drivers/usb/storage/uas.c

   1 /*
   2  * USB Attached SCSI
   3  * Note that this is not the same as the USB Mass Storage driver
   4  *
   5  * Copyright Matthew Wilcox for Intel Corp, 2010
   6  * Copyright Sarah Sharp for Intel Corp, 2010
   7  *
   8  * Distributed under the terms of the GNU GPL, version two.
   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/hcd.h>
  17 #include <linux/usb/storage.h>
  18 #include <linux/usb/uas.h>
  19
  20 #include <scsi/scsi.h>
  21 #include <scsi/scsi_dbg.h>
  22 #include <scsi/scsi_cmnd.h>
  23 #include <scsi/scsi_device.h>
  24 #include <scsi/scsi_host.h>
  25 #include <scsi/scsi_tcq.h>
  26
  27 /*
  28  * The r00-r01c specs define this version of the SENSE IU data structure.
  29  * It's still in use by several different firmware releases.
  30  */
  31 struct sense_iu_old {
  32         __u8 iu_id;
  33         __u8 rsvd1;
  34         __be16 tag;
  35         __be16 len;
  36         __u8 status;
  37         __u8 service_response;
  38         __u8 sense[SCSI_SENSE_BUFFERSIZE];
  39 };
  40
  41 struct uas_dev_info {
  42         struct usb_interface *intf;
  43         struct usb_device *udev;
  44         struct usb_anchor sense_urbs;
  45         struct usb_anchor data_urbs;
  46         int qdepth;
  47         unsigned cmd_pipe, status_pipe, data_in_pipe, data_out_pipe;
  48         unsigned use_streams:1;
  49         unsigned uas_sense_old:1;
  50         struct scsi_cmnd *cmnd;
  51 };
  52
  53 enum {
  54         SUBMIT_STATUS_URB       = (1 << 1),
  55         ALLOC_DATA_IN_URB       = (1 << 2),
  56         SUBMIT_DATA_IN_URB      = (1 << 3),
  57         ALLOC_DATA_OUT_URB      = (1 << 4),
  58         SUBMIT_DATA_OUT_URB     = (1 << 5),
  59         ALLOC_CMD_URB           = (1 << 6),
  60         SUBMIT_CMD_URB          = (1 << 7),
  61         COMMAND_INFLIGHT        = (1 << 8),
  62         DATA_IN_URB_INFLIGHT    = (1 << 9),
  63         DATA_OUT_URB_INFLIGHT   = (1 << 10),
  64         COMMAND_COMPLETED       = (1 << 11),
  65 };
  66
  67 /* Overrides scsi_pointer */
  68 struct uas_cmd_info {
  69         unsigned int state;
  70         unsigned int stream;
  71         struct urb *cmd_urb;
  72         struct urb *data_in_urb;
  73         struct urb *data_out_urb;
  74         struct list_head list;
  75 };
  76
  77 /* I hate forward declarations, but I actually have a loop */
  78 static int uas_submit_urbs(struct scsi_cmnd *cmnd,
  79                                 struct uas_dev_info *devinfo, gfp_t gfp);
  80 static void uas_do_work(struct work_struct *work);
  81
  82 static DECLARE_WORK(uas_work, uas_do_work);
  83 static DEFINE_SPINLOCK(uas_work_lock);
  84 static LIST_HEAD(uas_work_list);
  85
  86 static void uas_do_work(struct work_struct *work)
  87 {
  88         struct uas_cmd_info *cmdinfo;
  89         struct uas_cmd_info *temp;
  90         struct list_head list;
  91         int err;
  92
  93         spin_lock_irq(&uas_work_lock);
  94         list_replace_init(&uas_work_list, &list);
  95         spin_unlock_irq(&uas_work_lock);
  96
  97         list_for_each_entry_safe(cmdinfo, temp, &list, list) {
  98                 struct scsi_pointer *scp = (void *)cmdinfo;
  99                 struct scsi_cmnd *cmnd = container_of(scp,
 100                                                         struct scsi_cmnd, SCp);
 101                 err = uas_submit_urbs(cmnd, cmnd->device->hostdata, GFP_NOIO);
 102                 if (err) {
 103                         list_del(&cmdinfo->list);
 104                         spin_lock_irq(&uas_work_lock);
 105                         list_add_tail(&cmdinfo->list, &uas_work_list);
 106                         spin_unlock_irq(&uas_work_lock);
 107                         schedule_work(&uas_work);
 108                 }
 109         }
 110 }
 111
 112 static void uas_sense(struct urb *urb, struct scsi_cmnd *cmnd)
 113 {
 114         struct sense_iu *sense_iu = urb->transfer_buffer;
 115         struct scsi_device *sdev = cmnd->device;
