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 #ifdef CONFIG_PCI
  40
  41 static unsigned ehci_read_frame_index(struct ehci_hcd *ehci)
  42 {
  43         unsigned uf;
  44
  45         /*
  46          * The MosChip MCS9990 controller updates its microframe counter
  47          * a little before the frame counter, and occasionally we will read
  48          * the invalid intermediate value.  Avoid problems by checking the
  49          * microframe number (the low-order 3 bits); if they are 0 then
  50          * re-read the register to get the correct value.
  51          */
  52         uf = ehci_readl(ehci, &ehci->regs->frame_index);
  53         if (unlikely(ehci->frame_index_bug && ((uf & 7) == 0)))
  54                 uf = ehci_readl(ehci, &ehci->regs->frame_index);
  55         return uf;
  56 }
  57
  58 #endif
  59
  60 /*-------------------------------------------------------------------------*/
  61
  62 /*
  63  * periodic_next_shadow - return "next" pointer on shadow list
  64  * @periodic: host pointer to qh/itd/sitd
  65  * @tag: hardware tag for type of this record
  66  */
  67 static union ehci_shadow *
  68 periodic_next_shadow(struct ehci_hcd *ehci, union ehci_shadow *periodic,
  69                 __hc32 tag)
  70 {
  71         switch (hc32_to_cpu(ehci, tag)) {
  72         case Q_TYPE_QH:
  73                 return &periodic->qh->qh_next;
  74         case Q_TYPE_FSTN:
  75                 return &periodic->fstn->fstn_next;
  76         case Q_TYPE_ITD:
  77                 return &periodic->itd->itd_next;
  78         // case Q_TYPE_SITD:
  79         default:
  80                 return &periodic->sitd->sitd_next;
  81         }
  82 }
  83
  84 static __hc32 *
  85 shadow_next_periodic(struct ehci_hcd *ehci, union ehci_shadow *periodic,
  86                 __hc32 tag)
  87 {
  88         switch (hc32_to_cpu(ehci, tag)) {
  89         /* our ehci_shadow.qh is actually software part */
  90         case Q_TYPE_QH:
  91                 return &periodic->qh->hw->hw_next;
  92         /* others are hw parts */
  93         default:
  94                 return periodic->hw_next;
  95         }
  96 }
  97
  98 /* caller must hold ehci->lock */
  99 static void periodic_unlink (struct ehci_hcd *ehci, unsigned frame, void *ptr)
 100 {
 101         union ehci_shadow       *prev_p = &ehci->pshadow[frame];
 102         __hc32                  *hw_p = &ehci->periodic[frame];
 103         union ehci_shadow       here = *prev_p;
 104
 105         /* find predecessor of "ptr"; hw and shadow lists are in sync */
 106         while (here.ptr && here.ptr != ptr) {
 107                 prev_p = periodic_next_shadow(ehci, prev_p,
 108                                 Q_NEXT_TYPE(ehci, *hw_p));
 109                 hw_p = shadow_next_periodic(ehci, &here,
 110                                 Q_NEXT_TYPE(ehci, *hw_p));
 111                 here = *prev_p;
 112         }
 113         /* an interrupt entry (at list end) could have been shared */
 114         if (!here.ptr)
 115                 return;
 116
 117         /* update shadow and hardware lists ... the old "next" pointers
 118          * from ptr may still be in use, the caller updates them.
 119          */
 120         *prev_p = *periodic_next_shadow(ehci, &here,
 121                         Q_NEXT_TYPE(ehci, *hw_p));
 122
 123         if (!ehci->use_dummy_qh ||
 124             *shadow_next_periodic(ehci, &here, Q_NEXT_TYPE(ehci, *hw_p))
 125                         != EHCI_LIST_END(ehci))
 126                 *hw_p = *shadow_next_periodic(ehci, &here,
 127                                 Q_NEXT_TYPE(ehci, *hw_p));
 128         else
 129                 *hw_p = ehci->dummy->qh_dma;
 130 }
 131
 132 /* how many of the uframe's 125 usecs are allocated? */
 133 static unsigned short
 134 periodic_usecs (struct ehci_hcd *ehci, unsigned frame, unsigned uframe)
 135 {
 136         __hc32                  *hw_p = &ehci->periodic [frame];
 137         union ehci_shadow       *q = &ehci->pshadow [frame];
 138         unsigned                usecs = 0;
 139         struct ehci_qh_hw       *hw;
 140
 141         while (q->ptr) {
 142                 switch (hc32_to_cpu(ehci, Q_NEXT_TYPE(ehci, *hw_p))) {
 143                 case Q_TYPE_QH:
 144                         hw = q->qh->hw;
 145                         /* is it in the S-mask? */
 146                         if (hw->hw_info2 & cpu_to_hc32(ehci, 1 << uframe))
 147                                 usecs += q->qh->usecs;
 148                         /* ... or C-mask? */
 149                         if (hw->hw_info2 & cpu_to_hc32(ehci,
 150                                         1 << (8 + uframe)))
 151                                 usecs += q->qh->c_usecs;
 152                         hw_p = &hw->hw_next;
 153                         q = &q->qh->qh_next;
 154                         break;
 155                 // case Q_TYPE_FSTN:
 156                 default:
 157                         /* for "save place" FSTNs, count the relevant INTR
 158                          * bandwidth from the previous frame
 159                          */
 160                         if (q->fstn->hw_prev != EHCI_LIST_END(ehci)) {
 161                                 ehci_dbg (ehci, "ignoring FSTN cost ...\n");
 162                         }
 163                         hw_p = &q->fstn->hw_next;
 164                         q = &q->fstn->fstn_next;
 165                         break;
 166                 case Q_TYPE_ITD:
 167                         if (q->itd->hw_transaction[uframe])
 168                                 usecs += q->itd->stream->usecs;
 169                         hw_p = &q->itd->hw_next;
 170                         q = &q->itd->itd_next;
 171                         break;
 172                 case Q_TYPE_SITD:
 173                         /* is it in the S-mask?  (count SPLIT, DATA) */
 174                         if (q->sitd->hw_uframe & cpu_to_hc32(ehci,
 175                                         1 << uframe)) {
 176                                 if (q->sitd->hw_fullspeed_ep &
 177                                                 cpu_to_hc32(ehci, 1<<31))
 178                                         usecs += q->sitd->stream->usecs;
 179                                 else    /* worst case for OUT start-split */
 180                                         usecs += HS_USECS_ISO (188);
 181                         }
 182
 183                         /* ... C-mask?  (count CSPLIT, DATA) */
 184                         if (q->sitd->hw_uframe &
 185                                         cpu_to_hc32(ehci, 1 << (8 + uframe))) {
 186                                 /* worst case for IN complete-split */
 187                                 usecs += q->sitd->stream->c_usecs;
 188                         }
 189
 190                         hw_p = &q->sitd->hw_next;
 191                         q = &q->sitd->sitd_next;
 192                         break;
 193                 }
 194         }
 195 #ifdef  DEBUG
 196         if (usecs > ehci->uframe_periodic_max)
 197                 ehci_err (ehci, "uframe %d sched overrun: %d usecs\n",
 198                         frame * 8 + uframe, usecs);
 199 #endif
 200         return usecs;
 201 }
 202
 203 /*-------------------------------------------------------------------------*/
 204
 205 static int same_tt (struct usb_device *dev1, struct usb_device *dev2)
 206 {
 207         if (!dev1->tt || !dev2->tt)
 208                 return 0;
 209         if (dev1->tt != dev2->tt)
 210                 return 0;
 211         if (dev1->tt->multi)
 212                 return dev1->ttport == dev2->ttport;
 213         else
 214                 return 1;
 215 }
 216
 217 #ifdef CONFIG_USB_EHCI_TT_NEWSCHED
 218
 219 /* Which uframe does the low/fullspeed transfer start in?
 220  *
 221  * The parameter is the mask of ssplits in "H-frame" terms
 222  * and this returns the transfer start uframe in "B-frame" terms,
 223  * which allows both to match, e.g. a ssplit in "H-frame" uframe 0
 224  * will cause a transfer in "B-frame" uframe 0.  "B-frames" lag
 225  * "H-frames" by 1 uframe.  See the EHCI spec sec 4.5 and figure 4.7.
 226  */
 227 static inline unsigned char tt_start_uframe(struct ehci_hcd *ehci, __hc32 mask)
 228 {
 229         unsigned char smask = QH_SMASK & hc32_to_cpu(ehci, mask);
 230         if (!smask) {
 231                 ehci_err(ehci, "invalid empty smask!\n");
 232                 /* uframe 7 can't have bw so this will indicate failure */
 233                 return 7;
 234         }
 235         return ffs(smask) - 1;
 236 }
 237
 238 static const unsigned char
 239 max_tt_usecs[] = { 125, 125, 125, 125, 125, 125, 30, 0 };
 240
 241 /* carryover low/fullspeed bandwidth that crosses uframe boundries */
 242 static inline void carryover_tt_bandwidth(unsigned short tt_usecs[8])
 243 {
 244         int i;
 245         for (i=0; i<7; i++) {
 246                 if (max_tt_usecs[i] < tt_usecs[i]) {
 247                         tt_usecs[i+1] += tt_usecs[i] - max_tt_usecs[i];
 248                         tt_usecs[i] = max_tt_usecs[i];
 249                 }
 250         }
 251 }
 252
 253 /* How many of the tt's periodic downstream 1000 usecs are allocated?
 254  *
 255  * While this measures the bandwidth in terms of usecs/uframe,
 256  * the low/fullspeed bus has no notion of uframes, so any particular
 257  * low/fullspeed transfer can "carry over" from one uframe to the next,
 258  * since the TT just performs downstream transfers in sequence.
 259  *
 260  * For example two separate 100 usec transfers can start in the same uframe,
 261  * and the second one would "carry over" 75 usecs into the next uframe.
 262  */
 263 static void
 264 periodic_tt_usecs (
 265         struct ehci_hcd *ehci,
 266         struct usb_device *dev,
 267         unsigned frame,
 268         unsigned short tt_usecs[8]
 269 )
 270 {
 271         __hc32                  *hw_p = &ehci->periodic [frame];
 272         union ehci_shadow       *q = &ehci->pshadow [frame];
 273         unsigned char           uf;
 274
 275         memset(tt_usecs, 0, 16);
 276
 277         while (q->ptr) {
 278                 switch (hc32_to_cpu(ehci, Q_NEXT_TYPE(ehci, *hw_p))) {
 279                 case Q_TYPE_ITD:
 280                         hw_p = &q->itd->hw_next;
 281                         q = &q->itd->itd_next;
 282                         continue;
 283                 case Q_TYPE_QH:
 284                         if (same_tt(dev, q->qh->dev)) {
 285                                 uf = tt_start_uframe(ehci, q->qh->hw->hw_info2);
 286                                 tt_usecs[uf] += q->qh->tt_usecs;
 287                         }
 288                         hw_p = &q->qh->hw->hw_next;
 289                         q = &q->qh->qh_next;
 290                         continue;
 291                 case Q_TYPE_SITD:
 292                         if (same_tt(dev, q->sitd->urb->dev)) {
 293                                 uf = tt_start_uframe(ehci, q->sitd->hw_uframe);
 294                                 tt_usecs[uf] += q->sitd->stream->tt_usecs;
 295                         }
 296                         hw_p = &q->sitd->hw_next;
 297                         q = &q->sitd->sitd_next;
 298                         continue;
 299                 // case Q_TYPE_FSTN:
 300                 default:
 301                         ehci_dbg(ehci, "ignoring periodic frame %d FSTN\n",
 302                                         frame);
 303                         hw_p = &q->fstn->hw_next;
 304                         q = &q->fstn->fstn_next;
 305                 }
 306         }
 307
 308         carryover_tt_bandwidth(tt_usecs);
 309
 310         if (max_tt_usecs[7] < tt_usecs[7])
 311                 ehci_err(ehci, "frame %d tt sched overrun: %d usecs\n",
 312                         frame, tt_usecs[7] - max_tt_usecs[7]);
 313 }
 314
 315 /*
 316  * Return true if the device's tt's downstream bus is available for a
 317  * periodic transfer of the specified length (usecs), starting at the
 318  * specified frame/uframe.  Note that (as summarized in section 11.19
 319  * of the usb 2.0 spec) TTs can buffer multiple transactions for each
 320  * uframe.
