drivers/usb/storage/uas.c

   1 /*
   2  * USB Attached SCSI
   3  * Note that this is not the same as the USB Mass Storage driver
   4  *
   5  * Copyright Matthew Wilcox for Intel Corp, 2010
   6  * Copyright Sarah Sharp for Intel Corp, 2010
   7  *
   8  * Distributed under the terms of the GNU GPL, version two.
   9  */
  10
  11 #include <linux/blkdev.h>
  12 #include <linux/slab.h>
  13 #include <linux/types.h>
  14 #include <linux/module.h>
  15 #include <linux/usb.h>
  16 #include <linux/usb/hcd.h>
  17 #include <linux/usb/storage.h>
  18 #include <linux/usb/uas.h>
  19
  20 #include <scsi/scsi.h>
  21 #include <scsi/scsi_dbg.h>
  22 #include <scsi/scsi_cmnd.h>
  23 #include <scsi/scsi_device.h>
  24 #include <scsi/scsi_host.h>
  25 #include <scsi/scsi_tcq.h>
  26
  27 /*
  28  * The r00-r01c specs define this version of the SENSE IU data structure.
  29  * It's still in use by several different firmware releases.
  30  */
  31 struct sense_iu_old {
  32         __u8 iu_id;
  33         __u8 rsvd1;
  34         __be16 tag;
  35         __be16 len;
  36         __u8 status;
  37         __u8 service_response;
  38         __u8 sense[SCSI_SENSE_BUFFERSIZE];
  39 };
  40
  41 struct uas_dev_info {
  42         struct usb_interface *intf;
  43         struct usb_device *udev;
  44         int qdepth;
  45         unsigned cmd_pipe, status_pipe, data_in_pipe, data_out_pipe;
  46         unsigned use_streams:1;
  47         unsigned uas_sense_old:1;
  48         struct scsi_cmnd *cmnd;
  49         struct urb *status_urb; /* used only if stream support is available */
  50 };
  51
  52 enum {
  53         ALLOC_STATUS_URB        = (1 << 0),
  54         SUBMIT_STATUS_URB       = (1 << 1),
  55         ALLOC_DATA_IN_URB       = (1 << 2),
  56         SUBMIT_DATA_IN_URB      = (1 << 3),
  57         ALLOC_DATA_OUT_URB      = (1 << 4),
  58         SUBMIT_DATA_OUT_URB     = (1 << 5),
  59         ALLOC_CMD_URB           = (1 << 6),
  60         SUBMIT_CMD_URB          = (1 << 7),
  61 };
  62
  63 /* Overrides scsi_pointer */
  64 struct uas_cmd_info {
  65         unsigned int state;
  66         unsigned int stream;
  67         struct urb *cmd_urb;
  68         /* status_urb is used only if stream support isn't available */
  69         struct urb *status_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         cmnd->scsi_done(cmnd);
 132 }
 133
 134 static void uas_sense_old(struct urb *urb, struct scsi_cmnd *cmnd)
 135 {
 136         struct sense_iu_old *sense_iu = urb->transfer_buffer;
 137         struct scsi_device *sdev = cmnd->device;
 138
 139         if (urb->actual_length > 8) {
 140                 unsigned len = be16_to_cpup(&sense_iu->len) - 2;
 141                 if (len + 8 != urb->actual_length) {
 142                         int newlen = min(len + 8, urb->actual_length) - 8;
 143                         if (newlen < 0)
 144                                 newlen = 0;
 145                         sdev_printk(KERN_INFO, sdev, "%s: urb length %d "
 146                                 "disagrees with IU sense data length %d, "
 147                                 "using %d bytes of sense data\n", __func__,
 148                                         urb->actual_length, len, newlen);
 149                         len = newlen;
 150                 }
 151                 memcpy(cmnd->sense_buffer, sense_iu->sense, len);
