linux/drivers/firewire/sbp2.c
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   1/*
   2 * SBP2 driver (SCSI over IEEE1394)
   3 *
   4 * Copyright (C) 2005-2007  Kristian Hoegsberg <krh@bitplanet.net>
   5 *
   6 * This program is free software; you can redistribute it and/or modify
   7 * it under the terms of the GNU General Public License as published by
   8 * the Free Software Foundation; either version 2 of the License, or
   9 * (at your option) any later version.
  10 *
  11 * This program is distributed in the hope that it will be useful,
  12 * but WITHOUT ANY WARRANTY; without even the implied warranty of
  13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14 * GNU General Public License for more details.
  15 *
  16 * You should have received a copy of the GNU General Public License
  17 * along with this program; if not, write to the Free Software Foundation,
  18 * Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
  19 */
  20
  21/*
  22 * The basic structure of this driver is based on the old storage driver,
  23 * drivers/ieee1394/sbp2.c, originally written by
  24 *     James Goodwin <jamesg@filanet.com>
  25 * with later contributions and ongoing maintenance from
  26 *     Ben Collins <bcollins@debian.org>,
  27 *     Stefan Richter <stefanr@s5r6.in-berlin.de>
  28 * and many others.
  29 */
  30
  31#include <linux/blkdev.h>
  32#include <linux/bug.h>
  33#include <linux/completion.h>
  34#include <linux/delay.h>
  35#include <linux/device.h>
  36#include <linux/dma-mapping.h>
  37#include <linux/firewire.h>
  38#include <linux/firewire-constants.h>
  39#include <linux/init.h>
  40#include <linux/jiffies.h>
  41#include <linux/kernel.h>
  42#include <linux/kref.h>
  43#include <linux/list.h>
  44#include <linux/mod_devicetable.h>
  45#include <linux/module.h>
  46#include <linux/moduleparam.h>
  47#include <linux/scatterlist.h>
  48#include <linux/slab.h>
  49#include <linux/spinlock.h>
  50#include <linux/string.h>
  51#include <linux/stringify.h>
  52#include <linux/workqueue.h>
  53
  54#include <asm/byteorder.h>
  55
  56#include <scsi/scsi.h>
  57#include <scsi/scsi_cmnd.h>
  58#include <scsi/scsi_device.h>
  59#include <scsi/scsi_host.h>
  60
  61/*
  62 * So far only bridges from Oxford Semiconductor are known to support
  63 * concurrent logins. Depending on firmware, four or two concurrent logins
  64 * are possible on OXFW911 and newer Oxsemi bridges.
  65 *
  66 * Concurrent logins are useful together with cluster filesystems.
  67 */
  68static bool sbp2_param_exclusive_login = 1;
  69module_param_named(exclusive_login, sbp2_param_exclusive_login, bool, 0644);
  70MODULE_PARM_DESC(exclusive_login, "Exclusive login to sbp2 device "
  71                 "(default = Y, use N for concurrent initiators)");
  72
  73/*
  74 * Flags for firmware oddities
  75 *
  76 * - 128kB max transfer
  77 *   Limit transfer size. Necessary for some old bridges.
  78 *
  79 * - 36 byte inquiry
  80 *   When scsi_mod probes the device, let the inquiry command look like that
  81 *   from MS Windows.
  82 *
  83 * - skip mode page 8
  84 *   Suppress sending of mode_sense for mode page 8 if the device pretends to
  85 *   support the SCSI Primary Block commands instead of Reduced Block Commands.
  86 *
  87 * - fix capacity
  88 *   Tell sd_mod to correct the last sector number reported by read_capacity.
  89 *   Avoids access beyond actual disk limits on devices with an off-by-one bug.
  90 *   Don't use this with devices which don't have this bug.
  91 *
  92 * - delay inquiry
  93 *   Wait extra SBP2_INQUIRY_DELAY seconds after login before SCSI inquiry.
  94 *
  95 * - power condition
  96 *   Set the power condition field in the START STOP UNIT commands sent by
  97 *   sd_mod on suspend, resume, and shutdown (if manage_start_stop is on).
  98 *   Some disks need this to spin down or to resume properly.
  99 *
 100 * - override internal blacklist
 101 *   Instead of adding to the built-in blacklist, use only the workarounds
 102 *   specified in the module load parameter.
 103 *   Useful if a blacklist entry interfered with a non-broken device.
 104 */
 105#define SBP2_WORKAROUND_128K_MAX_TRANS  0x1
 106#define SBP2_WORKAROUND_INQUIRY_36      0x2
 107#define SBP2_WORKAROUND_MODE_SENSE_8    0x4
 108#define SBP2_WORKAROUND_FIX_CAPACITY    0x8
 109#define SBP2_WORKAROUND_DELAY_INQUIRY   0x10
 110#define SBP2_INQUIRY_DELAY              12
 111#define SBP2_WORKAROUND_POWER_CONDITION 0x20
 112#define SBP2_WORKAROUND_OVERRIDE        0x100
 113
 114static int sbp2_param_workarounds;
 115module_param_named(workarounds, sbp2_param_workarounds, int, 0644);
 116MODULE_PARM_DESC(workarounds, "Work around device bugs (default = 0"
 117        ", 128kB max transfer = " __stringify(SBP2_WORKAROUND_128K_MAX_TRANS)
 118        ", 36 byte inquiry = "    __stringify(SBP2_WORKAROUND_INQUIRY_36)
 119        ", skip mode page 8 = "   __stringify(SBP2_WORKAROUND_MODE_SENSE_8)
 120        ", fix capacity = "       __stringify(SBP2_WORKAROUND_FIX_CAPACITY)
 121        ", delay inquiry = "      __stringify(SBP2_WORKAROUND_DELAY_INQUIRY)
 122        ", set power condition in start stop unit = "
 123                                  __stringify(SBP2_WORKAROUND_POWER_CONDITION)
 124        ", override internal blacklist = " __stringify(SBP2_WORKAROUND_OVERRIDE)
 125        ", or a combination)");
 126
 127/*
 128 * We create one struct sbp2_logical_unit per SBP-2 Logical Unit Number Entry
 129 * and one struct scsi_device per sbp2_logical_unit.
 130 */
 131struct sbp2_logical_unit {
 132        struct sbp2_target *tgt;
 133        struct list_head link;
 134        struct fw_address_handler address_handler;
 135        struct list_head orb_list;
 136
 137        u64 command_block_agent_address;
 138        u16 lun;
 139        int login_id;
 140
 141        /*
 142         * The generation is updated once we've logged in or reconnected
 143         * to the logical unit.  Thus, I/O to the device will automatically
 144         * fail and get retried if it happens in a window where the device
 145         * is not ready, e.g. after a bus reset but before we reconnect.
 146         */
 147        int generation;
 148        int retries;
 149        work_func_t workfn;
 150        struct delayed_work work;
 151        bool has_sdev;
 152        bool blocked;
 153};
 154
 155static void sbp2_queue_work(struct sbp2_logical_unit *lu, unsigned long delay)
 156{
 157        queue_delayed_work(fw_workqueue, &lu->work, delay);
 158}
 159
 160/*
 161 * We create one struct sbp2_target per IEEE 1212 Unit Directory
 162 * and one struct Scsi_Host per sbp2_target.
 163 */
 164struct sbp2_target {
 165        struct fw_unit *unit;
 166        struct list_head lu_list;
 167
 168        u64 management_agent_address;
 169        u64 guid;
 170        int directory_id;
 171        int node_id;
 172        int address_high;
 173        unsigned int workarounds;
 174        unsigned int mgt_orb_timeout;
 175        unsigned int max_payload;
 176
 177        spinlock_t lock;
 178        int dont_block; /* counter for each logical unit */
 179        int blocked;    /* ditto */
 180};
 181
 182static struct fw_device *target_parent_device(struct sbp2_target *tgt)
 183{
 184        return fw_parent_device(tgt->unit);
 185}
 186
 187static const struct device *tgt_dev(const struct sbp2_target *tgt)
 188{
 189        return &tgt->unit->device;
 190}
 191
 192static const struct device *lu_dev(const struct sbp2_logical_unit *lu)
 193{
 194        return &lu->tgt->unit->device;
 195}
 196
 197/* Impossible login_id, to detect logout attempt before successful login */
 198#define INVALID_LOGIN_ID 0x10000
 199
 200#define SBP2_ORB_TIMEOUT                2000U           /* Timeout in ms */
 201#define SBP2_ORB_NULL                   0x80000000
 202#define SBP2_RETRY_LIMIT                0xf             /* 15 retries */
 203#define SBP2_CYCLE_LIMIT                (0xc8 << 12)    /* 200 125us cycles */
 204
 205/*
 206 * There is no transport protocol limit to the CDB length,  but we implement
 207 * a fixed length only.  16 bytes is enough for disks larger than 2 TB.
