drivers/usb/wusbcore/wa-xfer.c

   1 /*
   2  * WUSB Wire Adapter
   3  * Data transfer and URB enqueing
   4  *
   5  * Copyright (C) 2005-2006 Intel Corporation
   6  * Inaky Perez-Gonzalez <inaky.perez-gonzalez@intel.com>
   7  *
   8  * This program is free software; you can redistribute it and/or
   9  * modify it under the terms of the GNU General Public License version
  10  * 2 as published by the Free Software Foundation.
  11  *
  12  * This program is distributed in the hope that it will be useful,
  13  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15  * GNU General Public License for more details.
  16  *
  17  * You should have received a copy of the GNU General Public License
  18  * along with this program; if not, write to the Free Software
  19  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
  20  * 02110-1301, USA.
  21  *
  22  *
  23  * How transfers work: get a buffer, break it up in segments (segment
  24  * size is a multiple of the maxpacket size). For each segment issue a
  25  * segment request (struct wa_xfer_*), then send the data buffer if
  26  * out or nothing if in (all over the DTO endpoint).
  27  *
  28  * For each submitted segment request, a notification will come over
  29  * the NEP endpoint and a transfer result (struct xfer_result) will
  30  * arrive in the DTI URB. Read it, get the xfer ID, see if there is
  31  * data coming (inbound transfer), schedule a read and handle it.
  32  *
  33  * Sounds simple, it is a pain to implement.
  34  *
  35  *
  36  * ENTRY POINTS
  37  *
  38  *   FIXME
  39  *
  40  * LIFE CYCLE / STATE DIAGRAM
  41  *
  42  *   FIXME
  43  *
  44  * THIS CODE IS DISGUSTING
  45  *
  46  *   Warned you are; it's my second try and still not happy with it.
  47  *
  48  * NOTES:
  49  *
  50  *   - No iso
  51  *
  52  *   - Supports DMA xfers, control, bulk and maybe interrupt
  53  *
  54  *   - Does not recycle unused rpipes
  55  *
  56  *     An rpipe is assigned to an endpoint the first time it is used,
  57  *     and then it's there, assigned, until the endpoint is disabled
  58  *     (destroyed [{h,d}wahc_op_ep_disable()]. The assignment of the
  59  *     rpipe to the endpoint is done under the wa->rpipe_sem semaphore
  60  *     (should be a mutex).
  61  *
  62  *     Two methods it could be done:
  63  *
  64  *     (a) set up a timer every time an rpipe's use count drops to 1
  65  *         (which means unused) or when a transfer ends. Reset the
  66  *         timer when a xfer is queued. If the timer expires, release
  67  *         the rpipe [see rpipe_ep_disable()].
  68  *
  69  *     (b) when looking for free rpipes to attach [rpipe_get_by_ep()],
  70  *         when none are found go over the list, check their endpoint
  71  *         and their activity record (if no last-xfer-done-ts in the
  72  *         last x seconds) take it
  73  *
  74  *     However, due to the fact that we have a set of limited
  75  *     resources (max-segments-at-the-same-time per xfer,
  76  *     xfers-per-ripe, blocks-per-rpipe, rpipes-per-host), at the end
  77  *     we are going to have to rebuild all this based on an scheduler,
  78  *     to where we have a list of transactions to do and based on the
  79  *     availability of the different required components (blocks,
  80  *     rpipes, segment slots, etc), we go scheduling them. Painful.
  81  */
  82 #include <linux/init.h>
  83 #include <linux/spinlock.h>
  84 #include <linux/slab.h>
  85 #include <linux/hash.h>
  86 #include <linux/ratelimit.h>
  87 #include <linux/export.h>
  88
  89 #include "wa-hc.h"
  90 #include "wusbhc.h"
  91
  92 enum {
  93         WA_SEGS_MAX = 255,
  94 };
  95
  96 enum wa_seg_status {
  97         WA_SEG_NOTREADY,
  98         WA_SEG_READY,
  99         WA_SEG_DELAYED,
 100         WA_SEG_SUBMITTED,
 101         WA_SEG_PENDING,
 102         WA_SEG_DTI_PENDING,
 103         WA_SEG_DONE,
 104         WA_SEG_ERROR,
 105         WA_SEG_ABORTED,
 106 };
 107
 108 static void wa_xfer_delayed_run(struct wa_rpipe *);
 109
 110 /*
 111  * Life cycle governed by 'struct urb' (the refcount of the struct is
 112  * that of the 'struct urb' and usb_free_urb() would free the whole
 113  * struct).
 114  */
 115 struct wa_seg {
 116         struct urb urb;
 117         struct urb *dto_urb;            /* for data output? */
 118         struct list_head list_node;     /* for rpipe->req_list */
 119         struct wa_xfer *xfer;           /* out xfer */
 120         u8 index;                       /* which segment we are */
 121         enum wa_seg_status status;
 122         ssize_t result;                 /* bytes xfered or error */
 123         struct wa_xfer_hdr xfer_hdr;
 124         u8 xfer_extra[];                /* xtra space for xfer_hdr_ctl */
 125 };
 126
 127 static void wa_seg_init(struct wa_seg *seg)
 128 {
 129         /* usb_init_urb() repeats a lot of work, so we do it here */
 130         kref_init(&seg->urb.kref);
 131 }
 132
 133 /*
 134  * Protected by xfer->lock
 135  *
 136  */
 137 struct wa_xfer {
 138         struct kref refcnt;
 139         struct list_head list_node;
 140         spinlock_t lock;
 141         u32 id;
 142
 143         struct wahc *wa;                /* Wire adapter we are plugged to */
 144         struct usb_host_endpoint *ep;
 145         struct urb *urb;                /* URB we are transferring for */
 146         struct wa_seg **seg;            /* transfer segments */
 147         u8 segs, segs_submitted, segs_done;
 148         unsigned is_inbound:1;
 149         unsigned is_dma:1;
 150         size_t seg_size;
 151         int result;
 152
 153         gfp_t gfp;                      /* allocation mask */
 154
 155         struct wusb_dev *wusb_dev;      /* for activity timestamps */
 156 };
 157
 158 static inline void wa_xfer_init(struct wa_xfer *xfer)
 159 {
 160         kref_init(&xfer->refcnt);
 161         INIT_LIST_HEAD(&xfer->list_node);
 162         spin_lock_init(&xfer->lock);
 163 }
 164
 165 /*
 166  * Destroy a transfer structure
 167  *
 168  * Note that the xfer->seg[index] thingies follow the URB life cycle,
 169  * so we need to put them, not free them.
 170  */
 171 static void wa_xfer_destroy(struct kref *_xfer)
 172 {
 173         struct wa_xfer *xfer = container_of(_xfer, struct wa_xfer, refcnt);
 174         if (xfer->seg) {
 175                 unsigned cnt;
 176                 for (cnt = 0; cnt < xfer->segs; cnt++) {
 177                         if (xfer->is_inbound)
 178                                 usb_put_urb(xfer->seg[cnt]->dto_urb);
 179                         usb_put_urb(&xfer->seg[cnt]->urb);
 180                 }
 181         }
 182         kfree(xfer);
 183 }
 184
 185 static void wa_xfer_get(struct wa_xfer *xfer)
 186 {
 187         kref_get(&xfer->refcnt);
 188 }
 189
 190 static void wa_xfer_put(struct wa_xfer *xfer)
 191 {
 192         kref_put(&xfer->refcnt, wa_xfer_destroy);
 193 }
 194
 195 /*
 196  * xfer is referenced
 197  *
 198  * xfer->lock has to be unlocked
 199  *
 200  * We take xfer->lock for setting the result; this is a barrier
 201  * against drivers/usb/core/hcd.c:unlink1() being called after we call
 202  * usb_hcd_giveback_urb() and wa_urb_dequeue() trying to get a
 203  * reference to the transfer.
