1 // SPDX-License-Identifier: GPL-2.0+
2 /*
3 * Copyright (C) 2001-2004 by David Brownell
4 */
5
6 /* this file is part of ehci-hcd.c */
7
8 /*-------------------------------------------------------------------------*/
9
10 /*
11 * EHCI hardware queue manipulation ... the core. QH/QTD manipulation.
12 *
13 * Control, bulk, and interrupt traffic all use "qh" lists. They list "qtd"
14 * entries describing USB transactions, max 16-20kB/entry (with 4kB-aligned
15 * buffers needed for the larger number). We use one QH per endpoint, queue
16 * multiple urbs (all three types) per endpoint. URBs may need several qtds.
17 *
18 * ISO traffic uses "ISO TD" (itd, and sitd) records, and (along with
19 * interrupts) needs careful scheduling. Performance improvements can be
20 * an ongoing challenge. That's in "ehci-sched.c".
21 *
22 * USB 1.1 devices are handled (a) by "companion" OHCI or UHCI root hubs,
23 * or otherwise through transaction translators (TTs) in USB 2.0 hubs using
24 * (b) special fields in qh entries or (c) split iso entries. TTs will
25 * buffer low/full speed data so the host collects it at high speed.
26 */
27
28 /*-------------------------------------------------------------------------*/
29
30 /* PID Codes that are used here, from EHCI specification, Table 3-16. */
31 #define PID_CODE_IN 1
32 #define PID_CODE_SETUP 2
33
34 /* fill a qtd, returning how much of the buffer we were able to queue up */
35
36 static unsigned int
qtd_fill(struct ehci_hcd * ehci,struct ehci_qtd * qtd,dma_addr_t buf,size_t len,int token,int maxpacket)37 qtd_fill(struct ehci_hcd *ehci, struct ehci_qtd *qtd, dma_addr_t buf,
38 size_t len, int token, int maxpacket)
39 {
40 unsigned int count;
41 u64 addr = buf;
42 int i;
43
44 /* one buffer entry per 4K ... first might be short or unaligned */
45 qtd->hw_buf[0] = cpu_to_hc32(ehci, (u32)addr);
46 qtd->hw_buf_hi[0] = cpu_to_hc32(ehci, (u32)(addr >> 32));
47 count = 0x1000 - (buf & 0x0fff); /* rest of that page */
48 if (likely (len < count)) /* ... iff needed */
49 count = len;
50 else {
51 buf += 0x1000;
52 buf &= ~0x0fff;
53
54 /* per-qtd limit: from 16K to 20K (best alignment) */
55 for (i = 1; count < len && i < 5; i++) {
56 addr = buf;
57 qtd->hw_buf[i] = cpu_to_hc32(ehci, (u32)addr);
58 qtd->hw_buf_hi[i] = cpu_to_hc32(ehci,
59 (u32)(addr >> 32));
60 buf += 0x1000;
61 if ((count + 0x1000) < len)
62 count += 0x1000;
63 else
64 count = len;
65 }
66
67 /* short packets may only terminate transfers */
68 if (count != len)
69 count -= (count % maxpacket);
70 }
71 qtd->hw_token = cpu_to_hc32(ehci, (count << 16) | token);
72 qtd->length = count;
73
74 return count;
75 }
76
77 /*-------------------------------------------------------------------------*/
78
79 static inline void
qh_update(struct ehci_hcd * ehci,struct ehci_qh * qh,struct ehci_qtd * qtd)80 qh_update (struct ehci_hcd *ehci, struct ehci_qh *qh, struct ehci_qtd *qtd)
81 {
82 struct ehci_qh_hw *hw = qh->hw;
83
84 /* writes to an active overlay are unsafe */
85 WARN_ON(qh->qh_state != QH_STATE_IDLE);
86
87 hw->hw_qtd_next = QTD_NEXT(ehci, qtd->qtd_dma);
88 hw->hw_alt_next = EHCI_LIST_END(ehci);
89
90 /* Except for control endpoints, we make hardware maintain data
91 * toggle (like OHCI) ... here (re)initialize the toggle in the QH,
92 * and set the pseudo-toggle in udev. Only usb_clear_halt() will
93 * ever clear it.
94 */
95 if (!(hw->hw_info1 & cpu_to_hc32(ehci, QH_TOGGLE_CTL))) {
96 unsigned is_out, epnum;
97
98 is_out = qh->is_out;
99 epnum = (hc32_to_cpup(ehci, &hw->hw_info1) >> 8) & 0x0f;
100 if (unlikely(!usb_gettoggle(qh->ps.udev, epnum, is_out))) {
101 hw->hw_token &= ~cpu_to_hc32(ehci, QTD_TOGGLE);
102 usb_settoggle(qh->ps.udev, epnum, is_out, 1);
103 }
104 }
105
106 hw->hw_token &= cpu_to_hc32(ehci, QTD_TOGGLE | QTD_STS_PING);
107 }
108
109 /* if it weren't for a common silicon quirk (writing the dummy into the qh
110 * overlay, so qh->hw_token wrongly becomes inactive/halted), only fault
111 * recovery (including urb dequeue) would need software changes to a QH...
112 */
113 static void
qh_refresh(struct ehci_hcd * ehci,struct ehci_qh * qh)114 qh_refresh (struct ehci_hcd *ehci, struct ehci_qh *qh)
115 {
116 struct ehci_qtd *qtd;
117
118 qtd = list_entry(qh->qtd_list.next, struct ehci_qtd, qtd_list);
119
120 /*
121 * first qtd may already be partially processed.
122 * If we come here during unlink, the QH overlay region
123 * might have reference to the just unlinked qtd. The
124 * qtd is updated in qh_completions(). Update the QH
125 * overlay here.
126 */
127 if (qh->hw->hw_token & ACTIVE_BIT(ehci)) {
128 qh->hw->hw_qtd_next = qtd->hw_next;
129 if (qh->should_be_inactive)
130 ehci_warn(ehci, "qh %p should be inactive!\n", qh);
131 } else {
132 qh_update(ehci, qh, qtd);
133 }
134 qh->should_be_inactive = 0;
135 }
136
137 /*-------------------------------------------------------------------------*/
138
139 static void qh_link_async(struct ehci_hcd *ehci, struct ehci_qh *qh);
140
ehci_clear_tt_buffer_complete(struct usb_hcd * hcd,struct usb_host_endpoint * ep)141 static void ehci_clear_tt_buffer_complete(struct usb_hcd *hcd,
142 struct usb_host_endpoint *ep)
143 {
144 struct ehci_hcd *ehci = hcd_to_ehci(hcd);
145 struct ehci_qh *qh = ep->hcpriv;
146 unsigned long flags;
147
148 spin_lock_irqsave(&ehci->lock, flags);
149 qh->clearing_tt = 0;
150 if (qh->qh_state == QH_STATE_IDLE && !list_empty(&qh->qtd_list)
151 && ehci->rh_state == EHCI_RH_RUNNING)
152 qh_link_async(ehci, qh);
153 spin_unlock_irqrestore(&ehci->lock, flags);
154 }
155
ehci_clear_tt_buffer(struct ehci_hcd * ehci,struct ehci_qh * qh,struct urb * urb,u32 token)156 static void ehci_clear_tt_buffer(struct ehci_hcd *ehci, struct ehci_qh *qh,
157 struct urb *urb, u32 token)
158 {
159
160 /* If an async split transaction gets an error or is unlinked,
161 * the TT buffer may be left in an indeterminate state. We
162 * have to clear the TT buffer.
163 *
164 * Note: this routine is never called for Isochronous transfers.