 152         }
 153
 154         cmnd->result = sense_iu->status;
 155         cmnd->scsi_done(cmnd);
 156 }
 157
 158 static void uas_xfer_data(struct urb *urb, struct scsi_cmnd *cmnd,
 159                                                         unsigned direction)
 160 {
 161         struct uas_cmd_info *cmdinfo = (void *)&cmnd->SCp;
 162         int err;
 163
 164         cmdinfo->state = direction;
 165         err = uas_submit_urbs(cmnd, cmnd->device->hostdata, GFP_ATOMIC);
 166         if (err) {
 167                 spin_lock(&uas_work_lock);
 168                 list_add_tail(&cmdinfo->list, &uas_work_list);
 169                 spin_unlock(&uas_work_lock);
 170                 schedule_work(&uas_work);
 171         }
 172 }
 173
 174 static void uas_stat_cmplt(struct urb *urb)
 175 {
 176         struct iu *iu = urb->transfer_buffer;
 177         struct Scsi_Host *shost = urb->context;
 178         struct uas_dev_info *devinfo = (void *)shost->hostdata[0];
 179         struct scsi_cmnd *cmnd;
 180         u16 tag;
 181         int ret;
 182
 183         if (urb->status) {
 184                 dev_err(&urb->dev->dev, "URB BAD STATUS %d\n", urb->status);
 185                 if (devinfo->use_streams)
 186                         usb_free_urb(urb);
 187                 return;
 188         }
 189
 190         tag = be16_to_cpup(&iu->tag) - 1;
 191         if (tag == 0)
 192                 cmnd = devinfo->cmnd;
 193         else
 194                 cmnd = scsi_host_find_tag(shost, tag - 1);
 195         if (!cmnd) {
 196                 if (devinfo->use_streams) {
 197                         usb_free_urb(urb);
 198                         return;
 199                 }
 200                 ret = usb_submit_urb(urb, GFP_ATOMIC);
 201                 if (ret)
 202                         dev_err(&urb->dev->dev, "failed submit status urb\n");
 203                 return;
 204         }
 205
 206         switch (iu->iu_id) {
 207         case IU_ID_STATUS:
 208                 if (devinfo->cmnd == cmnd)
 209                         devinfo->cmnd = NULL;
 210
 211                 if (urb->actual_length < 16)
 212                         devinfo->uas_sense_old = 1;
 213                 if (devinfo->uas_sense_old)
 214                         uas_sense_old(urb, cmnd);
 215                 else
 216                         uas_sense(urb, cmnd);
 217                 break;
 218         case IU_ID_READ_READY:
 219                 uas_xfer_data(urb, cmnd, SUBMIT_DATA_IN_URB);
 220                 break;
 221         case IU_ID_WRITE_READY:
 222                 uas_xfer_data(urb, cmnd, SUBMIT_DATA_OUT_URB);
 223                 break;
 224         default:
 225                 scmd_printk(KERN_ERR, cmnd,
 226                         "Bogus IU (%d) received on status pipe\n", iu->iu_id);
 227         }
 228
 229         if (devinfo->use_streams) {
 230                 usb_free_urb(urb);
 231                 return;
 232         }
 233
 234         ret = usb_submit_urb(urb, GFP_ATOMIC);
 235         if (ret)
 236                 dev_err(&urb->dev->dev, "failed submit status urb\n");
 237 }
 238
 239 static void uas_data_cmplt(struct urb *urb)
 240 {
 241         struct scsi_data_buffer *sdb = urb->context;
 242         sdb->resid = sdb->length - urb->actual_length;
