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/bug.h>
  33 #include <linux/delay.h>
  34 #include <linux/device.h>
  35 #include <linux/dma-mapping.h>
  36 #include <linux/kernel.h>
  37 #include <linux/mod_devicetable.h>
  38 #include <linux/module.h>
  39 #include <linux/moduleparam.h>
  40 #include <linux/scatterlist.h>
  41 #include <linux/string.h>
  42 #include <linux/stringify.h>
  43 #include <linux/timer.h>
  44 #include <linux/workqueue.h>
  45 #include <asm/system.h>
  46
  47 #include <scsi/scsi.h>
  48 #include <scsi/scsi_cmnd.h>
  49 #include <scsi/scsi_device.h>
  50 #include <scsi/scsi_host.h>
  51
  52 #include "fw-device.h"
  53 #include "fw-topology.h"
  54 #include "fw-transaction.h"
  55
  56 /*
  57  * So far only bridges from Oxford Semiconductor are known to support
  58  * concurrent logins. Depending on firmware, four or two concurrent logins
  59  * are possible on OXFW911 and newer Oxsemi bridges.
  60  *
  61  * Concurrent logins are useful together with cluster filesystems.
  62  */
  63 static int sbp2_param_exclusive_login = 1;
  64 module_param_named(exclusive_login, sbp2_param_exclusive_login, bool, 0644);
  65 MODULE_PARM_DESC(exclusive_login, "Exclusive login to sbp2 device "
  66                  "(default = Y, use N for concurrent initiators)");
  67
  68 /*
  69  * Flags for firmware oddities
  70  *
  71  * - 128kB max transfer
  72  *   Limit transfer size. Necessary for some old bridges.
  73  *
  74  * - 36 byte inquiry
  75  *   When scsi_mod probes the device, let the inquiry command look like that
  76  *   from MS Windows.
  77  *
  78  * - skip mode page 8
  79  *   Suppress sending of mode_sense for mode page 8 if the device pretends to
  80  *   support the SCSI Primary Block commands instead of Reduced Block Commands.
  81  *
  82  * - fix capacity
  83  *   Tell sd_mod to correct the last sector number reported by read_capacity.
  84  *   Avoids access beyond actual disk limits on devices with an off-by-one bug.
  85  *   Don't use this with devices which don't have this bug.
  86  *
  87  * - delay inquiry
  88  *   Wait extra SBP2_INQUIRY_DELAY seconds after login before SCSI inquiry.
  89  *
  90  * - power condition
  91  *   Set the power condition field in the START STOP UNIT commands sent by
  92  *   sd_mod on suspend, resume, and shutdown (if manage_start_stop is on).
  93  *   Some disks need this to spin down or to resume properly.
  94  *
  95  * - override internal blacklist
  96  *   Instead of adding to the built-in blacklist, use only the workarounds
  97  *   specified in the module load parameter.
  98  *   Useful if a blacklist entry interfered with a non-broken device.
  99  */
 100 #define SBP2_WORKAROUND_128K_MAX_TRANS  0x1
 101 #define SBP2_WORKAROUND_INQUIRY_36      0x2
 102 #define SBP2_WORKAROUND_MODE_SENSE_8    0x4
 103 #define SBP2_WORKAROUND_FIX_CAPACITY    0x8
 104 #define SBP2_WORKAROUND_DELAY_INQUIRY   0x10
 105 #define SBP2_INQUIRY_DELAY              12
 106 #define SBP2_WORKAROUND_POWER_CONDITION 0x20
 107 #define SBP2_WORKAROUND_OVERRIDE        0x100
 108
 109 static int sbp2_param_workarounds;
 110 module_param_named(workarounds, sbp2_param_workarounds, int, 0644);
 111 MODULE_PARM_DESC(workarounds, "Work around device bugs (default = 0"
 112         ", 128kB max transfer = " __stringify(SBP2_WORKAROUND_128K_MAX_TRANS)
 113         ", 36 byte inquiry = "    __stringify(SBP2_WORKAROUND_INQUIRY_36)
 114         ", skip mode page 8 = "   __stringify(SBP2_WORKAROUND_MODE_SENSE_8)
 115         ", fix capacity = "       __stringify(SBP2_WORKAROUND_FIX_CAPACITY)
 116         ", delay inquiry = "      __stringify(SBP2_WORKAROUND_DELAY_INQUIRY)
 117         ", set power condition in start stop unit = "
 118                                   __stringify(SBP2_WORKAROUND_POWER_CONDITION)
 119         ", override internal blacklist = " __stringify(SBP2_WORKAROUND_OVERRIDE)
 120         ", or a combination)");
 121
 122 /* I don't know why the SCSI stack doesn't define something like this... */
 123 typedef void (*scsi_done_fn_t)(struct scsi_cmnd *);
 124
 125 static const char sbp2_driver_name[] = "sbp2";
 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         struct delayed_work work;
 150         bool has_sdev;
 151         bool blocked;
 152 };
 153
 154 /*
 155  * We create one struct sbp2_target per IEEE 1212 Unit Directory
 156  * and one struct Scsi_Host per sbp2_target.
 157  */
 158 struct sbp2_target {
 159         struct kref kref;
 160         struct fw_unit *unit;
 161         const char *bus_id;
 162         struct list_head lu_list;
 163
 164         u64 management_agent_address;
 165         u64 guid;
 166         int directory_id;
 167         int node_id;
 168         int address_high;
 169         unsigned int workarounds;
 170         unsigned int mgt_orb_timeout;
 171
 172         int dont_block; /* counter for each logical unit */
 173         int blocked;    /* ditto */
 174 };
 175
 176 /*
 177  * Per section 7.4.8 of the SBP-2 spec, a mgt_ORB_timeout value can be
 178  * provided in the config rom. Most devices do provide a value, which
 179  * we'll use for login management orbs, but with some sane limits.
 180  */
 181 #define SBP2_MIN_LOGIN_ORB_TIMEOUT      5000U   /* Timeout in ms */
 182 #define SBP2_MAX_LOGIN_ORB_TIMEOUT      40000U  /* Timeout in ms */
 183 #define SBP2_ORB_TIMEOUT                2000U   /* Timeout in ms */
 184 #define SBP2_ORB_NULL                   0x80000000
 185 #define SBP2_RETRY_LIMIT                0xf             /* 15 retries */
 186 #define SBP2_CYCLE_LIMIT                (0xc8 << 12)    /* 200 125us cycles */
 187
 188 /*
 189  * The default maximum s/g segment size of a FireWire controller is
 190  * usually 0x10000, but SBP-2 only allows 0xffff. Since buffers have to
 191  * be quadlet-aligned, we set the length limit to 0xffff & ~3.