 208 */
 209#define SBP2_MAX_CDB_SIZE               16
 210
 211/*
 212 * The maximum SBP-2 data buffer size is 0xffff.  We quadlet-align this
 213 * for compatibility with earlier versions of this driver.
 214 */
 215#define SBP2_MAX_SEG_SIZE               0xfffc
 216
 217/* Unit directory keys */
 218#define SBP2_CSR_UNIT_CHARACTERISTICS   0x3a
 219#define SBP2_CSR_FIRMWARE_REVISION      0x3c
 220#define SBP2_CSR_LOGICAL_UNIT_NUMBER    0x14
 221#define SBP2_CSR_UNIT_UNIQUE_ID         0x8d
 222#define SBP2_CSR_LOGICAL_UNIT_DIRECTORY 0xd4
 223
 224/* Management orb opcodes */
 225#define SBP2_LOGIN_REQUEST              0x0
 226#define SBP2_QUERY_LOGINS_REQUEST       0x1
 227#define SBP2_RECONNECT_REQUEST          0x3
 228#define SBP2_SET_PASSWORD_REQUEST       0x4
 229#define SBP2_LOGOUT_REQUEST             0x7
 230#define SBP2_ABORT_TASK_REQUEST         0xb
 231#define SBP2_ABORT_TASK_SET             0xc
 232#define SBP2_LOGICAL_UNIT_RESET         0xe
 233#define SBP2_TARGET_RESET_REQUEST       0xf
 234
 235/* Offsets for command block agent registers */
 236#define SBP2_AGENT_STATE                0x00
 237#define SBP2_AGENT_RESET                0x04
 238#define SBP2_ORB_POINTER                0x08
 239#define SBP2_DOORBELL                   0x10
 240#define SBP2_UNSOLICITED_STATUS_ENABLE  0x14
 241
 242/* Status write response codes */
 243#define SBP2_STATUS_REQUEST_COMPLETE    0x0
 244#define SBP2_STATUS_TRANSPORT_FAILURE   0x1
 245#define SBP2_STATUS_ILLEGAL_REQUEST     0x2
 246#define SBP2_STATUS_VENDOR_DEPENDENT    0x3
 247
 248#define STATUS_GET_ORB_HIGH(v)          ((v).status & 0xffff)
 249#define STATUS_GET_SBP_STATUS(v)        (((v).status >> 16) & 0xff)
 250#define STATUS_GET_LEN(v)               (((v).status >> 24) & 0x07)
 251#define STATUS_GET_DEAD(v)              (((v).status >> 27) & 0x01)
 252#define STATUS_GET_RESPONSE(v)          (((v).status >> 28) & 0x03)
 253#define STATUS_GET_SOURCE(v)            (((v).status >> 30) & 0x03)
 254#define STATUS_GET_ORB_LOW(v)           ((v).orb_low)
 255#define STATUS_GET_DATA(v)              ((v).data)
 256
 257struct sbp2_status {
 258        u32 status;
 259        u32 orb_low;
 260        u8 data[24];
 261};
 262
 263struct sbp2_pointer {
 264        __be32 high;
 265        __be32 low;
 266};
 267
 268struct sbp2_orb {
 269        struct fw_transaction t;
 270        struct kref kref;
 271        dma_addr_t request_bus;
 272        int rcode;
 273        void (*callback)(struct sbp2_orb * orb, struct sbp2_status * status);
 274        struct sbp2_logical_unit *lu;
 275        struct list_head link;
 276};
 277
 278#define MANAGEMENT_ORB_LUN(v)                   ((v))
 279#define MANAGEMENT_ORB_FUNCTION(v)              ((v) << 16)
 280#define MANAGEMENT_ORB_RECONNECT(v)             ((v) << 20)
 281#define MANAGEMENT_ORB_EXCLUSIVE(v)             ((v) ? 1 << 28 : 0)
 282#define MANAGEMENT_ORB_REQUEST_FORMAT(v)        ((v) << 29)
 283#define MANAGEMENT_ORB_NOTIFY                   ((1) << 31)
 284
 285#define MANAGEMENT_ORB_RESPONSE_LENGTH(v)       ((v))
 286#define MANAGEMENT_ORB_PASSWORD_LENGTH(v)       ((v) << 16)
 287
 288struct sbp2_management_orb {
 289        struct sbp2_orb base;
 290        struct {
 291                struct sbp2_pointer password;
 292                struct sbp2_pointer response;
 293                __be32 misc;
 294                __be32 length;
 295                struct sbp2_pointer status_fifo;
 296        } request;
 297        __be32 response[4];
 298        dma_addr_t response_bus;
 299        struct completion done;
 300        struct sbp2_status status;
 301};
 302
 303struct sbp2_login_response {
 304        __be32 misc;
 305        struct sbp2_pointer command_block_agent;
 306        __be32 reconnect_hold;
 307};
 308#define COMMAND_ORB_DATA_SIZE(v)        ((v))
 309#define COMMAND_ORB_PAGE_SIZE(v)        ((v) << 16)
 310#define COMMAND_ORB_PAGE_TABLE_PRESENT  ((1) << 19)
 311#define COMMAND_ORB_MAX_PAYLOAD(v)      ((v) << 20)
 312#define COMMAND_ORB_SPEED(v)            ((v) << 24)
 313#define COMMAND_ORB_DIRECTION           ((1) << 27)
 314#define COMMAND_ORB_REQUEST_FORMAT(v)   ((v) << 29)
 315#define COMMAND_ORB_NOTIFY              ((1) << 31)
 316
 317struct sbp2_command_orb {
 318        struct sbp2_orb base;
 319        struct {
 320                struct sbp2_pointer next;
 321                struct sbp2_pointer data_descriptor;
 322                __be32 misc;
 323                u8 command_block[SBP2_MAX_CDB_SIZE];
 324        } request;
 325        struct scsi_cmnd *cmd;
 326
 327        struct sbp2_pointer page_table[SG_ALL] __attribute__((aligned(8)));
 328        dma_addr_t page_table_bus;
 329};
 330
 331#define SBP2_ROM_VALUE_WILDCARD ~0         /* match all */
 332#define SBP2_ROM_VALUE_MISSING  0xff000000 /* not present in the unit dir. */
 333
 334/*
 335 * List of devices with known bugs.
 336 *
 337 * The firmware_revision field, masked with 0xffff00, is the best
 338 * indicator for the type of bridge chip of a device.  It yields a few
 339 * false positives but this did not break correctly behaving devices
 340 * so far.