 321  *
 322  * The uframe parameter is when the fullspeed/lowspeed transfer
 323  * should be executed in "B-frame" terms, which is the same as the
 324  * highspeed ssplit's uframe (which is in "H-frame" terms).  For example
 325  * a ssplit in "H-frame" 0 causes a transfer in "B-frame" 0.
 326  * See the EHCI spec sec 4.5 and fig 4.7.
 327  *
 328  * This checks if the full/lowspeed bus, at the specified starting uframe,
 329  * has the specified bandwidth available, according to rules listed
 330  * in USB 2.0 spec section 11.18.1 fig 11-60.
 331  *
 332  * This does not check if the transfer would exceed the max ssplit
 333  * limit of 16, specified in USB 2.0 spec section 11.18.4 requirement #4,
 334  * since proper scheduling limits ssplits to less than 16 per uframe.
 335  */
 336 static int tt_available (
 337         struct ehci_hcd         *ehci,
 338         unsigned                period,
 339         struct usb_device       *dev,
 340         unsigned                frame,
 341         unsigned                uframe,
 342         u16                     usecs
 343 )
 344 {
 345         if ((period == 0) || (uframe >= 7))     /* error */
 346                 return 0;
 347
 348         for (; frame < ehci->periodic_size; frame += period) {
 349                 unsigned short tt_usecs[8];
 350
 351                 periodic_tt_usecs (ehci, dev, frame, tt_usecs);
 352
 353                 ehci_vdbg(ehci, "tt frame %d check %d usecs start uframe %d in"
 354                         " schedule %d/%d/%d/%d/%d/%d/%d/%d\n",
 355                         frame, usecs, uframe,
 356                         tt_usecs[0], tt_usecs[1], tt_usecs[2], tt_usecs[3],
 357                         tt_usecs[4], tt_usecs[5], tt_usecs[6], tt_usecs[7]);
 358
 359                 if (max_tt_usecs[uframe] <= tt_usecs[uframe]) {
 360                         ehci_vdbg(ehci, "frame %d uframe %d fully scheduled\n",
 361                                 frame, uframe);
 362                         return 0;
 363                 }
 364
 365                 /* special case for isoc transfers larger than 125us:
 366                  * the first and each subsequent fully used uframe
 367                  * must be empty, so as to not illegally delay
 368                  * already scheduled transactions
 369                  */
 370                 if (125 < usecs) {
 371                         int ufs = (usecs / 125);
 372                         int i;
 373                         for (i = uframe; i < (uframe + ufs) && i < 8; i++)
 374                                 if (0 < tt_usecs[i]) {
 375                                         ehci_vdbg(ehci,
 376                                                 "multi-uframe xfer can't fit "
 377                                                 "in frame %d uframe %d\n",
 378                                                 frame, i);
 379                                         return 0;
 380                                 }
 381                 }
 382
 383                 tt_usecs[uframe] += usecs;
 384
 385                 carryover_tt_bandwidth(tt_usecs);
 386
 387                 /* fail if the carryover pushed bw past the last uframe's limit */
 388                 if (max_tt_usecs[7] < tt_usecs[7]) {
 389                         ehci_vdbg(ehci,
 390                                 "tt unavailable usecs %d frame %d uframe %d\n",
 391                                 usecs, frame, uframe);
 392                         return 0;
 393                 }
 394         }
 395
 396         return 1;
 397 }
 398
 399 #else
 400
 401 /* return true iff the device's transaction translator is available
 402  * for a periodic transfer starting at the specified frame, using
 403  * all the uframes in the mask.
 404  */
 405 static int tt_no_collision (
 406         struct ehci_hcd         *ehci,
 407         unsigned                period,
 408         struct usb_device       *dev,
 409         unsigned                frame,
 410         u32                     uf_mask
 411 )
 412 {
 413         if (period == 0)        /* error */
 414                 return 0;
 415
 416         /* note bandwidth wastage:  split never follows csplit
 417          * (different dev or endpoint) until the next uframe.
 418          * calling convention doesn't make that distinction.
 419          */
 420         for (; frame < ehci->periodic_size; frame += period) {
 421                 union ehci_shadow       here;
 422                 __hc32                  type;
 423                 struct ehci_qh_hw       *hw;
 424
 425                 here = ehci->pshadow [frame];
 426                 type = Q_NEXT_TYPE(ehci, ehci->periodic [frame]);
 427                 while (here.ptr) {
 428                         switch (hc32_to_cpu(ehci, type)) {
 429                         case Q_TYPE_ITD:
 430                                 type = Q_NEXT_TYPE(ehci, here.itd->hw_next);
 431                                 here = here.itd->itd_next;
 432                                 continue;
 433                         case Q_TYPE_QH:
 434                                 hw = here.qh->hw;
 435                                 if (same_tt (dev, here.qh->dev)) {
 436                                         u32             mask;
 437
 438                                         mask = hc32_to_cpu(ehci,
 439                                                         hw->hw_info2);
 440                                         /* "knows" no gap is needed */
 441                                         mask |= mask >> 8;
 442                                         if (mask & uf_mask)
 443                                                 break;
 444                                 }
 445                                 type = Q_NEXT_TYPE(ehci, hw->hw_next);
 446                                 here = here.qh->qh_next;
 447                                 continue;
 448                         case Q_TYPE_SITD:
 449                                 if (same_tt (dev, here.sitd->urb->dev)) {
 450                                         u16             mask;
 451
 452                                         mask = hc32_to_cpu(ehci, here.sitd
 453                                                                 ->hw_uframe);
 454                                         /* FIXME assumes no gap for IN! */
 455                                         mask |= mask >> 8;
 456                                         if (mask & uf_mask)
 457                                                 break;
 458                                 }
 459                                 type = Q_NEXT_TYPE(ehci, here.sitd->hw_next);
 460                                 here = here.sitd->sitd_next;
 461                                 continue;
 462                         // case Q_TYPE_FSTN:
 463                         default:
 464                                 ehci_dbg (ehci,
 465                                         "periodic frame %d bogus type %d\n",
 466                                         frame, type);
 467                         }
 468
 469                         /* collision or error */
 470                         return 0;
 471                 }
 472         }
 473
 474         /* no collision */
 475         return 1;
 476 }
 477
 478 #endif /* CONFIG_USB_EHCI_TT_NEWSCHED */
 479
 480 /*-------------------------------------------------------------------------*/
 481
 482 static int enable_periodic (struct ehci_hcd *ehci)
 483 {
 484         u32     cmd;
 485         int     status;
 486
 487         if (ehci->periodic_sched++)
 488                 return 0;
 489
 490         /* did clearing PSE did take effect yet?
 491          * takes effect only at frame boundaries...
 492          */
 493         status = handshake_on_error_set_halt(ehci, &ehci->regs->status,
 494                                              STS_PSS, 0, 9 * 125);
 495         if (status) {
 496                 usb_hc_died(ehci_to_hcd(ehci));
 497                 return status;
 498         }
 499
 500         cmd = ehci_readl(ehci, &ehci->regs->command) | CMD_PSE;
 501         ehci_writel(ehci, cmd, &ehci->regs->command);
 502         /* posted write ... PSS happens later */
 503
 504         /* make sure ehci_work scans these */
 505         ehci->next_uframe = ehci_read_frame_index(ehci)
 506                 % (ehci->periodic_size << 3);
 507         if (unlikely(ehci->broken_periodic))
 508                 ehci->last_periodic_enable = ktime_get_real();
 509         return 0;
 510 }
 511
 512 static int disable_periodic (struct ehci_hcd *ehci)
 513 {
 514         u32     cmd;
 515         int     status;
 516
 517         if (--ehci->periodic_sched)
 518                 return 0;
 519
 520         if (unlikely(ehci->broken_periodic)) {
 521                 /* delay experimentally determined */
 522                 ktime_t safe = ktime_add_us(ehci->last_periodic_enable, 1000);
 523                 ktime_t now = ktime_get_real();
 524                 s64 delay = ktime_us_delta(safe, now);
 525
 526                 if (unlikely(delay > 0))
 527                         udelay(delay);
 528         }
 529
 530         /* did setting PSE not take effect yet?
 531          * takes effect only at frame boundaries...
 532          */
 533         status = handshake_on_error_set_halt(ehci, &ehci->regs->status,
 534                                              STS_PSS, STS_PSS, 9 * 125);
 535         if (status) {
 536                 usb_hc_died(ehci_to_hcd(ehci));
 537                 return status;
 538         }
 539
 540         cmd = ehci_readl(ehci, &ehci->regs->command) & ~CMD_PSE;
 541         ehci_writel(ehci, cmd, &ehci->regs->command);
 542         /* posted write ... */
 543
 544         free_cached_lists(ehci);
 545
 546         ehci->next_uframe = -1;
 547         return 0;
 548 }
 549
 550 /*-------------------------------------------------------------------------*/
 551
 552 /* periodic schedule slots have iso tds (normal or split) first, then a
 553  * sparse tree for active interrupt transfers.
 554  *
 555  * this just links in a qh; caller guarantees uframe masks are set right.
 556  * no FSTN support (yet; ehci 0.96+)
 557  */
 558 static int qh_link_periodic (struct ehci_hcd *ehci, struct ehci_qh *qh)
 559 {
 560         unsigned        i;
 561         unsigned        period = qh->period;
 562
 563         dev_dbg (&qh->dev->dev,
 564                 "link qh%d-%04x/%p start %d [%d/%d us]\n",
 565                 period, hc32_to_cpup(ehci, &qh->hw->hw_info2)
 566                         & (QH_CMASK | QH_SMASK),
 567                 qh, qh->start, qh->usecs, qh->c_usecs);
 568
 569         /* high bandwidth, or otherwise every microframe */
 570         if (period == 0)
 571                 period = 1;
 572
 573         for (i = qh->start; i < ehci->periodic_size; i += period) {
 574                 union ehci_shadow       *prev = &ehci->pshadow[i];
 575                 __hc32                  *hw_p = &ehci->periodic[i];
 576                 union ehci_shadow       here = *prev;
 577                 __hc32                  type = 0;
 578
 579                 /* skip the iso nodes at list head */
 580                 while (here.ptr) {
 581                         type = Q_NEXT_TYPE(ehci, *hw_p);
 582                         if (type == cpu_to_hc32(ehci, Q_TYPE_QH))
 583                                 break;
 584                         prev = periodic_next_shadow(ehci, prev, type);
 585                         hw_p = shadow_next_periodic(ehci, &here, type);
 586                         here = *prev;
 587                 }
 588
 589                 /* sorting each branch by period (slow-->fast)
 590                  * enables sharing interior tree nodes
 591                  */
 592                 while (here.ptr && qh != here.qh) {
 593                         if (qh->period > here.qh->period)
 594                                 break;
 595                         prev = &here.qh->qh_next;
 596                         hw_p = &here.qh->hw->hw_next;
 597                         here = *prev;
 598                 }
 599                 /* link in this qh, unless some earlier pass did that */
 600                 if (qh != here.qh) {
 601                         qh->qh_next = here;
 602                         if (here.qh)
 603                                 qh->hw->hw_next = *hw_p;
 604                         wmb ();
 605                         prev->qh = qh;
 606                         *hw_p = QH_NEXT (ehci, qh->qh_dma);
 607                 }
 608         }
 609         qh->qh_state = QH_STATE_LINKED;
 610         qh->xacterrs = 0;
 611         qh_get (qh);
 612
 613         /* update per-qh bandwidth for usbfs */
 614         ehci_to_hcd(ehci)->self.bandwidth_allocated += qh->period
 615                 ? ((qh->usecs + qh->c_usecs) / qh->period)
 616                 : (qh->usecs * 8);
 617
 618         /* maybe enable periodic schedule processing */
 619         return enable_periodic(ehci);
 620 }
 621
 622 static int qh_unlink_periodic(struct ehci_hcd *ehci, struct ehci_qh *qh)
 623 {
 624         unsigned        i;
 625         unsigned        period;
 626
 627         // FIXME:
 628         // IF this isn't high speed
 629         //   and this qh is active in the current uframe
 630         //   (and overlay token SplitXstate is false?)