 243         usb_free_urb(urb);
 244 }
 245
 246 static struct urb *uas_alloc_data_urb(struct uas_dev_info *devinfo, gfp_t gfp,
 247                                 unsigned int pipe, u16 stream_id,
 248                                 struct scsi_data_buffer *sdb,
 249                                 enum dma_data_direction dir)
 250 {
 251         struct usb_device *udev = devinfo->udev;
 252         struct urb *urb = usb_alloc_urb(0, gfp);
 253
 254         if (!urb)
 255                 goto out;
 256         usb_fill_bulk_urb(urb, udev, pipe, NULL, sdb->length, uas_data_cmplt,
 257                                                                         sdb);
 258         if (devinfo->use_streams)
 259                 urb->stream_id = stream_id;
 260         urb->num_sgs = udev->bus->sg_tablesize ? sdb->table.nents : 0;
 261         urb->sg = sdb->table.sgl;
 262  out:
 263         return urb;
 264 }
 265
 266 static struct urb *uas_alloc_sense_urb(struct uas_dev_info *devinfo, gfp_t gfp,
 267                 struct Scsi_Host *shost, u16 stream_id)
 268 {
 269         struct usb_device *udev = devinfo->udev;
 270         struct urb *urb = usb_alloc_urb(0, gfp);
 271         struct sense_iu *iu;
 272
 273         if (!urb)
 274                 goto out;
 275
 276         iu = kzalloc(sizeof(*iu), gfp);
 277         if (!iu)
 278                 goto free;
 279
 280         usb_fill_bulk_urb(urb, udev, devinfo->status_pipe, iu, sizeof(*iu),
 281                                                 uas_stat_cmplt, shost);
 282         urb->stream_id = stream_id;
 283         urb->transfer_flags |= URB_FREE_BUFFER;
 284  out:
 285         return urb;
 286  free:
 287         usb_free_urb(urb);
 288         return NULL;
 289 }
 290
 291 static struct urb *uas_alloc_cmd_urb(struct uas_dev_info *devinfo, gfp_t gfp,
 292                                         struct scsi_cmnd *cmnd, u16 stream_id)
 293 {
 294         struct usb_device *udev = devinfo->udev;
 295         struct scsi_device *sdev = cmnd->device;
 296         struct urb *urb = usb_alloc_urb(0, gfp);
 297         struct command_iu *iu;
 298         int len;
 299
 300         if (!urb)
 301                 goto out;
 302
 303         len = cmnd->cmd_len - 16;
 304         if (len < 0)
 305                 len = 0;
 306         len = ALIGN(len, 4);
 307         iu = kzalloc(sizeof(*iu) + len, gfp);
 308         if (!iu)
 309                 goto free;
 310
 311         iu->iu_id = IU_ID_COMMAND;
 312         if (blk_rq_tagged(cmnd->request))
 313                 iu->tag = cpu_to_be16(cmnd->request->tag + 2);
 314         else
 315                 iu->tag = cpu_to_be16(1);
 316         iu->prio_attr = UAS_SIMPLE_TAG;
 317         iu->len = len;
 318         int_to_scsilun(sdev->lun, &iu->lun);
 319         memcpy(iu->cdb, cmnd->cmnd, cmnd->cmd_len);
 320
 321         usb_fill_bulk_urb(urb, udev, devinfo->cmd_pipe, iu, sizeof(*iu) + len,
 322                                                         usb_free_urb, NULL);
 323         urb->transfer_flags |= URB_FREE_BUFFER;
 324  out:
 325         return urb;
 326  free:
 327         usb_free_urb(urb);
 328         return NULL;
 329 }
 330
 331 /*
 332  * Why should I request the Status IU before sending the Command IU?  Spec
 333  * says to, but also says the device may receive them in any order.  Seems
 334  * daft to me.
