drivers/firewire/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/bug.h>
  33 #include <linux/completion.h>
  34 #include <linux/delay.h>
  35 #include <linux/device.h>
  36 #include <linux/dma-mapping.h>
  37 #include <linux/firewire.h>
  38 #include <linux/firewire-constants.h>
  39 #include <linux/init.h>
  40 #include <linux/jiffies.h>
  41 #include <linux/kernel.h>
  42 #include <linux/kref.h>
  43 #include <linux/list.h>
  44 #include <linux/mod_devicetable.h>
  45 #include <linux/module.h>
  46 #include <linux/moduleparam.h>
  47 #include <linux/scatterlist.h>
  48 #include <linux/slab.h>
  49 #include <linux/spinlock.h>
  50 #include <linux/string.h>
  51 #include <linux/stringify.h>
  52 #include <linux/workqueue.h>
  53
  54 #include <asm/byteorder.h>
  55
  56 #include <scsi/scsi.h>
  57 #include <scsi/scsi_cmnd.h>
  58 #include <scsi/scsi_device.h>
  59 #include <scsi/scsi_host.h>
  60
  61 /*
  62  * So far only bridges from Oxford Semiconductor are known to support
  63  * concurrent logins. Depending on firmware, four or two concurrent logins
  64  * are possible on OXFW911 and newer Oxsemi bridges.
  65  *
  66  * Concurrent logins are useful together with cluster filesystems.
  67  */
  68 static bool sbp2_param_exclusive_login = 1;
  69 module_param_named(exclusive_login, sbp2_param_exclusive_login, bool, 0644);
  70 MODULE_PARM_DESC(exclusive_login, "Exclusive login to sbp2 device "
  71                  "(default = Y, use N for concurrent initiators)");
  72
  73 /*
  74  * Flags for firmware oddities
  75  *
  76  * - 128kB max transfer
  77  *   Limit transfer size. Necessary for some old bridges.
  78  *
  79  * - 36 byte inquiry
  80  *   When scsi_mod probes the device, let the inquiry command look like that
  81  *   from MS Windows.
  82  *
  83  * - skip mode page 8
  84  *   Suppress sending of mode_sense for mode page 8 if the device pretends to
  85  *   support the SCSI Primary Block commands instead of Reduced Block Commands.
  86  *
  87  * - fix capacity
  88  *   Tell sd_mod to correct the last sector number reported by read_capacity.
  89  *   Avoids access beyond actual disk limits on devices with an off-by-one bug.
  90  *   Don't use this with devices which don't have this bug.
  91  *
  92  * - delay inquiry
  93  *   Wait extra SBP2_INQUIRY_DELAY seconds after login before SCSI inquiry.
  94  *
  95  * - power condition
  96  *   Set the power condition field in the START STOP UNIT commands sent by
  97  *   sd_mod on suspend, resume, and shutdown (if manage_start_stop is on).
  98  *   Some disks need this to spin down or to resume properly.
  99  *
 100  * - override internal blacklist
 101  *   Instead of adding to the built-in blacklist, use only the workarounds
 102  *   specified in the module load parameter.
 103  *   Useful if a blacklist entry interfered with a non-broken device.
 104  */
 105 #define SBP2_WORKAROUND_128K_MAX_TRANS  0x1
 106 #define SBP2_WORKAROUND_INQUIRY_36      0x2
 107 #define SBP2_WORKAROUND_MODE_SENSE_8    0x4
 108 #define SBP2_WORKAROUND_FIX_CAPACITY    0x8
 109 #define SBP2_WORKAROUND_DELAY_INQUIRY   0x10
 110 #define SBP2_INQUIRY_DELAY              12
 111 #define SBP2_WORKAROUND_POWER_CONDITION 0x20
 112 #define SBP2_WORKAROUND_OVERRIDE        0x100
 113
 114 static int sbp2_param_workarounds;
 115 module_param_named(workarounds, sbp2_param_workarounds, int, 0644);
 116 MODULE_PARM_DESC(workarounds, "Work around device bugs (default = 0"
 117         ", 128kB max transfer = " __stringify(SBP2_WORKAROUND_128K_MAX_TRANS)
 118         ", 36 byte inquiry = "    __stringify(SBP2_WORKAROUND_INQUIRY_36)
 119         ", skip mode page 8 = "   __stringify(SBP2_WORKAROUND_MODE_SENSE_8)
 120         ", fix capacity = "       __stringify(SBP2_WORKAROUND_FIX_CAPACITY)
 121         ", delay inquiry = "      __stringify(SBP2_WORKAROUND_DELAY_INQUIRY)
 122         ", set power condition in start stop unit = "
 123                                   __stringify(SBP2_WORKAROUND_POWER_CONDITION)
 124         ", override internal blacklist = " __stringify(SBP2_WORKAROUND_OVERRIDE)
 125         ", or a combination)");
 126
 127 /*
 128  * We create one struct sbp2_logical_unit per SBP-2 Logical Unit Number Entry
 129  * and one struct scsi_device per sbp2_logical_unit.
 130  */
 131 struct sbp2_logical_unit {
 132         struct sbp2_target *tgt;
 133         struct list_head link;
 134         struct fw_address_handler address_handler;
 135         struct list_head orb_list;
 136
 137         u64 command_block_agent_address;
 138         u16 lun;
 139         int login_id;
 140
 141         /*
 142          * The generation is updated once we've logged in or reconnected
 143          * to the logical unit.  Thus, I/O to the device will automatically
 144          * fail and get retried if it happens in a window where the device
 145          * is not ready, e.g. after a bus reset but before we reconnect.
 146          */
 147         int generation;
 148         int retries;
 149         work_func_t workfn;
 150         struct delayed_work work;
 151         bool has_sdev;
 152         bool blocked;
 153 };
 154
 155 static void sbp2_queue_work(struct sbp2_logical_unit *lu, unsigned long delay)
 156 {
 157         queue_delayed_work(fw_workqueue, &lu->work, delay);
 158 }
 159
 160 /*
 161  * We create one struct sbp2_target per IEEE 1212 Unit Directory
 162  * and one struct Scsi_Host per sbp2_target.
 163  */
 164 struct sbp2_target {
 165         struct fw_unit *unit;
 166         struct list_head lu_list;
 167
 168         u64 management_agent_address;
 169         u64 guid;
 170         int directory_id;
 171         int node_id;
 172         int address_high;
 173         unsigned int workarounds;
 174         unsigned int mgt_orb_timeout;
 175         unsigned int max_payload;
 176
 177         int dont_block; /* counter for each logical unit */
 178         int blocked;    /* ditto */
 179 };
 180
 181 static struct fw_device *target_parent_device(struct sbp2_target *tgt)
 182 {
 183         return fw_parent_device(tgt->unit);
 184 }
 185
 186 static const struct device *tgt_dev(const struct sbp2_target *tgt)
 187 {
 188         return &tgt->unit->device;
 189 }
 190
 191 static const struct device *lu_dev(const struct sbp2_logical_unit *lu)
 192 {
 193         return &lu->tgt->unit->device;
 194 }
 195
 196 /* Impossible login_id, to detect logout attempt before successful login */
 197 #define INVALID_LOGIN_ID 0x10000
 198
 199 #define SBP2_ORB_TIMEOUT                2000U           /* Timeout in ms */
 200 #define SBP2_ORB_NULL                   0x80000000
 201 #define SBP2_RETRY_LIMIT                0xf             /* 15 retries */
 202 #define SBP2_CYCLE_LIMIT                (0xc8 << 12)    /* 200 125us cycles */
 203
 204 /*
 205  * There is no transport protocol limit to the CDB length,  but we implement
 206  * a fixed length only.  16 bytes is enough for disks larger than 2 TB.
 207  */
 208 #define SBP2_MAX_CDB_SIZE               16
 209
 210 /*
 211  * The maximum SBP-2 data buffer size is 0xffff.  We quadlet-align this
 212  * for compatibility with earlier versions of this driver.
