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/storage.h>
  17
  18 #include <scsi/scsi.h>
  19 #include <scsi/scsi_dbg.h>
  20 #include <scsi/scsi_cmnd.h>
  21 #include <scsi/scsi_device.h>
  22 #include <scsi/scsi_host.h>
  23 #include <scsi/scsi_tcq.h>
  24
  25 /* Common header for all IUs */
  26 struct iu {
  27         __u8 iu_id;
  28         __u8 rsvd1;
  29         __be16 tag;
  30 };
  31
  32 enum {
  33         IU_ID_COMMAND           = 0x01,
  34         IU_ID_STATUS            = 0x03,
  35         IU_ID_RESPONSE          = 0x04,
  36         IU_ID_TASK_MGMT         = 0x05,
  37         IU_ID_READ_READY        = 0x06,
  38         IU_ID_WRITE_READY       = 0x07,
  39 };
  40
  41 struct command_iu {
  42         __u8 iu_id;
  43         __u8 rsvd1;
  44         __be16 tag;
  45         __u8 prio_attr;
  46         __u8 rsvd5;
  47         __u8 len;
  48         __u8 rsvd7;
  49         struct scsi_lun lun;
  50         __u8 cdb[16];   /* XXX: Overflow-checking tools may misunderstand */
  51 };
  52
  53 /*
  54  * Also used for the Read Ready and Write Ready IUs since they have the
  55  * same first four bytes
  56  */
  57 struct sense_iu {
  58         __u8 iu_id;
  59         __u8 rsvd1;
  60         __be16 tag;
  61         __be16 status_qual;
  62         __u8 status;
  63         __u8 rsvd7[7];
  64         __be16 len;
  65         __u8 sense[SCSI_SENSE_BUFFERSIZE];
  66 };
  67
  68 /*
  69  * The r00-r01c specs define this version of the SENSE IU data structure.
  70  * It's still in use by several different firmware releases.
  71  */
  72 struct sense_iu_old {
  73         __u8 iu_id;
  74         __u8 rsvd1;
  75         __be16 tag;
  76         __be16 len;
  77         __u8 status;
  78         __u8 service_response;
  79         __u8 sense[SCSI_SENSE_BUFFERSIZE];
  80 };
  81
  82 enum {
  83         CMD_PIPE_ID             = 1,
  84         STATUS_PIPE_ID          = 2,
  85         DATA_IN_PIPE_ID         = 3,
  86         DATA_OUT_PIPE_ID        = 4,
  87
  88         UAS_SIMPLE_TAG          = 0,
  89         UAS_HEAD_TAG            = 1,
  90         UAS_ORDERED_TAG         = 2,
  91         UAS_ACA                 = 4,
  92 };
  93
  94 struct uas_dev_info {
  95         struct usb_interface *intf;
  96         struct usb_device *udev;
  97         int qdepth;
  98         unsigned cmd_pipe, status_pipe, data_in_pipe, data_out_pipe;
  99         unsigned use_streams:1;
 100         unsigned uas_sense_old:1;
 101 };
 102
 103 enum {
 104         ALLOC_STATUS_URB        = (1 << 0),
 105         SUBMIT_STATUS_URB       = (1 << 1),
 106         ALLOC_DATA_IN_URB       = (1 << 2),
 107         SUBMIT_DATA_IN_URB      = (1 << 3),
 108         ALLOC_DATA_OUT_URB      = (1 << 4),
 109         SUBMIT_DATA_OUT_URB     = (1 << 5),
 110         ALLOC_CMD_URB           = (1 << 6),
 111         SUBMIT_CMD_URB          = (1 << 7),
 112 };
 113
 114 /* Overrides scsi_pointer */
 115 struct uas_cmd_info {
 116         unsigned int state;
 117         unsigned int stream;
 118         struct urb *cmd_urb;
 119         struct urb *status_urb;
 120         struct urb *data_in_urb;
 121         struct urb *data_out_urb;
 122         struct list_head list;
 123 };
 124
 125 /* I hate forward declarations, but I actually have a loop */
 126 static int uas_submit_urbs(struct scsi_cmnd *cmnd,
 127                                 struct uas_dev_info *devinfo, gfp_t gfp);
 128 static void uas_do_work(struct work_struct *work);
 129
 130 static DECLARE_WORK(uas_work, uas_do_work);
 131 static DEFINE_SPINLOCK(uas_work_lock);
 132 static LIST_HEAD(uas_work_list);
 133
 134 static void uas_do_work(struct work_struct *work)
 135 {
 136         struct uas_cmd_info *cmdinfo;
 137         struct uas_cmd_info *temp;
 138         struct list_head list;
 139         int err;
