drivers/usb/host/ohci-q.c

   1 /*
   2  * OHCI HCD (Host Controller Driver) for USB.
   3  *
   4  * (C) Copyright 1999 Roman Weissgaerber <weissg@vienna.at>
   5  * (C) Copyright 2000-2002 David Brownell <dbrownell@users.sourceforge.net>
   6  *
   7  * This file is licenced under the GPL.
   8  */
   9
  10 #include <linux/irq.h>
  11
  12 static void urb_free_priv (struct ohci_hcd *hc, urb_priv_t *urb_priv)
  13 {
  14         int             last = urb_priv->length - 1;
  15
  16         if (last >= 0) {
  17                 int             i;
  18                 struct td       *td;
  19
  20                 for (i = 0; i <= last; i++) {
  21                         td = urb_priv->td [i];
  22                         if (td)
  23                                 td_free (hc, td);
  24                 }
  25         }
  26
  27         list_del (&urb_priv->pending);
  28         kfree (urb_priv);
  29 }
  30
  31 /*-------------------------------------------------------------------------*/
  32
  33 /*
  34  * URB goes back to driver, and isn't reissued.
  35  * It's completely gone from HC data structures.
  36  * PRECONDITION:  ohci lock held, irqs blocked.
  37  */
  38 static void
  39 finish_urb(struct ohci_hcd *ohci, struct urb *urb, int status)
  40 __releases(ohci->lock)
  41 __acquires(ohci->lock)
  42 {
  43         // ASSERT (urb->hcpriv != 0);
  44
  45         urb_free_priv (ohci, urb->hcpriv);
  46         if (likely(status == -EINPROGRESS))
  47                 status = 0;
  48
  49         switch (usb_pipetype (urb->pipe)) {
  50         case PIPE_ISOCHRONOUS:
  51                 ohci_to_hcd(ohci)->self.bandwidth_isoc_reqs--;
  52                 break;
  53         case PIPE_INTERRUPT:
  54                 ohci_to_hcd(ohci)->self.bandwidth_int_reqs--;
  55                 break;
  56         }
  57
  58 #ifdef OHCI_VERBOSE_DEBUG
  59         urb_print(urb, "RET", usb_pipeout (urb->pipe), status);
  60 #endif
  61
  62         /* urb->complete() can reenter this HCD */
  63         usb_hcd_unlink_urb_from_ep(ohci_to_hcd(ohci), urb);
  64         spin_unlock (&ohci->lock);
  65         usb_hcd_giveback_urb(ohci_to_hcd(ohci), urb, status);
  66         spin_lock (&ohci->lock);
  67
  68         /* stop periodic dma if it's not needed */
  69         if (ohci_to_hcd(ohci)->self.bandwidth_isoc_reqs == 0
  70                         && ohci_to_hcd(ohci)->self.bandwidth_int_reqs == 0) {
  71                 ohci->hc_control &= ~(OHCI_CTRL_PLE|OHCI_CTRL_IE);
  72                 ohci_writel (ohci, ohci->hc_control, &ohci->regs->control);
  73         }
  74 }
  75
  76
  77 /*-------------------------------------------------------------------------*
  78  * ED handling functions
  79  *-------------------------------------------------------------------------*/
  80
  81 /* search for the right schedule branch to use for a periodic ed.
  82  * does some load balancing; returns the branch, or negative errno.
  83  */
  84 static int balance (struct ohci_hcd *ohci, int interval, int load)
  85 {
  86         int     i, branch = -ENOSPC;
  87
  88         /* iso periods can be huge; iso tds specify frame numbers */
  89         if (interval > NUM_INTS)
  90                 interval = NUM_INTS;
  91
  92         /* search for the least loaded schedule branch of that period
  93          * that has enough bandwidth left unreserved.
  94          */
  95         for (i = 0; i < interval ; i++) {
  96                 if (branch < 0 || ohci->load [branch] > ohci->load [i]) {
  97                         int     j;
  98
  99                         /* usb 1.1 says 90% of one frame */
 100                         for (j = i; j < NUM_INTS; j += interval) {
 101                                 if ((ohci->load [j] + load) > 900)
 102                                         break;
 103                         }
 104                         if (j < NUM_INTS)
 105                                 continue;
 106                         branch = i;
 107                 }
 108         }
 109         return branch;
 110 }
 111
 112 /*-------------------------------------------------------------------------*/
 113
 114 /* both iso and interrupt requests have periods; this routine puts them
 115  * into the schedule tree in the apppropriate place.  most iso devices use
 116  * 1msec periods, but that's not required.
 117  */
 118 static void periodic_link (struct ohci_hcd *ohci, struct ed *ed)
 119 {
 120         unsigned        i;
 121
 122         ohci_vdbg (ohci, "link %sed %p branch %d [%dus.], interval %d\n",
 123                 (ed->hwINFO & cpu_to_hc32 (ohci, ED_ISO)) ? "iso " : "",
 124                 ed, ed->branch, ed->load, ed->interval);
 125
 126         for (i = ed->branch; i < NUM_INTS; i += ed->interval) {
 127                 struct ed       **prev = &ohci->periodic [i];
 128                 __hc32          *prev_p = &ohci->hcca->int_table [i];
 129                 struct ed       *here = *prev;
 130
 131                 /* sorting each branch by period (slow before fast)
 132                  * lets us share the faster parts of the tree.
