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
  41 /*
  42  * periodic_next_shadow - return "next" pointer on shadow list
  43  * @periodic: host pointer to qh/itd/sitd
  44  * @tag: hardware tag for type of this record
  45  */
  46 static union ehci_shadow *
  47 periodic_next_shadow(struct ehci_hcd *ehci, union ehci_shadow *periodic,
  48                 __hc32 tag)
  49 {
  50         switch (hc32_to_cpu(ehci, tag)) {
  51         case Q_TYPE_QH:
  52                 return &periodic->qh->qh_next;
  53         case Q_TYPE_FSTN:
  54                 return &periodic->fstn->fstn_next;
  55         case Q_TYPE_ITD:
  56                 return &periodic->itd->itd_next;
  57         // case Q_TYPE_SITD:
  58         default:
  59                 return &periodic->sitd->sitd_next;
  60         }
  61 }
  62
  63 static __hc32 *
  64 shadow_next_periodic(struct ehci_hcd *ehci, union ehci_shadow *periodic,
  65                 __hc32 tag)
  66 {
  67         switch (hc32_to_cpu(ehci, tag)) {
  68         /* our ehci_shadow.qh is actually software part */
  69         case Q_TYPE_QH:
  70                 return &periodic->qh->hw->hw_next;
  71         /* others are hw parts */
  72         default:
  73                 return periodic->hw_next;
  74         }
  75 }
  76
  77 /* caller must hold ehci->lock */
  78 static void periodic_unlink (struct ehci_hcd *ehci, unsigned frame, void *ptr)
  79 {
  80         union ehci_shadow       *prev_p = &ehci->pshadow[frame];
  81         __hc32                  *hw_p = &ehci->periodic[frame];
  82         union ehci_shadow       here = *prev_p;
  83
  84         /* find predecessor of "ptr"; hw and shadow lists are in sync */
  85         while (here.ptr && here.ptr != ptr) {
  86                 prev_p = periodic_next_shadow(ehci, prev_p,
  87                                 Q_NEXT_TYPE(ehci, *hw_p));
  88                 hw_p = shadow_next_periodic(ehci, &here,
  89                                 Q_NEXT_TYPE(ehci, *hw_p));
  90                 here = *prev_p;
  91         }
  92         /* an interrupt entry (at list end) could have been shared */
  93         if (!here.ptr)
  94                 return;
  95
  96         /* update shadow and hardware lists ... the old "next" pointers
  97          * from ptr may still be in use, the caller updates them.
  98          */
  99         *prev_p = *periodic_next_shadow(ehci, &here,
 100                         Q_NEXT_TYPE(ehci, *hw_p));
 101         *hw_p = *shadow_next_periodic(ehci, &here, Q_NEXT_TYPE(ehci, *hw_p));
 102 }
 103
 104 /* how many of the uframe's 125 usecs are allocated? */
 105 static unsigned short
 106 periodic_usecs (struct ehci_hcd *ehci, unsigned frame, unsigned uframe)
 107 {
 108         __hc32                  *hw_p = &ehci->periodic [frame];
 109         union ehci_shadow       *q = &ehci->pshadow [frame];
 110         unsigned                usecs = 0;
 111         struct ehci_qh_hw       *hw;
 112
 113         while (q->ptr) {
 114                 switch (hc32_to_cpu(ehci, Q_NEXT_TYPE(ehci, *hw_p))) {
 115                 case Q_TYPE_QH:
 116                         hw = q->qh->hw;
 117                         /* is it in the S-mask? */
 118                         if (hw->hw_info2 & cpu_to_hc32(ehci, 1 << uframe))
 119                                 usecs += q->qh->usecs;
 120                         /* ... or C-mask? */
 121                         if (hw->hw_info2 & cpu_to_hc32(ehci,
 122                                         1 << (8 + uframe)))
 123                                 usecs += q->qh->c_usecs;
 124                         hw_p = &hw->hw_next;
 125                         q = &q->qh->qh_next;
 126                         break;
 127                 // case Q_TYPE_FSTN:
 128                 default:
 129                         /* for "save place" FSTNs, count the relevant INTR
 130                          * bandwidth from the previous frame
 131                          */
 132                         if (q->fstn->hw_prev != EHCI_LIST_END(ehci)) {
 133                                 ehci_dbg (ehci, "ignoring FSTN cost ...\n");
 134                         }
 135                         hw_p = &q->fstn->hw_next;
 136                         q = &q->fstn->fstn_next;
 137                         break;
 138                 case Q_TYPE_ITD:
 139                         if (q->itd->hw_transaction[uframe])
 140                                 usecs += q->itd->stream->usecs;
 141                         hw_p = &q->itd->hw_next;
 142                         q = &q->itd->itd_next;
 143                         break;
 144                 case Q_TYPE_SITD:
 145                         /* is it in the S-mask?  (count SPLIT, DATA) */
 146                         if (q->sitd->hw_uframe & cpu_to_hc32(ehci,
 147                                         1 << uframe)) {
 148                                 if (q->sitd->hw_fullspeed_ep &
 149                                                 cpu_to_hc32(ehci, 1<<31))
 150                                         usecs += q->sitd->stream->usecs;
 151                                 else    /* worst case for OUT start-split */
 152                                         usecs += HS_USECS_ISO (188);
 153                         }
 154
 155                         /* ... C-mask?  (count CSPLIT, DATA) */
 156                         if (q->sitd->hw_uframe &
 157                                         cpu_to_hc32(ehci, 1 << (8 + uframe))) {
 158                                 /* worst case for IN complete-split */
 159                                 usecs += q->sitd->stream->c_usecs;
 160                         }
 161
 162                         hw_p = &q->sitd->hw_next;
 163                         q = &q->sitd->sitd_next;
 164                         break;
 165                 }
 166         }
 167 #ifdef  DEBUG
 168         if (usecs > 100)
 169                 ehci_err (ehci, "uframe %d sched overrun: %d usecs\n",
 170                         frame * 8 + uframe, usecs);
 171 #endif
 172         return usecs;
 173 }
 174
 175 /*-------------------------------------------------------------------------*/
 176
 177 static int same_tt (struct usb_device *dev1, struct usb_device *dev2)
 178 {
 179         if (!dev1->tt || !dev2->tt)
 180                 return 0;
 181         if (dev1->tt != dev2->tt)
 182                 return 0;
 183         if (dev1->tt->multi)
 184                 return dev1->ttport == dev2->ttport;
 185         else
 186                 return 1;
 187 }
 188
 189 #ifdef CONFIG_USB_EHCI_TT_NEWSCHED
 190
 191 /* Which uframe does the low/fullspeed transfer start in?
 192  *
 193  * The parameter is the mask of ssplits in "H-frame" terms
 194  * and this returns the transfer start uframe in "B-frame" terms,
 195  * which allows both to match, e.g. a ssplit in "H-frame" uframe 0
 196  * will cause a transfer in "B-frame" uframe 0.  "B-frames" lag
 197  * "H-frames" by 1 uframe.  See the EHCI spec sec 4.5 and figure 4.7.
 198  */
 199 static inline unsigned char tt_start_uframe(struct ehci_hcd *ehci, __hc32 mask)
 200 {
 201         unsigned char smask = QH_SMASK & hc32_to_cpu(ehci, mask);
 202         if (!smask) {
 203                 ehci_err(ehci, "invalid empty smask!\n");
 204                 /* uframe 7 can't have bw so this will indicate failure */
 205                 return 7;
 206         }
 207         return ffs(smask) - 1;
 208 }
 209
 210 static const unsigned char
 211 max_tt_usecs[] = { 125, 125, 125, 125, 125, 125, 30, 0 };
 212
 213 /* carryover low/fullspeed bandwidth that crosses uframe boundries */
 214 static inline void carryover_tt_bandwidth(unsigned short tt_usecs[8])
 215 {
 216         int i;
 217         for (i=0; i<7; i++) {
 218                 if (max_tt_usecs[i] < tt_usecs[i]) {
 219                         tt_usecs[i+1] += tt_usecs[i] - max_tt_usecs[i];
 220                         tt_usecs[i] = max_tt_usecs[i];
 221                 }
 222         }
 223 }
 224
 225 /* How many of the tt's periodic downstream 1000 usecs are allocated?
 226  *
 227  * While this measures the bandwidth in terms of usecs/uframe,
 228  * the low/fullspeed bus has no notion of uframes, so any particular
 229  * low/fullspeed transfer can "carry over" from one uframe to the next,
 230  * since the TT just performs downstream transfers in sequence.
 231  *
 232  * For example two separate 100 usec transfers can start in the same uframe,
 233  * and the second one would "carry over" 75 usecs into the next uframe.
 234  */
 235 static void
 236 periodic_tt_usecs (
 237         struct ehci_hcd *ehci,
 238         struct usb_device *dev,
 239         unsigned frame,
 240         unsigned short tt_usecs[8]
 241 )
 242 {
 243         __hc32                  *hw_p = &ehci->periodic [frame];
 244         union ehci_shadow       *q = &ehci->pshadow [frame];
 245         unsigned char           uf;
 246
 247         memset(tt_usecs, 0, 16);
 248
 249         while (q->ptr) {
 250                 switch (hc32_to_cpu(ehci, Q_NEXT_TYPE(ehci, *hw_p))) {
 251                 case Q_TYPE_ITD:
 252                         hw_p = &q->itd->hw_next;
 253                         q = &q->itd->itd_next;
 254                         continue;
 255                 case Q_TYPE_QH:
 256                         if (same_tt(dev, q->qh->dev)) {
 257                                 uf = tt_start_uframe(ehci, q->qh->hw->hw_info2);
 258                                 tt_usecs[uf] += q->qh->tt_usecs;
 259                         }
 260                         hw_p = &q->qh->hw->hw_next;
 261                         q = &q->qh->qh_next;
 262                         continue;
 263                 case Q_TYPE_SITD:
 264                         if (same_tt(dev, q->sitd->urb->dev)) {
 265                                 uf = tt_start_uframe(ehci, q->sitd->hw_uframe);
 266                                 tt_usecs[uf] += q->sitd->stream->tt_usecs;
 267                         }
 268                         hw_p = &q->sitd->hw_next;
 269                         q = &q->sitd->sitd_next;
 270                         continue;
 271                 // case Q_TYPE_FSTN:
 272                 default:
 273                         ehci_dbg(ehci, "ignoring periodic frame %d FSTN\n",
 274                                         frame);
 275                         hw_p = &q->fstn->hw_next;
 276                         q = &q->fstn->fstn_next;
 277                 }
 278         }
 279
 280         carryover_tt_bandwidth(tt_usecs);
 281
 282         if (max_tt_usecs[7] < tt_usecs[7])
 283                 ehci_err(ehci, "frame %d tt sched overrun: %d usecs\n",
 284                         frame, tt_usecs[7] - max_tt_usecs[7]);
 285 }
 286
 287 /*
 288  * Return true if the device's tt's downstream bus is available for a
 289  * periodic transfer of the specified length (usecs), starting at the
 290  * specified frame/uframe.  Note that (as summarized in section 11.19
 291  * of the usb 2.0 spec) TTs can buffer multiple transactions for each
 292  * uframe.
 293  *
 294  * The uframe parameter is when the fullspeed/lowspeed transfer
 295  * should be executed in "B-frame" terms, which is the same as the
 296  * highspeed ssplit's uframe (which is in "H-frame" terms).  For example
 297  * a ssplit in "H-frame" 0 causes a transfer in "B-frame" 0.
 298  * See the EHCI spec sec 4.5 and fig 4.7.
 299  *
 300  * This checks if the full/lowspeed bus, at the specified starting uframe,
 301  * has the specified bandwidth available, according to rules listed
 302  * in USB 2.0 spec section 11.18.1 fig 11-60.
 303  *
 304  * This does not check if the transfer would exceed the max ssplit
 305  * limit of 16, specified in USB 2.0 spec section 11.18.4 requirement #4,
 306  * since proper scheduling limits ssplits to less than 16 per uframe.