165 */
166 if (urb->dev->tt && !usb_pipeint(urb->pipe) && !qh->clearing_tt) {
167 #ifdef CONFIG_DYNAMIC_DEBUG
168 struct usb_device *tt = urb->dev->tt->hub;
169 dev_dbg(&tt->dev,
170 "clear tt buffer port %d, a%d ep%d t%08x\n",
171 urb->dev->ttport, urb->dev->devnum,
172 usb_pipeendpoint(urb->pipe), token);
173 #endif /* CONFIG_DYNAMIC_DEBUG */
174 if (!ehci_is_TDI(ehci)
175 || urb->dev->tt->hub !=
176 ehci_to_hcd(ehci)->self.root_hub) {
177 if (usb_hub_clear_tt_buffer(urb) == 0)
178 qh->clearing_tt = 1;
179 } else {
180
181 /* REVISIT ARC-derived cores don't clear the root
182 * hub TT buffer in this way...
183 */
184 }
185 }
186 }
187
qtd_copy_status(struct ehci_hcd * ehci,struct urb * urb,size_t length,u32 token)188 static int qtd_copy_status (
189 struct ehci_hcd *ehci,
190 struct urb *urb,
191 size_t length,
192 u32 token
193 )
194 {
195 int status = -EINPROGRESS;
196
197 /* count IN/OUT bytes, not SETUP (even short packets) */
198 if (likely(QTD_PID(token) != PID_CODE_SETUP))
199 urb->actual_length += length - QTD_LENGTH (token);
200
201 /* don't modify error codes */
202 if (unlikely(urb->unlinked))
203 return status;
204
205 /* force cleanup after short read; not always an error */
206 if (unlikely (IS_SHORT_READ (token)))
207 status = -EREMOTEIO;
208
209 /* serious "can't proceed" faults reported by the hardware */
210 if (token & QTD_STS_HALT) {
211 if (token & QTD_STS_BABBLE) {
212 /* FIXME "must" disable babbling device's port too */
213 status = -EOVERFLOW;
214 /*
215 * When MMF is active and PID Code is IN, queue is halted.
216 * EHCI Specification, Table 4-13.
217 */
218 } else if ((token & QTD_STS_MMF) &&
219 (QTD_PID(token) == PID_CODE_IN)) {
220 status = -EPROTO;
221 /* CERR nonzero + halt --> stall */
222 } else if (QTD_CERR(token)) {
223 status = -EPIPE;
224
225 /* In theory, more than one of the following bits can be set
226 * since they are sticky and the transaction is retried.
227 * Which to test first is rather arbitrary.
228 */
229 } else if (token & QTD_STS_MMF) {
230 /* fs/ls interrupt xfer missed the complete-split */
231 status = -EPROTO;
232 } else if (token & QTD_STS_DBE) {
233 status = (QTD_PID (token) == 1) /* IN ? */
234 ? -ENOSR /* hc couldn't read data */
235 : -ECOMM; /* hc couldn't write data */
236 } else if (token & QTD_STS_XACT) {
237 /* timeout, bad CRC, wrong PID, etc */
238 ehci_dbg(ehci, "devpath %s ep%d%s 3strikes\n",
239 urb->dev->devpath,
240 usb_pipeendpoint(urb->pipe),
241 usb_pipein(urb->pipe) ? "in" : "out");
242 status = -EPROTO;
243 } else { /* unknown */
244 status = -EPROTO;
245 }
246 }
247
248 return status;
249 }
250
251 static void
ehci_urb_done(struct ehci_hcd * ehci,struct urb * urb,int status)252 ehci_urb_done(struct ehci_hcd *ehci, struct urb *urb, int status)
253 {
254 if (usb_pipetype(urb->pipe) == PIPE_INTERRUPT) {
255 /* ... update hc-wide periodic stats */
256 ehci_to_hcd(ehci)->self.bandwidth_int_reqs--;
257 }
258
259 if (unlikely(urb->unlinked)) {
260 INCR(ehci->stats.unlink);
261 } else {
262 /* report non-error and short read status as zero */
263 if (status == -EINPROGRESS || status == -EREMOTEIO)
264 status = 0;
265 INCR(ehci->stats.complete);
266 }
267
268 #ifdef EHCI_URB_TRACE
269 ehci_dbg (ehci,
270 "%s %s urb %p ep%d%s status %d len %d/%d\n",
271 __func__, urb->dev->devpath, urb,
272 usb_pipeendpoint (urb->pipe),
273 usb_pipein (urb->pipe) ? "in" : "out",
274 status,
275 urb->actual_length, urb->transfer_buffer_length);
276 #endif
277
278 usb_hcd_unlink_urb_from_ep(ehci_to_hcd(ehci), urb);
279 usb_hcd_giveback_urb(ehci_to_hcd(ehci), urb, status);
280 }
281
282 static int qh_schedule (struct ehci_hcd *ehci, struct ehci_qh *qh);
283
284 /*
285 * Process and free completed qtds for a qh, returning URBs to drivers.
286 * Chases up to qh->hw_current. Returns nonzero if the caller should
287 * unlink qh.
288 */
289 static unsigned
qh_completions(struct ehci_hcd * ehci,struct ehci_qh * qh)290 qh_completions (struct ehci_hcd *ehci, struct ehci_qh *qh)
291 {
292 struct ehci_qtd *last, *end = qh->dummy;
293 struct list_head *entry, *tmp;
294 int last_status;
295 int stopped;
296 u8 state;
297 struct ehci_qh_hw *hw = qh->hw;
298
299 /* completions (or tasks on other cpus) must never clobber HALT
300 * till we've gone through and cleaned everything up, even when
301 * they add urbs to this qh's queue or mark them for unlinking.
302 *
303 * NOTE: unlinking expects to be done in queue order.
304 *
305 * It's a bug for qh->qh_state to be anything other than
306 * QH_STATE_IDLE, unless our caller is scan_async() or
307 * scan_intr().
308 */
309 state = qh->qh_state;
310 qh->qh_state = QH_STATE_COMPLETING;
311 stopped = (state == QH_STATE_IDLE);
312
313 rescan:
314 last = NULL;
315 last_status = -EINPROGRESS;
316 qh->dequeue_during_giveback = 0;
317
318 /* remove de-activated QTDs from front of queue.
319 * after faults (including short reads), cleanup this urb
320 * then let the queue advance.
321 * if queue is stopped, handles unlinks.
322 */
323 list_for_each_safe (entry, tmp, &qh->qtd_list) {
324 struct ehci_qtd *qtd;
325 struct urb *urb;
326 u32 token = 0;
327
328 qtd = list_entry (entry, struct ehci_qtd, qtd_list);
329 urb = qtd->urb;
330
331 /* clean up any state from previous QTD ...*/
332 if (last) {
333 if (likely (last->urb != urb)) {
334 ehci_urb_done(ehci, last->urb, last_status);
335 last_status = -EINPROGRESS;
336 }
337 ehci_qtd_free (ehci, last);
338 last = NULL;
339 }
340
341 /* ignore urbs submitted during completions we reported */
342 if (qtd == end)
343 break;
344
345 /* hardware copies qtd out of qh overlay */
346 rmb ();
347 token = hc32_to_cpu(ehci, qtd->hw_token);
348
349 /* always clean up qtds the hc de-activated */
350 retry_xacterr:
351 if ((token & QTD_STS_ACTIVE) == 0) {
352
353 /* Report Data Buffer Error: non-fatal but useful */
354 if (token & QTD_STS_DBE)
355 ehci_dbg(ehci,
356 "detected DataBufferErr for urb %p ep%d%s len %d, qtd %p [qh %p]\n",
357 urb,
358 usb_endpoint_num(&urb->ep->desc),
359 usb_endpoint_dir_in(&urb->ep->desc) ? "in" : "out",
360 urb->transfer_buffer_length,
361 qtd,
362 qh);
363
364 /* on STALL, error, and short reads this urb must
365 * complete and all its qtds must be recycled.