 341 */
 342static const struct {
 343        u32 firmware_revision;
 344        u32 model;
 345        unsigned int workarounds;
 346} sbp2_workarounds_table[] = {
 347        /* DViCO Momobay CX-1 with TSB42AA9 bridge */ {
 348                .firmware_revision      = 0x002800,
 349                .model                  = 0x001010,
 350                .workarounds            = SBP2_WORKAROUND_INQUIRY_36 |
 351                                          SBP2_WORKAROUND_MODE_SENSE_8 |
 352                                          SBP2_WORKAROUND_POWER_CONDITION,
 353        },
 354        /* DViCO Momobay FX-3A with TSB42AA9A bridge */ {
 355                .firmware_revision      = 0x002800,
 356                .model                  = 0x000000,
 357                .workarounds            = SBP2_WORKAROUND_POWER_CONDITION,
 358        },
 359        /* Initio bridges, actually only needed for some older ones */ {
 360                .firmware_revision      = 0x000200,
 361                .model                  = SBP2_ROM_VALUE_WILDCARD,
 362                .workarounds            = SBP2_WORKAROUND_INQUIRY_36,
 363        },
 364        /* PL-3507 bridge with Prolific firmware */ {
 365                .firmware_revision      = 0x012800,
 366                .model                  = SBP2_ROM_VALUE_WILDCARD,
 367                .workarounds            = SBP2_WORKAROUND_POWER_CONDITION,
 368        },
 369        /* Symbios bridge */ {
 370                .firmware_revision      = 0xa0b800,
 371                .model                  = SBP2_ROM_VALUE_WILDCARD,
 372                .workarounds            = SBP2_WORKAROUND_128K_MAX_TRANS,
 373        },
 374        /* Datafab MD2-FW2 with Symbios/LSILogic SYM13FW500 bridge */ {
 375                .firmware_revision      = 0x002600,
 376                .model                  = SBP2_ROM_VALUE_WILDCARD,
 377                .workarounds            = SBP2_WORKAROUND_128K_MAX_TRANS,
 378        },
 379        /*
 380         * iPod 2nd generation: needs 128k max transfer size workaround
 381         * iPod 3rd generation: needs fix capacity workaround
 382         */
 383        {
 384                .firmware_revision      = 0x0a2700,
 385                .model                  = 0x000000,
 386                .workarounds            = SBP2_WORKAROUND_128K_MAX_TRANS |
 387                                          SBP2_WORKAROUND_FIX_CAPACITY,
 388        },
 389        /* iPod 4th generation */ {
 390                .firmware_revision      = 0x0a2700,
 391                .model                  = 0x000021,
 392                .workarounds            = SBP2_WORKAROUND_FIX_CAPACITY,
 393        },
 394        /* iPod mini */ {
 395                .firmware_revision      = 0x0a2700,
 396                .model                  = 0x000022,
 397                .workarounds            = SBP2_WORKAROUND_FIX_CAPACITY,
 398        },
 399        /* iPod mini */ {
 400                .firmware_revision      = 0x0a2700,
 401                .model                  = 0x000023,
 402                .workarounds            = SBP2_WORKAROUND_FIX_CAPACITY,
 403        },
 404        /* iPod Photo */ {
 405                .firmware_revision      = 0x0a2700,
 406                .model                  = 0x00007e,
 407                .workarounds            = SBP2_WORKAROUND_FIX_CAPACITY,
 408        }
 409};
 410
 411static void free_orb(struct kref *kref)
 412{
 413        struct sbp2_orb *orb = container_of(kref, struct sbp2_orb, kref);
 414
 415        kfree(orb);
 416}
 417
 418static void sbp2_status_write(struct fw_card *card, struct fw_request *request,
 419                              int tcode, int destination, int source,
 420                              int generation, unsigned long long offset,
 421                              void *payload, size_t length, void *callback_data)
 422{
 423        struct sbp2_logical_unit *lu = callback_data;
 424        struct sbp2_orb *orb;
 425        struct sbp2_status status;
 426        unsigned long flags;
 427
 428        if (tcode != TCODE_WRITE_BLOCK_REQUEST ||
 429            length < 8 || length > sizeof(status)) {
 430                fw_send_response(card, request, RCODE_TYPE_ERROR);
 431                return;
 432        }
 433
 434        status.status  = be32_to_cpup(payload);
 435        status.orb_low = be32_to_cpup(payload + 4);
 436        memset(status.data, 0, sizeof(status.data));
 437        if (length > 8)
 438                memcpy(status.data, payload + 8, length - 8);
 439
 440        if (STATUS_GET_SOURCE(status) == 2 || STATUS_GET_SOURCE(status) == 3) {
 441                dev_notice(lu_dev(lu),
 442                           "non-ORB related status write, not handled\n");
 443                fw_send_response(card, request, RCODE_COMPLETE);
 444                return;
 445        }
 446
 447        /* Lookup the orb corresponding to this status write. */
 448        spin_lock_irqsave(&lu->tgt->lock, flags);
 449        list_for_each_entry(orb, &lu->orb_list, link) {
 450                if (STATUS_GET_ORB_HIGH(status) == 0 &&
 451                    STATUS_GET_ORB_LOW(status) == orb->request_bus) {
 452                        orb->rcode = RCODE_COMPLETE;
 453                        list_del(&orb->link);
 454                        break;
 455                }
 456        }
 457        spin_unlock_irqrestore(&lu->tgt->lock, flags);
 458
 459        if (&orb->link != &lu->orb_list) {
 460                orb->callback(orb, &status);
 461                kref_put(&orb->kref, free_orb); /* orb callback reference */
 462        } else {
 463                dev_err(lu_dev(lu), "status write for unknown ORB\n");
 464        }
 465
 466        fw_send_response(card, request, RCODE_COMPLETE);
 467}
 468
 469static void complete_transaction(struct fw_card *card, int rcode,
 470                                 void *payload, size_t length, void *data)
 471{
 472        struct sbp2_orb *orb = data;
 473        unsigned long flags;
 474
 475        /*
 476         * This is a little tricky.  We can get the status write for
 477         * the orb before we get this callback.  The status write
 478         * handler above will assume the orb pointer transaction was
 479         * successful and set the rcode to RCODE_COMPLETE for the orb.
 480         * So this callback only sets the rcode if it hasn't already
 481         * been set and only does the cleanup if the transaction
 482         * failed and we didn't already get a status write.
 483         */
 484        spin_lock_irqsave(&orb->lu->tgt->lock, flags);
 485
 486        if (orb->rcode == -1)
 487                orb->rcode = rcode;
 488        if (orb->rcode != RCODE_COMPLETE) {
 489                list_del(&orb->link);
 490                spin_unlock_irqrestore(&orb->lu->tgt->lock, flags);
 491
 492                orb->callback(orb, NULL);
 493                kref_put(&orb->kref, free_orb); /* orb callback reference */
 494        } else {
 495                spin_unlock_irqrestore(&orb->lu->tgt->lock, flags);
 496        }
 497
 498        kref_put(&orb->kref, free_orb); /* transaction callback reference */
 499}
 500
 501static void sbp2_send_orb(struct sbp2_orb *orb, struct sbp2_logical_unit *lu,
 502                          int node_id, int generation, u64 offset)
 503{
 504        struct fw_device *device = target_parent_device(lu->tgt);
 505        struct sbp2_pointer orb_pointer;
 506        unsigned long flags;
 507
 508        orb_pointer.high = 0;
 509        orb_pointer.low = cpu_to_be32(orb->request_bus);
 510
 511        orb->lu = lu;
 512        spin_lock_irqsave(&lu->tgt->lock, flags);
 513        list_add_tail(&orb->link, &lu->orb_list);
 514        spin_unlock_irqrestore(&lu->tgt->lock, flags);
 515
 516        kref_get(&orb->kref); /* transaction callback reference */
 517        kref_get(&orb->kref); /* orb callback reference */
 518
 519        fw_send_request(device->card, &orb->t, TCODE_WRITE_BLOCK_REQUEST,
 520                        node_id, generation, device->max_speed, offset,
 521                        &orb_pointer, 8, complete_transaction, orb);
 522}
 523
 524static int sbp2_cancel_orbs(struct sbp2_logical_unit *lu)
 525{
 526        struct fw_device *device = target_parent_device(lu->tgt);
 527        struct sbp2_orb *orb, *next;
 528        struct list_head list;
 529        int retval = -ENOENT;
 530
 531        INIT_LIST_HEAD(&list);
 532        spin_lock_irq(&lu->tgt->lock);
 533        list_splice_init(&lu->orb_list, &list);
 534        spin_unlock_irq(&lu->tgt->lock);
 535
 536        list_for_each_entry_safe(orb, next, &list, link) {
 537                retval = 0;
 538                if (fw_cancel_transaction(device->card, &orb->t) == 0)
 539                        continue;
 540
 541                orb->rcode = RCODE_CANCELLED;
 542                orb->callback(orb, NULL);
 543                kref_put(&orb->kref, free_orb); /* orb callback reference */
 544        }
 545
 546        return retval;
 547}
 548
 549static void complete_management_orb(struct sbp2_orb *base_orb,
 550                                    struct sbp2_status *status)
 551{
 552        struct sbp2_management_orb *orb =