 335  */
 336
 337 static int uas_submit_urbs(struct scsi_cmnd *cmnd,
 338                                         struct uas_dev_info *devinfo, gfp_t gfp)
 339 {
 340         struct uas_cmd_info *cmdinfo = (void *)&cmnd->SCp;
 341
 342         if (cmdinfo->state & ALLOC_STATUS_URB) {
 343                 cmdinfo->status_urb = uas_alloc_sense_urb(devinfo, gfp,
 344                                 cmnd->device->host, cmdinfo->stream);
 345                 if (!cmdinfo->status_urb)
 346                         return SCSI_MLQUEUE_DEVICE_BUSY;
 347                 cmdinfo->state &= ~ALLOC_STATUS_URB;
 348         }
 349
 350         if (cmdinfo->state & SUBMIT_STATUS_URB) {
 351                 if (usb_submit_urb(cmdinfo->status_urb, gfp)) {
 352                         scmd_printk(KERN_INFO, cmnd,
 353                                         "sense urb submission failure\n");
 354                         return SCSI_MLQUEUE_DEVICE_BUSY;
 355                 }
 356                 cmdinfo->state &= ~SUBMIT_STATUS_URB;
 357         }
 358
 359         if (cmdinfo->state & ALLOC_DATA_IN_URB) {
 360                 cmdinfo->data_in_urb = uas_alloc_data_urb(devinfo, gfp,
 361                                         devinfo->data_in_pipe, cmdinfo->stream,
 362                                         scsi_in(cmnd), DMA_FROM_DEVICE);
 363                 if (!cmdinfo->data_in_urb)
 364                         return SCSI_MLQUEUE_DEVICE_BUSY;
 365                 cmdinfo->state &= ~ALLOC_DATA_IN_URB;
 366         }
 367
 368         if (cmdinfo->state & SUBMIT_DATA_IN_URB) {
 369                 if (usb_submit_urb(cmdinfo->data_in_urb, gfp)) {
 370                         scmd_printk(KERN_INFO, cmnd,
 371                                         "data in urb submission failure\n");
 372                         return SCSI_MLQUEUE_DEVICE_BUSY;
 373                 }
 374                 cmdinfo->state &= ~SUBMIT_DATA_IN_URB;
 375         }
 376
 377         if (cmdinfo->state & ALLOC_DATA_OUT_URB) {
 378                 cmdinfo->data_out_urb = uas_alloc_data_urb(devinfo, gfp,
 379                                         devinfo->data_out_pipe, cmdinfo->stream,
 380                                         scsi_out(cmnd), DMA_TO_DEVICE);
 381                 if (!cmdinfo->data_out_urb)
 382                         return SCSI_MLQUEUE_DEVICE_BUSY;
 383                 cmdinfo->state &= ~ALLOC_DATA_OUT_URB;
 384         }
 385
 386         if (cmdinfo->state & SUBMIT_DATA_OUT_URB) {
 387                 if (usb_submit_urb(cmdinfo->data_out_urb, gfp)) {
 388                         scmd_printk(KERN_INFO, cmnd,
 389                                         "data out urb submission failure\n");
 390                         return SCSI_MLQUEUE_DEVICE_BUSY;
 391                 }
 392                 cmdinfo->state &= ~SUBMIT_DATA_OUT_URB;
 393         }
 394
 395         if (cmdinfo->state & ALLOC_CMD_URB) {
 396                 cmdinfo->cmd_urb = uas_alloc_cmd_urb(devinfo, gfp, cmnd,
 397                                                         cmdinfo->stream);
 398                 if (!cmdinfo->cmd_urb)
 399                         return SCSI_MLQUEUE_DEVICE_BUSY;
 400                 cmdinfo->state &= ~ALLOC_CMD_URB;
 401         }
 402
 403         if (cmdinfo->state & SUBMIT_CMD_URB) {
 404                 if (usb_submit_urb(cmdinfo->cmd_urb, gfp)) {
 405                         scmd_printk(KERN_INFO, cmnd,
 406                                         "cmd urb submission failure\n");
 407                         return SCSI_MLQUEUE_DEVICE_BUSY;
 408                 }