 192  */
 193 #define SBP2_MAX_SEG_SIZE               0xfffc
 194
 195 /* Unit directory keys */
 196 #define SBP2_CSR_UNIT_CHARACTERISTICS   0x3a
 197 #define SBP2_CSR_FIRMWARE_REVISION      0x3c
 198 #define SBP2_CSR_LOGICAL_UNIT_NUMBER    0x14
 199 #define SBP2_CSR_LOGICAL_UNIT_DIRECTORY 0xd4
 200
 201 /* Management orb opcodes */
 202 #define SBP2_LOGIN_REQUEST              0x0
 203 #define SBP2_QUERY_LOGINS_REQUEST       0x1
 204 #define SBP2_RECONNECT_REQUEST          0x3
 205 #define SBP2_SET_PASSWORD_REQUEST       0x4
 206 #define SBP2_LOGOUT_REQUEST             0x7
 207 #define SBP2_ABORT_TASK_REQUEST         0xb
 208 #define SBP2_ABORT_TASK_SET             0xc
 209 #define SBP2_LOGICAL_UNIT_RESET         0xe
 210 #define SBP2_TARGET_RESET_REQUEST       0xf
 211
 212 /* Offsets for command block agent registers */
 213 #define SBP2_AGENT_STATE                0x00
 214 #define SBP2_AGENT_RESET                0x04
 215 #define SBP2_ORB_POINTER                0x08
 216 #define SBP2_DOORBELL                   0x10
 217 #define SBP2_UNSOLICITED_STATUS_ENABLE  0x14
 218
 219 /* Status write response codes */
 220 #define SBP2_STATUS_REQUEST_COMPLETE    0x0
 221 #define SBP2_STATUS_TRANSPORT_FAILURE   0x1
 222 #define SBP2_STATUS_ILLEGAL_REQUEST     0x2
 223 #define SBP2_STATUS_VENDOR_DEPENDENT    0x3
 224
 225 #define STATUS_GET_ORB_HIGH(v)          ((v).status & 0xffff)
 226 #define STATUS_GET_SBP_STATUS(v)        (((v).status >> 16) & 0xff)
 227 #define STATUS_GET_LEN(v)               (((v).status >> 24) & 0x07)
 228 #define STATUS_GET_DEAD(v)              (((v).status >> 27) & 0x01)
 229 #define STATUS_GET_RESPONSE(v)          (((v).status >> 28) & 0x03)
 230 #define STATUS_GET_SOURCE(v)            (((v).status >> 30) & 0x03)
 231 #define STATUS_GET_ORB_LOW(v)           ((v).orb_low)
 232 #define STATUS_GET_DATA(v)              ((v).data)
 233
 234 struct sbp2_status {
 235         u32 status;
 236         u32 orb_low;
 237         u8 data[24];
 238 };
 239
 240 struct sbp2_pointer {
 241         __be32 high;
 242         __be32 low;
 243 };
 244
 245 struct sbp2_orb {
 246         struct fw_transaction t;
 247         struct kref kref;
 248         dma_addr_t request_bus;
 249         int rcode;
 250         struct sbp2_pointer pointer;
 251         void (*callback)(struct sbp2_orb * orb, struct sbp2_status * status);
 252         struct list_head link;
 253 };
 254
 255 #define MANAGEMENT_ORB_LUN(v)                   ((v))
 256 #define MANAGEMENT_ORB_FUNCTION(v)              ((v) << 16)
 257 #define MANAGEMENT_ORB_RECONNECT(v)             ((v) << 20)
 258 #define MANAGEMENT_ORB_EXCLUSIVE(v)             ((v) ? 1 << 28 : 0)
 259 #define MANAGEMENT_ORB_REQUEST_FORMAT(v)        ((v) << 29)
 260 #define MANAGEMENT_ORB_NOTIFY                   ((1) << 31)
 261
 262 #define MANAGEMENT_ORB_RESPONSE_LENGTH(v)       ((v))
 263 #define MANAGEMENT_ORB_PASSWORD_LENGTH(v)       ((v) << 16)
 264
 265 struct sbp2_management_orb {
 266         struct sbp2_orb base;
 267         struct {
 268                 struct sbp2_pointer password;
 269                 struct sbp2_pointer response;
 270                 __be32 misc;
 271                 __be32 length;
 272                 struct sbp2_pointer status_fifo;
 273         } request;
 274         __be32 response[4];
 275         dma_addr_t response_bus;
 276         struct completion done;
 277         struct sbp2_status status;
 278 };
 279
 280 struct sbp2_login_response {
 281         __be32 misc;
 282         struct sbp2_pointer command_block_agent;
 283         __be32 reconnect_hold;
 284 };
 285 #define COMMAND_ORB_DATA_SIZE(v)        ((v))
 286 #define COMMAND_ORB_PAGE_SIZE(v)        ((v) << 16)
 287 #define COMMAND_ORB_PAGE_TABLE_PRESENT  ((1) << 19)
 288 #define COMMAND_ORB_MAX_PAYLOAD(v)      ((v) << 20)
 289 #define COMMAND_ORB_SPEED(v)            ((v) << 24)
 290 #define COMMAND_ORB_DIRECTION           ((1) << 27)
 291 #define COMMAND_ORB_REQUEST_FORMAT(v)   ((v) << 29)
 292 #define COMMAND_ORB_NOTIFY              ((1) << 31)
 293
 294 struct sbp2_command_orb {
 295         struct sbp2_orb base;
 296         struct {
 297                 struct sbp2_pointer next;
 298                 struct sbp2_pointer data_descriptor;
 299                 __be32 misc;
 300                 u8 command_block[12];
 301         } request;
 302         struct scsi_cmnd *cmd;
 303         scsi_done_fn_t done;
 304         struct sbp2_logical_unit *lu;
 305
 306         struct sbp2_pointer page_table[SG_ALL] __attribute__((aligned(8)));
 307         dma_addr_t page_table_bus;
 308 };
 309
 310 /*
 311  * List of devices with known bugs.
 312  *
 313  * The firmware_revision field, masked with 0xffff00, is the best
 314  * indicator for the type of bridge chip of a device.  It yields a few
 315  * false positives but this did not break correctly behaving devices
 316  * so far.  We use ~0 as a wildcard, since the 24 bit values we get
 317  * from the config rom can never match that.
 318  */
 319 static const struct {
 320         u32 firmware_revision;
 321         u32 model;
 322         unsigned int workarounds;
 323 } sbp2_workarounds_table[] = {
 324         /* DViCO Momobay CX-1 with TSB42AA9 bridge */ {
 325                 .firmware_revision      = 0x002800,
 326                 .model                  = 0x001010,
 327                 .workarounds            = SBP2_WORKAROUND_INQUIRY_36 |
 328                                           SBP2_WORKAROUND_MODE_SENSE_8 |
 329                                           SBP2_WORKAROUND_POWER_CONDITION,
 330         },
 331         /* DViCO Momobay FX-3A with TSB42AA9A bridge */ {
 332                 .firmware_revision      = 0x002800,
 333                 .model                  = 0x000000,
 334                 .workarounds            = SBP2_WORKAROUND_DELAY_INQUIRY |
 335                                           SBP2_WORKAROUND_POWER_CONDITION,
 336         },
 337         /* Initio bridges, actually only needed for some older ones */ {
 338                 .firmware_revision      = 0x000200,
 339                 .model                  = ~0,
 340                 .workarounds            = SBP2_WORKAROUND_INQUIRY_36,
 341         },
 342         /* PL-3507 bridge with Prolific firmware */ {
 343                 .firmware_revision      = 0x012800,
 344                 .model                  = ~0,
 345                 .workarounds            = SBP2_WORKAROUND_POWER_CONDITION,
 346         },
 347         /* Symbios bridge */ {
 348                 .firmware_revision      = 0xa0b800,
 349                 .model                  = ~0,
 350                 .workarounds            = SBP2_WORKAROUND_128K_MAX_TRANS,
 351         },
 352         /* Datafab MD2-FW2 with Symbios/LSILogic SYM13FW500 bridge */ {
 353                 .firmware_revision      = 0x002600,
 354                 .model                  = ~0,
 355                 .workarounds            = SBP2_WORKAROUND_128K_MAX_TRANS,
 356         },
 357
 358         /*
 359          * There are iPods (2nd gen, 3rd gen) with model_id == 0, but
 360          * these iPods do not feature the read_capacity bug according
 361          * to one report.  Read_capacity behaviour as well as model_id
 362          * could change due to Apple-supplied firmware updates though.
 363          */
 364
 365         /* iPod 4th generation. */ {
 366                 .firmware_revision      = 0x0a2700,
 367                 .model                  = 0x000021,
 368                 .workarounds            = SBP2_WORKAROUND_FIX_CAPACITY,
 369         },
 370         /* iPod mini */ {
 371                 .firmware_revision      = 0x0a2700,
 372                 .model                  = 0x000023,
 373                 .workarounds            = SBP2_WORKAROUND_FIX_CAPACITY,
 374         },
 375         /* iPod Photo */ {
 376                 .firmware_revision      = 0x0a2700,
 377                 .model                  = 0x00007e,
 378                 .workarounds            = SBP2_WORKAROUND_FIX_CAPACITY,
 379         }
 380 };
 381
 382 static void
 383 free_orb(struct kref *kref)
 384 {
 385         struct sbp2_orb *orb = container_of(kref, struct sbp2_orb, kref);
 386
 387         kfree(orb);
 388 }
 389
 390 static void
 391 sbp2_status_write(struct fw_card *card, struct fw_request *request,
 392                   int tcode, int destination, int source,
 393                   int generation, int speed,
 394                   unsigned long long offset,
 395                   void *payload, size_t length, void *callback_data)
 396 {
 397         struct sbp2_logical_unit *lu = callback_data;
 398         struct sbp2_orb *orb;
 399         struct sbp2_status status;
 400         size_t header_size;
 401         unsigned long flags;
 402
 403         if (tcode != TCODE_WRITE_BLOCK_REQUEST ||
 404             length == 0 || length > sizeof(status)) {
 405                 fw_send_response(card, request, RCODE_TYPE_ERROR);
 406                 return;
 407         }
 408
 409         header_size = min(length, 2 * sizeof(u32));
 410         fw_memcpy_from_be32(&status, payload, header_size);
 411         if (length > header_size)
 412                 memcpy(status.data, payload + 8, length - header_size);
 413         if (STATUS_GET_SOURCE(status) == 2 || STATUS_GET_SOURCE(status) == 3) {
 414                 fw_notify("non-orb related status write, not handled\n");
 415                 fw_send_response(card, request, RCODE_COMPLETE);
 416                 return;
 417         }
 418
 419         /* Lookup the orb corresponding to this status write. */
 420         spin_lock_irqsave(&card->lock, flags);
 421         list_for_each_entry(orb, &lu->orb_list, link) {
 422                 if (STATUS_GET_ORB_HIGH(status) == 0 &&
 423                     STATUS_GET_ORB_LOW(status) == orb->request_bus) {
 424                         orb->rcode = RCODE_COMPLETE;
 425                         list_del(&orb->link);
 426                         break;
 427                 }
 428         }
 429         spin_unlock_irqrestore(&card->lock, flags);
 430
 431         if (&orb->link != &lu->orb_list)
 432                 orb->callback(orb, &status);
 433         else
 434                 fw_error("status write for unknown orb\n");
 435
 436         kref_put(&orb->kref, free_orb);
 437
 438         fw_send_response(card, request, RCODE_COMPLETE);
 439 }
 440
 441 static void
 442 complete_transaction(struct fw_card *card, int rcode,
 443                      void *payload, size_t length, void *data)
 444 {
 445         struct sbp2_orb *orb = data;
 446         unsigned long flags;
 447
 448         /*
 449          * This is a little tricky.  We can get the status write for
 450          * the orb before we get this callback.  The status write
 451          * handler above will assume the orb pointer transaction was
 452          * successful and set the rcode to RCODE_COMPLETE for the orb.
