linux/drivers/scsi/libsas/sas_scsi_host.c
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   1/*
   2 * Serial Attached SCSI (SAS) class SCSI Host glue.
   3 *
   4 * Copyright (C) 2005 Adaptec, Inc.  All rights reserved.
   5 * Copyright (C) 2005 Luben Tuikov <luben_tuikov@adaptec.com>
   6 *
   7 * This file is licensed under GPLv2.
   8 *
   9 * This program is free software; you can redistribute it and/or
  10 * modify it under the terms of the GNU General Public License as
  11 * published by the Free Software Foundation; either version 2 of the
  12 * License, or (at your option) any later version.
  13 *
  14 * This program is distributed in the hope that it will be useful, but
  15 * WITHOUT ANY WARRANTY; without even the implied warranty of
  16 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  17 * General Public License for more details.
  18 *
  19 * You should have received a copy of the GNU General Public License
  20 * along with this program; if not, write to the Free Software
  21 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307
  22 * USA
  23 *
  24 */
  25
  26#include <linux/kthread.h>
  27#include <linux/firmware.h>
  28#include <linux/export.h>
  29#include <linux/ctype.h>
  30
  31#include "sas_internal.h"
  32
  33#include <scsi/scsi_host.h>
  34#include <scsi/scsi_device.h>
  35#include <scsi/scsi_tcq.h>
  36#include <scsi/scsi.h>
  37#include <scsi/scsi_eh.h>
  38#include <scsi/scsi_transport.h>
  39#include <scsi/scsi_transport_sas.h>
  40#include <scsi/sas_ata.h>
  41#include "../scsi_sas_internal.h"
  42#include "../scsi_transport_api.h"
  43#include "../scsi_priv.h"
  44
  45#include <linux/err.h>
  46#include <linux/blkdev.h>
  47#include <linux/freezer.h>
  48#include <linux/gfp.h>
  49#include <linux/scatterlist.h>
  50#include <linux/libata.h>
  51
  52/* record final status and free the task */
  53static void sas_end_task(struct scsi_cmnd *sc, struct sas_task *task)
  54{
  55        struct task_status_struct *ts = &task->task_status;
  56        int hs = 0, stat = 0;
  57
  58        if (ts->resp == SAS_TASK_UNDELIVERED) {
  59                /* transport error */
  60                hs = DID_NO_CONNECT;
  61        } else { /* ts->resp == SAS_TASK_COMPLETE */
  62                /* task delivered, what happened afterwards? */
  63                switch (ts->stat) {
  64                case SAS_DEV_NO_RESPONSE:
  65                case SAS_INTERRUPTED:
  66                case SAS_PHY_DOWN:
  67                case SAS_NAK_R_ERR:
  68                case SAS_OPEN_TO:
  69                        hs = DID_NO_CONNECT;
  70                        break;
  71                case SAS_DATA_UNDERRUN:
  72                        scsi_set_resid(sc, ts->residual);
  73                        if (scsi_bufflen(sc) - scsi_get_resid(sc) < sc->underflow)
  74                                hs = DID_ERROR;
  75                        break;
  76                case SAS_DATA_OVERRUN:
  77                        hs = DID_ERROR;
  78                        break;
  79                case SAS_QUEUE_FULL:
  80                        hs = DID_SOFT_ERROR; /* retry */
  81                        break;
  82                case SAS_DEVICE_UNKNOWN:
  83                        hs = DID_BAD_TARGET;
  84                        break;
  85                case SAS_SG_ERR:
  86                        hs = DID_PARITY;
  87                        break;
  88                case SAS_OPEN_REJECT:
  89                        if (ts->open_rej_reason == SAS_OREJ_RSVD_RETRY)
  90                                hs = DID_SOFT_ERROR; /* retry */
  91                        else
  92                                hs = DID_ERROR;
  93                        break;
  94                case SAS_PROTO_RESPONSE:
  95                        SAS_DPRINTK("LLDD:%s sent SAS_PROTO_RESP for an SSP "
  96                                    "task; please report this\n",
  97                                    task->dev->port->ha->sas_ha_name);
  98                        break;
  99                case SAS_ABORTED_TASK:
 100                        hs = DID_ABORT;
 101                        break;
 102                case SAM_STAT_CHECK_CONDITION:
 103                        memcpy(sc->sense_buffer, ts->buf,
 104                               min(SCSI_SENSE_BUFFERSIZE, ts->buf_valid_size));
 105                        stat = SAM_STAT_CHECK_CONDITION;
 106                        break;
 107                default:
 108                        stat = ts->stat;
 109                        break;
 110                }
 111        }
 112
 113        sc->result = (hs << 16) | stat;
 114        ASSIGN_SAS_TASK(sc, NULL);
 115        sas_free_task(task);
 116}
 117
 118static void sas_scsi_task_done(struct sas_task *task)
 119{
 120        struct scsi_cmnd *sc = task->uldd_task;
 121        struct domain_device *dev = task->dev;
 122        struct sas_ha_struct *ha = dev->port->ha;
 123        unsigned long flags;
 124
 125        spin_lock_irqsave(&dev->done_lock, flags);
 126        if (test_bit(SAS_HA_FROZEN, &ha->state))
 127                task = NULL;
 128        else
 129                ASSIGN_SAS_TASK(sc, NULL);
 130        spin_unlock_irqrestore(&dev->done_lock, flags);
 131
 132        if (unlikely(!task)) {
 133                /* task will be completed by the error handler */
 134                SAS_DPRINTK("task done but aborted\n");
 135                return;
 136        }
 137
 138        if (unlikely(!sc)) {
 139                SAS_DPRINTK("task_done called with non existing SCSI cmnd!\n");
 140                sas_free_task(task);
 141                return;
 142        }
 143
 144        sas_end_task(sc, task);
 145        sc->scsi_done(sc);
 146}
 147
 148static struct sas_task *sas_create_task(struct scsi_cmnd *cmd,
 149                                               struct domain_device *dev,
 150                                               gfp_t gfp_flags)
 151{
 152        struct sas_task *task = sas_alloc_task(gfp_flags);
 153        struct scsi_lun lun;
 154
 155        if (!task)
 156                return NULL;
 157
 158        task->uldd_task = cmd;
 159        ASSIGN_SAS_TASK(cmd, task);
 160
 161        task->dev = dev;
 162        task->task_proto = task->dev->tproto; /* BUG_ON(!SSP) */
 163
 164        task->ssp_task.retry_count = 1;
 165        int_to_scsilun(cmd->device->lun, &lun);
 166        memcpy(task->ssp_task.LUN, &lun.scsi_lun, 8);
 167        task->ssp_task.task_attr = TASK_ATTR_SIMPLE;
 168        task->ssp_task.cmd = cmd;
 169
 170        task->scatter = scsi_sglist(cmd);
 171        task->num_scatter = scsi_sg_count(cmd);
 172        task->total_xfer_len = scsi_bufflen(cmd);
 173        task->data_dir = cmd->sc_data_direction;
 174
 175        task->task_done = sas_scsi_task_done;
 176
 177        return task;
 178}
 179
 180int sas_queuecommand(struct Scsi_Host *host, struct scsi_cmnd *cmd)
 181{
 182        struct sas_internal *i = to_sas_internal(host->transportt);
 183        struct domain_device *dev = cmd_to_domain_dev(cmd);
 184        struct sas_task *task;
 185        int res = 0;
 186
 187        /* If the device fell off, no sense in issuing commands */
 188        if (test_bit(SAS_DEV_GONE, &dev->state)) {
 189                cmd->result = DID_BAD_TARGET << 16;
 190                goto out_done;
 191        }
 192
 193        if (dev_is_sata(dev)) {
 194                spin_lock_irq(dev->sata_dev.ap->lock);
 195                res = ata_sas_queuecmd(cmd, dev->sata_dev.ap);
 196                spin_unlock_irq(dev->sata_dev.ap->lock);
 197                return res;
 198        }
 199
 200        task = sas_create_task(cmd, dev, GFP_ATOMIC);
 201        if (!task)
 202                return SCSI_MLQUEUE_HOST_BUSY;
 203
 204        res = i->dft->lldd_execute_task(task, GFP_ATOMIC);
 205        if (res)
 206                goto out_free_task;
 207        return 0;
 208
 209out_free_task:
 210        SAS_DPRINTK("lldd_execute_task returned: %d\n", res);
 211        ASSIGN_SAS_TASK(cmd, NULL);
 212        sas_free_task(task);
 213        if (res == -SAS_QUEUE_FULL)
 214                cmd->result = DID_SOFT_ERROR << 16; /* retry */
 215        else
 216                cmd->result = DID_ERROR << 16;
 217out_done:
 218        cmd->scsi_done(cmd);
 219        return 0;
 220}
 221
 222static void sas_eh_finish_cmd(struct scsi_cmnd *cmd)
 223{
 224        struct sas_ha_struct *sas_ha = SHOST_TO_SAS_HA(cmd->device->host);
 225        struct sas_task *task = TO_SAS_TASK(cmd);
 226
 227        /* At this point, we only get called following an actual abort
 228         * of the task, so we should be guaranteed not to be racing with
 229         * any completions from the LLD.  Task is freed after this.
 230         */
 231        sas_end_task(cmd, task);
 232
 233        /* now finish the command and move it on to the error
 234         * handler done list, this also takes it off the
 235         * error handler pending list.
