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 /* PID Codes that are used here, from EHCI specification, Table 3-16. */
44 #define PID_CODE_IN 1
45 #define PID_CODE_SETUP 2
46
47 /* fill a qtd, returning how much of the buffer we were able to queue up */
48
49 static int
qtd_fill(struct ehci_hcd * ehci,struct ehci_qtd * qtd,dma_addr_t buf,size_t len,int token,int maxpacket)50 qtd_fill(struct ehci_hcd *ehci, struct ehci_qtd *qtd, dma_addr_t buf,
51 size_t len, int token, int maxpacket)
52 {
53 int i, count;
54 u64 addr = buf;
55
56 /* one buffer entry per 4K ... first might be short or unaligned */
57 qtd->hw_buf[0] = cpu_to_hc32(ehci, (u32)addr);
58 qtd->hw_buf_hi[0] = cpu_to_hc32(ehci, (u32)(addr >> 32));
59 count = 0x1000 - (buf & 0x0fff); /* rest of that page */
60 if (likely (len < count)) /* ... iff needed */
61 count = len;
62 else {
63 buf += 0x1000;
64 buf &= ~0x0fff;
65
66 /* per-qtd limit: from 16K to 20K (best alignment) */
67 for (i = 1; count < len && i < 5; i++) {
68 addr = buf;
69 qtd->hw_buf[i] = cpu_to_hc32(ehci, (u32)addr);
70 qtd->hw_buf_hi[i] = cpu_to_hc32(ehci,
71 (u32)(addr >> 32));
72 buf += 0x1000;
73 if ((count + 0x1000) < len)
74 count += 0x1000;
75 else
76 count = len;
77 }
78
79 /* short packets may only terminate transfers */
80 if (count != len)
81 count -= (count % maxpacket);
82 }
83 qtd->hw_token = cpu_to_hc32(ehci, (count << 16) | token);
84 qtd->length = count;
85
86 return count;
87 }
88
89 /*-------------------------------------------------------------------------*/
90
91 static inline void
qh_update(struct ehci_hcd * ehci,struct ehci_qh * qh,struct ehci_qtd * qtd)92 qh_update (struct ehci_hcd *ehci, struct ehci_qh *qh, struct ehci_qtd *qtd)
93 {
94 struct ehci_qh_hw *hw = qh->hw;
95
96 /* writes to an active overlay are unsafe */
97 WARN_ON(qh->qh_state != QH_STATE_IDLE);
98
99 hw->hw_qtd_next = QTD_NEXT(ehci, qtd->qtd_dma);
100 hw->hw_alt_next = EHCI_LIST_END(ehci);
101
102 /* Except for control endpoints, we make hardware maintain data
103 * toggle (like OHCI) ... here (re)initialize the toggle in the QH,
104 * and set the pseudo-toggle in udev. Only usb_clear_halt() will
105 * ever clear it.
106 */
107 if (!(hw->hw_info1 & cpu_to_hc32(ehci, QH_TOGGLE_CTL))) {
108 unsigned is_out, epnum;
109
110 is_out = qh->is_out;
111 epnum = (hc32_to_cpup(ehci, &hw->hw_info1) >> 8) & 0x0f;
112 if (unlikely(!usb_gettoggle(qh->ps.udev, epnum, is_out))) {
113 hw->hw_token &= ~cpu_to_hc32(ehci, QTD_TOGGLE);
114 usb_settoggle(qh->ps.udev, epnum, is_out, 1);
115 }
116 }
117
118 hw->hw_token &= cpu_to_hc32(ehci, QTD_TOGGLE | QTD_STS_PING);
119 }
120
121 /* if it weren't for a common silicon quirk (writing the dummy into the qh
122 * overlay, so qh->hw_token wrongly becomes inactive/halted), only fault
123 * recovery (including urb dequeue) would need software changes to a QH...
124 */
125 static void
qh_refresh(struct ehci_hcd * ehci,struct ehci_qh * qh)126 qh_refresh (struct ehci_hcd *ehci, struct ehci_qh *qh)
127 {
128 struct ehci_qtd *qtd;
129
130 qtd = list_entry(qh->qtd_list.next, struct ehci_qtd, qtd_list);
131
132 /*
133 * first qtd may already be partially processed.
134 * If we come here during unlink, the QH overlay region
135 * might have reference to the just unlinked qtd. The
136 * qtd is updated in qh_completions(). Update the QH
137 * overlay here.
138 */
139 if (qh->hw->hw_token & ACTIVE_BIT(ehci))
140 qh->hw->hw_qtd_next = qtd->hw_next;
141 else
142 qh_update(ehci, qh, qtd);
143 }
144
145 /*-------------------------------------------------------------------------*/
146
147 static void qh_link_async(struct ehci_hcd *ehci, struct ehci_qh *qh);
148
ehci_clear_tt_buffer_complete(struct usb_hcd * hcd,struct usb_host_endpoint * ep)149 static void ehci_clear_tt_buffer_complete(struct usb_hcd *hcd,
150 struct usb_host_endpoint *ep)
151 {
152 struct ehci_hcd *ehci = hcd_to_ehci(hcd);
153 struct ehci_qh *qh = ep->hcpriv;
154 unsigned long flags;
155
156 spin_lock_irqsave(&ehci->lock, flags);
157 qh->clearing_tt = 0;
158 if (qh->qh_state == QH_STATE_IDLE && !list_empty(&qh->qtd_list)
159 && ehci->rh_state == EHCI_RH_RUNNING)
160 qh_link_async(ehci, qh);
161 spin_unlock_irqrestore(&ehci->lock, flags);
162 }
163
ehci_clear_tt_buffer(struct ehci_hcd * ehci,struct ehci_qh * qh,struct urb * urb,u32 token)164 static void ehci_clear_tt_buffer(struct ehci_hcd *ehci, struct ehci_qh *qh,
165 struct urb *urb, u32 token)
166 {
167
168 /* If an async split transaction gets an error or is unlinked,
169 * the TT buffer may be left in an indeterminate state. We
170 * have to clear the TT buffer.
171 *
172 * Note: this routine is never called for Isochronous transfers.
173 */
174 if (urb->dev->tt && !usb_pipeint(urb->pipe) && !qh->clearing_tt) {
175 #ifdef CONFIG_DYNAMIC_DEBUG
176 struct usb_device *tt = urb->dev->tt->hub;
177 dev_dbg(&tt->dev,
178 "clear tt buffer port %d, a%d ep%d t%08x\n",
179 urb->dev->ttport, urb->dev->devnum,
180 usb_pipeendpoint(urb->pipe), token);
181 #endif /* CONFIG_DYNAMIC_DEBUG */
182 if (!ehci_is_TDI(ehci)
183 || urb->dev->tt->hub !=
184 ehci_to_hcd(ehci)->self.root_hub) {
185 if (usb_hub_clear_tt_buffer(urb) == 0)
186 qh->clearing_tt = 1;
187 } else {
188
189 /* REVISIT ARC-derived cores don't clear the root
190 * hub TT buffer in this way...