 204  */
 205 static void wa_xfer_giveback(struct wa_xfer *xfer)
 206 {
 207         unsigned long flags;
 208
 209         spin_lock_irqsave(&xfer->wa->xfer_list_lock, flags);
 210         list_del_init(&xfer->list_node);
 211         spin_unlock_irqrestore(&xfer->wa->xfer_list_lock, flags);
 212         /* FIXME: segmentation broken -- kills DWA */
 213         wusbhc_giveback_urb(xfer->wa->wusb, xfer->urb, xfer->result);
 214         wa_put(xfer->wa);
 215         wa_xfer_put(xfer);
 216 }
 217
 218 /*
 219  * xfer is referenced
 220  *
 221  * xfer->lock has to be unlocked
 222  */
 223 static void wa_xfer_completion(struct wa_xfer *xfer)
 224 {
 225         if (xfer->wusb_dev)
 226                 wusb_dev_put(xfer->wusb_dev);
 227         rpipe_put(xfer->ep->hcpriv);
 228         wa_xfer_giveback(xfer);
 229 }
 230
 231 /*
 232  * If transfer is done, wrap it up and return true
 233  *
 234  * xfer->lock has to be locked
 235  */
 236 static unsigned __wa_xfer_is_done(struct wa_xfer *xfer)
 237 {
 238         struct device *dev = &xfer->wa->usb_iface->dev;
 239         unsigned result, cnt;
 240         struct wa_seg *seg;
 241         struct urb *urb = xfer->urb;
 242         unsigned found_short = 0;
 243
 244         result = xfer->segs_done == xfer->segs_submitted;
 245         if (result == 0)
 246                 goto out;
 247         urb->actual_length = 0;
 248         for (cnt = 0; cnt < xfer->segs; cnt++) {
 249                 seg = xfer->seg[cnt];
 250                 switch (seg->status) {
 251                 case WA_SEG_DONE:
 252                         if (found_short && seg->result > 0) {
 253                                 dev_dbg(dev, "xfer %p#%u: bad short segments (%zu)\n",
 254                                         xfer, cnt, seg->result);
 255                                 urb->status = -EINVAL;
 256                                 goto out;
 257                         }
 258                         urb->actual_length += seg->result;
 259                         if (seg->result < xfer->seg_size
 260                             && cnt != xfer->segs-1)
 261                                 found_short = 1;
 262                         dev_dbg(dev, "xfer %p#%u: DONE short %d "
 263                                 "result %zu urb->actual_length %d\n",
 264                                 xfer, seg->index, found_short, seg->result,
 265                                 urb->actual_length);
 266                         break;
 267                 case WA_SEG_ERROR:
 268                         xfer->result = seg->result;
 269                         dev_dbg(dev, "xfer %p#%u: ERROR result %zu\n",
 270                                 xfer, seg->index, seg->result);
 271                         goto out;
 272                 case WA_SEG_ABORTED:
 273                         dev_dbg(dev, "xfer %p#%u ABORTED: result %d\n",
 274                                 xfer, seg->index, urb->status);
 275                         xfer->result = urb->status;
 276                         goto out;
 277                 default:
 278                         dev_warn(dev, "xfer %p#%u: is_done bad state %d\n",
 279                                  xfer, cnt, seg->status);
 280                         xfer->result = -EINVAL;
 281                         goto out;
 282                 }
 283         }
 284         xfer->result = 0;
 285 out:
 286         return result;
 287 }
 288
 289 /*
 290  * Initialize a transfer's ID
 291  *
 292  * We need to use a sequential number; if we use the pointer or the
 293  * hash of the pointer, it can repeat over sequential transfers and
 294  * then it will confuse the HWA....wonder why in hell they put a 32
 295  * bit handle in there then.
 296  */
 297 static void wa_xfer_id_init(struct wa_xfer *xfer)
 298 {
 299         xfer->id = atomic_add_return(1, &xfer->wa->xfer_id_count);
 300 }
 301
 302 /*
 303  * Return the xfer's ID associated with xfer
 304  *
 305  * Need to generate a
 306  */
 307 static u32 wa_xfer_id(struct wa_xfer *xfer)
 308 {
 309         return xfer->id;
 310 }
 311
 312 /*
 313  * Search for a transfer list ID on the HCD's URB list
 314  *
 315  * For 32 bit architectures, we use the pointer itself; for 64 bits, a
 316  * 32-bit hash of the pointer.
 317  *
 318  * @returns NULL if not found.
 319  */
 320 static struct wa_xfer *wa_xfer_get_by_id(struct wahc *wa, u32 id)
 321 {
 322         unsigned long flags;
 323         struct wa_xfer *xfer_itr;
 324         spin_lock_irqsave(&wa->xfer_list_lock, flags);
 325         list_for_each_entry(xfer_itr, &wa->xfer_list, list_node) {
 326                 if (id == xfer_itr->id) {
 327                         wa_xfer_get(xfer_itr);
 328                         goto out;
 329                 }
 330         }
 331         xfer_itr = NULL;
 332 out:
 333         spin_unlock_irqrestore(&wa->xfer_list_lock, flags);
 334         return xfer_itr;
 335 }
 336
 337 struct wa_xfer_abort_buffer {
 338         struct urb urb;
 339         struct wa_xfer_abort cmd;
 340 };
 341
 342 static void __wa_xfer_abort_cb(struct urb *urb)
 343 {
 344         struct wa_xfer_abort_buffer *b = urb->context;
 345         usb_put_urb(&b->urb);
 346 }
 347
 348 /*
 349  * Aborts an ongoing transaction
 350  *
 351  * Assumes the transfer is referenced and locked and in a submitted
 352  * state (mainly that there is an endpoint/rpipe assigned).
 353  *
 354  * The callback (see above) does nothing but freeing up the data by
 355  * putting the URB. Because the URB is allocated at the head of the
 356  * struct, the whole space we allocated is kfreed.
 357  *
 358  * We'll get an 'aborted transaction' xfer result on DTI, that'll
 359  * politely ignore because at this point the transaction has been
 360  * marked as aborted already.
 361  */
 362 static void __wa_xfer_abort(struct wa_xfer *xfer)
 363 {
 364         int result;
 365         struct device *dev = &xfer->wa->usb_iface->dev;
 366         struct wa_xfer_abort_buffer *b;
 367         struct wa_rpipe *rpipe = xfer->ep->hcpriv;
 368
 369         b = kmalloc(sizeof(*b), GFP_ATOMIC);
 370         if (b == NULL)
 371                 goto error_kmalloc;
 372         b->cmd.bLength =  sizeof(b->cmd);
 373         b->cmd.bRequestType = WA_XFER_ABORT;
 374         b->cmd.wRPipe = rpipe->descr.wRPipeIndex;
 375         b->cmd.dwTransferID = wa_xfer_id(xfer);
 376
 377         usb_init_urb(&b->urb);
 378         usb_fill_bulk_urb(&b->urb, xfer->wa->usb_dev,
 379                 usb_sndbulkpipe(xfer->wa->usb_dev,
 380                                 xfer->wa->dto_epd->bEndpointAddress),
 381                 &b->cmd, sizeof(b->cmd), __wa_xfer_abort_cb, b);
 382         result = usb_submit_urb(&b->urb, GFP_ATOMIC);
 383         if (result < 0)
 384                 goto error_submit;
 385         return;                         /* callback frees! */
 386
 387
 388 error_submit:
 389         if (printk_ratelimit())
 390                 dev_err(dev, "xfer %p: Can't submit abort request: %d\n",
 391                         xfer, result);
 392         kfree(b);
 393 error_kmalloc:
 394         return;
 395
 396 }
 397
 398 /*
 399  *
 400  * @returns < 0 on error, transfer segment request size if ok
 401  */
 402 static ssize_t __wa_xfer_setup_sizes(struct wa_xfer *xfer,
 403                                      enum wa_xfer_type *pxfer_type)
 404 {
 405         ssize_t result;
 406         struct device *dev = &xfer->wa->usb_iface->dev;
 407         size_t maxpktsize;
 408         struct urb *urb = xfer->urb;
 409         struct wa_rpipe *rpipe = xfer->ep->hcpriv;
 410
 411         switch (rpipe->descr.bmAttribute & 0x3) {
 412         case USB_ENDPOINT_XFER_CONTROL:
 413                 *pxfer_type = WA_XFER_TYPE_CTL;
 414                 result = sizeof(struct wa_xfer_ctl);
 415                 break;
 416         case USB_ENDPOINT_XFER_INT:
 417         case USB_ENDPOINT_XFER_BULK:
 418                 *pxfer_type = WA_XFER_TYPE_BI;
 419                 result = sizeof(struct wa_xfer_bi);
 420                 break;
 421         case USB_ENDPOINT_XFER_ISOC:
 422                 dev_err(dev, "FIXME: ISOC not implemented\n");
 423                 result = -ENOSYS;
 424                 goto error;
 425         default:
 426                 /* never happens */
 427                 BUG();
 428                 result = -EINVAL;       /* shut gcc up */
 429         };
 430         xfer->is_inbound = urb->pipe & USB_DIR_IN ? 1 : 0;
 431         xfer->is_dma = urb->transfer_flags & URB_NO_TRANSFER_DMA_MAP ? 1 : 0;
 432         xfer->seg_size = le16_to_cpu(rpipe->descr.wBlocks)
 433                 * 1 << (xfer->wa->wa_descr->bRPipeBlockSize - 1);
 434         /* Compute the segment size and make sure it is a multiple of
 435          * the maxpktsize (WUSB1.0[8.3.3.1])...not really too much of
 436          * a check (FIXME) */
 437         maxpktsize = le16_to_cpu(rpipe->descr.wMaxPacketSize);
 438         if (xfer->seg_size < maxpktsize) {
 439                 dev_err(dev, "HW BUG? seg_size %zu smaller than maxpktsize "
 440                         "%zu\n", xfer->seg_size, maxpktsize);
 441                 result = -EINVAL;
 442                 goto error;
 443         }
 444         xfer->seg_size = (xfer->seg_size / maxpktsize) * maxpktsize;
 445         xfer->segs = (urb->transfer_buffer_length + xfer->seg_size - 1)
 446                 / xfer->seg_size;
 447         if (xfer->segs >= WA_SEGS_MAX) {
 448                 dev_err(dev, "BUG? ops, number of segments %d bigger than %d\n",
 449                         (int)(urb->transfer_buffer_length / xfer->seg_size),
 450                         WA_SEGS_MAX);
 451                 result = -EINVAL;
 452                 goto error;
 453         }
 454         if (xfer->segs == 0 && *pxfer_type == WA_XFER_TYPE_CTL)
 455                 xfer->segs = 1;
 456 error:
 457         return result;
 458 }
 459
 460 /* Fill in the common request header and xfer-type specific data. */
 461 static void __wa_xfer_setup_hdr0(struct wa_xfer *xfer,
 462                                  struct wa_xfer_hdr *xfer_hdr0,
 463                                  enum wa_xfer_type xfer_type,
 464                                  size_t xfer_hdr_size)
 465 {
 466         struct wa_rpipe *rpipe = xfer->ep->hcpriv;
 467
 468         xfer_hdr0 = &xfer->seg[0]->xfer_hdr;
 469         xfer_hdr0->bLength = xfer_hdr_size;
 470         xfer_hdr0->bRequestType = xfer_type;
 471         xfer_hdr0->wRPipe = rpipe->descr.wRPipeIndex;
 472         xfer_hdr0->dwTransferID = wa_xfer_id(xfer);
 473         xfer_hdr0->bTransferSegment = 0;
 474         switch (xfer_type) {
 475         case WA_XFER_TYPE_CTL: {
 476                 struct wa_xfer_ctl *xfer_ctl =
 477                         container_of(xfer_hdr0, struct wa_xfer_ctl, hdr);
 478                 xfer_ctl->bmAttribute = xfer->is_inbound ? 1 : 0;
 479                 memcpy(&xfer_ctl->baSetupData, xfer->urb->setup_packet,
 480                        sizeof(xfer_ctl->baSetupData));
 481                 break;
 482         }
 483         case WA_XFER_TYPE_BI:
 484                 break;
 485         case WA_XFER_TYPE_ISO:
 486                 printk(KERN_ERR "FIXME: ISOC not implemented\n");
 487         default:
 488                 BUG();
 489         };
 490 }
 491
 492 /*
 493  * Callback for the OUT data phase of the segment request
 494  *
 495  * Check wa_seg_cb(); most comments also apply here because this
 496  * function does almost the same thing and they work closely
 497  * together.