366 */
367 if ((token & QTD_STS_HALT) != 0) {
368
369 /* retry transaction errors until we
370 * reach the software xacterr limit
371 */
372 if ((token & QTD_STS_XACT) &&
373 QTD_CERR(token) == 0 &&
374 ++qh->xacterrs < QH_XACTERR_MAX &&
375 !urb->unlinked) {
376 ehci_dbg(ehci,
377 "detected XactErr len %zu/%zu retry %d\n",
378 qtd->length - QTD_LENGTH(token), qtd->length, qh->xacterrs);
379
380 /* reset the token in the qtd and the
381 * qh overlay (which still contains
382 * the qtd) so that we pick up from
383 * where we left off
384 */
385 token &= ~QTD_STS_HALT;
386 token |= QTD_STS_ACTIVE |
387 (EHCI_TUNE_CERR << 10);
388 qtd->hw_token = cpu_to_hc32(ehci,
389 token);
390 wmb();
391 hw->hw_token = cpu_to_hc32(ehci,
392 token);
393 goto retry_xacterr;
394 }
395 stopped = 1;
396 qh->unlink_reason |= QH_UNLINK_HALTED;
397
398 /* magic dummy for some short reads; qh won't advance.
399 * that silicon quirk can kick in with this dummy too.
400 *
401 * other short reads won't stop the queue, including
402 * control transfers (status stage handles that) or
403 * most other single-qtd reads ... the queue stops if
404 * URB_SHORT_NOT_OK was set so the driver submitting
405 * the urbs could clean it up.
406 */
407 } else if (IS_SHORT_READ (token)
408 && !(qtd->hw_alt_next
409 & EHCI_LIST_END(ehci))) {
410 stopped = 1;
411 qh->unlink_reason |= QH_UNLINK_SHORT_READ;
412 }
413
414 /* stop scanning when we reach qtds the hc is using */
415 } else if (likely (!stopped
416 && ehci->rh_state >= EHCI_RH_RUNNING)) {
417 break;
418
419 /* scan the whole queue for unlinks whenever it stops */
420 } else {
421 stopped = 1;
422
423 /* cancel everything if we halt, suspend, etc */
424 if (ehci->rh_state < EHCI_RH_RUNNING) {
425 last_status = -ESHUTDOWN;
426 qh->unlink_reason |= QH_UNLINK_SHUTDOWN;
427 }
428
429 /* this qtd is active; skip it unless a previous qtd
430 * for its urb faulted, or its urb was canceled.
431 */
432 else if (last_status == -EINPROGRESS && !urb->unlinked)
433 continue;
434
435 /*
436 * If this was the active qtd when the qh was unlinked
437 * and the overlay's token is active, then the overlay
438 * hasn't been written back to the qtd yet so use its
439 * token instead of the qtd's. After the qtd is
440 * processed and removed, the overlay won't be valid
441 * any more.
442 */
443 if (state == QH_STATE_IDLE &&
444 qh->qtd_list.next == &qtd->qtd_list &&
445 (hw->hw_token & ACTIVE_BIT(ehci))) {
446 token = hc32_to_cpu(ehci, hw->hw_token);
447 hw->hw_token &= ~ACTIVE_BIT(ehci);
448 qh->should_be_inactive = 1;
449
450 /* An unlink may leave an incomplete
451 * async transaction in the TT buffer.
452 * We have to clear it.
453 */
454 ehci_clear_tt_buffer(ehci, qh, urb, token);
455 }
456 }
457
458 /* unless we already know the urb's status, collect qtd status
459 * and update count of bytes transferred. in common short read
460 * cases with only one data qtd (including control transfers),
461 * queue processing won't halt. but with two or more qtds (for
462 * example, with a 32 KB transfer), when the first qtd gets a
463 * short read the second must be removed by hand.
464 */
465 if (last_status == -EINPROGRESS) {
466 last_status = qtd_copy_status(ehci, urb,
467 qtd->length, token);
468 if (last_status == -EREMOTEIO
469 && (qtd->hw_alt_next
470 & EHCI_LIST_END(ehci)))
471 last_status = -EINPROGRESS;
472
473 /* As part of low/full-speed endpoint-halt processing
474 * we must clear the TT buffer (11.17.5).
475 */
476 if (unlikely(last_status != -EINPROGRESS &&
477 last_status != -EREMOTEIO)) {
478 /* The TT's in some hubs malfunction when they
479 * receive this request following a STALL (they
480 * stop sending isochronous packets). Since a
481 * STALL can't leave the TT buffer in a busy
482 * state (if you believe Figures 11-48 - 11-51
483 * in the USB 2.0 spec), we won't clear the TT
484 * buffer in this case. Strictly speaking this
485 * is a violation of the spec.
486 */
487 if (last_status != -EPIPE)
488 ehci_clear_tt_buffer(ehci, qh, urb,
489 token);
490 }
491 }
492
493 /* if we're removing something not at the queue head,
494 * patch the hardware queue pointer.
495 */
496 if (stopped && qtd->qtd_list.prev != &qh->qtd_list) {
497 last = list_entry (qtd->qtd_list.prev,
498 struct ehci_qtd, qtd_list);
499 last->hw_next = qtd->hw_next;
500 }
501
502 /* remove qtd; it's recycled after possible urb completion */
503 list_del (&qtd->qtd_list);
504 last = qtd;
505
506 /* reinit the xacterr counter for the next qtd */
507 qh->xacterrs = 0;
508 }
509
510 /* last urb's completion might still need calling */
511 if (likely (last != NULL)) {
512 ehci_urb_done(ehci, last->urb, last_status);
513 ehci_qtd_free (ehci, last);
514 }
515
516 /* Do we need to rescan for URBs dequeued during a giveback? */
517 if (unlikely(qh->dequeue_during_giveback)) {
518 /* If the QH is already unlinked, do the rescan now. */
519 if (state == QH_STATE_IDLE)
520 goto rescan;
521
522 /* Otherwise the caller must unlink the QH. */
523 }
524
525 /* restore original state; caller must unlink or relink */
526 qh->qh_state = state;
527
528 /* be sure the hardware's done with the qh before refreshing
529 * it after fault cleanup, or recovering from silicon wrongly
530 * overlaying the dummy qtd (which reduces DMA chatter).
531 *
532 * We won't refresh a QH that's linked (after the HC
533 * stopped the queue). That avoids a race:
534 * - HC reads first part of QH;
535 * - CPU updates that first part and the token;
536 * - HC reads rest of that QH, including token
537 * Result: HC gets an inconsistent image, and then
538 * DMAs to/from the wrong memory (corrupting it).
539 *
540 * That should be rare for interrupt transfers,
541 * except maybe high bandwidth ...
542 */
543 if (stopped != 0 || hw->hw_qtd_next == EHCI_LIST_END(ehci))
544 qh->unlink_reason |= QH_UNLINK_DUMMY_OVERLAY;
545
546 /* Let the caller know if the QH needs to be unlinked. */
547 return qh->unlink_reason;
548 }
549
550 /*-------------------------------------------------------------------------*/
551
552 /*
553 * reverse of qh_urb_transaction: free a list of TDs.
554 * used for cleanup after errors, before HC sees an URB's TDs.
555 */
qtd_list_free(struct ehci_hcd * ehci,struct urb * urb,struct list_head * qtd_list)556 static void qtd_list_free (
557 struct ehci_hcd *ehci,
558 struct urb *urb,
559 struct list_head *qtd_list
560 ) {
561 struct list_head *entry, *temp;
562
563 list_for_each_safe (entry, temp, qtd_list) {
564 struct ehci_qtd *qtd;
565
566 qtd = list_entry (entry, struct ehci_qtd, qtd_list);
567 list_del (&qtd->qtd_list);
568 ehci_qtd_free (ehci, qtd);
569 }
570 }
571
572 /*
573 * create a list of filled qtds for this URB; won't link into qh.
