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
  37static int ehci_get_frame(struct usb_hcd *hcd);
  38
  39/*
  40 * periodic_next_shadow - return "next" pointer on shadow list
  41 * @periodic: host pointer to qh/itd/sitd
  42 * @tag: hardware tag for type of this record
  43 */
  44static union ehci_shadow *
  45periodic_next_shadow(struct ehci_hcd *ehci, union ehci_shadow *periodic,
  46		__hc32 tag)
  47{
  48	switch (hc32_to_cpu(ehci, tag)) {
  49	case Q_TYPE_QH:
  50		return &periodic->qh->qh_next;
  51	case Q_TYPE_FSTN:
  52		return &periodic->fstn->fstn_next;
  53	case Q_TYPE_ITD:
  54		return &periodic->itd->itd_next;
  55	/* case Q_TYPE_SITD: */
  56	default:
  57		return &periodic->sitd->sitd_next;
  58	}
  59}
  60
  61static __hc32 *
  62shadow_next_periodic(struct ehci_hcd *ehci, union ehci_shadow *periodic,
  63		__hc32 tag)
  64{
  65	switch (hc32_to_cpu(ehci, tag)) {
  66	/* our ehci_shadow.qh is actually software part */
  67	case Q_TYPE_QH:
  68		return &periodic->qh->hw->hw_next;
  69	/* others are hw parts */
  70	default:
  71		return periodic->hw_next;
  72	}
  73}
  74
  75/* caller must hold ehci->lock */
  76static void periodic_unlink(struct ehci_hcd *ehci, unsigned frame, void *ptr)
  77{
  78	union ehci_shadow	*prev_p = &ehci->pshadow[frame];
  79	__hc32			*hw_p = &ehci->periodic[frame];
  80	union ehci_shadow	here = *prev_p;
  81
  82	/* find predecessor of "ptr"; hw and shadow lists are in sync */
  83	while (here.ptr && here.ptr != ptr) {
  84		prev_p = periodic_next_shadow(ehci, prev_p,
  85				Q_NEXT_TYPE(ehci, *hw_p));
  86		hw_p = shadow_next_periodic(ehci, &here,
  87				Q_NEXT_TYPE(ehci, *hw_p));
  88		here = *prev_p;
  89	}
  90	/* an interrupt entry (at list end) could have been shared */
  91	if (!here.ptr)
  92		return;
  93
  94	/* update shadow and hardware lists ... the old "next" pointers
  95	 * from ptr may still be in use, the caller updates them.
  96	 */
  97	*prev_p = *periodic_next_shadow(ehci, &here,
  98			Q_NEXT_TYPE(ehci, *hw_p));
  99
 100	if (!ehci->use_dummy_qh ||
 101	    *shadow_next_periodic(ehci, &here, Q_NEXT_TYPE(ehci, *hw_p))
 102			!= EHCI_LIST_END(ehci))
 103		*hw_p = *shadow_next_periodic(ehci, &here,
 104				Q_NEXT_TYPE(ehci, *hw_p));
 105	else
 106		*hw_p = cpu_to_hc32(ehci, ehci->dummy->qh_dma);
 107}
 108
 109/*-------------------------------------------------------------------------*/
 110
 111/* Bandwidth and TT management */
 112
 113/* Find the TT data structure for this device; create it if necessary */
 114static struct ehci_tt *find_tt(struct usb_device *udev)
 115{
 116	struct usb_tt		*utt = udev->tt;
 117	struct ehci_tt		*tt, **tt_index, **ptt;
 118	unsigned		port;
 119	bool			allocated_index = false;
 120
 121	if (!utt)
 122		return NULL;		/* Not below a TT */
 123
 124	/*
 125	 * Find/create our data structure.
 126	 * For hubs with a single TT, we get it directly.
 127	 * For hubs with multiple TTs, there's an extra level of pointers.
 128	 */
 129	tt_index = NULL;
 130	if (utt->multi) {
 131		tt_index = utt->hcpriv;
 132		if (!tt_index) {		/* Create the index array */
 133			tt_index = kzalloc(utt->hub->maxchild *
 134					sizeof(*tt_index), GFP_ATOMIC);
 
 135			if (!tt_index)
 136				return ERR_PTR(-ENOMEM);
 137			utt->hcpriv = tt_index;
 138			allocated_index = true;
 139		}
 140		port = udev->ttport - 1;
 141		ptt = &tt_index[port];
 142	} else {
 143		port = 0;
 144		ptt = (struct ehci_tt **) &utt->hcpriv;
 145	}
 146
 147	tt = *ptt;
 148	if (!tt) {				/* Create the ehci_tt */
 149		struct ehci_hcd		*ehci =
 150				hcd_to_ehci(bus_to_hcd(udev->bus));
 151
 152		tt = kzalloc(sizeof(*tt), GFP_ATOMIC);
 153		if (!tt) {
 154			if (allocated_index) {
 155				utt->hcpriv = NULL;
 156				kfree(tt_index);
 157			}
 158			return ERR_PTR(-ENOMEM);
 159		}
 160		list_add_tail(&tt->tt_list, &ehci->tt_list);
 161		INIT_LIST_HEAD(&tt->ps_list);
 162		tt->usb_tt = utt;
 163		tt->tt_port = port;
 164		*ptt = tt;
 165	}
 166
 167	return tt;
 168}
 169
 170/* Release the TT above udev, if it's not in use */
 171static void drop_tt(struct usb_device *udev)
 172{
 173	struct usb_tt		*utt = udev->tt;
 174	struct ehci_tt		*tt, **tt_index, **ptt;
 175	int			cnt, i;
 176
 177	if (!utt || !utt->hcpriv)
 178		return;		/* Not below a TT, or never allocated */
 179
 180	cnt = 0;
 181	if (utt->multi) {
 182		tt_index = utt->hcpriv;
 183		ptt = &tt_index[udev->ttport - 1];
 184
 185		/* How many entries are left in tt_index? */
 186		for (i = 0; i < utt->hub->maxchild; ++i)
 187			cnt += !!tt_index[i];
 188	} else {
 189		tt_index = NULL;
 190		ptt = (struct ehci_tt **) &utt->hcpriv;
 191	}
 192
 193	tt = *ptt;
 194	if (!tt || !list_empty(&tt->ps_list))
 195		return;		/* never allocated, or still in use */
 196
 197	list_del(&tt->tt_list);
 198	*ptt = NULL;
 199	kfree(tt);
 200	if (cnt == 1) {
 201		utt->hcpriv = NULL;
 202		kfree(tt_index);
 203	}
 204}
 205
 206static void bandwidth_dbg(struct ehci_hcd *ehci, int sign, char *type,
 207		struct ehci_per_sched *ps)
 208{
 209	dev_dbg(&ps->udev->dev,
 210			"ep %02x: %s %s @ %u+%u (%u.%u+%u) [%u/%u us] mask %04x\n",
 211			ps->ep->desc.bEndpointAddress,
 212			(sign >= 0 ? "reserve" : "release"), type,
 213			(ps->bw_phase << 3) + ps->phase_uf, ps->bw_uperiod,
 214			ps->phase, ps->phase_uf, ps->period,
 215			ps->usecs, ps->c_usecs, ps->cs_mask);
 216}
 217
 218static void reserve_release_intr_bandwidth(struct ehci_hcd *ehci,
 219		struct ehci_qh *qh, int sign)
 220{
 221	unsigned		start_uf;
 222	unsigned		i, j, m;
 223	int			usecs = qh->ps.usecs;
 224	int			c_usecs = qh->ps.c_usecs;
 225	int			tt_usecs = qh->ps.tt_usecs;
 226	struct ehci_tt		*tt;
 227
 228	if (qh->ps.phase == NO_FRAME)	/* Bandwidth wasn't reserved */
 229		return;
 230	start_uf = qh->ps.bw_phase << 3;
 231
 232	bandwidth_dbg(ehci, sign, "intr", &qh->ps);
 233
 234	if (sign < 0) {		/* Release bandwidth */
 235		usecs = -usecs;
 236		c_usecs = -c_usecs;
 237		tt_usecs = -tt_usecs;
 238	}
 239
 240	/* Entire transaction (high speed) or start-split (full/low speed) */
 241	for (i = start_uf + qh->ps.phase_uf; i < EHCI_BANDWIDTH_SIZE;
 242			i += qh->ps.bw_uperiod)
 243		ehci->bandwidth[i] += usecs;
 244
 245	/* Complete-split (full/low speed) */
 246	if (qh->ps.c_usecs) {
 247		/* NOTE: adjustments needed for FSTN */
 248		for (i = start_uf; i < EHCI_BANDWIDTH_SIZE;
 249				i += qh->ps.bw_uperiod) {
 250			for ((j = 2, m = 1 << (j+8)); j < 8; (++j, m <<= 1)) {
 251				if (qh->ps.cs_mask & m)
 252					ehci->bandwidth[i+j] += c_usecs;
 253			}
 254		}
 255	}
 256
 257	/* FS/LS bus bandwidth */
 258	if (tt_usecs) {
 259		tt = find_tt(qh->ps.udev);
 260		if (sign > 0)
 261			list_add_tail(&qh->ps.ps_list, &tt->ps_list);
 262		else
 263			list_del(&qh->ps.ps_list);
 264
 265		for (i = start_uf >> 3; i < EHCI_BANDWIDTH_FRAMES;
 266				i += qh->ps.bw_period)
 267			tt->bandwidth[i] += tt_usecs;
 268	}
 269}
 270
 271/*-------------------------------------------------------------------------*/
 272
 273static void compute_tt_budget(u8 budget_table[EHCI_BANDWIDTH_SIZE],
 274		struct ehci_tt *tt)
 275{
 276	struct ehci_per_sched	*ps;
 277	unsigned		uframe, uf, x;
 278	u8			*budget_line;
 279
 280	if (!tt)
 281		return;
 282	memset(budget_table, 0, EHCI_BANDWIDTH_SIZE);
 283
 284	/* Add up the contributions from all the endpoints using this TT */
 285	list_for_each_entry(ps, &tt->ps_list, ps_list) {
 286		for (uframe = ps->bw_phase << 3; uframe < EHCI_BANDWIDTH_SIZE;
 287				uframe += ps->bw_uperiod) {
 288			budget_line = &budget_table[uframe];
 289			x = ps->tt_usecs;
 290
 291			/* propagate the time forward */
 292			for (uf = ps->phase_uf; uf < 8; ++uf) {
 293				x += budget_line[uf];
 294
 295				/* Each microframe lasts 125 us */
 296				if (x <= 125) {
 297					budget_line[uf] = x;
 298					break;
 299				}
 300				budget_line[uf] = 125;
 301				x -= 125;
 302			}
 303		}
 304	}
 305}
 306
 307static int __maybe_unused same_tt(struct usb_device *dev1,
 308		struct usb_device *dev2)
 309{
 310	if (!dev1->tt || !dev2->tt)
 311		return 0;
 312	if (dev1->tt != dev2->tt)
 313		return 0;
 314	if (dev1->tt->multi)
 315		return dev1->ttport == dev2->ttport;
 316	else
 317		return 1;
 318}
 319
 320#ifdef CONFIG_USB_EHCI_TT_NEWSCHED
 321
 322/* Which uframe does the low/fullspeed transfer start in?
 323 *
 324 * The parameter is the mask of ssplits in "H-frame" terms
 325 * and this returns the transfer start uframe in "B-frame" terms,
 326 * which allows both to match, e.g. a ssplit in "H-frame" uframe 0
 327 * will cause a transfer in "B-frame" uframe 0.  "B-frames" lag
 328 * "H-frames" by 1 uframe.  See the EHCI spec sec 4.5 and figure 4.7.
