158         struct kref kref;
 159         struct fw_unit *unit;
 160         const char *bus_id;
 161         struct list_head lu_list;
 162
 163         u64 management_agent_address;
 164         u64 guid;
 165         int directory_id;
 166         int node_id;
 167         int address_high;
 168         unsigned int workarounds;
 169         unsigned int mgt_orb_timeout;
 170
 171         int dont_block; /* counter for each logical unit */
 172         int blocked;    /* ditto */
 173 };
 174
 175 /*
 176  * Per section 7.4.8 of the SBP-2 spec, a mgt_ORB_timeout value can be
 177  * provided in the config rom. Most devices do provide a value, which
 178  * we'll use for login management orbs, but with some sane limits.
 179  */
 180 #define SBP2_MIN_LOGIN_ORB_TIMEOUT      5000U   /* Timeout in ms */
 181 #define SBP2_MAX_LOGIN_ORB_TIMEOUT      40000U  /* Timeout in ms */
 182 #define SBP2_ORB_TIMEOUT                2000U   /* Timeout in ms */
 183 #define SBP2_ORB_NULL                   0x80000000
 184 #define SBP2_MAX_SG_ELEMENT_LENGTH      0xf000
 185 #define SBP2_RETRY_LIMIT                0xf             /* 15 retries */
 186 #define SBP2_CYCLE_LIMIT                (0xc8 << 12)    /* 200 125us cycles */
 187
 188 /* Unit directory keys */
 189 #define SBP2_CSR_UNIT_CHARACTERISTICS   0x3a
 190 #define SBP2_CSR_FIRMWARE_REVISION      0x3c
 191 #define SBP2_CSR_LOGICAL_UNIT_NUMBER    0x14
 192 #define SBP2_CSR_LOGICAL_UNIT_DIRECTORY 0xd4
 193
 194 /* Management orb opcodes */
 195 #define SBP2_LOGIN_REQUEST              0x0
 196 #define SBP2_QUERY_LOGINS_REQUEST       0x1
 197 #define SBP2_RECONNECT_REQUEST          0x3
 198 #define SBP2_SET_PASSWORD_REQUEST       0x4
 199 #define SBP2_LOGOUT_REQUEST             0x7
 200 #define SBP2_ABORT_TASK_REQUEST         0xb
 201 #define SBP2_ABORT_TASK_SET             0xc
 202 #define SBP2_LOGICAL_UNIT_RESET         0xe
 203 #define SBP2_TARGET_RESET_REQUEST       0xf
 204
 205 /* Offsets for command block agent registers */
 206 #define SBP2_AGENT_STATE                0x00
 207 #define SBP2_AGENT_RESET                0x04
 208 #define SBP2_ORB_POINTER                0x08
 209 #define SBP2_DOORBELL                   0x10
 210 #define SBP2_UNSOLICITED_STATUS_ENABLE  0x14
 211
 212 /* Status write response codes */
 213 #define SBP2_STATUS_REQUEST_COMPLETE    0x0
 214 #define SBP2_STATUS_TRANSPORT_FAILURE   0x1
 215 #define SBP2_STATUS_ILLEGAL_REQUEST     0x2
 216 #define SBP2_STATUS_VENDOR_DEPENDENT    0x3
 217
 218 #define STATUS_GET_ORB_HIGH(v)          ((v).status & 0xffff)
 219 #define STATUS_GET_SBP_STATUS(v)        (((v).status >> 16) & 0xff)
 220 #define STATUS_GET_LEN(v)               (((v).status >> 24) & 0x07)
 221 #define STATUS_GET_DEAD(v)              (((v).status >> 27) & 0x01)
 222 #define STATUS_GET_RESPONSE(v)          (((v).status >> 28) & 0x03)
 223 #define STATUS_GET_SOURCE(v)            (((v).status >> 30) & 0x03)
 224 #define STATUS_GET_ORB_LOW(v)           ((v).orb_low)
 225 #define STATUS_GET_DATA(v)              ((v).data)
 226
 227 struct sbp2_status {
 228         u32 status;
 229         u32 orb_low;
 230         u8 data[24];
 231 };
 232
 233 struct sbp2_pointer {
 234         __be32 high;
 235         __be32 low;
 236 };
 237
 238 struct sbp2_orb {
 239         struct fw_transaction t;
 240         struct kref kref;
 241         dma_addr_t request_bus;
 242         int rcode;
 243         struct sbp2_pointer pointer;
 244         void (*callback)(struct sbp2_orb * orb, struct sbp2_status * status);
 245         struct list_head link;
 246 };
 247
 248 #define MANAGEMENT_ORB_LUN(v)                   ((v))
 249 #define MANAGEMENT_ORB_FUNCTION(v)              ((v) << 16)
 250 #define MANAGEMENT_ORB_RECONNECT(v)             ((v) << 20)
 251 #define MANAGEMENT_ORB_EXCLUSIVE(v)             ((v) ? 1 << 28 : 0)
 252 #define MANAGEMENT_ORB_REQUEST_FORMAT(v)        ((v) << 29)
 253 #define MANAGEMENT_ORB_NOTIFY                   ((1) << 31)
 254
 255 #define MANAGEMENT_ORB_RESPONSE_LENGTH(v)       ((v))
 256 #define MANAGEMENT_ORB_PASSWORD_LENGTH(v)       ((v) << 16)
 257
 258 struct sbp2_management_orb {
 259         struct sbp2_orb base;
 260         struct {
 261                 struct sbp2_pointer password;
 262                 struct sbp2_pointer response;
 263                 __be32 misc;
 264                 __be32 length;
 265                 struct sbp2_pointer status_fifo;
 266         } request;
 267         __be32 response[4];
 268         dma_addr_t response_bus;
 269         struct completion done;
 270         struct sbp2_status status;
 271 };
 272
 273 struct sbp2_login_response {
 274         __be32 misc;
 275         struct sbp2_pointer command_block_agent;
 276         __be32 reconnect_hold;
 277 };
 278 #define COMMAND_ORB_DATA_SIZE(v)        ((v))
 279 #define COMMAND_ORB_PAGE_SIZE(v)        ((v) << 16)
 280 #define COMMAND_ORB_PAGE_TABLE_PRESENT  ((1) << 19)
 281 #define COMMAND_ORB_MAX_PAYLOAD(v)      ((v) << 20)
 282 #define COMMAND_ORB_SPEED(v)            ((v) << 24)
 283 #define COMMAND_ORB_DIRECTION           ((1) << 27)
 284 #define COMMAND_ORB_REQUEST_FORMAT(v)   ((v) << 29)
 285 #define COMMAND_ORB_NOTIFY              ((1) << 31)
 286
 287 struct sbp2_command_orb {
 288         struct sbp2_orb base;
 289         struct {
 290                 struct sbp2_pointer next;
 291                 struct sbp2_pointer data_descriptor;
 292                 __be32 misc;
 293                 u8 command_block[12];
 294         } request;
 295         struct scsi_cmnd *cmd;
 296         scsi_done_fn_t done;
 297         struct sbp2_logical_unit *lu;
 298
 299         struct sbp2_pointer page_table[SG_ALL] __attribute__((aligned(8)));
 300         dma_addr_t page_table_bus;
 301 };
 302
 303 /*
 304  * List of devices with known bugs.
 305  *
 306  * The firmware_revision field, masked with 0xffff00, is the best
 307  * indicator for the type of bridge chip of a device.  It yields a few
 308  * false positives but this did not break correctly behaving devices
 309  * so far.  We use ~0 as a wildcard, since the 24 bit values we get
 310  * from the config rom can never match that.
