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