 553                container_of(base_orb, struct sbp2_management_orb, base);
 554
 555        if (status)
 556                memcpy(&orb->status, status, sizeof(*status));
 557        complete(&orb->done);
 558}
 559
 560static int sbp2_send_management_orb(struct sbp2_logical_unit *lu, int node_id,
 561                                    int generation, int function,
 562                                    int lun_or_login_id, void *response)
 563{
 564        struct fw_device *device = target_parent_device(lu->tgt);
 565        struct sbp2_management_orb *orb;
 566        unsigned int timeout;
 567        int retval = -ENOMEM;
 568
 569        if (function == SBP2_LOGOUT_REQUEST && fw_device_is_shutdown(device))
 570                return 0;
 571
 572        orb = kzalloc(sizeof(*orb), GFP_NOIO);
 573        if (orb == NULL)
 574                return -ENOMEM;
 575
 576        kref_init(&orb->base.kref);
 577        orb->response_bus =
 578                dma_map_single(device->card->device, &orb->response,
 579                               sizeof(orb->response), DMA_FROM_DEVICE);
 580        if (dma_mapping_error(device->card->device, orb->response_bus))
 581                goto fail_mapping_response;
 582
 583        orb->request.response.high = 0;
 584        orb->request.response.low  = cpu_to_be32(orb->response_bus);
 585
 586        orb->request.misc = cpu_to_be32(
 587                MANAGEMENT_ORB_NOTIFY |
 588                MANAGEMENT_ORB_FUNCTION(function) |
 589                MANAGEMENT_ORB_LUN(lun_or_login_id));
 590        orb->request.length = cpu_to_be32(
 591                MANAGEMENT_ORB_RESPONSE_LENGTH(sizeof(orb->response)));
 592
 593        orb->request.status_fifo.high =
 594                cpu_to_be32(lu->address_handler.offset >> 32);
 595        orb->request.status_fifo.low  =
 596                cpu_to_be32(lu->address_handler.offset);
 597
 598        if (function == SBP2_LOGIN_REQUEST) {
 599                /* Ask for 2^2 == 4 seconds reconnect grace period */
 600                orb->request.misc |= cpu_to_be32(
 601                        MANAGEMENT_ORB_RECONNECT(2) |
 602                        MANAGEMENT_ORB_EXCLUSIVE(sbp2_param_exclusive_login));
 603                timeout = lu->tgt->mgt_orb_timeout;
 604        } else {
 605                timeout = SBP2_ORB_TIMEOUT;
 606        }
 607
 608        init_completion(&orb->done);
 609        orb->base.callback = complete_management_orb;
 610
 611        orb->base.request_bus =
 612                dma_map_single(device->card->device, &orb->request,
 613                               sizeof(orb->request), DMA_TO_DEVICE);
 614        if (dma_mapping_error(device->card->device, orb->base.request_bus))
 615                goto fail_mapping_request;
 616
 617        sbp2_send_orb(&orb->base, lu, node_id, generation,
 618                      lu->tgt->management_agent_address);
 619
 620        wait_for_completion_timeout(&orb->done, msecs_to_jiffies(timeout));
 621
 622        retval = -EIO;
 623        if (sbp2_cancel_orbs(lu) == 0) {
 624                dev_err(lu_dev(lu), "ORB reply timed out, rcode 0x%02x\n",
 625                        orb->base.rcode);
 626                goto out;
 627        }
 628
 629        if (orb->base.rcode != RCODE_COMPLETE) {
 630                dev_err(lu_dev(lu), "management write failed, rcode 0x%02x\n",
 631                        orb->base.rcode);
 632                goto out;
 633        }
 634
 635        if (STATUS_GET_RESPONSE(orb->status) != 0 ||
 636            STATUS_GET_SBP_STATUS(orb->status) != 0) {
 637                dev_err(lu_dev(lu), "error status: %d:%d\n",
 638                         STATUS_GET_RESPONSE(orb->status),
 639                         STATUS_GET_SBP_STATUS(orb->status));
 640                goto out;
 641        }
 642
 643        retval = 0;
 644 out:
 645        dma_unmap_single(device->card->device, orb->base.request_bus,
 646                         sizeof(orb->request), DMA_TO_DEVICE);
 647 fail_mapping_request:
 648        dma_unmap_single(device->card->device, orb->response_bus,
 649                         sizeof(orb->response), DMA_FROM_DEVICE);
 650 fail_mapping_response:
 651        if (response)
 652                memcpy(response, orb->response, sizeof(orb->response));
 653        kref_put(&orb->base.kref, free_orb);
 654
 655        return retval;
 656}
 657
 658static void sbp2_agent_reset(struct sbp2_logical_unit *lu)
 659{
 660        struct fw_device *device = target_parent_device(lu->tgt);
 661        __be32 d = 0;
 662
 663        fw_run_transaction(device->card, TCODE_WRITE_QUADLET_REQUEST,
 664                           lu->tgt->node_id, lu->generation, device->max_speed,
 665                           lu->command_block_agent_address + SBP2_AGENT_RESET,
 666                           &d, 4);
 667}
 668
 669static void complete_agent_reset_write_no_wait(struct fw_card *card,
 670                int rcode, void *payload, size_t length, void *data)
 671{
 672        kfree(data);
 673}
 674
 675static void sbp2_agent_reset_no_wait(struct sbp2_logical_unit *lu)
 676{
 677        struct fw_device *device = target_parent_device(lu->tgt);
 678        struct fw_transaction *t;
 679        static __be32 d;
 680
 681        t = kmalloc(sizeof(*t), GFP_ATOMIC);
 682        if (t == NULL)
 683                return;
 684
 685        fw_send_request(device->card, t, TCODE_WRITE_QUADLET_REQUEST,
 686                        lu->tgt->node_id, lu->generation, device->max_speed,
 687                        lu->command_block_agent_address + SBP2_AGENT_RESET,
 688                        &d, 4, complete_agent_reset_write_no_wait, t);
 689}
 690
 691static inline void sbp2_allow_block(struct sbp2_target *tgt)
 692{
 693        spin_lock_irq(&tgt->lock);
 694        --tgt->dont_block;
 695        spin_unlock_irq(&tgt->lock);
 696}
 697
 698/*
 699 * Blocks lu->tgt if all of the following conditions are met:
 700 *   - Login, INQUIRY, and high-level SCSI setup of all of the target's
 701 *     logical units have been finished (indicated by dont_block == 0).
 702 *   - lu->generation is stale.
 703 *
 704 * Note, scsi_block_requests() must be called while holding tgt->lock,
 705 * otherwise it might foil sbp2_[conditionally_]unblock()'s attempt to
 706 * unblock the target.
 707 */
 708static void sbp2_conditionally_block(struct sbp2_logical_unit *lu)
 709{
 710        struct sbp2_target *tgt = lu->tgt;
 711        struct fw_card *card = target_parent_device(tgt)->card;
 712        struct Scsi_Host *shost =
 713                container_of((void *)tgt, struct Scsi_Host, hostdata[0]);
 714        unsigned long flags;
 715
 716        spin_lock_irqsave(&tgt->lock, flags);
 717        if (!tgt->dont_block && !lu->blocked &&
 718            lu->generation != card->generation) {
 719                lu->blocked = true;
 720                if (++tgt->blocked == 1)
 721                        scsi_block_requests(shost);
 722        }
 723        spin_unlock_irqrestore(&tgt->lock, flags);
 724}
 725
 726/*
 727 * Unblocks lu->tgt as soon as all its logical units can be unblocked.
 728 * Note, it is harmless to run scsi_unblock_requests() outside the
 729 * tgt->lock protected section.  On the other hand, running it inside
 730 * the section might clash with shost->host_lock.
 731 */
 732static void sbp2_conditionally_unblock(struct sbp2_logical_unit *lu)
 733{
 734        struct sbp2_target *tgt = lu->tgt;
 735        struct fw_card *card = target_parent_device(tgt)->card;
 736        struct Scsi_Host *shost =
 737                container_of((void *)tgt, struct Scsi_Host, hostdata[0]);
 738        bool unblock = false;
 739
 740        spin_lock_irq(&tgt->lock);
 741        if (lu->blocked && lu->generation == card->generation) {
 742                lu->blocked = false;
 743                unblock = --tgt->blocked == 0;
 744        }
 745        spin_unlock_irq(&tgt->lock);
 746
 747        if (unblock)
 748                scsi_unblock_requests(shost);
 749}
 750
 751/*
 752 * Prevents future blocking of tgt and unblocks it.
 753 * Note, it is harmless to run scsi_unblock_requests() outside the
 754 * tgt->lock protected section.  On the other hand, running it inside
 755 * the section might clash with shost->host_lock.
 756 */
 757static void sbp2_unblock(struct sbp2_target *tgt)
 758{
 759        struct Scsi_Host *shost =
 760                container_of((void *)tgt, struct Scsi_Host, hostdata[0]);
 761
 762        spin_lock_irq(&tgt->lock);
 763        ++tgt->dont_block;
 764        spin_unlock_irq(&tgt->lock);
 765
 766        scsi_unblock_requests(shost);
 767}
 768
 769static int sbp2_lun2int(u16 lun)
 770{
 771        struct scsi_lun eight_bytes_lun;
 772
 773        memset(&eight_bytes_lun, 0, sizeof(eight_bytes_lun));
 774        eight_bytes_lun.scsi_lun[0] = (lun >> 8) & 0xff;
 775        eight_bytes_lun.scsi_lun[1] = lun & 0xff;
 776
 777        return scsilun_to_int(&eight_bytes_lun);
 778}
 779
 780/*
 781 * Write retransmit retry values into the BUSY_TIMEOUT register.
 782 * - The single-phase retry protocol is supported by all SBP-2 devices, but the
 783 *   default retry_limit value is 0 (i.e. never retry transmission). We write a
 784 *   saner value after logging into the device.
