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         u32 high;
 228         u32 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                 u32 misc;
 257                 u32 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 #define LOGIN_RESPONSE_GET_LOGIN_ID(v)  ((v).misc & 0xffff)
 267 #define LOGIN_RESPONSE_GET_LENGTH(v)    (((v).misc >> 16) & 0xffff)
 268
 269 struct sbp2_login_response {
 270         u32 misc;
 271         struct sbp2_pointer command_block_agent;
 272         u32 reconnect_hold;
 273 };
 274 #define COMMAND_ORB_DATA_SIZE(v)        ((v))
 275 #define COMMAND_ORB_PAGE_SIZE(v)        ((v) << 16)
 276 #define COMMAND_ORB_PAGE_TABLE_PRESENT  ((1) << 19)
 277 #define COMMAND_ORB_MAX_PAYLOAD(v)      ((v) << 20)
 278 #define COMMAND_ORB_SPEED(v)            ((v) << 24)
 279 #define COMMAND_ORB_DIRECTION(v)        ((v) << 27)
 280 #define COMMAND_ORB_REQUEST_FORMAT(v)   ((v) << 29)
 281 #define COMMAND_ORB_NOTIFY              ((1) << 31)
 282
 283 struct sbp2_command_orb {
 284         struct sbp2_orb base;
 285         struct {
 286                 struct sbp2_pointer next;
 287                 struct sbp2_pointer data_descriptor;
 288                 u32 misc;
 289                 u8 command_block[12];
 290         } request;
 291         struct scsi_cmnd *cmd;
 292         scsi_done_fn_t done;
 293         struct sbp2_logical_unit *lu;
 294
 295         struct sbp2_pointer page_table[SG_ALL] __attribute__((aligned(8)));
 296         dma_addr_t page_table_bus;
 297 };
 298
 299 /*
 300  * List of devices with known bugs.
 301  *
 302  * The firmware_revision field, masked with 0xffff00, is the best
 303  * indicator for the type of bridge chip of a device.  It yields a few
 304  * false positives but this did not break correctly behaving devices
 305  * so far.  We use ~0 as a wildcard, since the 24 bit values we get
 306  * from the config rom can never match that.
 307  */
 308 static const struct {
 309         u32 firmware_revision;
 310         u32 model;
 311         unsigned int workarounds;
 312 } sbp2_workarounds_table[] = {
 313         /* DViCO Momobay CX-1 with TSB42AA9 bridge */ {
 314                 .firmware_revision      = 0x002800,
 315                 .model                  = 0x001010,
 316                 .workarounds            = SBP2_WORKAROUND_INQUIRY_36 |
 317                                           SBP2_WORKAROUND_MODE_SENSE_8,
 318         },
 319         /* DViCO Momobay FX-3A with TSB42AA9A bridge */ {
 320                 .firmware_revision      = 0x002800,
 321                 .model                  = 0x000000,
 322                 .workarounds            = SBP2_WORKAROUND_DELAY_INQUIRY,
 323         },
 324         /* Initio bridges, actually only needed for some older ones */ {
 325                 .firmware_revision      = 0x000200,
 326                 .model                  = ~0,
 327                 .workarounds            = SBP2_WORKAROUND_INQUIRY_36,
 328         },
 329         /* Symbios bridge */ {
 330                 .firmware_revision      = 0xa0b800,
 331                 .model                  = ~0,
 332                 .workarounds            = SBP2_WORKAROUND_128K_MAX_TRANS,
 333         },
 334
 335         /*
 336          * There are iPods (2nd gen, 3rd gen) with model_id == 0, but
 337          * these iPods do not feature the read_capacity bug according
 338          * to one report.  Read_capacity behaviour as well as model_id
 339          * could change due to Apple-supplied firmware updates though.
 340          */
 341
 342         /* iPod 4th generation. */ {
 343                 .firmware_revision      = 0x0a2700,
 344                 .model                  = 0x000021,
 345                 .workarounds            = SBP2_WORKAROUND_FIX_CAPACITY,
 346         },
 347         /* iPod mini */ {
 348                 .firmware_revision      = 0x0a2700,
 349                 .model                  = 0x000023,
 350                 .workarounds            = SBP2_WORKAROUND_FIX_CAPACITY,
 351         },
 352         /* iPod Photo */ {
 353                 .firmware_revision      = 0x0a2700,
 354                 .model                  = 0x00007e,
 355                 .workarounds            = SBP2_WORKAROUND_FIX_CAPACITY,
 356         }
 357 };
 358
 359 static void
 360 free_orb(struct kref *kref)
 361 {
 362         struct sbp2_orb *orb = container_of(kref, struct sbp2_orb, kref);
 363
 364         kfree(orb);
 365 }
 366
 367 static void
 368 sbp2_status_write(struct fw_card *card, struct fw_request *request,
 369                   int tcode, int destination, int source,
 370                   int generation, int speed,
 371                   unsigned long long offset,
 372                   void *payload, size_t length, void *callback_data)
 373 {
 374         struct sbp2_logical_unit *lu = callback_data;
 375         struct sbp2_orb *orb;
 376         struct sbp2_status status;
 377         size_t header_size;
 378         unsigned long flags;
 379
 380         if (tcode != TCODE_WRITE_BLOCK_REQUEST ||
 381             length == 0 || length > sizeof(status)) {
 382                 fw_send_response(card, request, RCODE_TYPE_ERROR);
 383                 return;
 384         }
 385
 386         header_size = min(length, 2 * sizeof(u32));
 387         fw_memcpy_from_be32(&status, payload, header_size);
 388         if (length > header_size)
 389                 memcpy(status.data, payload + 8, length - header_size);
 390         if (STATUS_GET_SOURCE(status) == 2 || STATUS_GET_SOURCE(status) == 3) {
 391                 fw_notify("non-orb related status write, not handled\n");
 392                 fw_send_response(card, request, RCODE_COMPLETE);
 393                 return;
 394         }
 395
 396         /* Lookup the orb corresponding to this status write. */
 397         spin_lock_irqsave(&card->lock, flags);
 398         list_for_each_entry(orb, &lu->orb_list, link) {
 399                 if (STATUS_GET_ORB_HIGH(status) == 0 &&
 400                     STATUS_GET_ORB_LOW(status) == orb->request_bus) {
 401                         orb->rcode = RCODE_COMPLETE;
 402                         list_del(&orb->link);
 403                         break;
 404                 }
 405         }
 406         spin_unlock_irqrestore(&card->lock, flags);
 407
 408         if (&orb->link != &lu->orb_list)
 409                 orb->callback(orb, &status);
 410         else
 411                 fw_error("status write for unknown orb\n");
 412
 413         kref_put(&orb->kref, free_orb);
 414
 415         fw_send_response(card, request, RCODE_COMPLETE);
 416 }
 417
 418 static void
 419 complete_transaction(struct fw_card *card, int rcode,
 420                      void *payload, size_t length, void *data)
 421 {
 422         struct sbp2_orb *orb = data;
 423         unsigned long flags;
 424
 425         /*
 426          * This is a little tricky.  We can get the status write for
 427          * the orb before we get this callback.  The status write
 428          * handler above will assume the orb pointer transaction was
 429          * successful and set the rcode to RCODE_COMPLETE for the orb.
