drivers/usb/storage/uas.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  * USB Attached SCSI
   4  * Note that this is not the same as the USB Mass Storage driver
   5  *
   6  * Copyright Hans de Goede <hdegoede@redhat.com> for Red Hat, Inc. 2013 - 2016
   7  * Copyright Matthew Wilcox for Intel Corp, 2010
   8  * Copyright Sarah Sharp for Intel Corp, 2010
   9  */
  10
  11 #include <linux/blkdev.h>
  12 #include <linux/slab.h>
  13 #include <linux/types.h>
  14 #include <linux/module.h>
  15 #include <linux/usb.h>
  16 #include <linux/usb_usual.h>
  17 #include <linux/usb/hcd.h>
  18 #include <linux/usb/storage.h>
  19 #include <linux/usb/uas.h>
  20
  21 #include <scsi/scsi.h>
  22 #include <scsi/scsi_eh.h>
  23 #include <scsi/scsi_dbg.h>
  24 #include <scsi/scsi_cmnd.h>
  25 #include <scsi/scsi_device.h>
  26 #include <scsi/scsi_host.h>
  27 #include <scsi/scsi_tcq.h>
  28
  29 #include "uas-detect.h"
  30 #include "scsiglue.h"
  31
  32 #define MAX_CMNDS 256
  33
  34 struct uas_dev_info {
  35         struct usb_interface *intf;
  36         struct usb_device *udev;
  37         struct usb_anchor cmd_urbs;
  38         struct usb_anchor sense_urbs;
  39         struct usb_anchor data_urbs;
  40         unsigned long flags;
  41         int qdepth, resetting;
  42         unsigned cmd_pipe, status_pipe, data_in_pipe, data_out_pipe;
  43         unsigned use_streams:1;
  44         unsigned shutdown:1;
  45         struct scsi_cmnd *cmnd[MAX_CMNDS];
  46         spinlock_t lock;
  47         struct work_struct work;
  48         struct work_struct scan_work;      /* for async scanning */
  49 };
  50
  51 enum {
  52         SUBMIT_STATUS_URB       = BIT(1),
  53         ALLOC_DATA_IN_URB       = BIT(2),
  54         SUBMIT_DATA_IN_URB      = BIT(3),
  55         ALLOC_DATA_OUT_URB      = BIT(4),
  56         SUBMIT_DATA_OUT_URB     = BIT(5),
  57         ALLOC_CMD_URB           = BIT(6),
  58         SUBMIT_CMD_URB          = BIT(7),
  59         COMMAND_INFLIGHT        = BIT(8),
  60         DATA_IN_URB_INFLIGHT    = BIT(9),
  61         DATA_OUT_URB_INFLIGHT   = BIT(10),
  62         COMMAND_ABORTED         = BIT(11),
  63         IS_IN_WORK_LIST         = BIT(12),
  64 };
  65
  66 /* Overrides scsi_pointer */
  67 struct uas_cmd_info {
  68         unsigned int state;
  69         unsigned int uas_tag;
  70         struct urb *cmd_urb;
  71         struct urb *data_in_urb;
  72         struct urb *data_out_urb;
  73 };
  74
  75 /* I hate forward declarations, but I actually have a loop */
  76 static int uas_submit_urbs(struct scsi_cmnd *cmnd,
  77                                 struct uas_dev_info *devinfo);
  78 static void uas_do_work(struct work_struct *work);
  79 static int uas_try_complete(struct scsi_cmnd *cmnd, const char *caller);
  80 static void uas_free_streams(struct uas_dev_info *devinfo);
  81 static void uas_log_cmd_state(struct scsi_cmnd *cmnd, const char *prefix,
  82                                 int status);
  83
  84 /*
  85  * This driver needs its own workqueue, as we need to control memory allocation.
  86  *
  87  * In the course of error handling and power management uas_wait_for_pending_cmnds()
  88  * needs to flush pending work items. In these contexts we cannot allocate memory
  89  * by doing block IO as we would deadlock. For the same reason we cannot wait
  90  * for anything allocating memory not heeding these constraints.
  91  *
  92  * So we have to control all work items that can be on the workqueue we flush.
  93  * Hence we cannot share a queue and need our own.
  94  */
  95 static struct workqueue_struct *workqueue;
  96
  97 static void uas_do_work(struct work_struct *work)
  98 {
  99         struct uas_dev_info *devinfo =
 100                 container_of(work, struct uas_dev_info, work);
 101         struct uas_cmd_info *cmdinfo;
 102         struct scsi_cmnd *cmnd;
 103         unsigned long flags;
 104         int i, err;
 105
 106         spin_lock_irqsave(&devinfo->lock, flags);
 107
 108         if (devinfo->resetting)
 109                 goto out;
 110
 111         for (i = 0; i < devinfo->qdepth; i++) {
 112                 if (!devinfo->cmnd[i])
 113                         continue;
 114
 115                 cmnd = devinfo->cmnd[i];
 116                 cmdinfo = scsi_cmd_priv(cmnd);
 117
 118                 if (!(cmdinfo->state & IS_IN_WORK_LIST))
 119                         continue;
 120
 121                 err = uas_submit_urbs(cmnd, cmnd->device->hostdata);
 122                 if (!err)
 123                         cmdinfo->state &= ~IS_IN_WORK_LIST;
 124                 else
 125                         queue_work(workqueue, &devinfo->work);
 126         }
 127 out:
 128         spin_unlock_irqrestore(&devinfo->lock, flags);
 129 }
 130
 131 static void uas_scan_work(struct work_struct *work)
 132 {
 133         struct uas_dev_info *devinfo =
 134                 container_of(work, struct uas_dev_info, scan_work);
 135         struct Scsi_Host *shost = usb_get_intfdata(devinfo->intf);
 136
 137         dev_dbg(&devinfo->intf->dev, "starting scan\n");
 138         scsi_scan_host(shost);
 139         dev_dbg(&devinfo->intf->dev, "scan complete\n");
 140 }
 141
 142 static void uas_add_work(struct scsi_cmnd *cmnd)
 143 {
 144         struct uas_cmd_info *cmdinfo = scsi_cmd_priv(cmnd);
 145         struct uas_dev_info *devinfo = cmnd->device->hostdata;
 146
 147         lockdep_assert_held(&devinfo->lock);
 148         cmdinfo->state |= IS_IN_WORK_LIST;
 149         queue_work(workqueue, &devinfo->work);
 150 }
 151
 152 static void uas_zap_pending(struct uas_dev_info *devinfo, int result)
 153 {
 154         struct uas_cmd_info *cmdinfo;
 155         struct scsi_cmnd *cmnd;
 156         unsigned long flags;
 157         int i, err;
 158