 329 */
 330static inline unsigned char tt_start_uframe(struct ehci_hcd *ehci, __hc32 mask)
 331{
 332	unsigned char smask = hc32_to_cpu(ehci, mask) & QH_SMASK;
 333
 334	if (!smask) {
 335		ehci_err(ehci, "invalid empty smask!\n");
 336		/* uframe 7 can't have bw so this will indicate failure */
 337		return 7;
 338	}
 339	return ffs(smask) - 1;
 340}
 341
 342static const unsigned char
 343max_tt_usecs[] = { 125, 125, 125, 125, 125, 125, 30, 0 };
 344
 345/* carryover low/fullspeed bandwidth that crosses uframe boundries */
 346static inline void carryover_tt_bandwidth(unsigned short tt_usecs[8])
 347{
 348	int i;
 349
 350	for (i = 0; i < 7; i++) {
 351		if (max_tt_usecs[i] < tt_usecs[i]) {
 352			tt_usecs[i+1] += tt_usecs[i] - max_tt_usecs[i];
 353			tt_usecs[i] = max_tt_usecs[i];
 354		}
 355	}
 356}
 357
 358/*
 359 * Return true if the device's tt's downstream bus is available for a
 360 * periodic transfer of the specified length (usecs), starting at the
 361 * specified frame/uframe.  Note that (as summarized in section 11.19
 362 * of the usb 2.0 spec) TTs can buffer multiple transactions for each
 363 * uframe.
 364 *
 365 * The uframe parameter is when the fullspeed/lowspeed transfer
 366 * should be executed in "B-frame" terms, which is the same as the
 367 * highspeed ssplit's uframe (which is in "H-frame" terms).  For example
 368 * a ssplit in "H-frame" 0 causes a transfer in "B-frame" 0.
 369 * See the EHCI spec sec 4.5 and fig 4.7.
 370 *
 371 * This checks if the full/lowspeed bus, at the specified starting uframe,
 372 * has the specified bandwidth available, according to rules listed
 373 * in USB 2.0 spec section 11.18.1 fig 11-60.
 374 *
 375 * This does not check if the transfer would exceed the max ssplit
 376 * limit of 16, specified in USB 2.0 spec section 11.18.4 requirement #4,
 377 * since proper scheduling limits ssplits to less than 16 per uframe.
 378 */
 379static int tt_available(
 380	struct ehci_hcd		*ehci,
 381	struct ehci_per_sched	*ps,
 382	struct ehci_tt		*tt,
 383	unsigned		frame,
 384	unsigned		uframe
 385)
 386{
 387	unsigned		period = ps->bw_period;
 388	unsigned		usecs = ps->tt_usecs;
 389
 390	if ((period == 0) || (uframe >= 7))	/* error */
 391		return 0;
 392
 393	for (frame &= period - 1; frame < EHCI_BANDWIDTH_FRAMES;
 394			frame += period) {
 395		unsigned	i, uf;
 396		unsigned short	tt_usecs[8];
 397
 398		if (tt->bandwidth[frame] + usecs > 900)
 399			return 0;
 400
 401		uf = frame << 3;
 402		for (i = 0; i < 8; (++i, ++uf))
 403			tt_usecs[i] = ehci->tt_budget[uf];
 404
 405		if (max_tt_usecs[uframe] <= tt_usecs[uframe])
 406			return 0;
 407
 408		/* special case for isoc transfers larger than 125us:
 409		 * the first and each subsequent fully used uframe
 410		 * must be empty, so as to not illegally delay
 411		 * already scheduled transactions
 412		 */
 413		if (usecs > 125) {
 414			int ufs = (usecs / 125);
 415
 416			for (i = uframe; i < (uframe + ufs) && i < 8; i++)
 417				if (tt_usecs[i] > 0)
 418					return 0;
 419		}
 420
 421		tt_usecs[uframe] += usecs;
 422
 423		carryover_tt_bandwidth(tt_usecs);
 424
 425		/* fail if the carryover pushed bw past the last uframe's limit */
 426		if (max_tt_usecs[7] < tt_usecs[7])
 427			return 0;
 428	}
 429
 430	return 1;
 431}
 432
 433#else
 434
 435/* return true iff the device's transaction translator is available
 436 * for a periodic transfer starting at the specified frame, using
 437 * all the uframes in the mask.
 438 */
 439static int tt_no_collision(
 440	struct ehci_hcd		*ehci,
 441	unsigned		period,
 442	struct usb_device	*dev,
 443	unsigned		frame,
 444	u32			uf_mask
 445)
 446{
 447	if (period == 0)	/* error */
 448		return 0;
 449
 450	/* note bandwidth wastage:  split never follows csplit
 451	 * (different dev or endpoint) until the next uframe.
 452	 * calling convention doesn't make that distinction.
 453	 */
 454	for (; frame < ehci->periodic_size; frame += period) {
 455		union ehci_shadow	here;
 456		__hc32			type;
 457		struct ehci_qh_hw	*hw;
 458
 459		here = ehci->pshadow[frame];
 460		type = Q_NEXT_TYPE(ehci, ehci->periodic[frame]);
 461		while (here.ptr) {
 462			switch (hc32_to_cpu(ehci, type)) {
 463			case Q_TYPE_ITD:
 464				type = Q_NEXT_TYPE(ehci, here.itd->hw_next);
 465				here = here.itd->itd_next;
 466				continue;
 467			case Q_TYPE_QH:
 468				hw = here.qh->hw;
 469				if (same_tt(dev, here.qh->ps.udev)) {
 470					u32		mask;
 471
 472					mask = hc32_to_cpu(ehci,
 473							hw->hw_info2);
 474					/* "knows" no gap is needed */
 475					mask |= mask >> 8;
 476					if (mask & uf_mask)
 477						break;
 478				}
 479				type = Q_NEXT_TYPE(ehci, hw->hw_next);
 480				here = here.qh->qh_next;
 481				continue;
 482			case Q_TYPE_SITD:
 483				if (same_tt(dev, here.sitd->urb->dev)) {
 484					u16		mask;
 485
 486					mask = hc32_to_cpu(ehci, here.sitd
 487								->hw_uframe);
 488					/* FIXME assumes no gap for IN! */
 489					mask |= mask >> 8;
 490					if (mask & uf_mask)
 491						break;
 492				}
 493				type = Q_NEXT_TYPE(ehci, here.sitd->hw_next);
 494				here = here.sitd->sitd_next;
 495				continue;
 496			/* case Q_TYPE_FSTN: */
 497			default:
 498				ehci_dbg(ehci,
 499					"periodic frame %d bogus type %d\n",
 500					frame, type);
 501			}
 502
 503			/* collision or error */
 504			return 0;
 505		}
 506	}
 507
 508	/* no collision */
 509	return 1;
 510}
 511
 512#endif /* CONFIG_USB_EHCI_TT_NEWSCHED */
 513
 514/*-------------------------------------------------------------------------*/
 515
 516static void enable_periodic(struct ehci_hcd *ehci)
 517{
 518	if (ehci->periodic_count++)
 519		return;
 520
 521	/* Stop waiting to turn off the periodic schedule */
 522	ehci->enabled_hrtimer_events &= ~BIT(EHCI_HRTIMER_DISABLE_PERIODIC);
 523
 524	/* Don't start the schedule until PSS is 0 */
 525	ehci_poll_PSS(ehci);
 526	turn_on_io_watchdog(ehci);
 527}
 528
 529static void disable_periodic(struct ehci_hcd *ehci)
 530{
 531	if (--ehci->periodic_count)
 532		return;
 533
 534	/* Don't turn off the schedule until PSS is 1 */
 535	ehci_poll_PSS(ehci);
 536}
 537
 538/*-------------------------------------------------------------------------*/
 539
 540/* periodic schedule slots have iso tds (normal or split) first, then a
 541 * sparse tree for active interrupt transfers.
 542 *
 543 * this just links in a qh; caller guarantees uframe masks are set right.
 544 * no FSTN support (yet; ehci 0.96+)
 545 */
 546static void qh_link_periodic(struct ehci_hcd *ehci, struct ehci_qh *qh)
 547{
 548	unsigned	i;
 549	unsigned	period = qh->ps.period;
 550
 551	dev_dbg(&qh->ps.udev->dev,
 552		"link qh%d-%04x/%p start %d [%d/%d us]\n",
 553		period, hc32_to_cpup(ehci, &qh->hw->hw_info2)
 554			& (QH_CMASK | QH_SMASK),
 555		qh, qh->ps.phase, qh->ps.usecs, qh->ps.c_usecs);
 556
 557	/* high bandwidth, or otherwise every microframe */
 558	if (period == 0)
 559		period = 1;
 560
 561	for (i = qh->ps.phase; i < ehci->periodic_size; i += period) {
 562		union ehci_shadow	*prev = &ehci->pshadow[i];
 563		__hc32			*hw_p = &ehci->periodic[i];
 564		union ehci_shadow	here = *prev;
 565		__hc32			type = 0;
 566
 567		/* skip the iso nodes at list head */
 568		while (here.ptr) {
 569			type = Q_NEXT_TYPE(ehci, *hw_p);
 570			if (type == cpu_to_hc32(ehci, Q_TYPE_QH))
 571				break;
 572			prev = periodic_next_shadow(ehci, prev, type);
 573			hw_p = shadow_next_periodic(ehci, &here, type);
 574			here = *prev;
 575		}
 576
 577		/* sorting each branch by period (slow-->fast)
 578		 * enables sharing interior tree nodes
 579		 */
 580		while (here.ptr && qh != here.qh) {
 581			if (qh->ps.period > here.qh->ps.period)
 582				break;
 583			prev = &here.qh->qh_next;
 584			hw_p = &here.qh->hw->hw_next;
 585			here = *prev;
 586		}
 587		/* link in this qh, unless some earlier pass did that */
 588		if (qh != here.qh) {
 589			qh->qh_next = here;
 590			if (here.qh)
 591				qh->hw->hw_next = *hw_p;
 592			wmb();
 593			prev->qh = qh;
 594			*hw_p = QH_NEXT(ehci, qh->qh_dma);
 595		}
 596	}
 597	qh->qh_state = QH_STATE_LINKED;
 598	qh->xacterrs = 0;
 599	qh->unlink_reason = 0;
 600
 601	/* update per-qh bandwidth for debugfs */
 602	ehci_to_hcd(ehci)->self.bandwidth_allocated += qh->ps.bw_period
 603		? ((qh->ps.usecs + qh->ps.c_usecs) / qh->ps.bw_period)
 604		: (qh->ps.usecs * 8);
 605
 606	list_add(&qh->intr_node, &ehci->intr_qh_list);
 607
 608	/* maybe enable periodic schedule processing */
 609	++ehci->intr_count;
 610	enable_periodic(ehci);
 611}
 612
 613static void qh_unlink_periodic(struct ehci_hcd *ehci, struct ehci_qh *qh)
 614{
 615	unsigned	i;
 616	unsigned	period;
 617
 618	/*
 619	 * If qh is for a low/full-speed device, simply unlinking it
 620	 * could interfere with an ongoing split transaction.  To unlink
 621	 * it safely would require setting the QH_INACTIVATE bit and
 622	 * waiting at least one frame, as described in EHCI 4.12.2.5.
 623	 *
 624	 * We won't bother with any of this.  Instead, we assume that the
 625	 * only reason for unlinking an interrupt QH while the current URB
 626	 * is still active is to dequeue all the URBs (flush the whole
 627	 * endpoint queue).
 628	 *
 629	 * If rebalancing the periodic schedule is ever implemented, this
 630	 * approach will no longer be valid.