 430          * So this callback only sets the rcode if it hasn't already
 431          * been set and only does the cleanup if the transaction
 432          * failed and we didn't already get a status write.
 433          */
 434         spin_lock_irqsave(&card->lock, flags);
 435
 436         if (orb->rcode == -1)
 437                 orb->rcode = rcode;
 438         if (orb->rcode != RCODE_COMPLETE) {
 439                 list_del(&orb->link);
 440                 spin_unlock_irqrestore(&card->lock, flags);
 441                 orb->callback(orb, NULL);
 442         } else {
 443                 spin_unlock_irqrestore(&card->lock, flags);
 444         }
 445
 446         kref_put(&orb->kref, free_orb);
 447 }
 448
 449 static void
 450 sbp2_send_orb(struct sbp2_orb *orb, struct sbp2_logical_unit *lu,
 451               int node_id, int generation, u64 offset)
 452 {
 453         struct fw_device *device = fw_device(lu->tgt->unit->device.parent);
 454         unsigned long flags;
 455
 456         orb->pointer.high = 0;
 457         orb->pointer.low = orb->request_bus;
 458         fw_memcpy_to_be32(&orb->pointer, &orb->pointer, sizeof(orb->pointer));
 459
 460         spin_lock_irqsave(&device->card->lock, flags);
 461         list_add_tail(&orb->link, &lu->orb_list);
 462         spin_unlock_irqrestore(&device->card->lock, flags);
 463
 464         /* Take a ref for the orb list and for the transaction callback. */
 465         kref_get(&orb->kref);
 466         kref_get(&orb->kref);
 467
 468         fw_send_request(device->card, &orb->t, TCODE_WRITE_BLOCK_REQUEST,
 469                         node_id, generation, device->max_speed, offset,
 470                         &orb->pointer, sizeof(orb->pointer),
 471                         complete_transaction, orb);
 472 }
 473
 474 static int sbp2_cancel_orbs(struct sbp2_logical_unit *lu)
 475 {
 476         struct fw_device *device = fw_device(lu->tgt->unit->device.parent);
 477         struct sbp2_orb *orb, *next;
 478         struct list_head list;
 479         unsigned long flags;
 480         int retval = -ENOENT;
 481
 482         INIT_LIST_HEAD(&list);
 483         spin_lock_irqsave(&device->card->lock, flags);
 484         list_splice_init(&lu->orb_list, &list);
 485         spin_unlock_irqrestore(&device->card->lock, flags);
 486
 487         list_for_each_entry_safe(orb, next, &list, link) {
 488                 retval = 0;
 489                 if (fw_cancel_transaction(device->card, &orb->t) == 0)
 490                         continue;
 491
 492                 orb->rcode = RCODE_CANCELLED;
 493                 orb->callback(orb, NULL);
 494         }
 495
 496         return retval;
 497 }
 498
 499 static void
 500 complete_management_orb(struct sbp2_orb *base_orb, struct sbp2_status *status)
 501 {
 502         struct sbp2_management_orb *orb =
 503                 container_of(base_orb, struct sbp2_management_orb, base);
 504
 505         if (status)
 506                 memcpy(&orb->status, status, sizeof(*status));
 507         complete(&orb->done);
 508 }
 509
 510 static int
 511 sbp2_send_management_orb(struct sbp2_logical_unit *lu, int node_id,
 512                          int generation, int function, int lun_or_login_id,
 513                          void *response)
 514 {
 515         struct fw_device *device = fw_device(lu->tgt->unit->device.parent);
 516         struct sbp2_management_orb *orb;
 517         unsigned int timeout;
 518         int retval = -ENOMEM;
 519
 520         if (function == SBP2_LOGOUT_REQUEST && fw_device_is_shutdown(device))
 521                 return 0;
 522
 523         orb = kzalloc(sizeof(*orb), GFP_ATOMIC);
 524         if (orb == NULL)
 525                 return -ENOMEM;
 526
 527         kref_init(&orb->base.kref);
 528         orb->response_bus =
 529                 dma_map_single(device->card->device, &orb->response,
 530                                sizeof(orb->response), DMA_FROM_DEVICE);
 531         if (dma_mapping_error(orb->response_bus))
 532                 goto fail_mapping_response;
 533
 534         orb->request.response.high    = 0;
 535         orb->request.response.low     = orb->response_bus;
 536
 537         orb->request.misc =
 538                 MANAGEMENT_ORB_NOTIFY |
 539                 MANAGEMENT_ORB_FUNCTION(function) |
 540                 MANAGEMENT_ORB_LUN(lun_or_login_id);
 541         orb->request.length =
 542                 MANAGEMENT_ORB_RESPONSE_LENGTH(sizeof(orb->response));
 543
 544         orb->request.status_fifo.high = lu->address_handler.offset >> 32;
 545         orb->request.status_fifo.low  = lu->address_handler.offset;
 546
 547         if (function == SBP2_LOGIN_REQUEST) {
 548                 /* Ask for 2^2 == 4 seconds reconnect grace period */
 549                 orb->request.misc |=
 550                         MANAGEMENT_ORB_RECONNECT(2) |
 551                         MANAGEMENT_ORB_EXCLUSIVE(sbp2_param_exclusive_login);
 552                 timeout = lu->tgt->mgt_orb_timeout;
 553         } else {
