1 /*
2 * Copyright (C) 2001-2004 by David Brownell
3 *
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.
8 *
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.
13 *
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.
17 */
18
19 /* this file is part of ehci-hcd.c */
20
21 /*-------------------------------------------------------------------------*/
22
23 /*
24 * EHCI hardware queue manipulation ... the core. QH/QTD manipulation.
25 *
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.
30 *
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".
34 *
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.
39 */
40
41 /*-------------------------------------------------------------------------*/
42
43 /* fill a qtd, returning how much of the buffer we were able to queue up */
44
45 static int
qtd_fill(struct ehci_hcd * ehci,struct ehci_qtd * qtd,dma_addr_t buf,size_t len,int token,int maxpacket)46 qtd_fill(struct ehci_hcd *ehci, struct ehci_qtd *qtd, dma_addr_t buf,
47 size_t len, int token, int maxpacket)
48 {
49 int i, count;
50 u64 addr = buf;
51
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;
61
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;
73 }
74
75 /* short packets may only terminate transfers */
76 if (count != len)
77 count -= (count % maxpacket);
78 }
79 qtd->hw_token = cpu_to_hc32(ehci, (count << 16) | token);
80 qtd->length = count;
81
82 return count;
83 }
84
85 /*-------------------------------------------------------------------------*/
86
87 static inline void
qh_update(struct ehci_hcd * ehci,struct ehci_qh * qh,struct ehci_qtd * qtd)88 qh_update (struct ehci_hcd *ehci, struct ehci_qh *qh, struct ehci_qtd *qtd)
89 {
90 struct ehci_qh_hw *hw = qh->hw;
91
92 /* writes to an active overlay are unsafe */
93 WARN_ON(qh->qh_state != QH_STATE_IDLE);
94
95 hw->hw_qtd_next = QTD_NEXT(ehci, qtd->qtd_dma);
96 hw->hw_alt_next = EHCI_LIST_END(ehci);
97
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.
102 */
103 if (!(hw->hw_info1 & cpu_to_hc32(ehci, QH_TOGGLE_CTL))) {
104 unsigned is_out, epnum;
105
106 is_out = qh->is_out;
107 epnum = (hc32_to_cpup(ehci, &hw->hw_info1) >> 8) & 0x0f;
108 if (unlikely(!usb_gettoggle(qh->ps.udev, epnum, is_out))) {
109 hw->hw_token &= ~cpu_to_hc32(ehci, QTD_TOGGLE);
110 usb_settoggle(qh->ps.udev, epnum, is_out, 1);
111 }
112 }
113
114 hw->hw_token &= cpu_to_hc32(ehci, QTD_TOGGLE | QTD_STS_PING);
115 }
116
117 /* if it weren't for a common silicon quirk (writing the dummy into the qh
118 * overlay, so qh->hw_token wrongly becomes inactive/halted), only fault
119 * recovery (including urb dequeue) would need software changes to a QH...
120 */
121 static void
qh_refresh(struct ehci_hcd * ehci,struct ehci_qh * qh)122 qh_refresh (struct ehci_hcd *ehci, struct ehci_qh *qh)
123 {
124 struct ehci_qtd *qtd;
125
126 qtd = list_entry(qh->qtd_list.next, struct ehci_qtd, qtd_list);
127
128 /*
129 * first qtd may already be partially processed.
130 * If we come here during unlink, the QH overlay region
131 * might have reference to the just unlinked qtd. The
132 * qtd is updated in qh_completions(). Update the QH
133 * overlay here.
134 */
135 if (qh->hw->hw_token & ACTIVE_BIT(ehci))
136 qh->hw->hw_qtd_next = qtd->hw_next;
137 else
138 qh_update(ehci, qh, qtd);
139 }
140
141 /*-------------------------------------------------------------------------*/
142
143 static void qh_link_async(struct ehci_hcd *ehci, struct ehci_qh *qh);
144
ehci_clear_tt_buffer_complete(struct usb_hcd * hcd,struct usb_host_endpoint * ep)145 static void ehci_clear_tt_buffer_complete(struct usb_hcd *hcd,
146 struct usb_host_endpoint *ep)
147 {
148 struct ehci_hcd *ehci = hcd_to_ehci(hcd);
149 struct ehci_qh *qh = ep->hcpriv;
150 unsigned long flags;
151
152 spin_lock_irqsave(&ehci->lock, flags);
153 qh->clearing_tt = 0;
154 if (qh->qh_state == QH_STATE_IDLE && !list_empty(&qh->qtd_list)
155 && ehci->rh_state == EHCI_RH_RUNNING)
156 qh_link_async(ehci, qh);
157 spin_unlock_irqrestore(&ehci->lock, flags);
158 }
159
ehci_clear_tt_buffer(struct ehci_hcd * ehci,struct ehci_qh * qh,struct urb * urb,u32 token)160 static void ehci_clear_tt_buffer(struct ehci_hcd *ehci, struct ehci_qh *qh,
161 struct urb *urb, u32 token)
162 {
163
164 /* If an async split transaction gets an error or is unlinked,
165 * the TT buffer may be left in an indeterminate state. We
166 * have to clear the TT buffer.
167 *
168 * Note: this routine is never called for Isochronous transfers.
169 */
170 if (urb->dev->tt && !usb_pipeint(urb->pipe) && !qh->clearing_tt) {
171 #ifdef CONFIG_DYNAMIC_DEBUG
172 struct usb_device *tt = urb->dev->tt->hub;
173 dev_dbg(&tt->dev,
174 "clear tt buffer port %d, a%d ep%d t%08x\n",
175 urb->dev->ttport, urb->dev->devnum,
176 usb_pipeendpoint(urb->pipe), token);
177 #endif /* CONFIG_DYNAMIC_DEBUG */
178 if (!ehci_is_TDI(ehci)
179 || urb->dev->tt->hub !=
180 ehci_to_hcd(ehci)->self.root_hub) {
181 if (usb_hub_clear_tt_buffer(urb) == 0)
182 qh->clearing_tt = 1;
183 } else {
184
185 /* REVISIT ARC-derived cores don't clear the root
186 * hub TT buffer in this way...
187 */
188 }
189 }
190 }
191
qtd_copy_status(struct ehci_hcd * ehci,struct urb * urb,size_t length,u32 token)192 static int qtd_copy_status (
193 struct ehci_hcd *ehci,
194 struct urb *urb,
195 size_t length,
196 u32 token
197 )
198 {
199 int status = -EINPROGRESS;
200
201 /* count IN/OUT bytes, not SETUP (even short packets) */
202 if (likely (QTD_PID (token) != 2))
203 urb->actual_length += length - QTD_LENGTH (token);
204
205 /* don't modify error codes */
206 if (unlikely(urb->unlinked))
207 return status;
208
209 /* force cleanup after short read; not always an error */
210 if (unlikely (IS_SHORT_READ (token)))
211 status = -EREMOTEIO;
212
213 /* serious "can't proceed" faults reported by the hardware */
214 if (token & QTD_STS_HALT) {
215 if (token & QTD_STS_BABBLE) {
216 /* FIXME "must" disable babbling device's port too */
217 status = -EOVERFLOW;
218 /* CERR nonzero + halt --> stall */
219 } else if (QTD_CERR(token)) {
220 status = -EPIPE;
221
222 /* In theory, more than one of the following bits can be set
223 * since they are sticky and the transaction is retried.