 213  */
 214 #define SBP2_MAX_SEG_SIZE               0xfffc
 215
 216 /* Unit directory keys */
 217 #define SBP2_CSR_UNIT_CHARACTERISTICS   0x3a
 218 #define SBP2_CSR_FIRMWARE_REVISION      0x3c
 219 #define SBP2_CSR_LOGICAL_UNIT_NUMBER    0x14
 220 #define SBP2_CSR_UNIT_UNIQUE_ID         0x8d
 221 #define SBP2_CSR_LOGICAL_UNIT_DIRECTORY 0xd4
 222
 223 /* Management orb opcodes */
 224 #define SBP2_LOGIN_REQUEST              0x0
 225 #define SBP2_QUERY_LOGINS_REQUEST       0x1
 226 #define SBP2_RECONNECT_REQUEST          0x3
 227 #define SBP2_SET_PASSWORD_REQUEST       0x4
 228 #define SBP2_LOGOUT_REQUEST             0x7
 229 #define SBP2_ABORT_TASK_REQUEST         0xb
 230 #define SBP2_ABORT_TASK_SET             0xc
 231 #define SBP2_LOGICAL_UNIT_RESET         0xe
 232 #define SBP2_TARGET_RESET_REQUEST       0xf
 233
 234 /* Offsets for command block agent registers */
 235 #define SBP2_AGENT_STATE                0x00
 236 #define SBP2_AGENT_RESET                0x04
 237 #define SBP2_ORB_POINTER                0x08
 238 #define SBP2_DOORBELL                   0x10
 239 #define SBP2_UNSOLICITED_STATUS_ENABLE  0x14
 240
 241 /* Status write response codes */
 242 #define SBP2_STATUS_REQUEST_COMPLETE    0x0
 243 #define SBP2_STATUS_TRANSPORT_FAILURE   0x1
 244 #define SBP2_STATUS_ILLEGAL_REQUEST     0x2
 245 #define SBP2_STATUS_VENDOR_DEPENDENT    0x3
 246
 247 #define STATUS_GET_ORB_HIGH(v)          ((v).status & 0xffff)
 248 #define STATUS_GET_SBP_STATUS(v)        (((v).status >> 16) & 0xff)
 249 #define STATUS_GET_LEN(v)               (((v).status >> 24) & 0x07)
 250 #define STATUS_GET_DEAD(v)              (((v).status >> 27) & 0x01)
 251 #define STATUS_GET_RESPONSE(v)          (((v).status >> 28) & 0x03)
 252 #define STATUS_GET_SOURCE(v)            (((v).status >> 30) & 0x03)
 253 #define STATUS_GET_ORB_LOW(v)           ((v).orb_low)
 254 #define STATUS_GET_DATA(v)              ((v).data)
 255
 256 struct sbp2_status {
 257         u32 status;
 258         u32 orb_low;
 259         u8 data[24];
 260 };
 261
 262 struct sbp2_pointer {
 263         __be32 high;
 264         __be32 low;
 265 };
 266
 267 struct sbp2_orb {
 268         struct fw_transaction t;
 269         struct kref kref;
 270         dma_addr_t request_bus;
 271         int rcode;
 272         void (*callback)(struct sbp2_orb * orb, struct sbp2_status * status);
 273         struct list_head link;
 274 };
 275
 276 #define MANAGEMENT_ORB_LUN(v)                   ((v))
 277 #define MANAGEMENT_ORB_FUNCTION(v)              ((v) << 16)
 278 #define MANAGEMENT_ORB_RECONNECT(v)             ((v) << 20)
 279 #define MANAGEMENT_ORB_EXCLUSIVE(v)             ((v) ? 1 << 28 : 0)
 280 #define MANAGEMENT_ORB_REQUEST_FORMAT(v)        ((v) << 29)
 281 #define MANAGEMENT_ORB_NOTIFY                   ((1) << 31)
 282
 283 #define MANAGEMENT_ORB_RESPONSE_LENGTH(v)       ((v))
 284 #define MANAGEMENT_ORB_PASSWORD_LENGTH(v)       ((v) << 16)
 285
 286 struct sbp2_management_orb {
 287         struct sbp2_orb base;
 288         struct {
 289                 struct sbp2_pointer password;
 290                 struct sbp2_pointer response;
 291                 __be32 misc;
 292                 __be32 length;
 293                 struct sbp2_pointer status_fifo;
 294         } request;
 295         __be32 response[4];
 296         dma_addr_t response_bus;
 297         struct completion done;
 298         struct sbp2_status status;
 299 };
 300
 301 struct sbp2_login_response {
 302         __be32 misc;
 303         struct sbp2_pointer command_block_agent;
 304         __be32 reconnect_hold;
 305 };
 306 #define COMMAND_ORB_DATA_SIZE(v)        ((v))
 307 #define COMMAND_ORB_PAGE_SIZE(v)        ((v) << 16)
 308 #define COMMAND_ORB_PAGE_TABLE_PRESENT  ((1) << 19)
 309 #define COMMAND_ORB_MAX_PAYLOAD(v)      ((v) << 20)
 310 #define COMMAND_ORB_SPEED(v)            ((v) << 24)
 311 #define COMMAND_ORB_DIRECTION           ((1) << 27)
 312 #define COMMAND_ORB_REQUEST_FORMAT(v)   ((v) << 29)
 313 #define COMMAND_ORB_NOTIFY              ((1) << 31)
 314
 315 struct sbp2_command_orb {
 316         struct sbp2_orb base;
 317         struct {
 318                 struct sbp2_pointer next;
 319                 struct sbp2_pointer data_descriptor;
 320                 __be32 misc;
 321                 u8 command_block[SBP2_MAX_CDB_SIZE];
 322         } request;
 323         struct scsi_cmnd *cmd;
 324         struct sbp2_logical_unit *lu;
 325
 326         struct sbp2_pointer page_table[SG_ALL] __attribute__((aligned(8)));
 327         dma_addr_t page_table_bus;
 328 };
 329
 330 #define SBP2_ROM_VALUE_WILDCARD ~0         /* match all */
 331 #define SBP2_ROM_VALUE_MISSING  0xff000000 /* not present in the unit dir. */
 332
 333 /*
 334  * List of devices with known bugs.
 335  *
 336  * The firmware_revision field, masked with 0xffff00, is the best
 337  * indicator for the type of bridge chip of a device.  It yields a few
 338  * false positives but this did not break correctly behaving devices
 339  * so far.
 340  */
 341 static const struct {
 342         u32 firmware_revision;
 343         u32 model;
 344         unsigned int workarounds;
 345 } sbp2_workarounds_table[] = {
 346         /* DViCO Momobay CX-1 with TSB42AA9 bridge */ {
 347                 .firmware_revision      = 0x002800,
 348                 .model                  = 0x001010,
 349                 .workarounds            = SBP2_WORKAROUND_INQUIRY_36 |
 350                                           SBP2_WORKAROUND_MODE_SENSE_8 |
 351                                           SBP2_WORKAROUND_POWER_CONDITION,
 352         },
 353         /* DViCO Momobay FX-3A with TSB42AA9A bridge */ {
 354                 .firmware_revision      = 0x002800,
 355                 .model                  = 0x000000,
 356                 .workarounds            = SBP2_WORKAROUND_POWER_CONDITION,
 357         },
 358         /* Initio bridges, actually only needed for some older ones */ {
 359                 .firmware_revision      = 0x000200,
 360                 .model                  = SBP2_ROM_VALUE_WILDCARD,
 361                 .workarounds            = SBP2_WORKAROUND_INQUIRY_36,
 362         },
 363         /* PL-3507 bridge with Prolific firmware */ {
 364                 .firmware_revision      = 0x012800,
 365                 .model                  = SBP2_ROM_VALUE_WILDCARD,
 366                 .workarounds            = SBP2_WORKAROUND_POWER_CONDITION,
 367         },
 368         /* Symbios bridge */ {
 369                 .firmware_revision      = 0xa0b800,
 370                 .model                  = SBP2_ROM_VALUE_WILDCARD,
 371                 .workarounds            = SBP2_WORKAROUND_128K_MAX_TRANS,
 372         },
 373         /* Datafab MD2-FW2 with Symbios/LSILogic SYM13FW500 bridge */ {
 374                 .firmware_revision      = 0x002600,
 375                 .model                  = SBP2_ROM_VALUE_WILDCARD,
 376                 .workarounds            = SBP2_WORKAROUND_128K_MAX_TRANS,
 377         },
 378         /*
 379          * iPod 2nd generation: needs 128k max transfer size workaround
 380          * iPod 3rd generation: needs fix capacity workaround
 381          */
 382         {
 383                 .firmware_revision      = 0x0a2700,
 384                 .model                  = 0x000000,
 385                 .workarounds            = SBP2_WORKAROUND_128K_MAX_TRANS |
 386                                           SBP2_WORKAROUND_FIX_CAPACITY,
 387         },
 388         /* iPod 4th generation */ {
 389                 .firmware_revision      = 0x0a2700,
 390                 .model                  = 0x000021,
 391                 .workarounds            = SBP2_WORKAROUND_FIX_CAPACITY,
 392         },
 393         /* iPod mini */ {
 394                 .firmware_revision      = 0x0a2700,
 395                 .model                  = 0x000022,
 396                 .workarounds            = SBP2_WORKAROUND_FIX_CAPACITY,
 397         },
 398         /* iPod mini */ {
 399                 .firmware_revision      = 0x0a2700,
 400                 .model                  = 0x000023,
 401                 .workarounds            = SBP2_WORKAROUND_FIX_CAPACITY,