 631	 */
 632
 633	/* high bandwidth, or otherwise part of every microframe */
 634	period = qh->ps.period ? : 1;
 635
 636	for (i = qh->ps.phase; i < ehci->periodic_size; i += period)
 637		periodic_unlink(ehci, i, qh);
 638
 639	/* update per-qh bandwidth for debugfs */
 640	ehci_to_hcd(ehci)->self.bandwidth_allocated -= qh->ps.bw_period
 641		? ((qh->ps.usecs + qh->ps.c_usecs) / qh->ps.bw_period)
 642		: (qh->ps.usecs * 8);
 643
 644	dev_dbg(&qh->ps.udev->dev,
 645		"unlink qh%d-%04x/%p start %d [%d/%d us]\n",
 646		qh->ps.period,
 647		hc32_to_cpup(ehci, &qh->hw->hw_info2) & (QH_CMASK | QH_SMASK),
 648		qh, qh->ps.phase, qh->ps.usecs, qh->ps.c_usecs);
 649
 650	/* qh->qh_next still "live" to HC */
 651	qh->qh_state = QH_STATE_UNLINK;
 652	qh->qh_next.ptr = NULL;
 653
 654	if (ehci->qh_scan_next == qh)
 655		ehci->qh_scan_next = list_entry(qh->intr_node.next,
 656				struct ehci_qh, intr_node);
 657	list_del(&qh->intr_node);
 658}
 659
 660static void cancel_unlink_wait_intr(struct ehci_hcd *ehci, struct ehci_qh *qh)
 661{
 662	if (qh->qh_state != QH_STATE_LINKED ||
 663			list_empty(&qh->unlink_node))
 664		return;
 665
 666	list_del_init(&qh->unlink_node);
 667
 668	/*
 669	 * TODO: disable the event of EHCI_HRTIMER_START_UNLINK_INTR for
 670	 * avoiding unnecessary CPU wakeup
 671	 */
 672}
 673
 674static void start_unlink_intr(struct ehci_hcd *ehci, struct ehci_qh *qh)
 675{
 676	/* If the QH isn't linked then there's nothing we can do. */
 677	if (qh->qh_state != QH_STATE_LINKED)
 678		return;
 679
 680	/* if the qh is waiting for unlink, cancel it now */
 681	cancel_unlink_wait_intr(ehci, qh);
 682
 683	qh_unlink_periodic(ehci, qh);
 684
 685	/* Make sure the unlinks are visible before starting the timer */
 686	wmb();
 687
 688	/*
 689	 * The EHCI spec doesn't say how long it takes the controller to
 690	 * stop accessing an unlinked interrupt QH.  The timer delay is
 691	 * 9 uframes; presumably that will be long enough.
 692	 */
 693	qh->unlink_cycle = ehci->intr_unlink_cycle;
 694
 695	/* New entries go at the end of the intr_unlink list */
 696	list_add_tail(&qh->unlink_node, &ehci->intr_unlink);
 697
 698	if (ehci->intr_unlinking)
 699		;	/* Avoid recursive calls */
 700	else if (ehci->rh_state < EHCI_RH_RUNNING)
 701		ehci_handle_intr_unlinks(ehci);
 702	else if (ehci->intr_unlink.next == &qh->unlink_node) {
 703		ehci_enable_event(ehci, EHCI_HRTIMER_UNLINK_INTR, true);
 704		++ehci->intr_unlink_cycle;
 705	}
 706}
 707
 708/*
 709 * It is common only one intr URB is scheduled on one qh, and
 710 * given complete() is run in tasklet context, introduce a bit
 711 * delay to avoid unlink qh too early.
 712 */
 713static void start_unlink_intr_wait(struct ehci_hcd *ehci,
 714				   struct ehci_qh *qh)
 715{
 716	qh->unlink_cycle = ehci->intr_unlink_wait_cycle;
 717
 718	/* New entries go at the end of the intr_unlink_wait list */
 719	list_add_tail(&qh->unlink_node, &ehci->intr_unlink_wait);
 720
 721	if (ehci->rh_state < EHCI_RH_RUNNING)
 722		ehci_handle_start_intr_unlinks(ehci);
 723	else if (ehci->intr_unlink_wait.next == &qh->unlink_node) {
 724		ehci_enable_event(ehci, EHCI_HRTIMER_START_UNLINK_INTR, true);
 725		++ehci->intr_unlink_wait_cycle;
 726	}
 727}
 728
 729static void end_unlink_intr(struct ehci_hcd *ehci, struct ehci_qh *qh)
 730{
 731	struct ehci_qh_hw	*hw = qh->hw;
 732	int			rc;
 733
 734	qh->qh_state = QH_STATE_IDLE;
 735	hw->hw_next = EHCI_LIST_END(ehci);
 736
 737	if (!list_empty(&qh->qtd_list))
 738		qh_completions(ehci, qh);
 739
 740	/* reschedule QH iff another request is queued */
 741	if (!list_empty(&qh->qtd_list) && ehci->rh_state == EHCI_RH_RUNNING) {
 742		rc = qh_schedule(ehci, qh);
 743		if (rc == 0) {
 744			qh_refresh(ehci, qh);
 745			qh_link_periodic(ehci, qh);
 746		}
 747
 748		/* An error here likely indicates handshake failure
 749		 * or no space left in the schedule.  Neither fault
 750		 * should happen often ...
 751		 *
 752		 * FIXME kill the now-dysfunctional queued urbs
 753		 */
 754		else {
 755			ehci_err(ehci, "can't reschedule qh %p, err %d\n",
 756					qh, rc);
 757		}
 758	}
 759
 760	/* maybe turn off periodic schedule */
 761	--ehci->intr_count;
 762	disable_periodic(ehci);
 763}
 764
 765/*-------------------------------------------------------------------------*/
 766
 767static int check_period(
 768	struct ehci_hcd *ehci,
 769	unsigned	frame,
 770	unsigned	uframe,
 771	unsigned	uperiod,
 772	unsigned	usecs
 773) {
 774	/* complete split running into next frame?
 775	 * given FSTN support, we could sometimes check...
 776	 */
 777	if (uframe >= 8)
 778		return 0;
 779
 780	/* convert "usecs we need" to "max already claimed" */
 781	usecs = ehci->uframe_periodic_max - usecs;
 782
 783	for (uframe += frame << 3; uframe < EHCI_BANDWIDTH_SIZE;
 784			uframe += uperiod) {
 785		if (ehci->bandwidth[uframe] > usecs)
 786			return 0;
 787	}
 788
 789	/* success! */
 790	return 1;
 791}
 792
 793static int check_intr_schedule(
 794	struct ehci_hcd		*ehci,
 795	unsigned		frame,
 796	unsigned		uframe,
 797	struct ehci_qh		*qh,
 798	unsigned		*c_maskp,
 799	struct ehci_tt		*tt
 800)
 801{
 802	int		retval = -ENOSPC;
 803	u8		mask = 0;
 804
 805	if (qh->ps.c_usecs && uframe >= 6)	/* FSTN territory? */
 806		goto done;
 807
 808	if (!check_period(ehci, frame, uframe, qh->ps.bw_uperiod, qh->ps.usecs))
 809		goto done;
 810	if (!qh->ps.c_usecs) {
 811		retval = 0;
 812		*c_maskp = 0;
 813		goto done;
 814	}
 815
 816#ifdef CONFIG_USB_EHCI_TT_NEWSCHED
 817	if (tt_available(ehci, &qh->ps, tt, frame, uframe)) {
 818		unsigned i;
 819
 820		/* TODO : this may need FSTN for SSPLIT in uframe 5. */
 821		for (i = uframe+2; i < 8 && i <= uframe+4; i++)
 822			if (!check_period(ehci, frame, i,
 823					qh->ps.bw_uperiod, qh->ps.c_usecs))
 824				goto done;
 825			else
 826				mask |= 1 << i;
 827
 828		retval = 0;
 829
 830		*c_maskp = mask;
 831	}
 832#else
 833	/* Make sure this tt's buffer is also available for CSPLITs.
 834	 * We pessimize a bit; probably the typical full speed case
 835	 * doesn't need the second CSPLIT.
 836	 *
 837	 * NOTE:  both SPLIT and CSPLIT could be checked in just
 838	 * one smart pass...
 839	 */
 840	mask = 0x03 << (uframe + qh->gap_uf);
 841	*c_maskp = mask;
 842
 843	mask |= 1 << uframe;
 844	if (tt_no_collision(ehci, qh->ps.bw_period, qh->ps.udev, frame, mask)) {
 845		if (!check_period(ehci, frame, uframe + qh->gap_uf + 1,
 846				qh->ps.bw_uperiod, qh->ps.c_usecs))
 847			goto done;
 848		if (!check_period(ehci, frame, uframe + qh->gap_uf,
 849				qh->ps.bw_uperiod, qh->ps.c_usecs))
 850			goto done;
 851		retval = 0;
 852	}
 853#endif
 854done:
 855	return retval;
 856}
 857
 858/* "first fit" scheduling policy used the first time through,
 859 * or when the previous schedule slot can't be re-used.
 860 */
 861static int qh_schedule(struct ehci_hcd *ehci, struct ehci_qh *qh)
 862{
 863	int		status = 0;
 864	unsigned	uframe;
 865	unsigned	c_mask;
 866	struct ehci_qh_hw	*hw = qh->hw;
 867	struct ehci_tt		*tt;
 868
 869	hw->hw_next = EHCI_LIST_END(ehci);
 870
 871	/* reuse the previous schedule slots, if we can */
 872	if (qh->ps.phase != NO_FRAME) {
 873		ehci_dbg(ehci, "reused qh %p schedule\n", qh);
 874		return 0;
 875	}
 876
 877	uframe = 0;
 878	c_mask = 0;
 879	tt = find_tt(qh->ps.udev);
 880	if (IS_ERR(tt)) {
 881		status = PTR_ERR(tt);
 882		goto done;
 883	}
 884	compute_tt_budget(ehci->tt_budget, tt);
 885
 886	/* else scan the schedule to find a group of slots such that all
 887	 * uframes have enough periodic bandwidth available.
 888	 */
 889	/* "normal" case, uframing flexible except with splits */
 890	if (qh->ps.bw_period) {
 891		int		i;
 892		unsigned	frame;
 893
 894		for (i = qh->ps.bw_period; i > 0; --i) {
 895			frame = ++ehci->random_frame & (qh->ps.bw_period - 1);
 896			for (uframe = 0; uframe < 8; uframe++) {
 897				status = check_intr_schedule(ehci,
 898						frame, uframe, qh, &c_mask, tt);
 899				if (status == 0)
 900					goto got_it;
 901			}
 902		}
 903
 904	/* qh->ps.bw_period == 0 means every uframe */
 905	} else {
 906		status = check_intr_schedule(ehci, 0, 0, qh, &c_mask, tt);
 907	}
 908	if (status)
 909		goto done;
 910
 911 got_it:
 912	qh->ps.phase = (qh->ps.period ? ehci->random_frame &
 913			(qh->ps.period - 1) : 0);
 914	qh->ps.bw_phase = qh->ps.phase & (qh->ps.bw_period - 1);
 915	qh->ps.phase_uf = uframe;
 916	qh->ps.cs_mask = qh->ps.period ?
 917			(c_mask << 8) | (1 << uframe) :
 918			QH_SMASK;
 919
 920	/* reset S-frame and (maybe) C-frame masks */
 921	hw->hw_info2 &= cpu_to_hc32(ehci, ~(QH_CMASK | QH_SMASK));
 922	hw->hw_info2 |= cpu_to_hc32(ehci, qh->ps.cs_mask);
 923	reserve_release_intr_bandwidth(ehci, qh, 1);
 924
 925done:
 926	return status;
 927}
 928
 929static int intr_submit(
 930	struct ehci_hcd		*ehci,
 931	struct urb		*urb,
 932	struct list_head	*qtd_list,
 933	gfp_t			mem_flags
 934) {
 935	unsigned		epnum;
 936	unsigned long		flags;
 937	struct ehci_qh		*qh;
 938	int			status;
 939	struct list_head	empty;
 940
 941	/* get endpoint and transfer/schedule data */
 942	epnum = urb->ep->desc.bEndpointAddress;
 943
 944	spin_lock_irqsave(&ehci->lock, flags);
 945
 946	if (unlikely(!HCD_HW_ACCESSIBLE(ehci_to_hcd(ehci)))) {
 947		status = -ESHUTDOWN;
 948		goto done_not_linked;
 949	}
 950	status = usb_hcd_link_urb_to_ep(ehci_to_hcd(ehci), urb);
 951	if (unlikely(status))
 952		goto done_not_linked;
 953
 954	/* get qh and force any scheduling errors */
 955	INIT_LIST_HEAD(&empty);
 956	qh = qh_append_tds(ehci, urb, &empty, epnum, &urb->ep->hcpriv);
 957	if (qh == NULL) {
 958		status = -ENOMEM;
 959		goto done;
 960	}
 961	if (qh->qh_state == QH_STATE_IDLE) {
 962		status = qh_schedule(ehci, qh);
 963		if (status)
 964			goto done;
 965	}
 966
 967	/* then queue the urb's tds to the qh */
 968	qh = qh_append_tds(ehci, urb, qtd_list, epnum, &urb->ep->hcpriv);
 969	BUG_ON(qh == NULL);
 970
 971	/* stuff into the periodic schedule */
 972	if (qh->qh_state == QH_STATE_IDLE) {
 973		qh_refresh(ehci, qh);
 974		qh_link_periodic(ehci, qh);
 975	} else {
 976		/* cancel unlink wait for the qh */
 977		cancel_unlink_wait_intr(ehci, qh);
 978	}
 979
 980	/* ... update usbfs periodic stats */
 981	ehci_to_hcd(ehci)->self.bandwidth_int_reqs++;
 982
 983done:
 984	if (unlikely(status))
 985		usb_hcd_unlink_urb_from_ep(ehci_to_hcd(ehci), urb);
 986done_not_linked:
 987	spin_unlock_irqrestore(&ehci->lock, flags);
 988	if (status)
 989		qtd_list_free(ehci, urb, qtd_list);
 990
 991	return status;
 992}
 993
 994static void scan_intr(struct ehci_hcd *ehci)
 995{
 996	struct ehci_qh		*qh;
 997
 998	list_for_each_entry_safe(qh, ehci->qh_scan_next, &ehci->intr_qh_list,
 999			intr_node) {
1000
1001		/* clean any finished work for this qh */
1002		if (!list_empty(&qh->qtd_list)) {
1003			int temp;
1004
1005			/*
1006			 * Unlinks could happen here; completion reporting
1007			 * drops the lock.  That's why ehci->qh_scan_next
1008			 * always holds the next qh to scan; if the next qh
1009			 * gets unlinked then ehci->qh_scan_next is adjusted
1010			 * in qh_unlink_periodic().
