linux/drivers/scsi/libsas/sas_scsi_host.c
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   1// SPDX-License-Identifier: GPL-2.0-only
   2/*
   3 * Serial Attached SCSI (SAS) class SCSI Host glue.
   4 *
   5 * Copyright (C) 2005 Adaptec, Inc.  All rights reserved.
   6 * Copyright (C) 2005 Luben Tuikov <luben_tuikov@adaptec.com>
   7 */
   8
   9#include <linux/kthread.h>
  10#include <linux/firmware.h>
  11#include <linux/export.h>
  12#include <linux/ctype.h>
  13#include <linux/kernel.h>
  14
  15#include "sas_internal.h"
  16
  17#include <scsi/scsi_host.h>
  18#include <scsi/scsi_device.h>
  19#include <scsi/scsi_tcq.h>
  20#include <scsi/scsi.h>
  21#include <scsi/scsi_eh.h>
  22#include <scsi/scsi_transport.h>
  23#include <scsi/scsi_transport_sas.h>
  24#include <scsi/sas_ata.h>
  25#include "../scsi_sas_internal.h"
  26#include "../scsi_transport_api.h"
  27#include "../scsi_priv.h"
  28
  29#include <linux/err.h>
  30#include <linux/blkdev.h>
  31#include <linux/freezer.h>
  32#include <linux/gfp.h>
  33#include <linux/scatterlist.h>
  34#include <linux/libata.h>
  35
  36/* record final status and free the task */
  37static void sas_end_task(struct scsi_cmnd *sc, struct sas_task *task)
  38{
  39        struct task_status_struct *ts = &task->task_status;
  40        int hs = 0, stat = 0;
  41
  42        if (ts->resp == SAS_TASK_UNDELIVERED) {
  43                /* transport error */
  44                hs = DID_NO_CONNECT;
  45        } else { /* ts->resp == SAS_TASK_COMPLETE */
  46                /* task delivered, what happened afterwards? */
  47                switch (ts->stat) {
  48                case SAS_DEV_NO_RESPONSE:
  49                case SAS_INTERRUPTED:
  50                case SAS_PHY_DOWN:
  51                case SAS_NAK_R_ERR:
  52                case SAS_OPEN_TO:
  53                        hs = DID_NO_CONNECT;
  54                        break;
  55                case SAS_DATA_UNDERRUN:
  56                        scsi_set_resid(sc, ts->residual);
  57                        if (scsi_bufflen(sc) - scsi_get_resid(sc) < sc->underflow)
  58                                hs = DID_ERROR;
  59                        break;
  60                case SAS_DATA_OVERRUN:
  61                        hs = DID_ERROR;
  62                        break;
  63                case SAS_QUEUE_FULL:
  64                        hs = DID_SOFT_ERROR; /* retry */
  65                        break;
  66                case SAS_DEVICE_UNKNOWN:
  67                        hs = DID_BAD_TARGET;
  68                        break;
  69                case SAS_SG_ERR:
  70                        hs = DID_PARITY;
  71                        break;
  72                case SAS_OPEN_REJECT:
  73                        if (ts->open_rej_reason == SAS_OREJ_RSVD_RETRY)
  74                                hs = DID_SOFT_ERROR; /* retry */
  75                        else
  76                                hs = DID_ERROR;
  77                        break;
  78                case SAS_PROTO_RESPONSE:
  79                        pr_notice("LLDD:%s sent SAS_PROTO_RESP for an SSP task; please report this\n",
  80                                  task->dev->port->ha->sas_ha_name);
  81                        break;
  82                case SAS_ABORTED_TASK:
  83                        hs = DID_ABORT;
  84                        break;
  85                case SAM_STAT_CHECK_CONDITION:
  86                        memcpy(sc->sense_buffer, ts->buf,
  87                               min(SCSI_SENSE_BUFFERSIZE, ts->buf_valid_size));
  88                        stat = SAM_STAT_CHECK_CONDITION;
  89                        break;
  90                default:
  91                        stat = ts->stat;
  92                        break;
  93                }
  94        }
  95
  96        sc->result = (hs << 16) | stat;
  97        ASSIGN_SAS_TASK(sc, NULL);
  98        sas_free_task(task);
  99}
 100
 101static void sas_scsi_task_done(struct sas_task *task)
 102{
 103        struct scsi_cmnd *sc = task->uldd_task;
 104        struct domain_device *dev = task->dev;
 105        struct sas_ha_struct *ha = dev->port->ha;
 106        unsigned long flags;
 107
 108        spin_lock_irqsave(&dev->done_lock, flags);
