drivers/usb/host/ehci-sched.c

   1 /*
   2  * Copyright (c) 2001-2004 by David Brownell
   3  * Copyright (c) 2003 Michal Sojka, for high-speed iso transfers
   4  *
   5  * This program is free software; you can redistribute it and/or modify it
   6  * under the terms of the GNU General Public License as published by the
   7  * Free Software Foundation; either version 2 of the License, or (at your
   8  * option) any later version.
   9  *
  10  * This program is distributed in the hope that it will be useful, but
  11  * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
  12  * or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  13  * for more details.
  14  *
  15  * You should have received a copy of the GNU General Public License
  16  * along with this program; if not, write to the Free Software Foundation,
  17  * Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  18  */
  19
  20 /* this file is part of ehci-hcd.c */
  21
  22 /*-------------------------------------------------------------------------*/
  23
  24 /*
  25  * EHCI scheduled transaction support:  interrupt, iso, split iso
  26  * These are called "periodic" transactions in the EHCI spec.
  27  *
  28  * Note that for interrupt transfers, the QH/QTD manipulation is shared
  29  * with the "asynchronous" transaction support (control/bulk transfers).
  30  * The only real difference is in how interrupt transfers are scheduled.
  31  *
  32  * For ISO, we make an "iso_stream" head to serve the same role as a QH.
  33  * It keeps track of every ITD (or SITD) that's linked, and holds enough
  34  * pre-calculated schedule data to make appending to the queue be quick.
  35  */
  36
  37 static int ehci_get_frame (struct usb_hcd *hcd);
  38
  39 /*
  40  * periodic_next_shadow - return "next" pointer on shadow list
  41  * @periodic: host pointer to qh/itd/sitd
  42  * @tag: hardware tag for type of this record
  43  */
  44 static union ehci_shadow *
  45 periodic_next_shadow(struct ehci_hcd *ehci, union ehci_shadow *periodic,
  46                 __hc32 tag)
  47 {
  48         switch (hc32_to_cpu(ehci, tag)) {
  49         case Q_TYPE_QH:
  50                 return &periodic->qh->qh_next;
  51         case Q_TYPE_FSTN:
  52                 return &periodic->fstn->fstn_next;
  53         case Q_TYPE_ITD:
  54                 return &periodic->itd->itd_next;
  55         // case Q_TYPE_SITD:
  56         default:
  57                 return &periodic->sitd->sitd_next;
  58         }
  59 }
  60
  61 static __hc32 *
  62 shadow_next_periodic(struct ehci_hcd *ehci, union ehci_shadow *periodic,
  63                 __hc32 tag)
  64 {
  65         switch (hc32_to_cpu(ehci, tag)) {
  66         /* our ehci_shadow.qh is actually software part */
  67         case Q_TYPE_QH:
  68                 return &periodic->qh->hw->hw_next;
  69         /* others are hw parts */
  70         default:
  71                 return periodic->hw_next;
  72         }
  73 }
  74
  75 /* caller must hold ehci->lock */
  76 static void periodic_unlink (struct ehci_hcd *ehci, unsigned frame, void *ptr)
  77 {
  78         union ehci_shadow       *prev_p = &ehci->pshadow[frame];
  79         __hc32                  *hw_p = &ehci->periodic[frame];
  80         union ehci_shadow       here = *prev_p;
  81
  82         /* find predecessor of "ptr"; hw and shadow lists are in sync */
  83         while (here.ptr && here.ptr != ptr) {
  84                 prev_p = periodic_next_shadow(ehci, prev_p,
  85                                 Q_NEXT_TYPE(ehci, *hw_p));
  86                 hw_p = shadow_next_periodic(ehci, &here,
  87                                 Q_NEXT_TYPE(ehci, *hw_p));
  88                 here = *prev_p;
  89         }
  90         /* an interrupt entry (at list end) could have been shared */
  91         if (!here.ptr)
  92                 return;
  93
  94         /* update shadow and hardware lists ... the old "next" pointers
  95          * from ptr may still be in use, the caller updates them.
  96          */
  97         *prev_p = *periodic_next_shadow(ehci, &here,
  98                         Q_NEXT_TYPE(ehci, *hw_p));
  99
 100         if (!ehci->use_dummy_qh ||
 101             *shadow_next_periodic(ehci, &here, Q_NEXT_TYPE(ehci, *hw_p))
 102                         != EHCI_LIST_END(ehci))
 103                 *hw_p = *shadow_next_periodic(ehci, &here,
 104                                 Q_NEXT_TYPE(ehci, *hw_p));
 105         else
 106                 *hw_p = ehci->dummy->qh_dma;
 107 }
 108
 109 /* how many of the uframe's 125 usecs are allocated? */
 110 static unsigned short
 111 periodic_usecs (struct ehci_hcd *ehci, unsigned frame, unsigned uframe)
 112 {
 113         __hc32                  *hw_p = &ehci->periodic [frame];
 114         union ehci_shadow       *q = &ehci->pshadow [frame];
 115         unsigned                usecs = 0;
 116         struct ehci_qh_hw       *hw;
 117
 118         while (q->ptr) {
 119                 switch (hc32_to_cpu(ehci, Q_NEXT_TYPE(ehci, *hw_p))) {
 120                 case Q_TYPE_QH:
 121                         hw = q->qh->hw;
 122                         /* is it in the S-mask? */
 123                         if (hw->hw_info2 & cpu_to_hc32(ehci, 1 << uframe))
 124                                 usecs += q->qh->usecs;
 125                         /* ... or C-mask? */
 126                         if (hw->hw_info2 & cpu_to_hc32(ehci,
 127                                         1 << (8 + uframe)))
 128                                 usecs += q->qh->c_usecs;
 129                         hw_p = &hw->hw_next;
 130                         q = &q->qh->qh_next;
 131                         break;
 132                 // case Q_TYPE_FSTN:
 133                 default:
 134                         /* for "save place" FSTNs, count the relevant INTR
 135                          * bandwidth from the previous frame
 136                          */
 137                         if (q->fstn->hw_prev != EHCI_LIST_END(ehci)) {
 138                                 ehci_dbg (ehci, "ignoring FSTN cost ...\n");
 139                         }
 140                         hw_p = &q->fstn->hw_next;
 141                         q = &q->fstn->fstn_next;
 142                         break;
 143                 case Q_TYPE_ITD:
 144                         if (q->itd->hw_transaction[uframe])
 145                                 usecs += q->itd->stream->usecs;
 146                         hw_p = &q->itd->hw_next;
 147                         q = &q->itd->itd_next;
 148                         break;
 149                 case Q_TYPE_SITD:
 150                         /* is it in the S-mask?  (count SPLIT, DATA) */
 151                         if (q->sitd->hw_uframe & cpu_to_hc32(ehci,
 152                                         1 << uframe)) {
 153                                 if (q->sitd->hw_fullspeed_ep &
 154                                                 cpu_to_hc32(ehci, 1<<31))
 155                                         usecs += q->sitd->stream->usecs;
 156                                 else    /* worst case for OUT start-split */
 157                                         usecs += HS_USECS_ISO (188);
 158                         }
 159
 160                         /* ... C-mask?  (count CSPLIT, DATA) */
 161                         if (q->sitd->hw_uframe &
 162                                         cpu_to_hc32(ehci, 1 << (8 + uframe))) {
 163                                 /* worst case for IN complete-split */
 164                                 usecs += q->sitd->stream->c_usecs;
 165                         }
 166
 167                         hw_p = &q->sitd->hw_next;
 168                         q = &q->sitd->sitd_next;
 169                         break;
 170                 }
 171         }
 172 #if defined(DEBUG) || defined(CONFIG_DYNAMIC_DEBUG)
 173         if (usecs > ehci->uframe_periodic_max)
 174                 ehci_err (ehci, "uframe %d sched overrun: %d usecs\n",
 175                         frame * 8 + uframe, usecs);
 176 #endif
 177         return usecs;
 178 }
 179
 180 /*-------------------------------------------------------------------------*/
 181
 182 static int same_tt (struct usb_device *dev1, struct usb_device *dev2)
 183 {
 184         if (!dev1->tt || !dev2->tt)
 185                 return 0;
 186         if (dev1->tt != dev2->tt)
 187                 return 0;
 188         if (dev1->tt->multi)
 189                 return dev1->ttport == dev2->ttport;
 190         else
 191                 return 1;
 192 }
 193
 194 #ifdef CONFIG_USB_EHCI_TT_NEWSCHED
 195
 196 /* Which uframe does the low/fullspeed transfer start in?
 197  *
 198  * The parameter is the mask of ssplits in "H-frame" terms
 199  * and this returns the transfer start uframe in "B-frame" terms,
 200  * which allows both to match, e.g. a ssplit in "H-frame" uframe 0
 201  * will cause a transfer in "B-frame" uframe 0.  "B-frames" lag
 202  * "H-frames" by 1 uframe.  See the EHCI spec sec 4.5 and figure 4.7.
 203  */
 204 static inline unsigned char tt_start_uframe(struct ehci_hcd *ehci, __hc32 mask)
 205 {
 206         unsigned char smask = QH_SMASK & hc32_to_cpu(ehci, mask);
 207         if (!smask) {
 208                 ehci_err(ehci, "invalid empty smask!\n");
 209                 /* uframe 7 can't have bw so this will indicate failure */
 210                 return 7;
 211         }
 212         return ffs(smask) - 1;
 213 }
 214
 215 static const unsigned char
 216 max_tt_usecs[] = { 125, 125, 125, 125, 125, 125, 30, 0 };
 217
 218 /* carryover low/fullspeed bandwidth that crosses uframe boundries */
 219 static inline void carryover_tt_bandwidth(unsigned short tt_usecs[8])
 220 {
 221         int i;
 222         for (i=0; i<7; i++) {
 223                 if (max_tt_usecs[i] < tt_usecs[i]) {
 224                         tt_usecs[i+1] += tt_usecs[i] - max_tt_usecs[i];
 225                         tt_usecs[i] = max_tt_usecs[i];
 226                 }
 227         }
 228 }
 229
 230 /* How many of the tt's periodic downstream 1000 usecs are allocated?
 231  *
 232  * While this measures the bandwidth in terms of usecs/uframe,
 233  * the low/fullspeed bus has no notion of uframes, so any particular
 234  * low/fullspeed transfer can "carry over" from one uframe to the next,
 235  * since the TT just performs downstream transfers in sequence.
 236  *
 237  * For example two separate 100 usec transfers can start in the same uframe,
 238  * and the second one would "carry over" 75 usecs into the next uframe.
