Add linux-next specific files for 20110831
[linux-2.6/next.git] / drivers / usb / host / ehci-q.c
blob6ce0b3a9a0f9af53366a7c8092046e36e89ae29c
1 /*
2 * Copyright (C) 2001-2004 by David Brownell
4 * This program is free software; you can redistribute it and/or modify it
5 * under the terms of the GNU General Public License as published by the
6 * Free Software Foundation; either version 2 of the License, or (at your
7 * option) any later version.
9 * This program is distributed in the hope that it will be useful, but
10 * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
11 * or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
12 * for more details.
14 * You should have received a copy of the GNU General Public License
15 * along with this program; if not, write to the Free Software Foundation,
16 * Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
19 /* this file is part of ehci-hcd.c */
21 /*-------------------------------------------------------------------------*/
24 * EHCI hardware queue manipulation ... the core. QH/QTD manipulation.
26 * Control, bulk, and interrupt traffic all use "qh" lists. They list "qtd"
27 * entries describing USB transactions, max 16-20kB/entry (with 4kB-aligned
28 * buffers needed for the larger number). We use one QH per endpoint, queue
29 * multiple urbs (all three types) per endpoint. URBs may need several qtds.
31 * ISO traffic uses "ISO TD" (itd, and sitd) records, and (along with
32 * interrupts) needs careful scheduling. Performance improvements can be
33 * an ongoing challenge. That's in "ehci-sched.c".
35 * USB 1.1 devices are handled (a) by "companion" OHCI or UHCI root hubs,
36 * or otherwise through transaction translators (TTs) in USB 2.0 hubs using
37 * (b) special fields in qh entries or (c) split iso entries. TTs will
38 * buffer low/full speed data so the host collects it at high speed.
41 /*-------------------------------------------------------------------------*/
43 /* fill a qtd, returning how much of the buffer we were able to queue up */
45 static int
46 qtd_fill(struct ehci_hcd *ehci, struct ehci_qtd *qtd, dma_addr_t buf,
47 size_t len, int token, int maxpacket)
49 int i, count;
50 u64 addr = buf;
52 /* one buffer entry per 4K ... first might be short or unaligned */
53 qtd->hw_buf[0] = cpu_to_hc32(ehci, (u32)addr);
54 qtd->hw_buf_hi[0] = cpu_to_hc32(ehci, (u32)(addr >> 32));
55 count = 0x1000 - (buf & 0x0fff); /* rest of that page */
56 if (likely (len < count)) /* ... iff needed */
57 count = len;
58 else {
59 buf += 0x1000;
60 buf &= ~0x0fff;
62 /* per-qtd limit: from 16K to 20K (best alignment) */
63 for (i = 1; count < len && i < 5; i++) {
64 addr = buf;
65 qtd->hw_buf[i] = cpu_to_hc32(ehci, (u32)addr);
66 qtd->hw_buf_hi[i] = cpu_to_hc32(ehci,
67 (u32)(addr >> 32));
68 buf += 0x1000;
69 if ((count + 0x1000) < len)
70 count += 0x1000;
71 else
72 count = len;
75 /* short packets may only terminate transfers */
76 if (count != len)
77 count -= (count % maxpacket);
79 qtd->hw_token = cpu_to_hc32(ehci, (count << 16) | token);
80 qtd->length = count;
82 return count;
85 /*-------------------------------------------------------------------------*/
87 static inline void
88 qh_update (struct ehci_hcd *ehci, struct ehci_qh *qh, struct ehci_qtd *qtd)
90 struct ehci_qh_hw *hw = qh->hw;
92 /* writes to an active overlay are unsafe */
93 BUG_ON(qh->qh_state != QH_STATE_IDLE);
95 hw->hw_qtd_next = QTD_NEXT(ehci, qtd->qtd_dma);
96 hw->hw_alt_next = EHCI_LIST_END(ehci);
98 /* Except for control endpoints, we make hardware maintain data
99 * toggle (like OHCI) ... here (re)initialize the toggle in the QH,
100 * and set the pseudo-toggle in udev. Only usb_clear_halt() will
101 * ever clear it.
103 if (!(hw->hw_info1 & cpu_to_hc32(ehci, 1 << 14))) {
104 unsigned is_out, epnum;
106 is_out = qh->is_out;
107 epnum = (hc32_to_cpup(ehci, &hw->hw_info1) >> 8) & 0x0f;
108 if (unlikely (!usb_gettoggle (qh->dev, epnum, is_out))) {
109 hw->hw_token &= ~cpu_to_hc32(ehci, QTD_TOGGLE);
110 usb_settoggle (qh->dev, epnum, is_out, 1);
114 /* HC must see latest qtd and qh data before we clear ACTIVE+HALT */
115 wmb ();
116 hw->hw_token &= cpu_to_hc32(ehci, QTD_TOGGLE | QTD_STS_PING);
119 /* if it weren't for a common silicon quirk (writing the dummy into the qh
120 * overlay, so qh->hw_token wrongly becomes inactive/halted), only fault
121 * recovery (including urb dequeue) would need software changes to a QH...
123 static void
124 qh_refresh (struct ehci_hcd *ehci, struct ehci_qh *qh)
126 struct ehci_qtd *qtd;
128 if (list_empty (&qh->qtd_list))
129 qtd = qh->dummy;
130 else {
131 qtd = list_entry (qh->qtd_list.next,
132 struct ehci_qtd, qtd_list);
133 /* first qtd may already be partially processed */
134 if (cpu_to_hc32(ehci, qtd->qtd_dma) == qh->hw->hw_current)
135 qtd = NULL;
138 if (qtd)
139 qh_update (ehci, qh, qtd);
142 /*-------------------------------------------------------------------------*/
144 static void qh_link_async(struct ehci_hcd *ehci, struct ehci_qh *qh);
146 static void ehci_clear_tt_buffer_complete(struct usb_hcd *hcd,
147 struct usb_host_endpoint *ep)
149 struct ehci_hcd *ehci = hcd_to_ehci(hcd);
150 struct ehci_qh *qh = ep->hcpriv;
151 unsigned long flags;
153 spin_lock_irqsave(&ehci->lock, flags);
154 qh->clearing_tt = 0;
155 if (qh->qh_state == QH_STATE_IDLE && !list_empty(&qh->qtd_list)
156 && ehci->rh_state == EHCI_RH_RUNNING)
157 qh_link_async(ehci, qh);
158 spin_unlock_irqrestore(&ehci->lock, flags);
161 static void ehci_clear_tt_buffer(struct ehci_hcd *ehci, struct ehci_qh *qh,
162 struct urb *urb, u32 token)
165 /* If an async split transaction gets an error or is unlinked,
166 * the TT buffer may be left in an indeterminate state. We
167 * have to clear the TT buffer.