 402         },
 403         /* iPod Photo */ {
 404                 .firmware_revision      = 0x0a2700,
 405                 .model                  = 0x00007e,
 406                 .workarounds            = SBP2_WORKAROUND_FIX_CAPACITY,
 407         }
 408 };
 409
 410 static void free_orb(struct kref *kref)
 411 {
 412         struct sbp2_orb *orb = container_of(kref, struct sbp2_orb, kref);
 413
 414         kfree(orb);
 415 }
 416
 417 static void sbp2_status_write(struct fw_card *card, struct fw_request *request,
 418                               int tcode, int destination, int source,
 419                               int generation, unsigned long long offset,
 420                               void *payload, size_t length, void *callback_data)
 421 {
 422         struct sbp2_logical_unit *lu = callback_data;
 423         struct sbp2_orb *orb;
 424         struct sbp2_status status;
 425         unsigned long flags;
 426
 427         if (tcode != TCODE_WRITE_BLOCK_REQUEST ||
 428             length < 8 || length > sizeof(status)) {
 429                 fw_send_response(card, request, RCODE_TYPE_ERROR);
 430                 return;
 431         }
 432
 433         status.status  = be32_to_cpup(payload);
 434         status.orb_low = be32_to_cpup(payload + 4);
 435         memset(status.data, 0, sizeof(status.data));
 436         if (length > 8)
 437                 memcpy(status.data, payload + 8, length - 8);
 438
 439         if (STATUS_GET_SOURCE(status) == 2 || STATUS_GET_SOURCE(status) == 3) {
 440                 dev_notice(lu_dev(lu),
 441                            "non-ORB related status write, not handled\n");
 442                 fw_send_response(card, request, RCODE_COMPLETE);
 443                 return;
 444         }
 445
 446         /* Lookup the orb corresponding to this status write. */
 447         spin_lock_irqsave(&card->lock, flags);
 448         list_for_each_entry(orb, &lu->orb_list, link) {
 449                 if (STATUS_GET_ORB_HIGH(status) == 0 &&
 450                     STATUS_GET_ORB_LOW(status) == orb->request_bus) {
 451                         orb->rcode = RCODE_COMPLETE;
 452                         list_del(&orb->link);
 453                         break;
 454                 }
 455         }
 456         spin_unlock_irqrestore(&card->lock, flags);
 457
 458         if (&orb->link != &lu->orb_list) {
 459                 orb->callback(orb, &status);
 460                 kref_put(&orb->kref, free_orb); /* orb callback reference */
 461         } else {
 462                 dev_err(lu_dev(lu), "status write for unknown ORB\n");
 463         }
 464
 465         fw_send_response(card, request, RCODE_COMPLETE);
 466 }
 467
 468 static void complete_transaction(struct fw_card *card, int rcode,
 469                                  void *payload, size_t length, void *data)
 470 {
 471         struct sbp2_orb *orb = data;
 472         unsigned long flags;
 473
 474         /*
 475          * This is a little tricky.  We can get the status write for
 476          * the orb before we get this callback.  The status write
 477          * handler above will assume the orb pointer transaction was
 478          * successful and set the rcode to RCODE_COMPLETE for the orb.
 479          * So this callback only sets the rcode if it hasn't already
 480          * been set and only does the cleanup if the transaction
 481          * failed and we didn't already get a status write.
 482          */
 483         spin_lock_irqsave(&card->lock, flags);
 484
 485         if (orb->rcode == -1)
 486                 orb->rcode = rcode;
 487         if (orb->rcode != RCODE_COMPLETE) {
 488                 list_del(&orb->link);
 489                 spin_unlock_irqrestore(&card->lock, flags);
 490
 491                 orb->callback(orb, NULL);
 492                 kref_put(&orb->kref, free_orb); /* orb callback reference */
 493         } else {
 494                 spin_unlock_irqrestore(&card->lock, flags);
 495         }
 496
 497         kref_put(&orb->kref, free_orb); /* transaction callback reference */
 498 }
 499
 500 static void sbp2_send_orb(struct sbp2_orb *orb, struct sbp2_logical_unit *lu,
 501                           int node_id, int generation, u64 offset)
 502 {
 503         struct fw_device *device = target_parent_device(lu->tgt);
 504         struct sbp2_pointer orb_pointer;
 505         unsigned long flags;
 506
 507         orb_pointer.high = 0;
 508         orb_pointer.low = cpu_to_be32(orb->request_bus);
 509
 510         spin_lock_irqsave(&device->card->lock, flags);
 511         list_add_tail(&orb->link, &lu->orb_list);
 512         spin_unlock_irqrestore(&device->card->lock, flags);
 513
 514         kref_get(&orb->kref); /* transaction callback reference */
 515         kref_get(&orb->kref); /* orb callback reference */
 516
 517         fw_send_request(device->card, &orb->t, TCODE_WRITE_BLOCK_REQUEST,
 518                         node_id, generation, device->max_speed, offset,
 519                         &orb_pointer, 8, complete_transaction, orb);
 520 }
 521
 522 static int sbp2_cancel_orbs(struct sbp2_logical_unit *lu)
 523 {
 524         struct fw_device *device = target_parent_device(lu->tgt);
 525         struct sbp2_orb *orb, *next;
 526         struct list_head list;
 527         int retval = -ENOENT;
 528
 529         INIT_LIST_HEAD(&list);
 530         spin_lock_irq(&device->card->lock);
 531         list_splice_init(&lu->orb_list, &list);
 532         spin_unlock_irq(&device->card->lock);
 533
 534         list_for_each_entry_safe(orb, next, &list, link) {
 535                 retval = 0;
 536                 if (fw_cancel_transaction(device->card, &orb->t) == 0)
 537                         continue;
 538
 539                 orb->rcode = RCODE_CANCELLED;
 540                 orb->callback(orb, NULL);
 541                 kref_put(&orb->kref, free_orb); /* orb callback reference */
 542         }
 543
 544         return retval;
 545 }
 546
 547 static void complete_management_orb(struct sbp2_orb *base_orb,
 548                                     struct sbp2_status *status)
 549 {
 550         struct sbp2_management_orb *orb =
 551                 container_of(base_orb, struct sbp2_management_orb, base);
 552
 553         if (status)
 554                 memcpy(&orb->status, status, sizeof(*status));
 555         complete(&orb->done);
 556 }
 557
 558 static int sbp2_send_management_orb(struct sbp2_logical_unit *lu, int node_id,
 559                                     int generation, int function,
 560                                     int lun_or_login_id, void *response)
 561 {
 562         struct fw_device *device = target_parent_device(lu->tgt);
 563         struct sbp2_management_orb *orb;
 564         unsigned int timeout;
 565         int retval = -ENOMEM;
 566
 567         if (function == SBP2_LOGOUT_REQUEST && fw_device_is_shutdown(device))
 568                 return 0;
 569
 570         orb = kzalloc(sizeof(*orb), GFP_NOIO);
 571         if (orb == NULL)
 572                 return -ENOMEM;
 573
 574         kref_init(&orb->base.kref);
 575         orb->response_bus =
 576                 dma_map_single(device->card->device, &orb->response,
 577                                sizeof(orb->response), DMA_FROM_DEVICE);
 578         if (dma_mapping_error(device->card->device, orb->response_bus))
 579                 goto fail_mapping_response;
 580
 581         orb->request.response.high = 0;
 582         orb->request.response.low  = cpu_to_be32(orb->response_bus);
 583
 584         orb->request.misc = cpu_to_be32(
 585                 MANAGEMENT_ORB_NOTIFY |
 586                 MANAGEMENT_ORB_FUNCTION(function) |
 587                 MANAGEMENT_ORB_LUN(lun_or_login_id));
 588         orb->request.length = cpu_to_be32(
 589                 MANAGEMENT_ORB_RESPONSE_LENGTH(sizeof(orb->response)));
 590
 591         orb->request.status_fifo.high =
 592                 cpu_to_be32(lu->address_handler.offset >> 32);
 593         orb->request.status_fifo.low  =
 594                 cpu_to_be32(lu->address_handler.offset);
 595
 596         if (function == SBP2_LOGIN_REQUEST) {
 597                 /* Ask for 2^2 == 4 seconds reconnect grace period */