 239  */
 240 static void
 241 periodic_tt_usecs (
 242         struct ehci_hcd *ehci,
 243         struct usb_device *dev,
 244         unsigned frame,
 245         unsigned short tt_usecs[8]
 246 )
 247 {
 248         __hc32                  *hw_p = &ehci->periodic [frame];
 249         union ehci_shadow       *q = &ehci->pshadow [frame];
 250         unsigned char           uf;
 251
 252         memset(tt_usecs, 0, 16);
 253
 254         while (q->ptr) {
 255                 switch (hc32_to_cpu(ehci, Q_NEXT_TYPE(ehci, *hw_p))) {
 256                 case Q_TYPE_ITD:
 257                         hw_p = &q->itd->hw_next;
 258                         q = &q->itd->itd_next;
 259                         continue;
 260                 case Q_TYPE_QH:
 261                         if (same_tt(dev, q->qh->dev)) {
 262                                 uf = tt_start_uframe(ehci, q->qh->hw->hw_info2);
 263                                 tt_usecs[uf] += q->qh->tt_usecs;
 264                         }
 265                         hw_p = &q->qh->hw->hw_next;
 266                         q = &q->qh->qh_next;
 267                         continue;
 268                 case Q_TYPE_SITD:
 269                         if (same_tt(dev, q->sitd->urb->dev)) {
 270                                 uf = tt_start_uframe(ehci, q->sitd->hw_uframe);
 271                                 tt_usecs[uf] += q->sitd->stream->tt_usecs;
 272                         }
 273                         hw_p = &q->sitd->hw_next;
 274                         q = &q->sitd->sitd_next;
 275                         continue;
 276                 // case Q_TYPE_FSTN:
 277                 default:
 278                         ehci_dbg(ehci, "ignoring periodic frame %d FSTN\n",
 279                                         frame);
 280                         hw_p = &q->fstn->hw_next;
 281                         q = &q->fstn->fstn_next;
 282                 }
 283         }
 284
 285         carryover_tt_bandwidth(tt_usecs);
 286
 287         if (max_tt_usecs[7] < tt_usecs[7])
 288                 ehci_err(ehci, "frame %d tt sched overrun: %d usecs\n",
 289                         frame, tt_usecs[7] - max_tt_usecs[7]);
 290 }
 291
 292 /*
 293  * Return true if the device's tt's downstream bus is available for a
 294  * periodic transfer of the specified length (usecs), starting at the
 295  * specified frame/uframe.  Note that (as summarized in section 11.19
 296  * of the usb 2.0 spec) TTs can buffer multiple transactions for each
 297  * uframe.
 298  *
 299  * The uframe parameter is when the fullspeed/lowspeed transfer
 300  * should be executed in "B-frame" terms, which is the same as the
 301  * highspeed ssplit's uframe (which is in "H-frame" terms).  For example
 302  * a ssplit in "H-frame" 0 causes a transfer in "B-frame" 0.
 303  * See the EHCI spec sec 4.5 and fig 4.7.
 304  *
 305  * This checks if the full/lowspeed bus, at the specified starting uframe,
 306  * has the specified bandwidth available, according to rules listed
 307  * in USB 2.0 spec section 11.18.1 fig 11-60.
 308  *
 309  * This does not check if the transfer would exceed the max ssplit
 310  * limit of 16, specified in USB 2.0 spec section 11.18.4 requirement #4,
 311  * since proper scheduling limits ssplits to less than 16 per uframe.
 312  */
 313 static int tt_available (
 314         struct ehci_hcd         *ehci,
 315         unsigned                period,
 316         struct usb_device       *dev,
 317         unsigned                frame,
 318         unsigned                uframe,
 319         u16                     usecs
 320 )
 321 {
 322         if ((period == 0) || (uframe >= 7))     /* error */
 323                 return 0;
 324
 325         for (; frame < ehci->periodic_size; frame += period) {
 326                 unsigned short tt_usecs[8];
 327
 328                 periodic_tt_usecs (ehci, dev, frame, tt_usecs);
 329
 330                 if (max_tt_usecs[uframe] <= tt_usecs[uframe])
 331                         return 0;
 332
 333                 /* special case for isoc transfers larger than 125us:
 334                  * the first and each subsequent fully used uframe
 335                  * must be empty, so as to not illegally delay
 336                  * already scheduled transactions
 337                  */
 338                 if (125 < usecs) {
 339                         int ufs = (usecs / 125);
 340                         int i;
 341                         for (i = uframe; i < (uframe + ufs) && i < 8; i++)
 342                                 if (0 < tt_usecs[i])
 343                                         return 0;
 344                 }
 345
 346                 tt_usecs[uframe] += usecs;
 347
 348                 carryover_tt_bandwidth(tt_usecs);
 349
 350                 /* fail if the carryover pushed bw past the last uframe's limit */
 351                 if (max_tt_usecs[7] < tt_usecs[7])
 352                         return 0;
 353         }
 354
 355         return 1;
 356 }
 357
 358 #else
 359
 360 /* return true iff the device's transaction translator is available
 361  * for a periodic transfer starting at the specified frame, using
 362  * all the uframes in the mask.
 363  */
 364 static int tt_no_collision (
 365         struct ehci_hcd         *ehci,
 366         unsigned                period,
 367         struct usb_device       *dev,
 368         unsigned                frame,
 369         u32                     uf_mask
 370 )
 371 {
 372         if (period == 0)        /* error */
 373                 return 0;
 374
 375         /* note bandwidth wastage:  split never follows csplit
 376          * (different dev or endpoint) until the next uframe.
 377          * calling convention doesn't make that distinction.
 378          */
 379         for (; frame < ehci->periodic_size; frame += period) {
 380                 union ehci_shadow       here;
 381                 __hc32                  type;
 382                 struct ehci_qh_hw       *hw;
 383
 384                 here = ehci->pshadow [frame];
 385                 type = Q_NEXT_TYPE(ehci, ehci->periodic [frame]);
 386                 while (here.ptr) {
 387                         switch (hc32_to_cpu(ehci, type)) {
 388                         case Q_TYPE_ITD:
 389                                 type = Q_NEXT_TYPE(ehci, here.itd->hw_next);
 390                                 here = here.itd->itd_next;
 391                                 continue;
 392                         case Q_TYPE_QH:
 393                                 hw = here.qh->hw;
 394                                 if (same_tt (dev, here.qh->dev)) {
 395                                         u32             mask;
 396
 397                                         mask = hc32_to_cpu(ehci,
 398                                                         hw->hw_info2);
 399                                         /* "knows" no gap is needed */
 400                                         mask |= mask >> 8;
 401                                         if (mask & uf_mask)
 402                                                 break;
 403                                 }
 404                                 type = Q_NEXT_TYPE(ehci, hw->hw_next);
 405                                 here = here.qh->qh_next;
 406                                 continue;
 407                         case Q_TYPE_SITD:
 408                                 if (same_tt (dev, here.sitd->urb->dev)) {
 409                                         u16             mask;
 410
 411                                         mask = hc32_to_cpu(ehci, here.sitd
 412                                                                 ->hw_uframe);
 413                                         /* FIXME assumes no gap for IN! */
 414                                         mask |= mask >> 8;
 415                                         if (mask & uf_mask)
 416                                                 break;
 417                                 }
 418                                 type = Q_NEXT_TYPE(ehci, here.sitd->hw_next);
 419                                 here = here.sitd->sitd_next;
 420                                 continue;
 421                         // case Q_TYPE_FSTN:
 422                         default:
 423                                 ehci_dbg (ehci,
 424                                         "periodic frame %d bogus type %d\n",
 425                                         frame, type);
 426                         }
 427
 428                         /* collision or error */
 429                         return 0;
 430                 }
 431         }
 432
 433         /* no collision */
 434         return 1;
 435 }
 436
 437 #endif /* CONFIG_USB_EHCI_TT_NEWSCHED */
 438
 439 /*-------------------------------------------------------------------------*/
 440
 441 static void enable_periodic(struct ehci_hcd *ehci)
 442 {
 443         if (ehci->periodic_count++)
 444                 return;
 445
 446         /* Stop waiting to turn off the periodic schedule */
 447         ehci->enabled_hrtimer_events &= ~BIT(EHCI_HRTIMER_DISABLE_PERIODIC);
 448
 449         /* Don't start the schedule until PSS is 0 */
 450         ehci_poll_PSS(ehci);
 451         turn_on_io_watchdog(ehci);
 452 }
 453
 454 static void disable_periodic(struct ehci_hcd *ehci)
 455 {
 456         if (--ehci->periodic_count)
 457                 return;
 458
 459         /* Don't turn off the schedule until PSS is 1 */
 460         ehci_poll_PSS(ehci);
 461 }
 462
 463 /*-------------------------------------------------------------------------*/
 464
 465 /* periodic schedule slots have iso tds (normal or split) first, then a
 466  * sparse tree for active interrupt transfers.
 467  *
 468  * this just links in a qh; caller guarantees uframe masks are set right.
 469  * no FSTN support (yet; ehci 0.96+)
 470  */
 471 static void qh_link_periodic(struct ehci_hcd *ehci, struct ehci_qh *qh)
 472 {
 473         unsigned        i;
 474         unsigned        period = qh->period;
 475
 476         dev_dbg (&qh->dev->dev,
 477                 "link qh%d-%04x/%p start %d [%d/%d us]\n",
 478                 period, hc32_to_cpup(ehci, &qh->hw->hw_info2)
 479                         & (QH_CMASK | QH_SMASK),
 480                 qh, qh->start, qh->usecs, qh->c_usecs);
 481
 482         /* high bandwidth, or otherwise every microframe */
 483         if (period == 0)
 484                 period = 1;
 485
 486         for (i = qh->start; i < ehci->periodic_size; i += period) {
 487                 union ehci_shadow       *prev = &ehci->pshadow[i];
 488                 __hc32                  *hw_p = &ehci->periodic[i];
 489                 union ehci_shadow       here = *prev;
 490                 __hc32                  type = 0;
 491
 492                 /* skip the iso nodes at list head */
 493                 while (here.ptr) {
 494                         type = Q_NEXT_TYPE(ehci, *hw_p);
 495                         if (type == cpu_to_hc32(ehci, Q_TYPE_QH))
 496                                 break;
 497                         prev = periodic_next_shadow(ehci, prev, type);
 498                         hw_p = shadow_next_periodic(ehci, &here, type);
 499                         here = *prev;
 500                 }
 501
 502                 /* sorting each branch by period (slow-->fast)
 503                  * enables sharing interior tree nodes
 504                  */
 505                 while (here.ptr && qh != here.qh) {
 506                         if (qh->period > here.qh->period)
 507                                 break;
 508                         prev = &here.qh->qh_next;
 509                         hw_p = &here.qh->hw->hw_next;
 510                         here = *prev;
 511                 }
 512                 /* link in this qh, unless some earlier pass did that */
 513                 if (qh != here.qh) {
 514                         qh->qh_next = here;
 515                         if (here.qh)
 516                                 qh->hw->hw_next = *hw_p;
 517                         wmb ();
 518                         prev->qh = qh;
 519                         *hw_p = QH_NEXT (ehci, qh->qh_dma);
 520                 }
 521         }
 522         qh->qh_state = QH_STATE_LINKED;
 523         qh->xacterrs = 0;
 524         qh->exception = 0;
 525
 526         /* update per-qh bandwidth for usbfs */
 527         ehci_to_hcd(ehci)->self.bandwidth_allocated += qh->period
 528                 ? ((qh->usecs + qh->c_usecs) / qh->period)
 529                 : (qh->usecs * 8);
 530
 531         list_add(&qh->intr_node, &ehci->intr_qh_list);
 532
 533         /* maybe enable periodic schedule processing */
 534         ++ehci->intr_count;
 535         enable_periodic(ehci);
 536 }
 537
 538 static void qh_unlink_periodic(struct ehci_hcd *ehci, struct ehci_qh *qh)
 539 {
 540         unsigned        i;
 541         unsigned        period;
 542
 543         /*
 544          * If qh is for a low/full-speed device, simply unlinking it
 545          * could interfere with an ongoing split transaction.  To unlink
 546          * it safely would require setting the QH_INACTIVATE bit and
 547          * waiting at least one frame, as described in EHCI 4.12.2.5.
 548          *
 549          * We won't bother with any of this.  Instead, we assume that the
 550          * only reason for unlinking an interrupt QH while the current URB
 551          * is still active is to dequeue all the URBs (flush the whole
 552          * endpoint queue).
 553          *
 554          * If rebalancing the periodic schedule is ever implemented, this
 555          * approach will no longer be valid.