 554                 timeout = SBP2_ORB_TIMEOUT;
 555         }
 556
 557         fw_memcpy_to_be32(&orb->request, &orb->request, sizeof(orb->request));
 558
 559         init_completion(&orb->done);
 560         orb->base.callback = complete_management_orb;
 561
 562         orb->base.request_bus =
 563                 dma_map_single(device->card->device, &orb->request,
 564                                sizeof(orb->request), DMA_TO_DEVICE);
 565         if (dma_mapping_error(orb->base.request_bus))
 566                 goto fail_mapping_request;
 567
 568         sbp2_send_orb(&orb->base, lu, node_id, generation,
 569                       lu->tgt->management_agent_address);
 570
 571         wait_for_completion_timeout(&orb->done, msecs_to_jiffies(timeout));
 572
 573         retval = -EIO;
 574         if (sbp2_cancel_orbs(lu) == 0) {
 575                 fw_error("%s: orb reply timed out, rcode=0x%02x\n",
 576                          lu->tgt->bus_id, orb->base.rcode);
 577                 goto out;
 578         }
 579
 580         if (orb->base.rcode != RCODE_COMPLETE) {
 581                 fw_error("%s: management write failed, rcode 0x%02x\n",
 582                          lu->tgt->bus_id, orb->base.rcode);
 583                 goto out;
 584         }
 585
 586         if (STATUS_GET_RESPONSE(orb->status) != 0 ||
 587             STATUS_GET_SBP_STATUS(orb->status) != 0) {
 588                 fw_error("%s: error status: %d:%d\n", lu->tgt->bus_id,
 589                          STATUS_GET_RESPONSE(orb->status),
 590                          STATUS_GET_SBP_STATUS(orb->status));
 591                 goto out;
 592         }
 593
 594         retval = 0;
 595  out:
 596         dma_unmap_single(device->card->device, orb->base.request_bus,
 597                          sizeof(orb->request), DMA_TO_DEVICE);
 598  fail_mapping_request:
 599         dma_unmap_single(device->card->device, orb->response_bus,
 600                          sizeof(orb->response), DMA_FROM_DEVICE);
 601  fail_mapping_response:
 602         if (response)
 603                 fw_memcpy_from_be32(response,
 604                                     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         put_device(&tgt->unit->device);
 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         /* Get command block agent offset and login id. */
 884         lu->command_block_agent_address =
 885                 ((u64) (response.command_block_agent.high & 0xffff) << 32) |
 886                 response.command_block_agent.low;
 887         lu->login_id = LOGIN_RESPONSE_GET_LOGIN_ID(response);
 888
 889         fw_notify("%s: logged in to LUN %04x (%d retries)\n",
 890                   tgt->bus_id, lu->lun, lu->retries);
 891
 892         /* set appropriate retry limit(s) in BUSY_TIMEOUT register */
 893         sbp2_set_busy_timeout(lu);
 894
 895         PREPARE_DELAYED_WORK(&lu->work, sbp2_reconnect);
 896         sbp2_agent_reset(lu);
 897
 898         /* This was a re-login. */
 899         if (lu->has_sdev) {
 900                 sbp2_cancel_orbs(lu);
 901                 sbp2_conditionally_unblock(lu);
 902                 goto out;
 903         }
 904
 905         if (lu->tgt->workarounds & SBP2_WORKAROUND_DELAY_INQUIRY)
 906                 ssleep(SBP2_INQUIRY_DELAY);
 907
 908         shost = container_of((void *)tgt, struct Scsi_Host, hostdata[0]);
 909         sdev = __scsi_add_device(shost, 0, 0, sbp2_lun2int(lu->lun), lu);
 910         /*
 911          * FIXME:  We are unable to perform reconnects while in sbp2_login().
 912          * Therefore __scsi_add_device() will get into trouble if a bus reset
 913          * happens in parallel.  It will either fail or leave us with an
 914          * unusable sdev.  As a workaround we check for this and retry the
 915          * whole login and SCSI probing.
 916          */
 917
 918         /* Reported error during __scsi_add_device() */
 919         if (IS_ERR(sdev))
 920                 goto out_logout_login;
 921
 922         /* Unreported error during __scsi_add_device() */
 923         smp_rmb(); /* get current card generation */
 924         if (generation != device->card->generation) {
 925                 scsi_remove_device(sdev);
 926                 scsi_device_put(sdev);
 927                 goto out_logout_login;
 928         }
 929
 930         /* No error during __scsi_add_device() */
 931         lu->has_sdev = true;
 932         scsi_device_put(sdev);
 933         sbp2_allow_block(lu);
 934         goto out;
 935
 936  out_logout_login:
 937         smp_rmb(); /* generation may have changed */
 938         generation = device->generation;
 939         smp_rmb(); /* node_id must not be older than generation */
 940
 941         sbp2_send_management_orb(lu, device->node_id, generation,
 942                                  SBP2_LOGOUT_REQUEST, lu->login_id, NULL);
 943         /*
 944          * If a bus reset happened, sbp2_update will have requeued
 945          * lu->work already.  Reset the work from reconnect to login.