 236         */
 237        scsi_eh_finish_cmd(cmd, &sas_ha->eh_done_q);
 238}
 239
 240static void sas_eh_defer_cmd(struct scsi_cmnd *cmd)
 241{
 242        struct domain_device *dev = cmd_to_domain_dev(cmd);
 243        struct sas_ha_struct *ha = dev->port->ha;
 244        struct sas_task *task = TO_SAS_TASK(cmd);
 245
 246        if (!dev_is_sata(dev)) {
 247                sas_eh_finish_cmd(cmd);
 248                return;
 249        }
 250
 251        /* report the timeout to libata */
 252        sas_end_task(cmd, task);
 253        list_move_tail(&cmd->eh_entry, &ha->eh_ata_q);
 254}
 255
 256static void sas_scsi_clear_queue_lu(struct list_head *error_q, struct scsi_cmnd *my_cmd)
 257{
 258        struct scsi_cmnd *cmd, *n;
 259
 260        list_for_each_entry_safe(cmd, n, error_q, eh_entry) {
 261                if (cmd->device->sdev_target == my_cmd->device->sdev_target &&
 262                    cmd->device->lun == my_cmd->device->lun)
 263                        sas_eh_defer_cmd(cmd);
 264        }
 265}
 266
 267static void sas_scsi_clear_queue_I_T(struct list_head *error_q,
 268                                     struct domain_device *dev)
 269{
 270        struct scsi_cmnd *cmd, *n;
 271
 272        list_for_each_entry_safe(cmd, n, error_q, eh_entry) {
 273                struct domain_device *x = cmd_to_domain_dev(cmd);
 274
 275                if (x == dev)
 276                        sas_eh_finish_cmd(cmd);
 277        }
 278}
 279
 280static void sas_scsi_clear_queue_port(struct list_head *error_q,
 281                                      struct asd_sas_port *port)
 282{
 283        struct scsi_cmnd *cmd, *n;
 284
 285        list_for_each_entry_safe(cmd, n, error_q, eh_entry) {
 286                struct domain_device *dev = cmd_to_domain_dev(cmd);
 287                struct asd_sas_port *x = dev->port;
 288
 289                if (x == port)
 290                        sas_eh_finish_cmd(cmd);
 291        }
 292}
 293
 294enum task_disposition {
 295        TASK_IS_DONE,
 296        TASK_IS_ABORTED,
 297        TASK_IS_AT_LU,
 298        TASK_IS_NOT_AT_LU,
 299        TASK_ABORT_FAILED,
 300};
 301
 302static enum task_disposition sas_scsi_find_task(struct sas_task *task)
 303{
 304        unsigned long flags;
 305        int i, res;
 306        struct sas_internal *si =
 307                to_sas_internal(task->dev->port->ha->core.shost->transportt);
 308
 309        for (i = 0; i < 5; i++) {
 310                SAS_DPRINTK("%s: aborting task 0x%p\n", __func__, task);
 311                res = si->dft->lldd_abort_task(task);
 312
 313                spin_lock_irqsave(&task->task_state_lock, flags);
 314                if (task->task_state_flags & SAS_TASK_STATE_DONE) {
 315                        spin_unlock_irqrestore(&task->task_state_lock, flags);
 316                        SAS_DPRINTK("%s: task 0x%p is done\n", __func__,
 317                                    task);
 318                        return TASK_IS_DONE;
 319                }
 320                spin_unlock_irqrestore(&task->task_state_lock, flags);
 321
 322                if (res == TMF_RESP_FUNC_COMPLETE) {
 323                        SAS_DPRINTK("%s: task 0x%p is aborted\n",
 324                                    __func__, task);
 325                        return TASK_IS_ABORTED;
 326                } else if (si->dft->lldd_query_task) {
 327                        SAS_DPRINTK("%s: querying task 0x%p\n",
 328                                    __func__, task);
 329                        res = si->dft->lldd_query_task(task);
 330                        switch (res) {
 331                        case TMF_RESP_FUNC_SUCC:
 332                                SAS_DPRINTK("%s: task 0x%p at LU\n",
 333                                            __func__, task);
 334                                return TASK_IS_AT_LU;
 335                        case TMF_RESP_FUNC_COMPLETE:
 336                                SAS_DPRINTK("%s: task 0x%p not at LU\n",
 337                                            __func__, task);
 338                                return TASK_IS_NOT_AT_LU;
 339                        case TMF_RESP_FUNC_FAILED:
 340                                SAS_DPRINTK("%s: task 0x%p failed to abort\n",
 341                                                __func__, task);
 342                                return TASK_ABORT_FAILED;
 343                        }
 344
 345                }
 346        }
 347        return res;
 348}
 349
 350static int sas_recover_lu(struct domain_device *dev, struct scsi_cmnd *cmd)
 351{
 352        int res = TMF_RESP_FUNC_FAILED;
 353        struct scsi_lun lun;
 354        struct sas_internal *i =
 355                to_sas_internal(dev->port->ha->core.shost->transportt);
 356
 357        int_to_scsilun(cmd->device->lun, &lun);
 358
 359        SAS_DPRINTK("eh: device %llx LUN %llx has the task\n",
 360                    SAS_ADDR(dev->sas_addr),
 361                    cmd->device->lun);
 362
 363        if (i->dft->lldd_abort_task_set)
 364                res = i->dft->lldd_abort_task_set(dev, lun.scsi_lun);
 365
 366        if (res == TMF_RESP_FUNC_FAILED) {
 367                if (i->dft->lldd_clear_task_set)
 368                        res = i->dft->lldd_clear_task_set(dev, lun.scsi_lun);
 369        }
 370