224 * Which to test first is rather arbitrary.
225 */
226 } else if (token & QTD_STS_MMF) {
227 /* fs/ls interrupt xfer missed the complete-split */
228 status = -EPROTO;
229 } else if (token & QTD_STS_DBE) {
230 status = (QTD_PID (token) == 1) /* IN ? */
231 ? -ENOSR /* hc couldn't read data */
232 : -ECOMM; /* hc couldn't write data */
233 } else if (token & QTD_STS_XACT) {
234 /* timeout, bad CRC, wrong PID, etc */
235 ehci_dbg(ehci, "devpath %s ep%d%s 3strikes\n",
236 urb->dev->devpath,
237 usb_pipeendpoint(urb->pipe),
238 usb_pipein(urb->pipe) ? "in" : "out");
239 status = -EPROTO;
240 } else { /* unknown */
241 status = -EPROTO;
242 }
243 }
244
245 return status;
246 }
247
248 static void
ehci_urb_done(struct ehci_hcd * ehci,struct urb * urb,int status)249 ehci_urb_done(struct ehci_hcd *ehci, struct urb *urb, int status)
250 {
251 if (usb_pipetype(urb->pipe) == PIPE_INTERRUPT) {
252 /* ... update hc-wide periodic stats */
253 ehci_to_hcd(ehci)->self.bandwidth_int_reqs--;
254 }
255
256 if (unlikely(urb->unlinked)) {
257 COUNT(ehci->stats.unlink);
258 } else {
259 /* report non-error and short read status as zero */
260 if (status == -EINPROGRESS || status == -EREMOTEIO)
261 status = 0;
262 COUNT(ehci->stats.complete);
263 }
264
265 #ifdef EHCI_URB_TRACE
266 ehci_dbg (ehci,
267 "%s %s urb %p ep%d%s status %d len %d/%d\n",
268 __func__, urb->dev->devpath, urb,
269 usb_pipeendpoint (urb->pipe),
270 usb_pipein (urb->pipe) ? "in" : "out",
271 status,
272 urb->actual_length, urb->transfer_buffer_length);
273 #endif
274
275 usb_hcd_unlink_urb_from_ep(ehci_to_hcd(ehci), urb);
276 usb_hcd_giveback_urb(ehci_to_hcd(ehci), urb, status);
277 }
278
279 static int qh_schedule (struct ehci_hcd *ehci, struct ehci_qh *qh);
280
281 /*
282 * Process and free completed qtds for a qh, returning URBs to drivers.
283 * Chases up to qh->hw_current. Returns nonzero if the caller should
284 * unlink qh.
285 */
286 static unsigned
qh_completions(struct ehci_hcd * ehci,struct ehci_qh * qh)287 qh_completions (struct ehci_hcd *ehci, struct ehci_qh *qh)
288 {
289 struct ehci_qtd *last, *end = qh->dummy;
290 struct list_head *entry, *tmp;
291 int last_status;
292 int stopped;
293 u8 state;
294 struct ehci_qh_hw *hw = qh->hw;
295
296 /* completions (or tasks on other cpus) must never clobber HALT
297 * till we've gone through and cleaned everything up, even when
298 * they add urbs to this qh's queue or mark them for unlinking.
299 *
300 * NOTE: unlinking expects to be done in queue order.
301 *
302 * It's a bug for qh->qh_state to be anything other than
303 * QH_STATE_IDLE, unless our caller is scan_async() or
304 * scan_intr().
305 */
306 state = qh->qh_state;
307 qh->qh_state = QH_STATE_COMPLETING;
308 stopped = (state == QH_STATE_IDLE);
309
310 rescan:
311 last = NULL;
312 last_status = -EINPROGRESS;
313 qh->dequeue_during_giveback = 0;
314
315 /* remove de-activated QTDs from front of queue.
316 * after faults (including short reads), cleanup this urb
317 * then let the queue advance.
318 * if queue is stopped, handles unlinks.
319 */
320 list_for_each_safe (entry, tmp, &qh->qtd_list) {
321 struct ehci_qtd *qtd;
322 struct urb *urb;
323 u32 token = 0;
324
325 qtd = list_entry (entry, struct ehci_qtd, qtd_list);
326 urb = qtd->urb;
327
328 /* clean up any state from previous QTD ...*/
329 if (last) {
330 if (likely (last->urb != urb)) {
331 ehci_urb_done(ehci, last->urb, last_status);
332 last_status = -EINPROGRESS;
333 }
334 ehci_qtd_free (ehci, last);
335 last = NULL;
336 }
337
338 /* ignore urbs submitted during completions we reported */
339 if (qtd == end)
340 break;
341
342 /* hardware copies qtd out of qh overlay */
343 rmb ();
344 token = hc32_to_cpu(ehci, qtd->hw_token);
345
346 /* always clean up qtds the hc de-activated */
347 retry_xacterr:
348 if ((token & QTD_STS_ACTIVE) == 0) {
349
350 /* Report Data Buffer Error: non-fatal but useful */
351 if (token & QTD_STS_DBE)
352 ehci_dbg(ehci,
353 "detected DataBufferErr for urb %p ep%d%s len %d, qtd %p [qh %p]\n",
354 urb,
355 usb_endpoint_num(&urb->ep->desc),
356 usb_endpoint_dir_in(&urb->ep->desc) ? "in" : "out",
357 urb->transfer_buffer_length,
358 qtd,
359 qh);
360
361 /* on STALL, error, and short reads this urb must
362 * complete and all its qtds must be recycled.
363 */
364 if ((token & QTD_STS_HALT) != 0) {
365
366 /* retry transaction errors until we
367 * reach the software xacterr limit
368 */
369 if ((token & QTD_STS_XACT) &&
370 QTD_CERR(token) == 0 &&
371 ++qh->xacterrs < QH_XACTERR_MAX &&
372 !urb->unlinked) {
373 ehci_dbg(ehci,
374 "detected XactErr len %zu/%zu retry %d\n",
375 qtd->length - QTD_LENGTH(token), qtd->length, qh->xacterrs);
376
377 /* reset the token in the qtd and the
378 * qh overlay (which still contains
379 * the qtd) so that we pick up from
380 * where we left off
381 */
382 token &= ~QTD_STS_HALT;
383 token |= QTD_STS_ACTIVE |
384 (EHCI_TUNE_CERR << 10);
385 qtd->hw_token = cpu_to_hc32(ehci,
386 token);
387 wmb();
388 hw->hw_token = cpu_to_hc32(ehci,
389 token);
390 goto retry_xacterr;
391 }
392 stopped = 1;
393
394 /* magic dummy for some short reads; qh won't advance.
395 * that silicon quirk can kick in with this dummy too.
396 *
397 * other short reads won't stop the queue, including
398 * control transfers (status stage handles that) or
399 * most other single-qtd reads ... the queue stops if
400 * URB_SHORT_NOT_OK was set so the driver submitting
401 * the urbs could clean it up.