169 * Note: this routine is never called for Isochronous transfers.
171 if (urb->dev->tt && !usb_pipeint(urb->pipe) && !qh->clearing_tt) {
172 #ifdef DEBUG
173 struct usb_device *tt = urb->dev->tt->hub;
174 dev_dbg(&tt->dev,
175 "clear tt buffer port %d, a%d ep%d t%08x\n",
176 urb->dev->ttport, urb->dev->devnum,
177 usb_pipeendpoint(urb->pipe), token);
178 #endif /* DEBUG */
179 if (!ehci_is_TDI(ehci)
180 || urb->dev->tt->hub !=
181 ehci_to_hcd(ehci)->self.root_hub) {
182 if (usb_hub_clear_tt_buffer(urb) == 0)
183 qh->clearing_tt = 1;
184 } else {
186 /* REVISIT ARC-derived cores don't clear the root
187 * hub TT buffer in this way...
193 static int qtd_copy_status (
194 struct ehci_hcd *ehci,
195 struct urb *urb,
196 size_t length,
197 u32 token
200 int status = -EINPROGRESS;
202 /* count IN/OUT bytes, not SETUP (even short packets) */
203 if (likely (QTD_PID (token) != 2))
204 urb->actual_length += length - QTD_LENGTH (token);
206 /* don't modify error codes */
207 if (unlikely(urb->unlinked))
208 return status;
210 /* force cleanup after short read; not always an error */
211 if (unlikely (IS_SHORT_READ (token)))
212 status = -EREMOTEIO;
214 /* serious "can't proceed" faults reported by the hardware */
215 if (token & QTD_STS_HALT) {
216 if (token & QTD_STS_BABBLE) {
217 /* FIXME "must" disable babbling device's port too */
218 status = -EOVERFLOW;
219 /* CERR nonzero + halt --> stall */
220 } else if (QTD_CERR(token)) {
221 status = -EPIPE;
223 /* In theory, more than one of the following bits can be set
224 * since they are sticky and the transaction is retried.
225 * Which to test first is rather arbitrary.
227 } else if (token & QTD_STS_MMF) {
228 /* fs/ls interrupt xfer missed the complete-split */
229 status = -EPROTO;
230 } else if (token & QTD_STS_DBE) {
231 status = (QTD_PID (token) == 1) /* IN ? */
232 ? -ENOSR /* hc couldn't read data */
233 : -ECOMM; /* hc couldn't write data */
234 } else if (token & QTD_STS_XACT) {
235 /* timeout, bad CRC, wrong PID, etc */
236 ehci_dbg(ehci, "devpath %s ep%d%s 3strikes\n",
237 urb->dev->devpath,
238 usb_pipeendpoint(urb->pipe),
239 usb_pipein(urb->pipe) ? "in" : "out");
240 status = -EPROTO;
241 } else { /* unknown */
242 status = -EPROTO;
245 ehci_vdbg (ehci,
246 "dev%d ep%d%s qtd token %08x --> status %d\n",
247 usb_pipedevice (urb->pipe),
248 usb_pipeendpoint (urb->pipe),
249 usb_pipein (urb->pipe) ? "in" : "out",
250 token, status);
253 return status;
256 static void
257 ehci_urb_done(struct ehci_hcd *ehci, struct urb *urb, int status)
258 __releases(ehci->lock)
259 __acquires(ehci->lock)
261 if (likely (urb->hcpriv != NULL)) {
262 struct ehci_qh *qh = (struct ehci_qh *) urb->hcpriv;
264 /* S-mask in a QH means it's an interrupt urb */
265 if ((qh->hw->hw_info2 & cpu_to_hc32(ehci, QH_SMASK)) != 0) {
267 /* ... update hc-wide periodic stats (for usbfs) */
268 ehci_to_hcd(ehci)->self.bandwidth_int_reqs--;
270 qh_put (qh);
273 if (unlikely(urb->unlinked)) {
274 COUNT(ehci->stats.unlink);
275 } else {
276 /* report non-error and short read status as zero */
277 if (status == -EINPROGRESS || status == -EREMOTEIO)
278 status = 0;
279 COUNT(ehci->stats.complete);
282 #ifdef EHCI_URB_TRACE
283 ehci_dbg (ehci,
284 "%s %s urb %p ep%d%s status %d len %d/%d\n",
285 __func__, urb->dev->devpath, urb,
286 usb_pipeendpoint (urb->pipe),
287 usb_pipein (urb->pipe) ? "in" : "out",
288 status,
289 urb->actual_length, urb->transfer_buffer_length);
290 #endif
292 /* complete() can reenter this HCD */
293 usb_hcd_unlink_urb_from_ep(ehci_to_hcd(ehci), urb);
294 spin_unlock (&ehci->lock);
295 usb_hcd_giveback_urb(ehci_to_hcd(ehci), urb, status);
296 spin_lock (&ehci->lock);
299 static void start_unlink_async (struct ehci_hcd *ehci, struct ehci_qh *qh);
300 static void unlink_async (struct ehci_hcd *ehci, struct ehci_qh *qh);
302 static int qh_schedule (struct ehci_hcd *ehci, struct ehci_qh *qh);
305 * Process and free completed qtds for a qh, returning URBs to drivers.
306 * Chases up to qh->hw_current. Returns number of completions called,
307 * indicating how much "real" work we did.