 140
 141         spin_lock_irq(&uas_work_lock);
 142         list_replace_init(&uas_work_list, &list);
 143         spin_unlock_irq(&uas_work_lock);
 144
 145         list_for_each_entry_safe(cmdinfo, temp, &list, list) {
 146                 struct scsi_pointer *scp = (void *)cmdinfo;
 147                 struct scsi_cmnd *cmnd = container_of(scp,
 148                                                         struct scsi_cmnd, SCp);
 149                 err = uas_submit_urbs(cmnd, cmnd->device->hostdata, GFP_NOIO);
 150                 if (err) {
 151                         list_del(&cmdinfo->list);
 152                         spin_lock_irq(&uas_work_lock);
 153                         list_add_tail(&cmdinfo->list, &uas_work_list);
 154                         spin_unlock_irq(&uas_work_lock);
 155                         schedule_work(&uas_work);
 156                 }
 157         }
 158 }
 159
 160 static void uas_sense(struct urb *urb, struct scsi_cmnd *cmnd)
 161 {
 162         struct sense_iu *sense_iu = urb->transfer_buffer;
 163         struct scsi_device *sdev = cmnd->device;
 164
 165         if (urb->actual_length > 16) {
 166                 unsigned len = be16_to_cpup(&sense_iu->len);
 167                 if (len + 16 != urb->actual_length) {
 168                         int newlen = min(len + 16, urb->actual_length) - 16;
 169                         if (newlen < 0)
 170                                 newlen = 0;
 171                         sdev_printk(KERN_INFO, sdev, "%s: urb length %d "
 172                                 "disagrees with IU sense data length %d, "
 173                                 "using %d bytes of sense data\n", __func__,
 174                                         urb->actual_length, len, newlen);
 175                         len = newlen;
 176                 }
 177                 memcpy(cmnd->sense_buffer, sense_iu->sense, len);
 178         }
 179
 180         cmnd->result = sense_iu->status;
 181         if (sdev->current_cmnd)
 182                 sdev->current_cmnd = NULL;
 183         cmnd->scsi_done(cmnd);
 184         usb_free_urb(urb);
 185 }
 186
 187 static void uas_sense_old(struct urb *urb, struct scsi_cmnd *cmnd)
 188 {
 189         struct sense_iu_old *sense_iu = urb->transfer_buffer;
 190         struct scsi_device *sdev = cmnd->device;
 191
 192         if (urb->actual_length > 8) {
 193                 unsigned len = be16_to_cpup(&sense_iu->len) - 2;
 194                 if (len + 8 != urb->actual_length) {
 195                         int newlen = min(len + 8, urb->actual_length) - 8;
 196                         if (newlen < 0)
 197                                 newlen = 0;
 198                         sdev_printk(KERN_INFO, sdev, "%s: urb length %d "
 199                                 "disagrees with IU sense data length %d, "
 200                                 "using %d bytes of sense data\n", __func__,
 201                                         urb->actual_length, len, newlen);
 202                         len = newlen;
 203                 }
 204                 memcpy(cmnd->sense_buffer, sense_iu->sense, len);
 205         }
 206
 207         cmnd->result = sense_iu->status;
 208         if (sdev->current_cmnd)
 209                 sdev->current_cmnd = NULL;
 210         cmnd->scsi_done(cmnd);
 211         usb_free_urb(urb);
 212 }
 213
 214 static void uas_xfer_data(struct urb *urb, struct scsi_cmnd *cmnd,
 215                                                         unsigned direction)
 216 {
 217         struct uas_cmd_info *cmdinfo = (void *)&cmnd->SCp;
 218         int err;
 219
 220         cmdinfo->state = direction | SUBMIT_STATUS_URB;
 221         err = uas_submit_urbs(cmnd, cmnd->device->hostdata, GFP_ATOMIC);
 222         if (err) {
 223                 spin_lock(&uas_work_lock);