 307  */
 308 static int tt_available (
 309         struct ehci_hcd         *ehci,
 310         unsigned                period,
 311         struct usb_device       *dev,
 312         unsigned                frame,
 313         unsigned                uframe,
 314         u16                     usecs
 315 )
 316 {
 317         if ((period == 0) || (uframe >= 7))     /* error */
 318                 return 0;
 319
 320         for (; frame < ehci->periodic_size; frame += period) {
 321                 unsigned short tt_usecs[8];
 322
 323                 periodic_tt_usecs (ehci, dev, frame, tt_usecs);
 324
 325                 ehci_vdbg(ehci, "tt frame %d check %d usecs start uframe %d in"
 326                         " schedule %d/%d/%d/%d/%d/%d/%d/%d\n",
 327                         frame, usecs, uframe,
 328                         tt_usecs[0], tt_usecs[1], tt_usecs[2], tt_usecs[3],
 329                         tt_usecs[4], tt_usecs[5], tt_usecs[6], tt_usecs[7]);
 330
 331                 if (max_tt_usecs[uframe] <= tt_usecs[uframe]) {
 332                         ehci_vdbg(ehci, "frame %d uframe %d fully scheduled\n",
 333                                 frame, uframe);
 334                         return 0;
 335                 }
 336
 337                 /* special case for isoc transfers larger than 125us:
 338                  * the first and each subsequent fully used uframe
 339                  * must be empty, so as to not illegally delay
 340                  * already scheduled transactions
 341                  */
 342                 if (125 < usecs) {
 343                         int ufs = (usecs / 125);
 344                         int i;
 345                         for (i = uframe; i < (uframe + ufs) && i < 8; i++)
 346                                 if (0 < tt_usecs[i]) {
 347                                         ehci_vdbg(ehci,
 348                                                 "multi-uframe xfer can't fit "
 349                                                 "in frame %d uframe %d\n",
 350                                                 frame, i);
 351                                         return 0;
 352                                 }
 353                 }
 354
 355                 tt_usecs[uframe] += usecs;
 356
 357                 carryover_tt_bandwidth(tt_usecs);
 358
 359                 /* fail if the carryover pushed bw past the last uframe's limit */
 360                 if (max_tt_usecs[7] < tt_usecs[7]) {
 361                         ehci_vdbg(ehci,
 362                                 "tt unavailable usecs %d frame %d uframe %d\n",
 363                                 usecs, frame, uframe);
 364                         return 0;
 365                 }
 366         }
 367
 368         return 1;
 369 }
 370
 371 #else
 372
 373 /* return true iff the device's transaction translator is available
 374  * for a periodic transfer starting at the specified frame, using
 375  * all the uframes in the mask.
 376  */
 377 static int tt_no_collision (
 378         struct ehci_hcd         *ehci,
 379         unsigned                period,
 380         struct usb_device       *dev,
 381         unsigned                frame,
 382         u32                     uf_mask
 383 )
 384 {
 385         if (period == 0)        /* error */
 386                 return 0;
 387
 388         /* note bandwidth wastage:  split never follows csplit
 389          * (different dev or endpoint) until the next uframe.
 390          * calling convention doesn't make that distinction.
 391          */
 392         for (; frame < ehci->periodic_size; frame += period) {
 393                 union ehci_shadow       here;
 394                 __hc32                  type;
 395                 struct ehci_qh_hw       *hw;
 396
 397                 here = ehci->pshadow [frame];
 398                 type = Q_NEXT_TYPE(ehci, ehci->periodic [frame]);
 399                 while (here.ptr) {
 400                         switch (hc32_to_cpu(ehci, type)) {
 401                         case Q_TYPE_ITD:
 402                                 type = Q_NEXT_TYPE(ehci, here.itd->hw_next);
 403                                 here = here.itd->itd_next;
 404                                 continue;
 405                         case Q_TYPE_QH:
 406                                 hw = here.qh->hw;
 407                                 if (same_tt (dev, here.qh->dev)) {
 408                                         u32             mask;
 409
 410                                         mask = hc32_to_cpu(ehci,
 411                                                         hw->hw_info2);
 412                                         /* "knows" no gap is needed */
 413                                         mask |= mask >> 8;
 414                                         if (mask & uf_mask)
 415                                                 break;
 416                                 }
 417                                 type = Q_NEXT_TYPE(ehci, hw->hw_next);
 418                                 here = here.qh->qh_next;
 419                                 continue;
 420                         case Q_TYPE_SITD:
 421                                 if (same_tt (dev, here.sitd->urb->dev)) {
 422                                         u16             mask;
 423
 424                                         mask = hc32_to_cpu(ehci, here.sitd
 425                                                                 ->hw_uframe);
 426                                         /* FIXME assumes no gap for IN! */
 427                                         mask |= mask >> 8;
 428                                         if (mask & uf_mask)
 429                                                 break;
 430                                 }
 431                                 type = Q_NEXT_TYPE(ehci, here.sitd->hw_next);
 432                                 here = here.sitd->sitd_next;
 433                                 continue;
 434                         // case Q_TYPE_FSTN:
 435                         default:
 436                                 ehci_dbg (ehci,
 437                                         "periodic frame %d bogus type %d\n",
 438                                         frame, type);
 439                         }
 440
 441                         /* collision or error */
 442                         return 0;
 443                 }
 444         }
 445
 446         /* no collision */
 447         return 1;
 448 }
 449
 450 #endif /* CONFIG_USB_EHCI_TT_NEWSCHED */
 451
 452 /*-------------------------------------------------------------------------*/
 453
 454 static int enable_periodic (struct ehci_hcd *ehci)
 455 {
 456         u32     cmd;
 457         int     status;
 458
 459         if (ehci->periodic_sched++)
 460                 return 0;
 461
 462         /* did clearing PSE did take effect yet?
 463          * takes effect only at frame boundaries...
 464          */
 465         status = handshake_on_error_set_halt(ehci, &ehci->regs->status,
 466                                              STS_PSS, 0, 9 * 125);
 467         if (status)
 468                 return status;
 469
 470         cmd = ehci_readl(ehci, &ehci->regs->command) | CMD_PSE;
 471         ehci_writel(ehci, cmd, &ehci->regs->command);
 472         /* posted write ... PSS happens later */
 473         ehci_to_hcd(ehci)->state = HC_STATE_RUNNING;
 474
 475         /* make sure ehci_work scans these */
 476         ehci->next_uframe = ehci_readl(ehci, &ehci->regs->frame_index)
 477                 % (ehci->periodic_size << 3);
 478         if (unlikely(ehci->broken_periodic))
 479                 ehci->last_periodic_enable = ktime_get_real();
 480         return 0;
 481 }
 482
 483 static int disable_periodic (struct ehci_hcd *ehci)
 484 {
 485         u32     cmd;
 486         int     status;
 487
 488         if (--ehci->periodic_sched)
 489                 return 0;
 490
 491         if (unlikely(ehci->broken_periodic)) {
 492                 /* delay experimentally determined */
 493                 ktime_t safe = ktime_add_us(ehci->last_periodic_enable, 1000);
 494                 ktime_t now = ktime_get_real();
 495                 s64 delay = ktime_us_delta(safe, now);
 496
 497                 if (unlikely(delay > 0))
 498                         udelay(delay);
 499         }
 500
 501         /* did setting PSE not take effect yet?
 502          * takes effect only at frame boundaries...
 503          */
 504         status = handshake_on_error_set_halt(ehci, &ehci->regs->status,
 505                                              STS_PSS, STS_PSS, 9 * 125);
 506         if (status)
 507                 return status;
 508
 509         cmd = ehci_readl(ehci, &ehci->regs->command) & ~CMD_PSE;
 510         ehci_writel(ehci, cmd, &ehci->regs->command);
 511         /* posted write ... */
 512
 513         free_cached_lists(ehci);
 514
 515         ehci->next_uframe = -1;
 516         return 0;
 517 }
 518
 519 /*-------------------------------------------------------------------------*/
 520
 521 /* periodic schedule slots have iso tds (normal or split) first, then a
 522  * sparse tree for active interrupt transfers.
 523  *
 524  * this just links in a qh; caller guarantees uframe masks are set right.
 525  * no FSTN support (yet; ehci 0.96+)
 526  */
 527 static int qh_link_periodic (struct ehci_hcd *ehci, struct ehci_qh *qh)
 528 {
 529         unsigned        i;
 530         unsigned        period = qh->period;
 531
 532         dev_dbg (&qh->dev->dev,
 533                 "link qh%d-%04x/%p start %d [%d/%d us]\n",
 534                 period, hc32_to_cpup(ehci, &qh->hw->hw_info2)
 535                         & (QH_CMASK | QH_SMASK),
 536                 qh, qh->start, qh->usecs, qh->c_usecs);
 537
 538         /* high bandwidth, or otherwise every microframe */
 539         if (period == 0)
 540                 period = 1;
 541
 542         for (i = qh->start; i < ehci->periodic_size; i += period) {
 543                 union ehci_shadow       *prev = &ehci->pshadow[i];
 544                 __hc32                  *hw_p = &ehci->periodic[i];
 545                 union ehci_shadow       here = *prev;
 546                 __hc32                  type = 0;
 547
 548                 /* skip the iso nodes at list head */
 549                 while (here.ptr) {
 550                         type = Q_NEXT_TYPE(ehci, *hw_p);
 551                         if (type == cpu_to_hc32(ehci, Q_TYPE_QH))
 552                                 break;
 553                         prev = periodic_next_shadow(ehci, prev, type);
 554                         hw_p = shadow_next_periodic(ehci, &here, type);
 555                         here = *prev;
 556                 }
 557
 558                 /* sorting each branch by period (slow-->fast)
 559                  * enables sharing interior tree nodes
 560                  */
 561                 while (here.ptr && qh != here.qh) {
 562                         if (qh->period > here.qh->period)
 563                                 break;
 564                         prev = &here.qh->qh_next;
 565                         hw_p = &here.qh->hw->hw_next;
 566                         here = *prev;
 567                 }
 568                 /* link in this qh, unless some earlier pass did that */
 569                 if (qh != here.qh) {
 570                         qh->qh_next = here;
 571                         if (here.qh)
 572                                 qh->hw->hw_next = *hw_p;
 573                         wmb ();
 574                         prev->qh = qh;
 575                         *hw_p = QH_NEXT (ehci, qh->qh_dma);
 576                 }
 577         }
 578         qh->qh_state = QH_STATE_LINKED;
 579         qh->xacterrs = 0;
 580         qh_get (qh);
 581
 582         /* update per-qh bandwidth for usbfs */
 583         ehci_to_hcd(ehci)->self.bandwidth_allocated += qh->period
 584                 ? ((qh->usecs + qh->c_usecs) / qh->period)
 585                 : (qh->usecs * 8);
 586
 587         /* maybe enable periodic schedule processing */
 588         return enable_periodic(ehci);
 589 }
 590
 591 static int qh_unlink_periodic(struct ehci_hcd *ehci, struct ehci_qh *qh)
 592 {
 593         unsigned        i;
 594         unsigned        period;
 595
 596         // FIXME:
 597         // IF this isn't high speed
 598         //   and this qh is active in the current uframe
 599         //   (and overlay token SplitXstate is false?)