 311  */
 312 static const struct {
 313         u32 firmware_revision;
 314         u32 model;
 315         unsigned int workarounds;
 316 } sbp2_workarounds_table[] = {
 317         /* DViCO Momobay CX-1 with TSB42AA9 bridge */ {
 318                 .firmware_revision      = 0x002800,
 319                 .model                  = 0x001010,
 320                 .workarounds            = SBP2_WORKAROUND_INQUIRY_36 |
 321                                           SBP2_WORKAROUND_MODE_SENSE_8 |
 322                                           SBP2_WORKAROUND_POWER_CONDITION,
 323         },
 324         /* DViCO Momobay FX-3A with TSB42AA9A bridge */ {
 325                 .firmware_revision      = 0x002800,
 326                 .model                  = 0x000000,
 327                 .workarounds            = SBP2_WORKAROUND_DELAY_INQUIRY |
 328                                           SBP2_WORKAROUND_POWER_CONDITION,
 329         },
 330         /* Initio bridges, actually only needed for some older ones */ {
 331                 .firmware_revision      = 0x000200,
 332                 .model                  = ~0,
 333                 .workarounds            = SBP2_WORKAROUND_INQUIRY_36,
 334         },
 335         /* PL-3507 bridge with Prolific firmware */ {
 336                 .firmware_revision      = 0x012800,
 337                 .model                  = ~0,
 338                 .workarounds            = SBP2_WORKAROUND_POWER_CONDITION,
 339         },
 340         /* Symbios bridge */ {
 341                 .firmware_revision      = 0xa0b800,
 342                 .model                  = ~0,
 343                 .workarounds            = SBP2_WORKAROUND_128K_MAX_TRANS,
 344         },
 345         /* Datafab MD2-FW2 with Symbios/LSILogic SYM13FW500 bridge */ {
 346                 .firmware_revision      = 0x002600,
 347                 .model                  = ~0,
 348                 .workarounds            = SBP2_WORKAROUND_128K_MAX_TRANS,
 349         },
 350
 351         /*
 352          * There are iPods (2nd gen, 3rd gen) with model_id == 0, but
 353          * these iPods do not feature the read_capacity bug according
 354          * to one report.  Read_capacity behaviour as well as model_id
 355          * could change due to Apple-supplied firmware updates though.
 356          */
 357
 358         /* iPod 4th generation. */ {
 359                 .firmware_revision      = 0x0a2700,
 360                 .model                  = 0x000021,
 361                 .workarounds            = SBP2_WORKAROUND_FIX_CAPACITY,
 362         },
 363         /* iPod mini */ {
 364                 .firmware_revision      = 0x0a2700,
 365                 .model                  = 0x000023,
 366                 .workarounds            = SBP2_WORKAROUND_FIX_CAPACITY,
 367         },
 368         /* iPod Photo */ {
 369                 .firmware_revision      = 0x0a2700,
 370                 .model                  = 0x00007e,
 371                 .workarounds            = SBP2_WORKAROUND_FIX_CAPACITY,
 372         }
 373 };
 374
 375 static void
 376 free_orb(struct kref *kref)
 377 {
 378         struct sbp2_orb *orb = container_of(kref, struct sbp2_orb, kref);
 379
 380         kfree(orb);
 381 }
 382
 383 static void
 384 sbp2_status_write(struct fw_card *card, struct fw_request *request,
 385                   int tcode, int destination, int source,
 386                   int generation, int speed,
 387                   unsigned long long offset,
 388                   void *payload, size_t length, void *callback_data)
 389 {
 390         struct sbp2_logical_unit *lu = callback_data;
 391         struct sbp2_orb *orb;
 392         struct sbp2_status status;
 393         size_t header_size;
 394         unsigned long flags;
 395
 396         if (tcode != TCODE_WRITE_BLOCK_REQUEST ||
 397             length == 0 || length > sizeof(status)) {
 398                 fw_send_response(card, request, RCODE_TYPE_ERROR);
 399                 return;
 400         }
 401
 402         header_size = min(length, 2 * sizeof(u32));
 403         fw_memcpy_from_be32(&status, payload, header_size);
 404         if (length > header_size)
 405                 memcpy(status.data, payload + 8, length - header_size);
 406         if (STATUS_GET_SOURCE(status) == 2 || STATUS_GET_SOURCE(status) == 3) {
 407                 fw_notify("non-orb related status write, not handled\n");
 408                 fw_send_response(card, request, RCODE_COMPLETE);
 409                 return;
 410         }
 411
 412         /* Lookup the orb corresponding to this status write. */
 413         spin_lock_irqsave(&card->lock, flags);
 414         list_for_each_entry(orb, &lu->orb_list, link) {
 415                 if (STATUS_GET_ORB_HIGH(status) == 0 &&
 416                     STATUS_GET_ORB_LOW(status) == orb->request_bus) {
 417                         orb->rcode = RCODE_COMPLETE;
 418                         list_del(&orb->link);
 419                         break;
 420                 }
 421         }
 422         spin_unlock_irqrestore(&card->lock, flags);
 423
 424         if (&orb->link != &lu->orb_list)
 425                 orb->callback(orb, &status);
 426         else
 427                 fw_error("status write for unknown orb\n");
 428
 429         kref_put(&orb->kref, free_orb);
 430
 431         fw_send_response(card, request, RCODE_COMPLETE);
 432 }
 433
 434 static void
 435 complete_transaction(struct fw_card *card, int rcode,
 436                      void *payload, size_t length, void *data)
 437 {
 438         struct sbp2_orb *orb = data;
 439         unsigned long flags;
 440
 441         /*
 442          * This is a little tricky.  We can get the status write for
 443          * the orb before we get this callback.  The status write
 444          * handler above will assume the orb pointer transaction was
 445          * successful and set the rcode to RCODE_COMPLETE for the orb.
 446          * So this callback only sets the rcode if it hasn't already
 447          * been set and only does the cleanup if the transaction
 448          * failed and we didn't already get a status write.
 449          */
 450         spin_lock_irqsave(&card->lock, flags);
 451
 452         if (orb->rcode == -1)
 453                 orb->rcode = rcode;
 454         if (orb->rcode != RCODE_COMPLETE) {
 455                 list_del(&orb->link);
 456                 spin_unlock_irqrestore(&card->lock, flags);
 457                 orb->callback(orb, NULL);
 458         } else {
 459                 spin_unlock_irqrestore(&card->lock, flags);
 460         }
 461
 462         kref_put(&orb->kref, free_orb);
 463 }
 464
 465 static void
 466 sbp2_send_orb(struct sbp2_orb *orb, struct sbp2_logical_unit *lu,
 467               int node_id, int generation, u64 offset)
 468 {
 469         struct fw_device *device = fw_device(lu->tgt->unit->device.parent);
 470         unsigned long flags;
 471
 472         orb->pointer.high = 0;
 473         orb->pointer.low = cpu_to_be32(orb->request_bus);
 474
 475         spin_lock_irqsave(&device->card->lock, flags);
 476         list_add_tail(&orb->link, &lu->orb_list);
 477         spin_unlock_irqrestore(&device->card->lock, flags);
 478
 479         /* Take a ref for the orb list and for the transaction callback. */
 480         kref_get(&orb->kref);
 481         kref_get(&orb->kref);
 482
 483         fw_send_request(device->card, &orb->t, TCODE_WRITE_BLOCK_REQUEST,
 484                         node_id, generation, device->max_speed, offset,
 485                         &orb->pointer, sizeof(orb->pointer),
 486                         complete_transaction, orb);
 487 }
 488
 489 static int sbp2_cancel_orbs(struct sbp2_logical_unit *lu)
 490 {
 491         struct fw_device *device = fw_device(lu->tgt->unit->device.parent);
 492         struct sbp2_orb *orb, *next;
 493         struct list_head list;
 494         unsigned long flags;
 495         int retval = -ENOENT;
 496
 497         INIT_LIST_HEAD(&list);
 498         spin_lock_irqsave(&device->card->lock, flags);
 499         list_splice_init(&lu->orb_list, &list);
 500         spin_unlock_irqrestore(&device->card->lock, flags);
