drivers/usb/host/uhci-q.c

   1 /*
   2  * Universal Host Controller Interface driver for USB.
   3  *
   4  * Maintainer: Alan Stern <stern@rowland.harvard.edu>
   5  *
   6  * (C) Copyright 1999 Linus Torvalds
   7  * (C) Copyright 1999-2002 Johannes Erdfelt, johannes@erdfelt.com
   8  * (C) Copyright 1999 Randy Dunlap
   9  * (C) Copyright 1999 Georg Acher, acher@in.tum.de
  10  * (C) Copyright 1999 Deti Fliegl, deti@fliegl.de
  11  * (C) Copyright 1999 Thomas Sailer, sailer@ife.ee.ethz.ch
  12  * (C) Copyright 1999 Roman Weissgaerber, weissg@vienna.at
  13  * (C) Copyright 2000 Yggdrasil Computing, Inc. (port of new PCI interface
  14  *               support from usb-ohci.c by Adam Richter, adam@yggdrasil.com).
  15  * (C) Copyright 1999 Gregory P. Smith (from usb-ohci.c)
  16  * (C) Copyright 2004-2007 Alan Stern, stern@rowland.harvard.edu
  17  */
  18
  19
  20 /*
  21  * Technically, updating td->status here is a race, but it's not really a
  22  * problem. The worst that can happen is that we set the IOC bit again
  23  * generating a spurious interrupt. We could fix this by creating another
  24  * QH and leaving the IOC bit always set, but then we would have to play
  25  * games with the FSBR code to make sure we get the correct order in all
  26  * the cases. I don't think it's worth the effort
  27  */
  28 static void uhci_set_next_interrupt(struct uhci_hcd *uhci)
  29 {
  30         if (uhci->is_stopped)
  31                 mod_timer(&uhci_to_hcd(uhci)->rh_timer, jiffies);
  32         uhci->term_td->status |= cpu_to_le32(TD_CTRL_IOC);
  33 }
  34
  35 static inline void uhci_clear_next_interrupt(struct uhci_hcd *uhci)
  36 {
  37         uhci->term_td->status &= ~cpu_to_le32(TD_CTRL_IOC);
  38 }
  39
  40
  41 /*
  42  * Full-Speed Bandwidth Reclamation (FSBR).
  43  * We turn on FSBR whenever a queue that wants it is advancing,
  44  * and leave it on for a short time thereafter.
  45  */
  46 static void uhci_fsbr_on(struct uhci_hcd *uhci)
  47 {
  48         struct uhci_qh *lqh;
  49
  50         /* The terminating skeleton QH always points back to the first
  51          * FSBR QH.  Make the last async QH point to the terminating
  52          * skeleton QH. */
  53         uhci->fsbr_is_on = 1;
  54         lqh = list_entry(uhci->skel_async_qh->node.prev,
  55                         struct uhci_qh, node);
  56         lqh->link = LINK_TO_QH(uhci->skel_term_qh);
  57 }
  58
  59 static void uhci_fsbr_off(struct uhci_hcd *uhci)
  60 {
  61         struct uhci_qh *lqh;
  62
  63         /* Remove the link from the last async QH to the terminating
  64          * skeleton QH. */
  65         uhci->fsbr_is_on = 0;
  66         lqh = list_entry(uhci->skel_async_qh->node.prev,
  67                         struct uhci_qh, node);
  68         lqh->link = UHCI_PTR_TERM;
  69 }
  70
  71 static void uhci_add_fsbr(struct uhci_hcd *uhci, struct urb *urb)
  72 {
  73         struct urb_priv *urbp = urb->hcpriv;
  74
  75         if (!(urb->transfer_flags & URB_NO_FSBR))
  76                 urbp->fsbr = 1;
  77 }
  78
  79 static void uhci_urbp_wants_fsbr(struct uhci_hcd *uhci, struct urb_priv *urbp)
  80 {
  81         if (urbp->fsbr) {
  82                 uhci->fsbr_is_wanted = 1;
  83                 if (!uhci->fsbr_is_on)
  84                         uhci_fsbr_on(uhci);
  85                 else if (uhci->fsbr_expiring) {
  86                         uhci->fsbr_expiring = 0;
  87                         del_timer(&uhci->fsbr_timer);
  88                 }
  89         }
  90 }
  91
  92 static void uhci_fsbr_timeout(unsigned long _uhci)
  93 {
  94         struct uhci_hcd *uhci = (struct uhci_hcd *) _uhci;
  95         unsigned long flags;
  96
  97         spin_lock_irqsave(&uhci->lock, flags);
  98         if (uhci->fsbr_expiring) {
  99                 uhci->fsbr_expiring = 0;
 100                 uhci_fsbr_off(uhci);
 101         }
 102         spin_unlock_irqrestore(&uhci->lock, flags);
 103 }
 104
 105
 106 static struct uhci_td *uhci_alloc_td(struct uhci_hcd *uhci)
 107 {
 108         dma_addr_t dma_handle;
 109         struct uhci_td *td;
 110
 111         td = dma_pool_alloc(uhci->td_pool, GFP_ATOMIC, &dma_handle);
 112         if (!td)
 113                 return NULL;
 114
 115         td->dma_handle = dma_handle;
 116         td->frame = -1;
 117
 118         INIT_LIST_HEAD(&td->list);
 119         INIT_LIST_HEAD(&td->fl_list);
 120
 121         return td;
 122 }
 123
 124 static void uhci_free_td(struct uhci_hcd *uhci, struct uhci_td *td)
 125 {
 126         if (!list_empty(&td->list))
 127                 dev_WARN(uhci_dev(uhci), "td %p still in list!\n", td);
 128         if (!list_empty(&td->fl_list))
 129                 dev_WARN(uhci_dev(uhci), "td %p still in fl_list!\n", td);
 130
 131         dma_pool_free(uhci->td_pool, td, td->dma_handle);
 132 }
 133
 134 static inline void uhci_fill_td(struct uhci_td *td, u32 status,
 135                 u32 token, u32 buffer)
 136 {
 137         td->status = cpu_to_le32(status);
 138         td->token = cpu_to_le32(token);
 139         td->buffer = cpu_to_le32(buffer);
 140 }
 141
 142 static void uhci_add_td_to_urbp(struct uhci_td *td, struct urb_priv *urbp)
 143 {
 144         list_add_tail(&td->list, &urbp->td_list);
 145 }
 146
 147 static void uhci_remove_td_from_urbp(struct uhci_td *td)
 148 {
 149         list_del_init(&td->list);
 150 }
 151
 152 /*
 153  * We insert Isochronous URBs directly into the frame list at the beginning
 154  */
 155 static inline void uhci_insert_td_in_frame_list(struct uhci_hcd *uhci,
 156                 struct uhci_td *td, unsigned framenum)
 157 {
 158         framenum &= (UHCI_NUMFRAMES - 1);
 159
 160         td->frame = framenum;
 161
 162         /* Is there a TD already mapped there? */
 163         if (uhci->frame_cpu[framenum]) {
 164                 struct uhci_td *ftd, *ltd;
 165
 166                 ftd = uhci->frame_cpu[framenum];
 167                 ltd = list_entry(ftd->fl_list.prev, struct uhci_td, fl_list);
 168
 169                 list_add_tail(&td->fl_list, &ftd->fl_list);
 170
 171                 td->link = ltd->link;
 172                 wmb();
 173                 ltd->link = LINK_TO_TD(td);
 174         } else {
 175                 td->link = uhci->frame[framenum];
 176                 wmb();
 177                 uhci->frame[framenum] = LINK_TO_TD(td);
 178                 uhci->frame_cpu[framenum] = td;
 179         }
 180 }
 181
 182 static inline void uhci_remove_td_from_frame_list(struct uhci_hcd *uhci,
 183                 struct uhci_td *td)
 184 {
 185         /* If it's not inserted, don't remove it */
 186         if (td->frame == -1) {
 187                 WARN_ON(!list_empty(&td->fl_list));
 188                 return;
 189         }
 190
 191         if (uhci->frame_cpu[td->frame] == td) {
 192                 if (list_empty(&td->fl_list)) {
 193                         uhci->frame[td->frame] = td->link;
 194                         uhci->frame_cpu[td->frame] = NULL;
 195                 } else {
 196                         struct uhci_td *ntd;
 197
 198                         ntd = list_entry(td->fl_list.next,
 199                                          struct uhci_td,
 200                                          fl_list);
 201                         uhci->frame[td->frame] = LINK_TO_TD(ntd);
 202                         uhci->frame_cpu[td->frame] = ntd;
 203                 }
 204         } else {
 205                 struct uhci_td *ptd;
 206
 207                 ptd = list_entry(td->fl_list.prev, struct uhci_td, fl_list);
 208                 ptd->link = td->link;
 209         }
 210
 211         list_del_init(&td->fl_list);
 212         td->frame = -1;
 213 }
 214
 215 static inline void uhci_remove_tds_from_frame(struct uhci_hcd *uhci,
 216                 unsigned int framenum)
 217 {
 218         struct uhci_td *ftd, *ltd;
 219
 220         framenum &= (UHCI_NUMFRAMES - 1);
 221
 222         ftd = uhci->frame_cpu[framenum];
 223         if (ftd) {
 224                 ltd = list_entry(ftd->fl_list.prev, struct uhci_td, fl_list);
 225                 uhci->frame[framenum] = ltd->link;
 226                 uhci->frame_cpu[framenum] = NULL;
 227
 228                 while (!list_empty(&ftd->fl_list))
 229                         list_del_init(ftd->fl_list.prev);
 230         }
 231 }
 232
 233 /*
 234  * Remove all the TDs for an Isochronous URB from the frame list
 235  */
 236 static void uhci_unlink_isochronous_tds(struct uhci_hcd *uhci, struct urb *urb)
 237 {
 238         struct urb_priv *urbp = (struct urb_priv *) urb->hcpriv;
 239         struct uhci_td *td;
 240
 241         list_for_each_entry(td, &urbp->td_list, list)
 242                 uhci_remove_td_from_frame_list(uhci, td);
 243 }
 244