191 */
192 }
193 }
194 }
195
qtd_copy_status(struct ehci_hcd * ehci,struct urb * urb,size_t length,u32 token)196 static int qtd_copy_status (
197 struct ehci_hcd *ehci,
198 struct urb *urb,
199 size_t length,
200 u32 token
201 )
202 {
203 int status = -EINPROGRESS;
204
205 /* count IN/OUT bytes, not SETUP (even short packets) */
206 if (likely(QTD_PID(token) != PID_CODE_SETUP))
207 urb->actual_length += length - QTD_LENGTH (token);
208
209 /* don't modify error codes */
210 if (unlikely(urb->unlinked))
211 return status;
212
213 /* force cleanup after short read; not always an error */
214 if (unlikely (IS_SHORT_READ (token)))
215 status = -EREMOTEIO;
216
217 /* serious "can't proceed" faults reported by the hardware */
218 if (token & QTD_STS_HALT) {
219 if (token & QTD_STS_BABBLE) {
220 /* FIXME "must" disable babbling device's port too */
221 status = -EOVERFLOW;
222 /*
223 * When MMF is active and PID Code is IN, queue is halted.
224 * EHCI Specification, Table 4-13.
225 */
226 } else if ((token & QTD_STS_MMF) &&
227 (QTD_PID(token) == PID_CODE_IN)) {
228 status = -EPROTO;
229 /* CERR nonzero + halt --> stall */
230 } else if (QTD_CERR(token)) {
231 status = -EPIPE;
232
233 /* In theory, more than one of the following bits can be set
234 * since they are sticky and the transaction is retried.
235 * Which to test first is rather arbitrary.
236 */
237 } else if (token & QTD_STS_MMF) {
238 /* fs/ls interrupt xfer missed the complete-split */
239 status = -EPROTO;
240 } else if (token & QTD_STS_DBE) {
241 status = (QTD_PID (token) == 1) /* IN ? */
242 ? -ENOSR /* hc couldn't read data */
243 : -ECOMM; /* hc couldn't write data */
244 } else if (token & QTD_STS_XACT) {
245 /* timeout, bad CRC, wrong PID, etc */
246 ehci_dbg(ehci, "devpath %s ep%d%s 3strikes\n",
247 urb->dev->devpath,
248 usb_pipeendpoint(urb->pipe),
249 usb_pipein(urb->pipe) ? "in" : "out");
250 status = -EPROTO;
251 } else { /* unknown */
252 status = -EPROTO;
253 }
254 }
255
256 return status;
257 }
258
259 static void
ehci_urb_done(struct ehci_hcd * ehci,struct urb * urb,int status)260 ehci_urb_done(struct ehci_hcd *ehci, struct urb *urb, int status)
261 {
262 if (usb_pipetype(urb->pipe) == PIPE_INTERRUPT) {
263 /* ... update hc-wide periodic stats */
264 ehci_to_hcd(ehci)->self.bandwidth_int_reqs--;
265 }
266
267 if (unlikely(urb->unlinked)) {
268 COUNT(ehci->stats.unlink);
269 } else {
270 /* report non-error and short read status as zero */
271 if (status == -EINPROGRESS || status == -EREMOTEIO)
272 status = 0;
273 COUNT(ehci->stats.complete);
274 }
275
276 #ifdef EHCI_URB_TRACE
277 ehci_dbg (ehci,
278 "%s %s urb %p ep%d%s status %d len %d/%d\n",
279 __func__, urb->dev->devpath, urb,
280 usb_pipeendpoint (urb->pipe),
281 usb_pipein (urb->pipe) ? "in" : "out",
282 status,
283 urb->actual_length, urb->transfer_buffer_length);
284 #endif
285
286 usb_hcd_unlink_urb_from_ep(ehci_to_hcd(ehci), urb);
287 usb_hcd_giveback_urb(ehci_to_hcd(ehci), urb, status);
288 }
289
290 static int qh_schedule (struct ehci_hcd *ehci, struct ehci_qh *qh);
291
292 /*
293 * Process and free completed qtds for a qh, returning URBs to drivers.
294 * Chases up to qh->hw_current. Returns nonzero if the caller should
295 * unlink qh.
296 */
297 static unsigned
qh_completions(struct ehci_hcd * ehci,struct ehci_qh * qh)298 qh_completions (struct ehci_hcd *ehci, struct ehci_qh *qh)
299 {
300 struct ehci_qtd *last, *end = qh->dummy;
301 struct list_head *entry, *tmp;
302 int last_status;
303 int stopped;
304 u8 state;
305 struct ehci_qh_hw *hw = qh->hw;
306
307 /* completions (or tasks on other cpus) must never clobber HALT
308 * till we've gone through and cleaned everything up, even when
309 * they add urbs to this qh's queue or mark them for unlinking.
310 *
311 * NOTE: unlinking expects to be done in queue order.
312 *
313 * It's a bug for qh->qh_state to be anything other than
314 * QH_STATE_IDLE, unless our caller is scan_async() or
315 * scan_intr().
316 */
317 state = qh->qh_state;
318 qh->qh_state = QH_STATE_COMPLETING;
319 stopped = (state == QH_STATE_IDLE);
320
321 rescan:
322 last = NULL;
323 last_status = -EINPROGRESS;
324 qh->dequeue_during_giveback = 0;
325
326 /* remove de-activated QTDs from front of queue.
327 * after faults (including short reads), cleanup this urb
328 * then let the queue advance.
329 * if queue is stopped, handles unlinks.
330 */
331 list_for_each_safe (entry, tmp, &qh->qtd_list) {
332 struct ehci_qtd *qtd;
333 struct urb *urb;
334 u32 token = 0;
335
336 qtd = list_entry (entry, struct ehci_qtd, qtd_list);
337 urb = qtd->urb;
338
339 /* clean up any state from previous QTD ...*/
340 if (last) {
341 if (likely (last->urb != urb)) {
342 ehci_urb_done(ehci, last->urb, last_status);
343 last_status = -EINPROGRESS;
344 }
345 ehci_qtd_free (ehci, last);
346 last = NULL;
347 }
348
349 /* ignore urbs submitted during completions we reported */
350 if (qtd == end)
351 break;
352
353 /* hardware copies qtd out of qh overlay */
354 rmb ();
355 token = hc32_to_cpu(ehci, qtd->hw_token);
356
357 /* always clean up qtds the hc de-activated */
358 retry_xacterr:
359 if ((token & QTD_STS_ACTIVE) == 0) {
360
361 /* Report Data Buffer Error: non-fatal but useful */
362 if (token & QTD_STS_DBE)
363 ehci_dbg(ehci,
364 "detected DataBufferErr for urb %p ep%d%s len %d, qtd %p [qh %p]\n",
365 urb,
366 usb_endpoint_num(&urb->ep->desc),
367 usb_endpoint_dir_in(&urb->ep->desc) ? "in" : "out",
368 urb->transfer_buffer_length,
369 qtd,
370 qh);
371
372 /* on STALL, error, and short reads this urb must
373 * complete and all its qtds must be recycled.
374 */
375 if ((token & QTD_STS_HALT) != 0) {
376
377 /* retry transaction errors until we
378 * reach the software xacterr limit
379 */
380 if ((token & QTD_STS_XACT) &&
381 QTD_CERR(token) == 0 &&
382 ++qh->xacterrs < QH_XACTERR_MAX &&
383 !urb->unlinked) {
384 ehci_dbg(ehci,
385 "detected XactErr len %zu/%zu retry %d\n",
386 qtd->length - QTD_LENGTH(token), qtd->length, qh->xacterrs);
387
388 /* reset the token in the qtd and the
389 * qh overlay (which still contains
390 * the qtd) so that we pick up from
391 * where we left off
392 */
393 token &= ~QTD_STS_HALT;
394 token |= QTD_STS_ACTIVE |
395 (EHCI_TUNE_CERR << 10);
396 qtd->hw_token = cpu_to_hc32(ehci,
397 token);
398 wmb();
399 hw->hw_token = cpu_to_hc32(ehci,
400 token);
401 goto retry_xacterr;
402 }
403 stopped = 1;
404
405 /* magic dummy for some short reads; qh won't advance.