 109        if (test_bit(SAS_HA_FROZEN, &ha->state))
 110                task = NULL;
 111        else
 112                ASSIGN_SAS_TASK(sc, NULL);
 113        spin_unlock_irqrestore(&dev->done_lock, flags);
 114
 115        if (unlikely(!task)) {
 116                /* task will be completed by the error handler */
 117                pr_debug("task done but aborted\n");
 118                return;
 119        }
 120
 121        if (unlikely(!sc)) {
 122                pr_debug("task_done called with non existing SCSI cmnd!\n");
 123                sas_free_task(task);
 124                return;
 125        }
 126
 127        sas_end_task(sc, task);
 128        sc->scsi_done(sc);
 129}
 130
 131static struct sas_task *sas_create_task(struct scsi_cmnd *cmd,
 132                                               struct domain_device *dev,
 133                                               gfp_t gfp_flags)
 134{
 135        struct sas_task *task = sas_alloc_task(gfp_flags);
 136        struct scsi_lun lun;
 137
 138        if (!task)
 139                return NULL;
 140
 141        task->uldd_task = cmd;
 142        ASSIGN_SAS_TASK(cmd, task);
 143
 144        task->dev = dev;
 145        task->task_proto = task->dev->tproto; /* BUG_ON(!SSP) */
 146
 147        task->ssp_task.retry_count = 1;
 148        int_to_scsilun(cmd->device->lun, &lun);
 149        memcpy(task->ssp_task.LUN, &lun.scsi_lun, 8);
 150        task->ssp_task.task_attr = TASK_ATTR_SIMPLE;
 151        task->ssp_task.cmd = cmd;
 152
 153        task->scatter = scsi_sglist(cmd);
 154        task->num_scatter = scsi_sg_count(cmd);
 155        task->total_xfer_len = scsi_bufflen(cmd);
 156        task->data_dir = cmd->sc_data_direction;
 157
 158        task->task_done = sas_scsi_task_done;
 159
 160        return task;
 161}
 162
 163int sas_queuecommand(struct Scsi_Host *host, struct scsi_cmnd *cmd)
 164{
 165        struct sas_internal *i = to_sas_internal(host->transportt);
 166        struct domain_device *dev = cmd_to_domain_dev(cmd);
 167        struct sas_task *task;
 168        int res = 0;
 169
 170        /* If the device fell off, no sense in issuing commands */
 171        if (test_bit(SAS_DEV_GONE, &dev->state)) {
 172                cmd->result = DID_BAD_TARGET << 16;
 173                goto out_done;
 174        }
 175
 176        if (dev_is_sata(dev)) {
 177                spin_lock_irq(dev->sata_dev.ap->lock);
 178                res = ata_sas_queuecmd(cmd, dev->sata_dev.ap);
 179                spin_unlock_irq(dev->sata_dev.ap->lock);
 180                return res;
 181        }
 182
 183        task = sas_create_task(cmd, dev, GFP_ATOMIC);
 184        if (!task)
 185                return SCSI_MLQUEUE_HOST_BUSY;
 186
 187        res = i->dft->lldd_execute_task(task, GFP_ATOMIC);
 188        if (res)
 189                goto out_free_task;
 190        return 0;
 191
 192out_free_task:
 193        pr_debug("lldd_execute_task returned: %d\n", res);
 194        ASSIGN_SAS_TASK(cmd, NULL);
 195        sas_free_task(task);
 196        if (res == -SAS_QUEUE_FULL)
 197                cmd->result = DID_SOFT_ERROR << 16; /* retry */
 198        else
 199                cmd->result = DID_ERROR << 16;
 200out_done:
 201        cmd->scsi_done(cmd);
 202        return 0;
 203}
 204
 205static void sas_eh_finish_cmd(struct scsi_cmnd *cmd)
 206{
 207        struct sas_ha_struct *sas_ha = SHOST_TO_SAS_HA(cmd->device->host);
 208        struct domain_device *dev = cmd_to_domain_dev(cmd);
 209        struct sas_task *task = TO_SAS_TASK(cmd);
 210
 211        /* At this point, we only get called following an actual abort
 212         * of the task, so we should be guaranteed not to be racing with
 213         * any completions from the LLD.  Task is freed after this.
 214         */
 215        sas_end_task(cmd, task);
 216
 217        if (dev_is_sata(dev)) {
 218                /* defer commands to libata so that libata EH can
 219                 * handle ata qcs correctly
 220                 */
 221                list_move_tail(&cmd->eh_entry, &sas_ha->eh_ata_q);
 222                return;
 223        }
 224
 225        /* now finish the command and move it on to the error
 226         * handler done list, this also takes it off the
 227         * error handler pending list.