 946          */
 947         PREPARE_DELAYED_WORK(&lu->work, sbp2_login);
 948  out:
 949         sbp2_target_put(tgt);
 950 }
 951
 952 static int sbp2_add_logical_unit(struct sbp2_target *tgt, int lun_entry)
 953 {
 954         struct sbp2_logical_unit *lu;
 955
 956         lu = kmalloc(sizeof(*lu), GFP_KERNEL);
 957         if (!lu)
 958                 return -ENOMEM;
 959
 960         lu->address_handler.length           = 0x100;
 961         lu->address_handler.address_callback = sbp2_status_write;
 962         lu->address_handler.callback_data    = lu;
 963
 964         if (fw_core_add_address_handler(&lu->address_handler,
 965                                         &fw_high_memory_region) < 0) {
 966                 kfree(lu);
 967                 return -ENOMEM;
 968         }
 969
 970         lu->tgt      = tgt;
 971         lu->lun      = lun_entry & 0xffff;
 972         lu->retries  = 0;
 973         lu->has_sdev = false;
 974         lu->blocked  = false;
 975         ++tgt->dont_block;
 976         INIT_LIST_HEAD(&lu->orb_list);
 977         INIT_DELAYED_WORK(&lu->work, sbp2_login);
 978
 979         list_add_tail(&lu->link, &tgt->lu_list);
 980         return 0;
 981 }
 982
 983 static int sbp2_scan_logical_unit_dir(struct sbp2_target *tgt, u32 *directory)
 984 {
 985         struct fw_csr_iterator ci;
 986         int key, value;
 987
 988         fw_csr_iterator_init(&ci, directory);
 989         while (fw_csr_iterator_next(&ci, &key, &value))
 990                 if (key == SBP2_CSR_LOGICAL_UNIT_NUMBER &&
 991                     sbp2_add_logical_unit(tgt, value) < 0)
 992                         return -ENOMEM;
 993         return 0;
 994 }
 995
 996 static int sbp2_scan_unit_dir(struct sbp2_target *tgt, u32 *directory,
 997                               u32 *model, u32 *firmware_revision)
 998 {
 999         struct fw_csr_iterator ci;
1000         int key, value;
1001         unsigned int timeout;
1002
1003         fw_csr_iterator_init(&ci, directory);
1004         while (fw_csr_iterator_next(&ci, &key, &value)) {
1005                 switch (key) {
1006
1007                 case CSR_DEPENDENT_INFO | CSR_OFFSET:
1008                         tgt->management_agent_address =
1009                                         CSR_REGISTER_BASE + 4 * value;
1010                         break;
1011
1012                 case CSR_DIRECTORY_ID:
1013                         tgt->directory_id = value;
1014                         break;
1015
1016                 case CSR_MODEL:
1017                         *model = value;
1018                         break;
1019
1020                 case SBP2_CSR_FIRMWARE_REVISION:
1021                         *firmware_revision = value;
1022                         break;
1023
1024                 case SBP2_CSR_UNIT_CHARACTERISTICS:
1025                         /* the timeout value is stored in 500ms units */
1026                         timeout = ((unsigned int) value >> 8 & 0xff) * 500;
1027                         timeout = max(timeout, SBP2_MIN_LOGIN_ORB_TIMEOUT);
1028                         tgt->mgt_orb_timeout =
1029                                   min(timeout, SBP2_MAX_LOGIN_ORB_TIMEOUT);
1030
1031                         if (timeout > tgt->mgt_orb_timeout)
1032                                 fw_notify("%s: config rom contains %ds "
1033                                           "management ORB timeout, limiting "
1034                                           "to %ds\n", tgt->bus_id,
1035                                           timeout / 1000,
1036                                           tgt->mgt_orb_timeout / 1000);
1037                         break;
1038
1039                 case SBP2_CSR_LOGICAL_UNIT_NUMBER:
1040                         if (sbp2_add_logical_unit(tgt, value) < 0)
1041                                 return -ENOMEM;
1042                         break;
1043
1044                 case SBP2_CSR_LOGICAL_UNIT_DIRECTORY:
1045                         if (sbp2_scan_logical_unit_dir(tgt, ci.p + value) < 0)
1046                                 return -ENOMEM;
1047                         break;
1048                 }
1049         }
1050         return 0;
1051 }
1052
1053 static void sbp2_init_workarounds(struct sbp2_target *tgt, u32 model,
1054                                   u32 firmware_revision)
1055 {
1056         int i;
1057         unsigned int w = sbp2_param_workarounds;
1058
1059         if (w)
1060                 fw_notify("Please notify linux1394-devel@lists.sourceforge.net "
1061                           "if you need the workarounds parameter for %s\n",
1062                           tgt->bus_id);
1063
1064         if (w & SBP2_WORKAROUND_OVERRIDE)
1065                 goto out;
1066
1067         for (i = 0; i < ARRAY_SIZE(sbp2_workarounds_table); i++) {
1068
1069                 if (sbp2_workarounds_table[i].firmware_revision !=
1070                     (firmware_revision & 0xffffff00))
1071                         continue;
1072