 371        if (res == TMF_RESP_FUNC_FAILED) {
 372                if (i->dft->lldd_lu_reset)
 373                        res = i->dft->lldd_lu_reset(dev, lun.scsi_lun);
 374        }
 375
 376        return res;
 377}
 378
 379static int sas_recover_I_T(struct domain_device *dev)
 380{
 381        int res = TMF_RESP_FUNC_FAILED;
 382        struct sas_internal *i =
 383                to_sas_internal(dev->port->ha->core.shost->transportt);
 384
 385        SAS_DPRINTK("I_T nexus reset for dev %016llx\n",
 386                    SAS_ADDR(dev->sas_addr));
 387
 388        if (i->dft->lldd_I_T_nexus_reset)
 389                res = i->dft->lldd_I_T_nexus_reset(dev);
 390
 391        return res;
 392}
 393
 394/* take a reference on the last known good phy for this device */
 395struct sas_phy *sas_get_local_phy(struct domain_device *dev)
 396{
 397        struct sas_ha_struct *ha = dev->port->ha;
 398        struct sas_phy *phy;
 399        unsigned long flags;
 400
 401        /* a published domain device always has a valid phy, it may be
 402         * stale, but it is never NULL
 403         */
 404        BUG_ON(!dev->phy);
 405
 406        spin_lock_irqsave(&ha->phy_port_lock, flags);
 407        phy = dev->phy;
 408        get_device(&phy->dev);
 409        spin_unlock_irqrestore(&ha->phy_port_lock, flags);
 410
 411        return phy;
 412}
 413EXPORT_SYMBOL_GPL(sas_get_local_phy);
 414
 415static void sas_wait_eh(struct domain_device *dev)
 416{
 417        struct sas_ha_struct *ha = dev->port->ha;
 418        DEFINE_WAIT(wait);
 419
 420        if (dev_is_sata(dev)) {
 421                ata_port_wait_eh(dev->sata_dev.ap);
 422                return;
 423        }
 424 retry:
 425        spin_lock_irq(&ha->lock);
 426
 427        while (test_bit(SAS_DEV_EH_PENDING, &dev->state)) {
 428                prepare_to_wait(&ha->eh_wait_q, &wait, TASK_UNINTERRUPTIBLE);
 429                spin_unlock_irq(&ha->lock);
 430                schedule();
 431                spin_lock_irq(&ha->lock);
 432        }
 433        finish_wait(&ha->eh_wait_q, &wait);
 434
 435        spin_unlock_irq(&ha->lock);
 436
 437        /* make sure SCSI EH is complete */
 438        if (scsi_host_in_recovery(ha->core.shost)) {
 439                msleep(10);
 440                goto retry;
 441        }
 442}
 443EXPORT_SYMBOL(sas_wait_eh);
 444
 445static int sas_queue_reset(struct domain_device *dev, int reset_type,
 446                           u64 lun, int wait)
 447{
 448        struct sas_ha_struct *ha = dev->port->ha;
 449        int scheduled = 0, tries = 100;
 450
 451        /* ata: promote lun reset to bus reset */
 452        if (dev_is_sata(dev)) {
 453                sas_ata_schedule_reset(dev);
 454                if (wait)
 455                        sas_ata_wait_eh(dev);
 456                return SUCCESS;
 457        }
 458
 459        while (!scheduled && tries--) {
 460                spin_lock_irq(&ha->lock);
 461                if (!test_bit(SAS_DEV_EH_PENDING, &dev->state) &&
 462                    !test_bit(reset_type, &dev->state)) {
 463                        scheduled = 1;
 464                        ha->eh_active++;
 465                        list_add_tail(&dev->ssp_dev.eh_list_node, &ha->eh_dev_q);
 466                        set_bit(SAS_DEV_EH_PENDING, &dev->state);
 467                        set_bit(reset_type, &dev->state);
 468                        int_to_scsilun(lun, &dev->ssp_dev.reset_lun);
 469                        scsi_schedule_eh(ha->core.shost);
 470                }
 471                spin_unlock_irq(&ha->lock);
 472
 473                if (wait)
 474                        sas_wait_eh(dev);
 475
 476                if (scheduled)
 477                        return SUCCESS;
 478        }
 479
 480        SAS_DPRINTK("%s reset of %s failed\n",
 481                    reset_type == SAS_DEV_LU_RESET ? "LUN" : "Bus",
 482                    dev_name(&dev->rphy->dev));
 483
 484        return FAILED;
 485}
 486
 487int sas_eh_abort_handler(struct scsi_cmnd *cmd)
 488{
 489        int res;
 490        struct sas_task *task = TO_SAS_TASK(cmd);
 491        struct Scsi_Host *host = cmd->device->host;
 492        struct sas_internal *i = to_sas_internal(host->transportt);
 493
 494        if (current != host->ehandler)
 495                return FAILED;
 496
 497        if (!i->dft->lldd_abort_task)
 498                return FAILED;
 499
 500        res = i->dft->lldd_abort_task(task);
 501        if (res == TMF_RESP_FUNC_SUCC || res == TMF_RESP_FUNC_COMPLETE)
 502                return SUCCESS;
 503
 504        return FAILED;
 505}
 506EXPORT_SYMBOL_GPL(sas_eh_abort_handler);
 507
 508/* Attempt to send a LUN reset message to a device */
 509int sas_eh_device_reset_handler(struct scsi_cmnd *cmd)
 510{
 511        int res;
 512        struct scsi_lun lun;
 513        struct Scsi_Host *host = cmd->device->host;
 514        struct domain_device *dev = cmd_to_domain_dev(cmd);
 515        struct sas_internal *i = to_sas_internal(host->transportt);
 516
 517        if (current != host->ehandler)
 518                return sas_queue_reset(dev, SAS_DEV_LU_RESET, cmd->device->lun, 0);
 519
 520        int_to_scsilun(cmd->device->lun, &lun);
 521
 522        if (!i->dft->lldd_lu_reset)
 523                return FAILED;
 524
