xref: /linux/drivers/usb/host/xhci-ring.c (revision 7056741fd9fc14a65608549a4657cf5178f05f63)
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 = 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 	/* find the command trb matched by cd from command ring */
1232 	for (cmd_trb = xhci->cmd_ring->dequeue;
1233 			cmd_trb != xhci->cmd_ring->enqueue;
1234 			next_trb(xhci, xhci->cmd_ring, &cur_seg, &cmd_trb)) {
1235 		/* If the trb is link trb, continue */
1236 		if (TRB_TYPE_LINK_LE32(cmd_trb->generic.field[3]))
1237 			continue;
1238 
1239 		if (cur_cd->cmd_trb == cmd_trb) {
1240 
1241 			/* If the command in device's command list, we should
1242 			 * finish it and free the command structure.
1243 			 */
1244 			if (cur_cd->command)
1245 				xhci_complete_cmd_in_cmd_wait_list(xhci,
1246 					cur_cd->command, COMP_CMD_STOP);
1247 
1248 			/* get cycle state from the origin command trb */
1249 			cycle_state = le32_to_cpu(cmd_trb->generic.field[3])
1250 				& TRB_CYCLE;
1251 
1252 			/* modify the command trb to NO OP command */
1253 			cmd_trb->generic.field[0] = 0;
1254 			cmd_trb->generic.field[1] = 0;
1255 			cmd_trb->generic.field[2] = 0;
1256 			cmd_trb->generic.field[3] = cpu_to_le32(
1257 					TRB_TYPE(TRB_CMD_NOOP) | cycle_state);
1258 			break;
1259 		}
1260 	}
1261 }
1262 
1263 static void xhci_cancel_cmd_in_cd_list(struct xhci_hcd *xhci)
1264 {
1265 	struct xhci_cd *cur_cd, *next_cd;
1266 
1267 	if (list_empty(&xhci->cancel_cmd_list))
1268 		return;
1269 
1270 	list_for_each_entry_safe(cur_cd, next_cd,
1271 			&xhci->cancel_cmd_list, cancel_cmd_list) {
1272 		xhci_cmd_to_noop(xhci, cur_cd);
1273 		list_del(&cur_cd->cancel_cmd_list);
1274 		kfree(cur_cd);
1275 	}
1276 }
1277 
1278 /*
1279  * traversing the cancel_cmd_list. If the command descriptor according
1280  * to cmd_trb is found, the function free it and return 1, otherwise
1281  * return 0.
1282  */
1283 static int xhci_search_cmd_trb_in_cd_list(struct xhci_hcd *xhci,
1284 		union xhci_trb *cmd_trb)
1285 {
1286 	struct xhci_cd *cur_cd, *next_cd;
1287 
1288 	if (list_empty(&xhci->cancel_cmd_list))
1289 		return 0;
1290 
1291 	list_for_each_entry_safe(cur_cd, next_cd,
1292 			&xhci->cancel_cmd_list, cancel_cmd_list) {
1293 		if (cur_cd->cmd_trb == cmd_trb) {
1294 			if (cur_cd->command)
1295 				xhci_complete_cmd_in_cmd_wait_list(xhci,
1296 					cur_cd->command, COMP_CMD_STOP);
1297 			list_del(&cur_cd->cancel_cmd_list);
1298 			kfree(cur_cd);
1299 			return 1;
1300 		}
1301 	}
1302 
1303 	return 0;
1304 }
1305 
1306 /*
1307  * If the cmd_trb_comp_code is COMP_CMD_ABORT, we just check whether the
1308  * trb pointed by the command ring dequeue pointer is the trb we want to
1309  * cancel or not. And if the cmd_trb_comp_code is COMP_CMD_STOP, we will
1310  * traverse the cancel_cmd_list to trun the all of the commands according
1311  * to command descriptor to NO-OP trb.
1312  */
1313 static int handle_stopped_cmd_ring(struct xhci_hcd *xhci,
1314 		int cmd_trb_comp_code)
1315 {
1316 	int cur_trb_is_good = 0;
1317 
1318 	/* Searching the cmd trb pointed by the command ring dequeue
1319 	 * pointer in command descriptor list. If it is found, free it.
1320 	 */
1321 	cur_trb_is_good = xhci_search_cmd_trb_in_cd_list(xhci,
1322 			xhci->cmd_ring->dequeue);
1323 
1324 	if (cmd_trb_comp_code == COMP_CMD_ABORT)
1325 		xhci->cmd_ring_state = CMD_RING_STATE_STOPPED;
1326 	else if (cmd_trb_comp_code == COMP_CMD_STOP) {
1327 		/* traversing the cancel_cmd_list and canceling
1328 		 * the command according to command descriptor
1329 		 */
1330 		xhci_cancel_cmd_in_cd_list(xhci);
1331 
1332 		xhci->cmd_ring_state = CMD_RING_STATE_RUNNING;
1333 		/*
1334 		 * ring command ring doorbell again to restart the
1335 		 * command ring
1336 		 */
1337 		if (xhci->cmd_ring->dequeue != xhci->cmd_ring->enqueue)
1338 			xhci_ring_cmd_db(xhci);
1339 	}
1340 	return cur_trb_is_good;
1341 }
1342 
1343 static void handle_cmd_completion(struct xhci_hcd *xhci,
1344 		struct xhci_event_cmd *event)
1345 {
1346 	int slot_id = TRB_TO_SLOT_ID(le32_to_cpu(event->flags));
1347 	u64 cmd_dma;
1348 	dma_addr_t cmd_dequeue_dma;
1349 	struct xhci_input_control_ctx *ctrl_ctx;
1350 	struct xhci_virt_device *virt_dev;
1351 	unsigned int ep_index;
1352 	struct xhci_ring *ep_ring;
1353 	unsigned int ep_state;
1354 
1355 	cmd_dma = le64_to_cpu(event->cmd_trb);
1356 	cmd_dequeue_dma = xhci_trb_virt_to_dma(xhci->cmd_ring->deq_seg,
1357 			xhci->cmd_ring->dequeue);
1358 	/* Is the command ring deq ptr out of sync with the deq seg ptr? */
1359 	if (cmd_dequeue_dma == 0) {
1360 		xhci->error_bitmask |= 1 << 4;
1361 		return;
1362 	}
1363 	/* Does the DMA address match our internal dequeue pointer address? */
1364 	if (cmd_dma != (u64) cmd_dequeue_dma) {
1365 		xhci->error_bitmask |= 1 << 5;
1366 		return;
1367 	}
1368 
1369 	if ((GET_COMP_CODE(le32_to_cpu(event->status)) == COMP_CMD_ABORT) ||
1370 		(GET_COMP_CODE(le32_to_cpu(event->status)) == COMP_CMD_STOP)) {
1371 		/* If the return value is 0, we think the trb pointed by
1372 		 * command ring dequeue pointer is a good trb. The good
1373 		 * trb means we don't want to cancel the trb, but it have
1374 		 * been stopped by host. So we should handle it normally.
1375 		 * Otherwise, driver should invoke inc_deq() and return.
1376 		 */
1377 		if (handle_stopped_cmd_ring(xhci,
1378 				GET_COMP_CODE(le32_to_cpu(event->status)))) {
1379 			inc_deq(xhci, xhci->cmd_ring);
1380 			return;
1381 		}
1382 	}
1383 
1384 	switch (le32_to_cpu(xhci->cmd_ring->dequeue->generic.field[3])
1385 		& TRB_TYPE_BITMASK) {
1386 	case TRB_TYPE(TRB_ENABLE_SLOT):
1387 		if (GET_COMP_CODE(le32_to_cpu(event->status)) == COMP_SUCCESS)
1388 			xhci->slot_id = slot_id;
1389 		else
1390 			xhci->slot_id = 0;
1391 		complete(&xhci->addr_dev);
1392 		break;
1393 	case TRB_TYPE(TRB_DISABLE_SLOT):
1394 		if (xhci->devs[slot_id]) {
1395 			if (xhci->quirks & XHCI_EP_LIMIT_QUIRK)
1396 				/* Delete default control endpoint resources */
1397 				xhci_free_device_endpoint_resources(xhci,
1398 						xhci->devs[slot_id], true);
1399 			xhci_free_virt_device(xhci, slot_id);
1400 		}
1401 		break;
1402 	case TRB_TYPE(TRB_CONFIG_EP):
1403 		virt_dev = xhci->devs[slot_id];
1404 		if (handle_cmd_in_cmd_wait_list(xhci, virt_dev, event))
1405 			break;
1406 		/*
1407 		 * Configure endpoint commands can come from the USB core
1408 		 * configuration or alt setting changes, or because the HW
1409 		 * needed an extra configure endpoint command after a reset
1410 		 * endpoint command or streams were being configured.
1411 		 * If the command was for a halted endpoint, the xHCI driver
1412 		 * is not waiting on the configure endpoint command.
1413 		 */
1414 		ctrl_ctx = xhci_get_input_control_ctx(xhci,
1415 				virt_dev->in_ctx);
1416 		/* Input ctx add_flags are the endpoint index plus one */
1417 		ep_index = xhci_last_valid_endpoint(le32_to_cpu(ctrl_ctx->add_flags)) - 1;
1418 		/* A usb_set_interface() call directly after clearing a halted
1419 		 * condition may race on this quirky hardware.  Not worth
1420 		 * worrying about, since this is prototype hardware.  Not sure
1421 		 * if this will work for streams, but streams support was
1422 		 * untested on this prototype.
1423 		 */
1424 		if (xhci->quirks & XHCI_RESET_EP_QUIRK &&
1425 				ep_index != (unsigned int) -1 &&
1426 		    le32_to_cpu(ctrl_ctx->add_flags) - SLOT_FLAG ==
1427 		    le32_to_cpu(ctrl_ctx->drop_flags)) {
1428 			ep_ring = xhci->devs[slot_id]->eps[ep_index].ring;
1429 			ep_state = xhci->devs[slot_id]->eps[ep_index].ep_state;
1430 			if (!(ep_state & EP_HALTED))
1431 				goto bandwidth_change;
1432 			xhci_dbg(xhci, "Completed config ep cmd - "
1433 					"last ep index = %d, state = %d\n",
1434 					ep_index, ep_state);
1435 			/* Clear internal halted state and restart ring(s) */
1436 			xhci->devs[slot_id]->eps[ep_index].ep_state &=
1437 				~EP_HALTED;
1438 			ring_doorbell_for_active_rings(xhci, slot_id, ep_index);
1439 			break;
1440 		}
1441 bandwidth_change:
1442 		xhci_dbg(xhci, "Completed config ep cmd\n");
1443 		xhci->devs[slot_id]->cmd_status =
1444 			GET_COMP_CODE(le32_to_cpu(event->status));
1445 		complete(&xhci->devs[slot_id]->cmd_completion);
1446 		break;
1447 	case TRB_TYPE(TRB_EVAL_CONTEXT):
1448 		virt_dev = xhci->devs[slot_id];
1449 		if (handle_cmd_in_cmd_wait_list(xhci, virt_dev, event))
1450 			break;
1451 		xhci->devs[slot_id]->cmd_status = GET_COMP_CODE(le32_to_cpu(event->status));
1452 		complete(&xhci->devs[slot_id]->cmd_completion);
1453 		break;
1454 	case TRB_TYPE(TRB_ADDR_DEV):
1455 		xhci->devs[slot_id]->cmd_status = GET_COMP_CODE(le32_to_cpu(event->status));
1456 		complete(&xhci->addr_dev);
1457 		break;
1458 	case TRB_TYPE(TRB_STOP_RING):
1459 		handle_stopped_endpoint(xhci, xhci->cmd_ring->dequeue, event);
1460 		break;
1461 	case TRB_TYPE(TRB_SET_DEQ):
1462 		handle_set_deq_completion(xhci, event, xhci->cmd_ring->dequeue);
1463 		break;
1464 	case TRB_TYPE(TRB_CMD_NOOP):
1465 		break;
1466 	case TRB_TYPE(TRB_RESET_EP):
1467 		handle_reset_ep_completion(xhci, event, xhci->cmd_ring->dequeue);
1468 		break;
1469 	case TRB_TYPE(TRB_RESET_DEV):
1470 		xhci_dbg(xhci, "Completed reset device command.\n");
1471 		slot_id = TRB_TO_SLOT_ID(
1472 			le32_to_cpu(xhci->cmd_ring->dequeue->generic.field[3]));
1473 		virt_dev = xhci->devs[slot_id];
1474 		if (virt_dev)
1475 			handle_cmd_in_cmd_wait_list(xhci, virt_dev, event);
1476 		else
1477 			xhci_warn(xhci, "Reset device command completion "
1478 					"for disabled slot %u\n", slot_id);
1479 		break;
1480 	case TRB_TYPE(TRB_NEC_GET_FW):
1481 		if (!(xhci->quirks & XHCI_NEC_HOST)) {
1482 			xhci->error_bitmask |= 1 << 6;
1483 			break;
1484 		}
1485 		xhci_dbg(xhci, "NEC firmware version %2x.%02x\n",
1486 			 NEC_FW_MAJOR(le32_to_cpu(event->status)),
1487 			 NEC_FW_MINOR(le32_to_cpu(event->status)));
1488 		break;
1489 	default:
1490 		/* Skip over unknown commands on the event ring */
1491 		xhci->error_bitmask |= 1 << 6;
1492 		break;
1493 	}
1494 	inc_deq(xhci, xhci->cmd_ring);
1495 }
1496 
1497 static void handle_vendor_event(struct xhci_hcd *xhci,
1498 		union xhci_trb *event)
1499 {
1500 	u32 trb_type;
1501 
1502 	trb_type = TRB_FIELD_TO_TYPE(le32_to_cpu(event->generic.field[3]));
1503 	xhci_dbg(xhci, "Vendor specific event TRB type = %u\n", trb_type);
1504 	if (trb_type == TRB_NEC_CMD_COMP && (xhci->quirks & XHCI_NEC_HOST))
1505 		handle_cmd_completion(xhci, &event->event_cmd);
1506 }
1507 
1508 /* @port_id: the one-based port ID from the hardware (indexed from array of all
1509  * port registers -- USB 3.0 and USB 2.0).