 228         */
 229        scsi_eh_finish_cmd(cmd, &sas_ha->eh_done_q);
 230}
 231
 232static void sas_scsi_clear_queue_lu(struct list_head *error_q, struct scsi_cmnd *my_cmd)
 233{
 234        struct scsi_cmnd *cmd, *n;
 235
 236        list_for_each_entry_safe(cmd, n, error_q, eh_entry) {
 237                if (cmd->device->sdev_target == my_cmd->device->sdev_target &&
 238                    cmd->device->lun == my_cmd->device->lun)
 239                        sas_eh_finish_cmd(cmd);
 240        }
 241}
 242
 243static void sas_scsi_clear_queue_I_T(struct list_head *error_q,
 244                                     struct domain_device *dev)
 245{
 246        struct scsi_cmnd *cmd, *n;
 247
 248        list_for_each_entry_safe(cmd, n, error_q, eh_entry) {
 249                struct domain_device *x = cmd_to_domain_dev(cmd);
 250
 251                if (x == dev)
 252                        sas_eh_finish_cmd(cmd);
 253        }
 254}
 255
 256static void sas_scsi_clear_queue_port(struct list_head *error_q,
 257                                      struct asd_sas_port *port)
 258{
 259        struct scsi_cmnd *cmd, *n;
 260
 261        list_for_each_entry_safe(cmd, n, error_q, eh_entry) {
 262                struct domain_device *dev = cmd_to_domain_dev(cmd);
 263                struct asd_sas_port *x = dev->port;
 264
 265                if (x == port)
 266                        sas_eh_finish_cmd(cmd);
 267        }
 268}
 269
 270enum task_disposition {
 271        TASK_IS_DONE,
 272        TASK_IS_ABORTED,
 273        TASK_IS_AT_LU,
 274        TASK_IS_NOT_AT_LU,
 275        TASK_ABORT_FAILED,
 276};
 277
 278static enum task_disposition sas_scsi_find_task(struct sas_task *task)
 279{
 280        unsigned long flags;
 281        int i, res;
 282        struct sas_internal *si =
 283                to_sas_internal(task->dev->port->ha->core.shost->transportt);
 284
 285        for (i = 0; i < 5; i++) {
 286                pr_notice("%s: aborting task 0x%p\n", __func__, task);
 287                res = si->dft->lldd_abort_task(task);
 288
 289                spin_lock_irqsave(&task->task_state_lock, flags);
 290                if (task->task_state_flags & SAS_TASK_STATE_DONE) {
 291                        spin_unlock_irqrestore(&task->task_state_lock, flags);
 292                        pr_debug("%s: task 0x%p is done\n", __func__, task);
 293                        return TASK_IS_DONE;
 294                }
 295                spin_unlock_irqrestore(&task->task_state_lock, flags);
 296
 297                if (res == TMF_RESP_FUNC_COMPLETE) {
 298                        pr_notice("%s: task 0x%p is aborted\n",
 299                                  __func__, task);
 300                        return TASK_IS_ABORTED;
 301                } else if (si->dft->lldd_query_task) {
 302                        pr_notice("%s: querying task 0x%p\n", __func__, task);
 303                        res = si->dft->lldd_query_task(task);
 304                        switch (res) {
 305                        case TMF_RESP_FUNC_SUCC:
 306                                pr_notice("%s: task 0x%p at LU\n", __func__,
 307                                          task);
 308                                return TASK_IS_AT_LU;
 309                        case TMF_RESP_FUNC_COMPLETE:
 310                                pr_notice("%s: task 0x%p not at LU\n",
 311                                          __func__, task);
 312                                return TASK_IS_NOT_AT_LU;
 313                        case TMF_RESP_FUNC_FAILED:
 314                                pr_notice("%s: task 0x%p failed to abort\n",
 315                                          __func__, task);
 316                                return TASK_ABORT_FAILED;
 317                        }
 318
 319                }
 320        }
 321        return res;
 322}
 323
 324static int sas_recover_lu(struct domain_device *dev, struct scsi_cmnd *cmd)
 325{
 326        int res = TMF_RESP_FUNC_FAILED;
 327        struct scsi_lun lun;
 328        struct sas_internal *i =
 329                to_sas_internal(dev->port->ha->core.shost->transportt);
 330
 331        int_to_scsilun(cmd->device->lun, &lun);
 332
 333        pr_notice("eh: device %016llx LUN 0x%llx has the task\n",
 334                  SAS_ADDR(dev->sas_addr),
 335                  cmd->device->lun);
 336
 337        if (i->dft->lldd_abort_task_set)
 338                res = i->dft->lldd_abort_task_set(dev, lun.scsi_lun);
 339
 340        if (res == TMF_RESP_FUNC_FAILED) {
 341                if (i->dft->lldd_clear_task_set)
 342                        res = i->dft->lldd_clear_task_set(dev, lun.scsi_lun);
 343        }
 344
 345        if (res == TMF_RESP_FUNC_FAILED) {
 346                if (i->dft->lldd_lu_reset)
 347                        res = i->dft->lldd_lu_reset(dev, lun.scsi_lun);
 348        }
 349
 350        return res;
 351}
 352
 353static int sas_recover_I_T(struct domain_device *dev)
 354{
 355        int res = TMF_RESP_FUNC_FAILED;
 356        struct sas_internal *i =
 357                to_sas_internal(dev->port->ha->core.shost->transportt);
 358
 359        pr_notice("I_T nexus reset for dev %016llx\n",