406 * that silicon quirk can kick in with this dummy too.
407 *
408 * other short reads won't stop the queue, including
409 * control transfers (status stage handles that) or
410 * most other single-qtd reads ... the queue stops if
411 * URB_SHORT_NOT_OK was set so the driver submitting
412 * the urbs could clean it up.
413 */
414 } else if (IS_SHORT_READ (token)
415 && !(qtd->hw_alt_next
416 & EHCI_LIST_END(ehci))) {
417 stopped = 1;
418 }
419
420 /* stop scanning when we reach qtds the hc is using */
421 } else if (likely (!stopped
422 && ehci->rh_state >= EHCI_RH_RUNNING)) {
423 break;
424
425 /* scan the whole queue for unlinks whenever it stops */
426 } else {
427 stopped = 1;
428
429 /* cancel everything if we halt, suspend, etc */
430 if (ehci->rh_state < EHCI_RH_RUNNING)
431 last_status = -ESHUTDOWN;
432
433 /* this qtd is active; skip it unless a previous qtd
434 * for its urb faulted, or its urb was canceled.
435 */
436 else if (last_status == -EINPROGRESS && !urb->unlinked)
437 continue;
438
439 /*
440 * If this was the active qtd when the qh was unlinked
441 * and the overlay's token is active, then the overlay
442 * hasn't been written back to the qtd yet so use its
443 * token instead of the qtd's. After the qtd is
444 * processed and removed, the overlay won't be valid
445 * any more.
446 */
447 if (state == QH_STATE_IDLE &&
448 qh->qtd_list.next == &qtd->qtd_list &&
449 (hw->hw_token & ACTIVE_BIT(ehci))) {
450 token = hc32_to_cpu(ehci, hw->hw_token);
451 hw->hw_token &= ~ACTIVE_BIT(ehci);
452
453 /* An unlink may leave an incomplete
454 * async transaction in the TT buffer.
455 * We have to clear it.
456 */
457 ehci_clear_tt_buffer(ehci, qh, urb, token);
458 }
459 }
460
461 /* unless we already know the urb's status, collect qtd status
462 * and update count of bytes transferred. in common short read
463 * cases with only one data qtd (including control transfers),
464 * queue processing won't halt. but with two or more qtds (for
465 * example, with a 32 KB transfer), when the first qtd gets a
466 * short read the second must be removed by hand.
467 */
468 if (last_status == -EINPROGRESS) {
469 last_status = qtd_copy_status(ehci, urb,
470 qtd->length, token);
471 if (last_status == -EREMOTEIO
472 && (qtd->hw_alt_next
473 & EHCI_LIST_END(ehci)))
474 last_status = -EINPROGRESS;
475
476 /* As part of low/full-speed endpoint-halt processing
477 * we must clear the TT buffer (11.17.5).
478 */
479 if (unlikely(last_status != -EINPROGRESS &&
480 last_status != -EREMOTEIO)) {
481 /* The TT's in some hubs malfunction when they
482 * receive this request following a STALL (they
483 * stop sending isochronous packets). Since a
484 * STALL can't leave the TT buffer in a busy
485 * state (if you believe Figures 11-48 - 11-51
486 * in the USB 2.0 spec), we won't clear the TT
487 * buffer in this case. Strictly speaking this
488 * is a violation of the spec.
489 */
490 if (last_status != -EPIPE)
491 ehci_clear_tt_buffer(ehci, qh, urb,
492 token);
493 }
494 }
495
496 /* if we're removing something not at the queue head,
497 * patch the hardware queue pointer.
498 */
499 if (stopped && qtd->qtd_list.prev != &qh->qtd_list) {
500 last = list_entry (qtd->qtd_list.prev,
501 struct ehci_qtd, qtd_list);
502 last->hw_next = qtd->hw_next;
503 }
504
505 /* remove qtd; it's recycled after possible urb completion */
506 list_del (&qtd->qtd_list);
507 last = qtd;
508
509 /* reinit the xacterr counter for the next qtd */
510 qh->xacterrs = 0;
511 }
512
513 /* last urb's completion might still need calling */
514 if (likely (last != NULL)) {
515 ehci_urb_done(ehci, last->urb, last_status);
516 ehci_qtd_free (ehci, last);
517 }
518
519 /* Do we need to rescan for URBs dequeued during a giveback? */
520 if (unlikely(qh->dequeue_during_giveback)) {
521 /* If the QH is already unlinked, do the rescan now. */
522 if (state == QH_STATE_IDLE)
523 goto rescan;
524
525 /* Otherwise the caller must unlink the QH. */
526 }
527
528 /* restore original state; caller must unlink or relink */
529 qh->qh_state = state;
530
531 /* be sure the hardware's done with the qh before refreshing
532 * it after fault cleanup, or recovering from silicon wrongly
533 * overlaying the dummy qtd (which reduces DMA chatter).
534 *
535 * We won't refresh a QH that's linked (after the HC
536 * stopped the queue). That avoids a race:
537 * - HC reads first part of QH;
538 * - CPU updates that first part and the token;
539 * - HC reads rest of that QH, including token
540 * Result: HC gets an inconsistent image, and then
541 * DMAs to/from the wrong memory (corrupting it).
542 *
543 * That should be rare for interrupt transfers,
544 * except maybe high bandwidth ...
545 */
546 if (stopped != 0 || hw->hw_qtd_next == EHCI_LIST_END(ehci))
547 qh->exception = 1;
548
549 /* Let the caller know if the QH needs to be unlinked. */
550 return qh->exception;
551 }
552
553 /*-------------------------------------------------------------------------*/
554
555 // high bandwidth multiplier, as encoded in highspeed endpoint descriptors
556 #define hb_mult(wMaxPacketSize) (1 + (((wMaxPacketSize) >> 11) & 0x03))
557 // ... and packet size, for any kind of endpoint descriptor
558 #define max_packet(wMaxPacketSize) ((wMaxPacketSize) & 0x07ff)
559
560 /*
561 * reverse of qh_urb_transaction: free a list of TDs.
562 * used for cleanup after errors, before HC sees an URB's TDs.
563 */
qtd_list_free(struct ehci_hcd * ehci,struct urb * urb,struct list_head * qtd_list)564 static void qtd_list_free (
565 struct ehci_hcd *ehci,
566 struct urb *urb,
567 struct list_head *qtd_list
568 ) {
569 struct list_head *entry, *temp;
570
571 list_for_each_safe (entry, temp, qtd_list) {
572 struct ehci_qtd *qtd;
573
574 qtd = list_entry (entry, struct ehci_qtd, qtd_list);
575 list_del (&qtd->qtd_list);
576 ehci_qtd_free (ehci, qtd);
577 }
578 }
579
580 /*
581 * create a list of filled qtds for this URB; won't link into qh.