1510  *
1511  * Returns a zero-based port number, which is suitable for indexing into each of
1512  * the split roothubs' port arrays and bus state arrays.
1513  * Add one to it in order to call xhci_find_slot_id_by_port.
1514  */
1515 static unsigned int find_faked_portnum_from_hw_portnum(struct usb_hcd *hcd,
1516 		struct xhci_hcd *xhci, u32 port_id)
1517 {
1518 	unsigned int i;
1519 	unsigned int num_similar_speed_ports = 0;
1520 
1521 	/* port_id from the hardware is 1-based, but port_array[], usb3_ports[],
1522 	 * and usb2_ports are 0-based indexes.  Count the number of similar
1523 	 * speed ports, up to 1 port before this port.
1524 	 */
1525 	for (i = 0; i < (port_id - 1); i++) {
1526 		u8 port_speed = xhci->port_array[i];
1527 
1528 		/*
1529 		 * Skip ports that don't have known speeds, or have duplicate
1530 		 * Extended Capabilities port speed entries.
1531 		 */
1532 		if (port_speed == 0 || port_speed == DUPLICATE_ENTRY)
1533 			continue;
1534 
1535 		/*
1536 		 * USB 3.0 ports are always under a USB 3.0 hub.  USB 2.0 and
1537 		 * 1.1 ports are under the USB 2.0 hub.  If the port speed
1538 		 * matches the device speed, it's a similar speed port.
1539 		 */
1540 		if ((port_speed == 0x03) == (hcd->speed == HCD_USB3))
1541 			num_similar_speed_ports++;
1542 	}
1543 	return num_similar_speed_ports;
1544 }
1545 
1546 static void handle_device_notification(struct xhci_hcd *xhci,
1547 		union xhci_trb *event)
1548 {
1549 	u32 slot_id;
1550 	struct usb_device *udev;
1551 
1552 	slot_id = TRB_TO_SLOT_ID(event->generic.field[3]);
1553 	if (!xhci->devs[slot_id]) {
1554 		xhci_warn(xhci, "Device Notification event for "
1555 				"unused slot %u\n", slot_id);
1556 		return;
1557 	}
1558 
1559 	xhci_dbg(xhci, "Device Wake Notification event for slot ID %u\n",
1560 			slot_id);
1561 	udev = xhci->devs[slot_id]->udev;
1562 	if (udev && udev->parent)
1563 		usb_wakeup_notification(udev->parent, udev->portnum);
1564 }
1565 
1566 static void handle_port_status(struct xhci_hcd *xhci,
1567 		union xhci_trb *event)
1568 {
1569 	struct usb_hcd *hcd;
1570 	u32 port_id;
1571 	u32 temp, temp1;
1572 	int max_ports;
1573 	int slot_id;
1574 	unsigned int faked_port_index;
1575 	u8 major_revision;
1576 	struct xhci_bus_state *bus_state;
1577 	__le32 __iomem **port_array;
1578 	bool bogus_port_status = false;
1579 
1580 	/* Port status change events always have a successful completion code */
1581 	if (GET_COMP_CODE(le32_to_cpu(event->generic.field[2])) != COMP_SUCCESS) {
1582 		xhci_warn(xhci, "WARN: xHC returned failed port status event\n");
1583 		xhci->error_bitmask |= 1 << 8;
1584 	}
1585 	port_id = GET_PORT_ID(le32_to_cpu(event->generic.field[0]));
1586 	xhci_dbg(xhci, "Port Status Change Event for port %d\n", port_id);
1587 
1588 	max_ports = HCS_MAX_PORTS(xhci->hcs_params1);
1589 	if ((port_id <= 0) || (port_id > max_ports)) {
1590 		xhci_warn(xhci, "Invalid port id %d\n", port_id);
1591 		bogus_port_status = true;
1592 		goto cleanup;
1593 	}
1594 
1595 	/* Figure out which usb_hcd this port is attached to:
1596 	 * is it a USB 3.0 port or a USB 2.0/1.1 port?
1597 	 */
1598 	major_revision = xhci->port_array[port_id - 1];
1599 	if (major_revision == 0) {
1600 		xhci_warn(xhci, "Event for port %u not in "
1601 				"Extended Capabilities, ignoring.\n",
1602 				port_id);
1603 		bogus_port_status = true;
1604 		goto cleanup;
1605 	}
1606 	if (major_revision == DUPLICATE_ENTRY) {
1607 		xhci_warn(xhci, "Event for port %u duplicated in"
1608 				"Extended Capabilities, ignoring.\n",
1609 				port_id);
1610 		bogus_port_status = true;
1611 		goto cleanup;
1612 	}
1613 
1614 	/*
1615 	 * Hardware port IDs reported by a Port Status Change Event include USB
1616 	 * 3.0 and USB 2.0 ports.  We want to check if the port has reported a
1617 	 * resume event, but we first need to translate the hardware port ID
1618 	 * into the index into the ports on the correct split roothub, and the
1619 	 * correct bus_state structure.
1620 	 */
1621 	/* Find the right roothub. */
1622 	hcd = xhci_to_hcd(xhci);
1623 	if ((major_revision == 0x03) != (hcd->speed == HCD_USB3))
1624 		hcd = xhci->shared_hcd;
1625 	bus_state = &xhci->bus_state[hcd_index(hcd)];
1626 	if (hcd->speed == HCD_USB3)
1627 		port_array = xhci->usb3_ports;
1628 	else
1629 		port_array = xhci->usb2_ports;
1630 	/* Find the faked port hub number */
1631 	faked_port_index = find_faked_portnum_from_hw_portnum(hcd, xhci,
1632 			port_id);
1633 
1634 	temp = xhci_readl(xhci, port_array[faked_port_index]);
1635 	if (hcd->state == HC_STATE_SUSPENDED) {
1636 		xhci_dbg(xhci, "resume root hub\n");
1637 		usb_hcd_resume_root_hub(hcd);
1638 	}
1639 
1640 	if ((temp & PORT_PLC) && (temp & PORT_PLS_MASK) == XDEV_RESUME) {
1641 		xhci_dbg(xhci, "port resume event for port %d\n", port_id);
1642 
1643 		temp1 = xhci_readl(xhci, &xhci->op_regs->command);
1644 		if (!(temp1 & CMD_RUN)) {
1645 			xhci_warn(xhci, "xHC is not running.\n");
1646 			goto cleanup;
1647 		}
1648 
1649 		if (DEV_SUPERSPEED(temp)) {
1650 			xhci_dbg(xhci, "remote wake SS port %d\n", port_id);
1651 			/* Set a flag to say the port signaled remote wakeup,
1652 			 * so we can tell the difference between the end of
1653 			 * device and host initiated resume.
1654 			 */
1655 			bus_state->port_remote_wakeup |= 1 << faked_port_index;
1656 			xhci_test_and_clear_bit(xhci, port_array,
1657 					faked_port_index, PORT_PLC);
1658 			xhci_set_link_state(xhci, port_array, faked_port_index,
1659 						XDEV_U0);
1660 			/* Need to wait until the next link state change
1661 			 * indicates the device is actually in U0.
1662 			 */
1663 			bogus_port_status = true;
1664 			goto cleanup;
1665 		} else {
1666 			xhci_dbg(xhci, "resume HS port %d\n", port_id);
1667 			bus_state->resume_done[faked_port_index] = jiffies +
1668 				msecs_to_jiffies(20);
1669 			set_bit(faked_port_index, &bus_state->resuming_ports);
1670 			mod_timer(&hcd->rh_timer,
1671 				  bus_state->resume_done[faked_port_index]);
1672 			/* Do the rest in GetPortStatus */
1673 		}
1674 	}
1675 
1676 	if ((temp & PORT_PLC) && (temp & PORT_PLS_MASK) == XDEV_U0 &&
1677 			DEV_SUPERSPEED(temp)) {
1678 		xhci_dbg(xhci, "resume SS port %d finished\n", port_id);
1679 		/* We've just brought the device into U0 through either the
1680 		 * Resume state after a device remote wakeup, or through the
1681 		 * U3Exit state after a host-initiated resume.  If it's a device
1682 		 * initiated remote wake, don't pass up the link state change,
1683 		 * so the roothub behavior is consistent with external
1684 		 * USB 3.0 hub behavior.
1685 		 */
1686 		slot_id = xhci_find_slot_id_by_port(hcd, xhci,
1687 				faked_port_index + 1);
1688 		if (slot_id && xhci->devs[slot_id])
1689 			xhci_ring_device(xhci, slot_id);
1690 		if (bus_state->port_remote_wakeup && (1 << faked_port_index)) {
1691 			bus_state->port_remote_wakeup &=
1692 				~(1 << faked_port_index);
1693 			xhci_test_and_clear_bit(xhci, port_array,
1694 					faked_port_index, PORT_PLC);
1695 			usb_wakeup_notification(hcd->self.root_hub,
1696 					faked_port_index + 1);
1697 			bogus_port_status = true;
1698 			goto cleanup;
1699 		}
1700 	}
1701 
1702 	if (hcd->speed != HCD_USB3)
1703 		xhci_test_and_clear_bit(xhci, port_array, faked_port_index,
1704 					PORT_PLC);
1705 
1706 cleanup:
1707 	/* Update event ring dequeue pointer before dropping the lock */
1708 	inc_deq(xhci, xhci->event_ring);
1709 
1710 	/* Don't make the USB core poll the roothub if we got a bad port status
1711 	 * change event.  Besides, at that point we can't tell which roothub
1712 	 * (USB 2.0 or USB 3.0) to kick.
1713 	 */
1714 	if (bogus_port_status)
1715 		return;
1716 
1717 	spin_unlock(&xhci->lock);
1718 	/* Pass this up to the core */
1719 	usb_hcd_poll_rh_status(hcd);
1720 	spin_lock(&xhci->lock);
1721 }
1722 
1723 /*
1724  * This TD is defined by the TRBs starting at start_trb in start_seg and ending
1725  * at end_trb, which may be in another segment.  If the suspect DMA address is a
1726  * TRB in this TD, this function returns that TRB's segment.  Otherwise it
1727  * returns 0.
1728  */
1729 struct xhci_segment *trb_in_td(struct xhci_segment *start_seg,
1730 		union xhci_trb	*start_trb,
1731 		union xhci_trb	*end_trb,
1732 		dma_addr_t	suspect_dma)
1733 {
1734 	dma_addr_t start_dma;
1735 	dma_addr_t end_seg_dma;
1736 	dma_addr_t end_trb_dma;
1737 	struct xhci_segment *cur_seg;
1738 
1739 	start_dma = xhci_trb_virt_to_dma(start_seg, start_trb);
1740 	cur_seg = start_seg;
1741 
1742 	do {
1743 		if (start_dma == 0)
1744 			return NULL;
1745 		/* We may get an event for a Link TRB in the middle of a TD */
1746 		end_seg_dma = xhci_trb_virt_to_dma(cur_seg,
1747 				&cur_seg->trbs[TRBS_PER_SEGMENT - 1]);
1748 		/* If the end TRB isn't in this segment, this is set to 0 */
1749 		end_trb_dma = xhci_trb_virt_to_dma(cur_seg, end_trb);
1750 
1751 		if (end_trb_dma > 0) {
1752 			/* The end TRB is in this segment, so suspect should be here */
1753 			if (start_dma <= end_trb_dma) {
1754 				if (suspect_dma >= start_dma && suspect_dma <= end_trb_dma)
1755 					return cur_seg;
1756 			} else {
1757 				/* Case for one segment with
1758 				 * a TD wrapped around to the top
1759 				 */
1760 				if ((suspect_dma >= start_dma &&
1761 							suspect_dma <= end_seg_dma) ||
1762 						(suspect_dma >= cur_seg->dma &&
1763 						 suspect_dma <= end_trb_dma))
1764 					return cur_seg;
1765 			}
1766 			return NULL;
1767 		} else {
1768 			/* Might still be somewhere in this segment */
1769 			if (suspect_dma >= start_dma && suspect_dma <= end_seg_dma)
1770 				return cur_seg;
1771 		}
1772 		cur_seg = cur_seg->next;
1773 		start_dma = xhci_trb_virt_to_dma(cur_seg, &cur_seg->trbs[0]);
1774 	} while (cur_seg != start_seg);
1775 
1776 	return NULL;
1777 }
1778 
1779 static void xhci_cleanup_halted_endpoint(struct xhci_hcd *xhci,
1780 		unsigned int slot_id, unsigned int ep_index,
1781 		unsigned int stream_id,
1782 		struct xhci_td *td, union xhci_trb *event_trb)
1783 {
1784 	struct xhci_virt_ep *ep = &xhci->devs[slot_id]->eps[ep_index];
1785 	ep->ep_state |= EP_HALTED;
1786 	ep->stopped_td = td;
1787 	ep->stopped_trb = event_trb;
1788 	ep->stopped_stream = stream_id;
1789 
1790 	xhci_queue_reset_ep(xhci, slot_id, ep_index);
1791 	xhci_cleanup_stalled_ring(xhci, td->urb->dev, ep_index);
1792 
1793 	ep->stopped_td = NULL;
1794 	ep->stopped_trb = NULL;
1795 	ep->stopped_stream = 0;
1796 
1797 	xhci_ring_cmd_db(xhci);
1798 }
1799 
1800 /* Check if an error has halted the endpoint ring.  The class driver will
1801  * cleanup the halt for a non-default control endpoint if we indicate a stall.
1802  * However, a babble and other errors also halt the endpoint ring, and the class
1803  * driver won't clear the halt in that case, so we need to issue a Set Transfer
1804  * Ring Dequeue Pointer command manually.
1805  */
1806 static int xhci_requires_manual_halt_cleanup(struct xhci_hcd *xhci,
1807 		struct xhci_ep_ctx *ep_ctx,
1808 		unsigned int trb_comp_code)
1809 {
1810 	/* TRB completion codes that may require a manual halt cleanup */
1811 	if (trb_comp_code == COMP_TX_ERR ||
1812 			trb_comp_code == COMP_BABBLE ||
1813 			trb_comp_code == COMP_SPLIT_ERR)
1814 		/* The 0.96 spec says a babbling control endpoint
1815 		 * is not halted. The 0.96 spec says it is.  Some HW
1816 		 * claims to be 0.95 compliant, but it halts the control
1817 		 * endpoint anyway.  Check if a babble halted the
1818 		 * endpoint.