574 */
575 static struct list_head *
qh_urb_transaction(struct ehci_hcd * ehci,struct urb * urb,struct list_head * head,gfp_t flags)576 qh_urb_transaction (
577 struct ehci_hcd *ehci,
578 struct urb *urb,
579 struct list_head *head,
580 gfp_t flags
581 ) {
582 struct ehci_qtd *qtd, *qtd_prev;
583 dma_addr_t buf;
584 int len, this_sg_len, maxpacket;
585 int is_input;
586 u32 token;
587 int i;
588 struct scatterlist *sg;
589
590 /*
591 * URBs map to sequences of QTDs: one logical transaction
592 */
593 qtd = ehci_qtd_alloc (ehci, flags);
594 if (unlikely (!qtd))
595 return NULL;
596 list_add_tail (&qtd->qtd_list, head);
597 qtd->urb = urb;
598
599 token = QTD_STS_ACTIVE;
600 token |= (EHCI_TUNE_CERR << 10);
601 /* for split transactions, SplitXState initialized to zero */
602
603 len = urb->transfer_buffer_length;
604 is_input = usb_pipein (urb->pipe);
605 if (usb_pipecontrol (urb->pipe)) {
606 /* SETUP pid */
607 qtd_fill(ehci, qtd, urb->setup_dma,
608 sizeof (struct usb_ctrlrequest),
609 token | (2 /* "setup" */ << 8), 8);
610
611 /* ... and always at least one more pid */
612 token ^= QTD_TOGGLE;
613 qtd_prev = qtd;
614 qtd = ehci_qtd_alloc (ehci, flags);
615 if (unlikely (!qtd))
616 goto cleanup;
617 qtd->urb = urb;
618 qtd_prev->hw_next = QTD_NEXT(ehci, qtd->qtd_dma);
619 list_add_tail (&qtd->qtd_list, head);
620
621 /* for zero length DATA stages, STATUS is always IN */
622 if (len == 0)
623 token |= (1 /* "in" */ << 8);
624 }
625
626 /*
627 * data transfer stage: buffer setup
628 */
629 i = urb->num_mapped_sgs;
630 if (len > 0 && i > 0) {
631 sg = urb->sg;
632 buf = sg_dma_address(sg);
633
634 /* urb->transfer_buffer_length may be smaller than the
635 * size of the scatterlist (or vice versa)
636 */
637 this_sg_len = min_t(int, sg_dma_len(sg), len);
638 } else {
639 sg = NULL;
640 buf = urb->transfer_dma;
641 this_sg_len = len;
642 }
643
644 if (is_input)
645 token |= (1 /* "in" */ << 8);
646 /* else it's already initted to "out" pid (0 << 8) */
647
648 maxpacket = usb_endpoint_maxp(&urb->ep->desc);
649
650 /*
651 * buffer gets wrapped in one or more qtds;
652 * last one may be "short" (including zero len)
653 * and may serve as a control status ack
654 */
655 for (;;) {
656 unsigned int this_qtd_len;
657
658 this_qtd_len = qtd_fill(ehci, qtd, buf, this_sg_len, token,
659 maxpacket);
660 this_sg_len -= this_qtd_len;
661 len -= this_qtd_len;
662 buf += this_qtd_len;
663
664 /*
665 * short reads advance to a "magic" dummy instead of the next
666 * qtd ... that forces the queue to stop, for manual cleanup.
667 * (this will usually be overridden later.)
668 */
669 if (is_input)
670 qtd->hw_alt_next = ehci->async->hw->hw_alt_next;
671
672 /* qh makes control packets use qtd toggle; maybe switch it */
673 if ((maxpacket & (this_qtd_len + (maxpacket - 1))) == 0)
674 token ^= QTD_TOGGLE;
675
676 if (likely(this_sg_len <= 0)) {
677 if (--i <= 0 || len <= 0)
678 break;
679 sg = sg_next(sg);
680 buf = sg_dma_address(sg);
681 this_sg_len = min_t(int, sg_dma_len(sg), len);
682 }
683
684 qtd_prev = qtd;
685 qtd = ehci_qtd_alloc (ehci, flags);
686 if (unlikely (!qtd))
687 goto cleanup;
688 qtd->urb = urb;
689 qtd_prev->hw_next = QTD_NEXT(ehci, qtd->qtd_dma);
690 list_add_tail (&qtd->qtd_list, head);
691 }
692
693 /*
694 * unless the caller requires manual cleanup after short reads,
695 * have the alt_next mechanism keep the queue running after the
696 * last data qtd (the only one, for control and most other cases).
697 */
698 if (likely ((urb->transfer_flags & URB_SHORT_NOT_OK) == 0
699 || usb_pipecontrol (urb->pipe)))
700 qtd->hw_alt_next = EHCI_LIST_END(ehci);
701
702 /*
703 * control requests may need a terminating data "status" ack;
704 * other OUT ones may need a terminating short packet
705 * (zero length).
706 */
707 if (likely (urb->transfer_buffer_length != 0)) {
708 int one_more = 0;
709
710 if (usb_pipecontrol (urb->pipe)) {
711 one_more = 1;
712 token ^= 0x0100; /* "in" <--> "out" */
713 token |= QTD_TOGGLE; /* force DATA1 */
714 } else if (usb_pipeout(urb->pipe)
715 && (urb->transfer_flags & URB_ZERO_PACKET)
716 && !(urb->transfer_buffer_length % maxpacket)) {
717 one_more = 1;
718 }
719 if (one_more) {
720 qtd_prev = qtd;
721 qtd = ehci_qtd_alloc (ehci, flags);
722 if (unlikely (!qtd))
723 goto cleanup;
724 qtd->urb = urb;
725 qtd_prev->hw_next = QTD_NEXT(ehci, qtd->qtd_dma);
726 list_add_tail (&qtd->qtd_list, head);
727
728 /* never any data in such packets */
729 qtd_fill(ehci, qtd, 0, 0, token, 0);
730 }
731 }
732
733 /* by default, enable interrupt on urb completion */
734 if (likely (!(urb->transfer_flags & URB_NO_INTERRUPT)))
735 qtd->hw_token |= cpu_to_hc32(ehci, QTD_IOC);
736 return head;
737
738 cleanup:
739 qtd_list_free (ehci, urb, head);
740 return NULL;
741 }
742
743 /*-------------------------------------------------------------------------*/
744
745 // Would be best to create all qh's from config descriptors,
746 // when each interface/altsetting is established. Unlink
747 // any previous qh and cancel its urbs first; endpoints are
748 // implicitly reset then (data toggle too).
749 // That'd mean updating how usbcore talks to HCDs. (2.7?)
750
751
752 /*
753 * Each QH holds a qtd list; a QH is used for everything except iso.
754 *
755 * For interrupt urbs, the scheduler must set the microframe scheduling
756 * mask(s) each time the QH gets scheduled. For highspeed, that's
757 * just one microframe in the s-mask. For split interrupt transactions
758 * there are additional complications: c-mask, maybe FSTNs.
759 */
760 static struct ehci_qh *
qh_make(struct ehci_hcd * ehci,struct urb * urb,gfp_t flags)761 qh_make (
762 struct ehci_hcd *ehci,
763 struct urb *urb,
764 gfp_t flags
765 ) {
766 struct ehci_qh *qh = ehci_qh_alloc (ehci, flags);
767 struct usb_host_endpoint *ep;
768 u32 info1 = 0, info2 = 0;
769 int is_input, type;
770 int maxp = 0;
771 int mult;
772 struct usb_tt *tt = urb->dev->tt;
773 struct ehci_qh_hw *hw;
774
775 if (!qh)
776 return qh;
777
778 /*
779 * init endpoint/device data for this QH
780 */
781 info1 |= usb_pipeendpoint (urb->pipe) << 8;
782 info1 |= usb_pipedevice (urb->pipe) << 0;
783
784 is_input = usb_pipein (urb->pipe);
785 type = usb_pipetype (urb->pipe);
786 ep = usb_pipe_endpoint (urb->dev, urb->pipe);
787 maxp = usb_endpoint_maxp (&ep->desc);
788 mult = usb_endpoint_maxp_mult (&ep->desc);
789
790 /* 1024 byte maxpacket is a hardware ceiling. High bandwidth
791 * acts like up to 3KB, but is built from smaller packets.