 556          */
 557
 558         /* high bandwidth, or otherwise part of every microframe */
 559         if ((period = qh->period) == 0)
 560                 period = 1;
 561
 562         for (i = qh->start; i < ehci->periodic_size; i += period)
 563                 periodic_unlink (ehci, i, qh);
 564
 565         /* update per-qh bandwidth for usbfs */
 566         ehci_to_hcd(ehci)->self.bandwidth_allocated -= qh->period
 567                 ? ((qh->usecs + qh->c_usecs) / qh->period)
 568                 : (qh->usecs * 8);
 569
 570         dev_dbg (&qh->dev->dev,
 571                 "unlink qh%d-%04x/%p start %d [%d/%d us]\n",
 572                 qh->period,
 573                 hc32_to_cpup(ehci, &qh->hw->hw_info2) & (QH_CMASK | QH_SMASK),
 574                 qh, qh->start, qh->usecs, qh->c_usecs);
 575
 576         /* qh->qh_next still "live" to HC */
 577         qh->qh_state = QH_STATE_UNLINK;
 578         qh->qh_next.ptr = NULL;
 579
 580         if (ehci->qh_scan_next == qh)
 581                 ehci->qh_scan_next = list_entry(qh->intr_node.next,
 582                                 struct ehci_qh, intr_node);
 583         list_del(&qh->intr_node);
 584 }
 585
 586 static void cancel_unlink_wait_intr(struct ehci_hcd *ehci, struct ehci_qh *qh)
 587 {
 588         if (qh->qh_state != QH_STATE_LINKED ||
 589                         list_empty(&qh->unlink_node))
 590                 return;
 591
 592         list_del_init(&qh->unlink_node);
 593
 594         /*
 595          * TODO: disable the event of EHCI_HRTIMER_START_UNLINK_INTR for
 596          * avoiding unnecessary CPU wakeup
 597          */
 598 }
 599
 600 static void start_unlink_intr(struct ehci_hcd *ehci, struct ehci_qh *qh)
 601 {
 602         /* If the QH isn't linked then there's nothing we can do. */
 603         if (qh->qh_state != QH_STATE_LINKED)
 604                 return;
 605
 606         /* if the qh is waiting for unlink, cancel it now */
 607         cancel_unlink_wait_intr(ehci, qh);
 608
 609         qh_unlink_periodic (ehci, qh);
 610
 611         /* Make sure the unlinks are visible before starting the timer */
 612         wmb();
 613
 614         /*
 615          * The EHCI spec doesn't say how long it takes the controller to
 616          * stop accessing an unlinked interrupt QH.  The timer delay is
 617          * 9 uframes; presumably that will be long enough.
 618          */
 619         qh->unlink_cycle = ehci->intr_unlink_cycle;
 620
 621         /* New entries go at the end of the intr_unlink list */
 622         list_add_tail(&qh->unlink_node, &ehci->intr_unlink);
 623
 624         if (ehci->intr_unlinking)
 625                 ;       /* Avoid recursive calls */
 626         else if (ehci->rh_state < EHCI_RH_RUNNING)
 627                 ehci_handle_intr_unlinks(ehci);
 628         else if (ehci->intr_unlink.next == &qh->unlink_node) {
 629                 ehci_enable_event(ehci, EHCI_HRTIMER_UNLINK_INTR, true);
 630                 ++ehci->intr_unlink_cycle;
 631         }
 632 }
 633
 634 /*
 635  * It is common only one intr URB is scheduled on one qh, and
 636  * given complete() is run in tasklet context, introduce a bit
 637  * delay to avoid unlink qh too early.
 638  */
 639 static void start_unlink_intr_wait(struct ehci_hcd *ehci,
 640                                    struct ehci_qh *qh)
 641 {
 642         qh->unlink_cycle = ehci->intr_unlink_wait_cycle;
 643
 644         /* New entries go at the end of the intr_unlink_wait list */
 645         list_add_tail(&qh->unlink_node, &ehci->intr_unlink_wait);
 646
 647         if (ehci->rh_state < EHCI_RH_RUNNING)
 648                 ehci_handle_start_intr_unlinks(ehci);
 649         else if (ehci->intr_unlink_wait.next == &qh->unlink_node) {
 650                 ehci_enable_event(ehci, EHCI_HRTIMER_START_UNLINK_INTR, true);
 651                 ++ehci->intr_unlink_wait_cycle;
 652         }
 653 }
 654
 655 static void end_unlink_intr(struct ehci_hcd *ehci, struct ehci_qh *qh)
 656 {
 657         struct ehci_qh_hw       *hw = qh->hw;
 658         int                     rc;
 659
 660         qh->qh_state = QH_STATE_IDLE;
 661         hw->hw_next = EHCI_LIST_END(ehci);
 662
 663         if (!list_empty(&qh->qtd_list))
 664                 qh_completions(ehci, qh);
 665
 666         /* reschedule QH iff another request is queued */
 667         if (!list_empty(&qh->qtd_list) && ehci->rh_state == EHCI_RH_RUNNING) {
 668                 rc = qh_schedule(ehci, qh);
 669                 if (rc == 0) {
 670                         qh_refresh(ehci, qh);
 671                         qh_link_periodic(ehci, qh);
 672                 }
 673
 674                 /* An error here likely indicates handshake failure
 675                  * or no space left in the schedule.  Neither fault
 676                  * should happen often ...
 677                  *
 678                  * FIXME kill the now-dysfunctional queued urbs
 679                  */
 680                 else {
 681                         ehci_err(ehci, "can't reschedule qh %p, err %d\n",
 682                                         qh, rc);
 683                 }
 684         }
 685
 686         /* maybe turn off periodic schedule */
 687         --ehci->intr_count;
 688         disable_periodic(ehci);
 689 }
 690
 691 /*-------------------------------------------------------------------------*/
 692
 693 static int check_period (
 694         struct ehci_hcd *ehci,
 695         unsigned        frame,
 696         unsigned        uframe,
 697         unsigned        period,
 698         unsigned        usecs
 699 ) {
 700         int             claimed;
 701
 702         /* complete split running into next frame?
 703          * given FSTN support, we could sometimes check...
 704          */
 705         if (uframe >= 8)
 706                 return 0;
 707
 708         /* convert "usecs we need" to "max already claimed" */
 709         usecs = ehci->uframe_periodic_max - usecs;
 710
 711         /* we "know" 2 and 4 uframe intervals were rejected; so
 712          * for period 0, check _every_ microframe in the schedule.
 713          */
 714         if (unlikely (period == 0)) {
 715                 do {
 716                         for (uframe = 0; uframe < 7; uframe++) {
 717                                 claimed = periodic_usecs (ehci, frame, uframe);
 718                                 if (claimed > usecs)
 719                                         return 0;
 720                         }
 721                 } while ((frame += 1) < ehci->periodic_size);
 722
 723         /* just check the specified uframe, at that period */
 724         } else {
 725                 do {
 726                         claimed = periodic_usecs (ehci, frame, uframe);
 727                         if (claimed > usecs)
 728                                 return 0;
 729                 } while ((frame += period) < ehci->periodic_size);
 730         }
 731
 732         // success!
 733         return 1;
 734 }
 735
 736 static int check_intr_schedule (
 737         struct ehci_hcd         *ehci,
 738         unsigned                frame,
 739         unsigned                uframe,
 740         const struct ehci_qh    *qh,
 741         __hc32                  *c_maskp
 742 )
 743 {
 744         int             retval = -ENOSPC;
 745         u8              mask = 0;
 746
 747         if (qh->c_usecs && uframe >= 6)         /* FSTN territory? */
 748                 goto done;
 749
 750         if (!check_period (ehci, frame, uframe, qh->period, qh->usecs))
 751                 goto done;
 752         if (!qh->c_usecs) {
 753                 retval = 0;
 754                 *c_maskp = 0;
 755                 goto done;
 756         }
 757
 758 #ifdef CONFIG_USB_EHCI_TT_NEWSCHED
 759         if (tt_available (ehci, qh->period, qh->dev, frame, uframe,
 760                                 qh->tt_usecs)) {
 761                 unsigned i;
 762
 763                 /* TODO : this may need FSTN for SSPLIT in uframe 5. */
 764                 for (i=uframe+1; i<8 && i<uframe+4; i++)
 765                         if (!check_period (ehci, frame, i,
 766                                                 qh->period, qh->c_usecs))
 767                                 goto done;
 768                         else
 769                                 mask |= 1 << i;
 770
 771                 retval = 0;
 772
 773                 *c_maskp = cpu_to_hc32(ehci, mask << 8);
 774         }
 775 #else
 776         /* Make sure this tt's buffer is also available for CSPLITs.
 777          * We pessimize a bit; probably the typical full speed case
 778          * doesn't need the second CSPLIT.
 779          *
 780          * NOTE:  both SPLIT and CSPLIT could be checked in just
 781          * one smart pass...
 782          */
 783         mask = 0x03 << (uframe + qh->gap_uf);
 784         *c_maskp = cpu_to_hc32(ehci, mask << 8);
 785
 786         mask |= 1 << uframe;
 787         if (tt_no_collision (ehci, qh->period, qh->dev, frame, mask)) {
 788                 if (!check_period (ehci, frame, uframe + qh->gap_uf + 1,
 789                                         qh->period, qh->c_usecs))
 790                         goto done;
 791                 if (!check_period (ehci, frame, uframe + qh->gap_uf,
 792                                         qh->period, qh->c_usecs))
 793                         goto done;
 794                 retval = 0;
 795         }
 796 #endif
 797 done:
 798         return retval;
 799 }
 800
 801 /* "first fit" scheduling policy used the first time through,
 802  * or when the previous schedule slot can't be re-used.
 803  */
 804 static int qh_schedule(struct ehci_hcd *ehci, struct ehci_qh *qh)
 805 {
 806         int             status;
 807         unsigned        uframe;
 808         __hc32          c_mask;
 809         unsigned        frame;          /* 0..(qh->period - 1), or NO_FRAME */
 810         struct ehci_qh_hw       *hw = qh->hw;
 811
 812         hw->hw_next = EHCI_LIST_END(ehci);
 813         frame = qh->start;
 814
 815         /* reuse the previous schedule slots, if we can */
 816         if (frame < qh->period) {
 817                 uframe = ffs(hc32_to_cpup(ehci, &hw->hw_info2) & QH_SMASK);
 818                 status = check_intr_schedule (ehci, frame, --uframe,
 819                                 qh, &c_mask);
 820         } else {
 821                 uframe = 0;
 822                 c_mask = 0;
 823                 status = -ENOSPC;
 824         }
 825
 826         /* else scan the schedule to find a group of slots such that all
 827          * uframes have enough periodic bandwidth available.