1073                 if (sbp2_workarounds_table[i].model != model &&
1074                     sbp2_workarounds_table[i].model != ~0)
1075                         continue;
1076
1077                 w |= sbp2_workarounds_table[i].workarounds;
1078                 break;
1079         }
1080  out:
1081         if (w)
1082                 fw_notify("Workarounds for %s: 0x%x "
1083                           "(firmware_revision 0x%06x, model_id 0x%06x)\n",
1084                           tgt->bus_id, w, firmware_revision, model);
1085         tgt->workarounds = w;
1086 }
1087
1088 static struct scsi_host_template scsi_driver_template;
1089
1090 static int sbp2_probe(struct device *dev)
1091 {
1092         struct fw_unit *unit = fw_unit(dev);
1093         struct fw_device *device = fw_device(unit->device.parent);
1094         struct sbp2_target *tgt;
1095         struct sbp2_logical_unit *lu;
1096         struct Scsi_Host *shost;
1097         u32 model, firmware_revision;
1098
1099         shost = scsi_host_alloc(&scsi_driver_template, sizeof(*tgt));
1100         if (shost == NULL)
1101                 return -ENOMEM;
1102
1103         tgt = (struct sbp2_target *)shost->hostdata;
1104         unit->device.driver_data = tgt;
1105         tgt->unit = unit;
1106         kref_init(&tgt->kref);
1107         INIT_LIST_HEAD(&tgt->lu_list);
1108         tgt->bus_id = unit->device.bus_id;
1109
1110         if (fw_device_enable_phys_dma(device) < 0)
1111                 goto fail_shost_put;
1112
1113         if (scsi_add_host(shost, &unit->device) < 0)
1114                 goto fail_shost_put;
1115
1116         fw_device_get(device);
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         get_device(&unit->device);
1133
1134         /* Do the login in a workqueue so we can easily reschedule retries. */
1135         list_for_each_entry(lu, &tgt->lu_list, link)
1136                 sbp2_queue_work(lu, 0);
1137         return 0;
1138
1139  fail_tgt_put:
1140         sbp2_target_put(tgt);
1141         return -ENOMEM;
1142
1143  fail_shost_put:
1144         scsi_host_put(shost);
1145         return -ENOMEM;
1146 }
1147
1148 static int sbp2_remove(struct device *dev)
1149 {
1150         struct fw_unit *unit = fw_unit(dev);
1151         struct sbp2_target *tgt = unit->device.driver_data;
1152
1153         sbp2_target_put(tgt);
1154         return 0;
1155 }
1156
1157 static void sbp2_reconnect(struct work_struct *work)
1158 {
1159         struct sbp2_logical_unit *lu =
1160                 container_of(work, struct sbp2_logical_unit, work.work);
1161         struct sbp2_target *tgt = lu->tgt;
1162         struct fw_device *device = fw_device(tgt->unit->device.parent);
1163         int generation, node_id, local_node_id;
1164
1165         if (fw_device_is_shutdown(device))
1166                 goto out;
1167
1168         generation    = device->generation;
1169         smp_rmb();    /* node_id must not be older than generation */
1170         node_id       = device->node_id;
1171         local_node_id = device->card->node_id;
1172
1173         if (sbp2_send_management_orb(lu, node_id, generation,
1174                                      SBP2_RECONNECT_REQUEST,
1175                                      lu->login_id, NULL) < 0) {
1176                 /*
1177                  * If reconnect was impossible even though we are in the
1178                  * current generation, fall back and try to log in again.
1179                  *
1180                  * We could check for "Function rejected" status, but
1181                  * looking at the bus generation as simpler and more general.
1182                  */
1183                 smp_rmb(); /* get current card generation */
1184                 if (generation == device->card->generation ||
1185                     lu->retries++ >= 5) {
1186                         fw_error("%s: failed to reconnect\n", tgt->bus_id);
1187                         lu->retries = 0;
1188                         PREPARE_DELAYED_WORK(&lu->work, sbp2_login);
1189                 }
1190                 sbp2_queue_work(lu, DIV_ROUND_UP(HZ, 5));
1191                 goto out;
1192         }
1193
1194         tgt->node_id      = node_id;
1195         tgt->address_high = local_node_id << 16;
1196         sbp2_set_generation(lu, generation);
1197
1198         fw_notify("%s: reconnected to LUN %04x (%d retries)\n",
1199                   tgt->bus_id, lu->lun, lu->retries);
1200
1201         sbp2_agent_reset(lu);
1202         sbp2_cancel_orbs(lu);
1203         sbp2_conditionally_unblock(lu);
1204  out:
1205         sbp2_target_put(tgt);
1206 }
1207
1208 static void sbp2_update(struct fw_unit *unit)
1209 {
1210         struct sbp2_target *tgt = unit->device.driver_data;
1211         struct sbp2_logical_unit *lu;
1212
1213         fw_device_enable_phys_dma(fw_device(unit->device.parent));
1214
1215         /*
1216          * Fw-core serializes sbp2_update() against sbp2_remove().
1217          * Iteration over tgt->lu_list is therefore safe here.
