xref: /openbmc/linux/drivers/usb/host/xhci-ring.c (revision 7b6d864b)
1 /*
2  * xHCI host controller driver
3  *
4  * Copyright (C) 2008 Intel Corp.
5  *
6  * Author: Sarah Sharp
7  * Some code borrowed from the Linux EHCI driver.
8  *
9  * This program is free software; you can redistribute it and/or modify
10  * it under the terms of the GNU General Public License version 2 as
11  * published by the Free Software Foundation.
12  *
13  * This program is distributed in the hope that it will be useful, but
14  * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
15  * or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
16  * for more details.
17  *
18  * You should have received a copy of the GNU General Public License
19  * along with this program; if not, write to the Free Software Foundation,
20  * Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
21  */
22 
23 /*
24  * Ring initialization rules:
25  * 1. Each segment is initialized to zero, except for link TRBs.
26  * 2. Ring cycle state = 0.  This represents Producer Cycle State (PCS) or
27  *    Consumer Cycle State (CCS), depending on ring function.
28  * 3. Enqueue pointer = dequeue pointer = address of first TRB in the segment.
29  *
30  * Ring behavior rules:
31  * 1. A ring is empty if enqueue == dequeue.  This means there will always be at
32  *    least one free TRB in the ring.  This is useful if you want to turn that
33  *    into a link TRB and expand the ring.
34  * 2. When incrementing an enqueue or dequeue pointer, if the next TRB is a
35  *    link TRB, then load the pointer with the address in the link TRB.  If the
36  *    link TRB had its toggle bit set, you may need to update the ring cycle
37  *    state (see cycle bit rules).  You may have to do this multiple times
38  *    until you reach a non-link TRB.
39  * 3. A ring is full if enqueue++ (for the definition of increment above)
40  *    equals the dequeue pointer.
41  *
42  * Cycle bit rules:
43  * 1. When a consumer increments a dequeue pointer and encounters a toggle bit
44  *    in a link TRB, it must toggle the ring cycle state.
45  * 2. When a producer increments an enqueue pointer and encounters a toggle bit
46  *    in a link TRB, it must toggle the ring cycle state.
47  *
48  * Producer rules:
49  * 1. Check if ring is full before you enqueue.
50  * 2. Write the ring cycle state to the cycle bit in the TRB you're enqueuing.
51  *    Update enqueue pointer between each write (which may update the ring
52  *    cycle state).
53  * 3. Notify consumer.  If SW is producer, it rings the doorbell for command
54  *    and endpoint rings.  If HC is the producer for the event ring,
55  *    and it generates an interrupt according to interrupt modulation rules.
56  *
57  * Consumer rules:
58  * 1. Check if TRB belongs to you.  If the cycle bit == your ring cycle state,
59  *    the TRB is owned by the consumer.
60  * 2. Update dequeue pointer (which may update the ring cycle state) and
61  *    continue processing TRBs until you reach a TRB which is not owned by you.
62  * 3. Notify the producer.  SW is the consumer for the event ring, and it
63  *   updates event ring dequeue pointer.  HC is the consumer for the command and
64  *   endpoint rings; it generates events on the event ring for these.
65  */
66 
67 #include <linux/scatterlist.h>
68 #include <linux/slab.h>
69 #include "xhci.h"
70 
71 static int handle_cmd_in_cmd_wait_list(struct xhci_hcd *xhci,
72 		struct xhci_virt_device *virt_dev,
73 		struct xhci_event_cmd *event);
74 
75 /*
76  * Returns zero if the TRB isn't in this segment, otherwise it returns the DMA
77  * address of the TRB.
78  */
79 dma_addr_t xhci_trb_virt_to_dma(struct xhci_segment *seg,
80 		union xhci_trb *trb)
81 {
82 	unsigned long segment_offset;
83 
84 	if (!seg || !trb || trb < seg->trbs)
85 		return 0;
86 	/* offset in TRBs */
87 	segment_offset = trb - seg->trbs;
88 	if (segment_offset > TRBS_PER_SEGMENT)
89 		return 0;
90 	return seg->dma + (segment_offset * sizeof(*trb));
91 }
92 
93 /* Does this link TRB point to the first segment in a ring,
94  * or was the previous TRB the last TRB on the last segment in the ERST?
95  */
96 static bool last_trb_on_last_seg(struct xhci_hcd *xhci, struct xhci_ring *ring,
97 		struct xhci_segment *seg, union xhci_trb *trb)
98 {
99 	if (ring == xhci->event_ring)
100 		return (trb == &seg->trbs[TRBS_PER_SEGMENT]) &&
101 			(seg->next == xhci->event_ring->first_seg);
102 	else
103 		return le32_to_cpu(trb->link.control) & LINK_TOGGLE;
104 }
105 
106 /* Is this TRB a link TRB or was the last TRB the last TRB in this event ring
107  * segment?  I.e. would the updated event TRB pointer step off the end of the
108  * event seg?
109  */
110 static int last_trb(struct xhci_hcd *xhci, struct xhci_ring *ring,
111 		struct xhci_segment *seg, union xhci_trb *trb)
112 {
113 	if (ring == xhci->event_ring)
114 		return trb == &seg->trbs[TRBS_PER_SEGMENT];
115 	else
116 		return TRB_TYPE_LINK_LE32(trb->link.control);
117 }
118 
119 static int enqueue_is_link_trb(struct xhci_ring *ring)
120 {
121 	struct xhci_link_trb *link = &ring->enqueue->link;
122 	return TRB_TYPE_LINK_LE32(link->control);
123 }
124 
125 /* Updates trb to point to the next TRB in the ring, and updates seg if the next
126  * TRB is in a new segment.  This does not skip over link TRBs, and it does not
127  * effect the ring dequeue or enqueue pointers.
128  */
129 static void next_trb(struct xhci_hcd *xhci,
130 		struct xhci_ring *ring,
131 		struct xhci_segment **seg,
132 		union xhci_trb **trb)
133 {
134 	if (last_trb(xhci, ring, *seg, *trb)) {
135 		*seg = (*seg)->next;
136 		*trb = ((*seg)->trbs);
137 	} else {
138 		(*trb)++;
139 	}
140 }
141 
142 /*
143  * See Cycle bit rules. SW is the consumer for the event ring only.
144  * Don't make a ring full of link TRBs.  That would be dumb and this would loop.
145  */
146 static void inc_deq(struct xhci_hcd *xhci, struct xhci_ring *ring)
147 {
148 	unsigned long long addr;
149 
150 	ring->deq_updates++;
151 
152 	/*
153 	 * If this is not event ring, and the dequeue pointer
154 	 * is not on a link TRB, there is one more usable TRB
155 	 */
156 	if (ring->type != TYPE_EVENT &&
157 			!last_trb(xhci, ring, ring->deq_seg, ring->dequeue))
158 		ring->num_trbs_free++;
159 
160 	do {
161 		/*
162 		 * Update the dequeue pointer further if that was a link TRB or
163 		 * we're at the end of an event ring segment (which doesn't have
164 		 * link TRBS)
165 		 */
166 		if (last_trb(xhci, ring, ring->deq_seg, ring->dequeue)) {
167 			if (ring->type == TYPE_EVENT &&
168 					last_trb_on_last_seg(xhci, ring,
169 						ring->deq_seg, ring->dequeue)) {
170 				ring->cycle_state = (ring->cycle_state ? 0 : 1);
171 			}
172 			ring->deq_seg = ring->deq_seg->next;
173 			ring->dequeue = ring->deq_seg->trbs;
174 		} else {
175 			ring->dequeue++;
176 		}
177 	} while (last_trb(xhci, ring, ring->deq_seg, ring->dequeue));
178 
179 	addr = (unsigned long long) xhci_trb_virt_to_dma(ring->deq_seg, ring->dequeue);
180 }
181 
182 /*
183  * See Cycle bit rules. SW is the consumer for the event ring only.
184  * Don't make a ring full of link TRBs.  That would be dumb and this would loop.
185  *
186  * If we've just enqueued a TRB that is in the middle of a TD (meaning the
187  * chain bit is set), then set the chain bit in all the following link TRBs.
188  * If we've enqueued the last TRB in a TD, make sure the following link TRBs
189  * have their chain bit cleared (so that each Link TRB is a separate TD).
190  *
191  * Section 6.4.4.1 of the 0.95 spec says link TRBs cannot have the chain bit
192  * set, but other sections talk about dealing with the chain bit set.  This was
193  * fixed in the 0.96 specification errata, but we have to assume that all 0.95
194  * xHCI hardware can't handle the chain bit being cleared on a link TRB.
195  *
196  * @more_trbs_coming:	Will you enqueue more TRBs before calling
197  *			prepare_transfer()?
198  */
199 static void inc_enq(struct xhci_hcd *xhci, struct xhci_ring *ring,
200 			bool more_trbs_coming)
201 {
202 	u32 chain;
203 	union xhci_trb *next;
204 	unsigned long long addr;
205 
206 	chain = le32_to_cpu(ring->enqueue->generic.field[3]) & TRB_CHAIN;
207 	/* If this is not event ring, there is one less usable TRB */
208 	if (ring->type != TYPE_EVENT &&
209 			!last_trb(xhci, ring, ring->enq_seg, ring->enqueue))
210 		ring->num_trbs_free--;
211 	next = ++(ring->enqueue);
212 
213 	ring->enq_updates++;
214 	/* Update the dequeue pointer further if that was a link TRB or we're at
215 	 * the end of an event ring segment (which doesn't have link TRBS)
216 	 */
217 	while (last_trb(xhci, ring, ring->enq_seg, next)) {
218 		if (ring->type != TYPE_EVENT) {
219 			/*
220 			 * If the caller doesn't plan on enqueueing more
221 			 * TDs before ringing the doorbell, then we
222 			 * don't want to give the link TRB to the
223 			 * hardware just yet.  We'll give the link TRB
224 			 * back in prepare_ring() just before we enqueue
225 			 * the TD at the top of the ring.
226 			 */
227 			if (!chain && !more_trbs_coming)
228 				break;
229 
230 			/* If we're not dealing with 0.95 hardware or
231 			 * isoc rings on AMD 0.96 host,
232 			 * carry over the chain bit of the previous TRB
233 			 * (which may mean the chain bit is cleared).
234 			 */
235 			if (!(ring->type == TYPE_ISOC &&
236 					(xhci->quirks & XHCI_AMD_0x96_HOST))
237 						&& !xhci_link_trb_quirk(xhci)) {
238 				next->link.control &=
239 					cpu_to_le32(~TRB_CHAIN);
240 				next->link.control |=
241 					cpu_to_le32(chain);
242 			}
243 			/* Give this link TRB to the hardware */
244 			wmb();
245 			next->link.control ^= cpu_to_le32(TRB_CYCLE);
246 
247 			/* Toggle the cycle bit after the last ring segment. */
248 			if (last_trb_on_last_seg(xhci, ring, ring->enq_seg, next)) {
249 				ring->cycle_state = (ring->cycle_state ? 0 : 1);
250 			}
251 		}
252 		ring->enq_seg = ring->enq_seg->next;
253 		ring->enqueue = ring->enq_seg->trbs;
254 		next = ring->enqueue;
255 	}
256 	addr = (unsigned long long) xhci_trb_virt_to_dma(ring->enq_seg, ring->enqueue);
257 }
258 
259 /*
260  * Check to see if there's room to enqueue num_trbs on the ring and make sure
261  * enqueue pointer will not advance into dequeue segment. See rules above.
262  */
263 static inline int room_on_ring(struct xhci_hcd *xhci, struct xhci_ring *ring,
264 		unsigned int num_trbs)
265 {
266 	int num_trbs_in_deq_seg;
267 
268 	if (ring->num_trbs_free < num_trbs)
269 		return 0;
270 
271 	if (ring->type != TYPE_COMMAND && ring->type != TYPE_EVENT) {
272 		num_trbs_in_deq_seg = ring->dequeue - ring->deq_seg->trbs;
273 		if (ring->num_trbs_free < num_trbs + num_trbs_in_deq_seg)
274 			return 0;
275 	}
276 
277 	return 1;
278 }
279 
280 /* Ring the host controller doorbell after placing a command on the ring */
281 void xhci_ring_cmd_db(struct xhci_hcd *xhci)
282 {
283 	if (!(xhci->cmd_ring_state & CMD_RING_STATE_RUNNING))
284 		return;
285 
286 	xhci_dbg(xhci, "// Ding dong!\n");
287 	xhci_writel(xhci, DB_VALUE_HOST, &xhci->dba->doorbell[0]);
288 	/* Flush PCI posted writes */
289 	xhci_readl(xhci, &xhci->dba->doorbell[0]);
290 }
291 
292 static int xhci_abort_cmd_ring(struct xhci_hcd *xhci)
293 {
294 	u64 temp_64;
295 	int ret;
296 
297 	xhci_dbg(xhci, "Abort command ring\n");
298 
299 	if (!(xhci->cmd_ring_state & CMD_RING_STATE_RUNNING)) {
300 		xhci_dbg(xhci, "The command ring isn't running, "
301 				"Have the command ring been stopped?\n");
302 		return 0;
303 	}
304 
305 	temp_64 = xhci_read_64(xhci, &xhci->op_regs->cmd_ring);
306 	if (!(temp_64 & CMD_RING_RUNNING)) {
307 		xhci_dbg(xhci, "Command ring had been stopped\n");
308 		return 0;
309 	}
310 	xhci->cmd_ring_state = CMD_RING_STATE_ABORTED;
311 	xhci_write_64(xhci, temp_64 | CMD_RING_ABORT,
312 			&xhci->op_regs->cmd_ring);
313 
314 	/* Section 4.6.1.2 of xHCI 1.0 spec says software should
315 	 * time the completion od all xHCI commands, including
316 	 * the Command Abort operation. If software doesn't see
317 	 * CRR negated in a timely manner (e.g. longer than 5
318 	 * seconds), then it should assume that the there are
319 	 * larger problems with the xHC and assert HCRST.
320 	 */
321 	ret = xhci_handshake(xhci, &xhci->op_regs->cmd_ring,
322 			CMD_RING_RUNNING, 0, 5 * 1000 * 1000);
323 	if (ret < 0) {
324 		xhci_err(xhci, "Stopped the command ring failed, "
325 				"maybe the host is dead\n");
326 		xhci->xhc_state |= XHCI_STATE_DYING;
327 		xhci_quiesce(xhci);
328 		xhci_halt(xhci);
329 		return -ESHUTDOWN;
330 	}
331 
332 	return 0;
333 }
334 
335 static int xhci_queue_cd(struct xhci_hcd *xhci,
336 		struct xhci_command *command,
337 		union xhci_trb *cmd_trb)
338 {
339 	struct xhci_cd *cd;
340 	cd = kzalloc(sizeof(struct xhci_cd), GFP_ATOMIC);
341 	if (!cd)
342 		return -ENOMEM;
343 	INIT_LIST_HEAD(&cd->cancel_cmd_list);
344 
345 	cd->command = command;
346 	cd->cmd_trb = cmd_trb;
347 	list_add_tail(&cd->cancel_cmd_list, &xhci->cancel_cmd_list);
348 
349 	return 0;
350 }
351 
352 /*
353  * Cancel the command which has issue.
354  *
355  * Some commands may hang due to waiting for acknowledgement from
356  * usb device. It is outside of the xHC's ability to control and
357  * will cause the command ring is blocked. When it occurs software
358  * should intervene to recover the command ring.
359  * See Section 4.6.1.1 and 4.6.1.2
360  */
361 int xhci_cancel_cmd(struct xhci_hcd *xhci, struct xhci_command *command,
362 		union xhci_trb *cmd_trb)
363 {
364 	int retval = 0;
365 	unsigned long flags;
366 
367 	spin_lock_irqsave(&xhci->lock, flags);
368 
369 	if (xhci->xhc_state & XHCI_STATE_DYING) {
370 		xhci_warn(xhci, "Abort the command ring,"
371 				" but the xHCI is dead.\n");
372 		retval = -ESHUTDOWN;
373 		goto fail;
374 	}
375 
376 	/* queue the cmd desriptor to cancel_cmd_list */
377 	retval = xhci_queue_cd(xhci, command, cmd_trb);
378 	if (retval) {
379 		xhci_warn(xhci, "Queuing command descriptor failed.\n");
380 		goto fail;
381 	}
382 
383 	/* abort command ring */
384 	retval = xhci_abort_cmd_ring(xhci);
385 	if (retval) {
386 		xhci_err(xhci, "Abort command ring failed\n");
387 		if (unlikely(retval == -ESHUTDOWN)) {
388 			spin_unlock_irqrestore(&xhci->lock, flags);
389 			usb_hc_died(xhci_to_hcd(xhci)->primary_hcd);
390 			xhci_dbg(xhci, "xHCI host controller is dead.\n");
391 			return retval;
392 		}
393 	}
394 
395 fail:
396 	spin_unlock_irqrestore(&xhci->lock, flags);
397 	return retval;
398 }
399 
400 void xhci_ring_ep_doorbell(struct xhci_hcd *xhci,
401 		unsigned int slot_id,
402 		unsigned int ep_index,
403 		unsigned int stream_id)
404 {
405 	__le32 __iomem *db_addr = &xhci->dba->doorbell[slot_id];
406 	struct xhci_virt_ep *ep = &xhci->devs[slot_id]->eps[ep_index];
407 	unsigned int ep_state = ep->ep_state;
408 
409 	/* Don't ring the doorbell for this endpoint if there are pending
410 	 * cancellations because we don't want to interrupt processing.
411 	 * We don't want to restart any stream rings if there's a set dequeue
412 	 * pointer command pending because the device can choose to start any
413 	 * stream once the endpoint is on the HW schedule.
414 	 * FIXME - check all the stream rings for pending cancellations.
415 	 */
416 	if ((ep_state & EP_HALT_PENDING) || (ep_state & SET_DEQ_PENDING) ||
417 	    (ep_state & EP_HALTED))
418 		return;
419 	xhci_writel(xhci, DB_VALUE(ep_index, stream_id), db_addr);
420 	/* The CPU has better things to do at this point than wait for a
421 	 * write-posting flush.  It'll get there soon enough.
422 	 */
423 }
424 
425 /* Ring the doorbell for any rings with pending URBs */
426 static void ring_doorbell_for_active_rings(struct xhci_hcd *xhci,
427 		unsigned int slot_id,
428 		unsigned int ep_index)
429 {
430 	unsigned int stream_id;
431 	struct xhci_virt_ep *ep;
432 
433 	ep = &xhci->devs[slot_id]->eps[ep_index];
434 
435 	/* A ring has pending URBs if its TD list is not empty */
436 	if (!(ep->ep_state & EP_HAS_STREAMS)) {
437 		if (!(list_empty(&ep->ring->td_list)))
438 			xhci_ring_ep_doorbell(xhci, slot_id, ep_index, 0);
439 		return;
440 	}
441 
442 	for (stream_id = 1; stream_id < ep->stream_info->num_streams;
443 			stream_id++) {
444 		struct xhci_stream_info *stream_info = ep->stream_info;
445 		if (!list_empty(&stream_info->stream_rings[stream_id]->td_list))
446 			xhci_ring_ep_doorbell(xhci, slot_id, ep_index,
447 						stream_id);
448 	}
449 }
450 
451 /*
452  * Find the segment that trb is in.  Start searching in start_seg.
453  * If we must move past a segment that has a link TRB with a toggle cycle state
454  * bit set, then we will toggle the value pointed at by cycle_state.
455  */
456 static struct xhci_segment *find_trb_seg(
457 		struct xhci_segment *start_seg,
458 		union xhci_trb	*trb, int *cycle_state)
459 {
460 	struct xhci_segment *cur_seg = start_seg;
461 	struct xhci_generic_trb *generic_trb;
462 
463 	while (cur_seg->trbs > trb ||
464 			&cur_seg->trbs[TRBS_PER_SEGMENT - 1] < trb) {
465 		generic_trb = &cur_seg->trbs[TRBS_PER_SEGMENT - 1].generic;
466 		if (generic_trb->field[3] & cpu_to_le32(LINK_TOGGLE))
467 			*cycle_state ^= 0x1;
468 		cur_seg = cur_seg->next;
469 		if (cur_seg == start_seg)
470 			/* Looped over the entire list.  Oops! */
471 			return NULL;
472 	}
473 	return cur_seg;
474 }
475 
476 
477 static struct xhci_ring *xhci_triad_to_transfer_ring(struct xhci_hcd *xhci,
478 		unsigned int slot_id, unsigned int ep_index,
479 		unsigned int stream_id)
480 {
481 	struct xhci_virt_ep *ep;
482 
483 	ep = &xhci->devs[slot_id]->eps[ep_index];
484 	/* Common case: no streams */
485 	if (!(ep->ep_state & EP_HAS_STREAMS))
486 		return ep->ring;
487 
488 	if (stream_id == 0) {
489 		xhci_warn(xhci,
490 				"WARN: Slot ID %u, ep index %u has streams, "
491 				"but URB has no stream ID.\n",
492 				slot_id, ep_index);
493 		return NULL;
494 	}
495 
496 	if (stream_id < ep->stream_info->num_streams)
497 		return ep->stream_info->stream_rings[stream_id];
498 
499 	xhci_warn(xhci,
500 			"WARN: Slot ID %u, ep index %u has "
501 			"stream IDs 1 to %u allocated, "
502 			"but stream ID %u is requested.\n",
503 			slot_id, ep_index,
504 			ep->stream_info->num_streams - 1,
505 			stream_id);
506 	return NULL;
507 }
508 
509 /* Get the right ring for the given URB.
510  * If the endpoint supports streams, boundary check the URB's stream ID.
511  * If the endpoint doesn't support streams, return the singular endpoint ring.
512  */
513 static struct xhci_ring *xhci_urb_to_transfer_ring(struct xhci_hcd *xhci,
514 		struct urb *urb)
515 {
516 	return xhci_triad_to_transfer_ring(xhci, urb->dev->slot_id,
517 		xhci_get_endpoint_index(&urb->ep->desc), urb->stream_id);
518 }
519 
520 /*
521  * Move the xHC's endpoint ring dequeue pointer past cur_td.
522  * Record the new state of the xHC's endpoint ring dequeue segment,
523  * dequeue pointer, and new consumer cycle state in state.
524  * Update our internal representation of the ring's dequeue pointer.
525  *
526  * We do this in three jumps:
527  *  - First we update our new ring state to be the same as when the xHC stopped.
528  *  - Then we traverse the ring to find the segment that contains
529  *    the last TRB in the TD.  We toggle the xHC's new cycle state when we pass
530  *    any link TRBs with the toggle cycle bit set.
531  *  - Finally we move the dequeue state one TRB further, toggling the cycle bit
532  *    if we've moved it past a link TRB with the toggle cycle bit set.
533  *
534  * Some of the uses of xhci_generic_trb are grotty, but if they're done
535  * with correct __le32 accesses they should work fine.  Only users of this are
536  * in here.