 600         // THEN
 601         //   qh->hw_info1 |= cpu_to_hc32(1 << 7 /* "ignore" */);
 602
 603         /* high bandwidth, or otherwise part of every microframe */
 604         if ((period = qh->period) == 0)
 605                 period = 1;
 606
 607         for (i = qh->start; i < ehci->periodic_size; i += period)
 608                 periodic_unlink (ehci, i, qh);
 609
 610         /* update per-qh bandwidth for usbfs */
 611         ehci_to_hcd(ehci)->self.bandwidth_allocated -= qh->period
 612                 ? ((qh->usecs + qh->c_usecs) / qh->period)
 613                 : (qh->usecs * 8);
 614
 615         dev_dbg (&qh->dev->dev,
 616                 "unlink qh%d-%04x/%p start %d [%d/%d us]\n",
 617                 qh->period,
 618                 hc32_to_cpup(ehci, &qh->hw->hw_info2) & (QH_CMASK | QH_SMASK),
 619                 qh, qh->start, qh->usecs, qh->c_usecs);
 620
 621         /* qh->qh_next still "live" to HC */
 622         qh->qh_state = QH_STATE_UNLINK;
 623         qh->qh_next.ptr = NULL;
 624         qh_put (qh);
 625
 626         /* maybe turn off periodic schedule */
 627         return disable_periodic(ehci);
 628 }
 629
 630 static void intr_deschedule (struct ehci_hcd *ehci, struct ehci_qh *qh)
 631 {
 632         unsigned                wait;
 633         struct ehci_qh_hw       *hw = qh->hw;
 634         int                     rc;
 635
 636         /* If the QH isn't linked then there's nothing we can do
 637          * unless we were called during a giveback, in which case
 638          * qh_completions() has to deal with it.
 639          */
 640         if (qh->qh_state != QH_STATE_LINKED) {
 641                 if (qh->qh_state == QH_STATE_COMPLETING)
 642                         qh->needs_rescan = 1;
 643                 return;
 644         }
 645
 646         qh_unlink_periodic (ehci, qh);
 647
 648         /* simple/paranoid:  always delay, expecting the HC needs to read
 649          * qh->hw_next or finish a writeback after SPLIT/CSPLIT ... and
 650          * expect khubd to clean up after any CSPLITs we won't issue.
 651          * active high speed queues may need bigger delays...
 652          */
 653         if (list_empty (&qh->qtd_list)
 654                         || (cpu_to_hc32(ehci, QH_CMASK)
 655                                         & hw->hw_info2) != 0)
 656                 wait = 2;
 657         else
 658                 wait = 55;      /* worst case: 3 * 1024 */
 659
 660         udelay (wait);
 661         qh->qh_state = QH_STATE_IDLE;
 662         hw->hw_next = EHCI_LIST_END(ehci);
 663         wmb ();
 664
 665         qh_completions(ehci, qh);
 666
 667         /* reschedule QH iff another request is queued */
 668         if (!list_empty(&qh->qtd_list) &&
 669                         HC_IS_RUNNING(ehci_to_hcd(ehci)->state)) {
 670                 rc = qh_schedule(ehci, qh);
 671
 672                 /* An error here likely indicates handshake failure
 673                  * or no space left in the schedule.  Neither fault
 674                  * should happen often ...
 675                  *
 676                  * FIXME kill the now-dysfunctional queued urbs
 677                  */
 678                 if (rc != 0)
 679                         ehci_err(ehci, "can't reschedule qh %p, err %d\n",
 680                                         qh, rc);
 681         }
 682 }
 683
 684 /*-------------------------------------------------------------------------*/
 685
 686 static int check_period (
 687         struct ehci_hcd *ehci,
 688         unsigned        frame,
 689         unsigned        uframe,
 690         unsigned        period,
 691         unsigned        usecs
 692 ) {
 693         int             claimed;
 694
 695         /* complete split running into next frame?
 696          * given FSTN support, we could sometimes check...
 697          */
 698         if (uframe >= 8)
 699                 return 0;
 700
 701         /*
 702          * 80% periodic == 100 usec/uframe available
 703          * convert "usecs we need" to "max already claimed"
 704          */
 705         usecs = 100 - usecs;
 706
 707         /* we "know" 2 and 4 uframe intervals were rejected; so
 708          * for period 0, check _every_ microframe in the schedule.
 709          */
 710         if (unlikely (period == 0)) {
 711                 do {
 712                         for (uframe = 0; uframe < 7; uframe++) {
 713                                 claimed = periodic_usecs (ehci, frame, uframe);
 714                                 if (claimed > usecs)
 715                                         return 0;
 716                         }
 717                 } while ((frame += 1) < ehci->periodic_size);
 718
 719         /* just check the specified uframe, at that period */
 720         } else {
 721                 do {
 722                         claimed = periodic_usecs (ehci, frame, uframe);
 723                         if (claimed > usecs)
 724                                 return 0;
 725                 } while ((frame += period) < ehci->periodic_size);
 726         }
 727
 728         // success!
 729         return 1;
 730 }
 731
 732 static int check_intr_schedule (
 733         struct ehci_hcd         *ehci,
 734         unsigned                frame,
 735         unsigned                uframe,
 736         const struct ehci_qh    *qh,
 737         __hc32                  *c_maskp
 738 )
 739 {
 740         int             retval = -ENOSPC;
 741         u8              mask = 0;
 742
 743         if (qh->c_usecs && uframe >= 6)         /* FSTN territory? */
 744                 goto done;
 745
 746         if (!check_period (ehci, frame, uframe, qh->period, qh->usecs))
 747                 goto done;
 748         if (!qh->c_usecs) {
 749                 retval = 0;
 750                 *c_maskp = 0;
 751                 goto done;
 752         }
 753
 754 #ifdef CONFIG_USB_EHCI_TT_NEWSCHED
 755         if (tt_available (ehci, qh->period, qh->dev, frame, uframe,
 756                                 qh->tt_usecs)) {
 757                 unsigned i;
 758
 759                 /* TODO : this may need FSTN for SSPLIT in uframe 5. */
 760                 for (i=uframe+1; i<8 && i<uframe+4; i++)
 761                         if (!check_period (ehci, frame, i,
 762                                                 qh->period, qh->c_usecs))
 763                                 goto done;
 764                         else
 765                                 mask |= 1 << i;
 766
 767                 retval = 0;
 768
 769                 *c_maskp = cpu_to_hc32(ehci, mask << 8);
 770         }
 771 #else
 772         /* Make sure this tt's buffer is also available for CSPLITs.
 773          * We pessimize a bit; probably the typical full speed case
 774          * doesn't need the second CSPLIT.
 775          *
 776          * NOTE:  both SPLIT and CSPLIT could be checked in just
 777          * one smart pass...
 778          */
 779         mask = 0x03 << (uframe + qh->gap_uf);
 780         *c_maskp = cpu_to_hc32(ehci, mask << 8);
 781
 782         mask |= 1 << uframe;
 783         if (tt_no_collision (ehci, qh->period, qh->dev, frame, mask)) {
 784                 if (!check_period (ehci, frame, uframe + qh->gap_uf + 1,
 785                                         qh->period, qh->c_usecs))
 786                         goto done;
 787                 if (!check_period (ehci, frame, uframe + qh->gap_uf,
 788                                         qh->period, qh->c_usecs))
 789                         goto done;
 790                 retval = 0;
 791         }
 792 #endif
 793 done:
 794         return retval;
 795 }
 796
 797 /* "first fit" scheduling policy used the first time through,
 798  * or when the previous schedule slot can't be re-used.
 799  */
 800 static int qh_schedule(struct ehci_hcd *ehci, struct ehci_qh *qh)
 801 {
 802         int             status;
 803         unsigned        uframe;
 804         __hc32          c_mask;
 805         unsigned        frame;          /* 0..(qh->period - 1), or NO_FRAME */
 806         struct ehci_qh_hw       *hw = qh->hw;
 807
 808         qh_refresh(ehci, qh);
 809         hw->hw_next = EHCI_LIST_END(ehci);
 810         frame = qh->start;
 811
 812         /* reuse the previous schedule slots, if we can */
 813         if (frame < qh->period) {
 814                 uframe = ffs(hc32_to_cpup(ehci, &hw->hw_info2) & QH_SMASK);
 815                 status = check_intr_schedule (ehci, frame, --uframe,
 816                                 qh, &c_mask);
 817         } else {
 818                 uframe = 0;
 819                 c_mask = 0;
 820                 status = -ENOSPC;
 821         }
 822
 823         /* else scan the schedule to find a group of slots such that all
 824          * uframes have enough periodic bandwidth available.
 825          */
 826         if (status) {
 827                 /* "normal" case, uframing flexible except with splits */
 828                 if (qh->period) {
 829                         int             i;
 830
 831                         for (i = qh->period; status && i > 0; --i) {
 832                                 frame = ++ehci->random_frame % qh->period;
 833                                 for (uframe = 0; uframe < 8; uframe++) {
 834                                         status = check_intr_schedule (ehci,
 835                                                         frame, uframe, qh,
 836                                                         &c_mask);
 837                                         if (status == 0)
 838                                                 break;
 839                                 }
 840                         }
 841
 842                 /* qh->period == 0 means every uframe */
 843                 } else {
 844                         frame = 0;
 845                         status = check_intr_schedule (ehci, 0, 0, qh, &c_mask);
 846                 }
 847                 if (status)
 848                         goto done;
 849                 qh->start = frame;
 850
 851                 /* reset S-frame and (maybe) C-frame masks */
 852                 hw->hw_info2 &= cpu_to_hc32(ehci, ~(QH_CMASK | QH_SMASK));
 853                 hw->hw_info2 |= qh->period
 854                         ? cpu_to_hc32(ehci, 1 << uframe)
 855                         : cpu_to_hc32(ehci, QH_SMASK);
 856                 hw->hw_info2 |= c_mask;
 857         } else
 858                 ehci_dbg (ehci, "reused qh %p schedule\n", qh);
 859
 860         /* stuff into the periodic schedule */
 861         status = qh_link_periodic (ehci, qh);
 862 done:
 863         return status;
 864 }
 865
 866 static int intr_submit (
 867         struct ehci_hcd         *ehci,
 868         struct urb              *urb,
 869         struct list_head        *qtd_list,
 870         gfp_t                   mem_flags
 871 ) {
 872         unsigned                epnum;
 873         unsigned long           flags;
 874         struct ehci_qh          *qh;
 875         int                     status;
 876         struct list_head        empty;
 877
 878         /* get endpoint and transfer/schedule data */
 879         epnum = urb->ep->desc.bEndpointAddress;
 880
 881         spin_lock_irqsave (&ehci->lock, flags);
 882
 883         if (unlikely(!test_bit(HCD_FLAG_HW_ACCESSIBLE,
 884                         &ehci_to_hcd(ehci)->flags))) {
 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         /* ... update usbfs periodic stats */
 909         ehci_to_hcd(ehci)->self.bandwidth_int_reqs++;
 910
 911 done:
 912         if (unlikely(status))
 913                 usb_hcd_unlink_urb_from_ep(ehci_to_hcd(ehci), urb);
 914 done_not_linked:
 915         spin_unlock_irqrestore (&ehci->lock, flags);
 916         if (status)
 917                 qtd_list_free (ehci, urb, qtd_list);
 918
 919         return status;
 920 }
 921
 922 /*-------------------------------------------------------------------------*/
 923
 924 /* ehci_iso_stream ops work with both ITD and SITD */
 925
 926 static struct ehci_iso_stream *
 927 iso_stream_alloc (gfp_t mem_flags)
 928 {
 929         struct ehci_iso_stream *stream;
 930
 931         stream = kzalloc(sizeof *stream, mem_flags);
 932         if (likely (stream != NULL)) {
 933                 INIT_LIST_HEAD(&stream->td_list);
 934                 INIT_LIST_HEAD(&stream->free_list);
 935                 stream->next_uframe = -1;
 936                 stream->refcount = 1;
 937         }
 938         return stream;
 939 }
 940
 941 static void
 942 iso_stream_init (
 943         struct ehci_hcd         *ehci,
 944         struct ehci_iso_stream  *stream,
 945         struct usb_device       *dev,
 946         int                     pipe,
 947         unsigned                interval
 948 )
 949 {
 950         static const u8 smask_out [] = { 0x01, 0x03, 0x07, 0x0f, 0x1f, 0x3f };
 951
 952         u32                     buf1;
 953         unsigned                epnum, maxp;
 954         int                     is_input;
 955         long                    bandwidth;
 956
 957         /*
 958          * this might be a "high bandwidth" highspeed endpoint,
 959          * as encoded in the ep descriptor's wMaxPacket field
 960          */
 961         epnum = usb_pipeendpoint (pipe);
 962         is_input = usb_pipein (pipe) ? USB_DIR_IN : 0;
 963         maxp = usb_maxpacket(dev, pipe, !is_input);
 964         if (is_input) {
 965                 buf1 = (1 << 11);
 966         } else {
 967                 buf1 = 0;
 968         }
 969
 970         /* knows about ITD vs SITD */
 971         if (dev->speed == USB_SPEED_HIGH) {
 972                 unsigned multi = hb_mult(maxp);
 973
 974                 stream->highspeed = 1;
 975
 976                 maxp = max_packet(maxp);
 977                 buf1 |= maxp;
 978                 maxp *= multi;
 979
 980                 stream->buf0 = cpu_to_hc32(ehci, (epnum << 8) | dev->devnum);
 981                 stream->buf1 = cpu_to_hc32(ehci, buf1);
 982                 stream->buf2 = cpu_to_hc32(ehci, multi);
 983
 984                 /* usbfs wants to report the average usecs per frame tied up
 985                  * when transfers on this endpoint are scheduled ...