 116
 117         if (urb->actual_length > 16) {
 118                 unsigned len = be16_to_cpup(&sense_iu->len);
 119                 if (len + 16 != urb->actual_length) {
 120                         int newlen = min(len + 16, urb->actual_length) - 16;
 121                         if (newlen < 0)
 122                                 newlen = 0;
 123                         sdev_printk(KERN_INFO, sdev, "%s: urb length %d "
 124                                 "disagrees with IU sense data length %d, "
 125                                 "using %d bytes of sense data\n", __func__,
 126                                         urb->actual_length, len, newlen);
 127                         len = newlen;
 128                 }
 129                 memcpy(cmnd->sense_buffer, sense_iu->sense, len);
 130         }
 131
 132         cmnd->result = sense_iu->status;
 133 }
 134
 135 static void uas_sense_old(struct urb *urb, struct scsi_cmnd *cmnd)
 136 {
 137         struct sense_iu_old *sense_iu = urb->transfer_buffer;
 138         struct scsi_device *sdev = cmnd->device;
 139
 140         if (urb->actual_length > 8) {
 141                 unsigned len = be16_to_cpup(&sense_iu->len) - 2;
 142                 if (len + 8 != urb->actual_length) {
 143                         int newlen = min(len + 8, urb->actual_length) - 8;
 144                         if (newlen < 0)
 145                                 newlen = 0;
 146                         sdev_printk(KERN_INFO, sdev, "%s: urb length %d "
 147                                 "disagrees with IU sense data length %d, "
 148                                 "using %d bytes of sense data\n", __func__,
 149                                         urb->actual_length, len, newlen);
 150                         len = newlen;
 151                 }
 152                 memcpy(cmnd->sense_buffer, sense_iu->sense, len);
 153         }
 154
 155         cmnd->result = sense_iu->status;
 156 }
 157
 158 static void uas_log_cmd_state(struct scsi_cmnd *cmnd, const char *caller)
 159 {
 160         struct uas_cmd_info *ci = (void *)&cmnd->SCp;
 161
 162         scmd_printk(KERN_INFO, cmnd, "%s %p tag %d, inflight:"
 163                     "%s%s%s%s%s%s%s%s%s%s%s\n",
 164                     caller, cmnd, cmnd->request->tag,
 165                     (ci->state & SUBMIT_STATUS_URB)     ? " s-st"  : "",
 166                     (ci->state & ALLOC_DATA_IN_URB)     ? " a-in"  : "",
 167                     (ci->state & SUBMIT_DATA_IN_URB)    ? " s-in"  : "",
 168                     (ci->state & ALLOC_DATA_OUT_URB)    ? " a-out" : "",
 169                     (ci->state & SUBMIT_DATA_OUT_URB)   ? " s-out" : "",
 170                     (ci->state & ALLOC_CMD_URB)         ? " a-cmd" : "",
 171                     (ci->state & SUBMIT_CMD_URB)        ? " s-cmd" : "",
 172                     (ci->state & COMMAND_INFLIGHT)      ? " CMD"   : "",
 173                     (ci->state & DATA_IN_URB_INFLIGHT)  ? " IN"    : "",
 174                     (ci->state & DATA_OUT_URB_INFLIGHT) ? " OUT"   : "",
 175                     (ci->state & COMMAND_COMPLETED)     ? " done"  : "");
 176 }
 177
 178 static int uas_try_complete(struct scsi_cmnd *cmnd, const char *caller)
 179 {
 180         struct uas_cmd_info *cmdinfo = (void *)&cmnd->SCp;
 181
 182         if (cmdinfo->state & (COMMAND_INFLIGHT |
 183                               DATA_IN_URB_INFLIGHT |
 184                               DATA_OUT_URB_INFLIGHT))
 185                 return -EBUSY;
 186         BUG_ON(cmdinfo->state & COMMAND_COMPLETED);
 187         cmdinfo->state |= COMMAND_COMPLETED;
 188         usb_free_urb(cmdinfo->data_in_urb);
 189         usb_free_urb(cmdinfo->data_out_urb);
 190         cmnd->scsi_done(cmnd);
 191         return 0;
 192 }
 193
 194 static void uas_xfer_data(struct urb *urb, struct scsi_cmnd *cmnd,
 195                           unsigned direction)
 196 {
 197         struct uas_cmd_info *cmdinfo = (void *)&cmnd->SCp;