 828          */
 829         if (status) {
 830                 /* "normal" case, uframing flexible except with splits */
 831                 if (qh->period) {
 832                         int             i;
 833
 834                         for (i = qh->period; status && i > 0; --i) {
 835                                 frame = ++ehci->random_frame % qh->period;
 836                                 for (uframe = 0; uframe < 8; uframe++) {
 837                                         status = check_intr_schedule (ehci,
 838                                                         frame, uframe, qh,
 839                                                         &c_mask);
 840                                         if (status == 0)
 841                                                 break;
 842                                 }
 843                         }
 844
 845                 /* qh->period == 0 means every uframe */
 846                 } else {
 847                         frame = 0;
 848                         status = check_intr_schedule (ehci, 0, 0, qh, &c_mask);
 849                 }
 850                 if (status)
 851                         goto done;
 852                 qh->start = frame;
 853
 854                 /* reset S-frame and (maybe) C-frame masks */
 855                 hw->hw_info2 &= cpu_to_hc32(ehci, ~(QH_CMASK | QH_SMASK));
 856                 hw->hw_info2 |= qh->period
 857                         ? cpu_to_hc32(ehci, 1 << uframe)
 858                         : cpu_to_hc32(ehci, QH_SMASK);
 859                 hw->hw_info2 |= c_mask;
 860         } else
 861                 ehci_dbg (ehci, "reused qh %p schedule\n", qh);
 862
 863 done:
 864         return status;
 865 }
 866
 867 static int intr_submit (
 868         struct ehci_hcd         *ehci,
 869         struct urb              *urb,
 870         struct list_head        *qtd_list,
 871         gfp_t                   mem_flags
 872 ) {
 873         unsigned                epnum;
 874         unsigned long           flags;
 875         struct ehci_qh          *qh;
 876         int                     status;
 877         struct list_head        empty;
 878
 879         /* get endpoint and transfer/schedule data */
 880         epnum = urb->ep->desc.bEndpointAddress;
 881
 882         spin_lock_irqsave (&ehci->lock, flags);
 883
 884         if (unlikely(!HCD_HW_ACCESSIBLE(ehci_to_hcd(ehci)))) {
 885                 status = -ESHUTDOWN;
 886                 goto done_not_linked;
 887         }
 888         status = usb_hcd_link_urb_to_ep(ehci_to_hcd(ehci), urb);
 889         if (unlikely(status))
 890                 goto done_not_linked;
 891
 892         /* get qh and force any scheduling errors */
 893         INIT_LIST_HEAD (&empty);
 894         qh = qh_append_tds(ehci, urb, &empty, epnum, &urb->ep->hcpriv);
 895         if (qh == NULL) {
 896                 status = -ENOMEM;
 897                 goto done;
 898         }
 899         if (qh->qh_state == QH_STATE_IDLE) {
 900                 if ((status = qh_schedule (ehci, qh)) != 0)
 901                         goto done;
 902         }
 903
 904         /* then queue the urb's tds to the qh */
 905         qh = qh_append_tds(ehci, urb, qtd_list, epnum, &urb->ep->hcpriv);
 906         BUG_ON (qh == NULL);
 907
 908         /* stuff into the periodic schedule */
 909         if (qh->qh_state == QH_STATE_IDLE) {
 910                 qh_refresh(ehci, qh);
 911                 qh_link_periodic(ehci, qh);
 912         } else {
 913                 /* cancel unlink wait for the qh */
 914                 cancel_unlink_wait_intr(ehci, qh);
 915         }
 916
 917         /* ... update usbfs periodic stats */
 918         ehci_to_hcd(ehci)->self.bandwidth_int_reqs++;
 919
 920 done:
 921         if (unlikely(status))
 922                 usb_hcd_unlink_urb_from_ep(ehci_to_hcd(ehci), urb);
 923 done_not_linked:
 924         spin_unlock_irqrestore (&ehci->lock, flags);
 925         if (status)
 926                 qtd_list_free (ehci, urb, qtd_list);
 927
 928         return status;
 929 }
 930
 931 static void scan_intr(struct ehci_hcd *ehci)
 932 {
 933         struct ehci_qh          *qh;
 934
 935         list_for_each_entry_safe(qh, ehci->qh_scan_next, &ehci->intr_qh_list,
 936                         intr_node) {
 937
 938                 /* clean any finished work for this qh */
 939                 if (!list_empty(&qh->qtd_list)) {
 940                         int temp;
 941
 942                         /*
 943                          * Unlinks could happen here; completion reporting
 944                          * drops the lock.  That's why ehci->qh_scan_next
 945                          * always holds the next qh to scan; if the next qh
 946                          * gets unlinked then ehci->qh_scan_next is adjusted
 947                          * in qh_unlink_periodic().
 948                          */
 949                         temp = qh_completions(ehci, qh);
 950                         if (unlikely(temp))
 951                                 start_unlink_intr(ehci, qh);
 952                         else if (unlikely(list_empty(&qh->qtd_list) &&
 953                                         qh->qh_state == QH_STATE_LINKED))
 954                                 start_unlink_intr_wait(ehci, qh);
 955                 }
 956         }
 957 }
 958
 959 /*-------------------------------------------------------------------------*/
 960
 961 /* ehci_iso_stream ops work with both ITD and SITD */
 962
 963 static struct ehci_iso_stream *
 964 iso_stream_alloc (gfp_t mem_flags)
 965 {
 966         struct ehci_iso_stream *stream;
 967
 968         stream = kzalloc(sizeof *stream, mem_flags);
 969         if (likely (stream != NULL)) {
 970                 INIT_LIST_HEAD(&stream->td_list);
 971                 INIT_LIST_HEAD(&stream->free_list);
 972                 stream->next_uframe = -1;
 973         }
 974         return stream;
 975 }
 976
 977 static void
 978 iso_stream_init (
 979         struct ehci_hcd         *ehci,
 980         struct ehci_iso_stream  *stream,
 981         struct usb_device       *dev,
 982         int                     pipe,
 983         unsigned                interval
 984 )
 985 {
 986         static const u8 smask_out [] = { 0x01, 0x03, 0x07, 0x0f, 0x1f, 0x3f };
 987
 988         u32                     buf1;
 989         unsigned                epnum, maxp;
 990         int                     is_input;
 991         long                    bandwidth;
 992
 993         /*
 994          * this might be a "high bandwidth" highspeed endpoint,
 995          * as encoded in the ep descriptor's wMaxPacket field
 996          */
 997         epnum = usb_pipeendpoint (pipe);
 998         is_input = usb_pipein (pipe) ? USB_DIR_IN : 0;
 999         maxp = usb_maxpacket(dev, pipe, !is_input);
1000         if (is_input) {
1001                 buf1 = (1 << 11);
1002         } else {
1003                 buf1 = 0;
1004         }
1005
1006         /* knows about ITD vs SITD */
1007         if (dev->speed == USB_SPEED_HIGH) {
1008                 unsigned multi = hb_mult(maxp);
1009
1010                 stream->highspeed = 1;
1011
1012                 maxp = max_packet(maxp);
1013                 buf1 |= maxp;
1014                 maxp *= multi;
1015
1016                 stream->buf0 = cpu_to_hc32(ehci, (epnum << 8) | dev->devnum);
1017                 stream->buf1 = cpu_to_hc32(ehci, buf1);
1018                 stream->buf2 = cpu_to_hc32(ehci, multi);
1019
1020                 /* usbfs wants to report the average usecs per frame tied up
1021                  * when transfers on this endpoint are scheduled ...
1022                  */
1023                 stream->usecs = HS_USECS_ISO (maxp);
1024                 bandwidth = stream->usecs * 8;
1025                 bandwidth /= interval;
1026
1027         } else {
1028                 u32             addr;
1029                 int             think_time;
1030                 int             hs_transfers;
1031
1032                 addr = dev->ttport << 24;
1033                 if (!ehci_is_TDI(ehci)
1034                                 || (dev->tt->hub !=
1035                                         ehci_to_hcd(ehci)->self.root_hub))
1036                         addr |= dev->tt->hub->devnum << 16;
1037                 addr |= epnum << 8;
1038                 addr |= dev->devnum;
1039                 stream->usecs = HS_USECS_ISO (maxp);
1040                 think_time = dev->tt ? dev->tt->think_time : 0;
1041                 stream->tt_usecs = NS_TO_US (think_time + usb_calc_bus_time (
1042                                 dev->speed, is_input, 1, maxp));
1043                 hs_transfers = max (1u, (maxp + 187) / 188);
1044                 if (is_input) {
1045                         u32     tmp;
1046
1047                         addr |= 1 << 31;
1048                         stream->c_usecs = stream->usecs;
1049                         stream->usecs = HS_USECS_ISO (1);
1050                         stream->raw_mask = 1;
1051
1052                         /* c-mask as specified in USB 2.0 11.18.4 3.c */
1053                         tmp = (1 << (hs_transfers + 2)) - 1;
1054                         stream->raw_mask |= tmp << (8 + 2);
1055                 } else
1056                         stream->raw_mask = smask_out [hs_transfers - 1];
1057                 bandwidth = stream->usecs + stream->c_usecs;
1058                 bandwidth /= interval << 3;
1059
1060                 /* stream->splits gets created from raw_mask later */
1061                 stream->address = cpu_to_hc32(ehci, addr);
1062         }
1063         stream->bandwidth = bandwidth;
1064
1065         stream->udev = dev;
1066
1067         stream->bEndpointAddress = is_input | epnum;
1068         stream->interval = interval;
1069         stream->maxp = maxp;
1070 }
1071
1072 static struct ehci_iso_stream *
1073 iso_stream_find (struct ehci_hcd *ehci, struct urb *urb)
1074 {
1075         unsigned                epnum;
1076         struct ehci_iso_stream  *stream;
1077         struct usb_host_endpoint *ep;
1078         unsigned long           flags;
1079
1080         epnum = usb_pipeendpoint (urb->pipe);
1081         if (usb_pipein(urb->pipe))
1082                 ep = urb->dev->ep_in[epnum];
1083         else
1084                 ep = urb->dev->ep_out[epnum];
1085
1086         spin_lock_irqsave (&ehci->lock, flags);
1087         stream = ep->hcpriv;
1088
1089         if (unlikely (stream == NULL)) {
1090                 stream = iso_stream_alloc(GFP_ATOMIC);
1091                 if (likely (stream != NULL)) {
1092                         ep->hcpriv = stream;
1093                         stream->ep = ep;
1094                         iso_stream_init(ehci, stream, urb->dev, urb->pipe,
1095                                         urb->interval);
1096                 }
1097
1098         /* if dev->ep [epnum] is a QH, hw is set */
1099         } else if (unlikely (stream->hw != NULL)) {
1100                 ehci_dbg (ehci, "dev %s ep%d%s, not iso??\n",
1101                         urb->dev->devpath, epnum,
1102                         usb_pipein(urb->pipe) ? "in" : "out");
1103                 stream = NULL;
1104         }
1105
1106         spin_unlock_irqrestore (&ehci->lock, flags);
1107         return stream;
1108 }
1109
1110 /*-------------------------------------------------------------------------*/
1111
1112 /* ehci_iso_sched ops can be ITD-only or SITD-only */
1113
1114 static struct ehci_iso_sched *
1115 iso_sched_alloc (unsigned packets, gfp_t mem_flags)
1116 {
1117         struct ehci_iso_sched   *iso_sched;
1118         int                     size = sizeof *iso_sched;
1119
1120         size += packets * sizeof (struct ehci_iso_packet);
1121         iso_sched = kzalloc(size, mem_flags);
1122         if (likely (iso_sched != NULL)) {
1123                 INIT_LIST_HEAD (&iso_sched->td_list);
1124         }
1125         return iso_sched;
1126 }
1127
1128 static inline void
1129 itd_sched_init(
1130         struct ehci_hcd         *ehci,
1131         struct ehci_iso_sched   *iso_sched,
1132         struct ehci_iso_stream  *stream,
1133         struct urb              *urb
1134 )
1135 {
1136         unsigned        i;
1137         dma_addr_t      dma = urb->transfer_dma;
1138
1139         /* how many uframes are needed for these transfers */
1140         iso_sched->span = urb->number_of_packets * stream->interval;
1141
1142         /* figure out per-uframe itd fields that we'll need later
1143          * when we fit new itds into the schedule.