 159         spin_lock_irqsave(&devinfo->lock, flags);
 160         for (i = 0; i < devinfo->qdepth; i++) {
 161                 if (!devinfo->cmnd[i])
 162                         continue;
 163
 164                 cmnd = devinfo->cmnd[i];
 165                 cmdinfo = scsi_cmd_priv(cmnd);
 166                 uas_log_cmd_state(cmnd, __func__, 0);
 167                 /* Sense urbs were killed, clear COMMAND_INFLIGHT manually */
 168                 cmdinfo->state &= ~COMMAND_INFLIGHT;
 169                 cmnd->result = result << 16;
 170                 err = uas_try_complete(cmnd, __func__);
 171                 WARN_ON(err != 0);
 172         }
 173         spin_unlock_irqrestore(&devinfo->lock, flags);
 174 }
 175
 176 static void uas_sense(struct urb *urb, struct scsi_cmnd *cmnd)
 177 {
 178         struct sense_iu *sense_iu = urb->transfer_buffer;
 179         struct scsi_device *sdev = cmnd->device;
 180
 181         if (urb->actual_length > 16) {
 182                 unsigned len = be16_to_cpup(&sense_iu->len);
 183                 if (len + 16 != urb->actual_length) {
 184                         int newlen = min(len + 16, urb->actual_length) - 16;
 185                         if (newlen < 0)
 186                                 newlen = 0;
 187                         sdev_printk(KERN_INFO, sdev, "%s: urb length %d "
 188                                 "disagrees with IU sense data length %d, "
 189                                 "using %d bytes of sense data\n", __func__,
 190                                         urb->actual_length, len, newlen);
 191                         len = newlen;
 192                 }
 193                 memcpy(cmnd->sense_buffer, sense_iu->sense, len);
 194         }
 195
 196         cmnd->result = sense_iu->status;
 197 }
 198
 199 static void uas_log_cmd_state(struct scsi_cmnd *cmnd, const char *prefix,
 200                               int status)
 201 {
 202         struct uas_cmd_info *ci = scsi_cmd_priv(cmnd);
 203
 204         if (status == -ENODEV) /* too late */
 205                 return;
 206
 207         scmd_printk(KERN_INFO, cmnd,
 208                     "%s %d uas-tag %d inflight:%s%s%s%s%s%s%s%s%s%s%s%s ",
 209                     prefix, status, ci->uas_tag,
 210                     (ci->state & SUBMIT_STATUS_URB)     ? " s-st"  : "",
 211                     (ci->state & ALLOC_DATA_IN_URB)     ? " a-in"  : "",
 212                     (ci->state & SUBMIT_DATA_IN_URB)    ? " s-in"  : "",
 213                     (ci->state & ALLOC_DATA_OUT_URB)    ? " a-out" : "",
 214                     (ci->state & SUBMIT_DATA_OUT_URB)   ? " s-out" : "",
 215                     (ci->state & ALLOC_CMD_URB)         ? " a-cmd" : "",
 216                     (ci->state & SUBMIT_CMD_URB)        ? " s-cmd" : "",
 217                     (ci->state & COMMAND_INFLIGHT)      ? " CMD"   : "",
 218                     (ci->state & DATA_IN_URB_INFLIGHT)  ? " IN"    : "",
 219                     (ci->state & DATA_OUT_URB_INFLIGHT) ? " OUT"   : "",
 220                     (ci->state & COMMAND_ABORTED)       ? " abort" : "",
 221                     (ci->state & IS_IN_WORK_LIST)       ? " work"  : "");
 222         scsi_print_command(cmnd);
 223 }
 224
 225 static void uas_free_unsubmitted_urbs(struct scsi_cmnd *cmnd)
 226 {
 227         struct uas_cmd_info *cmdinfo;
 228
 229         if (!cmnd)
 230                 return;
 231
 232         cmdinfo = scsi_cmd_priv(cmnd);
 233
 234         if (cmdinfo->state & SUBMIT_CMD_URB)
 235                 usb_free_urb(cmdinfo->cmd_urb);
 236
 237         /* data urbs may have never gotten their submit flag set */
 238         if (!(cmdinfo->state & DATA_IN_URB_INFLIGHT))
 239                 usb_free_urb(cmdinfo->data_in_urb);
 240         if (!(cmdinfo->state & DATA_OUT_URB_INFLIGHT))
 241                 usb_free_urb(cmdinfo->data_out_urb);
 242 }
 243
 244 static int uas_try_complete(struct scsi_cmnd *cmnd, const char *caller)
 245 {
 246         struct uas_cmd_info *cmdinfo = scsi_cmd_priv(cmnd);
 247         struct uas_dev_info *devinfo = (void *)cmnd->device->hostdata;
 248
 249         lockdep_assert_held(&devinfo->lock);
 250         if (cmdinfo->state & (COMMAND_INFLIGHT |
 251                               DATA_IN_URB_INFLIGHT |
 252                               DATA_OUT_URB_INFLIGHT |
 253                               COMMAND_ABORTED))
 254                 return -EBUSY;
 255         devinfo->cmnd[cmdinfo->uas_tag - 1] = NULL;
 256         uas_free_unsubmitted_urbs(cmnd);
 257         scsi_done(cmnd);
 258         return 0;
 259 }
 260
 261 static void uas_xfer_data(struct urb *urb, struct scsi_cmnd *cmnd,
 262                           unsigned direction)
 263 {
 264         struct uas_cmd_info *cmdinfo = scsi_cmd_priv(cmnd);
 265         int err;
 266
 267         cmdinfo->state |= direction | SUBMIT_STATUS_URB;
 268         err = uas_submit_urbs(cmnd, cmnd->device->hostdata);
 269         if (err) {
 270                 uas_add_work(cmnd);
 271         }
 272 }
 273
 274 static bool uas_evaluate_response_iu(struct response_iu *riu, struct scsi_cmnd *cmnd)
 275 {
 276         u8 response_code = riu->response_code;
 277
 278         switch (response_code) {
 279         case RC_INCORRECT_LUN:
 280                 set_host_byte(cmnd, DID_BAD_TARGET);
 281                 break;
 282         case RC_TMF_SUCCEEDED:
 283                 set_host_byte(cmnd, DID_OK);
 284                 break;
 285         case RC_TMF_NOT_SUPPORTED:
 286                 set_host_byte(cmnd, DID_BAD_TARGET);
 287                 break;
 288         default:
 289                 uas_log_cmd_state(cmnd, "response iu", response_code);
 290                 set_host_byte(cmnd, DID_ERROR);
 291                 break;
 292         }
 293
 294         return response_code == RC_TMF_SUCCEEDED;
 295 }