1011			 */
1012			temp = qh_completions(ehci, qh);
1013			if (unlikely(temp))
1014				start_unlink_intr(ehci, qh);
1015			else if (unlikely(list_empty(&qh->qtd_list) &&
1016					qh->qh_state == QH_STATE_LINKED))
1017				start_unlink_intr_wait(ehci, qh);
1018		}
1019	}
1020}
1021
1022/*-------------------------------------------------------------------------*/
1023
1024/* ehci_iso_stream ops work with both ITD and SITD */
1025
1026static struct ehci_iso_stream *
1027iso_stream_alloc(gfp_t mem_flags)
1028{
1029	struct ehci_iso_stream *stream;
1030
1031	stream = kzalloc(sizeof(*stream), mem_flags);
1032	if (likely(stream != NULL)) {
1033		INIT_LIST_HEAD(&stream->td_list);
1034		INIT_LIST_HEAD(&stream->free_list);
1035		stream->next_uframe = NO_FRAME;
1036		stream->ps.phase = NO_FRAME;
1037	}
1038	return stream;
1039}
1040
1041static void
1042iso_stream_init(
1043	struct ehci_hcd		*ehci,
1044	struct ehci_iso_stream	*stream,
1045	struct urb		*urb
1046)
1047{
1048	static const u8 smask_out[] = { 0x01, 0x03, 0x07, 0x0f, 0x1f, 0x3f };
1049
1050	struct usb_device	*dev = urb->dev;
1051	u32			buf1;
1052	unsigned		epnum, maxp;
1053	int			is_input;
1054	unsigned		tmp;
1055
1056	/*
1057	 * this might be a "high bandwidth" highspeed endpoint,
1058	 * as encoded in the ep descriptor's wMaxPacket field
1059	 */
1060	epnum = usb_pipeendpoint(urb->pipe);
1061	is_input = usb_pipein(urb->pipe) ? USB_DIR_IN : 0;
1062	maxp = usb_endpoint_maxp(&urb->ep->desc);
1063	buf1 = is_input ? 1 << 11 : 0;
1064
1065	/* knows about ITD vs SITD */
1066	if (dev->speed == USB_SPEED_HIGH) {
1067		unsigned multi = hb_mult(maxp);
1068
1069		stream->highspeed = 1;
1070
1071		maxp = max_packet(maxp);
1072		buf1 |= maxp;
1073		maxp *= multi;
1074
1075		stream->buf0 = cpu_to_hc32(ehci, (epnum << 8) | dev->devnum);
1076		stream->buf1 = cpu_to_hc32(ehci, buf1);
1077		stream->buf2 = cpu_to_hc32(ehci, multi);
1078
1079		/* usbfs wants to report the average usecs per frame tied up
1080		 * when transfers on this endpoint are scheduled ...
1081		 */
1082		stream->ps.usecs = HS_USECS_ISO(maxp);
1083
1084		/* period for bandwidth allocation */
1085		tmp = min_t(unsigned, EHCI_BANDWIDTH_SIZE,
1086				1 << (urb->ep->desc.bInterval - 1));
1087
1088		/* Allow urb->interval to override */
1089		stream->ps.bw_uperiod = min_t(unsigned, tmp, urb->interval);
1090
1091		stream->uperiod = urb->interval;
1092		stream->ps.period = urb->interval >> 3;
1093		stream->bandwidth = stream->ps.usecs * 8 /
1094				stream->ps.bw_uperiod;
1095
1096	} else {
1097		u32		addr;
1098		int		think_time;
1099		int		hs_transfers;
1100
1101		addr = dev->ttport << 24;
1102		if (!ehci_is_TDI(ehci)
1103				|| (dev->tt->hub !=
1104					ehci_to_hcd(ehci)->self.root_hub))
1105			addr |= dev->tt->hub->devnum << 16;
1106		addr |= epnum << 8;
1107		addr |= dev->devnum;
1108		stream->ps.usecs = HS_USECS_ISO(maxp);
1109		think_time = dev->tt ? dev->tt->think_time : 0;
1110		stream->ps.tt_usecs = NS_TO_US(think_time + usb_calc_bus_time(
1111				dev->speed, is_input, 1, maxp));
1112		hs_transfers = max(1u, (maxp + 187) / 188);
1113		if (is_input) {
1114			u32	tmp;
1115
1116			addr |= 1 << 31;
1117			stream->ps.c_usecs = stream->ps.usecs;
1118			stream->ps.usecs = HS_USECS_ISO(1);
1119			stream->ps.cs_mask = 1;
1120
1121			/* c-mask as specified in USB 2.0 11.18.4 3.c */
1122			tmp = (1 << (hs_transfers + 2)) - 1;
1123			stream->ps.cs_mask |= tmp << (8 + 2);
1124		} else
1125			stream->ps.cs_mask = smask_out[hs_transfers - 1];
1126
1127		/* period for bandwidth allocation */
1128		tmp = min_t(unsigned, EHCI_BANDWIDTH_FRAMES,
1129				1 << (urb->ep->desc.bInterval - 1));
1130
1131		/* Allow urb->interval to override */
1132		stream->ps.bw_period = min_t(unsigned, tmp, urb->interval);
1133		stream->ps.bw_uperiod = stream->ps.bw_period << 3;
1134
1135		stream->ps.period = urb->interval;
1136		stream->uperiod = urb->interval << 3;
1137		stream->bandwidth = (stream->ps.usecs + stream->ps.c_usecs) /
1138				stream->ps.bw_period;
1139
1140		/* stream->splits gets created from cs_mask later */
1141		stream->address = cpu_to_hc32(ehci, addr);
1142	}
1143
1144	stream->ps.udev = dev;
1145	stream->ps.ep = urb->ep;
1146
1147	stream->bEndpointAddress = is_input | epnum;
1148	stream->maxp = maxp;
1149}
1150
1151static struct ehci_iso_stream *
1152iso_stream_find(struct ehci_hcd *ehci, struct urb *urb)
1153{
1154	unsigned		epnum;
1155	struct ehci_iso_stream	*stream;
1156	struct usb_host_endpoint *ep;
1157	unsigned long		flags;
1158
1159	epnum = usb_pipeendpoint (urb->pipe);
1160	if (usb_pipein(urb->pipe))
1161		ep = urb->dev->ep_in[epnum];
1162	else
1163		ep = urb->dev->ep_out[epnum];
1164
1165	spin_lock_irqsave(&ehci->lock, flags);
1166	stream = ep->hcpriv;
1167
1168	if (unlikely(stream == NULL)) {
1169		stream = iso_stream_alloc(GFP_ATOMIC);
1170		if (likely(stream != NULL)) {
1171			ep->hcpriv = stream;
1172			iso_stream_init(ehci, stream, urb);
1173		}
1174
1175	/* if dev->ep [epnum] is a QH, hw is set */
1176	} else if (unlikely(stream->hw != NULL)) {
1177		ehci_dbg(ehci, "dev %s ep%d%s, not iso??\n",
1178			urb->dev->devpath, epnum,
1179			usb_pipein(urb->pipe) ? "in" : "out");
1180		stream = NULL;
1181	}
1182
1183	spin_unlock_irqrestore(&ehci->lock, flags);
1184	return stream;
1185}
1186
1187/*-------------------------------------------------------------------------*/
1188
1189/* ehci_iso_sched ops can be ITD-only or SITD-only */
1190
1191static struct ehci_iso_sched *
1192iso_sched_alloc(unsigned packets, gfp_t mem_flags)
1193{
1194	struct ehci_iso_sched	*iso_sched;
1195	int			size = sizeof(*iso_sched);
1196
1197	size += packets * sizeof(struct ehci_iso_packet);
1198	iso_sched = kzalloc(size, mem_flags);
1199	if (likely(iso_sched != NULL))
1200		INIT_LIST_HEAD(&iso_sched->td_list);
1201
1202	return iso_sched;
1203}
1204
1205static inline void
1206itd_sched_init(
1207	struct ehci_hcd		*ehci,
1208	struct ehci_iso_sched	*iso_sched,
1209	struct ehci_iso_stream	*stream,
1210	struct urb		*urb
1211)
1212{
1213	unsigned	i;
1214	dma_addr_t	dma = urb->transfer_dma;
1215
1216	/* how many uframes are needed for these transfers */
1217	iso_sched->span = urb->number_of_packets * stream->uperiod;
1218
1219	/* figure out per-uframe itd fields that we'll need later
1220	 * when we fit new itds into the schedule.
1221	 */
1222	for (i = 0; i < urb->number_of_packets; i++) {
1223		struct ehci_iso_packet	*uframe = &iso_sched->packet[i];
1224		unsigned		length;
1225		dma_addr_t		buf;
1226		u32			trans;
1227
1228		length = urb->iso_frame_desc[i].length;
1229		buf = dma + urb->iso_frame_desc[i].offset;
1230
1231		trans = EHCI_ISOC_ACTIVE;
1232		trans |= buf & 0x0fff;
1233		if (unlikely(((i + 1) == urb->number_of_packets))
1234				&& !(urb->transfer_flags & URB_NO_INTERRUPT))
1235			trans |= EHCI_ITD_IOC;
1236		trans |= length << 16;
1237		uframe->transaction = cpu_to_hc32(ehci, trans);
1238
1239		/* might need to cross a buffer page within a uframe */
1240		uframe->bufp = (buf & ~(u64)0x0fff);
1241		buf += length;
1242		if (unlikely((uframe->bufp != (buf & ~(u64)0x0fff))))
1243			uframe->cross = 1;
1244	}
1245}
1246
1247static void
1248iso_sched_free(
1249	struct ehci_iso_stream	*stream,
1250	struct ehci_iso_sched	*iso_sched
1251)
1252{
1253	if (!iso_sched)
1254		return;
1255	/* caller must hold ehci->lock! */
1256	list_splice(&iso_sched->td_list, &stream->free_list);
1257	kfree(iso_sched);
1258}
1259
1260static int
1261itd_urb_transaction(
1262	struct ehci_iso_stream	*stream,
1263	struct ehci_hcd		*ehci,
1264	struct urb		*urb,
1265	gfp_t			mem_flags
1266)
1267{
1268	struct ehci_itd		*itd;
1269	dma_addr_t		itd_dma;
1270	int			i;
1271	unsigned		num_itds;
1272	struct ehci_iso_sched	*sched;
1273	unsigned long		flags;
1274
1275	sched = iso_sched_alloc(urb->number_of_packets, mem_flags);
1276	if (unlikely(sched == NULL))
1277		return -ENOMEM;
1278
1279	itd_sched_init(ehci, sched, stream, urb);
1280
1281	if (urb->interval < 8)
1282		num_itds = 1 + (sched->span + 7) / 8;
1283	else
1284		num_itds = urb->number_of_packets;
1285
1286	/* allocate/init ITDs */
1287	spin_lock_irqsave(&ehci->lock, flags);
1288	for (i = 0; i < num_itds; i++) {
1289
1290		/*
1291		 * Use iTDs from the free list, but not iTDs that may
1292		 * still be in use by the hardware.