 198         int err;
 199
 200         cmdinfo->state |= direction | SUBMIT_STATUS_URB;
 201         err = uas_submit_urbs(cmnd, cmnd->device->hostdata, GFP_ATOMIC);
 202         if (err) {
 203                 spin_lock(&uas_work_lock);
 204                 list_add_tail(&cmdinfo->list, &uas_work_list);
 205                 spin_unlock(&uas_work_lock);
 206                 schedule_work(&uas_work);
 207         }
 208 }
 209
 210 static void uas_stat_cmplt(struct urb *urb)
 211 {
 212         struct iu *iu = urb->transfer_buffer;
 213         struct Scsi_Host *shost = urb->context;
 214         struct uas_dev_info *devinfo = (void *)shost->hostdata[0];
 215         struct scsi_cmnd *cmnd;
 216         struct uas_cmd_info *cmdinfo;
 217         u16 tag;
 218
 219         if (urb->status) {
 220                 dev_err(&urb->dev->dev, "URB BAD STATUS %d\n", urb->status);
 221                 usb_free_urb(urb);
 222                 return;
 223         }
 224
 225         tag = be16_to_cpup(&iu->tag) - 1;
 226         if (tag == 0)
 227                 cmnd = devinfo->cmnd;
 228         else
 229                 cmnd = scsi_host_find_tag(shost, tag - 1);
 230         if (!cmnd) {
 231                 usb_free_urb(urb);
 232                 return;
 233         }
 234         cmdinfo = (void *)&cmnd->SCp;
 235
 236         switch (iu->iu_id) {
 237         case IU_ID_STATUS:
 238                 if (devinfo->cmnd == cmnd)
 239                         devinfo->cmnd = NULL;
 240
 241                 if (urb->actual_length < 16)
 242                         devinfo->uas_sense_old = 1;
 243                 if (devinfo->uas_sense_old)
 244                         uas_sense_old(urb, cmnd);
 245                 else
 246                         uas_sense(urb, cmnd);
 247                 if (cmnd->result != 0) {
 248                         /* cancel data transfers on error */
 249                         if (cmdinfo->state & DATA_IN_URB_INFLIGHT)
 250                                 usb_unlink_urb(cmdinfo->data_in_urb);
 251                         if (cmdinfo->state & DATA_OUT_URB_INFLIGHT)
 252                                 usb_unlink_urb(cmdinfo->data_out_urb);
 253                 }
 254                 cmdinfo->state &= ~COMMAND_INFLIGHT;
 255                 uas_try_complete(cmnd, __func__);
 256                 break;
 257         case IU_ID_READ_READY:
 258                 uas_xfer_data(urb, cmnd, SUBMIT_DATA_IN_URB);
 259                 break;
 260         case IU_ID_WRITE_READY:
 261                 uas_xfer_data(urb, cmnd, SUBMIT_DATA_OUT_URB);
 262                 break;
 263         default:
 264                 scmd_printk(KERN_ERR, cmnd,
 265                         "Bogus IU (%d) received on status pipe\n", iu->iu_id);
 266         }
 267         usb_free_urb(urb);
 268 }
 269
 270 static void uas_data_cmplt(struct urb *urb)
 271 {
 272         struct scsi_cmnd *cmnd = urb->context;
 273         struct uas_cmd_info *cmdinfo = (void *)&cmnd->SCp;
 274         struct scsi_data_buffer *sdb = NULL;
 275
 276         if (cmdinfo->data_in_urb == urb) {
 277                 sdb = scsi_in(cmnd);
 278                 cmdinfo->state &= ~DATA_IN_URB_INFLIGHT;
 279         } else if (cmdinfo->data_out_urb == urb) {
 280                 sdb = scsi_out(cmnd);
 281                 cmdinfo->state &= ~DATA_OUT_URB_INFLIGHT;
 282         }
 283         BUG_ON(sdb == NULL);
 284         if (urb->status) {
 285                 /* error: no data transfered */
 286                 sdb->resid = sdb->length;
 287         } else {
 288                 sdb->resid = sdb->length - urb->actual_length;
 289         }
 290         uas_try_complete(cmnd, __func__);
 291 }
 292
 293 static struct urb *uas_alloc_data_urb(struct uas_dev_info *devinfo, gfp_t gfp,
 294                                       unsigned int pipe, u16 stream_id,
 295                                       struct scsi_cmnd *cmnd,
 296                                       enum dma_data_direction dir)
 297 {