1144          */
1145         for (i = 0; i < urb->number_of_packets; i++) {
1146                 struct ehci_iso_packet  *uframe = &iso_sched->packet [i];
1147                 unsigned                length;
1148                 dma_addr_t              buf;
1149                 u32                     trans;
1150
1151                 length = urb->iso_frame_desc [i].length;
1152                 buf = dma + urb->iso_frame_desc [i].offset;
1153
1154                 trans = EHCI_ISOC_ACTIVE;
1155                 trans |= buf & 0x0fff;
1156                 if (unlikely (((i + 1) == urb->number_of_packets))
1157                                 && !(urb->transfer_flags & URB_NO_INTERRUPT))
1158                         trans |= EHCI_ITD_IOC;
1159                 trans |= length << 16;
1160                 uframe->transaction = cpu_to_hc32(ehci, trans);
1161
1162                 /* might need to cross a buffer page within a uframe */
1163                 uframe->bufp = (buf & ~(u64)0x0fff);
1164                 buf += length;
1165                 if (unlikely ((uframe->bufp != (buf & ~(u64)0x0fff))))
1166                         uframe->cross = 1;
1167         }
1168 }
1169
1170 static void
1171 iso_sched_free (
1172         struct ehci_iso_stream  *stream,
1173         struct ehci_iso_sched   *iso_sched
1174 )
1175 {
1176         if (!iso_sched)
1177                 return;
1178         // caller must hold ehci->lock!
1179         list_splice (&iso_sched->td_list, &stream->free_list);
1180         kfree (iso_sched);
1181 }
1182
1183 static int
1184 itd_urb_transaction (
1185         struct ehci_iso_stream  *stream,
1186         struct ehci_hcd         *ehci,
1187         struct urb              *urb,
1188         gfp_t                   mem_flags
1189 )
1190 {
1191         struct ehci_itd         *itd;
1192         dma_addr_t              itd_dma;
1193         int                     i;
1194         unsigned                num_itds;
1195         struct ehci_iso_sched   *sched;
1196         unsigned long           flags;
1197
1198         sched = iso_sched_alloc (urb->number_of_packets, mem_flags);
1199         if (unlikely (sched == NULL))
1200                 return -ENOMEM;
1201
1202         itd_sched_init(ehci, sched, stream, urb);
1203
1204         if (urb->interval < 8)
1205                 num_itds = 1 + (sched->span + 7) / 8;
1206         else
1207                 num_itds = urb->number_of_packets;
1208
1209         /* allocate/init ITDs */
1210         spin_lock_irqsave (&ehci->lock, flags);
1211         for (i = 0; i < num_itds; i++) {
1212
1213                 /*
1214                  * Use iTDs from the free list, but not iTDs that may
1215                  * still be in use by the hardware.
1216                  */
1217                 if (likely(!list_empty(&stream->free_list))) {
1218                         itd = list_first_entry(&stream->free_list,
1219                                         struct ehci_itd, itd_list);
1220                         if (itd->frame == ehci->now_frame)
1221                                 goto alloc_itd;
1222                         list_del (&itd->itd_list);
1223                         itd_dma = itd->itd_dma;
1224                 } else {
1225  alloc_itd:
1226                         spin_unlock_irqrestore (&ehci->lock, flags);
1227                         itd = dma_pool_alloc (ehci->itd_pool, mem_flags,
1228                                         &itd_dma);
1229                         spin_lock_irqsave (&ehci->lock, flags);
1230                         if (!itd) {
1231                                 iso_sched_free(stream, sched);
1232                                 spin_unlock_irqrestore(&ehci->lock, flags);
1233                                 return -ENOMEM;
1234                         }
1235                 }
1236
1237                 memset (itd, 0, sizeof *itd);
1238                 itd->itd_dma = itd_dma;
1239                 itd->frame = 9999;              /* an invalid value */
1240                 list_add (&itd->itd_list, &sched->td_list);
1241         }
1242         spin_unlock_irqrestore (&ehci->lock, flags);
1243
1244         /* temporarily store schedule info in hcpriv */
1245         urb->hcpriv = sched;
1246         urb->error_count = 0;
1247         return 0;
1248 }
1249
1250 /*-------------------------------------------------------------------------*/
1251
1252 static inline int
1253 itd_slot_ok (
1254         struct ehci_hcd         *ehci,
1255         u32                     mod,
1256         u32                     uframe,
1257         u8                      usecs,
1258         u32                     period
1259 )
1260 {
1261         uframe %= period;
1262         do {
1263                 /* can't commit more than uframe_periodic_max usec */
1264                 if (periodic_usecs (ehci, uframe >> 3, uframe & 0x7)
1265                                 > (ehci->uframe_periodic_max - usecs))
1266                         return 0;
1267
1268                 /* we know urb->interval is 2^N uframes */
1269                 uframe += period;
1270         } while (uframe < mod);
1271         return 1;
1272 }
1273
1274 static inline int
1275 sitd_slot_ok (
1276         struct ehci_hcd         *ehci,
1277         u32                     mod,
1278         struct ehci_iso_stream  *stream,
1279         u32                     uframe,
1280         struct ehci_iso_sched   *sched,
1281         u32                     period_uframes
1282 )
1283 {
1284         u32                     mask, tmp;
1285         u32                     frame, uf;
1286
1287         mask = stream->raw_mask << (uframe & 7);
1288
1289         /* for IN, don't wrap CSPLIT into the next frame */
1290         if (mask & ~0xffff)
1291                 return 0;
1292
1293         /* check bandwidth */
1294         uframe %= period_uframes;
1295         frame = uframe >> 3;
1296
1297 #ifdef CONFIG_USB_EHCI_TT_NEWSCHED
1298         /* The tt's fullspeed bus bandwidth must be available.
1299          * tt_available scheduling guarantees 10+% for control/bulk.
1300          */
1301         uf = uframe & 7;
1302         if (!tt_available(ehci, period_uframes >> 3,
1303                         stream->udev, frame, uf, stream->tt_usecs))
1304                 return 0;
1305 #else
1306         /* tt must be idle for start(s), any gap, and csplit.
1307          * assume scheduling slop leaves 10+% for control/bulk.
1308          */
1309         if (!tt_no_collision(ehci, period_uframes >> 3,
1310                         stream->udev, frame, mask))
1311                 return 0;
1312 #endif
1313
1314         /* this multi-pass logic is simple, but performance may
1315          * suffer when the schedule data isn't cached.
1316          */
1317         do {
1318                 u32             max_used;
1319
1320                 frame = uframe >> 3;
1321                 uf = uframe & 7;
1322
1323                 /* check starts (OUT uses more than one) */
1324                 max_used = ehci->uframe_periodic_max - stream->usecs;
1325                 for (tmp = stream->raw_mask & 0xff; tmp; tmp >>= 1, uf++) {
1326                         if (periodic_usecs (ehci, frame, uf) > max_used)
1327                                 return 0;
1328                 }
1329
1330                 /* for IN, check CSPLIT */
1331                 if (stream->c_usecs) {
1332                         uf = uframe & 7;
1333                         max_used = ehci->uframe_periodic_max - stream->c_usecs;
1334                         do {
1335                                 tmp = 1 << uf;
1336                                 tmp <<= 8;
1337                                 if ((stream->raw_mask & tmp) == 0)
1338                                         continue;
1339                                 if (periodic_usecs (ehci, frame, uf)
1340                                                 > max_used)
1341                                         return 0;
1342                         } while (++uf < 8);
1343                 }
1344
1345                 /* we know urb->interval is 2^N uframes */
1346                 uframe += period_uframes;
1347         } while (uframe < mod);
1348
1349         stream->splits = cpu_to_hc32(ehci, stream->raw_mask << (uframe & 7));
1350         return 1;
1351 }
1352
1353 /*
1354  * This scheduler plans almost as far into the future as it has actual
1355  * periodic schedule slots.  (Affected by TUNE_FLS, which defaults to
1356  * "as small as possible" to be cache-friendlier.)  That limits the size
1357  * transfers you can stream reliably; avoid more than 64 msec per urb.
1358  * Also avoid queue depths of less than ehci's worst irq latency (affected
1359  * by the per-urb URB_NO_INTERRUPT hint, the log2_irq_thresh module parameter,
1360  * and other factors); or more than about 230 msec total (for portability,
1361  * given EHCI_TUNE_FLS and the slop).  Or, write a smarter scheduler!
1362  */
1363
1364 #define SCHEDULING_DELAY        40      /* microframes */
1365
1366 static int
1367 iso_stream_schedule (
1368         struct ehci_hcd         *ehci,
1369         struct urb              *urb,
1370         struct ehci_iso_stream  *stream
1371 )
1372 {
1373         u32                     now, base, next, start, period, span;
1374         int                     status;
1375         unsigned                mod = ehci->periodic_size << 3;
1376         struct ehci_iso_sched   *sched = urb->hcpriv;
1377
1378         period = urb->interval;
1379         span = sched->span;
1380         if (!stream->highspeed) {
1381                 period <<= 3;
1382                 span <<= 3;
1383         }
1384
1385         now = ehci_read_frame_index(ehci) & (mod - 1);
1386
1387         /* Typical case: reuse current schedule, stream is still active.
1388          * Hopefully there are no gaps from the host falling behind
1389          * (irq delays etc).  If there are, the behavior depends on
1390          * whether URB_ISO_ASAP is set.
1391          */
1392         if (likely (!list_empty (&stream->td_list))) {
1393
1394                 /* Take the isochronous scheduling threshold into account */
1395                 if (ehci->i_thresh)
1396                         next = now + ehci->i_thresh;    /* uframe cache */
1397                 else
1398                         next = (now + 2 + 7) & ~0x07;   /* full frame cache */
1399
1400                 /*
1401                  * Use ehci->last_iso_frame as the base.  There can't be any
1402                  * TDs scheduled for earlier than that.
1403                  */
1404                 base = ehci->last_iso_frame << 3;
1405                 next = (next - base) & (mod - 1);
1406                 start = (stream->next_uframe - base) & (mod - 1);
1407
1408                 /* Is the schedule already full? */
1409                 if (unlikely(start < period)) {
1410                         ehci_dbg(ehci, "iso sched full %p (%u-%u < %u mod %u)\n",
1411                                         urb, stream->next_uframe, base,
1412                                         period, mod);
1413                         status = -ENOSPC;
1414                         goto fail;
1415                 }
1416
1417                 /* Behind the scheduling threshold? */
1418                 if (unlikely(start < next)) {
1419                         unsigned now2 = (now - base) & (mod - 1);
1420
1421                         /* USB_ISO_ASAP: Round up to the first available slot */
1422                         if (urb->transfer_flags & URB_ISO_ASAP)
1423                                 start += (next - start + period - 1) & -period;
1424
1425                         /*
1426                          * Not ASAP: Use the next slot in the stream,
1427                          * no matter what.
1428                          */
1429                         else if (start + span - period < now2) {
1430                                 ehci_dbg(ehci, "iso underrun %p (%u+%u < %u)\n",
1431                                                 urb, start + base,
1432                                                 span - period, now2 + base);
1433                         }
1434                 }
1435
1436                 start += base;
1437         }
1438
1439         /* need to schedule; when's the next (u)frame we could start?
1440          * this is bigger than ehci->i_thresh allows; scheduling itself
1441          * isn't free, the delay should handle reasonably slow cpus.  it
1442          * can also help high bandwidth if the dma and irq loads don't
1443          * jump until after the queue is primed.
1444          */
1445         else {
1446                 int done = 0;
1447
1448                 base = now & ~0x07;
1449                 start = base + SCHEDULING_DELAY;
1450
1451                 /* find a uframe slot with enough bandwidth.
1452                  * Early uframes are more precious because full-speed
1453                  * iso IN transfers can't use late uframes,
1454                  * and therefore they should be allocated last.