 360                  SAS_ADDR(dev->sas_addr));
 361
 362        if (i->dft->lldd_I_T_nexus_reset)
 363                res = i->dft->lldd_I_T_nexus_reset(dev);
 364
 365        return res;
 366}
 367
 368/* take a reference on the last known good phy for this device */
 369struct sas_phy *sas_get_local_phy(struct domain_device *dev)
 370{
 371        struct sas_ha_struct *ha = dev->port->ha;
 372        struct sas_phy *phy;
 373        unsigned long flags;
 374
 375        /* a published domain device always has a valid phy, it may be
 376         * stale, but it is never NULL
 377         */
 378        BUG_ON(!dev->phy);
 379
 380        spin_lock_irqsave(&ha->phy_port_lock, flags);
 381        phy = dev->phy;
 382        get_device(&phy->dev);
 383        spin_unlock_irqrestore(&ha->phy_port_lock, flags);
 384
 385        return phy;
 386}
 387EXPORT_SYMBOL_GPL(sas_get_local_phy);
 388
 389static void sas_wait_eh(struct domain_device *dev)
 390{
 391        struct sas_ha_struct *ha = dev->port->ha;
 392        DEFINE_WAIT(wait);
 393
 394        if (dev_is_sata(dev)) {
 395                ata_port_wait_eh(dev->sata_dev.ap);
 396                return;
 397        }
 398 retry:
 399        spin_lock_irq(&ha->lock);
 400
 401        while (test_bit(SAS_DEV_EH_PENDING, &dev->state)) {
 402                prepare_to_wait(&ha->eh_wait_q, &wait, TASK_UNINTERRUPTIBLE);
 403                spin_unlock_irq(&ha->lock);
 404                schedule();
 405                spin_lock_irq(&ha->lock);
 406        }
 407        finish_wait(&ha->eh_wait_q, &wait);
 408
 409        spin_unlock_irq(&ha->lock);
 410
 411        /* make sure SCSI EH is complete */
 412        if (scsi_host_in_recovery(ha->core.shost)) {
 413                msleep(10);
 414                goto retry;
 415        }
 416}
 417
 418static int sas_queue_reset(struct domain_device *dev, int reset_type,
 419                           u64 lun, int wait)
 420{
 421        struct sas_ha_struct *ha = dev->port->ha;
 422        int scheduled = 0, tries = 100;
 423
 424        /* ata: promote lun reset to bus reset */
 425        if (dev_is_sata(dev)) {
 426                sas_ata_schedule_reset(dev);
 427                if (wait)
 428                        sas_ata_wait_eh(dev);
 429                return SUCCESS;
 430        }
 431
 432        while (!scheduled && tries--) {
 433                spin_lock_irq(&ha->lock);
 434                if (!test_bit(SAS_DEV_EH_PENDING, &dev->state) &&
 435                    !test_bit(reset_type, &dev->state)) {
 436                        scheduled = 1;
 437                        ha->eh_active++;
 438                        list_add_tail(&dev->ssp_dev.eh_list_node, &ha->eh_dev_q);
 439                        set_bit(SAS_DEV_EH_PENDING, &dev->state);
 440                        set_bit(reset_type, &dev->state);
 441                        int_to_scsilun(lun, &dev->ssp_dev.reset_lun);
 442                        scsi_schedule_eh(ha->core.shost);
 443                }
 444                spin_unlock_irq(&ha->lock);
 445
 446                if (wait)
 447                        sas_wait_eh(dev);
 448
 449                if (scheduled)
 450                        return SUCCESS;
 451        }
 452
 453        pr_warn("%s reset of %s failed\n",
 454                reset_type == SAS_DEV_LU_RESET ? "LUN" : "Bus",
 455                dev_name(&dev->rphy->dev));
 456
 457        return FAILED;
 458}
 459
 460int sas_eh_abort_handler(struct scsi_cmnd *cmd)
 461{
 462        int res = TMF_RESP_FUNC_FAILED;
 463        struct sas_task *task = TO_SAS_TASK(cmd);
 464        struct Scsi_Host *host = cmd->device->host;
 465        struct domain_device *dev = cmd_to_domain_dev(cmd);
 466        struct sas_internal *i = to_sas_internal(host->transportt);
 467        unsigned long flags;
 468
 469        if (!i->dft->lldd_abort_task)
 470                return FAILED;
 471
 472        spin_lock_irqsave(host->host_lock, flags);
 473        /* We cannot do async aborts for SATA devices */
 474        if (dev_is_sata(dev) && !host->host_eh_scheduled) {
 475                spin_unlock_irqrestore(host->host_lock, flags);
 476                return FAILED;
 477        }
 478        spin_unlock_irqrestore(host->host_lock, flags);
 479
 480        if (task)
 481                res = i->dft->lldd_abort_task(task);
 482        else
 483                pr_notice("no task to abort\n");
 484        if (res == TMF_RESP_FUNC_SUCC || res == TMF_RESP_FUNC_COMPLETE)
 485                return SUCCESS;
 486
 487        return FAILED;
 488}
 489EXPORT_SYMBOL_GPL(sas_eh_abort_handler);
 490
 491/* Attempt to send a LUN reset message to a device */
 492int sas_eh_device_reset_handler(struct scsi_cmnd *cmd)
 493{
 494        int res;
 495        struct scsi_lun lun;
 496        struct Scsi_Host *host = cmd->device->host;
 497        struct domain_device *dev = cmd_to_domain_dev(cmd);
 498        struct sas_internal *i = to_sas_internal(host->transportt);
 499
 500        if (current != host->ehandler)
 501                return sas_queue_reset(dev, SAS_DEV_LU_RESET, cmd->device->lun, 0);
 502
 503        int_to_scsilun(cmd->device->lun, &lun);
 504
 505        if (!i->dft->lldd_lu_reset)
 506                return FAILED;