 245 static struct uhci_qh *uhci_alloc_qh(struct uhci_hcd *uhci,
 246                 struct usb_device *udev, struct usb_host_endpoint *hep)
 247 {
 248         dma_addr_t dma_handle;
 249         struct uhci_qh *qh;
 250
 251         qh = dma_pool_alloc(uhci->qh_pool, GFP_ATOMIC, &dma_handle);
 252         if (!qh)
 253                 return NULL;
 254
 255         memset(qh, 0, sizeof(*qh));
 256         qh->dma_handle = dma_handle;
 257
 258         qh->element = UHCI_PTR_TERM;
 259         qh->link = UHCI_PTR_TERM;
 260
 261         INIT_LIST_HEAD(&qh->queue);
 262         INIT_LIST_HEAD(&qh->node);
 263
 264         if (udev) {             /* Normal QH */
 265                 qh->type = usb_endpoint_type(&hep->desc);
 266                 if (qh->type != USB_ENDPOINT_XFER_ISOC) {
 267                         qh->dummy_td = uhci_alloc_td(uhci);
 268                         if (!qh->dummy_td) {
 269                                 dma_pool_free(uhci->qh_pool, qh, dma_handle);
 270                                 return NULL;
 271                         }
 272                 }
 273                 qh->state = QH_STATE_IDLE;
 274                 qh->hep = hep;
 275                 qh->udev = udev;
 276                 hep->hcpriv = qh;
 277
 278                 if (qh->type == USB_ENDPOINT_XFER_INT ||
 279                                 qh->type == USB_ENDPOINT_XFER_ISOC)
 280                         qh->load = usb_calc_bus_time(udev->speed,
 281                                         usb_endpoint_dir_in(&hep->desc),
 282                                         qh->type == USB_ENDPOINT_XFER_ISOC,
 283                                         le16_to_cpu(hep->desc.wMaxPacketSize))
 284                                 / 1000 + 1;
 285
 286         } else {                /* Skeleton QH */
 287                 qh->state = QH_STATE_ACTIVE;
 288                 qh->type = -1;
 289         }
 290         return qh;
 291 }
 292
 293 static void uhci_free_qh(struct uhci_hcd *uhci, struct uhci_qh *qh)
 294 {
 295         WARN_ON(qh->state != QH_STATE_IDLE && qh->udev);
 296         if (!list_empty(&qh->queue))
 297                 dev_WARN(uhci_dev(uhci), "qh %p list not empty!\n", qh);
 298
 299         list_del(&qh->node);
 300         if (qh->udev) {
 301                 qh->hep->hcpriv = NULL;
 302                 if (qh->dummy_td)
 303                         uhci_free_td(uhci, qh->dummy_td);
 304         }
 305         dma_pool_free(uhci->qh_pool, qh, qh->dma_handle);
 306 }
 307
 308 /*
 309  * When a queue is stopped and a dequeued URB is given back, adjust
 310  * the previous TD link (if the URB isn't first on the queue) or
 311  * save its toggle value (if it is first and is currently executing).
 312  *
 313  * Returns 0 if the URB should not yet be given back, 1 otherwise.
 314  */
 315 static int uhci_cleanup_queue(struct uhci_hcd *uhci, struct uhci_qh *qh,
 316                 struct urb *urb)
 317 {
 318         struct urb_priv *urbp = urb->hcpriv;
 319         struct uhci_td *td;
 320         int ret = 1;
 321
 322         /* Isochronous pipes don't use toggles and their TD link pointers
 323          * get adjusted during uhci_urb_dequeue().  But since their queues
 324          * cannot truly be stopped, we have to watch out for dequeues
 325          * occurring after the nominal unlink frame. */
 326         if (qh->type == USB_ENDPOINT_XFER_ISOC) {
 327                 ret = (uhci->frame_number + uhci->is_stopped !=
 328                                 qh->unlink_frame);
 329                 goto done;
 330         }
 331
 332         /* If the URB isn't first on its queue, adjust the link pointer
 333          * of the last TD in the previous URB.  The toggle doesn't need
 334          * to be saved since this URB can't be executing yet. */
 335         if (qh->queue.next != &urbp->node) {
 336                 struct urb_priv *purbp;
 337                 struct uhci_td *ptd;
 338
 339                 purbp = list_entry(urbp->node.prev, struct urb_priv, node);
 340                 WARN_ON(list_empty(&purbp->td_list));
 341                 ptd = list_entry(purbp->td_list.prev, struct uhci_td,
 342                                 list);
 343                 td = list_entry(urbp->td_list.prev, struct uhci_td,
 344                                 list);
 345                 ptd->link = td->link;
 346                 goto done;
 347         }
 348
 349         /* If the QH element pointer is UHCI_PTR_TERM then then currently
 350          * executing URB has already been unlinked, so this one isn't it. */
 351         if (qh_element(qh) == UHCI_PTR_TERM)
 352                 goto done;
 353         qh->element = UHCI_PTR_TERM;
 354
 355         /* Control pipes don't have to worry about toggles */
 356         if (qh->type == USB_ENDPOINT_XFER_CONTROL)
 357                 goto done;
 358
 359         /* Save the next toggle value */
 360         WARN_ON(list_empty(&urbp->td_list));
 361         td = list_entry(urbp->td_list.next, struct uhci_td, list);
 362         qh->needs_fixup = 1;
 363         qh->initial_toggle = uhci_toggle(td_token(td));
 364
 365 done:
 366         return ret;
 367 }
 368
 369 /*
 370  * Fix up the data toggles for URBs in a queue, when one of them
 371  * terminates early (short transfer, error, or dequeued).
 372  */
 373 static void uhci_fixup_toggles(struct uhci_qh *qh, int skip_first)
 374 {
 375         struct urb_priv *urbp = NULL;
 376         struct uhci_td *td;
 377         unsigned int toggle = qh->initial_toggle;
 378         unsigned int pipe;
 379
 380         /* Fixups for a short transfer start with the second URB in the
 381          * queue (the short URB is the first). */
 382         if (skip_first)
 383                 urbp = list_entry(qh->queue.next, struct urb_priv, node);
 384
 385         /* When starting with the first URB, if the QH element pointer is
 386          * still valid then we know the URB's toggles are okay. */
 387         else if (qh_element(qh) != UHCI_PTR_TERM)
 388                 toggle = 2;
 389
 390         /* Fix up the toggle for the URBs in the queue.  Normally this
 391          * loop won't run more than once: When an error or short transfer
 392          * occurs, the queue usually gets emptied. */
 393         urbp = list_prepare_entry(urbp, &qh->queue, node);
 394         list_for_each_entry_continue(urbp, &qh->queue, node) {
 395
 396                 /* If the first TD has the right toggle value, we don't
 397                  * need to change any toggles in this URB */
 398                 td = list_entry(urbp->td_list.next, struct uhci_td, list);
 399                 if (toggle > 1 || uhci_toggle(td_token(td)) == toggle) {
 400                         td = list_entry(urbp->td_list.prev, struct uhci_td,
 401                                         list);
 402                         toggle = uhci_toggle(td_token(td)) ^ 1;
 403
 404                 /* Otherwise all the toggles in the URB have to be switched */
 405                 } else {
 406                         list_for_each_entry(td, &urbp->td_list, list) {
 407                                 td->token ^= cpu_to_le32(
 408                                                         TD_TOKEN_TOGGLE);
 409                                 toggle ^= 1;
 410                         }
 411                 }
 412         }
 413
 414         wmb();
 415         pipe = list_entry(qh->queue.next, struct urb_priv, node)->urb->pipe;
 416         usb_settoggle(qh->udev, usb_pipeendpoint(pipe),
 417                         usb_pipeout(pipe), toggle);
 418         qh->needs_fixup = 0;
 419 }
 420
 421 /*
 422  * Link an Isochronous QH into its skeleton's list
 423  */
 424 static inline void link_iso(struct uhci_hcd *uhci, struct uhci_qh *qh)
 425 {
 426         list_add_tail(&qh->node, &uhci->skel_iso_qh->node);
 427
 428         /* Isochronous QHs aren't linked by the hardware */
 429 }
 430
 431 /*
 432  * Link a high-period interrupt QH into the schedule at the end of its
 433  * skeleton's list
 434  */
 435 static void link_interrupt(struct uhci_hcd *uhci, struct uhci_qh *qh)
 436 {
 437         struct uhci_qh *pqh;
 438
 439         list_add_tail(&qh->node, &uhci->skelqh[qh->skel]->node);
 440
 441         pqh = list_entry(qh->node.prev, struct uhci_qh, node);
 442         qh->link = pqh->link;
 443         wmb();
 444         pqh->link = LINK_TO_QH(qh);
 445 }
 446
 447 /*
 448  * Link a period-1 interrupt or async QH into the schedule at the
 449  * correct spot in the async skeleton's list, and update the FSBR link
 450  */
 451 static void link_async(struct uhci_hcd *uhci, struct uhci_qh *qh)
 452 {
 453         struct uhci_qh *pqh;
 454         __le32 link_to_new_qh;
 455
 456         /* Find the predecessor QH for our new one and insert it in the list.
