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