 453          * So this callback only sets the rcode if it hasn't already
 454          * been set and only does the cleanup if the transaction
 455          * failed and we didn't already get a status write.
 456          */
 457         spin_lock_irqsave(&card->lock, flags);
 458
 459         if (orb->rcode == -1)
 460                 orb->rcode = rcode;
 461         if (orb->rcode != RCODE_COMPLETE) {
 462                 list_del(&orb->link);
 463                 spin_unlock_irqrestore(&card->lock, flags);
 464                 orb->callback(orb, NULL);
 465         } else {
 466                 spin_unlock_irqrestore(&card->lock, flags);
 467         }
 468
 469         kref_put(&orb->kref, free_orb);
 470 }
 471
 472 static void
 473 sbp2_send_orb(struct sbp2_orb *orb, struct sbp2_logical_unit *lu,
 474               int node_id, int generation, u64 offset)
 475 {
 476         struct fw_device *device = fw_device(lu->tgt->unit->device.parent);
 477         unsigned long flags;
 478
 479         orb->pointer.high = 0;
 480         orb->pointer.low = cpu_to_be32(orb->request_bus);
 481
 482         spin_lock_irqsave(&device->card->lock, flags);
 483         list_add_tail(&orb->link, &lu->orb_list);
 484         spin_unlock_irqrestore(&device->card->lock, flags);
 485
 486         /* Take a ref for the orb list and for the transaction callback. */
 487         kref_get(&orb->kref);
 488         kref_get(&orb->kref);
 489
 490         fw_send_request(device->card, &orb->t, TCODE_WRITE_BLOCK_REQUEST,
 491                         node_id, generation, device->max_speed, offset,
 492                         &orb->pointer, sizeof(orb->pointer),
 493                         complete_transaction, orb);
 494 }
 495
 496 static int sbp2_cancel_orbs(struct sbp2_logical_unit *lu)
 497 {
 498         struct fw_device *device = fw_device(lu->tgt->unit->device.parent);
 499         struct sbp2_orb *orb, *next;
 500         struct list_head list;
 501         unsigned long flags;
 502         int retval = -ENOENT;
 503
 504         INIT_LIST_HEAD(&list);
 505         spin_lock_irqsave(&device->card->lock, flags);
 506         list_splice_init(&lu->orb_list, &list);
 507         spin_unlock_irqrestore(&device->card->lock, flags);
 508
 509         list_for_each_entry_safe(orb, next, &list, link) {
 510                 retval = 0;
 511                 if (fw_cancel_transaction(device->card, &orb->t) == 0)
 512                         continue;
 513
 514                 orb->rcode = RCODE_CANCELLED;
 515                 orb->callback(orb, NULL);
 516         }
 517
 518         return retval;
 519 }
 520
 521 static void
 522 complete_management_orb(struct sbp2_orb *base_orb, struct sbp2_status *status)
 523 {
 524         struct sbp2_management_orb *orb =
 525                 container_of(base_orb, struct sbp2_management_orb, base);
 526
 527         if (status)
 528                 memcpy(&orb->status, status, sizeof(*status));
 529         complete(&orb->done);
 530 }
 531
 532 static int
 533 sbp2_send_management_orb(struct sbp2_logical_unit *lu, int node_id,
 534                          int generation, int function, int lun_or_login_id,
 535                          void *response)
 536 {
 537         struct fw_device *device = fw_device(lu->tgt->unit->device.parent);
 538         struct sbp2_management_orb *orb;
 539         unsigned int timeout;
 540         int retval = -ENOMEM;
 541
 542         if (function == SBP2_LOGOUT_REQUEST && fw_device_is_shutdown(device))
 543                 return 0;
 544
 545         orb = kzalloc(sizeof(*orb), GFP_ATOMIC);
 546         if (orb == NULL)
 547                 return -ENOMEM;
 548
 549         kref_init(&orb->base.kref);
 550         orb->response_bus =
 551                 dma_map_single(device->card->device, &orb->response,
 552                                sizeof(orb->response), DMA_FROM_DEVICE);
 553         if (dma_mapping_error(device->card->device, orb->response_bus))
 554                 goto fail_mapping_response;
 555
 556         orb->request.response.high = 0;
 557         orb->request.response.low  = cpu_to_be32(orb->response_bus);
 558
 559         orb->request.misc = cpu_to_be32(
 560                 MANAGEMENT_ORB_NOTIFY |
 561                 MANAGEMENT_ORB_FUNCTION(function) |
 562                 MANAGEMENT_ORB_LUN(lun_or_login_id));
 563         orb->request.length = cpu_to_be32(
 564                 MANAGEMENT_ORB_RESPONSE_LENGTH(sizeof(orb->response)));
 565
 566         orb->request.status_fifo.high =
 567                 cpu_to_be32(lu->address_handler.offset >> 32);
 568         orb->request.status_fifo.low  =
 569                 cpu_to_be32(lu->address_handler.offset);
 570
 571         if (function == SBP2_LOGIN_REQUEST) {
 572                 /* Ask for 2^2 == 4 seconds reconnect grace period */
 573                 orb->request.misc |= cpu_to_be32(
 574                         MANAGEMENT_ORB_RECONNECT(2) |
 575                         MANAGEMENT_ORB_EXCLUSIVE(sbp2_param_exclusive_login));
 576                 timeout = lu->tgt->mgt_orb_timeout;
 577         } else {
 578                 timeout = SBP2_ORB_TIMEOUT;
 579         }
 580
 581         init_completion(&orb->done);
 582         orb->base.callback = complete_management_orb;
 583
 584         orb->base.request_bus =
 585                 dma_map_single(device->card->device, &orb->request,
 586                                sizeof(orb->request), DMA_TO_DEVICE);
 587         if (dma_mapping_error(device->card->device, orb->base.request_bus))
 588                 goto fail_mapping_request;
 589
 590         sbp2_send_orb(&orb->base, lu, node_id, generation,
 591                       lu->tgt->management_agent_address);
 592
 593         wait_for_completion_timeout(&orb->done, msecs_to_jiffies(timeout));
 594
 595         retval = -EIO;
 596         if (sbp2_cancel_orbs(lu) == 0) {
 597                 fw_error("%s: orb reply timed out, rcode=0x%02x\n",
 598                          lu->tgt->bus_id, orb->base.rcode);
 599                 goto out;
 600         }
 601
 602         if (orb->base.rcode != RCODE_COMPLETE) {
 603                 fw_error("%s: management write failed, rcode 0x%02x\n",
 604                          lu->tgt->bus_id, orb->base.rcode);
 605                 goto out;
 606         }
 607
 608         if (STATUS_GET_RESPONSE(orb->status) != 0 ||
 609             STATUS_GET_SBP_STATUS(orb->status) != 0) {
 610                 fw_error("%s: error status: %d:%d\n", lu->tgt->bus_id,
 611                          STATUS_GET_RESPONSE(orb->status),
 612                          STATUS_GET_SBP_STATUS(orb->status));
 613                 goto out;
 614         }
 615
 616         retval = 0;
 617  out:
 618         dma_unmap_single(device->card->device, orb->base.request_bus,
 619                          sizeof(orb->request), DMA_TO_DEVICE);
 620  fail_mapping_request:
 621         dma_unmap_single(device->card->device, orb->response_bus,
 622                          sizeof(orb->response), DMA_FROM_DEVICE);
 623  fail_mapping_response:
 624         if (response)
 625                 memcpy(response, orb->response, sizeof(orb->response));
 626         kref_put(&orb->base.kref, free_orb);
 627
 628         return retval;
 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         __be32 d = 0;
 635
 636         fw_run_transaction(device->card, TCODE_WRITE_QUADLET_REQUEST,
 637                            lu->tgt->node_id, lu->generation, device->max_speed,
 638                            lu->command_block_agent_address + SBP2_AGENT_RESET,
 639                            &d, sizeof(d));
 640 }
 641
 642 static void
 643 complete_agent_reset_write_no_wait(struct fw_card *card, int rcode,
 644                                    void *payload, size_t length, void *data)
 645 {
 646         kfree(data);
 647 }
 648
 649 static void sbp2_agent_reset_no_wait(struct sbp2_logical_unit *lu)
 650 {
 651         struct fw_device *device = fw_device(lu->tgt->unit->device.parent);
 652         struct fw_transaction *t;
 653         static __be32 d;
 654
 655         t = kmalloc(sizeof(*t), GFP_ATOMIC);
 656         if (t == NULL)
 657                 return;
 658
 659         fw_send_request(device->card, t, TCODE_WRITE_QUADLET_REQUEST,
 660                         lu->tgt->node_id, lu->generation, device->max_speed,
 661                         lu->command_block_agent_address + SBP2_AGENT_RESET,
 662                         &d, sizeof(d), complete_agent_reset_write_no_wait, t);
 663 }
 664
 665 static void sbp2_set_generation(struct sbp2_logical_unit *lu, int generation)
 666 {
 667         struct fw_card *card = fw_device(lu->tgt->unit->device.parent)->card;
 668         unsigned long flags;
 669
 670         /* serialize with comparisons of lu->generation and card->generation */
 671         spin_lock_irqsave(&card->lock, flags);
 672         lu->generation = generation;
 673         spin_unlock_irqrestore(&card->lock, flags);
 674 }
 675
 676 static inline void sbp2_allow_block(struct sbp2_logical_unit *lu)
 677 {
 678         /*
 679          * We may access dont_block without taking card->lock here:
 680          * All callers of sbp2_allow_block() and all callers of sbp2_unblock()
 681          * are currently serialized against each other.