 457          * The list of QHs is expected to be short, so linear search won't
 458          * take too long. */
 459         list_for_each_entry_reverse(pqh, &uhci->skel_async_qh->node, node) {
 460                 if (pqh->skel <= qh->skel)
 461                         break;
 462         }
 463         list_add(&qh->node, &pqh->node);
 464
 465         /* Link it into the schedule */
 466         qh->link = pqh->link;
 467         wmb();
 468         link_to_new_qh = LINK_TO_QH(qh);
 469         pqh->link = link_to_new_qh;
 470
 471         /* If this is now the first FSBR QH, link the terminating skeleton
 472          * QH to it. */
 473         if (pqh->skel < SKEL_FSBR && qh->skel >= SKEL_FSBR)
 474                 uhci->skel_term_qh->link = link_to_new_qh;
 475 }
 476
 477 /*
 478  * Put a QH on the schedule in both hardware and software
 479  */
 480 static void uhci_activate_qh(struct uhci_hcd *uhci, struct uhci_qh *qh)
 481 {
 482         WARN_ON(list_empty(&qh->queue));
 483
 484         /* Set the element pointer if it isn't set already.
 485          * This isn't needed for Isochronous queues, but it doesn't hurt. */
 486         if (qh_element(qh) == UHCI_PTR_TERM) {
 487                 struct urb_priv *urbp = list_entry(qh->queue.next,
 488                                 struct urb_priv, node);
 489                 struct uhci_td *td = list_entry(urbp->td_list.next,
 490                                 struct uhci_td, list);
 491
 492                 qh->element = LINK_TO_TD(td);
 493         }
 494
 495         /* Treat the queue as if it has just advanced */
 496         qh->wait_expired = 0;
 497         qh->advance_jiffies = jiffies;
 498
 499         if (qh->state == QH_STATE_ACTIVE)
 500                 return;
 501         qh->state = QH_STATE_ACTIVE;
 502
 503         /* Move the QH from its old list to the correct spot in the appropriate
 504          * skeleton's list */
 505         if (qh == uhci->next_qh)
 506                 uhci->next_qh = list_entry(qh->node.next, struct uhci_qh,
 507                                 node);
 508         list_del(&qh->node);
 509
 510         if (qh->skel == SKEL_ISO)
 511                 link_iso(uhci, qh);
 512         else if (qh->skel < SKEL_ASYNC)
 513                 link_interrupt(uhci, qh);
 514         else
 515                 link_async(uhci, qh);
 516 }
 517
 518 /*
 519  * Unlink a high-period interrupt QH from the schedule
 520  */
 521 static void unlink_interrupt(struct uhci_hcd *uhci, struct uhci_qh *qh)
 522 {
 523         struct uhci_qh *pqh;
 524
 525         pqh = list_entry(qh->node.prev, struct uhci_qh, node);
 526         pqh->link = qh->link;
 527         mb();
 528 }
 529
 530 /*
 531  * Unlink a period-1 interrupt or async QH from the schedule
 532  */
 533 static void unlink_async(struct uhci_hcd *uhci, struct uhci_qh *qh)
 534 {
 535         struct uhci_qh *pqh;
 536         __le32 link_to_next_qh = qh->link;
 537
 538         pqh = list_entry(qh->node.prev, struct uhci_qh, node);
 539         pqh->link = link_to_next_qh;
 540
 541         /* If this was the old first FSBR QH, link the terminating skeleton
 542          * QH to the next (new first FSBR) QH. */
 543         if (pqh->skel < SKEL_FSBR && qh->skel >= SKEL_FSBR)
 544                 uhci->skel_term_qh->link = link_to_next_qh;
 545         mb();
 546 }
 547
 548 /*
 549  * Take a QH off the hardware schedule
 550  */
 551 static void uhci_unlink_qh(struct uhci_hcd *uhci, struct uhci_qh *qh)
 552 {
 553         if (qh->state == QH_STATE_UNLINKING)
 554                 return;
 555         WARN_ON(qh->state != QH_STATE_ACTIVE || !qh->udev);
 556         qh->state = QH_STATE_UNLINKING;
 557
 558         /* Unlink the QH from the schedule and record when we did it */
 559         if (qh->skel == SKEL_ISO)
 560                 ;
 561         else if (qh->skel < SKEL_ASYNC)
 562                 unlink_interrupt(uhci, qh);
 563         else
 564                 unlink_async(uhci, qh);
 565
 566         uhci_get_current_frame_number(uhci);
 567         qh->unlink_frame = uhci->frame_number;
 568
 569         /* Force an interrupt so we know when the QH is fully unlinked */
 570         if (list_empty(&uhci->skel_unlink_qh->node) || uhci->is_stopped)
 571                 uhci_set_next_interrupt(uhci);
 572
 573         /* Move the QH from its old list to the end of the unlinking list */
 574         if (qh == uhci->next_qh)
 575                 uhci->next_qh = list_entry(qh->node.next, struct uhci_qh,
 576                                 node);
 577         list_move_tail(&qh->node, &uhci->skel_unlink_qh->node);
 578 }
 579
 580 /*
 581  * When we and the controller are through with a QH, it becomes IDLE.
 582  * This happens when a QH has been off the schedule (on the unlinking
 583  * list) for more than one frame, or when an error occurs while adding
 584  * the first URB onto a new QH.
 585  */
 586 static void uhci_make_qh_idle(struct uhci_hcd *uhci, struct uhci_qh *qh)
 587 {
 588         WARN_ON(qh->state == QH_STATE_ACTIVE);
 589
 590         if (qh == uhci->next_qh)
 591                 uhci->next_qh = list_entry(qh->node.next, struct uhci_qh,
 592                                 node);
 593         list_move(&qh->node, &uhci->idle_qh_list);
 594         qh->state = QH_STATE_IDLE;
 595
 596         /* Now that the QH is idle, its post_td isn't being used */
 597         if (qh->post_td) {
 598                 uhci_free_td(uhci, qh->post_td);
 599                 qh->post_td = NULL;
 600         }
 601
 602         /* If anyone is waiting for a QH to become idle, wake them up */
 603         if (uhci->num_waiting)
 604                 wake_up_all(&uhci->waitqh);
 605 }
 606
 607 /*
 608  * Find the highest existing bandwidth load for a given phase and period.
 609  */
 610 static int uhci_highest_load(struct uhci_hcd *uhci, int phase, int period)
 611 {
 612         int highest_load = uhci->load[phase];
 613
 614         for (phase += period; phase < MAX_PHASE; phase += period)
 615                 highest_load = max_t(int, highest_load, uhci->load[phase]);
 616         return highest_load;
 617 }
 618
 619 /*
 620  * Set qh->phase to the optimal phase for a periodic transfer and
 621  * check whether the bandwidth requirement is acceptable.