 986                  */
 987                 stream->usecs = HS_USECS_ISO (maxp);
 988                 bandwidth = stream->usecs * 8;
 989                 bandwidth /= interval;
 990
 991         } else {
 992                 u32             addr;
 993                 int             think_time;
 994                 int             hs_transfers;
 995
 996                 addr = dev->ttport << 24;
 997                 if (!ehci_is_TDI(ehci)
 998                                 || (dev->tt->hub !=
 999                                         ehci_to_hcd(ehci)->self.root_hub))
1000                         addr |= dev->tt->hub->devnum << 16;
1001                 addr |= epnum << 8;
1002                 addr |= dev->devnum;
1003                 stream->usecs = HS_USECS_ISO (maxp);
1004                 think_time = dev->tt ? dev->tt->think_time : 0;
1005                 stream->tt_usecs = NS_TO_US (think_time + usb_calc_bus_time (
1006                                 dev->speed, is_input, 1, maxp));
1007                 hs_transfers = max (1u, (maxp + 187) / 188);
1008                 if (is_input) {
1009                         u32     tmp;
1010
1011                         addr |= 1 << 31;
1012                         stream->c_usecs = stream->usecs;
1013                         stream->usecs = HS_USECS_ISO (1);
1014                         stream->raw_mask = 1;
1015
1016                         /* c-mask as specified in USB 2.0 11.18.4 3.c */
1017                         tmp = (1 << (hs_transfers + 2)) - 1;
1018                         stream->raw_mask |= tmp << (8 + 2);
1019                 } else
1020                         stream->raw_mask = smask_out [hs_transfers - 1];
1021                 bandwidth = stream->usecs + stream->c_usecs;
1022                 bandwidth /= interval << 3;
1023
1024                 /* stream->splits gets created from raw_mask later */
1025                 stream->address = cpu_to_hc32(ehci, addr);
1026         }
1027         stream->bandwidth = bandwidth;
1028
1029         stream->udev = dev;
1030
1031         stream->bEndpointAddress = is_input | epnum;
1032         stream->interval = interval;
1033         stream->maxp = maxp;
1034 }
1035
1036 static void
1037 iso_stream_put(struct ehci_hcd *ehci, struct ehci_iso_stream *stream)
1038 {
1039         stream->refcount--;
1040
1041         /* free whenever just a dev->ep reference remains.
1042          * not like a QH -- no persistent state (toggle, halt)
1043          */
1044         if (stream->refcount == 1) {
1045                 int             is_in;
1046
1047                 // BUG_ON (!list_empty(&stream->td_list));
1048
1049                 while (!list_empty (&stream->free_list)) {
1050                         struct list_head        *entry;
1051
1052                         entry = stream->free_list.next;
1053                         list_del (entry);
1054
1055                         /* knows about ITD vs SITD */
1056                         if (stream->highspeed) {
1057                                 struct ehci_itd         *itd;
1058
1059                                 itd = list_entry (entry, struct ehci_itd,
1060                                                 itd_list);
1061                                 dma_pool_free (ehci->itd_pool, itd,
1062                                                 itd->itd_dma);
1063                         } else {
1064                                 struct ehci_sitd        *sitd;
1065
1066                                 sitd = list_entry (entry, struct ehci_sitd,
1067                                                 sitd_list);
1068                                 dma_pool_free (ehci->sitd_pool, sitd,
1069                                                 sitd->sitd_dma);
1070                         }
1071                 }
1072
1073                 is_in = (stream->bEndpointAddress & USB_DIR_IN) ? 0x10 : 0;
1074                 stream->bEndpointAddress &= 0x0f;
1075                 if (stream->ep)
1076                         stream->ep->hcpriv = NULL;
1077
1078                 if (stream->rescheduled) {
1079                         ehci_info (ehci, "ep%d%s-iso rescheduled "
1080                                 "%lu times in %lu seconds\n",
1081                                 stream->bEndpointAddress, is_in ? "in" : "out",
1082                                 stream->rescheduled,
1083                                 ((jiffies - stream->start)/HZ)
1084                                 );
1085                 }
1086
1087                 kfree(stream);
1088         }
1089 }
1090
1091 static inline struct ehci_iso_stream *
1092 iso_stream_get (struct ehci_iso_stream *stream)
1093 {
1094         if (likely (stream != NULL))
1095                 stream->refcount++;
1096         return stream;
1097 }
1098
1099 static struct ehci_iso_stream *
1100 iso_stream_find (struct ehci_hcd *ehci, struct urb *urb)
1101 {
1102         unsigned                epnum;
1103         struct ehci_iso_stream  *stream;
1104         struct usb_host_endpoint *ep;
1105         unsigned long           flags;
1106
1107         epnum = usb_pipeendpoint (urb->pipe);
1108         if (usb_pipein(urb->pipe))
1109                 ep = urb->dev->ep_in[epnum];
1110         else
1111                 ep = urb->dev->ep_out[epnum];
1112
1113         spin_lock_irqsave (&ehci->lock, flags);
1114         stream = ep->hcpriv;
1115
1116         if (unlikely (stream == NULL)) {
1117                 stream = iso_stream_alloc(GFP_ATOMIC);
1118                 if (likely (stream != NULL)) {
1119                         /* dev->ep owns the initial refcount */
1120                         ep->hcpriv = stream;
1121                         stream->ep = ep;
1122                         iso_stream_init(ehci, stream, urb->dev, urb->pipe,
1123                                         urb->interval);
1124                 }
1125
1126         /* if dev->ep [epnum] is a QH, hw is set */
1127         } else if (unlikely (stream->hw != NULL)) {
1128                 ehci_dbg (ehci, "dev %s ep%d%s, not iso??\n",
1129                         urb->dev->devpath, epnum,
1130                         usb_pipein(urb->pipe) ? "in" : "out");
1131                 stream = NULL;
1132         }
1133
1134         /* caller guarantees an eventual matching iso_stream_put */
1135         stream = iso_stream_get (stream);
1136
1137         spin_unlock_irqrestore (&ehci->lock, flags);
1138         return stream;
1139 }
1140
1141 /*-------------------------------------------------------------------------*/
1142
1143 /* ehci_iso_sched ops can be ITD-only or SITD-only */
1144
1145 static struct ehci_iso_sched *
1146 iso_sched_alloc (unsigned packets, gfp_t mem_flags)
1147 {
1148         struct ehci_iso_sched   *iso_sched;
1149         int                     size = sizeof *iso_sched;
1150
1151         size += packets * sizeof (struct ehci_iso_packet);
1152         iso_sched = kzalloc(size, mem_flags);
1153         if (likely (iso_sched != NULL)) {
1154                 INIT_LIST_HEAD (&iso_sched->td_list);
1155         }
1156         return iso_sched;
1157 }
1158
1159 static inline void
1160 itd_sched_init(
1161         struct ehci_hcd         *ehci,
1162         struct ehci_iso_sched   *iso_sched,
1163         struct ehci_iso_stream  *stream,
1164         struct urb              *urb
1165 )
1166 {
1167         unsigned        i;
1168         dma_addr_t      dma = urb->transfer_dma;
1169
1170         /* how many uframes are needed for these transfers */
1171         iso_sched->span = urb->number_of_packets * stream->interval;
1172
1173         /* figure out per-uframe itd fields that we'll need later
1174          * when we fit new itds into the schedule.
1175          */
1176         for (i = 0; i < urb->number_of_packets; i++) {
1177                 struct ehci_iso_packet  *uframe = &iso_sched->packet [i];
1178                 unsigned                length;
1179                 dma_addr_t              buf;
1180                 u32                     trans;
1181
1182                 length = urb->iso_frame_desc [i].length;
1183                 buf = dma + urb->iso_frame_desc [i].offset;
1184
1185                 trans = EHCI_ISOC_ACTIVE;
1186                 trans |= buf & 0x0fff;
1187                 if (unlikely (((i + 1) == urb->number_of_packets))
1188                                 && !(urb->transfer_flags & URB_NO_INTERRUPT))
1189                         trans |= EHCI_ITD_IOC;
1190                 trans |= length << 16;
1191                 uframe->transaction = cpu_to_hc32(ehci, trans);
1192
1193                 /* might need to cross a buffer page within a uframe */
1194                 uframe->bufp = (buf & ~(u64)0x0fff);
1195                 buf += length;
1196                 if (unlikely ((uframe->bufp != (buf & ~(u64)0x0fff))))
1197                         uframe->cross = 1;
1198         }
1199 }
1200
1201 static void
1202 iso_sched_free (
1203         struct ehci_iso_stream  *stream,
1204         struct ehci_iso_sched   *iso_sched
1205 )
1206 {
1207         if (!iso_sched)
1208                 return;
1209         // caller must hold ehci->lock!
1210         list_splice (&iso_sched->td_list, &stream->free_list);
1211         kfree (iso_sched);
1212 }
1213
1214 static int
1215 itd_urb_transaction (
1216         struct ehci_iso_stream  *stream,
1217         struct ehci_hcd         *ehci,
1218         struct urb              *urb,
1219         gfp_t                   mem_flags
1220 )
1221 {
1222         struct ehci_itd         *itd;
1223         dma_addr_t              itd_dma;
1224         int                     i;
1225         unsigned                num_itds;
1226         struct ehci_iso_sched   *sched;
1227         unsigned long           flags;
1228
1229         sched = iso_sched_alloc (urb->number_of_packets, mem_flags);
1230         if (unlikely (sched == NULL))
1231                 return -ENOMEM;
1232
1233         itd_sched_init(ehci, sched, stream, urb);
1234
1235         if (urb->interval < 8)
1236                 num_itds = 1 + (sched->span + 7) / 8;
1237         else
1238                 num_itds = urb->number_of_packets;
1239
1240         /* allocate/init ITDs */
1241         spin_lock_irqsave (&ehci->lock, flags);
1242         for (i = 0; i < num_itds; i++) {
1243
1244                 /* free_list.next might be cache-hot ... but maybe
1245                  * the HC caches it too. avoid that issue for now.