582 */
583 static struct list_head *
qh_urb_transaction(struct ehci_hcd * ehci,struct urb * urb,struct list_head * head,gfp_t flags)584 qh_urb_transaction (
585 struct ehci_hcd *ehci,
586 struct urb *urb,
587 struct list_head *head,
588 gfp_t flags
589 ) {
590 struct ehci_qtd *qtd, *qtd_prev;
591 dma_addr_t buf;
592 int len, this_sg_len, maxpacket;
593 int is_input;
594 u32 token;
595 int i;
596 struct scatterlist *sg;
597
598 /*
599 * URBs map to sequences of QTDs: one logical transaction
600 */
601 qtd = ehci_qtd_alloc (ehci, flags);
602 if (unlikely (!qtd))
603 return NULL;
604 list_add_tail (&qtd->qtd_list, head);
605 qtd->urb = urb;
606
607 token = QTD_STS_ACTIVE;
608 token |= (EHCI_TUNE_CERR << 10);
609 /* for split transactions, SplitXState initialized to zero */
610
611 len = urb->transfer_buffer_length;
612 is_input = usb_pipein (urb->pipe);
613 if (usb_pipecontrol (urb->pipe)) {
614 /* SETUP pid */
615 qtd_fill(ehci, qtd, urb->setup_dma,
616 sizeof (struct usb_ctrlrequest),
617 token | (2 /* "setup" */ << 8), 8);
618
619 /* ... and always at least one more pid */
620 token ^= QTD_TOGGLE;
621 qtd_prev = qtd;
622 qtd = ehci_qtd_alloc (ehci, flags);
623 if (unlikely (!qtd))
624 goto cleanup;
625 qtd->urb = urb;
626 qtd_prev->hw_next = QTD_NEXT(ehci, qtd->qtd_dma);
627 list_add_tail (&qtd->qtd_list, head);
628
629 /* for zero length DATA stages, STATUS is always IN */
630 if (len == 0)
631 token |= (1 /* "in" */ << 8);
632 }
633
634 /*
635 * data transfer stage: buffer setup
636 */
637 i = urb->num_mapped_sgs;
638 if (len > 0 && i > 0) {
639 sg = urb->sg;
640 buf = sg_dma_address(sg);
641
642 /* urb->transfer_buffer_length may be smaller than the
643 * size of the scatterlist (or vice versa)
644 */
645 this_sg_len = min_t(int, sg_dma_len(sg), len);
646 } else {
647 sg = NULL;
648 buf = urb->transfer_dma;
649 this_sg_len = len;
650 }
651
652 if (is_input)
653 token |= (1 /* "in" */ << 8);
654 /* else it's already initted to "out" pid (0 << 8) */
655
656 maxpacket = max_packet(usb_maxpacket(urb->dev, urb->pipe, !is_input));
657
658 /*
659 * buffer gets wrapped in one or more qtds;
660 * last one may be "short" (including zero len)
661 * and may serve as a control status ack
662 */
663 for (;;) {
664 int this_qtd_len;
665
666 this_qtd_len = qtd_fill(ehci, qtd, buf, this_sg_len, token,
667 maxpacket);
668 this_sg_len -= this_qtd_len;
669 len -= this_qtd_len;
670 buf += this_qtd_len;
671
672 /*
673 * short reads advance to a "magic" dummy instead of the next
674 * qtd ... that forces the queue to stop, for manual cleanup.
675 * (this will usually be overridden later.)
676 */
677 if (is_input)
678 qtd->hw_alt_next = ehci->async->hw->hw_alt_next;
679
680 /* qh makes control packets use qtd toggle; maybe switch it */
681 if ((maxpacket & (this_qtd_len + (maxpacket - 1))) == 0)
682 token ^= QTD_TOGGLE;
683
684 if (likely(this_sg_len <= 0)) {
685 if (--i <= 0 || len <= 0)
686 break;
687 sg = sg_next(sg);
688 buf = sg_dma_address(sg);
689 this_sg_len = min_t(int, sg_dma_len(sg), len);
690 }
691
692 qtd_prev = qtd;
693 qtd = ehci_qtd_alloc (ehci, flags);
694 if (unlikely (!qtd))
695 goto cleanup;
696 qtd->urb = urb;
697 qtd_prev->hw_next = QTD_NEXT(ehci, qtd->qtd_dma);
698 list_add_tail (&qtd->qtd_list, head);
699 }
700
701 /*
702 * unless the caller requires manual cleanup after short reads,
703 * have the alt_next mechanism keep the queue running after the
704 * last data qtd (the only one, for control and most other cases).
705 */
706 if (likely ((urb->transfer_flags & URB_SHORT_NOT_OK) == 0
707 || usb_pipecontrol (urb->pipe)))
708 qtd->hw_alt_next = EHCI_LIST_END(ehci);
709
710 /*
711 * control requests may need a terminating data "status" ack;
712 * other OUT ones may need a terminating short packet
713 * (zero length).
714 */
715 if (likely (urb->transfer_buffer_length != 0)) {
716 int one_more = 0;
717
718 if (usb_pipecontrol (urb->pipe)) {
719 one_more = 1;
720 token ^= 0x0100; /* "in" <--> "out" */
721 token |= QTD_TOGGLE; /* force DATA1 */
722 } else if (usb_pipeout(urb->pipe)
723 && (urb->transfer_flags & URB_ZERO_PACKET)
724 && !(urb->transfer_buffer_length % maxpacket)) {
725 one_more = 1;
726 }
727 if (one_more) {
728 qtd_prev = qtd;
729 qtd = ehci_qtd_alloc (ehci, flags);
730 if (unlikely (!qtd))
731 goto cleanup;
732 qtd->urb = urb;
733 qtd_prev->hw_next = QTD_NEXT(ehci, qtd->qtd_dma);
734 list_add_tail (&qtd->qtd_list, head);
735
736 /* never any data in such packets */
737 qtd_fill(ehci, qtd, 0, 0, token, 0);
738 }
739 }
740
741 /* by default, enable interrupt on urb completion */
742 if (likely (!(urb->transfer_flags & URB_NO_INTERRUPT)))
743 qtd->hw_token |= cpu_to_hc32(ehci, QTD_IOC);
744 return head;
745
746 cleanup:
747 qtd_list_free (ehci, urb, head);
748 return NULL;
749 }
750
751 /*-------------------------------------------------------------------------*/
752
753 // Would be best to create all qh's from config descriptors,
754 // when each interface/altsetting is established. Unlink
755 // any previous qh and cancel its urbs first; endpoints are
756 // implicitly reset then (data toggle too).
757 // That'd mean updating how usbcore talks to HCDs. (2.7?)
758
759
760 /*
761 * Each QH holds a qtd list; a QH is used for everything except iso.
762 *
763 * For interrupt urbs, the scheduler must set the microframe scheduling
764 * mask(s) each time the QH gets scheduled. For highspeed, that's
765 * just one microframe in the s-mask. For split interrupt transactions
766 * there are additional complications: c-mask, maybe FSTNs.
767 */
768 static struct ehci_qh *
qh_make(struct ehci_hcd * ehci,struct urb * urb,gfp_t flags)769 qh_make (
770 struct ehci_hcd *ehci,
771 struct urb *urb,
772 gfp_t flags
773 ) {
774 struct ehci_qh *qh = ehci_qh_alloc (ehci, flags);
775 u32 info1 = 0, info2 = 0;
776 int is_input, type;
777 int maxp = 0;
778 struct usb_tt *tt = urb->dev->tt;
779 struct ehci_qh_hw *hw;
780
781 if (!qh)
782 return qh;
783
784 /*
785 * init endpoint/device data for this QH
786 */
787 info1 |= usb_pipeendpoint (urb->pipe) << 8;
788 info1 |= usb_pipedevice (urb->pipe) << 0;
789
790 is_input = usb_pipein (urb->pipe);
791 type = usb_pipetype (urb->pipe);
792 maxp = usb_maxpacket (urb->dev, urb->pipe, !is_input);
793
794 /* 1024 byte maxpacket is a hardware ceiling. High bandwidth
795 * acts like up to 3KB, but is built from smaller packets.