 498  *
 499  * If the seg request has failed but this DTO phase has succeeded,
 500  * wa_seg_cb() has already failed the segment and moved the
 501  * status to WA_SEG_ERROR, so this will go through 'case 0' and
 502  * effectively do nothing.
 503  */
 504 static void wa_seg_dto_cb(struct urb *urb)
 505 {
 506         struct wa_seg *seg = urb->context;
 507         struct wa_xfer *xfer = seg->xfer;
 508         struct wahc *wa;
 509         struct device *dev;
 510         struct wa_rpipe *rpipe;
 511         unsigned long flags;
 512         unsigned rpipe_ready = 0;
 513         u8 done = 0;
 514
 515         switch (urb->status) {
 516         case 0:
 517                 spin_lock_irqsave(&xfer->lock, flags);
 518                 wa = xfer->wa;
 519                 dev = &wa->usb_iface->dev;
 520                 dev_dbg(dev, "xfer %p#%u: data out done (%d bytes)\n",
 521                         xfer, seg->index, urb->actual_length);
 522                 if (seg->status < WA_SEG_PENDING)
 523                         seg->status = WA_SEG_PENDING;
 524                 seg->result = urb->actual_length;
 525                 spin_unlock_irqrestore(&xfer->lock, flags);
 526                 break;
 527         case -ECONNRESET:       /* URB unlinked; no need to do anything */
 528         case -ENOENT:           /* as it was done by the who unlinked us */
 529                 break;
 530         default:                /* Other errors ... */
 531                 spin_lock_irqsave(&xfer->lock, flags);
 532                 wa = xfer->wa;
 533                 dev = &wa->usb_iface->dev;
 534                 rpipe = xfer->ep->hcpriv;
 535                 dev_dbg(dev, "xfer %p#%u: data out error %d\n",
 536                         xfer, seg->index, urb->status);
 537                 if (edc_inc(&wa->nep_edc, EDC_MAX_ERRORS,
 538                             EDC_ERROR_TIMEFRAME)){
 539                         dev_err(dev, "DTO: URB max acceptable errors "
 540                                 "exceeded, resetting device\n");
 541                         wa_reset_all(wa);
 542                 }
 543                 if (seg->status != WA_SEG_ERROR) {
 544                         seg->status = WA_SEG_ERROR;
 545                         seg->result = urb->status;
 546                         xfer->segs_done++;
 547                         __wa_xfer_abort(xfer);
 548                         rpipe_ready = rpipe_avail_inc(rpipe);
 549                         done = __wa_xfer_is_done(xfer);
 550                 }
 551                 spin_unlock_irqrestore(&xfer->lock, flags);
 552                 if (done)
 553                         wa_xfer_completion(xfer);
 554                 if (rpipe_ready)
 555                         wa_xfer_delayed_run(rpipe);
 556         }
 557 }
 558
 559 /*
 560  * Callback for the segment request
 561  *
 562  * If successful transition state (unless already transitioned or
 563  * outbound transfer); otherwise, take a note of the error, mark this
 564  * segment done and try completion.
 565  *
 566  * Note we don't access until we are sure that the transfer hasn't
 567  * been cancelled (ECONNRESET, ENOENT), which could mean that
 568  * seg->xfer could be already gone.
 569  *
 570  * We have to check before setting the status to WA_SEG_PENDING
 571  * because sometimes the xfer result callback arrives before this
 572  * callback (geeeeeeze), so it might happen that we are already in
 573  * another state. As well, we don't set it if the transfer is inbound,
 574  * as in that case, wa_seg_dto_cb will do it when the OUT data phase
 575  * finishes.
 576  */
 577 static void wa_seg_cb(struct urb *urb)
 578 {
 579         struct wa_seg *seg = urb->context;
 580         struct wa_xfer *xfer = seg->xfer;
 581         struct wahc *wa;
 582         struct device *dev;
 583         struct wa_rpipe *rpipe;
 584         unsigned long flags;
 585         unsigned rpipe_ready;
 586         u8 done = 0;
 587
 588         switch (urb->status) {
 589         case 0:
 590                 spin_lock_irqsave(&xfer->lock, flags);
 591                 wa = xfer->wa;
 592                 dev = &wa->usb_iface->dev;
 593                 dev_dbg(dev, "xfer %p#%u: request done\n", xfer, seg->index);
 594                 if (xfer->is_inbound && seg->status < WA_SEG_PENDING)
 595                         seg->status = WA_SEG_PENDING;
 596                 spin_unlock_irqrestore(&xfer->lock, flags);
 597                 break;
 598         case -ECONNRESET:       /* URB unlinked; no need to do anything */
 599         case -ENOENT:           /* as it was done by the who unlinked us */
 600                 break;
 601         default:                /* Other errors ... */
 602                 spin_lock_irqsave(&xfer->lock, flags);
 603                 wa = xfer->wa;
 604                 dev = &wa->usb_iface->dev;
 605                 rpipe = xfer->ep->hcpriv;
 606                 if (printk_ratelimit())
 607                         dev_err(dev, "xfer %p#%u: request error %d\n",
 608                                 xfer, seg->index, urb->status);
 609                 if (edc_inc(&wa->nep_edc, EDC_MAX_ERRORS,
 610                             EDC_ERROR_TIMEFRAME)){
 611                         dev_err(dev, "DTO: URB max acceptable errors "
 612                                 "exceeded, resetting device\n");
 613                         wa_reset_all(wa);
 614                 }
 615                 usb_unlink_urb(seg->dto_urb);
 616                 seg->status = WA_SEG_ERROR;
 617                 seg->result = urb->status;
 618                 xfer->segs_done++;
 619                 __wa_xfer_abort(xfer);
 620                 rpipe_ready = rpipe_avail_inc(rpipe);
 621                 done = __wa_xfer_is_done(xfer);
 622                 spin_unlock_irqrestore(&xfer->lock, flags);
 623                 if (done)
 624                         wa_xfer_completion(xfer);
 625                 if (rpipe_ready)
 626                         wa_xfer_delayed_run(rpipe);
 627         }
 628 }
 629
 630 /*
 631  * Allocate the segs array and initialize each of them
 632  *
 633  * The segments are freed by wa_xfer_destroy() when the xfer use count
 634  * drops to zero; however, because each segment is given the same life
 635  * cycle as the USB URB it contains, it is actually freed by
 636  * usb_put_urb() on the contained USB URB (twisted, eh?).
