drivers/firewire/fw-sbp2.c

   1 /*
   2  * SBP2 driver (SCSI over IEEE1394)
   3  *
   4  * Copyright (C) 2005-2007  Kristian Hoegsberg <krh@bitplanet.net>
   5  *
   6  * This program is free software; you can redistribute it and/or modify
   7  * it under the terms of the GNU General Public License as published by
   8  * the Free Software Foundation; either version 2 of the License, or
   9  * (at your option) any later version.
  10  *
  11  * This program is distributed in the hope that it will be useful,
  12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14  * GNU General Public License for more details.
  15  *
  16  * You should have received a copy of the GNU General Public License
  17  * along with this program; if not, write to the Free Software Foundation,
  18  * Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
  19  */
  20
  21 /*
  22  * The basic structure of this driver is based on the old storage driver,
  23  * drivers/ieee1394/sbp2.c, originally written by
  24  *     James Goodwin <jamesg@filanet.com>
  25  * with later contributions and ongoing maintenance from
  26  *     Ben Collins <bcollins@debian.org>,
  27  *     Stefan Richter <stefanr@s5r6.in-berlin.de>
  28  * and many others.
  29  */
  30
  31 #include <linux/blkdev.h>
  32 #include <linux/delay.h>
  33 #include <linux/device.h>
  34 #include <linux/dma-mapping.h>
  35 #include <linux/kernel.h>
  36 #include <linux/mod_devicetable.h>
  37 #include <linux/module.h>
  38 #include <linux/moduleparam.h>
  39 #include <linux/scatterlist.h>
  40 #include <linux/string.h>
  41 #include <linux/stringify.h>
  42 #include <linux/timer.h>
  43 #include <linux/workqueue.h>
  44 #include <asm/system.h>
  45
  46 #include <scsi/scsi.h>
  47 #include <scsi/scsi_cmnd.h>
  48 #include <scsi/scsi_device.h>
  49 #include <scsi/scsi_host.h>
  50
  51 #include "fw-device.h"
  52 #include "fw-topology.h"
  53 #include "fw-transaction.h"
  54
  55 /*
  56  * So far only bridges from Oxford Semiconductor are known to support
  57  * concurrent logins. Depending on firmware, four or two concurrent logins
  58  * are possible on OXFW911 and newer Oxsemi bridges.
  59  *
  60  * Concurrent logins are useful together with cluster filesystems.
  61  */
  62 static int sbp2_param_exclusive_login = 1;
  63 module_param_named(exclusive_login, sbp2_param_exclusive_login, bool, 0644);
  64 MODULE_PARM_DESC(exclusive_login, "Exclusive login to sbp2 device "
  65                  "(default = Y, use N for concurrent initiators)");
  66
  67 /*
  68  * Flags for firmware oddities
  69  *
  70  * - 128kB max transfer
  71  *   Limit transfer size. Necessary for some old bridges.
  72  *
  73  * - 36 byte inquiry
  74  *   When scsi_mod probes the device, let the inquiry command look like that
  75  *   from MS Windows.
  76  *
  77  * - skip mode page 8
  78  *   Suppress sending of mode_sense for mode page 8 if the device pretends to
  79  *   support the SCSI Primary Block commands instead of Reduced Block Commands.
  80  *
  81  * - fix capacity
  82  *   Tell sd_mod to correct the last sector number reported by read_capacity.
  83  *   Avoids access beyond actual disk limits on devices with an off-by-one bug.
  84  *   Don't use this with devices which don't have this bug.
  85  *
  86  * - delay inquiry
  87  *   Wait extra SBP2_INQUIRY_DELAY seconds after login before SCSI inquiry.
  88  *
  89  * - override internal blacklist
  90  *   Instead of adding to the built-in blacklist, use only the workarounds
  91  *   specified in the module load parameter.
  92  *   Useful if a blacklist entry interfered with a non-broken device.
  93  */
  94 #define SBP2_WORKAROUND_128K_MAX_TRANS  0x1
  95 #define SBP2_WORKAROUND_INQUIRY_36      0x2
  96 #define SBP2_WORKAROUND_MODE_SENSE_8    0x4
  97 #define SBP2_WORKAROUND_FIX_CAPACITY    0x8
  98 #define SBP2_WORKAROUND_DELAY_INQUIRY   0x10
  99 #define SBP2_INQUIRY_DELAY              12
 100 #define SBP2_WORKAROUND_OVERRIDE        0x100
 101
 102 static int sbp2_param_workarounds;
 103 module_param_named(workarounds, sbp2_param_workarounds, int, 0644);
 104 MODULE_PARM_DESC(workarounds, "Work around device bugs (default = 0"
 105         ", 128kB max transfer = " __stringify(SBP2_WORKAROUND_128K_MAX_TRANS)
 106         ", 36 byte inquiry = "    __stringify(SBP2_WORKAROUND_INQUIRY_36)
 107         ", skip mode page 8 = "   __stringify(SBP2_WORKAROUND_MODE_SENSE_8)
 108         ", fix capacity = "       __stringify(SBP2_WORKAROUND_FIX_CAPACITY)
 109         ", delay inquiry = "      __stringify(SBP2_WORKAROUND_DELAY_INQUIRY)
 110         ", override internal blacklist = " __stringify(SBP2_WORKAROUND_OVERRIDE)
 111         ", or a combination)");
 112
 113 /* I don't know why the SCSI stack doesn't define something like this... */
 114 typedef void (*scsi_done_fn_t)(struct scsi_cmnd *);
 115
 116 static const char sbp2_driver_name[] = "sbp2";
 117
 118 /*
 119  * We create one struct sbp2_logical_unit per SBP-2 Logical Unit Number Entry
 120  * and one struct scsi_device per sbp2_logical_unit.
 121  */
 122 struct sbp2_logical_unit {
 123         struct sbp2_target *tgt;
 124         struct list_head link;
 125         struct fw_address_handler address_handler;
 126         struct list_head orb_list;
 127
 128         u64 command_block_agent_address;
 129         u16 lun;
 130         int login_id;
 131
 132         /*
 133          * The generation is updated once we've logged in or reconnected
 134          * to the logical unit.  Thus, I/O to the device will automatically
 135          * fail and get retried if it happens in a window where the device
 136          * is not ready, e.g. after a bus reset but before we reconnect.
 137          */
 138         int generation;
 139         int retries;
 140         struct delayed_work work;
 141         bool has_sdev;
 142         bool blocked;
 143 };
 144
 145 /*
 146  * We create one struct sbp2_target per IEEE 1212 Unit Directory
 147  * and one struct Scsi_Host per sbp2_target.
 148  */
 149 struct sbp2_target {
 150         struct kref kref;
 151         struct fw_unit *unit;
 152         const char *bus_id;
 153         struct list_head lu_list;
 154
 155         u64 management_agent_address;
 156         int directory_id;
 157         int node_id;
 158         int address_high;
 159         unsigned int workarounds;
 160         unsigned int mgt_orb_timeout;
 161
 162         int dont_block; /* counter for each logical unit */
 163         int blocked;    /* ditto */
 164 };
 165
 166 /*
 167  * Per section 7.4.8 of the SBP-2 spec, a mgt_ORB_timeout value can be
 168  * provided in the config rom. Most devices do provide a value, which
 169  * we'll use for login management orbs, but with some sane limits.