1293		 */
1294		if (likely(!list_empty(&stream->free_list))) {
1295			itd = list_first_entry(&stream->free_list,
1296					struct ehci_itd, itd_list);
1297			if (itd->frame == ehci->now_frame)
1298				goto alloc_itd;
1299			list_del(&itd->itd_list);
1300			itd_dma = itd->itd_dma;
1301		} else {
1302 alloc_itd:
1303			spin_unlock_irqrestore(&ehci->lock, flags);
1304			itd = dma_pool_alloc(ehci->itd_pool, mem_flags,
1305					&itd_dma);
1306			spin_lock_irqsave(&ehci->lock, flags);
1307			if (!itd) {
1308				iso_sched_free(stream, sched);
1309				spin_unlock_irqrestore(&ehci->lock, flags);
1310				return -ENOMEM;
1311			}
1312		}
1313
1314		memset(itd, 0, sizeof(*itd));
1315		itd->itd_dma = itd_dma;
1316		itd->frame = NO_FRAME;
1317		list_add(&itd->itd_list, &sched->td_list);
1318	}
1319	spin_unlock_irqrestore(&ehci->lock, flags);
1320
1321	/* temporarily store schedule info in hcpriv */
1322	urb->hcpriv = sched;
1323	urb->error_count = 0;
1324	return 0;
1325}
1326
1327/*-------------------------------------------------------------------------*/
1328
1329static void reserve_release_iso_bandwidth(struct ehci_hcd *ehci,
1330		struct ehci_iso_stream *stream, int sign)
1331{
1332	unsigned		uframe;
1333	unsigned		i, j;
1334	unsigned		s_mask, c_mask, m;
1335	int			usecs = stream->ps.usecs;
1336	int			c_usecs = stream->ps.c_usecs;
1337	int			tt_usecs = stream->ps.tt_usecs;
1338	struct ehci_tt		*tt;
1339
1340	if (stream->ps.phase == NO_FRAME)	/* Bandwidth wasn't reserved */
1341		return;
1342	uframe = stream->ps.bw_phase << 3;
1343
1344	bandwidth_dbg(ehci, sign, "iso", &stream->ps);
1345
1346	if (sign < 0) {		/* Release bandwidth */
1347		usecs = -usecs;
1348		c_usecs = -c_usecs;
1349		tt_usecs = -tt_usecs;
1350	}
1351
1352	if (!stream->splits) {		/* High speed */
1353		for (i = uframe + stream->ps.phase_uf; i < EHCI_BANDWIDTH_SIZE;
1354				i += stream->ps.bw_uperiod)
1355			ehci->bandwidth[i] += usecs;
1356
1357	} else {			/* Full speed */
1358		s_mask = stream->ps.cs_mask;
1359		c_mask = s_mask >> 8;
1360
1361		/* NOTE: adjustment needed for frame overflow */
1362		for (i = uframe; i < EHCI_BANDWIDTH_SIZE;
1363				i += stream->ps.bw_uperiod) {
1364			for ((j = stream->ps.phase_uf, m = 1 << j); j < 8;
1365					(++j, m <<= 1)) {
1366				if (s_mask & m)
1367					ehci->bandwidth[i+j] += usecs;
1368				else if (c_mask & m)
1369					ehci->bandwidth[i+j] += c_usecs;
1370			}
1371		}
1372
1373		tt = find_tt(stream->ps.udev);
1374		if (sign > 0)
1375			list_add_tail(&stream->ps.ps_list, &tt->ps_list);
1376		else
1377			list_del(&stream->ps.ps_list);
1378
1379		for (i = uframe >> 3; i < EHCI_BANDWIDTH_FRAMES;
1380				i += stream->ps.bw_period)
1381			tt->bandwidth[i] += tt_usecs;
1382	}
1383}
1384
1385static inline int
1386itd_slot_ok(
1387	struct ehci_hcd		*ehci,
1388	struct ehci_iso_stream	*stream,
1389	unsigned		uframe
1390)
1391{
1392	unsigned		usecs;
1393
1394	/* convert "usecs we need" to "max already claimed" */
1395	usecs = ehci->uframe_periodic_max - stream->ps.usecs;
1396
1397	for (uframe &= stream->ps.bw_uperiod - 1; uframe < EHCI_BANDWIDTH_SIZE;
1398			uframe += stream->ps.bw_uperiod) {
1399		if (ehci->bandwidth[uframe] > usecs)
1400			return 0;
1401	}
1402	return 1;
1403}
1404
1405static inline int
1406sitd_slot_ok(
1407	struct ehci_hcd		*ehci,
1408	struct ehci_iso_stream	*stream,
1409	unsigned		uframe,
1410	struct ehci_iso_sched	*sched,
1411	struct ehci_tt		*tt
1412)
1413{
1414	unsigned		mask, tmp;
1415	unsigned		frame, uf;
1416
1417	mask = stream->ps.cs_mask << (uframe & 7);
1418
1419	/* for OUT, don't wrap SSPLIT into H-microframe 7 */
1420	if (((stream->ps.cs_mask & 0xff) << (uframe & 7)) >= (1 << 7))
1421		return 0;
1422
1423	/* for IN, don't wrap CSPLIT into the next frame */
1424	if (mask & ~0xffff)
1425		return 0;
1426
1427	/* check bandwidth */
1428	uframe &= stream->ps.bw_uperiod - 1;
1429	frame = uframe >> 3;
1430
1431#ifdef CONFIG_USB_EHCI_TT_NEWSCHED
1432	/* The tt's fullspeed bus bandwidth must be available.
1433	 * tt_available scheduling guarantees 10+% for control/bulk.
1434	 */
1435	uf = uframe & 7;
1436	if (!tt_available(ehci, &stream->ps, tt, frame, uf))
1437		return 0;
1438#else
1439	/* tt must be idle for start(s), any gap, and csplit.
1440	 * assume scheduling slop leaves 10+% for control/bulk.
1441	 */
1442	if (!tt_no_collision(ehci, stream->ps.bw_period,
1443			stream->ps.udev, frame, mask))
1444		return 0;
1445#endif
1446
1447	do {
1448		unsigned	max_used;
1449		unsigned	i;
1450
1451		/* check starts (OUT uses more than one) */
1452		uf = uframe;
1453		max_used = ehci->uframe_periodic_max - stream->ps.usecs;
1454		for (tmp = stream->ps.cs_mask & 0xff; tmp; tmp >>= 1, uf++) {
1455			if (ehci->bandwidth[uf] > max_used)
1456				return 0;
1457		}
1458
1459		/* for IN, check CSPLIT */
1460		if (stream->ps.c_usecs) {
1461			max_used = ehci->uframe_periodic_max -
1462					stream->ps.c_usecs;
1463			uf = uframe & ~7;
1464			tmp = 1 << (2+8);
1465			for (i = (uframe & 7) + 2; i < 8; (++i, tmp <<= 1)) {
1466				if ((stream->ps.cs_mask & tmp) == 0)
1467					continue;
1468				if (ehci->bandwidth[uf+i] > max_used)
1469					return 0;
1470			}
1471		}
1472
1473		uframe += stream->ps.bw_uperiod;
1474	} while (uframe < EHCI_BANDWIDTH_SIZE);
1475
1476	stream->ps.cs_mask <<= uframe & 7;
1477	stream->splits = cpu_to_hc32(ehci, stream->ps.cs_mask);
1478	return 1;
1479}
1480
1481/*
1482 * This scheduler plans almost as far into the future as it has actual
1483 * periodic schedule slots.  (Affected by TUNE_FLS, which defaults to
1484 * "as small as possible" to be cache-friendlier.)  That limits the size
1485 * transfers you can stream reliably; avoid more than 64 msec per urb.
1486 * Also avoid queue depths of less than ehci's worst irq latency (affected
1487 * by the per-urb URB_NO_INTERRUPT hint, the log2_irq_thresh module parameter,
1488 * and other factors); or more than about 230 msec total (for portability,
1489 * given EHCI_TUNE_FLS and the slop).  Or, write a smarter scheduler!
1490 */
1491
1492static int
1493iso_stream_schedule(
1494	struct ehci_hcd		*ehci,
1495	struct urb		*urb,
1496	struct ehci_iso_stream	*stream
1497)
1498{
1499	u32			now, base, next, start, period, span, now2;
1500	u32			wrap = 0, skip = 0;
1501	int			status = 0;
1502	unsigned		mod = ehci->periodic_size << 3;
1503	struct ehci_iso_sched	*sched = urb->hcpriv;
1504	bool			empty = list_empty(&stream->td_list);
1505	bool			new_stream = false;
1506
1507	period = stream->uperiod;
1508	span = sched->span;
1509	if (!stream->highspeed)
1510		span <<= 3;
1511
1512	/* Start a new isochronous stream? */
1513	if (unlikely(empty && !hcd_periodic_completion_in_progress(
1514			ehci_to_hcd(ehci), urb->ep))) {
1515
1516		/* Schedule the endpoint */
1517		if (stream->ps.phase == NO_FRAME) {
1518			int		done = 0;
1519			struct ehci_tt	*tt = find_tt(stream->ps.udev);
1520
1521			if (IS_ERR(tt)) {
1522				status = PTR_ERR(tt);
1523				goto fail;
1524			}
1525			compute_tt_budget(ehci->tt_budget, tt);
1526
1527			start = ((-(++ehci->random_frame)) << 3) & (period - 1);
1528
1529			/* find a uframe slot with enough bandwidth.
1530			 * Early uframes are more precious because full-speed
1531			 * iso IN transfers can't use late uframes,
1532			 * and therefore they should be allocated last.
1533			 */
1534			next = start;
1535			start += period;
1536			do {
1537				start--;
1538				/* check schedule: enough space? */
1539				if (stream->highspeed) {
1540					if (itd_slot_ok(ehci, stream, start))
1541						done = 1;
1542				} else {
1543					if ((start % 8) >= 6)
1544						continue;
1545					if (sitd_slot_ok(ehci, stream, start,
1546							sched, tt))
1547						done = 1;
1548				}
1549			} while (start > next && !done);
1550
1551			/* no room in the schedule */
1552			if (!done) {
1553				ehci_dbg(ehci, "iso sched full %p", urb);
1554				status = -ENOSPC;
1555				goto fail;
1556			}
1557			stream->ps.phase = (start >> 3) &
1558					(stream->ps.period - 1);
1559			stream->ps.bw_phase = stream->ps.phase &
1560					(stream->ps.bw_period - 1);
1561			stream->ps.phase_uf = start & 7;
1562			reserve_release_iso_bandwidth(ehci, stream, 1);
1563		}
1564
1565		/* New stream is already scheduled; use the upcoming slot */
1566		else {
1567			start = (stream->ps.phase << 3) + stream->ps.phase_uf;
1568		}
1569
1570		stream->next_uframe = start;
1571		new_stream = true;
1572	}
1573
1574	now = ehci_read_frame_index(ehci) & (mod - 1);
1575
1576	/* Take the isochronous scheduling threshold into account */
1577	if (ehci->i_thresh)
1578		next = now + ehci->i_thresh;	/* uframe cache */
1579	else
1580		next = (now + 2 + 7) & ~0x07;	/* full frame cache */
1581
1582	/* If needed, initialize last_iso_frame so that this URB will be seen */
1583	if (ehci->isoc_count == 0)
1584		ehci->last_iso_frame = now >> 3;
1585
1586	/*
1587	 * Use ehci->last_iso_frame as the base.  There can't be any
1588	 * TDs scheduled for earlier than that.