796 */
797 if (max_packet(maxp) > 1024) {
798 ehci_dbg(ehci, "bogus qh maxpacket %d\n", max_packet(maxp));
799 goto done;
800 }
801
802 /* Compute interrupt scheduling parameters just once, and save.
803 * - allowing for high bandwidth, how many nsec/uframe are used?
804 * - split transactions need a second CSPLIT uframe; same question
805 * - splits also need a schedule gap (for full/low speed I/O)
806 * - qh has a polling interval
807 *
808 * For control/bulk requests, the HC or TT handles these.
809 */
810 if (type == PIPE_INTERRUPT) {
811 unsigned tmp;
812
813 qh->ps.usecs = NS_TO_US(usb_calc_bus_time(USB_SPEED_HIGH,
814 is_input, 0,
815 hb_mult(maxp) * max_packet(maxp)));
816 qh->ps.phase = NO_FRAME;
817
818 if (urb->dev->speed == USB_SPEED_HIGH) {
819 qh->ps.c_usecs = 0;
820 qh->gap_uf = 0;
821
822 if (urb->interval > 1 && urb->interval < 8) {
823 /* NOTE interval 2 or 4 uframes could work.
824 * But interval 1 scheduling is simpler, and
825 * includes high bandwidth.
826 */
827 urb->interval = 1;
828 } else if (urb->interval > ehci->periodic_size << 3) {
829 urb->interval = ehci->periodic_size << 3;
830 }
831 qh->ps.period = urb->interval >> 3;
832
833 /* period for bandwidth allocation */
834 tmp = min_t(unsigned, EHCI_BANDWIDTH_SIZE,
835 1 << (urb->ep->desc.bInterval - 1));
836
837 /* Allow urb->interval to override */
838 qh->ps.bw_uperiod = min_t(unsigned, tmp, urb->interval);
839 qh->ps.bw_period = qh->ps.bw_uperiod >> 3;
840 } else {
841 int think_time;
842
843 /* gap is f(FS/LS transfer times) */
844 qh->gap_uf = 1 + usb_calc_bus_time (urb->dev->speed,
845 is_input, 0, maxp) / (125 * 1000);
846
847 /* FIXME this just approximates SPLIT/CSPLIT times */
848 if (is_input) { // SPLIT, gap, CSPLIT+DATA
849 qh->ps.c_usecs = qh->ps.usecs + HS_USECS(0);
850 qh->ps.usecs = HS_USECS(1);
851 } else { // SPLIT+DATA, gap, CSPLIT
852 qh->ps.usecs += HS_USECS(1);
853 qh->ps.c_usecs = HS_USECS(0);
854 }
855
856 think_time = tt ? tt->think_time : 0;
857 qh->ps.tt_usecs = NS_TO_US(think_time +
858 usb_calc_bus_time (urb->dev->speed,
859 is_input, 0, max_packet (maxp)));
860 if (urb->interval > ehci->periodic_size)
861 urb->interval = ehci->periodic_size;
862 qh->ps.period = urb->interval;
863
864 /* period for bandwidth allocation */
865 tmp = min_t(unsigned, EHCI_BANDWIDTH_FRAMES,
866 urb->ep->desc.bInterval);
867 tmp = rounddown_pow_of_two(tmp);
868
869 /* Allow urb->interval to override */
870 qh->ps.bw_period = min_t(unsigned, tmp, urb->interval);
871 qh->ps.bw_uperiod = qh->ps.bw_period << 3;
872 }
873 }
874
875 /* support for tt scheduling, and access to toggles */
876 qh->ps.udev = urb->dev;
877 qh->ps.ep = urb->ep;
878
879 /* using TT? */
880 switch (urb->dev->speed) {
881 case USB_SPEED_LOW:
882 info1 |= QH_LOW_SPEED;
883 /* FALL THROUGH */
884
885 case USB_SPEED_FULL:
886 /* EPS 0 means "full" */
887 if (type != PIPE_INTERRUPT)
888 info1 |= (EHCI_TUNE_RL_TT << 28);
889 if (type == PIPE_CONTROL) {
890 info1 |= QH_CONTROL_EP; /* for TT */
891 info1 |= QH_TOGGLE_CTL; /* toggle from qtd */
892 }
893 info1 |= maxp << 16;
894
895 info2 |= (EHCI_TUNE_MULT_TT << 30);
896
897 /* Some Freescale processors have an erratum in which the
898 * port number in the queue head was 0..N-1 instead of 1..N.
899 */
900 if (ehci_has_fsl_portno_bug(ehci))
901 info2 |= (urb->dev->ttport-1) << 23;
902 else
903 info2 |= urb->dev->ttport << 23;
904
905 /* set the address of the TT; for TDI's integrated
906 * root hub tt, leave it zeroed.
907 */
908 if (tt && tt->hub != ehci_to_hcd(ehci)->self.root_hub)
909 info2 |= tt->hub->devnum << 16;
910
911 /* NOTE: if (PIPE_INTERRUPT) { scheduler sets c-mask } */
912
913 break;
914
915 case USB_SPEED_HIGH: /* no TT involved */
916 info1 |= QH_HIGH_SPEED;
917 if (type == PIPE_CONTROL) {
918 info1 |= (EHCI_TUNE_RL_HS << 28);
919 info1 |= 64 << 16; /* usb2 fixed maxpacket */
920 info1 |= QH_TOGGLE_CTL; /* toggle from qtd */
921 info2 |= (EHCI_TUNE_MULT_HS << 30);
922 } else if (type == PIPE_BULK) {
923 info1 |= (EHCI_TUNE_RL_HS << 28);
924 /* The USB spec says that high speed bulk endpoints
925 * always use 512 byte maxpacket. But some device
926 * vendors decided to ignore that, and MSFT is happy
927 * to help them do so. So now people expect to use
928 * such nonconformant devices with Linux too; sigh.