 170  */
 171 #define SBP2_MIN_LOGIN_ORB_TIMEOUT      5000U   /* Timeout in ms */
 172 #define SBP2_MAX_LOGIN_ORB_TIMEOUT      40000U  /* Timeout in ms */
 173 #define SBP2_ORB_TIMEOUT                2000U   /* Timeout in ms */
 174 #define SBP2_ORB_NULL                   0x80000000
 175 #define SBP2_MAX_SG_ELEMENT_LENGTH      0xf000
 176 #define SBP2_RETRY_LIMIT                0xf     /* 15 retries */
 177
 178 #define SBP2_DIRECTION_TO_MEDIA         0x0
 179 #define SBP2_DIRECTION_FROM_MEDIA       0x1
 180
 181 /* Unit directory keys */
 182 #define SBP2_CSR_UNIT_CHARACTERISTICS   0x3a
 183 #define SBP2_CSR_FIRMWARE_REVISION      0x3c
 184 #define SBP2_CSR_LOGICAL_UNIT_NUMBER    0x14
 185 #define SBP2_CSR_LOGICAL_UNIT_DIRECTORY 0xd4
 186
 187 /* Management orb opcodes */
 188 #define SBP2_LOGIN_REQUEST              0x0
 189 #define SBP2_QUERY_LOGINS_REQUEST       0x1
 190 #define SBP2_RECONNECT_REQUEST          0x3
 191 #define SBP2_SET_PASSWORD_REQUEST       0x4
 192 #define SBP2_LOGOUT_REQUEST             0x7
 193 #define SBP2_ABORT_TASK_REQUEST         0xb
 194 #define SBP2_ABORT_TASK_SET             0xc
 195 #define SBP2_LOGICAL_UNIT_RESET         0xe
 196 #define SBP2_TARGET_RESET_REQUEST       0xf
 197
 198 /* Offsets for command block agent registers */
 199 #define SBP2_AGENT_STATE                0x00
 200 #define SBP2_AGENT_RESET                0x04
 201 #define SBP2_ORB_POINTER                0x08
 202 #define SBP2_DOORBELL                   0x10
 203 #define SBP2_UNSOLICITED_STATUS_ENABLE  0x14
 204
 205 /* Status write response codes */
 206 #define SBP2_STATUS_REQUEST_COMPLETE    0x0
 207 #define SBP2_STATUS_TRANSPORT_FAILURE   0x1
 208 #define SBP2_STATUS_ILLEGAL_REQUEST     0x2
 209 #define SBP2_STATUS_VENDOR_DEPENDENT    0x3
 210
 211 #define STATUS_GET_ORB_HIGH(v)          ((v).status & 0xffff)
 212 #define STATUS_GET_SBP_STATUS(v)        (((v).status >> 16) & 0xff)
 213 #define STATUS_GET_LEN(v)               (((v).status >> 24) & 0x07)
 214 #define STATUS_GET_DEAD(v)              (((v).status >> 27) & 0x01)
 215 #define STATUS_GET_RESPONSE(v)          (((v).status >> 28) & 0x03)
 216 #define STATUS_GET_SOURCE(v)            (((v).status >> 30) & 0x03)
 217 #define STATUS_GET_ORB_LOW(v)           ((v).orb_low)
 218 #define STATUS_GET_DATA(v)              ((v).data)
 219
 220 struct sbp2_status {
 221         u32 status;
 222         u32 orb_low;
 223         u8 data[24];
 224 };
 225
 226 struct sbp2_pointer {
 227         __be32 high;
 228         __be32 low;
 229 };
 230
 231 struct sbp2_orb {
 232         struct fw_transaction t;
 233         struct kref kref;
 234         dma_addr_t request_bus;
 235         int rcode;
 236         struct sbp2_pointer pointer;
 237         void (*callback)(struct sbp2_orb * orb, struct sbp2_status * status);
 238         struct list_head link;
 239 };
 240
 241 #define MANAGEMENT_ORB_LUN(v)                   ((v))
 242 #define MANAGEMENT_ORB_FUNCTION(v)              ((v) << 16)
 243 #define MANAGEMENT_ORB_RECONNECT(v)             ((v) << 20)
 244 #define MANAGEMENT_ORB_EXCLUSIVE(v)             ((v) ? 1 << 28 : 0)
 245 #define MANAGEMENT_ORB_REQUEST_FORMAT(v)        ((v) << 29)
 246 #define MANAGEMENT_ORB_NOTIFY                   ((1) << 31)
 247
 248 #define MANAGEMENT_ORB_RESPONSE_LENGTH(v)       ((v))
 249 #define MANAGEMENT_ORB_PASSWORD_LENGTH(v)       ((v) << 16)
 250
 251 struct sbp2_management_orb {
 252         struct sbp2_orb base;
 253         struct {
 254                 struct sbp2_pointer password;
 255                 struct sbp2_pointer response;
 256                 __be32 misc;
 257                 __be32 length;
 258                 struct sbp2_pointer status_fifo;
 259         } request;
 260         __be32 response[4];
 261         dma_addr_t response_bus;
 262         struct completion done;
 263         struct sbp2_status status;
 264 };
 265
 266 struct sbp2_login_response {
 267         __be32 misc;
 268         struct sbp2_pointer command_block_agent;
 269         __be32 reconnect_hold;
 270 };
 271 #define COMMAND_ORB_DATA_SIZE(v)        ((v))
 272 #define COMMAND_ORB_PAGE_SIZE(v)        ((v) << 16)
 273 #define COMMAND_ORB_PAGE_TABLE_PRESENT  ((1) << 19)
 274 #define COMMAND_ORB_MAX_PAYLOAD(v)      ((v) << 20)
 275 #define COMMAND_ORB_SPEED(v)            ((v) << 24)
 276 #define COMMAND_ORB_DIRECTION(v)        ((v) << 27)
 277 #define COMMAND_ORB_REQUEST_FORMAT(v)   ((v) << 29)
 278 #define COMMAND_ORB_NOTIFY              ((1) << 31)
 279
 280 struct sbp2_command_orb {
 281         struct sbp2_orb base;
 282         struct {
 283                 struct sbp2_pointer next;
 284                 struct sbp2_pointer data_descriptor;
 285                 __be32 misc;
 286                 u8 command_block[12];
 287         } request;
 288         struct scsi_cmnd *cmd;
 289         scsi_done_fn_t done;
 290         struct sbp2_logical_unit *lu;
 291
 292         struct sbp2_pointer page_table[SG_ALL] __attribute__((aligned(8)));
 293         dma_addr_t page_table_bus;
 294 };
 295
 296 /*
 297  * List of devices with known bugs.
 298  *
 299  * The firmware_revision field, masked with 0xffff00, is the best
 300  * indicator for the type of bridge chip of a device.  It yields a few
 301  * false positives but this did not break correctly behaving devices
 302  * so far.  We use ~0 as a wildcard, since the 24 bit values we get
 303  * from the config rom can never match that.
 304  */
 305 static const struct {
 306         u32 firmware_revision;
 307         u32 model;
 308         unsigned int workarounds;
 309 } sbp2_workarounds_table[] = {
 310         /* DViCO Momobay CX-1 with TSB42AA9 bridge */ {
 311                 .firmware_revision      = 0x002800,
 312                 .model                  = 0x001010,
 313                 .workarounds            = SBP2_WORKAROUND_INQUIRY_36 |
 314                                           SBP2_WORKAROUND_MODE_SENSE_8,
 315         },
 316         /* DViCO Momobay FX-3A with TSB42AA9A bridge */ {
 317                 .firmware_revision      = 0x002800,
 318                 .model                  = 0x000000,
 319                 .workarounds            = SBP2_WORKAROUND_DELAY_INQUIRY,
 320         },
 321         /* Initio bridges, actually only needed for some older ones */ {
 322                 .firmware_revision      = 0x000200,
 323                 .model                  = ~0,
 324                 .workarounds            = SBP2_WORKAROUND_INQUIRY_36,
 325         },
 326         /* Symbios bridge */ {
 327                 .firmware_revision      = 0xa0b800,
 328                 .model                  = ~0,
 329                 .workarounds            = SBP2_WORKAROUND_128K_MAX_TRANS,
 330         },
 331         /* Datafab MD2-FW2 with Symbios/LSILogic SYM13FW500 bridge */ {
 332                 .firmware_revision      = 0x002600,
 333                 .model                  = ~0,
 334                 .workarounds            = SBP2_WORKAROUND_128K_MAX_TRANS,
 335         },
 336
 337         /*
 338          * There are iPods (2nd gen, 3rd gen) with model_id == 0, but
 339          * these iPods do not feature the read_capacity bug according
 340          * to one report.  Read_capacity behaviour as well as model_id
 341          * could change due to Apple-supplied firmware updates though.