402 */
403 } else if (IS_SHORT_READ (token)
404 && !(qtd->hw_alt_next
405 & EHCI_LIST_END(ehci))) {
406 stopped = 1;
407 }
408
409 /* stop scanning when we reach qtds the hc is using */
410 } else if (likely (!stopped
411 && ehci->rh_state >= EHCI_RH_RUNNING)) {
412 break;
413
414 /* scan the whole queue for unlinks whenever it stops */
415 } else {
416 stopped = 1;
417
418 /* cancel everything if we halt, suspend, etc */
419 if (ehci->rh_state < EHCI_RH_RUNNING)
420 last_status = -ESHUTDOWN;
421
422 /* this qtd is active; skip it unless a previous qtd
423 * for its urb faulted, or its urb was canceled.
424 */
425 else if (last_status == -EINPROGRESS && !urb->unlinked)
426 continue;
427
428 /*
429 * If this was the active qtd when the qh was unlinked
430 * and the overlay's token is active, then the overlay
431 * hasn't been written back to the qtd yet so use its
432 * token instead of the qtd's. After the qtd is
433 * processed and removed, the overlay won't be valid
434 * any more.
435 */
436 if (state == QH_STATE_IDLE &&
437 qh->qtd_list.next == &qtd->qtd_list &&
438 (hw->hw_token & ACTIVE_BIT(ehci))) {
439 token = hc32_to_cpu(ehci, hw->hw_token);
440 hw->hw_token &= ~ACTIVE_BIT(ehci);
441
442 /* An unlink may leave an incomplete
443 * async transaction in the TT buffer.
444 * We have to clear it.
445 */
446 ehci_clear_tt_buffer(ehci, qh, urb, token);
447 }
448 }
449
450 /* unless we already know the urb's status, collect qtd status
451 * and update count of bytes transferred. in common short read
452 * cases with only one data qtd (including control transfers),
453 * queue processing won't halt. but with two or more qtds (for
454 * example, with a 32 KB transfer), when the first qtd gets a
455 * short read the second must be removed by hand.
456 */
457 if (last_status == -EINPROGRESS) {
458 last_status = qtd_copy_status(ehci, urb,
459 qtd->length, token);
460 if (last_status == -EREMOTEIO
461 && (qtd->hw_alt_next
462 & EHCI_LIST_END(ehci)))
463 last_status = -EINPROGRESS;
464
465 /* As part of low/full-speed endpoint-halt processing
466 * we must clear the TT buffer (11.17.5).
467 */
468 if (unlikely(last_status != -EINPROGRESS &&
469 last_status != -EREMOTEIO)) {
470 /* The TT's in some hubs malfunction when they
471 * receive this request following a STALL (they
472 * stop sending isochronous packets). Since a
473 * STALL can't leave the TT buffer in a busy
474 * state (if you believe Figures 11-48 - 11-51
475 * in the USB 2.0 spec), we won't clear the TT
476 * buffer in this case. Strictly speaking this
477 * is a violation of the spec.
478 */
479 if (last_status != -EPIPE)
480 ehci_clear_tt_buffer(ehci, qh, urb,
481 token);
482 }
483 }
484
485 /* if we're removing something not at the queue head,
486 * patch the hardware queue pointer.
487 */
488 if (stopped && qtd->qtd_list.prev != &qh->qtd_list) {
489 last = list_entry (qtd->qtd_list.prev,
490 struct ehci_qtd, qtd_list);
491 last->hw_next = qtd->hw_next;
492 }
493
494 /* remove qtd; it's recycled after possible urb completion */
495 list_del (&qtd->qtd_list);
496 last = qtd;
497
498 /* reinit the xacterr counter for the next qtd */
499 qh->xacterrs = 0;
500 }
501
502 /* last urb's completion might still need calling */
503 if (likely (last != NULL)) {
504 ehci_urb_done(ehci, last->urb, last_status);
505 ehci_qtd_free (ehci, last);
506 }
507
508 /* Do we need to rescan for URBs dequeued during a giveback? */
509 if (unlikely(qh->dequeue_during_giveback)) {
510 /* If the QH is already unlinked, do the rescan now. */
511 if (state == QH_STATE_IDLE)
512 goto rescan;
513
514 /* Otherwise the caller must unlink the QH. */
515 }
516
517 /* restore original state; caller must unlink or relink */
518 qh->qh_state = state;
519
520 /* be sure the hardware's done with the qh before refreshing
521 * it after fault cleanup, or recovering from silicon wrongly
522 * overlaying the dummy qtd (which reduces DMA chatter).
523 *
524 * We won't refresh a QH that's linked (after the HC
525 * stopped the queue). That avoids a race:
526 * - HC reads first part of QH;
527 * - CPU updates that first part and the token;
528 * - HC reads rest of that QH, including token
529 * Result: HC gets an inconsistent image, and then
530 * DMAs to/from the wrong memory (corrupting it).
531 *
532 * That should be rare for interrupt transfers,
533 * except maybe high bandwidth ...
534 */
535 if (stopped != 0 || hw->hw_qtd_next == EHCI_LIST_END(ehci))
536 qh->exception = 1;
537
538 /* Let the caller know if the QH needs to be unlinked. */
539 return qh->exception;
540 }
541
542 /*-------------------------------------------------------------------------*/
543
544 // high bandwidth multiplier, as encoded in highspeed endpoint descriptors
545 #define hb_mult(wMaxPacketSize) (1 + (((wMaxPacketSize) >> 11) & 0x03))
546 // ... and packet size, for any kind of endpoint descriptor
547 #define max_packet(wMaxPacketSize) ((wMaxPacketSize) & 0x07ff)
548
549 /*
550 * reverse of qh_urb_transaction: free a list of TDs.
551 * used for cleanup after errors, before HC sees an URB's TDs.
552 */
qtd_list_free(struct ehci_hcd * ehci,struct urb * urb,struct list_head * qtd_list)553 static void qtd_list_free (
554 struct ehci_hcd *ehci,
555 struct urb *urb,
556 struct list_head *qtd_list
557 ) {
558 struct list_head *entry, *temp;
559
560 list_for_each_safe (entry, temp, qtd_list) {
561 struct ehci_qtd *qtd;
562
563 qtd = list_entry (entry, struct ehci_qtd, qtd_list);
564 list_del (&qtd->qtd_list);
565 ehci_qtd_free (ehci, qtd);
566 }
567 }
568
569 /*
570 * create a list of filled qtds for this URB; won't link into qh.