 598                 orb->request.misc |= cpu_to_be32(
 599                         MANAGEMENT_ORB_RECONNECT(2) |
 600                         MANAGEMENT_ORB_EXCLUSIVE(sbp2_param_exclusive_login));
 601                 timeout = lu->tgt->mgt_orb_timeout;
 602         } else {
 603                 timeout = SBP2_ORB_TIMEOUT;
 604         }
 605
 606         init_completion(&orb->done);
 607         orb->base.callback = complete_management_orb;
 608
 609         orb->base.request_bus =
 610                 dma_map_single(device->card->device, &orb->request,
 611                                sizeof(orb->request), DMA_TO_DEVICE);
 612         if (dma_mapping_error(device->card->device, orb->base.request_bus))
 613                 goto fail_mapping_request;
 614
 615         sbp2_send_orb(&orb->base, lu, node_id, generation,
 616                       lu->tgt->management_agent_address);
 617
 618         wait_for_completion_timeout(&orb->done, msecs_to_jiffies(timeout));
 619
 620         retval = -EIO;
 621         if (sbp2_cancel_orbs(lu) == 0) {
 622                 dev_err(lu_dev(lu), "ORB reply timed out, rcode 0x%02x\n",
 623                         orb->base.rcode);
 624                 goto out;
 625         }
 626
 627         if (orb->base.rcode != RCODE_COMPLETE) {
 628                 dev_err(lu_dev(lu), "management write failed, rcode 0x%02x\n",
 629                         orb->base.rcode);
 630                 goto out;
 631         }
 632
 633         if (STATUS_GET_RESPONSE(orb->status) != 0 ||
 634             STATUS_GET_SBP_STATUS(orb->status) != 0) {
 635                 dev_err(lu_dev(lu), "error status: %d:%d\n",
 636                          STATUS_GET_RESPONSE(orb->status),
 637                          STATUS_GET_SBP_STATUS(orb->status));
 638                 goto out;
 639         }
 640
 641         retval = 0;
 642  out:
 643         dma_unmap_single(device->card->device, orb->base.request_bus,
 644                          sizeof(orb->request), DMA_TO_DEVICE);
 645  fail_mapping_request:
 646         dma_unmap_single(device->card->device, orb->response_bus,
 647                          sizeof(orb->response), DMA_FROM_DEVICE);
 648  fail_mapping_response:
 649         if (response)
 650                 memcpy(response, orb->response, sizeof(orb->response));
 651         kref_put(&orb->base.kref, free_orb);
 652
 653         return retval;
 654 }
 655
 656 static void sbp2_agent_reset(struct sbp2_logical_unit *lu)
 657 {
 658         struct fw_device *device = target_parent_device(lu->tgt);
 659         __be32 d = 0;
 660
 661         fw_run_transaction(device->card, TCODE_WRITE_QUADLET_REQUEST,
 662                            lu->tgt->node_id, lu->generation, device->max_speed,
 663                            lu->command_block_agent_address + SBP2_AGENT_RESET,
 664                            &d, 4);
 665 }
 666
 667 static void complete_agent_reset_write_no_wait(struct fw_card *card,
 668                 int rcode, void *payload, size_t length, void *data)
 669 {
 670         kfree(data);
 671 }
 672
 673 static void sbp2_agent_reset_no_wait(struct sbp2_logical_unit *lu)
 674 {
 675         struct fw_device *device = target_parent_device(lu->tgt);
 676         struct fw_transaction *t;
 677         static __be32 d;
 678
 679         t = kmalloc(sizeof(*t), GFP_ATOMIC);
 680         if (t == NULL)
 681                 return;
 682
 683         fw_send_request(device->card, t, TCODE_WRITE_QUADLET_REQUEST,
 684                         lu->tgt->node_id, lu->generation, device->max_speed,
 685                         lu->command_block_agent_address + SBP2_AGENT_RESET,
 686                         &d, 4, complete_agent_reset_write_no_wait, t);
 687 }
 688
 689 static inline void sbp2_allow_block(struct sbp2_logical_unit *lu)
 690 {
 691         struct sbp2_target *tgt = lu->tgt;
 692         struct fw_card *card = target_parent_device(tgt)->card;
 693
 694         spin_lock_irq(&card->lock);
 695         --tgt->dont_block;
 696         spin_unlock_irq(&card->lock);
 697 }
 698
 699 /*
 700  * Blocks lu->tgt if all of the following conditions are met:
 701  *   - Login, INQUIRY, and high-level SCSI setup of all of the target's
 702  *     logical units have been finished (indicated by dont_block == 0).
 703  *   - lu->generation is stale.
 704  *
 705  * Note, scsi_block_requests() must be called while holding card->lock,
 706  * otherwise it might foil sbp2_[conditionally_]unblock()'s attempt to
 707  * unblock the target.
 708  */
 709 static void sbp2_conditionally_block(struct sbp2_logical_unit *lu)
 710 {
 711         struct sbp2_target *tgt = lu->tgt;
 712         struct fw_card *card = target_parent_device(tgt)->card;
 713         struct Scsi_Host *shost =
 714                 container_of((void *)tgt, struct Scsi_Host, hostdata[0]);
 715         unsigned long flags;
 716
 717         spin_lock_irqsave(&card->lock, flags);
 718         if (!tgt->dont_block && !lu->blocked &&
 719             lu->generation != card->generation) {
 720                 lu->blocked = true;
 721                 if (++tgt->blocked == 1)
 722                         scsi_block_requests(shost);
 723         }
 724         spin_unlock_irqrestore(&card->lock, flags);
 725 }
 726
 727 /*
 728  * Unblocks lu->tgt as soon as all its logical units can be unblocked.
 729  * Note, it is harmless to run scsi_unblock_requests() outside the
 730  * card->lock protected section.  On the other hand, running it inside
 731  * the section might clash with shost->host_lock.
 732  */
 733 static void sbp2_conditionally_unblock(struct sbp2_logical_unit *lu)
 734 {
 735         struct sbp2_target *tgt = lu->tgt;
 736         struct fw_card *card = target_parent_device(tgt)->card;
 737         struct Scsi_Host *shost =
 738                 container_of((void *)tgt, struct Scsi_Host, hostdata[0]);
 739         bool unblock = false;
 740
 741         spin_lock_irq(&card->lock);
 742         if (lu->blocked && lu->generation == card->generation) {
 743                 lu->blocked = false;
 744                 unblock = --tgt->blocked == 0;
 745         }
 746         spin_unlock_irq(&card->lock);
 747
 748         if (unblock)
 749                 scsi_unblock_requests(shost);
 750 }
 751
 752 /*
 753  * Prevents future blocking of tgt and unblocks it.
 754  * Note, it is harmless to run scsi_unblock_requests() outside the
 755  * card->lock protected section.  On the other hand, running it inside
 756  * the section might clash with shost->host_lock.
 757  */
 758 static void sbp2_unblock(struct sbp2_target *tgt)
 759 {
 760         struct fw_card *card = target_parent_device(tgt)->card;
 761         struct Scsi_Host *shost =
 762                 container_of((void *)tgt, struct Scsi_Host, hostdata[0]);
 763
 764         spin_lock_irq(&card->lock);
 765         ++tgt->dont_block;
 766         spin_unlock_irq(&card->lock);
 767
 768         scsi_unblock_requests(shost);
 769 }
 770
 771 static int sbp2_lun2int(u16 lun)
 772 {
 773         struct scsi_lun eight_bytes_lun;
 774
 775         memset(&eight_bytes_lun, 0, sizeof(eight_bytes_lun));
 776         eight_bytes_lun.scsi_lun[0] = (lun >> 8) & 0xff;
 777         eight_bytes_lun.scsi_lun[1] = lun & 0xff;
 778
 779         return scsilun_to_int(&eight_bytes_lun);
 780 }
 781
 782 /*
 783  * Write retransmit retry values into the BUSY_TIMEOUT register.
 784  * - The single-phase retry protocol is supported by all SBP-2 devices, but the
 785  *   default retry_limit value is 0 (i.e. never retry transmission). We write a
 786  *   saner value after logging into the device.
 787  * - The dual-phase retry protocol is optional to implement, and if not
 788  *   supported, writes to the dual-phase portion of the register will be
 789  *   ignored. We try to write the original 1394-1995 default here.
 790  * - In the case of devices that are also SBP-3-compliant, all writes are
 791  *   ignored, as the register is read-only, but contains single-phase retry of
 792  *   15, which is what we're trying to set for all SBP-2 device anyway, so this
 793  *   write attempt is safe and yields more consistent behavior for all devices.