1819 		 */
1820 		if ((ep_ctx->ep_info & cpu_to_le32(EP_STATE_MASK)) ==
1821 		    cpu_to_le32(EP_STATE_HALTED))
1822 			return 1;
1823 
1824 	return 0;
1825 }
1826 
1827 int xhci_is_vendor_info_code(struct xhci_hcd *xhci, unsigned int trb_comp_code)
1828 {
1829 	if (trb_comp_code >= 224 && trb_comp_code <= 255) {
1830 		/* Vendor defined "informational" completion code,
1831 		 * treat as not-an-error.
1832 		 */
1833 		xhci_dbg(xhci, "Vendor defined info completion code %u\n",
1834 				trb_comp_code);
1835 		xhci_dbg(xhci, "Treating code as success.\n");
1836 		return 1;
1837 	}
1838 	return 0;
1839 }
1840 
1841 /*
1842  * Finish the td processing, remove the td from td list;
1843  * Return 1 if the urb can be given back.
1844  */
1845 static int finish_td(struct xhci_hcd *xhci, struct xhci_td *td,
1846 	union xhci_trb *event_trb, struct xhci_transfer_event *event,
1847 	struct xhci_virt_ep *ep, int *status, bool skip)
1848 {
1849 	struct xhci_virt_device *xdev;
1850 	struct xhci_ring *ep_ring;
1851 	unsigned int slot_id;
1852 	int ep_index;
1853 	struct urb *urb = NULL;
1854 	struct xhci_ep_ctx *ep_ctx;
1855 	int ret = 0;
1856 	struct urb_priv	*urb_priv;
1857 	u32 trb_comp_code;
1858 
1859 	slot_id = TRB_TO_SLOT_ID(le32_to_cpu(event->flags));
1860 	xdev = xhci->devs[slot_id];
1861 	ep_index = TRB_TO_EP_ID(le32_to_cpu(event->flags)) - 1;
1862 	ep_ring = xhci_dma_to_transfer_ring(ep, le64_to_cpu(event->buffer));
1863 	ep_ctx = xhci_get_ep_ctx(xhci, xdev->out_ctx, ep_index);
1864 	trb_comp_code = GET_COMP_CODE(le32_to_cpu(event->transfer_len));
1865 
1866 	if (skip)
1867 		goto td_cleanup;
1868 
1869 	if (trb_comp_code == COMP_STOP_INVAL ||
1870 			trb_comp_code == COMP_STOP) {
1871 		/* The Endpoint Stop Command completion will take care of any
1872 		 * stopped TDs.  A stopped TD may be restarted, so don't update
1873 		 * the ring dequeue pointer or take this TD off any lists yet.
1874 		 */
1875 		ep->stopped_td = td;
1876 		ep->stopped_trb = event_trb;
1877 		return 0;
1878 	} else {
1879 		if (trb_comp_code == COMP_STALL) {
1880 			/* The transfer is completed from the driver's
1881 			 * perspective, but we need to issue a set dequeue
1882 			 * command for this stalled endpoint to move the dequeue
1883 			 * pointer past the TD.  We can't do that here because
1884 			 * the halt condition must be cleared first.  Let the
1885 			 * USB class driver clear the stall later.
1886 			 */
1887 			ep->stopped_td = td;
1888 			ep->stopped_trb = event_trb;
1889 			ep->stopped_stream = ep_ring->stream_id;
1890 		} else if (xhci_requires_manual_halt_cleanup(xhci,
1891 					ep_ctx, trb_comp_code)) {
1892 			/* Other types of errors halt the endpoint, but the
1893 			 * class driver doesn't call usb_reset_endpoint() unless
1894 			 * the error is -EPIPE.  Clear the halted status in the
1895 			 * xHCI hardware manually.
1896 			 */
1897 			xhci_cleanup_halted_endpoint(xhci,
1898 					slot_id, ep_index, ep_ring->stream_id,
1899 					td, event_trb);
1900 		} else {
1901 			/* Update ring dequeue pointer */
1902 			while (ep_ring->dequeue != td->last_trb)
1903 				inc_deq(xhci, ep_ring);
1904 			inc_deq(xhci, ep_ring);
1905 		}
1906 
1907 td_cleanup:
1908 		/* Clean up the endpoint's TD list */
1909 		urb = td->urb;
1910 		urb_priv = urb->hcpriv;
1911 
1912 		/* Do one last check of the actual transfer length.
1913 		 * If the host controller said we transferred more data than
1914 		 * the buffer length, urb->actual_length will be a very big
1915 		 * number (since it's unsigned).  Play it safe and say we didn't
1916 		 * transfer anything.
1917 		 */
1918 		if (urb->actual_length > urb->transfer_buffer_length) {
1919 			xhci_warn(xhci, "URB transfer length is wrong, "
1920 					"xHC issue? req. len = %u, "
1921 					"act. len = %u\n",
1922 					urb->transfer_buffer_length,
1923 					urb->actual_length);
1924 			urb->actual_length = 0;
1925 			if (td->urb->transfer_flags & URB_SHORT_NOT_OK)
1926 				*status = -EREMOTEIO;
1927 			else
1928 				*status = 0;
1929 		}
1930 		list_del_init(&td->td_list);
1931 		/* Was this TD slated to be cancelled but completed anyway? */
1932 		if (!list_empty(&td->cancelled_td_list))
1933 			list_del_init(&td->cancelled_td_list);
1934 
1935 		urb_priv->td_cnt++;
1936 		/* Giveback the urb when all the tds are completed */
1937 		if (urb_priv->td_cnt == urb_priv->length) {
1938 			ret = 1;
1939 			if (usb_pipetype(urb->pipe) == PIPE_ISOCHRONOUS) {
1940 				xhci_to_hcd(xhci)->self.bandwidth_isoc_reqs--;
1941 				if (xhci_to_hcd(xhci)->self.bandwidth_isoc_reqs
1942 					== 0) {
1943 					if (xhci->quirks & XHCI_AMD_PLL_FIX)
1944 						usb_amd_quirk_pll_enable();
1945 				}
1946 			}
1947 		}
1948 	}
1949 
1950 	return ret;
1951 }
1952 
1953 /*
1954  * Process control tds, update urb status and actual_length.
1955  */
1956 static int process_ctrl_td(struct xhci_hcd *xhci, struct xhci_td *td,
1957 	union xhci_trb *event_trb, struct xhci_transfer_event *event,
1958 	struct xhci_virt_ep *ep, int *status)
1959 {
1960 	struct xhci_virt_device *xdev;
1961 	struct xhci_ring *ep_ring;
1962 	unsigned int slot_id;
1963 	int ep_index;
1964 	struct xhci_ep_ctx *ep_ctx;
1965 	u32 trb_comp_code;
1966 
1967 	slot_id = TRB_TO_SLOT_ID(le32_to_cpu(event->flags));
1968 	xdev = xhci->devs[slot_id];
1969 	ep_index = TRB_TO_EP_ID(le32_to_cpu(event->flags)) - 1;
1970 	ep_ring = xhci_dma_to_transfer_ring(ep, le64_to_cpu(event->buffer));
1971 	ep_ctx = xhci_get_ep_ctx(xhci, xdev->out_ctx, ep_index);
1972 	trb_comp_code = GET_COMP_CODE(le32_to_cpu(event->transfer_len));
1973 
1974 	switch (trb_comp_code) {
1975 	case COMP_SUCCESS:
1976 		if (event_trb == ep_ring->dequeue) {
1977 			xhci_warn(xhci, "WARN: Success on ctrl setup TRB "
1978 					"without IOC set??\n");
1979 			*status = -ESHUTDOWN;
1980 		} else if (event_trb != td->last_trb) {
1981 			xhci_warn(xhci, "WARN: Success on ctrl data TRB "
1982 					"without IOC set??\n");
1983 			*status = -ESHUTDOWN;
1984 		} else {
1985 			*status = 0;
1986 		}
1987 		break;
1988 	case COMP_SHORT_TX:
1989 		if (td->urb->transfer_flags & URB_SHORT_NOT_OK)
1990 			*status = -EREMOTEIO;
1991 		else
1992 			*status = 0;
1993 		break;
1994 	case COMP_STOP_INVAL:
1995 	case COMP_STOP:
1996 		return finish_td(xhci, td, event_trb, event, ep, status, false);
1997 	default:
1998 		if (!xhci_requires_manual_halt_cleanup(xhci,
1999 					ep_ctx, trb_comp_code))
2000 			break;
2001 		xhci_dbg(xhci, "TRB error code %u, "
2002 				"halted endpoint index = %u\n",
2003 				trb_comp_code, ep_index);
2004 		/* else fall through */
2005 	case COMP_STALL:
2006 		/* Did we transfer part of the data (middle) phase? */
2007 		if (event_trb != ep_ring->dequeue &&
2008 				event_trb != td->last_trb)
2009 			td->urb->actual_length =
2010 				td->urb->transfer_buffer_length
2011 				- TRB_LEN(le32_to_cpu(event->transfer_len));
2012 		else
2013 			td->urb->actual_length = 0;
2014 
2015 		xhci_cleanup_halted_endpoint(xhci,
2016 			slot_id, ep_index, 0, td, event_trb);
2017 		return finish_td(xhci, td, event_trb, event, ep, status, true);
2018 	}
2019 	/*
2020 	 * Did we transfer any data, despite the errors that might have
2021 	 * happened?  I.e. did we get past the setup stage?
2022 	 */
2023 	if (event_trb != ep_ring->dequeue) {
2024 		/* The event was for the status stage */
2025 		if (event_trb == td->last_trb) {
2026 			if (td->urb->actual_length != 0) {
2027 				/* Don't overwrite a previously set error code
2028 				 */
2029 				if ((*status == -EINPROGRESS || *status == 0) &&
2030 						(td->urb->transfer_flags
2031 						 & URB_SHORT_NOT_OK))
2032 					/* Did we already see a short data
2033 					 * stage? */
2034 					*status = -EREMOTEIO;
2035 			} else {
2036 				td->urb->actual_length =
2037 					td->urb->transfer_buffer_length;
2038 			}
2039 		} else {
2040 		/* Maybe the event was for the data stage? */
2041 			td->urb->actual_length =
2042 				td->urb->transfer_buffer_length -
2043 				TRB_LEN(le32_to_cpu(event->transfer_len));
2044 			xhci_dbg(xhci, "Waiting for status "
2045 					"stage event\n");
2046 			return 0;
2047 		}
2048 	}
2049 
2050 	return finish_td(xhci, td, event_trb, event, ep, status, false);
2051 }
2052 
2053 /*
2054  * Process isochronous tds, update urb packet status and actual_length.
2055  */
2056 static int process_isoc_td(struct xhci_hcd *xhci, struct xhci_td *td,
2057 	union xhci_trb *event_trb, struct xhci_transfer_event *event,
2058 	struct xhci_virt_ep *ep, int *status)
2059 {
2060 	struct xhci_ring *ep_ring;
2061 	struct urb_priv *urb_priv;
2062 	int idx;
2063 	int len = 0;
2064 	union xhci_trb *cur_trb;
2065 	struct xhci_segment *cur_seg;
2066 	struct usb_iso_packet_descriptor *frame;
2067 	u32 trb_comp_code;
2068 	bool skip_td = false;
2069 
2070 	ep_ring = xhci_dma_to_transfer_ring(ep, le64_to_cpu(event->buffer));
2071 	trb_comp_code = GET_COMP_CODE(le32_to_cpu(event->transfer_len));
2072 	urb_priv = td->urb->hcpriv;
2073 	idx = urb_priv->td_cnt;
2074 	frame = &td->urb->iso_frame_desc[idx];
2075 
2076 	/* handle completion code */
2077 	switch (trb_comp_code) {
2078 	case COMP_SUCCESS:
2079 		if (TRB_LEN(le32_to_cpu(event->transfer_len)) == 0) {
2080 			frame->status = 0;
2081 			break;
2082 		}
2083 		if ((xhci->quirks & XHCI_TRUST_TX_LENGTH))
2084 			trb_comp_code = COMP_SHORT_TX;
2085 	case COMP_SHORT_TX:
2086 		frame->status = td->urb->transfer_flags & URB_SHORT_NOT_OK ?
2087 				-EREMOTEIO : 0;
2088 		break;
2089 	case COMP_BW_OVER:
2090 		frame->status = -ECOMM;
2091 		skip_td = true;
2092 		break;
2093 	case COMP_BUFF_OVER:
2094 	case COMP_BABBLE:
2095 		frame->status = -EOVERFLOW;
2096 		skip_td = true;
2097 		break;
2098 	case COMP_DEV_ERR:
2099 	case COMP_STALL:
2100 	case COMP_TX_ERR:
2101 		frame->status = -EPROTO;
2102 		skip_td = true;
2103 		break;
2104 	case COMP_STOP:
2105 	case COMP_STOP_INVAL:
2106 		break;
2107 	default:
2108 		frame->status = -1;
2109 		break;
2110 	}
2111 
2112 	if (trb_comp_code == COMP_SUCCESS || skip_td) {
2113 		frame->actual_length = frame->length;
2114 		td->urb->actual_length += frame->length;
2115 	} else {
2116 		for (cur_trb = ep_ring->dequeue,
2117 		     cur_seg = ep_ring->deq_seg; cur_trb != event_trb;
2118 		     next_trb(xhci, ep_ring, &cur_seg, &cur_trb)) {
2119 			if (!TRB_TYPE_NOOP_LE32(cur_trb->generic.field[3]) &&
2120 			    !TRB_TYPE_LINK_LE32(cur_trb->generic.field[3]))
2121 				len += TRB_LEN(le32_to_cpu(cur_trb->generic.field[2]));
2122 		}
2123 		len += TRB_LEN(le32_to_cpu(cur_trb->generic.field[2])) -
2124 			TRB_LEN(le32_to_cpu(event->transfer_len));
2125 
2126 		if (trb_comp_code != COMP_STOP_INVAL) {
2127 			frame->actual_length = len;
2128 			td->urb->actual_length += len;
2129 		}
2130 	}
2131 
2132 	return finish_td(xhci, td, event_trb, event, ep, status, false);
2133 }
2134 
2135 static int skip_isoc_td(struct xhci_hcd *xhci, struct xhci_td *td,
2136 			struct xhci_transfer_event *event,
2137 			struct xhci_virt_ep *ep, int *status)
2138 {
2139 	struct xhci_ring *ep_ring;
2140 	struct urb_priv *urb_priv;
2141 	struct usb_iso_packet_descriptor *frame;
2142 	int idx;
2143 
2144 	ep_ring = xhci_dma_to_transfer_ring(ep, le64_to_cpu(event->buffer));
2145 	urb_priv = td->urb->hcpriv;
2146 	idx = urb_priv->td_cnt;
2147 	frame = &td->urb->iso_frame_desc[idx];
2148 
2149 	/* The transfer is partly done. */
2150 	frame->status = -EXDEV;
2151 
2152 	/* calc actual length */
2153 	frame->actual_length = 0;
2154 
2155 	/* Update ring dequeue pointer */
2156 	while (ep_ring->dequeue != td->last_trb)
2157 		inc_deq(xhci, ep_ring);
2158 	inc_deq(xhci, ep_ring);
2159 
2160 	return finish_td(xhci, td, NULL, event, ep, status, true);
2161 }
2162 
2163 /*
2164  * Process bulk and interrupt tds, update urb status and actual_length.