 622  */
 623 static int uhci_check_bandwidth(struct uhci_hcd *uhci, struct uhci_qh *qh)
 624 {
 625         int minimax_load;
 626
 627         /* Find the optimal phase (unless it is already set) and get
 628          * its load value. */
 629         if (qh->phase >= 0)
 630                 minimax_load = uhci_highest_load(uhci, qh->phase, qh->period);
 631         else {
 632                 int phase, load;
 633                 int max_phase = min_t(int, MAX_PHASE, qh->period);
 634
 635                 qh->phase = 0;
 636                 minimax_load = uhci_highest_load(uhci, qh->phase, qh->period);
 637                 for (phase = 1; phase < max_phase; ++phase) {
 638                         load = uhci_highest_load(uhci, phase, qh->period);
 639                         if (load < minimax_load) {
 640                                 minimax_load = load;
 641                                 qh->phase = phase;
 642                         }
 643                 }
 644         }
 645
 646         /* Maximum allowable periodic bandwidth is 90%, or 900 us per frame */
 647         if (minimax_load + qh->load > 900) {
 648                 dev_dbg(uhci_dev(uhci), "bandwidth allocation failed: "
 649                                 "period %d, phase %d, %d + %d us\n",
 650                                 qh->period, qh->phase, minimax_load, qh->load);
 651                 return -ENOSPC;
 652         }
 653         return 0;
 654 }
 655
 656 /*
 657  * Reserve a periodic QH's bandwidth in the schedule
 658  */
 659 static void uhci_reserve_bandwidth(struct uhci_hcd *uhci, struct uhci_qh *qh)
 660 {
 661         int i;
 662         int load = qh->load;
 663         char *p = "??";
 664
 665         for (i = qh->phase; i < MAX_PHASE; i += qh->period) {
 666                 uhci->load[i] += load;
 667                 uhci->total_load += load;
 668         }
 669         uhci_to_hcd(uhci)->self.bandwidth_allocated =
 670                         uhci->total_load / MAX_PHASE;
 671         switch (qh->type) {
 672         case USB_ENDPOINT_XFER_INT:
 673                 ++uhci_to_hcd(uhci)->self.bandwidth_int_reqs;
 674                 p = "INT";
 675                 break;
 676         case USB_ENDPOINT_XFER_ISOC:
 677                 ++uhci_to_hcd(uhci)->self.bandwidth_isoc_reqs;
 678                 p = "ISO";
 679                 break;
 680         }
 681         qh->bandwidth_reserved = 1;
 682         dev_dbg(uhci_dev(uhci),
 683                         "%s dev %d ep%02x-%s, period %d, phase %d, %d us\n",
 684                         "reserve", qh->udev->devnum,
 685                         qh->hep->desc.bEndpointAddress, p,
 686                         qh->period, qh->phase, load);
 687 }
 688
 689 /*
 690  * Release a periodic QH's bandwidth reservation
 691  */
 692 static void uhci_release_bandwidth(struct uhci_hcd *uhci, struct uhci_qh *qh)
 693 {
 694         int i;
 695         int load = qh->load;
 696         char *p = "??";
 697
 698         for (i = qh->phase; i < MAX_PHASE; i += qh->period) {
 699                 uhci->load[i] -= load;
 700                 uhci->total_load -= load;
 701         }
 702         uhci_to_hcd(uhci)->self.bandwidth_allocated =
 703                         uhci->total_load / MAX_PHASE;
 704         switch (qh->type) {
 705         case USB_ENDPOINT_XFER_INT:
 706                 --uhci_to_hcd(uhci)->self.bandwidth_int_reqs;
 707                 p = "INT";
 708                 break;
 709         case USB_ENDPOINT_XFER_ISOC:
 710                 --uhci_to_hcd(uhci)->self.bandwidth_isoc_reqs;
 711                 p = "ISO";
 712                 break;
 713         }
 714         qh->bandwidth_reserved = 0;
 715         dev_dbg(uhci_dev(uhci),
 716                         "%s dev %d ep%02x-%s, period %d, phase %d, %d us\n",
 717                         "release", qh->udev->devnum,
 718                         qh->hep->desc.bEndpointAddress, p,
 719                         qh->period, qh->phase, load);
 720 }
 721
 722 static inline struct urb_priv *uhci_alloc_urb_priv(struct uhci_hcd *uhci,
 723                 struct urb *urb)
 724 {
 725         struct urb_priv *urbp;
 726
 727         urbp = kmem_cache_zalloc(uhci_up_cachep, GFP_ATOMIC);
 728         if (!urbp)
 729                 return NULL;
 730
 731         urbp->urb = urb;
 732         urb->hcpriv = urbp;
 733
 734         INIT_LIST_HEAD(&urbp->node);
 735         INIT_LIST_HEAD(&urbp->td_list);
 736
 737         return urbp;
 738 }
 739
 740 static void uhci_free_urb_priv(struct uhci_hcd *uhci,
 741                 struct urb_priv *urbp)
 742 {
 743         struct uhci_td *td, *tmp;
 744
 745         if (!list_empty(&urbp->node))
 746                 dev_WARN(uhci_dev(uhci), "urb %p still on QH's list!\n",
 747                                 urbp->urb);
 748
 749         list_for_each_entry_safe(td, tmp, &urbp->td_list, list) {
 750                 uhci_remove_td_from_urbp(td);
 751                 uhci_free_td(uhci, td);
 752         }
 753
 754         kmem_cache_free(uhci_up_cachep, urbp);
 755 }
 756
 757 /*
 758  * Map status to standard result codes
 759  *
 760  * <status> is (td_status(td) & 0xF60000), a.k.a.
 761  * uhci_status_bits(td_status(td)).
 762  * Note: <status> does not include the TD_CTRL_NAK bit.
 763  * <dir_out> is True for output TDs and False for input TDs.
 764  */
 765 static int uhci_map_status(int status, int dir_out)
 766 {
 767         if (!status)
 768                 return 0;
 769         if (status & TD_CTRL_BITSTUFF)                  /* Bitstuff error */
 770                 return -EPROTO;
 771         if (status & TD_CTRL_CRCTIMEO) {                /* CRC/Timeout */
 772                 if (dir_out)
 773                         return -EPROTO;
 774                 else
 775                         return -EILSEQ;
 776         }
 777         if (status & TD_CTRL_BABBLE)                    /* Babble */
 778                 return -EOVERFLOW;
 779         if (status & TD_CTRL_DBUFERR)                   /* Buffer error */
 780                 return -ENOSR;
 781         if (status & TD_CTRL_STALLED)                   /* Stalled */
 782                 return -EPIPE;
 783         return 0;
 784 }
 785
 786 /*
 787  * Control transfers
 788  */
 789 static int uhci_submit_control(struct uhci_hcd *uhci, struct urb *urb,
 790                 struct uhci_qh *qh)
 791 {
 792         struct uhci_td *td;
 793         unsigned long destination, status;
 794         int maxsze = le16_to_cpu(qh->hep->desc.wMaxPacketSize);
 795         int len = urb->transfer_buffer_length;
 796         dma_addr_t data = urb->transfer_dma;
 797         __le32 *plink;
 798         struct urb_priv *urbp = urb->hcpriv;
 799         int skel;
 800
 801         /* The "pipe" thing contains the destination in bits 8--18 */
 802         destination = (urb->pipe & PIPE_DEVEP_MASK) | USB_PID_SETUP;
 803
 804         /* 3 errors, dummy TD remains inactive */
 805         status = uhci_maxerr(3);
 806         if (urb->dev->speed == USB_SPEED_LOW)
 807                 status |= TD_CTRL_LS;
 808
 809         /*
 810          * Build the TD for the control request setup packet
 811          */
 812         td = qh->dummy_td;
 813         uhci_add_td_to_urbp(td, urbp);
 814         uhci_fill_td(td, status, destination | uhci_explen(8),
 815                         urb->setup_dma);
 816         plink = &td->link;
 817         status |= TD_CTRL_ACTIVE;
 818
 819         /*
 820          * If direction is "send", change the packet ID from SETUP (0x2D)
 821          * to OUT (0xE1).  Else change it from SETUP to IN (0x69) and
 822          * set Short Packet Detect (SPD) for all data packets.
 823          *
 824          * 0-length transfers always get treated as "send".
 825          */
 826         if (usb_pipeout(urb->pipe) || len == 0)
 827                 destination ^= (USB_PID_SETUP ^ USB_PID_OUT);
 828         else {
 829                 destination ^= (USB_PID_SETUP ^ USB_PID_IN);
 830                 status |= TD_CTRL_SPD;
 831         }
 832
 833         /*
 834          * Build the DATA TDs
 835          */
 836         while (len > 0) {
 837                 int pktsze = maxsze;
 838
 839                 if (len <= pktsze) {            /* The last data packet */
 840                         pktsze = len;
 841                         status &= ~TD_CTRL_SPD;
 842                 }
 843
 844                 td = uhci_alloc_td(uhci);
 845                 if (!td)
 846                         goto nomem;
 847                 *plink = LINK_TO_TD(td);
 848
 849                 /* Alternate Data0/1 (start with Data1) */
 850                 destination ^= TD_TOKEN_TOGGLE;
 851
 852                 uhci_add_td_to_urbp(td, urbp);
 853                 uhci_fill_td(td, status, destination | uhci_explen(pktsze),
 854                                 data);
 855                 plink = &td->link;
 856
 857                 data += pktsze;
 858                 len -= pktsze;
 859         }
 860
 861         /*
 862          * Build the final TD for control status
 863          */
 864         td = uhci_alloc_td(uhci);
 865         if (!td)
 866                 goto nomem;
 867         *plink = LINK_TO_TD(td);
 868
 869         /* Change direction for the status transaction */
 870         destination ^= (USB_PID_IN ^ USB_PID_OUT);
 871         destination |= TD_TOKEN_TOGGLE;         /* End in Data1 */
 872
 873         uhci_add_td_to_urbp(td, urbp);
 874         uhci_fill_td(td, status | TD_CTRL_IOC,
 875                         destination | uhci_explen(0), 0);
 876         plink = &td->link;
 877
 878         /*
 879          * Build the new dummy TD and activate the old one
 880          */
 881         td = uhci_alloc_td(uhci);
 882         if (!td)
 883                 goto nomem;
 884         *plink = LINK_TO_TD(td);
 885
 886         uhci_fill_td(td, 0, USB_PID_OUT | uhci_explen(0), 0);
 887         wmb();
 888         qh->dummy_td->status |= cpu_to_le32(TD_CTRL_ACTIVE);
 889         qh->dummy_td = td;
 890
 891         /* Low-speed transfers get a different queue, and won't hog the bus.
