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         iu->tag = cpu_to_be16(stream_id);
 347         iu->prio_attr = UAS_SIMPLE_TAG;
 348         iu->len = len;
 349         int_to_scsilun(sdev->lun, &iu->lun);
 350         memcpy(iu->cdb, cmnd->cmnd, cmnd->cmd_len);
 351
 352         usb_fill_bulk_urb(urb, udev, devinfo->cmd_pipe, iu, sizeof(*iu) + len,
 353                                                         usb_free_urb, NULL);
 354         urb->transfer_flags |= URB_FREE_BUFFER;
 355  out:
 356         return urb;
 357  free:
 358         usb_free_urb(urb);
 359         return NULL;
 360 }
 361
 362 /*
 363  * Why should I request the Status IU before sending the Command IU?  Spec
 364  * says to, but also says the device may receive them in any order.  Seems
 365  * daft to me.
 366  */
 367
 368 static int uas_submit_urbs(struct scsi_cmnd *cmnd,
 369                                         struct uas_dev_info *devinfo, gfp_t gfp)
 370 {
 371         struct uas_cmd_info *cmdinfo = (void *)&cmnd->SCp;
 372
 373         if (cmdinfo->state & ALLOC_STATUS_URB) {
 374                 cmdinfo->status_urb = uas_alloc_sense_urb(devinfo, gfp, cmnd,
 375                                                           cmdinfo->stream);
 376                 if (!cmdinfo->status_urb)
 377                         return SCSI_MLQUEUE_DEVICE_BUSY;
 378                 cmdinfo->state &= ~ALLOC_STATUS_URB;
 379         }
 380
 381         if (cmdinfo->state & SUBMIT_STATUS_URB) {
 382                 if (usb_submit_urb(cmdinfo->status_urb, gfp)) {
 383                         scmd_printk(KERN_INFO, cmnd,
 384                                         "sense urb submission failure\n");
 385                         return SCSI_MLQUEUE_DEVICE_BUSY;
 386                 }
 387                 cmdinfo->state &= ~SUBMIT_STATUS_URB;
 388         }
 389
 390         if (cmdinfo->state & ALLOC_DATA_IN_URB) {
 391                 cmdinfo->data_in_urb = uas_alloc_data_urb(devinfo, gfp,
 392                                         devinfo->data_in_pipe, cmdinfo->stream,
 393                                         scsi_in(cmnd), DMA_FROM_DEVICE);
 394                 if (!cmdinfo->data_in_urb)
 395                         return SCSI_MLQUEUE_DEVICE_BUSY;
 396                 cmdinfo->state &= ~ALLOC_DATA_IN_URB;
 397         }
 398
 399         if (cmdinfo->state & SUBMIT_DATA_IN_URB) {
 400                 if (usb_submit_urb(cmdinfo->data_in_urb, gfp)) {
 401                         scmd_printk(KERN_INFO, cmnd,
 402                                         "data in urb submission failure\n");
 403                         return SCSI_MLQUEUE_DEVICE_BUSY;
 404                 }
 405                 cmdinfo->state &= ~SUBMIT_DATA_IN_URB;
 406         }
 407
 408         if (cmdinfo->state & ALLOC_DATA_OUT_URB) {
 409                 cmdinfo->data_out_urb = uas_alloc_data_urb(devinfo, gfp,
 410                                         devinfo->data_out_pipe, cmdinfo->stream,
 411                                         scsi_out(cmnd), DMA_TO_DEVICE);
 412                 if (!cmdinfo->data_out_urb)
 413                         return SCSI_MLQUEUE_DEVICE_BUSY;
 414                 cmdinfo->state &= ~ALLOC_DATA_OUT_URB;
 415         }
 416
 417         if (cmdinfo->state & SUBMIT_DATA_OUT_URB) {
 418                 if (usb_submit_urb(cmdinfo->data_out_urb, gfp)) {
 419                         scmd_printk(KERN_INFO, cmnd,
 420                                         "data out urb submission failure\n");
 421                         return SCSI_MLQUEUE_DEVICE_BUSY;
 422                 }
 423                 cmdinfo->state &= ~SUBMIT_DATA_OUT_URB;