 409                 cmdinfo->state &= ~SUBMIT_CMD_URB;
 410         }
 411
 412         return 0;
 413 }
 414
 415 static int uas_queuecommand_lck(struct scsi_cmnd *cmnd,
 416                                         void (*done)(struct scsi_cmnd *))
 417 {
 418         struct scsi_device *sdev = cmnd->device;
 419         struct uas_dev_info *devinfo = sdev->hostdata;
 420         struct uas_cmd_info *cmdinfo = (void *)&cmnd->SCp;
 421         int err;
 422
 423         BUILD_BUG_ON(sizeof(struct uas_cmd_info) > sizeof(struct scsi_pointer));
 424
 425         if (devinfo->cmnd)
 426                 return SCSI_MLQUEUE_DEVICE_BUSY;
 427
 428         if (blk_rq_tagged(cmnd->request)) {
 429                 cmdinfo->stream = cmnd->request->tag + 2;
 430         } else {
 431                 devinfo->cmnd = cmnd;
 432                 cmdinfo->stream = 1;
 433         }
 434
 435         cmnd->scsi_done = done;
 436
 437         cmdinfo->state = ALLOC_STATUS_URB | SUBMIT_STATUS_URB |
 438                         ALLOC_CMD_URB | SUBMIT_CMD_URB;
 439
 440         switch (cmnd->sc_data_direction) {
 441         case DMA_FROM_DEVICE:
 442                 cmdinfo->state |= ALLOC_DATA_IN_URB | SUBMIT_DATA_IN_URB;
 443                 break;
 444         case DMA_BIDIRECTIONAL:
 445                 cmdinfo->state |= ALLOC_DATA_IN_URB | SUBMIT_DATA_IN_URB;
 446         case DMA_TO_DEVICE:
 447                 cmdinfo->state |= ALLOC_DATA_OUT_URB | SUBMIT_DATA_OUT_URB;
 448         case DMA_NONE:
 449                 break;
 450         }
 451
 452         if (!devinfo->use_streams) {
 453                 cmdinfo->state &= ~(SUBMIT_DATA_IN_URB | SUBMIT_DATA_OUT_URB |
 454                                 ALLOC_STATUS_URB | SUBMIT_STATUS_URB);
 455                 cmdinfo->stream = 0;
 456         }
 457
 458         err = uas_submit_urbs(cmnd, devinfo, GFP_ATOMIC);
 459         if (err) {
 460                 /* If we did nothing, give up now */
 461                 if (cmdinfo->state & SUBMIT_STATUS_URB) {
 462                         usb_free_urb(cmdinfo->status_urb);
 463                         return SCSI_MLQUEUE_DEVICE_BUSY;
 464                 }
 465                 spin_lock(&uas_work_lock);
 466                 list_add_tail(&cmdinfo->list, &uas_work_list);
 467                 spin_unlock(&uas_work_lock);
 468                 schedule_work(&uas_work);
 469         }
 470
 471         return 0;
 472 }
 473
 474 static DEF_SCSI_QCMD(uas_queuecommand)
 475
 476 static int uas_eh_abort_handler(struct scsi_cmnd *cmnd)
 477 {
 478         struct scsi_device *sdev = cmnd->device;
 479         sdev_printk(KERN_INFO, sdev, "%s tag %d\n", __func__,
 480                                                         cmnd->request->tag);
 481
 482 /* XXX: Send ABORT TASK Task Management command */
 483         return FAILED;
 484 }
 485
 486 static int uas_eh_device_reset_handler(struct scsi_cmnd *cmnd)
 487 {
 488         struct scsi_device *sdev = cmnd->device;
 489         sdev_printk(KERN_INFO, sdev, "%s tag %d\n", __func__,
 490                                                         cmnd->request->tag);
 491
 492 /* XXX: Send LOGICAL UNIT RESET Task Management command */
 493         return FAILED;
 494 }
 495
 496 static int uas_eh_target_reset_handler(struct scsi_cmnd *cmnd)
 497 {
 498         struct scsi_device *sdev = cmnd->device;
 499         sdev_printk(KERN_INFO, sdev, "%s tag %d\n", __func__,
 500                                                         cmnd->request->tag);
 501
 502 /* XXX: Can we reset just the one USB interface?
 503  * Would calling usb_set_interface() have the right effect?