1246                  */
1247
1248                 /* prefer previously-allocated itds */
1249                 if (likely (!list_empty(&stream->free_list))) {
1250                         itd = list_entry (stream->free_list.prev,
1251                                         struct ehci_itd, itd_list);
1252                         list_del (&itd->itd_list);
1253                         itd_dma = itd->itd_dma;
1254                 } else {
1255                         spin_unlock_irqrestore (&ehci->lock, flags);
1256                         itd = dma_pool_alloc (ehci->itd_pool, mem_flags,
1257                                         &itd_dma);
1258                         spin_lock_irqsave (&ehci->lock, flags);
1259                         if (!itd) {
1260                                 iso_sched_free(stream, sched);
1261                                 spin_unlock_irqrestore(&ehci->lock, flags);
1262                                 return -ENOMEM;
1263                         }
1264                 }
1265
1266                 memset (itd, 0, sizeof *itd);
1267                 itd->itd_dma = itd_dma;
1268                 list_add (&itd->itd_list, &sched->td_list);
1269         }
1270         spin_unlock_irqrestore (&ehci->lock, flags);
1271
1272         /* temporarily store schedule info in hcpriv */
1273         urb->hcpriv = sched;
1274         urb->error_count = 0;
1275         return 0;
1276 }
1277
1278 /*-------------------------------------------------------------------------*/
1279
1280 static inline int
1281 itd_slot_ok (
1282         struct ehci_hcd         *ehci,
1283         u32                     mod,
1284         u32                     uframe,
1285         u8                      usecs,
1286         u32                     period
1287 )
1288 {
1289         uframe %= period;
1290         do {
1291                 /* can't commit more than 80% periodic == 100 usec */
1292                 if (periodic_usecs (ehci, uframe >> 3, uframe & 0x7)
1293                                 > (100 - usecs))
1294                         return 0;
1295
1296                 /* we know urb->interval is 2^N uframes */
1297                 uframe += period;
1298         } while (uframe < mod);
1299         return 1;
1300 }
1301
1302 static inline int
1303 sitd_slot_ok (
1304         struct ehci_hcd         *ehci,
1305         u32                     mod,
1306         struct ehci_iso_stream  *stream,
1307         u32                     uframe,
1308         struct ehci_iso_sched   *sched,
1309         u32                     period_uframes
1310 )
1311 {
1312         u32                     mask, tmp;
1313         u32                     frame, uf;
1314
1315         mask = stream->raw_mask << (uframe & 7);
1316
1317         /* for IN, don't wrap CSPLIT into the next frame */
1318         if (mask & ~0xffff)
1319                 return 0;
1320
1321         /* this multi-pass logic is simple, but performance may
1322          * suffer when the schedule data isn't cached.
1323          */
1324
1325         /* check bandwidth */
1326         uframe %= period_uframes;
1327         do {
1328                 u32             max_used;
1329
1330                 frame = uframe >> 3;
1331                 uf = uframe & 7;
1332
1333 #ifdef CONFIG_USB_EHCI_TT_NEWSCHED
1334                 /* The tt's fullspeed bus bandwidth must be available.
1335                  * tt_available scheduling guarantees 10+% for control/bulk.
1336                  */
1337                 if (!tt_available (ehci, period_uframes << 3,
1338                                 stream->udev, frame, uf, stream->tt_usecs))
1339                         return 0;
1340 #else
1341                 /* tt must be idle for start(s), any gap, and csplit.
1342                  * assume scheduling slop leaves 10+% for control/bulk.
1343                  */
1344                 if (!tt_no_collision (ehci, period_uframes << 3,
1345                                 stream->udev, frame, mask))
1346                         return 0;
1347 #endif
1348
1349                 /* check starts (OUT uses more than one) */
1350                 max_used = 100 - stream->usecs;
1351                 for (tmp = stream->raw_mask & 0xff; tmp; tmp >>= 1, uf++) {
1352                         if (periodic_usecs (ehci, frame, uf) > max_used)
1353                                 return 0;
1354                 }
1355
1356                 /* for IN, check CSPLIT */
1357                 if (stream->c_usecs) {
1358                         uf = uframe & 7;
1359                         max_used = 100 - stream->c_usecs;
1360                         do {
1361                                 tmp = 1 << uf;
1362                                 tmp <<= 8;
1363                                 if ((stream->raw_mask & tmp) == 0)
1364                                         continue;
1365                                 if (periodic_usecs (ehci, frame, uf)
1366                                                 > max_used)
1367                                         return 0;
1368                         } while (++uf < 8);
1369                 }
1370
1371                 /* we know urb->interval is 2^N uframes */
1372                 uframe += period_uframes;
1373         } while (uframe < mod);
1374
1375         stream->splits = cpu_to_hc32(ehci, stream->raw_mask << (uframe & 7));
1376         return 1;
1377 }
1378
1379 /*
1380  * This scheduler plans almost as far into the future as it has actual
1381  * periodic schedule slots.  (Affected by TUNE_FLS, which defaults to
1382  * "as small as possible" to be cache-friendlier.)  That limits the size
1383  * transfers you can stream reliably; avoid more than 64 msec per urb.
1384  * Also avoid queue depths of less than ehci's worst irq latency (affected
1385  * by the per-urb URB_NO_INTERRUPT hint, the log2_irq_thresh module parameter,
1386  * and other factors); or more than about 230 msec total (for portability,
1387  * given EHCI_TUNE_FLS and the slop).  Or, write a smarter scheduler!
1388  */
1389
1390 #define SCHEDULE_SLOP   80      /* microframes */
1391
1392 static int
1393 iso_stream_schedule (
1394         struct ehci_hcd         *ehci,
1395         struct urb              *urb,
1396         struct ehci_iso_stream  *stream
1397 )
1398 {
1399         u32                     now, next, start, period;
1400         int                     status;
1401         unsigned                mod = ehci->periodic_size << 3;
1402         struct ehci_iso_sched   *sched = urb->hcpriv;
1403         struct pci_dev          *pdev;
1404
1405         if (sched->span > (mod - SCHEDULE_SLOP)) {
1406                 ehci_dbg (ehci, "iso request %p too long\n", urb);
1407                 status = -EFBIG;
1408                 goto fail;
1409         }
1410
1411         if ((stream->depth + sched->span) > mod) {
1412                 ehci_dbg (ehci, "request %p would overflow (%d+%d>%d)\n",
1413                         urb, stream->depth, sched->span, mod);
1414                 status = -EFBIG;
1415                 goto fail;
1416         }
1417
1418         period = urb->interval;
1419         if (!stream->highspeed)
1420                 period <<= 3;
1421
1422         now = ehci_readl(ehci, &ehci->regs->frame_index) % mod;
1423
1424         /* Typical case: reuse current schedule, stream is still active.
1425          * Hopefully there are no gaps from the host falling behind
1426          * (irq delays etc), but if there are we'll take the next
1427          * slot in the schedule, implicitly assuming URB_ISO_ASAP.
1428          */
1429         if (likely (!list_empty (&stream->td_list))) {
1430                 pdev = to_pci_dev(ehci_to_hcd(ehci)->self.controller);
1431                 start = stream->next_uframe;
1432
1433                 /* For high speed devices, allow scheduling within the
1434                  * isochronous scheduling threshold.  For full speed devices,
1435                  * don't. (Work around for Intel ICH9 bug.)
1436                  */
1437                 if (!stream->highspeed &&
1438                                 pdev->vendor == PCI_VENDOR_ID_INTEL)
1439                         next = now + ehci->i_thresh;
1440                 else
1441                         next = now;
1442
1443                 /* Fell behind (by up to twice the slop amount)? */
1444                 if (((start - next) & (mod - 1)) >=
1445                                 mod - 2 * SCHEDULE_SLOP)
1446                         start += period * DIV_ROUND_UP(
1447                                         (next - start) & (mod - 1),
1448                                         period);
1449
1450                 /* Tried to schedule too far into the future? */
1451                 if (unlikely(((start - now) & (mod - 1)) + sched->span
1452                                         >= mod - 2 * SCHEDULE_SLOP)) {
1453                         status = -EFBIG;
1454                         goto fail;
1455                 }
1456                 stream->next_uframe = start;
1457                 goto ready;
1458         }
1459
1460         /* need to schedule; when's the next (u)frame we could start?
1461          * this is bigger than ehci->i_thresh allows; scheduling itself
1462          * isn't free, the slop should handle reasonably slow cpus.  it
1463          * can also help high bandwidth if the dma and irq loads don't
1464          * jump until after the queue is primed.
1465          */
1466         start = SCHEDULE_SLOP + (now & ~0x07);
1467         start %= mod;
1468         stream->next_uframe = start;
1469
1470         /* NOTE:  assumes URB_ISO_ASAP, to limit complexity/bugs */
1471
1472         /* find a uframe slot with enough bandwidth */
1473         for (; start < (stream->next_uframe + period); start++) {
1474                 int             enough_space;
1475
1476                 /* check schedule: enough space? */
1477                 if (stream->highspeed)
1478                         enough_space = itd_slot_ok (ehci, mod, start,
1479                                         stream->usecs, period);
1480                 else {
1481                         if ((start % 8) >= 6)
1482                                 continue;
1483                         enough_space = sitd_slot_ok (ehci, mod, stream,
1484                                         start, sched, period);
1485                 }
1486
1487                 /* schedule it here if there's enough bandwidth */
1488                 if (enough_space) {
1489                         stream->next_uframe = start % mod;
1490                         goto ready;
1491                 }
1492         }
1493
1494         /* no room in the schedule */
1495         ehci_dbg (ehci, "iso %ssched full %p (now %d max %d)\n",
1496                 list_empty (&stream->td_list) ? "" : "re",
1497                 urb, now, now + mod);
1498         status = -ENOSPC;
1499
1500 fail:
1501         iso_sched_free (stream, sched);
1502         urb->hcpriv = NULL;
1503         return status;
1504
1505 ready:
1506         /* report high speed start in uframes; full speed, in frames */
1507         urb->start_frame = stream->next_uframe;
1508         if (!stream->highspeed)
1509                 urb->start_frame >>= 3;
1510         return 0;
1511 }
1512
1513 /*-------------------------------------------------------------------------*/
1514
1515 static inline void
1516 itd_init(struct ehci_hcd *ehci, struct ehci_iso_stream *stream,
1517                 struct ehci_itd *itd)
1518 {
1519         int i;
1520
1521         /* it's been recently zeroed */
1522         itd->hw_next = EHCI_LIST_END(ehci);
1523         itd->hw_bufp [0] = stream->buf0;
1524         itd->hw_bufp [1] = stream->buf1;
1525         itd->hw_bufp [2] = stream->buf2;
1526
1527         for (i = 0; i < 8; i++)
1528                 itd->index[i] = -1;
1529
1530         /* All other fields are filled when scheduling */
1531 }
1532
1533 static inline void
1534 itd_patch(
1535         struct ehci_hcd         *ehci,
1536         struct ehci_itd         *itd,
1537         struct ehci_iso_sched   *iso_sched,
1538         unsigned                index,
1539         u16                     uframe
1540 )
1541 {
1542         struct ehci_iso_packet  *uf = &iso_sched->packet [index];
1543         unsigned                pg = itd->pg;
1544
1545         // BUG_ON (pg == 6 && uf->cross);
1546
1547         uframe &= 0x07;
1548         itd->index [uframe] = index;
1549
1550         itd->hw_transaction[uframe] = uf->transaction;
1551         itd->hw_transaction[uframe] |= cpu_to_hc32(ehci, pg << 12);
1552         itd->hw_bufp[pg] |= cpu_to_hc32(ehci, uf->bufp & ~(u32)0);
1553         itd->hw_bufp_hi[pg] |= cpu_to_hc32(ehci, (u32)(uf->bufp >> 32));
1554
1555         /* iso_frame_desc[].offset must be strictly increasing */
1556         if (unlikely (uf->cross)) {
1557                 u64     bufp = uf->bufp + 4096;
1558
1559                 itd->pg = ++pg;
1560                 itd->hw_bufp[pg] |= cpu_to_hc32(ehci, bufp & ~(u32)0);
1561                 itd->hw_bufp_hi[pg] |= cpu_to_hc32(ehci, (u32)(bufp >> 32));
1562         }
1563 }
1564
1565 static inline void
1566 itd_link (struct ehci_hcd *ehci, unsigned frame, struct ehci_itd *itd)
1567 {
1568         union ehci_shadow       *prev = &ehci->pshadow[frame];
1569         __hc32                  *hw_p = &ehci->periodic[frame];
1570         union ehci_shadow       here = *prev;
1571         __hc32                  type = 0;
1572
1573         /* skip any iso nodes which might belong to previous microframes */
1574         while (here.ptr) {
1575                 type = Q_NEXT_TYPE(ehci, *hw_p);
1576                 if (type == cpu_to_hc32(ehci, Q_TYPE_QH))
1577                         break;
1578                 prev = periodic_next_shadow(ehci, prev, type);
1579                 hw_p = shadow_next_periodic(ehci, &here, type);
1580                 here = *prev;
1581         }
1582
1583         itd->itd_next = here;
1584         itd->hw_next = *hw_p;
1585         prev->itd = itd;
1586         itd->frame = frame;
1587         wmb ();
1588         *hw_p = cpu_to_hc32(ehci, itd->itd_dma | Q_TYPE_ITD);
1589 }
1590
1591 /* fit urb's itds into the selected schedule slot; activate as needed */
1592 static int
1593 itd_link_urb (
1594         struct ehci_hcd         *ehci,
1595         struct urb              *urb,
1596         unsigned                mod,
1597         struct ehci_iso_stream  *stream
1598 )
1599 {
1600         int                     packet;
1601         unsigned                next_uframe, uframe, frame;
1602         struct ehci_iso_sched   *iso_sched = urb->hcpriv;
1603         struct ehci_itd         *itd;
1604
1605         next_uframe = stream->next_uframe % mod;
1606
1607         if (unlikely (list_empty(&stream->td_list))) {
1608                 ehci_to_hcd(ehci)->self.bandwidth_allocated
1609                                 += stream->bandwidth;
1610                 ehci_vdbg (ehci,
1611                         "schedule devp %s ep%d%s-iso period %d start %d.%d\n",
1612                         urb->dev->devpath, stream->bEndpointAddress & 0x0f,
1613                         (stream->bEndpointAddress & USB_DIR_IN) ? "in" : "out",
1614                         urb->interval,
1615                         next_uframe >> 3, next_uframe & 0x7);
1616                 stream->start = jiffies;
1617         }
1618         ehci_to_hcd(ehci)->self.bandwidth_isoc_reqs++;
1619
1620         /* fill iTDs uframe by uframe */
1621         for (packet = 0, itd = NULL; packet < urb->number_of_packets; ) {
1622                 if (itd == NULL) {
1623                         /* ASSERT:  we have all necessary itds */
1624                         // BUG_ON (list_empty (&iso_sched->td_list));
1625
1626                         /* ASSERT:  no itds for this endpoint in this uframe */
1627
1628                         itd = list_entry (iso_sched->td_list.next,
1629                                         struct ehci_itd, itd_list);
1630                         list_move_tail (&itd->itd_list, &stream->td_list);
1631                         itd->stream = iso_stream_get (stream);
1632                         itd->urb = urb;
1633                         itd_init (ehci, stream, itd);
1634                 }
1635
1636                 uframe = next_uframe & 0x07;
1637                 frame = next_uframe >> 3;
1638
1639                 itd_patch(ehci, itd, iso_sched, packet, uframe);
1640
1641                 next_uframe += stream->interval;
1642                 stream->depth += stream->interval;
1643                 next_uframe %= mod;
1644                 packet++;
1645
1646                 /* link completed itds into the schedule */
1647                 if (((next_uframe >> 3) != frame)
1648                                 || packet == urb->number_of_packets) {
1649                         itd_link (ehci, frame % ehci->periodic_size, itd);
1650                         itd = NULL;
1651                 }
1652         }
1653         stream->next_uframe = next_uframe;
1654
1655         /* don't need that schedule data any more */
1656         iso_sched_free (stream, iso_sched);
1657         urb->hcpriv = NULL;
1658
1659         timer_action (ehci, TIMER_IO_WATCHDOG);
1660         return enable_periodic(ehci);
1661 }
1662
1663 #define ISO_ERRS (EHCI_ISOC_BUF_ERR | EHCI_ISOC_BABBLE | EHCI_ISOC_XACTERR)
1664
1665 /* Process and recycle a completed ITD.  Return true iff its urb completed,
1666  * and hence its completion callback probably added things to the hardware
1667  * schedule.