792 */
793 if (maxp > 1024) {
794 ehci_dbg(ehci, "bogus qh maxpacket %d\n", maxp);
795 goto done;
796 }
797
798 /* Compute interrupt scheduling parameters just once, and save.
799 * - allowing for high bandwidth, how many nsec/uframe are used?
800 * - split transactions need a second CSPLIT uframe; same question
801 * - splits also need a schedule gap (for full/low speed I/O)
802 * - qh has a polling interval
803 *
804 * For control/bulk requests, the HC or TT handles these.
805 */
806 if (type == PIPE_INTERRUPT) {
807 unsigned tmp;
808
809 qh->ps.usecs = NS_TO_US(usb_calc_bus_time(USB_SPEED_HIGH,
810 is_input, 0, mult * maxp));
811 qh->ps.phase = NO_FRAME;
812
813 if (urb->dev->speed == USB_SPEED_HIGH) {
814 qh->ps.c_usecs = 0;
815 qh->gap_uf = 0;
816
817 if (urb->interval > 1 && urb->interval < 8) {
818 /* NOTE interval 2 or 4 uframes could work.
819 * But interval 1 scheduling is simpler, and
820 * includes high bandwidth.
821 */
822 urb->interval = 1;
823 } else if (urb->interval > ehci->periodic_size << 3) {
824 urb->interval = ehci->periodic_size << 3;
825 }
826 qh->ps.period = urb->interval >> 3;
827
828 /* period for bandwidth allocation */
829 tmp = min_t(unsigned, EHCI_BANDWIDTH_SIZE,
830 1 << (urb->ep->desc.bInterval - 1));
831
832 /* Allow urb->interval to override */
833 qh->ps.bw_uperiod = min_t(unsigned, tmp, urb->interval);
834 qh->ps.bw_period = qh->ps.bw_uperiod >> 3;
835 } else {
836 int think_time;
837
838 /* gap is f(FS/LS transfer times) */
839 qh->gap_uf = 1 + usb_calc_bus_time (urb->dev->speed,
840 is_input, 0, maxp) / (125 * 1000);
841
842 /* FIXME this just approximates SPLIT/CSPLIT times */
843 if (is_input) { // SPLIT, gap, CSPLIT+DATA
844 qh->ps.c_usecs = qh->ps.usecs + HS_USECS(0);
845 qh->ps.usecs = HS_USECS(1);
846 } else { // SPLIT+DATA, gap, CSPLIT
847 qh->ps.usecs += HS_USECS(1);
848 qh->ps.c_usecs = HS_USECS(0);
849 }
850
851 think_time = tt ? tt->think_time : 0;
852 qh->ps.tt_usecs = NS_TO_US(think_time +
853 usb_calc_bus_time (urb->dev->speed,
854 is_input, 0, maxp));
855 if (urb->interval > ehci->periodic_size)
856 urb->interval = ehci->periodic_size;
857 qh->ps.period = urb->interval;
858
859 /* period for bandwidth allocation */
860 tmp = min_t(unsigned, EHCI_BANDWIDTH_FRAMES,
861 urb->ep->desc.bInterval);
862 tmp = rounddown_pow_of_two(tmp);
863
864 /* Allow urb->interval to override */
865 qh->ps.bw_period = min_t(unsigned, tmp, urb->interval);
866 qh->ps.bw_uperiod = qh->ps.bw_period << 3;
867 }
868 }
869
870 /* support for tt scheduling, and access to toggles */
871 qh->ps.udev = urb->dev;
872 qh->ps.ep = urb->ep;
873
874 /* using TT? */
875 switch (urb->dev->speed) {
876 case USB_SPEED_LOW:
877 info1 |= QH_LOW_SPEED;
878 fallthrough;
879
880 case USB_SPEED_FULL:
881 /* EPS 0 means "full" */
882 if (type != PIPE_INTERRUPT)
883 info1 |= (EHCI_TUNE_RL_TT << 28);
884 if (type == PIPE_CONTROL) {
885 info1 |= QH_CONTROL_EP; /* for TT */
886 info1 |= QH_TOGGLE_CTL; /* toggle from qtd */
887 }
888 info1 |= maxp << 16;
889
890 info2 |= (EHCI_TUNE_MULT_TT << 30);
891
892 /* Some Freescale processors have an erratum in which the
893 * port number in the queue head was 0..N-1 instead of 1..N.
894 */
895 if (ehci_has_fsl_portno_bug(ehci))
896 info2 |= (urb->dev->ttport-1) << 23;
897 else
898 info2 |= urb->dev->ttport << 23;
899
900 /* set the address of the TT; for TDI's integrated
901 * root hub tt, leave it zeroed.
902 */
903 if (tt && tt->hub != ehci_to_hcd(ehci)->self.root_hub)
904 info2 |= tt->hub->devnum << 16;
905
906 /* NOTE: if (PIPE_INTERRUPT) { scheduler sets c-mask } */
907
908 break;
909
910 case USB_SPEED_HIGH: /* no TT involved */
911 info1 |= QH_HIGH_SPEED;
912 if (type == PIPE_CONTROL) {
913 info1 |= (EHCI_TUNE_RL_HS << 28);
914 info1 |= 64 << 16; /* usb2 fixed maxpacket */
915 info1 |= QH_TOGGLE_CTL; /* toggle from qtd */
916 info2 |= (EHCI_TUNE_MULT_HS << 30);
917 } else if (type == PIPE_BULK) {
918 info1 |= (EHCI_TUNE_RL_HS << 28);
919 /* The USB spec says that high speed bulk endpoints
920 * always use 512 byte maxpacket. But some device
921 * vendors decided to ignore that, and MSFT is happy
922 * to help them do so. So now people expect to use
923 * such nonconformant devices with Linux too; sigh.