 501
 502         list_for_each_entry_safe(orb, next, &list, link) {
 503                 retval = 0;
 504                 if (fw_cancel_transaction(device->card, &orb->t) == 0)
 505                         continue;
 506
 507                 orb->rcode = RCODE_CANCELLED;
 508                 orb->callback(orb, NULL);
 509         }
 510
 511         return retval;
 512 }
 513
 514 static void
 515 complete_management_orb(struct sbp2_orb *base_orb, struct sbp2_status *status)
 516 {
 517         struct sbp2_management_orb *orb =
 518                 container_of(base_orb, struct sbp2_management_orb, base);
 519
 520         if (status)
 521                 memcpy(&orb->status, status, sizeof(*status));
 522         complete(&orb->done);
 523 }
 524
 525 static int
 526 sbp2_send_management_orb(struct sbp2_logical_unit *lu, int node_id,
 527                          int generation, int function, int lun_or_login_id,
 528                          void *response)
 529 {
 530         struct fw_device *device = fw_device(lu->tgt->unit->device.parent);
 531         struct sbp2_management_orb *orb;
 532         unsigned int timeout;
 533         int retval = -ENOMEM;
 534
 535         if (function == SBP2_LOGOUT_REQUEST && fw_device_is_shutdown(device))
 536                 return 0;
 537
 538         orb = kzalloc(sizeof(*orb), GFP_ATOMIC);
 539         if (orb == NULL)
 540                 return -ENOMEM;
 541
 542         kref_init(&orb->base.kref);
 543         orb->response_bus =
 544                 dma_map_single(device->card->device, &orb->response,
 545                                sizeof(orb->response), DMA_FROM_DEVICE);
 546         if (dma_mapping_error(orb->response_bus))
 547                 goto fail_mapping_response;
 548
 549         orb->request.response.high = 0;
 550         orb->request.response.low  = cpu_to_be32(orb->response_bus);
 551
 552         orb->request.misc = cpu_to_be32(
 553                 MANAGEMENT_ORB_NOTIFY |
 554                 MANAGEMENT_ORB_FUNCTION(function) |
 555                 MANAGEMENT_ORB_LUN(lun_or_login_id));
 556         orb->request.length = cpu_to_be32(
 557                 MANAGEMENT_ORB_RESPONSE_LENGTH(sizeof(orb->response)));
 558
 559         orb->request.status_fifo.high =
 560                 cpu_to_be32(lu->address_handler.offset >> 32);
 561         orb->request.status_fifo.low  =
 562                 cpu_to_be32(lu->address_handler.offset);
 563
 564         if (function == SBP2_LOGIN_REQUEST) {
 565                 /* Ask for 2^2 == 4 seconds reconnect grace period */
 566                 orb->request.misc |= cpu_to_be32(
 567                         MANAGEMENT_ORB_RECONNECT(2) |
 568                         MANAGEMENT_ORB_EXCLUSIVE(sbp2_param_exclusive_login));
 569                 timeout = lu->tgt->mgt_orb_timeout;
 570         } else {
 571                 timeout = SBP2_ORB_TIMEOUT;
 572         }
 573
 574         init_completion(&orb->done);
 575         orb->base.callback = complete_management_orb;
 576
 577         orb->base.request_bus =
 578                 dma_map_single(device->card->device, &orb->request,
 579                                sizeof(orb->request), DMA_TO_DEVICE);
 580         if (dma_mapping_error(orb->base.request_bus))
 581                 goto fail_mapping_request;
 582
 583         sbp2_send_orb(&orb->base, lu, node_id, generation,
 584                       lu->tgt->management_agent_address);
 585
 586         wait_for_completion_timeout(&orb->done, msecs_to_jiffies(timeout));
 587
 588         retval = -EIO;
 589         if (sbp2_cancel_orbs(lu) == 0) {
 590                 fw_error("%s: orb reply timed out, rcode=0x%02x\n",
 591                          lu->tgt->bus_id, orb->base.rcode);
 592                 goto out;
 593         }
 594
 595         if (orb->base.rcode != RCODE_COMPLETE) {
 596                 fw_error("%s: management write failed, rcode 0x%02x\n",
 597                          lu->tgt->bus_id, orb->base.rcode);
 598                 goto out;
 599         }
 600
 601         if (STATUS_GET_RESPONSE(orb->status) != 0 ||
 602             STATUS_GET_SBP_STATUS(orb->status) != 0) {
 603                 fw_error("%s: error status: %d:%d\n", lu->tgt->bus_id,
 604                          STATUS_GET_RESPONSE(orb->status),
 605                          STATUS_GET_SBP_STATUS(orb->status));
 606                 goto out;
 607         }
 608
 609         retval = 0;
 610  out:
 611         dma_unmap_single(device->card->device, orb->base.request_bus,
 612                          sizeof(orb->request), DMA_TO_DEVICE);
 613  fail_mapping_request:
 614         dma_unmap_single(device->card->device, orb->response_bus,
 615                          sizeof(orb->response), DMA_FROM_DEVICE);
 616  fail_mapping_response:
 617         if (response)
 618                 memcpy(response, orb->response, sizeof(orb->response));
 619         kref_put(&orb->base.kref, free_orb);
 620
 621         return retval;
 622 }
 623
 624 static void
 625 complete_agent_reset_write(struct fw_card *card, int rcode,
 626                            void *payload, size_t length, void *done)
 627 {
 628         complete(done);
 629 }
 630
 631 static void sbp2_agent_reset(struct sbp2_logical_unit *lu)
 632 {
 633         struct fw_device *device = fw_device(lu->tgt->unit->device.parent);
 634         DECLARE_COMPLETION_ONSTACK(done);
 635         struct fw_transaction t;
 636         static u32 z;
 637
 638         fw_send_request(device->card, &t, TCODE_WRITE_QUADLET_REQUEST,
 639                         lu->tgt->node_id, lu->generation, device->max_speed,
 640                         lu->command_block_agent_address + SBP2_AGENT_RESET,
 641                         &z, sizeof(z), complete_agent_reset_write, &done);
 642         wait_for_completion(&done);
 643 }
 644
 645 static void
 646 complete_agent_reset_write_no_wait(struct fw_card *card, int rcode,
 647                                    void *payload, size_t length, void *data)
 648 {
 649         kfree(data);
 650 }
 651
 652 static void sbp2_agent_reset_no_wait(struct sbp2_logical_unit *lu)
 653 {
 654         struct fw_device *device = fw_device(lu->tgt->unit->device.parent);
 655         struct fw_transaction *t;
 656         static u32 z;
 657
 658         t = kmalloc(sizeof(*t), GFP_ATOMIC);
 659         if (t == NULL)
 660                 return;
 661
 662         fw_send_request(device->card, t, TCODE_WRITE_QUADLET_REQUEST,
 663                         lu->tgt->node_id, lu->generation, device->max_speed,
 664                         lu->command_block_agent_address + SBP2_AGENT_RESET,
 665                         &z, sizeof(z), complete_agent_reset_write_no_wait, t);
 666 }
 667
 668 static void sbp2_set_generation(struct sbp2_logical_unit *lu, int generation)
 669 {
 670         struct fw_card *card = fw_device(lu->tgt->unit->device.parent)->card;
 671         unsigned long flags;
 672
 673         /* serialize with comparisons of lu->generation and card->generation */
 674         spin_lock_irqsave(&card->lock, flags);
 675         lu->generation = generation;
 676         spin_unlock_irqrestore(&card->lock, flags);
 677 }
 678
 679 static inline void sbp2_allow_block(struct sbp2_logical_unit *lu)
 680 {
 681         /*
 682          * We may access dont_block without taking card->lock here:
 683          * All callers of sbp2_allow_block() and all callers of sbp2_unblock()
 684          * are currently serialized against each other.
 685          * And a wrong result in sbp2_conditionally_block()'s access of
 686          * dont_block is rather harmless, it simply misses its first chance.
 687          */
 688         --lu->tgt->dont_block;
 689 }
 690
 691 /*
 692  * Blocks lu->tgt if all of the following conditions are met:
 693  *   - Login, INQUIRY, and high-level SCSI setup of all of the target's
 694  *     logical units have been finished (indicated by dont_block == 0).
 695  *   - lu->generation is stale.
 696  *
 697  * Note, scsi_block_requests() must be called while holding card->lock,
 698  * otherwise it might foil sbp2_[conditionally_]unblock()'s attempt to
 699  * unblock the target.