 133                  * (plus maybe: put interrupt eds before iso)
 134                  */
 135                 while (here && ed != here) {
 136                         if (ed->interval > here->interval)
 137                                 break;
 138                         prev = &here->ed_next;
 139                         prev_p = &here->hwNextED;
 140                         here = *prev;
 141                 }
 142                 if (ed != here) {
 143                         ed->ed_next = here;
 144                         if (here)
 145                                 ed->hwNextED = *prev_p;
 146                         wmb ();
 147                         *prev = ed;
 148                         *prev_p = cpu_to_hc32(ohci, ed->dma);
 149                         wmb();
 150                 }
 151                 ohci->load [i] += ed->load;
 152         }
 153         ohci_to_hcd(ohci)->self.bandwidth_allocated += ed->load / ed->interval;
 154 }
 155
 156 /* link an ed into one of the HC chains */
 157
 158 static int ed_schedule (struct ohci_hcd *ohci, struct ed *ed)
 159 {
 160         int     branch;
 161
 162         ed->state = ED_OPER;
 163         ed->ed_prev = NULL;
 164         ed->ed_next = NULL;
 165         ed->hwNextED = 0;
 166         if (quirk_zfmicro(ohci)
 167                         && (ed->type == PIPE_INTERRUPT)
 168                         && !(ohci->eds_scheduled++))
 169                 mod_timer(&ohci->unlink_watchdog, round_jiffies(jiffies + HZ));
 170         wmb ();
 171
 172         /* we care about rm_list when setting CLE/BLE in case the HC was at
 173          * work on some TD when CLE/BLE was turned off, and isn't quiesced
 174          * yet.  finish_unlinks() restarts as needed, some upcoming INTR_SF.
 175          *
 176          * control and bulk EDs are doubly linked (ed_next, ed_prev), but
 177          * periodic ones are singly linked (ed_next). that's because the
 178          * periodic schedule encodes a tree like figure 3-5 in the ohci
 179          * spec:  each qh can have several "previous" nodes, and the tree
 180          * doesn't have unused/idle descriptors.
 181          */
 182         switch (ed->type) {
 183         case PIPE_CONTROL:
 184                 if (ohci->ed_controltail == NULL) {
 185                         WARN_ON (ohci->hc_control & OHCI_CTRL_CLE);
 186                         ohci_writel (ohci, ed->dma,
 187                                         &ohci->regs->ed_controlhead);
 188                 } else {
 189                         ohci->ed_controltail->ed_next = ed;
 190                         ohci->ed_controltail->hwNextED = cpu_to_hc32 (ohci,
 191                                                                 ed->dma);
 192                 }
 193                 ed->ed_prev = ohci->ed_controltail;
 194                 if (!ohci->ed_controltail && !ohci->ed_rm_list) {
 195                         wmb();
 196                         ohci->hc_control |= OHCI_CTRL_CLE;
 197                         ohci_writel (ohci, 0, &ohci->regs->ed_controlcurrent);
 198                         ohci_writel (ohci, ohci->hc_control,
 199                                         &ohci->regs->control);
 200                 }
 201                 ohci->ed_controltail = ed;
 202                 break;
 203
 204         case PIPE_BULK:
 205                 if (ohci->ed_bulktail == NULL) {
 206                         WARN_ON (ohci->hc_control & OHCI_CTRL_BLE);
 207                         ohci_writel (ohci, ed->dma, &ohci->regs->ed_bulkhead);
 208                 } else {
 209                         ohci->ed_bulktail->ed_next = ed;
 210                         ohci->ed_bulktail->hwNextED = cpu_to_hc32 (ohci,
 211                                                                 ed->dma);
 212                 }
 213                 ed->ed_prev = ohci->ed_bulktail;
 214                 if (!ohci->ed_bulktail && !ohci->ed_rm_list) {
 215                         wmb();
 216                         ohci->hc_control |= OHCI_CTRL_BLE;
 217                         ohci_writel (ohci, 0, &ohci->regs->ed_bulkcurrent);
 218                         ohci_writel (ohci, ohci->hc_control,
 219                                         &ohci->regs->control);
 220                 }
 221                 ohci->ed_bulktail = ed;
 222                 break;
 223
 224         // case PIPE_INTERRUPT:
 225         // case PIPE_ISOCHRONOUS:
 226         default:
 227                 branch = balance (ohci, ed->interval, ed->load);
 228                 if (branch < 0) {
 229                         ohci_dbg (ohci,
 230                                 "ERR %d, interval %d msecs, load %d\n",
 231                                 branch, ed->interval, ed->load);
 232                         // FIXME if there are TDs queued, fail them!
 233                         return branch;
 234                 }
 235                 ed->branch = branch;
 236                 periodic_link (ohci, ed);
 237         }
 238
 239         /* the HC may not see the schedule updates yet, but if it does
 240          * then they'll be properly ordered.
 241          */
 242         return 0;
 243 }
 244
 245 /*-------------------------------------------------------------------------*/
 246
 247 /* scan the periodic table to find and unlink this ED */
 248 static void periodic_unlink (struct ohci_hcd *ohci, struct ed *ed)
 249 {
 250         int     i;
 251
 252         for (i = ed->branch; i < NUM_INTS; i += ed->interval) {
 253                 struct ed       *temp;
 254                 struct ed       **prev = &ohci->periodic [i];
 255                 __hc32          *prev_p = &ohci->hcca->int_table [i];
 256
 257                 while (*prev && (temp = *prev) != ed) {
 258                         prev_p = &temp->hwNextED;
 259                         prev = &temp->ed_next;
 260                 }
 261                 if (*prev) {
 262                         *prev_p = ed->hwNextED;
 263                         *prev = ed->ed_next;
 264                 }
 265                 ohci->load [i] -= ed->load;
 266         }
 267         ohci_to_hcd(ohci)->self.bandwidth_allocated -= ed->load / ed->interval;
 268
 269         ohci_vdbg (ohci, "unlink %sed %p branch %d [%dus.], interval %d\n",
 270                 (ed->hwINFO & cpu_to_hc32 (ohci, ED_ISO)) ? "iso " : "",
 271                 ed, ed->branch, ed->load, ed->interval);
 272 }
 273
 274 /* unlink an ed from one of the HC chains.
 275  * just the link to the ed is unlinked.
 276  * the link from the ed still points to another operational ed or 0
 277  * so the HC can eventually finish the processing of the unlinked ed
 278  * (assuming it already started that, which needn't be true).
 279  *
 280  * ED_UNLINK is a transient state: the HC may still see this ED, but soon
 281  * it won't.  ED_SKIP means the HC will finish its current transaction,
 282  * but won't start anything new.  The TD queue may still grow; device
 283  * drivers don't know about this HCD-internal state.