537  */
538 void xhci_find_new_dequeue_state(struct xhci_hcd *xhci,
539 		unsigned int slot_id, unsigned int ep_index,
540 		unsigned int stream_id, struct xhci_td *cur_td,
541 		struct xhci_dequeue_state *state)
542 {
543 	struct xhci_virt_device *dev = xhci->devs[slot_id];
544 	struct xhci_ring *ep_ring;
545 	struct xhci_generic_trb *trb;
546 	struct xhci_ep_ctx *ep_ctx;
547 	dma_addr_t addr;
548 
549 	ep_ring = xhci_triad_to_transfer_ring(xhci, slot_id,
550 			ep_index, stream_id);
551 	if (!ep_ring) {
552 		xhci_warn(xhci, "WARN can't find new dequeue state "
553 				"for invalid stream ID %u.\n",
554 				stream_id);
555 		return;
556 	}
557 	state->new_cycle_state = 0;
558 	xhci_dbg(xhci, "Finding segment containing stopped TRB.\n");
559 	state->new_deq_seg = find_trb_seg(cur_td->start_seg,
560 			dev->eps[ep_index].stopped_trb,
561 			&state->new_cycle_state);
562 	if (!state->new_deq_seg) {
563 		WARN_ON(1);
564 		return;
565 	}
566 
567 	/* Dig out the cycle state saved by the xHC during the stop ep cmd */
568 	xhci_dbg(xhci, "Finding endpoint context\n");
569 	ep_ctx = xhci_get_ep_ctx(xhci, dev->out_ctx, ep_index);
570 	state->new_cycle_state = 0x1 & le64_to_cpu(ep_ctx->deq);
571 
572 	state->new_deq_ptr = cur_td->last_trb;
573 	xhci_dbg(xhci, "Finding segment containing last TRB in TD.\n");
574 	state->new_deq_seg = find_trb_seg(state->new_deq_seg,
575 			state->new_deq_ptr,
576 			&state->new_cycle_state);
577 	if (!state->new_deq_seg) {
578 		WARN_ON(1);
579 		return;
580 	}
581 
582 	trb = &state->new_deq_ptr->generic;
583 	if (TRB_TYPE_LINK_LE32(trb->field[3]) &&
584 	    (trb->field[3] & cpu_to_le32(LINK_TOGGLE)))
585 		state->new_cycle_state ^= 0x1;
586 	next_trb(xhci, ep_ring, &state->new_deq_seg, &state->new_deq_ptr);
587 
588 	/*
589 	 * If there is only one segment in a ring, find_trb_seg()'s while loop
590 	 * will not run, and it will return before it has a chance to see if it
591 	 * needs to toggle the cycle bit.  It can't tell if the stalled transfer
592 	 * ended just before the link TRB on a one-segment ring, or if the TD
593 	 * wrapped around the top of the ring, because it doesn't have the TD in
594 	 * question.  Look for the one-segment case where stalled TRB's address
595 	 * is greater than the new dequeue pointer address.
596 	 */
597 	if (ep_ring->first_seg == ep_ring->first_seg->next &&
598 			state->new_deq_ptr < dev->eps[ep_index].stopped_trb)
599 		state->new_cycle_state ^= 0x1;
600 	xhci_dbg(xhci, "Cycle state = 0x%x\n", state->new_cycle_state);
601 
602 	/* Don't update the ring cycle state for the producer (us). */
603 	xhci_dbg(xhci, "New dequeue segment = %p (virtual)\n",
604 			state->new_deq_seg);
605 	addr = xhci_trb_virt_to_dma(state->new_deq_seg, state->new_deq_ptr);
606 	xhci_dbg(xhci, "New dequeue pointer = 0x%llx (DMA)\n",
607 			(unsigned long long) addr);
608 }
609 
610 /* flip_cycle means flip the cycle bit of all but the first and last TRB.
611  * (The last TRB actually points to the ring enqueue pointer, which is not part
612  * of this TD.)  This is used to remove partially enqueued isoc TDs from a ring.
613  */
614 static void td_to_noop(struct xhci_hcd *xhci, struct xhci_ring *ep_ring,
615 		struct xhci_td *cur_td, bool flip_cycle)
616 {
617 	struct xhci_segment *cur_seg;
618 	union xhci_trb *cur_trb;
619 
620 	for (cur_seg = cur_td->start_seg, cur_trb = cur_td->first_trb;
621 			true;
622 			next_trb(xhci, ep_ring, &cur_seg, &cur_trb)) {
623 		if (TRB_TYPE_LINK_LE32(cur_trb->generic.field[3])) {
624 			/* Unchain any chained Link TRBs, but
625 			 * leave the pointers intact.
626 			 */
627 			cur_trb->generic.field[3] &= cpu_to_le32(~TRB_CHAIN);
628 			/* Flip the cycle bit (link TRBs can't be the first
629 			 * or last TRB).
630 			 */
631 			if (flip_cycle)
632 				cur_trb->generic.field[3] ^=
633 					cpu_to_le32(TRB_CYCLE);
634 			xhci_dbg(xhci, "Cancel (unchain) link TRB\n");
635 			xhci_dbg(xhci, "Address = %p (0x%llx dma); "
636 					"in seg %p (0x%llx dma)\n",
637 					cur_trb,
638 					(unsigned long long)xhci_trb_virt_to_dma(cur_seg, cur_trb),
639 					cur_seg,
640 					(unsigned long long)cur_seg->dma);
641 		} else {
642 			cur_trb->generic.field[0] = 0;
643 			cur_trb->generic.field[1] = 0;
644 			cur_trb->generic.field[2] = 0;
645 			/* Preserve only the cycle bit of this TRB */
646 			cur_trb->generic.field[3] &= cpu_to_le32(TRB_CYCLE);
647 			/* Flip the cycle bit except on the first or last TRB */
648 			if (flip_cycle && cur_trb != cur_td->first_trb &&
649 					cur_trb != cur_td->last_trb)
650 				cur_trb->generic.field[3] ^=
651 					cpu_to_le32(TRB_CYCLE);
652 			cur_trb->generic.field[3] |= cpu_to_le32(
653 				TRB_TYPE(TRB_TR_NOOP));
654 			xhci_dbg(xhci, "TRB to noop at offset 0x%llx\n",
655 					(unsigned long long)
656 					xhci_trb_virt_to_dma(cur_seg, cur_trb));
657 		}
658 		if (cur_trb == cur_td->last_trb)
659 			break;
660 	}
661 }
662 
663 static int queue_set_tr_deq(struct xhci_hcd *xhci, int slot_id,
664 		unsigned int ep_index, unsigned int stream_id,
665 		struct xhci_segment *deq_seg,
666 		union xhci_trb *deq_ptr, u32 cycle_state);
667 
668 void xhci_queue_new_dequeue_state(struct xhci_hcd *xhci,
669 		unsigned int slot_id, unsigned int ep_index,
670 		unsigned int stream_id,
671 		struct xhci_dequeue_state *deq_state)
672 {
673 	struct xhci_virt_ep *ep = &xhci->devs[slot_id]->eps[ep_index];
674 
675 	xhci_dbg(xhci, "Set TR Deq Ptr cmd, new deq seg = %p (0x%llx dma), "
676 			"new deq ptr = %p (0x%llx dma), new cycle = %u\n",
677 			deq_state->new_deq_seg,
678 			(unsigned long long)deq_state->new_deq_seg->dma,
679 			deq_state->new_deq_ptr,
680 			(unsigned long long)xhci_trb_virt_to_dma(deq_state->new_deq_seg, deq_state->new_deq_ptr),
681 			deq_state->new_cycle_state);
682 	queue_set_tr_deq(xhci, slot_id, ep_index, stream_id,
683 			deq_state->new_deq_seg,
684 			deq_state->new_deq_ptr,
685 			(u32) deq_state->new_cycle_state);
686 	/* Stop the TD queueing code from ringing the doorbell until
687 	 * this command completes.  The HC won't set the dequeue pointer
688 	 * if the ring is running, and ringing the doorbell starts the
689 	 * ring running.
690 	 */
691 	ep->ep_state |= SET_DEQ_PENDING;
692 }
693 
694 static void xhci_stop_watchdog_timer_in_irq(struct xhci_hcd *xhci,
695 		struct xhci_virt_ep *ep)
696 {
697 	ep->ep_state &= ~EP_HALT_PENDING;
698 	/* Can't del_timer_sync in interrupt, so we attempt to cancel.  If the
699 	 * timer is running on another CPU, we don't decrement stop_cmds_pending
700 	 * (since we didn't successfully stop the watchdog timer).
701 	 */
702 	if (del_timer(&ep->stop_cmd_timer))
703 		ep->stop_cmds_pending--;
704 }
705 
706 /* Must be called with xhci->lock held in interrupt context */
707 static void xhci_giveback_urb_in_irq(struct xhci_hcd *xhci,
708 		struct xhci_td *cur_td, int status, char *adjective)
709 {
710 	struct usb_hcd *hcd;
711 	struct urb	*urb;
712 	struct urb_priv	*urb_priv;
713 
714 	urb = cur_td->urb;
715 	urb_priv = urb->hcpriv;
716 	urb_priv->td_cnt++;
717 	hcd = bus_to_hcd(urb->dev->bus);
718 
719 	/* Only giveback urb when this is the last td in urb */
720 	if (urb_priv->td_cnt == urb_priv->length) {
721 		if (usb_pipetype(urb->pipe) == PIPE_ISOCHRONOUS) {
722 			xhci_to_hcd(xhci)->self.bandwidth_isoc_reqs--;
723 			if (xhci_to_hcd(xhci)->self.bandwidth_isoc_reqs	== 0) {
724 				if (xhci->quirks & XHCI_AMD_PLL_FIX)
725 					usb_amd_quirk_pll_enable();
726 			}
727 		}
728 		usb_hcd_unlink_urb_from_ep(hcd, urb);
729 
730 		spin_unlock(&xhci->lock);
731 		usb_hcd_giveback_urb(hcd, urb, status);
732 		xhci_urb_free_priv(xhci, urb_priv);
733 		spin_lock(&xhci->lock);
734 	}
735 }
736 
737 /*
738  * When we get a command completion for a Stop Endpoint Command, we need to
739  * unlink any cancelled TDs from the ring.  There are two ways to do that:
740  *
741  *  1. If the HW was in the middle of processing the TD that needs to be
742  *     cancelled, then we must move the ring's dequeue pointer past the last TRB
743  *     in the TD with a Set Dequeue Pointer Command.
744  *  2. Otherwise, we turn all the TRBs in the TD into No-op TRBs (with the chain
745  *     bit cleared) so that the HW will skip over them.
746  */
747 static void handle_stopped_endpoint(struct xhci_hcd *xhci,
748 		union xhci_trb *trb, struct xhci_event_cmd *event)
749 {
750 	unsigned int slot_id;
751 	unsigned int ep_index;
752 	struct xhci_virt_device *virt_dev;
753 	struct xhci_ring *ep_ring;
754 	struct xhci_virt_ep *ep;
755 	struct list_head *entry;
756 	struct xhci_td *cur_td = NULL;
757 	struct xhci_td *last_unlinked_td;
758 
759 	struct xhci_dequeue_state deq_state;
760 
761 	if (unlikely(TRB_TO_SUSPEND_PORT(
762 			     le32_to_cpu(xhci->cmd_ring->dequeue->generic.field[3])))) {
763 		slot_id = TRB_TO_SLOT_ID(
764 			le32_to_cpu(xhci->cmd_ring->dequeue->generic.field[3]));
765 		virt_dev = xhci->devs[slot_id];
766 		if (virt_dev)
767 			handle_cmd_in_cmd_wait_list(xhci, virt_dev,
768 				event);
769 		else
770 			xhci_warn(xhci, "Stop endpoint command "
771 				"completion for disabled slot %u\n",
772 				slot_id);
773 		return;
774 	}
775 
776 	memset(&deq_state, 0, sizeof(deq_state));
777 	slot_id = TRB_TO_SLOT_ID(le32_to_cpu(trb->generic.field[3]));
778 	ep_index = TRB_TO_EP_INDEX(le32_to_cpu(trb->generic.field[3]));
779 	ep = &xhci->devs[slot_id]->eps[ep_index];
780 
781 	if (list_empty(&ep->cancelled_td_list)) {
782 		xhci_stop_watchdog_timer_in_irq(xhci, ep);
783 		ep->stopped_td = NULL;
784 		ep->stopped_trb = NULL;
785 		ring_doorbell_for_active_rings(xhci, slot_id, ep_index);
786 		return;
787 	}
788 
789 	/* Fix up the ep ring first, so HW stops executing cancelled TDs.
790 	 * We have the xHCI lock, so nothing can modify this list until we drop
791 	 * it.  We're also in the event handler, so we can't get re-interrupted
792 	 * if another Stop Endpoint command completes
793 	 */
794 	list_for_each(entry, &ep->cancelled_td_list) {
795 		cur_td = list_entry(entry, struct xhci_td, cancelled_td_list);
796 		xhci_dbg(xhci, "Removing canceled TD starting at 0x%llx (dma).\n",
797 				(unsigned long long)xhci_trb_virt_to_dma(
798 					cur_td->start_seg, cur_td->first_trb));
799 		ep_ring = xhci_urb_to_transfer_ring(xhci, cur_td->urb);
800 		if (!ep_ring) {
801 			/* This shouldn't happen unless a driver is mucking
802 			 * with the stream ID after submission.  This will
803 			 * leave the TD on the hardware ring, and the hardware
804 			 * will try to execute it, and may access a buffer
805 			 * that has already been freed.  In the best case, the
806 			 * hardware will execute it, and the event handler will
807 			 * ignore the completion event for that TD, since it was
808 			 * removed from the td_list for that endpoint.  In
809 			 * short, don't muck with the stream ID after
810 			 * submission.
811 			 */
812 			xhci_warn(xhci, "WARN Cancelled URB %p "
813 					"has invalid stream ID %u.\n",
814 					cur_td->urb,
815 					cur_td->urb->stream_id);
816 			goto remove_finished_td;
817 		}
818 		/*
819 		 * If we stopped on the TD we need to cancel, then we have to
820 		 * move the xHC endpoint ring dequeue pointer past this TD.
821 		 */
822 		if (cur_td == ep->stopped_td)
823 			xhci_find_new_dequeue_state(xhci, slot_id, ep_index,
824 					cur_td->urb->stream_id,
825 					cur_td, &deq_state);
826 		else
827 			td_to_noop(xhci, ep_ring, cur_td, false);
828 remove_finished_td:
829 		/*
830 		 * The event handler won't see a completion for this TD anymore,
831 		 * so remove it from the endpoint ring's TD list.  Keep it in
832 		 * the cancelled TD list for URB completion later.
833 		 */
834 		list_del_init(&cur_td->td_list);
835 	}
836 	last_unlinked_td = cur_td;
837 	xhci_stop_watchdog_timer_in_irq(xhci, ep);
838 
839 	/* If necessary, queue a Set Transfer Ring Dequeue Pointer command */
840 	if (deq_state.new_deq_ptr && deq_state.new_deq_seg) {
841 		xhci_queue_new_dequeue_state(xhci,
842 				slot_id, ep_index,
843 				ep->stopped_td->urb->stream_id,
844 				&deq_state);
845 		xhci_ring_cmd_db(xhci);
846 	} else {
847 		/* Otherwise ring the doorbell(s) to restart queued transfers */
848 		ring_doorbell_for_active_rings(xhci, slot_id, ep_index);
849 	}
850 	ep->stopped_td = NULL;
851 	ep->stopped_trb = NULL;
852 
853 	/*
854 	 * Drop the lock and complete the URBs in the cancelled TD list.
855 	 * New TDs to be cancelled might be added to the end of the list before
856 	 * we can complete all the URBs for the TDs we already unlinked.
857 	 * So stop when we've completed the URB for the last TD we unlinked.
858 	 */
859 	do {
860 		cur_td = list_entry(ep->cancelled_td_list.next,
861 				struct xhci_td, cancelled_td_list);
862 		list_del_init(&cur_td->cancelled_td_list);
863 
864 		/* Clean up the cancelled URB */
865 		/* Doesn't matter what we pass for status, since the core will
866 		 * just overwrite it (because the URB has been unlinked).
867 		 */
868 		xhci_giveback_urb_in_irq(xhci, cur_td, 0, "cancelled");
869 
870 		/* Stop processing the cancelled list if the watchdog timer is
871 		 * running.
872 		 */
873 		if (xhci->xhc_state & XHCI_STATE_DYING)
874 			return;
875 	} while (cur_td != last_unlinked_td);
876 
877 	/* Return to the event handler with xhci->lock re-acquired */
878 }
879 
880 /* Watchdog timer function for when a stop endpoint command fails to complete.
881  * In this case, we assume the host controller is broken or dying or dead.  The
882  * host may still be completing some other events, so we have to be careful to
883  * let the event ring handler and the URB dequeueing/enqueueing functions know
884  * through xhci->state.
885  *
886  * The timer may also fire if the host takes a very long time to respond to the
887  * command, and the stop endpoint command completion handler cannot delete the
888  * timer before the timer function is called.  Another endpoint cancellation may
889  * sneak in before the timer function can grab the lock, and that may queue
890  * another stop endpoint command and add the timer back.  So we cannot use a
891  * simple flag to say whether there is a pending stop endpoint command for a
892  * particular endpoint.
893  *
894  * Instead we use a combination of that flag and a counter for the number of
895  * pending stop endpoint commands.  If the timer is the tail end of the last
896  * stop endpoint command, and the endpoint's command is still pending, we assume
897  * the host is dying.
898  */
899 void xhci_stop_endpoint_command_watchdog(unsigned long arg)
900 {
901 	struct xhci_hcd *xhci;
902 	struct xhci_virt_ep *ep;
903 	struct xhci_virt_ep *temp_ep;
904 	struct xhci_ring *ring;
905 	struct xhci_td *cur_td;
906 	int ret, i, j;
907 	unsigned long flags;
908 
909 	ep = (struct xhci_virt_ep *) arg;
910 	xhci = ep->xhci;
911 
912 	spin_lock_irqsave(&xhci->lock, flags);
913 
914 	ep->stop_cmds_pending--;
915 	if (xhci->xhc_state & XHCI_STATE_DYING) {
916 		xhci_dbg(xhci, "Stop EP timer ran, but another timer marked "
917 				"xHCI as DYING, exiting.\n");
918 		spin_unlock_irqrestore(&xhci->lock, flags);
919 		return;
920 	}
921 	if (!(ep->stop_cmds_pending == 0 && (ep->ep_state & EP_HALT_PENDING))) {
922 		xhci_dbg(xhci, "Stop EP timer ran, but no command pending, "
923 				"exiting.\n");
924 		spin_unlock_irqrestore(&xhci->lock, flags);
925 		return;
926 	}
927 
928 	xhci_warn(xhci, "xHCI host not responding to stop endpoint command.\n");
929 	xhci_warn(xhci, "Assuming host is dying, halting host.\n");
930 	/* Oops, HC is dead or dying or at least not responding to the stop
931 	 * endpoint command.
932 	 */
933 	xhci->xhc_state |= XHCI_STATE_DYING;
934 	/* Disable interrupts from the host controller and start halting it */
935 	xhci_quiesce(xhci);
936 	spin_unlock_irqrestore(&xhci->lock, flags);
937 
938 	ret = xhci_halt(xhci);
939 
940 	spin_lock_irqsave(&xhci->lock, flags);
941 	if (ret < 0) {
942 		/* This is bad; the host is not responding to commands and it's
943 		 * not allowing itself to be halted.  At least interrupts are
944 		 * disabled. If we call usb_hc_died(), it will attempt to
945 		 * disconnect all device drivers under this host.  Those
946 		 * disconnect() methods will wait for all URBs to be unlinked,
947 		 * so we must complete them.
948 		 */
949 		xhci_warn(xhci, "Non-responsive xHCI host is not halting.\n");
950 		xhci_warn(xhci, "Completing active URBs anyway.\n");
951 		/* We could turn all TDs on the rings to no-ops.  This won't
952 		 * help if the host has cached part of the ring, and is slow if
953 		 * we want to preserve the cycle bit.  Skip it and hope the host
954 		 * doesn't touch the memory.
955 		 */
956 	}
957 	for (i = 0; i < MAX_HC_SLOTS; i++) {
958 		if (!xhci->devs[i])
959 			continue;
960 		for (j = 0; j < 31; j++) {
961 			temp_ep = &xhci->devs[i]->eps[j];
962 			ring = temp_ep->ring;
963 			if (!ring)
964 				continue;
965 			xhci_dbg(xhci, "Killing URBs for slot ID %u, "
966 					"ep index %u\n", i, j);
967 			while (!list_empty(&ring->td_list)) {
968 				cur_td = list_first_entry(&ring->td_list,
969 						struct xhci_td,
970 						td_list);
971 				list_del_init(&cur_td->td_list);
972 				if (!list_empty(&cur_td->cancelled_td_list))
973 					list_del_init(&cur_td->cancelled_td_list);
974 				xhci_giveback_urb_in_irq(xhci, cur_td,
975 						-ESHUTDOWN, "killed");
976 			}
977 			while (!list_empty(&temp_ep->cancelled_td_list)) {
978 				cur_td = list_first_entry(
979 						&temp_ep->cancelled_td_list,
980 						struct xhci_td,
981 						cancelled_td_list);
982 				list_del_init(&cur_td->cancelled_td_list);
983 				xhci_giveback_urb_in_irq(xhci, cur_td,
984 						-ESHUTDOWN, "killed");
985 			}
986 		}
987 	}
988 	spin_unlock_irqrestore(&xhci->lock, flags);
989 	xhci_dbg(xhci, "Calling usb_hc_died()\n");
990 	usb_hc_died(xhci_to_hcd(xhci)->primary_hcd);
991 	xhci_dbg(xhci, "xHCI host controller is dead.\n");
992 }
993 
994 
995 static void update_ring_for_set_deq_completion(struct xhci_hcd *xhci,
996 		struct xhci_virt_device *dev,
997 		struct xhci_ring *ep_ring,
998 		unsigned int ep_index)
999 {
1000 	union xhci_trb *dequeue_temp;
1001 	int num_trbs_free_temp;
1002 	bool revert = false;
1003 
1004 	num_trbs_free_temp = ep_ring->num_trbs_free;
1005 	dequeue_temp = ep_ring->dequeue;
1006 
1007 	/* If we get two back-to-back stalls, and the first stalled transfer
1008 	 * ends just before a link TRB, the dequeue pointer will be left on
1009 	 * the link TRB by the code in the while loop.  So we have to update
1010 	 * the dequeue pointer one segment further, or we'll jump off
1011 	 * the segment into la-la-land.