 298         struct usb_device *udev = devinfo->udev;
 299         struct urb *urb = usb_alloc_urb(0, gfp);
 300         struct scsi_data_buffer *sdb = (dir == DMA_FROM_DEVICE)
 301                 ? scsi_in(cmnd) : scsi_out(cmnd);
 302
 303         if (!urb)
 304                 goto out;
 305         usb_fill_bulk_urb(urb, udev, pipe, NULL, sdb->length,
 306                           uas_data_cmplt, cmnd);
 307         if (devinfo->use_streams)
 308                 urb->stream_id = stream_id;
 309         urb->num_sgs = udev->bus->sg_tablesize ? sdb->table.nents : 0;
 310         urb->sg = sdb->table.sgl;
 311  out:
 312         return urb;
 313 }
 314
 315 static struct urb *uas_alloc_sense_urb(struct uas_dev_info *devinfo, gfp_t gfp,
 316                                        struct Scsi_Host *shost, u16 stream_id)
 317 {
 318         struct usb_device *udev = devinfo->udev;
 319         struct urb *urb = usb_alloc_urb(0, gfp);
 320         struct sense_iu *iu;
 321
 322         if (!urb)
 323                 goto out;
 324
 325         iu = kzalloc(sizeof(*iu), gfp);
 326         if (!iu)
 327                 goto free;
 328
 329         usb_fill_bulk_urb(urb, udev, devinfo->status_pipe, iu, sizeof(*iu),
 330                                                 uas_stat_cmplt, shost);
 331         urb->stream_id = stream_id;
 332         urb->transfer_flags |= URB_FREE_BUFFER;
 333  out:
 334         return urb;
 335  free:
 336         usb_free_urb(urb);
 337         return NULL;
 338 }
 339
 340 static struct urb *uas_alloc_cmd_urb(struct uas_dev_info *devinfo, gfp_t gfp,
 341                                         struct scsi_cmnd *cmnd, u16 stream_id)
 342 {
 343         struct usb_device *udev = devinfo->udev;
 344         struct scsi_device *sdev = cmnd->device;
 345         struct urb *urb = usb_alloc_urb(0, gfp);
 346         struct command_iu *iu;
 347         int len;
 348
 349         if (!urb)
 350                 goto out;
 351
 352         len = cmnd->cmd_len - 16;
 353         if (len < 0)
 354                 len = 0;
 355         len = ALIGN(len, 4);
 356         iu = kzalloc(sizeof(*iu) + len, gfp);
 357         if (!iu)
 358                 goto free;
 359
 360         iu->iu_id = IU_ID_COMMAND;
 361         if (blk_rq_tagged(cmnd->request))
 362                 iu->tag = cpu_to_be16(cmnd->request->tag + 2);
 363         else
 364                 iu->tag = cpu_to_be16(1);
 365         iu->prio_attr = UAS_SIMPLE_TAG;
 366         iu->len = len;
 367         int_to_scsilun(sdev->lun, &iu->lun);
 368         memcpy(iu->cdb, cmnd->cmnd, cmnd->cmd_len);
 369
 370         usb_fill_bulk_urb(urb, udev, devinfo->cmd_pipe, iu, sizeof(*iu) + len,
 371                                                         usb_free_urb, NULL);
 372         urb->transfer_flags |= URB_FREE_BUFFER;
 373  out:
 374         return urb;
 375  free:
 376         usb_free_urb(urb);
 377         return NULL;
 378 }
 379
 380 /*
 381  * Why should I request the Status IU before sending the Command IU?  Spec
 382  * says to, but also says the device may receive them in any order.  Seems
 383  * daft to me.
 384  */
 385
 386 static int uas_submit_sense_urb(struct Scsi_Host *shost,
 387                                 gfp_t gfp, unsigned int stream)
 388 {
 389         struct uas_dev_info *devinfo = (void *)shost->hostdata[0];
 390         struct urb *urb;
 391
 392         urb = uas_alloc_sense_urb(devinfo, gfp, shost, stream);
 393         if (!urb)
 394                 return SCSI_MLQUEUE_DEVICE_BUSY;
 395         if (usb_submit_urb(urb, gfp)) {
 396                 shost_printk(KERN_INFO, shost,
 397                              "sense urb submission failure\n");
 398                 usb_free_urb(urb);
 399                 return SCSI_MLQUEUE_DEVICE_BUSY;
 400         }
 401         usb_anchor_urb(urb, &devinfo->sense_urbs);
 402         return 0;
 403 }
 404
 405 static int uas_submit_urbs(struct scsi_cmnd *cmnd,
 406                            struct uas_dev_info *devinfo, gfp_t gfp)