 504  */
 505         return FAILED;
 506 }
 507
 508 static int uas_eh_bus_reset_handler(struct scsi_cmnd *cmnd)
 509 {
 510         struct scsi_device *sdev = cmnd->device;
 511         struct uas_dev_info *devinfo = sdev->hostdata;
 512         struct usb_device *udev = devinfo->udev;
 513
 514         sdev_printk(KERN_INFO, sdev, "%s tag %d\n", __func__,
 515                                                         cmnd->request->tag);
 516
 517         if (usb_reset_device(udev))
 518                 return SUCCESS;
 519
 520         return FAILED;
 521 }
 522
 523 static int uas_slave_alloc(struct scsi_device *sdev)
 524 {
 525         sdev->hostdata = (void *)sdev->host->hostdata[0];
 526         return 0;
 527 }
 528
 529 static int uas_slave_configure(struct scsi_device *sdev)
 530 {
 531         struct uas_dev_info *devinfo = sdev->hostdata;
 532         scsi_set_tag_type(sdev, MSG_ORDERED_TAG);
 533         scsi_activate_tcq(sdev, devinfo->qdepth - 2);
 534         return 0;
 535 }
 536
 537 static struct scsi_host_template uas_host_template = {
 538         .module = THIS_MODULE,
 539         .name = "uas",
 540         .queuecommand = uas_queuecommand,
 541         .slave_alloc = uas_slave_alloc,
 542         .slave_configure = uas_slave_configure,
 543         .eh_abort_handler = uas_eh_abort_handler,
 544         .eh_device_reset_handler = uas_eh_device_reset_handler,
 545         .eh_target_reset_handler = uas_eh_target_reset_handler,
 546         .eh_bus_reset_handler = uas_eh_bus_reset_handler,
 547         .can_queue = 65536,     /* Is there a limit on the _host_ ? */
 548         .this_id = -1,
 549         .sg_tablesize = SG_NONE,
 550         .cmd_per_lun = 1,       /* until we override it */
 551         .skip_settle_delay = 1,
 552         .ordered_tag = 1,
 553 };
 554
 555 static struct usb_device_id uas_usb_ids[] = {
 556         { USB_INTERFACE_INFO(USB_CLASS_MASS_STORAGE, USB_SC_SCSI, USB_PR_BULK) },
 557         { USB_INTERFACE_INFO(USB_CLASS_MASS_STORAGE, USB_SC_SCSI, USB_PR_UAS) },
 558         /* 0xaa is a prototype device I happen to have access to */
 559         { USB_INTERFACE_INFO(USB_CLASS_MASS_STORAGE, USB_SC_SCSI, 0xaa) },
 560         { }
 561 };
 562 MODULE_DEVICE_TABLE(usb, uas_usb_ids);
 563
 564 static int uas_is_interface(struct usb_host_interface *intf)
 565 {
 566         return (intf->desc.bInterfaceClass == USB_CLASS_MASS_STORAGE &&
 567                 intf->desc.bInterfaceSubClass == USB_SC_SCSI &&
 568                 intf->desc.bInterfaceProtocol == USB_PR_UAS);
 569 }
 570
 571 static int uas_isnt_supported(struct usb_device *udev)
 572 {
 573         struct usb_hcd *hcd = bus_to_hcd(udev->bus);
 574
 575         dev_warn(&udev->dev, "The driver for the USB controller %s does not "
 576                         "support scatter-gather which is\n",
 577                         hcd->driver->description);
 578         dev_warn(&udev->dev, "required by the UAS driver. Please try an"
 579                         "alternative USB controller if you wish to use UAS.\n");
 580         return -ENODEV;
 581 }
 582
 583 static int uas_switch_interface(struct usb_device *udev,
 584                                                 struct usb_interface *intf)
 585 {
 586         int i;
 587         int sg_supported = udev->bus->sg_tablesize != 0;
 588
 589         for (i = 0; i < intf->num_altsetting; i++) {
 590                 struct usb_host_interface *alt = &intf->altsetting[i];
 591
 592                 if (uas_is_interface(alt)) {
 593                         if (!sg_supported)
 594                                 return uas_isnt_supported(udev);
 595                         return usb_set_interface(udev,
 596                                                 alt->desc.bInterfaceNumber,
 597                                                 alt->desc.bAlternateSetting);
 598                 }
 599         }
 600
 601         return -ENODEV;
 602 }
 603
 604 static void uas_configure_endpoints(struct uas_dev_info *devinfo)
 605 {
 606         struct usb_host_endpoint *eps[4] = { };
 607         struct usb_interface *intf = devinfo->intf;
 608         struct usb_device *udev = devinfo->udev;
 609         struct usb_host_endpoint *endpoint = intf->cur_altsetting->endpoint;
 610         unsigned i, n_endpoints = intf->cur_altsetting->desc.bNumEndpoints;
 611
 612         devinfo->uas_sense_old = 0;
 613         devinfo->cmnd = NULL;
 614
 615         for (i = 0; i < n_endpoints; i++) {
 616                 unsigned char *extra = endpoint[i].extra;
 617                 int len = endpoint[i].extralen;
 618                 while (len > 1) {
 619                         if (extra[1] == USB_DT_PIPE_USAGE) {
 620                                 unsigned pipe_id = extra[2];
 621                                 if (pipe_id > 0 && pipe_id < 5)
 622                                         eps[pipe_id - 1] = &endpoint[i];
 623                                 break;
 624                         }
 625                         len -= extra[0];
 626                         extra += extra[0];
 627                 }
 628         }
 629
 630         /*
 631          * Assume that if we didn't find a control pipe descriptor, we're
 632          * using a device with old firmware that happens to be set up like
 633          * this.