 224                 list_add_tail(&cmdinfo->list, &uas_work_list);
 225                 spin_unlock(&uas_work_lock);
 226                 schedule_work(&uas_work);
 227         }
 228 }
 229
 230 static void uas_stat_cmplt(struct urb *urb)
 231 {
 232         struct iu *iu = urb->transfer_buffer;
 233         struct scsi_device *sdev = urb->context;
 234         struct uas_dev_info *devinfo = sdev->hostdata;
 235         struct scsi_cmnd *cmnd;
 236         u16 tag;
 237
 238         if (urb->status) {
 239                 dev_err(&urb->dev->dev, "URB BAD STATUS %d\n", urb->status);
 240                 usb_free_urb(urb);
 241                 return;
 242         }
 243
 244         tag = be16_to_cpup(&iu->tag) - 1;
 245         if (sdev->current_cmnd)
 246                 cmnd = sdev->current_cmnd;
 247         else
 248                 cmnd = scsi_find_tag(sdev, tag);
 249         if (!cmnd)
 250                 return;
 251
 252         switch (iu->iu_id) {
 253         case IU_ID_STATUS:
 254                 if (urb->actual_length < 16)
 255                         devinfo->uas_sense_old = 1;
 256                 if (devinfo->uas_sense_old)
 257                         uas_sense_old(urb, cmnd);
 258                 else
 259                         uas_sense(urb, cmnd);
 260                 break;
 261         case IU_ID_READ_READY:
 262                 uas_xfer_data(urb, cmnd, SUBMIT_DATA_IN_URB);
 263                 break;
 264         case IU_ID_WRITE_READY:
 265                 uas_xfer_data(urb, cmnd, SUBMIT_DATA_OUT_URB);
 266                 break;
 267         default:
 268                 scmd_printk(KERN_ERR, cmnd,
 269                         "Bogus IU (%d) received on status pipe\n", iu->iu_id);
 270         }
 271 }
 272
 273 static void uas_data_cmplt(struct urb *urb)
 274 {
 275         struct scsi_data_buffer *sdb = urb->context;
 276         sdb->resid = sdb->length - urb->actual_length;
 277         usb_free_urb(urb);
 278 }
 279
 280 static struct urb *uas_alloc_data_urb(struct uas_dev_info *devinfo, gfp_t gfp,
 281                                 unsigned int pipe, u16 stream_id,
 282                                 struct scsi_data_buffer *sdb,
 283                                 enum dma_data_direction dir)
 284 {
 285         struct usb_device *udev = devinfo->udev;
 286         struct urb *urb = usb_alloc_urb(0, gfp);
 287
 288         if (!urb)
 289                 goto out;
 290         usb_fill_bulk_urb(urb, udev, pipe, NULL, sdb->length, uas_data_cmplt,
 291                                                                         sdb);
 292         if (devinfo->use_streams)
 293                 urb->stream_id = stream_id;
 294         urb->num_sgs = udev->bus->sg_tablesize ? sdb->table.nents : 0;
 295         urb->sg = sdb->table.sgl;
 296  out:
 297         return urb;
 298 }
 299
 300 static struct urb *uas_alloc_sense_urb(struct uas_dev_info *devinfo, gfp_t gfp,
 301                                         struct scsi_cmnd *cmnd, u16 stream_id)
 302 {
 303         struct usb_device *udev = devinfo->udev;
 304         struct urb *urb = usb_alloc_urb(0, gfp);
 305         struct sense_iu *iu;
 306
 307         if (!urb)
 308                 goto out;
 309
 310         iu = kzalloc(sizeof(*iu), gfp);
 311         if (!iu)
 312                 goto free;
 313
 314         usb_fill_bulk_urb(urb, udev, devinfo->status_pipe, iu, sizeof(*iu),
 315                                                 uas_stat_cmplt, cmnd->device);
 316         urb->stream_id = stream_id;
 317         urb->transfer_flags |= URB_FREE_BUFFER;
 318  out:
 319         return urb;
 320  free:
 321         usb_free_urb(urb);
 322         return NULL;
 323 }
 324
 325 static struct urb *uas_alloc_cmd_urb(struct uas_dev_info *devinfo, gfp_t gfp,
 326                                         struct scsi_cmnd *cmnd, u16 stream_id)