309 static unsigned
310 qh_completions (struct ehci_hcd *ehci, struct ehci_qh *qh)
312 struct ehci_qtd *last, *end = qh->dummy;
313 struct list_head *entry, *tmp;
314 int last_status;
315 int stopped;
316 unsigned count = 0;
317 u8 state;
318 struct ehci_qh_hw *hw = qh->hw;
320 if (unlikely (list_empty (&qh->qtd_list)))
321 return count;
323 /* completions (or tasks on other cpus) must never clobber HALT
324 * till we've gone through and cleaned everything up, even when
325 * they add urbs to this qh's queue or mark them for unlinking.
327 * NOTE: unlinking expects to be done in queue order.
329 * It's a bug for qh->qh_state to be anything other than
330 * QH_STATE_IDLE, unless our caller is scan_async() or
331 * scan_periodic().
333 state = qh->qh_state;
334 qh->qh_state = QH_STATE_COMPLETING;
335 stopped = (state == QH_STATE_IDLE);
337 rescan:
338 last = NULL;
339 last_status = -EINPROGRESS;
340 qh->needs_rescan = 0;
342 /* remove de-activated QTDs from front of queue.
343 * after faults (including short reads), cleanup this urb
344 * then let the queue advance.
345 * if queue is stopped, handles unlinks.
347 list_for_each_safe (entry, tmp, &qh->qtd_list) {
348 struct ehci_qtd *qtd;
349 struct urb *urb;
350 u32 token = 0;
352 qtd = list_entry (entry, struct ehci_qtd, qtd_list);
353 urb = qtd->urb;
355 /* clean up any state from previous QTD ...*/
356 if (last) {
357 if (likely (last->urb != urb)) {
358 ehci_urb_done(ehci, last->urb, last_status);
359 count++;
360 last_status = -EINPROGRESS;
362 ehci_qtd_free (ehci, last);
363 last = NULL;
366 /* ignore urbs submitted during completions we reported */
367 if (qtd == end)
368 break;
370 /* hardware copies qtd out of qh overlay */
371 rmb ();
372 token = hc32_to_cpu(ehci, qtd->hw_token);
374 /* always clean up qtds the hc de-activated */
375 retry_xacterr:
376 if ((token & QTD_STS_ACTIVE) == 0) {
378 /* on STALL, error, and short reads this urb must
379 * complete and all its qtds must be recycled.
381 if ((token & QTD_STS_HALT) != 0) {
383 /* retry transaction errors until we
384 * reach the software xacterr limit
386 if ((token & QTD_STS_XACT) &&
387 QTD_CERR(token) == 0 &&
388 ++qh->xacterrs < QH_XACTERR_MAX &&
389 !urb->unlinked) {
390 ehci_dbg(ehci,
391 "detected XactErr len %zu/%zu retry %d\n",
392 qtd->length - QTD_LENGTH(token), qtd->length, qh->xacterrs);
394 /* reset the token in the qtd and the
395 * qh overlay (which still contains
396 * the qtd) so that we pick up from
397 * where we left off
399 token &= ~QTD_STS_HALT;
400 token |= QTD_STS_ACTIVE |
401 (EHCI_TUNE_CERR << 10);
402 qtd->hw_token = cpu_to_hc32(ehci,
403 token);
404 wmb();
405 hw->hw_token = cpu_to_hc32(ehci,
406 token);
407 goto retry_xacterr;
409 stopped = 1;
411 /* magic dummy for some short reads; qh won't advance.
412 * that silicon quirk can kick in with this dummy too.
414 * other short reads won't stop the queue, including
415 * control transfers (status stage handles that) or
416 * most other single-qtd reads ... the queue stops if
417 * URB_SHORT_NOT_OK was set so the driver submitting
418 * the urbs could clean it up.
420 } else if (IS_SHORT_READ (token)
421 && !(qtd->hw_alt_next
422 & EHCI_LIST_END(ehci))) {
423 stopped = 1;
426 /* stop scanning when we reach qtds the hc is using */
427 } else if (likely (!stopped
428 && ehci->rh_state == EHCI_RH_RUNNING)) {
429 break;
431 /* scan the whole queue for unlinks whenever it stops */
432 } else {
433 stopped = 1;
435 /* cancel everything if we halt, suspend, etc */
436 if (ehci->rh_state != EHCI_RH_RUNNING)
437 last_status = -ESHUTDOWN;
439 /* this qtd is active; skip it unless a previous qtd
440 * for its urb faulted, or its urb was canceled.
442 else if (last_status == -EINPROGRESS && !urb->unlinked)
443 continue;
445 /* qh unlinked; token in overlay may be most current */
446 if (state == QH_STATE_IDLE
447 && cpu_to_hc32(ehci, qtd->qtd_dma)
448 == hw->hw_current) {
449 token = hc32_to_cpu(ehci, hw->hw_token);
451 /* An unlink may leave an incomplete
452 * async transaction in the TT buffer.
453 * We have to clear it.
455 ehci_clear_tt_buffer(ehci, qh, urb, token);
459 /* unless we already know the urb's status, collect qtd status
460 * and update count of bytes transferred. in common short read
461 * cases with only one data qtd (including control transfers),
462 * queue processing won't halt. but with two or more qtds (for
463 * example, with a 32 KB transfer), when the first qtd gets a
464 * short read the second must be removed by hand.
466 if (last_status == -EINPROGRESS) {
467 last_status = qtd_copy_status(ehci, urb,
468 qtd->length, token);
469 if (last_status == -EREMOTEIO
470 && (qtd->hw_alt_next
471 & EHCI_LIST_END(ehci)))
472 last_status = -EINPROGRESS;
474 /* As part of low/full-speed endpoint-halt processing
475 * we must clear the TT buffer (11.17.5).