1012 	 */
1013 	if (last_trb(xhci, ep_ring, ep_ring->deq_seg, ep_ring->dequeue)) {
1014 		ep_ring->deq_seg = ep_ring->deq_seg->next;
1015 		ep_ring->dequeue = ep_ring->deq_seg->trbs;
1016 	}
1017 
1018 	while (ep_ring->dequeue != dev->eps[ep_index].queued_deq_ptr) {
1019 		/* We have more usable TRBs */
1020 		ep_ring->num_trbs_free++;
1021 		ep_ring->dequeue++;
1022 		if (last_trb(xhci, ep_ring, ep_ring->deq_seg,
1023 				ep_ring->dequeue)) {
1024 			if (ep_ring->dequeue ==
1025 					dev->eps[ep_index].queued_deq_ptr)
1026 				break;
1027 			ep_ring->deq_seg = ep_ring->deq_seg->next;
1028 			ep_ring->dequeue = ep_ring->deq_seg->trbs;
1029 		}
1030 		if (ep_ring->dequeue == dequeue_temp) {
1031 			revert = true;
1032 			break;
1033 		}
1034 	}
1035 
1036 	if (revert) {
1037 		xhci_dbg(xhci, "Unable to find new dequeue pointer\n");
1038 		ep_ring->num_trbs_free = num_trbs_free_temp;
1039 	}
1040 }
1041 
1042 /*
1043  * When we get a completion for a Set Transfer Ring Dequeue Pointer command,
1044  * we need to clear the set deq pending flag in the endpoint ring state, so that
1045  * the TD queueing code can ring the doorbell again.  We also need to ring the
1046  * endpoint doorbell to restart the ring, but only if there aren't more
1047  * cancellations pending.
1048  */
1049 static void handle_set_deq_completion(struct xhci_hcd *xhci,
1050 		struct xhci_event_cmd *event,
1051 		union xhci_trb *trb)
1052 {
1053 	unsigned int slot_id;
1054 	unsigned int ep_index;
1055 	unsigned int stream_id;
1056 	struct xhci_ring *ep_ring;
1057 	struct xhci_virt_device *dev;
1058 	struct xhci_ep_ctx *ep_ctx;
1059 	struct xhci_slot_ctx *slot_ctx;
1060 
1061 	slot_id = TRB_TO_SLOT_ID(le32_to_cpu(trb->generic.field[3]));
1062 	ep_index = TRB_TO_EP_INDEX(le32_to_cpu(trb->generic.field[3]));
1063 	stream_id = TRB_TO_STREAM_ID(le32_to_cpu(trb->generic.field[2]));
1064 	dev = xhci->devs[slot_id];
1065 
1066 	ep_ring = xhci_stream_id_to_ring(dev, ep_index, stream_id);
1067 	if (!ep_ring) {
1068 		xhci_warn(xhci, "WARN Set TR deq ptr command for "
1069 				"freed stream ID %u\n",
1070 				stream_id);
1071 		/* XXX: Harmless??? */
1072 		dev->eps[ep_index].ep_state &= ~SET_DEQ_PENDING;
1073 		return;
1074 	}
1075 
1076 	ep_ctx = xhci_get_ep_ctx(xhci, dev->out_ctx, ep_index);
1077 	slot_ctx = xhci_get_slot_ctx(xhci, dev->out_ctx);
1078 
1079 	if (GET_COMP_CODE(le32_to_cpu(event->status)) != COMP_SUCCESS) {
1080 		unsigned int ep_state;
1081 		unsigned int slot_state;
1082 
1083 		switch (GET_COMP_CODE(le32_to_cpu(event->status))) {
1084 		case COMP_TRB_ERR:
1085 			xhci_warn(xhci, "WARN Set TR Deq Ptr cmd invalid because "
1086 					"of stream ID configuration\n");
1087 			break;
1088 		case COMP_CTX_STATE:
1089 			xhci_warn(xhci, "WARN Set TR Deq Ptr cmd failed due "
1090 					"to incorrect slot or ep state.\n");
1091 			ep_state = le32_to_cpu(ep_ctx->ep_info);
1092 			ep_state &= EP_STATE_MASK;
1093 			slot_state = le32_to_cpu(slot_ctx->dev_state);
1094 			slot_state = GET_SLOT_STATE(slot_state);
1095 			xhci_dbg(xhci, "Slot state = %u, EP state = %u\n",
1096 					slot_state, ep_state);
1097 			break;
1098 		case COMP_EBADSLT:
1099 			xhci_warn(xhci, "WARN Set TR Deq Ptr cmd failed because "
1100 					"slot %u was not enabled.\n", slot_id);
1101 			break;
1102 		default:
1103 			xhci_warn(xhci, "WARN Set TR Deq Ptr cmd with unknown "
1104 					"completion code of %u.\n",
1105 				  GET_COMP_CODE(le32_to_cpu(event->status)));
1106 			break;
1107 		}
1108 		/* OK what do we do now?  The endpoint state is hosed, and we
1109 		 * should never get to this point if the synchronization between
1110 		 * queueing, and endpoint state are correct.  This might happen
1111 		 * if the device gets disconnected after we've finished
1112 		 * cancelling URBs, which might not be an error...
1113 		 */
1114 	} else {
1115 		xhci_dbg(xhci, "Successful Set TR Deq Ptr cmd, deq = @%08llx\n",
1116 			 le64_to_cpu(ep_ctx->deq));
1117 		if (xhci_trb_virt_to_dma(dev->eps[ep_index].queued_deq_seg,
1118 					 dev->eps[ep_index].queued_deq_ptr) ==
1119 		    (le64_to_cpu(ep_ctx->deq) & ~(EP_CTX_CYCLE_MASK))) {
1120 			/* Update the ring's dequeue segment and dequeue pointer
1121 			 * to reflect the new position.
1122 			 */
1123 			update_ring_for_set_deq_completion(xhci, dev,
1124 				ep_ring, ep_index);
1125 		} else {
1126 			xhci_warn(xhci, "Mismatch between completed Set TR Deq "
1127 					"Ptr command & xHCI internal state.\n");
1128 			xhci_warn(xhci, "ep deq seg = %p, deq ptr = %p\n",
1129 					dev->eps[ep_index].queued_deq_seg,
1130 					dev->eps[ep_index].queued_deq_ptr);
1131 		}
1132 	}
1133 
1134 	dev->eps[ep_index].ep_state &= ~SET_DEQ_PENDING;
1135 	dev->eps[ep_index].queued_deq_seg = NULL;
1136 	dev->eps[ep_index].queued_deq_ptr = NULL;
1137 	/* Restart any rings with pending URBs */
1138 	ring_doorbell_for_active_rings(xhci, slot_id, ep_index);
1139 }
1140 
1141 static void handle_reset_ep_completion(struct xhci_hcd *xhci,
1142 		struct xhci_event_cmd *event,
1143 		union xhci_trb *trb)
1144 {
1145 	int slot_id;
1146 	unsigned int ep_index;
1147 
1148 	slot_id = TRB_TO_SLOT_ID(le32_to_cpu(trb->generic.field[3]));
1149 	ep_index = TRB_TO_EP_INDEX(le32_to_cpu(trb->generic.field[3]));
1150 	/* This command will only fail if the endpoint wasn't halted,
1151 	 * but we don't care.
1152 	 */
1153 	xhci_dbg(xhci, "Ignoring reset ep completion code of %u\n",
1154 		 GET_COMP_CODE(le32_to_cpu(event->status)));
1155 
1156 	/* HW with the reset endpoint quirk needs to have a configure endpoint
1157 	 * command complete before the endpoint can be used.  Queue that here
1158 	 * because the HW can't handle two commands being queued in a row.
1159 	 */
1160 	if (xhci->quirks & XHCI_RESET_EP_QUIRK) {
1161 		xhci_dbg(xhci, "Queueing configure endpoint command\n");
1162 		xhci_queue_configure_endpoint(xhci,
1163 				xhci->devs[slot_id]->in_ctx->dma, slot_id,
1164 				false);
1165 		xhci_ring_cmd_db(xhci);
1166 	} else {
1167 		/* Clear our internal halted state and restart the ring(s) */
1168 		xhci->devs[slot_id]->eps[ep_index].ep_state &= ~EP_HALTED;
1169 		ring_doorbell_for_active_rings(xhci, slot_id, ep_index);
1170 	}
1171 }
1172 
1173 /* Complete the command and detele it from the devcie's command queue.
1174  */
1175 static void xhci_complete_cmd_in_cmd_wait_list(struct xhci_hcd *xhci,
1176 		struct xhci_command *command, u32 status)
1177 {
1178 	command->status = status;
1179 	list_del(&command->cmd_list);
1180 	if (command->completion)
1181 		complete(command->completion);
1182 	else
1183 		xhci_free_command(xhci, command);
1184 }
1185 
1186 
1187 /* Check to see if a command in the device's command queue matches this one.
1188  * Signal the completion or free the command, and return 1.  Return 0 if the
1189  * completed command isn't at the head of the command list.
1190  */
1191 static int handle_cmd_in_cmd_wait_list(struct xhci_hcd *xhci,
1192 		struct xhci_virt_device *virt_dev,
1193 		struct xhci_event_cmd *event)
1194 {
1195 	struct xhci_command *command;
1196 
1197 	if (list_empty(&virt_dev->cmd_list))
1198 		return 0;
1199 
1200 	command = list_entry(virt_dev->cmd_list.next,
1201 			struct xhci_command, cmd_list);
1202 	if (xhci->cmd_ring->dequeue != command->command_trb)
1203 		return 0;
1204 
1205 	xhci_complete_cmd_in_cmd_wait_list(xhci, command,
1206 			GET_COMP_CODE(le32_to_cpu(event->status)));
1207 	return 1;
1208 }
1209 
1210 /*
1211  * Finding the command trb need to be cancelled and modifying it to
1212  * NO OP command. And if the command is in device's command wait
1213  * list, finishing and freeing it.
1214  *
1215  * If we can't find the command trb, we think it had already been
1216  * executed.
1217  */
1218 static void xhci_cmd_to_noop(struct xhci_hcd *xhci, struct xhci_cd *cur_cd)
1219 {
1220 	struct xhci_segment *cur_seg;
1221 	union xhci_trb *cmd_trb;
1222 	u32 cycle_state;
1223 
1224 	if (xhci->cmd_ring->dequeue == xhci->cmd_ring->enqueue)
1225 		return;
1226 
1227 	/* find the current segment of command ring */
1228 	cur_seg = find_trb_seg(xhci->cmd_ring->first_seg,
1229 			xhci->cmd_ring->dequeue, &cycle_state);
1230 
1231 	if (!cur_seg) {
1232 		xhci_warn(xhci, "Command ring mismatch, dequeue = %p %llx (dma)\n",
1233 				xhci->cmd_ring->dequeue,
1234 				(unsigned long long)
1235 				xhci_trb_virt_to_dma(xhci->cmd_ring->deq_seg,
1236 					xhci->cmd_ring->dequeue));
1237 		xhci_debug_ring(xhci, xhci->cmd_ring);
1238 		xhci_dbg_ring_ptrs(xhci, xhci->cmd_ring);
1239 		return;
1240 	}
1241 
1242 	/* find the command trb matched by cd from command ring */
1243 	for (cmd_trb = xhci->cmd_ring->dequeue;
1244 			cmd_trb != xhci->cmd_ring->enqueue;
1245 			next_trb(xhci, xhci->cmd_ring, &cur_seg, &cmd_trb)) {
1246 		/* If the trb is link trb, continue */
1247 		if (TRB_TYPE_LINK_LE32(cmd_trb->generic.field[3]))
1248 			continue;
1249 
1250 		if (cur_cd->cmd_trb == cmd_trb) {
1251 
1252 			/* If the command in device's command list, we should
1253 			 * finish it and free the command structure.
1254 			 */
1255 			if (cur_cd->command)
1256 				xhci_complete_cmd_in_cmd_wait_list(xhci,
1257 					cur_cd->command, COMP_CMD_STOP);
1258 
1259 			/* get cycle state from the origin command trb */
1260 			cycle_state = le32_to_cpu(cmd_trb->generic.field[3])
1261 				& TRB_CYCLE;
1262 
1263 			/* modify the command trb to NO OP command */
1264 			cmd_trb->generic.field[0] = 0;
1265 			cmd_trb->generic.field[1] = 0;
1266 			cmd_trb->generic.field[2] = 0;
1267 			cmd_trb->generic.field[3] = cpu_to_le32(
1268 					TRB_TYPE(TRB_CMD_NOOP) | cycle_state);
1269 			break;
1270 		}
1271 	}
1272 }
1273 
1274 static void xhci_cancel_cmd_in_cd_list(struct xhci_hcd *xhci)
1275 {
1276 	struct xhci_cd *cur_cd, *next_cd;
1277 
1278 	if (list_empty(&xhci->cancel_cmd_list))
1279 		return;
1280 
1281 	list_for_each_entry_safe(cur_cd, next_cd,
1282 			&xhci->cancel_cmd_list, cancel_cmd_list) {
1283 		xhci_cmd_to_noop(xhci, cur_cd);
1284 		list_del(&cur_cd->cancel_cmd_list);
1285 		kfree(cur_cd);
1286 	}
1287 }
1288 
1289 /*
1290  * traversing the cancel_cmd_list. If the command descriptor according
1291  * to cmd_trb is found, the function free it and return 1, otherwise
1292  * return 0.
1293  */
1294 static int xhci_search_cmd_trb_in_cd_list(struct xhci_hcd *xhci,
1295 		union xhci_trb *cmd_trb)
1296 {
1297 	struct xhci_cd *cur_cd, *next_cd;
1298 
1299 	if (list_empty(&xhci->cancel_cmd_list))
1300 		return 0;
1301 
1302 	list_for_each_entry_safe(cur_cd, next_cd,
1303 			&xhci->cancel_cmd_list, cancel_cmd_list) {
1304 		if (cur_cd->cmd_trb == cmd_trb) {
1305 			if (cur_cd->command)
1306 				xhci_complete_cmd_in_cmd_wait_list(xhci,
1307 					cur_cd->command, COMP_CMD_STOP);
1308 			list_del(&cur_cd->cancel_cmd_list);
1309 			kfree(cur_cd);
1310 			return 1;
1311 		}
1312 	}
1313 
1314 	return 0;
1315 }
1316 
1317 /*
1318  * If the cmd_trb_comp_code is COMP_CMD_ABORT, we just check whether the
1319  * trb pointed by the command ring dequeue pointer is the trb we want to
1320  * cancel or not. And if the cmd_trb_comp_code is COMP_CMD_STOP, we will
1321  * traverse the cancel_cmd_list to trun the all of the commands according
1322  * to command descriptor to NO-OP trb.
1323  */
1324 static int handle_stopped_cmd_ring(struct xhci_hcd *xhci,
1325 		int cmd_trb_comp_code)
1326 {
1327 	int cur_trb_is_good = 0;
1328 
1329 	/* Searching the cmd trb pointed by the command ring dequeue
1330 	 * pointer in command descriptor list. If it is found, free it.
1331 	 */
1332 	cur_trb_is_good = xhci_search_cmd_trb_in_cd_list(xhci,
1333 			xhci->cmd_ring->dequeue);
1334 
1335 	if (cmd_trb_comp_code == COMP_CMD_ABORT)
1336 		xhci->cmd_ring_state = CMD_RING_STATE_STOPPED;
1337 	else if (cmd_trb_comp_code == COMP_CMD_STOP) {
1338 		/* traversing the cancel_cmd_list and canceling
1339 		 * the command according to command descriptor
1340 		 */
1341 		xhci_cancel_cmd_in_cd_list(xhci);
1342 
1343 		xhci->cmd_ring_state = CMD_RING_STATE_RUNNING;
1344 		/*
1345 		 * ring command ring doorbell again to restart the
1346 		 * command ring
1347 		 */
1348 		if (xhci->cmd_ring->dequeue != xhci->cmd_ring->enqueue)
1349 			xhci_ring_cmd_db(xhci);
1350 	}
1351 	return cur_trb_is_good;
1352 }
1353 
1354 static void handle_cmd_completion(struct xhci_hcd *xhci,
1355 		struct xhci_event_cmd *event)
1356 {
1357 	int slot_id = TRB_TO_SLOT_ID(le32_to_cpu(event->flags));
1358 	u64 cmd_dma;
1359 	dma_addr_t cmd_dequeue_dma;
1360 	struct xhci_input_control_ctx *ctrl_ctx;
1361 	struct xhci_virt_device *virt_dev;
1362 	unsigned int ep_index;
1363 	struct xhci_ring *ep_ring;
1364 	unsigned int ep_state;
1365 
1366 	cmd_dma = le64_to_cpu(event->cmd_trb);
1367 	cmd_dequeue_dma = xhci_trb_virt_to_dma(xhci->cmd_ring->deq_seg,
1368 			xhci->cmd_ring->dequeue);
1369 	/* Is the command ring deq ptr out of sync with the deq seg ptr? */
1370 	if (cmd_dequeue_dma == 0) {
1371 		xhci->error_bitmask |= 1 << 4;
1372 		return;
1373 	}
1374 	/* Does the DMA address match our internal dequeue pointer address? */
1375 	if (cmd_dma != (u64) cmd_dequeue_dma) {
1376 		xhci->error_bitmask |= 1 << 5;
1377 		return;
1378 	}
1379 
1380 	if ((GET_COMP_CODE(le32_to_cpu(event->status)) == COMP_CMD_ABORT) ||
1381 		(GET_COMP_CODE(le32_to_cpu(event->status)) == COMP_CMD_STOP)) {
1382 		/* If the return value is 0, we think the trb pointed by
1383 		 * command ring dequeue pointer is a good trb. The good
1384 		 * trb means we don't want to cancel the trb, but it have
1385 		 * been stopped by host. So we should handle it normally.
1386 		 * Otherwise, driver should invoke inc_deq() and return.
1387 		 */
1388 		if (handle_stopped_cmd_ring(xhci,
1389 				GET_COMP_CODE(le32_to_cpu(event->status)))) {
1390 			inc_deq(xhci, xhci->cmd_ring);
1391 			return;
1392 		}
1393 	}
1394 
1395 	switch (le32_to_cpu(xhci->cmd_ring->dequeue->generic.field[3])
1396 		& TRB_TYPE_BITMASK) {
1397 	case TRB_TYPE(TRB_ENABLE_SLOT):
1398 		if (GET_COMP_CODE(le32_to_cpu(event->status)) == COMP_SUCCESS)
1399 			xhci->slot_id = slot_id;
1400 		else
1401 			xhci->slot_id = 0;
1402 		complete(&xhci->addr_dev);
1403 		break;
1404 	case TRB_TYPE(TRB_DISABLE_SLOT):
1405 		if (xhci->devs[slot_id]) {
1406 			if (xhci->quirks & XHCI_EP_LIMIT_QUIRK)
1407 				/* Delete default control endpoint resources */
1408 				xhci_free_device_endpoint_resources(xhci,
1409 						xhci->devs[slot_id], true);
1410 			xhci_free_virt_device(xhci, slot_id);
1411 		}
1412 		break;
1413 	case TRB_TYPE(TRB_CONFIG_EP):
1414 		virt_dev = xhci->devs[slot_id];
1415 		if (handle_cmd_in_cmd_wait_list(xhci, virt_dev, event))
1416 			break;
1417 		/*
1418 		 * Configure endpoint commands can come from the USB core
1419 		 * configuration or alt setting changes, or because the HW
1420 		 * needed an extra configure endpoint command after a reset
1421 		 * endpoint command or streams were being configured.
1422 		 * If the command was for a halted endpoint, the xHCI driver
1423 		 * is not waiting on the configure endpoint command.
1424 		 */
1425 		ctrl_ctx = xhci_get_input_control_ctx(xhci,
1426 				virt_dev->in_ctx);
1427 		if (!ctrl_ctx) {
1428 			xhci_warn(xhci, "Could not get input context, bad type.\n");
1429 			break;
1430 		}
1431 		/* Input ctx add_flags are the endpoint index plus one */
1432 		ep_index = xhci_last_valid_endpoint(le32_to_cpu(ctrl_ctx->add_flags)) - 1;
1433 		/* A usb_set_interface() call directly after clearing a halted
1434 		 * condition may race on this quirky hardware.  Not worth
1435 		 * worrying about, since this is prototype hardware.  Not sure
1436 		 * if this will work for streams, but streams support was
1437 		 * untested on this prototype.
1438 		 */
1439 		if (xhci->quirks & XHCI_RESET_EP_QUIRK &&
1440 				ep_index != (unsigned int) -1 &&
1441 		    le32_to_cpu(ctrl_ctx->add_flags) - SLOT_FLAG ==
1442 		    le32_to_cpu(ctrl_ctx->drop_flags)) {
1443 			ep_ring = xhci->devs[slot_id]->eps[ep_index].ring;
1444 			ep_state = xhci->devs[slot_id]->eps[ep_index].ep_state;
1445 			if (!(ep_state & EP_HALTED))
1446 				goto bandwidth_change;
1447 			xhci_dbg(xhci, "Completed config ep cmd - "
1448 					"last ep index = %d, state = %d\n",
1449 					ep_index, ep_state);
1450 			/* Clear internal halted state and restart ring(s) */
1451 			xhci->devs[slot_id]->eps[ep_index].ep_state &=
1452 				~EP_HALTED;
1453 			ring_doorbell_for_active_rings(xhci, slot_id, ep_index);
1454 			break;
1455 		}
1456 bandwidth_change:
1457 		xhci_dbg(xhci, "Completed config ep cmd\n");
1458 		xhci->devs[slot_id]->cmd_status =
1459 			GET_COMP_CODE(le32_to_cpu(event->status));
1460 		complete(&xhci->devs[slot_id]->cmd_completion);
1461 		break;
1462 	case TRB_TYPE(TRB_EVAL_CONTEXT):
1463 		virt_dev = xhci->devs[slot_id];
1464 		if (handle_cmd_in_cmd_wait_list(xhci, virt_dev, event))
1465 			break;
1466 		xhci->devs[slot_id]->cmd_status = GET_COMP_CODE(le32_to_cpu(event->status));
1467 		complete(&xhci->devs[slot_id]->cmd_completion);
1468 		break;
1469 	case TRB_TYPE(TRB_ADDR_DEV):
1470 		xhci->devs[slot_id]->cmd_status = GET_COMP_CODE(le32_to_cpu(event->status));
1471 		complete(&xhci->addr_dev);
1472 		break;
1473 	case TRB_TYPE(TRB_STOP_RING):
1474 		handle_stopped_endpoint(xhci, xhci->cmd_ring->dequeue, event);
1475 		break;
1476 	case TRB_TYPE(TRB_SET_DEQ):
1477 		handle_set_deq_completion(xhci, event, xhci->cmd_ring->dequeue);
1478 		break;
1479 	case TRB_TYPE(TRB_CMD_NOOP):
1480 		break;
1481 	case TRB_TYPE(TRB_RESET_EP):
1482 		handle_reset_ep_completion(xhci, event, xhci->cmd_ring->dequeue);
1483 		break;
1484 	case TRB_TYPE(TRB_RESET_DEV):
1485 		xhci_dbg(xhci, "Completed reset device command.\n");
1486 		slot_id = TRB_TO_SLOT_ID(
1487 			le32_to_cpu(xhci->cmd_ring->dequeue->generic.field[3]));
1488 		virt_dev = xhci->devs[slot_id];
1489 		if (virt_dev)
1490 			handle_cmd_in_cmd_wait_list(xhci, virt_dev, event);
1491 		else
1492 			xhci_warn(xhci, "Reset device command completion "
1493 					"for disabled slot %u\n", slot_id);
1494 		break;
1495 	case TRB_TYPE(TRB_NEC_GET_FW):
1496 		if (!(xhci->quirks & XHCI_NEC_HOST)) {
1497 			xhci->error_bitmask |= 1 << 6;
1498 			break;
1499 		}
1500 		xhci_dbg(xhci, "NEC firmware version %2x.%02x\n",
1501 			 NEC_FW_MAJOR(le32_to_cpu(event->status)),
1502 			 NEC_FW_MINOR(le32_to_cpu(event->status)));
1503 		break;
1504 	default:
1505 		/* Skip over unknown commands on the event ring */
1506 		xhci->error_bitmask |= 1 << 6;
1507 		break;
1508 	}
1509 	inc_deq(xhci, xhci->cmd_ring);
1510 }
1511 
1512 static void handle_vendor_event(struct xhci_hcd *xhci,
1513 		union xhci_trb *event)
1514 {
1515 	u32 trb_type;
1516 
1517 	trb_type = TRB_FIELD_TO_TYPE(le32_to_cpu(event->generic.field[3]));
1518 	xhci_dbg(xhci, "Vendor specific event TRB type = %u\n", trb_type);
1519 	if (trb_type == TRB_NEC_CMD_COMP && (xhci->quirks & XHCI_NEC_HOST))
1520 		handle_cmd_completion(xhci, &event->event_cmd);
1521 }
1522 
1523 /* @port_id: the one-based port ID from the hardware (indexed from array of all
1524  * port registers -- USB 3.0 and USB 2.0).