924 */
925 info1 |= maxp << 16;
926 info2 |= (EHCI_TUNE_MULT_HS << 30);
927 } else { /* PIPE_INTERRUPT */
928 info1 |= maxp << 16;
929 info2 |= mult << 30;
930 }
931 break;
932 default:
933 ehci_dbg(ehci, "bogus dev %p speed %d\n", urb->dev,
934 urb->dev->speed);
935 done:
936 qh_destroy(ehci, qh);
937 return NULL;
938 }
939
940 /* NOTE: if (PIPE_INTERRUPT) { scheduler sets s-mask } */
941
942 /* init as live, toggle clear */
943 qh->qh_state = QH_STATE_IDLE;
944 hw = qh->hw;
945 hw->hw_info1 = cpu_to_hc32(ehci, info1);
946 hw->hw_info2 = cpu_to_hc32(ehci, info2);
947 qh->is_out = !is_input;
948 usb_settoggle (urb->dev, usb_pipeendpoint (urb->pipe), !is_input, 1);
949 return qh;
950 }
951
952 /*-------------------------------------------------------------------------*/
953
enable_async(struct ehci_hcd * ehci)954 static void enable_async(struct ehci_hcd *ehci)
955 {
956 if (ehci->async_count++)
957 return;
958
959 /* Stop waiting to turn off the async schedule */
960 ehci->enabled_hrtimer_events &= ~BIT(EHCI_HRTIMER_DISABLE_ASYNC);
961
962 /* Don't start the schedule until ASS is 0 */
963 ehci_poll_ASS(ehci);
964 turn_on_io_watchdog(ehci);
965 }
966
disable_async(struct ehci_hcd * ehci)967 static void disable_async(struct ehci_hcd *ehci)
968 {
969 if (--ehci->async_count)
970 return;
971
972 /* The async schedule and unlink lists are supposed to be empty */
973 WARN_ON(ehci->async->qh_next.qh || !list_empty(&ehci->async_unlink) ||
974 !list_empty(&ehci->async_idle));
975
976 /* Don't turn off the schedule until ASS is 1 */
977 ehci_poll_ASS(ehci);
978 }
979
980 /* move qh (and its qtds) onto async queue; maybe enable queue. */
981
qh_link_async(struct ehci_hcd * ehci,struct ehci_qh * qh)982 static void qh_link_async (struct ehci_hcd *ehci, struct ehci_qh *qh)
983 {
984 __hc32 dma = QH_NEXT(ehci, qh->qh_dma);
985 struct ehci_qh *head;
986
987 /* Don't link a QH if there's a Clear-TT-Buffer pending */
988 if (unlikely(qh->clearing_tt))
989 return;
990
991 WARN_ON(qh->qh_state != QH_STATE_IDLE);
992
993 /* clear halt and/or toggle; and maybe recover from silicon quirk */
994 qh_refresh(ehci, qh);
995
996 /* splice right after start */
997 head = ehci->async;
998 qh->qh_next = head->qh_next;
999 qh->hw->hw_next = head->hw->hw_next;
1000 wmb ();
1001
1002 head->qh_next.qh = qh;
1003 head->hw->hw_next = dma;
1004
1005 qh->qh_state = QH_STATE_LINKED;
1006 qh->xacterrs = 0;
1007 qh->unlink_reason = 0;
1008 /* qtd completions reported later by interrupt */
1009
1010 enable_async(ehci);
1011 }
1012
1013 /*-------------------------------------------------------------------------*/
1014
1015 /*
1016 * For control/bulk/interrupt, return QH with these TDs appended.
1017 * Allocates and initializes the QH if necessary.
1018 * Returns null if it can't allocate a QH it needs to.
1019 * If the QH has TDs (urbs) already, that's great.
1020 */
qh_append_tds(struct ehci_hcd * ehci,struct urb * urb,struct list_head * qtd_list,int epnum,void ** ptr)1021 static struct ehci_qh *qh_append_tds (
1022 struct ehci_hcd *ehci,
1023 struct urb *urb,
1024 struct list_head *qtd_list,
1025 int epnum,
1026 void **ptr
1027 )
1028 {
1029 struct ehci_qh *qh = NULL;
1030 __hc32 qh_addr_mask = cpu_to_hc32(ehci, 0x7f);
1031
1032 qh = (struct ehci_qh *) *ptr;
1033 if (unlikely (qh == NULL)) {
1034 /* can't sleep here, we have ehci->lock... */
1035 qh = qh_make (ehci, urb, GFP_ATOMIC);
1036 *ptr = qh;
1037 }
1038 if (likely (qh != NULL)) {
1039 struct ehci_qtd *qtd;
1040
1041 if (unlikely (list_empty (qtd_list)))
1042 qtd = NULL;
1043 else
1044 qtd = list_entry (qtd_list->next, struct ehci_qtd,
1045 qtd_list);
1046
1047 /* control qh may need patching ... */
1048 if (unlikely (epnum == 0)) {
1049
1050 /* usb_reset_device() briefly reverts to address 0 */
1051 if (usb_pipedevice (urb->pipe) == 0)
1052 qh->hw->hw_info1 &= ~qh_addr_mask;
1053 }
1054
1055 /* just one way to queue requests: swap with the dummy qtd.
1056 * only hc or qh_refresh() ever modify the overlay.
1057 */
1058 if (likely (qtd != NULL)) {
1059 struct ehci_qtd *dummy;
1060 dma_addr_t dma;
1061 __hc32 token;
1062
1063 /* to avoid racing the HC, use the dummy td instead of
1064 * the first td of our list (becomes new dummy). both
1065 * tds stay deactivated until we're done, when the
1066 * HC is allowed to fetch the old dummy (4.10.2).
1067 */
1068 token = qtd->hw_token;
1069 qtd->hw_token = HALT_BIT(ehci);
1070
1071 dummy = qh->dummy;
1072
1073 dma = dummy->qtd_dma;
1074 *dummy = *qtd;
1075 dummy->qtd_dma = dma;
1076
1077 list_del (&qtd->qtd_list);
1078 list_add (&dummy->qtd_list, qtd_list);
1079 list_splice_tail(qtd_list, &qh->qtd_list);
1080
1081 ehci_qtd_init(ehci, qtd, qtd->qtd_dma);
1082 qh->dummy = qtd;
1083
1084 /* hc must see the new dummy at list end */
1085 dma = qtd->qtd_dma;
1086 qtd = list_entry (qh->qtd_list.prev,
1087 struct ehci_qtd, qtd_list);
1088 qtd->hw_next = QTD_NEXT(ehci, dma);
1089
1090 /* let the hc process these next qtds */
1091 wmb ();
1092 dummy->hw_token = token;
1093
1094 urb->hcpriv = qh;
1095 }
1096 }
1097 return qh;
1098 }
1099
1100 /*-------------------------------------------------------------------------*/
1101
1102 static int
submit_async(struct ehci_hcd * ehci,struct urb * urb,struct list_head * qtd_list,gfp_t mem_flags)1103 submit_async (
1104 struct ehci_hcd *ehci,
1105 struct urb *urb,
1106 struct list_head *qtd_list,
1107 gfp_t mem_flags
1108 ) {
1109 int epnum;
1110 unsigned long flags;
1111 struct ehci_qh *qh = NULL;
1112 int rc;
1113
1114 epnum = urb->ep->desc.bEndpointAddress;
1115
1116 #ifdef EHCI_URB_TRACE
1117 {
1118 struct ehci_qtd *qtd;
1119 qtd = list_entry(qtd_list->next, struct ehci_qtd, qtd_list);
1120 ehci_dbg(ehci,
1121 "%s %s urb %p ep%d%s len %d, qtd %p [qh %p]\n",
1122 __func__, urb->dev->devpath, urb,
1123 epnum & 0x0f, (epnum & USB_DIR_IN) ? "in" : "out",
1124 urb->transfer_buffer_length,
1125 qtd, urb->ep->hcpriv);
1126 }
1127 #endif
1128
1129 spin_lock_irqsave (&ehci->lock, flags);
1130 if (unlikely(!HCD_HW_ACCESSIBLE(ehci_to_hcd(ehci)))) {
1131 rc = -ESHUTDOWN;
1132 goto done;
1133 }
1134 rc = usb_hcd_link_urb_to_ep(ehci_to_hcd(ehci), urb);
1135 if (unlikely(rc))
1136 goto done;
1137
1138 qh = qh_append_tds(ehci, urb, qtd_list, epnum, &urb->ep->hcpriv);
1139 if (unlikely(qh == NULL)) {
1140 usb_hcd_unlink_urb_from_ep(ehci_to_hcd(ehci), urb);
1141 rc = -ENOMEM;
1142 goto done;
1143 }
1144
1145 /* Control/bulk operations through TTs don't need scheduling,
1146 * the HC and TT handle it when the TT has a buffer ready.
1147 */
1148 if (likely (qh->qh_state == QH_STATE_IDLE))
1149 qh_link_async(ehci, qh);
1150 done:
1151 spin_unlock_irqrestore (&ehci->lock, flags);
1152 if (unlikely (qh == NULL))
1153 qtd_list_free (ehci, urb, qtd_list);
1154 return rc;
1155 }
1156
1157 /*-------------------------------------------------------------------------*/
1158 #ifdef CONFIG_USB_HCD_TEST_MODE
1159 /*
1160 * This function creates the qtds and submits them for the
1161 * SINGLE_STEP_SET_FEATURE Test.