 794  *
 795  * See section 8.3.2.3.5 of the 1394-1995 spec, section 6.2 of the SBP-2 spec,
 796  * and section 6.4 of the SBP-3 spec for further details.
 797  */
 798 static void sbp2_set_busy_timeout(struct sbp2_logical_unit *lu)
 799 {
 800         struct fw_device *device = target_parent_device(lu->tgt);
 801         __be32 d = cpu_to_be32(SBP2_CYCLE_LIMIT | SBP2_RETRY_LIMIT);
 802
 803         fw_run_transaction(device->card, TCODE_WRITE_QUADLET_REQUEST,
 804                            lu->tgt->node_id, lu->generation, device->max_speed,
 805                            CSR_REGISTER_BASE + CSR_BUSY_TIMEOUT, &d, 4);
 806 }
 807
 808 static void sbp2_reconnect(struct work_struct *work);
 809
 810 static void sbp2_login(struct work_struct *work)
 811 {
 812         struct sbp2_logical_unit *lu =
 813                 container_of(work, struct sbp2_logical_unit, work.work);
 814         struct sbp2_target *tgt = lu->tgt;
 815         struct fw_device *device = target_parent_device(tgt);
 816         struct Scsi_Host *shost;
 817         struct scsi_device *sdev;
 818         struct sbp2_login_response response;
 819         int generation, node_id, local_node_id;
 820
 821         if (fw_device_is_shutdown(device))
 822                 return;
 823
 824         generation    = device->generation;
 825         smp_rmb();    /* node IDs must not be older than generation */
 826         node_id       = device->node_id;
 827         local_node_id = device->card->node_id;
 828
 829         /* If this is a re-login attempt, log out, or we might be rejected. */
 830         if (lu->has_sdev)
 831                 sbp2_send_management_orb(lu, device->node_id, generation,
 832                                 SBP2_LOGOUT_REQUEST, lu->login_id, NULL);
 833
 834         if (sbp2_send_management_orb(lu, node_id, generation,
 835                                 SBP2_LOGIN_REQUEST, lu->lun, &response) < 0) {
 836                 if (lu->retries++ < 5) {
 837                         sbp2_queue_work(lu, DIV_ROUND_UP(HZ, 5));
 838                 } else {
 839                         dev_err(tgt_dev(tgt), "failed to login to LUN %04x\n",
 840                                 lu->lun);
 841                         /* Let any waiting I/O fail from now on. */
 842                         sbp2_unblock(lu->tgt);
 843                 }
 844                 return;
 845         }
 846
 847         tgt->node_id      = node_id;
 848         tgt->address_high = local_node_id << 16;
 849         smp_wmb();        /* node IDs must not be older than generation */
 850         lu->generation    = generation;
 851
 852         lu->command_block_agent_address =
 853                 ((u64)(be32_to_cpu(response.command_block_agent.high) & 0xffff)
 854                       << 32) | be32_to_cpu(response.command_block_agent.low);
 855         lu->login_id = be32_to_cpu(response.misc) & 0xffff;
 856
 857         dev_notice(tgt_dev(tgt), "logged in to LUN %04x (%d retries)\n",
 858                    lu->lun, lu->retries);
 859
 860         /* set appropriate retry limit(s) in BUSY_TIMEOUT register */
 861         sbp2_set_busy_timeout(lu);
 862
 863         lu->workfn = sbp2_reconnect;
 864         sbp2_agent_reset(lu);
 865
 866         /* This was a re-login. */
 867         if (lu->has_sdev) {
 868                 sbp2_cancel_orbs(lu);
 869                 sbp2_conditionally_unblock(lu);
 870
 871                 return;
 872         }
 873
 874         if (lu->tgt->workarounds & SBP2_WORKAROUND_DELAY_INQUIRY)
 875                 ssleep(SBP2_INQUIRY_DELAY);
 876
 877         shost = container_of((void *)tgt, struct Scsi_Host, hostdata[0]);
 878         sdev = __scsi_add_device(shost, 0, 0, sbp2_lun2int(lu->lun), lu);
 879         /*
 880          * FIXME:  We are unable to perform reconnects while in sbp2_login().
 881          * Therefore __scsi_add_device() will get into trouble if a bus reset
 882          * happens in parallel.  It will either fail or leave us with an
 883          * unusable sdev.  As a workaround we check for this and retry the
 884          * whole login and SCSI probing.
 885          */
 886
 887         /* Reported error during __scsi_add_device() */
 888         if (IS_ERR(sdev))
 889                 goto out_logout_login;
 890
 891         /* Unreported error during __scsi_add_device() */
 892         smp_rmb(); /* get current card generation */
 893         if (generation != device->card->generation) {
 894                 scsi_remove_device(sdev);
 895                 scsi_device_put(sdev);
 896                 goto out_logout_login;
 897         }
 898
 899         /* No error during __scsi_add_device() */
 900         lu->has_sdev = true;
 901         scsi_device_put(sdev);
 902         sbp2_allow_block(lu);
 903
 904         return;
 905
 906  out_logout_login:
 907         smp_rmb(); /* generation may have changed */
 908         generation = device->generation;
 909         smp_rmb(); /* node_id must not be older than generation */
 910
 911         sbp2_send_management_orb(lu, device->node_id, generation,
 912                                  SBP2_LOGOUT_REQUEST, lu->login_id, NULL);
 913         /*
 914          * If a bus reset happened, sbp2_update will have requeued
 915          * lu->work already.  Reset the work from reconnect to login.
 916          */
 917         lu->workfn = sbp2_login;
 918 }
 919
 920 static void sbp2_reconnect(struct work_struct *work)
 921 {
 922         struct sbp2_logical_unit *lu =
 923                 container_of(work, struct sbp2_logical_unit, work.work);
 924         struct sbp2_target *tgt = lu->tgt;
 925         struct fw_device *device = target_parent_device(tgt);
 926         int generation, node_id, local_node_id;
 927
 928         if (fw_device_is_shutdown(device))
 929                 return;
 930
 931         generation    = device->generation;
 932         smp_rmb();    /* node IDs must not be older than generation */
 933         node_id       = device->node_id;
 934         local_node_id = device->card->node_id;
 935
 936         if (sbp2_send_management_orb(lu, node_id, generation,
 937                                      SBP2_RECONNECT_REQUEST,
 938                                      lu->login_id, NULL) < 0) {
 939                 /*
 940                  * If reconnect was impossible even though we are in the
 941                  * current generation, fall back and try to log in again.
 942                  *
 943                  * We could check for "Function rejected" status, but
 944                  * looking at the bus generation as simpler and more general.