 507
 508        res = i->dft->lldd_lu_reset(dev, lun.scsi_lun);
 509        if (res == TMF_RESP_FUNC_SUCC || res == TMF_RESP_FUNC_COMPLETE)
 510                return SUCCESS;
 511
 512        return FAILED;
 513}
 514
 515int sas_eh_target_reset_handler(struct scsi_cmnd *cmd)
 516{
 517        int res;
 518        struct Scsi_Host *host = cmd->device->host;
 519        struct domain_device *dev = cmd_to_domain_dev(cmd);
 520        struct sas_internal *i = to_sas_internal(host->transportt);
 521
 522        if (current != host->ehandler)
 523                return sas_queue_reset(dev, SAS_DEV_RESET, 0, 0);
 524
 525        if (!i->dft->lldd_I_T_nexus_reset)
 526                return FAILED;
 527
 528        res = i->dft->lldd_I_T_nexus_reset(dev);
 529        if (res == TMF_RESP_FUNC_SUCC || res == TMF_RESP_FUNC_COMPLETE ||
 530            res == -ENODEV)
 531                return SUCCESS;
 532
 533        return FAILED;
 534}
 535
 536/* Try to reset a device */
 537static int try_to_reset_cmd_device(struct scsi_cmnd *cmd)
 538{
 539        int res;
 540        struct Scsi_Host *shost = cmd->device->host;
 541
 542        if (!shost->hostt->eh_device_reset_handler)
 543                goto try_target_reset;
 544
 545        res = shost->hostt->eh_device_reset_handler(cmd);
 546        if (res == SUCCESS)
 547                return res;
 548
 549try_target_reset:
 550        if (shost->hostt->eh_target_reset_handler)
 551                return shost->hostt->eh_target_reset_handler(cmd);
 552
 553        return FAILED;
 554}
 555
 556static void sas_eh_handle_sas_errors(struct Scsi_Host *shost, struct list_head *work_q)
 557{
 558        struct scsi_cmnd *cmd, *n;
 559        enum task_disposition res = TASK_IS_DONE;
 560        int tmf_resp, need_reset;
 561        struct sas_internal *i = to_sas_internal(shost->transportt);
 562        unsigned long flags;
 563        struct sas_ha_struct *ha = SHOST_TO_SAS_HA(shost);
 564        LIST_HEAD(done);
 565
 566        /* clean out any commands that won the completion vs eh race */
 567        list_for_each_entry_safe(cmd, n, work_q, eh_entry) {
 568                struct domain_device *dev = cmd_to_domain_dev(cmd);
 569                struct sas_task *task;
 570
 571                spin_lock_irqsave(&dev->done_lock, flags);
 572                /* by this point the lldd has either observed
 573                 * SAS_HA_FROZEN and is leaving the task alone, or has
 574                 * won the race with eh and decided to complete it
 575                 */
 576                task = TO_SAS_TASK(cmd);
 577                spin_unlock_irqrestore(&dev->done_lock, flags);
 578
 579                if (!task)
 580                        list_move_tail(&cmd->eh_entry, &done);
 581        }
 582
 583 Again:
 584        list_for_each_entry_safe(cmd, n, work_q, eh_entry) {
 585                struct sas_task *task = TO_SAS_TASK(cmd);
 586
 587                list_del_init(&cmd->eh_entry);
 588
 589                spin_lock_irqsave(&task->task_state_lock, flags);
 590                need_reset = task->task_state_flags & SAS_TASK_NEED_DEV_RESET;
 591                spin_unlock_irqrestore(&task->task_state_lock, flags);
 592
 593                if (need_reset) {
 594                        pr_notice("%s: task 0x%p requests reset\n",
 595                                  __func__, task);
 596                        goto reset;
 597                }
 598
 599                pr_debug("trying to find task 0x%p\n", task);
 600                res = sas_scsi_find_task(task);
 601
 602                switch (res) {
 603                case TASK_IS_DONE:
 604                        pr_notice("%s: task 0x%p is done\n", __func__,
 605                                    task);
 606                        sas_eh_finish_cmd(cmd);
 607                        continue;
 608                case TASK_IS_ABORTED:
 609                        pr_notice("%s: task 0x%p is aborted\n",
 610                                  __func__, task);
 611                        sas_eh_finish_cmd(cmd);
 612                        continue;
 613                case TASK_IS_AT_LU:
 614                        pr_info("task 0x%p is at LU: lu recover\n", task);
 615 reset:
 616                        tmf_resp = sas_recover_lu(task->dev, cmd);
 617                        if (tmf_resp == TMF_RESP_FUNC_COMPLETE) {
 618                                pr_notice("dev %016llx LU 0x%llx is recovered\n",
 619                                          SAS_ADDR(task->dev),
 620                                          cmd->device->lun);
 621                                sas_eh_finish_cmd(cmd);
 622                                sas_scsi_clear_queue_lu(work_q, cmd);
 623                                goto Again;
 624                        }
 625                        fallthrough;
 626                case TASK_IS_NOT_AT_LU:
 627                case TASK_ABORT_FAILED:
 628                        pr_notice("task 0x%p is not at LU: I_T recover\n",
 629                                  task);
 630                        tmf_resp = sas_recover_I_T(task->dev);
 631                        if (tmf_resp == TMF_RESP_FUNC_COMPLETE ||