 424         }
 425
 426         if (cmdinfo->state & ALLOC_CMD_URB) {
 427                 cmdinfo->cmd_urb = uas_alloc_cmd_urb(devinfo, gfp, cmnd,
 428                                                         cmdinfo->stream);
 429                 if (!cmdinfo->cmd_urb)
 430                         return SCSI_MLQUEUE_DEVICE_BUSY;
 431                 cmdinfo->state &= ~ALLOC_CMD_URB;
 432         }
 433
 434         if (cmdinfo->state & SUBMIT_CMD_URB) {
 435                 if (usb_submit_urb(cmdinfo->cmd_urb, gfp)) {
 436                         scmd_printk(KERN_INFO, cmnd,
 437                                         "cmd urb submission failure\n");
 438                         return SCSI_MLQUEUE_DEVICE_BUSY;
 439                 }
 440                 cmdinfo->state &= ~SUBMIT_CMD_URB;
 441         }
 442
 443         return 0;
 444 }
 445
 446 static int uas_queuecommand_lck(struct scsi_cmnd *cmnd,
 447                                         void (*done)(struct scsi_cmnd *))
 448 {
 449         struct scsi_device *sdev = cmnd->device;
 450         struct uas_dev_info *devinfo = sdev->hostdata;
 451         struct uas_cmd_info *cmdinfo = (void *)&cmnd->SCp;
 452         int err;
 453
 454         BUILD_BUG_ON(sizeof(struct uas_cmd_info) > sizeof(struct scsi_pointer));
 455
 456         if (!cmdinfo->status_urb && sdev->current_cmnd)
 457                 return SCSI_MLQUEUE_DEVICE_BUSY;
 458
 459         if (blk_rq_tagged(cmnd->request)) {
 460                 cmdinfo->stream = cmnd->request->tag + 1;
 461         } else {
 462                 sdev->current_cmnd = cmnd;
 463                 cmdinfo->stream = 1;
 464         }
 465
 466         cmnd->scsi_done = done;
 467
 468         cmdinfo->state = ALLOC_STATUS_URB | SUBMIT_STATUS_URB |
 469                         ALLOC_CMD_URB | SUBMIT_CMD_URB;
 470
 471         switch (cmnd->sc_data_direction) {
 472         case DMA_FROM_DEVICE:
 473                 cmdinfo->state |= ALLOC_DATA_IN_URB | SUBMIT_DATA_IN_URB;
 474                 break;
 475         case DMA_BIDIRECTIONAL:
 476                 cmdinfo->state |= ALLOC_DATA_IN_URB | SUBMIT_DATA_IN_URB;
 477         case DMA_TO_DEVICE:
 478                 cmdinfo->state |= ALLOC_DATA_OUT_URB | SUBMIT_DATA_OUT_URB;
 479         case DMA_NONE:
 480                 break;
 481         }
 482
 483         if (!devinfo->use_streams) {
 484                 cmdinfo->state &= ~(SUBMIT_DATA_IN_URB | SUBMIT_DATA_OUT_URB);
 485                 cmdinfo->stream = 0;
 486         }
 487
 488         err = uas_submit_urbs(cmnd, devinfo, GFP_ATOMIC);
 489         if (err) {
 490                 /* If we did nothing, give up now */
 491                 if (cmdinfo->state & SUBMIT_STATUS_URB) {
 492                         usb_free_urb(cmdinfo->status_urb);
 493                         return SCSI_MLQUEUE_DEVICE_BUSY;
 494                 }
 495                 spin_lock(&uas_work_lock);
 496                 list_add_tail(&cmdinfo->list, &uas_work_list);
 497                 spin_unlock(&uas_work_lock);
 498                 schedule_work(&uas_work);
 499         }
 500
 501         return 0;
 502 }
 503
 504 static DEF_SCSI_QCMD(uas_queuecommand)
 505
 506 static int uas_eh_abort_handler(struct scsi_cmnd *cmnd)
 507 {
 508         struct scsi_device *sdev = cmnd->device;
 509         sdev_printk(KERN_INFO, sdev, "%s tag %d\n", __func__,
 510                                                         cmnd->request->tag);
 511
 512 /* XXX: Send ABORT TASK Task Management command */
 513         return FAILED;
 514 }
 515
 516 static int uas_eh_device_reset_handler(struct scsi_cmnd *cmnd)
 517 {