1668  *
1669  * Note that we carefully avoid recycling this descriptor until after any
1670  * completion callback runs, so that it won't be reused quickly.  That is,
1671  * assuming (a) no more than two urbs per frame on this endpoint, and also
1672  * (b) only this endpoint's completions submit URBs.  It seems some silicon
1673  * corrupts things if you reuse completed descriptors very quickly...
1674  */
1675 static unsigned
1676 itd_complete (
1677         struct ehci_hcd *ehci,
1678         struct ehci_itd *itd
1679 ) {
1680         struct urb                              *urb = itd->urb;
1681         struct usb_iso_packet_descriptor        *desc;
1682         u32                                     t;
1683         unsigned                                uframe;
1684         int                                     urb_index = -1;
1685         struct ehci_iso_stream                  *stream = itd->stream;
1686         struct usb_device                       *dev;
1687         unsigned                                retval = false;
1688
1689         /* for each uframe with a packet */
1690         for (uframe = 0; uframe < 8; uframe++) {
1691                 if (likely (itd->index[uframe] == -1))
1692                         continue;
1693                 urb_index = itd->index[uframe];
1694                 desc = &urb->iso_frame_desc [urb_index];
1695
1696                 t = hc32_to_cpup(ehci, &itd->hw_transaction [uframe]);
1697                 itd->hw_transaction [uframe] = 0;
1698                 stream->depth -= stream->interval;
1699
1700                 /* report transfer status */
1701                 if (unlikely (t & ISO_ERRS)) {
1702                         urb->error_count++;
1703                         if (t & EHCI_ISOC_BUF_ERR)
1704                                 desc->status = usb_pipein (urb->pipe)
1705                                         ? -ENOSR  /* hc couldn't read */
1706                                         : -ECOMM; /* hc couldn't write */
1707                         else if (t & EHCI_ISOC_BABBLE)
1708                                 desc->status = -EOVERFLOW;
1709                         else /* (t & EHCI_ISOC_XACTERR) */
1710                                 desc->status = -EPROTO;
1711
1712                         /* HC need not update length with this error */
1713                         if (!(t & EHCI_ISOC_BABBLE)) {
1714                                 desc->actual_length = EHCI_ITD_LENGTH(t);
1715                                 urb->actual_length += desc->actual_length;
1716                         }
1717                 } else if (likely ((t & EHCI_ISOC_ACTIVE) == 0)) {
1718                         desc->status = 0;
1719                         desc->actual_length = EHCI_ITD_LENGTH(t);
1720                         urb->actual_length += desc->actual_length;
1721                 } else {
1722                         /* URB was too late */
1723                         desc->status = -EXDEV;
1724                 }
1725         }
1726
1727         /* handle completion now? */
1728         if (likely ((urb_index + 1) != urb->number_of_packets))
1729                 goto done;
1730
1731         /* ASSERT: it's really the last itd for this urb
1732         list_for_each_entry (itd, &stream->td_list, itd_list)
1733                 BUG_ON (itd->urb == urb);
1734          */
1735
1736         /* give urb back to the driver; completion often (re)submits */
1737         dev = urb->dev;
1738         ehci_urb_done(ehci, urb, 0);
1739         retval = true;
1740         urb = NULL;
1741         (void) disable_periodic(ehci);
1742         ehci_to_hcd(ehci)->self.bandwidth_isoc_reqs--;
1743
1744         if (unlikely(list_is_singular(&stream->td_list))) {
1745                 ehci_to_hcd(ehci)->self.bandwidth_allocated
1746                                 -= stream->bandwidth;
1747                 ehci_vdbg (ehci,
1748                         "deschedule devp %s ep%d%s-iso\n",
1749                         dev->devpath, stream->bEndpointAddress & 0x0f,
1750                         (stream->bEndpointAddress & USB_DIR_IN) ? "in" : "out");
1751         }
1752         iso_stream_put (ehci, stream);
1753
1754 done:
1755         itd->urb = NULL;
1756         if (ehci->clock_frame != itd->frame || itd->index[7] != -1) {
1757                 /* OK to recycle this ITD now. */
1758                 itd->stream = NULL;
1759                 list_move(&itd->itd_list, &stream->free_list);
1760                 iso_stream_put(ehci, stream);
1761         } else {
1762                 /* HW might remember this ITD, so we can't recycle it yet.
1763                  * Move it to a safe place until a new frame starts.
1764                  */
1765                 list_move(&itd->itd_list, &ehci->cached_itd_list);
1766                 if (stream->refcount == 2) {
1767                         /* If iso_stream_put() were called here, stream
1768                          * would be freed.  Instead, just prevent reuse.
1769                          */
1770                         stream->ep->hcpriv = NULL;
1771                         stream->ep = NULL;
1772                 }
1773         }
1774         return retval;
1775 }
1776
1777 /*-------------------------------------------------------------------------*/
1778
1779 static int itd_submit (struct ehci_hcd *ehci, struct urb *urb,
1780         gfp_t mem_flags)
1781 {
1782         int                     status = -EINVAL;
1783         unsigned long           flags;
1784         struct ehci_iso_stream  *stream;
1785
1786         /* Get iso_stream head */
1787         stream = iso_stream_find (ehci, urb);
1788         if (unlikely (stream == NULL)) {
1789                 ehci_dbg (ehci, "can't get iso stream\n");
1790                 return -ENOMEM;
1791         }
1792         if (unlikely (urb->interval != stream->interval)) {
1793                 ehci_dbg (ehci, "can't change iso interval %d --> %d\n",
1794                         stream->interval, urb->interval);
1795                 goto done;
1796         }
1797
1798 #ifdef EHCI_URB_TRACE
1799         ehci_dbg (ehci,
1800                 "%s %s urb %p ep%d%s len %d, %d pkts %d uframes [%p]\n",
1801                 __func__, urb->dev->devpath, urb,
1802                 usb_pipeendpoint (urb->pipe),
1803                 usb_pipein (urb->pipe) ? "in" : "out",
1804                 urb->transfer_buffer_length,
1805                 urb->number_of_packets, urb->interval,
1806                 stream);
1807 #endif
1808
1809         /* allocate ITDs w/o locking anything */
1810         status = itd_urb_transaction (stream, ehci, urb, mem_flags);
1811         if (unlikely (status < 0)) {
1812                 ehci_dbg (ehci, "can't init itds\n");
1813                 goto done;
1814         }
1815
1816         /* schedule ... need to lock */
1817         spin_lock_irqsave (&ehci->lock, flags);
1818         if (unlikely(!test_bit(HCD_FLAG_HW_ACCESSIBLE,
1819                                &ehci_to_hcd(ehci)->flags))) {
1820                 status = -ESHUTDOWN;
1821                 goto done_not_linked;
1822         }
1823         status = usb_hcd_link_urb_to_ep(ehci_to_hcd(ehci), urb);
1824         if (unlikely(status))
1825                 goto done_not_linked;
1826         status = iso_stream_schedule(ehci, urb, stream);
1827         if (likely (status == 0))
1828                 itd_link_urb (ehci, urb, ehci->periodic_size << 3, stream);
1829         else
1830                 usb_hcd_unlink_urb_from_ep(ehci_to_hcd(ehci), urb);
1831 done_not_linked:
1832         spin_unlock_irqrestore (&ehci->lock, flags);
1833
1834 done:
1835         if (unlikely (status < 0))
1836                 iso_stream_put (ehci, stream);
1837         return status;
1838 }
1839
1840 /*-------------------------------------------------------------------------*/
1841
1842 /*
1843  * "Split ISO TDs" ... used for USB 1.1 devices going through the
1844  * TTs in USB 2.0 hubs.  These need microframe scheduling.
1845  */
1846
1847 static inline void
1848 sitd_sched_init(
1849         struct ehci_hcd         *ehci,
1850         struct ehci_iso_sched   *iso_sched,
1851         struct ehci_iso_stream  *stream,
1852         struct urb              *urb
1853 )
1854 {
1855         unsigned        i;
1856         dma_addr_t      dma = urb->transfer_dma;
1857
1858         /* how many frames are needed for these transfers */
1859         iso_sched->span = urb->number_of_packets * stream->interval;
1860
1861         /* figure out per-frame sitd fields that we'll need later
1862          * when we fit new sitds into the schedule.