477 if (unlikely(last_status != -EINPROGRESS &&
478 last_status != -EREMOTEIO)) {
479 /* The TT's in some hubs malfunction when they
480 * receive this request following a STALL (they
481 * stop sending isochronous packets). Since a
482 * STALL can't leave the TT buffer in a busy
483 * state (if you believe Figures 11-48 - 11-51
484 * in the USB 2.0 spec), we won't clear the TT
485 * buffer in this case. Strictly speaking this
486 * is a violation of the spec.
488 if (last_status != -EPIPE)
489 ehci_clear_tt_buffer(ehci, qh, urb,
490 token);
494 /* if we're removing something not at the queue head,
495 * patch the hardware queue pointer.
497 if (stopped && qtd->qtd_list.prev != &qh->qtd_list) {
498 last = list_entry (qtd->qtd_list.prev,
499 struct ehci_qtd, qtd_list);
500 last->hw_next = qtd->hw_next;
503 /* remove qtd; it's recycled after possible urb completion */
504 list_del (&qtd->qtd_list);
505 last = qtd;
507 /* reinit the xacterr counter for the next qtd */
508 qh->xacterrs = 0;
511 /* last urb's completion might still need calling */
512 if (likely (last != NULL)) {
513 ehci_urb_done(ehci, last->urb, last_status);
514 count++;
515 ehci_qtd_free (ehci, last);
518 /* Do we need to rescan for URBs dequeued during a giveback? */
519 if (unlikely(qh->needs_rescan)) {
520 /* If the QH is already unlinked, do the rescan now. */
521 if (state == QH_STATE_IDLE)
522 goto rescan;
524 /* Otherwise we have to wait until the QH is fully unlinked.
525 * Our caller will start an unlink if qh->needs_rescan is
526 * set. But if an unlink has already started, nothing needs
527 * to be done.
529 if (state != QH_STATE_LINKED)
530 qh->needs_rescan = 0;
533 /* restore original state; caller must unlink or relink */
534 qh->qh_state = state;
536 /* be sure the hardware's done with the qh before refreshing
537 * it after fault cleanup, or recovering from silicon wrongly
538 * overlaying the dummy qtd (which reduces DMA chatter).
540 if (stopped != 0 || hw->hw_qtd_next == EHCI_LIST_END(ehci)) {
541 switch (state) {
542 case QH_STATE_IDLE:
543 qh_refresh(ehci, qh);
544 break;
545 case QH_STATE_LINKED:
546 /* We won't refresh a QH that's linked (after the HC
547 * stopped the queue). That avoids a race:
548 * - HC reads first part of QH;
549 * - CPU updates that first part and the token;
550 * - HC reads rest of that QH, including token
551 * Result: HC gets an inconsistent image, and then
552 * DMAs to/from the wrong memory (corrupting it).
554 * That should be rare for interrupt transfers,
555 * except maybe high bandwidth ...
558 /* Tell the caller to start an unlink */
559 qh->needs_rescan = 1;
560 break;
561 /* otherwise, unlink already started */
565 return count;
568 /*-------------------------------------------------------------------------*/
570 // high bandwidth multiplier, as encoded in highspeed endpoint descriptors
571 #define hb_mult(wMaxPacketSize) (1 + (((wMaxPacketSize) >> 11) & 0x03))
572 // ... and packet size, for any kind of endpoint descriptor
573 #define max_packet(wMaxPacketSize) ((wMaxPacketSize) & 0x07ff)
576 * reverse of qh_urb_transaction: free a list of TDs.
577 * used for cleanup after errors, before HC sees an URB's TDs.
579 static void qtd_list_free (
580 struct ehci_hcd *ehci,
581 struct urb *urb,
582 struct list_head *qtd_list
584 struct list_head *entry, *temp;
586 list_for_each_safe (entry, temp, qtd_list) {
587 struct ehci_qtd *qtd;
589 qtd = list_entry (entry, struct ehci_qtd, qtd_list);
590 list_del (&qtd->qtd_list);
591 ehci_qtd_free (ehci, qtd);
596 * create a list of filled qtds for this URB; won't link into qh.
598 static struct list_head *
599 qh_urb_transaction (
600 struct ehci_hcd *ehci,
601 struct urb *urb,
602 struct list_head *head,
603 gfp_t flags
605 struct ehci_qtd *qtd, *qtd_prev;
606 dma_addr_t buf;
607 int len, this_sg_len, maxpacket;
608 int is_input;
609 u32 token;
610 int i;
611 struct scatterlist *sg;
614 * URBs map to sequences of QTDs: one logical transaction
616 qtd = ehci_qtd_alloc (ehci, flags);
617 if (unlikely (!qtd))
618 return NULL;
619 list_add_tail (&qtd->qtd_list, head);
620 qtd->urb = urb;
622 token = QTD_STS_ACTIVE;
623 token |= (EHCI_TUNE_CERR << 10);
624 /* for split transactions, SplitXState initialized to zero */
626 len = urb->transfer_buffer_length;
627 is_input = usb_pipein (urb->pipe);
628 if (usb_pipecontrol (urb->pipe)) {
629 /* SETUP pid */
630 qtd_fill(ehci, qtd, urb->setup_dma,
631 sizeof (struct usb_ctrlrequest),
632 token | (2 /* "setup" */ << 8), 8);
634 /* ... and always at least one more pid */
635 token ^= QTD_TOGGLE;
636 qtd_prev = qtd;
637 qtd = ehci_qtd_alloc (ehci, flags);
638 if (unlikely (!qtd))
639 goto cleanup;
640 qtd->urb = urb;
641 qtd_prev->hw_next = QTD_NEXT(ehci, qtd->qtd_dma);
642 list_add_tail (&qtd->qtd_list, head);
644 /* for zero length DATA stages, STATUS is always IN */
645 if (len == 0)
646 token |= (1 /* "in" */ << 8);
650 * data transfer stage: buffer setup
652 i = urb->num_sgs;
653 if (len > 0 && i > 0) {
654 sg = urb->sg;
655 buf = sg_dma_address(sg);
657 /* urb->transfer_buffer_length may be smaller than the
658 * size of the scatterlist (or vice versa)
660 this_sg_len = min_t(int, sg_dma_len(sg), len);
661 } else {
662 sg = NULL;
663 buf = urb->transfer_dma;
664 this_sg_len = len;
667 if (is_input)
668 token |= (1 /* "in" */ << 8);
669 /* else it's already initted to "out" pid (0 << 8) */
671 maxpacket = max_packet(usb_maxpacket(urb->dev, urb->pipe, !is_input));
674 * buffer gets wrapped in one or more qtds;
675 * last one may be "short" (including zero len)
676 * and may serve as a control status ack
678 for (;;) {
679 int this_qtd_len;
681 this_qtd_len = qtd_fill(ehci, qtd, buf, this_sg_len, token,
682 maxpacket);
683 this_sg_len -= this_qtd_len;
684 len -= this_qtd_len;
685 buf += this_qtd_len;
688 * short reads advance to a "magic" dummy instead of the next
689 * qtd ... that forces the queue to stop, for manual cleanup.