 327 {
 328         struct usb_device *udev = devinfo->udev;
 329         struct scsi_device *sdev = cmnd->device;
 330         struct urb *urb = usb_alloc_urb(0, gfp);
 331         struct command_iu *iu;
 332         int len;
 333
 334         if (!urb)
 335                 goto out;
 336
 337         len = cmnd->cmd_len - 16;
 338         if (len < 0)
 339                 len = 0;
 340         len = ALIGN(len, 4);
 341         iu = kzalloc(sizeof(*iu) + len, gfp);
 342         if (!iu)
 343                 goto free;
 344
 345         iu->iu_id = IU_ID_COMMAND;
 346         if (blk_rq_tagged(cmnd->request))
 347                 iu->tag = cpu_to_be16(cmnd->request->tag + 1);
 348         else
 349                 iu->tag = cpu_to_be16(1);
 350         iu->prio_attr = UAS_SIMPLE_TAG;
 351         iu->len = len;
 352         int_to_scsilun(sdev->lun, &iu->lun);
 353         memcpy(iu->cdb, cmnd->cmnd, cmnd->cmd_len);
 354
 355         usb_fill_bulk_urb(urb, udev, devinfo->cmd_pipe, iu, sizeof(*iu) + len,
 356                                                         usb_free_urb, NULL);
 357         urb->transfer_flags |= URB_FREE_BUFFER;
 358  out:
 359         return urb;
 360  free:
 361         usb_free_urb(urb);
 362         return NULL;
 363 }
 364
 365 /*
 366  * Why should I request the Status IU before sending the Command IU?  Spec
 367  * says to, but also says the device may receive them in any order.  Seems
 368  * daft to me.
 369  */
 370
 371 static int uas_submit_urbs(struct scsi_cmnd *cmnd,
 372                                         struct uas_dev_info *devinfo, gfp_t gfp)
 373 {
 374         struct uas_cmd_info *cmdinfo = (void *)&cmnd->SCp;
 375
 376         if (cmdinfo->state & ALLOC_STATUS_URB) {
 377                 cmdinfo->status_urb = uas_alloc_sense_urb(devinfo, gfp, cmnd,
 378                                                           cmdinfo->stream);
 379                 if (!cmdinfo->status_urb)
 380                         return SCSI_MLQUEUE_DEVICE_BUSY;
 381                 cmdinfo->state &= ~ALLOC_STATUS_URB;
 382         }
 383
 384         if (cmdinfo->state & SUBMIT_STATUS_URB) {
 385                 if (usb_submit_urb(cmdinfo->status_urb, gfp)) {
 386                         scmd_printk(KERN_INFO, cmnd,
 387                                         "sense urb submission failure\n");
 388                         return SCSI_MLQUEUE_DEVICE_BUSY;
 389                 }
 390                 cmdinfo->state &= ~SUBMIT_STATUS_URB;
 391         }
 392
 393         if (cmdinfo->state & ALLOC_DATA_IN_URB) {
 394                 cmdinfo->data_in_urb = uas_alloc_data_urb(devinfo, gfp,
 395                                         devinfo->data_in_pipe, cmdinfo->stream,
 396                                         scsi_in(cmnd), DMA_FROM_DEVICE);
 397                 if (!cmdinfo->data_in_urb)
 398                         return SCSI_MLQUEUE_DEVICE_BUSY;
 399                 cmdinfo->state &= ~ALLOC_DATA_IN_URB;
 400         }
 401
 402         if (cmdinfo->state & SUBMIT_DATA_IN_URB) {
 403                 if (usb_submit_urb(cmdinfo->data_in_urb, gfp)) {
 404                         scmd_printk(KERN_INFO, cmnd,
 405                                         "data in urb submission failure\n");
 406                         return SCSI_MLQUEUE_DEVICE_BUSY;
 407                 }
 408                 cmdinfo->state &= ~SUBMIT_DATA_IN_URB;
 409         }
 410
 411         if (cmdinfo->state & ALLOC_DATA_OUT_URB) {
 412                 cmdinfo->data_out_urb = uas_alloc_data_urb(devinfo, gfp,
 413                                         devinfo->data_out_pipe, cmdinfo->stream,
 414                                         scsi_out(cmnd), DMA_TO_DEVICE);
 415                 if (!cmdinfo->data_out_urb)