 682          * And a wrong result in sbp2_conditionally_block()'s access of
 683          * dont_block is rather harmless, it simply misses its first chance.
 684          */
 685         --lu->tgt->dont_block;
 686 }
 687
 688 /*
 689  * Blocks lu->tgt if all of the following conditions are met:
 690  *   - Login, INQUIRY, and high-level SCSI setup of all of the target's
 691  *     logical units have been finished (indicated by dont_block == 0).
 692  *   - lu->generation is stale.
 693  *
 694  * Note, scsi_block_requests() must be called while holding card->lock,
 695  * otherwise it might foil sbp2_[conditionally_]unblock()'s attempt to
 696  * unblock the target.
 697  */
 698 static void sbp2_conditionally_block(struct sbp2_logical_unit *lu)
 699 {
 700         struct sbp2_target *tgt = lu->tgt;
 701         struct fw_card *card = fw_device(tgt->unit->device.parent)->card;
 702         struct Scsi_Host *shost =
 703                 container_of((void *)tgt, struct Scsi_Host, hostdata[0]);
 704         unsigned long flags;
 705
 706         spin_lock_irqsave(&card->lock, flags);
 707         if (!tgt->dont_block && !lu->blocked &&
 708             lu->generation != card->generation) {
 709                 lu->blocked = true;
 710                 if (++tgt->blocked == 1)
 711                         scsi_block_requests(shost);
 712         }
 713         spin_unlock_irqrestore(&card->lock, flags);
 714 }
 715
 716 /*
 717  * Unblocks lu->tgt as soon as all its logical units can be unblocked.
 718  * Note, it is harmless to run scsi_unblock_requests() outside the
 719  * card->lock protected section.  On the other hand, running it inside
 720  * the section might clash with shost->host_lock.
 721  */
 722 static void sbp2_conditionally_unblock(struct sbp2_logical_unit *lu)
 723 {
 724         struct sbp2_target *tgt = lu->tgt;
 725         struct fw_card *card = fw_device(tgt->unit->device.parent)->card;
 726         struct Scsi_Host *shost =
 727                 container_of((void *)tgt, struct Scsi_Host, hostdata[0]);
 728         unsigned long flags;
 729         bool unblock = false;
 730
 731         spin_lock_irqsave(&card->lock, flags);
 732         if (lu->blocked && lu->generation == card->generation) {
 733                 lu->blocked = false;
 734                 unblock = --tgt->blocked == 0;
 735         }
 736         spin_unlock_irqrestore(&card->lock, flags);
 737
 738         if (unblock)
 739                 scsi_unblock_requests(shost);
 740 }
 741
 742 /*
 743  * Prevents future blocking of tgt and unblocks it.
 744  * Note, it is harmless to run scsi_unblock_requests() outside the
 745  * card->lock protected section.  On the other hand, running it inside
 746  * the section might clash with shost->host_lock.
 747  */
 748 static void sbp2_unblock(struct sbp2_target *tgt)
 749 {
 750         struct fw_card *card = fw_device(tgt->unit->device.parent)->card;
 751         struct Scsi_Host *shost =
 752                 container_of((void *)tgt, struct Scsi_Host, hostdata[0]);
 753         unsigned long flags;
 754
 755         spin_lock_irqsave(&card->lock, flags);
 756         ++tgt->dont_block;
 757         spin_unlock_irqrestore(&card->lock, flags);
 758
 759         scsi_unblock_requests(shost);
 760 }
 761
 762 static int sbp2_lun2int(u16 lun)
 763 {
 764         struct scsi_lun eight_bytes_lun;
 765
 766         memset(&eight_bytes_lun, 0, sizeof(eight_bytes_lun));
 767         eight_bytes_lun.scsi_lun[0] = (lun >> 8) & 0xff;
 768         eight_bytes_lun.scsi_lun[1] = lun & 0xff;
 769
 770         return scsilun_to_int(&eight_bytes_lun);
 771 }
 772
 773 static void sbp2_release_target(struct kref *kref)
 774 {
 775         struct sbp2_target *tgt = container_of(kref, struct sbp2_target, kref);
 776         struct sbp2_logical_unit *lu, *next;
 777         struct Scsi_Host *shost =
 778                 container_of((void *)tgt, struct Scsi_Host, hostdata[0]);
 779         struct scsi_device *sdev;
 780         struct fw_device *device = fw_device(tgt->unit->device.parent);
 781
 782         /* prevent deadlocks */
 783         sbp2_unblock(tgt);
 784
 785         list_for_each_entry_safe(lu, next, &tgt->lu_list, link) {
 786                 sdev = scsi_device_lookup(shost, 0, 0, sbp2_lun2int(lu->lun));
 787                 if (sdev) {
 788                         scsi_remove_device(sdev);
 789                         scsi_device_put(sdev);
 790                 }
 791                 sbp2_send_management_orb(lu, tgt->node_id, lu->generation,
 792                                 SBP2_LOGOUT_REQUEST, lu->login_id, NULL);
 793
 794                 fw_core_remove_address_handler(&lu->address_handler);
 795                 list_del(&lu->link);
 796                 kfree(lu);
 797         }
 798         scsi_remove_host(shost);
 799         fw_notify("released %s, target %d:0:0\n", tgt->bus_id, shost->host_no);
 800
 801         fw_unit_put(tgt->unit);
 802         scsi_host_put(shost);
 803         fw_device_put(device);
 804 }
 805
 806 static struct workqueue_struct *sbp2_wq;
 807
 808 /*
 809  * Always get the target's kref when scheduling work on one its units.
 810  * Each workqueue job is responsible to call sbp2_target_put() upon return.
 811  */
 812 static void sbp2_queue_work(struct sbp2_logical_unit *lu, unsigned long delay)
 813 {
 814         if (queue_delayed_work(sbp2_wq, &lu->work, delay))
 815                 kref_get(&lu->tgt->kref);
 816 }
 817
 818 static void sbp2_target_put(struct sbp2_target *tgt)
 819 {
 820         kref_put(&tgt->kref, sbp2_release_target);
 821 }
 822
 823 /*
 824  * Write retransmit retry values into the BUSY_TIMEOUT register.