 631         // THEN
 632         //   qh->hw_info1 |= cpu_to_hc32(1 << 7 /* "ignore" */);
 633
 634         /* high bandwidth, or otherwise part of every microframe */
 635         if ((period = qh->period) == 0)
 636                 period = 1;
 637
 638         for (i = qh->start; i < ehci->periodic_size; i += period)
 639                 periodic_unlink (ehci, i, qh);
 640
 641         /* update per-qh bandwidth for usbfs */
 642         ehci_to_hcd(ehci)->self.bandwidth_allocated -= qh->period
 643                 ? ((qh->usecs + qh->c_usecs) / qh->period)
 644                 : (qh->usecs * 8);
 645
 646         dev_dbg (&qh->dev->dev,
 647                 "unlink qh%d-%04x/%p start %d [%d/%d us]\n",
 648                 qh->period,
 649                 hc32_to_cpup(ehci, &qh->hw->hw_info2) & (QH_CMASK | QH_SMASK),
 650                 qh, qh->start, qh->usecs, qh->c_usecs);
 651
 652         /* qh->qh_next still "live" to HC */
 653         qh->qh_state = QH_STATE_UNLINK;
 654         qh->qh_next.ptr = NULL;
 655         qh_put (qh);
 656
 657         /* maybe turn off periodic schedule */
 658         return disable_periodic(ehci);
 659 }
 660
 661 static void intr_deschedule (struct ehci_hcd *ehci, struct ehci_qh *qh)
 662 {
 663         unsigned                wait;
 664         struct ehci_qh_hw       *hw = qh->hw;
 665         int                     rc;
 666
 667         /* If the QH isn't linked then there's nothing we can do
 668          * unless we were called during a giveback, in which case
 669          * qh_completions() has to deal with it.
 670          */
 671         if (qh->qh_state != QH_STATE_LINKED) {
 672                 if (qh->qh_state == QH_STATE_COMPLETING)
 673                         qh->needs_rescan = 1;
 674                 return;
 675         }
 676
 677         qh_unlink_periodic (ehci, qh);
 678
 679         /* simple/paranoid:  always delay, expecting the HC needs to read
 680          * qh->hw_next or finish a writeback after SPLIT/CSPLIT ... and
 681          * expect khubd to clean up after any CSPLITs we won't issue.
 682          * active high speed queues may need bigger delays...
 683          */
 684         if (list_empty (&qh->qtd_list)
 685                         || (cpu_to_hc32(ehci, QH_CMASK)
 686                                         & hw->hw_info2) != 0)
 687                 wait = 2;
 688         else
 689                 wait = 55;      /* worst case: 3 * 1024 */
 690
 691         udelay (wait);
 692         qh->qh_state = QH_STATE_IDLE;
 693         hw->hw_next = EHCI_LIST_END(ehci);
 694         wmb ();
 695
 696         qh_completions(ehci, qh);
 697
 698         /* reschedule QH iff another request is queued */
 699         if (!list_empty(&qh->qtd_list) &&
 700                         ehci->rh_state == EHCI_RH_RUNNING) {
 701                 rc = qh_schedule(ehci, qh);
 702
 703                 /* An error here likely indicates handshake failure
 704                  * or no space left in the schedule.  Neither fault
 705                  * should happen often ...
 706                  *
 707                  * FIXME kill the now-dysfunctional queued urbs
 708                  */
 709                 if (rc != 0)
 710                         ehci_err(ehci, "can't reschedule qh %p, err %d\n",
 711                                         qh, rc);
 712         }
 713 }
 714
 715 /*-------------------------------------------------------------------------*/
 716
 717 static int check_period (
 718         struct ehci_hcd *ehci,
 719         unsigned        frame,
 720         unsigned        uframe,
 721         unsigned        period,
 722         unsigned        usecs
 723 ) {
 724         int             claimed;
 725
 726         /* complete split running into next frame?
 727          * given FSTN support, we could sometimes check...
 728          */
 729         if (uframe >= 8)
 730                 return 0;
 731
 732         /* convert "usecs we need" to "max already claimed" */
 733         usecs = ehci->uframe_periodic_max - usecs;
 734
 735         /* we "know" 2 and 4 uframe intervals were rejected; so
 736          * for period 0, check _every_ microframe in the schedule.
 737          */
 738         if (unlikely (period == 0)) {
 739                 do {
 740                         for (uframe = 0; uframe < 7; uframe++) {
 741                                 claimed = periodic_usecs (ehci, frame, uframe);
 742                                 if (claimed > usecs)
 743                                         return 0;
 744                         }
 745                 } while ((frame += 1) < ehci->periodic_size);
 746
 747         /* just check the specified uframe, at that period */
 748         } else {
 749                 do {
 750                         claimed = periodic_usecs (ehci, frame, uframe);
 751                         if (claimed > usecs)
 752                                 return 0;
 753                 } while ((frame += period) < ehci->periodic_size);
 754         }
 755
 756         // success!
 757         return 1;
 758 }
 759
 760 static int check_intr_schedule (
 761         struct ehci_hcd         *ehci,
 762         unsigned                frame,
 763         unsigned                uframe,
 764         const struct ehci_qh    *qh,
 765         __hc32                  *c_maskp
 766 )
 767 {
 768         int             retval = -ENOSPC;
 769         u8              mask = 0;
 770
 771         if (qh->c_usecs && uframe >= 6)         /* FSTN territory? */
 772                 goto done;
 773
 774         if (!check_period (ehci, frame, uframe, qh->period, qh->usecs))
 775                 goto done;
 776         if (!qh->c_usecs) {
 777                 retval = 0;
 778                 *c_maskp = 0;
 779                 goto done;
 780         }
 781
 782 #ifdef CONFIG_USB_EHCI_TT_NEWSCHED
 783         if (tt_available (ehci, qh->period, qh->dev, frame, uframe,
 784                                 qh->tt_usecs)) {
 785                 unsigned i;
 786
 787                 /* TODO : this may need FSTN for SSPLIT in uframe 5. */
 788                 for (i=uframe+1; i<8 && i<uframe+4; i++)
 789                         if (!check_period (ehci, frame, i,
 790                                                 qh->period, qh->c_usecs))
 791                                 goto done;
 792                         else
 793                                 mask |= 1 << i;
 794
 795                 retval = 0;
 796
 797                 *c_maskp = cpu_to_hc32(ehci, mask << 8);
 798         }
 799 #else
 800         /* Make sure this tt's buffer is also available for CSPLITs.
 801          * We pessimize a bit; probably the typical full speed case
 802          * doesn't need the second CSPLIT.
 803          *
 804          * NOTE:  both SPLIT and CSPLIT could be checked in just
 805          * one smart pass...
 806          */
 807         mask = 0x03 << (uframe + qh->gap_uf);
 808         *c_maskp = cpu_to_hc32(ehci, mask << 8);
 809
 810         mask |= 1 << uframe;
 811         if (tt_no_collision (ehci, qh->period, qh->dev, frame, mask)) {
 812                 if (!check_period (ehci, frame, uframe + qh->gap_uf + 1,
 813                                         qh->period, qh->c_usecs))
 814                         goto done;
 815                 if (!check_period (ehci, frame, uframe + qh->gap_uf,
 816                                         qh->period, qh->c_usecs))
 817                         goto done;
 818                 retval = 0;
 819         }
 820 #endif
 821 done:
 822         return retval;
 823 }
 824
 825 /* "first fit" scheduling policy used the first time through,
 826  * or when the previous schedule slot can't be re-used.
 827  */
 828 static int qh_schedule(struct ehci_hcd *ehci, struct ehci_qh *qh)
 829 {
 830         int             status;
 831         unsigned        uframe;
 832         __hc32          c_mask;
 833         unsigned        frame;          /* 0..(qh->period - 1), or NO_FRAME */
 834         struct ehci_qh_hw       *hw = qh->hw;
 835
 836         qh_refresh(ehci, qh);
 837         hw->hw_next = EHCI_LIST_END(ehci);
 838         frame = qh->start;
 839
 840         /* reuse the previous schedule slots, if we can */
 841         if (frame < qh->period) {
 842                 uframe = ffs(hc32_to_cpup(ehci, &hw->hw_info2) & QH_SMASK);
 843                 status = check_intr_schedule (ehci, frame, --uframe,
 844                                 qh, &c_mask);
 845         } else {
 846                 uframe = 0;
 847                 c_mask = 0;
 848                 status = -ENOSPC;
 849         }
 850
 851         /* else scan the schedule to find a group of slots such that all
 852          * uframes have enough periodic bandwidth available.
 853          */
 854         if (status) {
 855                 /* "normal" case, uframing flexible except with splits */
 856                 if (qh->period) {
 857                         int             i;
 858
 859                         for (i = qh->period; status && i > 0; --i) {
 860                                 frame = ++ehci->random_frame % qh->period;
 861                                 for (uframe = 0; uframe < 8; uframe++) {
 862                                         status = check_intr_schedule (ehci,
 863                                                         frame, uframe, qh,
 864                                                         &c_mask);
 865                                         if (status == 0)
 866                                                 break;
 867                                 }
 868                         }
 869
 870                 /* qh->period == 0 means every uframe */
 871                 } else {
 872                         frame = 0;
 873                         status = check_intr_schedule (ehci, 0, 0, qh, &c_mask);
 874                 }
 875                 if (status)
 876                         goto done;
 877                 qh->start = frame;
 878
 879                 /* reset S-frame and (maybe) C-frame masks */
 880                 hw->hw_info2 &= cpu_to_hc32(ehci, ~(QH_CMASK | QH_SMASK));
 881                 hw->hw_info2 |= qh->period
 882                         ? cpu_to_hc32(ehci, 1 << uframe)
 883                         : cpu_to_hc32(ehci, QH_SMASK);
 884                 hw->hw_info2 |= c_mask;
 885         } else
 886                 ehci_dbg (ehci, "reused qh %p schedule\n", qh);
 887
 888         /* stuff into the periodic schedule */
 889         status = qh_link_periodic (ehci, qh);
 890 done:
 891         return status;
 892 }
 893
 894 static int intr_submit (
 895         struct ehci_hcd         *ehci,
 896         struct urb              *urb,
 897         struct list_head        *qtd_list,
 898         gfp_t                   mem_flags
 899 ) {
 900         unsigned                epnum;
 901         unsigned long           flags;
 902         struct ehci_qh          *qh;
 903         int                     status;
 904         struct list_head        empty;
 905
 906         /* get endpoint and transfer/schedule data */
 907         epnum = urb->ep->desc.bEndpointAddress;
 908
 909         spin_lock_irqsave (&ehci->lock, flags);
 910
 911         if (unlikely(!HCD_HW_ACCESSIBLE(ehci_to_hcd(ehci)))) {
 912                 status = -ESHUTDOWN;
 913                 goto done_not_linked;
 914         }
 915         status = usb_hcd_link_urb_to_ep(ehci_to_hcd(ehci), urb);
 916         if (unlikely(status))
 917                 goto done_not_linked;
 918
 919         /* get qh and force any scheduling errors */
 920         INIT_LIST_HEAD (&empty);
 921         qh = qh_append_tds(ehci, urb, &empty, epnum, &urb->ep->hcpriv);
 922         if (qh == NULL) {
 923                 status = -ENOMEM;
 924                 goto done;
 925         }
 926         if (qh->qh_state == QH_STATE_IDLE) {
 927                 if ((status = qh_schedule (ehci, qh)) != 0)
 928                         goto done;
 929         }
 930
 931         /* then queue the urb's tds to the qh */
 932         qh = qh_append_tds(ehci, urb, qtd_list, epnum, &urb->ep->hcpriv);
 933         BUG_ON (qh == NULL);
 934
 935         /* ... update usbfs periodic stats */
 936         ehci_to_hcd(ehci)->self.bandwidth_int_reqs++;
 937
 938 done:
 939         if (unlikely(status))
 940                 usb_hcd_unlink_urb_from_ep(ehci_to_hcd(ehci), urb);
 941 done_not_linked:
 942         spin_unlock_irqrestore (&ehci->lock, flags);
 943         if (status)
 944                 qtd_list_free (ehci, urb, qtd_list);
 945
 946         return status;
 947 }
 948
 949 /*-------------------------------------------------------------------------*/
 950
 951 /* ehci_iso_stream ops work with both ITD and SITD */
 952
 953 static struct ehci_iso_stream *
 954 iso_stream_alloc (gfp_t mem_flags)
 955 {
 956         struct ehci_iso_stream *stream;
 957
 958         stream = kzalloc(sizeof *stream, mem_flags);
 959         if (likely (stream != NULL)) {
 960                 INIT_LIST_HEAD(&stream->td_list);
 961                 INIT_LIST_HEAD(&stream->free_list);
 962                 stream->next_uframe = -1;
 963                 stream->refcount = 1;
 964         }
 965         return stream;
 966 }
 967
 968 static void
 969 iso_stream_init (
 970         struct ehci_hcd         *ehci,
 971         struct ehci_iso_stream  *stream,
 972         struct usb_device       *dev,
 973         int                     pipe,
 974         unsigned                interval
 975 )
 976 {
 977         static const u8 smask_out [] = { 0x01, 0x03, 0x07, 0x0f, 0x1f, 0x3f };
 978
 979         u32                     buf1;
 980         unsigned                epnum, maxp;
 981         int                     is_input;
 982         long                    bandwidth;
 983
 984         /*
 985          * this might be a "high bandwidth" highspeed endpoint,
 986          * as encoded in the ep descriptor's wMaxPacket field
 987          */
 988         epnum = usb_pipeendpoint (pipe);
 989         is_input = usb_pipein (pipe) ? USB_DIR_IN : 0;
 990         maxp = usb_maxpacket(dev, pipe, !is_input);
 991         if (is_input) {
 992                 buf1 = (1 << 11);
 993         } else {
 994                 buf1 = 0;
 995         }
 996
 997         /* knows about ITD vs SITD */
 998         if (dev->speed == USB_SPEED_HIGH) {
 999                 unsigned multi = hb_mult(maxp);
1000
1001                 stream->highspeed = 1;
1002
1003                 maxp = max_packet(maxp);
1004                 buf1 |= maxp;
1005                 maxp *= multi;
1006
1007                 stream->buf0 = cpu_to_hc32(ehci, (epnum << 8) | dev->devnum);
1008                 stream->buf1 = cpu_to_hc32(ehci, buf1);
1009                 stream->buf2 = cpu_to_hc32(ehci, multi);
1010
1011                 /* usbfs wants to report the average usecs per frame tied up
1012                  * when transfers on this endpoint are scheduled ...