2165  */
2166 static int process_bulk_intr_td(struct xhci_hcd *xhci, struct xhci_td *td,
2167 	union xhci_trb *event_trb, struct xhci_transfer_event *event,
2168 	struct xhci_virt_ep *ep, int *status)
2169 {
2170 	struct xhci_ring *ep_ring;
2171 	union xhci_trb *cur_trb;
2172 	struct xhci_segment *cur_seg;
2173 	u32 trb_comp_code;
2174 
2175 	ep_ring = xhci_dma_to_transfer_ring(ep, le64_to_cpu(event->buffer));
2176 	trb_comp_code = GET_COMP_CODE(le32_to_cpu(event->transfer_len));
2177 
2178 	switch (trb_comp_code) {
2179 	case COMP_SUCCESS:
2180 		/* Double check that the HW transferred everything. */
2181 		if (event_trb != td->last_trb ||
2182 				TRB_LEN(le32_to_cpu(event->transfer_len)) != 0) {
2183 			xhci_warn(xhci, "WARN Successful completion "
2184 					"on short TX\n");
2185 			if (td->urb->transfer_flags & URB_SHORT_NOT_OK)
2186 				*status = -EREMOTEIO;
2187 			else
2188 				*status = 0;
2189 			if ((xhci->quirks & XHCI_TRUST_TX_LENGTH))
2190 				trb_comp_code = COMP_SHORT_TX;
2191 		} else {
2192 			*status = 0;
2193 		}
2194 		break;
2195 	case COMP_SHORT_TX:
2196 		if (td->urb->transfer_flags & URB_SHORT_NOT_OK)
2197 			*status = -EREMOTEIO;
2198 		else
2199 			*status = 0;
2200 		break;
2201 	default:
2202 		/* Others already handled above */
2203 		break;
2204 	}
2205 	if (trb_comp_code == COMP_SHORT_TX)
2206 		xhci_dbg(xhci, "ep %#x - asked for %d bytes, "
2207 				"%d bytes untransferred\n",
2208 				td->urb->ep->desc.bEndpointAddress,
2209 				td->urb->transfer_buffer_length,
2210 				TRB_LEN(le32_to_cpu(event->transfer_len)));
2211 	/* Fast path - was this the last TRB in the TD for this URB? */
2212 	if (event_trb == td->last_trb) {
2213 		if (TRB_LEN(le32_to_cpu(event->transfer_len)) != 0) {
2214 			td->urb->actual_length =
2215 				td->urb->transfer_buffer_length -
2216 				TRB_LEN(le32_to_cpu(event->transfer_len));
2217 			if (td->urb->transfer_buffer_length <
2218 					td->urb->actual_length) {
2219 				xhci_warn(xhci, "HC gave bad length "
2220 						"of %d bytes left\n",
2221 					  TRB_LEN(le32_to_cpu(event->transfer_len)));
2222 				td->urb->actual_length = 0;
2223 				if (td->urb->transfer_flags & URB_SHORT_NOT_OK)
2224 					*status = -EREMOTEIO;
2225 				else
2226 					*status = 0;
2227 			}
2228 			/* Don't overwrite a previously set error code */
2229 			if (*status == -EINPROGRESS) {
2230 				if (td->urb->transfer_flags & URB_SHORT_NOT_OK)
2231 					*status = -EREMOTEIO;
2232 				else
2233 					*status = 0;
2234 			}
2235 		} else {
2236 			td->urb->actual_length =
2237 				td->urb->transfer_buffer_length;
2238 			/* Ignore a short packet completion if the
2239 			 * untransferred length was zero.
2240 			 */
2241 			if (*status == -EREMOTEIO)
2242 				*status = 0;
2243 		}
2244 	} else {
2245 		/* Slow path - walk the list, starting from the dequeue
2246 		 * pointer, to get the actual length transferred.
2247 		 */
2248 		td->urb->actual_length = 0;
2249 		for (cur_trb = ep_ring->dequeue, cur_seg = ep_ring->deq_seg;
2250 				cur_trb != event_trb;
2251 				next_trb(xhci, ep_ring, &cur_seg, &cur_trb)) {
2252 			if (!TRB_TYPE_NOOP_LE32(cur_trb->generic.field[3]) &&
2253 			    !TRB_TYPE_LINK_LE32(cur_trb->generic.field[3]))
2254 				td->urb->actual_length +=
2255 					TRB_LEN(le32_to_cpu(cur_trb->generic.field[2]));
2256 		}
2257 		/* If the ring didn't stop on a Link or No-op TRB, add
2258 		 * in the actual bytes transferred from the Normal TRB
2259 		 */
2260 		if (trb_comp_code != COMP_STOP_INVAL)
2261 			td->urb->actual_length +=
2262 				TRB_LEN(le32_to_cpu(cur_trb->generic.field[2])) -
2263 				TRB_LEN(le32_to_cpu(event->transfer_len));
2264 	}
2265 
2266 	return finish_td(xhci, td, event_trb, event, ep, status, false);
2267 }
2268 
2269 /*
2270  * If this function returns an error condition, it means it got a Transfer
2271  * event with a corrupted Slot ID, Endpoint ID, or TRB DMA address.
2272  * At this point, the host controller is probably hosed and should be reset.
2273  */
2274 static int handle_tx_event(struct xhci_hcd *xhci,
2275 		struct xhci_transfer_event *event)
2276 	__releases(&xhci->lock)
2277 	__acquires(&xhci->lock)
2278 {
2279 	struct xhci_virt_device *xdev;
2280 	struct xhci_virt_ep *ep;
2281 	struct xhci_ring *ep_ring;
2282 	unsigned int slot_id;
2283 	int ep_index;
2284 	struct xhci_td *td = NULL;
2285 	dma_addr_t event_dma;
2286 	struct xhci_segment *event_seg;
2287 	union xhci_trb *event_trb;
2288 	struct urb *urb = NULL;
2289 	int status = -EINPROGRESS;
2290 	struct urb_priv *urb_priv;
2291 	struct xhci_ep_ctx *ep_ctx;
2292 	struct list_head *tmp;
2293 	u32 trb_comp_code;
2294 	int ret = 0;
2295 	int td_num = 0;
2296 
2297 	slot_id = TRB_TO_SLOT_ID(le32_to_cpu(event->flags));
2298 	xdev = xhci->devs[slot_id];
2299 	if (!xdev) {
2300 		xhci_err(xhci, "ERROR Transfer event pointed to bad slot\n");
2301 		xhci_err(xhci, "@%016llx %08x %08x %08x %08x\n",
2302 			 (unsigned long long) xhci_trb_virt_to_dma(
2303 				 xhci->event_ring->deq_seg,
2304 				 xhci->event_ring->dequeue),
2305 			 lower_32_bits(le64_to_cpu(event->buffer)),
2306 			 upper_32_bits(le64_to_cpu(event->buffer)),
2307 			 le32_to_cpu(event->transfer_len),
2308 			 le32_to_cpu(event->flags));
2309 		xhci_dbg(xhci, "Event ring:\n");
2310 		xhci_debug_segment(xhci, xhci->event_ring->deq_seg);
2311 		return -ENODEV;
2312 	}
2313 
2314 	/* Endpoint ID is 1 based, our index is zero based */
2315 	ep_index = TRB_TO_EP_ID(le32_to_cpu(event->flags)) - 1;
2316 	ep = &xdev->eps[ep_index];
2317 	ep_ring = xhci_dma_to_transfer_ring(ep, le64_to_cpu(event->buffer));
2318 	ep_ctx = xhci_get_ep_ctx(xhci, xdev->out_ctx, ep_index);
2319 	if (!ep_ring ||
2320 	    (le32_to_cpu(ep_ctx->ep_info) & EP_STATE_MASK) ==
2321 	    EP_STATE_DISABLED) {
2322 		xhci_err(xhci, "ERROR Transfer event for disabled endpoint "
2323 				"or incorrect stream ring\n");
2324 		xhci_err(xhci, "@%016llx %08x %08x %08x %08x\n",
2325 			 (unsigned long long) xhci_trb_virt_to_dma(
2326 				 xhci->event_ring->deq_seg,
2327 				 xhci->event_ring->dequeue),
2328 			 lower_32_bits(le64_to_cpu(event->buffer)),
2329 			 upper_32_bits(le64_to_cpu(event->buffer)),
2330 			 le32_to_cpu(event->transfer_len),
2331 			 le32_to_cpu(event->flags));
2332 		xhci_dbg(xhci, "Event ring:\n");
2333 		xhci_debug_segment(xhci, xhci->event_ring->deq_seg);
2334 		return -ENODEV;
2335 	}
2336 
2337 	/* Count current td numbers if ep->skip is set */
2338 	if (ep->skip) {
2339 		list_for_each(tmp, &ep_ring->td_list)
2340 			td_num++;
2341 	}
2342 
2343 	event_dma = le64_to_cpu(event->buffer);
2344 	trb_comp_code = GET_COMP_CODE(le32_to_cpu(event->transfer_len));
2345 	/* Look for common error cases */
2346 	switch (trb_comp_code) {
2347 	/* Skip codes that require special handling depending on
2348 	 * transfer type
2349 	 */
2350 	case COMP_SUCCESS:
2351 		if (TRB_LEN(le32_to_cpu(event->transfer_len)) == 0)
2352 			break;
2353 		if (xhci->quirks & XHCI_TRUST_TX_LENGTH)
2354 			trb_comp_code = COMP_SHORT_TX;
2355 		else
2356 			xhci_warn_ratelimited(xhci,
2357 					"WARN Successful completion on short TX: needs XHCI_TRUST_TX_LENGTH quirk?\n");
2358 	case COMP_SHORT_TX:
2359 		break;
2360 	case COMP_STOP:
2361 		xhci_dbg(xhci, "Stopped on Transfer TRB\n");
2362 		break;
2363 	case COMP_STOP_INVAL:
2364 		xhci_dbg(xhci, "Stopped on No-op or Link TRB\n");
2365 		break;
2366 	case COMP_STALL:
2367 		xhci_dbg(xhci, "Stalled endpoint\n");
2368 		ep->ep_state |= EP_HALTED;
2369 		status = -EPIPE;
2370 		break;
2371 	case COMP_TRB_ERR:
2372 		xhci_warn(xhci, "WARN: TRB error on endpoint\n");
2373 		status = -EILSEQ;
2374 		break;
2375 	case COMP_SPLIT_ERR:
2376 	case COMP_TX_ERR:
2377 		xhci_dbg(xhci, "Transfer error on endpoint\n");
2378 		status = -EPROTO;
2379 		break;
2380 	case COMP_BABBLE:
2381 		xhci_dbg(xhci, "Babble error on endpoint\n");
2382 		status = -EOVERFLOW;
2383 		break;
2384 	case COMP_DB_ERR:
2385 		xhci_warn(xhci, "WARN: HC couldn't access mem fast enough\n");
2386 		status = -ENOSR;
2387 		break;
2388 	case COMP_BW_OVER:
2389 		xhci_warn(xhci, "WARN: bandwidth overrun event on endpoint\n");
2390 		break;
2391 	case COMP_BUFF_OVER:
2392 		xhci_warn(xhci, "WARN: buffer overrun event on endpoint\n");
2393 		break;
2394 	case COMP_UNDERRUN:
2395 		/*
2396 		 * When the Isoch ring is empty, the xHC will generate
2397 		 * a Ring Overrun Event for IN Isoch endpoint or Ring
2398 		 * Underrun Event for OUT Isoch endpoint.
2399 		 */
2400 		xhci_dbg(xhci, "underrun event on endpoint\n");
2401 		if (!list_empty(&ep_ring->td_list))
2402 			xhci_dbg(xhci, "Underrun Event for slot %d ep %d "
2403 					"still with TDs queued?\n",
2404 				 TRB_TO_SLOT_ID(le32_to_cpu(event->flags)),
2405 				 ep_index);
2406 		goto cleanup;
2407 	case COMP_OVERRUN:
2408 		xhci_dbg(xhci, "overrun event on endpoint\n");
2409 		if (!list_empty(&ep_ring->td_list))
2410 			xhci_dbg(xhci, "Overrun Event for slot %d ep %d "
2411 					"still with TDs queued?\n",
2412 				 TRB_TO_SLOT_ID(le32_to_cpu(event->flags)),
2413 				 ep_index);
2414 		goto cleanup;
2415 	case COMP_DEV_ERR:
2416 		xhci_warn(xhci, "WARN: detect an incompatible device");
2417 		status = -EPROTO;
2418 		break;
2419 	case COMP_MISSED_INT:
2420 		/*
2421 		 * When encounter missed service error, one or more isoc tds
2422 		 * may be missed by xHC.
2423 		 * Set skip flag of the ep_ring; Complete the missed tds as
2424 		 * short transfer when process the ep_ring next time.
