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         int qdepth;
  45         unsigned cmd_pipe, status_pipe, data_in_pipe, data_out_pipe;
  46         unsigned use_streams:1;
  47         unsigned uas_sense_old:1;
  48         struct scsi_cmnd *cmnd;
  49         struct urb *status_urb; /* used only if stream support is available */
  50 };
  51
  52 enum {
  53         ALLOC_STATUS_URB        = (1 << 0),
  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         COMPLETED_DATA_IN       = (1 << 8),
  62         COMPLETED_DATA_OUT      = (1 << 9),
  63         DATA_COMPLETES_CMD      = (1 << 10),
  64 };
  65
  66 /* Overrides scsi_pointer */
  67 struct uas_cmd_info {
  68         unsigned int state;
  69         unsigned int stream;
  70         struct urb *cmd_urb;
  71         /* status_urb is used only if stream support isn't available */
  72         struct urb *status_urb;
  73         struct urb *data_in_urb;
  74         struct urb *data_out_urb;
  75         struct list_head list;
  76 };
  77
  78 /* I hate forward declarations, but I actually have a loop */
  79 static int uas_submit_urbs(struct scsi_cmnd *cmnd,
  80                                 struct uas_dev_info *devinfo, gfp_t gfp);
  81 static void uas_do_work(struct work_struct *work);
  82
  83 static DECLARE_WORK(uas_work, uas_do_work);
  84 static DEFINE_SPINLOCK(uas_work_lock);
  85 static LIST_HEAD(uas_work_list);
  86
  87 static void uas_do_work(struct work_struct *work)
  88 {
  89         struct uas_cmd_info *cmdinfo;
  90         struct uas_cmd_info *temp;
  91         struct list_head list;
  92         int err;
  93
  94         spin_lock_irq(&uas_work_lock);
  95         list_replace_init(&uas_work_list, &list);
  96         spin_unlock_irq(&uas_work_lock);
  97
  98         list_for_each_entry_safe(cmdinfo, temp, &list, list) {
  99                 struct scsi_pointer *scp = (void *)cmdinfo;
 100                 struct scsi_cmnd *cmnd = container_of(scp,
 101                                                         struct scsi_cmnd, SCp);
 102                 err = uas_submit_urbs(cmnd, cmnd->device->hostdata, GFP_NOIO);
 103                 if (err) {
 104                         list_del(&cmdinfo->list);
 105                         spin_lock_irq(&uas_work_lock);
 106                         list_add_tail(&cmdinfo->list, &uas_work_list);
 107                         spin_unlock_irq(&uas_work_lock);
 108                         schedule_work(&uas_work);
 109                 }
 110         }
 111 }
 112
 113 static void uas_sense(struct urb *urb, struct scsi_cmnd *cmnd)
 114 {
 115         struct sense_iu *sense_iu = urb->transfer_buffer;
 116         struct scsi_device *sdev = cmnd->device;
 117         struct uas_cmd_info *cmdinfo = (void *)&cmnd->SCp;
 118
 119         if (urb->actual_length > 16) {
 120                 unsigned len = be16_to_cpup(&sense_iu->len);
 121                 if (len + 16 != urb->actual_length) {
 122                         int newlen = min(len + 16, urb->actual_length) - 16;
 123                         if (newlen < 0)
 124                                 newlen = 0;
 125                         sdev_printk(KERN_INFO, sdev, "%s: urb length %d "
 126                                 "disagrees with IU sense data length %d, "
 127                                 "using %d bytes of sense data\n", __func__,
 128                                         urb->actual_length, len, newlen);
 129                         len = newlen;
 130                 }
 131                 memcpy(cmnd->sense_buffer, sense_iu->sense, len);
 132         }
 133
 134         cmnd->result = sense_iu->status;
 135         if (!(cmdinfo->state & DATA_COMPLETES_CMD))
 136                 cmnd->scsi_done(cmnd);
 137 }
 138
 139 static void uas_sense_old(struct urb *urb, struct scsi_cmnd *cmnd)
 140 {
 141         struct sense_iu_old *sense_iu = urb->transfer_buffer;
 142         struct scsi_device *sdev = cmnd->device;
 143         struct uas_cmd_info *cmdinfo = (void *)&cmnd->SCp;
 144
 145         if (urb->actual_length > 8) {
 146                 unsigned len = be16_to_cpup(&sense_iu->len) - 2;