1455                  */
1456                 next = start;
1457                 start += period;
1458                 do {
1459                         start--;
1460                         /* check schedule: enough space? */
1461                         if (stream->highspeed) {
1462                                 if (itd_slot_ok(ehci, mod, start,
1463                                                 stream->usecs, period))
1464                                         done = 1;
1465                         } else {
1466                                 if ((start % 8) >= 6)
1467                                         continue;
1468                                 if (sitd_slot_ok(ehci, mod, stream,
1469                                                 start, sched, period))
1470                                         done = 1;
1471                         }
1472                 } while (start > next && !done);
1473
1474                 /* no room in the schedule */
1475                 if (!done) {
1476                         ehci_dbg(ehci, "iso sched full %p", urb);
1477                         status = -ENOSPC;
1478                         goto fail;
1479                 }
1480         }
1481
1482         /* Tried to schedule too far into the future? */
1483         if (unlikely(start - base + span - period >= mod)) {
1484                 ehci_dbg(ehci, "request %p would overflow (%u+%u >= %u)\n",
1485                                 urb, start - base, span - period, mod);
1486                 status = -EFBIG;
1487                 goto fail;
1488         }
1489
1490         stream->next_uframe = start & (mod - 1);
1491
1492         /* report high speed start in uframes; full speed, in frames */
1493         urb->start_frame = stream->next_uframe;
1494         if (!stream->highspeed)
1495                 urb->start_frame >>= 3;
1496
1497         /* Make sure scan_isoc() sees these */
1498         if (ehci->isoc_count == 0)
1499                 ehci->last_iso_frame = now >> 3;
1500         return 0;
1501
1502  fail:
1503         iso_sched_free(stream, sched);
1504         urb->hcpriv = NULL;
1505         return status;
1506 }
1507
1508 /*-------------------------------------------------------------------------*/
1509
1510 static inline void
1511 itd_init(struct ehci_hcd *ehci, struct ehci_iso_stream *stream,
1512                 struct ehci_itd *itd)
1513 {
1514         int i;
1515
1516         /* it's been recently zeroed */
1517         itd->hw_next = EHCI_LIST_END(ehci);
1518         itd->hw_bufp [0] = stream->buf0;
1519         itd->hw_bufp [1] = stream->buf1;
1520         itd->hw_bufp [2] = stream->buf2;
1521
1522         for (i = 0; i < 8; i++)
1523                 itd->index[i] = -1;
1524
1525         /* All other fields are filled when scheduling */
1526 }
1527
1528 static inline void
1529 itd_patch(
1530         struct ehci_hcd         *ehci,
1531         struct ehci_itd         *itd,
1532         struct ehci_iso_sched   *iso_sched,
1533         unsigned                index,
1534         u16                     uframe
1535 )
1536 {
1537         struct ehci_iso_packet  *uf = &iso_sched->packet [index];
1538         unsigned                pg = itd->pg;
1539
1540         // BUG_ON (pg == 6 && uf->cross);
1541
1542         uframe &= 0x07;
1543         itd->index [uframe] = index;
1544
1545         itd->hw_transaction[uframe] = uf->transaction;
1546         itd->hw_transaction[uframe] |= cpu_to_hc32(ehci, pg << 12);
1547         itd->hw_bufp[pg] |= cpu_to_hc32(ehci, uf->bufp & ~(u32)0);
1548         itd->hw_bufp_hi[pg] |= cpu_to_hc32(ehci, (u32)(uf->bufp >> 32));
1549
1550         /* iso_frame_desc[].offset must be strictly increasing */
1551         if (unlikely (uf->cross)) {
1552                 u64     bufp = uf->bufp + 4096;
1553
1554                 itd->pg = ++pg;
1555                 itd->hw_bufp[pg] |= cpu_to_hc32(ehci, bufp & ~(u32)0);
1556                 itd->hw_bufp_hi[pg] |= cpu_to_hc32(ehci, (u32)(bufp >> 32));
1557         }
1558 }
1559
1560 static inline void
1561 itd_link (struct ehci_hcd *ehci, unsigned frame, struct ehci_itd *itd)
1562 {
1563         union ehci_shadow       *prev = &ehci->pshadow[frame];
1564         __hc32                  *hw_p = &ehci->periodic[frame];
1565         union ehci_shadow       here = *prev;
1566         __hc32                  type = 0;
1567
1568         /* skip any iso nodes which might belong to previous microframes */
1569         while (here.ptr) {
1570                 type = Q_NEXT_TYPE(ehci, *hw_p);
1571                 if (type == cpu_to_hc32(ehci, Q_TYPE_QH))
1572                         break;
1573                 prev = periodic_next_shadow(ehci, prev, type);
1574                 hw_p = shadow_next_periodic(ehci, &here, type);
1575                 here = *prev;
1576         }
1577
1578         itd->itd_next = here;
1579         itd->hw_next = *hw_p;
1580         prev->itd = itd;
1581         itd->frame = frame;
1582         wmb ();
1583         *hw_p = cpu_to_hc32(ehci, itd->itd_dma | Q_TYPE_ITD);
1584 }
1585
1586 /* fit urb's itds into the selected schedule slot; activate as needed */
1587 static void itd_link_urb(
1588         struct ehci_hcd         *ehci,
1589         struct urb              *urb,
1590         unsigned                mod,
1591         struct ehci_iso_stream  *stream
1592 )
1593 {
1594         int                     packet;
1595         unsigned                next_uframe, uframe, frame;
1596         struct ehci_iso_sched   *iso_sched = urb->hcpriv;
1597         struct ehci_itd         *itd;
1598
1599         next_uframe = stream->next_uframe & (mod - 1);
1600
1601         if (unlikely (list_empty(&stream->td_list)))
1602                 ehci_to_hcd(ehci)->self.bandwidth_allocated
1603                                 += stream->bandwidth;
1604
1605         if (ehci_to_hcd(ehci)->self.bandwidth_isoc_reqs == 0) {
1606                 if (ehci->amd_pll_fix == 1)
1607                         usb_amd_quirk_pll_disable();
1608         }
1609
1610         ehci_to_hcd(ehci)->self.bandwidth_isoc_reqs++;
1611
1612         /* fill iTDs uframe by uframe */
1613         for (packet = 0, itd = NULL; packet < urb->number_of_packets; ) {
1614                 if (itd == NULL) {
1615                         /* ASSERT:  we have all necessary itds */
1616                         // BUG_ON (list_empty (&iso_sched->td_list));
1617
1618                         /* ASSERT:  no itds for this endpoint in this uframe */
1619
1620                         itd = list_entry (iso_sched->td_list.next,
1621                                         struct ehci_itd, itd_list);
1622                         list_move_tail (&itd->itd_list, &stream->td_list);
1623                         itd->stream = stream;
1624                         itd->urb = urb;
1625                         itd_init (ehci, stream, itd);
1626                 }
1627
1628                 uframe = next_uframe & 0x07;
1629                 frame = next_uframe >> 3;
1630
1631                 itd_patch(ehci, itd, iso_sched, packet, uframe);
1632
1633                 next_uframe += stream->interval;
1634                 next_uframe &= mod - 1;
1635                 packet++;
1636
1637                 /* link completed itds into the schedule */
1638                 if (((next_uframe >> 3) != frame)
1639                                 || packet == urb->number_of_packets) {
1640                         itd_link(ehci, frame & (ehci->periodic_size - 1), itd);
1641                         itd = NULL;
1642                 }
1643         }
1644         stream->next_uframe = next_uframe;
1645
1646         /* don't need that schedule data any more */
1647         iso_sched_free (stream, iso_sched);
1648         urb->hcpriv = stream;
1649
1650         ++ehci->isoc_count;
1651         enable_periodic(ehci);
1652 }
1653
1654 #define ISO_ERRS (EHCI_ISOC_BUF_ERR | EHCI_ISOC_BABBLE | EHCI_ISOC_XACTERR)
1655
1656 /* Process and recycle a completed ITD.  Return true iff its urb completed,
1657  * and hence its completion callback probably added things to the hardware
1658  * schedule.
1659  *
1660  * Note that we carefully avoid recycling this descriptor until after any
1661  * completion callback runs, so that it won't be reused quickly.  That is,
1662  * assuming (a) no more than two urbs per frame on this endpoint, and also
1663  * (b) only this endpoint's completions submit URBs.  It seems some silicon
1664  * corrupts things if you reuse completed descriptors very quickly...
1665  */
1666 static bool itd_complete(struct ehci_hcd *ehci, struct ehci_itd *itd)
1667 {
1668         struct urb                              *urb = itd->urb;
1669         struct usb_iso_packet_descriptor        *desc;
1670         u32                                     t;
1671         unsigned                                uframe;
1672         int                                     urb_index = -1;
1673         struct ehci_iso_stream                  *stream = itd->stream;
1674         struct usb_device                       *dev;
1675         bool                                    retval = false;
1676
1677         /* for each uframe with a packet */
1678         for (uframe = 0; uframe < 8; uframe++) {
1679                 if (likely (itd->index[uframe] == -1))
1680                         continue;
1681                 urb_index = itd->index[uframe];
1682                 desc = &urb->iso_frame_desc [urb_index];
1683
1684                 t = hc32_to_cpup(ehci, &itd->hw_transaction [uframe]);
1685                 itd->hw_transaction [uframe] = 0;
1686
1687                 /* report transfer status */
1688                 if (unlikely (t & ISO_ERRS)) {
1689                         urb->error_count++;
1690                         if (t & EHCI_ISOC_BUF_ERR)
1691                                 desc->status = usb_pipein (urb->pipe)
1692                                         ? -ENOSR  /* hc couldn't read */
1693                                         : -ECOMM; /* hc couldn't write */
1694                         else if (t & EHCI_ISOC_BABBLE)
1695                                 desc->status = -EOVERFLOW;
1696                         else /* (t & EHCI_ISOC_XACTERR) */
1697                                 desc->status = -EPROTO;
1698
1699                         /* HC need not update length with this error */
1700                         if (!(t & EHCI_ISOC_BABBLE)) {
1701                                 desc->actual_length = EHCI_ITD_LENGTH(t);
1702                                 urb->actual_length += desc->actual_length;
1703                         }
1704                 } else if (likely ((t & EHCI_ISOC_ACTIVE) == 0)) {
1705                         desc->status = 0;
1706                         desc->actual_length = EHCI_ITD_LENGTH(t);
1707                         urb->actual_length += desc->actual_length;
1708                 } else {
1709                         /* URB was too late */
1710                         urb->error_count++;
1711                 }
1712         }
1713
1714         /* handle completion now? */
1715         if (likely ((urb_index + 1) != urb->number_of_packets))
1716                 goto done;
1717
1718         /* ASSERT: it's really the last itd for this urb
1719         list_for_each_entry (itd, &stream->td_list, itd_list)
1720                 BUG_ON (itd->urb == urb);
1721          */
1722
1723         /* give urb back to the driver; completion often (re)submits */
1724         dev = urb->dev;
1725         ehci_urb_done(ehci, urb, 0);
1726         retval = true;
1727         urb = NULL;
1728
1729         --ehci->isoc_count;
1730         disable_periodic(ehci);
1731
1732         ehci_to_hcd(ehci)->self.bandwidth_isoc_reqs--;
1733         if (ehci_to_hcd(ehci)->self.bandwidth_isoc_reqs == 0) {
1734                 if (ehci->amd_pll_fix == 1)
1735                         usb_amd_quirk_pll_enable();
1736         }
1737
1738         if (unlikely(list_is_singular(&stream->td_list)))
1739                 ehci_to_hcd(ehci)->self.bandwidth_allocated
1740                                 -= stream->bandwidth;
1741
1742 done:
1743         itd->urb = NULL;
1744
1745         /* Add to the end of the free list for later reuse */
1746         list_move_tail(&itd->itd_list, &stream->free_list);
1747
1748         /* Recycle the iTDs when the pipeline is empty (ep no longer in use) */
1749         if (list_empty(&stream->td_list)) {
1750                 list_splice_tail_init(&stream->free_list,
1751                                 &ehci->cached_itd_list);
1752                 start_free_itds(ehci);
1753         }
1754
1755         return retval;
1756 }
1757
1758 /*-------------------------------------------------------------------------*/
1759
1760 static int itd_submit (struct ehci_hcd *ehci, struct urb *urb,
1761         gfp_t mem_flags)
1762 {
1763         int                     status = -EINVAL;
1764         unsigned long           flags;
1765         struct ehci_iso_stream  *stream;
1766
1767         /* Get iso_stream head */
1768         stream = iso_stream_find (ehci, urb);
1769         if (unlikely (stream == NULL)) {
1770                 ehci_dbg (ehci, "can't get iso stream\n");
1771                 return -ENOMEM;
1772         }
1773         if (unlikely (urb->interval != stream->interval)) {
1774                 ehci_dbg (ehci, "can't change iso interval %d --> %d\n",
1775                         stream->interval, urb->interval);
1776                 goto done;
1777         }
1778
1779 #ifdef EHCI_URB_TRACE
1780         ehci_dbg (ehci,
1781                 "%s %s urb %p ep%d%s len %d, %d pkts %d uframes [%p]\n",
1782                 __func__, urb->dev->devpath, urb,
1783                 usb_pipeendpoint (urb->pipe),
1784                 usb_pipein (urb->pipe) ? "in" : "out",
1785                 urb->transfer_buffer_length,
1786                 urb->number_of_packets, urb->interval,
1787                 stream);
1788 #endif
1789
1790         /* allocate ITDs w/o locking anything */
1791         status = itd_urb_transaction (stream, ehci, urb, mem_flags);
1792         if (unlikely (status < 0)) {
1793                 ehci_dbg (ehci, "can't init itds\n");
1794                 goto done;
1795         }
1796
1797         /* schedule ... need to lock */
1798         spin_lock_irqsave (&ehci->lock, flags);
1799         if (unlikely(!HCD_HW_ACCESSIBLE(ehci_to_hcd(ehci)))) {
1800                 status = -ESHUTDOWN;
1801                 goto done_not_linked;
1802         }
1803         status = usb_hcd_link_urb_to_ep(ehci_to_hcd(ehci), urb);
1804         if (unlikely(status))
1805                 goto done_not_linked;
1806         status = iso_stream_schedule(ehci, urb, stream);
1807         if (likely (status == 0))
1808                 itd_link_urb (ehci, urb, ehci->periodic_size << 3, stream);
1809         else
1810                 usb_hcd_unlink_urb_from_ep(ehci_to_hcd(ehci), urb);
1811  done_not_linked:
1812         spin_unlock_irqrestore (&ehci->lock, flags);
1813  done:
1814         return status;
1815 }
1816
1817 /*-------------------------------------------------------------------------*/
1818
1819 /*
1820  * "Split ISO TDs" ... used for USB 1.1 devices going through the
1821  * TTs in USB 2.0 hubs.  These need microframe scheduling.