 284  *
 285  * When the HC can't see the ED, something changes ED_UNLINK to one of:
 286  *
 287  *  - ED_OPER: when there's any request queued, the ED gets rescheduled
 288  *    immediately.  HC should be working on them.
 289  *
 290  *  - ED_IDLE:  when there's no TD queue. there's no reason for the HC
 291  *    to care about this ED; safe to disable the endpoint.
 292  *
 293  * When finish_unlinks() runs later, after SOF interrupt, it will often
 294  * complete one or more URB unlinks before making that state change.
 295  */
 296 static void ed_deschedule (struct ohci_hcd *ohci, struct ed *ed)
 297 {
 298         ed->hwINFO |= cpu_to_hc32 (ohci, ED_SKIP);
 299         wmb ();
 300         ed->state = ED_UNLINK;
 301
 302         /* To deschedule something from the control or bulk list, just
 303          * clear CLE/BLE and wait.  There's no safe way to scrub out list
 304          * head/current registers until later, and "later" isn't very
 305          * tightly specified.  Figure 6-5 and Section 6.4.2.2 show how
 306          * the HC is reading the ED queues (while we modify them).
 307          *
 308          * For now, ed_schedule() is "later".  It might be good paranoia
 309          * to scrub those registers in finish_unlinks(), in case of bugs
 310          * that make the HC try to use them.
 311          */
 312         switch (ed->type) {
 313         case PIPE_CONTROL:
 314                 /* remove ED from the HC's list: */
 315                 if (ed->ed_prev == NULL) {
 316                         if (!ed->hwNextED) {
 317                                 ohci->hc_control &= ~OHCI_CTRL_CLE;
 318                                 ohci_writel (ohci, ohci->hc_control,
 319                                                 &ohci->regs->control);
 320                                 // a ohci_readl() later syncs CLE with the HC
 321                         } else
 322                                 ohci_writel (ohci,
 323                                         hc32_to_cpup (ohci, &ed->hwNextED),
 324                                         &ohci->regs->ed_controlhead);
 325                 } else {
 326                         ed->ed_prev->ed_next = ed->ed_next;
 327                         ed->ed_prev->hwNextED = ed->hwNextED;
 328                 }
 329                 /* remove ED from the HCD's list: */
 330                 if (ohci->ed_controltail == ed) {
 331                         ohci->ed_controltail = ed->ed_prev;
 332                         if (ohci->ed_controltail)
 333                                 ohci->ed_controltail->ed_next = NULL;
 334                 } else if (ed->ed_next) {
 335                         ed->ed_next->ed_prev = ed->ed_prev;
 336                 }
 337                 break;
 338
 339         case PIPE_BULK:
 340                 /* remove ED from the HC's list: */
 341                 if (ed->ed_prev == NULL) {
 342                         if (!ed->hwNextED) {
 343                                 ohci->hc_control &= ~OHCI_CTRL_BLE;
 344                                 ohci_writel (ohci, ohci->hc_control,
 345                                                 &ohci->regs->control);
 346                                 // a ohci_readl() later syncs BLE with the HC
 347                         } else
 348                                 ohci_writel (ohci,
 349                                         hc32_to_cpup (ohci, &ed->hwNextED),
 350                                         &ohci->regs->ed_bulkhead);
 351                 } else {
 352                         ed->ed_prev->ed_next = ed->ed_next;
 353                         ed->ed_prev->hwNextED = ed->hwNextED;
 354                 }
 355                 /* remove ED from the HCD's list: */
 356                 if (ohci->ed_bulktail == ed) {
 357                         ohci->ed_bulktail = ed->ed_prev;
 358                         if (ohci->ed_bulktail)
 359                                 ohci->ed_bulktail->ed_next = NULL;
 360                 } else if (ed->ed_next) {
 361                         ed->ed_next->ed_prev = ed->ed_prev;
 362                 }
 363                 break;
 364
 365         // case PIPE_INTERRUPT:
 366         // case PIPE_ISOCHRONOUS:
 367         default:
 368                 periodic_unlink (ohci, ed);
 369                 break;
 370         }
 371 }
 372
 373
 374 /*-------------------------------------------------------------------------*/
 375
 376 /* get and maybe (re)init an endpoint. init _should_ be done only as part
 377  * of enumeration, usb_set_configuration() or usb_set_interface().
 378  */
 379 static struct ed *ed_get (
 380         struct ohci_hcd         *ohci,
 381         struct usb_host_endpoint *ep,
 382         struct usb_device       *udev,
 383         unsigned int            pipe,
 384         int                     interval
 385 ) {
 386         struct ed               *ed;
 387         unsigned long           flags;
 388
 389         spin_lock_irqsave (&ohci->lock, flags);
 390
 391         if (!(ed = ep->hcpriv)) {
 392                 struct td       *td;
 393                 int             is_out;
 394                 u32             info;
 395
 396                 ed = ed_alloc (ohci, GFP_ATOMIC);
 397                 if (!ed) {
 398                         /* out of memory */
 399                         goto done;
 400                 }
 401
 402                 /* dummy td; end of td list for ed */
 403                 td = td_alloc (ohci, GFP_ATOMIC);
 404                 if (!td) {
 405                         /* out of memory */
 406                         ed_free (ohci, ed);
 407                         ed = NULL;
 408                         goto done;
 409                 }
 410                 ed->dummy = td;
 411                 ed->hwTailP = cpu_to_hc32 (ohci, td->td_dma);
 412                 ed->hwHeadP = ed->hwTailP;      /* ED_C, ED_H zeroed */
 413                 ed->state = ED_IDLE;
 414
 415                 is_out = !(ep->desc.bEndpointAddress & USB_DIR_IN);
 416
 417                 /* FIXME usbcore changes dev->devnum before SET_ADDRESS
 418                  * suceeds ... otherwise we wouldn't need "pipe".