 147                 if (len + 8 != urb->actual_length) {
 148                         int newlen = min(len + 8, urb->actual_length) - 8;
 149                         if (newlen < 0)
 150                                 newlen = 0;
 151                         sdev_printk(KERN_INFO, sdev, "%s: urb length %d "
 152                                 "disagrees with IU sense data length %d, "
 153                                 "using %d bytes of sense data\n", __func__,
 154                                         urb->actual_length, len, newlen);
 155                         len = newlen;
 156                 }
 157                 memcpy(cmnd->sense_buffer, sense_iu->sense, len);
 158         }
 159
 160         cmnd->result = sense_iu->status;
 161         if (!(cmdinfo->state & DATA_COMPLETES_CMD))
 162                 cmnd->scsi_done(cmnd);
 163 }
 164
 165 static void uas_xfer_data(struct urb *urb, struct scsi_cmnd *cmnd,
 166                                                         unsigned direction)
 167 {
 168         struct uas_cmd_info *cmdinfo = (void *)&cmnd->SCp;
 169         int err;
 170
 171         cmdinfo->state = direction;
 172         err = uas_submit_urbs(cmnd, cmnd->device->hostdata, GFP_ATOMIC);
 173         if (err) {
 174                 spin_lock(&uas_work_lock);
 175                 list_add_tail(&cmdinfo->list, &uas_work_list);
 176                 spin_unlock(&uas_work_lock);
 177                 schedule_work(&uas_work);
 178         }
 179 }
 180
 181 static void uas_stat_cmplt(struct urb *urb)
 182 {
 183         struct iu *iu = urb->transfer_buffer;
 184         struct Scsi_Host *shost = urb->context;
 185         struct uas_dev_info *devinfo = (void *)shost->hostdata[0];
 186         struct scsi_cmnd *cmnd;
 187         struct uas_cmd_info *cmdinfo;
 188         u16 tag;
 189         int ret;
 190
 191         if (urb->status) {
 192                 dev_err(&urb->dev->dev, "URB BAD STATUS %d\n", urb->status);
 193                 if (devinfo->use_streams)
 194                         usb_free_urb(urb);
 195                 return;
 196         }
 197
 198         tag = be16_to_cpup(&iu->tag) - 1;
 199         if (tag == 0)
 200                 cmnd = devinfo->cmnd;
 201         else
 202                 cmnd = scsi_host_find_tag(shost, tag - 1);
 203         if (!cmnd) {
 204                 if (devinfo->use_streams) {
 205                         usb_free_urb(urb);
 206                         return;
 207                 }
 208                 ret = usb_submit_urb(urb, GFP_ATOMIC);
 209                 if (ret)
 210                         dev_err(&urb->dev->dev, "failed submit status urb\n");
 211                 return;
 212         }
 213         cmdinfo = (void *)&cmnd->SCp;
 214
 215         switch (iu->iu_id) {
 216         case IU_ID_STATUS:
 217                 if (devinfo->cmnd == cmnd)
 218                         devinfo->cmnd = NULL;
 219
 220                 if (!(cmdinfo->state & COMPLETED_DATA_IN) &&
 221                                 cmdinfo->data_in_urb) {
 222                        if (devinfo->use_streams) {
 223                                cmdinfo->state |= DATA_COMPLETES_CMD;
 224                                usb_unlink_urb(cmdinfo->data_in_urb);
 225                        } else {
 226                                usb_free_urb(cmdinfo->data_in_urb);
 227                        }
 228                 }
 229                 if (!(cmdinfo->state & COMPLETED_DATA_OUT) &&
 230                                 cmdinfo->data_out_urb) {
 231                         if (devinfo->use_streams) {
 232                                 cmdinfo->state |= DATA_COMPLETES_CMD;
 233                                 usb_unlink_urb(cmdinfo->data_in_urb);
 234                         } else {
 235                                 usb_free_urb(cmdinfo->data_out_urb);
 236                         }
 237                 }
 238
 239                 if (urb->actual_length < 16)
 240                         devinfo->uas_sense_old = 1;
 241                 if (devinfo->uas_sense_old)
 242                         uas_sense_old(urb, cmnd);
 243                 else
 244                         uas_sense(urb, cmnd);