1525  *
1526  * Returns a zero-based port number, which is suitable for indexing into each of
1527  * the split roothubs' port arrays and bus state arrays.
1528  * Add one to it in order to call xhci_find_slot_id_by_port.
1529  */
1530 static unsigned int find_faked_portnum_from_hw_portnum(struct usb_hcd *hcd,
1531 		struct xhci_hcd *xhci, u32 port_id)
1532 {
1533 	unsigned int i;
1534 	unsigned int num_similar_speed_ports = 0;
1535 
1536 	/* port_id from the hardware is 1-based, but port_array[], usb3_ports[],
1537 	 * and usb2_ports are 0-based indexes.  Count the number of similar
1538 	 * speed ports, up to 1 port before this port.
1539 	 */
1540 	for (i = 0; i < (port_id - 1); i++) {
1541 		u8 port_speed = xhci->port_array[i];
1542 
1543 		/*
1544 		 * Skip ports that don't have known speeds, or have duplicate
1545 		 * Extended Capabilities port speed entries.
1546 		 */
1547 		if (port_speed == 0 || port_speed == DUPLICATE_ENTRY)
1548 			continue;
1549 
1550 		/*
1551 		 * USB 3.0 ports are always under a USB 3.0 hub.  USB 2.0 and
1552 		 * 1.1 ports are under the USB 2.0 hub.  If the port speed
1553 		 * matches the device speed, it's a similar speed port.
1554 		 */
1555 		if ((port_speed == 0x03) == (hcd->speed == HCD_USB3))
1556 			num_similar_speed_ports++;
1557 	}
1558 	return num_similar_speed_ports;
1559 }
1560 
1561 static void handle_device_notification(struct xhci_hcd *xhci,
1562 		union xhci_trb *event)
1563 {
1564 	u32 slot_id;
1565 	struct usb_device *udev;
1566 
1567 	slot_id = TRB_TO_SLOT_ID(event->generic.field[3]);
1568 	if (!xhci->devs[slot_id]) {
1569 		xhci_warn(xhci, "Device Notification event for "
1570 				"unused slot %u\n", slot_id);
1571 		return;
1572 	}
1573 
1574 	xhci_dbg(xhci, "Device Wake Notification event for slot ID %u\n",
1575 			slot_id);
1576 	udev = xhci->devs[slot_id]->udev;
1577 	if (udev && udev->parent)
1578 		usb_wakeup_notification(udev->parent, udev->portnum);
1579 }
1580 
1581 static void handle_port_status(struct xhci_hcd *xhci,
1582 		union xhci_trb *event)
1583 {
1584 	struct usb_hcd *hcd;
1585 	u32 port_id;
1586 	u32 temp, temp1;
1587 	int max_ports;
1588 	int slot_id;
1589 	unsigned int faked_port_index;
1590 	u8 major_revision;
1591 	struct xhci_bus_state *bus_state;
1592 	__le32 __iomem **port_array;
1593 	bool bogus_port_status = false;
1594 
1595 	/* Port status change events always have a successful completion code */
1596 	if (GET_COMP_CODE(le32_to_cpu(event->generic.field[2])) != COMP_SUCCESS) {
1597 		xhci_warn(xhci, "WARN: xHC returned failed port status event\n");
1598 		xhci->error_bitmask |= 1 << 8;
1599 	}
1600 	port_id = GET_PORT_ID(le32_to_cpu(event->generic.field[0]));
1601 	xhci_dbg(xhci, "Port Status Change Event for port %d\n", port_id);
1602 
1603 	max_ports = HCS_MAX_PORTS(xhci->hcs_params1);
1604 	if ((port_id <= 0) || (port_id > max_ports)) {
1605 		xhci_warn(xhci, "Invalid port id %d\n", port_id);
1606 		inc_deq(xhci, xhci->event_ring);
1607 		return;
1608 	}
1609 
1610 	/* Figure out which usb_hcd this port is attached to:
1611 	 * is it a USB 3.0 port or a USB 2.0/1.1 port?
1612 	 */
1613 	major_revision = xhci->port_array[port_id - 1];
1614 
1615 	/* Find the right roothub. */
1616 	hcd = xhci_to_hcd(xhci);
1617 	if ((major_revision == 0x03) != (hcd->speed == HCD_USB3))
1618 		hcd = xhci->shared_hcd;
1619 
1620 	if (major_revision == 0) {
1621 		xhci_warn(xhci, "Event for port %u not in "
1622 				"Extended Capabilities, ignoring.\n",
1623 				port_id);
1624 		bogus_port_status = true;
1625 		goto cleanup;
1626 	}
1627 	if (major_revision == DUPLICATE_ENTRY) {
1628 		xhci_warn(xhci, "Event for port %u duplicated in"
1629 				"Extended Capabilities, ignoring.\n",
1630 				port_id);
1631 		bogus_port_status = true;
1632 		goto cleanup;
1633 	}
1634 
1635 	/*
1636 	 * Hardware port IDs reported by a Port Status Change Event include USB
1637 	 * 3.0 and USB 2.0 ports.  We want to check if the port has reported a
1638 	 * resume event, but we first need to translate the hardware port ID
1639 	 * into the index into the ports on the correct split roothub, and the
1640 	 * correct bus_state structure.
1641 	 */
1642 	bus_state = &xhci->bus_state[hcd_index(hcd)];
1643 	if (hcd->speed == HCD_USB3)
1644 		port_array = xhci->usb3_ports;
1645 	else
1646 		port_array = xhci->usb2_ports;
1647 	/* Find the faked port hub number */
1648 	faked_port_index = find_faked_portnum_from_hw_portnum(hcd, xhci,
1649 			port_id);
1650 
1651 	temp = xhci_readl(xhci, port_array[faked_port_index]);
1652 	if (hcd->state == HC_STATE_SUSPENDED) {
1653 		xhci_dbg(xhci, "resume root hub\n");
1654 		usb_hcd_resume_root_hub(hcd);
1655 	}
1656 
1657 	if ((temp & PORT_PLC) && (temp & PORT_PLS_MASK) == XDEV_RESUME) {
1658 		xhci_dbg(xhci, "port resume event for port %d\n", port_id);
1659 
1660 		temp1 = xhci_readl(xhci, &xhci->op_regs->command);
1661 		if (!(temp1 & CMD_RUN)) {
1662 			xhci_warn(xhci, "xHC is not running.\n");
1663 			goto cleanup;
1664 		}
1665 
1666 		if (DEV_SUPERSPEED(temp)) {
1667 			xhci_dbg(xhci, "remote wake SS port %d\n", port_id);
1668 			/* Set a flag to say the port signaled remote wakeup,
1669 			 * so we can tell the difference between the end of
1670 			 * device and host initiated resume.
1671 			 */
1672 			bus_state->port_remote_wakeup |= 1 << faked_port_index;
1673 			xhci_test_and_clear_bit(xhci, port_array,
1674 					faked_port_index, PORT_PLC);
1675 			xhci_set_link_state(xhci, port_array, faked_port_index,
1676 						XDEV_U0);
1677 			/* Need to wait until the next link state change
1678 			 * indicates the device is actually in U0.
1679 			 */
1680 			bogus_port_status = true;
1681 			goto cleanup;
1682 		} else {
1683 			xhci_dbg(xhci, "resume HS port %d\n", port_id);
1684 			bus_state->resume_done[faked_port_index] = jiffies +
1685 				msecs_to_jiffies(20);
1686 			set_bit(faked_port_index, &bus_state->resuming_ports);
1687 			mod_timer(&hcd->rh_timer,
1688 				  bus_state->resume_done[faked_port_index]);
1689 			/* Do the rest in GetPortStatus */
1690 		}
1691 	}
1692 
1693 	if ((temp & PORT_PLC) && (temp & PORT_PLS_MASK) == XDEV_U0 &&
1694 			DEV_SUPERSPEED(temp)) {
1695 		xhci_dbg(xhci, "resume SS port %d finished\n", port_id);
1696 		/* We've just brought the device into U0 through either the
1697 		 * Resume state after a device remote wakeup, or through the
1698 		 * U3Exit state after a host-initiated resume.  If it's a device
1699 		 * initiated remote wake, don't pass up the link state change,
1700 		 * so the roothub behavior is consistent with external
1701 		 * USB 3.0 hub behavior.
1702 		 */
1703 		slot_id = xhci_find_slot_id_by_port(hcd, xhci,
1704 				faked_port_index + 1);
1705 		if (slot_id && xhci->devs[slot_id])
1706 			xhci_ring_device(xhci, slot_id);
1707 		if (bus_state->port_remote_wakeup & (1 << faked_port_index)) {
1708 			bus_state->port_remote_wakeup &=
1709 				~(1 << faked_port_index);
1710 			xhci_test_and_clear_bit(xhci, port_array,
1711 					faked_port_index, PORT_PLC);
1712 			usb_wakeup_notification(hcd->self.root_hub,
1713 					faked_port_index + 1);
1714 			bogus_port_status = true;
1715 			goto cleanup;
1716 		}
1717 	}
1718 
1719 	if (hcd->speed != HCD_USB3)
1720 		xhci_test_and_clear_bit(xhci, port_array, faked_port_index,
1721 					PORT_PLC);
1722 
1723 cleanup:
1724 	/* Update event ring dequeue pointer before dropping the lock */
1725 	inc_deq(xhci, xhci->event_ring);
1726 
1727 	/* Don't make the USB core poll the roothub if we got a bad port status
1728 	 * change event.  Besides, at that point we can't tell which roothub
1729 	 * (USB 2.0 or USB 3.0) to kick.
1730 	 */
1731 	if (bogus_port_status)
1732 		return;
1733 
1734 	/*
1735 	 * xHCI port-status-change events occur when the "or" of all the
1736 	 * status-change bits in the portsc register changes from 0 to 1.
1737 	 * New status changes won't cause an event if any other change
1738 	 * bits are still set.  When an event occurs, switch over to
1739 	 * polling to avoid losing status changes.
1740 	 */
1741 	xhci_dbg(xhci, "%s: starting port polling.\n", __func__);
1742 	set_bit(HCD_FLAG_POLL_RH, &hcd->flags);
1743 	spin_unlock(&xhci->lock);
1744 	/* Pass this up to the core */
1745 	usb_hcd_poll_rh_status(hcd);
1746 	spin_lock(&xhci->lock);
1747 }
1748 
1749 /*
1750  * This TD is defined by the TRBs starting at start_trb in start_seg and ending
1751  * at end_trb, which may be in another segment.  If the suspect DMA address is a
1752  * TRB in this TD, this function returns that TRB's segment.  Otherwise it
1753  * returns 0.
1754  */
1755 struct xhci_segment *trb_in_td(struct xhci_segment *start_seg,
1756 		union xhci_trb	*start_trb,
1757 		union xhci_trb	*end_trb,
1758 		dma_addr_t	suspect_dma)
1759 {
1760 	dma_addr_t start_dma;
1761 	dma_addr_t end_seg_dma;
1762 	dma_addr_t end_trb_dma;
1763 	struct xhci_segment *cur_seg;
1764 
1765 	start_dma = xhci_trb_virt_to_dma(start_seg, start_trb);
1766 	cur_seg = start_seg;
1767 
1768 	do {
1769 		if (start_dma == 0)
1770 			return NULL;
1771 		/* We may get an event for a Link TRB in the middle of a TD */
1772 		end_seg_dma = xhci_trb_virt_to_dma(cur_seg,
1773 				&cur_seg->trbs[TRBS_PER_SEGMENT - 1]);
1774 		/* If the end TRB isn't in this segment, this is set to 0 */
1775 		end_trb_dma = xhci_trb_virt_to_dma(cur_seg, end_trb);
1776 
1777 		if (end_trb_dma > 0) {
1778 			/* The end TRB is in this segment, so suspect should be here */
1779 			if (start_dma <= end_trb_dma) {
1780 				if (suspect_dma >= start_dma && suspect_dma <= end_trb_dma)
1781 					return cur_seg;
1782 			} else {
1783 				/* Case for one segment with
1784 				 * a TD wrapped around to the top
1785 				 */
1786 				if ((suspect_dma >= start_dma &&
1787 							suspect_dma <= end_seg_dma) ||
1788 						(suspect_dma >= cur_seg->dma &&
1789 						 suspect_dma <= end_trb_dma))
1790 					return cur_seg;
1791 			}
1792 			return NULL;
1793 		} else {
1794 			/* Might still be somewhere in this segment */
1795 			if (suspect_dma >= start_dma && suspect_dma <= end_seg_dma)
1796 				return cur_seg;
1797 		}
1798 		cur_seg = cur_seg->next;
1799 		start_dma = xhci_trb_virt_to_dma(cur_seg, &cur_seg->trbs[0]);
1800 	} while (cur_seg != start_seg);
1801 
1802 	return NULL;
1803 }
1804 
1805 static void xhci_cleanup_halted_endpoint(struct xhci_hcd *xhci,
1806 		unsigned int slot_id, unsigned int ep_index,
1807 		unsigned int stream_id,
1808 		struct xhci_td *td, union xhci_trb *event_trb)
1809 {
1810 	struct xhci_virt_ep *ep = &xhci->devs[slot_id]->eps[ep_index];
1811 	ep->ep_state |= EP_HALTED;
1812 	ep->stopped_td = td;
1813 	ep->stopped_trb = event_trb;
1814 	ep->stopped_stream = stream_id;
1815 
1816 	xhci_queue_reset_ep(xhci, slot_id, ep_index);
1817 	xhci_cleanup_stalled_ring(xhci, td->urb->dev, ep_index);
1818 
1819 	ep->stopped_td = NULL;
1820 	ep->stopped_trb = NULL;
1821 	ep->stopped_stream = 0;
1822 
1823 	xhci_ring_cmd_db(xhci);
1824 }
1825 
1826 /* Check if an error has halted the endpoint ring.  The class driver will
1827  * cleanup the halt for a non-default control endpoint if we indicate a stall.
1828  * However, a babble and other errors also halt the endpoint ring, and the class
1829  * driver won't clear the halt in that case, so we need to issue a Set Transfer
1830  * Ring Dequeue Pointer command manually.
1831  */
1832 static int xhci_requires_manual_halt_cleanup(struct xhci_hcd *xhci,
1833 		struct xhci_ep_ctx *ep_ctx,
1834 		unsigned int trb_comp_code)
1835 {
1836 	/* TRB completion codes that may require a manual halt cleanup */
1837 	if (trb_comp_code == COMP_TX_ERR ||
1838 			trb_comp_code == COMP_BABBLE ||
1839 			trb_comp_code == COMP_SPLIT_ERR)
1840 		/* The 0.96 spec says a babbling control endpoint
1841 		 * is not halted. The 0.96 spec says it is.  Some HW
1842 		 * claims to be 0.95 compliant, but it halts the control
1843 		 * endpoint anyway.  Check if a babble halted the
1844 		 * endpoint.
1845 		 */
1846 		if ((ep_ctx->ep_info & cpu_to_le32(EP_STATE_MASK)) ==
1847 		    cpu_to_le32(EP_STATE_HALTED))
1848 			return 1;
1849 
1850 	return 0;
1851 }
1852 
1853 int xhci_is_vendor_info_code(struct xhci_hcd *xhci, unsigned int trb_comp_code)
1854 {
1855 	if (trb_comp_code >= 224 && trb_comp_code <= 255) {
1856 		/* Vendor defined "informational" completion code,
1857 		 * treat as not-an-error.
1858 		 */
1859 		xhci_dbg(xhci, "Vendor defined info completion code %u\n",
1860 				trb_comp_code);
1861 		xhci_dbg(xhci, "Treating code as success.\n");
1862 		return 1;
1863 	}
1864 	return 0;
1865 }
1866 
1867 /*
1868  * Finish the td processing, remove the td from td list;
1869  * Return 1 if the urb can be given back.
1870  */
1871 static int finish_td(struct xhci_hcd *xhci, struct xhci_td *td,
1872 	union xhci_trb *event_trb, struct xhci_transfer_event *event,
1873 	struct xhci_virt_ep *ep, int *status, bool skip)
1874 {
1875 	struct xhci_virt_device *xdev;
1876 	struct xhci_ring *ep_ring;
1877 	unsigned int slot_id;
1878 	int ep_index;
1879 	struct urb *urb = NULL;
1880 	struct xhci_ep_ctx *ep_ctx;
1881 	int ret = 0;
1882 	struct urb_priv	*urb_priv;
1883 	u32 trb_comp_code;
1884 
1885 	slot_id = TRB_TO_SLOT_ID(le32_to_cpu(event->flags));
1886 	xdev = xhci->devs[slot_id];
1887 	ep_index = TRB_TO_EP_ID(le32_to_cpu(event->flags)) - 1;
1888 	ep_ring = xhci_dma_to_transfer_ring(ep, le64_to_cpu(event->buffer));
1889 	ep_ctx = xhci_get_ep_ctx(xhci, xdev->out_ctx, ep_index);
1890 	trb_comp_code = GET_COMP_CODE(le32_to_cpu(event->transfer_len));
1891 
1892 	if (skip)
1893 		goto td_cleanup;
1894 
1895 	if (trb_comp_code == COMP_STOP_INVAL ||
1896 			trb_comp_code == COMP_STOP) {
1897 		/* The Endpoint Stop Command completion will take care of any
1898 		 * stopped TDs.  A stopped TD may be restarted, so don't update
1899 		 * the ring dequeue pointer or take this TD off any lists yet.
1900 		 */
1901 		ep->stopped_td = td;
1902 		ep->stopped_trb = event_trb;
1903 		return 0;
1904 	} else {
1905 		if (trb_comp_code == COMP_STALL) {
1906 			/* The transfer is completed from the driver's
1907 			 * perspective, but we need to issue a set dequeue
1908 			 * command for this stalled endpoint to move the dequeue
1909 			 * pointer past the TD.  We can't do that here because
1910 			 * the halt condition must be cleared first.  Let the
1911 			 * USB class driver clear the stall later.
1912 			 */
1913 			ep->stopped_td = td;
1914 			ep->stopped_trb = event_trb;
1915 			ep->stopped_stream = ep_ring->stream_id;
1916 		} else if (xhci_requires_manual_halt_cleanup(xhci,
1917 					ep_ctx, trb_comp_code)) {
1918 			/* Other types of errors halt the endpoint, but the
1919 			 * class driver doesn't call usb_reset_endpoint() unless
1920 			 * the error is -EPIPE.  Clear the halted status in the
1921 			 * xHCI hardware manually.
1922 			 */
1923 			xhci_cleanup_halted_endpoint(xhci,
1924 					slot_id, ep_index, ep_ring->stream_id,
1925 					td, event_trb);
1926 		} else {
1927 			/* Update ring dequeue pointer */
1928 			while (ep_ring->dequeue != td->last_trb)
1929 				inc_deq(xhci, ep_ring);
1930 			inc_deq(xhci, ep_ring);
1931 		}
1932 
1933 td_cleanup:
1934 		/* Clean up the endpoint's TD list */
1935 		urb = td->urb;
1936 		urb_priv = urb->hcpriv;
1937 
1938 		/* Do one last check of the actual transfer length.
1939 		 * If the host controller said we transferred more data than
1940 		 * the buffer length, urb->actual_length will be a very big
1941 		 * number (since it's unsigned).  Play it safe and say we didn't
1942 		 * transfer anything.
1943 		 */
1944 		if (urb->actual_length > urb->transfer_buffer_length) {
1945 			xhci_warn(xhci, "URB transfer length is wrong, "
1946 					"xHC issue? req. len = %u, "
1947 					"act. len = %u\n",
1948 					urb->transfer_buffer_length,
1949 					urb->actual_length);
1950 			urb->actual_length = 0;
1951 			if (td->urb->transfer_flags & URB_SHORT_NOT_OK)
1952 				*status = -EREMOTEIO;
1953 			else
1954 				*status = 0;
1955 		}
1956 		list_del_init(&td->td_list);
1957 		/* Was this TD slated to be cancelled but completed anyway? */
1958 		if (!list_empty(&td->cancelled_td_list))
1959 			list_del_init(&td->cancelled_td_list);
1960 
1961 		urb_priv->td_cnt++;
1962 		/* Giveback the urb when all the tds are completed */
1963 		if (urb_priv->td_cnt == urb_priv->length) {
1964 			ret = 1;
1965 			if (usb_pipetype(urb->pipe) == PIPE_ISOCHRONOUS) {
1966 				xhci_to_hcd(xhci)->self.bandwidth_isoc_reqs--;
1967 				if (xhci_to_hcd(xhci)->self.bandwidth_isoc_reqs
1968 					== 0) {
1969 					if (xhci->quirks & XHCI_AMD_PLL_FIX)
1970 						usb_amd_quirk_pll_enable();
1971 				}
1972 			}
1973 		}
1974 	}
1975 
1976 	return ret;
1977 }
1978 
1979 /*
1980  * Process control tds, update urb status and actual_length.