 945                  */
 946                 smp_rmb(); /* get current card generation */
 947                 if (generation == device->card->generation ||
 948                     lu->retries++ >= 5) {
 949                         dev_err(tgt_dev(tgt), "failed to reconnect\n");
 950                         lu->retries = 0;
 951                         lu->workfn = sbp2_login;
 952                 }
 953                 sbp2_queue_work(lu, DIV_ROUND_UP(HZ, 5));
 954
 955                 return;
 956         }
 957
 958         tgt->node_id      = node_id;
 959         tgt->address_high = local_node_id << 16;
 960         smp_wmb();        /* node IDs must not be older than generation */
 961         lu->generation    = generation;
 962
 963         dev_notice(tgt_dev(tgt), "reconnected to LUN %04x (%d retries)\n",
 964                    lu->lun, lu->retries);
 965
 966         sbp2_agent_reset(lu);
 967         sbp2_cancel_orbs(lu);
 968         sbp2_conditionally_unblock(lu);
 969 }
 970
 971 static void sbp2_lu_workfn(struct work_struct *work)
 972 {
 973         struct sbp2_logical_unit *lu = container_of(to_delayed_work(work),
 974                                                 struct sbp2_logical_unit, work);
 975         lu->workfn(work);
 976 }
 977
 978 static int sbp2_add_logical_unit(struct sbp2_target *tgt, int lun_entry)
 979 {
 980         struct sbp2_logical_unit *lu;
 981
 982         lu = kmalloc(sizeof(*lu), GFP_KERNEL);
 983         if (!lu)
 984                 return -ENOMEM;
 985
 986         lu->address_handler.length           = 0x100;
 987         lu->address_handler.address_callback = sbp2_status_write;
 988         lu->address_handler.callback_data    = lu;
 989
 990         if (fw_core_add_address_handler(&lu->address_handler,
 991                                         &fw_high_memory_region) < 0) {
 992                 kfree(lu);
 993                 return -ENOMEM;
 994         }
 995
 996         lu->tgt      = tgt;
 997         lu->lun      = lun_entry & 0xffff;
 998         lu->login_id = INVALID_LOGIN_ID;
 999         lu->retries  = 0;
1000         lu->has_sdev = false;
1001         lu->blocked  = false;
1002         ++tgt->dont_block;
1003         INIT_LIST_HEAD(&lu->orb_list);
1004         lu->workfn = sbp2_login;
1005         INIT_DELAYED_WORK(&lu->work, sbp2_lu_workfn);
1006
1007         list_add_tail(&lu->link, &tgt->lu_list);
1008         return 0;
1009 }
1010
1011 static void sbp2_get_unit_unique_id(struct sbp2_target *tgt,
1012                                     const u32 *leaf)
1013 {
1014         if ((leaf[0] & 0xffff0000) == 0x00020000)
1015                 tgt->guid = (u64)leaf[1] << 32 | leaf[2];
1016 }
1017
1018 static int sbp2_scan_logical_unit_dir(struct sbp2_target *tgt,
1019                                       const u32 *directory)
1020 {
1021         struct fw_csr_iterator ci;
1022         int key, value;
1023
1024         fw_csr_iterator_init(&ci, directory);
1025         while (fw_csr_iterator_next(&ci, &key, &value))
1026                 if (key == SBP2_CSR_LOGICAL_UNIT_NUMBER &&
1027                     sbp2_add_logical_unit(tgt, value) < 0)
1028                         return -ENOMEM;
1029         return 0;
1030 }
1031
1032 static int sbp2_scan_unit_dir(struct sbp2_target *tgt, const u32 *directory,
1033                               u32 *model, u32 *firmware_revision)
1034 {
1035         struct fw_csr_iterator ci;
1036         int key, value;
1037
1038         fw_csr_iterator_init(&ci, directory);
1039         while (fw_csr_iterator_next(&ci, &key, &value)) {
1040                 switch (key) {
1041
1042                 case CSR_DEPENDENT_INFO | CSR_OFFSET:
1043                         tgt->management_agent_address =
1044                                         CSR_REGISTER_BASE + 4 * value;
1045                         break;
1046
1047                 case CSR_DIRECTORY_ID:
1048                         tgt->directory_id = value;
1049                         break;
1050
1051                 case CSR_MODEL:
1052                         *model = value;
1053                         break;
1054
1055                 case SBP2_CSR_FIRMWARE_REVISION:
1056                         *firmware_revision = value;
1057                         break;
1058
1059                 case SBP2_CSR_UNIT_CHARACTERISTICS:
1060                         /* the timeout value is stored in 500ms units */
1061                         tgt->mgt_orb_timeout = (value >> 8 & 0xff) * 500;
1062                         break;
1063
1064                 case SBP2_CSR_LOGICAL_UNIT_NUMBER:
1065                         if (sbp2_add_logical_unit(tgt, value) < 0)
1066                                 return -ENOMEM;
1067                         break;
1068
1069                 case SBP2_CSR_UNIT_UNIQUE_ID:
1070                         sbp2_get_unit_unique_id(tgt, ci.p - 1 + value);
1071                         break;
1072
1073                 case SBP2_CSR_LOGICAL_UNIT_DIRECTORY:
1074                         /* Adjust for the increment in the iterator */
1075                         if (sbp2_scan_logical_unit_dir(tgt, ci.p - 1 + value) < 0)
1076                                 return -ENOMEM;
1077                         break;
1078                 }
1079         }
1080         return 0;
1081 }
1082
1083 /*
1084  * Per section 7.4.8 of the SBP-2 spec, a mgt_ORB_timeout value can be
1085  * provided in the config rom. Most devices do provide a value, which
1086  * we'll use for login management orbs, but with some sane limits.
1087  */
1088 static void sbp2_clamp_management_orb_timeout(struct sbp2_target *tgt)
1089 {
1090         unsigned int timeout = tgt->mgt_orb_timeout;
1091
1092         if (timeout > 40000)
1093                 dev_notice(tgt_dev(tgt), "%ds mgt_ORB_timeout limited to 40s\n",
1094                            timeout / 1000);
1095
1096         tgt->mgt_orb_timeout = clamp_val(timeout, 5000, 40000);
1097 }
1098
1099 static void sbp2_init_workarounds(struct sbp2_target *tgt, u32 model,
1100                                   u32 firmware_revision)
1101 {
1102         int i;
1103         unsigned int w = sbp2_param_workarounds;
1104
1105         if (w)
1106                 dev_notice(tgt_dev(tgt),
1107                            "Please notify linux1394-devel@lists.sf.net "
1108                            "if you need the workarounds parameter\n");
1109
1110         if (w & SBP2_WORKAROUND_OVERRIDE)
1111                 goto out;
1112
1113         for (i = 0; i < ARRAY_SIZE(sbp2_workarounds_table); i++) {
1114
1115                 if (sbp2_workarounds_table[i].firmware_revision !=
1116                     (firmware_revision & 0xffffff00))
1117                         continue;
1118
1119                 if (sbp2_workarounds_table[i].model != model &&
1120                     sbp2_workarounds_table[i].model != SBP2_ROM_VALUE_WILDCARD)
1121                         continue;
1122
1123                 w |= sbp2_workarounds_table[i].workarounds;
1124                 break;
1125         }
1126  out:
1127         if (w)
1128                 dev_notice(tgt_dev(tgt), "workarounds 0x%x "
1129                            "(firmware_revision 0x%06x, model_id 0x%06x)\n",
1130                            w, firmware_revision, model);
1131         tgt->workarounds = w;
1132 }
1133
1134 static struct scsi_host_template scsi_driver_template;
1135 static void sbp2_remove(struct fw_unit *unit);
1136
1137 static int sbp2_probe(struct fw_unit *unit, const struct ieee1394_device_id *id)
1138 {
1139         struct fw_device *device = fw_parent_device(unit);
1140         struct sbp2_target *tgt;
1141         struct sbp2_logical_unit *lu;
1142         struct Scsi_Host *shost;
1143         u32 model, firmware_revision;
1144
1145         /* cannot (or should not) handle targets on the local node */
1146         if (device->is_local)
1147                 return -ENODEV;
1148
1149         if (dma_get_max_seg_size(device->card->device) > SBP2_MAX_SEG_SIZE)
1150                 WARN_ON(dma_set_max_seg_size(device->card->device,
1151                                              SBP2_MAX_SEG_SIZE));
1152
1153         shost = scsi_host_alloc(&scsi_driver_template, sizeof(*tgt));
1154         if (shost == NULL)
1155                 return -ENOMEM;
1156
1157         tgt = (struct sbp2_target *)shost->hostdata;
1158         dev_set_drvdata(&unit->device, tgt);
1159         tgt->unit = unit;
1160         INIT_LIST_HEAD(&tgt->lu_list);
1161         tgt->guid = (u64)device->config_rom[3] << 32 | device->config_rom[4];
1162
1163         if (fw_device_enable_phys_dma(device) < 0)
1164                 goto fail_shost_put;
1165
1166         shost->max_cmd_len = SBP2_MAX_CDB_SIZE;
1167
1168         if (scsi_add_host_with_dma(shost, &unit->device,
1169                                    device->card->device) < 0)
1170                 goto fail_shost_put;
1171
1172         /* implicit directory ID */
1173         tgt->directory_id = ((unit->directory - device->config_rom) * 4
1174                              + CSR_CONFIG_ROM) & 0xffffff;
1175
1176         firmware_revision = SBP2_ROM_VALUE_MISSING;
1177         model             = SBP2_ROM_VALUE_MISSING;
1178
1179         if (sbp2_scan_unit_dir(tgt, unit->directory, &model,
1180                                &firmware_revision) < 0)
1181                 goto fail_remove;
1182
1183         sbp2_clamp_management_orb_timeout(tgt);
1184         sbp2_init_workarounds(tgt, model, firmware_revision);
1185
1186         /*
1187          * At S100 we can do 512 bytes per packet, at S200 1024 bytes,
1188          * and so on up to 4096 bytes.  The SBP-2 max_payload field
1189          * specifies the max payload size as 2 ^ (max_payload + 2), so
1190          * if we set this to max_speed + 7, we get the right value.