 245                 break;
 246         case IU_ID_READ_READY:
 247                 uas_xfer_data(urb, cmnd, SUBMIT_DATA_IN_URB);
 248                 break;
 249         case IU_ID_WRITE_READY:
 250                 uas_xfer_data(urb, cmnd, SUBMIT_DATA_OUT_URB);
 251                 break;
 252         default:
 253                 scmd_printk(KERN_ERR, cmnd,
 254                         "Bogus IU (%d) received on status pipe\n", iu->iu_id);
 255         }
 256
 257         if (devinfo->use_streams) {
 258                 usb_free_urb(urb);
 259                 return;
 260         }
 261
 262         ret = usb_submit_urb(urb, GFP_ATOMIC);
 263         if (ret)
 264                 dev_err(&urb->dev->dev, "failed submit status urb\n");
 265 }
 266
 267 static void uas_data_out_cmplt(struct urb *urb)
 268 {
 269         struct scsi_cmnd *cmnd = urb->context;
 270         struct scsi_data_buffer *sdb = scsi_out(cmnd);
 271         struct uas_cmd_info *cmdinfo = (void *)&cmnd->SCp;
 272
 273         cmdinfo->state |= COMPLETED_DATA_OUT;
 274
 275         sdb->resid = sdb->length - urb->actual_length;
 276         usb_free_urb(urb);
 277
 278         if (cmdinfo->state & DATA_COMPLETES_CMD)
 279                 cmnd->scsi_done(cmnd);
 280 }
 281
 282 static void uas_data_in_cmplt(struct urb *urb)
 283 {
 284         struct scsi_cmnd *cmnd = urb->context;
 285         struct scsi_data_buffer *sdb = scsi_in(cmnd);
 286         struct uas_cmd_info *cmdinfo = (void *)&cmnd->SCp;
 287
 288         cmdinfo->state |= COMPLETED_DATA_IN;
 289
 290         sdb->resid = sdb->length - urb->actual_length;
 291         usb_free_urb(urb);
 292
 293         if (cmdinfo->state & DATA_COMPLETES_CMD)
 294                 cmnd->scsi_done(cmnd);
 295 }
 296
 297 static struct urb *uas_alloc_data_urb(struct uas_dev_info *devinfo, gfp_t gfp,
 298                 unsigned int pipe, struct scsi_cmnd *cmnd,
 299                 enum dma_data_direction dir)
 300 {
 301         struct uas_cmd_info *cmdinfo = (void *)&cmnd->SCp;
 302         struct usb_device *udev = devinfo->udev;
 303         struct urb *urb = usb_alloc_urb(0, gfp);
 304         struct scsi_data_buffer *sdb;
 305         usb_complete_t complete_fn;
 306         u16 stream_id = cmdinfo->stream;
 307
 308         if (!urb)
 309                 goto out;
 310         if (dir == DMA_FROM_DEVICE) {
 311                 sdb = scsi_in(cmnd);
 312                 complete_fn = uas_data_in_cmplt;
 313         } else {
 314                 sdb = scsi_out(cmnd);
 315                 complete_fn = uas_data_out_cmplt;
 316         }
 317         usb_fill_bulk_urb(urb, udev, pipe, NULL, sdb->length,
 318                         complete_fn, cmnd);
 319         urb->stream_id = stream_id;
 320         urb->num_sgs = udev->bus->sg_tablesize ? sdb->table.nents : 0;
 321         urb->sg = sdb->table.sgl;
 322  out:
 323         return urb;
 324 }
 325
 326 static struct urb *uas_alloc_sense_urb(struct uas_dev_info *devinfo, gfp_t gfp,
 327                 struct Scsi_Host *shost, u16 stream_id)
 328 {
 329         struct usb_device *udev = devinfo->udev;
 330         struct urb *urb = usb_alloc_urb(0, gfp);
 331         struct sense_iu *iu;
 332
 333         if (!urb)
 334                 goto out;
 335
 336         iu = kzalloc(sizeof(*iu), gfp);
 337         if (!iu)
 338                 goto free;
 339
 340         usb_fill_bulk_urb(urb, udev, devinfo->status_pipe, iu, sizeof(*iu),
 341                                                 uas_stat_cmplt, shost);
 342         urb->stream_id = stream_id;
 343         urb->transfer_flags |= URB_FREE_BUFFER;
 344  out:
 345         return urb;
 346  free:
 347         usb_free_urb(urb);
 348         return NULL;
 349 }
 350
 351 static struct urb *uas_alloc_cmd_urb(struct uas_dev_info *devinfo, gfp_t gfp,
 352                                         struct scsi_cmnd *cmnd, u16 stream_id)
 353 {
 354         struct usb_device *udev = devinfo->udev;
 355         struct scsi_device *sdev = cmnd->device;
 356         struct urb *urb = usb_alloc_urb(0, gfp);
 357         struct command_iu *iu;
 358         int len;
 359