1013                  */
1014                 stream->usecs = HS_USECS_ISO (maxp);
1015                 bandwidth = stream->usecs * 8;
1016                 bandwidth /= interval;
1017
1018         } else {
1019                 u32             addr;
1020                 int             think_time;
1021                 int             hs_transfers;
1022
1023                 addr = dev->ttport << 24;
1024                 if (!ehci_is_TDI(ehci)
1025                                 || (dev->tt->hub !=
1026                                         ehci_to_hcd(ehci)->self.root_hub))
1027                         addr |= dev->tt->hub->devnum << 16;
1028                 addr |= epnum << 8;
1029                 addr |= dev->devnum;
1030                 stream->usecs = HS_USECS_ISO (maxp);
1031                 think_time = dev->tt ? dev->tt->think_time : 0;
1032                 stream->tt_usecs = NS_TO_US (think_time + usb_calc_bus_time (
1033                                 dev->speed, is_input, 1, maxp));
1034                 hs_transfers = max (1u, (maxp + 187) / 188);
1035                 if (is_input) {
1036                         u32     tmp;
1037
1038                         addr |= 1 << 31;
1039                         stream->c_usecs = stream->usecs;
1040                         stream->usecs = HS_USECS_ISO (1);
1041                         stream->raw_mask = 1;
1042
1043                         /* c-mask as specified in USB 2.0 11.18.4 3.c */
1044                         tmp = (1 << (hs_transfers + 2)) - 1;
1045                         stream->raw_mask |= tmp << (8 + 2);
1046                 } else
1047                         stream->raw_mask = smask_out [hs_transfers - 1];
1048                 bandwidth = stream->usecs + stream->c_usecs;
1049                 bandwidth /= interval << 3;
1050
1051                 /* stream->splits gets created from raw_mask later */
1052                 stream->address = cpu_to_hc32(ehci, addr);
1053         }
1054         stream->bandwidth = bandwidth;
1055
1056         stream->udev = dev;
1057
1058         stream->bEndpointAddress = is_input | epnum;
1059         stream->interval = interval;
1060         stream->maxp = maxp;
1061 }
1062
1063 static void
1064 iso_stream_put(struct ehci_hcd *ehci, struct ehci_iso_stream *stream)
1065 {
1066         stream->refcount--;
1067
1068         /* free whenever just a dev->ep reference remains.
1069          * not like a QH -- no persistent state (toggle, halt)
1070          */
1071         if (stream->refcount == 1) {
1072                 // BUG_ON (!list_empty(&stream->td_list));
1073
1074                 while (!list_empty (&stream->free_list)) {
1075                         struct list_head        *entry;
1076
1077                         entry = stream->free_list.next;
1078                         list_del (entry);
1079
1080                         /* knows about ITD vs SITD */
1081                         if (stream->highspeed) {
1082                                 struct ehci_itd         *itd;
1083
1084                                 itd = list_entry (entry, struct ehci_itd,
1085                                                 itd_list);
1086                                 dma_pool_free (ehci->itd_pool, itd,
1087                                                 itd->itd_dma);
1088                         } else {
1089                                 struct ehci_sitd        *sitd;
1090
1091                                 sitd = list_entry (entry, struct ehci_sitd,
1092                                                 sitd_list);
1093                                 dma_pool_free (ehci->sitd_pool, sitd,
1094                                                 sitd->sitd_dma);
1095                         }
1096                 }
1097
1098                 stream->bEndpointAddress &= 0x0f;
1099                 if (stream->ep)
1100                         stream->ep->hcpriv = NULL;
1101
1102                 kfree(stream);
1103         }
1104 }
1105
1106 static inline struct ehci_iso_stream *
1107 iso_stream_get (struct ehci_iso_stream *stream)
1108 {
1109         if (likely (stream != NULL))
1110                 stream->refcount++;
1111         return stream;
1112 }
1113
1114 static struct ehci_iso_stream *
1115 iso_stream_find (struct ehci_hcd *ehci, struct urb *urb)
1116 {
1117         unsigned                epnum;
1118         struct ehci_iso_stream  *stream;
1119         struct usb_host_endpoint *ep;
1120         unsigned long           flags;
1121
1122         epnum = usb_pipeendpoint (urb->pipe);
1123         if (usb_pipein(urb->pipe))
1124                 ep = urb->dev->ep_in[epnum];
1125         else
1126                 ep = urb->dev->ep_out[epnum];
1127
1128         spin_lock_irqsave (&ehci->lock, flags);
1129         stream = ep->hcpriv;
1130
1131         if (unlikely (stream == NULL)) {
1132                 stream = iso_stream_alloc(GFP_ATOMIC);
1133                 if (likely (stream != NULL)) {
1134                         /* dev->ep owns the initial refcount */
1135                         ep->hcpriv = stream;
1136                         stream->ep = ep;
1137                         iso_stream_init(ehci, stream, urb->dev, urb->pipe,
1138                                         urb->interval);
1139                 }
1140
1141         /* if dev->ep [epnum] is a QH, hw is set */
1142         } else if (unlikely (stream->hw != NULL)) {
1143                 ehci_dbg (ehci, "dev %s ep%d%s, not iso??\n",
1144                         urb->dev->devpath, epnum,
1145                         usb_pipein(urb->pipe) ? "in" : "out");
1146                 stream = NULL;
1147         }
1148
1149         /* caller guarantees an eventual matching iso_stream_put */
1150         stream = iso_stream_get (stream);
1151
1152         spin_unlock_irqrestore (&ehci->lock, flags);
1153         return stream;
1154 }
1155
1156 /*-------------------------------------------------------------------------*/
1157
1158 /* ehci_iso_sched ops can be ITD-only or SITD-only */
1159
1160 static struct ehci_iso_sched *
1161 iso_sched_alloc (unsigned packets, gfp_t mem_flags)
1162 {
1163         struct ehci_iso_sched   *iso_sched;
1164         int                     size = sizeof *iso_sched;
1165
1166         size += packets * sizeof (struct ehci_iso_packet);
1167         iso_sched = kzalloc(size, mem_flags);
1168         if (likely (iso_sched != NULL)) {
1169                 INIT_LIST_HEAD (&iso_sched->td_list);
1170         }
1171         return iso_sched;
1172 }
1173
1174 static inline void
1175 itd_sched_init(
1176         struct ehci_hcd         *ehci,
1177         struct ehci_iso_sched   *iso_sched,
1178         struct ehci_iso_stream  *stream,
1179         struct urb              *urb
1180 )
1181 {
1182         unsigned        i;
1183         dma_addr_t      dma = urb->transfer_dma;
1184
1185         /* how many uframes are needed for these transfers */
1186         iso_sched->span = urb->number_of_packets * stream->interval;
1187
1188         /* figure out per-uframe itd fields that we'll need later
1189          * when we fit new itds into the schedule.
1190          */
1191         for (i = 0; i < urb->number_of_packets; i++) {
1192                 struct ehci_iso_packet  *uframe = &iso_sched->packet [i];
1193                 unsigned                length;
1194                 dma_addr_t              buf;
1195                 u32                     trans;
1196
1197                 length = urb->iso_frame_desc [i].length;
1198                 buf = dma + urb->iso_frame_desc [i].offset;
1199
1200                 trans = EHCI_ISOC_ACTIVE;
1201                 trans |= buf & 0x0fff;
1202                 if (unlikely (((i + 1) == urb->number_of_packets))
1203                                 && !(urb->transfer_flags & URB_NO_INTERRUPT))
1204                         trans |= EHCI_ITD_IOC;
1205                 trans |= length << 16;
1206                 uframe->transaction = cpu_to_hc32(ehci, trans);
1207
1208                 /* might need to cross a buffer page within a uframe */
1209                 uframe->bufp = (buf & ~(u64)0x0fff);
1210                 buf += length;
1211                 if (unlikely ((uframe->bufp != (buf & ~(u64)0x0fff))))
1212                         uframe->cross = 1;
1213         }
1214 }
1215
1216 static void
1217 iso_sched_free (
1218         struct ehci_iso_stream  *stream,
1219         struct ehci_iso_sched   *iso_sched
1220 )
1221 {
1222         if (!iso_sched)
1223                 return;
1224         // caller must hold ehci->lock!
1225         list_splice (&iso_sched->td_list, &stream->free_list);
1226         kfree (iso_sched);
1227 }
1228
1229 static int
1230 itd_urb_transaction (
1231         struct ehci_iso_stream  *stream,
1232         struct ehci_hcd         *ehci,
1233         struct urb              *urb,
1234         gfp_t                   mem_flags
1235 )
1236 {
1237         struct ehci_itd         *itd;
1238         dma_addr_t              itd_dma;
1239         int                     i;
1240         unsigned                num_itds;
1241         struct ehci_iso_sched   *sched;
1242         unsigned long           flags;
1243
1244         sched = iso_sched_alloc (urb->number_of_packets, mem_flags);
1245         if (unlikely (sched == NULL))
1246                 return -ENOMEM;
1247
1248         itd_sched_init(ehci, sched, stream, urb);
1249
1250         if (urb->interval < 8)
1251                 num_itds = 1 + (sched->span + 7) / 8;
1252         else
1253                 num_itds = urb->number_of_packets;
1254
1255         /* allocate/init ITDs */
1256         spin_lock_irqsave (&ehci->lock, flags);
1257         for (i = 0; i < num_itds; i++) {
1258
1259                 /* free_list.next might be cache-hot ... but maybe
1260                  * the HC caches it too. avoid that issue for now.