 525        res = i->dft->lldd_lu_reset(dev, lun.scsi_lun);
 526        if (res == TMF_RESP_FUNC_SUCC || res == TMF_RESP_FUNC_COMPLETE)
 527                return SUCCESS;
 528
 529        return FAILED;
 530}
 531
 532int sas_eh_bus_reset_handler(struct scsi_cmnd *cmd)
 533{
 534        int res;
 535        struct Scsi_Host *host = cmd->device->host;
 536        struct domain_device *dev = cmd_to_domain_dev(cmd);
 537        struct sas_internal *i = to_sas_internal(host->transportt);
 538
 539        if (current != host->ehandler)
 540                return sas_queue_reset(dev, SAS_DEV_RESET, 0, 0);
 541
 542        if (!i->dft->lldd_I_T_nexus_reset)
 543                return FAILED;
 544
 545        res = i->dft->lldd_I_T_nexus_reset(dev);
 546        if (res == TMF_RESP_FUNC_SUCC || res == TMF_RESP_FUNC_COMPLETE ||
 547            res == -ENODEV)
 548                return SUCCESS;
 549
 550        return FAILED;
 551}
 552
 553/* Try to reset a device */
 554static int try_to_reset_cmd_device(struct scsi_cmnd *cmd)
 555{
 556        int res;
 557        struct Scsi_Host *shost = cmd->device->host;
 558
 559        if (!shost->hostt->eh_device_reset_handler)
 560                goto try_bus_reset;
 561
 562        res = shost->hostt->eh_device_reset_handler(cmd);
 563        if (res == SUCCESS)
 564                return res;
 565
 566try_bus_reset:
 567        if (shost->hostt->eh_bus_reset_handler)
 568                return shost->hostt->eh_bus_reset_handler(cmd);
 569
 570        return FAILED;
 571}
 572
 573static void sas_eh_handle_sas_errors(struct Scsi_Host *shost, struct list_head *work_q)
 574{
 575        struct scsi_cmnd *cmd, *n;
 576        enum task_disposition res = TASK_IS_DONE;
 577        int tmf_resp, need_reset;
 578        struct sas_internal *i = to_sas_internal(shost->transportt);
 579        unsigned long flags;
 580        struct sas_ha_struct *ha = SHOST_TO_SAS_HA(shost);
 581        LIST_HEAD(done);
 582
 583        /* clean out any commands that won the completion vs eh race */
 584        list_for_each_entry_safe(cmd, n, work_q, eh_entry) {
 585                struct domain_device *dev = cmd_to_domain_dev(cmd);
 586                struct sas_task *task;
 587
 588                spin_lock_irqsave(&dev->done_lock, flags);
 589                /* by this point the lldd has either observed
 590                 * SAS_HA_FROZEN and is leaving the task alone, or has
 591                 * won the race with eh and decided to complete it
 592                 */
 593                task = TO_SAS_TASK(cmd);
 594                spin_unlock_irqrestore(&dev->done_lock, flags);
 595
 596                if (!task)
 597                        list_move_tail(&cmd->eh_entry, &done);
 598        }
 599
 600 Again:
 601        list_for_each_entry_safe(cmd, n, work_q, eh_entry) {
 602                struct sas_task *task = TO_SAS_TASK(cmd);
 603
 604                list_del_init(&cmd->eh_entry);
 605
 606                spin_lock_irqsave(&task->task_state_lock, flags);
 607                need_reset = task->task_state_flags & SAS_TASK_NEED_DEV_RESET;
 608                spin_unlock_irqrestore(&task->task_state_lock, flags);
 609
 610                if (need_reset) {
 611                        SAS_DPRINTK("%s: task 0x%p requests reset\n",
 612                                    __func__, task);
 613                        goto reset;
 614                }
 615
 616                SAS_DPRINTK("trying to find task 0x%p\n", task);
 617                res = sas_scsi_find_task(task);
 618
 619                cmd->eh_eflags = 0;
 620
 621                switch (res) {
 622                case TASK_IS_DONE:
 623                        SAS_DPRINTK("%s: task 0x%p is done\n", __func__,
 624                                    task);
 625                        sas_eh_defer_cmd(cmd);
 626                        continue;
 627                case TASK_IS_ABORTED:
 628                        SAS_DPRINTK("%s: task 0x%p is aborted\n",
 629                                    __func__, task);
 630                        sas_eh_defer_cmd(cmd);
 631                        continue;
 632                case TASK_IS_AT_LU:
 633                        SAS_DPRINTK("task 0x%p is at LU: lu recover\n", task);
 634 reset:
 635                        tmf_resp = sas_recover_lu(task->dev, cmd);
 636                        if (tmf_resp == TMF_RESP_FUNC_COMPLETE) {
 637                                SAS_DPRINTK("dev %016llx LU %llx is "
 638                                            "recovered\n",
 639                                            SAS_ADDR(task->dev),
 640                                            cmd->device->lun);
 641                                sas_eh_defer_cmd(cmd);
 642                                sas_scsi_clear_queue_lu(work_q, cmd);
 643                                goto Again;
 644                        }
 645                        /* fallthrough */
 646                case TASK_IS_NOT_AT_LU:
 647                case TASK_ABORT_FAILED:
 648                        SAS_DPRINTK("task 0x%p is not at LU: I_T recover\n",
 649                                    task);
 650                        tmf_resp = sas_recover_I_T(task->dev);
 651                        if (tmf_resp == TMF_RESP_FUNC_COMPLETE ||
 652                            tmf_resp == -ENODEV) {