929 */
930 info1 |= max_packet(maxp) << 16;
931 info2 |= (EHCI_TUNE_MULT_HS << 30);
932 } else { /* PIPE_INTERRUPT */
933 info1 |= max_packet (maxp) << 16;
934 info2 |= hb_mult (maxp) << 30;
935 }
936 break;
937 default:
938 ehci_dbg(ehci, "bogus dev %p speed %d\n", urb->dev,
939 urb->dev->speed);
940 done:
941 qh_destroy(ehci, qh);
942 return NULL;
943 }
944
945 /* NOTE: if (PIPE_INTERRUPT) { scheduler sets s-mask } */
946
947 /* init as live, toggle clear */
948 qh->qh_state = QH_STATE_IDLE;
949 hw = qh->hw;
950 hw->hw_info1 = cpu_to_hc32(ehci, info1);
951 hw->hw_info2 = cpu_to_hc32(ehci, info2);
952 qh->is_out = !is_input;
953 usb_settoggle (urb->dev, usb_pipeendpoint (urb->pipe), !is_input, 1);
954 return qh;
955 }
956
957 /*-------------------------------------------------------------------------*/
958
enable_async(struct ehci_hcd * ehci)959 static void enable_async(struct ehci_hcd *ehci)
960 {
961 if (ehci->async_count++)
962 return;
963
964 /* Stop waiting to turn off the async schedule */
965 ehci->enabled_hrtimer_events &= ~BIT(EHCI_HRTIMER_DISABLE_ASYNC);
966
967 /* Don't start the schedule until ASS is 0 */
968 ehci_poll_ASS(ehci);
969 turn_on_io_watchdog(ehci);
970 }
971
disable_async(struct ehci_hcd * ehci)972 static void disable_async(struct ehci_hcd *ehci)
973 {
974 if (--ehci->async_count)
975 return;
976
977 /* The async schedule and unlink lists are supposed to be empty */
978 WARN_ON(ehci->async->qh_next.qh || !list_empty(&ehci->async_unlink) ||
979 !list_empty(&ehci->async_idle));
980
981 /* Don't turn off the schedule until ASS is 1 */
982 ehci_poll_ASS(ehci);
983 }
984
985 /* move qh (and its qtds) onto async queue; maybe enable queue. */
986
qh_link_async(struct ehci_hcd * ehci,struct ehci_qh * qh)987 static void qh_link_async (struct ehci_hcd *ehci, struct ehci_qh *qh)
988 {
989 __hc32 dma = QH_NEXT(ehci, qh->qh_dma);
990 struct ehci_qh *head;
991
992 /* Don't link a QH if there's a Clear-TT-Buffer pending */
993 if (unlikely(qh->clearing_tt))
994 return;
995
996 WARN_ON(qh->qh_state != QH_STATE_IDLE);
997
998 /* clear halt and/or toggle; and maybe recover from silicon quirk */
999 qh_refresh(ehci, qh);
1000
1001 /* splice right after start */
1002 head = ehci->async;
1003 qh->qh_next = head->qh_next;
1004 qh->hw->hw_next = head->hw->hw_next;
1005 wmb ();
1006
1007 head->qh_next.qh = qh;
1008 head->hw->hw_next = dma;
1009
1010 qh->qh_state = QH_STATE_LINKED;
1011 qh->xacterrs = 0;
1012 qh->exception = 0;
1013 /* qtd completions reported later by interrupt */
1014
1015 enable_async(ehci);
1016 }
1017
1018 /*-------------------------------------------------------------------------*/
1019
1020 /*
1021 * For control/bulk/interrupt, return QH with these TDs appended.
1022 * Allocates and initializes the QH if necessary.
1023 * Returns null if it can't allocate a QH it needs to.
1024 * If the QH has TDs (urbs) already, that's great.
1025 */
qh_append_tds(struct ehci_hcd * ehci,struct urb * urb,struct list_head * qtd_list,int epnum,void ** ptr)1026 static struct ehci_qh *qh_append_tds (
1027 struct ehci_hcd *ehci,
1028 struct urb *urb,
1029 struct list_head *qtd_list,
1030 int epnum,
1031 void **ptr
1032 )
1033 {
1034 struct ehci_qh *qh = NULL;
1035 __hc32 qh_addr_mask = cpu_to_hc32(ehci, 0x7f);
1036
1037 qh = (struct ehci_qh *) *ptr;
1038 if (unlikely (qh == NULL)) {
1039 /* can't sleep here, we have ehci->lock... */
1040 qh = qh_make (ehci, urb, GFP_ATOMIC);
1041 *ptr = qh;
1042 }
1043 if (likely (qh != NULL)) {
1044 struct ehci_qtd *qtd;
1045
1046 if (unlikely (list_empty (qtd_list)))
1047 qtd = NULL;
1048 else
1049 qtd = list_entry (qtd_list->next, struct ehci_qtd,
1050 qtd_list);
1051
1052 /* control qh may need patching ... */
1053 if (unlikely (epnum == 0)) {
1054
1055 /* usb_reset_device() briefly reverts to address 0 */
1056 if (usb_pipedevice (urb->pipe) == 0)
1057 qh->hw->hw_info1 &= ~qh_addr_mask;
1058 }
1059
1060 /* just one way to queue requests: swap with the dummy qtd.
1061 * only hc or qh_refresh() ever modify the overlay.
1062 */
1063 if (likely (qtd != NULL)) {
1064 struct ehci_qtd *dummy;
1065 dma_addr_t dma;
1066 __hc32 token;
1067
1068 /* to avoid racing the HC, use the dummy td instead of
1069 * the first td of our list (becomes new dummy). both
1070 * tds stay deactivated until we're done, when the
1071 * HC is allowed to fetch the old dummy (4.10.2).
1072 */
1073 token = qtd->hw_token;
1074 qtd->hw_token = HALT_BIT(ehci);
1075
1076 dummy = qh->dummy;
1077
1078 dma = dummy->qtd_dma;
1079 *dummy = *qtd;
1080 dummy->qtd_dma = dma;
1081
1082 list_del (&qtd->qtd_list);
1083 list_add (&dummy->qtd_list, qtd_list);
1084 list_splice_tail(qtd_list, &qh->qtd_list);
1085
1086 ehci_qtd_init(ehci, qtd, qtd->qtd_dma);
1087 qh->dummy = qtd;
1088
1089 /* hc must see the new dummy at list end */
1090 dma = qtd->qtd_dma;
1091 qtd = list_entry (qh->qtd_list.prev,
1092 struct ehci_qtd, qtd_list);
1093 qtd->hw_next = QTD_NEXT(ehci, dma);
1094
1095 /* let the hc process these next qtds */
1096 wmb ();
1097 dummy->hw_token = token;
1098
1099 urb->hcpriv = qh;
1100 }
1101 }
1102 return qh;
1103 }
1104
1105 /*-------------------------------------------------------------------------*/
1106
1107 static int
submit_async(struct ehci_hcd * ehci,struct urb * urb,struct list_head * qtd_list,gfp_t mem_flags)1108 submit_async (
1109 struct ehci_hcd *ehci,
1110 struct urb *urb,
1111 struct list_head *qtd_list,
1112 gfp_t mem_flags
1113 ) {
1114 int epnum;
1115 unsigned long flags;
1116 struct ehci_qh *qh = NULL;
1117 int rc;
1118
1119 epnum = urb->ep->desc.bEndpointAddress;
1120
1121 #ifdef EHCI_URB_TRACE
1122 {
1123 struct ehci_qtd *qtd;
1124 qtd = list_entry(qtd_list->next, struct ehci_qtd, qtd_list);
1125 ehci_dbg(ehci,
1126 "%s %s urb %p ep%d%s len %d, qtd %p [qh %p]\n",
1127 __func__, urb->dev->devpath, urb,
1128 epnum & 0x0f, (epnum & USB_DIR_IN) ? "in" : "out",
1129 urb->transfer_buffer_length,
1130 qtd, urb->ep->hcpriv);
1131 }
1132 #endif
1133
1134 spin_lock_irqsave (&ehci->lock, flags);
1135 if (unlikely(!HCD_HW_ACCESSIBLE(ehci_to_hcd(ehci)))) {
1136 rc = -ESHUTDOWN;
1137 goto done;
1138 }
1139 rc = usb_hcd_link_urb_to_ep(ehci_to_hcd(ehci), urb);
1140 if (unlikely(rc))
1141 goto done;
1142
1143 qh = qh_append_tds(ehci, urb, qtd_list, epnum, &urb->ep->hcpriv);
1144 if (unlikely(qh == NULL)) {
1145 usb_hcd_unlink_urb_from_ep(ehci_to_hcd(ehci), urb);
1146 rc = -ENOMEM;
1147 goto done;
1148 }
1149
1150 /* Control/bulk operations through TTs don't need scheduling,
1151 * the HC and TT handle it when the TT has a buffer ready.