 700  */
 701 static void sbp2_conditionally_block(struct sbp2_logical_unit *lu)
 702 {
 703         struct sbp2_target *tgt = lu->tgt;
 704         struct fw_card *card = fw_device(tgt->unit->device.parent)->card;
 705         struct Scsi_Host *shost =
 706                 container_of((void *)tgt, struct Scsi_Host, hostdata[0]);
 707         unsigned long flags;
 708
 709         spin_lock_irqsave(&card->lock, flags);
 710         if (!tgt->dont_block && !lu->blocked &&
 711             lu->generation != card->generation) {
 712                 lu->blocked = true;
 713                 if (++tgt->blocked == 1)
 714                         scsi_block_requests(shost);
 715         }
 716         spin_unlock_irqrestore(&card->lock, flags);
 717 }
 718
 719 /*
 720  * Unblocks lu->tgt as soon as all its logical units can be unblocked.
 721  * Note, it is harmless to run scsi_unblock_requests() outside the
 722  * card->lock protected section.  On the other hand, running it inside
 723  * the section might clash with shost->host_lock.
 724  */
 725 static void sbp2_conditionally_unblock(struct sbp2_logical_unit *lu)
 726 {
 727         struct sbp2_target *tgt = lu->tgt;
 728         struct fw_card *card = fw_device(tgt->unit->device.parent)->card;
 729         struct Scsi_Host *shost =
 730                 container_of((void *)tgt, struct Scsi_Host, hostdata[0]);
 731         unsigned long flags;
 732         bool unblock = false;
 733
 734         spin_lock_irqsave(&card->lock, flags);
 735         if (lu->blocked && lu->generation == card->generation) {
 736                 lu->blocked = false;
 737                 unblock = --tgt->blocked == 0;
 738         }
 739         spin_unlock_irqrestore(&card->lock, flags);
 740
 741         if (unblock)
 742                 scsi_unblock_requests(shost);
 743 }
 744
 745 /*
 746  * Prevents future blocking of tgt and unblocks it.
 747  * Note, it is harmless to run scsi_unblock_requests() outside the
 748  * card->lock protected section.  On the other hand, running it inside
 749  * the section might clash with shost->host_lock.
 750  */
 751 static void sbp2_unblock(struct sbp2_target *tgt)
 752 {
 753         struct fw_card *card = fw_device(tgt->unit->device.parent)->card;
 754         struct Scsi_Host *shost =
 755                 container_of((void *)tgt, struct Scsi_Host, hostdata[0]);
 756         unsigned long flags;
 757
 758         spin_lock_irqsave(&card->lock, flags);
 759         ++tgt->dont_block;
 760         spin_unlock_irqrestore(&card->lock, flags);
 761
 762         scsi_unblock_requests(shost);
 763 }
 764
 765 static int sbp2_lun2int(u16 lun)
 766 {
 767         struct scsi_lun eight_bytes_lun;
 768
 769         memset(&eight_bytes_lun, 0, sizeof(eight_bytes_lun));
 770         eight_bytes_lun.scsi_lun[0] = (lun >> 8) & 0xff;
 771         eight_bytes_lun.scsi_lun[1] = lun & 0xff;
 772
 773         return scsilun_to_int(&eight_bytes_lun);
 774 }
 775
 776 static void sbp2_release_target(struct kref *kref)
 777 {
 778         struct sbp2_target *tgt = container_of(kref, struct sbp2_target, kref);
 779         struct sbp2_logical_unit *lu, *next;
 780         struct Scsi_Host *shost =
 781                 container_of((void *)tgt, struct Scsi_Host, hostdata[0]);
 782         struct scsi_device *sdev;
 783         struct fw_device *device = fw_device(tgt->unit->device.parent);
 784
 785         /* prevent deadlocks */
 786         sbp2_unblock(tgt);
 787
 788         list_for_each_entry_safe(lu, next, &tgt->lu_list, link) {
 789                 sdev = scsi_device_lookup(shost, 0, 0, sbp2_lun2int(lu->lun));
 790                 if (sdev) {
 791                         scsi_remove_device(sdev);
 792                         scsi_device_put(sdev);
 793                 }
 794                 sbp2_send_management_orb(lu, tgt->node_id, lu->generation,
 795                                 SBP2_LOGOUT_REQUEST, lu->login_id, NULL);
 796
 797                 fw_core_remove_address_handler(&lu->address_handler);
 798                 list_del(&lu->link);
 799                 kfree(lu);
 800         }
 801         scsi_remove_host(shost);
 802         fw_notify("released %s, target %d:0:0\n", tgt->bus_id, shost->host_no);
 803
 804         fw_unit_put(tgt->unit);
 805         scsi_host_put(shost);
 806         fw_device_put(device);
 807 }
 808
 809 static struct workqueue_struct *sbp2_wq;
 810
 811 /*
 812  * Always get the target's kref when scheduling work on one its units.
 813  * Each workqueue job is responsible to call sbp2_target_put() upon return.
 814  */
 815 static void sbp2_queue_work(struct sbp2_logical_unit *lu, unsigned long delay)
 816 {
 817         if (queue_delayed_work(sbp2_wq, &lu->work, delay))
 818                 kref_get(&lu->tgt->kref);
 819 }
 820
 821 static void sbp2_target_put(struct sbp2_target *tgt)
 822 {
 823         kref_put(&tgt->kref, sbp2_release_target);
 824 }
 825
 826 static void
 827 complete_set_busy_timeout(struct fw_card *card, int rcode,
 828                           void *payload, size_t length, void *done)
 829 {
 830         complete(done);
 831 }
 832
 833 /*
 834  * Write retransmit retry values into the BUSY_TIMEOUT register.
 835  * - The single-phase retry protocol is supported by all SBP-2 devices, but the
 836  *   default retry_limit value is 0 (i.e. never retry transmission). We write a
 837  *   saner value after logging into the device.
 838  * - The dual-phase retry protocol is optional to implement, and if not
 839  *   supported, writes to the dual-phase portion of the register will be
 840  *   ignored. We try to write the original 1394-1995 default here.
 841  * - In the case of devices that are also SBP-3-compliant, all writes are
 842  *   ignored, as the register is read-only, but contains single-phase retry of
 843  *   15, which is what we're trying to set for all SBP-2 device anyway, so this
 844  *   write attempt is safe and yields more consistent behavior for all devices.
 845  *
 846  * See section 8.3.2.3.5 of the 1394-1995 spec, section 6.2 of the SBP-2 spec,
 847  * and section 6.4 of the SBP-3 spec for further details.