 296
 297 static void uas_stat_cmplt(struct urb *urb)
 298 {
 299         struct iu *iu = urb->transfer_buffer;
 300         struct Scsi_Host *shost = urb->context;
 301         struct uas_dev_info *devinfo = (struct uas_dev_info *)shost->hostdata;
 302         struct urb *data_in_urb = NULL;
 303         struct urb *data_out_urb = NULL;
 304         struct scsi_cmnd *cmnd;
 305         struct uas_cmd_info *cmdinfo;
 306         unsigned long flags;
 307         unsigned int idx;
 308         int status = urb->status;
 309         bool success;
 310
 311         spin_lock_irqsave(&devinfo->lock, flags);
 312
 313         if (devinfo->resetting)
 314                 goto out;
 315
 316         if (status) {
 317                 if (status != -ENOENT && status != -ECONNRESET && status != -ESHUTDOWN)
 318                         dev_err(&urb->dev->dev, "stat urb: status %d\n", status);
 319                 goto out;
 320         }
 321
 322         idx = be16_to_cpup(&iu->tag) - 1;
 323         if (idx >= MAX_CMNDS || !devinfo->cmnd[idx]) {
 324                 dev_err(&urb->dev->dev,
 325                         "stat urb: no pending cmd for uas-tag %d\n", idx + 1);
 326                 goto out;
 327         }
 328
 329         cmnd = devinfo->cmnd[idx];
 330         cmdinfo = scsi_cmd_priv(cmnd);
 331
 332         if (!(cmdinfo->state & COMMAND_INFLIGHT)) {
 333                 uas_log_cmd_state(cmnd, "unexpected status cmplt", 0);
 334                 goto out;
 335         }
 336
 337         switch (iu->iu_id) {
 338         case IU_ID_STATUS:
 339                 uas_sense(urb, cmnd);
 340                 if (cmnd->result != 0) {
 341                         /* cancel data transfers on error */
 342                         data_in_urb = usb_get_urb(cmdinfo->data_in_urb);
 343                         data_out_urb = usb_get_urb(cmdinfo->data_out_urb);
 344                 }
 345                 cmdinfo->state &= ~COMMAND_INFLIGHT;
 346                 uas_try_complete(cmnd, __func__);
 347                 break;
 348         case IU_ID_READ_READY:
 349                 if (!cmdinfo->data_in_urb ||
 350                                 (cmdinfo->state & DATA_IN_URB_INFLIGHT)) {
 351                         uas_log_cmd_state(cmnd, "unexpected read rdy", 0);
 352                         break;
 353                 }
 354                 uas_xfer_data(urb, cmnd, SUBMIT_DATA_IN_URB);
 355                 break;
 356         case IU_ID_WRITE_READY:
 357                 if (!cmdinfo->data_out_urb ||
 358                                 (cmdinfo->state & DATA_OUT_URB_INFLIGHT)) {
 359                         uas_log_cmd_state(cmnd, "unexpected write rdy", 0);
 360                         break;
 361                 }
 362                 uas_xfer_data(urb, cmnd, SUBMIT_DATA_OUT_URB);
 363                 break;
 364         case IU_ID_RESPONSE:
 365                 cmdinfo->state &= ~COMMAND_INFLIGHT;
 366                 success = uas_evaluate_response_iu((struct response_iu *)iu, cmnd);
 367                 if (!success) {
 368                         /* Error, cancel data transfers */
 369                         data_in_urb = usb_get_urb(cmdinfo->data_in_urb);
 370                         data_out_urb = usb_get_urb(cmdinfo->data_out_urb);
 371                 }
 372                 uas_try_complete(cmnd, __func__);
 373                 break;
 374         default:
 375                 uas_log_cmd_state(cmnd, "bogus IU", iu->iu_id);
 376         }
 377 out:
 378         usb_free_urb(urb);
 379         spin_unlock_irqrestore(&devinfo->lock, flags);
 380
 381         /* Unlinking of data urbs must be done without holding the lock */
 382         if (data_in_urb) {
 383                 usb_unlink_urb(data_in_urb);
 384                 usb_put_urb(data_in_urb);
 385         }
 386         if (data_out_urb) {
 387                 usb_unlink_urb(data_out_urb);
 388                 usb_put_urb(data_out_urb);
 389         }
 390 }
 391
 392 static void uas_data_cmplt(struct urb *urb)
 393 {
 394         struct scsi_cmnd *cmnd = urb->context;
 395         struct uas_cmd_info *cmdinfo = scsi_cmd_priv(cmnd);
 396         struct uas_dev_info *devinfo = (void *)cmnd->device->hostdata;
 397         struct scsi_data_buffer *sdb = &cmnd->sdb;
 398         unsigned long flags;
 399         int status = urb->status;
 400
 401         spin_lock_irqsave(&devinfo->lock, flags);
 402
 403         if (cmdinfo->data_in_urb == urb) {
 404                 cmdinfo->state &= ~DATA_IN_URB_INFLIGHT;
 405                 cmdinfo->data_in_urb = NULL;
 406         } else if (cmdinfo->data_out_urb == urb) {
 407                 cmdinfo->state &= ~DATA_OUT_URB_INFLIGHT;
 408                 cmdinfo->data_out_urb = NULL;
 409         }
 410
 411         if (devinfo->resetting)
 412                 goto out;
 413
 414         /* Data urbs should not complete before the cmd urb is submitted */
 415         if (cmdinfo->state & SUBMIT_CMD_URB) {
 416                 uas_log_cmd_state(cmnd, "unexpected data cmplt", 0);
 417                 goto out;
 418         }
 419
 420         if (status) {
 421                 if (status != -ENOENT && status != -ECONNRESET && status != -ESHUTDOWN)
 422                         uas_log_cmd_state(cmnd, "data cmplt err", status);
 423                 /* error: no data transfered */
 424                 scsi_set_resid(cmnd, sdb->length);
 425         } else {
 426                 scsi_set_resid(cmnd, sdb->length - urb->actual_length);
 427         }
 428         uas_try_complete(cmnd, __func__);
 429 out:
 430         usb_free_urb(urb);
 431         spin_unlock_irqrestore(&devinfo->lock, flags);
 432 }
 433
 434 static void uas_cmd_cmplt(struct urb *urb)
 435 {
 436         if (urb->status)
 437                 dev_err(&urb->dev->dev, "cmd cmplt err %d\n", urb->status);