 407 {
 408         struct uas_cmd_info *cmdinfo = (void *)&cmnd->SCp;
 409         int err;
 410
 411         if (cmdinfo->state & SUBMIT_STATUS_URB) {
 412                 err = uas_submit_sense_urb(cmnd->device->host, gfp,
 413                                            cmdinfo->stream);
 414                 if (err) {
 415                         return err;
 416                 }
 417                 cmdinfo->state &= ~SUBMIT_STATUS_URB;
 418         }
 419
 420         if (cmdinfo->state & ALLOC_DATA_IN_URB) {
 421                 cmdinfo->data_in_urb = uas_alloc_data_urb(devinfo, gfp,
 422                                         devinfo->data_in_pipe, cmdinfo->stream,
 423                                         cmnd, DMA_FROM_DEVICE);
 424                 if (!cmdinfo->data_in_urb)
 425                         return SCSI_MLQUEUE_DEVICE_BUSY;
 426                 cmdinfo->state &= ~ALLOC_DATA_IN_URB;
 427         }
 428
 429         if (cmdinfo->state & SUBMIT_DATA_IN_URB) {
 430                 if (usb_submit_urb(cmdinfo->data_in_urb, gfp)) {
 431                         scmd_printk(KERN_INFO, cmnd,
 432                                         "data in urb submission failure\n");
 433                         return SCSI_MLQUEUE_DEVICE_BUSY;
 434                 }
 435                 cmdinfo->state &= ~SUBMIT_DATA_IN_URB;
 436                 cmdinfo->state |= DATA_IN_URB_INFLIGHT;
 437                 usb_anchor_urb(cmdinfo->data_in_urb, &devinfo->data_urbs);
 438         }
 439
 440         if (cmdinfo->state & ALLOC_DATA_OUT_URB) {
 441                 cmdinfo->data_out_urb = uas_alloc_data_urb(devinfo, gfp,
 442                                         devinfo->data_out_pipe, cmdinfo->stream,
 443                                         cmnd, DMA_TO_DEVICE);
 444                 if (!cmdinfo->data_out_urb)
 445                         return SCSI_MLQUEUE_DEVICE_BUSY;
 446                 cmdinfo->state &= ~ALLOC_DATA_OUT_URB;
 447         }
 448
 449         if (cmdinfo->state & SUBMIT_DATA_OUT_URB) {
 450                 if (usb_submit_urb(cmdinfo->data_out_urb, gfp)) {
 451                         scmd_printk(KERN_INFO, cmnd,
 452                                         "data out urb submission failure\n");
 453                         return SCSI_MLQUEUE_DEVICE_BUSY;
 454                 }
 455                 cmdinfo->state &= ~SUBMIT_DATA_OUT_URB;
 456                 cmdinfo->state |= DATA_OUT_URB_INFLIGHT;
 457                 usb_anchor_urb(cmdinfo->data_out_urb, &devinfo->data_urbs);
 458         }
 459
 460         if (cmdinfo->state & ALLOC_CMD_URB) {
 461                 cmdinfo->cmd_urb = uas_alloc_cmd_urb(devinfo, gfp, cmnd,
 462                                                         cmdinfo->stream);
 463                 if (!cmdinfo->cmd_urb)
 464                         return SCSI_MLQUEUE_DEVICE_BUSY;
 465                 cmdinfo->state &= ~ALLOC_CMD_URB;
 466         }
 467
 468         if (cmdinfo->state & SUBMIT_CMD_URB) {
 469                 if (usb_submit_urb(cmdinfo->cmd_urb, gfp)) {
 470                         scmd_printk(KERN_INFO, cmnd,
 471                                         "cmd urb submission failure\n");
 472                         return SCSI_MLQUEUE_DEVICE_BUSY;
 473                 }
 474                 cmdinfo->state &= ~SUBMIT_CMD_URB;
 475                 cmdinfo->state |= COMMAND_INFLIGHT;
 476         }
 477
 478         return 0;
 479 }
 480
 481 static int uas_queuecommand_lck(struct scsi_cmnd *cmnd,
 482                                         void (*done)(struct scsi_cmnd *))
 483 {
 484         struct scsi_device *sdev = cmnd->device;
 485         struct uas_dev_info *devinfo = sdev->hostdata;
 486         struct uas_cmd_info *cmdinfo = (void *)&cmnd->SCp;
 487         int err;
 488
 489         BUILD_BUG_ON(sizeof(struct uas_cmd_info) > sizeof(struct scsi_pointer));
 490
 491         if (devinfo->cmnd)
 492                 return SCSI_MLQUEUE_DEVICE_BUSY;
 493