 637  */
 638 static int __wa_xfer_setup_segs(struct wa_xfer *xfer, size_t xfer_hdr_size)
 639 {
 640         int result, cnt;
 641         size_t alloc_size = sizeof(*xfer->seg[0])
 642                 - sizeof(xfer->seg[0]->xfer_hdr) + xfer_hdr_size;
 643         struct usb_device *usb_dev = xfer->wa->usb_dev;
 644         const struct usb_endpoint_descriptor *dto_epd = xfer->wa->dto_epd;
 645         struct wa_seg *seg;
 646         size_t buf_itr, buf_size, buf_itr_size;
 647
 648         result = -ENOMEM;
 649         xfer->seg = kcalloc(xfer->segs, sizeof(xfer->seg[0]), GFP_ATOMIC);
 650         if (xfer->seg == NULL)
 651                 goto error_segs_kzalloc;
 652         buf_itr = 0;
 653         buf_size = xfer->urb->transfer_buffer_length;
 654         for (cnt = 0; cnt < xfer->segs; cnt++) {
 655                 seg = xfer->seg[cnt] = kzalloc(alloc_size, GFP_ATOMIC);
 656                 if (seg == NULL)
 657                         goto error_seg_kzalloc;
 658                 wa_seg_init(seg);
 659                 seg->xfer = xfer;
 660                 seg->index = cnt;
 661                 usb_fill_bulk_urb(&seg->urb, usb_dev,
 662                                   usb_sndbulkpipe(usb_dev,
 663                                                   dto_epd->bEndpointAddress),
 664                                   &seg->xfer_hdr, xfer_hdr_size,
 665                                   wa_seg_cb, seg);
 666                 buf_itr_size = buf_size > xfer->seg_size ?
 667                         xfer->seg_size : buf_size;
 668                 if (xfer->is_inbound == 0 && buf_size > 0) {
 669                         seg->dto_urb = usb_alloc_urb(0, GFP_ATOMIC);
 670                         if (seg->dto_urb == NULL)
 671                                 goto error_dto_alloc;
 672                         usb_fill_bulk_urb(
 673                                 seg->dto_urb, usb_dev,
 674                                 usb_sndbulkpipe(usb_dev,
 675                                                 dto_epd->bEndpointAddress),
 676                                 NULL, 0, wa_seg_dto_cb, seg);
 677                         if (xfer->is_dma) {
 678                                 seg->dto_urb->transfer_dma =
 679                                         xfer->urb->transfer_dma + buf_itr;
 680                                 seg->dto_urb->transfer_flags |=
 681                                         URB_NO_TRANSFER_DMA_MAP;
 682                         } else
 683                                 seg->dto_urb->transfer_buffer =
 684                                         xfer->urb->transfer_buffer + buf_itr;
 685                         seg->dto_urb->transfer_buffer_length = buf_itr_size;
 686                 }
 687                 seg->status = WA_SEG_READY;
 688                 buf_itr += buf_itr_size;
 689                 buf_size -= buf_itr_size;
 690         }
 691         return 0;
 692
 693 error_dto_alloc:
 694         kfree(xfer->seg[cnt]);
 695         cnt--;
 696 error_seg_kzalloc:
 697         /* use the fact that cnt is left at were it failed */
 698         for (; cnt > 0; cnt--) {
 699                 if (xfer->is_inbound == 0)
 700                         kfree(xfer->seg[cnt]->dto_urb);
 701                 kfree(xfer->seg[cnt]);
 702         }
 703 error_segs_kzalloc:
 704         return result;
 705 }
 706
 707 /*
 708  * Allocates all the stuff needed to submit a transfer
 709  *
 710  * Breaks the whole data buffer in a list of segments, each one has a
 711  * structure allocated to it and linked in xfer->seg[index]
 712  *
 713  * FIXME: merge setup_segs() and the last part of this function, no
 714  *        need to do two for loops when we could run everything in a
 715  *        single one
 716  */
 717 static int __wa_xfer_setup(struct wa_xfer *xfer, struct urb *urb)
 718 {
 719         int result;
 720         struct device *dev = &xfer->wa->usb_iface->dev;
 721         enum wa_xfer_type xfer_type = 0; /* shut up GCC */
 722         size_t xfer_hdr_size, cnt, transfer_size;
 723         struct wa_xfer_hdr *xfer_hdr0, *xfer_hdr;
 724
 725         result = __wa_xfer_setup_sizes(xfer, &xfer_type);
 726         if (result < 0)
 727                 goto error_setup_sizes;
 728         xfer_hdr_size = result;
 729         result = __wa_xfer_setup_segs(xfer, xfer_hdr_size);
 730         if (result < 0) {
 731                 dev_err(dev, "xfer %p: Failed to allocate %d segments: %d\n",
 732                         xfer, xfer->segs, result);
 733                 goto error_setup_segs;
 734         }
 735         /* Fill the first header */
 736         xfer_hdr0 = &xfer->seg[0]->xfer_hdr;
 737         wa_xfer_id_init(xfer);
 738         __wa_xfer_setup_hdr0(xfer, xfer_hdr0, xfer_type, xfer_hdr_size);
 739
 740         /* Fill remainig headers */
 741         xfer_hdr = xfer_hdr0;
 742         transfer_size = urb->transfer_buffer_length;
 743         xfer_hdr0->dwTransferLength = transfer_size > xfer->seg_size ?
 744                 xfer->seg_size : transfer_size;
 745         transfer_size -=  xfer->seg_size;
 746         for (cnt = 1; cnt < xfer->segs; cnt++) {
 747                 xfer_hdr = &xfer->seg[cnt]->xfer_hdr;
 748                 memcpy(xfer_hdr, xfer_hdr0, xfer_hdr_size);
 749                 xfer_hdr->bTransferSegment = cnt;
 750                 xfer_hdr->dwTransferLength = transfer_size > xfer->seg_size ?
 751                         cpu_to_le32(xfer->seg_size)
 752                         : cpu_to_le32(transfer_size);
 753                 xfer->seg[cnt]->status = WA_SEG_READY;
 754                 transfer_size -=  xfer->seg_size;
 755         }
 756         xfer_hdr->bTransferSegment |= 0x80;     /* this is the last segment */
 757         result = 0;
 758 error_setup_segs:
 759 error_setup_sizes:
 760         return result;
 761 }
 762
 763 /*
 764  *
 765  *
 766  * rpipe->seg_lock is held!
 767  */
 768 static int __wa_seg_submit(struct wa_rpipe *rpipe, struct wa_xfer *xfer,
 769                            struct wa_seg *seg)
 770 {
 771         int result;
 772         result = usb_submit_urb(&seg->urb, GFP_ATOMIC);
 773         if (result < 0) {
 774                 printk(KERN_ERR "xfer %p#%u: REQ submit failed: %d\n",
 775                        xfer, seg->index, result);
 776                 goto error_seg_submit;
 777         }
 778         if (seg->dto_urb) {
 779                 result = usb_submit_urb(seg->dto_urb, GFP_ATOMIC);
 780                 if (result < 0) {
 781                         printk(KERN_ERR "xfer %p#%u: DTO submit failed: %d\n",
 782                                xfer, seg->index, result);
 783                         goto error_dto_submit;
 784                 }
 785         }
 786         seg->status = WA_SEG_SUBMITTED;
 787         rpipe_avail_dec(rpipe);
 788         return 0;
 789
 790 error_dto_submit:
 791         usb_unlink_urb(&seg->urb);
 792 error_seg_submit:
 793         seg->status = WA_SEG_ERROR;
 794         seg->result = result;
 795         return result;
 796 }
 797
 798 /*
 799  * Execute more queued request segments until the maximum concurrent allowed
 800  *
 801  * The ugly unlock/lock sequence on the error path is needed as the
 802  * xfer->lock normally nests the seg_lock and not viceversa.