 438
 439         usb_free_urb(urb);
 440 }
 441
 442 static struct urb *uas_alloc_data_urb(struct uas_dev_info *devinfo, gfp_t gfp,
 443                                       struct scsi_cmnd *cmnd,
 444                                       enum dma_data_direction dir)
 445 {
 446         struct usb_device *udev = devinfo->udev;
 447         struct uas_cmd_info *cmdinfo = scsi_cmd_priv(cmnd);
 448         struct urb *urb = usb_alloc_urb(0, gfp);
 449         struct scsi_data_buffer *sdb = &cmnd->sdb;
 450         unsigned int pipe = (dir == DMA_FROM_DEVICE)
 451                 ? devinfo->data_in_pipe : devinfo->data_out_pipe;
 452
 453         if (!urb)
 454                 goto out;
 455         usb_fill_bulk_urb(urb, udev, pipe, NULL, sdb->length,
 456                           uas_data_cmplt, cmnd);
 457         if (devinfo->use_streams)
 458                 urb->stream_id = cmdinfo->uas_tag;
 459         urb->num_sgs = udev->bus->sg_tablesize ? sdb->table.nents : 0;
 460         urb->sg = sdb->table.sgl;
 461  out:
 462         return urb;
 463 }
 464
 465 static struct urb *uas_alloc_sense_urb(struct uas_dev_info *devinfo, gfp_t gfp,
 466                                        struct scsi_cmnd *cmnd)
 467 {
 468         struct usb_device *udev = devinfo->udev;
 469         struct uas_cmd_info *cmdinfo = scsi_cmd_priv(cmnd);
 470         struct urb *urb = usb_alloc_urb(0, gfp);
 471         struct sense_iu *iu;
 472
 473         if (!urb)
 474                 goto out;
 475
 476         iu = kzalloc(sizeof(*iu), gfp);
 477         if (!iu)
 478                 goto free;
 479
 480         usb_fill_bulk_urb(urb, udev, devinfo->status_pipe, iu, sizeof(*iu),
 481                           uas_stat_cmplt, cmnd->device->host);
 482         if (devinfo->use_streams)
 483                 urb->stream_id = cmdinfo->uas_tag;
 484         urb->transfer_flags |= URB_FREE_BUFFER;
 485  out:
 486         return urb;
 487  free:
 488         usb_free_urb(urb);
 489         return NULL;
 490 }
 491
 492 static struct urb *uas_alloc_cmd_urb(struct uas_dev_info *devinfo, gfp_t gfp,
 493                                         struct scsi_cmnd *cmnd)
 494 {
 495         struct usb_device *udev = devinfo->udev;
 496         struct scsi_device *sdev = cmnd->device;
 497         struct uas_cmd_info *cmdinfo = scsi_cmd_priv(cmnd);
 498         struct urb *urb = usb_alloc_urb(0, gfp);
 499         struct command_iu *iu;
 500         int len;
 501
 502         if (!urb)
 503                 goto out;
 504
 505         len = cmnd->cmd_len - 16;
 506         if (len < 0)
 507                 len = 0;
 508         len = ALIGN(len, 4);
 509         iu = kzalloc(sizeof(*iu) + len, gfp);
 510         if (!iu)
 511                 goto free;
 512
 513         iu->iu_id = IU_ID_COMMAND;
 514         iu->tag = cpu_to_be16(cmdinfo->uas_tag);
 515         iu->prio_attr = UAS_SIMPLE_TAG;
 516         iu->len = len;
 517         int_to_scsilun(sdev->lun, &iu->lun);
 518         memcpy(iu->cdb, cmnd->cmnd, cmnd->cmd_len);
 519
 520         usb_fill_bulk_urb(urb, udev, devinfo->cmd_pipe, iu, sizeof(*iu) + len,
 521                                                         uas_cmd_cmplt, NULL);
 522         urb->transfer_flags |= URB_FREE_BUFFER;
 523  out:
 524         return urb;
 525  free:
 526         usb_free_urb(urb);
 527         return NULL;
 528 }
 529
 530 /*
 531  * Why should I request the Status IU before sending the Command IU?  Spec
 532  * says to, but also says the device may receive them in any order.  Seems
 533  * daft to me.
 534  */
 535
 536 static struct urb *uas_submit_sense_urb(struct scsi_cmnd *cmnd, gfp_t gfp)
 537 {
 538         struct uas_dev_info *devinfo = cmnd->device->hostdata;
 539         struct urb *urb;
 540         int err;
 541
 542         urb = uas_alloc_sense_urb(devinfo, gfp, cmnd);
 543         if (!urb)
 544                 return NULL;
 545         usb_anchor_urb(urb, &devinfo->sense_urbs);
 546         err = usb_submit_urb(urb, gfp);
 547         if (err) {
 548                 usb_unanchor_urb(urb);
 549                 uas_log_cmd_state(cmnd, "sense submit err", err);
 550                 usb_free_urb(urb);
 551                 return NULL;
 552         }
 553         return urb;
 554 }
 555
 556 static int uas_submit_urbs(struct scsi_cmnd *cmnd,
 557                            struct uas_dev_info *devinfo)
 558 {
 559         struct uas_cmd_info *cmdinfo = scsi_cmd_priv(cmnd);
 560         struct urb *urb;
 561         int err;
 562
 563         lockdep_assert_held(&devinfo->lock);
 564         if (cmdinfo->state & SUBMIT_STATUS_URB) {
 565                 urb = uas_submit_sense_urb(cmnd, GFP_ATOMIC);
 566                 if (!urb)
 567                         return SCSI_MLQUEUE_DEVICE_BUSY;
 568                 cmdinfo->state &= ~SUBMIT_STATUS_URB;
 569         }
 570
 571         if (cmdinfo->state & ALLOC_DATA_IN_URB) {
 572                 cmdinfo->data_in_urb = uas_alloc_data_urb(devinfo, GFP_ATOMIC,
 573                                                         cmnd, DMA_FROM_DEVICE);
 574                 if (!cmdinfo->data_in_urb)
 575                         return SCSI_MLQUEUE_DEVICE_BUSY;
 576                 cmdinfo->state &= ~ALLOC_DATA_IN_URB;
 577         }
 578
 579         if (cmdinfo->state & SUBMIT_DATA_IN_URB) {
 580                 usb_anchor_urb(cmdinfo->data_in_urb, &devinfo->data_urbs);
 581                 err = usb_submit_urb(cmdinfo->data_in_urb, GFP_ATOMIC);
 582                 if (err) {
 583                         usb_unanchor_urb(cmdinfo->data_in_urb);
 584                         uas_log_cmd_state(cmnd, "data in submit err", err);
 585                         return SCSI_MLQUEUE_DEVICE_BUSY;
 586                 }
 587                 cmdinfo->state &= ~SUBMIT_DATA_IN_URB;