 342          */
 343
 344         /* iPod 4th generation. */ {
 345                 .firmware_revision      = 0x0a2700,
 346                 .model                  = 0x000021,
 347                 .workarounds            = SBP2_WORKAROUND_FIX_CAPACITY,
 348         },
 349         /* iPod mini */ {
 350                 .firmware_revision      = 0x0a2700,
 351                 .model                  = 0x000023,
 352                 .workarounds            = SBP2_WORKAROUND_FIX_CAPACITY,
 353         },
 354         /* iPod Photo */ {
 355                 .firmware_revision      = 0x0a2700,
 356                 .model                  = 0x00007e,
 357                 .workarounds            = SBP2_WORKAROUND_FIX_CAPACITY,
 358         }
 359 };
 360
 361 static void
 362 free_orb(struct kref *kref)
 363 {
 364         struct sbp2_orb *orb = container_of(kref, struct sbp2_orb, kref);
 365
 366         kfree(orb);
 367 }
 368
 369 static void
 370 sbp2_status_write(struct fw_card *card, struct fw_request *request,
 371                   int tcode, int destination, int source,
 372                   int generation, int speed,
 373                   unsigned long long offset,
 374                   void *payload, size_t length, void *callback_data)
 375 {
 376         struct sbp2_logical_unit *lu = callback_data;
 377         struct sbp2_orb *orb;
 378         struct sbp2_status status;
 379         size_t header_size;
 380         unsigned long flags;
 381
 382         if (tcode != TCODE_WRITE_BLOCK_REQUEST ||
 383             length == 0 || length > sizeof(status)) {
 384                 fw_send_response(card, request, RCODE_TYPE_ERROR);
 385                 return;
 386         }
 387
 388         header_size = min(length, 2 * sizeof(u32));
 389         fw_memcpy_from_be32(&status, payload, header_size);
 390         if (length > header_size)
 391                 memcpy(status.data, payload + 8, length - header_size);
 392         if (STATUS_GET_SOURCE(status) == 2 || STATUS_GET_SOURCE(status) == 3) {
 393                 fw_notify("non-orb related status write, not handled\n");
 394                 fw_send_response(card, request, RCODE_COMPLETE);
 395                 return;
 396         }
 397
 398         /* Lookup the orb corresponding to this status write. */
 399         spin_lock_irqsave(&card->lock, flags);
 400         list_for_each_entry(orb, &lu->orb_list, link) {
 401                 if (STATUS_GET_ORB_HIGH(status) == 0 &&
 402                     STATUS_GET_ORB_LOW(status) == orb->request_bus) {
 403                         orb->rcode = RCODE_COMPLETE;
 404                         list_del(&orb->link);
 405                         break;
 406                 }
 407         }
 408         spin_unlock_irqrestore(&card->lock, flags);
 409
 410         if (&orb->link != &lu->orb_list)
 411                 orb->callback(orb, &status);
 412         else
 413                 fw_error("status write for unknown orb\n");
 414
 415         kref_put(&orb->kref, free_orb);
 416
 417         fw_send_response(card, request, RCODE_COMPLETE);
 418 }
 419
 420 static void
 421 complete_transaction(struct fw_card *card, int rcode,
 422                      void *payload, size_t length, void *data)
 423 {
 424         struct sbp2_orb *orb = data;
 425         unsigned long flags;
 426
 427         /*
 428          * This is a little tricky.  We can get the status write for
 429          * the orb before we get this callback.  The status write
 430          * handler above will assume the orb pointer transaction was
 431          * successful and set the rcode to RCODE_COMPLETE for the orb.
 432          * So this callback only sets the rcode if it hasn't already
 433          * been set and only does the cleanup if the transaction
 434          * failed and we didn't already get a status write.
 435          */
 436         spin_lock_irqsave(&card->lock, flags);
 437
 438         if (orb->rcode == -1)
 439                 orb->rcode = rcode;
 440         if (orb->rcode != RCODE_COMPLETE) {
 441                 list_del(&orb->link);
 442                 spin_unlock_irqrestore(&card->lock, flags);
 443                 orb->callback(orb, NULL);
 444         } else {
 445                 spin_unlock_irqrestore(&card->lock, flags);
 446         }
 447
 448         kref_put(&orb->kref, free_orb);
 449 }
 450
 451 static void
 452 sbp2_send_orb(struct sbp2_orb *orb, struct sbp2_logical_unit *lu,
 453               int node_id, int generation, u64 offset)
 454 {
 455         struct fw_device *device = fw_device(lu->tgt->unit->device.parent);
 456         unsigned long flags;
 457
 458         orb->pointer.high = 0;
 459         orb->pointer.low = cpu_to_be32(orb->request_bus);
 460
 461         spin_lock_irqsave(&device->card->lock, flags);
 462         list_add_tail(&orb->link, &lu->orb_list);
 463         spin_unlock_irqrestore(&device->card->lock, flags);
 464
 465         /* Take a ref for the orb list and for the transaction callback. */
 466         kref_get(&orb->kref);
 467         kref_get(&orb->kref);
 468
 469         fw_send_request(device->card, &orb->t, TCODE_WRITE_BLOCK_REQUEST,
 470                         node_id, generation, device->max_speed, offset,
 471                         &orb->pointer, sizeof(orb->pointer),
 472                         complete_transaction, orb);
 473 }
 474
 475 static int sbp2_cancel_orbs(struct sbp2_logical_unit *lu)
 476 {
 477         struct fw_device *device = fw_device(lu->tgt->unit->device.parent);
 478         struct sbp2_orb *orb, *next;
 479         struct list_head list;
 480         unsigned long flags;
 481         int retval = -ENOENT;
 482
 483         INIT_LIST_HEAD(&list);
 484         spin_lock_irqsave(&device->card->lock, flags);
 485         list_splice_init(&lu->orb_list, &list);
 486         spin_unlock_irqrestore(&device->card->lock, flags);
 487
 488         list_for_each_entry_safe(orb, next, &list, link) {
 489                 retval = 0;
 490                 if (fw_cancel_transaction(device->card, &orb->t) == 0)
 491                         continue;
 492
 493                 orb->rcode = RCODE_CANCELLED;
 494                 orb->callback(orb, NULL);
 495         }
 496
 497         return retval;
 498 }
 499
 500 static void
 501 complete_management_orb(struct sbp2_orb *base_orb, struct sbp2_status *status)
 502 {
 503         struct sbp2_management_orb *orb =
 504                 container_of(base_orb, struct sbp2_management_orb, base);
 505
 506         if (status)
 507                 memcpy(&orb->status, status, sizeof(*status));
 508         complete(&orb->done);
 509 }
 510
 511 static int
 512 sbp2_send_management_orb(struct sbp2_logical_unit *lu, int node_id,
 513                          int generation, int function, int lun_or_login_id,
 514                          void *response)
 515 {
 516         struct fw_device *device = fw_device(lu->tgt->unit->device.parent);
 517         struct sbp2_management_orb *orb;
 518         unsigned int timeout;
 519         int retval = -ENOMEM;
 520
 521         if (function == SBP2_LOGOUT_REQUEST && fw_device_is_shutdown(device))
 522                 return 0;
 523
 524         orb = kzalloc(sizeof(*orb), GFP_ATOMIC);
 525         if (orb == NULL)
 526                 return -ENOMEM;
 527
 528         kref_init(&orb->base.kref);
 529         orb->response_bus =
 530                 dma_map_single(device->card->device, &orb->response,
 531                                sizeof(orb->response), DMA_FROM_DEVICE);
 532         if (dma_mapping_error(orb->response_bus))
 533                 goto fail_mapping_response;
 534
 535         orb->request.response.high = 0;
 536         orb->request.response.low  = cpu_to_be32(orb->response_bus);
 537
 538         orb->request.misc = cpu_to_be32(
 539                 MANAGEMENT_ORB_NOTIFY |
 540                 MANAGEMENT_ORB_FUNCTION(function) |
 541                 MANAGEMENT_ORB_LUN(lun_or_login_id));
 542         orb->request.length = cpu_to_be32(
 543                 MANAGEMENT_ORB_RESPONSE_LENGTH(sizeof(orb->response)));
 544
 545         orb->request.status_fifo.high =
 546                 cpu_to_be32(lu->address_handler.offset >> 32);
 547         orb->request.status_fifo.low  =
 548                 cpu_to_be32(lu->address_handler.offset);
 549
 550         if (function == SBP2_LOGIN_REQUEST) {
 551                 /* Ask for 2^2 == 4 seconds reconnect grace period */
 552                 orb->request.misc |= cpu_to_be32(
 553                         MANAGEMENT_ORB_RECONNECT(2) |
 554                         MANAGEMENT_ORB_EXCLUSIVE(sbp2_param_exclusive_login));
 555                 timeout = lu->tgt->mgt_orb_timeout;
 556         } else {
 557                 timeout = SBP2_ORB_TIMEOUT;
 558         }
 559
 560         init_completion(&orb->done);
 561         orb->base.callback = complete_management_orb;
 562
 563         orb->base.request_bus =
 564                 dma_map_single(device->card->device, &orb->request,
 565                                sizeof(orb->request), DMA_TO_DEVICE);
 566         if (dma_mapping_error(orb->base.request_bus))
 567                 goto fail_mapping_request;
 568
 569         sbp2_send_orb(&orb->base, lu, node_id, generation,
 570                       lu->tgt->management_agent_address);
 571