1981  */
1982 static int process_ctrl_td(struct xhci_hcd *xhci, struct xhci_td *td,
1983 	union xhci_trb *event_trb, struct xhci_transfer_event *event,
1984 	struct xhci_virt_ep *ep, int *status)
1985 {
1986 	struct xhci_virt_device *xdev;
1987 	struct xhci_ring *ep_ring;
1988 	unsigned int slot_id;
1989 	int ep_index;
1990 	struct xhci_ep_ctx *ep_ctx;
1991 	u32 trb_comp_code;
1992 
1993 	slot_id = TRB_TO_SLOT_ID(le32_to_cpu(event->flags));
1994 	xdev = xhci->devs[slot_id];
1995 	ep_index = TRB_TO_EP_ID(le32_to_cpu(event->flags)) - 1;
1996 	ep_ring = xhci_dma_to_transfer_ring(ep, le64_to_cpu(event->buffer));
1997 	ep_ctx = xhci_get_ep_ctx(xhci, xdev->out_ctx, ep_index);
1998 	trb_comp_code = GET_COMP_CODE(le32_to_cpu(event->transfer_len));
1999 
2000 	switch (trb_comp_code) {
2001 	case COMP_SUCCESS:
2002 		if (event_trb == ep_ring->dequeue) {
2003 			xhci_warn(xhci, "WARN: Success on ctrl setup TRB "
2004 					"without IOC set??\n");
2005 			*status = -ESHUTDOWN;
2006 		} else if (event_trb != td->last_trb) {
2007 			xhci_warn(xhci, "WARN: Success on ctrl data TRB "
2008 					"without IOC set??\n");
2009 			*status = -ESHUTDOWN;
2010 		} else {
2011 			*status = 0;
2012 		}
2013 		break;
2014 	case COMP_SHORT_TX:
2015 		if (td->urb->transfer_flags & URB_SHORT_NOT_OK)
2016 			*status = -EREMOTEIO;
2017 		else
2018 			*status = 0;
2019 		break;
2020 	case COMP_STOP_INVAL:
2021 	case COMP_STOP:
2022 		return finish_td(xhci, td, event_trb, event, ep, status, false);
2023 	default:
2024 		if (!xhci_requires_manual_halt_cleanup(xhci,
2025 					ep_ctx, trb_comp_code))
2026 			break;
2027 		xhci_dbg(xhci, "TRB error code %u, "
2028 				"halted endpoint index = %u\n",
2029 				trb_comp_code, ep_index);
2030 		/* else fall through */
2031 	case COMP_STALL:
2032 		/* Did we transfer part of the data (middle) phase? */
2033 		if (event_trb != ep_ring->dequeue &&
2034 				event_trb != td->last_trb)
2035 			td->urb->actual_length =
2036 				td->urb->transfer_buffer_length -
2037 				EVENT_TRB_LEN(le32_to_cpu(event->transfer_len));
2038 		else
2039 			td->urb->actual_length = 0;
2040 
2041 		xhci_cleanup_halted_endpoint(xhci,
2042 			slot_id, ep_index, 0, td, event_trb);
2043 		return finish_td(xhci, td, event_trb, event, ep, status, true);
2044 	}
2045 	/*
2046 	 * Did we transfer any data, despite the errors that might have
2047 	 * happened?  I.e. did we get past the setup stage?
2048 	 */
2049 	if (event_trb != ep_ring->dequeue) {
2050 		/* The event was for the status stage */
2051 		if (event_trb == td->last_trb) {
2052 			if (td->urb->actual_length != 0) {
2053 				/* Don't overwrite a previously set error code
2054 				 */
2055 				if ((*status == -EINPROGRESS || *status == 0) &&
2056 						(td->urb->transfer_flags
2057 						 & URB_SHORT_NOT_OK))
2058 					/* Did we already see a short data
2059 					 * stage? */
2060 					*status = -EREMOTEIO;
2061 			} else {
2062 				td->urb->actual_length =
2063 					td->urb->transfer_buffer_length;
2064 			}
2065 		} else {
2066 		/* Maybe the event was for the data stage? */
2067 			td->urb->actual_length =
2068 				td->urb->transfer_buffer_length -
2069 				EVENT_TRB_LEN(le32_to_cpu(event->transfer_len));
2070 			xhci_dbg(xhci, "Waiting for status "
2071 					"stage event\n");
2072 			return 0;
2073 		}
2074 	}
2075 
2076 	return finish_td(xhci, td, event_trb, event, ep, status, false);
2077 }
2078 
2079 /*
2080  * Process isochronous tds, update urb packet status and actual_length.
2081  */
2082 static int process_isoc_td(struct xhci_hcd *xhci, struct xhci_td *td,
2083 	union xhci_trb *event_trb, struct xhci_transfer_event *event,
2084 	struct xhci_virt_ep *ep, int *status)
2085 {
2086 	struct xhci_ring *ep_ring;
2087 	struct urb_priv *urb_priv;
2088 	int idx;
2089 	int len = 0;
2090 	union xhci_trb *cur_trb;
2091 	struct xhci_segment *cur_seg;
2092 	struct usb_iso_packet_descriptor *frame;
2093 	u32 trb_comp_code;
2094 	bool skip_td = false;
2095 
2096 	ep_ring = xhci_dma_to_transfer_ring(ep, le64_to_cpu(event->buffer));
2097 	trb_comp_code = GET_COMP_CODE(le32_to_cpu(event->transfer_len));
2098 	urb_priv = td->urb->hcpriv;
2099 	idx = urb_priv->td_cnt;
2100 	frame = &td->urb->iso_frame_desc[idx];
2101 
2102 	/* handle completion code */
2103 	switch (trb_comp_code) {
2104 	case COMP_SUCCESS:
2105 		if (EVENT_TRB_LEN(le32_to_cpu(event->transfer_len)) == 0) {
2106 			frame->status = 0;
2107 			break;
2108 		}
2109 		if ((xhci->quirks & XHCI_TRUST_TX_LENGTH))
2110 			trb_comp_code = COMP_SHORT_TX;
2111 	case COMP_SHORT_TX:
2112 		frame->status = td->urb->transfer_flags & URB_SHORT_NOT_OK ?
2113 				-EREMOTEIO : 0;
2114 		break;
2115 	case COMP_BW_OVER:
2116 		frame->status = -ECOMM;
2117 		skip_td = true;
2118 		break;
2119 	case COMP_BUFF_OVER:
2120 	case COMP_BABBLE:
2121 		frame->status = -EOVERFLOW;
2122 		skip_td = true;
2123 		break;
2124 	case COMP_DEV_ERR:
2125 	case COMP_STALL:
2126 	case COMP_TX_ERR:
2127 		frame->status = -EPROTO;
2128 		skip_td = true;
2129 		break;
2130 	case COMP_STOP:
2131 	case COMP_STOP_INVAL:
2132 		break;
2133 	default:
2134 		frame->status = -1;
2135 		break;
2136 	}
2137 
2138 	if (trb_comp_code == COMP_SUCCESS || skip_td) {
2139 		frame->actual_length = frame->length;
2140 		td->urb->actual_length += frame->length;
2141 	} else {
2142 		for (cur_trb = ep_ring->dequeue,
2143 		     cur_seg = ep_ring->deq_seg; cur_trb != event_trb;
2144 		     next_trb(xhci, ep_ring, &cur_seg, &cur_trb)) {
2145 			if (!TRB_TYPE_NOOP_LE32(cur_trb->generic.field[3]) &&
2146 			    !TRB_TYPE_LINK_LE32(cur_trb->generic.field[3]))
2147 				len += TRB_LEN(le32_to_cpu(cur_trb->generic.field[2]));
2148 		}
2149 		len += TRB_LEN(le32_to_cpu(cur_trb->generic.field[2])) -
2150 			EVENT_TRB_LEN(le32_to_cpu(event->transfer_len));
2151 
2152 		if (trb_comp_code != COMP_STOP_INVAL) {
2153 			frame->actual_length = len;
2154 			td->urb->actual_length += len;
2155 		}
2156 	}
2157 
2158 	return finish_td(xhci, td, event_trb, event, ep, status, false);
2159 }
2160 
2161 static int skip_isoc_td(struct xhci_hcd *xhci, struct xhci_td *td,
2162 			struct xhci_transfer_event *event,
2163 			struct xhci_virt_ep *ep, int *status)
2164 {
2165 	struct xhci_ring *ep_ring;
2166 	struct urb_priv *urb_priv;
2167 	struct usb_iso_packet_descriptor *frame;
2168 	int idx;
2169 
2170 	ep_ring = xhci_dma_to_transfer_ring(ep, le64_to_cpu(event->buffer));
2171 	urb_priv = td->urb->hcpriv;
2172 	idx = urb_priv->td_cnt;
2173 	frame = &td->urb->iso_frame_desc[idx];
2174 
2175 	/* The transfer is partly done. */
2176 	frame->status = -EXDEV;
2177 
2178 	/* calc actual length */
2179 	frame->actual_length = 0;
2180 
2181 	/* Update ring dequeue pointer */
2182 	while (ep_ring->dequeue != td->last_trb)
2183 		inc_deq(xhci, ep_ring);
2184 	inc_deq(xhci, ep_ring);
2185 
2186 	return finish_td(xhci, td, NULL, event, ep, status, true);
2187 }
2188 
2189 /*
2190  * Process bulk and interrupt tds, update urb status and actual_length.
2191  */
2192 static int process_bulk_intr_td(struct xhci_hcd *xhci, struct xhci_td *td,
2193 	union xhci_trb *event_trb, struct xhci_transfer_event *event,
2194 	struct xhci_virt_ep *ep, int *status)
2195 {
2196 	struct xhci_ring *ep_ring;
2197 	union xhci_trb *cur_trb;
2198 	struct xhci_segment *cur_seg;
2199 	u32 trb_comp_code;
2200 
2201 	ep_ring = xhci_dma_to_transfer_ring(ep, le64_to_cpu(event->buffer));
2202 	trb_comp_code = GET_COMP_CODE(le32_to_cpu(event->transfer_len));
2203 
2204 	switch (trb_comp_code) {
2205 	case COMP_SUCCESS:
2206 		/* Double check that the HW transferred everything. */
2207 		if (event_trb != td->last_trb ||
2208 		    EVENT_TRB_LEN(le32_to_cpu(event->transfer_len)) != 0) {
2209 			xhci_warn(xhci, "WARN Successful completion "
2210 					"on short TX\n");
2211 			if (td->urb->transfer_flags & URB_SHORT_NOT_OK)
2212 				*status = -EREMOTEIO;
2213 			else
2214 				*status = 0;
2215 			if ((xhci->quirks & XHCI_TRUST_TX_LENGTH))
2216 				trb_comp_code = COMP_SHORT_TX;
2217 		} else {
2218 			*status = 0;
2219 		}
2220 		break;
2221 	case COMP_SHORT_TX:
2222 		if (td->urb->transfer_flags & URB_SHORT_NOT_OK)
2223 			*status = -EREMOTEIO;
2224 		else
2225 			*status = 0;
2226 		break;
2227 	default:
2228 		/* Others already handled above */
2229 		break;
2230 	}
2231 	if (trb_comp_code == COMP_SHORT_TX)
2232 		xhci_dbg(xhci, "ep %#x - asked for %d bytes, "
2233 				"%d bytes untransferred\n",
2234 				td->urb->ep->desc.bEndpointAddress,
2235 				td->urb->transfer_buffer_length,
2236 				EVENT_TRB_LEN(le32_to_cpu(event->transfer_len)));
2237 	/* Fast path - was this the last TRB in the TD for this URB? */
2238 	if (event_trb == td->last_trb) {
2239 		if (EVENT_TRB_LEN(le32_to_cpu(event->transfer_len)) != 0) {
2240 			td->urb->actual_length =
2241 				td->urb->transfer_buffer_length -
2242 				EVENT_TRB_LEN(le32_to_cpu(event->transfer_len));
2243 			if (td->urb->transfer_buffer_length <
2244 					td->urb->actual_length) {
2245 				xhci_warn(xhci, "HC gave bad length "
2246 						"of %d bytes left\n",
2247 					  EVENT_TRB_LEN(le32_to_cpu(event->transfer_len)));
2248 				td->urb->actual_length = 0;
2249 				if (td->urb->transfer_flags & URB_SHORT_NOT_OK)
2250 					*status = -EREMOTEIO;
2251 				else
2252 					*status = 0;
2253 			}
2254 			/* Don't overwrite a previously set error code */
2255 			if (*status == -EINPROGRESS) {
2256 				if (td->urb->transfer_flags & URB_SHORT_NOT_OK)
2257 					*status = -EREMOTEIO;
2258 				else
2259 					*status = 0;
2260 			}
2261 		} else {
2262 			td->urb->actual_length =
2263 				td->urb->transfer_buffer_length;
2264 			/* Ignore a short packet completion if the
2265 			 * untransferred length was zero.
2266 			 */
2267 			if (*status == -EREMOTEIO)
2268 				*status = 0;
2269 		}
2270 	} else {
2271 		/* Slow path - walk the list, starting from the dequeue
2272 		 * pointer, to get the actual length transferred.
2273 		 */
2274 		td->urb->actual_length = 0;
2275 		for (cur_trb = ep_ring->dequeue, cur_seg = ep_ring->deq_seg;
2276 				cur_trb != event_trb;
2277 				next_trb(xhci, ep_ring, &cur_seg, &cur_trb)) {
2278 			if (!TRB_TYPE_NOOP_LE32(cur_trb->generic.field[3]) &&
2279 			    !TRB_TYPE_LINK_LE32(cur_trb->generic.field[3]))
2280 				td->urb->actual_length +=
2281 					TRB_LEN(le32_to_cpu(cur_trb->generic.field[2]));
2282 		}
2283 		/* If the ring didn't stop on a Link or No-op TRB, add
2284 		 * in the actual bytes transferred from the Normal TRB
2285 		 */
2286 		if (trb_comp_code != COMP_STOP_INVAL)
2287 			td->urb->actual_length +=
2288 				TRB_LEN(le32_to_cpu(cur_trb->generic.field[2])) -
2289 				EVENT_TRB_LEN(le32_to_cpu(event->transfer_len));
2290 	}
2291 
2292 	return finish_td(xhci, td, event_trb, event, ep, status, false);
2293 }
2294 
2295 /*
2296  * If this function returns an error condition, it means it got a Transfer
2297  * event with a corrupted Slot ID, Endpoint ID, or TRB DMA address.
2298  * At this point, the host controller is probably hosed and should be reset.
2299  */
2300 static int handle_tx_event(struct xhci_hcd *xhci,
2301 		struct xhci_transfer_event *event)
2302 	__releases(&xhci->lock)
2303 	__acquires(&xhci->lock)
2304 {
2305 	struct xhci_virt_device *xdev;
2306 	struct xhci_virt_ep *ep;
2307 	struct xhci_ring *ep_ring;
2308 	unsigned int slot_id;
2309 	int ep_index;
2310 	struct xhci_td *td = NULL;
2311 	dma_addr_t event_dma;
2312 	struct xhci_segment *event_seg;
2313 	union xhci_trb *event_trb;
2314 	struct urb *urb = NULL;
2315 	int status = -EINPROGRESS;
2316 	struct urb_priv *urb_priv;
2317 	struct xhci_ep_ctx *ep_ctx;
2318 	struct list_head *tmp;
2319 	u32 trb_comp_code;
2320 	int ret = 0;
2321 	int td_num = 0;
2322 
2323 	slot_id = TRB_TO_SLOT_ID(le32_to_cpu(event->flags));
2324 	xdev = xhci->devs[slot_id];
2325 	if (!xdev) {
2326 		xhci_err(xhci, "ERROR Transfer event pointed to bad slot\n");
2327 		xhci_err(xhci, "@%016llx %08x %08x %08x %08x\n",
2328 			 (unsigned long long) xhci_trb_virt_to_dma(
2329 				 xhci->event_ring->deq_seg,
2330 				 xhci->event_ring->dequeue),
2331 			 lower_32_bits(le64_to_cpu(event->buffer)),
2332 			 upper_32_bits(le64_to_cpu(event->buffer)),
2333 			 le32_to_cpu(event->transfer_len),
2334 			 le32_to_cpu(event->flags));
2335 		xhci_dbg(xhci, "Event ring:\n");
2336 		xhci_debug_segment(xhci, xhci->event_ring->deq_seg);
2337 		return -ENODEV;
2338 	}
2339 
2340 	/* Endpoint ID is 1 based, our index is zero based */
2341 	ep_index = TRB_TO_EP_ID(le32_to_cpu(event->flags)) - 1;
2342 	ep = &xdev->eps[ep_index];
2343 	ep_ring = xhci_dma_to_transfer_ring(ep, le64_to_cpu(event->buffer));
2344 	ep_ctx = xhci_get_ep_ctx(xhci, xdev->out_ctx, ep_index);
2345 	if (!ep_ring ||
2346 	    (le32_to_cpu(ep_ctx->ep_info) & EP_STATE_MASK) ==
2347 	    EP_STATE_DISABLED) {
2348 		xhci_err(xhci, "ERROR Transfer event for disabled endpoint "
2349 				"or incorrect stream ring\n");
2350 		xhci_err(xhci, "@%016llx %08x %08x %08x %08x\n",
2351 			 (unsigned long long) xhci_trb_virt_to_dma(
2352 				 xhci->event_ring->deq_seg,
2353 				 xhci->event_ring->dequeue),
2354 			 lower_32_bits(le64_to_cpu(event->buffer)),
2355 			 upper_32_bits(le64_to_cpu(event->buffer)),
2356 			 le32_to_cpu(event->transfer_len),
2357 			 le32_to_cpu(event->flags));
2358 		xhci_dbg(xhci, "Event ring:\n");
2359 		xhci_debug_segment(xhci, xhci->event_ring->deq_seg);
2360 		return -ENODEV;
2361 	}
2362 
2363 	/* Count current td numbers if ep->skip is set */
2364 	if (ep->skip) {
2365 		list_for_each(tmp, &ep_ring->td_list)
2366 			td_num++;
2367 	}
2368 
2369 	event_dma = le64_to_cpu(event->buffer);
2370 	trb_comp_code = GET_COMP_CODE(le32_to_cpu(event->transfer_len));
2371 	/* Look for common error cases */
2372 	switch (trb_comp_code) {
2373 	/* Skip codes that require special handling depending on
2374 	 * transfer type
2375 	 */
2376 	case COMP_SUCCESS:
2377 		if (EVENT_TRB_LEN(le32_to_cpu(event->transfer_len)) == 0)
2378 			break;
2379 		if (xhci->quirks & XHCI_TRUST_TX_LENGTH)
2380 			trb_comp_code = COMP_SHORT_TX;
2381 		else
2382 			xhci_warn_ratelimited(xhci,
2383 					"WARN Successful completion on short TX: needs XHCI_TRUST_TX_LENGTH quirk?\n");
2384 	case COMP_SHORT_TX:
2385 		break;
2386 	case COMP_STOP:
2387 		xhci_dbg(xhci, "Stopped on Transfer TRB\n");
2388 		break;
2389 	case COMP_STOP_INVAL:
2390 		xhci_dbg(xhci, "Stopped on No-op or Link TRB\n");
2391 		break;
2392 	case COMP_STALL:
2393 		xhci_dbg(xhci, "Stalled endpoint\n");
2394 		ep->ep_state |= EP_HALTED;
2395 		status = -EPIPE;
2396 		break;
2397 	case COMP_TRB_ERR:
2398 		xhci_warn(xhci, "WARN: TRB error on endpoint\n");
2399 		status = -EILSEQ;
2400 		break;
2401 	case COMP_SPLIT_ERR:
2402 	case COMP_TX_ERR:
2403 		xhci_dbg(xhci, "Transfer error on endpoint\n");
2404 		status = -EPROTO;
2405 		break;
2406 	case COMP_BABBLE:
2407 		xhci_dbg(xhci, "Babble error on endpoint\n");
2408 		status = -EOVERFLOW;
2409 		break;
2410 	case COMP_DB_ERR:
2411 		xhci_warn(xhci, "WARN: HC couldn't access mem fast enough\n");
2412 		status = -ENOSR;
2413 		break;
2414 	case COMP_BW_OVER:
2415 		xhci_warn(xhci, "WARN: bandwidth overrun event on endpoint\n");
2416 		break;
2417 	case COMP_BUFF_OVER:
2418 		xhci_warn(xhci, "WARN: buffer overrun event on endpoint\n");
2419 		break;
2420 	case COMP_UNDERRUN:
2421 		/*
2422 		 * When the Isoch ring is empty, the xHC will generate
2423 		 * a Ring Overrun Event for IN Isoch endpoint or Ring
2424 		 * Underrun Event for OUT Isoch endpoint.
2425 		 */
2426 		xhci_dbg(xhci, "underrun event on endpoint\n");
2427 		if (!list_empty(&ep_ring->td_list))
2428 			xhci_dbg(xhci, "Underrun Event for slot %d ep %d "
2429 					"still with TDs queued?\n",
2430 				 TRB_TO_SLOT_ID(le32_to_cpu(event->flags)),
2431 				 ep_index);
2432 		goto cleanup;
2433 	case COMP_OVERRUN:
2434 		xhci_dbg(xhci, "overrun event on endpoint\n");
2435 		if (!list_empty(&ep_ring->td_list))
2436 			xhci_dbg(xhci, "Overrun Event for slot %d ep %d "
2437 					"still with TDs queued?\n",
2438 				 TRB_TO_SLOT_ID(le32_to_cpu(event->flags)),
2439 				 ep_index);
2440 		goto cleanup;
2441 	case COMP_DEV_ERR:
2442 		xhci_warn(xhci, "WARN: detect an incompatible device");
2443 		status = -EPROTO;
2444 		break;
2445 	case COMP_MISSED_INT:
2446 		/*
2447 		 * When encounter missed service error, one or more isoc tds
2448 		 * may be missed by xHC.
2449 		 * Set skip flag of the ep_ring; Complete the missed tds as
2450 		 * short transfer when process the ep_ring next time.
2451 		 */
2452 		ep->skip = true;
2453 		xhci_dbg(xhci, "Miss service interval error, set skip flag\n");
2454 		goto cleanup;
2455 	default:
2456 		if (xhci_is_vendor_info_code(xhci, trb_comp_code)) {
2457 			status = 0;
2458 			break;
2459 		}
2460 		xhci_warn(xhci, "ERROR Unknown event condition, HC probably "
2461 				"busted\n");
2462 		goto cleanup;
2463 	}
2464 
2465 	do {
2466 		/* This TRB should be in the TD at the head of this ring's
2467 		 * TD list.
2468 		 */
2469 		if (list_empty(&ep_ring->td_list)) {
2470 			/*
2471 			 * A stopped endpoint may generate an extra completion
2472 			 * event if the device was suspended.  Don't print
2473 			 * warnings.