 588                 cmdinfo->state |= DATA_IN_URB_INFLIGHT;
 589         }
 590
 591         if (cmdinfo->state & ALLOC_DATA_OUT_URB) {
 592                 cmdinfo->data_out_urb = uas_alloc_data_urb(devinfo, GFP_ATOMIC,
 593                                                         cmnd, DMA_TO_DEVICE);
 594                 if (!cmdinfo->data_out_urb)
 595                         return SCSI_MLQUEUE_DEVICE_BUSY;
 596                 cmdinfo->state &= ~ALLOC_DATA_OUT_URB;
 597         }
 598
 599         if (cmdinfo->state & SUBMIT_DATA_OUT_URB) {
 600                 usb_anchor_urb(cmdinfo->data_out_urb, &devinfo->data_urbs);
 601                 err = usb_submit_urb(cmdinfo->data_out_urb, GFP_ATOMIC);
 602                 if (err) {
 603                         usb_unanchor_urb(cmdinfo->data_out_urb);
 604                         uas_log_cmd_state(cmnd, "data out submit err", err);
 605                         return SCSI_MLQUEUE_DEVICE_BUSY;
 606                 }
 607                 cmdinfo->state &= ~SUBMIT_DATA_OUT_URB;
 608                 cmdinfo->state |= DATA_OUT_URB_INFLIGHT;
 609         }
 610
 611         if (cmdinfo->state & ALLOC_CMD_URB) {
 612                 cmdinfo->cmd_urb = uas_alloc_cmd_urb(devinfo, GFP_ATOMIC, cmnd);
 613                 if (!cmdinfo->cmd_urb)
 614                         return SCSI_MLQUEUE_DEVICE_BUSY;
 615                 cmdinfo->state &= ~ALLOC_CMD_URB;
 616         }
 617
 618         if (cmdinfo->state & SUBMIT_CMD_URB) {
 619                 usb_anchor_urb(cmdinfo->cmd_urb, &devinfo->cmd_urbs);
 620                 err = usb_submit_urb(cmdinfo->cmd_urb, GFP_ATOMIC);
 621                 if (err) {
 622                         usb_unanchor_urb(cmdinfo->cmd_urb);
 623                         uas_log_cmd_state(cmnd, "cmd submit err", err);
 624                         return SCSI_MLQUEUE_DEVICE_BUSY;
 625                 }
 626                 cmdinfo->cmd_urb = NULL;
 627                 cmdinfo->state &= ~SUBMIT_CMD_URB;
 628                 cmdinfo->state |= COMMAND_INFLIGHT;
 629         }
 630
 631         return 0;
 632 }
 633
 634 static int uas_queuecommand_lck(struct scsi_cmnd *cmnd)
 635 {
 636         struct scsi_device *sdev = cmnd->device;
 637         struct uas_dev_info *devinfo = sdev->hostdata;
 638         struct uas_cmd_info *cmdinfo = scsi_cmd_priv(cmnd);
 639         unsigned long flags;
 640         int idx, err;
 641
 642         /* Re-check scsi_block_requests now that we've the host-lock */
 643         if (cmnd->device->host->host_self_blocked)
 644                 return SCSI_MLQUEUE_DEVICE_BUSY;
 645
 646         if ((devinfo->flags & US_FL_NO_ATA_1X) &&
 647                         (cmnd->cmnd[0] == ATA_12 || cmnd->cmnd[0] == ATA_16)) {
 648                 memcpy(cmnd->sense_buffer, usb_stor_sense_invalidCDB,
 649                        sizeof(usb_stor_sense_invalidCDB));
 650                 cmnd->result = SAM_STAT_CHECK_CONDITION;
 651                 scsi_done(cmnd);
 652                 return 0;
 653         }
 654
 655         spin_lock_irqsave(&devinfo->lock, flags);
 656
 657         if (devinfo->resetting) {
 658                 set_host_byte(cmnd, DID_ERROR);
 659                 scsi_done(cmnd);
 660                 goto zombie;
 661         }
 662
 663         /* Find a free uas-tag */
 664         for (idx = 0; idx < devinfo->qdepth; idx++) {
 665                 if (!devinfo->cmnd[idx])
 666                         break;
 667         }
 668         if (idx == devinfo->qdepth) {
 669                 spin_unlock_irqrestore(&devinfo->lock, flags);
 670                 return SCSI_MLQUEUE_DEVICE_BUSY;
 671         }
 672
 673         memset(cmdinfo, 0, sizeof(*cmdinfo));
 674         cmdinfo->uas_tag = idx + 1; /* uas-tag == usb-stream-id, so 1 based */
 675         cmdinfo->state = SUBMIT_STATUS_URB | ALLOC_CMD_URB | SUBMIT_CMD_URB;
 676
 677         switch (cmnd->sc_data_direction) {
 678         case DMA_FROM_DEVICE:
 679                 cmdinfo->state |= ALLOC_DATA_IN_URB | SUBMIT_DATA_IN_URB;
 680                 break;
 681         case DMA_BIDIRECTIONAL:
 682                 cmdinfo->state |= ALLOC_DATA_IN_URB | SUBMIT_DATA_IN_URB;
 683                 fallthrough;
 684         case DMA_TO_DEVICE:
 685                 cmdinfo->state |= ALLOC_DATA_OUT_URB | SUBMIT_DATA_OUT_URB;
 686                 break;
 687         case DMA_NONE:
 688                 break;
 689         }
 690
 691         if (!devinfo->use_streams)
 692                 cmdinfo->state &= ~(SUBMIT_DATA_IN_URB | SUBMIT_DATA_OUT_URB);
 693
 694         err = uas_submit_urbs(cmnd, devinfo);
 695         /*
 696          * in case of fatal errors the SCSI layer is peculiar
 697          * a command that has finished is a success for the purpose
 698          * of queueing, no matter how fatal the error
 699          */
 700         if (err == -ENODEV) {
 701                 set_host_byte(cmnd, DID_ERROR);
 702                 scsi_done(cmnd);
 703                 goto zombie;
 704         }
 705         if (err) {
 706                 /* If we did nothing, give up now */
 707                 if (cmdinfo->state & SUBMIT_STATUS_URB) {
 708                         spin_unlock_irqrestore(&devinfo->lock, flags);
 709                         return SCSI_MLQUEUE_DEVICE_BUSY;
 710                 }
 711                 uas_add_work(cmnd);
 712         }
 713
 714         devinfo->cmnd[idx] = cmnd;
 715 zombie:
 716         spin_unlock_irqrestore(&devinfo->lock, flags);
 717         return 0;
 718 }
 719
 720 static DEF_SCSI_QCMD(uas_queuecommand)
 721
 722 /*
 723  * For now we do not support actually sending an abort to the device, so
 724  * this eh always fails. Still we must define it to make sure that we've
 725  * dropped all references to the cmnd in question once this function exits.