 572         wait_for_completion_timeout(&orb->done, msecs_to_jiffies(timeout));
 573
 574         retval = -EIO;
 575         if (sbp2_cancel_orbs(lu) == 0) {
 576                 fw_error("%s: orb reply timed out, rcode=0x%02x\n",
 577                          lu->tgt->bus_id, orb->base.rcode);
 578                 goto out;
 579         }
 580
 581         if (orb->base.rcode != RCODE_COMPLETE) {
 582                 fw_error("%s: management write failed, rcode 0x%02x\n",
 583                          lu->tgt->bus_id, orb->base.rcode);
 584                 goto out;
 585         }
 586
 587         if (STATUS_GET_RESPONSE(orb->status) != 0 ||
 588             STATUS_GET_SBP_STATUS(orb->status) != 0) {
 589                 fw_error("%s: error status: %d:%d\n", lu->tgt->bus_id,
 590                          STATUS_GET_RESPONSE(orb->status),
 591                          STATUS_GET_SBP_STATUS(orb->status));
 592                 goto out;
 593         }
 594
 595         retval = 0;
 596  out:
 597         dma_unmap_single(device->card->device, orb->base.request_bus,
 598                          sizeof(orb->request), DMA_TO_DEVICE);
 599  fail_mapping_request:
 600         dma_unmap_single(device->card->device, orb->response_bus,
 601                          sizeof(orb->response), DMA_FROM_DEVICE);
 602  fail_mapping_response:
 603         if (response)
 604                 memcpy(response, orb->response, sizeof(orb->response));
 605         kref_put(&orb->base.kref, free_orb);
 606
 607         return retval;
 608 }
 609
 610 static void
 611 complete_agent_reset_write(struct fw_card *card, int rcode,
 612                            void *payload, size_t length, void *done)
 613 {
 614         complete(done);
 615 }
 616
 617 static void sbp2_agent_reset(struct sbp2_logical_unit *lu)
 618 {
 619         struct fw_device *device = fw_device(lu->tgt->unit->device.parent);
 620         DECLARE_COMPLETION_ONSTACK(done);
 621         struct fw_transaction t;
 622         static u32 z;
 623
 624         fw_send_request(device->card, &t, TCODE_WRITE_QUADLET_REQUEST,
 625                         lu->tgt->node_id, lu->generation, device->max_speed,
 626                         lu->command_block_agent_address + SBP2_AGENT_RESET,
 627                         &z, sizeof(z), complete_agent_reset_write, &done);
 628         wait_for_completion(&done);
 629 }
 630
 631 static void
 632 complete_agent_reset_write_no_wait(struct fw_card *card, int rcode,
 633                                    void *payload, size_t length, void *data)
 634 {
 635         kfree(data);
 636 }
 637
 638 static void sbp2_agent_reset_no_wait(struct sbp2_logical_unit *lu)
 639 {
 640         struct fw_device *device = fw_device(lu->tgt->unit->device.parent);
 641         struct fw_transaction *t;
 642         static u32 z;
 643
 644         t = kmalloc(sizeof(*t), GFP_ATOMIC);
 645         if (t == NULL)
 646                 return;
 647
 648         fw_send_request(device->card, t, TCODE_WRITE_QUADLET_REQUEST,
 649                         lu->tgt->node_id, lu->generation, device->max_speed,
 650                         lu->command_block_agent_address + SBP2_AGENT_RESET,
 651                         &z, sizeof(z), complete_agent_reset_write_no_wait, t);
 652 }
 653
 654 static void sbp2_set_generation(struct sbp2_logical_unit *lu, int generation)
 655 {
 656         struct fw_card *card = fw_device(lu->tgt->unit->device.parent)->card;
 657         unsigned long flags;
 658
 659         /* serialize with comparisons of lu->generation and card->generation */
 660         spin_lock_irqsave(&card->lock, flags);
 661         lu->generation = generation;
 662         spin_unlock_irqrestore(&card->lock, flags);
 663 }
 664
 665 static inline void sbp2_allow_block(struct sbp2_logical_unit *lu)
 666 {
 667         /*
 668          * We may access dont_block without taking card->lock here:
 669          * All callers of sbp2_allow_block() and all callers of sbp2_unblock()
 670          * are currently serialized against each other.
 671          * And a wrong result in sbp2_conditionally_block()'s access of
 672          * dont_block is rather harmless, it simply misses its first chance.
 673          */
 674         --lu->tgt->dont_block;
 675 }
 676
 677 /*
 678  * Blocks lu->tgt if all of the following conditions are met:
 679  *   - Login, INQUIRY, and high-level SCSI setup of all of the target's
 680  *     logical units have been finished (indicated by dont_block == 0).
 681  *   - lu->generation is stale.
 682  *
 683  * Note, scsi_block_requests() must be called while holding card->lock,
 684  * otherwise it might foil sbp2_[conditionally_]unblock()'s attempt to
 685  * unblock the target.
 686  */
 687 static void sbp2_conditionally_block(struct sbp2_logical_unit *lu)
 688 {
 689         struct sbp2_target *tgt = lu->tgt;
 690         struct fw_card *card = fw_device(tgt->unit->device.parent)->card;
 691         struct Scsi_Host *shost =
 692                 container_of((void *)tgt, struct Scsi_Host, hostdata[0]);
 693         unsigned long flags;
 694
 695         spin_lock_irqsave(&card->lock, flags);
 696         if (!tgt->dont_block && !lu->blocked &&
 697             lu->generation != card->generation) {
 698                 lu->blocked = true;
 699                 if (++tgt->blocked == 1) {
 700                         scsi_block_requests(shost);
 701                         fw_notify("blocked %s\n", lu->tgt->bus_id);
 702                 }
 703         }
 704         spin_unlock_irqrestore(&card->lock, flags);
 705 }
 706
 707 /*
 708  * Unblocks lu->tgt as soon as all its logical units can be unblocked.
 709  * Note, it is harmless to run scsi_unblock_requests() outside the
 710  * card->lock protected section.  On the other hand, running it inside
 711  * the section might clash with shost->host_lock.
 712  */
 713 static void sbp2_conditionally_unblock(struct sbp2_logical_unit *lu)
 714 {
 715         struct sbp2_target *tgt = lu->tgt;
 716         struct fw_card *card = fw_device(tgt->unit->device.parent)->card;
 717         struct Scsi_Host *shost =
 718                 container_of((void *)tgt, struct Scsi_Host, hostdata[0]);
 719         unsigned long flags;
 720         bool unblock = false;
 721
 722         spin_lock_irqsave(&card->lock, flags);
 723         if (lu->blocked && lu->generation == card->generation) {
 724                 lu->blocked = false;
 725                 unblock = --tgt->blocked == 0;
 726         }
 727         spin_unlock_irqrestore(&card->lock, flags);
 728
 729         if (unblock) {
 730                 scsi_unblock_requests(shost);
 731                 fw_notify("unblocked %s\n", lu->tgt->bus_id);
 732         }
 733 }
 734
 735 /*
 736  * Prevents future blocking of tgt and unblocks it.
 737  * Note, it is harmless to run scsi_unblock_requests() outside the
 738  * card->lock protected section.  On the other hand, running it inside
 739  * the section might clash with shost->host_lock.
 740  */
 741 static void sbp2_unblock(struct sbp2_target *tgt)
 742 {
 743         struct fw_card *card = fw_device(tgt->unit->device.parent)->card;
 744         struct Scsi_Host *shost =
 745                 container_of((void *)tgt, struct Scsi_Host, hostdata[0]);
 746         unsigned long flags;
 747
 748         spin_lock_irqsave(&card->lock, flags);
 749         ++tgt->dont_block;
 750         spin_unlock_irqrestore(&card->lock, flags);
 751
 752         scsi_unblock_requests(shost);
 753 }
 754
 755 static int sbp2_lun2int(u16 lun)
 756 {
 757         struct scsi_lun eight_bytes_lun;
 758
 759         memset(&eight_bytes_lun, 0, sizeof(eight_bytes_lun));
 760         eight_bytes_lun.scsi_lun[0] = (lun >> 8) & 0xff;
 761         eight_bytes_lun.scsi_lun[1] = lun & 0xff;
 762
 763         return scsilun_to_int(&eight_bytes_lun);
 764 }
 765
 766 static void sbp2_release_target(struct kref *kref)
 767 {
 768         struct sbp2_target *tgt = container_of(kref, struct sbp2_target, kref);
 769         struct sbp2_logical_unit *lu, *next;
 770         struct Scsi_Host *shost =
 771                 container_of((void *)tgt, struct Scsi_Host, hostdata[0]);
 772         struct scsi_device *sdev;
 773         struct fw_device *device = fw_device(tgt->unit->device.parent);
 774
 775         /* prevent deadlocks */
 776         sbp2_unblock(tgt);
 777
 778         list_for_each_entry_safe(lu, next, &tgt->lu_list, link) {
 779                 sdev = scsi_device_lookup(shost, 0, 0, sbp2_lun2int(lu->lun));
 780                 if (sdev) {
 781                         scsi_remove_device(sdev);
 782                         scsi_device_put(sdev);
 783                 }
 784                 sbp2_send_management_orb(lu, tgt->node_id, lu->generation,
 785                                 SBP2_LOGOUT_REQUEST, lu->login_id, NULL);
 786
 787                 fw_core_remove_address_handler(&lu->address_handler);
 788                 list_del(&lu->link);
 789                 kfree(lu);
 790         }
 791         scsi_remove_host(shost);
 792         fw_notify("released %s\n", tgt->bus_id);
 793
 794         fw_unit_put(tgt->unit);
 795         scsi_host_put(shost);
 796         fw_device_put(device);
 797 }
 798
 799 static struct workqueue_struct *sbp2_wq;
 800
 801 /*
 802  * Always get the target's kref when scheduling work on one its units.