 848  */
 849 static void sbp2_set_busy_timeout(struct sbp2_logical_unit *lu)
 850 {
 851         struct fw_device *device = fw_device(lu->tgt->unit->device.parent);
 852         DECLARE_COMPLETION_ONSTACK(done);
 853         struct fw_transaction t;
 854         static __be32 busy_timeout;
 855
 856         busy_timeout = cpu_to_be32(SBP2_CYCLE_LIMIT | SBP2_RETRY_LIMIT);
 857
 858         fw_send_request(device->card, &t, TCODE_WRITE_QUADLET_REQUEST,
 859                         lu->tgt->node_id, lu->generation, device->max_speed,
 860                         CSR_REGISTER_BASE + CSR_BUSY_TIMEOUT, &busy_timeout,
 861                         sizeof(busy_timeout), complete_set_busy_timeout, &done);
 862         wait_for_completion(&done);
 863 }
 864
 865 static void sbp2_reconnect(struct work_struct *work);
 866
 867 static void sbp2_login(struct work_struct *work)
 868 {
 869         struct sbp2_logical_unit *lu =
 870                 container_of(work, struct sbp2_logical_unit, work.work);
 871         struct sbp2_target *tgt = lu->tgt;
 872         struct fw_device *device = fw_device(tgt->unit->device.parent);
 873         struct Scsi_Host *shost;
 874         struct scsi_device *sdev;
 875         struct sbp2_login_response response;
 876         int generation, node_id, local_node_id;
 877
 878         if (fw_device_is_shutdown(device))
 879                 goto out;
 880
 881         generation    = device->generation;
 882         smp_rmb();    /* node_id must not be older than generation */
 883         node_id       = device->node_id;
 884         local_node_id = device->card->node_id;
 885
 886         /* If this is a re-login attempt, log out, or we might be rejected. */
 887         if (lu->has_sdev)
 888                 sbp2_send_management_orb(lu, device->node_id, generation,
 889                                 SBP2_LOGOUT_REQUEST, lu->login_id, NULL);
 890
 891         if (sbp2_send_management_orb(lu, node_id, generation,
 892                                 SBP2_LOGIN_REQUEST, lu->lun, &response) < 0) {
 893                 if (lu->retries++ < 5) {
 894                         sbp2_queue_work(lu, DIV_ROUND_UP(HZ, 5));
 895                 } else {
 896                         fw_error("%s: failed to login to LUN %04x\n",
 897                                  tgt->bus_id, lu->lun);
 898                         /* Let any waiting I/O fail from now on. */
 899                         sbp2_unblock(lu->tgt);
 900                 }
 901                 goto out;
 902         }
 903
 904         tgt->node_id      = node_id;
 905         tgt->address_high = local_node_id << 16;
 906         sbp2_set_generation(lu, generation);
 907
 908         lu->command_block_agent_address =
 909                 ((u64)(be32_to_cpu(response.command_block_agent.high) & 0xffff)
 910                       << 32) | be32_to_cpu(response.command_block_agent.low);
 911         lu->login_id = be32_to_cpu(response.misc) & 0xffff;
 912
 913         fw_notify("%s: logged in to LUN %04x (%d retries)\n",
 914                   tgt->bus_id, lu->lun, lu->retries);
 915
 916         /* set appropriate retry limit(s) in BUSY_TIMEOUT register */
 917         sbp2_set_busy_timeout(lu);
 918
 919         PREPARE_DELAYED_WORK(&lu->work, sbp2_reconnect);
 920         sbp2_agent_reset(lu);
 921
 922         /* This was a re-login. */
 923         if (lu->has_sdev) {
 924                 sbp2_cancel_orbs(lu);
 925                 sbp2_conditionally_unblock(lu);
 926                 goto out;
 927         }
 928
 929         if (lu->tgt->workarounds & SBP2_WORKAROUND_DELAY_INQUIRY)
 930                 ssleep(SBP2_INQUIRY_DELAY);
 931
 932         shost = container_of((void *)tgt, struct Scsi_Host, hostdata[0]);
 933         sdev = __scsi_add_device(shost, 0, 0, sbp2_lun2int(lu->lun), lu);
 934         /*
 935          * FIXME:  We are unable to perform reconnects while in sbp2_login().
 936          * Therefore __scsi_add_device() will get into trouble if a bus reset
 937          * happens in parallel.  It will either fail or leave us with an
 938          * unusable sdev.  As a workaround we check for this and retry the
 939          * whole login and SCSI probing.
 940          */
 941
 942         /* Reported error during __scsi_add_device() */
 943         if (IS_ERR(sdev))
 944                 goto out_logout_login;
 945
 946         /* Unreported error during __scsi_add_device() */
 947         smp_rmb(); /* get current card generation */
 948         if (generation != device->card->generation) {
 949                 scsi_remove_device(sdev);
 950                 scsi_device_put(sdev);
 951                 goto out_logout_login;
 952         }
 953
 954         /* No error during __scsi_add_device() */
 955         lu->has_sdev = true;
 956         scsi_device_put(sdev);
 957         sbp2_allow_block(lu);
 958         goto out;
 959
 960  out_logout_login:
 961         smp_rmb(); /* generation may have changed */
 962         generation = device->generation;
 963         smp_rmb(); /* node_id must not be older than generation */
 964
 965         sbp2_send_management_orb(lu, device->node_id, generation,
 966                                  SBP2_LOGOUT_REQUEST, lu->login_id, NULL);
 967         /*
 968          * If a bus reset happened, sbp2_update will have requeued
 969          * lu->work already.  Reset the work from reconnect to login.
 970          */
 971         PREPARE_DELAYED_WORK(&lu->work, sbp2_login);
 972  out:
 973         sbp2_target_put(tgt);
 974 }
 975
 976 static int sbp2_add_logical_unit(struct sbp2_target *tgt, int lun_entry)
 977 {
 978         struct sbp2_logical_unit *lu;
 979
 980         lu = kmalloc(sizeof(*lu), GFP_KERNEL);
 981         if (!lu)
 982                 return -ENOMEM;
 983
 984         lu->address_handler.length           = 0x100;
 985         lu->address_handler.address_callback = sbp2_status_write;
 986         lu->address_handler.callback_data    = lu;
 987
 988         if (fw_core_add_address_handler(&lu->address_handler,
 989                                         &fw_high_memory_region) < 0) {
 990                 kfree(lu);
 991                 return -ENOMEM;
 992         }
 993
 994         lu->tgt      = tgt;
 995         lu->lun      = lun_entry & 0xffff;
 996         lu->retries  = 0;
 997         lu->has_sdev = false;
 998         lu->blocked  = false;
 999         ++tgt->dont_block;
1000         INIT_LIST_HEAD(&lu->orb_list);
1001         INIT_DELAYED_WORK(&lu->work, sbp2_login);
1002
1003         list_add_tail(&lu->link, &tgt->lu_list);
1004         return 0;
1005 }
1006
1007 static int sbp2_scan_logical_unit_dir(struct sbp2_target *tgt, u32 *directory)
1008 {
1009         struct fw_csr_iterator ci;
1010         int key, value;
1011
1012         fw_csr_iterator_init(&ci, directory);
1013         while (fw_csr_iterator_next(&ci, &key, &value))
1014                 if (key == SBP2_CSR_LOGICAL_UNIT_NUMBER &&
1015                     sbp2_add_logical_unit(tgt, value) < 0)
1016                         return -ENOMEM;
1017         return 0;
1018 }
1019
1020 static int sbp2_scan_unit_dir(struct sbp2_target *tgt, u32 *directory,
1021                               u32 *model, u32 *firmware_revision)
1022 {
1023         struct fw_csr_iterator ci;
1024         int key, value;
1025         unsigned int timeout;
1026
1027         fw_csr_iterator_init(&ci, directory);
1028         while (fw_csr_iterator_next(&ci, &key, &value)) {
1029                 switch (key) {
1030
1031                 case CSR_DEPENDENT_INFO | CSR_OFFSET:
1032                         tgt->management_agent_address =
1033                                         CSR_REGISTER_BASE + 4 * value;
1034                         break;
1035
1036                 case CSR_DIRECTORY_ID:
1037                         tgt->directory_id = value;
1038                         break;
1039
1040                 case CSR_MODEL:
1041                         *model = value;
1042                         break;
1043
1044                 case SBP2_CSR_FIRMWARE_REVISION:
1045                         *firmware_revision = value;
1046                         break;
1047
1048                 case SBP2_CSR_UNIT_CHARACTERISTICS:
1049                         /* the timeout value is stored in 500ms units */
1050                         timeout = ((unsigned int) value >> 8 & 0xff) * 500;
1051                         timeout = max(timeout, SBP2_MIN_LOGIN_ORB_TIMEOUT);
1052                         tgt->mgt_orb_timeout =
1053                                   min(timeout, SBP2_MAX_LOGIN_ORB_TIMEOUT);
1054
1055                         if (timeout > tgt->mgt_orb_timeout)
1056                                 fw_notify("%s: config rom contains %ds "
1057                                           "management ORB timeout, limiting "
1058                                           "to %ds\n", tgt->bus_id,
1059                                           timeout / 1000,
1060                                           tgt->mgt_orb_timeout / 1000);
1061                         break;
1062
1063                 case SBP2_CSR_LOGICAL_UNIT_NUMBER:
1064                         if (sbp2_add_logical_unit(tgt, value) < 0)
1065                                 return -ENOMEM;
1066                         break;
1067
1068                 case SBP2_CSR_LOGICAL_UNIT_DIRECTORY:
1069                         /* Adjust for the increment in the iterator */
1070                         if (sbp2_scan_logical_unit_dir(tgt, ci.p - 1 + value) < 0)
1071                                 return -ENOMEM;
1072                         break;
1073                 }
1074         }
1075         return 0;
1076 }
1077
1078 static void sbp2_init_workarounds(struct sbp2_target *tgt, u32 model,
1079                                   u32 firmware_revision)
1080 {
1081         int i;
1082         unsigned int w = sbp2_param_workarounds;
1083
1084         if (w)
1085                 fw_notify("Please notify linux1394-devel@lists.sourceforge.net "
1086                           "if you need the workarounds parameter for %s\n",
1087                           tgt->bus_id);
1088
1089         if (w & SBP2_WORKAROUND_OVERRIDE)
1090                 goto out;
1091
1092         for (i = 0; i < ARRAY_SIZE(sbp2_workarounds_table); i++) {
1093
1094                 if (sbp2_workarounds_table[i].firmware_revision !=
1095                     (firmware_revision & 0xffffff00))
1096                         continue;
1097
1098                 if (sbp2_workarounds_table[i].model != model &&
1099                     sbp2_workarounds_table[i].model != ~0)
1100                         continue;
1101
1102                 w |= sbp2_workarounds_table[i].workarounds;
1103                 break;
1104         }
1105  out:
1106         if (w)
1107                 fw_notify("Workarounds for %s: 0x%x "
1108                           "(firmware_revision 0x%06x, model_id 0x%06x)\n",
1109                           tgt->bus_id, w, firmware_revision, model);
1110         tgt->workarounds = w;
1111 }
1112
1113 static struct scsi_host_template scsi_driver_template;
1114
1115 static int sbp2_probe(struct device *dev)
1116 {
1117         struct fw_unit *unit = fw_unit(dev);
1118         struct fw_device *device = fw_device(unit->device.parent);
1119         struct sbp2_target *tgt;
1120         struct sbp2_logical_unit *lu;
1121         struct Scsi_Host *shost;
1122         u32 model, firmware_revision;
1123
1124         shost = scsi_host_alloc(&scsi_driver_template, sizeof(*tgt));
1125         if (shost == NULL)
1126                 return -ENOMEM;
1127
1128         tgt = (struct sbp2_target *)shost->hostdata;
1129         unit->device.driver_data = tgt;
1130         tgt->unit = unit;
1131         kref_init(&tgt->kref);
1132         INIT_LIST_HEAD(&tgt->lu_list);
1133         tgt->bus_id = unit->device.bus_id;
1134         tgt->guid = (u64)device->config_rom[3] << 32 | device->config_rom[4];
1135
1136         if (fw_device_enable_phys_dma(device) < 0)
1137                 goto fail_shost_put;
1138
1139         if (scsi_add_host(shost, &unit->device) < 0)
1140                 goto fail_shost_put;
1141
1142         fw_device_get(device);
1143         fw_unit_get(unit);
1144
1145         /* Initialize to values that won't match anything in our table. */
1146         firmware_revision = 0xff000000;
1147         model = 0xff000000;
1148
1149         /* implicit directory ID */
1150         tgt->directory_id = ((unit->directory - device->config_rom) * 4
1151                              + CSR_CONFIG_ROM) & 0xffffff;
1152
1153         if (sbp2_scan_unit_dir(tgt, unit->directory, &model,
1154                                &firmware_revision) < 0)
1155                 goto fail_tgt_put;
1156
1157         sbp2_init_workarounds(tgt, model, firmware_revision);
1158
1159         /* Do the login in a workqueue so we can easily reschedule retries. */
1160         list_for_each_entry(lu, &tgt->lu_list, link)
1161                 sbp2_queue_work(lu, 0);
1162         return 0;
1163
1164  fail_tgt_put:
1165         sbp2_target_put(tgt);
1166         return -ENOMEM;
1167
1168  fail_shost_put:
1169         scsi_host_put(shost);
1170         return -ENOMEM;
1171 }
1172
1173 static int sbp2_remove(struct device *dev)
1174 {
1175         struct fw_unit *unit = fw_unit(dev);
1176         struct sbp2_target *tgt = unit->device.driver_data;
1177
1178         sbp2_target_put(tgt);
1179         return 0;
1180 }
1181
1182 static void sbp2_reconnect(struct work_struct *work)
1183 {
1184         struct sbp2_logical_unit *lu =
1185                 container_of(work, struct sbp2_logical_unit, work.work);
1186         struct sbp2_target *tgt = lu->tgt;
1187         struct fw_device *device = fw_device(tgt->unit->device.parent);
1188         int generation, node_id, local_node_id;
1189
1190         if (fw_device_is_shutdown(device))
1191                 goto out;
1192
1193         generation    = device->generation;
1194         smp_rmb();    /* node_id must not be older than generation */
1195         node_id       = device->node_id;
1196         local_node_id = device->card->node_id;
1197
1198         if (sbp2_send_management_orb(lu, node_id, generation,
1199                                      SBP2_RECONNECT_REQUEST,
1200                                      lu->login_id, NULL) < 0) {
1201                 /*
1202                  * If reconnect was impossible even though we are in the
1203                  * current generation, fall back and try to log in again.
1204                  *
1205                  * We could check for "Function rejected" status, but
1206                  * looking at the bus generation as simpler and more general.
1207                  */
1208                 smp_rmb(); /* get current card generation */
1209                 if (generation == device->card->generation ||
1210                     lu->retries++ >= 5) {
1211                         fw_error("%s: failed to reconnect\n", tgt->bus_id);
1212                         lu->retries = 0;
1213                         PREPARE_DELAYED_WORK(&lu->work, sbp2_login);
1214                 }
1215                 sbp2_queue_work(lu, DIV_ROUND_UP(HZ, 5));
1216                 goto out;
1217         }
1218
1219         tgt->node_id      = node_id;
1220         tgt->address_high = local_node_id << 16;
1221         sbp2_set_generation(lu, generation);
1222
1223         fw_notify("%s: reconnected to LUN %04x (%d retries)\n",
1224                   tgt->bus_id, lu->lun, lu->retries);
1225
1226         sbp2_agent_reset(lu);
1227         sbp2_cancel_orbs(lu);
1228         sbp2_conditionally_unblock(lu);
1229  out:
1230         sbp2_target_put(tgt);
1231 }
1232
1233 static void sbp2_update(struct fw_unit *unit)
1234 {
1235         struct sbp2_target *tgt = unit->device.driver_data;
1236         struct sbp2_logical_unit *lu;
1237
1238         fw_device_enable_phys_dma(fw_device(unit->device.parent));
1239
1240         /*
1241          * Fw-core serializes sbp2_update() against sbp2_remove().
1242          * Iteration over tgt->lu_list is therefore safe here.