 726  */
 727 static int uas_eh_abort_handler(struct scsi_cmnd *cmnd)
 728 {
 729         struct uas_cmd_info *cmdinfo = scsi_cmd_priv(cmnd);
 730         struct uas_dev_info *devinfo = (void *)cmnd->device->hostdata;
 731         struct urb *data_in_urb = NULL;
 732         struct urb *data_out_urb = NULL;
 733         unsigned long flags;
 734
 735         spin_lock_irqsave(&devinfo->lock, flags);
 736
 737         uas_log_cmd_state(cmnd, __func__, 0);
 738
 739         /* Ensure that try_complete does not call scsi_done */
 740         cmdinfo->state |= COMMAND_ABORTED;
 741
 742         /* Drop all refs to this cmnd, kill data urbs to break their ref */
 743         devinfo->cmnd[cmdinfo->uas_tag - 1] = NULL;
 744         if (cmdinfo->state & DATA_IN_URB_INFLIGHT)
 745                 data_in_urb = usb_get_urb(cmdinfo->data_in_urb);
 746         if (cmdinfo->state & DATA_OUT_URB_INFLIGHT)
 747                 data_out_urb = usb_get_urb(cmdinfo->data_out_urb);
 748
 749         uas_free_unsubmitted_urbs(cmnd);
 750
 751         spin_unlock_irqrestore(&devinfo->lock, flags);
 752
 753         if (data_in_urb) {
 754                 usb_kill_urb(data_in_urb);
 755                 usb_put_urb(data_in_urb);
 756         }
 757         if (data_out_urb) {
 758                 usb_kill_urb(data_out_urb);
 759                 usb_put_urb(data_out_urb);
 760         }
 761
 762         return FAILED;
 763 }
 764
 765 static int uas_eh_device_reset_handler(struct scsi_cmnd *cmnd)
 766 {
 767         struct scsi_device *sdev = cmnd->device;
 768         struct uas_dev_info *devinfo = sdev->hostdata;
 769         struct usb_device *udev = devinfo->udev;
 770         unsigned long flags;
 771         int err;
 772
 773         err = usb_lock_device_for_reset(udev, devinfo->intf);
 774         if (err) {
 775                 shost_printk(KERN_ERR, sdev->host,
 776                              "%s FAILED to get lock err %d\n", __func__, err);
 777                 return FAILED;
 778         }
 779
 780         shost_printk(KERN_INFO, sdev->host, "%s start\n", __func__);
 781
 782         spin_lock_irqsave(&devinfo->lock, flags);
 783         devinfo->resetting = 1;
 784         spin_unlock_irqrestore(&devinfo->lock, flags);
 785
 786         usb_kill_anchored_urbs(&devinfo->cmd_urbs);
 787         usb_kill_anchored_urbs(&devinfo->sense_urbs);
 788         usb_kill_anchored_urbs(&devinfo->data_urbs);
 789         uas_zap_pending(devinfo, DID_RESET);
 790
 791         err = usb_reset_device(udev);
 792
 793         spin_lock_irqsave(&devinfo->lock, flags);
 794         devinfo->resetting = 0;
 795         spin_unlock_irqrestore(&devinfo->lock, flags);
 796
 797         usb_unlock_device(udev);
 798
 799         if (err) {
 800                 shost_printk(KERN_INFO, sdev->host, "%s FAILED err %d\n",
 801                              __func__, err);
 802                 return FAILED;
 803         }
 804
 805         shost_printk(KERN_INFO, sdev->host, "%s success\n", __func__);
 806         return SUCCESS;
 807 }
 808
 809 static int uas_target_alloc(struct scsi_target *starget)
 810 {
 811         struct uas_dev_info *devinfo = (struct uas_dev_info *)
 812                         dev_to_shost(starget->dev.parent)->hostdata;
 813
 814         if (devinfo->flags & US_FL_NO_REPORT_LUNS)
 815                 starget->no_report_luns = 1;
 816
 817         return 0;
 818 }
 819
 820 static int uas_slave_alloc(struct scsi_device *sdev)
 821 {
 822         struct uas_dev_info *devinfo =
 823                 (struct uas_dev_info *)sdev->host->hostdata;
 824
 825         sdev->hostdata = devinfo;
 826
 827         /*
 828          * The protocol has no requirements on alignment in the strict sense.
 829          * Controllers may or may not have alignment restrictions.
 830          * As this is not exported, we use an extremely conservative guess.
 831          */
 832         blk_queue_update_dma_alignment(sdev->request_queue, (512 - 1));
 833
 834         if (devinfo->flags & US_FL_MAX_SECTORS_64)
 835                 blk_queue_max_hw_sectors(sdev->request_queue, 64);
 836         else if (devinfo->flags & US_FL_MAX_SECTORS_240)
 837                 blk_queue_max_hw_sectors(sdev->request_queue, 240);
 838
 839         return 0;
 840 }
 841
 842 static int uas_slave_configure(struct scsi_device *sdev)
 843 {
 844         struct uas_dev_info *devinfo = sdev->hostdata;
 845
 846         if (devinfo->flags & US_FL_NO_REPORT_OPCODES)
 847                 sdev->no_report_opcodes = 1;
 848
 849         /* A few buggy USB-ATA bridges don't understand FUA */
 850         if (devinfo->flags & US_FL_BROKEN_FUA)
 851                 sdev->broken_fua = 1;
 852
 853         /* UAS also needs to support FL_ALWAYS_SYNC */
 854         if (devinfo->flags & US_FL_ALWAYS_SYNC) {
 855                 sdev->skip_ms_page_3f = 1;
 856                 sdev->skip_ms_page_8 = 1;
 857                 sdev->wce_default_on = 1;
 858         }
 859
 860         /* Some disks cannot handle READ_CAPACITY_16 */
 861         if (devinfo->flags & US_FL_NO_READ_CAPACITY_16)
 862                 sdev->no_read_capacity_16 = 1;
 863
 864         /* Some disks cannot handle WRITE_SAME */
 865         if (devinfo->flags & US_FL_NO_SAME)
 866                 sdev->no_write_same = 1;
 867         /*
 868          * Some disks return the total number of blocks in response
 869          * to READ CAPACITY rather than the highest block number.
 870          * If this device makes that mistake, tell the sd driver.
 871          */
 872         if (devinfo->flags & US_FL_FIX_CAPACITY)
 873                 sdev->fix_capacity = 1;
 874
 875         /*
 876          * in some cases we have to guess
 877          */
 878         if (devinfo->flags & US_FL_CAPACITY_HEURISTICS)
 879                 sdev->guess_capacity = 1;
 880
 881         /*
 882          * Some devices don't like MODE SENSE with page=0x3f,
 883          * which is the command used for checking if a device
 884          * is write-protected.  Now that we tell the sd driver
 885          * to do a 192-byte transfer with this command the
 886          * majority of devices work fine, but a few still can't
 887          * handle it.  The sd driver will simply assume those
 888          * devices are write-enabled.