 803  * Each workqueue job is responsible to call sbp2_target_put() upon return.
 804  */
 805 static void sbp2_queue_work(struct sbp2_logical_unit *lu, unsigned long delay)
 806 {
 807         if (queue_delayed_work(sbp2_wq, &lu->work, delay))
 808                 kref_get(&lu->tgt->kref);
 809 }
 810
 811 static void sbp2_target_put(struct sbp2_target *tgt)
 812 {
 813         kref_put(&tgt->kref, sbp2_release_target);
 814 }
 815
 816 static void
 817 complete_set_busy_timeout(struct fw_card *card, int rcode,
 818                           void *payload, size_t length, void *done)
 819 {
 820         complete(done);
 821 }
 822
 823 static void sbp2_set_busy_timeout(struct sbp2_logical_unit *lu)
 824 {
 825         struct fw_device *device = fw_device(lu->tgt->unit->device.parent);
 826         DECLARE_COMPLETION_ONSTACK(done);
 827         struct fw_transaction t;
 828         static __be32 busy_timeout;
 829
 830         /* FIXME: we should try to set dual-phase cycle_limit too */
 831         busy_timeout = cpu_to_be32(SBP2_RETRY_LIMIT);
 832
 833         fw_send_request(device->card, &t, TCODE_WRITE_QUADLET_REQUEST,
 834                         lu->tgt->node_id, lu->generation, device->max_speed,
 835                         CSR_REGISTER_BASE + CSR_BUSY_TIMEOUT, &busy_timeout,
 836                         sizeof(busy_timeout), complete_set_busy_timeout, &done);
 837         wait_for_completion(&done);
 838 }
 839
 840 static void sbp2_reconnect(struct work_struct *work);
 841
 842 static void sbp2_login(struct work_struct *work)
 843 {
 844         struct sbp2_logical_unit *lu =
 845                 container_of(work, struct sbp2_logical_unit, work.work);
 846         struct sbp2_target *tgt = lu->tgt;
 847         struct fw_device *device = fw_device(tgt->unit->device.parent);
 848         struct Scsi_Host *shost;
 849         struct scsi_device *sdev;
 850         struct sbp2_login_response response;
 851         int generation, node_id, local_node_id;
 852
 853         if (fw_device_is_shutdown(device))
 854                 goto out;
 855
 856         generation    = device->generation;
 857         smp_rmb();    /* node_id must not be older than generation */
 858         node_id       = device->node_id;
 859         local_node_id = device->card->node_id;
 860
 861         /* If this is a re-login attempt, log out, or we might be rejected. */
 862         if (lu->has_sdev)
 863                 sbp2_send_management_orb(lu, device->node_id, generation,
 864                                 SBP2_LOGOUT_REQUEST, lu->login_id, NULL);
 865
 866         if (sbp2_send_management_orb(lu, node_id, generation,
 867                                 SBP2_LOGIN_REQUEST, lu->lun, &response) < 0) {
 868                 if (lu->retries++ < 5) {
 869                         sbp2_queue_work(lu, DIV_ROUND_UP(HZ, 5));
 870                 } else {
 871                         fw_error("%s: failed to login to LUN %04x\n",
 872                                  tgt->bus_id, lu->lun);
 873                         /* Let any waiting I/O fail from now on. */
 874                         sbp2_unblock(lu->tgt);
 875                 }
 876                 goto out;
 877         }
 878
 879         tgt->node_id      = node_id;
 880         tgt->address_high = local_node_id << 16;
 881         sbp2_set_generation(lu, generation);
 882
 883         lu->command_block_agent_address =
 884                 ((u64)(be32_to_cpu(response.command_block_agent.high) & 0xffff)
 885                       << 32) | be32_to_cpu(response.command_block_agent.low);
 886         lu->login_id = be32_to_cpu(response.misc) & 0xffff;
 887
 888         fw_notify("%s: logged in to LUN %04x (%d retries)\n",
 889                   tgt->bus_id, lu->lun, lu->retries);
 890
 891         /* set appropriate retry limit(s) in BUSY_TIMEOUT register */
 892         sbp2_set_busy_timeout(lu);
 893
 894         PREPARE_DELAYED_WORK(&lu->work, sbp2_reconnect);
 895         sbp2_agent_reset(lu);
 896
 897         /* This was a re-login. */
 898         if (lu->has_sdev) {
 899                 sbp2_cancel_orbs(lu);
 900                 sbp2_conditionally_unblock(lu);
 901                 goto out;
 902         }
 903
 904         if (lu->tgt->workarounds & SBP2_WORKAROUND_DELAY_INQUIRY)
 905                 ssleep(SBP2_INQUIRY_DELAY);
 906
 907         shost = container_of((void *)tgt, struct Scsi_Host, hostdata[0]);
 908         sdev = __scsi_add_device(shost, 0, 0, sbp2_lun2int(lu->lun), lu);
 909         /*
 910          * FIXME:  We are unable to perform reconnects while in sbp2_login().
 911          * Therefore __scsi_add_device() will get into trouble if a bus reset
 912          * happens in parallel.  It will either fail or leave us with an
 913          * unusable sdev.  As a workaround we check for this and retry the
 914          * whole login and SCSI probing.
 915          */
 916
 917         /* Reported error during __scsi_add_device() */
 918         if (IS_ERR(sdev))
 919                 goto out_logout_login;
 920
 921         /* Unreported error during __scsi_add_device() */
 922         smp_rmb(); /* get current card generation */
 923         if (generation != device->card->generation) {
 924                 scsi_remove_device(sdev);
 925                 scsi_device_put(sdev);
 926                 goto out_logout_login;
 927         }
 928
 929         /* No error during __scsi_add_device() */
 930         lu->has_sdev = true;
 931         scsi_device_put(sdev);
 932         sbp2_allow_block(lu);
 933         goto out;
 934
 935  out_logout_login:
 936         smp_rmb(); /* generation may have changed */
 937         generation = device->generation;
 938         smp_rmb(); /* node_id must not be older than generation */
 939
 940         sbp2_send_management_orb(lu, device->node_id, generation,
 941                                  SBP2_LOGOUT_REQUEST, lu->login_id, NULL);
 942         /*
 943          * If a bus reset happened, sbp2_update will have requeued
 944          * lu->work already.  Reset the work from reconnect to login.