 518         struct scsi_device *sdev = cmnd->device;
 519         sdev_printk(KERN_INFO, sdev, "%s tag %d\n", __func__,
 520                                                         cmnd->request->tag);
 521
 522 /* XXX: Send LOGICAL UNIT RESET Task Management command */
 523         return FAILED;
 524 }
 525
 526 static int uas_eh_target_reset_handler(struct scsi_cmnd *cmnd)
 527 {
 528         struct scsi_device *sdev = cmnd->device;
 529         sdev_printk(KERN_INFO, sdev, "%s tag %d\n", __func__,
 530                                                         cmnd->request->tag);
 531
 532 /* XXX: Can we reset just the one USB interface?
 533  * Would calling usb_set_interface() have the right effect?
 534  */
 535         return FAILED;
 536 }
 537
 538 static int uas_eh_bus_reset_handler(struct scsi_cmnd *cmnd)
 539 {
 540         struct scsi_device *sdev = cmnd->device;
 541         struct uas_dev_info *devinfo = sdev->hostdata;
 542         struct usb_device *udev = devinfo->udev;
 543
 544         sdev_printk(KERN_INFO, sdev, "%s tag %d\n", __func__,
 545                                                         cmnd->request->tag);
 546
 547         if (usb_reset_device(udev))
 548                 return SUCCESS;
 549
 550         return FAILED;
 551 }
 552
 553 static int uas_slave_alloc(struct scsi_device *sdev)
 554 {
 555         sdev->hostdata = (void *)sdev->host->hostdata[0];
 556         return 0;
 557 }
 558
 559 static int uas_slave_configure(struct scsi_device *sdev)
 560 {
 561         struct uas_dev_info *devinfo = sdev->hostdata;
 562         scsi_set_tag_type(sdev, MSG_ORDERED_TAG);
 563         scsi_activate_tcq(sdev, devinfo->qdepth - 1);
 564         return 0;
 565 }
 566
 567 static struct scsi_host_template uas_host_template = {
 568         .module = THIS_MODULE,
 569         .name = "uas",
 570         .queuecommand = uas_queuecommand,
 571         .slave_alloc = uas_slave_alloc,
 572         .slave_configure = uas_slave_configure,
 573         .eh_abort_handler = uas_eh_abort_handler,
 574         .eh_device_reset_handler = uas_eh_device_reset_handler,
 575         .eh_target_reset_handler = uas_eh_target_reset_handler,
 576         .eh_bus_reset_handler = uas_eh_bus_reset_handler,
 577         .can_queue = 65536,     /* Is there a limit on the _host_ ? */
 578         .this_id = -1,
 579         .sg_tablesize = SG_NONE,
 580         .cmd_per_lun = 1,       /* until we override it */
 581         .skip_settle_delay = 1,
 582         .ordered_tag = 1,
 583 };
 584
 585 static struct usb_device_id uas_usb_ids[] = {
 586         { USB_INTERFACE_INFO(USB_CLASS_MASS_STORAGE, USB_SC_SCSI, USB_PR_BULK) },
 587         { USB_INTERFACE_INFO(USB_CLASS_MASS_STORAGE, USB_SC_SCSI, USB_PR_UAS) },
 588         /* 0xaa is a prototype device I happen to have access to */
 589         { USB_INTERFACE_INFO(USB_CLASS_MASS_STORAGE, USB_SC_SCSI, 0xaa) },
 590         { }
 591 };
 592 MODULE_DEVICE_TABLE(usb, uas_usb_ids);
 593
 594 static int uas_is_interface(struct usb_host_interface *intf)
 595 {
 596         return (intf->desc.bInterfaceClass == USB_CLASS_MASS_STORAGE &&
 597                 intf->desc.bInterfaceSubClass == USB_SC_SCSI &&
 598                 intf->desc.bInterfaceProtocol == USB_PR_UAS);
 599 }
 600
 601 static int uas_switch_interface(struct usb_device *udev,
 602                                                 struct usb_interface *intf)
 603 {
 604         int i;
 605
 606         if (uas_is_interface(intf->cur_altsetting))
 607                 return 0;
 608
 609         for (i = 0; i < intf->num_altsetting; i++) {
 610                 struct usb_host_interface *alt = &intf->altsetting[i];