 785 * - The dual-phase retry protocol is optional to implement, and if not
 786 *   supported, writes to the dual-phase portion of the register will be
 787 *   ignored. We try to write the original 1394-1995 default here.
 788 * - In the case of devices that are also SBP-3-compliant, all writes are
 789 *   ignored, as the register is read-only, but contains single-phase retry of
 790 *   15, which is what we're trying to set for all SBP-2 device anyway, so this
 791 *   write attempt is safe and yields more consistent behavior for all devices.
 792 *
 793 * See section 8.3.2.3.5 of the 1394-1995 spec, section 6.2 of the SBP-2 spec,
 794 * and section 6.4 of the SBP-3 spec for further details.
 795 */
 796static void sbp2_set_busy_timeout(struct sbp2_logical_unit *lu)
 797{
 798        struct fw_device *device = target_parent_device(lu->tgt);
 799        __be32 d = cpu_to_be32(SBP2_CYCLE_LIMIT | SBP2_RETRY_LIMIT);
 800
 801        fw_run_transaction(device->card, TCODE_WRITE_QUADLET_REQUEST,
 802                           lu->tgt->node_id, lu->generation, device->max_speed,
 803                           CSR_REGISTER_BASE + CSR_BUSY_TIMEOUT, &d, 4);
 804}
 805
 806static void sbp2_reconnect(struct work_struct *work);
 807
 808static void sbp2_login(struct work_struct *work)
 809{
 810        struct sbp2_logical_unit *lu =
 811                container_of(work, struct sbp2_logical_unit, work.work);
 812        struct sbp2_target *tgt = lu->tgt;
 813        struct fw_device *device = target_parent_device(tgt);
 814        struct Scsi_Host *shost;
 815        struct scsi_device *sdev;
 816        struct sbp2_login_response response;
 817        int generation, node_id, local_node_id;
 818
 819        if (fw_device_is_shutdown(device))
 820                return;
 821
 822        generation    = device->generation;
 823        smp_rmb();    /* node IDs must not be older than generation */
 824        node_id       = device->node_id;
 825        local_node_id = device->card->node_id;
 826
 827        /* If this is a re-login attempt, log out, or we might be rejected. */
 828        if (lu->has_sdev)
 829                sbp2_send_management_orb(lu, device->node_id, generation,
 830                                SBP2_LOGOUT_REQUEST, lu->login_id, NULL);
 831
 832        if (sbp2_send_management_orb(lu, node_id, generation,
 833                                SBP2_LOGIN_REQUEST, lu->lun, &response) < 0) {
 834                if (lu->retries++ < 5) {
 835                        sbp2_queue_work(lu, DIV_ROUND_UP(HZ, 5));
 836                } else {
 837                        dev_err(tgt_dev(tgt), "failed to login to LUN %04x\n",
 838                                lu->lun);
 839                        /* Let any waiting I/O fail from now on. */
 840                        sbp2_unblock(lu->tgt);
 841                }
 842                return;
 843        }
 844
 845        tgt->node_id      = node_id;
 846        tgt->address_high = local_node_id << 16;
 847        smp_wmb();        /* node IDs must not be older than generation */
 848        lu->generation    = generation;
 849
 850        lu->command_block_agent_address =
 851                ((u64)(be32_to_cpu(response.command_block_agent.high) & 0xffff)
 852                      << 32) | be32_to_cpu(response.command_block_agent.low);
 853        lu->login_id = be32_to_cpu(response.misc) & 0xffff;
 854
 855        dev_notice(tgt_dev(tgt), "logged in to LUN %04x (%d retries)\n",
 856                   lu->lun, lu->retries);
 857
 858        /* set appropriate retry limit(s) in BUSY_TIMEOUT register */
 859        sbp2_set_busy_timeout(lu);
 860
 861        lu->workfn = sbp2_reconnect;
 862        sbp2_agent_reset(lu);
 863
 864        /* This was a re-login. */
 865        if (lu->has_sdev) {
 866                sbp2_cancel_orbs(lu);
 867                sbp2_conditionally_unblock(lu);
 868
 869                return;
 870        }
 871
 872        if (lu->tgt->workarounds & SBP2_WORKAROUND_DELAY_INQUIRY)
 873                ssleep(SBP2_INQUIRY_DELAY);
 874
 875        shost = container_of((void *)tgt, struct Scsi_Host, hostdata[0]);
 876        sdev = __scsi_add_device(shost, 0, 0, sbp2_lun2int(lu->lun), lu);
 877        /*
 878         * FIXME:  We are unable to perform reconnects while in sbp2_login().
 879         * Therefore __scsi_add_device() will get into trouble if a bus reset
 880         * happens in parallel.  It will either fail or leave us with an
 881         * unusable sdev.  As a workaround we check for this and retry the
 882         * whole login and SCSI probing.
 883         */
 884
 885        /* Reported error during __scsi_add_device() */
 886        if (IS_ERR(sdev))
 887                goto out_logout_login;
 888
 889        /* Unreported error during __scsi_add_device() */
 890        smp_rmb(); /* get current card generation */
 891        if (generation != device->card->generation) {
 892                scsi_remove_device(sdev);
 893                scsi_device_put(sdev);
 894                goto out_logout_login;
 895        }
 896
 897        /* No error during __scsi_add_device() */
 898        lu->has_sdev = true;
 899        scsi_device_put(sdev);
 900        sbp2_allow_block(tgt);
 901
 902        return;
 903
 904 out_logout_login:
 905        smp_rmb(); /* generation may have changed */
 906        generation = device->generation;
 907        smp_rmb(); /* node_id must not be older than generation */
 908
 909        sbp2_send_management_orb(lu, device->node_id, generation,
 910                                 SBP2_LOGOUT_REQUEST, lu->login_id, NULL);
 911        /*
 912         * If a bus reset happened, sbp2_update will have requeued
 913         * lu->work already.  Reset the work from reconnect to login.
 914         */
 915        lu->workfn = sbp2_login;
 916}
 917
 918static void sbp2_reconnect(struct work_struct *work)
 919{
 920        struct sbp2_logical_unit *lu =
 921                container_of(work, struct sbp2_logical_unit, work.work);
 922        struct sbp2_target *tgt = lu->tgt;
 923        struct fw_device *device = target_parent_device(tgt);
 924        int generation, node_id, local_node_id;
 925
 926        if (fw_device_is_shutdown(device))
 927                return;
 928
 929        generation    = device->generation;
 930        smp_rmb();    /* node IDs must not be older than generation */
 931        node_id       = device->node_id;
 932        local_node_id = device->card->node_id;
 933
 934        if (sbp2_send_management_orb(lu, node_id, generation,
 935                                     SBP2_RECONNECT_REQUEST,
 936                                     lu->login_id, NULL) < 0) {
 937                /*
 938                 * If reconnect was impossible even though we are in the
 939                 * current generation, fall back and try to log in again.
 940                 *
 941                 * We could check for "Function rejected" status, but
 942                 * looking at the bus generation as simpler and more general.