1218          */
1219         list_for_each_entry(lu, &tgt->lu_list, link) {
1220                 sbp2_conditionally_block(lu);
1221                 lu->retries = 0;
1222                 sbp2_queue_work(lu, 0);
1223         }
1224 }
1225
1226 #define SBP2_UNIT_SPEC_ID_ENTRY 0x0000609e
1227 #define SBP2_SW_VERSION_ENTRY   0x00010483
1228
1229 static const struct fw_device_id sbp2_id_table[] = {
1230         {
1231                 .match_flags  = FW_MATCH_SPECIFIER_ID | FW_MATCH_VERSION,
1232                 .specifier_id = SBP2_UNIT_SPEC_ID_ENTRY,
1233                 .version      = SBP2_SW_VERSION_ENTRY,
1234         },
1235         { }
1236 };
1237
1238 static struct fw_driver sbp2_driver = {
1239         .driver   = {
1240                 .owner  = THIS_MODULE,
1241                 .name   = sbp2_driver_name,
1242                 .bus    = &fw_bus_type,
1243                 .probe  = sbp2_probe,
1244                 .remove = sbp2_remove,
1245         },
1246         .update   = sbp2_update,
1247         .id_table = sbp2_id_table,
1248 };
1249
1250 static unsigned int
1251 sbp2_status_to_sense_data(u8 *sbp2_status, u8 *sense_data)
1252 {
1253         int sam_status;
1254
1255         sense_data[0] = 0x70;
1256         sense_data[1] = 0x0;
1257         sense_data[2] = sbp2_status[1];
1258         sense_data[3] = sbp2_status[4];
1259         sense_data[4] = sbp2_status[5];
1260         sense_data[5] = sbp2_status[6];
1261         sense_data[6] = sbp2_status[7];
1262         sense_data[7] = 10;
1263         sense_data[8] = sbp2_status[8];
1264         sense_data[9] = sbp2_status[9];
1265         sense_data[10] = sbp2_status[10];
1266         sense_data[11] = sbp2_status[11];
1267         sense_data[12] = sbp2_status[2];
1268         sense_data[13] = sbp2_status[3];
1269         sense_data[14] = sbp2_status[12];
1270         sense_data[15] = sbp2_status[13];
1271
1272         sam_status = sbp2_status[0] & 0x3f;
1273
1274         switch (sam_status) {
1275         case SAM_STAT_GOOD:
1276         case SAM_STAT_CHECK_CONDITION:
1277         case SAM_STAT_CONDITION_MET:
1278         case SAM_STAT_BUSY:
1279         case SAM_STAT_RESERVATION_CONFLICT:
1280         case SAM_STAT_COMMAND_TERMINATED:
1281                 return DID_OK << 16 | sam_status;
1282
1283         default:
1284                 return DID_ERROR << 16;
1285         }
1286 }
1287
1288 static void
1289 complete_command_orb(struct sbp2_orb *base_orb, struct sbp2_status *status)
1290 {
1291         struct sbp2_command_orb *orb =
1292                 container_of(base_orb, struct sbp2_command_orb, base);
1293         struct fw_device *device = fw_device(orb->lu->tgt->unit->device.parent);
1294         int result;
1295
1296         if (status != NULL) {
1297                 if (STATUS_GET_DEAD(*status))
1298                         sbp2_agent_reset_no_wait(orb->lu);
1299
1300                 switch (STATUS_GET_RESPONSE(*status)) {
1301                 case SBP2_STATUS_REQUEST_COMPLETE:
1302                         result = DID_OK << 16;
1303                         break;
1304                 case SBP2_STATUS_TRANSPORT_FAILURE:
1305                         result = DID_BUS_BUSY << 16;
1306                         break;
1307                 case SBP2_STATUS_ILLEGAL_REQUEST:
1308                 case SBP2_STATUS_VENDOR_DEPENDENT:
1309                 default:
1310                         result = DID_ERROR << 16;
1311                         break;
1312                 }
1313
1314                 if (result == DID_OK << 16 && STATUS_GET_LEN(*status) > 1)
1315                         result = sbp2_status_to_sense_data(STATUS_GET_DATA(*status),
1316                                                            orb->cmd->sense_buffer);
1317         } else {
1318                 /*
1319                  * If the orb completes with status == NULL, something
1320                  * went wrong, typically a bus reset happened mid-orb
1321                  * or when sending the write (less likely).
1322                  */
1323                 result = DID_BUS_BUSY << 16;
1324                 sbp2_conditionally_block(orb->lu);
1325         }
1326
1327         dma_unmap_single(device->card->device, orb->base.request_bus,
1328                          sizeof(orb->request), DMA_TO_DEVICE);
1329
1330         if (scsi_sg_count(orb->cmd) > 0)
1331                 dma_unmap_sg(device->card->device, scsi_sglist(orb->cmd),
1332                              scsi_sg_count(orb->cmd),
1333                              orb->cmd->sc_data_direction);
1334
1335         if (orb->page_table_bus != 0)
1336                 dma_unmap_single(device->card->device, orb->page_table_bus,
1337                                  sizeof(orb->page_table), DMA_TO_DEVICE);
1338
1339         orb->cmd->result = result;
1340         orb->done(orb->cmd);
1341 }
1342
1343 static int
1344 sbp2_map_scatterlist(struct sbp2_command_orb *orb, struct fw_device *device,
1345                      struct sbp2_logical_unit *lu)
1346 {
1347         struct scatterlist *sg;
1348         int sg_len, l, i, j, count;
1349         dma_addr_t sg_addr;
1350
1351         sg = scsi_sglist(orb->cmd);
1352         count = dma_map_sg(device->card->device, sg, scsi_sg_count(orb->cmd),
1353                            orb->cmd->sc_data_direction);
1354         if (count == 0)
1355                 goto fail;
1356
1357         /*
1358          * Handle the special case where there is only one element in
1359          * the scatter list by converting it to an immediate block
1360          * request. This is also a workaround for broken devices such
1361          * as the second generation iPod which doesn't support page
1362          * tables.
1363          */
1364         if (count == 1 && sg_dma_len(sg) < SBP2_MAX_SG_ELEMENT_LENGTH) {
1365                 orb->request.data_descriptor.high = lu->tgt->address_high;
1366                 orb->request.data_descriptor.low  = sg_dma_address(sg);
1367                 orb->request.misc |= COMMAND_ORB_DATA_SIZE(sg_dma_len(sg));
1368                 return 0;
1369         }
1370
1371         /*
1372          * Convert the scatterlist to an sbp2 page table.  If any
1373          * scatterlist entries are too big for sbp2, we split them as we
1374          * go.  Even if we ask the block I/O layer to not give us sg
1375          * elements larger than 65535 bytes, some IOMMUs may merge sg elements
1376          * during DMA mapping, and Linux currently doesn't prevent this.