 360         if (!urb)
 361                 goto out;
 362
 363         len = cmnd->cmd_len - 16;
 364         if (len < 0)
 365                 len = 0;
 366         len = ALIGN(len, 4);
 367         iu = kzalloc(sizeof(*iu) + len, gfp);
 368         if (!iu)
 369                 goto free;
 370
 371         iu->iu_id = IU_ID_COMMAND;
 372         if (blk_rq_tagged(cmnd->request))
 373                 iu->tag = cpu_to_be16(cmnd->request->tag + 2);
 374         else
 375                 iu->tag = cpu_to_be16(1);
 376         iu->prio_attr = UAS_SIMPLE_TAG;
 377         iu->len = len;
 378         int_to_scsilun(sdev->lun, &iu->lun);
 379         memcpy(iu->cdb, cmnd->cmnd, cmnd->cmd_len);
 380
 381         usb_fill_bulk_urb(urb, udev, devinfo->cmd_pipe, iu, sizeof(*iu) + len,
 382                                                         usb_free_urb, NULL);
 383         urb->transfer_flags |= URB_FREE_BUFFER;
 384  out:
 385         return urb;
 386  free:
 387         usb_free_urb(urb);
 388         return NULL;
 389 }
 390
 391 /*
 392  * Why should I request the Status IU before sending the Command IU?  Spec
 393  * says to, but also says the device may receive them in any order.  Seems
 394  * daft to me.
 395  */
 396
 397 static int uas_submit_urbs(struct scsi_cmnd *cmnd,
 398                                         struct uas_dev_info *devinfo, gfp_t gfp)
 399 {
 400         struct uas_cmd_info *cmdinfo = (void *)&cmnd->SCp;
 401
 402         if (cmdinfo->state & ALLOC_STATUS_URB) {
 403                 cmdinfo->status_urb = uas_alloc_sense_urb(devinfo, gfp,
 404                                 cmnd->device->host, cmdinfo->stream);
 405                 if (!cmdinfo->status_urb)
 406                         return SCSI_MLQUEUE_DEVICE_BUSY;
 407                 cmdinfo->state &= ~ALLOC_STATUS_URB;
 408         }
 409
 410         if (cmdinfo->state & SUBMIT_STATUS_URB) {
 411                 if (usb_submit_urb(cmdinfo->status_urb, gfp)) {
 412                         scmd_printk(KERN_INFO, cmnd,
 413                                         "sense urb submission failure\n");
 414                         return SCSI_MLQUEUE_DEVICE_BUSY;
 415                 }
 416                 cmdinfo->state &= ~SUBMIT_STATUS_URB;
 417         }
 418
 419         if (cmdinfo->state & ALLOC_DATA_IN_URB) {
 420                 cmdinfo->data_in_urb = uas_alloc_data_urb(devinfo, gfp,
 421                                         devinfo->data_in_pipe, cmnd,
 422                                         DMA_FROM_DEVICE);
 423                 if (!cmdinfo->data_in_urb)
 424                         return SCSI_MLQUEUE_DEVICE_BUSY;
 425                 cmdinfo->state &= ~ALLOC_DATA_IN_URB;
 426         }
 427
 428         if (cmdinfo->state & SUBMIT_DATA_IN_URB) {
 429                 if (usb_submit_urb(cmdinfo->data_in_urb, gfp)) {
 430                         scmd_printk(KERN_INFO, cmnd,
 431                                         "data in urb submission failure\n");
 432                         return SCSI_MLQUEUE_DEVICE_BUSY;
 433                 }
 434                 cmdinfo->state &= ~SUBMIT_DATA_IN_URB;
 435         }
 436
 437         if (cmdinfo->state & ALLOC_DATA_OUT_URB) {
 438                 cmdinfo->data_out_urb = uas_alloc_data_urb(devinfo, gfp,
 439                                         devinfo->data_out_pipe, cmnd,
 440                                         DMA_TO_DEVICE);
 441                 if (!cmdinfo->data_out_urb)
 442                         return SCSI_MLQUEUE_DEVICE_BUSY;
 443                 cmdinfo->state &= ~ALLOC_DATA_OUT_URB;
 444         }
 445
 446         if (cmdinfo->state & SUBMIT_DATA_OUT_URB) {
 447                 if (usb_submit_urb(cmdinfo->data_out_urb, gfp)) {
 448                         scmd_printk(KERN_INFO, cmnd,
 449                                         "data out urb submission failure\n");
 450                         return SCSI_MLQUEUE_DEVICE_BUSY;
 451                 }
 452                 cmdinfo->state &= ~SUBMIT_DATA_OUT_URB;
 453         }
 454
 455         if (cmdinfo->state & ALLOC_CMD_URB) {
 456                 cmdinfo->cmd_urb = uas_alloc_cmd_urb(devinfo, gfp, cmnd,