1589	 */
1590	base = ehci->last_iso_frame << 3;
1591	next = (next - base) & (mod - 1);
1592	start = (stream->next_uframe - base) & (mod - 1);
1593
1594	if (unlikely(new_stream))
1595		goto do_ASAP;
1596
1597	/*
1598	 * Typical case: reuse current schedule, stream may still be active.
1599	 * Hopefully there are no gaps from the host falling behind
1600	 * (irq delays etc).  If there are, the behavior depends on
1601	 * whether URB_ISO_ASAP is set.
1602	 */
1603	now2 = (now - base) & (mod - 1);
1604
1605	/* Is the schedule about to wrap around? */
1606	if (unlikely(!empty && start < period)) {
1607		ehci_dbg(ehci, "request %p would overflow (%u-%u < %u mod %u)\n",
1608				urb, stream->next_uframe, base, period, mod);
1609		status = -EFBIG;
1610		goto fail;
1611	}
1612
1613	/* Is the next packet scheduled after the base time? */
1614	if (likely(!empty || start <= now2 + period)) {
1615
1616		/* URB_ISO_ASAP: make sure that start >= next */
1617		if (unlikely(start < next &&
1618				(urb->transfer_flags & URB_ISO_ASAP)))
1619			goto do_ASAP;
1620
1621		/* Otherwise use start, if it's not in the past */
1622		if (likely(start >= now2))
1623			goto use_start;
1624
1625	/* Otherwise we got an underrun while the queue was empty */
1626	} else {
1627		if (urb->transfer_flags & URB_ISO_ASAP)
1628			goto do_ASAP;
1629		wrap = mod;
1630		now2 += mod;
1631	}
1632
1633	/* How many uframes and packets do we need to skip? */
1634	skip = (now2 - start + period - 1) & -period;
1635	if (skip >= span) {		/* Entirely in the past? */
1636		ehci_dbg(ehci, "iso underrun %p (%u+%u < %u) [%u]\n",
1637				urb, start + base, span - period, now2 + base,
1638				base);
1639
1640		/* Try to keep the last TD intact for scanning later */
1641		skip = span - period;
1642
1643		/* Will it come before the current scan position? */
1644		if (empty) {
1645			skip = span;	/* Skip the entire URB */
1646			status = 1;	/* and give it back immediately */
1647			iso_sched_free(stream, sched);
1648			sched = NULL;
1649		}
1650	}
1651	urb->error_count = skip / period;
1652	if (sched)
1653		sched->first_packet = urb->error_count;
1654	goto use_start;
1655
1656 do_ASAP:
1657	/* Use the first slot after "next" */
1658	start = next + ((start - next) & (period - 1));
1659
1660 use_start:
1661	/* Tried to schedule too far into the future? */
1662	if (unlikely(start + span - period >= mod + wrap)) {
1663		ehci_dbg(ehci, "request %p would overflow (%u+%u >= %u)\n",
1664				urb, start, span - period, mod + wrap);
1665		status = -EFBIG;
1666		goto fail;
1667	}
1668
1669	start += base;
1670	stream->next_uframe = (start + skip) & (mod - 1);
1671
1672	/* report high speed start in uframes; full speed, in frames */
1673	urb->start_frame = start & (mod - 1);
1674	if (!stream->highspeed)
1675		urb->start_frame >>= 3;
1676	return status;
1677
1678 fail:
1679	iso_sched_free(stream, sched);
1680	urb->hcpriv = NULL;
1681	return status;
1682}
1683
1684/*-------------------------------------------------------------------------*/
1685
1686static inline void
1687itd_init(struct ehci_hcd *ehci, struct ehci_iso_stream *stream,
1688		struct ehci_itd *itd)
1689{
1690	int i;
1691
1692	/* it's been recently zeroed */
1693	itd->hw_next = EHCI_LIST_END(ehci);
1694	itd->hw_bufp[0] = stream->buf0;
1695	itd->hw_bufp[1] = stream->buf1;
1696	itd->hw_bufp[2] = stream->buf2;
1697
1698	for (i = 0; i < 8; i++)
1699		itd->index[i] = -1;
1700
1701	/* All other fields are filled when scheduling */
1702}
1703
1704static inline void
1705itd_patch(
1706	struct ehci_hcd		*ehci,
1707	struct ehci_itd		*itd,
1708	struct ehci_iso_sched	*iso_sched,
1709	unsigned		index,
1710	u16			uframe
1711)
1712{
1713	struct ehci_iso_packet	*uf = &iso_sched->packet[index];
1714	unsigned		pg = itd->pg;
1715
1716	/* BUG_ON(pg == 6 && uf->cross); */
1717
1718	uframe &= 0x07;
1719	itd->index[uframe] = index;
1720
1721	itd->hw_transaction[uframe] = uf->transaction;
1722	itd->hw_transaction[uframe] |= cpu_to_hc32(ehci, pg << 12);
1723	itd->hw_bufp[pg] |= cpu_to_hc32(ehci, uf->bufp & ~(u32)0);
1724	itd->hw_bufp_hi[pg] |= cpu_to_hc32(ehci, (u32)(uf->bufp >> 32));
1725
1726	/* iso_frame_desc[].offset must be strictly increasing */
1727	if (unlikely(uf->cross)) {
1728		u64	bufp = uf->bufp + 4096;
1729
1730		itd->pg = ++pg;
1731		itd->hw_bufp[pg] |= cpu_to_hc32(ehci, bufp & ~(u32)0);
1732		itd->hw_bufp_hi[pg] |= cpu_to_hc32(ehci, (u32)(bufp >> 32));
1733	}
1734}
1735
1736static inline void
1737itd_link(struct ehci_hcd *ehci, unsigned frame, struct ehci_itd *itd)
1738{
1739	union ehci_shadow	*prev = &ehci->pshadow[frame];
1740	__hc32			*hw_p = &ehci->periodic[frame];
1741	union ehci_shadow	here = *prev;
1742	__hc32			type = 0;
1743
1744	/* skip any iso nodes which might belong to previous microframes */
1745	while (here.ptr) {
1746		type = Q_NEXT_TYPE(ehci, *hw_p);
1747		if (type == cpu_to_hc32(ehci, Q_TYPE_QH))
1748			break;
1749		prev = periodic_next_shadow(ehci, prev, type);
1750		hw_p = shadow_next_periodic(ehci, &here, type);
1751		here = *prev;
1752	}
1753
1754	itd->itd_next = here;
1755	itd->hw_next = *hw_p;
1756	prev->itd = itd;
1757	itd->frame = frame;
1758	wmb();
1759	*hw_p = cpu_to_hc32(ehci, itd->itd_dma | Q_TYPE_ITD);
1760}
1761
1762/* fit urb's itds into the selected schedule slot; activate as needed */
1763static void itd_link_urb(
1764	struct ehci_hcd		*ehci,
1765	struct urb		*urb,
1766	unsigned		mod,
1767	struct ehci_iso_stream	*stream
1768)
1769{
1770	int			packet;
1771	unsigned		next_uframe, uframe, frame;
1772	struct ehci_iso_sched	*iso_sched = urb->hcpriv;
1773	struct ehci_itd		*itd;
1774
1775	next_uframe = stream->next_uframe & (mod - 1);
1776
1777	if (unlikely(list_empty(&stream->td_list)))
1778		ehci_to_hcd(ehci)->self.bandwidth_allocated
1779				+= stream->bandwidth;
1780
1781	if (ehci_to_hcd(ehci)->self.bandwidth_isoc_reqs == 0) {
1782		if (ehci->amd_pll_fix == 1)
1783			usb_amd_quirk_pll_disable();
1784	}
1785
1786	ehci_to_hcd(ehci)->self.bandwidth_isoc_reqs++;
1787
1788	/* fill iTDs uframe by uframe */
1789	for (packet = iso_sched->first_packet, itd = NULL;
1790			packet < urb->number_of_packets;) {
1791		if (itd == NULL) {
1792			/* ASSERT:  we have all necessary itds */
1793			/* BUG_ON(list_empty(&iso_sched->td_list)); */
1794
1795			/* ASSERT:  no itds for this endpoint in this uframe */
1796
1797			itd = list_entry(iso_sched->td_list.next,
1798					struct ehci_itd, itd_list);
1799			list_move_tail(&itd->itd_list, &stream->td_list);
1800			itd->stream = stream;
1801			itd->urb = urb;
1802			itd_init(ehci, stream, itd);
1803		}
1804
1805		uframe = next_uframe & 0x07;
1806		frame = next_uframe >> 3;
1807
1808		itd_patch(ehci, itd, iso_sched, packet, uframe);
1809
1810		next_uframe += stream->uperiod;
1811		next_uframe &= mod - 1;
1812		packet++;
1813
1814		/* link completed itds into the schedule */
1815		if (((next_uframe >> 3) != frame)
1816				|| packet == urb->number_of_packets) {
1817			itd_link(ehci, frame & (ehci->periodic_size - 1), itd);
1818			itd = NULL;
1819		}
1820	}
1821	stream->next_uframe = next_uframe;
1822
1823	/* don't need that schedule data any more */
1824	iso_sched_free(stream, iso_sched);
1825	urb->hcpriv = stream;
1826
1827	++ehci->isoc_count;
1828	enable_periodic(ehci);
1829}
1830
1831#define	ISO_ERRS (EHCI_ISOC_BUF_ERR | EHCI_ISOC_BABBLE | EHCI_ISOC_XACTERR)
1832
1833/* Process and recycle a completed ITD.  Return true iff its urb completed,
1834 * and hence its completion callback probably added things to the hardware
1835 * schedule.
1836 *
1837 * Note that we carefully avoid recycling this descriptor until after any
1838 * completion callback runs, so that it won't be reused quickly.  That is,
1839 * assuming (a) no more than two urbs per frame on this endpoint, and also
1840 * (b) only this endpoint's completions submit URBs.  It seems some silicon
1841 * corrupts things if you reuse completed descriptors very quickly...