1162 * This is done in two parts: first SETUP req for GetDesc is sent then
1163 * 15 seconds later, the IN stage for GetDesc starts to req data from dev
1164 *
1165 * is_setup : i/p argument decides which of the two stage needs to be
1166 * performed; TRUE - SETUP and FALSE - IN+STATUS
1167 * Returns 0 if success
1168 */
ehci_submit_single_step_set_feature(struct usb_hcd * hcd,struct urb * urb,int is_setup)1169 static int ehci_submit_single_step_set_feature(
1170 struct usb_hcd *hcd,
1171 struct urb *urb,
1172 int is_setup
1173 ) {
1174 struct ehci_hcd *ehci = hcd_to_ehci(hcd);
1175 struct list_head qtd_list;
1176 struct list_head *head;
1177
1178 struct ehci_qtd *qtd, *qtd_prev;
1179 dma_addr_t buf;
1180 int len, maxpacket;
1181 u32 token;
1182
1183 INIT_LIST_HEAD(&qtd_list);
1184 head = &qtd_list;
1185
1186 /* URBs map to sequences of QTDs: one logical transaction */
1187 qtd = ehci_qtd_alloc(ehci, GFP_KERNEL);
1188 if (unlikely(!qtd))
1189 return -1;
1190 list_add_tail(&qtd->qtd_list, head);
1191 qtd->urb = urb;
1192
1193 token = QTD_STS_ACTIVE;
1194 token |= (EHCI_TUNE_CERR << 10);
1195
1196 len = urb->transfer_buffer_length;
1197 /*
1198 * Check if the request is to perform just the SETUP stage (getDesc)
1199 * as in SINGLE_STEP_SET_FEATURE test, DATA stage (IN) happens
1200 * 15 secs after the setup
1201 */
1202 if (is_setup) {
1203 /* SETUP pid, and interrupt after SETUP completion */
1204 qtd_fill(ehci, qtd, urb->setup_dma,
1205 sizeof(struct usb_ctrlrequest),
1206 QTD_IOC | token | (2 /* "setup" */ << 8), 8);
1207
1208 submit_async(ehci, urb, &qtd_list, GFP_ATOMIC);
1209 return 0; /*Return now; we shall come back after 15 seconds*/
1210 }
1211
1212 /*
1213 * IN: data transfer stage: buffer setup : start the IN txn phase for
1214 * the get_Desc SETUP which was sent 15seconds back
1215 */
1216 token ^= QTD_TOGGLE; /*We need to start IN with DATA-1 Pid-sequence*/
1217 buf = urb->transfer_dma;
1218
1219 token |= (1 /* "in" */ << 8); /*This is IN stage*/
1220
1221 maxpacket = usb_endpoint_maxp(&urb->ep->desc);
1222
1223 qtd_fill(ehci, qtd, buf, len, token, maxpacket);
1224
1225 /*
1226 * Our IN phase shall always be a short read; so keep the queue running
1227 * and let it advance to the next qtd which zero length OUT status
1228 */
1229 qtd->hw_alt_next = EHCI_LIST_END(ehci);
1230
1231 /* STATUS stage for GetDesc control request */
1232 token ^= 0x0100; /* "in" <--> "out" */
1233 token |= QTD_TOGGLE; /* force DATA1 */
1234
1235 qtd_prev = qtd;
1236 qtd = ehci_qtd_alloc(ehci, GFP_ATOMIC);
1237 if (unlikely(!qtd))
1238 goto cleanup;
1239 qtd->urb = urb;
1240 qtd_prev->hw_next = QTD_NEXT(ehci, qtd->qtd_dma);
1241 list_add_tail(&qtd->qtd_list, head);
1242
1243 /* Interrupt after STATUS completion */
1244 qtd_fill(ehci, qtd, 0, 0, token | QTD_IOC, 0);
1245
1246 submit_async(ehci, urb, &qtd_list, GFP_KERNEL);
1247
1248 return 0;
1249
1250 cleanup:
1251 qtd_list_free(ehci, urb, head);
1252 return -1;
1253 }
1254 #endif /* CONFIG_USB_HCD_TEST_MODE */
1255
1256 /*-------------------------------------------------------------------------*/
1257
single_unlink_async(struct ehci_hcd * ehci,struct ehci_qh * qh)1258 static void single_unlink_async(struct ehci_hcd *ehci, struct ehci_qh *qh)
1259 {
1260 struct ehci_qh *prev;
1261
1262 /* Add to the end of the list of QHs waiting for the next IAAD */
1263 qh->qh_state = QH_STATE_UNLINK_WAIT;
1264 list_add_tail(&qh->unlink_node, &ehci->async_unlink);
1265
1266 /* Unlink it from the schedule */
1267 prev = ehci->async;
1268 while (prev->qh_next.qh != qh)
1269 prev = prev->qh_next.qh;
1270
1271 prev->hw->hw_next = qh->hw->hw_next;
1272 prev->qh_next = qh->qh_next;
1273 if (ehci->qh_scan_next == qh)
1274 ehci->qh_scan_next = qh->qh_next.qh;
1275 }
1276
start_iaa_cycle(struct ehci_hcd * ehci)1277 static void start_iaa_cycle(struct ehci_hcd *ehci)
1278 {
1279 /* If the controller isn't running, we don't have to wait for it */
1280 if (unlikely(ehci->rh_state < EHCI_RH_RUNNING)) {
1281 end_unlink_async(ehci);
1282
1283 /* Otherwise start a new IAA cycle if one isn't already running */
1284 } else if (ehci->rh_state == EHCI_RH_RUNNING &&
1285 !ehci->iaa_in_progress) {
1286
1287 /* Make sure the unlinks are all visible to the hardware */
1288 wmb();
1289
1290 ehci_writel(ehci, ehci->command | CMD_IAAD,
1291 &ehci->regs->command);
1292 ehci_readl(ehci, &ehci->regs->command);
1293 ehci->iaa_in_progress = true;
1294 ehci_enable_event(ehci, EHCI_HRTIMER_IAA_WATCHDOG, true);
1295 }
1296 }
1297
end_iaa_cycle(struct ehci_hcd * ehci)1298 static void end_iaa_cycle(struct ehci_hcd *ehci)
1299 {
1300 if (ehci->has_synopsys_hc_bug)
1301 ehci_writel(ehci, (u32) ehci->async->qh_dma,
1302 &ehci->regs->async_next);
1303
1304 /* The current IAA cycle has ended */
1305 ehci->iaa_in_progress = false;
1306
1307 end_unlink_async(ehci);
1308 }
1309
1310 /* See if 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 (list_empty(&ehci->async_unlink))
1318 return;
1319 qh = list_first_entry(&ehci->async_unlink, struct ehci_qh,
1320 unlink_node); /* QH whose IAA cycle just ended */
1321
1322 /*
1323 * If async_unlinking is set then this routine is already running,
1324 * either on the stack or on another CPU.
1325 */
1326 early_exit = ehci->async_unlinking;
1327
1328 /* If the controller isn't running, process all the waiting QHs */
1329 if (ehci->rh_state < EHCI_RH_RUNNING)
1330 list_splice_tail_init(&ehci->async_unlink, &ehci->async_idle);
1331
1332 /*
1333 * Intel (?) bug: The HC can write back the overlay region even
1334 * after the IAA interrupt occurs. In self-defense, always go
1335 * through two IAA cycles for each QH.
1336 */
1337 else if (qh->qh_state == QH_STATE_UNLINK) {
1338 /*
1339 * Second IAA cycle has finished. Process only the first
1340 * waiting QH (NVIDIA (?) bug).