 419                  */
 420                 info = usb_pipedevice (pipe);
 421                 ed->type = usb_pipetype(pipe);
 422
 423                 info |= (ep->desc.bEndpointAddress & ~USB_DIR_IN) << 7;
 424                 info |= le16_to_cpu(ep->desc.wMaxPacketSize) << 16;
 425                 if (udev->speed == USB_SPEED_LOW)
 426                         info |= ED_LOWSPEED;
 427                 /* only control transfers store pids in tds */
 428                 if (ed->type != PIPE_CONTROL) {
 429                         info |= is_out ? ED_OUT : ED_IN;
 430                         if (ed->type != PIPE_BULK) {
 431                                 /* periodic transfers... */
 432                                 if (ed->type == PIPE_ISOCHRONOUS)
 433                                         info |= ED_ISO;
 434                                 else if (interval > 32) /* iso can be bigger */
 435                                         interval = 32;
 436                                 ed->interval = interval;
 437                                 ed->load = usb_calc_bus_time (
 438                                         udev->speed, !is_out,
 439                                         ed->type == PIPE_ISOCHRONOUS,
 440                                         le16_to_cpu(ep->desc.wMaxPacketSize))
 441                                                 / 1000;
 442                         }
 443                 }
 444                 ed->hwINFO = cpu_to_hc32(ohci, info);
 445
 446                 ep->hcpriv = ed;
 447         }
 448
 449 done:
 450         spin_unlock_irqrestore (&ohci->lock, flags);
 451         return ed;
 452 }
 453
 454 /*-------------------------------------------------------------------------*/
 455
 456 /* request unlinking of an endpoint from an operational HC.
 457  * put the ep on the rm_list
 458  * real work is done at the next start frame (SF) hardware interrupt
 459  * caller guarantees HCD is running, so hardware access is safe,
 460  * and that ed->state is ED_OPER
 461  */
 462 static void start_ed_unlink (struct ohci_hcd *ohci, struct ed *ed)
 463 {
 464         ed->hwINFO |= cpu_to_hc32 (ohci, ED_DEQUEUE);
 465         ed_deschedule (ohci, ed);
 466
 467         /* rm_list is just singly linked, for simplicity */
 468         ed->ed_next = ohci->ed_rm_list;
 469         ed->ed_prev = NULL;
 470         ohci->ed_rm_list = ed;
 471
 472         /* enable SOF interrupt */
 473         ohci_writel (ohci, OHCI_INTR_SF, &ohci->regs->intrstatus);
 474         ohci_writel (ohci, OHCI_INTR_SF, &ohci->regs->intrenable);
 475         // flush those writes, and get latest HCCA contents
 476         (void) ohci_readl (ohci, &ohci->regs->control);
 477
 478         /* SF interrupt might get delayed; record the frame counter value that
 479          * indicates when the HC isn't looking at it, so concurrent unlinks
 480          * behave.  frame_no wraps every 2^16 msec, and changes right before
 481          * SF is triggered.
 482          */
 483         ed->tick = ohci_frame_no(ohci) + 1;
 484
 485 }
 486
 487 /*-------------------------------------------------------------------------*
 488  * TD handling functions
 489  *-------------------------------------------------------------------------*/
 490
 491 /* enqueue next TD for this URB (OHCI spec 5.2.8.2) */
 492
 493 static void
 494 td_fill (struct ohci_hcd *ohci, u32 info,
 495         dma_addr_t data, int len,
 496         struct urb *urb, int index)
 497 {
 498         struct td               *td, *td_pt;
 499         struct urb_priv         *urb_priv = urb->hcpriv;
 500         int                     is_iso = info & TD_ISO;
 501         int                     hash;
 502
 503         // ASSERT (index < urb_priv->length);
 504
 505         /* aim for only one interrupt per urb.  mostly applies to control
 506          * and iso; other urbs rarely need more than one TD per urb.
 507          * this way, only final tds (or ones with an error) cause IRQs.
 508          * at least immediately; use DI=6 in case any control request is
 509          * tempted to die part way through.  (and to force the hc to flush
 510          * its donelist soonish, even on unlink paths.)
 511          *
 512          * NOTE: could delay interrupts even for the last TD, and get fewer
 513          * interrupts ... increasing per-urb latency by sharing interrupts.
 514          * Drivers that queue bulk urbs may request that behavior.
 515          */
 516         if (index != (urb_priv->length - 1)
 517                         || (urb->transfer_flags & URB_NO_INTERRUPT))
 518                 info |= TD_DI_SET (6);
 519
 520         /* use this td as the next dummy */
 521         td_pt = urb_priv->td [index];
 522
 523         /* fill the old dummy TD */
 524         td = urb_priv->td [index] = urb_priv->ed->dummy;
 525         urb_priv->ed->dummy = td_pt;
 526
 527         td->ed = urb_priv->ed;
 528         td->next_dl_td = NULL;
 529         td->index = index;
 530         td->urb = urb;
 531         td->data_dma = data;
 532         if (!len)
 533                 data = 0;
 534
 535         td->hwINFO = cpu_to_hc32 (ohci, info);
 536         if (is_iso) {
 537                 td->hwCBP = cpu_to_hc32 (ohci, data & 0xFFFFF000);
 538                 *ohci_hwPSWp(ohci, td, 0) = cpu_to_hc16 (ohci,
 539                                                 (data & 0x0FFF) | 0xE000);
 540                 td->ed->last_iso = info & 0xffff;
 541         } else {
 542                 td->hwCBP = cpu_to_hc32 (ohci, data);
 543         }
 544         if (data)
 545                 td->hwBE = cpu_to_hc32 (ohci, data + len - 1);
 546         else
 547                 td->hwBE = 0;
 548         td->hwNextTD = cpu_to_hc32 (ohci, td_pt->td_dma);
 549
 550         /* append to queue */
 551         list_add_tail (&td->td_list, &td->ed->td_list);
 552
 553         /* hash it for later reverse mapping */
 554         hash = TD_HASH_FUNC (td->td_dma);
 555         td->td_hash = ohci->td_hash [hash];
 556         ohci->td_hash [hash] = td;
 557
 558         /* HC might read the TD (or cachelines) right away ... */
 559         wmb ();
 560         td->ed->hwTailP = td->hwNextTD;
 561 }
 562
 563 /*-------------------------------------------------------------------------*/
 564
 565 /* Prepare all TDs of a transfer, and queue them onto the ED.