 803  *
 804  */
 805 static void wa_xfer_delayed_run(struct wa_rpipe *rpipe)
 806 {
 807         int result;
 808         struct device *dev = &rpipe->wa->usb_iface->dev;
 809         struct wa_seg *seg;
 810         struct wa_xfer *xfer;
 811         unsigned long flags;
 812
 813         spin_lock_irqsave(&rpipe->seg_lock, flags);
 814         while (atomic_read(&rpipe->segs_available) > 0
 815               && !list_empty(&rpipe->seg_list)) {
 816                 seg = list_entry(rpipe->seg_list.next, struct wa_seg,
 817                                  list_node);
 818                 list_del(&seg->list_node);
 819                 xfer = seg->xfer;
 820                 result = __wa_seg_submit(rpipe, xfer, seg);
 821                 dev_dbg(dev, "xfer %p#%u submitted from delayed [%d segments available] %d\n",
 822                         xfer, seg->index, atomic_read(&rpipe->segs_available), result);
 823                 if (unlikely(result < 0)) {
 824                         spin_unlock_irqrestore(&rpipe->seg_lock, flags);
 825                         spin_lock_irqsave(&xfer->lock, flags);
 826                         __wa_xfer_abort(xfer);
 827                         xfer->segs_done++;
 828                         spin_unlock_irqrestore(&xfer->lock, flags);
 829                         spin_lock_irqsave(&rpipe->seg_lock, flags);
 830                 }
 831         }
 832         spin_unlock_irqrestore(&rpipe->seg_lock, flags);
 833 }
 834
 835 /*
 836  *
 837  * xfer->lock is taken
 838  *
 839  * On failure submitting we just stop submitting and return error;
 840  * wa_urb_enqueue_b() will execute the completion path
 841  */
 842 static int __wa_xfer_submit(struct wa_xfer *xfer)
 843 {
 844         int result;
 845         struct wahc *wa = xfer->wa;
 846         struct device *dev = &wa->usb_iface->dev;
 847         unsigned cnt;
 848         struct wa_seg *seg;
 849         unsigned long flags;
 850         struct wa_rpipe *rpipe = xfer->ep->hcpriv;
 851         size_t maxrequests = le16_to_cpu(rpipe->descr.wRequests);
 852         u8 available;
 853         u8 empty;
 854
 855         spin_lock_irqsave(&wa->xfer_list_lock, flags);
 856         list_add_tail(&xfer->list_node, &wa->xfer_list);
 857         spin_unlock_irqrestore(&wa->xfer_list_lock, flags);
 858
 859         BUG_ON(atomic_read(&rpipe->segs_available) > maxrequests);
 860         result = 0;
 861         spin_lock_irqsave(&rpipe->seg_lock, flags);
 862         for (cnt = 0; cnt < xfer->segs; cnt++) {
 863                 available = atomic_read(&rpipe->segs_available);
 864                 empty = list_empty(&rpipe->seg_list);
 865                 seg = xfer->seg[cnt];
 866                 dev_dbg(dev, "xfer %p#%u: available %u empty %u (%s)\n",
 867                         xfer, cnt, available, empty,
 868                         available == 0 || !empty ? "delayed" : "submitted");
 869                 if (available == 0 || !empty) {
 870                         dev_dbg(dev, "xfer %p#%u: delayed\n", xfer, cnt);
 871                         seg->status = WA_SEG_DELAYED;
 872                         list_add_tail(&seg->list_node, &rpipe->seg_list);
 873                 } else {
 874                         result = __wa_seg_submit(rpipe, xfer, seg);
 875                         if (result < 0) {
 876                                 __wa_xfer_abort(xfer);
 877                                 goto error_seg_submit;
 878                         }
 879                 }
 880                 xfer->segs_submitted++;
 881         }
 882 error_seg_submit:
 883         spin_unlock_irqrestore(&rpipe->seg_lock, flags);
 884         return result;
 885 }
 886
 887 /*
 888  * Second part of a URB/transfer enqueuement
 889  *
 890  * Assumes this comes from wa_urb_enqueue() [maybe through
 891  * wa_urb_enqueue_run()]. At this point:
 892  *
 893  * xfer->wa     filled and refcounted
 894  * xfer->ep     filled with rpipe refcounted if
 895  *              delayed == 0
 896  * xfer->urb    filled and refcounted (this is the case when called
 897  *              from wa_urb_enqueue() as we come from usb_submit_urb()
 898  *              and when called by wa_urb_enqueue_run(), as we took an
 899  *              extra ref dropped by _run() after we return).
 900  * xfer->gfp    filled
 901  *
 902  * If we fail at __wa_xfer_submit(), then we just check if we are done
 903  * and if so, we run the completion procedure. However, if we are not
 904  * yet done, we do nothing and wait for the completion handlers from
 905  * the submitted URBs or from the xfer-result path to kick in. If xfer
 906  * result never kicks in, the xfer will timeout from the USB code and
 907  * dequeue() will be called.
 908  */
 909 static void wa_urb_enqueue_b(struct wa_xfer *xfer)
 910 {
 911         int result;
 912         unsigned long flags;
 913         struct urb *urb = xfer->urb;
 914         struct wahc *wa = xfer->wa;
 915         struct wusbhc *wusbhc = wa->wusb;
 916         struct wusb_dev *wusb_dev;
 917         unsigned done;
 918
 919         result = rpipe_get_by_ep(wa, xfer->ep, urb, xfer->gfp);
 920         if (result < 0)
 921                 goto error_rpipe_get;
 922         result = -ENODEV;
 923         /* FIXME: segmentation broken -- kills DWA */
 924         mutex_lock(&wusbhc->mutex);             /* get a WUSB dev */
 925         if (urb->dev == NULL) {
 926                 mutex_unlock(&wusbhc->mutex);
 927                 goto error_dev_gone;
 928         }
 929         wusb_dev = __wusb_dev_get_by_usb_dev(wusbhc, urb->dev);
 930         if (wusb_dev == NULL) {
 931                 mutex_unlock(&wusbhc->mutex);
 932                 goto error_dev_gone;
 933         }
 934         mutex_unlock(&wusbhc->mutex);
 935
 936         spin_lock_irqsave(&xfer->lock, flags);
 937         xfer->wusb_dev = wusb_dev;
 938         result = urb->status;
 939         if (urb->status != -EINPROGRESS)
 940                 goto error_dequeued;
 941
 942         result = __wa_xfer_setup(xfer, urb);
 943         if (result < 0)
 944                 goto error_xfer_setup;
 945         result = __wa_xfer_submit(xfer);
 946         if (result < 0)
 947                 goto error_xfer_submit;
 948         spin_unlock_irqrestore(&xfer->lock, flags);
 949         return;
 950
 951         /* this is basically wa_xfer_completion() broken up wa_xfer_giveback()
 952          * does a wa_xfer_put() that will call wa_xfer_destroy() and clean
 953          * upundo setup().
 954          */
 955 error_xfer_setup:
 956 error_dequeued:
 957         spin_unlock_irqrestore(&xfer->lock, flags);
 958         /* FIXME: segmentation broken, kills DWA */
 959         if (wusb_dev)
 960                 wusb_dev_put(wusb_dev);
 961 error_dev_gone:
 962         rpipe_put(xfer->ep->hcpriv);
 963 error_rpipe_get:
 964         xfer->result = result;
 965         wa_xfer_giveback(xfer);
 966         return;
 967
 968 error_xfer_submit:
 969         done = __wa_xfer_is_done(xfer);
 970         xfer->result = result;
 971         spin_unlock_irqrestore(&xfer->lock, flags);
 972         if (done)
 973                 wa_xfer_completion(xfer);
 974 }
 975
 976 /*
 977  * Execute the delayed transfers in the Wire Adapter @wa
 978  *
 979  * We need to be careful here, as dequeue() could be called in the
 980  * middle.  That's why we do the whole thing under the
 981  * wa->xfer_list_lock. If dequeue() jumps in, it first locks urb->lock
 982  * and then checks the list -- so as we would be acquiring in inverse
 983  * order, we just drop the lock once we have the xfer and reacquire it
 984  * later.
 985  */
 986 void wa_urb_enqueue_run(struct work_struct *ws)
 987 {
 988         struct wahc *wa = container_of(ws, struct wahc, xfer_work);
 989         struct wa_xfer *xfer, *next;
 990         struct urb *urb;
 991
 992         spin_lock_irq(&wa->xfer_list_lock);
 993         list_for_each_entry_safe(xfer, next, &wa->xfer_delayed_list,
 994                                  list_node) {
 995                 list_del_init(&xfer->list_node);
 996                 spin_unlock_irq(&wa->xfer_list_lock);
 997
 998                 urb = xfer->urb;
 999                 wa_urb_enqueue_b(xfer);
1000                 usb_put_urb(urb);       /* taken when queuing */
1001
1002                 spin_lock_irq(&wa->xfer_list_lock);
1003         }
1004         spin_unlock_irq(&wa->xfer_list_lock);
1005 }
1006 EXPORT_SYMBOL_GPL(wa_urb_enqueue_run);
1007
1008 /*
1009  * Submit a transfer to the Wire Adapter in a delayed way
1010  *
1011  * The process of enqueuing involves possible sleeps() [see
1012  * enqueue_b(), for the rpipe_get() and the mutex_lock()]. If we are
1013  * in an atomic section, we defer the enqueue_b() call--else we call direct.
1014  *
1015  * @urb: We own a reference to it done by the HCI Linux USB stack that
1016  *       will be given up by calling usb_hcd_giveback_urb() or by
1017  *       returning error from this function -> ergo we don't have to
1018  *       refcount it.