1842 */
1843static bool itd_complete(struct ehci_hcd *ehci, struct ehci_itd *itd)
1844{
1845	struct urb				*urb = itd->urb;
1846	struct usb_iso_packet_descriptor	*desc;
1847	u32					t;
1848	unsigned				uframe;
1849	int					urb_index = -1;
1850	struct ehci_iso_stream			*stream = itd->stream;
1851	struct usb_device			*dev;
1852	bool					retval = false;
1853
1854	/* for each uframe with a packet */
1855	for (uframe = 0; uframe < 8; uframe++) {
1856		if (likely(itd->index[uframe] == -1))
1857			continue;
1858		urb_index = itd->index[uframe];
1859		desc = &urb->iso_frame_desc[urb_index];
1860
1861		t = hc32_to_cpup(ehci, &itd->hw_transaction[uframe]);
1862		itd->hw_transaction[uframe] = 0;
1863
1864		/* report transfer status */
1865		if (unlikely(t & ISO_ERRS)) {
1866			urb->error_count++;
1867			if (t & EHCI_ISOC_BUF_ERR)
1868				desc->status = usb_pipein(urb->pipe)
1869					? -ENOSR  /* hc couldn't read */
1870					: -ECOMM; /* hc couldn't write */
1871			else if (t & EHCI_ISOC_BABBLE)
1872				desc->status = -EOVERFLOW;
1873			else /* (t & EHCI_ISOC_XACTERR) */
1874				desc->status = -EPROTO;
1875
1876			/* HC need not update length with this error */
1877			if (!(t & EHCI_ISOC_BABBLE)) {
1878				desc->actual_length = EHCI_ITD_LENGTH(t);
1879				urb->actual_length += desc->actual_length;
1880			}
1881		} else if (likely((t & EHCI_ISOC_ACTIVE) == 0)) {
1882			desc->status = 0;
1883			desc->actual_length = EHCI_ITD_LENGTH(t);
1884			urb->actual_length += desc->actual_length;
1885		} else {
1886			/* URB was too late */
1887			urb->error_count++;
1888		}
1889	}
1890
1891	/* handle completion now? */
1892	if (likely((urb_index + 1) != urb->number_of_packets))
1893		goto done;
1894
1895	/*
1896	 * ASSERT: it's really the last itd for this urb
1897	 * list_for_each_entry (itd, &stream->td_list, itd_list)
1898	 *	 BUG_ON(itd->urb == urb);
1899	 */
1900
1901	/* give urb back to the driver; completion often (re)submits */
1902	dev = urb->dev;
1903	ehci_urb_done(ehci, urb, 0);
1904	retval = true;
1905	urb = NULL;
1906
1907	--ehci->isoc_count;
1908	disable_periodic(ehci);
1909
1910	ehci_to_hcd(ehci)->self.bandwidth_isoc_reqs--;
1911	if (ehci_to_hcd(ehci)->self.bandwidth_isoc_reqs == 0) {
1912		if (ehci->amd_pll_fix == 1)
1913			usb_amd_quirk_pll_enable();
1914	}
1915
1916	if (unlikely(list_is_singular(&stream->td_list)))
1917		ehci_to_hcd(ehci)->self.bandwidth_allocated
1918				-= stream->bandwidth;
1919
1920done:
1921	itd->urb = NULL;
1922
1923	/* Add to the end of the free list for later reuse */
1924	list_move_tail(&itd->itd_list, &stream->free_list);
1925
1926	/* Recycle the iTDs when the pipeline is empty (ep no longer in use) */
1927	if (list_empty(&stream->td_list)) {
1928		list_splice_tail_init(&stream->free_list,
1929				&ehci->cached_itd_list);
1930		start_free_itds(ehci);
1931	}
1932
1933	return retval;
1934}
1935
1936/*-------------------------------------------------------------------------*/
1937
1938static int itd_submit(struct ehci_hcd *ehci, struct urb *urb,
1939	gfp_t mem_flags)
1940{
1941	int			status = -EINVAL;
1942	unsigned long		flags;
1943	struct ehci_iso_stream	*stream;
1944
1945	/* Get iso_stream head */
1946	stream = iso_stream_find(ehci, urb);
1947	if (unlikely(stream == NULL)) {
1948		ehci_dbg(ehci, "can't get iso stream\n");
1949		return -ENOMEM;
1950	}
1951	if (unlikely(urb->interval != stream->uperiod)) {
1952		ehci_dbg(ehci, "can't change iso interval %d --> %d\n",
1953			stream->uperiod, urb->interval);
1954		goto done;
1955	}
1956
1957#ifdef EHCI_URB_TRACE
1958	ehci_dbg(ehci,
1959		"%s %s urb %p ep%d%s len %d, %d pkts %d uframes [%p]\n",
1960		__func__, urb->dev->devpath, urb,
1961		usb_pipeendpoint(urb->pipe),
1962		usb_pipein(urb->pipe) ? "in" : "out",
1963		urb->transfer_buffer_length,
1964		urb->number_of_packets, urb->interval,
1965		stream);
1966#endif
1967
1968	/* allocate ITDs w/o locking anything */
1969	status = itd_urb_transaction(stream, ehci, urb, mem_flags);
1970	if (unlikely(status < 0)) {
1971		ehci_dbg(ehci, "can't init itds\n");
1972		goto done;
1973	}
1974
1975	/* schedule ... need to lock */
1976	spin_lock_irqsave(&ehci->lock, flags);
1977	if (unlikely(!HCD_HW_ACCESSIBLE(ehci_to_hcd(ehci)))) {
1978		status = -ESHUTDOWN;
1979		goto done_not_linked;
1980	}
1981	status = usb_hcd_link_urb_to_ep(ehci_to_hcd(ehci), urb);
1982	if (unlikely(status))
1983		goto done_not_linked;
1984	status = iso_stream_schedule(ehci, urb, stream);
1985	if (likely(status == 0)) {
1986		itd_link_urb(ehci, urb, ehci->periodic_size << 3, stream);
1987	} else if (status > 0) {
1988		status = 0;
1989		ehci_urb_done(ehci, urb, 0);
1990	} else {
1991		usb_hcd_unlink_urb_from_ep(ehci_to_hcd(ehci), urb);
1992	}
1993 done_not_linked:
1994	spin_unlock_irqrestore(&ehci->lock, flags);
1995 done:
1996	return status;
1997}
1998
1999/*-------------------------------------------------------------------------*/
2000
2001/*
2002 * "Split ISO TDs" ... used for USB 1.1 devices going through the
2003 * TTs in USB 2.0 hubs.  These need microframe scheduling.
2004 */
2005
2006static inline void
2007sitd_sched_init(
2008	struct ehci_hcd		*ehci,
2009	struct ehci_iso_sched	*iso_sched,
2010	struct ehci_iso_stream	*stream,
2011	struct urb		*urb
2012)
2013{
2014	unsigned	i;
2015	dma_addr_t	dma = urb->transfer_dma;
2016
2017	/* how many frames are needed for these transfers */
2018	iso_sched->span = urb->number_of_packets * stream->ps.period;
2019
2020	/* figure out per-frame sitd fields that we'll need later
2021	 * when we fit new sitds into the schedule.
2022	 */
2023	for (i = 0; i < urb->number_of_packets; i++) {
2024		struct ehci_iso_packet	*packet = &iso_sched->packet[i];
2025		unsigned		length;
2026		dma_addr_t		buf;
2027		u32			trans;
2028
2029		length = urb->iso_frame_desc[i].length & 0x03ff;
2030		buf = dma + urb->iso_frame_desc[i].offset;
2031
2032		trans = SITD_STS_ACTIVE;
2033		if (((i + 1) == urb->number_of_packets)
2034				&& !(urb->transfer_flags & URB_NO_INTERRUPT))
2035			trans |= SITD_IOC;
2036		trans |= length << 16;
2037		packet->transaction = cpu_to_hc32(ehci, trans);
2038
2039		/* might need to cross a buffer page within a td */
2040		packet->bufp = buf;
2041		packet->buf1 = (buf + length) & ~0x0fff;
2042		if (packet->buf1 != (buf & ~(u64)0x0fff))
2043			packet->cross = 1;
2044
2045		/* OUT uses multiple start-splits */
2046		if (stream->bEndpointAddress & USB_DIR_IN)
2047			continue;
2048		length = (length + 187) / 188;
2049		if (length > 1) /* BEGIN vs ALL */
2050			length |= 1 << 3;
2051		packet->buf1 |= length;
2052	}
2053}
2054
2055static int
2056sitd_urb_transaction(
2057	struct ehci_iso_stream	*stream,
2058	struct ehci_hcd		*ehci,
2059	struct urb		*urb,
2060	gfp_t			mem_flags
2061)
2062{
2063	struct ehci_sitd	*sitd;
2064	dma_addr_t		sitd_dma;
2065	int			i;
2066	struct ehci_iso_sched	*iso_sched;
2067	unsigned long		flags;
2068
2069	iso_sched = iso_sched_alloc(urb->number_of_packets, mem_flags);
2070	if (iso_sched == NULL)
2071		return -ENOMEM;
2072
2073	sitd_sched_init(ehci, iso_sched, stream, urb);
2074
2075	/* allocate/init sITDs */
2076	spin_lock_irqsave(&ehci->lock, flags);
2077	for (i = 0; i < urb->number_of_packets; i++) {
2078
2079		/* NOTE:  for now, we don't try to handle wraparound cases
2080		 * for IN (using sitd->hw_backpointer, like a FSTN), which
2081		 * means we never need two sitds for full speed packets.
2082		 */
2083
2084		/*
2085		 * Use siTDs from the free list, but not siTDs that may
2086		 * still be in use by the hardware.
2087		 */
2088		if (likely(!list_empty(&stream->free_list))) {
2089			sitd = list_first_entry(&stream->free_list,
2090					 struct ehci_sitd, sitd_list);
2091			if (sitd->frame == ehci->now_frame)
2092				goto alloc_sitd;
2093			list_del(&sitd->sitd_list);
2094			sitd_dma = sitd->sitd_dma;
2095		} else {
2096 alloc_sitd:
2097			spin_unlock_irqrestore(&ehci->lock, flags);
2098			sitd = dma_pool_alloc(ehci->sitd_pool, mem_flags,
2099					&sitd_dma);
2100			spin_lock_irqsave(&ehci->lock, flags);
2101			if (!sitd) {
2102				iso_sched_free(stream, iso_sched);
2103				spin_unlock_irqrestore(&ehci->lock, flags);
2104				return -ENOMEM;
2105			}
2106		}
2107
2108		memset(sitd, 0, sizeof(*sitd));
2109		sitd->sitd_dma = sitd_dma;
2110		sitd->frame = NO_FRAME;
2111		list_add(&sitd->sitd_list, &iso_sched->td_list);
2112	}
2113
2114	/* temporarily store schedule info in hcpriv */
2115	urb->hcpriv = iso_sched;
2116	urb->error_count = 0;
2117
2118	spin_unlock_irqrestore(&ehci->lock, flags);
2119	return 0;
2120}
2121
2122/*-------------------------------------------------------------------------*/
2123
2124static inline void
2125sitd_patch(
2126	struct ehci_hcd		*ehci,
2127	struct ehci_iso_stream	*stream,
2128	struct ehci_sitd	*sitd,
2129	struct ehci_iso_sched	*iso_sched,
2130	unsigned		index
2131)
2132{
2133	struct ehci_iso_packet	*uf = &iso_sched->packet[index];
2134	u64			bufp;
2135
2136	sitd->hw_next = EHCI_LIST_END(ehci);
2137	sitd->hw_fullspeed_ep = stream->address;
2138	sitd->hw_uframe = stream->splits;
2139	sitd->hw_results = uf->transaction;
2140	sitd->hw_backpointer = EHCI_LIST_END(ehci);
2141
2142	bufp = uf->bufp;
2143	sitd->hw_buf[0] = cpu_to_hc32(ehci, bufp);
2144	sitd->hw_buf_hi[0] = cpu_to_hc32(ehci, bufp >> 32);
2145
2146	sitd->hw_buf[1] = cpu_to_hc32(ehci, uf->buf1);
2147	if (uf->cross)
2148		bufp += 4096;
2149	sitd->hw_buf_hi[1] = cpu_to_hc32(ehci, bufp >> 32);
2150	sitd->index = index;
2151}
2152
2153static inline void
2154sitd_link(struct ehci_hcd *ehci, unsigned frame, struct ehci_sitd *sitd)
2155{
2156	/* note: sitd ordering could matter (CSPLIT then SSPLIT) */
2157	sitd->sitd_next = ehci->pshadow[frame];
2158	sitd->hw_next = ehci->periodic[frame];
2159	ehci->pshadow[frame].sitd = sitd;
2160	sitd->frame = frame;
2161	wmb();
2162	ehci->periodic[frame] = cpu_to_hc32(ehci, sitd->sitd_dma | Q_TYPE_SITD);
2163}
2164
2165/* fit urb's sitds into the selected schedule slot; activate as needed */
2166static void sitd_link_urb(
2167	struct ehci_hcd		*ehci,
2168	struct urb		*urb,
2169	unsigned		mod,
2170	struct ehci_iso_stream	*stream
2171)
2172{
2173	int			packet;
2174	unsigned		next_uframe;
2175	struct ehci_iso_sched	*sched = urb->hcpriv;
2176	struct ehci_sitd	*sitd;
2177
2178	next_uframe = stream->next_uframe;
2179
2180	if (list_empty(&stream->td_list))
2181		/* usbfs ignores TT bandwidth */
2182		ehci_to_hcd(ehci)->self.bandwidth_allocated
2183				+= stream->bandwidth;
2184
2185	if (ehci_to_hcd(ehci)->self.bandwidth_isoc_reqs == 0) {
2186		if (ehci->amd_pll_fix == 1)
2187			usb_amd_quirk_pll_disable();
2188	}
2189
2190	ehci_to_hcd(ehci)->self.bandwidth_isoc_reqs++;
2191
2192	/* fill sITDs frame by frame */
2193	for (packet = sched->first_packet, sitd = NULL;
2194			packet < urb->number_of_packets;
2195			packet++) {
2196
2197		/* ASSERT:  we have all necessary sitds */
2198		BUG_ON(list_empty(&sched->td_list));
2199
2200		/* ASSERT:  no itds for this endpoint in this frame */
2201
2202		sitd = list_entry(sched->td_list.next,
2203				struct ehci_sitd, sitd_list);
2204		list_move_tail(&sitd->sitd_list, &stream->td_list);
2205		sitd->stream = stream;
2206		sitd->urb = urb;
2207
2208		sitd_patch(ehci, stream, sitd, sched, packet);
2209		sitd_link(ehci, (next_uframe >> 3) & (ehci->periodic_size - 1),
2210				sitd);
2211
2212		next_uframe += stream->uperiod;
2213	}
2214	stream->next_uframe = next_uframe & (mod - 1);
2215
2216	/* don't need that schedule data any more */
2217	iso_sched_free(stream, sched);
2218	urb->hcpriv = stream;
2219
2220	++ehci->isoc_count;
2221	enable_periodic(ehci);
2222}
2223
2224/*-------------------------------------------------------------------------*/
2225
2226#define	SITD_ERRS (SITD_STS_ERR | SITD_STS_DBE | SITD_STS_BABBLE \
2227				| SITD_STS_XACT | SITD_STS_MMF)
2228
2229/* Process and recycle a completed SITD.  Return true iff its urb completed,
2230 * and hence its completion callback probably added things to the hardware
2231 * schedule.