 566  * Caller guarantees HC is active.
 567  * Usually the ED is already on the schedule, so TDs might be
 568  * processed as soon as they're queued.
 569  */
 570 static void td_submit_urb (
 571         struct ohci_hcd *ohci,
 572         struct urb      *urb
 573 ) {
 574         struct urb_priv *urb_priv = urb->hcpriv;
 575         dma_addr_t      data;
 576         int             data_len = urb->transfer_buffer_length;
 577         int             cnt = 0;
 578         u32             info = 0;
 579         int             is_out = usb_pipeout (urb->pipe);
 580         int             periodic = 0;
 581
 582         /* OHCI handles the bulk/interrupt data toggles itself.  We just
 583          * use the device toggle bits for resetting, and rely on the fact
 584          * that resetting toggle is meaningless if the endpoint is active.
 585          */
 586         if (!usb_gettoggle (urb->dev, usb_pipeendpoint (urb->pipe), is_out)) {
 587                 usb_settoggle (urb->dev, usb_pipeendpoint (urb->pipe),
 588                         is_out, 1);
 589                 urb_priv->ed->hwHeadP &= ~cpu_to_hc32 (ohci, ED_C);
 590         }
 591
 592         urb_priv->td_cnt = 0;
 593         list_add (&urb_priv->pending, &ohci->pending);
 594
 595         if (data_len)
 596                 data = urb->transfer_dma;
 597         else
 598                 data = 0;
 599
 600         /* NOTE:  TD_CC is set so we can tell which TDs the HC processed by
 601          * using TD_CC_GET, as well as by seeing them on the done list.
 602          * (CC = NotAccessed ... 0x0F, or 0x0E in PSWs for ISO.)
 603          */
 604         switch (urb_priv->ed->type) {
 605
 606         /* Bulk and interrupt are identical except for where in the schedule
 607          * their EDs live.
 608          */
 609         case PIPE_INTERRUPT:
 610                 /* ... and periodic urbs have extra accounting */
 611                 periodic = ohci_to_hcd(ohci)->self.bandwidth_int_reqs++ == 0
 612                         && ohci_to_hcd(ohci)->self.bandwidth_isoc_reqs == 0;
 613                 /* FALLTHROUGH */
 614         case PIPE_BULK:
 615                 info = is_out
 616                         ? TD_T_TOGGLE | TD_CC | TD_DP_OUT
 617                         : TD_T_TOGGLE | TD_CC | TD_DP_IN;
 618                 /* TDs _could_ transfer up to 8K each */
 619                 while (data_len > 4096) {
 620                         td_fill (ohci, info, data, 4096, urb, cnt);
 621                         data += 4096;
 622                         data_len -= 4096;
 623                         cnt++;
 624                 }
 625                 /* maybe avoid ED halt on final TD short read */
 626                 if (!(urb->transfer_flags & URB_SHORT_NOT_OK))
 627                         info |= TD_R;
 628                 td_fill (ohci, info, data, data_len, urb, cnt);
 629                 cnt++;
 630                 if ((urb->transfer_flags & URB_ZERO_PACKET)
 631                                 && cnt < urb_priv->length) {
 632                         td_fill (ohci, info, 0, 0, urb, cnt);
 633                         cnt++;
 634                 }
 635                 /* maybe kickstart bulk list */
 636                 if (urb_priv->ed->type == PIPE_BULK) {
 637                         wmb ();
 638                         ohci_writel (ohci, OHCI_BLF, &ohci->regs->cmdstatus);
 639                 }
 640                 break;
 641
 642         /* control manages DATA0/DATA1 toggle per-request; SETUP resets it,
 643          * any DATA phase works normally, and the STATUS ack is special.
 644          */
 645         case PIPE_CONTROL:
 646                 info = TD_CC | TD_DP_SETUP | TD_T_DATA0;
 647                 td_fill (ohci, info, urb->setup_dma, 8, urb, cnt++);
 648                 if (data_len > 0) {
 649                         info = TD_CC | TD_R | TD_T_DATA1;
 650                         info |= is_out ? TD_DP_OUT : TD_DP_IN;
 651                         /* NOTE:  mishandles transfers >8K, some >4K */
 652                         td_fill (ohci, info, data, data_len, urb, cnt++);
 653                 }
 654                 info = (is_out || data_len == 0)
 655                         ? TD_CC | TD_DP_IN | TD_T_DATA1
 656                         : TD_CC | TD_DP_OUT | TD_T_DATA1;
 657                 td_fill (ohci, info, data, 0, urb, cnt++);
 658                 /* maybe kickstart control list */
 659                 wmb ();
 660                 ohci_writel (ohci, OHCI_CLF, &ohci->regs->cmdstatus);
 661                 break;
 662
 663         /* ISO has no retransmit, so no toggle; and it uses special TDs.
 664          * Each TD could handle multiple consecutive frames (interval 1);
 665          * we could often reduce the number of TDs here.
 666          */
 667         case PIPE_ISOCHRONOUS:
 668                 for (cnt = 0; cnt < urb->number_of_packets; cnt++) {
 669                         int     frame = urb->start_frame;
 670
 671                         // FIXME scheduling should handle frame counter
 672                         // roll-around ... exotic case (and OHCI has
 673                         // a 2^16 iso range, vs other HCs max of 2^10)
 674                         frame += cnt * urb->interval;
 675                         frame &= 0xffff;
 676                         td_fill (ohci, TD_CC | TD_ISO | frame,
 677                                 data + urb->iso_frame_desc [cnt].offset,
 678                                 urb->iso_frame_desc [cnt].length, urb, cnt);
 679                 }
 680                 periodic = ohci_to_hcd(ohci)->self.bandwidth_isoc_reqs++ == 0
 681                         && ohci_to_hcd(ohci)->self.bandwidth_int_reqs == 0;
 682                 break;
 683         }
 684
 685         /* start periodic dma if needed */
 686         if (periodic) {
 687                 wmb ();
 688                 ohci->hc_control |= OHCI_CTRL_PLE|OHCI_CTRL_IE;
 689                 ohci_writel (ohci, ohci->hc_control, &ohci->regs->control);
 690         }
 691
 692         // ASSERT (urb_priv->length == cnt);
 693 }
 694
 695 /*-------------------------------------------------------------------------*
 696  * Done List handling functions
 697  *-------------------------------------------------------------------------*/
 698
 699 /* calculate transfer length/status and update the urb */
 700 static int td_done(struct ohci_hcd *ohci, struct urb *urb, struct td *td)
 701 {
 702         u32     tdINFO = hc32_to_cpup (ohci, &td->hwINFO);
 703         int     cc = 0;
 704         int     status = -EINPROGRESS;
 705
 706         list_del (&td->td_list);
 707
 708         /* ISO ... drivers see per-TD length/status */
 709         if (tdINFO & TD_ISO) {
 710                 u16     tdPSW = ohci_hwPSW(ohci, td, 0);
 711                 int     dlen = 0;
 712
 713                 /* NOTE:  assumes FC in tdINFO == 0, and that
 714                  * only the first of 0..MAXPSW psws is used.