1243          */
1244         list_for_each_entry(lu, &tgt->lu_list, link) {
1245                 sbp2_conditionally_block(lu);
1246                 lu->retries = 0;
1247                 sbp2_queue_work(lu, 0);
1248         }
1249 }
1250
1251 #define SBP2_UNIT_SPEC_ID_ENTRY 0x0000609e
1252 #define SBP2_SW_VERSION_ENTRY   0x00010483
1253
1254 static const struct fw_device_id sbp2_id_table[] = {
1255         {
1256                 .match_flags  = FW_MATCH_SPECIFIER_ID | FW_MATCH_VERSION,
1257                 .specifier_id = SBP2_UNIT_SPEC_ID_ENTRY,
1258                 .version      = SBP2_SW_VERSION_ENTRY,
1259         },
1260         { }
1261 };
1262
1263 static struct fw_driver sbp2_driver = {
1264         .driver   = {
1265                 .owner  = THIS_MODULE,
1266                 .name   = sbp2_driver_name,
1267                 .bus    = &fw_bus_type,
1268                 .probe  = sbp2_probe,
1269                 .remove = sbp2_remove,
1270         },
1271         .update   = sbp2_update,
1272         .id_table = sbp2_id_table,
1273 };
1274
1275 static unsigned int
1276 sbp2_status_to_sense_data(u8 *sbp2_status, u8 *sense_data)
1277 {
1278         int sam_status;
1279
1280         sense_data[0] = 0x70;
1281         sense_data[1] = 0x0;
1282         sense_data[2] = sbp2_status[1];
1283         sense_data[3] = sbp2_status[4];
1284         sense_data[4] = sbp2_status[5];
1285         sense_data[5] = sbp2_status[6];
1286         sense_data[6] = sbp2_status[7];
1287         sense_data[7] = 10;
1288         sense_data[8] = sbp2_status[8];
1289         sense_data[9] = sbp2_status[9];
1290         sense_data[10] = sbp2_status[10];
1291         sense_data[11] = sbp2_status[11];
1292         sense_data[12] = sbp2_status[2];
1293         sense_data[13] = sbp2_status[3];
1294         sense_data[14] = sbp2_status[12];
1295         sense_data[15] = sbp2_status[13];
1296
1297         sam_status = sbp2_status[0] & 0x3f;
1298
1299         switch (sam_status) {
1300         case SAM_STAT_GOOD:
1301         case SAM_STAT_CHECK_CONDITION:
1302         case SAM_STAT_CONDITION_MET:
1303         case SAM_STAT_BUSY:
1304         case SAM_STAT_RESERVATION_CONFLICT:
1305         case SAM_STAT_COMMAND_TERMINATED:
1306                 return DID_OK << 16 | sam_status;
1307
1308         default:
1309                 return DID_ERROR << 16;
1310         }
1311 }
1312
1313 static void
1314 complete_command_orb(struct sbp2_orb *base_orb, struct sbp2_status *status)
1315 {
1316         struct sbp2_command_orb *orb =
1317                 container_of(base_orb, struct sbp2_command_orb, base);
1318         struct fw_device *device = fw_device(orb->lu->tgt->unit->device.parent);
1319         int result;
1320
1321         if (status != NULL) {
1322                 if (STATUS_GET_DEAD(*status))
1323                         sbp2_agent_reset_no_wait(orb->lu);
1324
1325                 switch (STATUS_GET_RESPONSE(*status)) {
1326                 case SBP2_STATUS_REQUEST_COMPLETE:
1327                         result = DID_OK << 16;
1328                         break;
1329                 case SBP2_STATUS_TRANSPORT_FAILURE:
1330                         result = DID_BUS_BUSY << 16;
1331                         break;
1332                 case SBP2_STATUS_ILLEGAL_REQUEST:
1333                 case SBP2_STATUS_VENDOR_DEPENDENT:
1334                 default:
1335                         result = DID_ERROR << 16;
1336                         break;
1337                 }
1338
1339                 if (result == DID_OK << 16 && STATUS_GET_LEN(*status) > 1)
1340                         result = sbp2_status_to_sense_data(STATUS_GET_DATA(*status),
1341                                                            orb->cmd->sense_buffer);
1342         } else {
1343                 /*
1344                  * If the orb completes with status == NULL, something
1345                  * went wrong, typically a bus reset happened mid-orb
1346                  * or when sending the write (less likely).
1347                  */
1348                 result = DID_BUS_BUSY << 16;
1349                 sbp2_conditionally_block(orb->lu);
1350         }
1351
1352         dma_unmap_single(device->card->device, orb->base.request_bus,
1353                          sizeof(orb->request), DMA_TO_DEVICE);
1354
1355         if (scsi_sg_count(orb->cmd) > 0)
1356                 dma_unmap_sg(device->card->device, scsi_sglist(orb->cmd),
1357                              scsi_sg_count(orb->cmd),
1358                              orb->cmd->sc_data_direction);
1359
1360         if (orb->page_table_bus != 0)
1361                 dma_unmap_single(device->card->device, orb->page_table_bus,
1362                                  sizeof(orb->page_table), DMA_TO_DEVICE);
1363
1364         orb->cmd->result = result;
1365         orb->done(orb->cmd);
1366 }
1367
1368 static int
1369 sbp2_map_scatterlist(struct sbp2_command_orb *orb, struct fw_device *device,
1370                      struct sbp2_logical_unit *lu)
1371 {
1372         struct scatterlist *sg;
1373         int sg_len, l, i, j, count;
1374         dma_addr_t sg_addr;
1375
1376         sg = scsi_sglist(orb->cmd);
1377         count = dma_map_sg(device->card->device, sg, scsi_sg_count(orb->cmd),
1378                            orb->cmd->sc_data_direction);
1379         if (count == 0)
1380                 goto fail;
1381
1382         /*
1383          * Handle the special case where there is only one element in
1384          * the scatter list by converting it to an immediate block
1385          * request. This is also a workaround for broken devices such
1386          * as the second generation iPod which doesn't support page
1387          * tables.
1388          */
1389         if (count == 1 && sg_dma_len(sg) < SBP2_MAX_SG_ELEMENT_LENGTH) {
1390                 orb->request.data_descriptor.high =
1391                         cpu_to_be32(lu->tgt->address_high);
1392                 orb->request.data_descriptor.low  =
1393                         cpu_to_be32(sg_dma_address(sg));
1394                 orb->request.misc |=
1395                         cpu_to_be32(COMMAND_ORB_DATA_SIZE(sg_dma_len(sg)));
1396                 return 0;
1397         }
1398
1399         /*
1400          * Convert the scatterlist to an sbp2 page table.  If any
1401          * scatterlist entries are too big for sbp2, we split them as we
1402          * go.  Even if we ask the block I/O layer to not give us sg
1403          * elements larger than 65535 bytes, some IOMMUs may merge sg elements
1404          * during DMA mapping, and Linux currently doesn't prevent this.
1405          */
1406         for (i = 0, j = 0; i < count; i++, sg = sg_next(sg)) {
1407                 sg_len = sg_dma_len(sg);
1408                 sg_addr = sg_dma_address(sg);
1409                 while (sg_len) {
1410                         /* FIXME: This won't get us out of the pinch. */
1411                         if (unlikely(j >= ARRAY_SIZE(orb->page_table))) {
1412                                 fw_error("page table overflow\n");
1413                                 goto fail_page_table;
1414                         }
1415                         l = min(sg_len, SBP2_MAX_SG_ELEMENT_LENGTH);
1416                         orb->page_table[j].low = cpu_to_be32(sg_addr);
1417                         orb->page_table[j].high = cpu_to_be32(l << 16);
1418                         sg_addr += l;
1419                         sg_len -= l;
1420                         j++;
1421                 }
1422         }
1423
1424         orb->page_table_bus =
1425                 dma_map_single(device->card->device, orb->page_table,
1426                                sizeof(orb->page_table), DMA_TO_DEVICE);
1427         if (dma_mapping_error(orb->page_table_bus))
1428                 goto fail_page_table;
1429
1430         /*
1431          * The data_descriptor pointer is the one case where we need
1432          * to fill in the node ID part of the address.  All other
1433          * pointers assume that the data referenced reside on the
1434          * initiator (i.e. us), but data_descriptor can refer to data
1435          * on other nodes so we need to put our ID in descriptor.high.
1436          */
1437         orb->request.data_descriptor.high = cpu_to_be32(lu->tgt->address_high);
1438         orb->request.data_descriptor.low  = cpu_to_be32(orb->page_table_bus);
1439         orb->request.misc |= cpu_to_be32(COMMAND_ORB_PAGE_TABLE_PRESENT |
1440                                          COMMAND_ORB_DATA_SIZE(j));
1441
1442         return 0;
1443
1444  fail_page_table:
1445         dma_unmap_sg(device->card->device, sg, scsi_sg_count(orb->cmd),
1446                      orb->cmd->sc_data_direction);
1447  fail:
1448         return -ENOMEM;
1449 }
1450
1451 /* SCSI stack integration */
1452
1453 static int sbp2_scsi_queuecommand(struct scsi_cmnd *cmd, scsi_done_fn_t done)
1454 {
1455         struct sbp2_logical_unit *lu = cmd->device->hostdata;
1456         struct fw_device *device = fw_device(lu->tgt->unit->device.parent);
1457         struct sbp2_command_orb *orb;
1458         unsigned int max_payload;
1459         int retval = SCSI_MLQUEUE_HOST_BUSY;
1460
1461         /*
1462          * Bidirectional commands are not yet implemented, and unknown
1463          * transfer direction not handled.