690 * (this will usually be overridden later.)
692 if (is_input)
693 qtd->hw_alt_next = ehci->async->hw->hw_alt_next;
695 /* qh makes control packets use qtd toggle; maybe switch it */
696 if ((maxpacket & (this_qtd_len + (maxpacket - 1))) == 0)
697 token ^= QTD_TOGGLE;
699 if (likely(this_sg_len <= 0)) {
700 if (--i <= 0 || len <= 0)
701 break;
702 sg = sg_next(sg);
703 buf = sg_dma_address(sg);
704 this_sg_len = min_t(int, sg_dma_len(sg), len);
707 qtd_prev = qtd;
708 qtd = ehci_qtd_alloc (ehci, flags);
709 if (unlikely (!qtd))
710 goto cleanup;
711 qtd->urb = urb;
712 qtd_prev->hw_next = QTD_NEXT(ehci, qtd->qtd_dma);
713 list_add_tail (&qtd->qtd_list, head);
717 * unless the caller requires manual cleanup after short reads,
718 * have the alt_next mechanism keep the queue running after the
719 * last data qtd (the only one, for control and most other cases).
721 if (likely ((urb->transfer_flags & URB_SHORT_NOT_OK) == 0
722 || usb_pipecontrol (urb->pipe)))
723 qtd->hw_alt_next = EHCI_LIST_END(ehci);
726 * control requests may need a terminating data "status" ack;
727 * bulk ones may need a terminating short packet (zero length).
729 if (likely (urb->transfer_buffer_length != 0)) {
730 int one_more = 0;
732 if (usb_pipecontrol (urb->pipe)) {
733 one_more = 1;
734 token ^= 0x0100; /* "in" <--> "out" */
735 token |= QTD_TOGGLE; /* force DATA1 */
736 } else if (usb_pipebulk (urb->pipe)
737 && (urb->transfer_flags & URB_ZERO_PACKET)
738 && !(urb->transfer_buffer_length % maxpacket)) {
739 one_more = 1;
741 if (one_more) {
742 qtd_prev = qtd;
743 qtd = ehci_qtd_alloc (ehci, flags);
744 if (unlikely (!qtd))
745 goto cleanup;
746 qtd->urb = urb;
747 qtd_prev->hw_next = QTD_NEXT(ehci, qtd->qtd_dma);
748 list_add_tail (&qtd->qtd_list, head);
750 /* never any data in such packets */
751 qtd_fill(ehci, qtd, 0, 0, token, 0);
755 /* by default, enable interrupt on urb completion */
756 if (likely (!(urb->transfer_flags & URB_NO_INTERRUPT)))
757 qtd->hw_token |= cpu_to_hc32(ehci, QTD_IOC);
758 return head;
760 cleanup:
761 qtd_list_free (ehci, urb, head);
762 return NULL;
765 /*-------------------------------------------------------------------------*/
767 // Would be best to create all qh's from config descriptors,
768 // when each interface/altsetting is established. Unlink
769 // any previous qh and cancel its urbs first; endpoints are
770 // implicitly reset then (data toggle too).
771 // That'd mean updating how usbcore talks to HCDs. (2.7?)
775 * Each QH holds a qtd list; a QH is used for everything except iso.
777 * For interrupt urbs, the scheduler must set the microframe scheduling
778 * mask(s) each time the QH gets scheduled. For highspeed, that's
779 * just one microframe in the s-mask. For split interrupt transactions
780 * there are additional complications: c-mask, maybe FSTNs.
782 static struct ehci_qh *
783 qh_make (
784 struct ehci_hcd *ehci,
785 struct urb *urb,
786 gfp_t flags
788 struct ehci_qh *qh = ehci_qh_alloc (ehci, flags);
789 u32 info1 = 0, info2 = 0;
790 int is_input, type;
791 int maxp = 0;
792 struct usb_tt *tt = urb->dev->tt;
793 struct ehci_qh_hw *hw;
795 if (!qh)
796 return qh;
799 * init endpoint/device data for this QH
801 info1 |= usb_pipeendpoint (urb->pipe) << 8;
802 info1 |= usb_pipedevice (urb->pipe) << 0;
804 is_input = usb_pipein (urb->pipe);
805 type = usb_pipetype (urb->pipe);
806 maxp = usb_maxpacket (urb->dev, urb->pipe, !is_input);
808 /* 1024 byte maxpacket is a hardware ceiling. High bandwidth
809 * acts like up to 3KB, but is built from smaller packets.
811 if (max_packet(maxp) > 1024) {
812 ehci_dbg(ehci, "bogus qh maxpacket %d\n", max_packet(maxp));
813 goto done;
816 /* Compute interrupt scheduling parameters just once, and save.
817 * - allowing for high bandwidth, how many nsec/uframe are used?
818 * - split transactions need a second CSPLIT uframe; same question
819 * - splits also need a schedule gap (for full/low speed I/O)
820 * - qh has a polling interval
822 * For control/bulk requests, the HC or TT handles these.