 892          * Also, some devices enumerate better without FSBR; the easiest way
 893          * to do that is to put URBs on the low-speed queue while the device
 894          * isn't in the CONFIGURED state. */
 895         if (urb->dev->speed == USB_SPEED_LOW ||
 896                         urb->dev->state != USB_STATE_CONFIGURED)
 897                 skel = SKEL_LS_CONTROL;
 898         else {
 899                 skel = SKEL_FS_CONTROL;
 900                 uhci_add_fsbr(uhci, urb);
 901         }
 902         if (qh->state != QH_STATE_ACTIVE)
 903                 qh->skel = skel;
 904         return 0;
 905
 906 nomem:
 907         /* Remove the dummy TD from the td_list so it doesn't get freed */
 908         uhci_remove_td_from_urbp(qh->dummy_td);
 909         return -ENOMEM;
 910 }
 911
 912 /*
 913  * Common submit for bulk and interrupt
 914  */
 915 static int uhci_submit_common(struct uhci_hcd *uhci, struct urb *urb,
 916                 struct uhci_qh *qh)
 917 {
 918         struct uhci_td *td;
 919         unsigned long destination, status;
 920         int maxsze = le16_to_cpu(qh->hep->desc.wMaxPacketSize);
 921         int len = urb->transfer_buffer_length;
 922         int this_sg_len;
 923         dma_addr_t data;
 924         __le32 *plink;
 925         struct urb_priv *urbp = urb->hcpriv;
 926         unsigned int toggle;
 927         struct scatterlist  *sg;
 928         int i;
 929
 930         if (len < 0)
 931                 return -EINVAL;
 932
 933         /* The "pipe" thing contains the destination in bits 8--18 */
 934         destination = (urb->pipe & PIPE_DEVEP_MASK) | usb_packetid(urb->pipe);
 935         toggle = usb_gettoggle(urb->dev, usb_pipeendpoint(urb->pipe),
 936                          usb_pipeout(urb->pipe));
 937
 938         /* 3 errors, dummy TD remains inactive */
 939         status = uhci_maxerr(3);
 940         if (urb->dev->speed == USB_SPEED_LOW)
 941                 status |= TD_CTRL_LS;
 942         if (usb_pipein(urb->pipe))
 943                 status |= TD_CTRL_SPD;
 944
 945         i = urb->num_sgs;
 946         if (len > 0 && i > 0) {
 947                 sg = urb->sg;
 948                 data = sg_dma_address(sg);
 949
 950                 /* urb->transfer_buffer_length may be smaller than the
 951                  * size of the scatterlist (or vice versa)
 952                  */
 953                 this_sg_len = min_t(int, sg_dma_len(sg), len);
 954         } else {
 955                 sg = NULL;
 956                 data = urb->transfer_dma;
 957                 this_sg_len = len;
 958         }
 959         /*
 960          * Build the DATA TDs
 961          */
 962         plink = NULL;
 963         td = qh->dummy_td;
 964         for (;;) {      /* Allow zero length packets */
 965                 int pktsze = maxsze;
 966
 967                 if (len <= pktsze) {            /* The last packet */
 968                         pktsze = len;
 969                         if (!(urb->transfer_flags & URB_SHORT_NOT_OK))
 970                                 status &= ~TD_CTRL_SPD;
 971                 }
 972
 973                 if (plink) {
 974                         td = uhci_alloc_td(uhci);
 975                         if (!td)
 976                                 goto nomem;
 977                         *plink = LINK_TO_TD(td);
 978                 }
 979                 uhci_add_td_to_urbp(td, urbp);
 980                 uhci_fill_td(td, status,
 981                                 destination | uhci_explen(pktsze) |
 982                                         (toggle << TD_TOKEN_TOGGLE_SHIFT),
 983                                 data);
 984                 plink = &td->link;
 985                 status |= TD_CTRL_ACTIVE;
 986
 987                 toggle ^= 1;
 988                 data += pktsze;
 989                 this_sg_len -= pktsze;
 990                 len -= maxsze;
 991                 if (this_sg_len <= 0) {
 992                         if (--i <= 0 || len <= 0)
 993                                 break;
 994                         sg = sg_next(sg);
 995                         data = sg_dma_address(sg);
 996                         this_sg_len = min_t(int, sg_dma_len(sg), len);
 997                 }
 998         }
 999
1000         /*
1001          * URB_ZERO_PACKET means adding a 0-length packet, if direction
1002          * is OUT and the transfer_length was an exact multiple of maxsze,
1003          * hence (len = transfer_length - N * maxsze) == 0
1004          * however, if transfer_length == 0, the zero packet was already
1005          * prepared above.
1006          */
1007         if ((urb->transfer_flags & URB_ZERO_PACKET) &&
1008                         usb_pipeout(urb->pipe) && len == 0 &&
1009                         urb->transfer_buffer_length > 0) {
1010                 td = uhci_alloc_td(uhci);
1011                 if (!td)
1012                         goto nomem;
1013                 *plink = LINK_TO_TD(td);
1014
1015                 uhci_add_td_to_urbp(td, urbp);
1016                 uhci_fill_td(td, status,
1017                                 destination | uhci_explen(0) |
1018                                         (toggle << TD_TOKEN_TOGGLE_SHIFT),
1019                                 data);
1020                 plink = &td->link;
1021
1022                 toggle ^= 1;
1023         }
1024
1025         /* Set the interrupt-on-completion flag on the last packet.
1026          * A more-or-less typical 4 KB URB (= size of one memory page)
1027          * will require about 3 ms to transfer; that's a little on the
1028          * fast side but not enough to justify delaying an interrupt
1029          * more than 2 or 3 URBs, so we will ignore the URB_NO_INTERRUPT
1030          * flag setting. */
1031         td->status |= cpu_to_le32(TD_CTRL_IOC);
1032
1033         /*
1034          * Build the new dummy TD and activate the old one
1035          */
1036         td = uhci_alloc_td(uhci);
1037         if (!td)
1038                 goto nomem;
1039         *plink = LINK_TO_TD(td);
1040
1041         uhci_fill_td(td, 0, USB_PID_OUT | uhci_explen(0), 0);
1042         wmb();
1043         qh->dummy_td->status |= cpu_to_le32(TD_CTRL_ACTIVE);
1044         qh->dummy_td = td;
1045
1046         usb_settoggle(urb->dev, usb_pipeendpoint(urb->pipe),
1047                         usb_pipeout(urb->pipe), toggle);
1048         return 0;
1049
1050 nomem:
1051         /* Remove the dummy TD from the td_list so it doesn't get freed */
1052         uhci_remove_td_from_urbp(qh->dummy_td);
1053         return -ENOMEM;
1054 }
1055
1056 static int uhci_submit_bulk(struct uhci_hcd *uhci, struct urb *urb,
1057                 struct uhci_qh *qh)
1058 {
1059         int ret;
1060
1061         /* Can't have low-speed bulk transfers */
1062         if (urb->dev->speed == USB_SPEED_LOW)
1063                 return -EINVAL;
1064
1065         if (qh->state != QH_STATE_ACTIVE)
1066                 qh->skel = SKEL_BULK;
1067         ret = uhci_submit_common(uhci, urb, qh);
1068         if (ret == 0)
1069                 uhci_add_fsbr(uhci, urb);
1070         return ret;
1071 }
1072
1073 static int uhci_submit_interrupt(struct uhci_hcd *uhci, struct urb *urb,
1074                 struct uhci_qh *qh)
1075 {
1076         int ret;
1077
1078         /* USB 1.1 interrupt transfers only involve one packet per interval.
1079          * Drivers can submit URBs of any length, but longer ones will need
1080          * multiple intervals to complete.
1081          */
1082
1083         if (!qh->bandwidth_reserved) {
1084                 int exponent;
1085
1086                 /* Figure out which power-of-two queue to use */
1087                 for (exponent = 7; exponent >= 0; --exponent) {
1088                         if ((1 << exponent) <= urb->interval)
1089                                 break;
1090                 }
1091                 if (exponent < 0)
1092                         return -EINVAL;
1093
1094                 /* If the slot is full, try a lower period */
1095                 do {
1096                         qh->period = 1 << exponent;
1097                         qh->skel = SKEL_INDEX(exponent);
1098
1099                         /* For now, interrupt phase is fixed by the layout
1100                          * of the QH lists.