 494         if (blk_rq_tagged(cmnd->request)) {
 495                 cmdinfo->stream = cmnd->request->tag + 2;
 496         } else {
 497                 devinfo->cmnd = cmnd;
 498                 cmdinfo->stream = 1;
 499         }
 500
 501         cmnd->scsi_done = done;
 502
 503         cmdinfo->state = SUBMIT_STATUS_URB |
 504                         ALLOC_CMD_URB | SUBMIT_CMD_URB;
 505
 506         switch (cmnd->sc_data_direction) {
 507         case DMA_FROM_DEVICE:
 508                 cmdinfo->state |= ALLOC_DATA_IN_URB | SUBMIT_DATA_IN_URB;
 509                 break;
 510         case DMA_BIDIRECTIONAL:
 511                 cmdinfo->state |= ALLOC_DATA_IN_URB | SUBMIT_DATA_IN_URB;
 512         case DMA_TO_DEVICE:
 513                 cmdinfo->state |= ALLOC_DATA_OUT_URB | SUBMIT_DATA_OUT_URB;
 514         case DMA_NONE:
 515                 break;
 516         }
 517
 518         if (!devinfo->use_streams) {
 519                 cmdinfo->state &= ~(SUBMIT_DATA_IN_URB | SUBMIT_DATA_OUT_URB);
 520                 cmdinfo->stream = 0;
 521         }
 522
 523         err = uas_submit_urbs(cmnd, devinfo, GFP_ATOMIC);
 524         if (err) {
 525                 /* If we did nothing, give up now */
 526                 if (cmdinfo->state & SUBMIT_STATUS_URB) {
 527                         return SCSI_MLQUEUE_DEVICE_BUSY;
 528                 }
 529                 spin_lock(&uas_work_lock);
 530                 list_add_tail(&cmdinfo->list, &uas_work_list);
 531                 spin_unlock(&uas_work_lock);
 532                 schedule_work(&uas_work);
 533         }
 534
 535         return 0;
 536 }
 537
 538 static DEF_SCSI_QCMD(uas_queuecommand)
 539
 540 static int uas_eh_abort_handler(struct scsi_cmnd *cmnd)
 541 {
 542         uas_log_cmd_state(cmnd, __func__);
 543
 544 /* XXX: Send ABORT TASK Task Management command */
 545         return FAILED;
 546 }
 547
 548 static int uas_eh_device_reset_handler(struct scsi_cmnd *cmnd)
 549 {
 550         struct scsi_device *sdev = cmnd->device;
 551         sdev_printk(KERN_INFO, sdev, "%s tag %d\n", __func__,
 552                                                         cmnd->request->tag);
 553
 554 /* XXX: Send LOGICAL UNIT RESET Task Management command */
 555         return FAILED;
 556 }
 557
 558 static int uas_eh_target_reset_handler(struct scsi_cmnd *cmnd)
 559 {
 560         struct scsi_device *sdev = cmnd->device;
 561         sdev_printk(KERN_INFO, sdev, "%s tag %d\n", __func__,
 562                                                         cmnd->request->tag);
 563
 564 /* XXX: Can we reset just the one USB interface?
 565  * Would calling usb_set_interface() have the right effect?
 566  */
 567         return FAILED;
 568 }
 569
 570 static int uas_eh_bus_reset_handler(struct scsi_cmnd *cmnd)
 571 {
 572         struct scsi_device *sdev = cmnd->device;
 573         struct uas_dev_info *devinfo = sdev->hostdata;
 574         struct usb_device *udev = devinfo->udev;
 575
 576         sdev_printk(KERN_INFO, sdev, "%s tag %d\n", __func__,
 577                                                         cmnd->request->tag);
 578
 579         if (usb_reset_device(udev))
 580                 return SUCCESS;
 581
 582         return FAILED;
 583 }
 584
 585 static int uas_slave_alloc(struct scsi_device *sdev)
 586 {
 587         sdev->hostdata = (void *)sdev->host->hostdata[0];
 588         return 0;
 589 }
 590
 591 static int uas_slave_configure(struct scsi_device *sdev)
 592 {
 593         struct uas_dev_info *devinfo = sdev->hostdata;
 594         scsi_set_tag_type(sdev, MSG_ORDERED_TAG);
 595         scsi_activate_tcq(sdev, devinfo->qdepth - 2);
 596         return 0;
 597 }
 598
 599 static struct scsi_host_template uas_host_template = {
 600         .module = THIS_MODULE,
 601         .name = "uas",
 602         .queuecommand = uas_queuecommand,
 603         .slave_alloc = uas_slave_alloc,
 604         .slave_configure = uas_slave_configure,
 605         .eh_abort_handler = uas_eh_abort_handler,