1261                  */
1262
1263                 /* prefer previously-allocated itds */
1264                 if (likely (!list_empty(&stream->free_list))) {
1265                         itd = list_entry (stream->free_list.prev,
1266                                         struct ehci_itd, itd_list);
1267                         list_del (&itd->itd_list);
1268                         itd_dma = itd->itd_dma;
1269                 } else {
1270                         spin_unlock_irqrestore (&ehci->lock, flags);
1271                         itd = dma_pool_alloc (ehci->itd_pool, mem_flags,
1272                                         &itd_dma);
1273                         spin_lock_irqsave (&ehci->lock, flags);
1274                         if (!itd) {
1275                                 iso_sched_free(stream, sched);
1276                                 spin_unlock_irqrestore(&ehci->lock, flags);
1277                                 return -ENOMEM;
1278                         }
1279                 }
1280
1281                 memset (itd, 0, sizeof *itd);
1282                 itd->itd_dma = itd_dma;
1283                 list_add (&itd->itd_list, &sched->td_list);
1284         }
1285         spin_unlock_irqrestore (&ehci->lock, flags);
1286
1287         /* temporarily store schedule info in hcpriv */
1288         urb->hcpriv = sched;
1289         urb->error_count = 0;
1290         return 0;
1291 }
1292
1293 /*-------------------------------------------------------------------------*/
1294
1295 static inline int
1296 itd_slot_ok (
1297         struct ehci_hcd         *ehci,
1298         u32                     mod,
1299         u32                     uframe,
1300         u8                      usecs,
1301         u32                     period
1302 )
1303 {
1304         uframe %= period;
1305         do {
1306                 /* can't commit more than uframe_periodic_max usec */
1307                 if (periodic_usecs (ehci, uframe >> 3, uframe & 0x7)
1308                                 > (ehci->uframe_periodic_max - usecs))
1309                         return 0;
1310
1311                 /* we know urb->interval is 2^N uframes */
1312                 uframe += period;
1313         } while (uframe < mod);
1314         return 1;
1315 }
1316
1317 static inline int
1318 sitd_slot_ok (
1319         struct ehci_hcd         *ehci,
1320         u32                     mod,
1321         struct ehci_iso_stream  *stream,
1322         u32                     uframe,
1323         struct ehci_iso_sched   *sched,
1324         u32                     period_uframes
1325 )
1326 {
1327         u32                     mask, tmp;
1328         u32                     frame, uf;
1329
1330         mask = stream->raw_mask << (uframe & 7);
1331
1332         /* for IN, don't wrap CSPLIT into the next frame */
1333         if (mask & ~0xffff)
1334                 return 0;
1335
1336         /* this multi-pass logic is simple, but performance may
1337          * suffer when the schedule data isn't cached.
1338          */
1339
1340         /* check bandwidth */
1341         uframe %= period_uframes;
1342         do {
1343                 u32             max_used;
1344
1345                 frame = uframe >> 3;
1346                 uf = uframe & 7;
1347
1348 #ifdef CONFIG_USB_EHCI_TT_NEWSCHED
1349                 /* The tt's fullspeed bus bandwidth must be available.
1350                  * tt_available scheduling guarantees 10+% for control/bulk.
1351                  */
1352                 if (!tt_available (ehci, period_uframes << 3,
1353                                 stream->udev, frame, uf, stream->tt_usecs))
1354                         return 0;
1355 #else
1356                 /* tt must be idle for start(s), any gap, and csplit.
1357                  * assume scheduling slop leaves 10+% for control/bulk.
1358                  */
1359                 if (!tt_no_collision (ehci, period_uframes << 3,
1360                                 stream->udev, frame, mask))
1361                         return 0;
1362 #endif
1363
1364                 /* check starts (OUT uses more than one) */
1365                 max_used = ehci->uframe_periodic_max - stream->usecs;
1366                 for (tmp = stream->raw_mask & 0xff; tmp; tmp >>= 1, uf++) {
1367                         if (periodic_usecs (ehci, frame, uf) > max_used)
1368                                 return 0;
1369                 }
1370
1371                 /* for IN, check CSPLIT */
1372                 if (stream->c_usecs) {
1373                         uf = uframe & 7;
1374                         max_used = ehci->uframe_periodic_max - stream->c_usecs;
1375                         do {
1376                                 tmp = 1 << uf;
1377                                 tmp <<= 8;
1378                                 if ((stream->raw_mask & tmp) == 0)
1379                                         continue;
1380                                 if (periodic_usecs (ehci, frame, uf)
1381                                                 > max_used)
1382                                         return 0;
1383                         } while (++uf < 8);
1384                 }
1385
1386                 /* we know urb->interval is 2^N uframes */
1387                 uframe += period_uframes;
1388         } while (uframe < mod);
1389
1390         stream->splits = cpu_to_hc32(ehci, stream->raw_mask << (uframe & 7));
1391         return 1;
1392 }
1393
1394 /*
1395  * This scheduler plans almost as far into the future as it has actual
1396  * periodic schedule slots.  (Affected by TUNE_FLS, which defaults to
1397  * "as small as possible" to be cache-friendlier.)  That limits the size
1398  * transfers you can stream reliably; avoid more than 64 msec per urb.
1399  * Also avoid queue depths of less than ehci's worst irq latency (affected
1400  * by the per-urb URB_NO_INTERRUPT hint, the log2_irq_thresh module parameter,
1401  * and other factors); or more than about 230 msec total (for portability,
1402  * given EHCI_TUNE_FLS and the slop).  Or, write a smarter scheduler!
1403  */
1404
1405 #define SCHEDULE_SLOP   80      /* microframes */
1406
1407 static int
1408 iso_stream_schedule (
1409         struct ehci_hcd         *ehci,
1410         struct urb              *urb,
1411         struct ehci_iso_stream  *stream
1412 )
1413 {
1414         u32                     now, next, start, period, span;
1415         int                     status;
1416         unsigned                mod = ehci->periodic_size << 3;
1417         struct ehci_iso_sched   *sched = urb->hcpriv;
1418
1419         period = urb->interval;
1420         span = sched->span;
1421         if (!stream->highspeed) {
1422                 period <<= 3;
1423                 span <<= 3;
1424         }
1425
1426         if (span > mod - SCHEDULE_SLOP) {
1427                 ehci_dbg (ehci, "iso request %p too long\n", urb);
1428                 status = -EFBIG;
1429                 goto fail;
1430         }
1431
1432         now = ehci_read_frame_index(ehci) & (mod - 1);
1433
1434         /* Typical case: reuse current schedule, stream is still active.
1435          * Hopefully there are no gaps from the host falling behind
1436          * (irq delays etc), but if there are we'll take the next
1437          * slot in the schedule, implicitly assuming URB_ISO_ASAP.
1438          */
1439         if (likely (!list_empty (&stream->td_list))) {
1440                 u32     excess;
1441
1442                 /* For high speed devices, allow scheduling within the
1443                  * isochronous scheduling threshold.  For full speed devices
1444                  * and Intel PCI-based controllers, don't (work around for
1445                  * Intel ICH9 bug).
1446                  */
1447                 if (!stream->highspeed && ehci->fs_i_thresh)
1448                         next = now + ehci->i_thresh;
1449                 else
1450                         next = now;
1451
1452                 /* Fell behind (by up to twice the slop amount)?
1453                  * We decide based on the time of the last currently-scheduled
1454                  * slot, not the time of the next available slot.
1455                  */
1456                 excess = (stream->next_uframe - period - next) & (mod - 1);
1457                 if (excess >= mod - 2 * SCHEDULE_SLOP)
1458                         start = next + excess - mod + period *
1459                                         DIV_ROUND_UP(mod - excess, period);
1460                 else
1461                         start = next + excess + period;
1462                 if (start - now >= mod) {
1463                         ehci_dbg(ehci, "request %p would overflow (%d+%d >= %d)\n",
1464                                         urb, start - now - period, period,
1465                                         mod);
1466                         status = -EFBIG;
1467                         goto fail;
1468                 }
1469         }
1470
1471         /* need to schedule; when's the next (u)frame we could start?
1472          * this is bigger than ehci->i_thresh allows; scheduling itself
1473          * isn't free, the slop should handle reasonably slow cpus.  it
1474          * can also help high bandwidth if the dma and irq loads don't
1475          * jump until after the queue is primed.
1476          */
1477         else {
1478                 start = SCHEDULE_SLOP + (now & ~0x07);
1479
1480                 /* NOTE:  assumes URB_ISO_ASAP, to limit complexity/bugs */
1481
1482                 /* find a uframe slot with enough bandwidth */
1483                 next = start + period;
1484                 for (; start < next; start++) {
1485
1486                         /* check schedule: enough space? */
1487                         if (stream->highspeed) {
1488                                 if (itd_slot_ok(ehci, mod, start,
1489                                                 stream->usecs, period))
1490                                         break;
1491                         } else {
1492                                 if ((start % 8) >= 6)
1493                                         continue;
1494                                 if (sitd_slot_ok(ehci, mod, stream,
1495                                                 start, sched, period))
1496                                         break;
1497                         }
1498                 }
1499
1500                 /* no room in the schedule */
1501                 if (start == next) {
1502                         ehci_dbg(ehci, "iso resched full %p (now %d max %d)\n",
1503                                 urb, now, now + mod);
1504                         status = -ENOSPC;
1505                         goto fail;
1506                 }
1507         }
1508
1509         /* Tried to schedule too far into the future? */
1510         if (unlikely(start - now + span - period
1511                                 >= mod - 2 * SCHEDULE_SLOP)) {
1512                 ehci_dbg(ehci, "request %p would overflow (%d+%d >= %d)\n",
1513                                 urb, start - now, span - period,
1514                                 mod - 2 * SCHEDULE_SLOP);
1515                 status = -EFBIG;
1516                 goto fail;
1517         }
1518
1519         stream->next_uframe = start & (mod - 1);
1520
1521         /* report high speed start in uframes; full speed, in frames */
1522         urb->start_frame = stream->next_uframe;
1523         if (!stream->highspeed)
1524                 urb->start_frame >>= 3;
1525         return 0;
1526
1527  fail:
1528         iso_sched_free(stream, sched);
1529         urb->hcpriv = NULL;
1530         return status;
1531 }
1532
1533 /*-------------------------------------------------------------------------*/
1534
1535 static inline void
1536 itd_init(struct ehci_hcd *ehci, struct ehci_iso_stream *stream,
1537                 struct ehci_itd *itd)
1538 {
1539         int i;
1540
1541         /* it's been recently zeroed */
1542         itd->hw_next = EHCI_LIST_END(ehci);
1543         itd->hw_bufp [0] = stream->buf0;
1544         itd->hw_bufp [1] = stream->buf1;
1545         itd->hw_bufp [2] = stream->buf2;
1546
1547         for (i = 0; i < 8; i++)
1548                 itd->index[i] = -1;
1549
1550         /* All other fields are filled when scheduling */
1551 }
1552
1553 static inline void
1554 itd_patch(
1555         struct ehci_hcd         *ehci,
1556         struct ehci_itd         *itd,
1557         struct ehci_iso_sched   *iso_sched,
1558         unsigned                index,
1559         u16                     uframe
1560 )
1561 {
1562         struct ehci_iso_packet  *uf = &iso_sched->packet [index];
1563         unsigned                pg = itd->pg;
1564
1565         // BUG_ON (pg == 6 && uf->cross);
1566
1567         uframe &= 0x07;
1568         itd->index [uframe] = index;
1569
1570         itd->hw_transaction[uframe] = uf->transaction;
1571         itd->hw_transaction[uframe] |= cpu_to_hc32(ehci, pg << 12);
1572         itd->hw_bufp[pg] |= cpu_to_hc32(ehci, uf->bufp & ~(u32)0);
1573         itd->hw_bufp_hi[pg] |= cpu_to_hc32(ehci, (u32)(uf->bufp >> 32));
1574
1575         /* iso_frame_desc[].offset must be strictly increasing */
1576         if (unlikely (uf->cross)) {
1577                 u64     bufp = uf->bufp + 4096;
1578
1579                 itd->pg = ++pg;
1580                 itd->hw_bufp[pg] |= cpu_to_hc32(ehci, bufp & ~(u32)0);
1581                 itd->hw_bufp_hi[pg] |= cpu_to_hc32(ehci, (u32)(bufp >> 32));
1582         }
1583 }
1584
1585 static inline void
1586 itd_link (struct ehci_hcd *ehci, unsigned frame, struct ehci_itd *itd)
1587 {
1588         union ehci_shadow       *prev = &ehci->pshadow[frame];
1589         __hc32                  *hw_p = &ehci->periodic[frame];
1590         union ehci_shadow       here = *prev;
1591         __hc32                  type = 0;
1592
1593         /* skip any iso nodes which might belong to previous microframes */
1594         while (here.ptr) {
1595                 type = Q_NEXT_TYPE(ehci, *hw_p);
1596                 if (type == cpu_to_hc32(ehci, Q_TYPE_QH))
1597                         break;
1598                 prev = periodic_next_shadow(ehci, prev, type);
1599                 hw_p = shadow_next_periodic(ehci, &here, type);
1600                 here = *prev;
1601         }
1602
1603         itd->itd_next = here;
1604         itd->hw_next = *hw_p;
1605         prev->itd = itd;
1606         itd->frame = frame;
1607         wmb ();
1608         *hw_p = cpu_to_hc32(ehci, itd->itd_dma | Q_TYPE_ITD);
1609 }
1610
1611 /* fit urb's itds into the selected schedule slot; activate as needed */
1612 static int
1613 itd_link_urb (
1614         struct ehci_hcd         *ehci,
1615         struct urb              *urb,
1616         unsigned                mod,
1617         struct ehci_iso_stream  *stream
1618 )
1619 {
1620         int                     packet;
1621         unsigned                next_uframe, uframe, frame;
1622         struct ehci_iso_sched   *iso_sched = urb->hcpriv;
1623         struct ehci_itd         *itd;
1624
1625         next_uframe = stream->next_uframe & (mod - 1);
1626
1627         if (unlikely (list_empty(&stream->td_list))) {
1628                 ehci_to_hcd(ehci)->self.bandwidth_allocated
1629                                 += stream->bandwidth;
1630                 ehci_vdbg (ehci,
1631                         "schedule devp %s ep%d%s-iso period %d start %d.%d\n",
1632                         urb->dev->devpath, stream->bEndpointAddress & 0x0f,
1633                         (stream->bEndpointAddress & USB_DIR_IN) ? "in" : "out",
1634                         urb->interval,
1635                         next_uframe >> 3, next_uframe & 0x7);
1636         }
1637
1638         if (ehci_to_hcd(ehci)->self.bandwidth_isoc_reqs == 0) {
1639                 if (ehci->amd_pll_fix == 1)
1640                         usb_amd_quirk_pll_disable();
1641         }
1642
1643         ehci_to_hcd(ehci)->self.bandwidth_isoc_reqs++;
1644
1645         /* fill iTDs uframe by uframe */
1646         for (packet = 0, itd = NULL; packet < urb->number_of_packets; ) {
1647                 if (itd == NULL) {
1648                         /* ASSERT:  we have all necessary itds */
1649                         // BUG_ON (list_empty (&iso_sched->td_list));
1650
1651                         /* ASSERT:  no itds for this endpoint in this uframe */
1652
1653                         itd = list_entry (iso_sched->td_list.next,
1654                                         struct ehci_itd, itd_list);
1655                         list_move_tail (&itd->itd_list, &stream->td_list);
1656                         itd->stream = iso_stream_get (stream);
1657                         itd->urb = urb;
1658                         itd_init (ehci, stream, itd);
1659                 }
1660
1661                 uframe = next_uframe & 0x07;
1662                 frame = next_uframe >> 3;
1663
1664                 itd_patch(ehci, itd, iso_sched, packet, uframe);
1665
1666                 next_uframe += stream->interval;
1667                 next_uframe &= mod - 1;
1668                 packet++;
1669
1670                 /* link completed itds into the schedule */
1671                 if (((next_uframe >> 3) != frame)
1672                                 || packet == urb->number_of_packets) {
1673                         itd_link(ehci, frame & (ehci->periodic_size - 1), itd);
1674                         itd = NULL;
1675                 }
1676         }
1677         stream->next_uframe = next_uframe;
1678
1679         /* don't need that schedule data any more */
1680         iso_sched_free (stream, iso_sched);
1681         urb->hcpriv = NULL;
1682
1683         timer_action (ehci, TIMER_IO_WATCHDOG);
1684         return enable_periodic(ehci);
1685 }
1686
1687 #define ISO_ERRS (EHCI_ISOC_BUF_ERR | EHCI_ISOC_BABBLE | EHCI_ISOC_XACTERR)
1688
1689 /* Process and recycle a completed ITD.  Return true iff its urb completed,
1690  * and hence its completion callback probably added things to the hardware
1691  * schedule.