 416                         return SCSI_MLQUEUE_DEVICE_BUSY;
 417                 cmdinfo->state &= ~ALLOC_DATA_OUT_URB;
 418         }
 419
 420         if (cmdinfo->state & SUBMIT_DATA_OUT_URB) {
 421                 if (usb_submit_urb(cmdinfo->data_out_urb, gfp)) {
 422                         scmd_printk(KERN_INFO, cmnd,
 423                                         "data out urb submission failure\n");
 424                         return SCSI_MLQUEUE_DEVICE_BUSY;
 425                 }
 426                 cmdinfo->state &= ~SUBMIT_DATA_OUT_URB;
 427         }
 428
 429         if (cmdinfo->state & ALLOC_CMD_URB) {
 430                 cmdinfo->cmd_urb = uas_alloc_cmd_urb(devinfo, gfp, cmnd,
 431                                                         cmdinfo->stream);
 432                 if (!cmdinfo->cmd_urb)
 433                         return SCSI_MLQUEUE_DEVICE_BUSY;
 434                 cmdinfo->state &= ~ALLOC_CMD_URB;
 435         }
 436
 437         if (cmdinfo->state & SUBMIT_CMD_URB) {
 438                 if (usb_submit_urb(cmdinfo->cmd_urb, gfp)) {
 439                         scmd_printk(KERN_INFO, cmnd,
 440                                         "cmd urb submission failure\n");
 441                         return SCSI_MLQUEUE_DEVICE_BUSY;
 442                 }
 443                 cmdinfo->state &= ~SUBMIT_CMD_URB;
 444         }
 445
 446         return 0;
 447 }
 448
 449 static int uas_queuecommand_lck(struct scsi_cmnd *cmnd,
 450                                         void (*done)(struct scsi_cmnd *))
 451 {
 452         struct scsi_device *sdev = cmnd->device;
 453         struct uas_dev_info *devinfo = sdev->hostdata;
 454         struct uas_cmd_info *cmdinfo = (void *)&cmnd->SCp;
 455         int err;
 456
 457         BUILD_BUG_ON(sizeof(struct uas_cmd_info) > sizeof(struct scsi_pointer));
 458
 459         if (!cmdinfo->status_urb && sdev->current_cmnd)
 460                 return SCSI_MLQUEUE_DEVICE_BUSY;
 461
 462         if (blk_rq_tagged(cmnd->request)) {
 463                 cmdinfo->stream = cmnd->request->tag + 1;
 464         } else {
 465                 sdev->current_cmnd = cmnd;
 466                 cmdinfo->stream = 1;
 467         }
 468
 469         cmnd->scsi_done = done;
 470
 471         cmdinfo->state = ALLOC_STATUS_URB | SUBMIT_STATUS_URB |
 472                         ALLOC_CMD_URB | SUBMIT_CMD_URB;
 473
 474         switch (cmnd->sc_data_direction) {
 475         case DMA_FROM_DEVICE:
 476                 cmdinfo->state |= ALLOC_DATA_IN_URB | SUBMIT_DATA_IN_URB;
 477                 break;
 478         case DMA_BIDIRECTIONAL:
 479                 cmdinfo->state |= ALLOC_DATA_IN_URB | SUBMIT_DATA_IN_URB;
 480         case DMA_TO_DEVICE:
 481                 cmdinfo->state |= ALLOC_DATA_OUT_URB | SUBMIT_DATA_OUT_URB;
 482         case DMA_NONE:
 483                 break;
 484         }
 485
 486         if (!devinfo->use_streams) {
 487                 cmdinfo->state &= ~(SUBMIT_DATA_IN_URB | SUBMIT_DATA_OUT_URB);
 488                 cmdinfo->stream = 0;
 489         }
 490
 491         err = uas_submit_urbs(cmnd, devinfo, GFP_ATOMIC);
 492         if (err) {
 493                 /* If we did nothing, give up now */
 494                 if (cmdinfo->state & SUBMIT_STATUS_URB) {
 495                         usb_free_urb(cmdinfo->status_urb);
 496                         return SCSI_MLQUEUE_DEVICE_BUSY;
 497                 }
 498                 spin_lock(&uas_work_lock);
 499                 list_add_tail(&cmdinfo->list, &uas_work_list);
 500                 spin_unlock(&uas_work_lock);
 501                 schedule_work(&uas_work);
 502         }
 503
 504         return 0;
 505 }
 506
 507 static DEF_SCSI_QCMD(uas_queuecommand)
 508
 509 static int uas_eh_abort_handler(struct scsi_cmnd *cmnd)
 510 {
 511         struct scsi_device *sdev = cmnd->device;