 606         .eh_device_reset_handler = uas_eh_device_reset_handler,
 607         .eh_target_reset_handler = uas_eh_target_reset_handler,
 608         .eh_bus_reset_handler = uas_eh_bus_reset_handler,
 609         .can_queue = 65536,     /* Is there a limit on the _host_ ? */
 610         .this_id = -1,
 611         .sg_tablesize = SG_NONE,
 612         .cmd_per_lun = 1,       /* until we override it */
 613         .skip_settle_delay = 1,
 614         .ordered_tag = 1,
 615 };
 616
 617 static struct usb_device_id uas_usb_ids[] = {
 618         { USB_INTERFACE_INFO(USB_CLASS_MASS_STORAGE, USB_SC_SCSI, USB_PR_BULK) },
 619         { USB_INTERFACE_INFO(USB_CLASS_MASS_STORAGE, USB_SC_SCSI, USB_PR_UAS) },
 620         /* 0xaa is a prototype device I happen to have access to */
 621         { USB_INTERFACE_INFO(USB_CLASS_MASS_STORAGE, USB_SC_SCSI, 0xaa) },
 622         { }
 623 };
 624 MODULE_DEVICE_TABLE(usb, uas_usb_ids);
 625
 626 static int uas_is_interface(struct usb_host_interface *intf)
 627 {
 628         return (intf->desc.bInterfaceClass == USB_CLASS_MASS_STORAGE &&
 629                 intf->desc.bInterfaceSubClass == USB_SC_SCSI &&
 630                 intf->desc.bInterfaceProtocol == USB_PR_UAS);
 631 }
 632
 633 static int uas_isnt_supported(struct usb_device *udev)
 634 {
 635         struct usb_hcd *hcd = bus_to_hcd(udev->bus);
 636
 637         dev_warn(&udev->dev, "The driver for the USB controller %s does not "
 638                         "support scatter-gather which is\n",
 639                         hcd->driver->description);
 640         dev_warn(&udev->dev, "required by the UAS driver. Please try an"
 641                         "alternative USB controller if you wish to use UAS.\n");
 642         return -ENODEV;
 643 }
 644
 645 static int uas_switch_interface(struct usb_device *udev,
 646                                                 struct usb_interface *intf)
 647 {
 648         int i;
 649         int sg_supported = udev->bus->sg_tablesize != 0;
 650
 651         for (i = 0; i < intf->num_altsetting; i++) {
 652                 struct usb_host_interface *alt = &intf->altsetting[i];
 653
 654                 if (uas_is_interface(alt)) {
 655                         if (!sg_supported)
 656                                 return uas_isnt_supported(udev);
 657                         return usb_set_interface(udev,
 658                                                 alt->desc.bInterfaceNumber,
 659                                                 alt->desc.bAlternateSetting);
 660                 }
 661         }
 662
 663         return -ENODEV;
 664 }
 665
 666 static void uas_configure_endpoints(struct uas_dev_info *devinfo)
 667 {
 668         struct usb_host_endpoint *eps[4] = { };
 669         struct usb_interface *intf = devinfo->intf;
 670         struct usb_device *udev = devinfo->udev;
 671         struct usb_host_endpoint *endpoint = intf->cur_altsetting->endpoint;
 672         unsigned i, n_endpoints = intf->cur_altsetting->desc.bNumEndpoints;
 673
 674         devinfo->uas_sense_old = 0;
 675         devinfo->cmnd = NULL;
 676
 677         for (i = 0; i < n_endpoints; i++) {
 678                 unsigned char *extra = endpoint[i].extra;
 679                 int len = endpoint[i].extralen;
 680                 while (len > 1) {
 681                         if (extra[1] == USB_DT_PIPE_USAGE) {
 682                                 unsigned pipe_id = extra[2];
 683                                 if (pipe_id > 0 && pipe_id < 5)
 684                                         eps[pipe_id - 1] = &endpoint[i];
 685                                 break;
 686                         }
 687                         len -= extra[0];
 688                         extra += extra[0];
 689                 }
 690         }
 691
 692         /*
 693          * Assume that if we didn't find a control pipe descriptor, we're
 694          * using a device with old firmware that happens to be set up like
 695          * this.