1692  *
1693  * Note that we carefully avoid recycling this descriptor until after any
1694  * completion callback runs, so that it won't be reused quickly.  That is,
1695  * assuming (a) no more than two urbs per frame on this endpoint, and also
1696  * (b) only this endpoint's completions submit URBs.  It seems some silicon
1697  * corrupts things if you reuse completed descriptors very quickly...
1698  */
1699 static unsigned
1700 itd_complete (
1701         struct ehci_hcd *ehci,
1702         struct ehci_itd *itd
1703 ) {
1704         struct urb                              *urb = itd->urb;
1705         struct usb_iso_packet_descriptor        *desc;
1706         u32                                     t;
1707         unsigned                                uframe;
1708         int                                     urb_index = -1;
1709         struct ehci_iso_stream                  *stream = itd->stream;
1710         struct usb_device                       *dev;
1711         unsigned                                retval = false;
1712
1713         /* for each uframe with a packet */
1714         for (uframe = 0; uframe < 8; uframe++) {
1715                 if (likely (itd->index[uframe] == -1))
1716                         continue;
1717                 urb_index = itd->index[uframe];
1718                 desc = &urb->iso_frame_desc [urb_index];
1719
1720                 t = hc32_to_cpup(ehci, &itd->hw_transaction [uframe]);
1721                 itd->hw_transaction [uframe] = 0;
1722
1723                 /* report transfer status */
1724                 if (unlikely (t & ISO_ERRS)) {
1725                         urb->error_count++;
1726                         if (t & EHCI_ISOC_BUF_ERR)
1727                                 desc->status = usb_pipein (urb->pipe)
1728                                         ? -ENOSR  /* hc couldn't read */
1729                                         : -ECOMM; /* hc couldn't write */
1730                         else if (t & EHCI_ISOC_BABBLE)
1731                                 desc->status = -EOVERFLOW;
1732                         else /* (t & EHCI_ISOC_XACTERR) */
1733                                 desc->status = -EPROTO;
1734
1735                         /* HC need not update length with this error */
1736                         if (!(t & EHCI_ISOC_BABBLE)) {
1737                                 desc->actual_length = EHCI_ITD_LENGTH(t);
1738                                 urb->actual_length += desc->actual_length;
1739                         }
1740                 } else if (likely ((t & EHCI_ISOC_ACTIVE) == 0)) {
1741                         desc->status = 0;
1742                         desc->actual_length = EHCI_ITD_LENGTH(t);
1743                         urb->actual_length += desc->actual_length;
1744                 } else {
1745                         /* URB was too late */
1746                         desc->status = -EXDEV;
1747                 }
1748         }
1749
1750         /* handle completion now? */
1751         if (likely ((urb_index + 1) != urb->number_of_packets))
1752                 goto done;
1753
1754         /* ASSERT: it's really the last itd for this urb
1755         list_for_each_entry (itd, &stream->td_list, itd_list)
1756                 BUG_ON (itd->urb == urb);
1757          */
1758
1759         /* give urb back to the driver; completion often (re)submits */
1760         dev = urb->dev;
1761         ehci_urb_done(ehci, urb, 0);
1762         retval = true;
1763         urb = NULL;
1764         (void) disable_periodic(ehci);
1765         ehci_to_hcd(ehci)->self.bandwidth_isoc_reqs--;
1766
1767         if (ehci_to_hcd(ehci)->self.bandwidth_isoc_reqs == 0) {
1768                 if (ehci->amd_pll_fix == 1)
1769                         usb_amd_quirk_pll_enable();
1770         }
1771
1772         if (unlikely(list_is_singular(&stream->td_list))) {
1773                 ehci_to_hcd(ehci)->self.bandwidth_allocated
1774                                 -= stream->bandwidth;
1775                 ehci_vdbg (ehci,
1776                         "deschedule devp %s ep%d%s-iso\n",
1777                         dev->devpath, stream->bEndpointAddress & 0x0f,
1778                         (stream->bEndpointAddress & USB_DIR_IN) ? "in" : "out");
1779         }
1780         iso_stream_put (ehci, stream);
1781
1782 done:
1783         itd->urb = NULL;
1784         if (ehci->clock_frame != itd->frame || itd->index[7] != -1) {
1785                 /* OK to recycle this ITD now. */
1786                 itd->stream = NULL;
1787                 list_move(&itd->itd_list, &stream->free_list);
1788                 iso_stream_put(ehci, stream);
1789         } else {
1790                 /* HW might remember this ITD, so we can't recycle it yet.
1791                  * Move it to a safe place until a new frame starts.
1792                  */
1793                 list_move(&itd->itd_list, &ehci->cached_itd_list);
1794                 if (stream->refcount == 2) {
1795                         /* If iso_stream_put() were called here, stream
1796                          * would be freed.  Instead, just prevent reuse.
1797                          */
1798                         stream->ep->hcpriv = NULL;
1799                         stream->ep = NULL;
1800                 }
1801         }
1802         return retval;
1803 }
1804
1805 /*-------------------------------------------------------------------------*/
1806
1807 static int itd_submit (struct ehci_hcd *ehci, struct urb *urb,
1808         gfp_t mem_flags)
1809 {
1810         int                     status = -EINVAL;
1811         unsigned long           flags;
1812         struct ehci_iso_stream  *stream;
1813
1814         /* Get iso_stream head */
1815         stream = iso_stream_find (ehci, urb);
1816         if (unlikely (stream == NULL)) {
1817                 ehci_dbg (ehci, "can't get iso stream\n");
1818                 return -ENOMEM;
1819         }
1820         if (unlikely (urb->interval != stream->interval)) {
1821                 ehci_dbg (ehci, "can't change iso interval %d --> %d\n",
1822                         stream->interval, urb->interval);
1823                 goto done;
1824         }
1825
1826 #ifdef EHCI_URB_TRACE
1827         ehci_dbg (ehci,
1828                 "%s %s urb %p ep%d%s len %d, %d pkts %d uframes [%p]\n",
1829                 __func__, urb->dev->devpath, urb,
1830                 usb_pipeendpoint (urb->pipe),
1831                 usb_pipein (urb->pipe) ? "in" : "out",
1832                 urb->transfer_buffer_length,
1833                 urb->number_of_packets, urb->interval,
1834                 stream);
1835 #endif
1836
1837         /* allocate ITDs w/o locking anything */
1838         status = itd_urb_transaction (stream, ehci, urb, mem_flags);
1839         if (unlikely (status < 0)) {
1840                 ehci_dbg (ehci, "can't init itds\n");
1841                 goto done;
1842         }
1843
1844         /* schedule ... need to lock */
1845         spin_lock_irqsave (&ehci->lock, flags);
1846         if (unlikely(!HCD_HW_ACCESSIBLE(ehci_to_hcd(ehci)))) {
1847                 status = -ESHUTDOWN;
1848                 goto done_not_linked;
1849         }
1850         status = usb_hcd_link_urb_to_ep(ehci_to_hcd(ehci), urb);
1851         if (unlikely(status))
1852                 goto done_not_linked;
1853         status = iso_stream_schedule(ehci, urb, stream);
1854         if (likely (status == 0))
1855                 itd_link_urb (ehci, urb, ehci->periodic_size << 3, stream);
1856         else
1857                 usb_hcd_unlink_urb_from_ep(ehci_to_hcd(ehci), urb);
1858 done_not_linked:
1859         spin_unlock_irqrestore (&ehci->lock, flags);
1860
1861 done:
1862         if (unlikely (status < 0))
1863                 iso_stream_put (ehci, stream);
1864         return status;
1865 }
1866
1867 /*-------------------------------------------------------------------------*/
1868
1869 /*
1870  * "Split ISO TDs" ... used for USB 1.1 devices going through the
1871  * TTs in USB 2.0 hubs.  These need microframe scheduling.
1872  */
1873
1874 static inline void
1875 sitd_sched_init(
1876         struct ehci_hcd         *ehci,
1877         struct ehci_iso_sched   *iso_sched,
1878         struct ehci_iso_stream  *stream,
1879         struct urb              *urb
1880 )
1881 {
1882         unsigned        i;
1883         dma_addr_t      dma = urb->transfer_dma;
1884
1885         /* how many frames are needed for these transfers */
1886         iso_sched->span = urb->number_of_packets * stream->interval;
1887
1888         /* figure out per-frame sitd fields that we'll need later
1889          * when we fit new sitds into the schedule.