 945          */
 946         PREPARE_DELAYED_WORK(&lu->work, sbp2_login);
 947  out:
 948         sbp2_target_put(tgt);
 949 }
 950
 951 static int sbp2_add_logical_unit(struct sbp2_target *tgt, int lun_entry)
 952 {
 953         struct sbp2_logical_unit *lu;
 954
 955         lu = kmalloc(sizeof(*lu), GFP_KERNEL);
 956         if (!lu)
 957                 return -ENOMEM;
 958
 959         lu->address_handler.length           = 0x100;
 960         lu->address_handler.address_callback = sbp2_status_write;
 961         lu->address_handler.callback_data    = lu;
 962
 963         if (fw_core_add_address_handler(&lu->address_handler,
 964                                         &fw_high_memory_region) < 0) {
 965                 kfree(lu);
 966                 return -ENOMEM;
 967         }
 968
 969         lu->tgt      = tgt;
 970         lu->lun      = lun_entry & 0xffff;
 971         lu->retries  = 0;
 972         lu->has_sdev = false;
 973         lu->blocked  = false;
 974         ++tgt->dont_block;
 975         INIT_LIST_HEAD(&lu->orb_list);
 976         INIT_DELAYED_WORK(&lu->work, sbp2_login);
 977
 978         list_add_tail(&lu->link, &tgt->lu_list);
 979         return 0;
 980 }
 981
 982 static int sbp2_scan_logical_unit_dir(struct sbp2_target *tgt, u32 *directory)
 983 {
 984         struct fw_csr_iterator ci;
 985         int key, value;
 986
 987         fw_csr_iterator_init(&ci, directory);
 988         while (fw_csr_iterator_next(&ci, &key, &value))
 989                 if (key == SBP2_CSR_LOGICAL_UNIT_NUMBER &&
 990                     sbp2_add_logical_unit(tgt, value) < 0)
 991                         return -ENOMEM;
 992         return 0;
 993 }
 994
 995 static int sbp2_scan_unit_dir(struct sbp2_target *tgt, u32 *directory,
 996                               u32 *model, u32 *firmware_revision)
 997 {
 998         struct fw_csr_iterator ci;
 999         int key, value;
1000         unsigned int timeout;
1001
1002         fw_csr_iterator_init(&ci, directory);
1003         while (fw_csr_iterator_next(&ci, &key, &value)) {
1004                 switch (key) {
1005
1006                 case CSR_DEPENDENT_INFO | CSR_OFFSET:
1007                         tgt->management_agent_address =
1008                                         CSR_REGISTER_BASE + 4 * value;
1009                         break;
1010
1011                 case CSR_DIRECTORY_ID:
1012                         tgt->directory_id = value;
1013                         break;
1014
1015                 case CSR_MODEL:
1016                         *model = value;
1017                         break;
1018
1019                 case SBP2_CSR_FIRMWARE_REVISION:
1020                         *firmware_revision = value;
1021                         break;
1022
1023                 case SBP2_CSR_UNIT_CHARACTERISTICS:
1024                         /* the timeout value is stored in 500ms units */
1025                         timeout = ((unsigned int) value >> 8 & 0xff) * 500;
1026                         timeout = max(timeout, SBP2_MIN_LOGIN_ORB_TIMEOUT);
1027                         tgt->mgt_orb_timeout =
1028                                   min(timeout, SBP2_MAX_LOGIN_ORB_TIMEOUT);
1029
1030                         if (timeout > tgt->mgt_orb_timeout)
1031                                 fw_notify("%s: config rom contains %ds "
1032                                           "management ORB timeout, limiting "
1033                                           "to %ds\n", tgt->bus_id,
1034                                           timeout / 1000,
1035                                           tgt->mgt_orb_timeout / 1000);
1036                         break;
1037
1038                 case SBP2_CSR_LOGICAL_UNIT_NUMBER:
1039                         if (sbp2_add_logical_unit(tgt, value) < 0)
1040                                 return -ENOMEM;
1041                         break;
1042
1043                 case SBP2_CSR_LOGICAL_UNIT_DIRECTORY:
1044                         if (sbp2_scan_logical_unit_dir(tgt, ci.p + value) < 0)
1045                                 return -ENOMEM;
1046                         break;
1047                 }
1048         }
1049         return 0;
1050 }
1051
1052 static void sbp2_init_workarounds(struct sbp2_target *tgt, u32 model,
1053                                   u32 firmware_revision)
1054 {
1055         int i;
1056         unsigned int w = sbp2_param_workarounds;
1057
1058         if (w)
1059                 fw_notify("Please notify linux1394-devel@lists.sourceforge.net "
1060                           "if you need the workarounds parameter for %s\n",
1061                           tgt->bus_id);
1062
1063         if (w & SBP2_WORKAROUND_OVERRIDE)
1064                 goto out;
1065
1066         for (i = 0; i < ARRAY_SIZE(sbp2_workarounds_table); i++) {
1067
1068                 if (sbp2_workarounds_table[i].firmware_revision !=
1069                     (firmware_revision & 0xffffff00))
1070                         continue;
1071
1072                 if (sbp2_workarounds_table[i].model != model &&
1073                     sbp2_workarounds_table[i].model != ~0)
1074                         continue;
1075
1076                 w |= sbp2_workarounds_table[i].workarounds;
1077                 break;
1078         }
1079  out:
1080         if (w)
1081                 fw_notify("Workarounds for %s: 0x%x "
1082                           "(firmware_revision 0x%06x, model_id 0x%06x)\n",
1083                           tgt->bus_id, w, firmware_revision, model);
1084         tgt->workarounds = w;
1085 }
1086
1087 static struct scsi_host_template scsi_driver_template;
1088
1089 static int sbp2_probe(struct device *dev)
1090 {
1091         struct fw_unit *unit = fw_unit(dev);
1092         struct fw_device *device = fw_device(unit->device.parent);
1093         struct sbp2_target *tgt;
1094         struct sbp2_logical_unit *lu;
1095         struct Scsi_Host *shost;
1096         u32 model, firmware_revision;
1097
1098         shost = scsi_host_alloc(&scsi_driver_template, sizeof(*tgt));
1099         if (shost == NULL)
1100                 return -ENOMEM;
1101
1102         tgt = (struct sbp2_target *)shost->hostdata;
1103         unit->device.driver_data = tgt;
1104         tgt->unit = unit;
1105         kref_init(&tgt->kref);
1106         INIT_LIST_HEAD(&tgt->lu_list);
1107         tgt->bus_id = unit->device.bus_id;
1108
1109         if (fw_device_enable_phys_dma(device) < 0)
1110                 goto fail_shost_put;
1111
1112         if (scsi_add_host(shost, &unit->device) < 0)
1113                 goto fail_shost_put;
1114
1115         fw_device_get(device);
1116         fw_unit_get(unit);
1117
1118         /* Initialize to values that won't match anything in our table. */
1119         firmware_revision = 0xff000000;
1120         model = 0xff000000;
1121
1122         /* implicit directory ID */
1123         tgt->directory_id = ((unit->directory - device->config_rom) * 4
1124                              + CSR_CONFIG_ROM) & 0xffffff;
1125
1126         if (sbp2_scan_unit_dir(tgt, unit->directory, &model,
1127                                &firmware_revision) < 0)
1128                 goto fail_tgt_put;
1129
1130         sbp2_init_workarounds(tgt, model, firmware_revision);
1131
1132         /* Do the login in a workqueue so we can easily reschedule retries. */
1133         list_for_each_entry(lu, &tgt->lu_list, link)
1134                 sbp2_queue_work(lu, 0);
1135         return 0;
1136
1137  fail_tgt_put:
1138         sbp2_target_put(tgt);
1139         return -ENOMEM;
1140
1141  fail_shost_put:
1142         scsi_host_put(shost);
1143         return -ENOMEM;
1144 }
1145
1146 static int sbp2_remove(struct device *dev)
1147 {
1148         struct fw_unit *unit = fw_unit(dev);
1149         struct sbp2_target *tgt = unit->device.driver_data;
1150
1151         sbp2_target_put(tgt);
1152         return 0;
1153 }
1154
1155 static void sbp2_reconnect(struct work_struct *work)
1156 {
1157         struct sbp2_logical_unit *lu =
1158                 container_of(work, struct sbp2_logical_unit, work.work);
1159         struct sbp2_target *tgt = lu->tgt;
1160         struct fw_device *device = fw_device(tgt->unit->device.parent);
1161         int generation, node_id, local_node_id;
1162
1163         if (fw_device_is_shutdown(device))
1164                 goto out;
1165
1166         generation    = device->generation;
1167         smp_rmb();    /* node_id must not be older than generation */
1168         node_id       = device->node_id;
1169         local_node_id = device->card->node_id;
1170
1171         if (sbp2_send_management_orb(lu, node_id, generation,
1172                                      SBP2_RECONNECT_REQUEST,
1173                                      lu->login_id, NULL) < 0) {
1174                 /*
1175                  * If reconnect was impossible even though we are in the
1176                  * current generation, fall back and try to log in again.
1177                  *
1178                  * We could check for "Function rejected" status, but
1179                  * looking at the bus generation as simpler and more general.
1180                  */
1181                 smp_rmb(); /* get current card generation */
1182                 if (generation == device->card->generation ||
1183                     lu->retries++ >= 5) {
1184                         fw_error("%s: failed to reconnect\n", tgt->bus_id);
1185                         lu->retries = 0;
1186                         PREPARE_DELAYED_WORK(&lu->work, sbp2_login);
1187                 }
1188                 sbp2_queue_work(lu, DIV_ROUND_UP(HZ, 5));
1189                 goto out;
1190         }
1191
1192         tgt->node_id      = node_id;
1193         tgt->address_high = local_node_id << 16;
1194         sbp2_set_generation(lu, generation);
1195
1196         fw_notify("%s: reconnected to LUN %04x (%d retries)\n",
1197                   tgt->bus_id, lu->lun, lu->retries);
1198
1199         sbp2_agent_reset(lu);
1200         sbp2_cancel_orbs(lu);
1201         sbp2_conditionally_unblock(lu);
1202  out:
1203         sbp2_target_put(tgt);
1204 }
1205
1206 static void sbp2_update(struct fw_unit *unit)
1207 {
1208         struct sbp2_target *tgt = unit->device.driver_data;
1209         struct sbp2_logical_unit *lu;
1210
1211         fw_device_enable_phys_dma(fw_device(unit->device.parent));
1212
1213         /*
1214          * Fw-core serializes sbp2_update() against sbp2_remove().
1215          * Iteration over tgt->lu_list is therefore safe here.
