xref: /openbmc/linux/drivers/usb/host/ehci-q.c (revision d27c66ad)
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