1822  */
1823
1824 static inline void
1825 sitd_sched_init(
1826         struct ehci_hcd         *ehci,
1827         struct ehci_iso_sched   *iso_sched,
1828         struct ehci_iso_stream  *stream,
1829         struct urb              *urb
1830 )
1831 {
1832         unsigned        i;
1833         dma_addr_t      dma = urb->transfer_dma;
1834
1835         /* how many frames are needed for these transfers */
1836         iso_sched->span = urb->number_of_packets * stream->interval;
1837
1838         /* figure out per-frame sitd fields that we'll need later
1839          * when we fit new sitds into the schedule.
1840          */
1841         for (i = 0; i < urb->number_of_packets; i++) {
1842                 struct ehci_iso_packet  *packet = &iso_sched->packet [i];
1843                 unsigned                length;
1844                 dma_addr_t              buf;
1845                 u32                     trans;
1846
1847                 length = urb->iso_frame_desc [i].length & 0x03ff;
1848                 buf = dma + urb->iso_frame_desc [i].offset;
1849
1850                 trans = SITD_STS_ACTIVE;
1851                 if (((i + 1) == urb->number_of_packets)
1852                                 && !(urb->transfer_flags & URB_NO_INTERRUPT))
1853                         trans |= SITD_IOC;
1854                 trans |= length << 16;
1855                 packet->transaction = cpu_to_hc32(ehci, trans);
1856
1857                 /* might need to cross a buffer page within a td */
1858                 packet->bufp = buf;
1859                 packet->buf1 = (buf + length) & ~0x0fff;
1860                 if (packet->buf1 != (buf & ~(u64)0x0fff))
1861                         packet->cross = 1;
1862
1863                 /* OUT uses multiple start-splits */
1864                 if (stream->bEndpointAddress & USB_DIR_IN)
1865                         continue;
1866                 length = (length + 187) / 188;
1867                 if (length > 1) /* BEGIN vs ALL */
1868                         length |= 1 << 3;
1869                 packet->buf1 |= length;
1870         }
1871 }
1872
1873 static int
1874 sitd_urb_transaction (
1875         struct ehci_iso_stream  *stream,
1876         struct ehci_hcd         *ehci,
1877         struct urb              *urb,
1878         gfp_t                   mem_flags
1879 )
1880 {
1881         struct ehci_sitd        *sitd;
1882         dma_addr_t              sitd_dma;
1883         int                     i;
1884         struct ehci_iso_sched   *iso_sched;
1885         unsigned long           flags;
1886
1887         iso_sched = iso_sched_alloc (urb->number_of_packets, mem_flags);
1888         if (iso_sched == NULL)
1889                 return -ENOMEM;
1890
1891         sitd_sched_init(ehci, iso_sched, stream, urb);
1892
1893         /* allocate/init sITDs */
1894         spin_lock_irqsave (&ehci->lock, flags);
1895         for (i = 0; i < urb->number_of_packets; i++) {
1896
1897                 /* NOTE:  for now, we don't try to handle wraparound cases
1898                  * for IN (using sitd->hw_backpointer, like a FSTN), which
1899                  * means we never need two sitds for full speed packets.
1900                  */
1901
1902                 /*
1903                  * Use siTDs from the free list, but not siTDs that may
1904                  * still be in use by the hardware.
1905                  */
1906                 if (likely(!list_empty(&stream->free_list))) {
1907                         sitd = list_first_entry(&stream->free_list,
1908                                          struct ehci_sitd, sitd_list);
1909                         if (sitd->frame == ehci->now_frame)
1910                                 goto alloc_sitd;
1911                         list_del (&sitd->sitd_list);
1912                         sitd_dma = sitd->sitd_dma;
1913                 } else {
1914  alloc_sitd:
1915                         spin_unlock_irqrestore (&ehci->lock, flags);
1916                         sitd = dma_pool_alloc (ehci->sitd_pool, mem_flags,
1917                                         &sitd_dma);
1918                         spin_lock_irqsave (&ehci->lock, flags);
1919                         if (!sitd) {
1920                                 iso_sched_free(stream, iso_sched);
1921                                 spin_unlock_irqrestore(&ehci->lock, flags);
1922                                 return -ENOMEM;
1923                         }
1924                 }
1925
1926                 memset (sitd, 0, sizeof *sitd);
1927                 sitd->sitd_dma = sitd_dma;
1928                 sitd->frame = 9999;             /* an invalid value */
1929                 list_add (&sitd->sitd_list, &iso_sched->td_list);
1930         }
1931
1932         /* temporarily store schedule info in hcpriv */
1933         urb->hcpriv = iso_sched;
1934         urb->error_count = 0;
1935
1936         spin_unlock_irqrestore (&ehci->lock, flags);
1937         return 0;
1938 }
1939
1940 /*-------------------------------------------------------------------------*/
1941
1942 static inline void
1943 sitd_patch(
1944         struct ehci_hcd         *ehci,
1945         struct ehci_iso_stream  *stream,
1946         struct ehci_sitd        *sitd,
1947         struct ehci_iso_sched   *iso_sched,
1948         unsigned                index
1949 )
1950 {
1951         struct ehci_iso_packet  *uf = &iso_sched->packet [index];
1952         u64                     bufp = uf->bufp;
1953
1954         sitd->hw_next = EHCI_LIST_END(ehci);
1955         sitd->hw_fullspeed_ep = stream->address;
1956         sitd->hw_uframe = stream->splits;
1957         sitd->hw_results = uf->transaction;
1958         sitd->hw_backpointer = EHCI_LIST_END(ehci);
1959
1960         bufp = uf->bufp;
1961         sitd->hw_buf[0] = cpu_to_hc32(ehci, bufp);
1962         sitd->hw_buf_hi[0] = cpu_to_hc32(ehci, bufp >> 32);
1963
1964         sitd->hw_buf[1] = cpu_to_hc32(ehci, uf->buf1);
1965         if (uf->cross)
1966                 bufp += 4096;
1967         sitd->hw_buf_hi[1] = cpu_to_hc32(ehci, bufp >> 32);
1968         sitd->index = index;
1969 }
1970
1971 static inline void
1972 sitd_link (struct ehci_hcd *ehci, unsigned frame, struct ehci_sitd *sitd)
1973 {
1974         /* note: sitd ordering could matter (CSPLIT then SSPLIT) */
1975         sitd->sitd_next = ehci->pshadow [frame];
1976         sitd->hw_next = ehci->periodic [frame];
1977         ehci->pshadow [frame].sitd = sitd;
1978         sitd->frame = frame;
1979         wmb ();
1980         ehci->periodic[frame] = cpu_to_hc32(ehci, sitd->sitd_dma | Q_TYPE_SITD);
1981 }
1982
1983 /* fit urb's sitds into the selected schedule slot; activate as needed */
1984 static void sitd_link_urb(
1985         struct ehci_hcd         *ehci,
1986         struct urb              *urb,
1987         unsigned                mod,
1988         struct ehci_iso_stream  *stream
1989 )
1990 {
1991         int                     packet;
1992         unsigned                next_uframe;
1993         struct ehci_iso_sched   *sched = urb->hcpriv;
1994         struct ehci_sitd        *sitd;
1995
1996         next_uframe = stream->next_uframe;
1997
1998         if (list_empty(&stream->td_list))
1999                 /* usbfs ignores TT bandwidth */
2000                 ehci_to_hcd(ehci)->self.bandwidth_allocated
2001                                 += stream->bandwidth;
2002
2003         if (ehci_to_hcd(ehci)->self.bandwidth_isoc_reqs == 0) {
2004                 if (ehci->amd_pll_fix == 1)
2005                         usb_amd_quirk_pll_disable();
2006         }
2007
2008         ehci_to_hcd(ehci)->self.bandwidth_isoc_reqs++;
2009
2010         /* fill sITDs frame by frame */
2011         for (packet = 0, sitd = NULL;
2012                         packet < urb->number_of_packets;
2013                         packet++) {
2014
2015                 /* ASSERT:  we have all necessary sitds */
2016                 BUG_ON (list_empty (&sched->td_list));
2017
2018                 /* ASSERT:  no itds for this endpoint in this frame */
2019
2020                 sitd = list_entry (sched->td_list.next,
2021                                 struct ehci_sitd, sitd_list);
2022                 list_move_tail (&sitd->sitd_list, &stream->td_list);
2023                 sitd->stream = stream;
2024                 sitd->urb = urb;
2025
2026                 sitd_patch(ehci, stream, sitd, sched, packet);
2027                 sitd_link(ehci, (next_uframe >> 3) & (ehci->periodic_size - 1),
2028                                 sitd);
2029
2030                 next_uframe += stream->interval << 3;
2031         }
2032         stream->next_uframe = next_uframe & (mod - 1);
2033
2034         /* don't need that schedule data any more */
2035         iso_sched_free (stream, sched);
2036         urb->hcpriv = stream;
2037
2038         ++ehci->isoc_count;
2039         enable_periodic(ehci);
2040 }
2041
2042 /*-------------------------------------------------------------------------*/
2043
2044 #define SITD_ERRS (SITD_STS_ERR | SITD_STS_DBE | SITD_STS_BABBLE \
2045                                 | SITD_STS_XACT | SITD_STS_MMF)
2046
2047 /* Process and recycle a completed SITD.  Return true iff its urb completed,
2048  * and hence its completion callback probably added things to the hardware
2049  * schedule.