1341 */
1342 list_move_tail(&qh->unlink_node, &ehci->async_idle);
1343 }
1344
1345 /*
1346 * AMD/ATI (?) bug: The HC can continue to use an active QH long
1347 * after the IAA interrupt occurs. To prevent problems, QHs that
1348 * may still be active will wait until 2 ms have passed with no
1349 * change to the hw_current and hw_token fields (this delay occurs
1350 * between the two IAA cycles).
1351 *
1352 * The EHCI spec (4.8.2) says that active QHs must not be removed
1353 * from the async schedule and recommends waiting until the QH
1354 * goes inactive. This is ridiculous because the QH will _never_
1355 * become inactive if the endpoint NAKs indefinitely.
1356 */
1357
1358 /* Some reasons for unlinking guarantee the QH can't be active */
1359 else if (qh->unlink_reason & (QH_UNLINK_HALTED |
1360 QH_UNLINK_SHORT_READ | QH_UNLINK_DUMMY_OVERLAY))
1361 goto DelayDone;
1362
1363 /* The QH can't be active if the queue was and still is empty... */
1364 else if ((qh->unlink_reason & QH_UNLINK_QUEUE_EMPTY) &&
1365 list_empty(&qh->qtd_list))
1366 goto DelayDone;
1367
1368 /* ... or if the QH has halted */
1369 else if (qh->hw->hw_token & cpu_to_hc32(ehci, QTD_STS_HALT))
1370 goto DelayDone;
1371
1372 /* Otherwise we have to wait until the QH stops changing */
1373 else {
1374 __hc32 qh_current, qh_token;
1375
1376 qh_current = qh->hw->hw_current;
1377 qh_token = qh->hw->hw_token;
1378 if (qh_current != ehci->old_current ||
1379 qh_token != ehci->old_token) {
1380 ehci->old_current = qh_current;
1381 ehci->old_token = qh_token;
1382 ehci_enable_event(ehci,
1383 EHCI_HRTIMER_ACTIVE_UNLINK, true);
1384 return;
1385 }
1386 DelayDone:
1387 qh->qh_state = QH_STATE_UNLINK;
1388 early_exit = true;
1389 }
1390 ehci->old_current = ~0; /* Prepare for next QH */
1391
1392 /* Start a new IAA cycle if any QHs are waiting for it */
1393 if (!list_empty(&ehci->async_unlink))
1394 start_iaa_cycle(ehci);
1395
1396 /*
1397 * Don't allow nesting or concurrent calls,
1398 * or wait for the second IAA cycle for the next QH.
1399 */
1400 if (early_exit)
1401 return;
1402
1403 /* Process the idle QHs */
1404 ehci->async_unlinking = true;
1405 while (!list_empty(&ehci->async_idle)) {
1406 qh = list_first_entry(&ehci->async_idle, struct ehci_qh,
1407 unlink_node);
1408 list_del(&qh->unlink_node);
1409
1410 qh->qh_state = QH_STATE_IDLE;
1411 qh->qh_next.qh = NULL;
1412
1413 if (!list_empty(&qh->qtd_list))
1414 qh_completions(ehci, qh);
1415 if (!list_empty(&qh->qtd_list) &&
1416 ehci->rh_state == EHCI_RH_RUNNING)
1417 qh_link_async(ehci, qh);
1418 disable_async(ehci);
1419 }
1420 ehci->async_unlinking = false;
1421 }
1422
1423 static void start_unlink_async(struct ehci_hcd *ehci, struct ehci_qh *qh);
1424
unlink_empty_async(struct ehci_hcd * ehci)1425 static void unlink_empty_async(struct ehci_hcd *ehci)
1426 {
1427 struct ehci_qh *qh;
1428 struct ehci_qh *qh_to_unlink = NULL;
1429 int count = 0;
1430
1431 /* Find the last async QH which has been empty for a timer cycle */
1432 for (qh = ehci->async->qh_next.qh; qh; qh = qh->qh_next.qh) {
1433 if (list_empty(&qh->qtd_list) &&
1434 qh->qh_state == QH_STATE_LINKED) {
1435 ++count;
1436 if (qh->unlink_cycle != ehci->async_unlink_cycle)
1437 qh_to_unlink = qh;
1438 }
1439 }
1440
1441 /* If nothing else is being unlinked, unlink the last empty QH */
1442 if (list_empty(&ehci->async_unlink) && qh_to_unlink) {
1443 qh_to_unlink->unlink_reason |= QH_UNLINK_QUEUE_EMPTY;
1444 start_unlink_async(ehci, qh_to_unlink);
1445 --count;
1446 }
1447
1448 /* Other QHs will be handled later */
1449 if (count > 0) {
1450 ehci_enable_event(ehci, EHCI_HRTIMER_ASYNC_UNLINKS, true);
1451 ++ehci->async_unlink_cycle;
1452 }
1453 }
1454
1455 #ifdef CONFIG_PM
1456
1457 /* The root hub is suspended; unlink all the async QHs */
unlink_empty_async_suspended(struct ehci_hcd * ehci)1458 static void unlink_empty_async_suspended(struct ehci_hcd *ehci)
1459 {
1460 struct ehci_qh *qh;
1461
1462 while (ehci->async->qh_next.qh) {
1463 qh = ehci->async->qh_next.qh;
1464 WARN_ON(!list_empty(&qh->qtd_list));
1465 single_unlink_async(ehci, qh);
1466 }
1467 }
1468
1469 #endif
1470
1471 /* makes sure the async qh will become idle */
1472 /* caller must own ehci->lock */
1473
start_unlink_async(struct ehci_hcd * ehci,struct ehci_qh * qh)1474 static void start_unlink_async(struct ehci_hcd *ehci, struct ehci_qh *qh)
1475 {
1476 /* If the QH isn't linked then there's nothing we can do. */
1477 if (qh->qh_state != QH_STATE_LINKED)
1478 return;
1479
1480 single_unlink_async(ehci, qh);
1481 start_iaa_cycle(ehci);
1482 }
1483
1484 /*-------------------------------------------------------------------------*/
1485
scan_async(struct ehci_hcd * ehci)1486 static void scan_async (struct ehci_hcd *ehci)
1487 {
1488 struct ehci_qh *qh;
1489 bool check_unlinks_later = false;
1490
1491 ehci->qh_scan_next = ehci->async->qh_next.qh;
1492 while (ehci->qh_scan_next) {
1493 qh = ehci->qh_scan_next;
1494 ehci->qh_scan_next = qh->qh_next.qh;
1495
1496 /* clean any finished work for this qh */
1497 if (!list_empty(&qh->qtd_list)) {
1498 int temp;
1499
1500 /*
1501 * Unlinks could happen here; completion reporting
1502 * drops the lock. That's why ehci->qh_scan_next
1503 * always holds the next qh to scan; if the next qh
1504 * gets unlinked then ehci->qh_scan_next is adjusted
1505 * in single_unlink_async().
1506 */
1507 temp = qh_completions(ehci, qh);
1508 if (unlikely(temp)) {
1509 start_unlink_async(ehci, qh);
1510 } else if (list_empty(&qh->qtd_list)
1511 && qh->qh_state == QH_STATE_LINKED) {
1512 qh->unlink_cycle = ehci->async_unlink_cycle;
1513 check_unlinks_later = true;
1514 }
1515 }
1516 }
1517
1518 /*
1519 * Unlink empty entries, reducing DMA usage as well
1520 * as HCD schedule-scanning costs. Delay for any qh
1521 * we just scanned, there's a not-unusual case that it
1522 * doesn't stay idle for long.
1523 */
1524 if (check_unlinks_later && ehci->rh_state == EHCI_RH_RUNNING &&
1525 !(ehci->enabled_hrtimer_events &
1526 BIT(EHCI_HRTIMER_ASYNC_UNLINKS))) {
1527 ehci_enable_event(ehci, EHCI_HRTIMER_ASYNC_UNLINKS, true);
1528 ++ehci->async_unlink_cycle;
1529 }
1530 }
1531