571 */
572 static struct list_head *
qh_urb_transaction(struct ehci_hcd * ehci,struct urb * urb,struct list_head * head,gfp_t flags)573 qh_urb_transaction (
574 struct ehci_hcd *ehci,
575 struct urb *urb,
576 struct list_head *head,
577 gfp_t flags
578 ) {
579 struct ehci_qtd *qtd, *qtd_prev;
580 dma_addr_t buf;
581 int len, this_sg_len, maxpacket;
582 int is_input;
583 u32 token;
584 int i;
585 struct scatterlist *sg;
586
587 /*
588 * URBs map to sequences of QTDs: one logical transaction
589 */
590 qtd = ehci_qtd_alloc (ehci, flags);
591 if (unlikely (!qtd))
592 return NULL;
593 list_add_tail (&qtd->qtd_list, head);
594 qtd->urb = urb;
595
596 token = QTD_STS_ACTIVE;
597 token |= (EHCI_TUNE_CERR << 10);
598 /* for split transactions, SplitXState initialized to zero */
599
600 len = urb->transfer_buffer_length;
601 is_input = usb_pipein (urb->pipe);
602 if (usb_pipecontrol (urb->pipe)) {
603 /* SETUP pid */
604 qtd_fill(ehci, qtd, urb->setup_dma,
605 sizeof (struct usb_ctrlrequest),
606 token | (2 /* "setup" */ << 8), 8);
607
608 /* ... and always at least one more pid */
609 token ^= QTD_TOGGLE;
610 qtd_prev = qtd;
611 qtd = ehci_qtd_alloc (ehci, flags);
612 if (unlikely (!qtd))
613 goto cleanup;
614 qtd->urb = urb;
615 qtd_prev->hw_next = QTD_NEXT(ehci, qtd->qtd_dma);
616 list_add_tail (&qtd->qtd_list, head);
617
618 /* for zero length DATA stages, STATUS is always IN */
619 if (len == 0)
620 token |= (1 /* "in" */ << 8);
621 }
622
623 /*
624 * data transfer stage: buffer setup
625 */
626 i = urb->num_mapped_sgs;
627 if (len > 0 && i > 0) {
628 sg = urb->sg;
629 buf = sg_dma_address(sg);
630
631 /* urb->transfer_buffer_length may be smaller than the
632 * size of the scatterlist (or vice versa)
633 */
634 this_sg_len = min_t(int, sg_dma_len(sg), len);
635 } else {
636 sg = NULL;
637 buf = urb->transfer_dma;
638 this_sg_len = len;
639 }
640
641 if (is_input)
642 token |= (1 /* "in" */ << 8);
643 /* else it's already initted to "out" pid (0 << 8) */
644
645 maxpacket = max_packet(usb_maxpacket(urb->dev, urb->pipe, !is_input));
646
647 /*
648 * buffer gets wrapped in one or more qtds;
649 * last one may be "short" (including zero len)
650 * and may serve as a control status ack
651 */
652 for (;;) {
653 int this_qtd_len;
654
655 this_qtd_len = qtd_fill(ehci, qtd, buf, this_sg_len, token,
656 maxpacket);
657 this_sg_len -= this_qtd_len;
658 len -= this_qtd_len;
659 buf += this_qtd_len;
660
661 /*
662 * short reads advance to a "magic" dummy instead of the next
663 * qtd ... that forces the queue to stop, for manual cleanup.
664 * (this will usually be overridden later.)
665 */
666 if (is_input)
667 qtd->hw_alt_next = ehci->async->hw->hw_alt_next;
668
669 /* qh makes control packets use qtd toggle; maybe switch it */
670 if ((maxpacket & (this_qtd_len + (maxpacket - 1))) == 0)
671 token ^= QTD_TOGGLE;
672
673 if (likely(this_sg_len <= 0)) {
674 if (--i <= 0 || len <= 0)
675 break;
676 sg = sg_next(sg);
677 buf = sg_dma_address(sg);
678 this_sg_len = min_t(int, sg_dma_len(sg), len);
679 }
680
681 qtd_prev = qtd;
682 qtd = ehci_qtd_alloc (ehci, flags);
683 if (unlikely (!qtd))
684 goto cleanup;
685 qtd->urb = urb;
686 qtd_prev->hw_next = QTD_NEXT(ehci, qtd->qtd_dma);
687 list_add_tail (&qtd->qtd_list, head);
688 }
689
690 /*
691 * unless the caller requires manual cleanup after short reads,
692 * have the alt_next mechanism keep the queue running after the
693 * last data qtd (the only one, for control and most other cases).
694 */
695 if (likely ((urb->transfer_flags & URB_SHORT_NOT_OK) == 0
696 || usb_pipecontrol (urb->pipe)))
697 qtd->hw_alt_next = EHCI_LIST_END(ehci);
698
699 /*
700 * control requests may need a terminating data "status" ack;
701 * other OUT ones may need a terminating short packet
702 * (zero length).
703 */
704 if (likely (urb->transfer_buffer_length != 0)) {
705 int one_more = 0;
706
707 if (usb_pipecontrol (urb->pipe)) {
708 one_more = 1;
709 token ^= 0x0100; /* "in" <--> "out" */
710 token |= QTD_TOGGLE; /* force DATA1 */
711 } else if (usb_pipeout(urb->pipe)
712 && (urb->transfer_flags & URB_ZERO_PACKET)
713 && !(urb->transfer_buffer_length % maxpacket)) {
714 one_more = 1;
715 }
716 if (one_more) {
717 qtd_prev = qtd;
718 qtd = ehci_qtd_alloc (ehci, flags);
719 if (unlikely (!qtd))
720 goto cleanup;
721 qtd->urb = urb;
722 qtd_prev->hw_next = QTD_NEXT(ehci, qtd->qtd_dma);
723 list_add_tail (&qtd->qtd_list, head);
724
725 /* never any data in such packets */
726 qtd_fill(ehci, qtd, 0, 0, token, 0);
727 }
728 }
729
730 /* by default, enable interrupt on urb completion */
731 if (likely (!(urb->transfer_flags & URB_NO_INTERRUPT)))
732 qtd->hw_token |= cpu_to_hc32(ehci, QTD_IOC);
733 return head;
734
735 cleanup:
736 qtd_list_free (ehci, urb, head);
737 return NULL;
738 }
739
740 /*-------------------------------------------------------------------------*/
741
742 // Would be best to create all qh's from config descriptors,
743 // when each interface/altsetting is established. Unlink
744 // any previous qh and cancel its urbs first; endpoints are
745 // implicitly reset then (data toggle too).
746 // That'd mean updating how usbcore talks to HCDs. (2.7?)
747
748
749 /*
750 * Each QH holds a qtd list; a QH is used for everything except iso.
751 *
752 * For interrupt urbs, the scheduler must set the microframe scheduling
753 * mask(s) each time the QH gets scheduled. For highspeed, that's
754 * just one microframe in the s-mask. For split interrupt transactions
755 * there are additional complications: c-mask, maybe FSTNs.
756 */
757 static struct ehci_qh *
qh_make(struct ehci_hcd * ehci,struct urb * urb,gfp_t flags)758 qh_make (
759 struct ehci_hcd *ehci,
760 struct urb *urb,
761 gfp_t flags
762 ) {
763 struct ehci_qh *qh = ehci_qh_alloc (ehci, flags);
764 u32 info1 = 0, info2 = 0;
765 int is_input, type;
766 int maxp = 0;
767 struct usb_tt *tt = urb->dev->tt;
768 struct ehci_qh_hw *hw;
769
770 if (!qh)
771 return qh;
772
773 /*
774 * init endpoint/device data for this QH
775 */
776 info1 |= usb_pipeendpoint (urb->pipe) << 8;
777 info1 |= usb_pipedevice (urb->pipe) << 0;
778
779 is_input = usb_pipein (urb->pipe);
780 type = usb_pipetype (urb->pipe);
781 maxp = usb_maxpacket (urb->dev, urb->pipe, !is_input);
782
783 /* 1024 byte maxpacket is a hardware ceiling. High bandwidth
784 * acts like up to 3KB, but is built from smaller packets.