 825  * - The single-phase retry protocol is supported by all SBP-2 devices, but the
 826  *   default retry_limit value is 0 (i.e. never retry transmission). We write a
 827  *   saner value after logging into the device.
 828  * - The dual-phase retry protocol is optional to implement, and if not
 829  *   supported, writes to the dual-phase portion of the register will be
 830  *   ignored. We try to write the original 1394-1995 default here.
 831  * - In the case of devices that are also SBP-3-compliant, all writes are
 832  *   ignored, as the register is read-only, but contains single-phase retry of
 833  *   15, which is what we're trying to set for all SBP-2 device anyway, so this
 834  *   write attempt is safe and yields more consistent behavior for all devices.
 835  *
 836  * See section 8.3.2.3.5 of the 1394-1995 spec, section 6.2 of the SBP-2 spec,
 837  * and section 6.4 of the SBP-3 spec for further details.
 838  */
 839 static void sbp2_set_busy_timeout(struct sbp2_logical_unit *lu)
 840 {
 841         struct fw_device *device = fw_device(lu->tgt->unit->device.parent);
 842         __be32 d = cpu_to_be32(SBP2_CYCLE_LIMIT | SBP2_RETRY_LIMIT);
 843
 844         fw_run_transaction(device->card, TCODE_WRITE_QUADLET_REQUEST,
 845                            lu->tgt->node_id, lu->generation, device->max_speed,
 846                            CSR_REGISTER_BASE + CSR_BUSY_TIMEOUT,
 847                            &d, sizeof(d));
 848 }
 849
 850 static void sbp2_reconnect(struct work_struct *work);
 851
 852 static void sbp2_login(struct work_struct *work)
 853 {
 854         struct sbp2_logical_unit *lu =
 855                 container_of(work, struct sbp2_logical_unit, work.work);
 856         struct sbp2_target *tgt = lu->tgt;
 857         struct fw_device *device = fw_device(tgt->unit->device.parent);
 858         struct Scsi_Host *shost;
 859         struct scsi_device *sdev;
 860         struct sbp2_login_response response;
 861         int generation, node_id, local_node_id;
 862
 863         if (fw_device_is_shutdown(device))
 864                 goto out;
 865
 866         generation    = device->generation;
 867         smp_rmb();    /* node_id must not be older than generation */
 868         node_id       = device->node_id;
 869         local_node_id = device->card->node_id;
 870
 871         /* If this is a re-login attempt, log out, or we might be rejected. */
 872         if (lu->has_sdev)
 873                 sbp2_send_management_orb(lu, device->node_id, generation,
 874                                 SBP2_LOGOUT_REQUEST, lu->login_id, NULL);
 875
 876         if (sbp2_send_management_orb(lu, node_id, generation,
 877                                 SBP2_LOGIN_REQUEST, lu->lun, &response) < 0) {
 878                 if (lu->retries++ < 5) {
 879                         sbp2_queue_work(lu, DIV_ROUND_UP(HZ, 5));
 880                 } else {
 881                         fw_error("%s: failed to login to LUN %04x\n",
 882                                  tgt->bus_id, lu->lun);
 883                         /* Let any waiting I/O fail from now on. */
 884                         sbp2_unblock(lu->tgt);
 885                 }
 886                 goto out;
 887         }
 888
 889         tgt->node_id      = node_id;
 890         tgt->address_high = local_node_id << 16;
 891         sbp2_set_generation(lu, generation);
 892
 893         lu->command_block_agent_address =
 894                 ((u64)(be32_to_cpu(response.command_block_agent.high) & 0xffff)
 895                       << 32) | be32_to_cpu(response.command_block_agent.low);
 896         lu->login_id = be32_to_cpu(response.misc) & 0xffff;
 897
 898         fw_notify("%s: logged in to LUN %04x (%d retries)\n",
 899                   tgt->bus_id, lu->lun, lu->retries);
 900
 901         /* set appropriate retry limit(s) in BUSY_TIMEOUT register */
 902         sbp2_set_busy_timeout(lu);
 903
 904         PREPARE_DELAYED_WORK(&lu->work, sbp2_reconnect);
 905         sbp2_agent_reset(lu);
 906
 907         /* This was a re-login. */
 908         if (lu->has_sdev) {
 909                 sbp2_cancel_orbs(lu);
 910                 sbp2_conditionally_unblock(lu);
 911                 goto out;
 912         }
 913
 914         if (lu->tgt->workarounds & SBP2_WORKAROUND_DELAY_INQUIRY)
 915                 ssleep(SBP2_INQUIRY_DELAY);
 916
 917         shost = container_of((void *)tgt, struct Scsi_Host, hostdata[0]);
 918         sdev = __scsi_add_device(shost, 0, 0, sbp2_lun2int(lu->lun), lu);
 919         /*
 920          * FIXME:  We are unable to perform reconnects while in sbp2_login().
 921          * Therefore __scsi_add_device() will get into trouble if a bus reset
 922          * happens in parallel.  It will either fail or leave us with an
 923          * unusable sdev.  As a workaround we check for this and retry the
 924          * whole login and SCSI probing.
 925          */
 926
 927         /* Reported error during __scsi_add_device() */
 928         if (IS_ERR(sdev))
 929                 goto out_logout_login;
 930
 931         /* Unreported error during __scsi_add_device() */
 932         smp_rmb(); /* get current card generation */
 933         if (generation != device->card->generation) {
 934                 scsi_remove_device(sdev);
 935                 scsi_device_put(sdev);
 936                 goto out_logout_login;
 937         }
 938
 939         /* No error during __scsi_add_device() */
 940         lu->has_sdev = true;
 941         scsi_device_put(sdev);
 942         sbp2_allow_block(lu);
 943         goto out;
 944
 945  out_logout_login:
 946         smp_rmb(); /* generation may have changed */
 947         generation = device->generation;
 948         smp_rmb(); /* node_id must not be older than generation */
 949
 950         sbp2_send_management_orb(lu, device->node_id, generation,
 951                                  SBP2_LOGOUT_REQUEST, lu->login_id, NULL);
 952         /*
 953          * If a bus reset happened, sbp2_update will have requeued
 954          * lu->work already.  Reset the work from reconnect to login.