1019  */
1020 int wa_urb_enqueue(struct wahc *wa, struct usb_host_endpoint *ep,
1021                    struct urb *urb, gfp_t gfp)
1022 {
1023         int result;
1024         struct device *dev = &wa->usb_iface->dev;
1025         struct wa_xfer *xfer;
1026         unsigned long my_flags;
1027         unsigned cant_sleep = irqs_disabled() | in_atomic();
1028
1029         if (urb->transfer_buffer == NULL
1030             && !(urb->transfer_flags & URB_NO_TRANSFER_DMA_MAP)
1031             && urb->transfer_buffer_length != 0) {
1032                 dev_err(dev, "BUG? urb %p: NULL xfer buffer & NODMA\n", urb);
1033                 dump_stack();
1034         }
1035
1036         result = -ENOMEM;
1037         xfer = kzalloc(sizeof(*xfer), gfp);
1038         if (xfer == NULL)
1039                 goto error_kmalloc;
1040
1041         result = -ENOENT;
1042         if (urb->status != -EINPROGRESS)        /* cancelled */
1043                 goto error_dequeued;            /* before starting? */
1044         wa_xfer_init(xfer);
1045         xfer->wa = wa_get(wa);
1046         xfer->urb = urb;
1047         xfer->gfp = gfp;
1048         xfer->ep = ep;
1049         urb->hcpriv = xfer;
1050
1051         dev_dbg(dev, "xfer %p urb %p pipe 0x%02x [%d bytes] %s %s %s\n",
1052                 xfer, urb, urb->pipe, urb->transfer_buffer_length,
1053                 urb->transfer_flags & URB_NO_TRANSFER_DMA_MAP ? "dma" : "nodma",
1054                 urb->pipe & USB_DIR_IN ? "inbound" : "outbound",
1055                 cant_sleep ? "deferred" : "inline");
1056
1057         if (cant_sleep) {
1058                 usb_get_urb(urb);
1059                 spin_lock_irqsave(&wa->xfer_list_lock, my_flags);
1060                 list_add_tail(&xfer->list_node, &wa->xfer_delayed_list);
1061                 spin_unlock_irqrestore(&wa->xfer_list_lock, my_flags);
1062                 queue_work(wusbd, &wa->xfer_work);
1063         } else {
1064                 wa_urb_enqueue_b(xfer);
1065         }
1066         return 0;
1067
1068 error_dequeued:
1069         kfree(xfer);
1070 error_kmalloc:
1071         return result;
1072 }
1073 EXPORT_SYMBOL_GPL(wa_urb_enqueue);
1074
1075 /*
1076  * Dequeue a URB and make sure uwb_hcd_giveback_urb() [completion
1077  * handler] is called.
1078  *
1079  * Until a transfer goes successfully through wa_urb_enqueue() it
1080  * needs to be dequeued with completion calling; when stuck in delayed
1081  * or before wa_xfer_setup() is called, we need to do completion.
1082  *
1083  *  not setup  If there is no hcpriv yet, that means that that enqueue
1084  *             still had no time to set the xfer up. Because
1085  *             urb->status should be other than -EINPROGRESS,
1086  *             enqueue() will catch that and bail out.
1087  *
1088  * If the transfer has gone through setup, we just need to clean it
1089  * up. If it has gone through submit(), we have to abort it [with an
1090  * asynch request] and then make sure we cancel each segment.
1091  *
1092  */
1093 int wa_urb_dequeue(struct wahc *wa, struct urb *urb)
1094 {
1095         unsigned long flags, flags2;
1096         struct wa_xfer *xfer;
1097         struct wa_seg *seg;
1098         struct wa_rpipe *rpipe;
1099         unsigned cnt;
1100         unsigned rpipe_ready = 0;
1101
1102         xfer = urb->hcpriv;
1103         if (xfer == NULL) {
1104                 /* NOthing setup yet enqueue will see urb->status !=
1105                  * -EINPROGRESS (by hcd layer) and bail out with
1106                  * error, no need to do completion
1107                  */
1108                 BUG_ON(urb->status == -EINPROGRESS);
1109                 goto out;
1110         }
1111         spin_lock_irqsave(&xfer->lock, flags);
1112         rpipe = xfer->ep->hcpriv;
1113         /* Check the delayed list -> if there, release and complete */
1114         spin_lock_irqsave(&wa->xfer_list_lock, flags2);
1115         if (!list_empty(&xfer->list_node) && xfer->seg == NULL)
1116                 goto dequeue_delayed;
1117         spin_unlock_irqrestore(&wa->xfer_list_lock, flags2);
1118         if (xfer->seg == NULL)          /* still hasn't reached */
1119                 goto out_unlock;        /* setup(), enqueue_b() completes */
1120         /* Ok, the xfer is in flight already, it's been setup and submitted.*/
1121         __wa_xfer_abort(xfer);
1122         for (cnt = 0; cnt < xfer->segs; cnt++) {
1123                 seg = xfer->seg[cnt];
1124                 switch (seg->status) {
1125                 case WA_SEG_NOTREADY:
1126                 case WA_SEG_READY:
1127                         printk(KERN_ERR "xfer %p#%u: dequeue bad state %u\n",
1128                                xfer, cnt, seg->status);
1129                         WARN_ON(1);
1130                         break;
1131                 case WA_SEG_DELAYED:
1132                         seg->status = WA_SEG_ABORTED;
1133                         spin_lock_irqsave(&rpipe->seg_lock, flags2);
1134                         list_del(&seg->list_node);
1135                         xfer->segs_done++;
1136                         rpipe_ready = rpipe_avail_inc(rpipe);
1137                         spin_unlock_irqrestore(&rpipe->seg_lock, flags2);
1138                         break;
1139                 case WA_SEG_SUBMITTED:
1140                         seg->status = WA_SEG_ABORTED;
1141                         usb_unlink_urb(&seg->urb);
1142                         if (xfer->is_inbound == 0)
1143                                 usb_unlink_urb(seg->dto_urb);
1144                         xfer->segs_done++;
1145                         rpipe_ready = rpipe_avail_inc(rpipe);
1146                         break;
1147                 case WA_SEG_PENDING:
1148                         seg->status = WA_SEG_ABORTED;
1149                         xfer->segs_done++;
1150                         rpipe_ready = rpipe_avail_inc(rpipe);
1151                         break;
1152                 case WA_SEG_DTI_PENDING:
1153                         usb_unlink_urb(wa->dti_urb);
1154                         seg->status = WA_SEG_ABORTED;
1155                         xfer->segs_done++;
1156                         rpipe_ready = rpipe_avail_inc(rpipe);
1157                         break;
1158                 case WA_SEG_DONE:
1159                 case WA_SEG_ERROR:
1160                 case WA_SEG_ABORTED:
1161                         break;
1162                 }
1163         }
1164         xfer->result = urb->status;     /* -ENOENT or -ECONNRESET */
1165         __wa_xfer_is_done(xfer);
1166         spin_unlock_irqrestore(&xfer->lock, flags);
1167         wa_xfer_completion(xfer);
1168         if (rpipe_ready)
1169                 wa_xfer_delayed_run(rpipe);
1170         return 0;
1171
1172 out_unlock:
1173         spin_unlock_irqrestore(&xfer->lock, flags);
1174 out:
1175         return 0;
1176
1177 dequeue_delayed:
1178         list_del_init(&xfer->list_node);
1179         spin_unlock_irqrestore(&wa->xfer_list_lock, flags2);
1180         xfer->result = urb->status;
1181         spin_unlock_irqrestore(&xfer->lock, flags);
1182         wa_xfer_giveback(xfer);
1183         usb_put_urb(urb);               /* we got a ref in enqueue() */
1184         return 0;
1185 }
1186 EXPORT_SYMBOL_GPL(wa_urb_dequeue);
1187
1188 /*
1189  * Translation from WA status codes (WUSB1.0 Table 8.15) to errno
1190  * codes
1191  *
1192  * Positive errno values are internal inconsistencies and should be
1193  * flagged louder. Negative are to be passed up to the user in the
1194  * normal way.
1195  *
1196  * @status: USB WA status code -- high two bits are stripped.