785 */
786 if (max_packet(maxp) > 1024) {
787 ehci_dbg(ehci, "bogus qh maxpacket %d\n", max_packet(maxp));
788 goto done;
789 }
790
791 /* Compute interrupt scheduling parameters just once, and save.
792 * - allowing for high bandwidth, how many nsec/uframe are used?
793 * - split transactions need a second CSPLIT uframe; same question
794 * - splits also need a schedule gap (for full/low speed I/O)
795 * - qh has a polling interval
796 *
797 * For control/bulk requests, the HC or TT handles these.
798 */
799 if (type == PIPE_INTERRUPT) {
800 unsigned tmp;
801
802 qh->ps.usecs = NS_TO_US(usb_calc_bus_time(USB_SPEED_HIGH,
803 is_input, 0,
804 hb_mult(maxp) * max_packet(maxp)));
805 qh->ps.phase = NO_FRAME;
806
807 if (urb->dev->speed == USB_SPEED_HIGH) {
808 qh->ps.c_usecs = 0;
809 qh->gap_uf = 0;
810
811 if (urb->interval > 1 && urb->interval < 8) {
812 /* NOTE interval 2 or 4 uframes could work.
813 * But interval 1 scheduling is simpler, and
814 * includes high bandwidth.
815 */
816 urb->interval = 1;
817 } else if (urb->interval > ehci->periodic_size << 3) {
818 urb->interval = ehci->periodic_size << 3;
819 }
820 qh->ps.period = urb->interval >> 3;
821
822 /* period for bandwidth allocation */
823 tmp = min_t(unsigned, EHCI_BANDWIDTH_SIZE,
824 1 << (urb->ep->desc.bInterval - 1));
825
826 /* Allow urb->interval to override */
827 qh->ps.bw_uperiod = min_t(unsigned, tmp, urb->interval);
828 qh->ps.bw_period = qh->ps.bw_uperiod >> 3;
829 } else {
830 int think_time;
831
832 /* gap is f(FS/LS transfer times) */
833 qh->gap_uf = 1 + usb_calc_bus_time (urb->dev->speed,
834 is_input, 0, maxp) / (125 * 1000);
835
836 /* FIXME this just approximates SPLIT/CSPLIT times */
837 if (is_input) { // SPLIT, gap, CSPLIT+DATA
838 qh->ps.c_usecs = qh->ps.usecs + HS_USECS(0);
839 qh->ps.usecs = HS_USECS(1);
840 } else { // SPLIT+DATA, gap, CSPLIT
841 qh->ps.usecs += HS_USECS(1);
842 qh->ps.c_usecs = HS_USECS(0);
843 }
844
845 think_time = tt ? tt->think_time : 0;
846 qh->ps.tt_usecs = NS_TO_US(think_time +
847 usb_calc_bus_time (urb->dev->speed,
848 is_input, 0, max_packet (maxp)));
849 if (urb->interval > ehci->periodic_size)
850 urb->interval = ehci->periodic_size;
851 qh->ps.period = urb->interval;
852
853 /* period for bandwidth allocation */
854 tmp = min_t(unsigned, EHCI_BANDWIDTH_FRAMES,
855 urb->ep->desc.bInterval);
856 tmp = rounddown_pow_of_two(tmp);
857
858 /* Allow urb->interval to override */
859 qh->ps.bw_period = min_t(unsigned, tmp, urb->interval);
860 qh->ps.bw_uperiod = qh->ps.bw_period << 3;
861 }
862 }
863
864 /* support for tt scheduling, and access to toggles */
865 qh->ps.udev = urb->dev;
866 qh->ps.ep = urb->ep;
867
868 /* using TT? */
869 switch (urb->dev->speed) {
870 case USB_SPEED_LOW:
871 info1 |= QH_LOW_SPEED;
872 /* FALL THROUGH */
873
874 case USB_SPEED_FULL:
875 /* EPS 0 means "full" */
876 if (type != PIPE_INTERRUPT)
877 info1 |= (EHCI_TUNE_RL_TT << 28);
878 if (type == PIPE_CONTROL) {
879 info1 |= QH_CONTROL_EP; /* for TT */
880 info1 |= QH_TOGGLE_CTL; /* toggle from qtd */
881 }
882 info1 |= maxp << 16;
883
884 info2 |= (EHCI_TUNE_MULT_TT << 30);
885
886 /* Some Freescale processors have an erratum in which the
887 * port number in the queue head was 0..N-1 instead of 1..N.
888 */
889 if (ehci_has_fsl_portno_bug(ehci))
890 info2 |= (urb->dev->ttport-1) << 23;
891 else
892 info2 |= urb->dev->ttport << 23;
893
894 /* set the address of the TT; for TDI's integrated
895 * root hub tt, leave it zeroed.
896 */
897 if (tt && tt->hub != ehci_to_hcd(ehci)->self.root_hub)
898 info2 |= tt->hub->devnum << 16;
899
900 /* NOTE: if (PIPE_INTERRUPT) { scheduler sets c-mask } */
901
902 break;
903
904 case USB_SPEED_HIGH: /* no TT involved */
905 info1 |= QH_HIGH_SPEED;
906 if (type == PIPE_CONTROL) {
907 info1 |= (EHCI_TUNE_RL_HS << 28);
908 info1 |= 64 << 16; /* usb2 fixed maxpacket */
909 info1 |= QH_TOGGLE_CTL; /* toggle from qtd */
910 info2 |= (EHCI_TUNE_MULT_HS << 30);
911 } else if (type == PIPE_BULK) {
912 info1 |= (EHCI_TUNE_RL_HS << 28);
913 /* The USB spec says that high speed bulk endpoints
914 * always use 512 byte maxpacket. But some device
915 * vendors decided to ignore that, and MSFT is happy
916 * to help them do so. So now people expect to use
917 * such nonconformant devices with Linux too; sigh.