1191          */
1192         tgt->max_payload = min3(device->max_speed + 7, 10U,
1193                                 device->card->max_receive - 1);
1194
1195         /* Do the login in a workqueue so we can easily reschedule retries. */
1196         list_for_each_entry(lu, &tgt->lu_list, link)
1197                 sbp2_queue_work(lu, DIV_ROUND_UP(HZ, 5));
1198
1199         return 0;
1200
1201  fail_remove:
1202         sbp2_remove(unit);
1203         return -ENOMEM;
1204
1205  fail_shost_put:
1206         scsi_host_put(shost);
1207         return -ENOMEM;
1208 }
1209
1210 static void sbp2_update(struct fw_unit *unit)
1211 {
1212         struct sbp2_target *tgt = dev_get_drvdata(&unit->device);
1213         struct sbp2_logical_unit *lu;
1214
1215         fw_device_enable_phys_dma(fw_parent_device(unit));
1216
1217         /*
1218          * Fw-core serializes sbp2_update() against sbp2_remove().
1219          * Iteration over tgt->lu_list is therefore safe here.
1220          */
1221         list_for_each_entry(lu, &tgt->lu_list, link) {
1222                 sbp2_conditionally_block(lu);
1223                 lu->retries = 0;
1224                 sbp2_queue_work(lu, 0);
1225         }
1226 }
1227
1228 static void sbp2_remove(struct fw_unit *unit)
1229 {
1230         struct fw_device *device = fw_parent_device(unit);
1231         struct sbp2_target *tgt = dev_get_drvdata(&unit->device);
1232         struct sbp2_logical_unit *lu, *next;
1233         struct Scsi_Host *shost =
1234                 container_of((void *)tgt, struct Scsi_Host, hostdata[0]);
1235         struct scsi_device *sdev;
1236
1237         /* prevent deadlocks */
1238         sbp2_unblock(tgt);
1239
1240         list_for_each_entry_safe(lu, next, &tgt->lu_list, link) {
1241                 cancel_delayed_work_sync(&lu->work);
1242                 sdev = scsi_device_lookup(shost, 0, 0, sbp2_lun2int(lu->lun));
1243                 if (sdev) {
1244                         scsi_remove_device(sdev);
1245                         scsi_device_put(sdev);
1246                 }
1247                 if (lu->login_id != INVALID_LOGIN_ID) {
1248                         int generation, node_id;
1249                         /*
1250                          * tgt->node_id may be obsolete here if we failed
1251                          * during initial login or after a bus reset where
1252                          * the topology changed.
1253                          */
1254                         generation = device->generation;
1255                         smp_rmb(); /* node_id vs. generation */
1256                         node_id    = device->node_id;
1257                         sbp2_send_management_orb(lu, node_id, generation,
1258                                                  SBP2_LOGOUT_REQUEST,
1259                                                  lu->login_id, NULL);
1260                 }
1261                 fw_core_remove_address_handler(&lu->address_handler);
1262                 list_del(&lu->link);
1263                 kfree(lu);
1264         }
1265         scsi_remove_host(shost);
1266         dev_notice(&unit->device, "released target %d:0:0\n", shost->host_no);
1267
1268         scsi_host_put(shost);
1269 }
1270
1271 #define SBP2_UNIT_SPEC_ID_ENTRY 0x0000609e
1272 #define SBP2_SW_VERSION_ENTRY   0x00010483
1273
1274 static const struct ieee1394_device_id sbp2_id_table[] = {
1275         {
1276                 .match_flags  = IEEE1394_MATCH_SPECIFIER_ID |
1277                                 IEEE1394_MATCH_VERSION,
1278                 .specifier_id = SBP2_UNIT_SPEC_ID_ENTRY,
1279                 .version      = SBP2_SW_VERSION_ENTRY,
1280         },
1281         { }
1282 };
1283
1284 static struct fw_driver sbp2_driver = {
1285         .driver   = {
1286                 .owner  = THIS_MODULE,
1287                 .name   = KBUILD_MODNAME,
1288                 .bus    = &fw_bus_type,
1289         },
1290         .probe    = sbp2_probe,
1291         .update   = sbp2_update,
1292         .remove   = sbp2_remove,
1293         .id_table = sbp2_id_table,
1294 };
1295
1296 static void sbp2_unmap_scatterlist(struct device *card_device,
1297                                    struct sbp2_command_orb *orb)
1298 {
1299         scsi_dma_unmap(orb->cmd);
1300
1301         if (orb->request.misc & cpu_to_be32(COMMAND_ORB_PAGE_TABLE_PRESENT))
1302                 dma_unmap_single(card_device, orb->page_table_bus,
1303                                  sizeof(orb->page_table), DMA_TO_DEVICE);
1304 }
1305
1306 static unsigned int sbp2_status_to_sense_data(u8 *sbp2_status, u8 *sense_data)
1307 {
1308         int sam_status;
1309         int sfmt = (sbp2_status[0] >> 6) & 0x03;
1310
1311         if (sfmt == 2 || sfmt == 3) {
1312                 /*
1313                  * Reserved for future standardization (2) or
1314                  * Status block format vendor-dependent (3)
1315                  */
1316                 return DID_ERROR << 16;
1317         }
1318
1319         sense_data[0] = 0x70 | sfmt | (sbp2_status[1] & 0x80);
1320         sense_data[1] = 0x0;
1321         sense_data[2] = ((sbp2_status[1] << 1) & 0xe0) | (sbp2_status[1] & 0x0f);
1322         sense_data[3] = sbp2_status[4];
1323         sense_data[4] = sbp2_status[5];
1324         sense_data[5] = sbp2_status[6];
1325         sense_data[6] = sbp2_status[7];
1326         sense_data[7] = 10;
1327         sense_data[8] = sbp2_status[8];
1328         sense_data[9] = sbp2_status[9];
1329         sense_data[10] = sbp2_status[10];
1330         sense_data[11] = sbp2_status[11];
1331         sense_data[12] = sbp2_status[2];
1332         sense_data[13] = sbp2_status[3];
1333         sense_data[14] = sbp2_status[12];
1334         sense_data[15] = sbp2_status[13];
1335
1336         sam_status = sbp2_status[0] & 0x3f;
1337
1338         switch (sam_status) {
1339         case SAM_STAT_GOOD:
1340         case SAM_STAT_CHECK_CONDITION:
1341         case SAM_STAT_CONDITION_MET:
1342         case SAM_STAT_BUSY:
1343         case SAM_STAT_RESERVATION_CONFLICT:
1344         case SAM_STAT_COMMAND_TERMINATED:
1345                 return DID_OK << 16 | sam_status;
1346
1347         default:
1348                 return DID_ERROR << 16;
1349         }
1350 }
1351
1352 static void complete_command_orb(struct sbp2_orb *base_orb,
1353                                  struct sbp2_status *status)
1354 {
1355         struct sbp2_command_orb *orb =
1356                 container_of(base_orb, struct sbp2_command_orb, base);
1357         struct fw_device *device = target_parent_device(orb->lu->tgt);
1358         int result;
1359
1360         if (status != NULL) {
1361                 if (STATUS_GET_DEAD(*status))
1362                         sbp2_agent_reset_no_wait(orb->lu);
1363
1364                 switch (STATUS_GET_RESPONSE(*status)) {
1365                 case SBP2_STATUS_REQUEST_COMPLETE:
1366                         result = DID_OK << 16;
1367                         break;
1368                 case SBP2_STATUS_TRANSPORT_FAILURE:
1369                         result = DID_BUS_BUSY << 16;
1370                         break;
1371                 case SBP2_STATUS_ILLEGAL_REQUEST:
1372                 case SBP2_STATUS_VENDOR_DEPENDENT:
1373                 default:
1374                         result = DID_ERROR << 16;
1375                         break;
1376                 }
1377
1378                 if (result == DID_OK << 16 && STATUS_GET_LEN(*status) > 1)
1379                         result = sbp2_status_to_sense_data(STATUS_GET_DATA(*status),
1380                                                            orb->cmd->sense_buffer);
1381         } else {
1382                 /*
1383                  * If the orb completes with status == NULL, something
1384                  * went wrong, typically a bus reset happened mid-orb
1385                  * or when sending the write (less likely).
1386                  */
1387                 result = DID_BUS_BUSY << 16;
1388                 sbp2_conditionally_block(orb->lu);
1389         }
1390
1391         dma_unmap_single(device->card->device, orb->base.request_bus,
1392                          sizeof(orb->request), DMA_TO_DEVICE);
1393         sbp2_unmap_scatterlist(device->card->device, orb);
1394
1395         orb->cmd->result = result;
1396         orb->cmd->scsi_done(orb->cmd);
1397 }
1398
1399 static int sbp2_map_scatterlist(struct sbp2_command_orb *orb,
1400                 struct fw_device *device, struct sbp2_logical_unit *lu)
1401 {
1402         struct scatterlist *sg = scsi_sglist(orb->cmd);
1403         int i, n;
1404
1405         n = scsi_dma_map(orb->cmd);
1406         if (n <= 0)
1407                 goto fail;
1408
1409         /*
1410          * Handle the special case where there is only one element in
1411          * the scatter list by converting it to an immediate block
1412          * request. This is also a workaround for broken devices such
1413          * as the second generation iPod which doesn't support page
1414          * tables.