 943                 */
 944                smp_rmb(); /* get current card generation */
 945                if (generation == device->card->generation ||
 946                    lu->retries++ >= 5) {
 947                        dev_err(tgt_dev(tgt), "failed to reconnect\n");
 948                        lu->retries = 0;
 949                        lu->workfn = sbp2_login;
 950                }
 951                sbp2_queue_work(lu, DIV_ROUND_UP(HZ, 5));
 952
 953                return;
 954        }
 955
 956        tgt->node_id      = node_id;
 957        tgt->address_high = local_node_id << 16;
 958        smp_wmb();        /* node IDs must not be older than generation */
 959        lu->generation    = generation;
 960
 961        dev_notice(tgt_dev(tgt), "reconnected to LUN %04x (%d retries)\n",
 962                   lu->lun, lu->retries);
 963
 964        sbp2_agent_reset(lu);
 965        sbp2_cancel_orbs(lu);
 966        sbp2_conditionally_unblock(lu);
 967}
 968
 969static void sbp2_lu_workfn(struct work_struct *work)
 970{
 971        struct sbp2_logical_unit *lu = container_of(to_delayed_work(work),
 972                                                struct sbp2_logical_unit, work);
 973        lu->workfn(work);
 974}
 975
 976static int sbp2_add_logical_unit(struct sbp2_target *tgt, int lun_entry)
 977{
 978        struct sbp2_logical_unit *lu;
 979
 980        lu = kmalloc(sizeof(*lu), GFP_KERNEL);
 981        if (!lu)
 982                return -ENOMEM;
 983
 984        lu->address_handler.length           = 0x100;
 985        lu->address_handler.address_callback = sbp2_status_write;
 986        lu->address_handler.callback_data    = lu;
 987
 988        if (fw_core_add_address_handler(&lu->address_handler,
 989                                        &fw_high_memory_region) < 0) {
 990                kfree(lu);
 991                return -ENOMEM;
 992        }
 993
 994        lu->tgt      = tgt;
 995        lu->lun      = lun_entry & 0xffff;
 996        lu->login_id = INVALID_LOGIN_ID;
 997        lu->retries  = 0;
 998        lu->has_sdev = false;
 999        lu->blocked  = false;
1000        ++tgt->dont_block;
1001        INIT_LIST_HEAD(&lu->orb_list);
1002        lu->workfn = sbp2_login;
1003        INIT_DELAYED_WORK(&lu->work, sbp2_lu_workfn);
1004
1005        list_add_tail(&lu->link, &tgt->lu_list);
1006        return 0;
1007}
1008
1009static void sbp2_get_unit_unique_id(struct sbp2_target *tgt,
1010                                    const u32 *leaf)
1011{
1012        if ((leaf[0] & 0xffff0000) == 0x00020000)
1013                tgt->guid = (u64)leaf[1] << 32 | leaf[2];
1014}
1015
1016static int sbp2_scan_logical_unit_dir(struct sbp2_target *tgt,
1017                                      const u32 *directory)
1018{
1019        struct fw_csr_iterator ci;
1020        int key, value;
1021
1022        fw_csr_iterator_init(&ci, directory);
1023        while (fw_csr_iterator_next(&ci, &key, &value))
1024                if (key == SBP2_CSR_LOGICAL_UNIT_NUMBER &&
1025                    sbp2_add_logical_unit(tgt, value) < 0)
1026                        return -ENOMEM;
1027        return 0;
1028}
1029
1030static int sbp2_scan_unit_dir(struct sbp2_target *tgt, const u32 *directory,
1031                              u32 *model, u32 *firmware_revision)
1032{
1033        struct fw_csr_iterator ci;
1034        int key, value;
1035
1036        fw_csr_iterator_init(&ci, directory);
1037        while (fw_csr_iterator_next(&ci, &key, &value)) {
1038                switch (key) {
1039
1040                case CSR_DEPENDENT_INFO | CSR_OFFSET:
1041                        tgt->management_agent_address =
1042                                        CSR_REGISTER_BASE + 4 * value;
1043                        break;
1044
1045                case CSR_DIRECTORY_ID:
1046                        tgt->directory_id = value;
1047                        break;
1048
1049                case CSR_MODEL:
1050                        *model = value;
1051                        break;
1052
1053                case SBP2_CSR_FIRMWARE_REVISION:
1054                        *firmware_revision = value;
1055                        break;
1056
1057                case SBP2_CSR_UNIT_CHARACTERISTICS:
1058                        /* the timeout value is stored in 500ms units */
1059                        tgt->mgt_orb_timeout = (value >> 8 & 0xff) * 500;
1060                        break;
1061
1062                case SBP2_CSR_LOGICAL_UNIT_NUMBER:
1063                        if (sbp2_add_logical_unit(tgt, value) < 0)
1064                                return -ENOMEM;
1065                        break;
1066
1067                case SBP2_CSR_UNIT_UNIQUE_ID:
1068                        sbp2_get_unit_unique_id(tgt, ci.p - 1 + value);
1069                        break;
1070
1071                case SBP2_CSR_LOGICAL_UNIT_DIRECTORY:
1072                        /* Adjust for the increment in the iterator */
1073                        if (sbp2_scan_logical_unit_dir(tgt, ci.p - 1 + value) < 0)
1074                                return -ENOMEM;
1075                        break;
1076                }
1077        }
1078        return 0;
1079}
1080
1081/*
1082 * Per section 7.4.8 of the SBP-2 spec, a mgt_ORB_timeout value can be
1083 * provided in the config rom. Most devices do provide a value, which
1084 * we'll use for login management orbs, but with some sane limits.
1085 */
1086static void sbp2_clamp_management_orb_timeout(struct sbp2_target *tgt)
1087{
1088        unsigned int timeout = tgt->mgt_orb_timeout;
1089
1090        if (timeout > 40000)
1091                dev_notice(tgt_dev(tgt), "%ds mgt_ORB_timeout limited to 40s\n",
1092                           timeout / 1000);
1093
1094        tgt->mgt_orb_timeout = clamp_val(timeout, 5000, 40000);
1095}
1096
1097static void sbp2_init_workarounds(struct sbp2_target *tgt, u32 model,
1098                                  u32 firmware_revision)
1099{
1100        int i;
1101        unsigned int w = sbp2_param_workarounds;
1102
1103        if (w)
1104                dev_notice(tgt_dev(tgt),
1105                           "Please notify linux1394-devel@lists.sf.net "
1106                           "if you need the workarounds parameter\n");
1107
1108        if (w & SBP2_WORKAROUND_OVERRIDE)
1109                goto out;
1110
1111        for (i = 0; i < ARRAY_SIZE(sbp2_workarounds_table); i++) {
1112
1113                if (sbp2_workarounds_table[i].firmware_revision !=
1114                    (firmware_revision & 0xffffff00))
1115                        continue;
1116
1117                if (sbp2_workarounds_table[i].model != model &&
1118                    sbp2_workarounds_table[i].model != SBP2_ROM_VALUE_WILDCARD)
1119                        continue;
1120
1121                w |= sbp2_workarounds_table[i].workarounds;
1122                break;
1123        }
1124 out:
1125        if (w)
1126                dev_notice(tgt_dev(tgt), "workarounds 0x%x "
1127                           "(firmware_revision 0x%06x, model_id 0x%06x)\n",
1128                           w, firmware_revision, model);
1129        tgt->workarounds = w;
1130}
1131
1132static struct scsi_host_template scsi_driver_template;
1133static void sbp2_remove(struct fw_unit *unit);
1134
1135static int sbp2_probe(struct fw_unit *unit, const struct ieee1394_device_id *id)
1136{
1137        struct fw_device *device = fw_parent_device(unit);
1138        struct sbp2_target *tgt;
1139        struct sbp2_logical_unit *lu;
1140        struct Scsi_Host *shost;
1141        u32 model, firmware_revision;
1142
1143        /* cannot (or should not) handle targets on the local node */
1144        if (device->is_local)
1145                return -ENODEV;
1146
1147        shost = scsi_host_alloc(&scsi_driver_template, sizeof(*tgt));
1148        if (shost == NULL)
1149                return -ENOMEM;
1150
1151        tgt = (struct sbp2_target *)shost->hostdata;
1152        dev_set_drvdata(&unit->device, tgt);
1153        tgt->unit = unit;
1154        INIT_LIST_HEAD(&tgt->lu_list);
1155        spin_lock_init(&tgt->lock);
1156        tgt->guid = (u64)device->config_rom[3] << 32 | device->config_rom[4];
1157
1158        if (fw_device_enable_phys_dma(device) < 0)
1159                goto fail_shost_put;
1160
1161        shost->max_cmd_len = SBP2_MAX_CDB_SIZE;
1162
1163        if (scsi_add_host_with_dma(shost, &unit->device,
1164                                   device->card->device) < 0)
1165                goto fail_shost_put;
1166
1167        /* implicit directory ID */
1168        tgt->directory_id = ((unit->directory - device->config_rom) * 4
1169                             + CSR_CONFIG_ROM) & 0xffffff;
1170
1171        firmware_revision = SBP2_ROM_VALUE_MISSING;
1172        model             = SBP2_ROM_VALUE_MISSING;
1173
1174        if (sbp2_scan_unit_dir(tgt, unit->directory, &model,
1175                               &firmware_revision) < 0)
1176                goto fail_remove;
1177
1178        sbp2_clamp_management_orb_timeout(tgt);
1179        sbp2_init_workarounds(tgt, model, firmware_revision);
1180
1181        /*
1182         * At S100 we can do 512 bytes per packet, at S200 1024 bytes,
1183         * and so on up to 4096 bytes.  The SBP-2 max_payload field
1184         * specifies the max payload size as 2 ^ (max_payload + 2), so
1185         * if we set this to max_speed + 7, we get the right value.