824 if (type == PIPE_INTERRUPT) {
825 qh->usecs = NS_TO_US(usb_calc_bus_time(USB_SPEED_HIGH,
826 is_input, 0,
827 hb_mult(maxp) * max_packet(maxp)));
828 qh->start = NO_FRAME;
829 qh->stamp = ehci->periodic_stamp;
831 if (urb->dev->speed == USB_SPEED_HIGH) {
832 qh->c_usecs = 0;
833 qh->gap_uf = 0;
835 qh->period = urb->interval >> 3;
836 if (qh->period == 0 && urb->interval != 1) {
837 /* NOTE interval 2 or 4 uframes could work.
838 * But interval 1 scheduling is simpler, and
839 * includes high bandwidth.
841 urb->interval = 1;
842 } else if (qh->period > ehci->periodic_size) {
843 qh->period = ehci->periodic_size;
844 urb->interval = qh->period << 3;
846 } else {
847 int think_time;
849 /* gap is f(FS/LS transfer times) */
850 qh->gap_uf = 1 + usb_calc_bus_time (urb->dev->speed,
851 is_input, 0, maxp) / (125 * 1000);
853 /* FIXME this just approximates SPLIT/CSPLIT times */
854 if (is_input) { // SPLIT, gap, CSPLIT+DATA
855 qh->c_usecs = qh->usecs + HS_USECS (0);
856 qh->usecs = HS_USECS (1);
857 } else { // SPLIT+DATA, gap, CSPLIT
858 qh->usecs += HS_USECS (1);
859 qh->c_usecs = HS_USECS (0);
862 think_time = tt ? tt->think_time : 0;
863 qh->tt_usecs = NS_TO_US (think_time +
864 usb_calc_bus_time (urb->dev->speed,
865 is_input, 0, max_packet (maxp)));
866 qh->period = urb->interval;
867 if (qh->period > ehci->periodic_size) {
868 qh->period = ehci->periodic_size;
869 urb->interval = qh->period;
874 /* support for tt scheduling, and access to toggles */
875 qh->dev = urb->dev;
877 /* using TT? */
878 switch (urb->dev->speed) {
879 case USB_SPEED_LOW:
880 info1 |= (1 << 12); /* EPS "low" */
881 /* FALL THROUGH */
883 case USB_SPEED_FULL:
884 /* EPS 0 means "full" */
885 if (type != PIPE_INTERRUPT)
886 info1 |= (EHCI_TUNE_RL_TT << 28);
887 if (type == PIPE_CONTROL) {
888 info1 |= (1 << 27); /* for TT */
889 info1 |= 1 << 14; /* toggle from qtd */
891 info1 |= maxp << 16;
893 info2 |= (EHCI_TUNE_MULT_TT << 30);
895 /* Some Freescale processors have an erratum in which the
896 * port number in the queue head was 0..N-1 instead of 1..N.
898 if (ehci_has_fsl_portno_bug(ehci))
899 info2 |= (urb->dev->ttport-1) << 23;
900 else
901 info2 |= urb->dev->ttport << 23;
903 /* set the address of the TT; for TDI's integrated
904 * root hub tt, leave it zeroed.
906 if (tt && tt->hub != ehci_to_hcd(ehci)->self.root_hub)
907 info2 |= tt->hub->devnum << 16;
909 /* NOTE: if (PIPE_INTERRUPT) { scheduler sets c-mask } */
911 break;
913 case USB_SPEED_HIGH: /* no TT involved */
914 info1 |= (2 << 12); /* EPS "high" */
915 if (type == PIPE_CONTROL) {
916 info1 |= (EHCI_TUNE_RL_HS << 28);
917 info1 |= 64 << 16; /* usb2 fixed maxpacket */
918 info1 |= 1 << 14; /* toggle from qtd */
919 info2 |= (EHCI_TUNE_MULT_HS << 30);
920 } else if (type == PIPE_BULK) {
921 info1 |= (EHCI_TUNE_RL_HS << 28);
922 /* The USB spec says that high speed bulk endpoints
923 * always use 512 byte maxpacket. But some device
924 * vendors decided to ignore that, and MSFT is happy
925 * to help them do so. So now people expect to use
926 * such nonconformant devices with Linux too; sigh.
928 info1 |= max_packet(maxp) << 16;
929 info2 |= (EHCI_TUNE_MULT_HS << 30);
930 } else { /* PIPE_INTERRUPT */
931 info1 |= max_packet (maxp) << 16;
932 info2 |= hb_mult (maxp) << 30;
934 break;
935 default:
936 dbg ("bogus dev %p speed %d", urb->dev, urb->dev->speed);
937 done:
938 qh_put (qh);
939 return NULL;
942 /* NOTE: if (PIPE_INTERRUPT) { scheduler sets s-mask } */
944 /* init as live, toggle clear, advance to dummy */
945 qh->qh_state = QH_STATE_IDLE;
946 hw = qh->hw;
947 hw->hw_info1 = cpu_to_hc32(ehci, info1);
948 hw->hw_info2 = cpu_to_hc32(ehci, info2);
949 qh->is_out = !is_input;
950 usb_settoggle (urb->dev, usb_pipeendpoint (urb->pipe), !is_input, 1);
951 qh_refresh (ehci, qh);
952 return qh;
955 /*-------------------------------------------------------------------------*/
957 /* move qh (and its qtds) onto async queue; maybe enable queue. */
959 static void qh_link_async (struct ehci_hcd *ehci, struct ehci_qh *qh)
961 __hc32 dma = QH_NEXT(ehci, qh->qh_dma);
962 struct ehci_qh *head;
964 /* Don't link a QH if there's a Clear-TT-Buffer pending */
965 if (unlikely(qh->clearing_tt))
966 return;
968 WARN_ON(qh->qh_state != QH_STATE_IDLE);
970 /* (re)start the async schedule? */
971 head = ehci->async;
972 timer_action_done (ehci, TIMER_ASYNC_OFF);
973 if (!head->qh_next.qh) {
974 u32 cmd = ehci_readl(ehci, &ehci->regs->command);
976 if (!(cmd & CMD_ASE)) {
977 /* in case a clear of CMD_ASE didn't take yet */
978 (void)handshake(ehci, &ehci->regs->status,
979 STS_ASS, 0, 150);
980 cmd |= CMD_ASE;
981 ehci_writel(ehci, cmd, &ehci->regs->command);
982 /* posted write need not be known to HC yet ... */
986 /* clear halt and/or toggle; and maybe recover from silicon quirk */
987 qh_refresh(ehci, qh);
989 /* splice right after start */
990 qh->qh_next = head->qh_next;
991 qh->hw->hw_next = head->hw->hw_next;
992 wmb ();
994 head->qh_next.qh = qh;
995 head->hw->hw_next = dma;
997 qh_get(qh);
998 qh->xacterrs = 0;
999 qh->qh_state = QH_STATE_LINKED;
1000 /* qtd completions reported later by interrupt */
1003 /*-------------------------------------------------------------------------*/
1006 * For control/bulk/interrupt, return QH with these TDs appended.