 715                  */
 716
 717                 cc = (tdPSW >> 12) & 0xF;
 718                 if (tdINFO & TD_CC)     /* hc didn't touch? */
 719                         return status;
 720
 721                 if (usb_pipeout (urb->pipe))
 722                         dlen = urb->iso_frame_desc [td->index].length;
 723                 else {
 724                         /* short reads are always OK for ISO */
 725                         if (cc == TD_DATAUNDERRUN)
 726                                 cc = TD_CC_NOERROR;
 727                         dlen = tdPSW & 0x3ff;
 728                 }
 729                 urb->actual_length += dlen;
 730                 urb->iso_frame_desc [td->index].actual_length = dlen;
 731                 urb->iso_frame_desc [td->index].status = cc_to_error [cc];
 732
 733                 if (cc != TD_CC_NOERROR)
 734                         ohci_vdbg (ohci,
 735                                 "urb %p iso td %p (%d) len %d cc %d\n",
 736                                 urb, td, 1 + td->index, dlen, cc);
 737
 738         /* BULK, INT, CONTROL ... drivers see aggregate length/status,
 739          * except that "setup" bytes aren't counted and "short" transfers
 740          * might not be reported as errors.
 741          */
 742         } else {
 743                 int     type = usb_pipetype (urb->pipe);
 744                 u32     tdBE = hc32_to_cpup (ohci, &td->hwBE);
 745
 746                 cc = TD_CC_GET (tdINFO);
 747
 748                 /* update packet status if needed (short is normally ok) */
 749                 if (cc == TD_DATAUNDERRUN
 750                                 && !(urb->transfer_flags & URB_SHORT_NOT_OK))
 751                         cc = TD_CC_NOERROR;
 752                 if (cc != TD_CC_NOERROR && cc < 0x0E)
 753                         status = cc_to_error[cc];
 754
 755                 /* count all non-empty packets except control SETUP packet */
 756                 if ((type != PIPE_CONTROL || td->index != 0) && tdBE != 0) {
 757                         if (td->hwCBP == 0)
 758                                 urb->actual_length += tdBE - td->data_dma + 1;
 759                         else
 760                                 urb->actual_length +=
 761                                           hc32_to_cpup (ohci, &td->hwCBP)
 762                                         - td->data_dma;
 763                 }
 764
 765                 if (cc != TD_CC_NOERROR && cc < 0x0E)
 766                         ohci_vdbg (ohci,
 767                                 "urb %p td %p (%d) cc %d, len=%d/%d\n",
 768                                 urb, td, 1 + td->index, cc,
 769                                 urb->actual_length,
 770                                 urb->transfer_buffer_length);
 771         }
 772         return status;
 773 }
 774
 775 /*-------------------------------------------------------------------------*/
 776
 777 static void ed_halted(struct ohci_hcd *ohci, struct td *td, int cc)
 778 {
 779         struct urb              *urb = td->urb;
 780         urb_priv_t              *urb_priv = urb->hcpriv;
 781         struct ed               *ed = td->ed;
 782         struct list_head        *tmp = td->td_list.next;
 783         __hc32                  toggle = ed->hwHeadP & cpu_to_hc32 (ohci, ED_C);
 784
 785         /* clear ed halt; this is the td that caused it, but keep it inactive
 786          * until its urb->complete() has a chance to clean up.
 787          */
 788         ed->hwINFO |= cpu_to_hc32 (ohci, ED_SKIP);
 789         wmb ();
 790         ed->hwHeadP &= ~cpu_to_hc32 (ohci, ED_H);
 791
 792         /* Get rid of all later tds from this urb.  We don't have
 793          * to be careful: no errors and nothing was transferred.
 794          * Also patch the ed so it looks as if those tds completed normally.
 795          */
 796         while (tmp != &ed->td_list) {
 797                 struct td       *next;
 798
 799                 next = list_entry (tmp, struct td, td_list);
 800                 tmp = next->td_list.next;
 801
 802                 if (next->urb != urb)
 803                         break;
 804
 805                 /* NOTE: if multi-td control DATA segments get supported,
 806                  * this urb had one of them, this td wasn't the last td
 807                  * in that segment (TD_R clear), this ed halted because
 808                  * of a short read, _and_ URB_SHORT_NOT_OK is clear ...
 809                  * then we need to leave the control STATUS packet queued
 810                  * and clear ED_SKIP.