1216          */
1217         list_for_each_entry(lu, &tgt->lu_list, link) {
1218                 sbp2_conditionally_block(lu);
1219                 lu->retries = 0;
1220                 sbp2_queue_work(lu, 0);
1221         }
1222 }
1223
1224 #define SBP2_UNIT_SPEC_ID_ENTRY 0x0000609e
1225 #define SBP2_SW_VERSION_ENTRY   0x00010483
1226
1227 static const struct fw_device_id sbp2_id_table[] = {
1228         {
1229                 .match_flags  = FW_MATCH_SPECIFIER_ID | FW_MATCH_VERSION,
1230                 .specifier_id = SBP2_UNIT_SPEC_ID_ENTRY,
1231                 .version      = SBP2_SW_VERSION_ENTRY,
1232         },
1233         { }
1234 };
1235
1236 static struct fw_driver sbp2_driver = {
1237         .driver   = {
1238                 .owner  = THIS_MODULE,
1239                 .name   = sbp2_driver_name,
1240                 .bus    = &fw_bus_type,
1241                 .probe  = sbp2_probe,
1242                 .remove = sbp2_remove,
1243         },
1244         .update   = sbp2_update,
1245         .id_table = sbp2_id_table,
1246 };
1247
1248 static unsigned int
1249 sbp2_status_to_sense_data(u8 *sbp2_status, u8 *sense_data)
1250 {
1251         int sam_status;
1252
1253         sense_data[0] = 0x70;
1254         sense_data[1] = 0x0;
1255         sense_data[2] = sbp2_status[1];
1256         sense_data[3] = sbp2_status[4];
1257         sense_data[4] = sbp2_status[5];
1258         sense_data[5] = sbp2_status[6];
1259         sense_data[6] = sbp2_status[7];
1260         sense_data[7] = 10;
1261         sense_data[8] = sbp2_status[8];
1262         sense_data[9] = sbp2_status[9];
1263         sense_data[10] = sbp2_status[10];
1264         sense_data[11] = sbp2_status[11];
1265         sense_data[12] = sbp2_status[2];
1266         sense_data[13] = sbp2_status[3];
1267         sense_data[14] = sbp2_status[12];
1268         sense_data[15] = sbp2_status[13];
1269
1270         sam_status = sbp2_status[0] & 0x3f;
1271
1272         switch (sam_status) {
1273         case SAM_STAT_GOOD:
1274         case SAM_STAT_CHECK_CONDITION:
1275         case SAM_STAT_CONDITION_MET:
1276         case SAM_STAT_BUSY:
1277         case SAM_STAT_RESERVATION_CONFLICT:
1278         case SAM_STAT_COMMAND_TERMINATED:
1279                 return DID_OK << 16 | sam_status;
1280
1281         default:
1282                 return DID_ERROR << 16;
1283         }
1284 }
1285
1286 static void
1287 complete_command_orb(struct sbp2_orb *base_orb, struct sbp2_status *status)
1288 {
1289         struct sbp2_command_orb *orb =
1290                 container_of(base_orb, struct sbp2_command_orb, base);
1291         struct fw_device *device = fw_device(orb->lu->tgt->unit->device.parent);
1292         int result;
1293
1294         if (status != NULL) {
1295                 if (STATUS_GET_DEAD(*status))
1296                         sbp2_agent_reset_no_wait(orb->lu);
1297
1298                 switch (STATUS_GET_RESPONSE(*status)) {
1299                 case SBP2_STATUS_REQUEST_COMPLETE:
1300                         result = DID_OK << 16;
1301                         break;
1302                 case SBP2_STATUS_TRANSPORT_FAILURE:
1303                         result = DID_BUS_BUSY << 16;
1304                         break;
1305                 case SBP2_STATUS_ILLEGAL_REQUEST:
1306                 case SBP2_STATUS_VENDOR_DEPENDENT:
1307                 default:
1308                         result = DID_ERROR << 16;
1309                         break;
1310                 }
1311
1312                 if (result == DID_OK << 16 && STATUS_GET_LEN(*status) > 1)
1313                         result = sbp2_status_to_sense_data(STATUS_GET_DATA(*status),
1314                                                            orb->cmd->sense_buffer);
1315         } else {
1316                 /*
1317                  * If the orb completes with status == NULL, something
1318                  * went wrong, typically a bus reset happened mid-orb
1319                  * or when sending the write (less likely).
1320                  */
1321                 result = DID_BUS_BUSY << 16;
1322                 sbp2_conditionally_block(orb->lu);
1323         }
1324
1325         dma_unmap_single(device->card->device, orb->base.request_bus,
1326                          sizeof(orb->request), DMA_TO_DEVICE);
1327
1328         if (scsi_sg_count(orb->cmd) > 0)
1329                 dma_unmap_sg(device->card->device, scsi_sglist(orb->cmd),
1330                              scsi_sg_count(orb->cmd),
1331                              orb->cmd->sc_data_direction);
1332
1333         if (orb->page_table_bus != 0)
1334                 dma_unmap_single(device->card->device, orb->page_table_bus,
1335                                  sizeof(orb->page_table), DMA_TO_DEVICE);
1336
1337         orb->cmd->result = result;
1338         orb->done(orb->cmd);
1339 }
1340
1341 static int
1342 sbp2_map_scatterlist(struct sbp2_command_orb *orb, struct fw_device *device,
1343                      struct sbp2_logical_unit *lu)
1344 {
1345         struct scatterlist *sg;
1346         int sg_len, l, i, j, count;
1347         dma_addr_t sg_addr;
1348
1349         sg = scsi_sglist(orb->cmd);
1350         count = dma_map_sg(device->card->device, sg, scsi_sg_count(orb->cmd),
1351                            orb->cmd->sc_data_direction);
1352         if (count == 0)
1353                 goto fail;
1354
1355         /*
1356          * Handle the special case where there is only one element in
1357          * the scatter list by converting it to an immediate block
1358          * request. This is also a workaround for broken devices such
1359          * as the second generation iPod which doesn't support page
1360          * tables.
1361          */
1362         if (count == 1 && sg_dma_len(sg) < SBP2_MAX_SG_ELEMENT_LENGTH) {
1363                 orb->request.data_descriptor.high =
1364                         cpu_to_be32(lu->tgt->address_high);
1365                 orb->request.data_descriptor.low  =
1366                         cpu_to_be32(sg_dma_address(sg));
1367                 orb->request.misc |=
1368                         cpu_to_be32(COMMAND_ORB_DATA_SIZE(sg_dma_len(sg)));
1369                 return 0;
1370         }
1371
1372         /*
1373          * Convert the scatterlist to an sbp2 page table.  If any
1374          * scatterlist entries are too big for sbp2, we split them as we
1375          * go.  Even if we ask the block I/O layer to not give us sg
1376          * elements larger than 65535 bytes, some IOMMUs may merge sg elements
1377          * during DMA mapping, and Linux currently doesn't prevent this.
1378          */
1379         for (i = 0, j = 0; i < count; i++, sg = sg_next(sg)) {
1380                 sg_len = sg_dma_len(sg);
1381                 sg_addr = sg_dma_address(sg);
1382                 while (sg_len) {
1383                         /* FIXME: This won't get us out of the pinch. */
1384                         if (unlikely(j >= ARRAY_SIZE(orb->page_table))) {
1385                                 fw_error("page table overflow\n");
1386                                 goto fail_page_table;
1387                         }
1388                         l = min(sg_len, SBP2_MAX_SG_ELEMENT_LENGTH);
1389                         orb->page_table[j].low = cpu_to_be32(sg_addr);
1390                         orb->page_table[j].high = cpu_to_be32(l << 16);
1391                         sg_addr += l;
1392                         sg_len -= l;
1393                         j++;
1394                 }
1395         }
1396
1397         orb->page_table_bus =
1398                 dma_map_single(device->card->device, orb->page_table,
1399                                sizeof(orb->page_table), DMA_TO_DEVICE);
1400         if (dma_mapping_error(orb->page_table_bus))
1401                 goto fail_page_table;
1402
1403         /*
1404          * The data_descriptor pointer is the one case where we need
1405          * to fill in the node ID part of the address.  All other
1406          * pointers assume that the data referenced reside on the
1407          * initiator (i.e. us), but data_descriptor can refer to data
1408          * on other nodes so we need to put our ID in descriptor.high.
1409          */
1410         orb->request.data_descriptor.high = cpu_to_be32(lu->tgt->address_high);
1411         orb->request.data_descriptor.low  = cpu_to_be32(orb->page_table_bus);
1412         orb->request.misc |= cpu_to_be32(COMMAND_ORB_PAGE_TABLE_PRESENT |
1413                                          COMMAND_ORB_DATA_SIZE(j));
1414
1415         return 0;
1416
1417  fail_page_table:
1418         dma_unmap_sg(device->card->device, sg, scsi_sg_count(orb->cmd),
1419                      orb->cmd->sc_data_direction);
1420  fail:
1421         return -ENOMEM;
1422 }
1423
1424 /* SCSI stack integration */
1425
1426 static int sbp2_scsi_queuecommand(struct scsi_cmnd *cmd, scsi_done_fn_t done)
1427 {
1428         struct sbp2_logical_unit *lu = cmd->device->hostdata;
1429         struct fw_device *device = fw_device(lu->tgt->unit->device.parent);
1430         struct sbp2_command_orb *orb;
1431         unsigned int max_payload;
1432         int retval = SCSI_MLQUEUE_HOST_BUSY;
1433
1434         /*
1435          * Bidirectional commands are not yet implemented, and unknown
1436          * transfer direction not handled.