1377          */
1378         for (i = 0, j = 0; i < count; i++, sg = sg_next(sg)) {
1379                 sg_len = sg_dma_len(sg);
1380                 sg_addr = sg_dma_address(sg);
1381                 while (sg_len) {
1382                         /* FIXME: This won't get us out of the pinch. */
1383                         if (unlikely(j >= ARRAY_SIZE(orb->page_table))) {
1384                                 fw_error("page table overflow\n");
1385                                 goto fail_page_table;
1386                         }
1387                         l = min(sg_len, SBP2_MAX_SG_ELEMENT_LENGTH);
1388                         orb->page_table[j].low = sg_addr;
1389                         orb->page_table[j].high = (l << 16);
1390                         sg_addr += l;
1391                         sg_len -= l;
1392                         j++;
1393                 }
1394         }
1395
1396         fw_memcpy_to_be32(orb->page_table, orb->page_table,
1397                           sizeof(orb->page_table[0]) * j);
1398         orb->page_table_bus =
1399                 dma_map_single(device->card->device, orb->page_table,
1400                                sizeof(orb->page_table), DMA_TO_DEVICE);
1401         if (dma_mapping_error(orb->page_table_bus))
1402                 goto fail_page_table;
1403
1404         /*
1405          * The data_descriptor pointer is the one case where we need
1406          * to fill in the node ID part of the address.  All other
1407          * pointers assume that the data referenced reside on the
1408          * initiator (i.e. us), but data_descriptor can refer to data
1409          * on other nodes so we need to put our ID in descriptor.high.
1410          */
1411         orb->request.data_descriptor.high = lu->tgt->address_high;
1412         orb->request.data_descriptor.low  = orb->page_table_bus;
1413         orb->request.misc |=
1414                 COMMAND_ORB_PAGE_TABLE_PRESENT |
1415                 COMMAND_ORB_DATA_SIZE(j);
1416
1417         return 0;
1418
1419  fail_page_table:
1420         dma_unmap_sg(device->card->device, sg, scsi_sg_count(orb->cmd),
1421                      orb->cmd->sc_data_direction);
1422  fail:
1423         return -ENOMEM;
1424 }
1425
1426 /* SCSI stack integration */
1427
1428 static int sbp2_scsi_queuecommand(struct scsi_cmnd *cmd, scsi_done_fn_t done)
1429 {
1430         struct sbp2_logical_unit *lu = cmd->device->hostdata;
1431         struct fw_device *device = fw_device(lu->tgt->unit->device.parent);
1432         struct sbp2_command_orb *orb;
1433         unsigned int max_payload;
1434         int retval = SCSI_MLQUEUE_HOST_BUSY;
1435
1436         /*
1437          * Bidirectional commands are not yet implemented, and unknown
1438          * transfer direction not handled.
1439          */
1440         if (cmd->sc_data_direction == DMA_BIDIRECTIONAL) {
1441                 fw_error("Can't handle DMA_BIDIRECTIONAL, rejecting command\n");
1442                 cmd->result = DID_ERROR << 16;
1443                 done(cmd);
1444                 return 0;
1445         }
1446
1447         orb = kzalloc(sizeof(*orb), GFP_ATOMIC);
1448         if (orb == NULL) {
1449                 fw_notify("failed to alloc orb\n");
1450                 return SCSI_MLQUEUE_HOST_BUSY;
1451         }
1452
1453         /* Initialize rcode to something not RCODE_COMPLETE. */
1454         orb->base.rcode = -1;
1455         kref_init(&orb->base.kref);
1456
1457         orb->lu   = lu;
1458         orb->done = done;
1459         orb->cmd  = cmd;
1460
1461         orb->request.next.high   = SBP2_ORB_NULL;
1462         orb->request.next.low    = 0x0;
1463         /*
1464          * At speed 100 we can do 512 bytes per packet, at speed 200,
1465          * 1024 bytes per packet etc.  The SBP-2 max_payload field
1466          * specifies the max payload size as 2 ^ (max_payload + 2), so
1467          * if we set this to max_speed + 7, we get the right value.
1468          */
1469         max_payload = min(device->max_speed + 7,
1470                           device->card->max_receive - 1);
1471         orb->request.misc =
1472                 COMMAND_ORB_MAX_PAYLOAD(max_payload) |
1473                 COMMAND_ORB_SPEED(device->max_speed) |
1474                 COMMAND_ORB_NOTIFY;
1475
1476         if (cmd->sc_data_direction == DMA_FROM_DEVICE)
1477                 orb->request.misc |=
1478                         COMMAND_ORB_DIRECTION(SBP2_DIRECTION_FROM_MEDIA);
1479         else if (cmd->sc_data_direction == DMA_TO_DEVICE)
1480                 orb->request.misc |=
1481                         COMMAND_ORB_DIRECTION(SBP2_DIRECTION_TO_MEDIA);
1482
1483         if (scsi_sg_count(cmd) && sbp2_map_scatterlist(orb, device, lu) < 0)
1484                 goto out;
1485
1486         fw_memcpy_to_be32(&orb->request, &orb->request, sizeof(orb->request));
1487
1488         memset(orb->request.command_block,
1489                0, sizeof(orb->request.command_block));
1490         memcpy(orb->request.command_block, cmd->cmnd, COMMAND_SIZE(*cmd->cmnd));
1491
1492         orb->base.callback = complete_command_orb;
1493         orb->base.request_bus =
1494                 dma_map_single(device->card->device, &orb->request,