1863          */
1864         for (i = 0; i < urb->number_of_packets; i++) {
1865                 struct ehci_iso_packet  *packet = &iso_sched->packet [i];
1866                 unsigned                length;
1867                 dma_addr_t              buf;
1868                 u32                     trans;
1869
1870                 length = urb->iso_frame_desc [i].length & 0x03ff;
1871                 buf = dma + urb->iso_frame_desc [i].offset;
1872
1873                 trans = SITD_STS_ACTIVE;
1874                 if (((i + 1) == urb->number_of_packets)
1875                                 && !(urb->transfer_flags & URB_NO_INTERRUPT))
1876                         trans |= SITD_IOC;
1877                 trans |= length << 16;
1878                 packet->transaction = cpu_to_hc32(ehci, trans);
1879
1880                 /* might need to cross a buffer page within a td */
1881                 packet->bufp = buf;
1882                 packet->buf1 = (buf + length) & ~0x0fff;
1883                 if (packet->buf1 != (buf & ~(u64)0x0fff))
1884                         packet->cross = 1;
1885
1886                 /* OUT uses multiple start-splits */
1887                 if (stream->bEndpointAddress & USB_DIR_IN)
1888                         continue;
1889                 length = (length + 187) / 188;
1890                 if (length > 1) /* BEGIN vs ALL */
1891                         length |= 1 << 3;
1892                 packet->buf1 |= length;
1893         }
1894 }
1895
1896 static int
1897 sitd_urb_transaction (
1898         struct ehci_iso_stream  *stream,
1899         struct ehci_hcd         *ehci,
1900         struct urb              *urb,
1901         gfp_t                   mem_flags
1902 )
1903 {
1904         struct ehci_sitd        *sitd;
1905         dma_addr_t              sitd_dma;
1906         int                     i;
1907         struct ehci_iso_sched   *iso_sched;
1908         unsigned long           flags;
1909
1910         iso_sched = iso_sched_alloc (urb->number_of_packets, mem_flags);
1911         if (iso_sched == NULL)
1912                 return -ENOMEM;
1913
1914         sitd_sched_init(ehci, iso_sched, stream, urb);
1915
1916         /* allocate/init sITDs */
1917         spin_lock_irqsave (&ehci->lock, flags);
1918         for (i = 0; i < urb->number_of_packets; i++) {
1919
1920                 /* NOTE:  for now, we don't try to handle wraparound cases
1921                  * for IN (using sitd->hw_backpointer, like a FSTN), which
1922                  * means we never need two sitds for full speed packets.
1923                  */
1924
1925                 /* free_list.next might be cache-hot ... but maybe
1926                  * the HC caches it too. avoid that issue for now.
1927                  */
1928
1929                 /* prefer previously-allocated sitds */
1930                 if (!list_empty(&stream->free_list)) {
1931                         sitd = list_entry (stream->free_list.prev,
1932                                          struct ehci_sitd, sitd_list);
1933                         list_del (&sitd->sitd_list);
1934                         sitd_dma = sitd->sitd_dma;
1935                 } else {
1936                         spin_unlock_irqrestore (&ehci->lock, flags);
1937                         sitd = dma_pool_alloc (ehci->sitd_pool, mem_flags,
1938                                         &sitd_dma);
1939                         spin_lock_irqsave (&ehci->lock, flags);
1940                         if (!sitd) {
1941                                 iso_sched_free(stream, iso_sched);
1942                                 spin_unlock_irqrestore(&ehci->lock, flags);
1943                                 return -ENOMEM;
1944                         }
1945                 }
1946
1947                 memset (sitd, 0, sizeof *sitd);
1948                 sitd->sitd_dma = sitd_dma;
1949                 list_add (&sitd->sitd_list, &iso_sched->td_list);
1950         }
1951
1952         /* temporarily store schedule info in hcpriv */
1953         urb->hcpriv = iso_sched;
1954         urb->error_count = 0;
1955
1956         spin_unlock_irqrestore (&ehci->lock, flags);
1957         return 0;
1958 }
1959
1960 /*-------------------------------------------------------------------------*/
1961
1962 static inline void
1963 sitd_patch(
1964         struct ehci_hcd         *ehci,
1965         struct ehci_iso_stream  *stream,
1966         struct ehci_sitd        *sitd,
1967         struct ehci_iso_sched   *iso_sched,
1968         unsigned                index
1969 )
1970 {
1971         struct ehci_iso_packet  *uf = &iso_sched->packet [index];
1972         u64                     bufp = uf->bufp;
1973
1974         sitd->hw_next = EHCI_LIST_END(ehci);
1975         sitd->hw_fullspeed_ep = stream->address;
1976         sitd->hw_uframe = stream->splits;
1977         sitd->hw_results = uf->transaction;
1978         sitd->hw_backpointer = EHCI_LIST_END(ehci);
1979
1980         bufp = uf->bufp;
1981         sitd->hw_buf[0] = cpu_to_hc32(ehci, bufp);
1982         sitd->hw_buf_hi[0] = cpu_to_hc32(ehci, bufp >> 32);
1983
1984         sitd->hw_buf[1] = cpu_to_hc32(ehci, uf->buf1);
1985         if (uf->cross)
1986                 bufp += 4096;
1987         sitd->hw_buf_hi[1] = cpu_to_hc32(ehci, bufp >> 32);
1988         sitd->index = index;
1989 }
1990
1991 static inline void
1992 sitd_link (struct ehci_hcd *ehci, unsigned frame, struct ehci_sitd *sitd)
1993 {
1994         /* note: sitd ordering could matter (CSPLIT then SSPLIT) */
1995         sitd->sitd_next = ehci->pshadow [frame];
1996         sitd->hw_next = ehci->periodic [frame];
1997         ehci->pshadow [frame].sitd = sitd;
1998         sitd->frame = frame;
1999         wmb ();
2000         ehci->periodic[frame] = cpu_to_hc32(ehci, sitd->sitd_dma | Q_TYPE_SITD);
2001 }
2002
2003 /* fit urb's sitds into the selected schedule slot; activate as needed */
2004 static int
2005 sitd_link_urb (
2006         struct ehci_hcd         *ehci,
2007         struct urb              *urb,
2008         unsigned                mod,
2009         struct ehci_iso_stream  *stream
2010 )
2011 {
2012         int                     packet;
2013         unsigned                next_uframe;
2014         struct ehci_iso_sched   *sched = urb->hcpriv;
2015         struct ehci_sitd        *sitd;
2016
2017         next_uframe = stream->next_uframe;
2018
2019         if (list_empty(&stream->td_list)) {
2020                 /* usbfs ignores TT bandwidth */
2021                 ehci_to_hcd(ehci)->self.bandwidth_allocated
2022                                 += stream->bandwidth;
2023                 ehci_vdbg (ehci,
2024                         "sched devp %s ep%d%s-iso [%d] %dms/%04x\n",
2025                         urb->dev->devpath, stream->bEndpointAddress & 0x0f,
2026                         (stream->bEndpointAddress & USB_DIR_IN) ? "in" : "out",
2027                         (next_uframe >> 3) % ehci->periodic_size,
2028                         stream->interval, hc32_to_cpu(ehci, stream->splits));
2029                 stream->start = jiffies;
2030         }
2031         ehci_to_hcd(ehci)->self.bandwidth_isoc_reqs++;
2032
2033         /* fill sITDs frame by frame */
2034         for (packet = 0, sitd = NULL;
2035                         packet < urb->number_of_packets;
2036                         packet++) {
2037
2038                 /* ASSERT:  we have all necessary sitds */
2039                 BUG_ON (list_empty (&sched->td_list));
2040
2041                 /* ASSERT:  no itds for this endpoint in this frame */
2042
2043                 sitd = list_entry (sched->td_list.next,
2044                                 struct ehci_sitd, sitd_list);
2045                 list_move_tail (&sitd->sitd_list, &stream->td_list);
2046                 sitd->stream = iso_stream_get (stream);
2047                 sitd->urb = urb;
2048
2049                 sitd_patch(ehci, stream, sitd, sched, packet);
2050                 sitd_link (ehci, (next_uframe >> 3) % ehci->periodic_size,
2051                                 sitd);
2052
2053                 next_uframe += stream->interval << 3;
2054                 stream->depth += stream->interval << 3;
2055         }
2056         stream->next_uframe = next_uframe % mod;
2057
2058         /* don't need that schedule data any more */
2059         iso_sched_free (stream, sched);
2060         urb->hcpriv = NULL;
2061
2062         timer_action (ehci, TIMER_IO_WATCHDOG);
2063         return enable_periodic(ehci);
2064 }
2065
2066 /*-------------------------------------------------------------------------*/
2067
2068 #define SITD_ERRS (SITD_STS_ERR | SITD_STS_DBE | SITD_STS_BABBLE \
2069                                 | SITD_STS_XACT | SITD_STS_MMF)
2070
2071 /* Process and recycle a completed SITD.  Return true iff its urb completed,
2072  * and hence its completion callback probably added things to the hardware
2073  * schedule.
2074  *
2075  * Note that we carefully avoid recycling this descriptor until after any
2076  * completion callback runs, so that it won't be reused quickly.  That is,
2077  * assuming (a) no more than two urbs per frame on this endpoint, and also
2078  * (b) only this endpoint's completions submit URBs.  It seems some silicon
2079  * corrupts things if you reuse completed descriptors very quickly...
2080  */
2081 static unsigned
2082 sitd_complete (
2083         struct ehci_hcd         *ehci,
2084         struct ehci_sitd        *sitd
2085 ) {
2086         struct urb                              *urb = sitd->urb;
2087         struct usb_iso_packet_descriptor        *desc;
2088         u32                                     t;
2089         int                                     urb_index = -1;
2090         struct ehci_iso_stream                  *stream = sitd->stream;
2091         struct usb_device                       *dev;
2092         unsigned                                retval = false;
2093
2094         urb_index = sitd->index;
2095         desc = &urb->iso_frame_desc [urb_index];
2096         t = hc32_to_cpup(ehci, &sitd->hw_results);
2097
2098         /* report transfer status */
2099         if (t & SITD_ERRS) {
2100                 urb->error_count++;
2101                 if (t & SITD_STS_DBE)
2102                         desc->status = usb_pipein (urb->pipe)
2103                                 ? -ENOSR  /* hc couldn't read */
2104                                 : -ECOMM; /* hc couldn't write */
2105                 else if (t & SITD_STS_BABBLE)
2106                         desc->status = -EOVERFLOW;
2107                 else /* XACT, MMF, etc */
2108                         desc->status = -EPROTO;
2109         } else {
2110                 desc->status = 0;
2111                 desc->actual_length = desc->length - SITD_LENGTH(t);
2112                 urb->actual_length += desc->actual_length;
2113         }
2114         stream->depth -= stream->interval << 3;
2115
2116         /* handle completion now? */
2117         if ((urb_index + 1) != urb->number_of_packets)
2118                 goto done;
2119
2120         /* ASSERT: it's really the last sitd for this urb
2121         list_for_each_entry (sitd, &stream->td_list, sitd_list)
2122                 BUG_ON (sitd->urb == urb);
2123          */
2124
2125         /* give urb back to the driver; completion often (re)submits */
2126         dev = urb->dev;
2127         ehci_urb_done(ehci, urb, 0);
2128         retval = true;
2129         urb = NULL;
2130         (void) disable_periodic(ehci);
2131         ehci_to_hcd(ehci)->self.bandwidth_isoc_reqs--;
2132
2133         if (list_is_singular(&stream->td_list)) {
2134                 ehci_to_hcd(ehci)->self.bandwidth_allocated
2135                                 -= stream->bandwidth;
2136                 ehci_vdbg (ehci,
2137                         "deschedule devp %s ep%d%s-iso\n",
2138                         dev->devpath, stream->bEndpointAddress & 0x0f,
2139                         (stream->bEndpointAddress & USB_DIR_IN) ? "in" : "out");
2140         }
2141         iso_stream_put (ehci, stream);
2142
2143 done:
2144         sitd->urb = NULL;
2145         if (ehci->clock_frame != sitd->frame) {
2146                 /* OK to recycle this SITD now. */
2147                 sitd->stream = NULL;
2148                 list_move(&sitd->sitd_list, &stream->free_list);
2149                 iso_stream_put(ehci, stream);
2150         } else {
2151                 /* HW might remember this SITD, so we can't recycle it yet.