 632                            tmf_resp == -ENODEV) {
 633                                struct domain_device *dev = task->dev;
 634                                pr_notice("I_T %016llx recovered\n",
 635                                          SAS_ADDR(task->dev->sas_addr));
 636                                sas_eh_finish_cmd(cmd);
 637                                sas_scsi_clear_queue_I_T(work_q, dev);
 638                                goto Again;
 639                        }
 640                        /* Hammer time :-) */
 641                        try_to_reset_cmd_device(cmd);
 642                        if (i->dft->lldd_clear_nexus_port) {
 643                                struct asd_sas_port *port = task->dev->port;
 644                                pr_debug("clearing nexus for port:%d\n",
 645                                          port->id);
 646                                res = i->dft->lldd_clear_nexus_port(port);
 647                                if (res == TMF_RESP_FUNC_COMPLETE) {
 648                                        pr_notice("clear nexus port:%d succeeded\n",
 649                                                  port->id);
 650                                        sas_eh_finish_cmd(cmd);
 651                                        sas_scsi_clear_queue_port(work_q,
 652                                                                  port);
 653                                        goto Again;
 654                                }
 655                        }
 656                        if (i->dft->lldd_clear_nexus_ha) {
 657                                pr_debug("clear nexus ha\n");
 658                                res = i->dft->lldd_clear_nexus_ha(ha);
 659                                if (res == TMF_RESP_FUNC_COMPLETE) {
 660                                        pr_notice("clear nexus ha succeeded\n");
 661                                        sas_eh_finish_cmd(cmd);
 662                                        goto clear_q;
 663                                }
 664                        }
 665                        /* If we are here -- this means that no amount
 666                         * of effort could recover from errors.  Quite
 667                         * possibly the HA just disappeared.
 668                         */
 669                        pr_err("error from device %016llx, LUN 0x%llx couldn't be recovered in any way\n",
 670                               SAS_ADDR(task->dev->sas_addr),
 671                               cmd->device->lun);
 672
 673                        sas_eh_finish_cmd(cmd);
 674                        goto clear_q;
 675                }
 676        }
 677 out:
 678        list_splice_tail(&done, work_q);
 679        list_splice_tail_init(&ha->eh_ata_q, work_q);
 680        return;
 681
 682 clear_q:
 683        pr_debug("--- Exit %s -- clear_q\n", __func__);
 684        list_for_each_entry_safe(cmd, n, work_q, eh_entry)
 685                sas_eh_finish_cmd(cmd);
 686        goto out;
 687}
 688
 689static void sas_eh_handle_resets(struct Scsi_Host *shost)
 690{
 691        struct sas_ha_struct *ha = SHOST_TO_SAS_HA(shost);
 692        struct sas_internal *i = to_sas_internal(shost->transportt);
 693
 694        /* handle directed resets to sas devices */
 695        spin_lock_irq(&ha->lock);
 696        while (!list_empty(&ha->eh_dev_q)) {
 697                struct domain_device *dev;
 698                struct ssp_device *ssp;
 699
 700                ssp = list_entry(ha->eh_dev_q.next, typeof(*ssp), eh_list_node);
 701                list_del_init(&ssp->eh_list_node);
 702                dev = container_of(ssp, typeof(*dev), ssp_dev);
 703                kref_get(&dev->kref);
 704                WARN_ONCE(dev_is_sata(dev), "ssp reset to ata device?\n");
 705
 706                spin_unlock_irq(&ha->lock);
 707
 708                if (test_and_clear_bit(SAS_DEV_LU_RESET, &dev->state))
 709                        i->dft->lldd_lu_reset(dev, ssp->reset_lun.scsi_lun);
 710
 711                if (test_and_clear_bit(SAS_DEV_RESET, &dev->state))
 712                        i->dft->lldd_I_T_nexus_reset(dev);
 713
 714                sas_put_device(dev);
 715                spin_lock_irq(&ha->lock);
 716                clear_bit(SAS_DEV_EH_PENDING, &dev->state);
 717                ha->eh_active--;
 718        }
 719        spin_unlock_irq(&ha->lock);
 720}
 721
 722
 723void sas_scsi_recover_host(struct Scsi_Host *shost)
 724{
 725        struct sas_ha_struct *ha = SHOST_TO_SAS_HA(shost);
 726        LIST_HEAD(eh_work_q);
 727        int tries = 0;
 728        bool retry;
 729
 730retry:
 731        tries++;
 732        retry = true;
 733        spin_lock_irq(shost->host_lock);
 734        list_splice_init(&shost->eh_cmd_q, &eh_work_q);
 735        spin_unlock_irq(shost->host_lock);
 736
 737        pr_notice("Enter %s busy: %d failed: %d\n",
 738                  __func__, scsi_host_busy(shost), shost->host_failed);
 739        /*
 740         * Deal with commands that still have SAS tasks (i.e. they didn't
 741         * complete via the normal sas_task completion mechanism),
 742         * SAS_HA_FROZEN gives eh dominion over all sas_task completion.