1890          */
1891         for (i = 0; i < urb->number_of_packets; i++) {
1892                 struct ehci_iso_packet  *packet = &iso_sched->packet [i];
1893                 unsigned                length;
1894                 dma_addr_t              buf;
1895                 u32                     trans;
1896
1897                 length = urb->iso_frame_desc [i].length & 0x03ff;
1898                 buf = dma + urb->iso_frame_desc [i].offset;
1899
1900                 trans = SITD_STS_ACTIVE;
1901                 if (((i + 1) == urb->number_of_packets)
1902                                 && !(urb->transfer_flags & URB_NO_INTERRUPT))
1903                         trans |= SITD_IOC;
1904                 trans |= length << 16;
1905                 packet->transaction = cpu_to_hc32(ehci, trans);
1906
1907                 /* might need to cross a buffer page within a td */
1908                 packet->bufp = buf;
1909                 packet->buf1 = (buf + length) & ~0x0fff;
1910                 if (packet->buf1 != (buf & ~(u64)0x0fff))
1911                         packet->cross = 1;
1912
1913                 /* OUT uses multiple start-splits */
1914                 if (stream->bEndpointAddress & USB_DIR_IN)
1915                         continue;
1916                 length = (length + 187) / 188;
1917                 if (length > 1) /* BEGIN vs ALL */
1918                         length |= 1 << 3;
1919                 packet->buf1 |= length;
1920         }
1921 }
1922
1923 static int
1924 sitd_urb_transaction (
1925         struct ehci_iso_stream  *stream,
1926         struct ehci_hcd         *ehci,
1927         struct urb              *urb,
1928         gfp_t                   mem_flags
1929 )
1930 {
1931         struct ehci_sitd        *sitd;
1932         dma_addr_t              sitd_dma;
1933         int                     i;
1934         struct ehci_iso_sched   *iso_sched;
1935         unsigned long           flags;
1936
1937         iso_sched = iso_sched_alloc (urb->number_of_packets, mem_flags);
1938         if (iso_sched == NULL)
1939                 return -ENOMEM;
1940
1941         sitd_sched_init(ehci, iso_sched, stream, urb);
1942
1943         /* allocate/init sITDs */
1944         spin_lock_irqsave (&ehci->lock, flags);
1945         for (i = 0; i < urb->number_of_packets; i++) {
1946
1947                 /* NOTE:  for now, we don't try to handle wraparound cases
1948                  * for IN (using sitd->hw_backpointer, like a FSTN), which
1949                  * means we never need two sitds for full speed packets.
1950                  */
1951
1952                 /* free_list.next might be cache-hot ... but maybe
1953                  * the HC caches it too. avoid that issue for now.
1954                  */
1955
1956                 /* prefer previously-allocated sitds */
1957                 if (!list_empty(&stream->free_list)) {
1958                         sitd = list_entry (stream->free_list.prev,
1959                                          struct ehci_sitd, sitd_list);
1960                         list_del (&sitd->sitd_list);
1961                         sitd_dma = sitd->sitd_dma;
1962                 } else {
1963                         spin_unlock_irqrestore (&ehci->lock, flags);
1964                         sitd = dma_pool_alloc (ehci->sitd_pool, mem_flags,
1965                                         &sitd_dma);
1966                         spin_lock_irqsave (&ehci->lock, flags);
1967                         if (!sitd) {
1968                                 iso_sched_free(stream, iso_sched);
1969                                 spin_unlock_irqrestore(&ehci->lock, flags);
1970                                 return -ENOMEM;
1971                         }
1972                 }
1973
1974                 memset (sitd, 0, sizeof *sitd);
1975                 sitd->sitd_dma = sitd_dma;
1976                 list_add (&sitd->sitd_list, &iso_sched->td_list);
1977         }
1978
1979         /* temporarily store schedule info in hcpriv */
1980         urb->hcpriv = iso_sched;
1981         urb->error_count = 0;
1982
1983         spin_unlock_irqrestore (&ehci->lock, flags);
1984         return 0;
1985 }
1986
1987 /*-------------------------------------------------------------------------*/
1988
1989 static inline void
1990 sitd_patch(
1991         struct ehci_hcd         *ehci,
1992         struct ehci_iso_stream  *stream,
1993         struct ehci_sitd        *sitd,
1994         struct ehci_iso_sched   *iso_sched,
1995         unsigned                index
1996 )
1997 {
1998         struct ehci_iso_packet  *uf = &iso_sched->packet [index];
1999         u64                     bufp = uf->bufp;
2000
2001         sitd->hw_next = EHCI_LIST_END(ehci);
2002         sitd->hw_fullspeed_ep = stream->address;
2003         sitd->hw_uframe = stream->splits;
2004         sitd->hw_results = uf->transaction;
2005         sitd->hw_backpointer = EHCI_LIST_END(ehci);
2006
2007         bufp = uf->bufp;
2008         sitd->hw_buf[0] = cpu_to_hc32(ehci, bufp);
2009         sitd->hw_buf_hi[0] = cpu_to_hc32(ehci, bufp >> 32);
2010
2011         sitd->hw_buf[1] = cpu_to_hc32(ehci, uf->buf1);
2012         if (uf->cross)
2013                 bufp += 4096;
2014         sitd->hw_buf_hi[1] = cpu_to_hc32(ehci, bufp >> 32);
2015         sitd->index = index;
2016 }
2017
2018 static inline void
2019 sitd_link (struct ehci_hcd *ehci, unsigned frame, struct ehci_sitd *sitd)
2020 {
2021         /* note: sitd ordering could matter (CSPLIT then SSPLIT) */
2022         sitd->sitd_next = ehci->pshadow [frame];
2023         sitd->hw_next = ehci->periodic [frame];
2024         ehci->pshadow [frame].sitd = sitd;
2025         sitd->frame = frame;
2026         wmb ();
2027         ehci->periodic[frame] = cpu_to_hc32(ehci, sitd->sitd_dma | Q_TYPE_SITD);
2028 }
2029
2030 /* fit urb's sitds into the selected schedule slot; activate as needed */
2031 static int
2032 sitd_link_urb (
2033         struct ehci_hcd         *ehci,
2034         struct urb              *urb,
2035         unsigned                mod,
2036         struct ehci_iso_stream  *stream
2037 )
2038 {
2039         int                     packet;
2040         unsigned                next_uframe;
2041         struct ehci_iso_sched   *sched = urb->hcpriv;
2042         struct ehci_sitd        *sitd;
2043
2044         next_uframe = stream->next_uframe;
2045
2046         if (list_empty(&stream->td_list)) {
2047                 /* usbfs ignores TT bandwidth */
2048                 ehci_to_hcd(ehci)->self.bandwidth_allocated
2049                                 += stream->bandwidth;
2050                 ehci_vdbg (ehci,
2051                         "sched devp %s ep%d%s-iso [%d] %dms/%04x\n",
2052                         urb->dev->devpath, stream->bEndpointAddress & 0x0f,
2053                         (stream->bEndpointAddress & USB_DIR_IN) ? "in" : "out",
2054                         (next_uframe >> 3) & (ehci->periodic_size - 1),
2055                         stream->interval, hc32_to_cpu(ehci, stream->splits));
2056         }
2057
2058         if (ehci_to_hcd(ehci)->self.bandwidth_isoc_reqs == 0) {
2059                 if (ehci->amd_pll_fix == 1)
2060                         usb_amd_quirk_pll_disable();
2061         }
2062
2063         ehci_to_hcd(ehci)->self.bandwidth_isoc_reqs++;
2064
2065         /* fill sITDs frame by frame */
2066         for (packet = 0, sitd = NULL;
2067                         packet < urb->number_of_packets;
2068                         packet++) {
2069
2070                 /* ASSERT:  we have all necessary sitds */
2071                 BUG_ON (list_empty (&sched->td_list));
2072
2073                 /* ASSERT:  no itds for this endpoint in this frame */
2074
2075                 sitd = list_entry (sched->td_list.next,
2076                                 struct ehci_sitd, sitd_list);
2077                 list_move_tail (&sitd->sitd_list, &stream->td_list);
2078                 sitd->stream = iso_stream_get (stream);
2079                 sitd->urb = urb;
2080
2081                 sitd_patch(ehci, stream, sitd, sched, packet);
2082                 sitd_link(ehci, (next_uframe >> 3) & (ehci->periodic_size - 1),
2083                                 sitd);
2084
2085                 next_uframe += stream->interval << 3;
2086         }
2087         stream->next_uframe = next_uframe & (mod - 1);
2088
2089         /* don't need that schedule data any more */
2090         iso_sched_free (stream, sched);
2091         urb->hcpriv = NULL;
2092
2093         timer_action (ehci, TIMER_IO_WATCHDOG);
2094         return enable_periodic(ehci);
2095 }
2096
2097 /*-------------------------------------------------------------------------*/
2098
2099 #define SITD_ERRS (SITD_STS_ERR | SITD_STS_DBE | SITD_STS_BABBLE \
2100                                 | SITD_STS_XACT | SITD_STS_MMF)
2101
2102 /* Process and recycle a completed SITD.  Return true iff its urb completed,
2103  * and hence its completion callback probably added things to the hardware
2104  * schedule.
2105  *
2106  * Note that we carefully avoid recycling this descriptor until after any
2107  * completion callback runs, so that it won't be reused quickly.  That is,
2108  * assuming (a) no more than two urbs per frame on this endpoint, and also
2109  * (b) only this endpoint's completions submit URBs.  It seems some silicon
2110  * corrupts things if you reuse completed descriptors very quickly...
2111  */
2112 static unsigned
2113 sitd_complete (
2114         struct ehci_hcd         *ehci,
2115         struct ehci_sitd        *sitd
2116 ) {
2117         struct urb                              *urb = sitd->urb;
2118         struct usb_iso_packet_descriptor        *desc;
2119         u32                                     t;
2120         int                                     urb_index = -1;
2121         struct ehci_iso_stream                  *stream = sitd->stream;
2122         struct usb_device                       *dev;
2123         unsigned                                retval = false;
2124
2125         urb_index = sitd->index;
2126         desc = &urb->iso_frame_desc [urb_index];
2127         t = hc32_to_cpup(ehci, &sitd->hw_results);
2128
2129         /* report transfer status */
2130         if (t & SITD_ERRS) {
2131                 urb->error_count++;
2132                 if (t & SITD_STS_DBE)
2133                         desc->status = usb_pipein (urb->pipe)
2134                                 ? -ENOSR  /* hc couldn't read */
2135                                 : -ECOMM; /* hc couldn't write */
2136                 else if (t & SITD_STS_BABBLE)
2137                         desc->status = -EOVERFLOW;
2138                 else /* XACT, MMF, etc */
2139                         desc->status = -EPROTO;
2140         } else {
2141                 desc->status = 0;
2142                 desc->actual_length = desc->length - SITD_LENGTH(t);
2143                 urb->actual_length += desc->actual_length;
2144         }
2145
2146         /* handle completion now? */
2147         if ((urb_index + 1) != urb->number_of_packets)
2148                 goto done;
2149
2150         /* ASSERT: it's really the last sitd for this urb
2151         list_for_each_entry (sitd, &stream->td_list, sitd_list)
2152                 BUG_ON (sitd->urb == urb);
2153          */
2154
2155         /* give urb back to the driver; completion often (re)submits */
2156         dev = urb->dev;
2157         ehci_urb_done(ehci, urb, 0);
2158         retval = true;
2159         urb = NULL;
2160         (void) disable_periodic(ehci);
2161         ehci_to_hcd(ehci)->self.bandwidth_isoc_reqs--;
2162
2163         if (ehci_to_hcd(ehci)->self.bandwidth_isoc_reqs == 0) {
2164                 if (ehci->amd_pll_fix == 1)
2165                         usb_amd_quirk_pll_enable();
2166         }
2167
2168         if (list_is_singular(&stream->td_list)) {
2169                 ehci_to_hcd(ehci)->self.bandwidth_allocated
2170                                 -= stream->bandwidth;
2171                 ehci_vdbg (ehci,
2172                         "deschedule devp %s ep%d%s-iso\n",
2173                         dev->devpath, stream->bEndpointAddress & 0x0f,
2174                         (stream->bEndpointAddress & USB_DIR_IN) ? "in" : "out");
2175         }
2176         iso_stream_put (ehci, stream);
2177
2178 done:
2179         sitd->urb = NULL;
2180         if (ehci->clock_frame != sitd->frame) {
2181                 /* OK to recycle this SITD now. */
2182                 sitd->stream = NULL;
2183                 list_move(&sitd->sitd_list, &stream->free_list);
2184                 iso_stream_put(ehci, stream);
2185         } else {
2186                 /* HW might remember this SITD, so we can't recycle it yet.
2187                  * Move it to a safe place until a new frame starts.