2152                  * Move it to a safe place until a new frame starts.
2153                  */
2154                 list_move(&sitd->sitd_list, &ehci->cached_sitd_list);
2155                 if (stream->refcount == 2) {
2156                         /* If iso_stream_put() were called here, stream
2157                          * would be freed.  Instead, just prevent reuse.
2158                          */
2159                         stream->ep->hcpriv = NULL;
2160                         stream->ep = NULL;
2161                 }
2162         }
2163         return retval;
2164 }
2165
2166
2167 static int sitd_submit (struct ehci_hcd *ehci, struct urb *urb,
2168         gfp_t mem_flags)
2169 {
2170         int                     status = -EINVAL;
2171         unsigned long           flags;
2172         struct ehci_iso_stream  *stream;
2173
2174         /* Get iso_stream head */
2175         stream = iso_stream_find (ehci, urb);
2176         if (stream == NULL) {
2177                 ehci_dbg (ehci, "can't get iso stream\n");
2178                 return -ENOMEM;
2179         }
2180         if (urb->interval != stream->interval) {
2181                 ehci_dbg (ehci, "can't change iso interval %d --> %d\n",
2182                         stream->interval, urb->interval);
2183                 goto done;
2184         }
2185
2186 #ifdef EHCI_URB_TRACE
2187         ehci_dbg (ehci,
2188                 "submit %p dev%s ep%d%s-iso len %d\n",
2189                 urb, urb->dev->devpath,
2190                 usb_pipeendpoint (urb->pipe),
2191                 usb_pipein (urb->pipe) ? "in" : "out",
2192                 urb->transfer_buffer_length);
2193 #endif
2194
2195         /* allocate SITDs */
2196         status = sitd_urb_transaction (stream, ehci, urb, mem_flags);
2197         if (status < 0) {
2198                 ehci_dbg (ehci, "can't init sitds\n");
2199                 goto done;
2200         }
2201
2202         /* schedule ... need to lock */
2203         spin_lock_irqsave (&ehci->lock, flags);
2204         if (unlikely(!test_bit(HCD_FLAG_HW_ACCESSIBLE,
2205                                &ehci_to_hcd(ehci)->flags))) {
2206                 status = -ESHUTDOWN;
2207                 goto done_not_linked;
2208         }
2209         status = usb_hcd_link_urb_to_ep(ehci_to_hcd(ehci), urb);
2210         if (unlikely(status))
2211                 goto done_not_linked;
2212         status = iso_stream_schedule(ehci, urb, stream);
2213         if (status == 0)
2214                 sitd_link_urb (ehci, urb, ehci->periodic_size << 3, stream);
2215         else
2216                 usb_hcd_unlink_urb_from_ep(ehci_to_hcd(ehci), urb);
2217 done_not_linked:
2218         spin_unlock_irqrestore (&ehci->lock, flags);
2219
2220 done:
2221         if (status < 0)
2222                 iso_stream_put (ehci, stream);
2223         return status;
2224 }
2225
2226 /*-------------------------------------------------------------------------*/
2227
2228 static void free_cached_lists(struct ehci_hcd *ehci)
2229 {
2230         struct ehci_itd *itd, *n;
2231         struct ehci_sitd *sitd, *sn;
2232
2233         list_for_each_entry_safe(itd, n, &ehci->cached_itd_list, itd_list) {
2234                 struct ehci_iso_stream  *stream = itd->stream;
2235                 itd->stream = NULL;
2236                 list_move(&itd->itd_list, &stream->free_list);
2237                 iso_stream_put(ehci, stream);
2238         }
2239
2240         list_for_each_entry_safe(sitd, sn, &ehci->cached_sitd_list, sitd_list) {
2241                 struct ehci_iso_stream  *stream = sitd->stream;
2242                 sitd->stream = NULL;
2243                 list_move(&sitd->sitd_list, &stream->free_list);
2244                 iso_stream_put(ehci, stream);
2245         }
2246 }
2247
2248 /*-------------------------------------------------------------------------*/
2249
2250 static void
2251 scan_periodic (struct ehci_hcd *ehci)
2252 {
2253         unsigned        now_uframe, frame, clock, clock_frame, mod;
2254         unsigned        modified;
2255
2256         mod = ehci->periodic_size << 3;
2257
2258         /*
2259          * When running, scan from last scan point up to "now"
2260          * else clean up by scanning everything that's left.
2261          * Touches as few pages as possible:  cache-friendly.
2262          */
2263         now_uframe = ehci->next_uframe;
2264         if (HC_IS_RUNNING(ehci_to_hcd(ehci)->state)) {
2265                 clock = ehci_readl(ehci, &ehci->regs->frame_index);
2266                 clock_frame = (clock >> 3) % ehci->periodic_size;
2267         } else  {
2268                 clock = now_uframe + mod - 1;
2269                 clock_frame = -1;
2270         }
2271         if (ehci->clock_frame != clock_frame) {
2272                 free_cached_lists(ehci);
2273                 ehci->clock_frame = clock_frame;
2274         }
2275         clock %= mod;
2276         clock_frame = clock >> 3;
2277
2278         for (;;) {
2279                 union ehci_shadow       q, *q_p;
2280                 __hc32                  type, *hw_p;
2281                 unsigned                incomplete = false;
2282
2283                 frame = now_uframe >> 3;
2284
2285 restart:
2286                 /* scan each element in frame's queue for completions */
2287                 q_p = &ehci->pshadow [frame];
2288                 hw_p = &ehci->periodic [frame];
2289                 q.ptr = q_p->ptr;
2290                 type = Q_NEXT_TYPE(ehci, *hw_p);
2291                 modified = 0;
2292
2293                 while (q.ptr != NULL) {
2294                         unsigned                uf;
2295                         union ehci_shadow       temp;
2296                         int                     live;
2297
2298                         live = HC_IS_RUNNING (ehci_to_hcd(ehci)->state);
2299                         switch (hc32_to_cpu(ehci, type)) {
2300                         case Q_TYPE_QH:
2301                                 /* handle any completions */
2302                                 temp.qh = qh_get (q.qh);
2303                                 type = Q_NEXT_TYPE(ehci, q.qh->hw->hw_next);
2304                                 q = q.qh->qh_next;
2305                                 modified = qh_completions (ehci, temp.qh);
2306                                 if (unlikely(list_empty(&temp.qh->qtd_list) ||
2307                                                 temp.qh->needs_rescan))
2308                                         intr_deschedule (ehci, temp.qh);
2309                                 qh_put (temp.qh);
2310                                 break;
2311                         case Q_TYPE_FSTN:
2312                                 /* for "save place" FSTNs, look at QH entries
2313                                  * in the previous frame for completions.
2314                                  */
2315                                 if (q.fstn->hw_prev != EHCI_LIST_END(ehci)) {
2316                                         dbg ("ignoring completions from FSTNs");
2317                                 }
2318                                 type = Q_NEXT_TYPE(ehci, q.fstn->hw_next);
2319                                 q = q.fstn->fstn_next;
2320                                 break;
2321                         case Q_TYPE_ITD:
2322                                 /* If this ITD is still active, leave it for
2323                                  * later processing ... check the next entry.
2324                                  * No need to check for activity unless the
2325                                  * frame is current.
2326                                  */
2327                                 if (frame == clock_frame && live) {
2328                                         rmb();
2329                                         for (uf = 0; uf < 8; uf++) {
2330                                                 if (q.itd->hw_transaction[uf] &
2331                                                             ITD_ACTIVE(ehci))
2332                                                         break;
2333                                         }
2334                                         if (uf < 8) {
2335                                                 incomplete = true;
2336                                                 q_p = &q.itd->itd_next;
2337                                                 hw_p = &q.itd->hw_next;
2338                                                 type = Q_NEXT_TYPE(ehci,
2339                                                         q.itd->hw_next);
2340                                                 q = *q_p;
2341                                                 break;
2342                                         }
2343                                 }
2344
2345                                 /* Take finished ITDs out of the schedule
2346                                  * and process them:  recycle, maybe report
2347                                  * URB completion.  HC won't cache the
2348                                  * pointer for much longer, if at all.
2349                                  */
2350                                 *q_p = q.itd->itd_next;
2351                                 *hw_p = q.itd->hw_next;
2352                                 type = Q_NEXT_TYPE(ehci, q.itd->hw_next);
2353                                 wmb();
2354                                 modified = itd_complete (ehci, q.itd);
2355                                 q = *q_p;
2356                                 break;
2357                         case Q_TYPE_SITD:
2358                                 /* If this SITD is still active, leave it for
2359                                  * later processing ... check the next entry.
2360                                  * No need to check for activity unless the
2361                                  * frame is current.
2362                                  */
2363                                 if (((frame == clock_frame) ||
2364                                      (((frame + 1) % ehci->periodic_size)
2365                                       == clock_frame))
2366                                     && live
2367                                     && (q.sitd->hw_results &
2368                                         SITD_ACTIVE(ehci))) {
2369
2370                                         incomplete = true;
2371                                         q_p = &q.sitd->sitd_next;
2372                                         hw_p = &q.sitd->hw_next;
2373                                         type = Q_NEXT_TYPE(ehci,
2374                                                         q.sitd->hw_next);
2375                                         q = *q_p;
2376                                         break;
2377                                 }
2378
2379                                 /* Take finished SITDs out of the schedule
2380                                  * and process them:  recycle, maybe report
2381                                  * URB completion.
2382                                  */
2383                                 *q_p = q.sitd->sitd_next;
2384                                 *hw_p = q.sitd->hw_next;
2385                                 type = Q_NEXT_TYPE(ehci, q.sitd->hw_next);
2386                                 wmb();
2387                                 modified = sitd_complete (ehci, q.sitd);
2388                                 q = *q_p;
2389                                 break;
2390                         default:
2391                                 dbg ("corrupt type %d frame %d shadow %p",
2392                                         type, frame, q.ptr);
2393                                 // BUG ();
2394                                 q.ptr = NULL;
2395                         }
2396
2397                         /* assume completion callbacks modify the queue */
2398                         if (unlikely (modified)) {
2399                                 if (likely(ehci->periodic_sched > 0))
2400                                         goto restart;
2401                                 /* short-circuit this scan */
2402                                 now_uframe = clock;
2403                                 break;
2404                         }
2405                 }
2406
2407                 /* If we can tell we caught up to the hardware, stop now.
2408                  * We can't advance our scan without collecting the ISO
2409                  * transfers that are still pending in this frame.
2410                  */
2411                 if (incomplete && HC_IS_RUNNING(ehci_to_hcd(ehci)->state)) {
2412                         ehci->next_uframe = now_uframe;
2413                         break;
2414                 }
2415
2416                 // FIXME:  this assumes we won't get lapped when
2417                 // latencies climb; that should be rare, but...
2418                 // detect it, and just go all the way around.
2419                 // FLR might help detect this case, so long as latencies
2420                 // don't exceed periodic_size msec (default 1.024 sec).
2421
2422                 // FIXME:  likewise assumes HC doesn't halt mid-scan
2423
2424                 if (now_uframe == clock) {
2425                         unsigned        now;
2426
2427                         if (!HC_IS_RUNNING (ehci_to_hcd(ehci)->state)
2428                                         || ehci->periodic_sched == 0)
2429                                 break;
2430                         ehci->next_uframe = now_uframe;
2431                         now = ehci_readl(ehci, &ehci->regs->frame_index) % mod;
2432                         if (now_uframe == now)
2433                                 break;
2434
2435                         /* rescan the rest of this frame, then ... */
2436                         clock = now;
2437                         clock_frame = clock >> 3;
2438                         if (ehci->clock_frame != clock_frame) {
2439                                 free_cached_lists(ehci);
2440                                 ehci->clock_frame = clock_frame;
2441                         }
2442                 } else {
2443                         now_uframe++;
2444                         now_uframe %= mod;
2445                 }
2446         }
2447 }