 457                                                         cmdinfo->stream);
 458                 if (!cmdinfo->cmd_urb)
 459                         return SCSI_MLQUEUE_DEVICE_BUSY;
 460                 cmdinfo->state &= ~ALLOC_CMD_URB;
 461         }
 462
 463         if (cmdinfo->state & SUBMIT_CMD_URB) {
 464                 if (usb_submit_urb(cmdinfo->cmd_urb, gfp)) {
 465                         scmd_printk(KERN_INFO, cmnd,
 466                                         "cmd urb submission failure\n");
 467                         return SCSI_MLQUEUE_DEVICE_BUSY;
 468                 }
 469                 cmdinfo->state &= ~SUBMIT_CMD_URB;
 470         }
 471
 472         return 0;
 473 }
 474
 475 static int uas_queuecommand_lck(struct scsi_cmnd *cmnd,
 476                                         void (*done)(struct scsi_cmnd *))
 477 {
 478         struct scsi_device *sdev = cmnd->device;
 479         struct uas_dev_info *devinfo = sdev->hostdata;
 480         struct uas_cmd_info *cmdinfo = (void *)&cmnd->SCp;
 481         int err;
 482
 483         BUILD_BUG_ON(sizeof(struct uas_cmd_info) > sizeof(struct scsi_pointer));
 484
 485         if (devinfo->cmnd)
 486                 return SCSI_MLQUEUE_DEVICE_BUSY;
 487
 488         if (blk_rq_tagged(cmnd->request)) {
 489                 cmdinfo->stream = cmnd->request->tag + 2;
 490         } else {
 491                 devinfo->cmnd = cmnd;
 492                 cmdinfo->stream = 1;
 493         }
 494
 495         cmnd->scsi_done = done;
 496
 497         cmdinfo->state = ALLOC_STATUS_URB | SUBMIT_STATUS_URB |
 498                         ALLOC_CMD_URB | SUBMIT_CMD_URB;
 499
 500         switch (cmnd->sc_data_direction) {
 501         case DMA_FROM_DEVICE:
 502                 cmdinfo->state |= ALLOC_DATA_IN_URB | SUBMIT_DATA_IN_URB;
 503                 break;
 504         case DMA_BIDIRECTIONAL:
 505                 cmdinfo->state |= ALLOC_DATA_IN_URB | SUBMIT_DATA_IN_URB;
 506         case DMA_TO_DEVICE:
 507                 cmdinfo->state |= ALLOC_DATA_OUT_URB | SUBMIT_DATA_OUT_URB;
 508         case DMA_NONE:
 509                 break;
 510         }
 511
 512         if (!devinfo->use_streams) {
 513                 cmdinfo->state &= ~(SUBMIT_DATA_IN_URB | SUBMIT_DATA_OUT_URB |
 514                                 ALLOC_STATUS_URB | SUBMIT_STATUS_URB);
 515                 cmdinfo->stream = 0;
 516         }
 517
 518         err = uas_submit_urbs(cmnd, devinfo, GFP_ATOMIC);
 519         if (err) {
 520                 /* If we did nothing, give up now */
 521                 if (cmdinfo->state & SUBMIT_STATUS_URB) {
 522                         usb_free_urb(cmdinfo->status_urb);
 523                         return SCSI_MLQUEUE_DEVICE_BUSY;
 524                 }
 525                 spin_lock(&uas_work_lock);
 526                 list_add_tail(&cmdinfo->list, &uas_work_list);
 527                 spin_unlock(&uas_work_lock);
 528                 schedule_work(&uas_work);
 529         }
 530
 531         return 0;
 532 }
 533
 534 static DEF_SCSI_QCMD(uas_queuecommand)
 535
 536 static int uas_eh_abort_handler(struct scsi_cmnd *cmnd)
 537 {
 538         struct scsi_device *sdev = cmnd->device;
 539         sdev_printk(KERN_INFO, sdev, "%s tag %d\n", __func__,
 540                                                         cmnd->request->tag);
 541
 542 /* XXX: Send ABORT TASK Task Management command */
 543         return FAILED;
 544 }
 545
 546 static int uas_eh_device_reset_handler(struct scsi_cmnd *cmnd)
 547 {
 548         struct scsi_device *sdev = cmnd->device;
 549         sdev_printk(KERN_INFO, sdev, "%s tag %d\n", __func__,
 550                                                         cmnd->request->tag);
 551
 552 /* XXX: Send LOGICAL UNIT RESET Task Management command */
 553         return FAILED;
 554 }
 555
 556 static int uas_eh_target_reset_handler(struct scsi_cmnd *cmnd)
 557 {
 558         struct scsi_device *sdev = cmnd->device;
 559         sdev_printk(KERN_INFO, sdev, "%s tag %d\n", __func__,
 560                                                         cmnd->request->tag);
 561
 562 /* XXX: Can we reset just the one USB interface?