 512         sdev_printk(KERN_INFO, sdev, "%s tag %d\n", __func__,
 513                                                         cmnd->request->tag);
 514
 515 /* XXX: Send ABORT TASK Task Management command */
 516         return FAILED;
 517 }
 518
 519 static int uas_eh_device_reset_handler(struct scsi_cmnd *cmnd)
 520 {
 521         struct scsi_device *sdev = cmnd->device;
 522         sdev_printk(KERN_INFO, sdev, "%s tag %d\n", __func__,
 523                                                         cmnd->request->tag);
 524
 525 /* XXX: Send LOGICAL UNIT RESET Task Management command */
 526         return FAILED;
 527 }
 528
 529 static int uas_eh_target_reset_handler(struct scsi_cmnd *cmnd)
 530 {
 531         struct scsi_device *sdev = cmnd->device;
 532         sdev_printk(KERN_INFO, sdev, "%s tag %d\n", __func__,
 533                                                         cmnd->request->tag);
 534
 535 /* XXX: Can we reset just the one USB interface?
 536  * Would calling usb_set_interface() have the right effect?
 537  */
 538         return FAILED;
 539 }
 540
 541 static int uas_eh_bus_reset_handler(struct scsi_cmnd *cmnd)
 542 {
 543         struct scsi_device *sdev = cmnd->device;
 544         struct uas_dev_info *devinfo = sdev->hostdata;
 545         struct usb_device *udev = devinfo->udev;
 546
 547         sdev_printk(KERN_INFO, sdev, "%s tag %d\n", __func__,
 548                                                         cmnd->request->tag);
 549
 550         if (usb_reset_device(udev))
 551                 return SUCCESS;
 552
 553         return FAILED;
 554 }
 555
 556 static int uas_slave_alloc(struct scsi_device *sdev)
 557 {
 558         sdev->hostdata = (void *)sdev->host->hostdata[0];
 559         return 0;
 560 }
 561
 562 static int uas_slave_configure(struct scsi_device *sdev)
 563 {
 564         struct uas_dev_info *devinfo = sdev->hostdata;
 565         scsi_set_tag_type(sdev, MSG_ORDERED_TAG);
 566         scsi_activate_tcq(sdev, devinfo->qdepth - 1);
 567         return 0;
 568 }
 569
 570 static struct scsi_host_template uas_host_template = {
 571         .module = THIS_MODULE,
 572         .name = "uas",
 573         .queuecommand = uas_queuecommand,
 574         .slave_alloc = uas_slave_alloc,
 575         .slave_configure = uas_slave_configure,
 576         .eh_abort_handler = uas_eh_abort_handler,
 577         .eh_device_reset_handler = uas_eh_device_reset_handler,
 578         .eh_target_reset_handler = uas_eh_target_reset_handler,
 579         .eh_bus_reset_handler = uas_eh_bus_reset_handler,
 580         .can_queue = 65536,     /* Is there a limit on the _host_ ? */
 581         .this_id = -1,
 582         .sg_tablesize = SG_NONE,
 583         .cmd_per_lun = 1,       /* until we override it */
 584         .skip_settle_delay = 1,
 585         .ordered_tag = 1,
 586 };
 587
 588 static struct usb_device_id uas_usb_ids[] = {
 589         { USB_INTERFACE_INFO(USB_CLASS_MASS_STORAGE, USB_SC_SCSI, USB_PR_BULK) },
 590         { USB_INTERFACE_INFO(USB_CLASS_MASS_STORAGE, USB_SC_SCSI, USB_PR_UAS) },
 591         /* 0xaa is a prototype device I happen to have access to */
 592         { USB_INTERFACE_INFO(USB_CLASS_MASS_STORAGE, USB_SC_SCSI, 0xaa) },
 593         { }
 594 };
 595 MODULE_DEVICE_TABLE(usb, uas_usb_ids);
 596
 597 static int uas_is_interface(struct usb_host_interface *intf)
 598 {
 599         return (intf->desc.bInterfaceClass == USB_CLASS_MASS_STORAGE &&
 600                 intf->desc.bInterfaceSubClass == USB_SC_SCSI &&
 601                 intf->desc.bInterfaceProtocol == USB_PR_UAS);
 602 }
 603
 604 static int uas_switch_interface(struct usb_device *udev,
 605                                                 struct usb_interface *intf)
 606 {
 607         int i;
 608
 609         if (uas_is_interface(intf->cur_altsetting))