 611                 if (alt == intf->cur_altsetting)
 612                         continue;
 613                 if (uas_is_interface(alt))
 614                         return usb_set_interface(udev,
 615                                                 alt->desc.bInterfaceNumber,
 616                                                 alt->desc.bAlternateSetting);
 617         }
 618
 619         return -ENODEV;
 620 }
 621
 622 static void uas_configure_endpoints(struct uas_dev_info *devinfo)
 623 {
 624         struct usb_host_endpoint *eps[4] = { };
 625         struct usb_interface *intf = devinfo->intf;
 626         struct usb_device *udev = devinfo->udev;
 627         struct usb_host_endpoint *endpoint = intf->cur_altsetting->endpoint;
 628         unsigned i, n_endpoints = intf->cur_altsetting->desc.bNumEndpoints;
 629
 630         devinfo->uas_sense_old = 0;
 631
 632         for (i = 0; i < n_endpoints; i++) {
 633                 unsigned char *extra = endpoint[i].extra;
 634                 int len = endpoint[i].extralen;
 635                 while (len > 1) {
 636                         if (extra[1] == USB_DT_PIPE_USAGE) {
 637                                 unsigned pipe_id = extra[2];
 638                                 if (pipe_id > 0 && pipe_id < 5)
 639                                         eps[pipe_id - 1] = &endpoint[i];
 640                                 break;
 641                         }
 642                         len -= extra[0];
 643                         extra += extra[0];
 644                 }
 645         }
 646
 647         /*
 648          * Assume that if we didn't find a control pipe descriptor, we're
 649          * using a device with old firmware that happens to be set up like
 650          * this.
 651          */
 652         if (!eps[0]) {
 653                 devinfo->cmd_pipe = usb_sndbulkpipe(udev, 1);
 654                 devinfo->status_pipe = usb_rcvbulkpipe(udev, 1);
 655                 devinfo->data_in_pipe = usb_rcvbulkpipe(udev, 2);
 656                 devinfo->data_out_pipe = usb_sndbulkpipe(udev, 2);
 657
 658                 eps[1] = usb_pipe_endpoint(udev, devinfo->status_pipe);
 659                 eps[2] = usb_pipe_endpoint(udev, devinfo->data_in_pipe);
 660                 eps[3] = usb_pipe_endpoint(udev, devinfo->data_out_pipe);
 661         } else {
 662                 devinfo->cmd_pipe = usb_sndbulkpipe(udev,
 663                                                 eps[0]->desc.bEndpointAddress);
 664                 devinfo->status_pipe = usb_rcvbulkpipe(udev,
 665                                                 eps[1]->desc.bEndpointAddress);
 666                 devinfo->data_in_pipe = usb_rcvbulkpipe(udev,
 667                                                 eps[2]->desc.bEndpointAddress);
 668                 devinfo->data_out_pipe = usb_sndbulkpipe(udev,
 669                                                 eps[3]->desc.bEndpointAddress);
 670         }
 671
 672         devinfo->qdepth = usb_alloc_streams(devinfo->intf, eps + 1, 3, 256,
 673                                                                 GFP_KERNEL);
 674         if (devinfo->qdepth < 0) {
 675                 devinfo->qdepth = 256;
 676                 devinfo->use_streams = 0;
 677         } else {
 678                 devinfo->use_streams = 1;
 679         }
 680 }
 681
 682 /*
 683  * XXX: What I'd like to do here is register a SCSI host for each USB host in
 684  * the system.  Follow usb-storage's design of registering a SCSI host for
 685  * each USB device for the moment.  Can implement this by walking up the
 686  * USB hierarchy until we find a USB host.