1186         */
1187        tgt->max_payload = min3(device->max_speed + 7, 10U,
1188                                device->card->max_receive - 1);
1189
1190        /* Do the login in a workqueue so we can easily reschedule retries. */
1191        list_for_each_entry(lu, &tgt->lu_list, link)
1192                sbp2_queue_work(lu, DIV_ROUND_UP(HZ, 5));
1193
1194        return 0;
1195
1196 fail_remove:
1197        sbp2_remove(unit);
1198        return -ENOMEM;
1199
1200 fail_shost_put:
1201        scsi_host_put(shost);
1202        return -ENOMEM;
1203}
1204
1205static void sbp2_update(struct fw_unit *unit)
1206{
1207        struct sbp2_target *tgt = dev_get_drvdata(&unit->device);
1208        struct sbp2_logical_unit *lu;
1209
1210        fw_device_enable_phys_dma(fw_parent_device(unit));
1211
1212        /*
1213         * Fw-core serializes sbp2_update() against sbp2_remove().
1214         * Iteration over tgt->lu_list is therefore safe here.
1215         */
1216        list_for_each_entry(lu, &tgt->lu_list, link) {
1217                sbp2_conditionally_block(lu);
1218                lu->retries = 0;
1219                sbp2_queue_work(lu, 0);
1220        }
1221}
1222
1223static void sbp2_remove(struct fw_unit *unit)
1224{
1225        struct fw_device *device = fw_parent_device(unit);
1226        struct sbp2_target *tgt = dev_get_drvdata(&unit->device);
1227        struct sbp2_logical_unit *lu, *next;
1228        struct Scsi_Host *shost =
1229                container_of((void *)tgt, struct Scsi_Host, hostdata[0]);
1230        struct scsi_device *sdev;
1231
1232        /* prevent deadlocks */
1233        sbp2_unblock(tgt);
1234
1235        list_for_each_entry_safe(lu, next, &tgt->lu_list, link) {
1236                cancel_delayed_work_sync(&lu->work);
1237                sdev = scsi_device_lookup(shost, 0, 0, sbp2_lun2int(lu->lun));
1238                if (sdev) {
1239                        scsi_remove_device(sdev);
1240                        scsi_device_put(sdev);
1241                }
1242                if (lu->login_id != INVALID_LOGIN_ID) {
1243                        int generation, node_id;
1244                        /*
1245                         * tgt->node_id may be obsolete here if we failed
1246                         * during initial login or after a bus reset where
1247                         * the topology changed.
1248                         */
1249                        generation = device->generation;
1250                        smp_rmb(); /* node_id vs. generation */
1251                        node_id    = device->node_id;
1252                        sbp2_send_management_orb(lu, node_id, generation,
1253                                                 SBP2_LOGOUT_REQUEST,
1254                                                 lu->login_id, NULL);
1255                }
1256                fw_core_remove_address_handler(&lu->address_handler);
1257                list_del(&lu->link);
1258                kfree(lu);
1259        }
1260        scsi_remove_host(shost);
1261        dev_notice(&unit->device, "released target %d:0:0\n", shost->host_no);
1262
1263        scsi_host_put(shost);
1264}
1265
1266#define SBP2_UNIT_SPEC_ID_ENTRY 0x0000609e
1267#define SBP2_SW_VERSION_ENTRY   0x00010483
1268
1269static const struct ieee1394_device_id sbp2_id_table[] = {
1270        {
1271                .match_flags  = IEEE1394_MATCH_SPECIFIER_ID |
1272                                IEEE1394_MATCH_VERSION,
1273                .specifier_id = SBP2_UNIT_SPEC_ID_ENTRY,
1274                .version      = SBP2_SW_VERSION_ENTRY,
1275        },
1276        { }
1277};
1278
1279static struct fw_driver sbp2_driver = {
1280        .driver   = {
1281                .owner  = THIS_MODULE,
1282                .name   = KBUILD_MODNAME,
1283                .bus    = &fw_bus_type,
1284        },
1285        .probe    = sbp2_probe,
1286        .update   = sbp2_update,
1287        .remove   = sbp2_remove,
1288        .id_table = sbp2_id_table,
1289};
1290
1291static void sbp2_unmap_scatterlist(struct device *card_device,
1292                                   struct sbp2_command_orb *orb)
1293{
1294        scsi_dma_unmap(orb->cmd);
1295
1296        if (orb->request.misc & cpu_to_be32(COMMAND_ORB_PAGE_TABLE_PRESENT))
1297                dma_unmap_single(card_device, orb->page_table_bus,
1298                                 sizeof(orb->page_table), DMA_TO_DEVICE);
1299}
1300
1301static unsigned int sbp2_status_to_sense_data(u8 *sbp2_status, u8 *sense_data)
1302{
1303        int sam_status;
1304        int sfmt = (sbp2_status[0] >> 6) & 0x03;
1305
1306        if (sfmt == 2 || sfmt == 3) {
1307                /*
1308                 * Reserved for future standardization (2) or
1309                 * Status block format vendor-dependent (3)
1310                 */
1311                return DID_ERROR << 16;
1312        }
1313
1314        sense_data[0] = 0x70 | sfmt | (sbp2_status[1] & 0x80);
1315        sense_data[1] = 0x0;
1316        sense_data[2] = ((sbp2_status[1] << 1) & 0xe0) | (sbp2_status[1] & 0x0f);
1317        sense_data[3] = sbp2_status[4];
1318        sense_data[4] = sbp2_status[5];
1319        sense_data[5] = sbp2_status[6];
1320        sense_data[6] = sbp2_status[7];
1321        sense_data[7] = 10;
1322        sense_data[8] = sbp2_status[8];
1323        sense_data[9] = sbp2_status[9];
1324        sense_data[10] = sbp2_status[10];
1325        sense_data[11] = sbp2_status[11];
1326        sense_data[12] = sbp2_status[2];
1327        sense_data[13] = sbp2_status[3];
1328        sense_data[14] = sbp2_status[12];
1329        sense_data[15] = sbp2_status[13];
1330
1331        sam_status = sbp2_status[0] & 0x3f;
1332
1333        switch (sam_status) {
1334        case SAM_STAT_GOOD:
1335        case SAM_STAT_CHECK_CONDITION:
1336        case SAM_STAT_CONDITION_MET:
1337        case SAM_STAT_BUSY:
1338        case SAM_STAT_RESERVATION_CONFLICT:
1339        case SAM_STAT_COMMAND_TERMINATED:
1340                return DID_OK << 16 | sam_status;
1341
1342        default:
1343                return DID_ERROR << 16;
1344        }
1345}
1346
1347static void complete_command_orb(struct sbp2_orb *base_orb,
1348                                 struct sbp2_status *status)
1349{
1350        struct sbp2_command_orb *orb =
1351                container_of(base_orb, struct sbp2_command_orb, base);
1352        struct fw_device *device = target_parent_device(base_orb->lu->tgt);
1353        int result;
1354
1355        if (status != NULL) {
1356                if (STATUS_GET_DEAD(*status))
1357                        sbp2_agent_reset_no_wait(base_orb->lu);
1358
1359                switch (STATUS_GET_RESPONSE(*status)) {
1360                case SBP2_STATUS_REQUEST_COMPLETE:
1361                        result = DID_OK << 16;
1362                        break;
1363                case SBP2_STATUS_TRANSPORT_FAILURE:
1364                        result = DID_BUS_BUSY << 16;
1365                        break;
1366                case SBP2_STATUS_ILLEGAL_REQUEST:
1367                case SBP2_STATUS_VENDOR_DEPENDENT:
1368                default:
1369                        result = DID_ERROR << 16;
1370                        break;
1371                }
1372
1373                if (result == DID_OK << 16 && STATUS_GET_LEN(*status) > 1)
1374                        result = sbp2_status_to_sense_data(STATUS_GET_DATA(*status),
1375                                                           orb->cmd->sense_buffer);
1376        } else {
1377                /*
1378                 * If the orb completes with status == NULL, something
1379                 * went wrong, typically a bus reset happened mid-orb
1380                 * or when sending the write (less likely).
1381                 */
1382                result = DID_BUS_BUSY << 16;
1383                sbp2_conditionally_block(base_orb->lu);
1384        }
1385
1386        dma_unmap_single(device->card->device, orb->base.request_bus,
1387                         sizeof(orb->request), DMA_TO_DEVICE);
1388        sbp2_unmap_scatterlist(device->card->device, orb);
1389
1390        orb->cmd->result = result;
1391        orb->cmd->scsi_done(orb->cmd);
1392}
1393
1394static int sbp2_map_scatterlist(struct sbp2_command_orb *orb,
1395                struct fw_device *device, struct sbp2_logical_unit *lu)
1396{
1397        struct scatterlist *sg = scsi_sglist(orb->cmd);
1398        int i, n;
1399
1400        n = scsi_dma_map(orb->cmd);
1401        if (n <= 0)
1402                goto fail;
1403
1404        /*
1405         * Handle the special case where there is only one element in
1406         * the scatter list by converting it to an immediate block
1407         * request. This is also a workaround for broken devices such
1408         * as the second generation iPod which doesn't support page
1409         * tables.