1152 */
1153 if (likely (qh->qh_state == QH_STATE_IDLE))
1154 qh_link_async(ehci, qh);
1155 done:
1156 spin_unlock_irqrestore (&ehci->lock, flags);
1157 if (unlikely (qh == NULL))
1158 qtd_list_free (ehci, urb, qtd_list);
1159 return rc;
1160 }
1161
1162 /*-------------------------------------------------------------------------*/
1163 #ifdef CONFIG_USB_HCD_TEST_MODE
1164 /*
1165 * This function creates the qtds and submits them for the
1166 * SINGLE_STEP_SET_FEATURE Test.
1167 * This is done in two parts: first SETUP req for GetDesc is sent then
1168 * 15 seconds later, the IN stage for GetDesc starts to req data from dev
1169 *
1170 * is_setup : i/p arguement decides which of the two stage needs to be
1171 * performed; TRUE - SETUP and FALSE - IN+STATUS
1172 * Returns 0 if success
1173 */
submit_single_step_set_feature(struct usb_hcd * hcd,struct urb * urb,int is_setup)1174 static int submit_single_step_set_feature(
1175 struct usb_hcd *hcd,
1176 struct urb *urb,
1177 int is_setup
1178 ) {
1179 struct ehci_hcd *ehci = hcd_to_ehci(hcd);
1180 struct list_head qtd_list;
1181 struct list_head *head;
1182
1183 struct ehci_qtd *qtd, *qtd_prev;
1184 dma_addr_t buf;
1185 int len, maxpacket;
1186 u32 token;
1187
1188 INIT_LIST_HEAD(&qtd_list);
1189 head = &qtd_list;
1190
1191 /* URBs map to sequences of QTDs: one logical transaction */
1192 qtd = ehci_qtd_alloc(ehci, GFP_KERNEL);
1193 if (unlikely(!qtd))
1194 return -1;
1195 list_add_tail(&qtd->qtd_list, head);
1196 qtd->urb = urb;
1197
1198 token = QTD_STS_ACTIVE;
1199 token |= (EHCI_TUNE_CERR << 10);
1200
1201 len = urb->transfer_buffer_length;
1202 /*
1203 * Check if the request is to perform just the SETUP stage (getDesc)
1204 * as in SINGLE_STEP_SET_FEATURE test, DATA stage (IN) happens
1205 * 15 secs after the setup
1206 */
1207 if (is_setup) {
1208 /* SETUP pid */
1209 qtd_fill(ehci, qtd, urb->setup_dma,
1210 sizeof(struct usb_ctrlrequest),
1211 token | (2 /* "setup" */ << 8), 8);
1212
1213 submit_async(ehci, urb, &qtd_list, GFP_ATOMIC);
1214 return 0; /*Return now; we shall come back after 15 seconds*/
1215 }
1216
1217 /*
1218 * IN: data transfer stage: buffer setup : start the IN txn phase for
1219 * the get_Desc SETUP which was sent 15seconds back
1220 */
1221 token ^= QTD_TOGGLE; /*We need to start IN with DATA-1 Pid-sequence*/
1222 buf = urb->transfer_dma;
1223
1224 token |= (1 /* "in" */ << 8); /*This is IN stage*/
1225
1226 maxpacket = max_packet(usb_maxpacket(urb->dev, urb->pipe, 0));
1227
1228 qtd_fill(ehci, qtd, buf, len, token, maxpacket);
1229
1230 /*
1231 * Our IN phase shall always be a short read; so keep the queue running
1232 * and let it advance to the next qtd which zero length OUT status
1233 */
1234 qtd->hw_alt_next = EHCI_LIST_END(ehci);
1235
1236 /* STATUS stage for GetDesc control request */
1237 token ^= 0x0100; /* "in" <--> "out" */
1238 token |= QTD_TOGGLE; /* force DATA1 */
1239
1240 qtd_prev = qtd;
1241 qtd = ehci_qtd_alloc(ehci, GFP_ATOMIC);
1242 if (unlikely(!qtd))
1243 goto cleanup;
1244 qtd->urb = urb;
1245 qtd_prev->hw_next = QTD_NEXT(ehci, qtd->qtd_dma);
1246 list_add_tail(&qtd->qtd_list, head);
1247
1248 /* dont fill any data in such packets */
1249 qtd_fill(ehci, qtd, 0, 0, token, 0);
1250
1251 /* by default, enable interrupt on urb completion */
1252 if (likely(!(urb->transfer_flags & URB_NO_INTERRUPT)))
1253 qtd->hw_token |= cpu_to_hc32(ehci, QTD_IOC);
1254
1255 submit_async(ehci, urb, &qtd_list, GFP_KERNEL);
1256
1257 return 0;
1258
1259 cleanup:
1260 qtd_list_free(ehci, urb, head);
1261 return -1;
1262 }
1263 #endif /* CONFIG_USB_HCD_TEST_MODE */
1264
1265 /*-------------------------------------------------------------------------*/
1266
single_unlink_async(struct ehci_hcd * ehci,struct ehci_qh * qh)1267 static void single_unlink_async(struct ehci_hcd *ehci, struct ehci_qh *qh)
1268 {
1269 struct ehci_qh *prev;
1270
1271 /* Add to the end of the list of QHs waiting for the next IAAD */
1272 qh->qh_state = QH_STATE_UNLINK_WAIT;
1273 list_add_tail(&qh->unlink_node, &ehci->async_unlink);
1274
1275 /* Unlink it from the schedule */
1276 prev = ehci->async;
1277 while (prev->qh_next.qh != qh)
1278 prev = prev->qh_next.qh;
1279
1280 prev->hw->hw_next = qh->hw->hw_next;
1281 prev->qh_next = qh->qh_next;
1282 if (ehci->qh_scan_next == qh)
1283 ehci->qh_scan_next = qh->qh_next.qh;
1284 }
1285
start_iaa_cycle(struct ehci_hcd * ehci)1286 static void start_iaa_cycle(struct ehci_hcd *ehci)
1287 {
1288 /* Do nothing if an IAA cycle is already running */
1289 if (ehci->iaa_in_progress)
1290 return;
1291 ehci->iaa_in_progress = true;
1292
1293 /* If the controller isn't running, we don't have to wait for it */
1294 if (unlikely(ehci->rh_state < EHCI_RH_RUNNING)) {
1295 end_unlink_async(ehci);
1296
1297 /* Otherwise start a new IAA cycle */
1298 } else if (likely(ehci->rh_state == EHCI_RH_RUNNING)) {
1299
1300 /* Make sure the unlinks are all visible to the hardware */
1301 wmb();
1302
1303 ehci_writel(ehci, ehci->command | CMD_IAAD,
1304 &ehci->regs->command);
1305 ehci_readl(ehci, &ehci->regs->command);
1306 ehci_enable_event(ehci, EHCI_HRTIMER_IAA_WATCHDOG, true);
1307 }
1308 }
1309
1310 /* the async qh for the qtds being unlinked are now gone from the HC */
1311
end_unlink_async(struct ehci_hcd * ehci)1312 static void end_unlink_async(struct ehci_hcd *ehci)
1313 {
1314 struct ehci_qh *qh;
1315 bool early_exit;
1316
1317 if (ehci->has_synopsys_hc_bug)
1318 ehci_writel(ehci, (u32) ehci->async->qh_dma,
1319 &ehci->regs->async_next);
1320
1321 /* The current IAA cycle has ended */
1322 ehci->iaa_in_progress = false;
1323
1324 if (list_empty(&ehci->async_unlink))
1325 return;
1326 qh = list_first_entry(&ehci->async_unlink, struct ehci_qh,
1327 unlink_node); /* QH whose IAA cycle just ended */
1328
1329 /*
1330 * If async_unlinking is set then this routine is already running,
1331 * either on the stack or on another CPU.