1437          */
1438         if (cmd->sc_data_direction == DMA_BIDIRECTIONAL) {
1439                 fw_error("Can't handle DMA_BIDIRECTIONAL, rejecting command\n");
1440                 cmd->result = DID_ERROR << 16;
1441                 done(cmd);
1442                 return 0;
1443         }
1444
1445         orb = kzalloc(sizeof(*orb), GFP_ATOMIC);
1446         if (orb == NULL) {
1447                 fw_notify("failed to alloc orb\n");
1448                 return SCSI_MLQUEUE_HOST_BUSY;
1449         }
1450
1451         /* Initialize rcode to something not RCODE_COMPLETE. */
1452         orb->base.rcode = -1;
1453         kref_init(&orb->base.kref);
1454
1455         orb->lu   = lu;
1456         orb->done = done;
1457         orb->cmd  = cmd;
1458
1459         orb->request.next.high   = cpu_to_be32(SBP2_ORB_NULL);
1460         orb->request.next.low    = 0x0;
1461         /*
1462          * At speed 100 we can do 512 bytes per packet, at speed 200,
1463          * 1024 bytes per packet etc.  The SBP-2 max_payload field
1464          * specifies the max payload size as 2 ^ (max_payload + 2), so
1465          * if we set this to max_speed + 7, we get the right value.
1466          */
1467         max_payload = min(device->max_speed + 7,
1468                           device->card->max_receive - 1);
1469         orb->request.misc = cpu_to_be32(
1470                 COMMAND_ORB_MAX_PAYLOAD(max_payload) |
1471                 COMMAND_ORB_SPEED(device->max_speed) |
1472                 COMMAND_ORB_NOTIFY);
1473
1474         if (cmd->sc_data_direction == DMA_FROM_DEVICE)
1475                 orb->request.misc |= cpu_to_be32(
1476                         COMMAND_ORB_DIRECTION(SBP2_DIRECTION_FROM_MEDIA));
1477         else if (cmd->sc_data_direction == DMA_TO_DEVICE)
1478                 orb->request.misc |= cpu_to_be32(
1479                         COMMAND_ORB_DIRECTION(SBP2_DIRECTION_TO_MEDIA));
1480
1481         if (scsi_sg_count(cmd) && sbp2_map_scatterlist(orb, device, lu) < 0)
1482                 goto out;
1483
1484         memset(orb->request.command_block,
1485                0, sizeof(orb->request.command_block));
1486         memcpy(orb->request.command_block, cmd->cmnd, COMMAND_SIZE(*cmd->cmnd));
1487
1488         orb->base.callback = complete_command_orb;
1489         orb->base.request_bus =
1490                 dma_map_single(device->card->device, &orb->request,
1491                                sizeof(orb->request), DMA_TO_DEVICE);
1492         if (dma_mapping_error(orb->base.request_bus))
1493                 goto out;
1494
1495         sbp2_send_orb(&orb->base, lu, lu->tgt->node_id, lu->generation,
1496                       lu->command_block_agent_address + SBP2_ORB_POINTER);
1497         retval = 0;
1498  out:
1499         kref_put(&orb->base.kref, free_orb);
1500         return retval;
1501 }
1502
1503 static int sbp2_scsi_slave_alloc(struct scsi_device *sdev)
1504 {
1505         struct sbp2_logical_unit *lu = sdev->hostdata;
1506
1507         /* (Re-)Adding logical units via the SCSI stack is not supported. */
1508         if (!lu)
1509                 return -ENOSYS;
1510
1511         sdev->allow_restart = 1;
1512
1513         /* SBP-2 requires quadlet alignment of the data buffers. */
1514         blk_queue_update_dma_alignment(sdev->request_queue, 4 - 1);
1515
1516         if (lu->tgt->workarounds & SBP2_WORKAROUND_INQUIRY_36)
1517                 sdev->inquiry_len = 36;
1518
1519         return 0;
1520 }
1521
1522 static int sbp2_scsi_slave_configure(struct scsi_device *sdev)
1523 {
1524         struct sbp2_logical_unit *lu = sdev->hostdata;
1525
1526         sdev->use_10_for_rw = 1;
1527
1528         if (sdev->type == TYPE_ROM)
1529                 sdev->use_10_for_ms = 1;
1530
1531         if (sdev->type == TYPE_DISK &&
1532             lu->tgt->workarounds & SBP2_WORKAROUND_MODE_SENSE_8)
1533                 sdev->skip_ms_page_8 = 1;
1534
1535         if (lu->tgt->workarounds & SBP2_WORKAROUND_FIX_CAPACITY)
1536                 sdev->fix_capacity = 1;
1537
1538         if (lu->tgt->workarounds & SBP2_WORKAROUND_128K_MAX_TRANS)
1539                 blk_queue_max_sectors(sdev->request_queue, 128 * 1024 / 512);
1540
1541         return 0;
1542 }
1543
1544 /*
1545  * Called by scsi stack when something has really gone wrong.  Usually
1546  * called when a command has timed-out for some reason.
1547  */
1548 static int sbp2_scsi_abort(struct scsi_cmnd *cmd)
1549 {
1550         struct sbp2_logical_unit *lu = cmd->device->hostdata;
1551
1552         fw_notify("%s: sbp2_scsi_abort\n", lu->tgt->bus_id);
1553         sbp2_agent_reset(lu);
1554         sbp2_cancel_orbs(lu);
1555
1556         return SUCCESS;
1557 }
1558
1559 /*
1560  * Format of /sys/bus/scsi/devices/.../ieee1394_id:
1561  * u64 EUI-64 : u24 directory_ID : u16 LUN  (all printed in hexadecimal)
1562  *
1563  * This is the concatenation of target port identifier and logical unit
1564  * identifier as per SAM-2...SAM-4 annex A.
1565  */
1566 static ssize_t
1567 sbp2_sysfs_ieee1394_id_show(struct device *dev, struct device_attribute *attr,
1568                             char *buf)
1569 {
1570         struct scsi_device *sdev = to_scsi_device(dev);
1571         struct sbp2_logical_unit *lu;
1572         struct fw_device *device;
1573
1574         if (!sdev)
1575                 return 0;
1576
1577         lu = sdev->hostdata;
1578         device = fw_device(lu->tgt->unit->device.parent);
1579
1580         return sprintf(buf, "%08x%08x:%06x:%04x\n",
1581                         device->config_rom[3], device->config_rom[4],
1582                         lu->tgt->directory_id, lu->lun);
1583 }
1584
1585 static DEVICE_ATTR(ieee1394_id, S_IRUGO, sbp2_sysfs_ieee1394_id_show, NULL);
1586
1587 static struct device_attribute *sbp2_scsi_sysfs_attrs[] = {
1588         &dev_attr_ieee1394_id,
1589         NULL
1590 };
1591
1592 static struct scsi_host_template scsi_driver_template = {
1593         .module                 = THIS_MODULE,
1594         .name                   = "SBP-2 IEEE-1394",
1595         .proc_name              = sbp2_driver_name,
1596         .queuecommand           = sbp2_scsi_queuecommand,
1597         .slave_alloc            = sbp2_scsi_slave_alloc,
1598         .slave_configure        = sbp2_scsi_slave_configure,
1599         .eh_abort_handler       = sbp2_scsi_abort,
1600         .this_id                = -1,
1601         .sg_tablesize           = SG_ALL,
1602         .use_clustering         = ENABLE_CLUSTERING,
1603         .cmd_per_lun            = 1,
1604         .can_queue              = 1,
1605         .sdev_attrs             = sbp2_scsi_sysfs_attrs,
1606 };
1607
1608 MODULE_AUTHOR("Kristian Hoegsberg <krh@bitplanet.net>");
1609 MODULE_DESCRIPTION("SCSI over IEEE1394");
1610 MODULE_LICENSE("GPL");
1611 MODULE_DEVICE_TABLE(ieee1394, sbp2_id_table);
1612
1613 /* Provide a module alias so root-on-sbp2 initrds don't break. */
1614 #ifndef CONFIG_IEEE1394_SBP2_MODULE
1615 MODULE_ALIAS("sbp2");
1616 #endif
1617
1618 static int __init sbp2_init(void)
1619 {
1620         sbp2_wq = create_singlethread_workqueue(KBUILD_MODNAME);
1621         if (!sbp2_wq)
1622                 return -ENOMEM;
1623
1624         return driver_register(&sbp2_driver.driver);
1625 }
1626
1627 static void __exit sbp2_cleanup(void)
1628 {
1629         driver_unregister(&sbp2_driver.driver);
1630         destroy_workqueue(sbp2_wq);
1631 }
1632
1633 module_init(sbp2_init);
1634 module_exit(sbp2_cleanup);