918 */
919 info1 |= max_packet(maxp) << 16;
920 info2 |= (EHCI_TUNE_MULT_HS << 30);
921 } else { /* PIPE_INTERRUPT */
922 info1 |= max_packet (maxp) << 16;
923 info2 |= hb_mult (maxp) << 30;
924 }
925 break;
926 default:
927 ehci_dbg(ehci, "bogus dev %p speed %d\n", urb->dev,
928 urb->dev->speed);
929 done:
930 qh_destroy(ehci, qh);
931 return NULL;
932 }
933
934 /* NOTE: if (PIPE_INTERRUPT) { scheduler sets s-mask } */
935
936 /* init as live, toggle clear */
937 qh->qh_state = QH_STATE_IDLE;
938 hw = qh->hw;
939 hw->hw_info1 = cpu_to_hc32(ehci, info1);
940 hw->hw_info2 = cpu_to_hc32(ehci, info2);
941 qh->is_out = !is_input;
942 usb_settoggle (urb->dev, usb_pipeendpoint (urb->pipe), !is_input, 1);
943 return qh;
944 }
945
946 /*-------------------------------------------------------------------------*/
947
enable_async(struct ehci_hcd * ehci)948 static void enable_async(struct ehci_hcd *ehci)
949 {
950 if (ehci->async_count++)
951 return;
952
953 /* Stop waiting to turn off the async schedule */
954 ehci->enabled_hrtimer_events &= ~BIT(EHCI_HRTIMER_DISABLE_ASYNC);
955
956 /* Don't start the schedule until ASS is 0 */
957 ehci_poll_ASS(ehci);
958 turn_on_io_watchdog(ehci);
959 }
960
disable_async(struct ehci_hcd * ehci)961 static void disable_async(struct ehci_hcd *ehci)
962 {
963 if (--ehci->async_count)
964 return;
965
966 /* The async schedule and unlink lists are supposed to be empty */
967 WARN_ON(ehci->async->qh_next.qh || !list_empty(&ehci->async_unlink) ||
968 !list_empty(&ehci->async_idle));
969
970 /* Don't turn off the schedule until ASS is 1 */
971 ehci_poll_ASS(ehci);
972 }
973
974 /* move qh (and its qtds) onto async queue; maybe enable queue. */
975
qh_link_async(struct ehci_hcd * ehci,struct ehci_qh * qh)976 static void qh_link_async (struct ehci_hcd *ehci, struct ehci_qh *qh)
977 {
978 __hc32 dma = QH_NEXT(ehci, qh->qh_dma);
979 struct ehci_qh *head;
980
981 /* Don't link a QH if there's a Clear-TT-Buffer pending */
982 if (unlikely(qh->clearing_tt))
983 return;
984
985 WARN_ON(qh->qh_state != QH_STATE_IDLE);
986
987 /* clear halt and/or toggle; and maybe recover from silicon quirk */
988 qh_refresh(ehci, qh);
989
990 /* splice right after start */
991 head = ehci->async;
992 qh->qh_next = head->qh_next;
993 qh->hw->hw_next = head->hw->hw_next;
994 wmb ();
995
996 head->qh_next.qh = qh;
997 head->hw->hw_next = dma;
998
999 qh->qh_state = QH_STATE_LINKED;
1000 qh->xacterrs = 0;
1001 qh->exception = 0;
1002 /* qtd completions reported later by interrupt */
1003
1004 enable_async(ehci);
1005 }
1006
1007 /*-------------------------------------------------------------------------*/
1008
1009 /*
1010 * For control/bulk/interrupt, return QH with these TDs appended.
1011 * Allocates and initializes the QH if necessary.
1012 * Returns null if it can't allocate a QH it needs to.
1013 * If the QH has TDs (urbs) already, that's great.
1014 */
qh_append_tds(struct ehci_hcd * ehci,struct urb * urb,struct list_head * qtd_list,int epnum,void ** ptr)1015 static struct ehci_qh *qh_append_tds (
1016 struct ehci_hcd *ehci,
1017 struct urb *urb,
1018 struct list_head *qtd_list,
1019 int epnum,
1020 void **ptr
1021 )
1022 {
1023 struct ehci_qh *qh = NULL;
1024 __hc32 qh_addr_mask = cpu_to_hc32(ehci, 0x7f);
1025
1026 qh = (struct ehci_qh *) *ptr;
1027 if (unlikely (qh == NULL)) {
1028 /* can't sleep here, we have ehci->lock... */
1029 qh = qh_make (ehci, urb, GFP_ATOMIC);
1030 *ptr = qh;
1031 }
1032 if (likely (qh != NULL)) {
1033 struct ehci_qtd *qtd;
1034
1035 if (unlikely (list_empty (qtd_list)))
1036 qtd = NULL;
1037 else
1038 qtd = list_entry (qtd_list->next, struct ehci_qtd,
1039 qtd_list);
1040
1041 /* control qh may need patching ... */
1042 if (unlikely (epnum == 0)) {
1043
1044 /* usb_reset_device() briefly reverts to address 0 */
1045 if (usb_pipedevice (urb->pipe) == 0)
1046 qh->hw->hw_info1 &= ~qh_addr_mask;
1047 }
1048
1049 /* just one way to queue requests: swap with the dummy qtd.
1050 * only hc or qh_refresh() ever modify the overlay.
1051 */
1052 if (likely (qtd != NULL)) {
1053 struct ehci_qtd *dummy;
1054 dma_addr_t dma;
1055 __hc32 token;
1056
1057 /* to avoid racing the HC, use the dummy td instead of
1058 * the first td of our list (becomes new dummy). both
1059 * tds stay deactivated until we're done, when the
1060 * HC is allowed to fetch the old dummy (4.10.2).
1061 */
1062 token = qtd->hw_token;
1063 qtd->hw_token = HALT_BIT(ehci);
1064
1065 dummy = qh->dummy;
1066
1067 dma = dummy->qtd_dma;
1068 *dummy = *qtd;
1069 dummy->qtd_dma = dma;
1070
1071 list_del (&qtd->qtd_list);
1072 list_add (&dummy->qtd_list, qtd_list);
1073 list_splice_tail(qtd_list, &qh->qtd_list);
1074
1075 ehci_qtd_init(ehci, qtd, qtd->qtd_dma);
1076 qh->dummy = qtd;
1077
1078 /* hc must see the new dummy at list end */
1079 dma = qtd->qtd_dma;
1080 qtd = list_entry (qh->qtd_list.prev,
1081 struct ehci_qtd, qtd_list);
1082 qtd->hw_next = QTD_NEXT(ehci, dma);
1083
1084 /* let the hc process these next qtds */
1085 wmb ();
1086 dummy->hw_token = token;
1087
1088 urb->hcpriv = qh;
1089 }
1090 }
1091 return qh;
1092 }
1093
1094 /*-------------------------------------------------------------------------*/
1095
1096 static int
submit_async(struct ehci_hcd * ehci,struct urb * urb,struct list_head * qtd_list,gfp_t mem_flags)1097 submit_async (
1098 struct ehci_hcd *ehci,
1099 struct urb *urb,
1100 struct list_head *qtd_list,
1101 gfp_t mem_flags
1102 ) {
1103 int epnum;
1104 unsigned long flags;
1105 struct ehci_qh *qh = NULL;
1106 int rc;
1107
1108 epnum = urb->ep->desc.bEndpointAddress;
1109
1110 #ifdef EHCI_URB_TRACE
1111 {
1112 struct ehci_qtd *qtd;
1113 qtd = list_entry(qtd_list->next, struct ehci_qtd, qtd_list);
1114 ehci_dbg(ehci,
1115 "%s %s urb %p ep%d%s len %d, qtd %p [qh %p]\n",
1116 __func__, urb->dev->devpath, urb,
1117 epnum & 0x0f, (epnum & USB_DIR_IN) ? "in" : "out",
1118 urb->transfer_buffer_length,
1119 qtd, urb->ep->hcpriv);
1120 }
1121 #endif
1122
1123 spin_lock_irqsave (&ehci->lock, flags);
1124 if (unlikely(!HCD_HW_ACCESSIBLE(ehci_to_hcd(ehci)))) {
1125 rc = -ESHUTDOWN;
1126 goto done;
1127 }
1128 rc = usb_hcd_link_urb_to_ep(ehci_to_hcd(ehci), urb);
1129 if (unlikely(rc))
1130 goto done;
1131
1132 qh = qh_append_tds(ehci, urb, qtd_list, epnum, &urb->ep->hcpriv);
1133 if (unlikely(qh == NULL)) {
1134 usb_hcd_unlink_urb_from_ep(ehci_to_hcd(ehci), urb);
1135 rc = -ENOMEM;
1136 goto done;
1137 }
1138
1139 /* Control/bulk operations through TTs don't need scheduling,
1140 * the HC and TT handle it when the TT has a buffer ready.