1197  */
1198 static int wa_xfer_status_to_errno(u8 status)
1199 {
1200         int errno;
1201         u8 real_status = status;
1202         static int xlat[] = {
1203                 [WA_XFER_STATUS_SUCCESS] =              0,
1204                 [WA_XFER_STATUS_HALTED] =               -EPIPE,
1205                 [WA_XFER_STATUS_DATA_BUFFER_ERROR] =    -ENOBUFS,
1206                 [WA_XFER_STATUS_BABBLE] =               -EOVERFLOW,
1207                 [WA_XFER_RESERVED] =                    EINVAL,
1208                 [WA_XFER_STATUS_NOT_FOUND] =            0,
1209                 [WA_XFER_STATUS_INSUFFICIENT_RESOURCE] = -ENOMEM,
1210                 [WA_XFER_STATUS_TRANSACTION_ERROR] =    -EILSEQ,
1211                 [WA_XFER_STATUS_ABORTED] =              -EINTR,
1212                 [WA_XFER_STATUS_RPIPE_NOT_READY] =      EINVAL,
1213                 [WA_XFER_INVALID_FORMAT] =              EINVAL,
1214                 [WA_XFER_UNEXPECTED_SEGMENT_NUMBER] =   EINVAL,
1215                 [WA_XFER_STATUS_RPIPE_TYPE_MISMATCH] =  EINVAL,
1216         };
1217         status &= 0x3f;
1218
1219         if (status == 0)
1220                 return 0;
1221         if (status >= ARRAY_SIZE(xlat)) {
1222                 printk_ratelimited(KERN_ERR "%s(): BUG? "
1223                                "Unknown WA transfer status 0x%02x\n",
1224                                __func__, real_status);
1225                 return -EINVAL;
1226         }
1227         errno = xlat[status];
1228         if (unlikely(errno > 0)) {
1229                 printk_ratelimited(KERN_ERR "%s(): BUG? "
1230                                "Inconsistent WA status: 0x%02x\n",
1231                                __func__, real_status);
1232                 errno = -errno;
1233         }
1234         return errno;
1235 }
1236
1237 /*
1238  * Process a xfer result completion message
1239  *
1240  * inbound transfers: need to schedule a DTI read
1241  *
1242  * FIXME: this functio needs to be broken up in parts
1243  */
1244 static void wa_xfer_result_chew(struct wahc *wa, struct wa_xfer *xfer)
1245 {
1246         int result;
1247         struct device *dev = &wa->usb_iface->dev;
1248         unsigned long flags;
1249         u8 seg_idx;
1250         struct wa_seg *seg;
1251         struct wa_rpipe *rpipe;
1252         struct wa_xfer_result *xfer_result = wa->xfer_result;
1253         u8 done = 0;
1254         u8 usb_status;
1255         unsigned rpipe_ready = 0;
1256
1257         spin_lock_irqsave(&xfer->lock, flags);
1258         seg_idx = xfer_result->bTransferSegment & 0x7f;
1259         if (unlikely(seg_idx >= xfer->segs))
1260                 goto error_bad_seg;
1261         seg = xfer->seg[seg_idx];
1262         rpipe = xfer->ep->hcpriv;
1263         usb_status = xfer_result->bTransferStatus;
1264         dev_dbg(dev, "xfer %p#%u: bTransferStatus 0x%02x (seg %u)\n",
1265                 xfer, seg_idx, usb_status, seg->status);
1266         if (seg->status == WA_SEG_ABORTED
1267             || seg->status == WA_SEG_ERROR)     /* already handled */
1268                 goto segment_aborted;
1269         if (seg->status == WA_SEG_SUBMITTED)    /* ops, got here */
1270                 seg->status = WA_SEG_PENDING;   /* before wa_seg{_dto}_cb() */
1271         if (seg->status != WA_SEG_PENDING) {
1272                 if (printk_ratelimit())
1273                         dev_err(dev, "xfer %p#%u: Bad segment state %u\n",
1274                                 xfer, seg_idx, seg->status);
1275                 seg->status = WA_SEG_PENDING;   /* workaround/"fix" it */
1276         }
1277         if (usb_status & 0x80) {
1278                 seg->result = wa_xfer_status_to_errno(usb_status);
1279                 dev_err(dev, "DTI: xfer %p#%u failed (0x%02x)\n",
1280                         xfer, seg->index, usb_status);
1281                 goto error_complete;
1282         }
1283         /* FIXME: we ignore warnings, tally them for stats */
1284         if (usb_status & 0x40)          /* Warning?... */
1285                 usb_status = 0;         /* ... pass */
1286         if (xfer->is_inbound) { /* IN data phase: read to buffer */
1287                 seg->status = WA_SEG_DTI_PENDING;
1288                 BUG_ON(wa->buf_in_urb->status == -EINPROGRESS);
1289                 if (xfer->is_dma) {
1290                         wa->buf_in_urb->transfer_dma =
1291                                 xfer->urb->transfer_dma
1292                                 + seg_idx * xfer->seg_size;
1293                         wa->buf_in_urb->transfer_flags
1294                                 |= URB_NO_TRANSFER_DMA_MAP;
1295                 } else {
1296                         wa->buf_in_urb->transfer_buffer =
1297                                 xfer->urb->transfer_buffer
1298                                 + seg_idx * xfer->seg_size;
1299                         wa->buf_in_urb->transfer_flags
1300                                 &= ~URB_NO_TRANSFER_DMA_MAP;
1301                 }
1302                 wa->buf_in_urb->transfer_buffer_length =
1303                         le32_to_cpu(xfer_result->dwTransferLength);
1304                 wa->buf_in_urb->context = seg;
1305                 result = usb_submit_urb(wa->buf_in_urb, GFP_ATOMIC);
1306                 if (result < 0)
1307                         goto error_submit_buf_in;
1308         } else {
1309                 /* OUT data phase, complete it -- */
1310                 seg->status = WA_SEG_DONE;
1311                 seg->result = le32_to_cpu(xfer_result->dwTransferLength);
1312                 xfer->segs_done++;
1313                 rpipe_ready = rpipe_avail_inc(rpipe);
1314                 done = __wa_xfer_is_done(xfer);
1315         }
1316         spin_unlock_irqrestore(&xfer->lock, flags);
1317         if (done)
1318                 wa_xfer_completion(xfer);
1319         if (rpipe_ready)
1320                 wa_xfer_delayed_run(rpipe);
1321         return;
1322
1323 error_submit_buf_in:
1324         if (edc_inc(&wa->dti_edc, EDC_MAX_ERRORS, EDC_ERROR_TIMEFRAME)) {
1325                 dev_err(dev, "DTI: URB max acceptable errors "
1326                         "exceeded, resetting device\n");
1327                 wa_reset_all(wa);
1328         }
1329         if (printk_ratelimit())
1330                 dev_err(dev, "xfer %p#%u: can't submit DTI data phase: %d\n",
1331                         xfer, seg_idx, result);
1332         seg->result = result;
1333 error_complete:
1334         seg->status = WA_SEG_ERROR;
1335         xfer->segs_done++;
1336         rpipe_ready = rpipe_avail_inc(rpipe);
1337         __wa_xfer_abort(xfer);
1338         done = __wa_xfer_is_done(xfer);
1339         spin_unlock_irqrestore(&xfer->lock, flags);
1340         if (done)
1341                 wa_xfer_completion(xfer);
1342         if (rpipe_ready)
1343                 wa_xfer_delayed_run(rpipe);
1344         return;
1345
1346 error_bad_seg:
1347         spin_unlock_irqrestore(&xfer->lock, flags);
1348         wa_urb_dequeue(wa, xfer->urb);
1349         if (printk_ratelimit())
1350                 dev_err(dev, "xfer %p#%u: bad segment\n", xfer, seg_idx);
1351         if (edc_inc(&wa->dti_edc, EDC_MAX_ERRORS, EDC_ERROR_TIMEFRAME)) {
1352                 dev_err(dev, "DTI: URB max acceptable errors "
1353                         "exceeded, resetting device\n");
1354                 wa_reset_all(wa);
1355         }
1356         return;
1357
1358 segment_aborted:
1359         /* nothing to do, as the aborter did the completion */
1360         spin_unlock_irqrestore(&xfer->lock, flags);
1361 }
1362
1363 /*
1364  * Callback for the IN data phase
1365  *
1366  * If successful transition state; otherwise, take a note of the
1367  * error, mark this segment done and try completion.
1368  *
1369  * Note we don't access until we are sure that the transfer hasn't
1370  * been cancelled (ECONNRESET, ENOENT), which could mean that
1371  * seg->xfer could be already gone.
1372  */
1373 static void wa_buf_in_cb(struct urb *urb)
1374 {
1375         struct wa_seg *seg = urb->context;
1376         struct wa_xfer *xfer = seg->xfer;
1377         struct wahc *wa;
1378         struct device *dev;
1379         struct wa_rpipe *rpipe;
1380         unsigned rpipe_ready;
1381         unsigned long flags;
1382         u8 done = 0;
1383
1384         switch (urb->status) {
1385         case 0:
1386                 spin_lock_irqsave(&xfer->lock, flags);
1387                 wa = xfer->wa;
1388                 dev = &wa->usb_iface->dev;
1389                 rpipe = xfer->ep->hcpriv;
1390                 dev_dbg(dev, "xfer %p#%u: data in done (%zu bytes)\n",
1391                         xfer, seg->index, (size_t)urb->actual_length);
1392                 seg->status = WA_SEG_DONE;
1393                 seg->result = urb->actual_length;
1394                 xfer->segs_done++;
1395                 rpipe_ready = rpipe_avail_inc(rpipe);
1396                 done = __wa_xfer_is_done(xfer);
1397                 spin_unlock_irqrestore(&xfer->lock, flags);
1398                 if (done)
1399                         wa_xfer_completion(xfer);
1400                 if (rpipe_ready)
1401                         wa_xfer_delayed_run(rpipe);
1402                 break;
1403         case -ECONNRESET:       /* URB unlinked; no need to do anything */
1404         case -ENOENT:           /* as it was done by the who unlinked us */
1405                 break;
1406         default:                /* Other errors ... */
1407                 spin_lock_irqsave(&xfer->lock, flags);
1408                 wa = xfer->wa;
1409                 dev = &wa->usb_iface->dev;
1410                 rpipe = xfer->ep->hcpriv;
1411                 if (printk_ratelimit())
1412                         dev_err(dev, "xfer %p#%u: data in error %d\n",
1413                                 xfer, seg->index, urb->status);
1414                 if (edc_inc(&wa->nep_edc, EDC_MAX_ERRORS,
1415                             EDC_ERROR_TIMEFRAME)){
1416                         dev_err(dev, "DTO: URB max acceptable errors "
1417                                 "exceeded, resetting device\n");
1418                         wa_reset_all(wa);
1419                 }
1420                 seg->status = WA_SEG_ERROR;
1421                 seg->result = urb->status;
1422                 xfer->segs_done++;
1423                 rpipe_ready = rpipe_avail_inc(rpipe);
1424                 __wa_xfer_abort(xfer);
1425                 done = __wa_xfer_is_done(xfer);
1426                 spin_unlock_irqrestore(&xfer->lock, flags);
1427                 if (done)
1428                         wa_xfer_completion(xfer);
1429                 if (rpipe_ready)
1430                         wa_xfer_delayed_run(rpipe);
1431         }
1432 }
1433
1434 /*
1435  * Handle an incoming transfer result buffer
1436  *
1437  * Given a transfer result buffer, it completes the transfer (possibly
1438  * scheduling and buffer in read) and then resubmits the DTI URB for a
1439  * new transfer result read.