1101                          */
1102                         qh->phase = (qh->period / 2) & (MAX_PHASE - 1);
1103                         ret = uhci_check_bandwidth(uhci, qh);
1104                 } while (ret != 0 && --exponent >= 0);
1105                 if (ret)
1106                         return ret;
1107         } else if (qh->period > urb->interval)
1108                 return -EINVAL;         /* Can't decrease the period */
1109
1110         ret = uhci_submit_common(uhci, urb, qh);
1111         if (ret == 0) {
1112                 urb->interval = qh->period;
1113                 if (!qh->bandwidth_reserved)
1114                         uhci_reserve_bandwidth(uhci, qh);
1115         }
1116         return ret;
1117 }
1118
1119 /*
1120  * Fix up the data structures following a short transfer
1121  */
1122 static int uhci_fixup_short_transfer(struct uhci_hcd *uhci,
1123                 struct uhci_qh *qh, struct urb_priv *urbp)
1124 {
1125         struct uhci_td *td;
1126         struct list_head *tmp;
1127         int ret;
1128
1129         td = list_entry(urbp->td_list.prev, struct uhci_td, list);
1130         if (qh->type == USB_ENDPOINT_XFER_CONTROL) {
1131
1132                 /* When a control transfer is short, we have to restart
1133                  * the queue at the status stage transaction, which is
1134                  * the last TD. */
1135                 WARN_ON(list_empty(&urbp->td_list));
1136                 qh->element = LINK_TO_TD(td);
1137                 tmp = td->list.prev;
1138                 ret = -EINPROGRESS;
1139
1140         } else {
1141
1142                 /* When a bulk/interrupt transfer is short, we have to
1143                  * fix up the toggles of the following URBs on the queue
1144                  * before restarting the queue at the next URB. */
1145                 qh->initial_toggle = uhci_toggle(td_token(qh->post_td)) ^ 1;
1146                 uhci_fixup_toggles(qh, 1);
1147
1148                 if (list_empty(&urbp->td_list))
1149                         td = qh->post_td;
1150                 qh->element = td->link;
1151                 tmp = urbp->td_list.prev;
1152                 ret = 0;
1153         }
1154
1155         /* Remove all the TDs we skipped over, from tmp back to the start */
1156         while (tmp != &urbp->td_list) {
1157                 td = list_entry(tmp, struct uhci_td, list);
1158                 tmp = tmp->prev;
1159
1160                 uhci_remove_td_from_urbp(td);
1161                 uhci_free_td(uhci, td);
1162         }
1163         return ret;
1164 }
1165
1166 /*
1167  * Common result for control, bulk, and interrupt
1168  */
1169 static int uhci_result_common(struct uhci_hcd *uhci, struct urb *urb)
1170 {
1171         struct urb_priv *urbp = urb->hcpriv;
1172         struct uhci_qh *qh = urbp->qh;
1173         struct uhci_td *td, *tmp;
1174         unsigned status;
1175         int ret = 0;
1176
1177         list_for_each_entry_safe(td, tmp, &urbp->td_list, list) {
1178                 unsigned int ctrlstat;
1179                 int len;
1180
1181                 ctrlstat = td_status(td);
1182                 status = uhci_status_bits(ctrlstat);
1183                 if (status & TD_CTRL_ACTIVE)
1184                         return -EINPROGRESS;
1185
1186                 len = uhci_actual_length(ctrlstat);
1187                 urb->actual_length += len;
1188
1189                 if (status) {
1190                         ret = uhci_map_status(status,
1191                                         uhci_packetout(td_token(td)));
1192                         if ((debug == 1 && ret != -EPIPE) || debug > 1) {
1193                                 /* Some debugging code */
1194                                 dev_dbg(&urb->dev->dev,
1195                                                 "%s: failed with status %x\n",
1196                                                 __func__, status);
1197
1198                                 if (debug > 1 && errbuf) {
1199                                         /* Print the chain for debugging */
1200                                         uhci_show_qh(uhci, urbp->qh, errbuf,
1201                                                         ERRBUF_LEN, 0);
1202                                         lprintk(errbuf);
1203                                 }
1204                         }
1205
1206                 /* Did we receive a short packet? */
1207                 } else if (len < uhci_expected_length(td_token(td))) {
1208
1209                         /* For control transfers, go to the status TD if
1210                          * this isn't already the last data TD */
1211                         if (qh->type == USB_ENDPOINT_XFER_CONTROL) {
1212                                 if (td->list.next != urbp->td_list.prev)
1213                                         ret = 1;
1214                         }
1215
1216                         /* For bulk and interrupt, this may be an error */
1217                         else if (urb->transfer_flags & URB_SHORT_NOT_OK)
1218                                 ret = -EREMOTEIO;
1219
1220                         /* Fixup needed only if this isn't the URB's last TD */
1221                         else if (&td->list != urbp->td_list.prev)
1222                                 ret = 1;
1223                 }
1224
1225                 uhci_remove_td_from_urbp(td);
1226                 if (qh->post_td)
1227                         uhci_free_td(uhci, qh->post_td);
1228                 qh->post_td = td;
1229
1230                 if (ret != 0)
1231                         goto err;
1232         }
1233         return ret;
1234
1235 err:
1236         if (ret < 0) {
1237                 /* Note that the queue has stopped and save
1238                  * the next toggle value */
1239                 qh->element = UHCI_PTR_TERM;
1240                 qh->is_stopped = 1;
1241                 qh->needs_fixup = (qh->type != USB_ENDPOINT_XFER_CONTROL);
1242                 qh->initial_toggle = uhci_toggle(td_token(td)) ^
1243                                 (ret == -EREMOTEIO);
1244
1245         } else          /* Short packet received */
1246                 ret = uhci_fixup_short_transfer(uhci, qh, urbp);
1247         return ret;
1248 }
1249
1250 /*
1251  * Isochronous transfers
1252  */
1253 static int uhci_submit_isochronous(struct uhci_hcd *uhci, struct urb *urb,
1254                 struct uhci_qh *qh)
1255 {
1256         struct uhci_td *td = NULL;      /* Since urb->number_of_packets > 0 */
1257         int i, frame;
1258         unsigned long destination, status;
1259         struct urb_priv *urbp = (struct urb_priv *) urb->hcpriv;
1260
1261         /* Values must not be too big (could overflow below) */
1262         if (urb->interval >= UHCI_NUMFRAMES ||
1263                         urb->number_of_packets >= UHCI_NUMFRAMES)
1264                 return -EFBIG;
1265
1266         /* Check the period and figure out the starting frame number */
1267         if (!qh->bandwidth_reserved) {
1268                 qh->period = urb->interval;
1269                 if (urb->transfer_flags & URB_ISO_ASAP) {
1270                         qh->phase = -1;         /* Find the best phase */
1271                         i = uhci_check_bandwidth(uhci, qh);
1272                         if (i)
1273                                 return i;
1274
1275                         /* Allow a little time to allocate the TDs */
1276                         uhci_get_current_frame_number(uhci);
1277                         frame = uhci->frame_number + 10;
1278
1279                         /* Move forward to the first frame having the
1280                          * correct phase */
1281                         urb->start_frame = frame + ((qh->phase - frame) &
1282                                         (qh->period - 1));
1283                 } else {
1284                         i = urb->start_frame - uhci->last_iso_frame;
1285                         if (i <= 0 || i >= UHCI_NUMFRAMES)
1286                                 return -EINVAL;
1287                         qh->phase = urb->start_frame & (qh->period - 1);
1288                         i = uhci_check_bandwidth(uhci, qh);
1289                         if (i)
1290                                 return i;
1291                 }
1292
1293         } else if (qh->period != urb->interval) {
1294                 return -EINVAL;         /* Can't change the period */
1295
1296         } else {
1297                 /* Find the next unused frame */
1298                 if (list_empty(&qh->queue)) {
1299                         frame = qh->iso_frame;
1300                 } else {
1301                         struct urb *lurb;
1302
1303                         lurb = list_entry(qh->queue.prev,
1304                                         struct urb_priv, node)->urb;
1305                         frame = lurb->start_frame +
1306                                         lurb->number_of_packets *
1307                                         lurb->interval;
1308                 }
1309                 if (urb->transfer_flags & URB_ISO_ASAP) {
1310                         /* Skip some frames if necessary to insure
1311                          * the start frame is in the future.