 955          */
 956         PREPARE_DELAYED_WORK(&lu->work, sbp2_login);
 957  out:
 958         sbp2_target_put(tgt);
 959 }
 960
 961 static int sbp2_add_logical_unit(struct sbp2_target *tgt, int lun_entry)
 962 {
 963         struct sbp2_logical_unit *lu;
 964
 965         lu = kmalloc(sizeof(*lu), GFP_KERNEL);
 966         if (!lu)
 967                 return -ENOMEM;
 968
 969         lu->address_handler.length           = 0x100;
 970         lu->address_handler.address_callback = sbp2_status_write;
 971         lu->address_handler.callback_data    = lu;
 972
 973         if (fw_core_add_address_handler(&lu->address_handler,
 974                                         &fw_high_memory_region) < 0) {
 975                 kfree(lu);
 976                 return -ENOMEM;
 977         }
 978
 979         lu->tgt      = tgt;
 980         lu->lun      = lun_entry & 0xffff;
 981         lu->retries  = 0;
 982         lu->has_sdev = false;
 983         lu->blocked  = false;
 984         ++tgt->dont_block;
 985         INIT_LIST_HEAD(&lu->orb_list);
 986         INIT_DELAYED_WORK(&lu->work, sbp2_login);
 987
 988         list_add_tail(&lu->link, &tgt->lu_list);
 989         return 0;
 990 }
 991
 992 static int sbp2_scan_logical_unit_dir(struct sbp2_target *tgt, u32 *directory)
 993 {
 994         struct fw_csr_iterator ci;
 995         int key, value;
 996
 997         fw_csr_iterator_init(&ci, directory);
 998         while (fw_csr_iterator_next(&ci, &key, &value))
 999                 if (key == SBP2_CSR_LOGICAL_UNIT_NUMBER &&
1000                     sbp2_add_logical_unit(tgt, value) < 0)
1001                         return -ENOMEM;
1002         return 0;
1003 }
1004
1005 static int sbp2_scan_unit_dir(struct sbp2_target *tgt, u32 *directory,
1006                               u32 *model, u32 *firmware_revision)
1007 {
1008         struct fw_csr_iterator ci;
1009         int key, value;
1010         unsigned int timeout;
1011
1012         fw_csr_iterator_init(&ci, directory);
1013         while (fw_csr_iterator_next(&ci, &key, &value)) {
1014                 switch (key) {
1015
1016                 case CSR_DEPENDENT_INFO | CSR_OFFSET:
1017                         tgt->management_agent_address =
1018                                         CSR_REGISTER_BASE + 4 * value;
1019                         break;
1020
1021                 case CSR_DIRECTORY_ID:
1022                         tgt->directory_id = value;
1023                         break;
1024
1025                 case CSR_MODEL:
1026                         *model = value;
1027                         break;
1028
1029                 case SBP2_CSR_FIRMWARE_REVISION:
1030                         *firmware_revision = value;
1031                         break;
1032
1033                 case SBP2_CSR_UNIT_CHARACTERISTICS:
1034                         /* the timeout value is stored in 500ms units */
1035                         timeout = ((unsigned int) value >> 8 & 0xff) * 500;
1036                         timeout = max(timeout, SBP2_MIN_LOGIN_ORB_TIMEOUT);
1037                         tgt->mgt_orb_timeout =
1038                                   min(timeout, SBP2_MAX_LOGIN_ORB_TIMEOUT);
1039
1040                         if (timeout > tgt->mgt_orb_timeout)
1041                                 fw_notify("%s: config rom contains %ds "
1042                                           "management ORB timeout, limiting "
1043                                           "to %ds\n", tgt->bus_id,
1044                                           timeout / 1000,
1045                                           tgt->mgt_orb_timeout / 1000);
1046                         break;
1047
1048                 case SBP2_CSR_LOGICAL_UNIT_NUMBER:
1049                         if (sbp2_add_logical_unit(tgt, value) < 0)
1050                                 return -ENOMEM;
1051                         break;
1052
1053                 case SBP2_CSR_LOGICAL_UNIT_DIRECTORY:
1054                         /* Adjust for the increment in the iterator */
1055                         if (sbp2_scan_logical_unit_dir(tgt, ci.p - 1 + value) < 0)
1056                                 return -ENOMEM;
1057                         break;
1058                 }
1059         }
1060         return 0;
1061 }
1062
1063 static void sbp2_init_workarounds(struct sbp2_target *tgt, u32 model,
1064                                   u32 firmware_revision)
1065 {
1066         int i;
1067         unsigned int w = sbp2_param_workarounds;
1068
1069         if (w)
1070                 fw_notify("Please notify linux1394-devel@lists.sourceforge.net "
1071                           "if you need the workarounds parameter for %s\n",
1072                           tgt->bus_id);
1073
1074         if (w & SBP2_WORKAROUND_OVERRIDE)
1075                 goto out;
1076
1077         for (i = 0; i < ARRAY_SIZE(sbp2_workarounds_table); i++) {
1078
1079                 if (sbp2_workarounds_table[i].firmware_revision !=
1080                     (firmware_revision & 0xffffff00))
1081                         continue;
1082
1083                 if (sbp2_workarounds_table[i].model != model &&
1084                     sbp2_workarounds_table[i].model != ~0)
1085                         continue;
1086
1087                 w |= sbp2_workarounds_table[i].workarounds;
1088                 break;
1089         }
1090  out:
1091         if (w)
1092                 fw_notify("Workarounds for %s: 0x%x "
1093                           "(firmware_revision 0x%06x, model_id 0x%06x)\n",
1094                           tgt->bus_id, w, firmware_revision, model);
1095         tgt->workarounds = w;
1096 }
1097
1098 static struct scsi_host_template scsi_driver_template;
1099
1100 static int sbp2_probe(struct device *dev)
1101 {
1102         struct fw_unit *unit = fw_unit(dev);
1103         struct fw_device *device = fw_device(unit->device.parent);
1104         struct sbp2_target *tgt;
1105         struct sbp2_logical_unit *lu;
1106         struct Scsi_Host *shost;
1107         u32 model, firmware_revision;
1108
1109         if (dma_get_max_seg_size(device->card->device) > SBP2_MAX_SEG_SIZE)
1110                 BUG_ON(dma_set_max_seg_size(device->card->device,
1111                                             SBP2_MAX_SEG_SIZE));
1112
1113         shost = scsi_host_alloc(&scsi_driver_template, sizeof(*tgt));
1114         if (shost == NULL)
1115                 return -ENOMEM;
1116
1117         tgt = (struct sbp2_target *)shost->hostdata;
1118         unit->device.driver_data = tgt;
1119         tgt->unit = unit;
1120         kref_init(&tgt->kref);
1121         INIT_LIST_HEAD(&tgt->lu_list);
1122         tgt->bus_id = unit->device.bus_id;
1123         tgt->guid = (u64)device->config_rom[3] << 32 | device->config_rom[4];
1124
1125         if (fw_device_enable_phys_dma(device) < 0)
1126                 goto fail_shost_put;
1127
1128         if (scsi_add_host(shost, &unit->device) < 0)
1129                 goto fail_shost_put;
1130
1131         fw_device_get(device);
1132         fw_unit_get(unit);
1133
1134         /* Initialize to values that won't match anything in our table. */
1135         firmware_revision = 0xff000000;
1136         model = 0xff000000;
1137
1138         /* implicit directory ID */
1139         tgt->directory_id = ((unit->directory - device->config_rom) * 4
1140                              + CSR_CONFIG_ROM) & 0xffffff;
1141
1142         if (sbp2_scan_unit_dir(tgt, unit->directory, &model,
1143                                &firmware_revision) < 0)
1144                 goto fail_tgt_put;
1145
1146         sbp2_init_workarounds(tgt, model, firmware_revision);
1147
1148         /* Do the login in a workqueue so we can easily reschedule retries. */
1149         list_for_each_entry(lu, &tgt->lu_list, link)
1150                 sbp2_queue_work(lu, 0);
1151         return 0;
1152
1153  fail_tgt_put:
1154         sbp2_target_put(tgt);
1155         return -ENOMEM;
1156
1157  fail_shost_put:
1158         scsi_host_put(shost);
1159         return -ENOMEM;
1160 }
1161
1162 static int sbp2_remove(struct device *dev)
1163 {
1164         struct fw_unit *unit = fw_unit(dev);
1165         struct sbp2_target *tgt = unit->device.driver_data;
1166
1167         sbp2_target_put(tgt);
1168         return 0;
1169 }
1170
1171 static void sbp2_reconnect(struct work_struct *work)
1172 {
1173         struct sbp2_logical_unit *lu =
1174                 container_of(work, struct sbp2_logical_unit, work.work);
1175         struct sbp2_target *tgt = lu->tgt;
1176         struct fw_device *device = fw_device(tgt->unit->device.parent);
1177         int generation, node_id, local_node_id;
1178
1179         if (fw_device_is_shutdown(device))
1180                 goto out;
1181
1182         generation    = device->generation;
1183         smp_rmb();    /* node_id must not be older than generation */
1184         node_id       = device->node_id;
1185         local_node_id = device->card->node_id;
1186
1187         if (sbp2_send_management_orb(lu, node_id, generation,
1188                                      SBP2_RECONNECT_REQUEST,
1189                                      lu->login_id, NULL) < 0) {
1190                 /*
1191                  * If reconnect was impossible even though we are in the
1192                  * current generation, fall back and try to log in again.
1193                  *
1194                  * We could check for "Function rejected" status, but
1195                  * looking at the bus generation as simpler and more general.
1196                  */
1197                 smp_rmb(); /* get current card generation */
1198                 if (generation == device->card->generation ||
1199                     lu->retries++ >= 5) {
1200                         fw_error("%s: failed to reconnect\n", tgt->bus_id);
1201                         lu->retries = 0;
1202                         PREPARE_DELAYED_WORK(&lu->work, sbp2_login);
1203                 }
1204                 sbp2_queue_work(lu, DIV_ROUND_UP(HZ, 5));
1205                 goto out;
1206         }
1207
1208         tgt->node_id      = node_id;
1209         tgt->address_high = local_node_id << 16;
1210         sbp2_set_generation(lu, generation);
1211
1212         fw_notify("%s: reconnected to LUN %04x (%d retries)\n",
1213                   tgt->bus_id, lu->lun, lu->retries);
1214
1215         sbp2_agent_reset(lu);
1216         sbp2_cancel_orbs(lu);
1217         sbp2_conditionally_unblock(lu);
1218  out:
1219         sbp2_target_put(tgt);
1220 }
1221
1222 static void sbp2_update(struct fw_unit *unit)
1223 {
1224         struct sbp2_target *tgt = unit->device.driver_data;
1225         struct sbp2_logical_unit *lu;
1226
1227         fw_device_enable_phys_dma(fw_device(unit->device.parent));
1228
1229         /*
1230          * Fw-core serializes sbp2_update() against sbp2_remove().
1231          * Iteration over tgt->lu_list is therefore safe here.