 634          */
 635         if (!eps[0]) {
 636                 devinfo->cmd_pipe = usb_sndbulkpipe(udev, 1);
 637                 devinfo->status_pipe = usb_rcvbulkpipe(udev, 1);
 638                 devinfo->data_in_pipe = usb_rcvbulkpipe(udev, 2);
 639                 devinfo->data_out_pipe = usb_sndbulkpipe(udev, 2);
 640
 641                 eps[1] = usb_pipe_endpoint(udev, devinfo->status_pipe);
 642                 eps[2] = usb_pipe_endpoint(udev, devinfo->data_in_pipe);
 643                 eps[3] = usb_pipe_endpoint(udev, devinfo->data_out_pipe);
 644         } else {
 645                 devinfo->cmd_pipe = usb_sndbulkpipe(udev,
 646                                                 eps[0]->desc.bEndpointAddress);
 647                 devinfo->status_pipe = usb_rcvbulkpipe(udev,
 648                                                 eps[1]->desc.bEndpointAddress);
 649                 devinfo->data_in_pipe = usb_rcvbulkpipe(udev,
 650                                                 eps[2]->desc.bEndpointAddress);
 651                 devinfo->data_out_pipe = usb_sndbulkpipe(udev,
 652                                                 eps[3]->desc.bEndpointAddress);
 653         }
 654
 655         devinfo->qdepth = usb_alloc_streams(devinfo->intf, eps + 1, 3, 256,
 656                                                                 GFP_KERNEL);
 657         if (devinfo->qdepth < 0) {
 658                 devinfo->qdepth = 256;
 659                 devinfo->use_streams = 0;
 660         } else {
 661                 devinfo->use_streams = 1;
 662         }
 663 }
 664
 665 static int uas_alloc_status_urb(struct uas_dev_info *devinfo,
 666                 struct Scsi_Host *shost)
 667 {
 668         if (devinfo->use_streams) {
 669                 devinfo->status_urb = NULL;
 670                 return 0;
 671         }
 672
 673         devinfo->status_urb = uas_alloc_sense_urb(devinfo, GFP_KERNEL,
 674                         shost, 0);
 675         if (!devinfo->status_urb)
 676                 goto err_s_urb;
 677
 678         if (usb_submit_urb(devinfo->status_urb, GFP_KERNEL))
 679                 goto err_submit_urb;
 680
 681         return 0;
 682 err_submit_urb:
 683         usb_free_urb(devinfo->status_urb);
 684 err_s_urb:
 685         return -ENOMEM;
 686 }
 687
 688 static void uas_free_streams(struct uas_dev_info *devinfo)
 689 {
 690         struct usb_device *udev = devinfo->udev;
 691         struct usb_host_endpoint *eps[3];
 692
 693         eps[0] = usb_pipe_endpoint(udev, devinfo->status_pipe);
 694         eps[1] = usb_pipe_endpoint(udev, devinfo->data_in_pipe);
 695         eps[2] = usb_pipe_endpoint(udev, devinfo->data_out_pipe);
 696         usb_free_streams(devinfo->intf, eps, 3, GFP_KERNEL);
 697 }
 698
 699 /*
 700  * XXX: What I'd like to do here is register a SCSI host for each USB host in
 701  * the system.  Follow usb-storage's design of registering a SCSI host for
 702  * each USB device for the moment.  Can implement this by walking up the
 703  * USB hierarchy until we find a USB host.