1007 * Allocates and initializes the QH if necessary.
1008 * Returns null if it can't allocate a QH it needs to.
1009 * If the QH has TDs (urbs) already, that's great.
1011 static struct ehci_qh *qh_append_tds (
1012 struct ehci_hcd *ehci,
1013 struct urb *urb,
1014 struct list_head *qtd_list,
1015 int epnum,
1016 void **ptr
1019 struct ehci_qh *qh = NULL;
1020 __hc32 qh_addr_mask = cpu_to_hc32(ehci, 0x7f);
1022 qh = (struct ehci_qh *) *ptr;
1023 if (unlikely (qh == NULL)) {
1024 /* can't sleep here, we have ehci->lock... */
1025 qh = qh_make (ehci, urb, GFP_ATOMIC);
1026 *ptr = qh;
1028 if (likely (qh != NULL)) {
1029 struct ehci_qtd *qtd;
1031 if (unlikely (list_empty (qtd_list)))
1032 qtd = NULL;
1033 else
1034 qtd = list_entry (qtd_list->next, struct ehci_qtd,
1035 qtd_list);
1037 /* control qh may need patching ... */
1038 if (unlikely (epnum == 0)) {
1040 /* usb_reset_device() briefly reverts to address 0 */
1041 if (usb_pipedevice (urb->pipe) == 0)
1042 qh->hw->hw_info1 &= ~qh_addr_mask;
1045 /* just one way to queue requests: swap with the dummy qtd.
1046 * only hc or qh_refresh() ever modify the overlay.
1048 if (likely (qtd != NULL)) {
1049 struct ehci_qtd *dummy;
1050 dma_addr_t dma;
1051 __hc32 token;
1053 /* to avoid racing the HC, use the dummy td instead of
1054 * the first td of our list (becomes new dummy). both
1055 * tds stay deactivated until we're done, when the
1056 * HC is allowed to fetch the old dummy (4.10.2).
1058 token = qtd->hw_token;
1059 qtd->hw_token = HALT_BIT(ehci);
1060 wmb ();
1061 dummy = qh->dummy;
1063 dma = dummy->qtd_dma;
1064 *dummy = *qtd;
1065 dummy->qtd_dma = dma;
1067 list_del (&qtd->qtd_list);
1068 list_add (&dummy->qtd_list, qtd_list);
1069 list_splice_tail(qtd_list, &qh->qtd_list);
1071 ehci_qtd_init(ehci, qtd, qtd->qtd_dma);
1072 qh->dummy = qtd;
1074 /* hc must see the new dummy at list end */
1075 dma = qtd->qtd_dma;
1076 qtd = list_entry (qh->qtd_list.prev,
1077 struct ehci_qtd, qtd_list);
1078 qtd->hw_next = QTD_NEXT(ehci, dma);
1080 /* let the hc process these next qtds */
1081 wmb ();
1082 dummy->hw_token = token;
1084 urb->hcpriv = qh_get (qh);
1087 return qh;
1090 /*-------------------------------------------------------------------------*/
1092 static int
1093 submit_async (
1094 struct ehci_hcd *ehci,
1095 struct urb *urb,
1096 struct list_head *qtd_list,
1097 gfp_t mem_flags
1099 int epnum;
1100 unsigned long flags;
1101 struct ehci_qh *qh = NULL;
1102 int rc;
1104 epnum = urb->ep->desc.bEndpointAddress;
1106 #ifdef EHCI_URB_TRACE
1108 struct ehci_qtd *qtd;
1109 qtd = list_entry(qtd_list->next, struct ehci_qtd, qtd_list);
1110 ehci_dbg(ehci,
1111 "%s %s urb %p ep%d%s len %d, qtd %p [qh %p]\n",
1112 __func__, urb->dev->devpath, urb,
1113 epnum & 0x0f, (epnum & USB_DIR_IN) ? "in" : "out",
1114 urb->transfer_buffer_length,
1115 qtd, urb->ep->hcpriv);
1117 #endif
1119 spin_lock_irqsave (&ehci->lock, flags);
1120 if (unlikely(!HCD_HW_ACCESSIBLE(ehci_to_hcd(ehci)))) {
1121 rc = -ESHUTDOWN;
1122 goto done;
1124 rc = usb_hcd_link_urb_to_ep(ehci_to_hcd(ehci), urb);
1125 if (unlikely(rc))
1126 goto done;
1128 qh = qh_append_tds(ehci, urb, qtd_list, epnum, &urb->ep->hcpriv);
1129 if (unlikely(qh == NULL)) {
1130 usb_hcd_unlink_urb_from_ep(ehci_to_hcd(ehci), urb);
1131 rc = -ENOMEM;
1132 goto done;
1135 /* Control/bulk operations through TTs don't need scheduling,
1136 * the HC and TT handle it when the TT has a buffer ready.