 811                  */
 812
 813                 list_del(&next->td_list);
 814                 urb_priv->td_cnt++;
 815                 ed->hwHeadP = next->hwNextTD | toggle;
 816         }
 817
 818         /* help for troubleshooting:  report anything that
 819          * looks odd ... that doesn't include protocol stalls
 820          * (or maybe some other things)
 821          */
 822         switch (cc) {
 823         case TD_DATAUNDERRUN:
 824                 if ((urb->transfer_flags & URB_SHORT_NOT_OK) == 0)
 825                         break;
 826                 /* fallthrough */
 827         case TD_CC_STALL:
 828                 if (usb_pipecontrol (urb->pipe))
 829                         break;
 830                 /* fallthrough */
 831         default:
 832                 ohci_dbg (ohci,
 833                         "urb %p path %s ep%d%s %08x cc %d --> status %d\n",
 834                         urb, urb->dev->devpath,
 835                         usb_pipeendpoint (urb->pipe),
 836                         usb_pipein (urb->pipe) ? "in" : "out",
 837                         hc32_to_cpu (ohci, td->hwINFO),
 838                         cc, cc_to_error [cc]);
 839         }
 840 }
 841
 842 /* replies to the request have to be on a FIFO basis so
 843  * we unreverse the hc-reversed done-list
 844  */
 845 static struct td *dl_reverse_done_list (struct ohci_hcd *ohci)
 846 {
 847         u32             td_dma;
 848         struct td       *td_rev = NULL;
 849         struct td       *td = NULL;
 850
 851         td_dma = hc32_to_cpup (ohci, &ohci->hcca->done_head);
 852         ohci->hcca->done_head = 0;
 853         wmb();
 854
 855         /* get TD from hc's singly linked list, and
 856          * prepend to ours.  ed->td_list changes later.
 857          */
 858         while (td_dma) {
 859                 int             cc;
 860
 861                 td = dma_to_td (ohci, td_dma);
 862                 if (!td) {
 863                         ohci_err (ohci, "bad entry %8x\n", td_dma);
 864                         break;
 865                 }
 866
 867                 td->hwINFO |= cpu_to_hc32 (ohci, TD_DONE);
 868                 cc = TD_CC_GET (hc32_to_cpup (ohci, &td->hwINFO));
 869
 870                 /* Non-iso endpoints can halt on error; un-halt,
 871                  * and dequeue any other TDs from this urb.
 872                  * No other TD could have caused the halt.
 873                  */
 874                 if (cc != TD_CC_NOERROR
 875                                 && (td->ed->hwHeadP & cpu_to_hc32 (ohci, ED_H)))
 876                         ed_halted(ohci, td, cc);
 877
 878                 td->next_dl_td = td_rev;
 879                 td_rev = td;
 880                 td_dma = hc32_to_cpup (ohci, &td->hwNextTD);
 881         }
 882         return td_rev;
 883 }
 884
 885 /*-------------------------------------------------------------------------*/
 886
 887 /* there are some urbs/eds to unlink; called in_irq(), with HCD locked */
 888 static void
 889 finish_unlinks (struct ohci_hcd *ohci, u16 tick)
 890 {
 891         struct ed       *ed, **last;
 892
 893 rescan_all:
 894         for (last = &ohci->ed_rm_list, ed = *last; ed != NULL; ed = *last) {
 895                 struct list_head        *entry, *tmp;
 896                 int                     completed, modified;
 897                 __hc32                  *prev;
 898
 899                 /* only take off EDs that the HC isn't using, accounting for
 900                  * frame counter wraps and EDs with partially retired TDs
 901                  */
 902                 if (likely (HC_IS_RUNNING(ohci_to_hcd(ohci)->state))) {
 903                         if (tick_before (tick, ed->tick)) {
 904 skip_ed:
 905                                 last = &ed->ed_next;
 906                                 continue;
 907                         }
 908
 909                         if (!list_empty (&ed->td_list)) {
 910                                 struct td       *td;
 911                                 u32             head;
 912
 913                                 td = list_entry (ed->td_list.next, struct td,
 914                                                         td_list);
 915                                 head = hc32_to_cpu (ohci, ed->hwHeadP) &
 916                                                                 TD_MASK;
 917
 918                                 /* INTR_WDH may need to clean up first */
 919                                 if (td->td_dma != head) {
 920                                         if (ed == ohci->ed_to_check)
 921                                                 ohci->ed_to_check = NULL;
 922                                         else
 923                                                 goto skip_ed;
 924                                 }
 925                         }
 926                 }
 927
 928                 /* reentrancy:  if we drop the schedule lock, someone might
 929                  * have modified this list.  normally it's just prepending
 930                  * entries (which we'd ignore), but paranoia won't hurt.
 931                  */
 932                 *last = ed->ed_next;
 933                 ed->ed_next = NULL;
 934                 modified = 0;
 935
 936                 /* unlink urbs as requested, but rescan the list after
 937                  * we call a completion since it might have unlinked
 938                  * another (earlier) urb
 939                  *
 940                  * When we get here, the HC doesn't see this ed.  But it
 941                  * must not be rescheduled until all completed URBs have
 942                  * been given back to the driver.
 943                  */
 944 rescan_this:
 945                 completed = 0;
 946                 prev = &ed->hwHeadP;
 947                 list_for_each_safe (entry, tmp, &ed->td_list) {
 948                         struct td       *td;
 949                         struct urb      *urb;
 950                         urb_priv_t      *urb_priv;
 951                         __hc32          savebits;
 952                         u32             tdINFO;
 953
 954                         td = list_entry (entry, struct td, td_list);
 955                         urb = td->urb;
 956                         urb_priv = td->urb->hcpriv;
 957
 958                         if (!urb->unlinked) {
 959                                 prev = &td->hwNextTD;
 960                                 continue;
 961                         }
 962
 963                         /* patch pointer hc uses */
 964                         savebits = *prev & ~cpu_to_hc32 (ohci, TD_MASK);
 965                         *prev = td->hwNextTD | savebits;
 966
 967                         /* If this was unlinked, the TD may not have been
 968                          * retired ... so manually save the data toggle.
 969                          * The controller ignores the value we save for
 970                          * control and ISO endpoints.