1440  *
1441  *
1442  * The xfer_result DTI URB state machine
1443  *
1444  * States: OFF | RXR (Read-Xfer-Result) | RBI (Read-Buffer-In)
1445  *
1446  * We start in OFF mode, the first xfer_result notification [through
1447  * wa_handle_notif_xfer()] moves us to RXR by posting the DTI-URB to
1448  * read.
1449  *
1450  * We receive a buffer -- if it is not a xfer_result, we complain and
1451  * repost the DTI-URB. If it is a xfer_result then do the xfer seg
1452  * request accounting. If it is an IN segment, we move to RBI and post
1453  * a BUF-IN-URB to the right buffer. The BUF-IN-URB callback will
1454  * repost the DTI-URB and move to RXR state. if there was no IN
1455  * segment, it will repost the DTI-URB.
1456  *
1457  * We go back to OFF when we detect a ENOENT or ESHUTDOWN (or too many
1458  * errors) in the URBs.
1459  */
1460 static void wa_xfer_result_cb(struct urb *urb)
1461 {
1462         int result;
1463         struct wahc *wa = urb->context;
1464         struct device *dev = &wa->usb_iface->dev;
1465         struct wa_xfer_result *xfer_result;
1466         u32 xfer_id;
1467         struct wa_xfer *xfer;
1468         u8 usb_status;
1469
1470         BUG_ON(wa->dti_urb != urb);
1471         switch (wa->dti_urb->status) {
1472         case 0:
1473                 /* We have a xfer result buffer; check it */
1474                 dev_dbg(dev, "DTI: xfer result %d bytes at %p\n",
1475                         urb->actual_length, urb->transfer_buffer);
1476                 if (wa->dti_urb->actual_length != sizeof(*xfer_result)) {
1477                         dev_err(dev, "DTI Error: xfer result--bad size "
1478                                 "xfer result (%d bytes vs %zu needed)\n",
1479                                 urb->actual_length, sizeof(*xfer_result));
1480                         break;
1481                 }
1482                 xfer_result = wa->xfer_result;
1483                 if (xfer_result->hdr.bLength != sizeof(*xfer_result)) {
1484                         dev_err(dev, "DTI Error: xfer result--"
1485                                 "bad header length %u\n",
1486                                 xfer_result->hdr.bLength);
1487                         break;
1488                 }
1489                 if (xfer_result->hdr.bNotifyType != WA_XFER_RESULT) {
1490                         dev_err(dev, "DTI Error: xfer result--"
1491                                 "bad header type 0x%02x\n",
1492                                 xfer_result->hdr.bNotifyType);
1493                         break;
1494                 }
1495                 usb_status = xfer_result->bTransferStatus & 0x3f;
1496                 if (usb_status == WA_XFER_STATUS_ABORTED
1497                     || usb_status == WA_XFER_STATUS_NOT_FOUND)
1498                         /* taken care of already */
1499                         break;
1500                 xfer_id = xfer_result->dwTransferID;
1501                 xfer = wa_xfer_get_by_id(wa, xfer_id);
1502                 if (xfer == NULL) {
1503                         /* FIXME: transaction might have been cancelled */
1504                         dev_err(dev, "DTI Error: xfer result--"
1505                                 "unknown xfer 0x%08x (status 0x%02x)\n",
1506                                 xfer_id, usb_status);
1507                         break;
1508                 }
1509                 wa_xfer_result_chew(wa, xfer);
1510                 wa_xfer_put(xfer);
1511                 break;
1512         case -ENOENT:           /* (we killed the URB)...so, no broadcast */
1513         case -ESHUTDOWN:        /* going away! */
1514                 dev_dbg(dev, "DTI: going down! %d\n", urb->status);
1515                 goto out;
1516         default:
1517                 /* Unknown error */
1518                 if (edc_inc(&wa->dti_edc, EDC_MAX_ERRORS,
1519                             EDC_ERROR_TIMEFRAME)) {
1520                         dev_err(dev, "DTI: URB max acceptable errors "
1521                                 "exceeded, resetting device\n");
1522                         wa_reset_all(wa);
1523                         goto out;
1524                 }
1525                 if (printk_ratelimit())
1526                         dev_err(dev, "DTI: URB error %d\n", urb->status);
1527                 break;
1528         }
1529         /* Resubmit the DTI URB */
1530         result = usb_submit_urb(wa->dti_urb, GFP_ATOMIC);
1531         if (result < 0) {
1532                 dev_err(dev, "DTI Error: Could not submit DTI URB (%d), "
1533                         "resetting\n", result);
1534                 wa_reset_all(wa);
1535         }
1536 out:
1537         return;
1538 }
1539
1540 /*
1541  * Transfer complete notification
1542  *
1543  * Called from the notif.c code. We get a notification on EP2 saying
1544  * that some endpoint has some transfer result data available. We are
1545  * about to read it.
1546  *
1547  * To speed up things, we always have a URB reading the DTI URB; we
1548  * don't really set it up and start it until the first xfer complete
1549  * notification arrives, which is what we do here.
1550  *
1551  * Follow up in wa_xfer_result_cb(), as that's where the whole state
1552  * machine starts.
1553  *
1554  * So here we just initialize the DTI URB for reading transfer result
1555  * notifications and also the buffer-in URB, for reading buffers. Then
1556  * we just submit the DTI URB.
1557  *
1558  * @wa shall be referenced
1559  */
1560 void wa_handle_notif_xfer(struct wahc *wa, struct wa_notif_hdr *notif_hdr)
1561 {
1562         int result;
1563         struct device *dev = &wa->usb_iface->dev;
1564         struct wa_notif_xfer *notif_xfer;
1565         const struct usb_endpoint_descriptor *dti_epd = wa->dti_epd;
1566
1567         notif_xfer = container_of(notif_hdr, struct wa_notif_xfer, hdr);
1568         BUG_ON(notif_hdr->bNotifyType != WA_NOTIF_TRANSFER);
1569
1570         if ((0x80 | notif_xfer->bEndpoint) != dti_epd->bEndpointAddress) {
1571                 /* FIXME: hardcoded limitation, adapt */
1572                 dev_err(dev, "BUG: DTI ep is %u, not %u (hack me)\n",
1573                         notif_xfer->bEndpoint, dti_epd->bEndpointAddress);
1574                 goto error;
1575         }
1576         if (wa->dti_urb != NULL)        /* DTI URB already started */
1577                 goto out;
1578
1579         wa->dti_urb = usb_alloc_urb(0, GFP_KERNEL);
1580         if (wa->dti_urb == NULL) {
1581                 dev_err(dev, "Can't allocate DTI URB\n");
1582                 goto error_dti_urb_alloc;
1583         }
1584         usb_fill_bulk_urb(
1585                 wa->dti_urb, wa->usb_dev,
1586                 usb_rcvbulkpipe(wa->usb_dev, 0x80 | notif_xfer->bEndpoint),
1587                 wa->xfer_result, wa->xfer_result_size,
1588                 wa_xfer_result_cb, wa);
1589
1590         wa->buf_in_urb = usb_alloc_urb(0, GFP_KERNEL);
1591         if (wa->buf_in_urb == NULL) {
1592                 dev_err(dev, "Can't allocate BUF-IN URB\n");
1593                 goto error_buf_in_urb_alloc;
1594         }
1595         usb_fill_bulk_urb(
1596                 wa->buf_in_urb, wa->usb_dev,
1597                 usb_rcvbulkpipe(wa->usb_dev, 0x80 | notif_xfer->bEndpoint),
1598                 NULL, 0, wa_buf_in_cb, wa);
1599         result = usb_submit_urb(wa->dti_urb, GFP_KERNEL);
1600         if (result < 0) {
1601                 dev_err(dev, "DTI Error: Could not submit DTI URB (%d), "
1602                         "resetting\n", result);
1603                 goto error_dti_urb_submit;
1604         }
1605 out:
1606         return;
1607
1608 error_dti_urb_submit:
1609         usb_put_urb(wa->buf_in_urb);
1610 error_buf_in_urb_alloc:
1611         usb_put_urb(wa->dti_urb);
1612         wa->dti_urb = NULL;
1613 error_dti_urb_alloc:
1614 error:
1615         wa_reset_all(wa);
1616 }