2474 			 */
2475 			if (!(trb_comp_code == COMP_STOP ||
2476 						trb_comp_code == COMP_STOP_INVAL)) {
2477 				xhci_warn(xhci, "WARN Event TRB for slot %d ep %d with no TDs queued?\n",
2478 						TRB_TO_SLOT_ID(le32_to_cpu(event->flags)),
2479 						ep_index);
2480 				xhci_dbg(xhci, "Event TRB with TRB type ID %u\n",
2481 						(le32_to_cpu(event->flags) &
2482 						 TRB_TYPE_BITMASK)>>10);
2483 				xhci_print_trb_offsets(xhci, (union xhci_trb *) event);
2484 			}
2485 			if (ep->skip) {
2486 				ep->skip = false;
2487 				xhci_dbg(xhci, "td_list is empty while skip "
2488 						"flag set. Clear skip flag.\n");
2489 			}
2490 			ret = 0;
2491 			goto cleanup;
2492 		}
2493 
2494 		/* We've skipped all the TDs on the ep ring when ep->skip set */
2495 		if (ep->skip && td_num == 0) {
2496 			ep->skip = false;
2497 			xhci_dbg(xhci, "All tds on the ep_ring skipped. "
2498 						"Clear skip flag.\n");
2499 			ret = 0;
2500 			goto cleanup;
2501 		}
2502 
2503 		td = list_entry(ep_ring->td_list.next, struct xhci_td, td_list);
2504 		if (ep->skip)
2505 			td_num--;
2506 
2507 		/* Is this a TRB in the currently executing TD? */
2508 		event_seg = trb_in_td(ep_ring->deq_seg, ep_ring->dequeue,
2509 				td->last_trb, event_dma);
2510 
2511 		/*
2512 		 * Skip the Force Stopped Event. The event_trb(event_dma) of FSE
2513 		 * is not in the current TD pointed by ep_ring->dequeue because
2514 		 * that the hardware dequeue pointer still at the previous TRB
2515 		 * of the current TD. The previous TRB maybe a Link TD or the
2516 		 * last TRB of the previous TD. The command completion handle
2517 		 * will take care the rest.
2518 		 */
2519 		if (!event_seg && trb_comp_code == COMP_STOP_INVAL) {
2520 			ret = 0;
2521 			goto cleanup;
2522 		}
2523 
2524 		if (!event_seg) {
2525 			if (!ep->skip ||
2526 			    !usb_endpoint_xfer_isoc(&td->urb->ep->desc)) {
2527 				/* Some host controllers give a spurious
2528 				 * successful event after a short transfer.
2529 				 * Ignore it.
2530 				 */
2531 				if ((xhci->quirks & XHCI_SPURIOUS_SUCCESS) &&
2532 						ep_ring->last_td_was_short) {
2533 					ep_ring->last_td_was_short = false;
2534 					ret = 0;
2535 					goto cleanup;
2536 				}
2537 				/* HC is busted, give up! */
2538 				xhci_err(xhci,
2539 					"ERROR Transfer event TRB DMA ptr not "
2540 					"part of current TD\n");
2541 				return -ESHUTDOWN;
2542 			}
2543 
2544 			ret = skip_isoc_td(xhci, td, event, ep, &status);
2545 			goto cleanup;
2546 		}
2547 		if (trb_comp_code == COMP_SHORT_TX)
2548 			ep_ring->last_td_was_short = true;
2549 		else
2550 			ep_ring->last_td_was_short = false;
2551 
2552 		if (ep->skip) {
2553 			xhci_dbg(xhci, "Found td. Clear skip flag.\n");
2554 			ep->skip = false;
2555 		}
2556 
2557 		event_trb = &event_seg->trbs[(event_dma - event_seg->dma) /
2558 						sizeof(*event_trb)];
2559 		/*
2560 		 * No-op TRB should not trigger interrupts.
2561 		 * If event_trb is a no-op TRB, it means the
2562 		 * corresponding TD has been cancelled. Just ignore
2563 		 * the TD.
2564 		 */
2565 		if (TRB_TYPE_NOOP_LE32(event_trb->generic.field[3])) {
2566 			xhci_dbg(xhci,
2567 				 "event_trb is a no-op TRB. Skip it\n");
2568 			goto cleanup;
2569 		}
2570 
2571 		/* Now update the urb's actual_length and give back to
2572 		 * the core
2573 		 */
2574 		if (usb_endpoint_xfer_control(&td->urb->ep->desc))
2575 			ret = process_ctrl_td(xhci, td, event_trb, event, ep,
2576 						 &status);
2577 		else if (usb_endpoint_xfer_isoc(&td->urb->ep->desc))
2578 			ret = process_isoc_td(xhci, td, event_trb, event, ep,
2579 						 &status);
2580 		else
2581 			ret = process_bulk_intr_td(xhci, td, event_trb, event,
2582 						 ep, &status);
2583 
2584 cleanup:
2585 		/*
2586 		 * Do not update event ring dequeue pointer if ep->skip is set.
2587 		 * Will roll back to continue process missed tds.
2588 		 */
2589 		if (trb_comp_code == COMP_MISSED_INT || !ep->skip) {
2590 			inc_deq(xhci, xhci->event_ring);
2591 		}
2592 
2593 		if (ret) {
2594 			urb = td->urb;
2595 			urb_priv = urb->hcpriv;
2596 			/* Leave the TD around for the reset endpoint function
2597 			 * to use(but only if it's not a control endpoint,
2598 			 * since we already queued the Set TR dequeue pointer
2599 			 * command for stalled control endpoints).
2600 			 */
2601 			if (usb_endpoint_xfer_control(&urb->ep->desc) ||
2602 				(trb_comp_code != COMP_STALL &&
2603 					trb_comp_code != COMP_BABBLE))
2604 				xhci_urb_free_priv(xhci, urb_priv);
2605 			else
2606 				kfree(urb_priv);
2607 
2608 			usb_hcd_unlink_urb_from_ep(bus_to_hcd(urb->dev->bus), urb);
2609 			if ((urb->actual_length != urb->transfer_buffer_length &&
2610 						(urb->transfer_flags &
2611 						 URB_SHORT_NOT_OK)) ||
2612 					(status != 0 &&
2613 					 !usb_endpoint_xfer_isoc(&urb->ep->desc)))
2614 				xhci_dbg(xhci, "Giveback URB %p, len = %d, "
2615 						"expected = %d, status = %d\n",
2616 						urb, urb->actual_length,
2617 						urb->transfer_buffer_length,
2618 						status);
2619 			spin_unlock(&xhci->lock);
2620 			/* EHCI, UHCI, and OHCI always unconditionally set the
2621 			 * urb->status of an isochronous endpoint to 0.
2622 			 */
2623 			if (usb_pipetype(urb->pipe) == PIPE_ISOCHRONOUS)
2624 				status = 0;
2625 			usb_hcd_giveback_urb(bus_to_hcd(urb->dev->bus), urb, status);
2626 			spin_lock(&xhci->lock);
2627 		}
2628 
2629 	/*
2630 	 * If ep->skip is set, it means there are missed tds on the
2631 	 * endpoint ring need to take care of.
2632 	 * Process them as short transfer until reach the td pointed by
2633 	 * the event.
2634 	 */
2635 	} while (ep->skip && trb_comp_code != COMP_MISSED_INT);
2636 
2637 	return 0;
2638 }
2639 
2640 /*
2641  * This function handles all OS-owned events on the event ring.  It may drop
2642  * xhci->lock between event processing (e.g. to pass up port status changes).
2643  * Returns >0 for "possibly more events to process" (caller should call again),
2644  * otherwise 0 if done.  In future, <0 returns should indicate error code.
2645  */
2646 static int xhci_handle_event(struct xhci_hcd *xhci)
2647 {
2648 	union xhci_trb *event;
2649 	int update_ptrs = 1;
2650 	int ret;
2651 
2652 	if (!xhci->event_ring || !xhci->event_ring->dequeue) {
2653 		xhci->error_bitmask |= 1 << 1;
2654 		return 0;
2655 	}
2656 
2657 	event = xhci->event_ring->dequeue;
2658 	/* Does the HC or OS own the TRB? */
2659 	if ((le32_to_cpu(event->event_cmd.flags) & TRB_CYCLE) !=
2660 	    xhci->event_ring->cycle_state) {
2661 		xhci->error_bitmask |= 1 << 2;
2662 		return 0;
2663 	}
2664 
2665 	/*
2666 	 * Barrier between reading the TRB_CYCLE (valid) flag above and any
2667 	 * speculative reads of the event's flags/data below.
2668 	 */
2669 	rmb();
2670 	/* FIXME: Handle more event types. */
2671 	switch ((le32_to_cpu(event->event_cmd.flags) & TRB_TYPE_BITMASK)) {
2672 	case TRB_TYPE(TRB_COMPLETION):
2673 		handle_cmd_completion(xhci, &event->event_cmd);
2674 		break;
2675 	case TRB_TYPE(TRB_PORT_STATUS):
2676 		handle_port_status(xhci, event);
2677 		update_ptrs = 0;
2678 		break;
2679 	case TRB_TYPE(TRB_TRANSFER):
2680 		ret = handle_tx_event(xhci, &event->trans_event);
2681 		if (ret < 0)
2682 			xhci->error_bitmask |= 1 << 9;
2683 		else
2684 			update_ptrs = 0;
2685 		break;
2686 	case TRB_TYPE(TRB_DEV_NOTE):
2687 		handle_device_notification(xhci, event);
2688 		break;
2689 	default:
2690 		if ((le32_to_cpu(event->event_cmd.flags) & TRB_TYPE_BITMASK) >=
2691 		    TRB_TYPE(48))
2692 			handle_vendor_event(xhci, event);
2693 		else
2694 			xhci->error_bitmask |= 1 << 3;
2695 	}
2696 	/* Any of the above functions may drop and re-acquire the lock, so check
2697 	 * to make sure a watchdog timer didn't mark the host as non-responsive.
2698 	 */
2699 	if (xhci->xhc_state & XHCI_STATE_DYING) {
2700 		xhci_dbg(xhci, "xHCI host dying, returning from "
2701 				"event handler.\n");
2702 		return 0;
2703 	}
2704 
2705 	if (update_ptrs)
2706 		/* Update SW event ring dequeue pointer */
2707 		inc_deq(xhci, xhci->event_ring);
2708 
2709 	/* Are there more items on the event ring?  Caller will call us again to
2710 	 * check.
2711 	 */
2712 	return 1;
2713 }
2714 
2715 /*
2716  * xHCI spec says we can get an interrupt, and if the HC has an error condition,
2717  * we might get bad data out of the event ring.  Section 4.10.2.7 has a list of
2718  * indicators of an event TRB error, but we check the status *first* to be safe.
2719  */
2720 irqreturn_t xhci_irq(struct usb_hcd *hcd)
2721 {
2722 	struct xhci_hcd *xhci = hcd_to_xhci(hcd);
2723 	u32 status;
2724 	u64 temp_64;
2725 	union xhci_trb *event_ring_deq;
2726 	dma_addr_t deq;
2727 
2728 	spin_lock(&xhci->lock);
2729 	/* Check if the xHC generated the interrupt, or the irq is shared */
2730 	status = xhci_readl(xhci, &xhci->op_regs->status);
2731 	if (status == 0xffffffff)
2732 		goto hw_died;
2733 
2734 	if (!(status & STS_EINT)) {
2735 		spin_unlock(&xhci->lock);
2736 		return IRQ_NONE;
2737 	}
2738 	if (status & STS_FATAL) {
2739 		xhci_warn(xhci, "WARNING: Host System Error\n");
2740 		xhci_halt(xhci);
2741 hw_died:
2742 		spin_unlock(&xhci->lock);
2743 		return -ESHUTDOWN;
2744 	}
2745 
2746 	/*
2747 	 * Clear the op reg interrupt status first,
2748 	 * so we can receive interrupts from other MSI-X interrupters.
2749 	 * Write 1 to clear the interrupt status.
2750 	 */
2751 	status |= STS_EINT;
2752 	xhci_writel(xhci, status, &xhci->op_regs->status);
2753 	/* FIXME when MSI-X is supported and there are multiple vectors */
2754 	/* Clear the MSI-X event interrupt status */
2755 
2756 	if (hcd->irq) {
2757 		u32 irq_pending;
2758 		/* Acknowledge the PCI interrupt */
2759 		irq_pending = xhci_readl(xhci, &xhci->ir_set->irq_pending);
2760 		irq_pending |= IMAN_IP;
2761 		xhci_writel(xhci, irq_pending, &xhci->ir_set->irq_pending);
2762 	}
2763 
2764 	if (xhci->xhc_state & XHCI_STATE_DYING) {
2765 		xhci_dbg(xhci, "xHCI dying, ignoring interrupt. "
2766 				"Shouldn't IRQs be disabled?\n");
2767 		/* Clear the event handler busy flag (RW1C);
2768 		 * the event ring should be empty.
2769 		 */
2770 		temp_64 = xhci_read_64(xhci, &xhci->ir_set->erst_dequeue);
2771 		xhci_write_64(xhci, temp_64 | ERST_EHB,
2772 				&xhci->ir_set->erst_dequeue);
2773 		spin_unlock(&xhci->lock);
2774 
2775 		return IRQ_HANDLED;
2776 	}
2777 
2778 	event_ring_deq = xhci->event_ring->dequeue;
2779 	/* FIXME this should be a delayed service routine
2780 	 * that clears the EHB.
2781 	 */
2782 	while (xhci_handle_event(xhci) > 0) {}
2783 
2784 	temp_64 = xhci_read_64(xhci, &xhci->ir_set->erst_dequeue);
2785 	/* If necessary, update the HW's version of the event ring deq ptr. */
2786 	if (event_ring_deq != xhci->event_ring->dequeue) {
2787 		deq = xhci_trb_virt_to_dma(xhci->event_ring->deq_seg,
2788 				xhci->event_ring->dequeue);
2789 		if (deq == 0)
2790 			xhci_warn(xhci, "WARN something wrong with SW event "
2791 					"ring dequeue ptr.\n");
2792 		/* Update HC event ring dequeue pointer */
2793 		temp_64 &= ERST_PTR_MASK;
2794 		temp_64 |= ((u64) deq & (u64) ~ERST_PTR_MASK);
2795 	}
2796 
2797 	/* Clear the event handler busy flag (RW1C); event ring is empty. */
2798 	temp_64 |= ERST_EHB;
2799 	xhci_write_64(xhci, temp_64, &xhci->ir_set->erst_dequeue);
2800 
2801 	spin_unlock(&xhci->lock);
2802 
2803 	return IRQ_HANDLED;
2804 }
2805 
2806 irqreturn_t xhci_msi_irq(int irq, void *hcd)
2807 {
2808 	return xhci_irq(hcd);
2809 }
2810 
2811 /****		Endpoint Ring Operations	****/
2812 
2813 /*
2814  * Generic function for queueing a TRB on a ring.
2815  * The caller must have checked to make sure there's room on the ring.
2816  *
2817  * @more_trbs_coming:	Will you enqueue more TRBs before calling
2818  *			prepare_transfer()?
2819  */
2820 static void queue_trb(struct xhci_hcd *xhci, struct xhci_ring *ring,
2821 		bool more_trbs_coming,
2822 		u32 field1, u32 field2, u32 field3, u32 field4)
2823 {
2824 	struct xhci_generic_trb *trb;
2825 
2826 	trb = &ring->enqueue->generic;
2827 	trb->field[0] = cpu_to_le32(field1);
2828 	trb->field[1] = cpu_to_le32(field2);
2829 	trb->field[2] = cpu_to_le32(field3);
2830 	trb->field[3] = cpu_to_le32(field4);
2831 	inc_enq(xhci, ring, more_trbs_coming);
2832 }
2833 
2834 /*
2835  * Does various checks on the endpoint ring, and makes it ready to queue num_trbs.
2836  * FIXME allocate segments if the ring is full.
2837  */
2838 static int prepare_ring(struct xhci_hcd *xhci, struct xhci_ring *ep_ring,
2839 		u32 ep_state, unsigned int num_trbs, gfp_t mem_flags)
2840 {
2841 	unsigned int num_trbs_needed;
2842 
2843 	/* Make sure the endpoint has been added to xHC schedule */
2844 	switch (ep_state) {
2845 	case EP_STATE_DISABLED:
2846 		/*
2847 		 * USB core changed config/interfaces without notifying us,
2848 		 * or hardware is reporting the wrong state.
2849 		 */
2850 		xhci_warn(xhci, "WARN urb submitted to disabled ep\n");
2851 		return -ENOENT;
2852 	case EP_STATE_ERROR:
2853 		xhci_warn(xhci, "WARN waiting for error on ep to be cleared\n");
2854 		/* FIXME event handling code for error needs to clear it */
2855 		/* XXX not sure if this should be -ENOENT or not */
2856 		return -EINVAL;
2857 	case EP_STATE_HALTED:
2858 		xhci_dbg(xhci, "WARN halted endpoint, queueing URB anyway.\n");
2859 	case EP_STATE_STOPPED:
2860 	case EP_STATE_RUNNING:
2861 		break;
2862 	default:
2863 		xhci_err(xhci, "ERROR unknown endpoint state for ep\n");
2864 		/*
2865 		 * FIXME issue Configure Endpoint command to try to get the HC
2866 		 * back into a known state.
2867 		 */
2868 		return -EINVAL;
2869 	}
2870 
2871 	while (1) {
2872 		if (room_on_ring(xhci, ep_ring, num_trbs))
2873 			break;
2874 
2875 		if (ep_ring == xhci->cmd_ring) {
2876 			xhci_err(xhci, "Do not support expand command ring\n");
2877 			return -ENOMEM;
2878 		}
2879 
2880 		xhci_dbg(xhci, "ERROR no room on ep ring, "
2881 					"try ring expansion\n");
2882 		num_trbs_needed = num_trbs - ep_ring->num_trbs_free;
2883 		if (xhci_ring_expansion(xhci, ep_ring, num_trbs_needed,
2884 					mem_flags)) {
2885 			xhci_err(xhci, "Ring expansion failed\n");
2886 			return -ENOMEM;
2887 		}
2888 	}
2889 
2890 	if (enqueue_is_link_trb(ep_ring)) {
2891 		struct xhci_ring *ring = ep_ring;
2892 		union xhci_trb *next;
2893 
2894 		next = ring->enqueue;
2895 
2896 		while (last_trb(xhci, ring, ring->enq_seg, next)) {
2897 			/* If we're not dealing with 0.95 hardware or isoc rings
2898 			 * on AMD 0.96 host, clear the chain bit.
2899 			 */
2900 			if (!xhci_link_trb_quirk(xhci) &&
2901 					!(ring->type == TYPE_ISOC &&
2902 					 (xhci->quirks & XHCI_AMD_0x96_HOST)))
2903 				next->link.control &= cpu_to_le32(~TRB_CHAIN);
2904 			else
2905 				next->link.control |= cpu_to_le32(TRB_CHAIN);
2906 
2907 			wmb();
2908 			next->link.control ^= cpu_to_le32(TRB_CYCLE);
2909 
2910 			/* Toggle the cycle bit after the last ring segment. */
2911 			if (last_trb_on_last_seg(xhci, ring, ring->enq_seg, next)) {
2912 				ring->cycle_state = (ring->cycle_state ? 0 : 1);
2913 			}
2914 			ring->enq_seg = ring->enq_seg->next;
2915 			ring->enqueue = ring->enq_seg->trbs;
2916 			next = ring->enqueue;
2917 		}
2918 	}
2919 
2920 	return 0;
2921 }
2922 
2923 static int prepare_transfer(struct xhci_hcd *xhci,
2924 		struct xhci_virt_device *xdev,
2925 		unsigned int ep_index,
2926 		unsigned int stream_id,
2927 		unsigned int num_trbs,
2928 		struct urb *urb,
2929 		unsigned int td_index,
2930 		gfp_t mem_flags)
2931 {
2932 	int ret;
2933 	struct urb_priv *urb_priv;
2934 	struct xhci_td	*td;
2935 	struct xhci_ring *ep_ring;
2936 	struct xhci_ep_ctx *ep_ctx = xhci_get_ep_ctx(xhci, xdev->out_ctx, ep_index);
2937 
2938 	ep_ring = xhci_stream_id_to_ring(xdev, ep_index, stream_id);
2939 	if (!ep_ring) {
2940 		xhci_dbg(xhci, "Can't prepare ring for bad stream ID %u\n",
2941 				stream_id);
2942 		return -EINVAL;
2943 	}
2944 
2945 	ret = prepare_ring(xhci, ep_ring,
2946 			   le32_to_cpu(ep_ctx->ep_info) & EP_STATE_MASK,
2947 			   num_trbs, mem_flags);
2948 	if (ret)
2949 		return ret;
2950 
2951 	urb_priv = urb->hcpriv;
2952 	td = urb_priv->td[td_index];
2953 
2954 	INIT_LIST_HEAD(&td->td_list);
2955 	INIT_LIST_HEAD(&td->cancelled_td_list);
2956 
2957 	if (td_index == 0) {
2958 		ret = usb_hcd_link_urb_to_ep(bus_to_hcd(urb->dev->bus), urb);
2959 		if (unlikely(ret))
2960 			return ret;
2961 	}
2962 
2963 	td->urb = urb;
2964 	/* Add this TD to the tail of the endpoint ring's TD list */
2965 	list_add_tail(&td->td_list, &ep_ring->td_list);
2966 	td->start_seg = ep_ring->enq_seg;
2967 	td->first_trb = ep_ring->enqueue;
2968 
2969 	urb_priv->td[td_index] = td;
2970 
2971 	return 0;
2972 }
2973 
2974 static unsigned int count_sg_trbs_needed(struct xhci_hcd *xhci, struct urb *urb)
2975 {
2976 	int num_sgs, num_trbs, running_total, temp, i;
2977 	struct scatterlist *sg;
2978 
2979 	sg = NULL;
2980 	num_sgs = urb->num_mapped_sgs;
2981 	temp = urb->transfer_buffer_length;
2982 
2983 	num_trbs = 0;
2984 	for_each_sg(urb->sg, sg, num_sgs, i) {
2985 		unsigned int len = sg_dma_len(sg);
2986 
2987 		/* Scatter gather list entries may cross 64KB boundaries */
2988 		running_total = TRB_MAX_BUFF_SIZE -
2989 			(sg_dma_address(sg) & (TRB_MAX_BUFF_SIZE - 1));
2990 		running_total &= TRB_MAX_BUFF_SIZE - 1;
2991 		if (running_total != 0)
2992 			num_trbs++;
2993 
2994 		/* How many more 64KB chunks to transfer, how many more TRBs? */
2995 		while (running_total < sg_dma_len(sg) && running_total < temp) {
2996 			num_trbs++;
2997 			running_total += TRB_MAX_BUFF_SIZE;
2998 		}
2999 		len = min_t(int, len, temp);
3000 		temp -= len;
3001 		if (temp == 0)
3002 			break;
3003 	}
3004 	return num_trbs;
3005 }
3006 
3007 static void check_trb_math(struct urb *urb, int num_trbs, int running_total)
3008 {
3009 	if (num_trbs != 0)
3010 		dev_err(&urb->dev->dev, "%s - ep %#x - Miscalculated number of "
3011 				"TRBs, %d left\n", __func__,
3012 				urb->ep->desc.bEndpointAddress, num_trbs);
3013 	if (running_total != urb->transfer_buffer_length)
3014 		dev_err(&urb->dev->dev, "%s - ep %#x - Miscalculated tx length, "
3015 				"queued %#x (%d), asked for %#x (%d)\n",
3016 				__func__,
3017 				urb->ep->desc.bEndpointAddress,
3018 				running_total, running_total,
3019 				urb->transfer_buffer_length,
3020 				urb->transfer_buffer_length);
3021 }
3022 
3023 static void giveback_first_trb(struct xhci_hcd *xhci, int slot_id,
3024 		unsigned int ep_index, unsigned int stream_id, int start_cycle,
3025 		struct xhci_generic_trb *start_trb)
3026 {
3027 	/*
3028 	 * Pass all the TRBs to the hardware at once and make sure this write
3029 	 * isn't reordered.