 889          */
 890         if (devinfo->flags & US_FL_NO_WP_DETECT)
 891                 sdev->skip_ms_page_3f = 1;
 892
 893         scsi_change_queue_depth(sdev, devinfo->qdepth - 2);
 894         return 0;
 895 }
 896
 897 static const struct scsi_host_template uas_host_template = {
 898         .module = THIS_MODULE,
 899         .name = "uas",
 900         .queuecommand = uas_queuecommand,
 901         .target_alloc = uas_target_alloc,
 902         .slave_alloc = uas_slave_alloc,
 903         .slave_configure = uas_slave_configure,
 904         .eh_abort_handler = uas_eh_abort_handler,
 905         .eh_device_reset_handler = uas_eh_device_reset_handler,
 906         .this_id = -1,
 907         .skip_settle_delay = 1,
 908         .dma_boundary = PAGE_SIZE - 1,
 909         .cmd_size = sizeof(struct uas_cmd_info),
 910 };
 911
 912 #define UNUSUAL_DEV(id_vendor, id_product, bcdDeviceMin, bcdDeviceMax, \
 913                     vendorName, productName, useProtocol, useTransport, \
 914                     initFunction, flags) \
 915 { USB_DEVICE_VER(id_vendor, id_product, bcdDeviceMin, bcdDeviceMax), \
 916         .driver_info = (flags) }
 917
 918 static struct usb_device_id uas_usb_ids[] = {
 919 #       include "unusual_uas.h"
 920         { USB_INTERFACE_INFO(USB_CLASS_MASS_STORAGE, USB_SC_SCSI, USB_PR_BULK) },
 921         { USB_INTERFACE_INFO(USB_CLASS_MASS_STORAGE, USB_SC_SCSI, USB_PR_UAS) },
 922         { }
 923 };
 924 MODULE_DEVICE_TABLE(usb, uas_usb_ids);
 925
 926 #undef UNUSUAL_DEV
 927
 928 static int uas_switch_interface(struct usb_device *udev,
 929                                 struct usb_interface *intf)
 930 {
 931         struct usb_host_interface *alt;
 932
 933         alt = uas_find_uas_alt_setting(intf);
 934         if (!alt)
 935                 return -ENODEV;
 936
 937         return usb_set_interface(udev, alt->desc.bInterfaceNumber,
 938                         alt->desc.bAlternateSetting);
 939 }
 940
 941 static int uas_configure_endpoints(struct uas_dev_info *devinfo)
 942 {
 943         struct usb_host_endpoint *eps[4] = { };
 944         struct usb_device *udev = devinfo->udev;
 945         int r;
 946
 947         r = uas_find_endpoints(devinfo->intf->cur_altsetting, eps);
 948         if (r)
 949                 return r;
 950
 951         devinfo->cmd_pipe = usb_sndbulkpipe(udev,
 952                                             usb_endpoint_num(&eps[0]->desc));
 953         devinfo->status_pipe = usb_rcvbulkpipe(udev,
 954                                             usb_endpoint_num(&eps[1]->desc));
 955         devinfo->data_in_pipe = usb_rcvbulkpipe(udev,
 956                                             usb_endpoint_num(&eps[2]->desc));
 957         devinfo->data_out_pipe = usb_sndbulkpipe(udev,
 958                                             usb_endpoint_num(&eps[3]->desc));
 959
 960         if (udev->speed < USB_SPEED_SUPER) {
 961                 devinfo->qdepth = 32;
 962                 devinfo->use_streams = 0;
 963         } else {
 964                 devinfo->qdepth = usb_alloc_streams(devinfo->intf, eps + 1,
 965                                                     3, MAX_CMNDS, GFP_NOIO);
 966                 if (devinfo->qdepth < 0)
 967                         return devinfo->qdepth;
 968                 devinfo->use_streams = 1;
 969         }
 970
 971         return 0;
 972 }
 973
 974 static void uas_free_streams(struct uas_dev_info *devinfo)
 975 {
 976         struct usb_device *udev = devinfo->udev;
 977         struct usb_host_endpoint *eps[3];
 978
 979         eps[0] = usb_pipe_endpoint(udev, devinfo->status_pipe);
 980         eps[1] = usb_pipe_endpoint(udev, devinfo->data_in_pipe);
 981         eps[2] = usb_pipe_endpoint(udev, devinfo->data_out_pipe);
 982         usb_free_streams(devinfo->intf, eps, 3, GFP_NOIO);
 983 }
 984
 985 static int uas_probe(struct usb_interface *intf, const struct usb_device_id *id)
 986 {
 987         int result = -ENOMEM;
 988         struct Scsi_Host *shost = NULL;
 989         struct uas_dev_info *devinfo;
 990         struct usb_device *udev = interface_to_usbdev(intf);
 991         unsigned long dev_flags;
 992
 993         if (!uas_use_uas_driver(intf, id, &dev_flags))
 994                 return -ENODEV;
 995
 996         if (uas_switch_interface(udev, intf))
 997                 return -ENODEV;
 998
 999         shost = scsi_host_alloc(&uas_host_template,
1000                                 sizeof(struct uas_dev_info));
1001         if (!shost)
1002                 goto set_alt0;
1003
1004         shost->max_cmd_len = 16 + 252;
1005         shost->max_id = 1;
1006         shost->max_lun = 256;
1007         shost->max_channel = 0;
1008         shost->sg_tablesize = udev->bus->sg_tablesize;
1009
1010         devinfo = (struct uas_dev_info *)shost->hostdata;
1011         devinfo->intf = intf;
1012         devinfo->udev = udev;
1013         devinfo->resetting = 0;
1014         devinfo->shutdown = 0;
1015         devinfo->flags = dev_flags;
1016         init_usb_anchor(&devinfo->cmd_urbs);
1017         init_usb_anchor(&devinfo->sense_urbs);
1018         init_usb_anchor(&devinfo->data_urbs);
1019         spin_lock_init(&devinfo->lock);
1020         INIT_WORK(&devinfo->work, uas_do_work);
1021         INIT_WORK(&devinfo->scan_work, uas_scan_work);
1022
1023         result = uas_configure_endpoints(devinfo);
1024         if (result)
1025                 goto set_alt0;
1026
1027         /*
1028          * 1 tag is reserved for untagged commands +
1029          * 1 tag to avoid off by one errors in some bridge firmwares
1030          */
1031         shost->can_queue = devinfo->qdepth - 2;
1032
1033         usb_set_intfdata(intf, shost);
1034         result = scsi_add_host(shost, &intf->dev);
1035         if (result)
1036                 goto free_streams;
1037
1038         /* Submit the delayed_work for SCSI-device scanning */
1039         schedule_work(&devinfo->scan_work);
1040
1041         return result;
1042
1043 free_streams:
1044         uas_free_streams(devinfo);
1045         usb_set_intfdata(intf, NULL);
1046 set_alt0:
1047         usb_set_interface(udev, intf->altsetting[0].desc.bInterfaceNumber, 0);
1048         if (shost)
1049                 scsi_host_put(shost);
1050         return result;
1051 }
1052
1053 static int uas_cmnd_list_empty(struct uas_dev_info *devinfo)
1054 {
1055         unsigned long flags;
1056         int i, r = 1;
1057
1058         spin_lock_irqsave(&devinfo->lock, flags);
1059
1060         for (i = 0; i < devinfo->qdepth; i++) {
1061                 if (devinfo->cmnd[i]) {
1062                         r = 0; /* Not empty */
1063                         break;
1064                 }
1065         }
1066
1067         spin_unlock_irqrestore(&devinfo->lock, flags);
1068
1069         return r;
1070 }
1071
1072 /*
1073  * Wait for any pending cmnds to complete, on usb-2 sense_urbs may temporarily
1074  * get empty while there still is more work to do due to sense-urbs completing
1075  * with a READ/WRITE_READY iu code, so keep waiting until the list gets empty.