 563  * Would calling usb_set_interface() have the right effect?
 564  */
 565         return FAILED;
 566 }
 567
 568 static int uas_eh_bus_reset_handler(struct scsi_cmnd *cmnd)
 569 {
 570         struct scsi_device *sdev = cmnd->device;
 571         struct uas_dev_info *devinfo = sdev->hostdata;
 572         struct usb_device *udev = devinfo->udev;
 573
 574         sdev_printk(KERN_INFO, sdev, "%s tag %d\n", __func__,
 575                                                         cmnd->request->tag);
 576
 577         if (usb_reset_device(udev))
 578                 return SUCCESS;
 579
 580         return FAILED;
 581 }
 582
 583 static int uas_slave_alloc(struct scsi_device *sdev)
 584 {
 585         sdev->hostdata = (void *)sdev->host->hostdata[0];
 586         return 0;
 587 }
 588
 589 static int uas_slave_configure(struct scsi_device *sdev)
 590 {
 591         struct uas_dev_info *devinfo = sdev->hostdata;
 592         scsi_set_tag_type(sdev, MSG_ORDERED_TAG);
 593         scsi_activate_tcq(sdev, devinfo->qdepth - 2);
 594         return 0;
 595 }
 596
 597 static struct scsi_host_template uas_host_template = {
 598         .module = THIS_MODULE,
 599         .name = "uas",
 600         .queuecommand = uas_queuecommand,
 601         .slave_alloc = uas_slave_alloc,
 602         .slave_configure = uas_slave_configure,
 603         .eh_abort_handler = uas_eh_abort_handler,
 604         .eh_device_reset_handler = uas_eh_device_reset_handler,
 605         .eh_target_reset_handler = uas_eh_target_reset_handler,
 606         .eh_bus_reset_handler = uas_eh_bus_reset_handler,
 607         .can_queue = 65536,     /* Is there a limit on the _host_ ? */
 608         .this_id = -1,
 609         .sg_tablesize = SG_NONE,
 610         .cmd_per_lun = 1,       /* until we override it */
 611         .skip_settle_delay = 1,
 612         .ordered_tag = 1,
 613 };
 614
 615 static struct usb_device_id uas_usb_ids[] = {
 616         { USB_INTERFACE_INFO(USB_CLASS_MASS_STORAGE, USB_SC_SCSI, USB_PR_BULK) },
 617         { USB_INTERFACE_INFO(USB_CLASS_MASS_STORAGE, USB_SC_SCSI, USB_PR_UAS) },
 618         /* 0xaa is a prototype device I happen to have access to */
 619         { USB_INTERFACE_INFO(USB_CLASS_MASS_STORAGE, USB_SC_SCSI, 0xaa) },
 620         { }
 621 };
 622 MODULE_DEVICE_TABLE(usb, uas_usb_ids);
 623
 624 static int uas_is_interface(struct usb_host_interface *intf)
 625 {
 626         return (intf->desc.bInterfaceClass == USB_CLASS_MASS_STORAGE &&
 627                 intf->desc.bInterfaceSubClass == USB_SC_SCSI &&
 628                 intf->desc.bInterfaceProtocol == USB_PR_UAS);
 629 }
 630
 631 static int uas_isnt_supported(struct usb_device *udev)
 632 {
 633         struct usb_hcd *hcd = bus_to_hcd(udev->bus);
 634
 635         dev_warn(&udev->dev, "The driver for the USB controller %s does not "
 636                         "support scatter-gather which is\n",
 637                         hcd->driver->description);
 638         dev_warn(&udev->dev, "required by the UAS driver. Please try an"
 639                         "alternative USB controller if you wish to use UAS.\n");
 640         return -ENODEV;
 641 }
 642
 643 static int uas_switch_interface(struct usb_device *udev,
 644                                                 struct usb_interface *intf)
 645 {
 646         int i;
 647         int sg_supported = udev->bus->sg_tablesize != 0;
 648
 649         for (i = 0; i < intf->num_altsetting; i++) {
 650                 struct usb_host_interface *alt = &intf->altsetting[i];
 651
 652                 if (uas_is_interface(alt)) {
 653                         if (!sg_supported)
 654                                 return uas_isnt_supported(udev);
 655                         return usb_set_interface(udev,
 656                                                 alt->desc.bInterfaceNumber,
 657                                                 alt->desc.bAlternateSetting);
 658                 }
 659         }
 660
 661         return -ENODEV;
 662 }
 663
 664 static void uas_configure_endpoints(struct uas_dev_info *devinfo)
 665 {
 666         struct usb_host_endpoint *eps[4] = { };
 667         struct usb_interface *intf = devinfo->intf;
 668         struct usb_device *udev = devinfo->udev;