1332 */
1333 early_exit = ehci->async_unlinking;
1334
1335 /* If the controller isn't running, process all the waiting QHs */
1336 if (ehci->rh_state < EHCI_RH_RUNNING)
1337 list_splice_tail_init(&ehci->async_unlink, &ehci->async_idle);
1338
1339 /*
1340 * Intel (?) bug: The HC can write back the overlay region even
1341 * after the IAA interrupt occurs. In self-defense, always go
1342 * through two IAA cycles for each QH.
1343 */
1344 else if (qh->qh_state == QH_STATE_UNLINK_WAIT) {
1345 qh->qh_state = QH_STATE_UNLINK;
1346 early_exit = true;
1347 }
1348
1349 /* Otherwise process only the first waiting QH (NVIDIA bug?) */
1350 else
1351 list_move_tail(&qh->unlink_node, &ehci->async_idle);
1352
1353 /* Start a new IAA cycle if any QHs are waiting for it */
1354 if (!list_empty(&ehci->async_unlink))
1355 start_iaa_cycle(ehci);
1356
1357 /*
1358 * Don't allow nesting or concurrent calls,
1359 * or wait for the second IAA cycle for the next QH.
1360 */
1361 if (early_exit)
1362 return;
1363
1364 /* Process the idle QHs */
1365 ehci->async_unlinking = true;
1366 while (!list_empty(&ehci->async_idle)) {
1367 qh = list_first_entry(&ehci->async_idle, struct ehci_qh,
1368 unlink_node);
1369 list_del(&qh->unlink_node);
1370
1371 qh->qh_state = QH_STATE_IDLE;
1372 qh->qh_next.qh = NULL;
1373
1374 if (!list_empty(&qh->qtd_list))
1375 qh_completions(ehci, qh);
1376 if (!list_empty(&qh->qtd_list) &&
1377 ehci->rh_state == EHCI_RH_RUNNING)
1378 qh_link_async(ehci, qh);
1379 disable_async(ehci);
1380 }
1381 ehci->async_unlinking = false;
1382 }
1383
1384 static void start_unlink_async(struct ehci_hcd *ehci, struct ehci_qh *qh);
1385
unlink_empty_async(struct ehci_hcd * ehci)1386 static void unlink_empty_async(struct ehci_hcd *ehci)
1387 {
1388 struct ehci_qh *qh;
1389 struct ehci_qh *qh_to_unlink = NULL;
1390 int count = 0;
1391
1392 /* Find the last async QH which has been empty for a timer cycle */
1393 for (qh = ehci->async->qh_next.qh; qh; qh = qh->qh_next.qh) {
1394 if (list_empty(&qh->qtd_list) &&
1395 qh->qh_state == QH_STATE_LINKED) {
1396 ++count;
1397 if (qh->unlink_cycle != ehci->async_unlink_cycle)
1398 qh_to_unlink = qh;
1399 }
1400 }
1401
1402 /* If nothing else is being unlinked, unlink the last empty QH */
1403 if (list_empty(&ehci->async_unlink) && qh_to_unlink) {
1404 start_unlink_async(ehci, qh_to_unlink);
1405 --count;
1406 }
1407
1408 /* Other QHs will be handled later */
1409 if (count > 0) {
1410 ehci_enable_event(ehci, EHCI_HRTIMER_ASYNC_UNLINKS, true);
1411 ++ehci->async_unlink_cycle;
1412 }
1413 }
1414
1415 /* The root hub is suspended; unlink all the async QHs */
unlink_empty_async_suspended(struct ehci_hcd * ehci)1416 static void __maybe_unused unlink_empty_async_suspended(struct ehci_hcd *ehci)
1417 {
1418 struct ehci_qh *qh;
1419
1420 while (ehci->async->qh_next.qh) {
1421 qh = ehci->async->qh_next.qh;
1422 WARN_ON(!list_empty(&qh->qtd_list));
1423 single_unlink_async(ehci, qh);
1424 }
1425 start_iaa_cycle(ehci);
1426 }
1427
1428 /* makes sure the async qh will become idle */
1429 /* caller must own ehci->lock */
1430
start_unlink_async(struct ehci_hcd * ehci,struct ehci_qh * qh)1431 static void start_unlink_async(struct ehci_hcd *ehci, struct ehci_qh *qh)
1432 {
1433 /* If the QH isn't linked then there's nothing we can do. */
1434 if (qh->qh_state != QH_STATE_LINKED)
1435 return;
1436
1437 single_unlink_async(ehci, qh);
1438 start_iaa_cycle(ehci);
1439 }
1440
1441 /*-------------------------------------------------------------------------*/
1442
scan_async(struct ehci_hcd * ehci)1443 static void scan_async (struct ehci_hcd *ehci)
1444 {
1445 struct ehci_qh *qh;
1446 bool check_unlinks_later = false;
1447
1448 ehci->qh_scan_next = ehci->async->qh_next.qh;
1449 while (ehci->qh_scan_next) {
1450 qh = ehci->qh_scan_next;
1451 ehci->qh_scan_next = qh->qh_next.qh;
1452
1453 /* clean any finished work for this qh */
1454 if (!list_empty(&qh->qtd_list)) {
1455 int temp;
1456
1457 /*
1458 * Unlinks could happen here; completion reporting
1459 * drops the lock. That's why ehci->qh_scan_next
1460 * always holds the next qh to scan; if the next qh
1461 * gets unlinked then ehci->qh_scan_next is adjusted
1462 * in single_unlink_async().
1463 */
1464 temp = qh_completions(ehci, qh);
1465 if (unlikely(temp)) {
1466 start_unlink_async(ehci, qh);
1467 } else if (list_empty(&qh->qtd_list)
1468 && qh->qh_state == QH_STATE_LINKED) {
1469 qh->unlink_cycle = ehci->async_unlink_cycle;
1470 check_unlinks_later = true;
1471 }
1472 }
1473 }
1474
1475 /*
1476 * Unlink empty entries, reducing DMA usage as well
1477 * as HCD schedule-scanning costs. Delay for any qh
1478 * we just scanned, there's a not-unusual case that it
1479 * doesn't stay idle for long.
1480 */
1481 if (check_unlinks_later && ehci->rh_state == EHCI_RH_RUNNING &&
1482 !(ehci->enabled_hrtimer_events &
1483 BIT(EHCI_HRTIMER_ASYNC_UNLINKS))) {
1484 ehci_enable_event(ehci, EHCI_HRTIMER_ASYNC_UNLINKS, true);
1485 ++ehci->async_unlink_cycle;
1486 }
1487 }
1488