1495                                sizeof(orb->request), DMA_TO_DEVICE);
1496         if (dma_mapping_error(orb->base.request_bus))
1497                 goto out;
1498
1499         sbp2_send_orb(&orb->base, lu, lu->tgt->node_id, lu->generation,
1500                       lu->command_block_agent_address + SBP2_ORB_POINTER);
1501         retval = 0;
1502  out:
1503         kref_put(&orb->base.kref, free_orb);
1504         return retval;
1505 }
1506
1507 static int sbp2_scsi_slave_alloc(struct scsi_device *sdev)
1508 {
1509         struct sbp2_logical_unit *lu = sdev->hostdata;
1510
1511         /* (Re-)Adding logical units via the SCSI stack is not supported. */
1512         if (!lu)
1513                 return -ENOSYS;
1514
1515         sdev->allow_restart = 1;
1516
1517         /*
1518          * Update the dma alignment (minimum alignment requirements for
1519          * start and end of DMA transfers) to be a sector
1520          */
1521         blk_queue_update_dma_alignment(sdev->request_queue, 511);
1522
1523         if (lu->tgt->workarounds & SBP2_WORKAROUND_INQUIRY_36)
1524                 sdev->inquiry_len = 36;
1525
1526         return 0;
1527 }
1528
1529 static int sbp2_scsi_slave_configure(struct scsi_device *sdev)
1530 {
1531         struct sbp2_logical_unit *lu = sdev->hostdata;
1532
1533         sdev->use_10_for_rw = 1;
1534
1535         if (sdev->type == TYPE_ROM)
1536                 sdev->use_10_for_ms = 1;
1537
1538         if (sdev->type == TYPE_DISK &&
1539             lu->tgt->workarounds & SBP2_WORKAROUND_MODE_SENSE_8)
1540                 sdev->skip_ms_page_8 = 1;
1541
1542         if (lu->tgt->workarounds & SBP2_WORKAROUND_FIX_CAPACITY)
1543                 sdev->fix_capacity = 1;
1544
1545         if (lu->tgt->workarounds & SBP2_WORKAROUND_128K_MAX_TRANS)
1546                 blk_queue_max_sectors(sdev->request_queue, 128 * 1024 / 512);
1547
1548         return 0;
1549 }
1550
1551 /*
1552  * Called by scsi stack when something has really gone wrong.  Usually
1553  * called when a command has timed-out for some reason.
1554  */
1555 static int sbp2_scsi_abort(struct scsi_cmnd *cmd)
1556 {
1557         struct sbp2_logical_unit *lu = cmd->device->hostdata;
1558
1559         fw_notify("%s: sbp2_scsi_abort\n", lu->tgt->bus_id);
1560         sbp2_agent_reset(lu);
1561         sbp2_cancel_orbs(lu);
1562
1563         return SUCCESS;
1564 }
1565
1566 /*
1567  * Format of /sys/bus/scsi/devices/.../ieee1394_id:
1568  * u64 EUI-64 : u24 directory_ID : u16 LUN  (all printed in hexadecimal)
1569  *
1570  * This is the concatenation of target port identifier and logical unit
1571  * identifier as per SAM-2...SAM-4 annex A.
1572  */
1573 static ssize_t
1574 sbp2_sysfs_ieee1394_id_show(struct device *dev, struct device_attribute *attr,
1575                             char *buf)
1576 {
1577         struct scsi_device *sdev = to_scsi_device(dev);
1578         struct sbp2_logical_unit *lu;
1579         struct fw_device *device;
1580
1581         if (!sdev)
1582                 return 0;
1583
1584         lu = sdev->hostdata;
1585         device = fw_device(lu->tgt->unit->device.parent);
1586
1587         return sprintf(buf, "%08x%08x:%06x:%04x\n",
1588                         device->config_rom[3], device->config_rom[4],
1589                         lu->tgt->directory_id, lu->lun);
1590 }
1591
1592 static DEVICE_ATTR(ieee1394_id, S_IRUGO, sbp2_sysfs_ieee1394_id_show, NULL);
1593
1594 static struct device_attribute *sbp2_scsi_sysfs_attrs[] = {
1595         &dev_attr_ieee1394_id,
1596         NULL
1597 };
1598
1599 static struct scsi_host_template scsi_driver_template = {
1600         .module                 = THIS_MODULE,
1601         .name                   = "SBP-2 IEEE-1394",
1602         .proc_name              = sbp2_driver_name,
1603         .queuecommand           = sbp2_scsi_queuecommand,
1604         .slave_alloc            = sbp2_scsi_slave_alloc,
1605         .slave_configure        = sbp2_scsi_slave_configure,
1606         .eh_abort_handler       = sbp2_scsi_abort,
1607         .this_id                = -1,
1608         .sg_tablesize           = SG_ALL,
1609         .use_clustering         = ENABLE_CLUSTERING,
1610         .cmd_per_lun            = 1,
1611         .can_queue              = 1,
1612         .sdev_attrs             = sbp2_scsi_sysfs_attrs,
1613 };
1614
1615 MODULE_AUTHOR("Kristian Hoegsberg <krh@bitplanet.net>");
1616 MODULE_DESCRIPTION("SCSI over IEEE1394");
1617 MODULE_LICENSE("GPL");
1618 MODULE_DEVICE_TABLE(ieee1394, sbp2_id_table);
1619
1620 /* Provide a module alias so root-on-sbp2 initrds don't break. */
1621 #ifndef CONFIG_IEEE1394_SBP2_MODULE
1622 MODULE_ALIAS("sbp2");
1623 #endif
1624
1625 static int __init sbp2_init(void)
1626 {
1627         sbp2_wq = create_singlethread_workqueue(KBUILD_MODNAME);
1628         if (!sbp2_wq)
1629                 return -ENOMEM;
1630
1631         return driver_register(&sbp2_driver.driver);
1632 }
1633
1634 static void __exit sbp2_cleanup(void)
1635 {
1636         driver_unregister(&sbp2_driver.driver);
1637         destroy_workqueue(sbp2_wq);
1638 }
1639
1640 module_init(sbp2_init);
1641 module_exit(sbp2_cleanup);