1415          */
1416         if (n == 1) {
1417                 orb->request.data_descriptor.high =
1418                         cpu_to_be32(lu->tgt->address_high);
1419                 orb->request.data_descriptor.low  =
1420                         cpu_to_be32(sg_dma_address(sg));
1421                 orb->request.misc |=
1422                         cpu_to_be32(COMMAND_ORB_DATA_SIZE(sg_dma_len(sg)));
1423                 return 0;
1424         }
1425
1426         for_each_sg(sg, sg, n, i) {
1427                 orb->page_table[i].high = cpu_to_be32(sg_dma_len(sg) << 16);
1428                 orb->page_table[i].low = cpu_to_be32(sg_dma_address(sg));
1429         }
1430
1431         orb->page_table_bus =
1432                 dma_map_single(device->card->device, orb->page_table,
1433                                sizeof(orb->page_table), DMA_TO_DEVICE);
1434         if (dma_mapping_error(device->card->device, orb->page_table_bus))
1435                 goto fail_page_table;
1436
1437         /*
1438          * The data_descriptor pointer is the one case where we need
1439          * to fill in the node ID part of the address.  All other
1440          * pointers assume that the data referenced reside on the
1441          * initiator (i.e. us), but data_descriptor can refer to data
1442          * on other nodes so we need to put our ID in descriptor.high.
1443          */
1444         orb->request.data_descriptor.high = cpu_to_be32(lu->tgt->address_high);
1445         orb->request.data_descriptor.low  = cpu_to_be32(orb->page_table_bus);
1446         orb->request.misc |= cpu_to_be32(COMMAND_ORB_PAGE_TABLE_PRESENT |
1447                                          COMMAND_ORB_DATA_SIZE(n));
1448
1449         return 0;
1450
1451  fail_page_table:
1452         scsi_dma_unmap(orb->cmd);
1453  fail:
1454         return -ENOMEM;
1455 }
1456
1457 /* SCSI stack integration */
1458
1459 static int sbp2_scsi_queuecommand(struct Scsi_Host *shost,
1460                                   struct scsi_cmnd *cmd)
1461 {
1462         struct sbp2_logical_unit *lu = cmd->device->hostdata;
1463         struct fw_device *device = target_parent_device(lu->tgt);
1464         struct sbp2_command_orb *orb;
1465         int generation, retval = SCSI_MLQUEUE_HOST_BUSY;
1466
1467         /*
1468          * Bidirectional commands are not yet implemented, and unknown
1469          * transfer direction not handled.
1470          */
1471         if (cmd->sc_data_direction == DMA_BIDIRECTIONAL) {
1472                 dev_err(lu_dev(lu), "cannot handle bidirectional command\n");
1473                 cmd->result = DID_ERROR << 16;
1474                 cmd->scsi_done(cmd);
1475                 return 0;
1476         }
1477
1478         orb = kzalloc(sizeof(*orb), GFP_ATOMIC);
1479         if (orb == NULL)
1480                 return SCSI_MLQUEUE_HOST_BUSY;
1481
1482         /* Initialize rcode to something not RCODE_COMPLETE. */
1483         orb->base.rcode = -1;
1484         kref_init(&orb->base.kref);
1485         orb->lu = lu;
1486         orb->cmd = cmd;
1487         orb->request.next.high = cpu_to_be32(SBP2_ORB_NULL);
1488         orb->request.misc = cpu_to_be32(
1489                 COMMAND_ORB_MAX_PAYLOAD(lu->tgt->max_payload) |
1490                 COMMAND_ORB_SPEED(device->max_speed) |
1491                 COMMAND_ORB_NOTIFY);
1492
1493         if (cmd->sc_data_direction == DMA_FROM_DEVICE)
1494                 orb->request.misc |= cpu_to_be32(COMMAND_ORB_DIRECTION);
1495
1496         generation = device->generation;
1497         smp_rmb();    /* sbp2_map_scatterlist looks at tgt->address_high */
1498
1499         if (scsi_sg_count(cmd) && sbp2_map_scatterlist(orb, device, lu) < 0)
1500                 goto out;
1501
1502         memcpy(orb->request.command_block, cmd->cmnd, cmd->cmd_len);
1503
1504         orb->base.callback = complete_command_orb;
1505         orb->base.request_bus =
1506                 dma_map_single(device->card->device, &orb->request,
1507                                sizeof(orb->request), DMA_TO_DEVICE);
1508         if (dma_mapping_error(device->card->device, orb->base.request_bus)) {
1509                 sbp2_unmap_scatterlist(device->card->device, orb);
1510                 goto out;
1511         }
1512
1513         sbp2_send_orb(&orb->base, lu, lu->tgt->node_id, generation,
1514                       lu->command_block_agent_address + SBP2_ORB_POINTER);
1515         retval = 0;
1516  out:
1517         kref_put(&orb->base.kref, free_orb);
1518         return retval;
1519 }
1520
1521 static int sbp2_scsi_slave_alloc(struct scsi_device *sdev)
1522 {
1523         struct sbp2_logical_unit *lu = sdev->hostdata;
1524
1525         /* (Re-)Adding logical units via the SCSI stack is not supported. */
1526         if (!lu)
1527                 return -ENOSYS;
1528
1529         sdev->allow_restart = 1;
1530
1531         /*
1532          * SBP-2 does not require any alignment, but we set it anyway
1533          * for compatibility with earlier versions of this driver.
1534          */
1535         blk_queue_update_dma_alignment(sdev->request_queue, 4 - 1);
1536
1537         if (lu->tgt->workarounds & SBP2_WORKAROUND_INQUIRY_36)
1538                 sdev->inquiry_len = 36;
1539
1540         return 0;
1541 }
1542
1543 static int sbp2_scsi_slave_configure(struct scsi_device *sdev)
1544 {
1545         struct sbp2_logical_unit *lu = sdev->hostdata;
1546
1547         sdev->use_10_for_rw = 1;
1548
1549         if (sbp2_param_exclusive_login)
1550                 sdev->manage_start_stop = 1;
1551
1552         if (sdev->type == TYPE_ROM)
1553                 sdev->use_10_for_ms = 1;
1554
1555         if (sdev->type == TYPE_DISK &&
1556             lu->tgt->workarounds & SBP2_WORKAROUND_MODE_SENSE_8)
1557                 sdev->skip_ms_page_8 = 1;
1558
1559         if (lu->tgt->workarounds & SBP2_WORKAROUND_FIX_CAPACITY)
1560                 sdev->fix_capacity = 1;
1561
1562         if (lu->tgt->workarounds & SBP2_WORKAROUND_POWER_CONDITION)
1563                 sdev->start_stop_pwr_cond = 1;
1564
1565         if (lu->tgt->workarounds & SBP2_WORKAROUND_128K_MAX_TRANS)
1566                 blk_queue_max_hw_sectors(sdev->request_queue, 128 * 1024 / 512);
1567
1568         return 0;
1569 }
1570
1571 /*
1572  * Called by scsi stack when something has really gone wrong.  Usually
1573  * called when a command has timed-out for some reason.
1574  */
1575 static int sbp2_scsi_abort(struct scsi_cmnd *cmd)
1576 {
1577         struct sbp2_logical_unit *lu = cmd->device->hostdata;
1578
1579         dev_notice(lu_dev(lu), "sbp2_scsi_abort\n");
1580         sbp2_agent_reset(lu);
1581         sbp2_cancel_orbs(lu);
1582
1583         return SUCCESS;
1584 }
1585
1586 /*
1587  * Format of /sys/bus/scsi/devices/.../ieee1394_id:
1588  * u64 EUI-64 : u24 directory_ID : u16 LUN  (all printed in hexadecimal)
1589  *
1590  * This is the concatenation of target port identifier and logical unit
1591  * identifier as per SAM-2...SAM-4 annex A.
1592  */
1593 static ssize_t sbp2_sysfs_ieee1394_id_show(struct device *dev,
1594                         struct device_attribute *attr, 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",
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 MODULE_ALIAS("sbp2");
1639
1640 static int __init sbp2_init(void)
1641 {
1642         return driver_register(&sbp2_driver.driver);
1643 }
1644
1645 static void __exit sbp2_cleanup(void)
1646 {
1647         driver_unregister(&sbp2_driver.driver);
1648 }
1649
1650 module_init(sbp2_init);
1651 module_exit(sbp2_cleanup);