2425 		 */
2426 		ep->skip = true;
2427 		xhci_dbg(xhci, "Miss service interval error, set skip flag\n");
2428 		goto cleanup;
2429 	default:
2430 		if (xhci_is_vendor_info_code(xhci, trb_comp_code)) {
2431 			status = 0;
2432 			break;
2433 		}
2434 		xhci_warn(xhci, "ERROR Unknown event condition, HC probably "
2435 				"busted\n");
2436 		goto cleanup;
2437 	}
2438 
2439 	do {
2440 		/* This TRB should be in the TD at the head of this ring's
2441 		 * TD list.
2442 		 */
2443 		if (list_empty(&ep_ring->td_list)) {
2444 			xhci_warn(xhci, "WARN Event TRB for slot %d ep %d "
2445 					"with no TDs queued?\n",
2446 				  TRB_TO_SLOT_ID(le32_to_cpu(event->flags)),
2447 				  ep_index);
2448 			xhci_dbg(xhci, "Event TRB with TRB type ID %u\n",
2449 				 (le32_to_cpu(event->flags) &
2450 				  TRB_TYPE_BITMASK)>>10);
2451 			xhci_print_trb_offsets(xhci, (union xhci_trb *) event);
2452 			if (ep->skip) {
2453 				ep->skip = false;
2454 				xhci_dbg(xhci, "td_list is empty while skip "
2455 						"flag set. Clear skip flag.\n");
2456 			}
2457 			ret = 0;
2458 			goto cleanup;
2459 		}
2460 
2461 		/* We've skipped all the TDs on the ep ring when ep->skip set */
2462 		if (ep->skip && td_num == 0) {
2463 			ep->skip = false;
2464 			xhci_dbg(xhci, "All tds on the ep_ring skipped. "
2465 						"Clear skip flag.\n");
2466 			ret = 0;
2467 			goto cleanup;
2468 		}
2469 
2470 		td = list_entry(ep_ring->td_list.next, struct xhci_td, td_list);
2471 		if (ep->skip)
2472 			td_num--;
2473 
2474 		/* Is this a TRB in the currently executing TD? */
2475 		event_seg = trb_in_td(ep_ring->deq_seg, ep_ring->dequeue,
2476 				td->last_trb, event_dma);
2477 
2478 		/*
2479 		 * Skip the Force Stopped Event. The event_trb(event_dma) of FSE
2480 		 * is not in the current TD pointed by ep_ring->dequeue because
2481 		 * that the hardware dequeue pointer still at the previous TRB
2482 		 * of the current TD. The previous TRB maybe a Link TD or the
2483 		 * last TRB of the previous TD. The command completion handle
2484 		 * will take care the rest.
2485 		 */
2486 		if (!event_seg && trb_comp_code == COMP_STOP_INVAL) {
2487 			ret = 0;
2488 			goto cleanup;
2489 		}
2490 
2491 		if (!event_seg) {
2492 			if (!ep->skip ||
2493 			    !usb_endpoint_xfer_isoc(&td->urb->ep->desc)) {
2494 				/* Some host controllers give a spurious
2495 				 * successful event after a short transfer.
2496 				 * Ignore it.
2497 				 */
2498 				if ((xhci->quirks & XHCI_SPURIOUS_SUCCESS) &&
2499 						ep_ring->last_td_was_short) {
2500 					ep_ring->last_td_was_short = false;
2501 					ret = 0;
2502 					goto cleanup;
2503 				}
2504 				/* HC is busted, give up! */
2505 				xhci_err(xhci,
2506 					"ERROR Transfer event TRB DMA ptr not "
2507 					"part of current TD\n");
2508 				return -ESHUTDOWN;
2509 			}
2510 
2511 			ret = skip_isoc_td(xhci, td, event, ep, &status);
2512 			goto cleanup;
2513 		}
2514 		if (trb_comp_code == COMP_SHORT_TX)
2515 			ep_ring->last_td_was_short = true;
2516 		else
2517 			ep_ring->last_td_was_short = false;
2518 
2519 		if (ep->skip) {
2520 			xhci_dbg(xhci, "Found td. Clear skip flag.\n");
2521 			ep->skip = false;
2522 		}
2523 
2524 		event_trb = &event_seg->trbs[(event_dma - event_seg->dma) /
2525 						sizeof(*event_trb)];
2526 		/*
2527 		 * No-op TRB should not trigger interrupts.
2528 		 * If event_trb is a no-op TRB, it means the
2529 		 * corresponding TD has been cancelled. Just ignore
2530 		 * the TD.
2531 		 */
2532 		if (TRB_TYPE_NOOP_LE32(event_trb->generic.field[3])) {
2533 			xhci_dbg(xhci,
2534 				 "event_trb is a no-op TRB. Skip it\n");
2535 			goto cleanup;
2536 		}
2537 
2538 		/* Now update the urb's actual_length and give back to
2539 		 * the core
2540 		 */
2541 		if (usb_endpoint_xfer_control(&td->urb->ep->desc))
2542 			ret = process_ctrl_td(xhci, td, event_trb, event, ep,
2543 						 &status);
2544 		else if (usb_endpoint_xfer_isoc(&td->urb->ep->desc))
2545 			ret = process_isoc_td(xhci, td, event_trb, event, ep,
2546 						 &status);
2547 		else
2548 			ret = process_bulk_intr_td(xhci, td, event_trb, event,
2549 						 ep, &status);
2550 
2551 cleanup:
2552 		/*
2553 		 * Do not update event ring dequeue pointer if ep->skip is set.
2554 		 * Will roll back to continue process missed tds.
2555 		 */
2556 		if (trb_comp_code == COMP_MISSED_INT || !ep->skip) {
2557 			inc_deq(xhci, xhci->event_ring);
2558 		}
2559 
2560 		if (ret) {
2561 			urb = td->urb;
2562 			urb_priv = urb->hcpriv;
2563 			/* Leave the TD around for the reset endpoint function
2564 			 * to use(but only if it's not a control endpoint,
2565 			 * since we already queued the Set TR dequeue pointer
2566 			 * command for stalled control endpoints).
2567 			 */
2568 			if (usb_endpoint_xfer_control(&urb->ep->desc) ||
2569 				(trb_comp_code != COMP_STALL &&
2570 					trb_comp_code != COMP_BABBLE))
2571 				xhci_urb_free_priv(xhci, urb_priv);
2572 
2573 			usb_hcd_unlink_urb_from_ep(bus_to_hcd(urb->dev->bus), urb);
2574 			if ((urb->actual_length != urb->transfer_buffer_length &&
2575 						(urb->transfer_flags &
2576 						 URB_SHORT_NOT_OK)) ||
2577 					(status != 0 &&
2578 					 !usb_endpoint_xfer_isoc(&urb->ep->desc)))
2579 				xhci_dbg(xhci, "Giveback URB %p, len = %d, "
2580 						"expected = %d, status = %d\n",
2581 						urb, urb->actual_length,
2582 						urb->transfer_buffer_length,
2583 						status);
2584 			spin_unlock(&xhci->lock);
2585 			/* EHCI, UHCI, and OHCI always unconditionally set the
2586 			 * urb->status of an isochronous endpoint to 0.
2587 			 */
2588 			if (usb_pipetype(urb->pipe) == PIPE_ISOCHRONOUS)
2589 				status = 0;
2590 			usb_hcd_giveback_urb(bus_to_hcd(urb->dev->bus), urb, status);
2591 			spin_lock(&xhci->lock);
2592 		}
2593 
2594 	/*
2595 	 * If ep->skip is set, it means there are missed tds on the
2596 	 * endpoint ring need to take care of.
2597 	 * Process them as short transfer until reach the td pointed by
2598 	 * the event.
2599 	 */
2600 	} while (ep->skip && trb_comp_code != COMP_MISSED_INT);
2601 
2602 	return 0;
2603 }
2604 
2605 /*
2606  * This function handles all OS-owned events on the event ring.  It may drop
2607  * xhci->lock between event processing (e.g. to pass up port status changes).
2608  * Returns >0 for "possibly more events to process" (caller should call again),
2609  * otherwise 0 if done.  In future, <0 returns should indicate error code.
2610  */
2611 static int xhci_handle_event(struct xhci_hcd *xhci)
2612 {
2613 	union xhci_trb *event;
2614 	int update_ptrs = 1;
2615 	int ret;
2616 
2617 	if (!xhci->event_ring || !xhci->event_ring->dequeue) {
2618 		xhci->error_bitmask |= 1 << 1;
2619 		return 0;
2620 	}
2621 
2622 	event = xhci->event_ring->dequeue;
2623 	/* Does the HC or OS own the TRB? */
2624 	if ((le32_to_cpu(event->event_cmd.flags) & TRB_CYCLE) !=
2625 	    xhci->event_ring->cycle_state) {
2626 		xhci->error_bitmask |= 1 << 2;
2627 		return 0;
2628 	}
2629 
2630 	/*
2631 	 * Barrier between reading the TRB_CYCLE (valid) flag above and any
2632 	 * speculative reads of the event's flags/data below.
2633 	 */
2634 	rmb();
2635 	/* FIXME: Handle more event types. */
2636 	switch ((le32_to_cpu(event->event_cmd.flags) & TRB_TYPE_BITMASK)) {
2637 	case TRB_TYPE(TRB_COMPLETION):
2638 		handle_cmd_completion(xhci, &event->event_cmd);
2639 		break;
2640 	case TRB_TYPE(TRB_PORT_STATUS):
2641 		handle_port_status(xhci, event);
2642 		update_ptrs = 0;
2643 		break;
2644 	case TRB_TYPE(TRB_TRANSFER):
2645 		ret = handle_tx_event(xhci, &event->trans_event);
2646 		if (ret < 0)
2647 			xhci->error_bitmask |= 1 << 9;
2648 		else
2649 			update_ptrs = 0;
2650 		break;
2651 	case TRB_TYPE(TRB_DEV_NOTE):
2652 		handle_device_notification(xhci, event);
2653 		break;
2654 	default:
2655 		if ((le32_to_cpu(event->event_cmd.flags) & TRB_TYPE_BITMASK) >=
2656 		    TRB_TYPE(48))
2657 			handle_vendor_event(xhci, event);
2658 		else
2659 			xhci->error_bitmask |= 1 << 3;
2660 	}
2661 	/* Any of the above functions may drop and re-acquire the lock, so check
2662 	 * to make sure a watchdog timer didn't mark the host as non-responsive.
2663 	 */
2664 	if (xhci->xhc_state & XHCI_STATE_DYING) {
2665 		xhci_dbg(xhci, "xHCI host dying, returning from "
2666 				"event handler.\n");
2667 		return 0;
2668 	}
2669 
2670 	if (update_ptrs)
2671 		/* Update SW event ring dequeue pointer */
2672 		inc_deq(xhci, xhci->event_ring);
2673 
2674 	/* Are there more items on the event ring?  Caller will call us again to
2675 	 * check.
2676 	 */
2677 	return 1;
2678 }
2679 
2680 /*
2681  * xHCI spec says we can get an interrupt, and if the HC has an error condition,
2682  * we might get bad data out of the event ring.  Section 4.10.2.7 has a list of
2683  * indicators of an event TRB error, but we check the status *first* to be safe.
2684  */
2685 irqreturn_t xhci_irq(struct usb_hcd *hcd)
2686 {
2687 	struct xhci_hcd *xhci = hcd_to_xhci(hcd);
2688 	u32 status;
2689 	union xhci_trb *trb;
2690 	u64 temp_64;
2691 	union xhci_trb *event_ring_deq;
2692 	dma_addr_t deq;
2693 
2694 	spin_lock(&xhci->lock);
2695 	trb = xhci->event_ring->dequeue;
2696 	/* Check if the xHC generated the interrupt, or the irq is shared */
2697 	status = xhci_readl(xhci, &xhci->op_regs->status);
2698 	if (status == 0xffffffff)
2699 		goto hw_died;
2700 
2701 	if (!(status & STS_EINT)) {
2702 		spin_unlock(&xhci->lock);
2703 		return IRQ_NONE;
2704 	}
2705 	if (status & STS_FATAL) {
2706 		xhci_warn(xhci, "WARNING: Host System Error\n");
2707 		xhci_halt(xhci);
2708 hw_died:
2709 		spin_unlock(&xhci->lock);
2710 		return -ESHUTDOWN;
2711 	}
2712 
2713 	/*
2714 	 * Clear the op reg interrupt status first,
2715 	 * so we can receive interrupts from other MSI-X interrupters.
2716 	 * Write 1 to clear the interrupt status.
2717 	 */
2718 	status |= STS_EINT;
2719 	xhci_writel(xhci, status, &xhci->op_regs->status);
2720 	/* FIXME when MSI-X is supported and there are multiple vectors */
2721 	/* Clear the MSI-X event interrupt status */
2722 
2723 	if (hcd->irq) {
2724 		u32 irq_pending;
2725 		/* Acknowledge the PCI interrupt */
2726 		irq_pending = xhci_readl(xhci, &xhci->ir_set->irq_pending);
2727 		irq_pending |= IMAN_IP;
2728 		xhci_writel(xhci, irq_pending, &xhci->ir_set->irq_pending);
2729 	}
2730 
2731 	if (xhci->xhc_state & XHCI_STATE_DYING) {
2732 		xhci_dbg(xhci, "xHCI dying, ignoring interrupt. "
2733 				"Shouldn't IRQs be disabled?\n");
2734 		/* Clear the event handler busy flag (RW1C);
2735 		 * the event ring should be empty.
2736 		 */
2737 		temp_64 = xhci_read_64(xhci, &xhci->ir_set->erst_dequeue);
2738 		xhci_write_64(xhci, temp_64 | ERST_EHB,
2739 				&xhci->ir_set->erst_dequeue);
2740 		spin_unlock(&xhci->lock);
2741 
2742 		return IRQ_HANDLED;
2743 	}
2744 
2745 	event_ring_deq = xhci->event_ring->dequeue;
2746 	/* FIXME this should be a delayed service routine
2747 	 * that clears the EHB.