3030 	 */
3031 	wmb();
3032 	if (start_cycle)
3033 		start_trb->field[3] |= cpu_to_le32(start_cycle);
3034 	else
3035 		start_trb->field[3] &= cpu_to_le32(~TRB_CYCLE);
3036 	xhci_ring_ep_doorbell(xhci, slot_id, ep_index, stream_id);
3037 }
3038 
3039 /*
3040  * xHCI uses normal TRBs for both bulk and interrupt.  When the interrupt
3041  * endpoint is to be serviced, the xHC will consume (at most) one TD.  A TD
3042  * (comprised of sg list entries) can take several service intervals to
3043  * transmit.
3044  */
3045 int xhci_queue_intr_tx(struct xhci_hcd *xhci, gfp_t mem_flags,
3046 		struct urb *urb, int slot_id, unsigned int ep_index)
3047 {
3048 	struct xhci_ep_ctx *ep_ctx = xhci_get_ep_ctx(xhci,
3049 			xhci->devs[slot_id]->out_ctx, ep_index);
3050 	int xhci_interval;
3051 	int ep_interval;
3052 
3053 	xhci_interval = EP_INTERVAL_TO_UFRAMES(le32_to_cpu(ep_ctx->ep_info));
3054 	ep_interval = urb->interval;
3055 	/* Convert to microframes */
3056 	if (urb->dev->speed == USB_SPEED_LOW ||
3057 			urb->dev->speed == USB_SPEED_FULL)
3058 		ep_interval *= 8;
3059 	/* FIXME change this to a warning and a suggestion to use the new API
3060 	 * to set the polling interval (once the API is added).
3061 	 */
3062 	if (xhci_interval != ep_interval) {
3063 		if (printk_ratelimit())
3064 			dev_dbg(&urb->dev->dev, "Driver uses different interval"
3065 					" (%d microframe%s) than xHCI "
3066 					"(%d microframe%s)\n",
3067 					ep_interval,
3068 					ep_interval == 1 ? "" : "s",
3069 					xhci_interval,
3070 					xhci_interval == 1 ? "" : "s");
3071 		urb->interval = xhci_interval;
3072 		/* Convert back to frames for LS/FS devices */
3073 		if (urb->dev->speed == USB_SPEED_LOW ||
3074 				urb->dev->speed == USB_SPEED_FULL)
3075 			urb->interval /= 8;
3076 	}
3077 	return xhci_queue_bulk_tx(xhci, mem_flags, urb, slot_id, ep_index);
3078 }
3079 
3080 /*
3081  * The TD size is the number of bytes remaining in the TD (including this TRB),
3082  * right shifted by 10.
3083  * It must fit in bits 21:17, so it can't be bigger than 31.
3084  */
3085 static u32 xhci_td_remainder(unsigned int remainder)
3086 {
3087 	u32 max = (1 << (21 - 17 + 1)) - 1;
3088 
3089 	if ((remainder >> 10) >= max)
3090 		return max << 17;
3091 	else
3092 		return (remainder >> 10) << 17;
3093 }
3094 
3095 /*
3096  * For xHCI 1.0 host controllers, TD size is the number of max packet sized
3097  * packets remaining in the TD (*not* including this TRB).
3098  *
3099  * Total TD packet count = total_packet_count =
3100  *     DIV_ROUND_UP(TD size in bytes / wMaxPacketSize)
3101  *
3102  * Packets transferred up to and including this TRB = packets_transferred =
3103  *     rounddown(total bytes transferred including this TRB / wMaxPacketSize)
3104  *
3105  * TD size = total_packet_count - packets_transferred
3106  *
3107  * It must fit in bits 21:17, so it can't be bigger than 31.
3108  * The last TRB in a TD must have the TD size set to zero.
3109  */
3110 static u32 xhci_v1_0_td_remainder(int running_total, int trb_buff_len,
3111 		unsigned int total_packet_count, struct urb *urb,
3112 		unsigned int num_trbs_left)
3113 {
3114 	int packets_transferred;
3115 
3116 	/* One TRB with a zero-length data packet. */
3117 	if (num_trbs_left == 0 || (running_total == 0 && trb_buff_len == 0))
3118 		return 0;
3119 
3120 	/* All the TRB queueing functions don't count the current TRB in
3121 	 * running_total.
3122 	 */
3123 	packets_transferred = (running_total + trb_buff_len) /
3124 		GET_MAX_PACKET(usb_endpoint_maxp(&urb->ep->desc));
3125 
3126 	if ((total_packet_count - packets_transferred) > 31)
3127 		return 31 << 17;
3128 	return (total_packet_count - packets_transferred) << 17;
3129 }
3130 
3131 static int queue_bulk_sg_tx(struct xhci_hcd *xhci, gfp_t mem_flags,
3132 		struct urb *urb, int slot_id, unsigned int ep_index)
3133 {
3134 	struct xhci_ring *ep_ring;
3135 	unsigned int num_trbs;
3136 	struct urb_priv *urb_priv;
3137 	struct xhci_td *td;
3138 	struct scatterlist *sg;
3139 	int num_sgs;
3140 	int trb_buff_len, this_sg_len, running_total;
3141 	unsigned int total_packet_count;
3142 	bool first_trb;
3143 	u64 addr;
3144 	bool more_trbs_coming;
3145 
3146 	struct xhci_generic_trb *start_trb;
3147 	int start_cycle;
3148 
3149 	ep_ring = xhci_urb_to_transfer_ring(xhci, urb);
3150 	if (!ep_ring)
3151 		return -EINVAL;
3152 
3153 	num_trbs = count_sg_trbs_needed(xhci, urb);
3154 	num_sgs = urb->num_mapped_sgs;
3155 	total_packet_count = DIV_ROUND_UP(urb->transfer_buffer_length,
3156 			usb_endpoint_maxp(&urb->ep->desc));
3157 
3158 	trb_buff_len = prepare_transfer(xhci, xhci->devs[slot_id],
3159 			ep_index, urb->stream_id,
3160 			num_trbs, urb, 0, mem_flags);
3161 	if (trb_buff_len < 0)
3162 		return trb_buff_len;
3163 
3164 	urb_priv = urb->hcpriv;
3165 	td = urb_priv->td[0];
3166 
3167 	/*
3168 	 * Don't give the first TRB to the hardware (by toggling the cycle bit)
3169 	 * until we've finished creating all the other TRBs.  The ring's cycle
3170 	 * state may change as we enqueue the other TRBs, so save it too.
3171 	 */
3172 	start_trb = &ep_ring->enqueue->generic;
3173 	start_cycle = ep_ring->cycle_state;
3174 
3175 	running_total = 0;
3176 	/*
3177 	 * How much data is in the first TRB?
3178 	 *
3179 	 * There are three forces at work for TRB buffer pointers and lengths:
3180 	 * 1. We don't want to walk off the end of this sg-list entry buffer.
3181 	 * 2. The transfer length that the driver requested may be smaller than
3182 	 *    the amount of memory allocated for this scatter-gather list.
3183 	 * 3. TRBs buffers can't cross 64KB boundaries.
3184 	 */
3185 	sg = urb->sg;
3186 	addr = (u64) sg_dma_address(sg);
3187 	this_sg_len = sg_dma_len(sg);
3188 	trb_buff_len = TRB_MAX_BUFF_SIZE - (addr & (TRB_MAX_BUFF_SIZE - 1));
3189 	trb_buff_len = min_t(int, trb_buff_len, this_sg_len);
3190 	if (trb_buff_len > urb->transfer_buffer_length)
3191 		trb_buff_len = urb->transfer_buffer_length;
3192 
3193 	first_trb = true;
3194 	/* Queue the first TRB, even if it's zero-length */
3195 	do {
3196 		u32 field = 0;
3197 		u32 length_field = 0;
3198 		u32 remainder = 0;
3199 
3200 		/* Don't change the cycle bit of the first TRB until later */
3201 		if (first_trb) {
3202 			first_trb = false;
3203 			if (start_cycle == 0)
3204 				field |= 0x1;
3205 		} else
3206 			field |= ep_ring->cycle_state;
3207 
3208 		/* Chain all the TRBs together; clear the chain bit in the last
3209 		 * TRB to indicate it's the last TRB in the chain.
3210 		 */
3211 		if (num_trbs > 1) {
3212 			field |= TRB_CHAIN;
3213 		} else {
3214 			/* FIXME - add check for ZERO_PACKET flag before this */
3215 			td->last_trb = ep_ring->enqueue;
3216 			field |= TRB_IOC;
3217 		}
3218 
3219 		/* Only set interrupt on short packet for IN endpoints */
3220 		if (usb_urb_dir_in(urb))
3221 			field |= TRB_ISP;
3222 
3223 		if (TRB_MAX_BUFF_SIZE -
3224 				(addr & (TRB_MAX_BUFF_SIZE - 1)) < trb_buff_len) {
3225 			xhci_warn(xhci, "WARN: sg dma xfer crosses 64KB boundaries!\n");
3226 			xhci_dbg(xhci, "Next boundary at %#x, end dma = %#x\n",
3227 					(unsigned int) (addr + TRB_MAX_BUFF_SIZE) & ~(TRB_MAX_BUFF_SIZE - 1),
3228 					(unsigned int) addr + trb_buff_len);
3229 		}
3230 
3231 		/* Set the TRB length, TD size, and interrupter fields. */
3232 		if (xhci->hci_version < 0x100) {
3233 			remainder = xhci_td_remainder(
3234 					urb->transfer_buffer_length -
3235 					running_total);
3236 		} else {
3237 			remainder = xhci_v1_0_td_remainder(running_total,
3238 					trb_buff_len, total_packet_count, urb,
3239 					num_trbs - 1);
3240 		}
3241 		length_field = TRB_LEN(trb_buff_len) |
3242 			remainder |
3243 			TRB_INTR_TARGET(0);
3244 
3245 		if (num_trbs > 1)
3246 			more_trbs_coming = true;
3247 		else
3248 			more_trbs_coming = false;
3249 		queue_trb(xhci, ep_ring, more_trbs_coming,
3250 				lower_32_bits(addr),
3251 				upper_32_bits(addr),
3252 				length_field,
3253 				field | TRB_TYPE(TRB_NORMAL));
3254 		--num_trbs;
3255 		running_total += trb_buff_len;
3256 
3257 		/* Calculate length for next transfer --
3258 		 * Are we done queueing all the TRBs for this sg entry?
3259 		 */
3260 		this_sg_len -= trb_buff_len;
3261 		if (this_sg_len == 0) {
3262 			--num_sgs;
3263 			if (num_sgs == 0)
3264 				break;
3265 			sg = sg_next(sg);
3266 			addr = (u64) sg_dma_address(sg);
3267 			this_sg_len = sg_dma_len(sg);
3268 		} else {
3269 			addr += trb_buff_len;
3270 		}
3271 
3272 		trb_buff_len = TRB_MAX_BUFF_SIZE -
3273 			(addr & (TRB_MAX_BUFF_SIZE - 1));
3274 		trb_buff_len = min_t(int, trb_buff_len, this_sg_len);
3275 		if (running_total + trb_buff_len > urb->transfer_buffer_length)
3276 			trb_buff_len =
3277 				urb->transfer_buffer_length - running_total;
3278 	} while (running_total < urb->transfer_buffer_length);
3279 
3280 	check_trb_math(urb, num_trbs, running_total);
3281 	giveback_first_trb(xhci, slot_id, ep_index, urb->stream_id,
3282 			start_cycle, start_trb);
3283 	return 0;
3284 }
3285 
3286 /* This is very similar to what ehci-q.c qtd_fill() does */
3287 int xhci_queue_bulk_tx(struct xhci_hcd *xhci, gfp_t mem_flags,
3288 		struct urb *urb, int slot_id, unsigned int ep_index)
3289 {
3290 	struct xhci_ring *ep_ring;
3291 	struct urb_priv *urb_priv;
3292 	struct xhci_td *td;
3293 	int num_trbs;
3294 	struct xhci_generic_trb *start_trb;
3295 	bool first_trb;
3296 	bool more_trbs_coming;
3297 	int start_cycle;
3298 	u32 field, length_field;
3299 
3300 	int running_total, trb_buff_len, ret;
3301 	unsigned int total_packet_count;
3302 	u64 addr;
3303 
3304 	if (urb->num_sgs)
3305 		return queue_bulk_sg_tx(xhci, mem_flags, urb, slot_id, ep_index);
3306 
3307 	ep_ring = xhci_urb_to_transfer_ring(xhci, urb);
3308 	if (!ep_ring)
3309 		return -EINVAL;
3310 
3311 	num_trbs = 0;
3312 	/* How much data is (potentially) left before the 64KB boundary? */
3313 	running_total = TRB_MAX_BUFF_SIZE -
3314 		(urb->transfer_dma & (TRB_MAX_BUFF_SIZE - 1));
3315 	running_total &= TRB_MAX_BUFF_SIZE - 1;
3316 
3317 	/* If there's some data on this 64KB chunk, or we have to send a
3318 	 * zero-length transfer, we need at least one TRB
3319 	 */
3320 	if (running_total != 0 || urb->transfer_buffer_length == 0)
3321 		num_trbs++;
3322 	/* How many more 64KB chunks to transfer, how many more TRBs? */
3323 	while (running_total < urb->transfer_buffer_length) {
3324 		num_trbs++;
3325 		running_total += TRB_MAX_BUFF_SIZE;
3326 	}
3327 	/* FIXME: this doesn't deal with URB_ZERO_PACKET - need one more */
3328 
3329 	ret = prepare_transfer(xhci, xhci->devs[slot_id],
3330 			ep_index, urb->stream_id,
3331 			num_trbs, urb, 0, mem_flags);
3332 	if (ret < 0)
3333 		return ret;
3334 
3335 	urb_priv = urb->hcpriv;
3336 	td = urb_priv->td[0];
3337 
3338 	/*
3339 	 * Don't give the first TRB to the hardware (by toggling the cycle bit)
3340 	 * until we've finished creating all the other TRBs.  The ring's cycle
3341 	 * state may change as we enqueue the other TRBs, so save it too.
3342 	 */
3343 	start_trb = &ep_ring->enqueue->generic;
3344 	start_cycle = ep_ring->cycle_state;
3345 
3346 	running_total = 0;
3347 	total_packet_count = DIV_ROUND_UP(urb->transfer_buffer_length,
3348 			usb_endpoint_maxp(&urb->ep->desc));
3349 	/* How much data is in the first TRB? */
3350 	addr = (u64) urb->transfer_dma;
3351 	trb_buff_len = TRB_MAX_BUFF_SIZE -
3352 		(urb->transfer_dma & (TRB_MAX_BUFF_SIZE - 1));
3353 	if (trb_buff_len > urb->transfer_buffer_length)
3354 		trb_buff_len = urb->transfer_buffer_length;
3355 
3356 	first_trb = true;
3357 
3358 	/* Queue the first TRB, even if it's zero-length */
3359 	do {
3360 		u32 remainder = 0;
3361 		field = 0;
3362 
3363 		/* Don't change the cycle bit of the first TRB until later */
3364 		if (first_trb) {
3365 			first_trb = false;
3366 			if (start_cycle == 0)
3367 				field |= 0x1;
3368 		} else
3369 			field |= ep_ring->cycle_state;
3370 
3371 		/* Chain all the TRBs together; clear the chain bit in the last
3372 		 * TRB to indicate it's the last TRB in the chain.
3373 		 */
3374 		if (num_trbs > 1) {
3375 			field |= TRB_CHAIN;
3376 		} else {
3377 			/* FIXME - add check for ZERO_PACKET flag before this */
3378 			td->last_trb = ep_ring->enqueue;
3379 			field |= TRB_IOC;
3380 		}
3381 
3382 		/* Only set interrupt on short packet for IN endpoints */
3383 		if (usb_urb_dir_in(urb))
3384 			field |= TRB_ISP;
3385 
3386 		/* Set the TRB length, TD size, and interrupter fields. */
3387 		if (xhci->hci_version < 0x100) {
3388 			remainder = xhci_td_remainder(
3389 					urb->transfer_buffer_length -
3390 					running_total);
3391 		} else {
3392 			remainder = xhci_v1_0_td_remainder(running_total,
3393 					trb_buff_len, total_packet_count, urb,
3394 					num_trbs - 1);
3395 		}
3396 		length_field = TRB_LEN(trb_buff_len) |
3397 			remainder |
3398 			TRB_INTR_TARGET(0);
3399 
3400 		if (num_trbs > 1)
3401 			more_trbs_coming = true;
3402 		else
3403 			more_trbs_coming = false;
3404 		queue_trb(xhci, ep_ring, more_trbs_coming,
3405 				lower_32_bits(addr),
3406 				upper_32_bits(addr),
3407 				length_field,
3408 				field | TRB_TYPE(TRB_NORMAL));
3409 		--num_trbs;
3410 		running_total += trb_buff_len;
3411 
3412 		/* Calculate length for next transfer */
3413 		addr += trb_buff_len;
3414 		trb_buff_len = urb->transfer_buffer_length - running_total;
3415 		if (trb_buff_len > TRB_MAX_BUFF_SIZE)
3416 			trb_buff_len = TRB_MAX_BUFF_SIZE;
3417 	} while (running_total < urb->transfer_buffer_length);
3418 
3419 	check_trb_math(urb, num_trbs, running_total);
3420 	giveback_first_trb(xhci, slot_id, ep_index, urb->stream_id,
3421 			start_cycle, start_trb);
3422 	return 0;
3423 }
3424 
3425 /* Caller must have locked xhci->lock */
3426 int xhci_queue_ctrl_tx(struct xhci_hcd *xhci, gfp_t mem_flags,
3427 		struct urb *urb, int slot_id, unsigned int ep_index)
3428 {
3429 	struct xhci_ring *ep_ring;
3430 	int num_trbs;
3431 	int ret;
3432 	struct usb_ctrlrequest *setup;
3433 	struct xhci_generic_trb *start_trb;
3434 	int start_cycle;
3435 	u32 field, length_field;
3436 	struct urb_priv *urb_priv;
3437 	struct xhci_td *td;
3438 
3439 	ep_ring = xhci_urb_to_transfer_ring(xhci, urb);
3440 	if (!ep_ring)
3441 		return -EINVAL;
3442 
3443 	/*
3444 	 * Need to copy setup packet into setup TRB, so we can't use the setup
3445 	 * DMA address.
3446 	 */
3447 	if (!urb->setup_packet)
3448 		return -EINVAL;
3449 
3450 	/* 1 TRB for setup, 1 for status */
3451 	num_trbs = 2;
3452 	/*
3453 	 * Don't need to check if we need additional event data and normal TRBs,
3454 	 * since data in control transfers will never get bigger than 16MB
3455 	 * XXX: can we get a buffer that crosses 64KB boundaries?
3456 	 */
3457 	if (urb->transfer_buffer_length > 0)
3458 		num_trbs++;
3459 	ret = prepare_transfer(xhci, xhci->devs[slot_id],
3460 			ep_index, urb->stream_id,
3461 			num_trbs, urb, 0, mem_flags);
3462 	if (ret < 0)
3463 		return ret;
3464 
3465 	urb_priv = urb->hcpriv;
3466 	td = urb_priv->td[0];
3467 
3468 	/*
3469 	 * Don't give the first TRB to the hardware (by toggling the cycle bit)
3470 	 * until we've finished creating all the other TRBs.  The ring's cycle
3471 	 * state may change as we enqueue the other TRBs, so save it too.
3472 	 */
3473 	start_trb = &ep_ring->enqueue->generic;
3474 	start_cycle = ep_ring->cycle_state;
3475 
3476 	/* Queue setup TRB - see section 6.4.1.2.1 */
3477 	/* FIXME better way to translate setup_packet into two u32 fields? */
3478 	setup = (struct usb_ctrlrequest *) urb->setup_packet;
3479 	field = 0;
3480 	field |= TRB_IDT | TRB_TYPE(TRB_SETUP);
3481 	if (start_cycle == 0)
3482 		field |= 0x1;
3483 
3484 	/* xHCI 1.0 6.4.1.2.1: Transfer Type field */
3485 	if (xhci->hci_version == 0x100) {
3486 		if (urb->transfer_buffer_length > 0) {
3487 			if (setup->bRequestType & USB_DIR_IN)
3488 				field |= TRB_TX_TYPE(TRB_DATA_IN);
3489 			else
3490 				field |= TRB_TX_TYPE(TRB_DATA_OUT);
3491 		}
3492 	}
3493 
3494 	queue_trb(xhci, ep_ring, true,
3495 		  setup->bRequestType | setup->bRequest << 8 | le16_to_cpu(setup->wValue) << 16,
3496 		  le16_to_cpu(setup->wIndex) | le16_to_cpu(setup->wLength) << 16,
3497 		  TRB_LEN(8) | TRB_INTR_TARGET(0),
3498 		  /* Immediate data in pointer */
3499 		  field);
3500 
3501 	/* If there's data, queue data TRBs */
3502 	/* Only set interrupt on short packet for IN endpoints */
3503 	if (usb_urb_dir_in(urb))
3504 		field = TRB_ISP | TRB_TYPE(TRB_DATA);
3505 	else
3506 		field = TRB_TYPE(TRB_DATA);
3507 
3508 	length_field = TRB_LEN(urb->transfer_buffer_length) |
3509 		xhci_td_remainder(urb->transfer_buffer_length) |
3510 		TRB_INTR_TARGET(0);
3511 	if (urb->transfer_buffer_length > 0) {
3512 		if (setup->bRequestType & USB_DIR_IN)
3513 			field |= TRB_DIR_IN;
3514 		queue_trb(xhci, ep_ring, true,
3515 				lower_32_bits(urb->transfer_dma),
3516 				upper_32_bits(urb->transfer_dma),
3517 				length_field,
3518 				field | ep_ring->cycle_state);
3519 	}
3520 
3521 	/* Save the DMA address of the last TRB in the TD */
3522 	td->last_trb = ep_ring->enqueue;
3523 
3524 	/* Queue status TRB - see Table 7 and sections 4.11.2.2 and 6.4.1.2.3 */
3525 	/* If the device sent data, the status stage is an OUT transfer */
3526 	if (urb->transfer_buffer_length > 0 && setup->bRequestType & USB_DIR_IN)
3527 		field = 0;
3528 	else
3529 		field = TRB_DIR_IN;
3530 	queue_trb(xhci, ep_ring, false,
3531 			0,
3532 			0,
3533 			TRB_INTR_TARGET(0),
3534 			/* Event on completion */
3535 			field | TRB_IOC | TRB_TYPE(TRB_STATUS) | ep_ring->cycle_state);
3536 
3537 	giveback_first_trb(xhci, slot_id, ep_index, 0,
3538 			start_cycle, start_trb);
3539 	return 0;
3540 }
3541 
3542 static int count_isoc_trbs_needed(struct xhci_hcd *xhci,
3543 		struct urb *urb, int i)
3544 {
3545 	int num_trbs = 0;
3546 	u64 addr, td_len;
3547 
3548 	addr = (u64) (urb->transfer_dma + urb->iso_frame_desc[i].offset);
3549 	td_len = urb->iso_frame_desc[i].length;
3550 
3551 	num_trbs = DIV_ROUND_UP(td_len + (addr & (TRB_MAX_BUFF_SIZE - 1)),
3552 			TRB_MAX_BUFF_SIZE);
3553 	if (num_trbs == 0)
3554 		num_trbs++;
3555 
3556 	return num_trbs;
3557 }
3558 
3559 /*
3560  * The transfer burst count field of the isochronous TRB defines the number of
3561  * bursts that are required to move all packets in this TD.  Only SuperSpeed
3562  * devices can burst up to bMaxBurst number of packets per service interval.