1138 if (likely (qh->qh_state == QH_STATE_IDLE))
1139 qh_link_async(ehci, qh);
1140 done:
1141 spin_unlock_irqrestore (&ehci->lock, flags);
1142 if (unlikely (qh == NULL))
1143 qtd_list_free (ehci, urb, qtd_list);
1144 return rc;
1147 /*-------------------------------------------------------------------------*/
1149 /* the async qh for the qtds being reclaimed are now unlinked from the HC */
1151 static void end_unlink_async (struct ehci_hcd *ehci)
1153 struct ehci_qh *qh = ehci->reclaim;
1154 struct ehci_qh *next;
1156 iaa_watchdog_done(ehci);
1158 // qh->hw_next = cpu_to_hc32(qh->qh_dma);
1159 qh->qh_state = QH_STATE_IDLE;
1160 qh->qh_next.qh = NULL;
1161 qh_put (qh); // refcount from reclaim
1163 /* other unlink(s) may be pending (in QH_STATE_UNLINK_WAIT) */
1164 next = qh->reclaim;
1165 ehci->reclaim = next;
1166 qh->reclaim = NULL;
1168 qh_completions (ehci, qh);
1170 if (!list_empty(&qh->qtd_list) && ehci->rh_state == EHCI_RH_RUNNING) {
1171 qh_link_async (ehci, qh);
1172 } else {
1173 /* it's not free to turn the async schedule on/off; leave it
1174 * active but idle for a while once it empties.
1176 if (ehci->rh_state == EHCI_RH_RUNNING
1177 && ehci->async->qh_next.qh == NULL)
1178 timer_action (ehci, TIMER_ASYNC_OFF);
1180 qh_put(qh); /* refcount from async list */
1182 if (next) {
1183 ehci->reclaim = NULL;
1184 start_unlink_async (ehci, next);
1187 if (ehci->has_synopsys_hc_bug)
1188 ehci_writel(ehci, (u32) ehci->async->qh_dma,
1189 &ehci->regs->async_next);
1192 /* makes sure the async qh will become idle */
1193 /* caller must own ehci->lock */
1195 static void start_unlink_async (struct ehci_hcd *ehci, struct ehci_qh *qh)
1197 int cmd = ehci_readl(ehci, &ehci->regs->command);
1198 struct ehci_qh *prev;
1200 #ifdef DEBUG
1201 assert_spin_locked(&ehci->lock);
1202 if (ehci->reclaim
1203 || (qh->qh_state != QH_STATE_LINKED
1204 && qh->qh_state != QH_STATE_UNLINK_WAIT)
1206 BUG ();
1207 #endif
1209 /* stop async schedule right now? */
1210 if (unlikely (qh == ehci->async)) {
1211 /* can't get here without STS_ASS set */
1212 if (ehci->rh_state != EHCI_RH_HALTED
1213 && !ehci->reclaim) {
1214 /* ... and CMD_IAAD clear */
1215 ehci_writel(ehci, cmd & ~CMD_ASE,
1216 &ehci->regs->command);
1217 wmb ();
1218 // handshake later, if we need to
1219 timer_action_done (ehci, TIMER_ASYNC_OFF);
1221 return;
1224 qh->qh_state = QH_STATE_UNLINK;
1225 ehci->reclaim = qh = qh_get (qh);
1227 prev = ehci->async;
1228 while (prev->qh_next.qh != qh)
1229 prev = prev->qh_next.qh;
1231 prev->hw->hw_next = qh->hw->hw_next;
1232 prev->qh_next = qh->qh_next;
1233 if (ehci->qh_scan_next == qh)
1234 ehci->qh_scan_next = qh->qh_next.qh;
1235 wmb ();
1237 /* If the controller isn't running, we don't have to wait for it */
1238 if (unlikely(ehci->rh_state != EHCI_RH_RUNNING)) {
1239 /* if (unlikely (qh->reclaim != 0))
1240 * this will recurse, probably not much
1242 end_unlink_async (ehci);
1243 return;
1246 cmd |= CMD_IAAD;
1247 ehci_writel(ehci, cmd, &ehci->regs->command);
1248 (void)ehci_readl(ehci, &ehci->regs->command);
1249 iaa_watchdog_start(ehci);
1252 /*-------------------------------------------------------------------------*/
1254 static void scan_async (struct ehci_hcd *ehci)
1256 bool stopped;
1257 struct ehci_qh *qh;
1258 enum ehci_timer_action action = TIMER_IO_WATCHDOG;
1260 timer_action_done (ehci, TIMER_ASYNC_SHRINK);
1261 stopped = (ehci->rh_state != EHCI_RH_RUNNING);
1263 ehci->qh_scan_next = ehci->async->qh_next.qh;
1264 while (ehci->qh_scan_next) {
1265 qh = ehci->qh_scan_next;
1266 ehci->qh_scan_next = qh->qh_next.qh;
1267 rescan:
1268 /* clean any finished work for this qh */
1269 if (!list_empty(&qh->qtd_list)) {
1270 int temp;
1273 * Unlinks could happen here; completion reporting
1274 * drops the lock. That's why ehci->qh_scan_next
1275 * always holds the next qh to scan; if the next qh
1276 * gets unlinked then ehci->qh_scan_next is adjusted
1277 * in start_unlink_async().
1279 qh = qh_get(qh);
1280 temp = qh_completions(ehci, qh);
1281 if (qh->needs_rescan)
1282 unlink_async(ehci, qh);
1283 qh->unlink_time = jiffies + EHCI_SHRINK_JIFFIES;
1284 qh_put(qh);
1285 if (temp != 0)
1286 goto rescan;
1289 /* unlink idle entries, reducing DMA usage as well
1290 * as HCD schedule-scanning costs. delay for any qh
1291 * we just scanned, there's a not-unusual case that it
1292 * doesn't stay idle for long.
1293 * (plus, avoids some kind of re-activation race.)
1295 if (list_empty(&qh->qtd_list)
1296 && qh->qh_state == QH_STATE_LINKED) {
1297 if (!ehci->reclaim && (stopped ||
1298 time_after_eq(jiffies, qh->unlink_time)))
1299 start_unlink_async(ehci, qh);
1300 else
1301 action = TIMER_ASYNC_SHRINK;
1304 if (action == TIMER_ASYNC_SHRINK)
1305 timer_action (ehci, TIMER_ASYNC_SHRINK);