1464          */
1465         if (cmd->sc_data_direction == DMA_BIDIRECTIONAL) {
1466                 fw_error("Can't handle DMA_BIDIRECTIONAL, rejecting command\n");
1467                 cmd->result = DID_ERROR << 16;
1468                 done(cmd);
1469                 return 0;
1470         }
1471
1472         orb = kzalloc(sizeof(*orb), GFP_ATOMIC);
1473         if (orb == NULL) {
1474                 fw_notify("failed to alloc orb\n");
1475                 return SCSI_MLQUEUE_HOST_BUSY;
1476         }
1477
1478         /* Initialize rcode to something not RCODE_COMPLETE. */
1479         orb->base.rcode = -1;
1480         kref_init(&orb->base.kref);
1481
1482         orb->lu   = lu;
1483         orb->done = done;
1484         orb->cmd  = cmd;
1485
1486         orb->request.next.high   = cpu_to_be32(SBP2_ORB_NULL);
1487         /*
1488          * At speed 100 we can do 512 bytes per packet, at speed 200,
1489          * 1024 bytes per packet etc.  The SBP-2 max_payload field
1490          * specifies the max payload size as 2 ^ (max_payload + 2), so
1491          * if we set this to max_speed + 7, we get the right value.
1492          */
1493         max_payload = min(device->max_speed + 7,
1494                           device->card->max_receive - 1);
1495         orb->request.misc = cpu_to_be32(
1496                 COMMAND_ORB_MAX_PAYLOAD(max_payload) |
1497                 COMMAND_ORB_SPEED(device->max_speed) |
1498                 COMMAND_ORB_NOTIFY);
1499
1500         if (cmd->sc_data_direction == DMA_FROM_DEVICE)
1501                 orb->request.misc |= cpu_to_be32(COMMAND_ORB_DIRECTION);
1502
1503         if (scsi_sg_count(cmd) && sbp2_map_scatterlist(orb, device, lu) < 0)
1504                 goto out;
1505
1506         memcpy(orb->request.command_block, cmd->cmnd, cmd->cmd_len);
1507
1508         orb->base.callback = complete_command_orb;
1509         orb->base.request_bus =
1510                 dma_map_single(device->card->device, &orb->request,
1511                                sizeof(orb->request), DMA_TO_DEVICE);
1512         if (dma_mapping_error(orb->base.request_bus))
1513                 goto out;
1514
1515         sbp2_send_orb(&orb->base, lu, lu->tgt->node_id, lu->generation,
1516                       lu->command_block_agent_address + SBP2_ORB_POINTER);
1517         retval = 0;
1518  out:
1519         kref_put(&orb->base.kref, free_orb);
1520         return retval;
1521 }
1522
1523 static int sbp2_scsi_slave_alloc(struct scsi_device *sdev)
1524 {
1525         struct sbp2_logical_unit *lu = sdev->hostdata;
1526
1527         /* (Re-)Adding logical units via the SCSI stack is not supported. */
1528         if (!lu)
1529                 return -ENOSYS;
1530
1531         sdev->allow_restart = 1;
1532
1533         /* SBP-2 requires quadlet alignment of the data buffers. */
1534         blk_queue_update_dma_alignment(sdev->request_queue, 4 - 1);
1535
1536         if (lu->tgt->workarounds & SBP2_WORKAROUND_INQUIRY_36)
1537                 sdev->inquiry_len = 36;
1538
1539         return 0;
1540 }
1541
1542 static int sbp2_scsi_slave_configure(struct scsi_device *sdev)
1543 {
1544         struct sbp2_logical_unit *lu = sdev->hostdata;
1545
1546         sdev->use_10_for_rw = 1;
1547
1548         if (sbp2_param_exclusive_login)
1549                 sdev->manage_start_stop = 1;
1550
1551         if (sdev->type == TYPE_ROM)
1552                 sdev->use_10_for_ms = 1;
1553
1554         if (sdev->type == TYPE_DISK &&
1555             lu->tgt->workarounds & SBP2_WORKAROUND_MODE_SENSE_8)
1556                 sdev->skip_ms_page_8 = 1;
1557
1558         if (lu->tgt->workarounds & SBP2_WORKAROUND_FIX_CAPACITY)
1559                 sdev->fix_capacity = 1;
1560
1561         if (lu->tgt->workarounds & SBP2_WORKAROUND_POWER_CONDITION)
1562                 sdev->start_stop_pwr_cond = 1;
1563
1564         if (lu->tgt->workarounds & SBP2_WORKAROUND_128K_MAX_TRANS)
1565                 blk_queue_max_sectors(sdev->request_queue, 128 * 1024 / 512);
1566
1567         return 0;
1568 }
1569
1570 /*
1571  * Called by scsi stack when something has really gone wrong.  Usually
1572  * called when a command has timed-out for some reason.
1573  */
1574 static int sbp2_scsi_abort(struct scsi_cmnd *cmd)
1575 {
1576         struct sbp2_logical_unit *lu = cmd->device->hostdata;
1577
1578         fw_notify("%s: sbp2_scsi_abort\n", lu->tgt->bus_id);
1579         sbp2_agent_reset(lu);
1580         sbp2_cancel_orbs(lu);
1581
1582         return SUCCESS;
1583 }
1584
1585 /*
1586  * Format of /sys/bus/scsi/devices/.../ieee1394_id:
1587  * u64 EUI-64 : u24 directory_ID : u16 LUN  (all printed in hexadecimal)
1588  *
1589  * This is the concatenation of target port identifier and logical unit
1590  * identifier as per SAM-2...SAM-4 annex A.
1591  */
1592 static ssize_t
1593 sbp2_sysfs_ieee1394_id_show(struct device *dev, struct device_attribute *attr,
1594                             char *buf)
1595 {
1596         struct scsi_device *sdev = to_scsi_device(dev);
1597         struct sbp2_logical_unit *lu;
1598
1599         if (!sdev)
1600                 return 0;
1601
1602         lu = sdev->hostdata;
1603
1604         return sprintf(buf, "%016llx:%06x:%04x\n",
1605                         (unsigned long long)lu->tgt->guid,
1606                         lu->tgt->directory_id, lu->lun);
1607 }
1608
1609 static DEVICE_ATTR(ieee1394_id, S_IRUGO, sbp2_sysfs_ieee1394_id_show, NULL);
1610
1611 static struct device_attribute *sbp2_scsi_sysfs_attrs[] = {
1612         &dev_attr_ieee1394_id,
1613         NULL
1614 };
1615
1616 static struct scsi_host_template scsi_driver_template = {
1617         .module                 = THIS_MODULE,
1618         .name                   = "SBP-2 IEEE-1394",
1619         .proc_name              = sbp2_driver_name,
1620         .queuecommand           = sbp2_scsi_queuecommand,
1621         .slave_alloc            = sbp2_scsi_slave_alloc,
1622         .slave_configure        = sbp2_scsi_slave_configure,
1623         .eh_abort_handler       = sbp2_scsi_abort,
1624         .this_id                = -1,
1625         .sg_tablesize           = SG_ALL,
1626         .use_clustering         = ENABLE_CLUSTERING,
1627         .cmd_per_lun            = 1,
1628         .can_queue              = 1,
1629         .sdev_attrs             = sbp2_scsi_sysfs_attrs,
1630 };
1631
1632 MODULE_AUTHOR("Kristian Hoegsberg <krh@bitplanet.net>");
1633 MODULE_DESCRIPTION("SCSI over IEEE1394");
1634 MODULE_LICENSE("GPL");
1635 MODULE_DEVICE_TABLE(ieee1394, sbp2_id_table);
1636
1637 /* Provide a module alias so root-on-sbp2 initrds don't break. */
1638 #ifndef CONFIG_IEEE1394_SBP2_MODULE
1639 MODULE_ALIAS("sbp2");
1640 #endif
1641
1642 static int __init sbp2_init(void)
1643 {
1644         sbp2_wq = create_singlethread_workqueue(KBUILD_MODNAME);
1645         if (!sbp2_wq)
1646                 return -ENOMEM;
1647
1648         return driver_register(&sbp2_driver.driver);
1649 }
1650
1651 static void __exit sbp2_cleanup(void)
1652 {
1653         driver_unregister(&sbp2_driver.driver);
1654         destroy_workqueue(sbp2_wq);
1655 }
1656
1657 module_init(sbp2_init);
1658 module_exit(sbp2_cleanup);