2748 	 */
2749 	while (xhci_handle_event(xhci) > 0) {}
2750 
2751 	temp_64 = xhci_read_64(xhci, &xhci->ir_set->erst_dequeue);
2752 	/* If necessary, update the HW's version of the event ring deq ptr. */
2753 	if (event_ring_deq != xhci->event_ring->dequeue) {
2754 		deq = xhci_trb_virt_to_dma(xhci->event_ring->deq_seg,
2755 				xhci->event_ring->dequeue);
2756 		if (deq == 0)
2757 			xhci_warn(xhci, "WARN something wrong with SW event "
2758 					"ring dequeue ptr.\n");
2759 		/* Update HC event ring dequeue pointer */
2760 		temp_64 &= ERST_PTR_MASK;
2761 		temp_64 |= ((u64) deq & (u64) ~ERST_PTR_MASK);
2762 	}
2763 
2764 	/* Clear the event handler busy flag (RW1C); event ring is empty. */
2765 	temp_64 |= ERST_EHB;
2766 	xhci_write_64(xhci, temp_64, &xhci->ir_set->erst_dequeue);
2767 
2768 	spin_unlock(&xhci->lock);
2769 
2770 	return IRQ_HANDLED;
2771 }
2772 
2773 irqreturn_t xhci_msi_irq(int irq, struct usb_hcd *hcd)
2774 {
2775 	return xhci_irq(hcd);
2776 }
2777 
2778 /****		Endpoint Ring Operations	****/
2779 
2780 /*
2781  * Generic function for queueing a TRB on a ring.
2782  * The caller must have checked to make sure there's room on the ring.
2783  *
2784  * @more_trbs_coming:	Will you enqueue more TRBs before calling
2785  *			prepare_transfer()?
2786  */
2787 static void queue_trb(struct xhci_hcd *xhci, struct xhci_ring *ring,
2788 		bool more_trbs_coming,
2789 		u32 field1, u32 field2, u32 field3, u32 field4)
2790 {
2791 	struct xhci_generic_trb *trb;
2792 
2793 	trb = &ring->enqueue->generic;
2794 	trb->field[0] = cpu_to_le32(field1);
2795 	trb->field[1] = cpu_to_le32(field2);
2796 	trb->field[2] = cpu_to_le32(field3);
2797 	trb->field[3] = cpu_to_le32(field4);
2798 	inc_enq(xhci, ring, more_trbs_coming);
2799 }
2800 
2801 /*
2802  * Does various checks on the endpoint ring, and makes it ready to queue num_trbs.
2803  * FIXME allocate segments if the ring is full.
2804  */
2805 static int prepare_ring(struct xhci_hcd *xhci, struct xhci_ring *ep_ring,
2806 		u32 ep_state, unsigned int num_trbs, gfp_t mem_flags)
2807 {
2808 	unsigned int num_trbs_needed;
2809 
2810 	/* Make sure the endpoint has been added to xHC schedule */
2811 	switch (ep_state) {
2812 	case EP_STATE_DISABLED:
2813 		/*
2814 		 * USB core changed config/interfaces without notifying us,
2815 		 * or hardware is reporting the wrong state.
2816 		 */
2817 		xhci_warn(xhci, "WARN urb submitted to disabled ep\n");
2818 		return -ENOENT;
2819 	case EP_STATE_ERROR:
2820 		xhci_warn(xhci, "WARN waiting for error on ep to be cleared\n");
2821 		/* FIXME event handling code for error needs to clear it */
2822 		/* XXX not sure if this should be -ENOENT or not */
2823 		return -EINVAL;
2824 	case EP_STATE_HALTED:
2825 		xhci_dbg(xhci, "WARN halted endpoint, queueing URB anyway.\n");
2826 	case EP_STATE_STOPPED:
2827 	case EP_STATE_RUNNING:
2828 		break;
2829 	default:
2830 		xhci_err(xhci, "ERROR unknown endpoint state for ep\n");
2831 		/*
2832 		 * FIXME issue Configure Endpoint command to try to get the HC
2833 		 * back into a known state.
2834 		 */
2835 		return -EINVAL;
2836 	}
2837 
2838 	while (1) {
2839 		if (room_on_ring(xhci, ep_ring, num_trbs))
2840 			break;
2841 
2842 		if (ep_ring == xhci->cmd_ring) {
2843 			xhci_err(xhci, "Do not support expand command ring\n");
2844 			return -ENOMEM;
2845 		}
2846 
2847 		xhci_dbg(xhci, "ERROR no room on ep ring, "
2848 					"try ring expansion\n");
2849 		num_trbs_needed = num_trbs - ep_ring->num_trbs_free;
2850 		if (xhci_ring_expansion(xhci, ep_ring, num_trbs_needed,
2851 					mem_flags)) {
2852 			xhci_err(xhci, "Ring expansion failed\n");
2853 			return -ENOMEM;
2854 		}
2855 	}
2856 
2857 	if (enqueue_is_link_trb(ep_ring)) {
2858 		struct xhci_ring *ring = ep_ring;
2859 		union xhci_trb *next;
2860 
2861 		next = ring->enqueue;
2862 
2863 		while (last_trb(xhci, ring, ring->enq_seg, next)) {
2864 			/* If we're not dealing with 0.95 hardware or isoc rings
2865 			 * on AMD 0.96 host, clear the chain bit.
2866 			 */
2867 			if (!xhci_link_trb_quirk(xhci) &&
2868 					!(ring->type == TYPE_ISOC &&
2869 					 (xhci->quirks & XHCI_AMD_0x96_HOST)))
2870 				next->link.control &= cpu_to_le32(~TRB_CHAIN);
2871 			else
2872 				next->link.control |= cpu_to_le32(TRB_CHAIN);
2873 
2874 			wmb();
2875 			next->link.control ^= cpu_to_le32(TRB_CYCLE);
2876 
2877 			/* Toggle the cycle bit after the last ring segment. */
2878 			if (last_trb_on_last_seg(xhci, ring, ring->enq_seg, next)) {
2879 				ring->cycle_state = (ring->cycle_state ? 0 : 1);
2880 			}
2881 			ring->enq_seg = ring->enq_seg->next;
2882 			ring->enqueue = ring->enq_seg->trbs;
2883 			next = ring->enqueue;
2884 		}
2885 	}
2886 
2887 	return 0;
2888 }
2889 
2890 static int prepare_transfer(struct xhci_hcd *xhci,
2891 		struct xhci_virt_device *xdev,
2892 		unsigned int ep_index,
2893 		unsigned int stream_id,
2894 		unsigned int num_trbs,
2895 		struct urb *urb,
2896 		unsigned int td_index,
2897 		gfp_t mem_flags)
2898 {
2899 	int ret;
2900 	struct urb_priv *urb_priv;
2901 	struct xhci_td	*td;
2902 	struct xhci_ring *ep_ring;
2903 	struct xhci_ep_ctx *ep_ctx = xhci_get_ep_ctx(xhci, xdev->out_ctx, ep_index);
2904 
2905 	ep_ring = xhci_stream_id_to_ring(xdev, ep_index, stream_id);
2906 	if (!ep_ring) {
2907 		xhci_dbg(xhci, "Can't prepare ring for bad stream ID %u\n",
2908 				stream_id);
2909 		return -EINVAL;
2910 	}
2911 
2912 	ret = prepare_ring(xhci, ep_ring,
2913 			   le32_to_cpu(ep_ctx->ep_info) & EP_STATE_MASK,
2914 			   num_trbs, mem_flags);
2915 	if (ret)
2916 		return ret;
2917 
2918 	urb_priv = urb->hcpriv;
2919 	td = urb_priv->td[td_index];
2920 
2921 	INIT_LIST_HEAD(&td->td_list);
2922 	INIT_LIST_HEAD(&td->cancelled_td_list);
2923 
2924 	if (td_index == 0) {
2925 		ret = usb_hcd_link_urb_to_ep(bus_to_hcd(urb->dev->bus), urb);
2926 		if (unlikely(ret))
2927 			return ret;
2928 	}
2929 
2930 	td->urb = urb;
2931 	/* Add this TD to the tail of the endpoint ring's TD list */
2932 	list_add_tail(&td->td_list, &ep_ring->td_list);
2933 	td->start_seg = ep_ring->enq_seg;
2934 	td->first_trb = ep_ring->enqueue;
2935 
2936 	urb_priv->td[td_index] = td;
2937 
2938 	return 0;
2939 }
2940 
2941 static unsigned int count_sg_trbs_needed(struct xhci_hcd *xhci, struct urb *urb)
2942 {
2943 	int num_sgs, num_trbs, running_total, temp, i;
2944 	struct scatterlist *sg;
2945 
2946 	sg = NULL;
2947 	num_sgs = urb->num_mapped_sgs;
2948 	temp = urb->transfer_buffer_length;
2949 
2950 	num_trbs = 0;
2951 	for_each_sg(urb->sg, sg, num_sgs, i) {
2952 		unsigned int len = sg_dma_len(sg);
2953 
2954 		/* Scatter gather list entries may cross 64KB boundaries */
2955 		running_total = TRB_MAX_BUFF_SIZE -
2956 			(sg_dma_address(sg) & (TRB_MAX_BUFF_SIZE - 1));
2957 		running_total &= TRB_MAX_BUFF_SIZE - 1;
2958 		if (running_total != 0)
2959 			num_trbs++;
2960 
2961 		/* How many more 64KB chunks to transfer, how many more TRBs? */
2962 		while (running_total < sg_dma_len(sg) && running_total < temp) {
2963 			num_trbs++;
2964 			running_total += TRB_MAX_BUFF_SIZE;
2965 		}
2966 		len = min_t(int, len, temp);
2967 		temp -= len;
2968 		if (temp == 0)
2969 			break;
2970 	}
2971 	return num_trbs;
2972 }
2973 
2974 static void check_trb_math(struct urb *urb, int num_trbs, int running_total)
2975 {
2976 	if (num_trbs != 0)
2977 		dev_err(&urb->dev->dev, "%s - ep %#x - Miscalculated number of "
2978 				"TRBs, %d left\n", __func__,
2979 				urb->ep->desc.bEndpointAddress, num_trbs);
2980 	if (running_total != urb->transfer_buffer_length)
2981 		dev_err(&urb->dev->dev, "%s - ep %#x - Miscalculated tx length, "
2982 				"queued %#x (%d), asked for %#x (%d)\n",
2983 				__func__,
2984 				urb->ep->desc.bEndpointAddress,
2985 				running_total, running_total,
2986 				urb->transfer_buffer_length,
2987 				urb->transfer_buffer_length);
2988 }
2989 
2990 static void giveback_first_trb(struct xhci_hcd *xhci, int slot_id,
2991 		unsigned int ep_index, unsigned int stream_id, int start_cycle,
2992 		struct xhci_generic_trb *start_trb)
2993 {
2994 	/*
2995 	 * Pass all the TRBs to the hardware at once and make sure this write
2996 	 * isn't reordered.
2997 	 */
2998 	wmb();
2999 	if (start_cycle)
3000 		start_trb->field[3] |= cpu_to_le32(start_cycle);
3001 	else
3002 		start_trb->field[3] &= cpu_to_le32(~TRB_CYCLE);
3003 	xhci_ring_ep_doorbell(xhci, slot_id, ep_index, stream_id);
3004 }
3005 
3006 /*
3007  * xHCI uses normal TRBs for both bulk and interrupt.  When the interrupt
3008  * endpoint is to be serviced, the xHC will consume (at most) one TD.  A TD
3009  * (comprised of sg list entries) can take several service intervals to
3010  * transmit.
3011  */
3012 int xhci_queue_intr_tx(struct xhci_hcd *xhci, gfp_t mem_flags,
3013 		struct urb *urb, int slot_id, unsigned int ep_index)
3014 {
3015 	struct xhci_ep_ctx *ep_ctx = xhci_get_ep_ctx(xhci,
3016 			xhci->devs[slot_id]->out_ctx, ep_index);
3017 	int xhci_interval;
3018 	int ep_interval;
3019 
3020 	xhci_interval = EP_INTERVAL_TO_UFRAMES(le32_to_cpu(ep_ctx->ep_info));
3021 	ep_interval = urb->interval;
3022 	/* Convert to microframes */
3023 	if (urb->dev->speed == USB_SPEED_LOW ||
3024 			urb->dev->speed == USB_SPEED_FULL)
3025 		ep_interval *= 8;
3026 	/* FIXME change this to a warning and a suggestion to use the new API
3027 	 * to set the polling interval (once the API is added).
3028 	 */
3029 	if (xhci_interval != ep_interval) {
3030 		if (printk_ratelimit())
3031 			dev_dbg(&urb->dev->dev, "Driver uses different interval"
3032 					" (%d microframe%s) than xHCI "
3033 					"(%d microframe%s)\n",
3034 					ep_interval,
3035 					ep_interval == 1 ? "" : "s",
3036 					xhci_interval,
3037 					xhci_interval == 1 ? "" : "s");
3038 		urb->interval = xhci_interval;
3039 		/* Convert back to frames for LS/FS devices */
3040 		if (urb->dev->speed == USB_SPEED_LOW ||
3041 				urb->dev->speed == USB_SPEED_FULL)
3042 			urb->interval /= 8;
3043 	}
3044 	return xhci_queue_bulk_tx(xhci, mem_flags, urb, slot_id, ep_index);
3045 }
3046 
3047 /*
3048  * The TD size is the number of bytes remaining in the TD (including this TRB),
3049  * right shifted by 10.
3050  * It must fit in bits 21:17, so it can't be bigger than 31.
3051  */
3052 static u32 xhci_td_remainder(unsigned int remainder)
3053 {
3054 	u32 max = (1 << (21 - 17 + 1)) - 1;
3055 
3056 	if ((remainder >> 10) >= max)
3057 		return max << 17;
3058 	else
3059 		return (remainder >> 10) << 17;
3060 }
3061 
3062 /*
3063  * For xHCI 1.0 host controllers, TD size is the number of packets remaining in
3064  * the TD (*not* including this TRB).
3065  *
3066  * Total TD packet count = total_packet_count =
3067  *     roundup(TD size in bytes / wMaxPacketSize)
3068  *
3069  * Packets transferred up to and including this TRB = packets_transferred =
3070  *     rounddown(total bytes transferred including this TRB / wMaxPacketSize)
3071  *
3072  * TD size = total_packet_count - packets_transferred
3073  *
3074  * It must fit in bits 21:17, so it can't be bigger than 31.