1141 */
1142 if (likely (qh->qh_state == QH_STATE_IDLE))
1143 qh_link_async(ehci, qh);
1144 done:
1145 spin_unlock_irqrestore (&ehci->lock, flags);
1146 if (unlikely (qh == NULL))
1147 qtd_list_free (ehci, urb, qtd_list);
1148 return rc;
1149 }
1150
1151 /*-------------------------------------------------------------------------*/
1152 #ifdef CONFIG_USB_HCD_TEST_MODE
1153 /*
1154 * This function creates the qtds and submits them for the
1155 * SINGLE_STEP_SET_FEATURE Test.
1156 * This is done in two parts: first SETUP req for GetDesc is sent then
1157 * 15 seconds later, the IN stage for GetDesc starts to req data from dev
1158 *
1159 * is_setup : i/p arguement decides which of the two stage needs to be
1160 * performed; TRUE - SETUP and FALSE - IN+STATUS
1161 * Returns 0 if success
1162 */
submit_single_step_set_feature(struct usb_hcd * hcd,struct urb * urb,int is_setup)1163 static int submit_single_step_set_feature(
1164 struct usb_hcd *hcd,
1165 struct urb *urb,
1166 int is_setup
1167 ) {
1168 struct ehci_hcd *ehci = hcd_to_ehci(hcd);
1169 struct list_head qtd_list;
1170 struct list_head *head;
1171
1172 struct ehci_qtd *qtd, *qtd_prev;
1173 dma_addr_t buf;
1174 int len, maxpacket;
1175 u32 token;
1176
1177 INIT_LIST_HEAD(&qtd_list);
1178 head = &qtd_list;
1179
1180 /* URBs map to sequences of QTDs: one logical transaction */
1181 qtd = ehci_qtd_alloc(ehci, GFP_KERNEL);
1182 if (unlikely(!qtd))
1183 return -1;
1184 list_add_tail(&qtd->qtd_list, head);
1185 qtd->urb = urb;
1186
1187 token = QTD_STS_ACTIVE;
1188 token |= (EHCI_TUNE_CERR << 10);
1189
1190 len = urb->transfer_buffer_length;
1191 /*
1192 * Check if the request is to perform just the SETUP stage (getDesc)
1193 * as in SINGLE_STEP_SET_FEATURE test, DATA stage (IN) happens
1194 * 15 secs after the setup
1195 */
1196 if (is_setup) {
1197 /* SETUP pid */
1198 qtd_fill(ehci, qtd, urb->setup_dma,
1199 sizeof(struct usb_ctrlrequest),
1200 token | (2 /* "setup" */ << 8), 8);
1201
1202 submit_async(ehci, urb, &qtd_list, GFP_ATOMIC);
1203 return 0; /*Return now; we shall come back after 15 seconds*/
1204 }
1205
1206 /*
1207 * IN: data transfer stage: buffer setup : start the IN txn phase for
1208 * the get_Desc SETUP which was sent 15seconds back
1209 */
1210 token ^= QTD_TOGGLE; /*We need to start IN with DATA-1 Pid-sequence*/
1211 buf = urb->transfer_dma;
1212
1213 token |= (1 /* "in" */ << 8); /*This is IN stage*/
1214
1215 maxpacket = max_packet(usb_maxpacket(urb->dev, urb->pipe, 0));
1216
1217 qtd_fill(ehci, qtd, buf, len, token, maxpacket);
1218
1219 /*
1220 * Our IN phase shall always be a short read; so keep the queue running
1221 * and let it advance to the next qtd which zero length OUT status
1222 */
1223 qtd->hw_alt_next = EHCI_LIST_END(ehci);
1224
1225 /* STATUS stage for GetDesc control request */
1226 token ^= 0x0100; /* "in" <--> "out" */
1227 token |= QTD_TOGGLE; /* force DATA1 */
1228
1229 qtd_prev = qtd;
1230 qtd = ehci_qtd_alloc(ehci, GFP_ATOMIC);
1231 if (unlikely(!qtd))
1232 goto cleanup;
1233 qtd->urb = urb;
1234 qtd_prev->hw_next = QTD_NEXT(ehci, qtd->qtd_dma);
1235 list_add_tail(&qtd->qtd_list, head);
1236
1237 /* dont fill any data in such packets */
1238 qtd_fill(ehci, qtd, 0, 0, token, 0);
1239
1240 /* by default, enable interrupt on urb completion */
1241 if (likely(!(urb->transfer_flags & URB_NO_INTERRUPT)))
1242 qtd->hw_token |= cpu_to_hc32(ehci, QTD_IOC);
1243
1244 submit_async(ehci, urb, &qtd_list, GFP_KERNEL);
1245
1246 return 0;
1247
1248 cleanup:
1249 qtd_list_free(ehci, urb, head);
1250 return -1;
1251 }
1252 #endif /* CONFIG_USB_HCD_TEST_MODE */
1253
1254 /*-------------------------------------------------------------------------*/
1255
single_unlink_async(struct ehci_hcd * ehci,struct ehci_qh * qh)1256 static void single_unlink_async(struct ehci_hcd *ehci, struct ehci_qh *qh)
1257 {
1258 struct ehci_qh *prev;
1259
1260 /* Add to the end of the list of QHs waiting for the next IAAD */
1261 qh->qh_state = QH_STATE_UNLINK_WAIT;
1262 list_add_tail(&qh->unlink_node, &ehci->async_unlink);
1263
1264 /* Unlink it from the schedule */
1265 prev = ehci->async;
1266 while (prev->qh_next.qh != qh)
1267 prev = prev->qh_next.qh;
1268
1269 prev->hw->hw_next = qh->hw->hw_next;
1270 prev->qh_next = qh->qh_next;
1271 if (ehci->qh_scan_next == qh)
1272 ehci->qh_scan_next = qh->qh_next.qh;
1273 }
1274
start_iaa_cycle(struct ehci_hcd * ehci)1275 static void start_iaa_cycle(struct ehci_hcd *ehci)
1276 {
1277 /* Do nothing if an IAA cycle is already running */
1278 if (ehci->iaa_in_progress)
1279 return;
1280 ehci->iaa_in_progress = true;
1281
1282 /* If the controller isn't running, we don't have to wait for it */
1283 if (unlikely(ehci->rh_state < EHCI_RH_RUNNING)) {
1284 end_unlink_async(ehci);
1285
1286 /* Otherwise start a new IAA cycle */
1287 } else if (likely(ehci->rh_state == EHCI_RH_RUNNING)) {
1288
1289 /* Make sure the unlinks are all visible to the hardware */
1290 wmb();
1291
1292 ehci_writel(ehci, ehci->command | CMD_IAAD,
1293 &ehci->regs->command);
1294 ehci_readl(ehci, &ehci->regs->command);
1295 ehci_enable_event(ehci, EHCI_HRTIMER_IAA_WATCHDOG, true);
1296 }
1297 }
1298
1299 /* the async qh for the qtds being unlinked are now gone from the HC */
1300
end_unlink_async(struct ehci_hcd * ehci)1301 static void end_unlink_async(struct ehci_hcd *ehci)
1302 {
1303 struct ehci_qh *qh;
1304 bool early_exit;
1305
1306 if (ehci->has_synopsys_hc_bug)
1307 ehci_writel(ehci, (u32) ehci->async->qh_dma,
1308 &ehci->regs->async_next);
1309
1310 /* The current IAA cycle has ended */
1311 ehci->iaa_in_progress = false;
1312
1313 if (list_empty(&ehci->async_unlink))
1314 return;
1315 qh = list_first_entry(&ehci->async_unlink, struct ehci_qh,
1316 unlink_node); /* QH whose IAA cycle just ended */
1317
1318 /*
1319 * If async_unlinking is set then this routine is already running,
1320 * either on the stack or on another CPU.