 610                 return 0;
 611
 612         for (i = 0; i < intf->num_altsetting; i++) {
 613                 struct usb_host_interface *alt = &intf->altsetting[i];
 614                 if (alt == intf->cur_altsetting)
 615                         continue;
 616                 if (uas_is_interface(alt))
 617                         return usb_set_interface(udev,
 618                                                 alt->desc.bInterfaceNumber,
 619                                                 alt->desc.bAlternateSetting);
 620         }
 621
 622         return -ENODEV;
 623 }
 624
 625 static void uas_configure_endpoints(struct uas_dev_info *devinfo)
 626 {
 627         struct usb_host_endpoint *eps[4] = { };
 628         struct usb_interface *intf = devinfo->intf;
 629         struct usb_device *udev = devinfo->udev;
 630         struct usb_host_endpoint *endpoint = intf->cur_altsetting->endpoint;
 631         unsigned i, n_endpoints = intf->cur_altsetting->desc.bNumEndpoints;
 632
 633         devinfo->uas_sense_old = 0;
 634
 635         for (i = 0; i < n_endpoints; i++) {
 636                 unsigned char *extra = endpoint[i].extra;
 637                 int len = endpoint[i].extralen;
 638                 while (len > 1) {
 639                         if (extra[1] == USB_DT_PIPE_USAGE) {
 640                                 unsigned pipe_id = extra[2];
 641                                 if (pipe_id > 0 && pipe_id < 5)
 642                                         eps[pipe_id - 1] = &endpoint[i];
 643                                 break;
 644                         }
 645                         len -= extra[0];
 646                         extra += extra[0];
 647                 }
 648         }
 649
 650         /*
 651          * Assume that if we didn't find a control pipe descriptor, we're
 652          * using a device with old firmware that happens to be set up like
 653          * this.
 654          */
 655         if (!eps[0]) {
 656                 devinfo->cmd_pipe = usb_sndbulkpipe(udev, 1);
 657                 devinfo->status_pipe = usb_rcvbulkpipe(udev, 1);
 658                 devinfo->data_in_pipe = usb_rcvbulkpipe(udev, 2);
 659                 devinfo->data_out_pipe = usb_sndbulkpipe(udev, 2);
 660
 661                 eps[1] = usb_pipe_endpoint(udev, devinfo->status_pipe);
 662                 eps[2] = usb_pipe_endpoint(udev, devinfo->data_in_pipe);
 663                 eps[3] = usb_pipe_endpoint(udev, devinfo->data_out_pipe);
 664         } else {
 665                 devinfo->cmd_pipe = usb_sndbulkpipe(udev,
 666                                                 eps[0]->desc.bEndpointAddress);
 667                 devinfo->status_pipe = usb_rcvbulkpipe(udev,
 668                                                 eps[1]->desc.bEndpointAddress);
 669                 devinfo->data_in_pipe = usb_rcvbulkpipe(udev,
 670                                                 eps[2]->desc.bEndpointAddress);
 671                 devinfo->data_out_pipe = usb_sndbulkpipe(udev,
 672                                                 eps[3]->desc.bEndpointAddress);
 673         }
 674
 675         devinfo->qdepth = usb_alloc_streams(devinfo->intf, eps + 1, 3, 256,
 676                                                                 GFP_KERNEL);
 677         if (devinfo->qdepth < 0) {
 678                 devinfo->qdepth = 256;
 679                 devinfo->use_streams = 0;
 680         } else {
 681                 devinfo->use_streams = 1;
 682         }
 683 }
 684
 685 /*
 686  * XXX: What I'd like to do here is register a SCSI host for each USB host in
 687  * the system.  Follow usb-storage's design of registering a SCSI host for
 688  * each USB device for the moment.  Can implement this by walking up the
 689  * USB hierarchy until we find a USB host.