 696          */
 697         if (!eps[0]) {
 698                 devinfo->cmd_pipe = usb_sndbulkpipe(udev, 1);
 699                 devinfo->status_pipe = usb_rcvbulkpipe(udev, 1);
 700                 devinfo->data_in_pipe = usb_rcvbulkpipe(udev, 2);
 701                 devinfo->data_out_pipe = usb_sndbulkpipe(udev, 2);
 702
 703                 eps[1] = usb_pipe_endpoint(udev, devinfo->status_pipe);
 704                 eps[2] = usb_pipe_endpoint(udev, devinfo->data_in_pipe);
 705                 eps[3] = usb_pipe_endpoint(udev, devinfo->data_out_pipe);
 706         } else {
 707                 devinfo->cmd_pipe = usb_sndbulkpipe(udev,
 708                                                 eps[0]->desc.bEndpointAddress);
 709                 devinfo->status_pipe = usb_rcvbulkpipe(udev,
 710                                                 eps[1]->desc.bEndpointAddress);
 711                 devinfo->data_in_pipe = usb_rcvbulkpipe(udev,
 712                                                 eps[2]->desc.bEndpointAddress);
 713                 devinfo->data_out_pipe = usb_sndbulkpipe(udev,
 714                                                 eps[3]->desc.bEndpointAddress);
 715         }
 716
 717         devinfo->qdepth = usb_alloc_streams(devinfo->intf, eps + 1, 3, 256,
 718                                                                 GFP_KERNEL);
 719         if (devinfo->qdepth < 0) {
 720                 devinfo->qdepth = 256;
 721                 devinfo->use_streams = 0;
 722         } else {
 723                 devinfo->use_streams = 1;
 724         }
 725 }
 726
 727 static void uas_free_streams(struct uas_dev_info *devinfo)
 728 {
 729         struct usb_device *udev = devinfo->udev;
 730         struct usb_host_endpoint *eps[3];
 731
 732         eps[0] = usb_pipe_endpoint(udev, devinfo->status_pipe);
 733         eps[1] = usb_pipe_endpoint(udev, devinfo->data_in_pipe);
 734         eps[2] = usb_pipe_endpoint(udev, devinfo->data_out_pipe);
 735         usb_free_streams(devinfo->intf, eps, 3, GFP_KERNEL);
 736 }
 737
 738 /*
 739  * XXX: What I'd like to do here is register a SCSI host for each USB host in
 740  * the system.  Follow usb-storage's design of registering a SCSI host for
 741  * each USB device for the moment.  Can implement this by walking up the
 742  * USB hierarchy until we find a USB host.
 743  */
 744 static int uas_probe(struct usb_interface *intf, const struct usb_device_id *id)
 745 {
 746         int result;
 747         struct Scsi_Host *shost;
 748         struct uas_dev_info *devinfo;
 749         struct usb_device *udev = interface_to_usbdev(intf);
 750
 751         if (uas_switch_interface(udev, intf))
 752                 return -ENODEV;
 753
 754         devinfo = kmalloc(sizeof(struct uas_dev_info), GFP_KERNEL);
 755         if (!devinfo)
 756                 return -ENOMEM;
 757
 758         result = -ENOMEM;
 759         shost = scsi_host_alloc(&uas_host_template, sizeof(void *));
 760         if (!shost)
 761                 goto free;
 762
 763         shost->max_cmd_len = 16 + 252;
 764         shost->max_id = 1;
 765         shost->sg_tablesize = udev->bus->sg_tablesize;
 766
 767         devinfo->intf = intf;
 768         devinfo->udev = udev;
 769         init_usb_anchor(&devinfo->sense_urbs);
 770         init_usb_anchor(&devinfo->data_urbs);
 771         uas_configure_endpoints(devinfo);
 772
 773         result = scsi_init_shared_tag_map(shost, devinfo->qdepth - 2);
 774         if (result)
 775                 goto free;
 776
 777         result = scsi_add_host(shost, &intf->dev);
 778         if (result)
 779                 goto deconfig_eps;
 780
 781         shost->hostdata[0] = (unsigned long)devinfo;
 782
 783         scsi_scan_host(shost);
 784         usb_set_intfdata(intf, shost);
 785         return result;
 786
 787 deconfig_eps:
 788         uas_free_streams(devinfo);
 789  free:
 790         kfree(devinfo);
 791         if (shost)
 792                 scsi_host_put(shost);
 793         return result;
 794 }
 795
 796 static int uas_pre_reset(struct usb_interface *intf)
 797 {
 798 /* XXX: Need to return 1 if it's not our device in error handling */
 799         return 0;
 800 }
 801
 802 static int uas_post_reset(struct usb_interface *intf)
 803 {
 804 /* XXX: Need to return 1 if it's not our device in error handling */
 805         return 0;
 806 }
 807
 808 static void uas_disconnect(struct usb_interface *intf)
 809 {
 810         struct Scsi_Host *shost = usb_get_intfdata(intf);
 811         struct uas_dev_info *devinfo = (void *)shost->hostdata[0];
 812
 813         scsi_remove_host(shost);
 814         usb_kill_anchored_urbs(&devinfo->sense_urbs);
 815         usb_kill_anchored_urbs(&devinfo->data_urbs);
 816         uas_free_streams(devinfo);
 817         kfree(devinfo);
 818 }
 819
 820 /*
 821  * XXX: Should this plug into libusual so we can auto-upgrade devices from
 822  * Bulk-Only to UAS?
 823  */
 824 static struct usb_driver uas_driver = {
 825         .name = "uas",
 826         .probe = uas_probe,
 827         .disconnect = uas_disconnect,
 828         .pre_reset = uas_pre_reset,
 829         .post_reset = uas_post_reset,
 830         .id_table = uas_usb_ids,
 831 };
 832
 833 module_usb_driver(uas_driver);
 834
 835 MODULE_LICENSE("GPL");
 836 MODULE_AUTHOR("Matthew Wilcox and Sarah Sharp");