 743         */
 744        set_bit(SAS_HA_FROZEN, &ha->state);
 745        sas_eh_handle_sas_errors(shost, &eh_work_q);
 746        clear_bit(SAS_HA_FROZEN, &ha->state);
 747        if (list_empty(&eh_work_q))
 748                goto out;
 749
 750        /*
 751         * Now deal with SCSI commands that completed ok but have a an error
 752         * code (and hopefully sense data) attached.  This is roughly what
 753         * scsi_unjam_host does, but we skip scsi_eh_abort_cmds because any
 754         * command we see here has no sas_task and is thus unknown to the HA.
 755         */
 756        sas_ata_eh(shost, &eh_work_q, &ha->eh_done_q);
 757        if (!scsi_eh_get_sense(&eh_work_q, &ha->eh_done_q))
 758                scsi_eh_ready_devs(shost, &eh_work_q, &ha->eh_done_q);
 759
 760out:
 761        sas_eh_handle_resets(shost);
 762
 763        /* now link into libata eh --- if we have any ata devices */
 764        sas_ata_strategy_handler(shost);
 765
 766        scsi_eh_flush_done_q(&ha->eh_done_q);
 767
 768        /* check if any new eh work was scheduled during the last run */
 769        spin_lock_irq(&ha->lock);
 770        if (ha->eh_active == 0) {
 771                shost->host_eh_scheduled = 0;
 772                retry = false;
 773        }
 774        spin_unlock_irq(&ha->lock);
 775
 776        if (retry)
 777                goto retry;
 778
 779        pr_notice("--- Exit %s: busy: %d failed: %d tries: %d\n",
 780                  __func__, scsi_host_busy(shost),
 781                  shost->host_failed, tries);
 782}
 783
 784int sas_ioctl(struct scsi_device *sdev, unsigned int cmd, void __user *arg)
 785{
 786        struct domain_device *dev = sdev_to_domain_dev(sdev);
 787
 788        if (dev_is_sata(dev))
 789                return ata_sas_scsi_ioctl(dev->sata_dev.ap, sdev, cmd, arg);
 790
 791        return -EINVAL;
 792}
 793
 794struct domain_device *sas_find_dev_by_rphy(struct sas_rphy *rphy)
 795{
 796        struct Scsi_Host *shost = dev_to_shost(rphy->dev.parent);
 797        struct sas_ha_struct *ha = SHOST_TO_SAS_HA(shost);
 798        struct domain_device *found_dev = NULL;
 799        int i;
 800        unsigned long flags;
 801
 802        spin_lock_irqsave(&ha->phy_port_lock, flags);
 803        for (i = 0; i < ha->num_phys; i++) {
 804                struct asd_sas_port *port = ha->sas_port[i];
 805                struct domain_device *dev;
 806
 807                spin_lock(&port->dev_list_lock);
 808                list_for_each_entry(dev, &port->dev_list, dev_list_node) {
 809                        if (rphy == dev->rphy) {
 810                                found_dev = dev;
 811                                spin_unlock(&port->dev_list_lock);
 812                                goto found;
 813                        }
 814                }
 815                spin_unlock(&port->dev_list_lock);
 816        }
 817 found:
 818        spin_unlock_irqrestore(&ha->phy_port_lock, flags);
 819
 820        return found_dev;
 821}
 822
 823int sas_target_alloc(struct scsi_target *starget)
 824{
 825        struct sas_rphy *rphy = dev_to_rphy(starget->dev.parent);
 826        struct domain_device *found_dev = sas_find_dev_by_rphy(rphy);
 827
 828        if (!found_dev)
 829                return -ENODEV;
 830
 831        kref_get(&found_dev->kref);
 832        starget->hostdata = found_dev;
 833        return 0;
 834}
 835
 836#define SAS_DEF_QD 256
 837
 838int sas_slave_configure(struct scsi_device *scsi_dev)
 839{
 840        struct domain_device *dev = sdev_to_domain_dev(scsi_dev);
 841
 842        BUG_ON(dev->rphy->identify.device_type != SAS_END_DEVICE);
 843
 844        if (dev_is_sata(dev)) {
 845                ata_sas_slave_configure(scsi_dev, dev->sata_dev.ap);