 971                          */
 972                         tdINFO = hc32_to_cpup(ohci, &td->hwINFO);
 973                         if ((tdINFO & TD_T) == TD_T_DATA0)
 974                                 ed->hwHeadP &= ~cpu_to_hc32(ohci, ED_C);
 975                         else if ((tdINFO & TD_T) == TD_T_DATA1)
 976                                 ed->hwHeadP |= cpu_to_hc32(ohci, ED_C);
 977
 978                         /* HC may have partly processed this TD */
 979                         td_done (ohci, urb, td);
 980                         urb_priv->td_cnt++;
 981
 982                         /* if URB is done, clean up */
 983                         if (urb_priv->td_cnt == urb_priv->length) {
 984                                 modified = completed = 1;
 985                                 finish_urb(ohci, urb, 0);
 986                         }
 987                 }
 988                 if (completed && !list_empty (&ed->td_list))
 989                         goto rescan_this;
 990
 991                 /* ED's now officially unlinked, hc doesn't see */
 992                 ed->state = ED_IDLE;
 993                 if (quirk_zfmicro(ohci) && ed->type == PIPE_INTERRUPT)
 994                         ohci->eds_scheduled--;
 995                 ed->hwHeadP &= ~cpu_to_hc32(ohci, ED_H);
 996                 ed->hwNextED = 0;
 997                 wmb ();
 998                 ed->hwINFO &= ~cpu_to_hc32 (ohci, ED_SKIP | ED_DEQUEUE);
 999
1000                 /* but if there's work queued, reschedule */
1001                 if (!list_empty (&ed->td_list)) {
1002                         if (HC_IS_RUNNING(ohci_to_hcd(ohci)->state))
1003                                 ed_schedule (ohci, ed);
1004                 }
1005
1006                 if (modified)
1007                         goto rescan_all;
1008         }
1009
1010         /* maybe reenable control and bulk lists */
1011         if (HC_IS_RUNNING(ohci_to_hcd(ohci)->state)
1012                         && ohci_to_hcd(ohci)->state != HC_STATE_QUIESCING
1013                         && !ohci->ed_rm_list) {
1014                 u32     command = 0, control = 0;
1015
1016                 if (ohci->ed_controltail) {
1017                         command |= OHCI_CLF;
1018                         if (quirk_zfmicro(ohci))
1019                                 mdelay(1);
1020                         if (!(ohci->hc_control & OHCI_CTRL_CLE)) {
1021                                 control |= OHCI_CTRL_CLE;
1022                                 ohci_writel (ohci, 0,
1023                                         &ohci->regs->ed_controlcurrent);
1024                         }
1025                 }
1026                 if (ohci->ed_bulktail) {
1027                         command |= OHCI_BLF;
1028                         if (quirk_zfmicro(ohci))
1029                                 mdelay(1);
1030                         if (!(ohci->hc_control & OHCI_CTRL_BLE)) {
1031                                 control |= OHCI_CTRL_BLE;
1032                                 ohci_writel (ohci, 0,
1033                                         &ohci->regs->ed_bulkcurrent);
1034                         }
1035                 }
1036
1037                 /* CLE/BLE to enable, CLF/BLF to (maybe) kickstart */
1038                 if (control) {
1039                         ohci->hc_control |= control;
1040                         if (quirk_zfmicro(ohci))
1041                                 mdelay(1);
1042                         ohci_writel (ohci, ohci->hc_control,
1043                                         &ohci->regs->control);
1044                 }
1045                 if (command) {
1046                         if (quirk_zfmicro(ohci))
1047                                 mdelay(1);
1048                         ohci_writel (ohci, command, &ohci->regs->cmdstatus);
1049                 }
1050         }
1051 }
1052
1053
1054
1055 /*-------------------------------------------------------------------------*/
1056
1057 /*
1058  * Used to take back a TD from the host controller. This would normally be
1059  * called from within dl_done_list, however it may be called directly if the
1060  * HC no longer sees the TD and it has not appeared on the donelist (after
1061  * two frames).  This bug has been observed on ZF Micro systems.
1062  */
1063 static void takeback_td(struct ohci_hcd *ohci, struct td *td)
1064 {
1065         struct urb      *urb = td->urb;
1066         urb_priv_t      *urb_priv = urb->hcpriv;
1067         struct ed       *ed = td->ed;
1068         int             status;
1069
1070         /* update URB's length and status from TD */
1071         status = td_done(ohci, urb, td);
1072         urb_priv->td_cnt++;
1073
1074         /* If all this urb's TDs are done, call complete() */
1075         if (urb_priv->td_cnt == urb_priv->length)
1076                 finish_urb(ohci, urb, status);
1077
1078         /* clean schedule:  unlink EDs that are no longer busy */
1079         if (list_empty(&ed->td_list)) {
1080                 if (ed->state == ED_OPER)
1081                         start_ed_unlink(ohci, ed);
1082
1083         /* ... reenabling halted EDs only after fault cleanup */
1084         } else if ((ed->hwINFO & cpu_to_hc32(ohci, ED_SKIP | ED_DEQUEUE))
1085                         == cpu_to_hc32(ohci, ED_SKIP)) {
1086                 td = list_entry(ed->td_list.next, struct td, td_list);
1087                 if (!(td->hwINFO & cpu_to_hc32(ohci, TD_DONE))) {
1088                         ed->hwINFO &= ~cpu_to_hc32(ohci, ED_SKIP);
1089                         /* ... hc may need waking-up */
1090                         switch (ed->type) {
1091                         case PIPE_CONTROL:
1092                                 ohci_writel(ohci, OHCI_CLF,
1093                                                 &ohci->regs->cmdstatus);
1094                                 break;
1095                         case PIPE_BULK:
1096                                 ohci_writel(ohci, OHCI_BLF,
1097                                                 &ohci->regs->cmdstatus);
1098                                 break;
1099                         }
1100                 }
1101         }
1102 }
1103
1104 /*
1105  * Process normal completions (error or success) and clean the schedules.
1106  *
1107  * This is the main path for handing urbs back to drivers.  The only other
1108  * normal path is finish_unlinks(), which unlinks URBs using ed_rm_list,
1109  * instead of scanning the (re-reversed) donelist as this does.  There's
1110  * an abnormal path too, handling a quirk in some Compaq silicon:  URBs
1111  * with TDs that appear to be orphaned are directly reclaimed.
1112  */
1113 static void
1114 dl_done_list (struct ohci_hcd *ohci)
1115 {
1116         struct td       *td = dl_reverse_done_list (ohci);
1117
1118         while (td) {
1119                 struct td       *td_next = td->next_dl_td;
1120                 takeback_td(ohci, td);
1121                 td = td_next;
1122         }
1123 }