1312                          */
1313                         uhci_get_current_frame_number(uhci);
1314                         if (uhci_frame_before_eq(frame, uhci->frame_number)) {
1315                                 frame = uhci->frame_number + 1;
1316                                 frame += ((qh->phase - frame) &
1317                                         (qh->period - 1));
1318                         }
1319                 }       /* Otherwise pick up where the last URB leaves off */
1320                 urb->start_frame = frame;
1321         }
1322
1323         /* Make sure we won't have to go too far into the future */
1324         if (uhci_frame_before_eq(uhci->last_iso_frame + UHCI_NUMFRAMES,
1325                         urb->start_frame + urb->number_of_packets *
1326                                 urb->interval))
1327                 return -EFBIG;
1328
1329         status = TD_CTRL_ACTIVE | TD_CTRL_IOS;
1330         destination = (urb->pipe & PIPE_DEVEP_MASK) | usb_packetid(urb->pipe);
1331
1332         for (i = 0; i < urb->number_of_packets; i++) {
1333                 td = uhci_alloc_td(uhci);
1334                 if (!td)
1335                         return -ENOMEM;
1336
1337                 uhci_add_td_to_urbp(td, urbp);
1338                 uhci_fill_td(td, status, destination |
1339                                 uhci_explen(urb->iso_frame_desc[i].length),
1340                                 urb->transfer_dma +
1341                                         urb->iso_frame_desc[i].offset);
1342         }
1343
1344         /* Set the interrupt-on-completion flag on the last packet. */
1345         td->status |= cpu_to_le32(TD_CTRL_IOC);
1346
1347         /* Add the TDs to the frame list */
1348         frame = urb->start_frame;
1349         list_for_each_entry(td, &urbp->td_list, list) {
1350                 uhci_insert_td_in_frame_list(uhci, td, frame);
1351                 frame += qh->period;
1352         }
1353
1354         if (list_empty(&qh->queue)) {
1355                 qh->iso_packet_desc = &urb->iso_frame_desc[0];
1356                 qh->iso_frame = urb->start_frame;
1357         }
1358
1359         qh->skel = SKEL_ISO;
1360         if (!qh->bandwidth_reserved)
1361                 uhci_reserve_bandwidth(uhci, qh);
1362         return 0;
1363 }
1364
1365 static int uhci_result_isochronous(struct uhci_hcd *uhci, struct urb *urb)
1366 {
1367         struct uhci_td *td, *tmp;
1368         struct urb_priv *urbp = urb->hcpriv;
1369         struct uhci_qh *qh = urbp->qh;
1370
1371         list_for_each_entry_safe(td, tmp, &urbp->td_list, list) {
1372                 unsigned int ctrlstat;
1373                 int status;
1374                 int actlength;
1375
1376                 if (uhci_frame_before_eq(uhci->cur_iso_frame, qh->iso_frame))
1377                         return -EINPROGRESS;
1378
1379                 uhci_remove_tds_from_frame(uhci, qh->iso_frame);
1380
1381                 ctrlstat = td_status(td);
1382                 if (ctrlstat & TD_CTRL_ACTIVE) {
1383                         status = -EXDEV;        /* TD was added too late? */
1384                 } else {
1385                         status = uhci_map_status(uhci_status_bits(ctrlstat),
1386                                         usb_pipeout(urb->pipe));
1387                         actlength = uhci_actual_length(ctrlstat);
1388
1389                         urb->actual_length += actlength;
1390                         qh->iso_packet_desc->actual_length = actlength;
1391                         qh->iso_packet_desc->status = status;
1392                 }
1393                 if (status)
1394                         urb->error_count++;
1395
1396                 uhci_remove_td_from_urbp(td);
1397                 uhci_free_td(uhci, td);
1398                 qh->iso_frame += qh->period;
1399                 ++qh->iso_packet_desc;
1400         }
1401         return 0;
1402 }
1403
1404 static int uhci_urb_enqueue(struct usb_hcd *hcd,
1405                 struct urb *urb, gfp_t mem_flags)
1406 {
1407         int ret;
1408         struct uhci_hcd *uhci = hcd_to_uhci(hcd);
1409         unsigned long flags;
1410         struct urb_priv *urbp;
1411         struct uhci_qh *qh;
1412
1413         spin_lock_irqsave(&uhci->lock, flags);
1414
1415         ret = usb_hcd_link_urb_to_ep(hcd, urb);
1416         if (ret)
1417                 goto done_not_linked;
1418
1419         ret = -ENOMEM;
1420         urbp = uhci_alloc_urb_priv(uhci, urb);
1421         if (!urbp)
1422                 goto done;
1423
1424         if (urb->ep->hcpriv)
1425                 qh = urb->ep->hcpriv;
1426         else {
1427                 qh = uhci_alloc_qh(uhci, urb->dev, urb->ep);
1428                 if (!qh)
1429                         goto err_no_qh;
1430         }
1431         urbp->qh = qh;
1432
1433         switch (qh->type) {
1434         case USB_ENDPOINT_XFER_CONTROL:
1435                 ret = uhci_submit_control(uhci, urb, qh);
1436                 break;
1437         case USB_ENDPOINT_XFER_BULK:
1438                 ret = uhci_submit_bulk(uhci, urb, qh);
1439                 break;
1440         case USB_ENDPOINT_XFER_INT:
1441                 ret = uhci_submit_interrupt(uhci, urb, qh);
1442                 break;
1443         case USB_ENDPOINT_XFER_ISOC:
1444                 urb->error_count = 0;
1445                 ret = uhci_submit_isochronous(uhci, urb, qh);
1446                 break;
1447         }
1448         if (ret != 0)
1449                 goto err_submit_failed;
1450
1451         /* Add this URB to the QH */
1452         list_add_tail(&urbp->node, &qh->queue);
1453
1454         /* If the new URB is the first and only one on this QH then either
1455          * the QH is new and idle or else it's unlinked and waiting to
1456          * become idle, so we can activate it right away.  But only if the
1457          * queue isn't stopped. */
1458         if (qh->queue.next == &urbp->node && !qh->is_stopped) {
1459                 uhci_activate_qh(uhci, qh);
1460                 uhci_urbp_wants_fsbr(uhci, urbp);
1461         }
1462         goto done;
1463
1464 err_submit_failed:
1465         if (qh->state == QH_STATE_IDLE)
1466                 uhci_make_qh_idle(uhci, qh);    /* Reclaim unused QH */
1467 err_no_qh:
1468         uhci_free_urb_priv(uhci, urbp);
1469 done:
1470         if (ret)
1471                 usb_hcd_unlink_urb_from_ep(hcd, urb);
1472 done_not_linked:
1473         spin_unlock_irqrestore(&uhci->lock, flags);
1474         return ret;
1475 }
1476
1477 static int uhci_urb_dequeue(struct usb_hcd *hcd, struct urb *urb, int status)
1478 {
1479         struct uhci_hcd *uhci = hcd_to_uhci(hcd);
1480         unsigned long flags;
1481         struct uhci_qh *qh;
1482         int rc;
1483
1484         spin_lock_irqsave(&uhci->lock, flags);
1485         rc = usb_hcd_check_unlink_urb(hcd, urb, status);
1486         if (rc)
1487                 goto done;
1488
1489         qh = ((struct urb_priv *) urb->hcpriv)->qh;
1490
1491         /* Remove Isochronous TDs from the frame list ASAP */
1492         if (qh->type == USB_ENDPOINT_XFER_ISOC) {
1493                 uhci_unlink_isochronous_tds(uhci, urb);
1494                 mb();
1495
1496                 /* If the URB has already started, update the QH unlink time */
1497                 uhci_get_current_frame_number(uhci);
1498                 if (uhci_frame_before_eq(urb->start_frame, uhci->frame_number))
1499                         qh->unlink_frame = uhci->frame_number;
1500         }
1501
1502         uhci_unlink_qh(uhci, qh);
1503
1504 done:
1505         spin_unlock_irqrestore(&uhci->lock, flags);
1506         return rc;
1507 }
1508
1509 /*
1510  * Finish unlinking an URB and give it back
1511  */
1512 static void uhci_giveback_urb(struct uhci_hcd *uhci, struct uhci_qh *qh,
1513                 struct urb *urb, int status)
1514 __releases(uhci->lock)
1515 __acquires(uhci->lock)
1516 {
1517         struct urb_priv *urbp = (struct urb_priv *) urb->hcpriv;
1518
1519         if (qh->type == USB_ENDPOINT_XFER_CONTROL) {
1520
1521                 /* Subtract off the length of the SETUP packet from
1522                  * urb->actual_length.