 846                return 0;
 847        }
 848
 849        sas_read_port_mode_page(scsi_dev);
 850
 851        if (scsi_dev->tagged_supported) {
 852                scsi_change_queue_depth(scsi_dev, SAS_DEF_QD);
 853        } else {
 854                pr_notice("device %016llx, LUN 0x%llx doesn't support TCQ\n",
 855                          SAS_ADDR(dev->sas_addr), scsi_dev->lun);
 856                scsi_change_queue_depth(scsi_dev, 1);
 857        }
 858
 859        scsi_dev->allow_restart = 1;
 860
 861        return 0;
 862}
 863
 864int sas_change_queue_depth(struct scsi_device *sdev, int depth)
 865{
 866        struct domain_device *dev = sdev_to_domain_dev(sdev);
 867
 868        if (dev_is_sata(dev))
 869                return __ata_change_queue_depth(dev->sata_dev.ap, sdev, depth);
 870
 871        if (!sdev->tagged_supported)
 872                depth = 1;
 873        return scsi_change_queue_depth(sdev, depth);
 874}
 875
 876int sas_bios_param(struct scsi_device *scsi_dev,
 877                          struct block_device *bdev,
 878                          sector_t capacity, int *hsc)
 879{
 880        hsc[0] = 255;
 881        hsc[1] = 63;
 882        sector_div(capacity, 255*63);
 883        hsc[2] = capacity;
 884
 885        return 0;
 886}
 887
 888/*
 889 * Tell an upper layer that it needs to initiate an abort for a given task.
 890 * This should only ever be called by an LLDD.
 891 */
 892void sas_task_abort(struct sas_task *task)
 893{
 894        struct scsi_cmnd *sc = task->uldd_task;
 895
 896        /* Escape for libsas internal commands */
 897        if (!sc) {
 898                struct sas_task_slow *slow = task->slow_task;
 899
 900                if (!slow)
 901                        return;
 902                if (!del_timer(&slow->timer))
 903                        return;
 904                slow->timer.function(&slow->timer);
 905                return;
 906        }
 907
 908        if (dev_is_sata(task->dev))
 909                sas_ata_task_abort(task);
 910        else
 911                blk_abort_request(sc->request);
 912}
 913
 914int sas_slave_alloc(struct scsi_device *sdev)
 915{
 916        if (dev_is_sata(sdev_to_domain_dev(sdev)) && sdev->lun)
 917                return -ENXIO;
 918
 919        return 0;
 920}
 921
 922void sas_target_destroy(struct scsi_target *starget)
 923{
 924        struct domain_device *found_dev = starget->hostdata;
 925
 926        if (!found_dev)
 927                return;
 928
 929        starget->hostdata = NULL;
 930        sas_put_device(found_dev);
 931}
 932
 933#define SAS_STRING_ADDR_SIZE    16
 934
 935int sas_request_addr(struct Scsi_Host *shost, u8 *addr)
 936{
 937        int res;
 938        const struct firmware *fw;
 939
 940        res = request_firmware(&fw, "sas_addr", &shost->shost_gendev);
 941        if (res)
 942                return res;
 943
 944        if (fw->size < SAS_STRING_ADDR_SIZE) {
 945                res = -ENODEV;
 946                goto out;
 947        }
 948
 949        res = hex2bin(addr, fw->data, strnlen(fw->data, SAS_ADDR_SIZE * 2) / 2);
 950        if (res)
 951                goto out;
 952
 953out:
 954        release_firmware(fw);
 955        return res;
 956}
 957EXPORT_SYMBOL_GPL(sas_request_addr);
 958
 959EXPORT_SYMBOL_GPL(sas_queuecommand);
 960EXPORT_SYMBOL_GPL(sas_target_alloc);
 961EXPORT_SYMBOL_GPL(sas_slave_configure);
 962EXPORT_SYMBOL_GPL(sas_change_queue_depth);
 963EXPORT_SYMBOL_GPL(sas_bios_param);
 964EXPORT_SYMBOL_GPL(sas_task_abort);
 965EXPORT_SYMBOL_GPL(sas_phy_reset);
 966EXPORT_SYMBOL_GPL(sas_eh_device_reset_handler);
 967EXPORT_SYMBOL_GPL(sas_eh_target_reset_handler);
 968EXPORT_SYMBOL_GPL(sas_slave_alloc);
 969EXPORT_SYMBOL_GPL(sas_target_destroy);
 970EXPORT_SYMBOL_GPL(sas_ioctl);
 971