1410         */
1411        if (n == 1) {
1412                orb->request.data_descriptor.high =
1413                        cpu_to_be32(lu->tgt->address_high);
1414                orb->request.data_descriptor.low  =
1415                        cpu_to_be32(sg_dma_address(sg));
1416                orb->request.misc |=
1417                        cpu_to_be32(COMMAND_ORB_DATA_SIZE(sg_dma_len(sg)));
1418                return 0;
1419        }
1420
1421        for_each_sg(sg, sg, n, i) {
1422                orb->page_table[i].high = cpu_to_be32(sg_dma_len(sg) << 16);
1423                orb->page_table[i].low = cpu_to_be32(sg_dma_address(sg));
1424        }
1425
1426        orb->page_table_bus =
1427                dma_map_single(device->card->device, orb->page_table,
1428                               sizeof(orb->page_table), DMA_TO_DEVICE);
1429        if (dma_mapping_error(device->card->device, orb->page_table_bus))
1430                goto fail_page_table;
1431
1432        /*
1433         * The data_descriptor pointer is the one case where we need
1434         * to fill in the node ID part of the address.  All other
1435         * pointers assume that the data referenced reside on the
1436         * initiator (i.e. us), but data_descriptor can refer to data
1437         * on other nodes so we need to put our ID in descriptor.high.
1438         */
1439        orb->request.data_descriptor.high = cpu_to_be32(lu->tgt->address_high);
1440        orb->request.data_descriptor.low  = cpu_to_be32(orb->page_table_bus);
1441        orb->request.misc |= cpu_to_be32(COMMAND_ORB_PAGE_TABLE_PRESENT |
1442                                         COMMAND_ORB_DATA_SIZE(n));
1443
1444        return 0;
1445
1446 fail_page_table:
1447        scsi_dma_unmap(orb->cmd);
1448 fail:
1449        return -ENOMEM;
1450}
1451
1452/* SCSI stack integration */
1453
1454static int sbp2_scsi_queuecommand(struct Scsi_Host *shost,
1455                                  struct scsi_cmnd *cmd)
1456{
1457        struct sbp2_logical_unit *lu = cmd->device->hostdata;
1458        struct fw_device *device = target_parent_device(lu->tgt);
1459        struct sbp2_command_orb *orb;
1460        int generation, retval = SCSI_MLQUEUE_HOST_BUSY;
1461
1462        orb = kzalloc(sizeof(*orb), GFP_ATOMIC);
1463        if (orb == NULL)
1464                return SCSI_MLQUEUE_HOST_BUSY;
1465
1466        /* Initialize rcode to something not RCODE_COMPLETE. */
1467        orb->base.rcode = -1;
1468        kref_init(&orb->base.kref);
1469        orb->cmd = cmd;
1470        orb->request.next.high = cpu_to_be32(SBP2_ORB_NULL);
1471        orb->request.misc = cpu_to_be32(
1472                COMMAND_ORB_MAX_PAYLOAD(lu->tgt->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 |= cpu_to_be32(COMMAND_ORB_DIRECTION);
1478
1479        generation = device->generation;
1480        smp_rmb();    /* sbp2_map_scatterlist looks at tgt->address_high */
1481
1482        if (scsi_sg_count(cmd) && sbp2_map_scatterlist(orb, device, lu) < 0)
1483                goto out;
1484
1485        memcpy(orb->request.command_block, cmd->cmnd, cmd->cmd_len);
1486
1487        orb->base.callback = complete_command_orb;
1488        orb->base.request_bus =
1489                dma_map_single(device->card->device, &orb->request,
1490                               sizeof(orb->request), DMA_TO_DEVICE);
1491        if (dma_mapping_error(device->card->device, orb->base.request_bus)) {
1492                sbp2_unmap_scatterlist(device->card->device, orb);
1493                goto out;
1494        }
1495
1496        sbp2_send_orb(&orb->base, lu, lu->tgt->node_id, generation,
1497                      lu->command_block_agent_address + SBP2_ORB_POINTER);
1498        retval = 0;
1499 out:
1500        kref_put(&orb->base.kref, free_orb);
1501        return retval;
1502}
1503
1504static int sbp2_scsi_slave_alloc(struct scsi_device *sdev)
1505{
1506        struct sbp2_logical_unit *lu = sdev->hostdata;
1507
1508        /* (Re-)Adding logical units via the SCSI stack is not supported. */
1509        if (!lu)
1510                return -ENOSYS;
1511
1512        sdev->allow_restart = 1;
1513
1514        /*
1515         * SBP-2 does not require any alignment, but we set it anyway
1516         * for compatibility with earlier versions of this driver.
1517         */
1518        blk_queue_update_dma_alignment(sdev->request_queue, 4 - 1);
1519
1520        if (lu->tgt->workarounds & SBP2_WORKAROUND_INQUIRY_36)
1521                sdev->inquiry_len = 36;
1522
1523        return 0;
1524}
1525
1526static int sbp2_scsi_slave_configure(struct scsi_device *sdev)
1527{
1528        struct sbp2_logical_unit *lu = sdev->hostdata;
1529
1530        sdev->use_10_for_rw = 1;
1531
1532        if (sbp2_param_exclusive_login)
1533                sdev->manage_start_stop = 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_POWER_CONDITION)
1546                sdev->start_stop_pwr_cond = 1;
1547
1548        if (lu->tgt->workarounds & SBP2_WORKAROUND_128K_MAX_TRANS)
1549                blk_queue_max_hw_sectors(sdev->request_queue, 128 * 1024 / 512);
1550
1551        return 0;
1552}
1553
1554/*
1555 * Called by scsi stack when something has really gone wrong.  Usually
1556 * called when a command has timed-out for some reason.
1557 */
1558static int sbp2_scsi_abort(struct scsi_cmnd *cmd)
1559{
1560        struct sbp2_logical_unit *lu = cmd->device->hostdata;
1561
1562        dev_notice(lu_dev(lu), "sbp2_scsi_abort\n");
1563        sbp2_agent_reset(lu);
1564        sbp2_cancel_orbs(lu);
1565
1566        return SUCCESS;
1567}
1568
1569/*
1570 * Format of /sys/bus/scsi/devices/.../ieee1394_id:
1571 * u64 EUI-64 : u24 directory_ID : u16 LUN  (all printed in hexadecimal)
1572 *
1573 * This is the concatenation of target port identifier and logical unit
1574 * identifier as per SAM-2...SAM-4 annex A.
1575 */
1576static ssize_t sbp2_sysfs_ieee1394_id_show(struct device *dev,
1577                        struct device_attribute *attr, char *buf)
1578{
1579        struct scsi_device *sdev = to_scsi_device(dev);
1580        struct sbp2_logical_unit *lu;
1581
1582        if (!sdev)
1583                return 0;
1584
1585        lu = sdev->hostdata;
1586
1587        return sprintf(buf, "%016llx:%06x:%04x\n",
1588                        (unsigned long long)lu->tgt->guid,
1589                        lu->tgt->directory_id, lu->lun);
1590}
1591
1592static DEVICE_ATTR(ieee1394_id, S_IRUGO, sbp2_sysfs_ieee1394_id_show, NULL);
1593
1594static struct device_attribute *sbp2_scsi_sysfs_attrs[] = {
1595        &dev_attr_ieee1394_id,
1596        NULL
1597};
1598
1599static struct scsi_host_template scsi_driver_template = {
1600        .module                 = THIS_MODULE,
1601        .name                   = "SBP-2 IEEE-1394",
1602        .proc_name              = "sbp2",
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        .max_segment_size       = SBP2_MAX_SEG_SIZE,
1610        .can_queue              = 1,
1611        .sdev_attrs             = sbp2_scsi_sysfs_attrs,
1612};
1613
1614MODULE_AUTHOR("Kristian Hoegsberg <krh@bitplanet.net>");
1615MODULE_DESCRIPTION("SCSI over IEEE1394");
1616MODULE_LICENSE("GPL");
1617MODULE_DEVICE_TABLE(ieee1394, sbp2_id_table);
1618
1619/* Provide a module alias so root-on-sbp2 initrds don't break. */
1620MODULE_ALIAS("sbp2");
1621
1622static int __init sbp2_init(void)
1623{
1624        return driver_register(&sbp2_driver.driver);
1625}
1626
1627static void __exit sbp2_cleanup(void)
1628{
1629        driver_unregister(&sbp2_driver.driver);
1630}
1631
1632module_init(sbp2_init);
1633module_exit(sbp2_cleanup);
1634