 653                                struct domain_device *dev = task->dev;
 654                                SAS_DPRINTK("I_T %016llx recovered\n",
 655                                            SAS_ADDR(task->dev->sas_addr));
 656                                sas_eh_finish_cmd(cmd);
 657                                sas_scsi_clear_queue_I_T(work_q, dev);
 658                                goto Again;
 659                        }
 660                        /* Hammer time :-) */
 661                        try_to_reset_cmd_device(cmd);
 662                        if (i->dft->lldd_clear_nexus_port) {
 663                                struct asd_sas_port *port = task->dev->port;
 664                                SAS_DPRINTK("clearing nexus for port:%d\n",
 665                                            port->id);
 666                                res = i->dft->lldd_clear_nexus_port(port);
 667                                if (res == TMF_RESP_FUNC_COMPLETE) {
 668                                        SAS_DPRINTK("clear nexus port:%d "
 669                                                    "succeeded\n", port->id);
 670                                        sas_eh_finish_cmd(cmd);
 671                                        sas_scsi_clear_queue_port(work_q,
 672                                                                  port);
 673                                        goto Again;
 674                                }
 675                        }
 676                        if (i->dft->lldd_clear_nexus_ha) {
 677                                SAS_DPRINTK("clear nexus ha\n");
 678                                res = i->dft->lldd_clear_nexus_ha(ha);
 679                                if (res == TMF_RESP_FUNC_COMPLETE) {
 680                                        SAS_DPRINTK("clear nexus ha "
 681                                                    "succeeded\n");
 682                                        sas_eh_finish_cmd(cmd);
 683                                        goto clear_q;
 684                                }
 685                        }
 686                        /* If we are here -- this means that no amount
 687                         * of effort could recover from errors.  Quite
 688                         * possibly the HA just disappeared.
 689                         */
 690                        SAS_DPRINTK("error from  device %llx, LUN %llx "
 691                                    "couldn't be recovered in any way\n",
 692                                    SAS_ADDR(task->dev->sas_addr),
 693                                    cmd->device->lun);
 694
 695                        sas_eh_finish_cmd(cmd);
 696                        goto clear_q;
 697                }
 698        }
 699 out:
 700        list_splice_tail(&done, work_q);
 701        list_splice_tail_init(&ha->eh_ata_q, work_q);
 702        return;
 703
 704 clear_q:
 705        SAS_DPRINTK("--- Exit %s -- clear_q\n", __func__);
 706        list_for_each_entry_safe(cmd, n, work_q, eh_entry)
 707                sas_eh_finish_cmd(cmd);
 708        goto out;
 709}
 710
 711static void sas_eh_handle_resets(struct Scsi_Host *shost)
 712{
 713        struct sas_ha_struct *ha = SHOST_TO_SAS_HA(shost);
 714        struct sas_internal *i = to_sas_internal(shost->transportt);
 715
 716        /* handle directed resets to sas devices */
 717        spin_lock_irq(&ha->lock);
 718        while (!list_empty(&ha->eh_dev_q)) {
 719                struct domain_device *dev;
 720                struct ssp_device *ssp;
 721
 722                ssp = list_entry(ha->eh_dev_q.next, typeof(*ssp), eh_list_node);
 723                list_del_init(&ssp->eh_list_node);
 724                dev = container_of(ssp, typeof(*dev), ssp_dev);
 725                kref_get(&dev->kref);
 726                WARN_ONCE(dev_is_sata(dev), "ssp reset to ata device?\n");
 727
 728                spin_unlock_irq(&ha->lock);
 729
 730                if (test_and_clear_bit(SAS_DEV_LU_RESET, &dev->state))
 731                        i->dft->lldd_lu_reset(dev, ssp->reset_lun.scsi_lun);
 732
 733                if (test_and_clear_bit(SAS_DEV_RESET, &dev->state))
 734                        i->dft->lldd_I_T_nexus_reset(dev);
 735
 736                sas_put_device(dev);
 737                spin_lock_irq(&ha->lock);
 738                clear_bit(SAS_DEV_EH_PENDING, &dev->state);
 739                ha->eh_active--;
 740        }
 741        spin_unlock_irq(&ha->lock);
 742}
 743
 744
 745void sas_scsi_recover_host(struct Scsi_Host *shost)
 746{
 747        struct sas_ha_struct *ha = SHOST_TO_SAS_HA(shost);
 748        LIST_HEAD(eh_work_q);
 749        int tries = 0;
 750        bool retry;
 751
 752retry:
 753        tries++;
 754        retry = true;
 755        spin_lock_irq(shost->host_lock);
 756        list_splice_init(&shost->eh_cmd_q, &eh_work_q);
 757        spin_unlock_irq(shost->host_lock);
 758
 759        SAS_DPRINTK("Enter %s busy: %d failed: %d\n",
 760                    __func__, atomic_read(&shost->host_busy), shost->host_failed);
 761        /*
 762         * Deal with commands that still have SAS tasks (i.e. they didn't
 763         * complete via the normal sas_task completion mechanism),
 764         * SAS_HA_FROZEN gives eh dominion over all sas_task completion.