3075  */
3076 
3077 static u32 xhci_v1_0_td_remainder(int running_total, int trb_buff_len,
3078 		unsigned int total_packet_count, struct urb *urb)
3079 {
3080 	int packets_transferred;
3081 
3082 	/* One TRB with a zero-length data packet. */
3083 	if (running_total == 0 && trb_buff_len == 0)
3084 		return 0;
3085 
3086 	/* All the TRB queueing functions don't count the current TRB in
3087 	 * running_total.
3088 	 */
3089 	packets_transferred = (running_total + trb_buff_len) /
3090 		usb_endpoint_maxp(&urb->ep->desc);
3091 
3092 	return xhci_td_remainder(total_packet_count - packets_transferred);
3093 }
3094 
3095 static int queue_bulk_sg_tx(struct xhci_hcd *xhci, gfp_t mem_flags,
3096 		struct urb *urb, int slot_id, unsigned int ep_index)
3097 {
3098 	struct xhci_ring *ep_ring;
3099 	unsigned int num_trbs;
3100 	struct urb_priv *urb_priv;
3101 	struct xhci_td *td;
3102 	struct scatterlist *sg;
3103 	int num_sgs;
3104 	int trb_buff_len, this_sg_len, running_total;
3105 	unsigned int total_packet_count;
3106 	bool first_trb;
3107 	u64 addr;
3108 	bool more_trbs_coming;
3109 
3110 	struct xhci_generic_trb *start_trb;
3111 	int start_cycle;
3112 
3113 	ep_ring = xhci_urb_to_transfer_ring(xhci, urb);
3114 	if (!ep_ring)
3115 		return -EINVAL;
3116 
3117 	num_trbs = count_sg_trbs_needed(xhci, urb);
3118 	num_sgs = urb->num_mapped_sgs;
3119 	total_packet_count = roundup(urb->transfer_buffer_length,
3120 			usb_endpoint_maxp(&urb->ep->desc));
3121 
3122 	trb_buff_len = prepare_transfer(xhci, xhci->devs[slot_id],
3123 			ep_index, urb->stream_id,
3124 			num_trbs, urb, 0, mem_flags);
3125 	if (trb_buff_len < 0)
3126 		return trb_buff_len;
3127 
3128 	urb_priv = urb->hcpriv;
3129 	td = urb_priv->td[0];
3130 
3131 	/*
3132 	 * Don't give the first TRB to the hardware (by toggling the cycle bit)
3133 	 * until we've finished creating all the other TRBs.  The ring's cycle
3134 	 * state may change as we enqueue the other TRBs, so save it too.
3135 	 */
3136 	start_trb = &ep_ring->enqueue->generic;
3137 	start_cycle = ep_ring->cycle_state;
3138 
3139 	running_total = 0;
3140 	/*
3141 	 * How much data is in the first TRB?
3142 	 *
3143 	 * There are three forces at work for TRB buffer pointers and lengths:
3144 	 * 1. We don't want to walk off the end of this sg-list entry buffer.
3145 	 * 2. The transfer length that the driver requested may be smaller than
3146 	 *    the amount of memory allocated for this scatter-gather list.
3147 	 * 3. TRBs buffers can't cross 64KB boundaries.
3148 	 */
3149 	sg = urb->sg;
3150 	addr = (u64) sg_dma_address(sg);
3151 	this_sg_len = sg_dma_len(sg);
3152 	trb_buff_len = TRB_MAX_BUFF_SIZE - (addr & (TRB_MAX_BUFF_SIZE - 1));
3153 	trb_buff_len = min_t(int, trb_buff_len, this_sg_len);
3154 	if (trb_buff_len > urb->transfer_buffer_length)
3155 		trb_buff_len = urb->transfer_buffer_length;
3156 
3157 	first_trb = true;
3158 	/* Queue the first TRB, even if it's zero-length */
3159 	do {
3160 		u32 field = 0;
3161 		u32 length_field = 0;
3162 		u32 remainder = 0;
3163 
3164 		/* Don't change the cycle bit of the first TRB until later */
3165 		if (first_trb) {
3166 			first_trb = false;
3167 			if (start_cycle == 0)
3168 				field |= 0x1;
3169 		} else
3170 			field |= ep_ring->cycle_state;
3171 
3172 		/* Chain all the TRBs together; clear the chain bit in the last
3173 		 * TRB to indicate it's the last TRB in the chain.
3174 		 */
3175 		if (num_trbs > 1) {
3176 			field |= TRB_CHAIN;
3177 		} else {
3178 			/* FIXME - add check for ZERO_PACKET flag before this */
3179 			td->last_trb = ep_ring->enqueue;
3180 			field |= TRB_IOC;
3181 		}
3182 
3183 		/* Only set interrupt on short packet for IN endpoints */
3184 		if (usb_urb_dir_in(urb))
3185 			field |= TRB_ISP;
3186 
3187 		if (TRB_MAX_BUFF_SIZE -
3188 				(addr & (TRB_MAX_BUFF_SIZE - 1)) < trb_buff_len) {
3189 			xhci_warn(xhci, "WARN: sg dma xfer crosses 64KB boundaries!\n");
3190 			xhci_dbg(xhci, "Next boundary at %#x, end dma = %#x\n",
3191 					(unsigned int) (addr + TRB_MAX_BUFF_SIZE) & ~(TRB_MAX_BUFF_SIZE - 1),
3192 					(unsigned int) addr + trb_buff_len);
3193 		}
3194 
3195 		/* Set the TRB length, TD size, and interrupter fields. */
3196 		if (xhci->hci_version < 0x100) {
3197 			remainder = xhci_td_remainder(
3198 					urb->transfer_buffer_length -
3199 					running_total);
3200 		} else {
3201 			remainder = xhci_v1_0_td_remainder(running_total,
3202 					trb_buff_len, total_packet_count, urb);
3203 		}
3204 		length_field = TRB_LEN(trb_buff_len) |
3205 			remainder |
3206 			TRB_INTR_TARGET(0);
3207 
3208 		if (num_trbs > 1)
3209 			more_trbs_coming = true;
3210 		else
3211 			more_trbs_coming = false;
3212 		queue_trb(xhci, ep_ring, more_trbs_coming,
3213 				lower_32_bits(addr),
3214 				upper_32_bits(addr),
3215 				length_field,
3216 				field | TRB_TYPE(TRB_NORMAL));
3217 		--num_trbs;
3218 		running_total += trb_buff_len;
3219 
3220 		/* Calculate length for next transfer --
3221 		 * Are we done queueing all the TRBs for this sg entry?
3222 		 */
3223 		this_sg_len -= trb_buff_len;
3224 		if (this_sg_len == 0) {
3225 			--num_sgs;
3226 			if (num_sgs == 0)
3227 				break;
3228 			sg = sg_next(sg);
3229 			addr = (u64) sg_dma_address(sg);
3230 			this_sg_len = sg_dma_len(sg);
3231 		} else {
3232 			addr += trb_buff_len;
3233 		}
3234 
3235 		trb_buff_len = TRB_MAX_BUFF_SIZE -
3236 			(addr & (TRB_MAX_BUFF_SIZE - 1));
3237 		trb_buff_len = min_t(int, trb_buff_len, this_sg_len);
3238 		if (running_total + trb_buff_len > urb->transfer_buffer_length)
3239 			trb_buff_len =
3240 				urb->transfer_buffer_length - running_total;
3241 	} while (running_total < urb->transfer_buffer_length);
3242 
3243 	check_trb_math(urb, num_trbs, running_total);
3244 	giveback_first_trb(xhci, slot_id, ep_index, urb->stream_id,
3245 			start_cycle, start_trb);
3246 	return 0;
3247 }
3248 
3249 /* This is very similar to what ehci-q.c qtd_fill() does */
3250 int xhci_queue_bulk_tx(struct xhci_hcd *xhci, gfp_t mem_flags,
3251 		struct urb *urb, int slot_id, unsigned int ep_index)
3252 {
3253 	struct xhci_ring *ep_ring;
3254 	struct urb_priv *urb_priv;
3255 	struct xhci_td *td;
3256 	int num_trbs;
3257 	struct xhci_generic_trb *start_trb;
3258 	bool first_trb;
3259 	bool more_trbs_coming;
3260 	int start_cycle;
3261 	u32 field, length_field;
3262 
3263 	int running_total, trb_buff_len, ret;
3264 	unsigned int total_packet_count;
3265 	u64 addr;
3266 
3267 	if (urb->num_sgs)
3268 		return queue_bulk_sg_tx(xhci, mem_flags, urb, slot_id, ep_index);
3269 
3270 	ep_ring = xhci_urb_to_transfer_ring(xhci, urb);
3271 	if (!ep_ring)
3272 		return -EINVAL;
3273 
3274 	num_trbs = 0;
3275 	/* How much data is (potentially) left before the 64KB boundary? */
3276 	running_total = TRB_MAX_BUFF_SIZE -
3277 		(urb->transfer_dma & (TRB_MAX_BUFF_SIZE - 1));
3278 	running_total &= TRB_MAX_BUFF_SIZE - 1;
3279 
3280 	/* If there's some data on this 64KB chunk, or we have to send a
3281 	 * zero-length transfer, we need at least one TRB
3282 	 */
3283 	if (running_total != 0 || urb->transfer_buffer_length == 0)
3284 		num_trbs++;
3285 	/* How many more 64KB chunks to transfer, how many more TRBs? */
3286 	while (running_total < urb->transfer_buffer_length) {
3287 		num_trbs++;
3288 		running_total += TRB_MAX_BUFF_SIZE;
3289 	}
3290 	/* FIXME: this doesn't deal with URB_ZERO_PACKET - need one more */
3291 
3292 	ret = prepare_transfer(xhci, xhci->devs[slot_id],
3293 			ep_index, urb->stream_id,
3294 			num_trbs, urb, 0, mem_flags);
3295 	if (ret < 0)
3296 		return ret;
3297 
3298 	urb_priv = urb->hcpriv;
3299 	td = urb_priv->td[0];
3300 
3301 	/*
3302 	 * Don't give the first TRB to the hardware (by toggling the cycle bit)
3303 	 * until we've finished creating all the other TRBs.  The ring's cycle
3304 	 * state may change as we enqueue the other TRBs, so save it too.
3305 	 */
3306 	start_trb = &ep_ring->enqueue->generic;
3307 	start_cycle = ep_ring->cycle_state;
3308 
3309 	running_total = 0;
3310 	total_packet_count = roundup(urb->transfer_buffer_length,
3311 			usb_endpoint_maxp(&urb->ep->desc));
3312 	/* How much data is in the first TRB? */
3313 	addr = (u64) urb->transfer_dma;
3314 	trb_buff_len = TRB_MAX_BUFF_SIZE -
3315 		(urb->transfer_dma & (TRB_MAX_BUFF_SIZE - 1));
3316 	if (trb_buff_len > urb->transfer_buffer_length)
3317 		trb_buff_len = urb->transfer_buffer_length;
3318 
3319 	first_trb = true;
3320 
3321 	/* Queue the first TRB, even if it's zero-length */
3322 	do {
3323 		u32 remainder = 0;
3324 		field = 0;
3325 
3326 		/* Don't change the cycle bit of the first TRB until later */
3327 		if (first_trb) {
3328 			first_trb = false;
3329 			if (start_cycle == 0)
3330 				field |= 0x1;
3331 		} else
3332 			field |= ep_ring->cycle_state;
3333 
3334 		/* Chain all the TRBs together; clear the chain bit in the last
3335 		 * TRB to indicate it's the last TRB in the chain.
3336 		 */
3337 		if (num_trbs > 1) {
3338 			field |= TRB_CHAIN;
3339 		} else {
3340 			/* FIXME - add check for ZERO_PACKET flag before this */
3341 			td->last_trb = ep_ring->enqueue;
3342 			field |= TRB_IOC;
3343 		}
3344 
3345 		/* Only set interrupt on short packet for IN endpoints */
3346 		if (usb_urb_dir_in(urb))
3347 			field |= TRB_ISP;
3348 
3349 		/* Set the TRB length, TD size, and interrupter fields. */
3350 		if (xhci->hci_version < 0x100) {
3351 			remainder = xhci_td_remainder(
3352 					urb->transfer_buffer_length -
3353 					running_total);
3354 		} else {
3355 			remainder = xhci_v1_0_td_remainder(running_total,
3356 					trb_buff_len, total_packet_count, urb);
3357 		}
3358 		length_field = TRB_LEN(trb_buff_len) |
3359 			remainder |
3360 			TRB_INTR_TARGET(0);
3361 
3362 		if (num_trbs > 1)
3363 			more_trbs_coming = true;
3364 		else
3365 			more_trbs_coming = false;
3366 		queue_trb(xhci, ep_ring, more_trbs_coming,
3367 				lower_32_bits(addr),
3368 				upper_32_bits(addr),
3369 				length_field,
3370 				field | TRB_TYPE(TRB_NORMAL));
3371 		--num_trbs;
3372 		running_total += trb_buff_len;
3373 
3374 		/* Calculate length for next transfer */
3375 		addr += trb_buff_len;
3376 		trb_buff_len = urb->transfer_buffer_length - running_total;
3377 		if (trb_buff_len > TRB_MAX_BUFF_SIZE)
3378 			trb_buff_len = TRB_MAX_BUFF_SIZE;
3379 	} while (running_total < urb->transfer_buffer_length);
3380 
3381 	check_trb_math(urb, num_trbs, running_total);
3382 	giveback_first_trb(xhci, slot_id, ep_index, urb->stream_id,
3383 			start_cycle, start_trb);
3384 	return 0;
3385 }
3386 
3387 /* Caller must have locked xhci->lock */
3388 int xhci_queue_ctrl_tx(struct xhci_hcd *xhci, gfp_t mem_flags,
3389 		struct urb *urb, int slot_id, unsigned int ep_index)
3390 {
3391 	struct xhci_ring *ep_ring;
3392 	int num_trbs;
3393 	int ret;
3394 	struct usb_ctrlrequest *setup;
3395 	struct xhci_generic_trb *start_trb;
3396 	int start_cycle;
3397 	u32 field, length_field;
3398 	struct urb_priv *urb_priv;
3399 	struct xhci_td *td;
3400 
3401 	ep_ring = xhci_urb_to_transfer_ring(xhci, urb);
3402 	if (!ep_ring)
3403 		return -EINVAL;
3404 
3405 	/*
3406 	 * Need to copy setup packet into setup TRB, so we can't use the setup
3407 	 * DMA address.