1232          */
1233         list_for_each_entry(lu, &tgt->lu_list, link) {
1234                 sbp2_conditionally_block(lu);
1235                 lu->retries = 0;
1236                 sbp2_queue_work(lu, 0);
1237         }
1238 }
1239
1240 #define SBP2_UNIT_SPEC_ID_ENTRY 0x0000609e
1241 #define SBP2_SW_VERSION_ENTRY   0x00010483
1242
1243 static const struct fw_device_id sbp2_id_table[] = {
1244         {
1245                 .match_flags  = FW_MATCH_SPECIFIER_ID | FW_MATCH_VERSION,
1246                 .specifier_id = SBP2_UNIT_SPEC_ID_ENTRY,
1247                 .version      = SBP2_SW_VERSION_ENTRY,
1248         },
1249         { }
1250 };
1251
1252 static struct fw_driver sbp2_driver = {
1253         .driver   = {
1254                 .owner  = THIS_MODULE,
1255                 .name   = sbp2_driver_name,
1256                 .bus    = &fw_bus_type,
1257                 .probe  = sbp2_probe,
1258                 .remove = sbp2_remove,
1259         },
1260         .update   = sbp2_update,
1261         .id_table = sbp2_id_table,
1262 };
1263
1264 static unsigned int
1265 sbp2_status_to_sense_data(u8 *sbp2_status, u8 *sense_data)
1266 {
1267         int sam_status;
1268
1269         sense_data[0] = 0x70;
1270         sense_data[1] = 0x0;
1271         sense_data[2] = sbp2_status[1];
1272         sense_data[3] = sbp2_status[4];
1273         sense_data[4] = sbp2_status[5];
1274         sense_data[5] = sbp2_status[6];
1275         sense_data[6] = sbp2_status[7];
1276         sense_data[7] = 10;
1277         sense_data[8] = sbp2_status[8];
1278         sense_data[9] = sbp2_status[9];
1279         sense_data[10] = sbp2_status[10];
1280         sense_data[11] = sbp2_status[11];
1281         sense_data[12] = sbp2_status[2];
1282         sense_data[13] = sbp2_status[3];
1283         sense_data[14] = sbp2_status[12];
1284         sense_data[15] = sbp2_status[13];
1285
1286         sam_status = sbp2_status[0] & 0x3f;
1287
1288         switch (sam_status) {
1289         case SAM_STAT_GOOD:
1290         case SAM_STAT_CHECK_CONDITION:
1291         case SAM_STAT_CONDITION_MET:
1292         case SAM_STAT_BUSY:
1293         case SAM_STAT_RESERVATION_CONFLICT:
1294         case SAM_STAT_COMMAND_TERMINATED:
1295                 return DID_OK << 16 | sam_status;
1296
1297         default:
1298                 return DID_ERROR << 16;
1299         }
1300 }
1301
1302 static void
1303 complete_command_orb(struct sbp2_orb *base_orb, struct sbp2_status *status)
1304 {
1305         struct sbp2_command_orb *orb =
1306                 container_of(base_orb, struct sbp2_command_orb, base);
1307         struct fw_device *device = fw_device(orb->lu->tgt->unit->device.parent);
1308         int result;
1309
1310         if (status != NULL) {
1311                 if (STATUS_GET_DEAD(*status))
1312                         sbp2_agent_reset_no_wait(orb->lu);
1313
1314                 switch (STATUS_GET_RESPONSE(*status)) {
1315                 case SBP2_STATUS_REQUEST_COMPLETE:
1316                         result = DID_OK << 16;
1317                         break;
1318                 case SBP2_STATUS_TRANSPORT_FAILURE:
1319                         result = DID_BUS_BUSY << 16;
1320                         break;
1321                 case SBP2_STATUS_ILLEGAL_REQUEST:
1322                 case SBP2_STATUS_VENDOR_DEPENDENT:
1323                 default:
1324                         result = DID_ERROR << 16;
1325                         break;
1326                 }
1327
1328                 if (result == DID_OK << 16 && STATUS_GET_LEN(*status) > 1)
1329                         result = sbp2_status_to_sense_data(STATUS_GET_DATA(*status),
1330                                                            orb->cmd->sense_buffer);
1331         } else {
1332                 /*
1333                  * If the orb completes with status == NULL, something
1334                  * went wrong, typically a bus reset happened mid-orb
1335                  * or when sending the write (less likely).
1336                  */
1337                 result = DID_BUS_BUSY << 16;
1338                 sbp2_conditionally_block(orb->lu);
1339         }
1340
1341         dma_unmap_single(device->card->device, orb->base.request_bus,
1342                          sizeof(orb->request), DMA_TO_DEVICE);
1343
1344         if (scsi_sg_count(orb->cmd) > 0)
1345                 dma_unmap_sg(device->card->device, scsi_sglist(orb->cmd),
1346                              scsi_sg_count(orb->cmd),
1347                              orb->cmd->sc_data_direction);
1348
1349         if (orb->page_table_bus != 0)
1350                 dma_unmap_single(device->card->device, orb->page_table_bus,
1351                                  sizeof(orb->page_table), DMA_TO_DEVICE);
1352
1353         orb->cmd->result = result;
1354         orb->done(orb->cmd);
1355 }
1356
1357 static int
1358 sbp2_map_scatterlist(struct sbp2_command_orb *orb, struct fw_device *device,
1359                      struct sbp2_logical_unit *lu)
1360 {
1361         struct scatterlist *sg = scsi_sglist(orb->cmd);
1362         int i, n;
1363
1364         n = dma_map_sg(device->card->device, sg, scsi_sg_count(orb->cmd),
1365                        orb->cmd->sc_data_direction);
1366         if (n == 0)
1367                 goto fail;
1368
1369         /*
1370          * Handle the special case where there is only one element in
1371          * the scatter list by converting it to an immediate block
1372          * request. This is also a workaround for broken devices such
1373          * as the second generation iPod which doesn't support page
1374          * tables.
1375          */
1376         if (n == 1) {
1377                 orb->request.data_descriptor.high =
1378                         cpu_to_be32(lu->tgt->address_high);
1379                 orb->request.data_descriptor.low  =
1380                         cpu_to_be32(sg_dma_address(sg));
1381                 orb->request.misc |=
1382                         cpu_to_be32(COMMAND_ORB_DATA_SIZE(sg_dma_len(sg)));
1383                 return 0;
1384         }
1385
1386         for_each_sg(sg, sg, n, i) {
1387                 orb->page_table[i].high = cpu_to_be32(sg_dma_len(sg) << 16);
1388                 orb->page_table[i].low = cpu_to_be32(sg_dma_address(sg));
1389         }
1390
1391         orb->page_table_bus =
1392                 dma_map_single(device->card->device, orb->page_table,
1393                                sizeof(orb->page_table), DMA_TO_DEVICE);
1394         if (dma_mapping_error(device->card->device, orb->page_table_bus))
1395                 goto fail_page_table;
1396
1397         /*
1398          * The data_descriptor pointer is the one case where we need
1399          * to fill in the node ID part of the address.  All other
1400          * pointers assume that the data referenced reside on the
1401          * initiator (i.e. us), but data_descriptor can refer to data
1402          * on other nodes so we need to put our ID in descriptor.high.
1403          */
1404         orb->request.data_descriptor.high = cpu_to_be32(lu->tgt->address_high);
1405         orb->request.data_descriptor.low  = cpu_to_be32(orb->page_table_bus);
1406         orb->request.misc |= cpu_to_be32(COMMAND_ORB_PAGE_TABLE_PRESENT |
1407                                          COMMAND_ORB_DATA_SIZE(n));
1408
1409         return 0;
1410
1411  fail_page_table:
1412         dma_unmap_sg(device->card->device, scsi_sglist(orb->cmd),
1413                      scsi_sg_count(orb->cmd), orb->cmd->sc_data_direction);
1414  fail:
1415         return -ENOMEM;
1416 }
1417
1418 /* SCSI stack integration */
1419
1420 static int sbp2_scsi_queuecommand(struct scsi_cmnd *cmd, scsi_done_fn_t done)
1421 {
1422         struct sbp2_logical_unit *lu = cmd->device->hostdata;
1423         struct fw_device *device = fw_device(lu->tgt->unit->device.parent);
1424         struct sbp2_command_orb *orb;
1425         unsigned int max_payload;
1426         int generation, retval = SCSI_MLQUEUE_HOST_BUSY;
1427
1428         /*
1429          * Bidirectional commands are not yet implemented, and unknown
1430          * transfer direction not handled.