 669         struct usb_host_endpoint *endpoint = intf->cur_altsetting->endpoint;
 670         unsigned i, n_endpoints = intf->cur_altsetting->desc.bNumEndpoints;
 671
 672         devinfo->uas_sense_old = 0;
 673         devinfo->cmnd = NULL;
 674
 675         for (i = 0; i < n_endpoints; i++) {
 676                 unsigned char *extra = endpoint[i].extra;
 677                 int len = endpoint[i].extralen;
 678                 while (len > 1) {
 679                         if (extra[1] == USB_DT_PIPE_USAGE) {
 680                                 unsigned pipe_id = extra[2];
 681                                 if (pipe_id > 0 && pipe_id < 5)
 682                                         eps[pipe_id - 1] = &endpoint[i];
 683                                 break;
 684                         }
 685                         len -= extra[0];
 686                         extra += extra[0];
 687                 }
 688         }
 689
 690         /*
 691          * Assume that if we didn't find a control pipe descriptor, we're
 692          * using a device with old firmware that happens to be set up like
 693          * this.
 694          */
 695         if (!eps[0]) {
 696                 devinfo->cmd_pipe = usb_sndbulkpipe(udev, 1);
 697                 devinfo->status_pipe = usb_rcvbulkpipe(udev, 1);
 698                 devinfo->data_in_pipe = usb_rcvbulkpipe(udev, 2);
 699                 devinfo->data_out_pipe = usb_sndbulkpipe(udev, 2);
 700
 701                 eps[1] = usb_pipe_endpoint(udev, devinfo->status_pipe);
 702                 eps[2] = usb_pipe_endpoint(udev, devinfo->data_in_pipe);
 703                 eps[3] = usb_pipe_endpoint(udev, devinfo->data_out_pipe);
 704         } else {
 705                 devinfo->cmd_pipe = usb_sndbulkpipe(udev,
 706                                                 eps[0]->desc.bEndpointAddress);
 707                 devinfo->status_pipe = usb_rcvbulkpipe(udev,
 708                                                 eps[1]->desc.bEndpointAddress);
 709                 devinfo->data_in_pipe = usb_rcvbulkpipe(udev,
 710                                                 eps[2]->desc.bEndpointAddress);
 711                 devinfo->data_out_pipe = usb_sndbulkpipe(udev,
 712                                                 eps[3]->desc.bEndpointAddress);
 713         }
 714
 715         devinfo->qdepth = usb_alloc_streams(devinfo->intf, eps + 1, 3, 256,
 716                                                                 GFP_KERNEL);
 717         if (devinfo->qdepth < 0) {
 718                 devinfo->qdepth = 256;
 719                 devinfo->use_streams = 0;
 720         } else {
 721                 devinfo->use_streams = 1;
 722         }
 723 }
 724
 725 static int uas_alloc_status_urb(struct uas_dev_info *devinfo,
 726                 struct Scsi_Host *shost)
 727 {
 728         if (devinfo->use_streams) {
 729                 devinfo->status_urb = NULL;
 730                 return 0;
 731         }
 732
 733         devinfo->status_urb = uas_alloc_sense_urb(devinfo, GFP_KERNEL,
 734                         shost, 0);
 735         if (!devinfo->status_urb)
 736                 goto err_s_urb;
 737
 738         if (usb_submit_urb(devinfo->status_urb, GFP_KERNEL))
 739                 goto err_submit_urb;
 740
 741         return 0;
 742 err_submit_urb:
 743         usb_free_urb(devinfo->status_urb);
 744 err_s_urb:
 745         return -ENOMEM;
 746 }
 747
 748 static void uas_free_streams(struct uas_dev_info *devinfo)
 749 {
 750         struct usb_device *udev = devinfo->udev;
 751         struct usb_host_endpoint *eps[3];
 752
 753         eps[0] = usb_pipe_endpoint(udev, devinfo->status_pipe);
 754         eps[1] = usb_pipe_endpoint(udev, devinfo->data_in_pipe);
 755         eps[2] = usb_pipe_endpoint(udev, devinfo->data_out_pipe);
 756         usb_free_streams(devinfo->intf, eps, 3, GFP_KERNEL);
 757 }
 758
 759 /*
 760  * XXX: What I'd like to do here is register a SCSI host for each USB host in
 761  * the system.  Follow usb-storage's design of registering a SCSI host for
 762  * each USB device for the moment.  Can implement this by walking up the
 763  * USB hierarchy until we find a USB host.