3563  * This field is zero based, meaning a value of zero in the field means one
3564  * burst.  Basically, for everything but SuperSpeed devices, this field will be
3565  * zero.  Only xHCI 1.0 host controllers support this field.
3566  */
3567 static unsigned int xhci_get_burst_count(struct xhci_hcd *xhci,
3568 		struct usb_device *udev,
3569 		struct urb *urb, unsigned int total_packet_count)
3570 {
3571 	unsigned int max_burst;
3572 
3573 	if (xhci->hci_version < 0x100 || udev->speed != USB_SPEED_SUPER)
3574 		return 0;
3575 
3576 	max_burst = urb->ep->ss_ep_comp.bMaxBurst;
3577 	return roundup(total_packet_count, max_burst + 1) - 1;
3578 }
3579 
3580 /*
3581  * Returns the number of packets in the last "burst" of packets.  This field is
3582  * valid for all speeds of devices.  USB 2.0 devices can only do one "burst", so
3583  * the last burst packet count is equal to the total number of packets in the
3584  * TD.  SuperSpeed endpoints can have up to 3 bursts.  All but the last burst
3585  * must contain (bMaxBurst + 1) number of packets, but the last burst can
3586  * contain 1 to (bMaxBurst + 1) packets.
3587  */
3588 static unsigned int xhci_get_last_burst_packet_count(struct xhci_hcd *xhci,
3589 		struct usb_device *udev,
3590 		struct urb *urb, unsigned int total_packet_count)
3591 {
3592 	unsigned int max_burst;
3593 	unsigned int residue;
3594 
3595 	if (xhci->hci_version < 0x100)
3596 		return 0;
3597 
3598 	switch (udev->speed) {
3599 	case USB_SPEED_SUPER:
3600 		/* bMaxBurst is zero based: 0 means 1 packet per burst */
3601 		max_burst = urb->ep->ss_ep_comp.bMaxBurst;
3602 		residue = total_packet_count % (max_burst + 1);
3603 		/* If residue is zero, the last burst contains (max_burst + 1)
3604 		 * number of packets, but the TLBPC field is zero-based.
3605 		 */
3606 		if (residue == 0)
3607 			return max_burst;
3608 		return residue - 1;
3609 	default:
3610 		if (total_packet_count == 0)
3611 			return 0;
3612 		return total_packet_count - 1;
3613 	}
3614 }
3615 
3616 /* This is for isoc transfer */
3617 static int xhci_queue_isoc_tx(struct xhci_hcd *xhci, gfp_t mem_flags,
3618 		struct urb *urb, int slot_id, unsigned int ep_index)
3619 {
3620 	struct xhci_ring *ep_ring;
3621 	struct urb_priv *urb_priv;
3622 	struct xhci_td *td;
3623 	int num_tds, trbs_per_td;
3624 	struct xhci_generic_trb *start_trb;
3625 	bool first_trb;
3626 	int start_cycle;
3627 	u32 field, length_field;
3628 	int running_total, trb_buff_len, td_len, td_remain_len, ret;
3629 	u64 start_addr, addr;
3630 	int i, j;
3631 	bool more_trbs_coming;
3632 
3633 	ep_ring = xhci->devs[slot_id]->eps[ep_index].ring;
3634 
3635 	num_tds = urb->number_of_packets;
3636 	if (num_tds < 1) {
3637 		xhci_dbg(xhci, "Isoc URB with zero packets?\n");
3638 		return -EINVAL;
3639 	}
3640 
3641 	start_addr = (u64) urb->transfer_dma;
3642 	start_trb = &ep_ring->enqueue->generic;
3643 	start_cycle = ep_ring->cycle_state;
3644 
3645 	urb_priv = urb->hcpriv;
3646 	/* Queue the first TRB, even if it's zero-length */
3647 	for (i = 0; i < num_tds; i++) {
3648 		unsigned int total_packet_count;
3649 		unsigned int burst_count;
3650 		unsigned int residue;
3651 
3652 		first_trb = true;
3653 		running_total = 0;
3654 		addr = start_addr + urb->iso_frame_desc[i].offset;
3655 		td_len = urb->iso_frame_desc[i].length;
3656 		td_remain_len = td_len;
3657 		total_packet_count = DIV_ROUND_UP(td_len,
3658 				GET_MAX_PACKET(
3659 					usb_endpoint_maxp(&urb->ep->desc)));
3660 		/* A zero-length transfer still involves at least one packet. */
3661 		if (total_packet_count == 0)
3662 			total_packet_count++;
3663 		burst_count = xhci_get_burst_count(xhci, urb->dev, urb,
3664 				total_packet_count);
3665 		residue = xhci_get_last_burst_packet_count(xhci,
3666 				urb->dev, urb, total_packet_count);
3667 
3668 		trbs_per_td = count_isoc_trbs_needed(xhci, urb, i);
3669 
3670 		ret = prepare_transfer(xhci, xhci->devs[slot_id], ep_index,
3671 				urb->stream_id, trbs_per_td, urb, i, mem_flags);
3672 		if (ret < 0) {
3673 			if (i == 0)
3674 				return ret;
3675 			goto cleanup;
3676 		}
3677 
3678 		td = urb_priv->td[i];
3679 		for (j = 0; j < trbs_per_td; j++) {
3680 			u32 remainder = 0;
3681 			field = 0;
3682 
3683 			if (first_trb) {
3684 				field = TRB_TBC(burst_count) |
3685 					TRB_TLBPC(residue);
3686 				/* Queue the isoc TRB */
3687 				field |= TRB_TYPE(TRB_ISOC);
3688 				/* Assume URB_ISO_ASAP is set */
3689 				field |= TRB_SIA;
3690 				if (i == 0) {
3691 					if (start_cycle == 0)
3692 						field |= 0x1;
3693 				} else
3694 					field |= ep_ring->cycle_state;
3695 				first_trb = false;
3696 			} else {
3697 				/* Queue other normal TRBs */
3698 				field |= TRB_TYPE(TRB_NORMAL);
3699 				field |= ep_ring->cycle_state;
3700 			}
3701 
3702 			/* Only set interrupt on short packet for IN EPs */
3703 			if (usb_urb_dir_in(urb))
3704 				field |= TRB_ISP;
3705 
3706 			/* Chain all the TRBs together; clear the chain bit in
3707 			 * the last TRB to indicate it's the last TRB in the
3708 			 * chain.
3709 			 */
3710 			if (j < trbs_per_td - 1) {
3711 				field |= TRB_CHAIN;
3712 				more_trbs_coming = true;
3713 			} else {
3714 				td->last_trb = ep_ring->enqueue;
3715 				field |= TRB_IOC;
3716 				if (xhci->hci_version == 0x100 &&
3717 						!(xhci->quirks &
3718 							XHCI_AVOID_BEI)) {
3719 					/* Set BEI bit except for the last td */
3720 					if (i < num_tds - 1)
3721 						field |= TRB_BEI;
3722 				}
3723 				more_trbs_coming = false;
3724 			}
3725 
3726 			/* Calculate TRB length */
3727 			trb_buff_len = TRB_MAX_BUFF_SIZE -
3728 				(addr & ((1 << TRB_MAX_BUFF_SHIFT) - 1));
3729 			if (trb_buff_len > td_remain_len)
3730 				trb_buff_len = td_remain_len;
3731 
3732 			/* Set the TRB length, TD size, & interrupter fields. */
3733 			if (xhci->hci_version < 0x100) {
3734 				remainder = xhci_td_remainder(
3735 						td_len - running_total);
3736 			} else {
3737 				remainder = xhci_v1_0_td_remainder(
3738 						running_total, trb_buff_len,
3739 						total_packet_count, urb,
3740 						(trbs_per_td - j - 1));
3741 			}
3742 			length_field = TRB_LEN(trb_buff_len) |
3743 				remainder |
3744 				TRB_INTR_TARGET(0);
3745 
3746 			queue_trb(xhci, ep_ring, more_trbs_coming,
3747 				lower_32_bits(addr),
3748 				upper_32_bits(addr),
3749 				length_field,
3750 				field);
3751 			running_total += trb_buff_len;
3752 
3753 			addr += trb_buff_len;
3754 			td_remain_len -= trb_buff_len;
3755 		}
3756 
3757 		/* Check TD length */
3758 		if (running_total != td_len) {
3759 			xhci_err(xhci, "ISOC TD length unmatch\n");
3760 			ret = -EINVAL;
3761 			goto cleanup;
3762 		}
3763 	}
3764 
3765 	if (xhci_to_hcd(xhci)->self.bandwidth_isoc_reqs == 0) {
3766 		if (xhci->quirks & XHCI_AMD_PLL_FIX)
3767 			usb_amd_quirk_pll_disable();
3768 	}
3769 	xhci_to_hcd(xhci)->self.bandwidth_isoc_reqs++;
3770 
3771 	giveback_first_trb(xhci, slot_id, ep_index, urb->stream_id,
3772 			start_cycle, start_trb);
3773 	return 0;
3774 cleanup:
3775 	/* Clean up a partially enqueued isoc transfer. */
3776 
3777 	for (i--; i >= 0; i--)
3778 		list_del_init(&urb_priv->td[i]->td_list);
3779 
3780 	/* Use the first TD as a temporary variable to turn the TDs we've queued
3781 	 * into No-ops with a software-owned cycle bit. That way the hardware
3782 	 * won't accidentally start executing bogus TDs when we partially
3783 	 * overwrite them.  td->first_trb and td->start_seg are already set.
3784 	 */
3785 	urb_priv->td[0]->last_trb = ep_ring->enqueue;
3786 	/* Every TRB except the first & last will have its cycle bit flipped. */
3787 	td_to_noop(xhci, ep_ring, urb_priv->td[0], true);
3788 
3789 	/* Reset the ring enqueue back to the first TRB and its cycle bit. */
3790 	ep_ring->enqueue = urb_priv->td[0]->first_trb;
3791 	ep_ring->enq_seg = urb_priv->td[0]->start_seg;
3792 	ep_ring->cycle_state = start_cycle;
3793 	ep_ring->num_trbs_free = ep_ring->num_trbs_free_temp;
3794 	usb_hcd_unlink_urb_from_ep(bus_to_hcd(urb->dev->bus), urb);
3795 	return ret;
3796 }
3797 
3798 /*
3799  * Check transfer ring to guarantee there is enough room for the urb.
3800  * Update ISO URB start_frame and interval.
3801  * Update interval as xhci_queue_intr_tx does. Just use xhci frame_index to
3802  * update the urb->start_frame by now.
3803  * Always assume URB_ISO_ASAP set, and NEVER use urb->start_frame as input.
3804  */
3805 int xhci_queue_isoc_tx_prepare(struct xhci_hcd *xhci, gfp_t mem_flags,
3806 		struct urb *urb, int slot_id, unsigned int ep_index)
3807 {
3808 	struct xhci_virt_device *xdev;
3809 	struct xhci_ring *ep_ring;
3810 	struct xhci_ep_ctx *ep_ctx;
3811 	int start_frame;
3812 	int xhci_interval;
3813 	int ep_interval;
3814 	int num_tds, num_trbs, i;
3815 	int ret;
3816 
3817 	xdev = xhci->devs[slot_id];
3818 	ep_ring = xdev->eps[ep_index].ring;
3819 	ep_ctx = xhci_get_ep_ctx(xhci, xdev->out_ctx, ep_index);
3820 
3821 	num_trbs = 0;
3822 	num_tds = urb->number_of_packets;
3823 	for (i = 0; i < num_tds; i++)
3824 		num_trbs += count_isoc_trbs_needed(xhci, urb, i);
3825 
3826 	/* Check the ring to guarantee there is enough room for the whole urb.
3827 	 * Do not insert any td of the urb to the ring if the check failed.
3828 	 */
3829 	ret = prepare_ring(xhci, ep_ring, le32_to_cpu(ep_ctx->ep_info) & EP_STATE_MASK,
3830 			   num_trbs, mem_flags);
3831 	if (ret)
3832 		return ret;
3833 
3834 	start_frame = xhci_readl(xhci, &xhci->run_regs->microframe_index);
3835 	start_frame &= 0x3fff;
3836 
3837 	urb->start_frame = start_frame;
3838 	if (urb->dev->speed == USB_SPEED_LOW ||
3839 			urb->dev->speed == USB_SPEED_FULL)
3840 		urb->start_frame >>= 3;
3841 
3842 	xhci_interval = EP_INTERVAL_TO_UFRAMES(le32_to_cpu(ep_ctx->ep_info));
3843 	ep_interval = urb->interval;
3844 	/* Convert to microframes */
3845 	if (urb->dev->speed == USB_SPEED_LOW ||
3846 			urb->dev->speed == USB_SPEED_FULL)
3847 		ep_interval *= 8;
3848 	/* FIXME change this to a warning and a suggestion to use the new API
3849 	 * to set the polling interval (once the API is added).
3850 	 */
3851 	if (xhci_interval != ep_interval) {
3852 		if (printk_ratelimit())
3853 			dev_dbg(&urb->dev->dev, "Driver uses different interval"
3854 					" (%d microframe%s) than xHCI "
3855 					"(%d microframe%s)\n",
3856 					ep_interval,
3857 					ep_interval == 1 ? "" : "s",
3858 					xhci_interval,
3859 					xhci_interval == 1 ? "" : "s");
3860 		urb->interval = xhci_interval;
3861 		/* Convert back to frames for LS/FS devices */
3862 		if (urb->dev->speed == USB_SPEED_LOW ||
3863 				urb->dev->speed == USB_SPEED_FULL)
3864 			urb->interval /= 8;
3865 	}
3866 	ep_ring->num_trbs_free_temp = ep_ring->num_trbs_free;
3867 
3868 	return xhci_queue_isoc_tx(xhci, mem_flags, urb, slot_id, ep_index);
3869 }
3870 
3871 /****		Command Ring Operations		****/
3872 
3873 /* Generic function for queueing a command TRB on the command ring.
3874  * Check to make sure there's room on the command ring for one command TRB.
3875  * Also check that there's room reserved for commands that must not fail.
3876  * If this is a command that must not fail, meaning command_must_succeed = TRUE,
3877  * then only check for the number of reserved spots.
3878  * Don't decrement xhci->cmd_ring_reserved_trbs after we've queued the TRB
3879  * because the command event handler may want to resubmit a failed command.
3880  */
3881 static int queue_command(struct xhci_hcd *xhci, u32 field1, u32 field2,
3882 		u32 field3, u32 field4, bool command_must_succeed)
3883 {
3884 	int reserved_trbs = xhci->cmd_ring_reserved_trbs;
3885 	int ret;
3886 
3887 	if (!command_must_succeed)
3888 		reserved_trbs++;
3889 
3890 	ret = prepare_ring(xhci, xhci->cmd_ring, EP_STATE_RUNNING,
3891 			reserved_trbs, GFP_ATOMIC);
3892 	if (ret < 0) {
3893 		xhci_err(xhci, "ERR: No room for command on command ring\n");
3894 		if (command_must_succeed)
3895 			xhci_err(xhci, "ERR: Reserved TRB counting for "
3896 					"unfailable commands failed.\n");
3897 		return ret;
3898 	}
3899 	queue_trb(xhci, xhci->cmd_ring, false, field1, field2, field3,
3900 			field4 | xhci->cmd_ring->cycle_state);
3901 	return 0;
3902 }
3903 
3904 /* Queue a slot enable or disable request on the command ring */
3905 int xhci_queue_slot_control(struct xhci_hcd *xhci, u32 trb_type, u32 slot_id)
3906 {
3907 	return queue_command(xhci, 0, 0, 0,
3908 			TRB_TYPE(trb_type) | SLOT_ID_FOR_TRB(slot_id), false);
3909 }
3910 
3911 /* Queue an address device command TRB */
3912 int xhci_queue_address_device(struct xhci_hcd *xhci, dma_addr_t in_ctx_ptr,
3913 		u32 slot_id)
3914 {
3915 	return queue_command(xhci, lower_32_bits(in_ctx_ptr),
3916 			upper_32_bits(in_ctx_ptr), 0,
3917 			TRB_TYPE(TRB_ADDR_DEV) | SLOT_ID_FOR_TRB(slot_id),
3918 			false);
3919 }
3920 
3921 int xhci_queue_vendor_command(struct xhci_hcd *xhci,
3922 		u32 field1, u32 field2, u32 field3, u32 field4)
3923 {
3924 	return queue_command(xhci, field1, field2, field3, field4, false);
3925 }
3926 
3927 /* Queue a reset device command TRB */
3928 int xhci_queue_reset_device(struct xhci_hcd *xhci, u32 slot_id)
3929 {
3930 	return queue_command(xhci, 0, 0, 0,
3931 			TRB_TYPE(TRB_RESET_DEV) | SLOT_ID_FOR_TRB(slot_id),
3932 			false);
3933 }
3934 
3935 /* Queue a configure endpoint command TRB */
3936 int xhci_queue_configure_endpoint(struct xhci_hcd *xhci, dma_addr_t in_ctx_ptr,
3937 		u32 slot_id, bool command_must_succeed)
3938 {
3939 	return queue_command(xhci, lower_32_bits(in_ctx_ptr),
3940 			upper_32_bits(in_ctx_ptr), 0,
3941 			TRB_TYPE(TRB_CONFIG_EP) | SLOT_ID_FOR_TRB(slot_id),
3942 			command_must_succeed);
3943 }
3944 
3945 /* Queue an evaluate context command TRB */
3946 int xhci_queue_evaluate_context(struct xhci_hcd *xhci, dma_addr_t in_ctx_ptr,
3947 		u32 slot_id, bool command_must_succeed)
3948 {
3949 	return queue_command(xhci, lower_32_bits(in_ctx_ptr),
3950 			upper_32_bits(in_ctx_ptr), 0,
3951 			TRB_TYPE(TRB_EVAL_CONTEXT) | SLOT_ID_FOR_TRB(slot_id),
3952 			command_must_succeed);
3953 }
3954 
3955 /*
3956  * Suspend is set to indicate "Stop Endpoint Command" is being issued to stop
3957  * activity on an endpoint that is about to be suspended.
3958  */
3959 int xhci_queue_stop_endpoint(struct xhci_hcd *xhci, int slot_id,
3960 		unsigned int ep_index, int suspend)
3961 {
3962 	u32 trb_slot_id = SLOT_ID_FOR_TRB(slot_id);
3963 	u32 trb_ep_index = EP_ID_FOR_TRB(ep_index);
3964 	u32 type = TRB_TYPE(TRB_STOP_RING);
3965 	u32 trb_suspend = SUSPEND_PORT_FOR_TRB(suspend);
3966 
3967 	return queue_command(xhci, 0, 0, 0,
3968 			trb_slot_id | trb_ep_index | type | trb_suspend, false);
3969 }
3970 
3971 /* Set Transfer Ring Dequeue Pointer command.
3972  * This should not be used for endpoints that have streams enabled.
3973  */
3974 static int queue_set_tr_deq(struct xhci_hcd *xhci, int slot_id,
3975 		unsigned int ep_index, unsigned int stream_id,
3976 		struct xhci_segment *deq_seg,
3977 		union xhci_trb *deq_ptr, u32 cycle_state)
3978 {
3979 	dma_addr_t addr;
3980 	u32 trb_slot_id = SLOT_ID_FOR_TRB(slot_id);
3981 	u32 trb_ep_index = EP_ID_FOR_TRB(ep_index);
3982 	u32 trb_stream_id = STREAM_ID_FOR_TRB(stream_id);
3983 	u32 type = TRB_TYPE(TRB_SET_DEQ);
3984 	struct xhci_virt_ep *ep;
3985 
3986 	addr = xhci_trb_virt_to_dma(deq_seg, deq_ptr);
3987 	if (addr == 0) {
3988 		xhci_warn(xhci, "WARN Cannot submit Set TR Deq Ptr\n");
3989 		xhci_warn(xhci, "WARN deq seg = %p, deq pt = %p\n",
3990 				deq_seg, deq_ptr);
3991 		return 0;
3992 	}
3993 	ep = &xhci->devs[slot_id]->eps[ep_index];
3994 	if ((ep->ep_state & SET_DEQ_PENDING)) {
3995 		xhci_warn(xhci, "WARN Cannot submit Set TR Deq Ptr\n");
3996 		xhci_warn(xhci, "A Set TR Deq Ptr command is pending.\n");
3997 		return 0;
3998 	}
3999 	ep->queued_deq_seg = deq_seg;
4000 	ep->queued_deq_ptr = deq_ptr;
4001 	return queue_command(xhci, lower_32_bits(addr) | cycle_state,
4002 			upper_32_bits(addr), trb_stream_id,
4003 			trb_slot_id | trb_ep_index | type, false);
4004 }
4005 
4006 int xhci_queue_reset_ep(struct xhci_hcd *xhci, int slot_id,
4007 		unsigned int ep_index)
4008 {
4009 	u32 trb_slot_id = SLOT_ID_FOR_TRB(slot_id);
4010 	u32 trb_ep_index = EP_ID_FOR_TRB(ep_index);
4011 	u32 type = TRB_TYPE(TRB_RESET_EP);
4012 
4013 	return queue_command(xhci, 0, 0, 0, trb_slot_id | trb_ep_index | type,
4014 			false);
4015 }
4016