1431          */
1432         if (cmd->sc_data_direction == DMA_BIDIRECTIONAL) {
1433                 fw_error("Can't handle DMA_BIDIRECTIONAL, rejecting command\n");
1434                 cmd->result = DID_ERROR << 16;
1435                 done(cmd);
1436                 return 0;
1437         }
1438
1439         orb = kzalloc(sizeof(*orb), GFP_ATOMIC);
1440         if (orb == NULL) {
1441                 fw_notify("failed to alloc orb\n");
1442                 return SCSI_MLQUEUE_HOST_BUSY;
1443         }
1444
1445         /* Initialize rcode to something not RCODE_COMPLETE. */
1446         orb->base.rcode = -1;
1447         kref_init(&orb->base.kref);
1448
1449         orb->lu   = lu;
1450         orb->done = done;
1451         orb->cmd  = cmd;
1452
1453         orb->request.next.high   = cpu_to_be32(SBP2_ORB_NULL);
1454         /*
1455          * At speed 100 we can do 512 bytes per packet, at speed 200,
1456          * 1024 bytes per packet etc.  The SBP-2 max_payload field
1457          * specifies the max payload size as 2 ^ (max_payload + 2), so
1458          * if we set this to max_speed + 7, we get the right value.
1459          */
1460         max_payload = min(device->max_speed + 7,
1461                           device->card->max_receive - 1);
1462         orb->request.misc = cpu_to_be32(
1463                 COMMAND_ORB_MAX_PAYLOAD(max_payload) |
1464                 COMMAND_ORB_SPEED(device->max_speed) |
1465                 COMMAND_ORB_NOTIFY);
1466
1467         if (cmd->sc_data_direction == DMA_FROM_DEVICE)
1468                 orb->request.misc |= cpu_to_be32(COMMAND_ORB_DIRECTION);
1469
1470         generation = device->generation;
1471         smp_rmb();    /* sbp2_map_scatterlist looks at tgt->address_high */
1472
1473         if (scsi_sg_count(cmd) && sbp2_map_scatterlist(orb, device, lu) < 0)
1474                 goto out;
1475
1476         memcpy(orb->request.command_block, cmd->cmnd, cmd->cmd_len);
1477
1478         orb->base.callback = complete_command_orb;
1479         orb->base.request_bus =
1480                 dma_map_single(device->card->device, &orb->request,
1481                                sizeof(orb->request), DMA_TO_DEVICE);
1482         if (dma_mapping_error(device->card->device, orb->base.request_bus))
1483                 goto out;
1484
1485         sbp2_send_orb(&orb->base, lu, lu->tgt->node_id, generation,
1486                       lu->command_block_agent_address + SBP2_ORB_POINTER);
1487         retval = 0;
1488  out:
1489         kref_put(&orb->base.kref, free_orb);
1490         return retval;
1491 }
1492
1493 static int sbp2_scsi_slave_alloc(struct scsi_device *sdev)
1494 {
1495         struct sbp2_logical_unit *lu = sdev->hostdata;
1496
1497         /* (Re-)Adding logical units via the SCSI stack is not supported. */
1498         if (!lu)
1499                 return -ENOSYS;
1500
1501         sdev->allow_restart = 1;
1502
1503         /* SBP-2 requires quadlet alignment of the data buffers. */
1504         blk_queue_update_dma_alignment(sdev->request_queue, 4 - 1);
1505
1506         if (lu->tgt->workarounds & SBP2_WORKAROUND_INQUIRY_36)
1507                 sdev->inquiry_len = 36;
1508
1509         return 0;
1510 }
1511
1512 static int sbp2_scsi_slave_configure(struct scsi_device *sdev)
1513 {
1514         struct sbp2_logical_unit *lu = sdev->hostdata;
1515
1516         sdev->use_10_for_rw = 1;
1517
1518         if (sbp2_param_exclusive_login)
1519                 sdev->manage_start_stop = 1;
1520
1521         if (sdev->type == TYPE_ROM)
1522                 sdev->use_10_for_ms = 1;
1523
1524         if (sdev->type == TYPE_DISK &&
1525             lu->tgt->workarounds & SBP2_WORKAROUND_MODE_SENSE_8)
1526                 sdev->skip_ms_page_8 = 1;
1527
1528         if (lu->tgt->workarounds & SBP2_WORKAROUND_FIX_CAPACITY)
1529                 sdev->fix_capacity = 1;
1530
1531         if (lu->tgt->workarounds & SBP2_WORKAROUND_POWER_CONDITION)
1532                 sdev->start_stop_pwr_cond = 1;
1533
1534         if (lu->tgt->workarounds & SBP2_WORKAROUND_128K_MAX_TRANS)
1535                 blk_queue_max_sectors(sdev->request_queue, 128 * 1024 / 512);
1536
1537         blk_queue_max_segment_size(sdev->request_queue, SBP2_MAX_SEG_SIZE);
1538
1539         return 0;
1540 }
1541
1542 /*
1543  * Called by scsi stack when something has really gone wrong.  Usually
1544  * called when a command has timed-out for some reason.
1545  */
1546 static int sbp2_scsi_abort(struct scsi_cmnd *cmd)
1547 {
1548         struct sbp2_logical_unit *lu = cmd->device->hostdata;
1549
1550         fw_notify("%s: sbp2_scsi_abort\n", lu->tgt->bus_id);
1551         sbp2_agent_reset(lu);
1552         sbp2_cancel_orbs(lu);
1553
1554         return SUCCESS;
1555 }
1556
1557 /*
1558  * Format of /sys/bus/scsi/devices/.../ieee1394_id:
1559  * u64 EUI-64 : u24 directory_ID : u16 LUN  (all printed in hexadecimal)
1560  *
1561  * This is the concatenation of target port identifier and logical unit
1562  * identifier as per SAM-2...SAM-4 annex A.
1563  */
1564 static ssize_t
1565 sbp2_sysfs_ieee1394_id_show(struct device *dev, struct device_attribute *attr,
1566                             char *buf)
1567 {
1568         struct scsi_device *sdev = to_scsi_device(dev);
1569         struct sbp2_logical_unit *lu;
1570
1571         if (!sdev)
1572                 return 0;
1573
1574         lu = sdev->hostdata;
1575
1576         return sprintf(buf, "%016llx:%06x:%04x\n",
1577                         (unsigned long long)lu->tgt->guid,
1578                         lu->tgt->directory_id, lu->lun);
1579 }
1580
1581 static DEVICE_ATTR(ieee1394_id, S_IRUGO, sbp2_sysfs_ieee1394_id_show, NULL);
1582
1583 static struct device_attribute *sbp2_scsi_sysfs_attrs[] = {
1584         &dev_attr_ieee1394_id,
1585         NULL
1586 };
1587
1588 static struct scsi_host_template scsi_driver_template = {
1589         .module                 = THIS_MODULE,
1590         .name                   = "SBP-2 IEEE-1394",
1591         .proc_name              = sbp2_driver_name,
1592         .queuecommand           = sbp2_scsi_queuecommand,
1593         .slave_alloc            = sbp2_scsi_slave_alloc,
1594         .slave_configure        = sbp2_scsi_slave_configure,
1595         .eh_abort_handler       = sbp2_scsi_abort,
1596         .this_id                = -1,
1597         .sg_tablesize           = SG_ALL,
1598         .use_clustering         = ENABLE_CLUSTERING,
1599         .cmd_per_lun            = 1,
1600         .can_queue              = 1,
1601         .sdev_attrs             = sbp2_scsi_sysfs_attrs,
1602 };
1603
1604 MODULE_AUTHOR("Kristian Hoegsberg <krh@bitplanet.net>");
1605 MODULE_DESCRIPTION("SCSI over IEEE1394");
1606 MODULE_LICENSE("GPL");
1607 MODULE_DEVICE_TABLE(ieee1394, sbp2_id_table);
1608
1609 /* Provide a module alias so root-on-sbp2 initrds don't break. */
1610 #ifndef CONFIG_IEEE1394_SBP2_MODULE
1611 MODULE_ALIAS("sbp2");
1612 #endif
1613
1614 static int __init sbp2_init(void)
1615 {
1616         sbp2_wq = create_singlethread_workqueue(KBUILD_MODNAME);
1617         if (!sbp2_wq)
1618                 return -ENOMEM;
1619
1620         return driver_register(&sbp2_driver.driver);
1621 }
1622
1623 static void __exit sbp2_cleanup(void)
1624 {
1625         driver_unregister(&sbp2_driver.driver);
1626         destroy_workqueue(sbp2_wq);
1627 }
1628
1629 module_init(sbp2_init);
1630 module_exit(sbp2_cleanup);