 690  */
 691 static int uas_probe(struct usb_interface *intf, const struct usb_device_id *id)
 692 {
 693         int result;
 694         struct Scsi_Host *shost;
 695         struct uas_dev_info *devinfo;
 696         struct usb_device *udev = interface_to_usbdev(intf);
 697
 698         if (uas_switch_interface(udev, intf))
 699                 return -ENODEV;
 700
 701         devinfo = kmalloc(sizeof(struct uas_dev_info), GFP_KERNEL);
 702         if (!devinfo)
 703                 return -ENOMEM;
 704
 705         result = -ENOMEM;
 706         shost = scsi_host_alloc(&uas_host_template, sizeof(void *));
 707         if (!shost)
 708                 goto free;
 709
 710         shost->max_cmd_len = 16 + 252;
 711         shost->max_id = 1;
 712         shost->sg_tablesize = udev->bus->sg_tablesize;
 713
 714         result = scsi_add_host(shost, &intf->dev);
 715         if (result)
 716                 goto free;
 717         shost->hostdata[0] = (unsigned long)devinfo;
 718
 719         devinfo->intf = intf;
 720         devinfo->udev = udev;
 721         uas_configure_endpoints(devinfo);
 722
 723         scsi_scan_host(shost);
 724         usb_set_intfdata(intf, shost);
 725         return result;
 726  free:
 727         kfree(devinfo);
 728         if (shost)
 729                 scsi_host_put(shost);
 730         return result;
 731 }
 732
 733 static int uas_pre_reset(struct usb_interface *intf)
 734 {
 735 /* XXX: Need to return 1 if it's not our device in error handling */
 736         return 0;
 737 }
 738
 739 static int uas_post_reset(struct usb_interface *intf)
 740 {
 741 /* XXX: Need to return 1 if it's not our device in error handling */
 742         return 0;
 743 }
 744
 745 static void uas_disconnect(struct usb_interface *intf)
 746 {
 747         struct usb_device *udev = interface_to_usbdev(intf);
 748         struct usb_host_endpoint *eps[3];
 749         struct Scsi_Host *shost = usb_get_intfdata(intf);
 750         struct uas_dev_info *devinfo = (void *)shost->hostdata[0];
 751
 752         scsi_remove_host(shost);
 753
 754         eps[0] = usb_pipe_endpoint(udev, devinfo->status_pipe);
 755         eps[1] = usb_pipe_endpoint(udev, devinfo->data_in_pipe);
 756         eps[2] = usb_pipe_endpoint(udev, devinfo->data_out_pipe);
 757         usb_free_streams(intf, eps, 3, GFP_KERNEL);
 758
 759         kfree(devinfo);
 760 }
 761
 762 /*
 763  * XXX: Should this plug into libusual so we can auto-upgrade devices from
 764  * Bulk-Only to UAS?
 765  */
 766 static struct usb_driver uas_driver = {
 767         .name = "uas",
 768         .probe = uas_probe,
 769         .disconnect = uas_disconnect,
 770         .pre_reset = uas_pre_reset,
 771         .post_reset = uas_post_reset,
 772         .id_table = uas_usb_ids,
 773 };
 774
 775 static int uas_init(void)
 776 {
 777         return usb_register(&uas_driver);
 778 }
 779
 780 static void uas_exit(void)
 781 {
 782         usb_deregister(&uas_driver);
 783 }
 784
 785 module_init(uas_init);
 786 module_exit(uas_exit);
 787
 788 MODULE_LICENSE("GPL");
 789 MODULE_AUTHOR("Matthew Wilcox and Sarah Sharp");