2050  *
2051  * Note that we carefully avoid recycling this descriptor until after any
2052  * completion callback runs, so that it won't be reused quickly.  That is,
2053  * assuming (a) no more than two urbs per frame on this endpoint, and also
2054  * (b) only this endpoint's completions submit URBs.  It seems some silicon
2055  * corrupts things if you reuse completed descriptors very quickly...
2056  */
2057 static bool sitd_complete(struct ehci_hcd *ehci, struct ehci_sitd *sitd)
2058 {
2059         struct urb                              *urb = sitd->urb;
2060         struct usb_iso_packet_descriptor        *desc;
2061         u32                                     t;
2062         int                                     urb_index = -1;
2063         struct ehci_iso_stream                  *stream = sitd->stream;
2064         struct usb_device                       *dev;
2065         bool                                    retval = false;
2066
2067         urb_index = sitd->index;
2068         desc = &urb->iso_frame_desc [urb_index];
2069         t = hc32_to_cpup(ehci, &sitd->hw_results);
2070
2071         /* report transfer status */
2072         if (unlikely(t & SITD_ERRS)) {
2073                 urb->error_count++;
2074                 if (t & SITD_STS_DBE)
2075                         desc->status = usb_pipein (urb->pipe)
2076                                 ? -ENOSR  /* hc couldn't read */
2077                                 : -ECOMM; /* hc couldn't write */
2078                 else if (t & SITD_STS_BABBLE)
2079                         desc->status = -EOVERFLOW;
2080                 else /* XACT, MMF, etc */
2081                         desc->status = -EPROTO;
2082         } else if (unlikely(t & SITD_STS_ACTIVE)) {
2083                 /* URB was too late */
2084                 urb->error_count++;
2085         } else {
2086                 desc->status = 0;
2087                 desc->actual_length = desc->length - SITD_LENGTH(t);
2088                 urb->actual_length += desc->actual_length;
2089         }
2090
2091         /* handle completion now? */
2092         if ((urb_index + 1) != urb->number_of_packets)
2093                 goto done;
2094
2095         /* ASSERT: it's really the last sitd for this urb
2096         list_for_each_entry (sitd, &stream->td_list, sitd_list)
2097                 BUG_ON (sitd->urb == urb);
2098          */
2099
2100         /* give urb back to the driver; completion often (re)submits */
2101         dev = urb->dev;
2102         ehci_urb_done(ehci, urb, 0);
2103         retval = true;
2104         urb = NULL;
2105
2106         --ehci->isoc_count;
2107         disable_periodic(ehci);
2108
2109         ehci_to_hcd(ehci)->self.bandwidth_isoc_reqs--;
2110         if (ehci_to_hcd(ehci)->self.bandwidth_isoc_reqs == 0) {
2111                 if (ehci->amd_pll_fix == 1)
2112                         usb_amd_quirk_pll_enable();
2113         }
2114
2115         if (list_is_singular(&stream->td_list))
2116                 ehci_to_hcd(ehci)->self.bandwidth_allocated
2117                                 -= stream->bandwidth;
2118
2119 done:
2120         sitd->urb = NULL;
2121
2122         /* Add to the end of the free list for later reuse */
2123         list_move_tail(&sitd->sitd_list, &stream->free_list);
2124
2125         /* Recycle the siTDs when the pipeline is empty (ep no longer in use) */
2126         if (list_empty(&stream->td_list)) {
2127                 list_splice_tail_init(&stream->free_list,
2128                                 &ehci->cached_sitd_list);
2129                 start_free_itds(ehci);
2130         }
2131
2132         return retval;
2133 }
2134
2135
2136 static int sitd_submit (struct ehci_hcd *ehci, struct urb *urb,
2137         gfp_t mem_flags)
2138 {
2139         int                     status = -EINVAL;
2140         unsigned long           flags;
2141         struct ehci_iso_stream  *stream;
2142
2143         /* Get iso_stream head */
2144         stream = iso_stream_find (ehci, urb);
2145         if (stream == NULL) {
2146                 ehci_dbg (ehci, "can't get iso stream\n");
2147                 return -ENOMEM;
2148         }
2149         if (urb->interval != stream->interval) {
2150                 ehci_dbg (ehci, "can't change iso interval %d --> %d\n",
2151                         stream->interval, urb->interval);
2152                 goto done;
2153         }
2154
2155 #ifdef EHCI_URB_TRACE
2156         ehci_dbg (ehci,
2157                 "submit %p dev%s ep%d%s-iso len %d\n",
2158                 urb, urb->dev->devpath,
2159                 usb_pipeendpoint (urb->pipe),
2160                 usb_pipein (urb->pipe) ? "in" : "out",
2161                 urb->transfer_buffer_length);
2162 #endif
2163
2164         /* allocate SITDs */
2165         status = sitd_urb_transaction (stream, ehci, urb, mem_flags);
2166         if (status < 0) {
2167                 ehci_dbg (ehci, "can't init sitds\n");
2168                 goto done;
2169         }
2170
2171         /* schedule ... need to lock */
2172         spin_lock_irqsave (&ehci->lock, flags);
2173         if (unlikely(!HCD_HW_ACCESSIBLE(ehci_to_hcd(ehci)))) {
2174                 status = -ESHUTDOWN;
2175                 goto done_not_linked;
2176         }
2177         status = usb_hcd_link_urb_to_ep(ehci_to_hcd(ehci), urb);
2178         if (unlikely(status))
2179                 goto done_not_linked;
2180         status = iso_stream_schedule(ehci, urb, stream);
2181         if (status == 0)
2182                 sitd_link_urb (ehci, urb, ehci->periodic_size << 3, stream);
2183         else
2184                 usb_hcd_unlink_urb_from_ep(ehci_to_hcd(ehci), urb);
2185  done_not_linked:
2186         spin_unlock_irqrestore (&ehci->lock, flags);
2187  done:
2188         return status;
2189 }
2190
2191 /*-------------------------------------------------------------------------*/
2192
2193 static void scan_isoc(struct ehci_hcd *ehci)
2194 {
2195         unsigned        uf, now_frame, frame;
2196         unsigned        fmask = ehci->periodic_size - 1;
2197         bool            modified, live;
2198
2199         /*
2200          * When running, scan from last scan point up to "now"
2201          * else clean up by scanning everything that's left.
2202          * Touches as few pages as possible:  cache-friendly.
2203          */
2204         if (ehci->rh_state >= EHCI_RH_RUNNING) {
2205                 uf = ehci_read_frame_index(ehci);
2206                 now_frame = (uf >> 3) & fmask;
2207                 live = true;
2208         } else  {
2209                 now_frame = (ehci->last_iso_frame - 1) & fmask;
2210                 live = false;
2211         }
2212         ehci->now_frame = now_frame;
2213
2214         frame = ehci->last_iso_frame;
2215         for (;;) {
2216                 union ehci_shadow       q, *q_p;
2217                 __hc32                  type, *hw_p;
2218
2219 restart:
2220                 /* scan each element in frame's queue for completions */
2221                 q_p = &ehci->pshadow [frame];
2222                 hw_p = &ehci->periodic [frame];
2223                 q.ptr = q_p->ptr;
2224                 type = Q_NEXT_TYPE(ehci, *hw_p);
2225                 modified = false;
2226
2227                 while (q.ptr != NULL) {
2228                         switch (hc32_to_cpu(ehci, type)) {
2229                         case Q_TYPE_ITD:
2230                                 /* If this ITD is still active, leave it for
2231                                  * later processing ... check the next entry.
2232                                  * No need to check for activity unless the
2233                                  * frame is current.
2234                                  */
2235                                 if (frame == now_frame && live) {
2236                                         rmb();
2237                                         for (uf = 0; uf < 8; uf++) {
2238                                                 if (q.itd->hw_transaction[uf] &
2239                                                             ITD_ACTIVE(ehci))
2240                                                         break;
2241                                         }
2242                                         if (uf < 8) {
2243                                                 q_p = &q.itd->itd_next;
2244                                                 hw_p = &q.itd->hw_next;
2245                                                 type = Q_NEXT_TYPE(ehci,
2246                                                         q.itd->hw_next);
2247                                                 q = *q_p;
2248                                                 break;
2249                                         }
2250                                 }
2251
2252                                 /* Take finished ITDs out of the schedule
2253                                  * and process them:  recycle, maybe report
2254                                  * URB completion.  HC won't cache the
2255                                  * pointer for much longer, if at all.
2256                                  */
2257                                 *q_p = q.itd->itd_next;
2258                                 if (!ehci->use_dummy_qh ||
2259                                     q.itd->hw_next != EHCI_LIST_END(ehci))
2260                                         *hw_p = q.itd->hw_next;
2261                                 else
2262                                         *hw_p = ehci->dummy->qh_dma;
2263                                 type = Q_NEXT_TYPE(ehci, q.itd->hw_next);
2264                                 wmb();
2265                                 modified = itd_complete (ehci, q.itd);
2266                                 q = *q_p;
2267                                 break;
2268                         case Q_TYPE_SITD:
2269                                 /* If this SITD is still active, leave it for
2270                                  * later processing ... check the next entry.
2271                                  * No need to check for activity unless the
2272                                  * frame is current.
2273                                  */
2274                                 if (((frame == now_frame) ||
2275                                      (((frame + 1) & fmask) == now_frame))
2276                                     && live
2277                                     && (q.sitd->hw_results &
2278                                         SITD_ACTIVE(ehci))) {
2279
2280                                         q_p = &q.sitd->sitd_next;
2281                                         hw_p = &q.sitd->hw_next;
2282                                         type = Q_NEXT_TYPE(ehci,
2283                                                         q.sitd->hw_next);
2284                                         q = *q_p;
2285                                         break;
2286                                 }
2287
2288                                 /* Take finished SITDs out of the schedule
2289                                  * and process them:  recycle, maybe report
2290                                  * URB completion.
2291                                  */
2292                                 *q_p = q.sitd->sitd_next;
2293                                 if (!ehci->use_dummy_qh ||
2294                                     q.sitd->hw_next != EHCI_LIST_END(ehci))
2295                                         *hw_p = q.sitd->hw_next;
2296                                 else
2297                                         *hw_p = ehci->dummy->qh_dma;
2298                                 type = Q_NEXT_TYPE(ehci, q.sitd->hw_next);
2299                                 wmb();
2300                                 modified = sitd_complete (ehci, q.sitd);
2301                                 q = *q_p;
2302                                 break;
2303                         default:
2304                                 ehci_dbg(ehci, "corrupt type %d frame %d shadow %p\n",
2305                                         type, frame, q.ptr);
2306                                 // BUG ();
2307                                 /* FALL THROUGH */
2308                         case Q_TYPE_QH:
2309                         case Q_TYPE_FSTN:
2310                                 /* End of the iTDs and siTDs */
2311                                 q.ptr = NULL;
2312                                 break;
2313                         }
2314
2315                         /* assume completion callbacks modify the queue */
2316                         if (unlikely(modified && ehci->isoc_count > 0))
2317                                 goto restart;
2318                 }
2319
2320                 /* Stop when we have reached the current frame */
2321                 if (frame == now_frame)
2322                         break;
2323
2324                 /* The last frame may still have active siTDs */
2325                 ehci->last_iso_frame = frame;
2326                 frame = (frame + 1) & fmask;
2327         }
2328 }