 764  */
 765 static int uas_probe(struct usb_interface *intf, const struct usb_device_id *id)
 766 {
 767         int result;
 768         struct Scsi_Host *shost;
 769         struct uas_dev_info *devinfo;
 770         struct usb_device *udev = interface_to_usbdev(intf);
 771
 772         if (uas_switch_interface(udev, intf))
 773                 return -ENODEV;
 774
 775         devinfo = kmalloc(sizeof(struct uas_dev_info), GFP_KERNEL);
 776         if (!devinfo)
 777                 return -ENOMEM;
 778
 779         result = -ENOMEM;
 780         shost = scsi_host_alloc(&uas_host_template, sizeof(void *));
 781         if (!shost)
 782                 goto free;
 783
 784         shost->max_cmd_len = 16 + 252;
 785         shost->max_id = 1;
 786         shost->sg_tablesize = udev->bus->sg_tablesize;
 787
 788         devinfo->intf = intf;
 789         devinfo->udev = udev;
 790         uas_configure_endpoints(devinfo);
 791
 792         result = scsi_init_shared_tag_map(shost, devinfo->qdepth - 2);
 793         if (result)
 794                 goto free;
 795
 796         result = scsi_add_host(shost, &intf->dev);
 797         if (result)
 798                 goto deconfig_eps;
 799
 800         shost->hostdata[0] = (unsigned long)devinfo;
 801
 802         result = uas_alloc_status_urb(devinfo, shost);
 803         if (result)
 804                 goto err_alloc_status;
 805
 806         scsi_scan_host(shost);
 807         usb_set_intfdata(intf, shost);
 808         return result;
 809
 810 err_alloc_status:
 811         scsi_remove_host(shost);
 812         shost = NULL;
 813 deconfig_eps:
 814         uas_free_streams(devinfo);
 815  free:
 816         kfree(devinfo);
 817         if (shost)
 818                 scsi_host_put(shost);
 819         return result;
 820 }
 821
 822 static int uas_pre_reset(struct usb_interface *intf)
 823 {
 824 /* XXX: Need to return 1 if it's not our device in error handling */
 825         return 0;
 826 }
 827
 828 static int uas_post_reset(struct usb_interface *intf)
 829 {
 830 /* XXX: Need to return 1 if it's not our device in error handling */
 831         return 0;
 832 }
 833
 834 static void uas_disconnect(struct usb_interface *intf)
 835 {
 836         struct Scsi_Host *shost = usb_get_intfdata(intf);
 837         struct uas_dev_info *devinfo = (void *)shost->hostdata[0];
 838
 839         scsi_remove_host(shost);
 840         usb_kill_urb(devinfo->status_urb);
 841         usb_free_urb(devinfo->status_urb);
 842         uas_free_streams(devinfo);
 843         kfree(devinfo);
 844 }
 845
 846 /*
 847  * XXX: Should this plug into libusual so we can auto-upgrade devices from
 848  * Bulk-Only to UAS?
 849  */
 850 static struct usb_driver uas_driver = {
 851         .name = "uas",
 852         .probe = uas_probe,
 853         .disconnect = uas_disconnect,
 854         .pre_reset = uas_pre_reset,
 855         .post_reset = uas_post_reset,
 856         .id_table = uas_usb_ids,
 857 };
 858
 859 static int uas_init(void)
 860 {
 861         return usb_register(&uas_driver);
 862 }
 863
 864 static void uas_exit(void)
 865 {
 866         usb_deregister(&uas_driver);
 867 }
 868
 869 module_init(uas_init);
 870 module_exit(uas_exit);
 871
 872 MODULE_LICENSE("GPL");
 873 MODULE_AUTHOR("Matthew Wilcox and Sarah Sharp");