2232 *
2233 * Note that we carefully avoid recycling this descriptor until after any
2234 * completion callback runs, so that it won't be reused quickly.  That is,
2235 * assuming (a) no more than two urbs per frame on this endpoint, and also
2236 * (b) only this endpoint's completions submit URBs.  It seems some silicon
2237 * corrupts things if you reuse completed descriptors very quickly...
2238 */
2239static bool sitd_complete(struct ehci_hcd *ehci, struct ehci_sitd *sitd)
2240{
2241	struct urb				*urb = sitd->urb;
2242	struct usb_iso_packet_descriptor	*desc;
2243	u32					t;
2244	int					urb_index;
2245	struct ehci_iso_stream			*stream = sitd->stream;
2246	struct usb_device			*dev;
2247	bool					retval = false;
2248
2249	urb_index = sitd->index;
2250	desc = &urb->iso_frame_desc[urb_index];
2251	t = hc32_to_cpup(ehci, &sitd->hw_results);
2252
2253	/* report transfer status */
2254	if (unlikely(t & SITD_ERRS)) {
2255		urb->error_count++;
2256		if (t & SITD_STS_DBE)
2257			desc->status = usb_pipein(urb->pipe)
2258				? -ENOSR  /* hc couldn't read */
2259				: -ECOMM; /* hc couldn't write */
2260		else if (t & SITD_STS_BABBLE)
2261			desc->status = -EOVERFLOW;
2262		else /* XACT, MMF, etc */
2263			desc->status = -EPROTO;
2264	} else if (unlikely(t & SITD_STS_ACTIVE)) {
2265		/* URB was too late */
2266		urb->error_count++;
2267	} else {
2268		desc->status = 0;
2269		desc->actual_length = desc->length - SITD_LENGTH(t);
2270		urb->actual_length += desc->actual_length;
2271	}
2272
2273	/* handle completion now? */
2274	if ((urb_index + 1) != urb->number_of_packets)
2275		goto done;
2276
2277	/*
2278	 * ASSERT: it's really the last sitd for this urb
2279	 * list_for_each_entry (sitd, &stream->td_list, sitd_list)
2280	 *	 BUG_ON(sitd->urb == urb);
2281	 */
2282
2283	/* give urb back to the driver; completion often (re)submits */
2284	dev = urb->dev;
2285	ehci_urb_done(ehci, urb, 0);
2286	retval = true;
2287	urb = NULL;
2288
2289	--ehci->isoc_count;
2290	disable_periodic(ehci);
2291
2292	ehci_to_hcd(ehci)->self.bandwidth_isoc_reqs--;
2293	if (ehci_to_hcd(ehci)->self.bandwidth_isoc_reqs == 0) {
2294		if (ehci->amd_pll_fix == 1)
2295			usb_amd_quirk_pll_enable();
2296	}
2297
2298	if (list_is_singular(&stream->td_list))
2299		ehci_to_hcd(ehci)->self.bandwidth_allocated
2300				-= stream->bandwidth;
2301
2302done:
2303	sitd->urb = NULL;
2304
2305	/* Add to the end of the free list for later reuse */
2306	list_move_tail(&sitd->sitd_list, &stream->free_list);
2307
2308	/* Recycle the siTDs when the pipeline is empty (ep no longer in use) */
2309	if (list_empty(&stream->td_list)) {
2310		list_splice_tail_init(&stream->free_list,
2311				&ehci->cached_sitd_list);
2312		start_free_itds(ehci);
2313	}
2314
2315	return retval;
2316}
2317
2318
2319static int sitd_submit(struct ehci_hcd *ehci, struct urb *urb,
2320	gfp_t mem_flags)
2321{
2322	int			status = -EINVAL;
2323	unsigned long		flags;
2324	struct ehci_iso_stream	*stream;
2325
2326	/* Get iso_stream head */
2327	stream = iso_stream_find(ehci, urb);
2328	if (stream == NULL) {
2329		ehci_dbg(ehci, "can't get iso stream\n");
2330		return -ENOMEM;
2331	}
2332	if (urb->interval != stream->ps.period) {
2333		ehci_dbg(ehci, "can't change iso interval %d --> %d\n",
2334			stream->ps.period, urb->interval);
2335		goto done;
2336	}
2337
2338#ifdef EHCI_URB_TRACE
2339	ehci_dbg(ehci,
2340		"submit %p dev%s ep%d%s-iso len %d\n",
2341		urb, urb->dev->devpath,
2342		usb_pipeendpoint(urb->pipe),
2343		usb_pipein(urb->pipe) ? "in" : "out",
2344		urb->transfer_buffer_length);
2345#endif
2346
2347	/* allocate SITDs */
2348	status = sitd_urb_transaction(stream, ehci, urb, mem_flags);
2349	if (status < 0) {
2350		ehci_dbg(ehci, "can't init sitds\n");
2351		goto done;
2352	}
2353
2354	/* schedule ... need to lock */
2355	spin_lock_irqsave(&ehci->lock, flags);
2356	if (unlikely(!HCD_HW_ACCESSIBLE(ehci_to_hcd(ehci)))) {
2357		status = -ESHUTDOWN;
2358		goto done_not_linked;
2359	}
2360	status = usb_hcd_link_urb_to_ep(ehci_to_hcd(ehci), urb);
2361	if (unlikely(status))
2362		goto done_not_linked;
2363	status = iso_stream_schedule(ehci, urb, stream);
2364	if (likely(status == 0)) {
2365		sitd_link_urb(ehci, urb, ehci->periodic_size << 3, stream);
2366	} else if (status > 0) {
2367		status = 0;
2368		ehci_urb_done(ehci, urb, 0);
2369	} else {
2370		usb_hcd_unlink_urb_from_ep(ehci_to_hcd(ehci), urb);
2371	}
2372 done_not_linked:
2373	spin_unlock_irqrestore(&ehci->lock, flags);
2374 done:
2375	return status;
2376}
2377
2378/*-------------------------------------------------------------------------*/
2379
2380static void scan_isoc(struct ehci_hcd *ehci)
2381{
2382	unsigned		uf, now_frame, frame;
2383	unsigned		fmask = ehci->periodic_size - 1;
2384	bool			modified, live;
2385	union ehci_shadow	q, *q_p;
2386	__hc32			type, *hw_p;
2387
2388	/*
2389	 * When running, scan from last scan point up to "now"
2390	 * else clean up by scanning everything that's left.
2391	 * Touches as few pages as possible:  cache-friendly.
2392	 */
2393	if (ehci->rh_state >= EHCI_RH_RUNNING) {
2394		uf = ehci_read_frame_index(ehci);
2395		now_frame = (uf >> 3) & fmask;
2396		live = true;
2397	} else  {
2398		now_frame = (ehci->last_iso_frame - 1) & fmask;
2399		live = false;
2400	}
2401	ehci->now_frame = now_frame;
2402
2403	frame = ehci->last_iso_frame;
2404
2405restart:
2406	/* Scan each element in frame's queue for completions */
2407	q_p = &ehci->pshadow[frame];
2408	hw_p = &ehci->periodic[frame];
2409	q.ptr = q_p->ptr;
2410	type = Q_NEXT_TYPE(ehci, *hw_p);
2411	modified = false;
2412
2413	while (q.ptr != NULL) {
2414		switch (hc32_to_cpu(ehci, type)) {
2415		case Q_TYPE_ITD:
2416			/*
2417			 * If this ITD is still active, leave it for
2418			 * later processing ... check the next entry.
2419			 * No need to check for activity unless the
2420			 * frame is current.
2421			 */
2422			if (frame == now_frame && live) {
2423				rmb();
2424				for (uf = 0; uf < 8; uf++) {
2425					if (q.itd->hw_transaction[uf] &
2426							ITD_ACTIVE(ehci))
2427						break;
2428				}
2429				if (uf < 8) {
2430					q_p = &q.itd->itd_next;
2431					hw_p = &q.itd->hw_next;
2432					type = Q_NEXT_TYPE(ehci,
2433							q.itd->hw_next);
2434					q = *q_p;
2435					break;
2436				}
2437			}
2438
2439			/*
2440			 * Take finished ITDs out of the schedule
2441			 * and process them:  recycle, maybe report
2442			 * URB completion.  HC won't cache the
2443			 * pointer for much longer, if at all.
2444			 */
2445			*q_p = q.itd->itd_next;
2446			if (!ehci->use_dummy_qh ||
2447					q.itd->hw_next != EHCI_LIST_END(ehci))
2448				*hw_p = q.itd->hw_next;
2449			else
2450				*hw_p = cpu_to_hc32(ehci, ehci->dummy->qh_dma);
2451			type = Q_NEXT_TYPE(ehci, q.itd->hw_next);
2452			wmb();
2453			modified = itd_complete(ehci, q.itd);
2454			q = *q_p;
2455			break;
2456		case Q_TYPE_SITD:
2457			/*
2458			 * If this SITD is still active, leave it for
2459			 * later processing ... check the next entry.
2460			 * No need to check for activity unless the
2461			 * frame is current.
2462			 */
2463			if (((frame == now_frame) ||
2464					(((frame + 1) & fmask) == now_frame))
2465				&& live
2466				&& (q.sitd->hw_results & SITD_ACTIVE(ehci))) {
2467
2468				q_p = &q.sitd->sitd_next;
2469				hw_p = &q.sitd->hw_next;
2470				type = Q_NEXT_TYPE(ehci, q.sitd->hw_next);
2471				q = *q_p;
2472				break;
2473			}
2474
2475			/*
2476			 * Take finished SITDs out of the schedule
2477			 * and process them:  recycle, maybe report
2478			 * URB completion.
2479			 */
2480			*q_p = q.sitd->sitd_next;
2481			if (!ehci->use_dummy_qh ||
2482					q.sitd->hw_next != EHCI_LIST_END(ehci))
2483				*hw_p = q.sitd->hw_next;
2484			else
2485				*hw_p = cpu_to_hc32(ehci, ehci->dummy->qh_dma);
2486			type = Q_NEXT_TYPE(ehci, q.sitd->hw_next);
2487			wmb();
2488			modified = sitd_complete(ehci, q.sitd);
2489			q = *q_p;
2490			break;
2491		default:
2492			ehci_dbg(ehci, "corrupt type %d frame %d shadow %p\n",
2493					type, frame, q.ptr);
2494			/* BUG(); */
2495			/* FALL THROUGH */
2496		case Q_TYPE_QH:
2497		case Q_TYPE_FSTN:
2498			/* End of the iTDs and siTDs */
2499			q.ptr = NULL;
2500			break;
2501		}
2502
2503		/* Assume completion callbacks modify the queue */
2504		if (unlikely(modified && ehci->isoc_count > 0))
2505			goto restart;
2506	}
2507
2508	/* Stop when we have reached the current frame */
2509	if (frame == now_frame)
2510		return;
2511
2512	/* The last frame may still have active siTDs */
2513	ehci->last_iso_frame = frame;
2514	frame = (frame + 1) & fmask;
2515
2516	goto restart;
2517}