1076  */
1077 static int uas_wait_for_pending_cmnds(struct uas_dev_info *devinfo)
1078 {
1079         unsigned long start_time;
1080         int r;
1081
1082         start_time = jiffies;
1083         do {
1084                 flush_work(&devinfo->work);
1085
1086                 r = usb_wait_anchor_empty_timeout(&devinfo->sense_urbs, 5000);
1087                 if (r == 0)
1088                         return -ETIME;
1089
1090                 r = usb_wait_anchor_empty_timeout(&devinfo->data_urbs, 500);
1091                 if (r == 0)
1092                         return -ETIME;
1093
1094                 if (time_after(jiffies, start_time + 5 * HZ))
1095                         return -ETIME;
1096         } while (!uas_cmnd_list_empty(devinfo));
1097
1098         return 0;
1099 }
1100
1101 static int uas_pre_reset(struct usb_interface *intf)
1102 {
1103         struct Scsi_Host *shost = usb_get_intfdata(intf);
1104         struct uas_dev_info *devinfo = (struct uas_dev_info *)shost->hostdata;
1105         unsigned long flags;
1106
1107         if (devinfo->shutdown)
1108                 return 0;
1109
1110         /* Block new requests */
1111         spin_lock_irqsave(shost->host_lock, flags);
1112         scsi_block_requests(shost);
1113         spin_unlock_irqrestore(shost->host_lock, flags);
1114
1115         if (uas_wait_for_pending_cmnds(devinfo) != 0) {
1116                 shost_printk(KERN_ERR, shost, "%s: timed out\n", __func__);
1117                 scsi_unblock_requests(shost);
1118                 return 1;
1119         }
1120
1121         uas_free_streams(devinfo);
1122
1123         return 0;
1124 }
1125
1126 static int uas_post_reset(struct usb_interface *intf)
1127 {
1128         struct Scsi_Host *shost = usb_get_intfdata(intf);
1129         struct uas_dev_info *devinfo = (struct uas_dev_info *)shost->hostdata;
1130         unsigned long flags;
1131         int err;
1132
1133         if (devinfo->shutdown)
1134                 return 0;
1135
1136         err = uas_configure_endpoints(devinfo);
1137         if (err && err != -ENODEV)
1138                 shost_printk(KERN_ERR, shost,
1139                              "%s: alloc streams error %d after reset",
1140                              __func__, err);
1141
1142         /* we must unblock the host in every case lest we deadlock */
1143         spin_lock_irqsave(shost->host_lock, flags);
1144         scsi_report_bus_reset(shost, 0);
1145         spin_unlock_irqrestore(shost->host_lock, flags);
1146
1147         scsi_unblock_requests(shost);
1148
1149         return err ? 1 : 0;
1150 }
1151
1152 static int uas_suspend(struct usb_interface *intf, pm_message_t message)
1153 {
1154         struct Scsi_Host *shost = usb_get_intfdata(intf);
1155         struct uas_dev_info *devinfo = (struct uas_dev_info *)shost->hostdata;
1156
1157         if (uas_wait_for_pending_cmnds(devinfo) != 0) {
1158                 shost_printk(KERN_ERR, shost, "%s: timed out\n", __func__);
1159                 return -ETIME;
1160         }
1161
1162         return 0;
1163 }
1164
1165 static int uas_resume(struct usb_interface *intf)
1166 {
1167         return 0;
1168 }
1169
1170 static int uas_reset_resume(struct usb_interface *intf)
1171 {
1172         struct Scsi_Host *shost = usb_get_intfdata(intf);
1173         struct uas_dev_info *devinfo = (struct uas_dev_info *)shost->hostdata;
1174         unsigned long flags;
1175         int err;
1176
1177         err = uas_configure_endpoints(devinfo);
1178         if (err) {
1179                 shost_printk(KERN_ERR, shost,
1180                              "%s: alloc streams error %d after reset",
1181                              __func__, err);
1182                 return -EIO;
1183         }
1184
1185         spin_lock_irqsave(shost->host_lock, flags);
1186         scsi_report_bus_reset(shost, 0);
1187         spin_unlock_irqrestore(shost->host_lock, flags);
1188
1189         return 0;
1190 }
1191
1192 static void uas_disconnect(struct usb_interface *intf)
1193 {
1194         struct Scsi_Host *shost = usb_get_intfdata(intf);
1195         struct uas_dev_info *devinfo = (struct uas_dev_info *)shost->hostdata;
1196         unsigned long flags;
1197
1198         spin_lock_irqsave(&devinfo->lock, flags);
1199         devinfo->resetting = 1;
1200         spin_unlock_irqrestore(&devinfo->lock, flags);
1201
1202         cancel_work_sync(&devinfo->work);
1203         usb_kill_anchored_urbs(&devinfo->cmd_urbs);
1204         usb_kill_anchored_urbs(&devinfo->sense_urbs);
1205         usb_kill_anchored_urbs(&devinfo->data_urbs);
1206         uas_zap_pending(devinfo, DID_NO_CONNECT);
1207
1208         /*
1209          * Prevent SCSI scanning (if it hasn't started yet)
1210          * or wait for the SCSI-scanning routine to stop.
1211          */
1212         cancel_work_sync(&devinfo->scan_work);
1213
1214         scsi_remove_host(shost);
1215         uas_free_streams(devinfo);
1216         scsi_host_put(shost);
1217 }
1218
1219 /*
1220  * Put the device back in usb-storage mode on shutdown, as some BIOS-es
1221  * hang on reboot when the device is still in uas mode. Note the reset is
1222  * necessary as some devices won't revert to usb-storage mode without it.
1223  */
1224 static void uas_shutdown(struct device *dev)
1225 {
1226         struct usb_interface *intf = to_usb_interface(dev);
1227         struct usb_device *udev = interface_to_usbdev(intf);
1228         struct Scsi_Host *shost = usb_get_intfdata(intf);
1229         struct uas_dev_info *devinfo = (struct uas_dev_info *)shost->hostdata;
1230
1231         if (system_state != SYSTEM_RESTART)
1232                 return;
1233
1234         devinfo->shutdown = 1;
1235         uas_free_streams(devinfo);
1236         usb_set_interface(udev, intf->altsetting[0].desc.bInterfaceNumber, 0);
1237         usb_reset_device(udev);
1238 }
1239
1240 static struct usb_driver uas_driver = {
1241         .name = "uas",
1242         .probe = uas_probe,
1243         .disconnect = uas_disconnect,
1244         .pre_reset = uas_pre_reset,
1245         .post_reset = uas_post_reset,
1246         .suspend = uas_suspend,
1247         .resume = uas_resume,
1248         .reset_resume = uas_reset_resume,
1249         .drvwrap.driver.shutdown = uas_shutdown,
1250         .id_table = uas_usb_ids,
1251 };
1252
1253 static int __init uas_init(void)
1254 {
1255         int rv;
1256
1257         workqueue = alloc_workqueue("uas", WQ_MEM_RECLAIM, 0);
1258         if (!workqueue)
1259                 return -ENOMEM;
1260
1261         rv = usb_register(&uas_driver);
1262         if (rv) {
1263                 destroy_workqueue(workqueue);
1264                 return -ENOMEM;
1265         }
1266
1267         return 0;
1268 }
1269
1270 static void __exit uas_exit(void)
1271 {
1272         usb_deregister(&uas_driver);
1273         destroy_workqueue(workqueue);
1274 }
1275
1276 module_init(uas_init);
1277 module_exit(uas_exit);
1278
1279 MODULE_LICENSE("GPL");
1280 MODULE_IMPORT_NS(USB_STORAGE);
1281 MODULE_AUTHOR(
1282         "Hans de Goede <hdegoede@redhat.com>, Matthew Wilcox and Sarah Sharp");