1523                  */
1524                 urb->actual_length -= min_t(u32, 8, urb->actual_length);
1525         }
1526
1527         /* When giving back the first URB in an Isochronous queue,
1528          * reinitialize the QH's iso-related members for the next URB. */
1529         else if (qh->type == USB_ENDPOINT_XFER_ISOC &&
1530                         urbp->node.prev == &qh->queue &&
1531                         urbp->node.next != &qh->queue) {
1532                 struct urb *nurb = list_entry(urbp->node.next,
1533                                 struct urb_priv, node)->urb;
1534
1535                 qh->iso_packet_desc = &nurb->iso_frame_desc[0];
1536                 qh->iso_frame = nurb->start_frame;
1537         }
1538
1539         /* Take the URB off the QH's queue.  If the queue is now empty,
1540          * this is a perfect time for a toggle fixup. */
1541         list_del_init(&urbp->node);
1542         if (list_empty(&qh->queue) && qh->needs_fixup) {
1543                 usb_settoggle(urb->dev, usb_pipeendpoint(urb->pipe),
1544                                 usb_pipeout(urb->pipe), qh->initial_toggle);
1545                 qh->needs_fixup = 0;
1546         }
1547
1548         uhci_free_urb_priv(uhci, urbp);
1549         usb_hcd_unlink_urb_from_ep(uhci_to_hcd(uhci), urb);
1550
1551         spin_unlock(&uhci->lock);
1552         usb_hcd_giveback_urb(uhci_to_hcd(uhci), urb, status);
1553         spin_lock(&uhci->lock);
1554
1555         /* If the queue is now empty, we can unlink the QH and give up its
1556          * reserved bandwidth. */
1557         if (list_empty(&qh->queue)) {
1558                 uhci_unlink_qh(uhci, qh);
1559                 if (qh->bandwidth_reserved)
1560                         uhci_release_bandwidth(uhci, qh);
1561         }
1562 }
1563
1564 /*
1565  * Scan the URBs in a QH's queue
1566  */
1567 #define QH_FINISHED_UNLINKING(qh)                       \
1568                 (qh->state == QH_STATE_UNLINKING &&     \
1569                 uhci->frame_number + uhci->is_stopped != qh->unlink_frame)
1570
1571 static void uhci_scan_qh(struct uhci_hcd *uhci, struct uhci_qh *qh)
1572 {
1573         struct urb_priv *urbp;
1574         struct urb *urb;
1575         int status;
1576
1577         while (!list_empty(&qh->queue)) {
1578                 urbp = list_entry(qh->queue.next, struct urb_priv, node);
1579                 urb = urbp->urb;
1580
1581                 if (qh->type == USB_ENDPOINT_XFER_ISOC)
1582                         status = uhci_result_isochronous(uhci, urb);
1583                 else
1584                         status = uhci_result_common(uhci, urb);
1585                 if (status == -EINPROGRESS)
1586                         break;
1587
1588                 /* Dequeued but completed URBs can't be given back unless
1589                  * the QH is stopped or has finished unlinking. */
1590                 if (urb->unlinked) {
1591                         if (QH_FINISHED_UNLINKING(qh))
1592                                 qh->is_stopped = 1;
1593                         else if (!qh->is_stopped)
1594                                 return;
1595                 }
1596
1597                 uhci_giveback_urb(uhci, qh, urb, status);
1598                 if (status < 0)
1599                         break;
1600         }
1601
1602         /* If the QH is neither stopped nor finished unlinking (normal case),
1603          * our work here is done. */
1604         if (QH_FINISHED_UNLINKING(qh))
1605                 qh->is_stopped = 1;
1606         else if (!qh->is_stopped)
1607                 return;
1608
1609         /* Otherwise give back each of the dequeued URBs */
1610 restart:
1611         list_for_each_entry(urbp, &qh->queue, node) {
1612                 urb = urbp->urb;
1613                 if (urb->unlinked) {
1614
1615                         /* Fix up the TD links and save the toggles for
1616                          * non-Isochronous queues.  For Isochronous queues,
1617                          * test for too-recent dequeues. */
1618                         if (!uhci_cleanup_queue(uhci, qh, urb)) {
1619                                 qh->is_stopped = 0;
1620                                 return;
1621                         }
1622                         uhci_giveback_urb(uhci, qh, urb, 0);
1623                         goto restart;
1624                 }
1625         }
1626         qh->is_stopped = 0;
1627
1628         /* There are no more dequeued URBs.  If there are still URBs on the
1629          * queue, the QH can now be re-activated. */
1630         if (!list_empty(&qh->queue)) {
1631                 if (qh->needs_fixup)
1632                         uhci_fixup_toggles(qh, 0);
1633
1634                 /* If the first URB on the queue wants FSBR but its time
1635                  * limit has expired, set the next TD to interrupt on
1636                  * completion before reactivating the QH. */
1637                 urbp = list_entry(qh->queue.next, struct urb_priv, node);
1638                 if (urbp->fsbr && qh->wait_expired) {
1639                         struct uhci_td *td = list_entry(urbp->td_list.next,
1640                                         struct uhci_td, list);
1641
1642                         td->status |= __cpu_to_le32(TD_CTRL_IOC);
1643                 }
1644
1645                 uhci_activate_qh(uhci, qh);
1646         }
1647
1648         /* The queue is empty.  The QH can become idle if it is fully
1649          * unlinked. */
1650         else if (QH_FINISHED_UNLINKING(qh))
1651                 uhci_make_qh_idle(uhci, qh);
1652 }
1653
1654 /*
1655  * Check for queues that have made some forward progress.
1656  * Returns 0 if the queue is not Isochronous, is ACTIVE, and
1657  * has not advanced since last examined; 1 otherwise.
1658  *
1659  * Early Intel controllers have a bug which causes qh->element sometimes
1660  * not to advance when a TD completes successfully.  The queue remains
1661  * stuck on the inactive completed TD.  We detect such cases and advance
1662  * the element pointer by hand.
1663  */
1664 static int uhci_advance_check(struct uhci_hcd *uhci, struct uhci_qh *qh)
1665 {
1666         struct urb_priv *urbp = NULL;
1667         struct uhci_td *td;
1668         int ret = 1;
1669         unsigned status;
1670
1671         if (qh->type == USB_ENDPOINT_XFER_ISOC)
1672                 goto done;
1673
1674         /* Treat an UNLINKING queue as though it hasn't advanced.
1675          * This is okay because reactivation will treat it as though
1676          * it has advanced, and if it is going to become IDLE then
1677          * this doesn't matter anyway.  Furthermore it's possible
1678          * for an UNLINKING queue not to have any URBs at all, or
1679          * for its first URB not to have any TDs (if it was dequeued
1680          * just as it completed).  So it's not easy in any case to
1681          * test whether such queues have advanced. */
1682         if (qh->state != QH_STATE_ACTIVE) {
1683                 urbp = NULL;
1684                 status = 0;
1685
1686         } else {
1687                 urbp = list_entry(qh->queue.next, struct urb_priv, node);
1688                 td = list_entry(urbp->td_list.next, struct uhci_td, list);
1689                 status = td_status(td);
1690                 if (!(status & TD_CTRL_ACTIVE)) {
1691
1692                         /* We're okay, the queue has advanced */
1693                         qh->wait_expired = 0;
1694                         qh->advance_jiffies = jiffies;
1695                         goto done;
1696                 }
1697                 ret = uhci->is_stopped;
1698         }
1699
1700         /* The queue hasn't advanced; check for timeout */
1701         if (qh->wait_expired)
1702                 goto done;
1703
1704         if (time_after(jiffies, qh->advance_jiffies + QH_WAIT_TIMEOUT)) {
1705
1706                 /* Detect the Intel bug and work around it */
1707                 if (qh->post_td && qh_element(qh) == LINK_TO_TD(qh->post_td)) {
1708                         qh->element = qh->post_td->link;
1709                         qh->advance_jiffies = jiffies;
1710                         ret = 1;
1711                         goto done;
1712                 }
1713
1714                 qh->wait_expired = 1;
1715
1716                 /* If the current URB wants FSBR, unlink it temporarily
1717                  * so that we can safely set the next TD to interrupt on
1718                  * completion.  That way we'll know as soon as the queue
1719                  * starts moving again. */
1720                 if (urbp && urbp->fsbr && !(status & TD_CTRL_IOC))
1721                         uhci_unlink_qh(uhci, qh);
1722
1723         } else {
1724                 /* Unmoving but not-yet-expired queues keep FSBR alive */
1725                 if (urbp)
1726                         uhci_urbp_wants_fsbr(uhci, urbp);
1727         }
1728
1729 done:
1730         return ret;
1731 }
1732
1733 /*
1734  * Process events in the schedule, but only in one thread at a time
1735  */
1736 static void uhci_scan_schedule(struct uhci_hcd *uhci)
1737 {
1738         int i;
1739         struct uhci_qh *qh;
1740
1741         /* Don't allow re-entrant calls */
1742         if (uhci->scan_in_progress) {
1743                 uhci->need_rescan = 1;
1744                 return;
1745         }
1746         uhci->scan_in_progress = 1;
1747 rescan:
1748         uhci->need_rescan = 0;
1749         uhci->fsbr_is_wanted = 0;
1750
1751         uhci_clear_next_interrupt(uhci);
1752         uhci_get_current_frame_number(uhci);
1753         uhci->cur_iso_frame = uhci->frame_number;
1754
1755         /* Go through all the QH queues and process the URBs in each one */
1756         for (i = 0; i < UHCI_NUM_SKELQH - 1; ++i) {
1757                 uhci->next_qh = list_entry(uhci->skelqh[i]->node.next,
1758                                 struct uhci_qh, node);
1759                 while ((qh = uhci->next_qh) != uhci->skelqh[i]) {
1760                         uhci->next_qh = list_entry(qh->node.next,
1761                                         struct uhci_qh, node);
1762
1763                         if (uhci_advance_check(uhci, qh)) {
1764                                 uhci_scan_qh(uhci, qh);
1765                                 if (qh->state == QH_STATE_ACTIVE) {
1766                                         uhci_urbp_wants_fsbr(uhci,
1767         list_entry(qh->queue.next, struct urb_priv, node));
1768                                 }
1769                         }
1770                 }
1771         }
1772
1773         uhci->last_iso_frame = uhci->cur_iso_frame;
1774         if (uhci->need_rescan)
1775                 goto rescan;
1776         uhci->scan_in_progress = 0;
1777
1778         if (uhci->fsbr_is_on && !uhci->fsbr_is_wanted &&
1779                         !uhci->fsbr_expiring) {
1780                 uhci->fsbr_expiring = 1;
1781                 mod_timer(&uhci->fsbr_timer, jiffies + FSBR_OFF_DELAY);
1782         }
1783
1784         if (list_empty(&uhci->skel_unlink_qh->node))
1785                 uhci_clear_next_interrupt(uhci);
1786         else
1787                 uhci_set_next_interrupt(uhci);
1788 }