 687  */
 688 static int uas_probe(struct usb_interface *intf, const struct usb_device_id *id)
 689 {
 690         int result;
 691         struct Scsi_Host *shost;
 692         struct uas_dev_info *devinfo;
 693         struct usb_device *udev = interface_to_usbdev(intf);
 694
 695         if (uas_switch_interface(udev, intf))
 696                 return -ENODEV;
 697
 698         devinfo = kmalloc(sizeof(struct uas_dev_info), GFP_KERNEL);
 699         if (!devinfo)
 700                 return -ENOMEM;
 701
 702         result = -ENOMEM;
 703         shost = scsi_host_alloc(&uas_host_template, sizeof(void *));
 704         if (!shost)
 705                 goto free;
 706
 707         shost->max_cmd_len = 16 + 252;
 708         shost->max_id = 1;
 709         shost->sg_tablesize = udev->bus->sg_tablesize;
 710
 711         result = scsi_add_host(shost, &intf->dev);
 712         if (result)
 713                 goto free;
 714         shost->hostdata[0] = (unsigned long)devinfo;
 715
 716         devinfo->intf = intf;
 717         devinfo->udev = udev;
 718         uas_configure_endpoints(devinfo);
 719
 720         scsi_scan_host(shost);
 721         usb_set_intfdata(intf, shost);
 722         return result;
 723  free:
 724         kfree(devinfo);
 725         if (shost)
 726                 scsi_host_put(shost);
 727         return result;
 728 }
 729
 730 static int uas_pre_reset(struct usb_interface *intf)
 731 {
 732 /* XXX: Need to return 1 if it's not our device in error handling */
 733         return 0;
 734 }
 735
 736 static int uas_post_reset(struct usb_interface *intf)
 737 {
 738 /* XXX: Need to return 1 if it's not our device in error handling */
 739         return 0;
 740 }
 741
 742 static void uas_disconnect(struct usb_interface *intf)
 743 {
 744         struct usb_device *udev = interface_to_usbdev(intf);
 745         struct usb_host_endpoint *eps[3];
 746         struct Scsi_Host *shost = usb_get_intfdata(intf);
 747         struct uas_dev_info *devinfo = (void *)shost->hostdata[0];
 748
 749         scsi_remove_host(shost);
 750
 751         eps[0] = usb_pipe_endpoint(udev, devinfo->status_pipe);
 752         eps[1] = usb_pipe_endpoint(udev, devinfo->data_in_pipe);
 753         eps[2] = usb_pipe_endpoint(udev, devinfo->data_out_pipe);
 754         usb_free_streams(intf, eps, 3, GFP_KERNEL);
 755
 756         kfree(devinfo);
 757 }
 758
 759 /*
 760  * XXX: Should this plug into libusual so we can auto-upgrade devices from
 761  * Bulk-Only to UAS?
 762  */
 763 static struct usb_driver uas_driver = {
 764         .name = "uas",
 765         .probe = uas_probe,
 766         .disconnect = uas_disconnect,
 767         .pre_reset = uas_pre_reset,
 768         .post_reset = uas_post_reset,
 769         .id_table = uas_usb_ids,
 770 };
 771
 772 static int uas_init(void)
 773 {
 774         return usb_register(&uas_driver);
 775 }
 776
 777 static void uas_exit(void)
 778 {
 779         usb_deregister(&uas_driver);
 780 }
 781
 782 module_init(uas_init);
 783 module_exit(uas_exit);
 784
 785 MODULE_LICENSE("GPL");
 786 MODULE_AUTHOR("Matthew Wilcox and Sarah Sharp");