2188                  */
2189                 list_move(&sitd->sitd_list, &ehci->cached_sitd_list);
2190                 if (stream->refcount == 2) {
2191                         /* If iso_stream_put() were called here, stream
2192                          * would be freed.  Instead, just prevent reuse.
2193                          */
2194                         stream->ep->hcpriv = NULL;
2195                         stream->ep = NULL;
2196                 }
2197         }
2198         return retval;
2199 }
2200
2201
2202 static int sitd_submit (struct ehci_hcd *ehci, struct urb *urb,
2203         gfp_t mem_flags)
2204 {
2205         int                     status = -EINVAL;
2206         unsigned long           flags;
2207         struct ehci_iso_stream  *stream;
2208
2209         /* Get iso_stream head */
2210         stream = iso_stream_find (ehci, urb);
2211         if (stream == NULL) {
2212                 ehci_dbg (ehci, "can't get iso stream\n");
2213                 return -ENOMEM;
2214         }
2215         if (urb->interval != stream->interval) {
2216                 ehci_dbg (ehci, "can't change iso interval %d --> %d\n",
2217                         stream->interval, urb->interval);
2218                 goto done;
2219         }
2220
2221 #ifdef EHCI_URB_TRACE
2222         ehci_dbg (ehci,
2223                 "submit %p dev%s ep%d%s-iso len %d\n",
2224                 urb, urb->dev->devpath,
2225                 usb_pipeendpoint (urb->pipe),
2226                 usb_pipein (urb->pipe) ? "in" : "out",
2227                 urb->transfer_buffer_length);
2228 #endif
2229
2230         /* allocate SITDs */
2231         status = sitd_urb_transaction (stream, ehci, urb, mem_flags);
2232         if (status < 0) {
2233                 ehci_dbg (ehci, "can't init sitds\n");
2234                 goto done;
2235         }
2236
2237         /* schedule ... need to lock */
2238         spin_lock_irqsave (&ehci->lock, flags);
2239         if (unlikely(!HCD_HW_ACCESSIBLE(ehci_to_hcd(ehci)))) {
2240                 status = -ESHUTDOWN;
2241                 goto done_not_linked;
2242         }
2243         status = usb_hcd_link_urb_to_ep(ehci_to_hcd(ehci), urb);
2244         if (unlikely(status))
2245                 goto done_not_linked;
2246         status = iso_stream_schedule(ehci, urb, stream);
2247         if (status == 0)
2248                 sitd_link_urb (ehci, urb, ehci->periodic_size << 3, stream);
2249         else
2250                 usb_hcd_unlink_urb_from_ep(ehci_to_hcd(ehci), urb);
2251 done_not_linked:
2252         spin_unlock_irqrestore (&ehci->lock, flags);
2253
2254 done:
2255         if (status < 0)
2256                 iso_stream_put (ehci, stream);
2257         return status;
2258 }
2259
2260 /*-------------------------------------------------------------------------*/
2261
2262 static void free_cached_lists(struct ehci_hcd *ehci)
2263 {
2264         struct ehci_itd *itd, *n;
2265         struct ehci_sitd *sitd, *sn;
2266
2267         list_for_each_entry_safe(itd, n, &ehci->cached_itd_list, itd_list) {
2268                 struct ehci_iso_stream  *stream = itd->stream;
2269                 itd->stream = NULL;
2270                 list_move(&itd->itd_list, &stream->free_list);
2271                 iso_stream_put(ehci, stream);
2272         }
2273
2274         list_for_each_entry_safe(sitd, sn, &ehci->cached_sitd_list, sitd_list) {
2275                 struct ehci_iso_stream  *stream = sitd->stream;
2276                 sitd->stream = NULL;
2277                 list_move(&sitd->sitd_list, &stream->free_list);
2278                 iso_stream_put(ehci, stream);
2279         }
2280 }
2281
2282 /*-------------------------------------------------------------------------*/
2283
2284 static void
2285 scan_periodic (struct ehci_hcd *ehci)
2286 {
2287         unsigned        now_uframe, frame, clock, clock_frame, mod;
2288         unsigned        modified;
2289
2290         mod = ehci->periodic_size << 3;
2291
2292         /*
2293          * When running, scan from last scan point up to "now"
2294          * else clean up by scanning everything that's left.
2295          * Touches as few pages as possible:  cache-friendly.
2296          */
2297         now_uframe = ehci->next_uframe;
2298         if (ehci->rh_state == EHCI_RH_RUNNING) {
2299                 clock = ehci_read_frame_index(ehci);
2300                 clock_frame = (clock >> 3) & (ehci->periodic_size - 1);
2301         } else  {
2302                 clock = now_uframe + mod - 1;
2303                 clock_frame = -1;
2304         }
2305         if (ehci->clock_frame != clock_frame) {
2306                 free_cached_lists(ehci);
2307                 ehci->clock_frame = clock_frame;
2308         }
2309         clock &= mod - 1;
2310         clock_frame = clock >> 3;
2311         ++ehci->periodic_stamp;
2312
2313         for (;;) {
2314                 union ehci_shadow       q, *q_p;
2315                 __hc32                  type, *hw_p;
2316                 unsigned                incomplete = false;
2317
2318                 frame = now_uframe >> 3;
2319
2320 restart:
2321                 /* scan each element in frame's queue for completions */
2322                 q_p = &ehci->pshadow [frame];
2323                 hw_p = &ehci->periodic [frame];
2324                 q.ptr = q_p->ptr;
2325                 type = Q_NEXT_TYPE(ehci, *hw_p);
2326                 modified = 0;
2327
2328                 while (q.ptr != NULL) {
2329                         unsigned                uf;
2330                         union ehci_shadow       temp;
2331                         int                     live;
2332
2333                         live = (ehci->rh_state == EHCI_RH_RUNNING);
2334                         switch (hc32_to_cpu(ehci, type)) {
2335                         case Q_TYPE_QH:
2336                                 /* handle any completions */
2337                                 temp.qh = qh_get (q.qh);
2338                                 type = Q_NEXT_TYPE(ehci, q.qh->hw->hw_next);
2339                                 q = q.qh->qh_next;
2340                                 if (temp.qh->stamp != ehci->periodic_stamp) {
2341                                         modified = qh_completions(ehci, temp.qh);
2342                                         if (!modified)
2343                                                 temp.qh->stamp = ehci->periodic_stamp;
2344                                         if (unlikely(list_empty(&temp.qh->qtd_list) ||
2345                                                         temp.qh->needs_rescan))
2346                                                 intr_deschedule(ehci, temp.qh);
2347                                 }
2348                                 qh_put (temp.qh);
2349                                 break;
2350                         case Q_TYPE_FSTN:
2351                                 /* for "save place" FSTNs, look at QH entries
2352                                  * in the previous frame for completions.
2353                                  */
2354                                 if (q.fstn->hw_prev != EHCI_LIST_END(ehci)) {
2355                                         dbg ("ignoring completions from FSTNs");
2356                                 }
2357                                 type = Q_NEXT_TYPE(ehci, q.fstn->hw_next);
2358                                 q = q.fstn->fstn_next;
2359                                 break;
2360                         case Q_TYPE_ITD:
2361                                 /* If this ITD is still active, leave it for
2362                                  * later processing ... check the next entry.
2363                                  * No need to check for activity unless the
2364                                  * frame is current.
2365                                  */
2366                                 if (frame == clock_frame && live) {
2367                                         rmb();
2368                                         for (uf = 0; uf < 8; uf++) {
2369                                                 if (q.itd->hw_transaction[uf] &
2370                                                             ITD_ACTIVE(ehci))
2371                                                         break;
2372                                         }
2373                                         if (uf < 8) {
2374                                                 incomplete = true;
2375                                                 q_p = &q.itd->itd_next;
2376                                                 hw_p = &q.itd->hw_next;
2377                                                 type = Q_NEXT_TYPE(ehci,
2378                                                         q.itd->hw_next);
2379                                                 q = *q_p;
2380                                                 break;
2381                                         }
2382                                 }
2383
2384                                 /* Take finished ITDs out of the schedule
2385                                  * and process them:  recycle, maybe report
2386                                  * URB completion.  HC won't cache the
2387                                  * pointer for much longer, if at all.
2388                                  */
2389                                 *q_p = q.itd->itd_next;
2390                                 if (!ehci->use_dummy_qh ||
2391                                     q.itd->hw_next != EHCI_LIST_END(ehci))
2392                                         *hw_p = q.itd->hw_next;
2393                                 else
2394                                         *hw_p = ehci->dummy->qh_dma;
2395                                 type = Q_NEXT_TYPE(ehci, q.itd->hw_next);
2396                                 wmb();
2397                                 modified = itd_complete (ehci, q.itd);
2398                                 q = *q_p;
2399                                 break;
2400                         case Q_TYPE_SITD:
2401                                 /* If this SITD is still active, leave it for
2402                                  * later processing ... check the next entry.
2403                                  * No need to check for activity unless the
2404                                  * frame is current.
2405                                  */
2406                                 if (((frame == clock_frame) ||
2407                                      (((frame + 1) & (ehci->periodic_size - 1))
2408                                       == clock_frame))
2409                                     && live
2410                                     && (q.sitd->hw_results &
2411                                         SITD_ACTIVE(ehci))) {
2412
2413                                         incomplete = true;
2414                                         q_p = &q.sitd->sitd_next;
2415                                         hw_p = &q.sitd->hw_next;
2416                                         type = Q_NEXT_TYPE(ehci,
2417                                                         q.sitd->hw_next);
2418                                         q = *q_p;
2419                                         break;
2420                                 }
2421
2422                                 /* Take finished SITDs out of the schedule
2423                                  * and process them:  recycle, maybe report
2424                                  * URB completion.
2425                                  */
2426                                 *q_p = q.sitd->sitd_next;
2427                                 if (!ehci->use_dummy_qh ||
2428                                     q.sitd->hw_next != EHCI_LIST_END(ehci))
2429                                         *hw_p = q.sitd->hw_next;
2430                                 else
2431                                         *hw_p = ehci->dummy->qh_dma;
2432                                 type = Q_NEXT_TYPE(ehci, q.sitd->hw_next);
2433                                 wmb();
2434                                 modified = sitd_complete (ehci, q.sitd);
2435                                 q = *q_p;
2436                                 break;
2437                         default:
2438                                 dbg ("corrupt type %d frame %d shadow %p",
2439                                         type, frame, q.ptr);
2440                                 // BUG ();
2441                                 q.ptr = NULL;
2442                         }
2443
2444                         /* assume completion callbacks modify the queue */
2445                         if (unlikely (modified)) {
2446                                 if (likely(ehci->periodic_sched > 0))
2447                                         goto restart;
2448                                 /* short-circuit this scan */
2449                                 now_uframe = clock;
2450                                 break;
2451                         }
2452                 }
2453
2454                 /* If we can tell we caught up to the hardware, stop now.
2455                  * We can't advance our scan without collecting the ISO
2456                  * transfers that are still pending in this frame.
2457                  */
2458                 if (incomplete && ehci->rh_state == EHCI_RH_RUNNING) {
2459                         ehci->next_uframe = now_uframe;
2460                         break;
2461                 }
2462
2463                 // FIXME:  this assumes we won't get lapped when
2464                 // latencies climb; that should be rare, but...
2465                 // detect it, and just go all the way around.
2466                 // FLR might help detect this case, so long as latencies
2467                 // don't exceed periodic_size msec (default 1.024 sec).
2468
2469                 // FIXME:  likewise assumes HC doesn't halt mid-scan
2470
2471                 if (now_uframe == clock) {
2472                         unsigned        now;
2473
2474                         if (ehci->rh_state != EHCI_RH_RUNNING
2475                                         || ehci->periodic_sched == 0)
2476                                 break;
2477                         ehci->next_uframe = now_uframe;
2478                         now = ehci_read_frame_index(ehci) & (mod - 1);
2479                         if (now_uframe == now)
2480                                 break;
2481
2482                         /* rescan the rest of this frame, then ... */
2483                         clock = now;
2484                         clock_frame = clock >> 3;
2485                         if (ehci->clock_frame != clock_frame) {
2486                                 free_cached_lists(ehci);
2487                                 ehci->clock_frame = clock_frame;
2488                                 ++ehci->periodic_stamp;
2489                         }
2490                 } else {
2491                         now_uframe++;
2492                         now_uframe &= mod - 1;
2493                 }
2494         }
2495 }