 765         */
 766        set_bit(SAS_HA_FROZEN, &ha->state);
 767        sas_eh_handle_sas_errors(shost, &eh_work_q);
 768        clear_bit(SAS_HA_FROZEN, &ha->state);
 769        if (list_empty(&eh_work_q))
 770                goto out;
 771
 772        /*
 773         * Now deal with SCSI commands that completed ok but have a an error
 774         * code (and hopefully sense data) attached.  This is roughly what
 775         * scsi_unjam_host does, but we skip scsi_eh_abort_cmds because any
 776         * command we see here has no sas_task and is thus unknown to the HA.
 777         */
 778        sas_ata_eh(shost, &eh_work_q, &ha->eh_done_q);
 779        if (!scsi_eh_get_sense(&eh_work_q, &ha->eh_done_q))
 780                scsi_eh_ready_devs(shost, &eh_work_q, &ha->eh_done_q);
 781
 782out:
 783        sas_eh_handle_resets(shost);
 784
 785        /* now link into libata eh --- if we have any ata devices */
 786        sas_ata_strategy_handler(shost);
 787
 788        scsi_eh_flush_done_q(&ha->eh_done_q);
 789
 790        /* check if any new eh work was scheduled during the last run */
 791        spin_lock_irq(&ha->lock);
 792        if (ha->eh_active == 0) {
 793                shost->host_eh_scheduled = 0;
 794                retry = false;
 795        }
 796        spin_unlock_irq(&ha->lock);
 797
 798        if (retry)
 799                goto retry;
 800
 801        SAS_DPRINTK("--- Exit %s: busy: %d failed: %d tries: %d\n",
 802                    __func__, atomic_read(&shost->host_busy),
 803                    shost->host_failed, tries);
 804}
 805
 806enum blk_eh_timer_return sas_scsi_timed_out(struct scsi_cmnd *cmd)
 807{
 808        scmd_dbg(cmd, "command %p timed out\n", cmd);
 809
 810        return BLK_EH_NOT_HANDLED;
 811}
 812
 813int sas_ioctl(struct scsi_device *sdev, int cmd, void __user *arg)
 814{
 815        struct domain_device *dev = sdev_to_domain_dev(sdev);
 816
 817        if (dev_is_sata(dev))
 818                return ata_sas_scsi_ioctl(dev->sata_dev.ap, sdev, cmd, arg);
 819
 820        return -EINVAL;
 821}
 822
 823struct domain_device *sas_find_dev_by_rphy(struct sas_rphy *rphy)
 824{
 825        struct Scsi_Host *shost = dev_to_shost(rphy->dev.parent);
 826        struct sas_ha_struct *ha = SHOST_TO_SAS_HA(shost);
 827        struct domain_device *found_dev = NULL;
 828        int i;
 829        unsigned long flags;
 830
 831        spin_lock_irqsave(&ha->phy_port_lock, flags);
 832        for (i = 0; i < ha->num_phys; i++) {
 833                struct asd_sas_port *port = ha->sas_port[i];
 834                struct domain_device *dev;
 835
 836                spin_lock(&port->dev_list_lock);
 837                list_for_each_entry(dev, &port->dev_list, dev_list_node) {
 838                        if (rphy == dev->rphy) {
 839                                found_dev = dev;
 840                                spin_unlock(&port->dev_list_lock);
 841                                goto found;
 842                        }
 843                }
 844                spin_unlock(&port->dev_list_lock);
 845        }
 846 found:
 847        spin_unlock_irqrestore(&ha->phy_port_lock, flags);
 848
 849        return found_dev;
 850}
 851
 852int sas_target_alloc(struct scsi_target *starget)
 853{
 854        struct sas_rphy *rphy = dev_to_rphy(starget->dev.parent);
 855        struct domain_device *found_dev = sas_find_dev_by_rphy(rphy);
 856
 857        if (!found_dev)
 858                return -ENODEV;
 859
 860        kref_get(&found_dev->kref);
 861        starget->hostdata = found_dev;
 862        return 0;
 863}
 864
 865#define SAS_DEF_QD 256
 866
 867int sas_slave_configure(struct scsi_device *scsi_dev)
 868{
 869        struct domain_device *dev = sdev_to_domain_dev(scsi_dev);
 870        struct sas_ha_struct *sas_ha;
 871
 872        BUG_ON(dev->rphy->identify.device_type != SAS_END_DEVICE);
 873
 874        if (dev_is_sata(dev)) {
 875                ata_sas_slave_configure(scsi_dev, dev->sata_dev.ap);
 876                return 0;
 877        }
 878
 879        sas_ha = dev->port->ha;
 880
 881        sas_read_port_mode_page(scsi_dev);
 882