1321 */
1322 early_exit = ehci->async_unlinking;
1323
1324 /* If the controller isn't running, process all the waiting QHs */
1325 if (ehci->rh_state < EHCI_RH_RUNNING)
1326 list_splice_tail_init(&ehci->async_unlink, &ehci->async_idle);
1327
1328 /*
1329 * Intel (?) bug: The HC can write back the overlay region even
1330 * after the IAA interrupt occurs. In self-defense, always go
1331 * through two IAA cycles for each QH.
1332 */
1333 else if (qh->qh_state == QH_STATE_UNLINK_WAIT) {
1334 qh->qh_state = QH_STATE_UNLINK;
1335 early_exit = true;
1336 }
1337
1338 /* Otherwise process only the first waiting QH (NVIDIA bug?) */
1339 else
1340 list_move_tail(&qh->unlink_node, &ehci->async_idle);
1341
1342 /* Start a new IAA cycle if any QHs are waiting for it */
1343 if (!list_empty(&ehci->async_unlink))
1344 start_iaa_cycle(ehci);
1345
1346 /*
1347 * Don't allow nesting or concurrent calls,
1348 * or wait for the second IAA cycle for the next QH.
1349 */
1350 if (early_exit)
1351 return;
1352
1353 /* Process the idle QHs */
1354 ehci->async_unlinking = true;
1355 while (!list_empty(&ehci->async_idle)) {
1356 qh = list_first_entry(&ehci->async_idle, struct ehci_qh,
1357 unlink_node);
1358 list_del(&qh->unlink_node);
1359
1360 qh->qh_state = QH_STATE_IDLE;
1361 qh->qh_next.qh = NULL;
1362
1363 if (!list_empty(&qh->qtd_list))
1364 qh_completions(ehci, qh);
1365 if (!list_empty(&qh->qtd_list) &&
1366 ehci->rh_state == EHCI_RH_RUNNING)
1367 qh_link_async(ehci, qh);
1368 disable_async(ehci);
1369 }
1370 ehci->async_unlinking = false;
1371 }
1372
1373 static void start_unlink_async(struct ehci_hcd *ehci, struct ehci_qh *qh);
1374
unlink_empty_async(struct ehci_hcd * ehci)1375 static void unlink_empty_async(struct ehci_hcd *ehci)
1376 {
1377 struct ehci_qh *qh;
1378 struct ehci_qh *qh_to_unlink = NULL;
1379 int count = 0;
1380
1381 /* Find the last async QH which has been empty for a timer cycle */
1382 for (qh = ehci->async->qh_next.qh; qh; qh = qh->qh_next.qh) {
1383 if (list_empty(&qh->qtd_list) &&
1384 qh->qh_state == QH_STATE_LINKED) {
1385 ++count;
1386 if (qh->unlink_cycle != ehci->async_unlink_cycle)
1387 qh_to_unlink = qh;
1388 }
1389 }
1390
1391 /* If nothing else is being unlinked, unlink the last empty QH */
1392 if (list_empty(&ehci->async_unlink) && qh_to_unlink) {
1393 start_unlink_async(ehci, qh_to_unlink);
1394 --count;
1395 }
1396
1397 /* Other QHs will be handled later */
1398 if (count > 0) {
1399 ehci_enable_event(ehci, EHCI_HRTIMER_ASYNC_UNLINKS, true);
1400 ++ehci->async_unlink_cycle;
1401 }
1402 }
1403
1404 /* The root hub is suspended; unlink all the async QHs */
unlink_empty_async_suspended(struct ehci_hcd * ehci)1405 static void __maybe_unused unlink_empty_async_suspended(struct ehci_hcd *ehci)
1406 {
1407 struct ehci_qh *qh;
1408
1409 while (ehci->async->qh_next.qh) {
1410 qh = ehci->async->qh_next.qh;
1411 WARN_ON(!list_empty(&qh->qtd_list));
1412 single_unlink_async(ehci, qh);
1413 }
1414 start_iaa_cycle(ehci);
1415 }
1416
1417 /* makes sure the async qh will become idle */
1418 /* caller must own ehci->lock */
1419
start_unlink_async(struct ehci_hcd * ehci,struct ehci_qh * qh)1420 static void start_unlink_async(struct ehci_hcd *ehci, struct ehci_qh *qh)
1421 {
1422 /* If the QH isn't linked then there's nothing we can do. */
1423 if (qh->qh_state != QH_STATE_LINKED)
1424 return;
1425
1426 single_unlink_async(ehci, qh);
1427 start_iaa_cycle(ehci);
1428 }
1429
1430 /*-------------------------------------------------------------------------*/
1431
scan_async(struct ehci_hcd * ehci)1432 static void scan_async (struct ehci_hcd *ehci)
1433 {
1434 struct ehci_qh *qh;
1435 bool check_unlinks_later = false;
1436
1437 ehci->qh_scan_next = ehci->async->qh_next.qh;
1438 while (ehci->qh_scan_next) {
1439 qh = ehci->qh_scan_next;
1440 ehci->qh_scan_next = qh->qh_next.qh;
1441
1442 /* clean any finished work for this qh */
1443 if (!list_empty(&qh->qtd_list)) {
1444 int temp;
1445
1446 /*
1447 * Unlinks could happen here; completion reporting
1448 * drops the lock. That's why ehci->qh_scan_next
1449 * always holds the next qh to scan; if the next qh
1450 * gets unlinked then ehci->qh_scan_next is adjusted
1451 * in single_unlink_async().
1452 */
1453 temp = qh_completions(ehci, qh);
1454 if (unlikely(temp)) {
1455 start_unlink_async(ehci, qh);
1456 } else if (list_empty(&qh->qtd_list)
1457 && qh->qh_state == QH_STATE_LINKED) {
1458 qh->unlink_cycle = ehci->async_unlink_cycle;
1459 check_unlinks_later = true;
1460 }
1461 }
1462 }
1463
1464 /*
1465 * Unlink empty entries, reducing DMA usage as well
1466 * as HCD schedule-scanning costs. Delay for any qh
1467 * we just scanned, there's a not-unusual case that it
1468 * doesn't stay idle for long.
1469 */
1470 if (check_unlinks_later && ehci->rh_state == EHCI_RH_RUNNING &&
1471 !(ehci->enabled_hrtimer_events &
1472 BIT(EHCI_HRTIMER_ASYNC_UNLINKS))) {
1473 ehci_enable_event(ehci, EHCI_HRTIMER_ASYNC_UNLINKS, true);
1474 ++ehci->async_unlink_cycle;
1475 }
1476 }
1477