 704  */
 705 static int uas_probe(struct usb_interface *intf, const struct usb_device_id *id)
 706 {
 707         int result;
 708         struct Scsi_Host *shost;
 709         struct uas_dev_info *devinfo;
 710         struct usb_device *udev = interface_to_usbdev(intf);
 711
 712         if (uas_switch_interface(udev, intf))
 713                 return -ENODEV;
 714
 715         devinfo = kmalloc(sizeof(struct uas_dev_info), GFP_KERNEL);
 716         if (!devinfo)
 717                 return -ENOMEM;
 718
 719         result = -ENOMEM;
 720         shost = scsi_host_alloc(&uas_host_template, sizeof(void *));
 721         if (!shost)
 722                 goto free;
 723
 724         shost->max_cmd_len = 16 + 252;
 725         shost->max_id = 1;
 726         shost->sg_tablesize = udev->bus->sg_tablesize;
 727
 728         devinfo->intf = intf;
 729         devinfo->udev = udev;
 730         uas_configure_endpoints(devinfo);
 731
 732         result = scsi_init_shared_tag_map(shost, devinfo->qdepth - 2);
 733         if (result)
 734                 goto free;
 735
 736         result = scsi_add_host(shost, &intf->dev);
 737         if (result)
 738                 goto deconfig_eps;
 739
 740         shost->hostdata[0] = (unsigned long)devinfo;
 741
 742         result = uas_alloc_status_urb(devinfo, shost);
 743         if (result)
 744                 goto err_alloc_status;
 745
 746         scsi_scan_host(shost);
 747         usb_set_intfdata(intf, shost);
 748         return result;
 749
 750 err_alloc_status:
 751         scsi_remove_host(shost);
 752         shost = NULL;
 753 deconfig_eps:
 754         uas_free_streams(devinfo);
 755  free:
 756         kfree(devinfo);
 757         if (shost)
 758                 scsi_host_put(shost);
 759         return result;
 760 }
 761
 762 static int uas_pre_reset(struct usb_interface *intf)
 763 {
 764 /* XXX: Need to return 1 if it's not our device in error handling */
 765         return 0;
 766 }
 767
 768 static int uas_post_reset(struct usb_interface *intf)
 769 {
 770 /* XXX: Need to return 1 if it's not our device in error handling */
 771         return 0;
 772 }
 773
 774 static void uas_disconnect(struct usb_interface *intf)
 775 {
 776         struct Scsi_Host *shost = usb_get_intfdata(intf);
 777         struct uas_dev_info *devinfo = (void *)shost->hostdata[0];
 778
 779         scsi_remove_host(shost);
 780         usb_kill_urb(devinfo->status_urb);
 781         usb_free_urb(devinfo->status_urb);
 782         uas_free_streams(devinfo);
 783         kfree(devinfo);
 784 }
 785
 786 /*
 787  * XXX: Should this plug into libusual so we can auto-upgrade devices from
 788  * Bulk-Only to UAS?
 789  */
 790 static struct usb_driver uas_driver = {
 791         .name = "uas",
 792         .probe = uas_probe,
 793         .disconnect = uas_disconnect,
 794         .pre_reset = uas_pre_reset,
 795         .post_reset = uas_post_reset,
 796         .id_table = uas_usb_ids,
 797 };
 798
 799 static int uas_init(void)
 800 {
 801         return usb_register(&uas_driver);
 802 }
 803
 804 static void uas_exit(void)
 805 {
 806         usb_deregister(&uas_driver);
 807 }
 808
 809 module_init(uas_init);
 810 module_exit(uas_exit);
 811
 812 MODULE_LICENSE("GPL");
 813 MODULE_AUTHOR("Matthew Wilcox and Sarah Sharp");