 883        if (scsi_dev->tagged_supported) {
 884                scsi_change_queue_depth(scsi_dev, SAS_DEF_QD);
 885        } else {
 886                SAS_DPRINTK("device %llx, LUN %llx doesn't support "
 887                            "TCQ\n", SAS_ADDR(dev->sas_addr),
 888                            scsi_dev->lun);
 889                scsi_change_queue_depth(scsi_dev, 1);
 890        }
 891
 892        scsi_dev->allow_restart = 1;
 893
 894        return 0;
 895}
 896
 897int sas_change_queue_depth(struct scsi_device *sdev, int depth)
 898{
 899        struct domain_device *dev = sdev_to_domain_dev(sdev);
 900
 901        if (dev_is_sata(dev))
 902                return __ata_change_queue_depth(dev->sata_dev.ap, sdev, depth);
 903
 904        if (!sdev->tagged_supported)
 905                depth = 1;
 906        return scsi_change_queue_depth(sdev, depth);
 907}
 908
 909int sas_bios_param(struct scsi_device *scsi_dev,
 910                          struct block_device *bdev,
 911                          sector_t capacity, int *hsc)
 912{
 913        hsc[0] = 255;
 914        hsc[1] = 63;
 915        sector_div(capacity, 255*63);
 916        hsc[2] = capacity;
 917
 918        return 0;
 919}
 920
 921/*
 922 * Tell an upper layer that it needs to initiate an abort for a given task.
 923 * This should only ever be called by an LLDD.
 924 */
 925void sas_task_abort(struct sas_task *task)
 926{
 927        struct scsi_cmnd *sc = task->uldd_task;
 928
 929        /* Escape for libsas internal commands */
 930        if (!sc) {
 931                struct sas_task_slow *slow = task->slow_task;
 932
 933                if (!slow)
 934                        return;
 935                if (!del_timer(&slow->timer))
 936                        return;
 937                slow->timer.function(slow->timer.data);
 938                return;
 939        }
 940
 941        if (dev_is_sata(task->dev)) {
 942                sas_ata_task_abort(task);
 943        } else {
 944                struct request_queue *q = sc->device->request_queue;
 945                unsigned long flags;
 946
 947                spin_lock_irqsave(q->queue_lock, flags);
 948                blk_abort_request(sc->request);
 949                spin_unlock_irqrestore(q->queue_lock, flags);
 950        }
 951}
 952
 953void sas_target_destroy(struct scsi_target *starget)
 954{
 955        struct domain_device *found_dev = starget->hostdata;
 956
 957        if (!found_dev)
 958                return;
 959
 960        starget->hostdata = NULL;
 961        sas_put_device(found_dev);
 962}
 963
 964static void sas_parse_addr(u8 *sas_addr, const char *p)
 965{
 966        int i;
 967        for (i = 0; i < SAS_ADDR_SIZE; i++) {
 968                u8 h, l;
 969                if (!*p)
 970                        break;
 971                h = isdigit(*p) ? *p-'0' : toupper(*p)-'A'+10;
 972                p++;
 973                l = isdigit(*p) ? *p-'0' : toupper(*p)-'A'+10;
 974                p++;
 975                sas_addr[i] = (h<<4) | l;
 976        }
 977}
 978
 979#define SAS_STRING_ADDR_SIZE    16
 980
 981int sas_request_addr(struct Scsi_Host *shost, u8 *addr)
 982{
 983        int res;
 984        const struct firmware *fw;
 985
 986        res = request_firmware(&fw, "sas_addr", &shost->shost_gendev);
 987        if (res)
 988                return res;
 989
 990        if (fw->size < SAS_STRING_ADDR_SIZE) {
 991                res = -ENODEV;
 992                goto out;
 993        }
 994
 995        sas_parse_addr(addr, fw->data);
 996
 997out:
 998        release_firmware(fw);
 999        return res;
1000}
1001EXPORT_SYMBOL_GPL(sas_request_addr);
1002
1003EXPORT_SYMBOL_GPL(sas_queuecommand);
1004EXPORT_SYMBOL_GPL(sas_target_alloc);
1005EXPORT_SYMBOL_GPL(sas_slave_configure);
1006EXPORT_SYMBOL_GPL(sas_change_queue_depth);
1007EXPORT_SYMBOL_GPL(sas_bios_param);
1008EXPORT_SYMBOL_GPL(sas_task_abort);
1009EXPORT_SYMBOL_GPL(sas_phy_reset);
1010EXPORT_SYMBOL_GPL(sas_eh_device_reset_handler);
1011EXPORT_SYMBOL_GPL(sas_eh_bus_reset_handler);
1012EXPORT_SYMBOL_GPL(sas_target_destroy);
1013EXPORT_SYMBOL_GPL(sas_ioctl);
1014