3408 	 */
3409 	if (!urb->setup_packet)
3410 		return -EINVAL;
3411 
3412 	/* 1 TRB for setup, 1 for status */
3413 	num_trbs = 2;
3414 	/*
3415 	 * Don't need to check if we need additional event data and normal TRBs,
3416 	 * since data in control transfers will never get bigger than 16MB
3417 	 * XXX: can we get a buffer that crosses 64KB boundaries?
3418 	 */
3419 	if (urb->transfer_buffer_length > 0)
3420 		num_trbs++;
3421 	ret = prepare_transfer(xhci, xhci->devs[slot_id],
3422 			ep_index, urb->stream_id,
3423 			num_trbs, urb, 0, mem_flags);
3424 	if (ret < 0)
3425 		return ret;
3426 
3427 	urb_priv = urb->hcpriv;
3428 	td = urb_priv->td[0];
3429 
3430 	/*
3431 	 * Don't give the first TRB to the hardware (by toggling the cycle bit)
3432 	 * until we've finished creating all the other TRBs.  The ring's cycle
3433 	 * state may change as we enqueue the other TRBs, so save it too.
3434 	 */
3435 	start_trb = &ep_ring->enqueue->generic;
3436 	start_cycle = ep_ring->cycle_state;
3437 
3438 	/* Queue setup TRB - see section 6.4.1.2.1 */
3439 	/* FIXME better way to translate setup_packet into two u32 fields? */
3440 	setup = (struct usb_ctrlrequest *) urb->setup_packet;
3441 	field = 0;
3442 	field |= TRB_IDT | TRB_TYPE(TRB_SETUP);
3443 	if (start_cycle == 0)
3444 		field |= 0x1;
3445 
3446 	/* xHCI 1.0 6.4.1.2.1: Transfer Type field */
3447 	if (xhci->hci_version == 0x100) {
3448 		if (urb->transfer_buffer_length > 0) {
3449 			if (setup->bRequestType & USB_DIR_IN)
3450 				field |= TRB_TX_TYPE(TRB_DATA_IN);
3451 			else
3452 				field |= TRB_TX_TYPE(TRB_DATA_OUT);
3453 		}
3454 	}
3455 
3456 	queue_trb(xhci, ep_ring, true,
3457 		  setup->bRequestType | setup->bRequest << 8 | le16_to_cpu(setup->wValue) << 16,
3458 		  le16_to_cpu(setup->wIndex) | le16_to_cpu(setup->wLength) << 16,
3459 		  TRB_LEN(8) | TRB_INTR_TARGET(0),
3460 		  /* Immediate data in pointer */
3461 		  field);
3462 
3463 	/* If there's data, queue data TRBs */
3464 	/* Only set interrupt on short packet for IN endpoints */
3465 	if (usb_urb_dir_in(urb))
3466 		field = TRB_ISP | TRB_TYPE(TRB_DATA);
3467 	else
3468 		field = TRB_TYPE(TRB_DATA);
3469 
3470 	length_field = TRB_LEN(urb->transfer_buffer_length) |
3471 		xhci_td_remainder(urb->transfer_buffer_length) |
3472 		TRB_INTR_TARGET(0);
3473 	if (urb->transfer_buffer_length > 0) {
3474 		if (setup->bRequestType & USB_DIR_IN)
3475 			field |= TRB_DIR_IN;
3476 		queue_trb(xhci, ep_ring, true,
3477 				lower_32_bits(urb->transfer_dma),
3478 				upper_32_bits(urb->transfer_dma),
3479 				length_field,
3480 				field | ep_ring->cycle_state);
3481 	}
3482 
3483 	/* Save the DMA address of the last TRB in the TD */
3484 	td->last_trb = ep_ring->enqueue;
3485 
3486 	/* Queue status TRB - see Table 7 and sections 4.11.2.2 and 6.4.1.2.3 */
3487 	/* If the device sent data, the status stage is an OUT transfer */
3488 	if (urb->transfer_buffer_length > 0 && setup->bRequestType & USB_DIR_IN)
3489 		field = 0;
3490 	else
3491 		field = TRB_DIR_IN;
3492 	queue_trb(xhci, ep_ring, false,
3493 			0,
3494 			0,
3495 			TRB_INTR_TARGET(0),
3496 			/* Event on completion */
3497 			field | TRB_IOC | TRB_TYPE(TRB_STATUS) | ep_ring->cycle_state);
3498 
3499 	giveback_first_trb(xhci, slot_id, ep_index, 0,
3500 			start_cycle, start_trb);
3501 	return 0;
3502 }
3503 
3504 static int count_isoc_trbs_needed(struct xhci_hcd *xhci,
3505 		struct urb *urb, int i)
3506 {
3507 	int num_trbs = 0;
3508 	u64 addr, td_len;
3509 
3510 	addr = (u64) (urb->transfer_dma + urb->iso_frame_desc[i].offset);
3511 	td_len = urb->iso_frame_desc[i].length;
3512 
3513 	num_trbs = DIV_ROUND_UP(td_len + (addr & (TRB_MAX_BUFF_SIZE - 1)),
3514 			TRB_MAX_BUFF_SIZE);
3515 	if (num_trbs == 0)
3516 		num_trbs++;
3517 
3518 	return num_trbs;
3519 }
3520 
3521 /*
3522  * The transfer burst count field of the isochronous TRB defines the number of
3523  * bursts that are required to move all packets in this TD.  Only SuperSpeed
3524  * devices can burst up to bMaxBurst number of packets per service interval.
3525  * This field is zero based, meaning a value of zero in the field means one
3526  * burst.  Basically, for everything but SuperSpeed devices, this field will be
3527  * zero.  Only xHCI 1.0 host controllers support this field.
3528  */
3529 static unsigned int xhci_get_burst_count(struct xhci_hcd *xhci,
3530 		struct usb_device *udev,
3531 		struct urb *urb, unsigned int total_packet_count)
3532 {
3533 	unsigned int max_burst;
3534 
3535 	if (xhci->hci_version < 0x100 || udev->speed != USB_SPEED_SUPER)
3536 		return 0;
3537 
3538 	max_burst = urb->ep->ss_ep_comp.bMaxBurst;
3539 	return roundup(total_packet_count, max_burst + 1) - 1;
3540 }
3541 
3542 /*
3543  * Returns the number of packets in the last "burst" of packets.  This field is
3544  * valid for all speeds of devices.  USB 2.0 devices can only do one "burst", so
3545  * the last burst packet count is equal to the total number of packets in the
3546  * TD.  SuperSpeed endpoints can have up to 3 bursts.  All but the last burst
3547  * must contain (bMaxBurst + 1) number of packets, but the last burst can
3548  * contain 1 to (bMaxBurst + 1) packets.
3549  */
3550 static unsigned int xhci_get_last_burst_packet_count(struct xhci_hcd *xhci,
3551 		struct usb_device *udev,
3552 		struct urb *urb, unsigned int total_packet_count)
3553 {
3554 	unsigned int max_burst;
3555 	unsigned int residue;
3556 
3557 	if (xhci->hci_version < 0x100)
3558 		return 0;
3559 
3560 	switch (udev->speed) {
3561 	case USB_SPEED_SUPER:
3562 		/* bMaxBurst is zero based: 0 means 1 packet per burst */
3563 		max_burst = urb->ep->ss_ep_comp.bMaxBurst;
3564 		residue = total_packet_count % (max_burst + 1);
3565 		/* If residue is zero, the last burst contains (max_burst + 1)
3566 		 * number of packets, but the TLBPC field is zero-based.
3567 		 */
3568 		if (residue == 0)
3569 			return max_burst;
3570 		return residue - 1;
3571 	default:
3572 		if (total_packet_count == 0)
3573 			return 0;
3574 		return total_packet_count - 1;
3575 	}
3576 }
3577 
3578 /* This is for isoc transfer */
3579 static int xhci_queue_isoc_tx(struct xhci_hcd *xhci, gfp_t mem_flags,
3580 		struct urb *urb, int slot_id, unsigned int ep_index)
3581 {
3582 	struct xhci_ring *ep_ring;
3583 	struct urb_priv *urb_priv;
3584 	struct xhci_td *td;
3585 	int num_tds, trbs_per_td;
3586 	struct xhci_generic_trb *start_trb;
3587 	bool first_trb;
3588 	int start_cycle;
3589 	u32 field, length_field;
3590 	int running_total, trb_buff_len, td_len, td_remain_len, ret;
3591 	u64 start_addr, addr;
3592 	int i, j;
3593 	bool more_trbs_coming;
3594 
3595 	ep_ring = xhci->devs[slot_id]->eps[ep_index].ring;
3596 
3597 	num_tds = urb->number_of_packets;
3598 	if (num_tds < 1) {
3599 		xhci_dbg(xhci, "Isoc URB with zero packets?\n");
3600 		return -EINVAL;
3601 	}
3602 
3603 	start_addr = (u64) urb->transfer_dma;
3604 	start_trb = &ep_ring->enqueue->generic;
3605 	start_cycle = ep_ring->cycle_state;
3606 
3607 	urb_priv = urb->hcpriv;
3608 	/* Queue the first TRB, even if it's zero-length */
3609 	for (i = 0; i < num_tds; i++) {
3610 		unsigned int total_packet_count;
3611 		unsigned int burst_count;
3612 		unsigned int residue;
3613 
3614 		first_trb = true;
3615 		running_total = 0;
3616 		addr = start_addr + urb->iso_frame_desc[i].offset;
3617 		td_len = urb->iso_frame_desc[i].length;
3618 		td_remain_len = td_len;
3619 		total_packet_count = roundup(td_len,
3620 				usb_endpoint_maxp(&urb->ep->desc));
3621 		/* A zero-length transfer still involves at least one packet. */
3622 		if (total_packet_count == 0)
3623 			total_packet_count++;
3624 		burst_count = xhci_get_burst_count(xhci, urb->dev, urb,
3625 				total_packet_count);
3626 		residue = xhci_get_last_burst_packet_count(xhci,
3627 				urb->dev, urb, total_packet_count);
3628 
3629 		trbs_per_td = count_isoc_trbs_needed(xhci, urb, i);
3630 
3631 		ret = prepare_transfer(xhci, xhci->devs[slot_id], ep_index,
3632 				urb->stream_id, trbs_per_td, urb, i, mem_flags);
3633 		if (ret < 0) {
3634 			if (i == 0)
3635 				return ret;
3636 			goto cleanup;
3637 		}
3638 
3639 		td = urb_priv->td[i];
3640 		for (j = 0; j < trbs_per_td; j++) {
3641 			u32 remainder = 0;
3642 			field = TRB_TBC(burst_count) | TRB_TLBPC(residue);
3643 
3644 			if (first_trb) {
3645 				/* Queue the isoc TRB */
3646 				field |= TRB_TYPE(TRB_ISOC);
3647 				/* Assume URB_ISO_ASAP is set */
3648 				field |= TRB_SIA;
3649 				if (i == 0) {
3650 					if (start_cycle == 0)
3651 						field |= 0x1;
3652 				} else
3653 					field |= ep_ring->cycle_state;
3654 				first_trb = false;
3655 			} else {
3656 				/* Queue other normal TRBs */
3657 				field |= TRB_TYPE(TRB_NORMAL);
3658 				field |= ep_ring->cycle_state;
3659 			}
3660 
3661 			/* Only set interrupt on short packet for IN EPs */
3662 			if (usb_urb_dir_in(urb))
3663 				field |= TRB_ISP;
3664 
3665 			/* Chain all the TRBs together; clear the chain bit in
3666 			 * the last TRB to indicate it's the last TRB in the
3667 			 * chain.
3668 			 */
3669 			if (j < trbs_per_td - 1) {
3670 				field |= TRB_CHAIN;
3671 				more_trbs_coming = true;
3672 			} else {
3673 				td->last_trb = ep_ring->enqueue;
3674 				field |= TRB_IOC;
3675 				if (xhci->hci_version == 0x100 &&
3676 						!(xhci->quirks &
3677 							XHCI_AVOID_BEI)) {
3678 					/* Set BEI bit except for the last td */
3679 					if (i < num_tds - 1)
3680 						field |= TRB_BEI;
3681 				}
3682 				more_trbs_coming = false;
3683 			}
3684 
3685 			/* Calculate TRB length */
3686 			trb_buff_len = TRB_MAX_BUFF_SIZE -
3687 				(addr & ((1 << TRB_MAX_BUFF_SHIFT) - 1));
3688 			if (trb_buff_len > td_remain_len)
3689 				trb_buff_len = td_remain_len;
3690 
3691 			/* Set the TRB length, TD size, & interrupter fields. */
3692 			if (xhci->hci_version < 0x100) {
3693 				remainder = xhci_td_remainder(
3694 						td_len - running_total);
3695 			} else {
3696 				remainder = xhci_v1_0_td_remainder(
3697 						running_total, trb_buff_len,
3698 						total_packet_count, urb);
3699 			}
3700 			length_field = TRB_LEN(trb_buff_len) |
3701 				remainder |
3702 				TRB_INTR_TARGET(0);
3703 
3704 			queue_trb(xhci, ep_ring, more_trbs_coming,
3705 				lower_32_bits(addr),
3706 				upper_32_bits(addr),
3707 				length_field,
3708 				field);
3709 			running_total += trb_buff_len;
3710 
3711 			addr += trb_buff_len;
3712 			td_remain_len -= trb_buff_len;
3713 		}
3714 
3715 		/* Check TD length */
3716 		if (running_total != td_len) {
3717 			xhci_err(xhci, "ISOC TD length unmatch\n");
3718 			ret = -EINVAL;
3719 			goto cleanup;
3720 		}
3721 	}
3722 
3723 	if (xhci_to_hcd(xhci)->self.bandwidth_isoc_reqs == 0) {
3724 		if (xhci->quirks & XHCI_AMD_PLL_FIX)
3725 			usb_amd_quirk_pll_disable();
3726 	}
3727 	xhci_to_hcd(xhci)->self.bandwidth_isoc_reqs++;
3728 
3729 	giveback_first_trb(xhci, slot_id, ep_index, urb->stream_id,
3730 			start_cycle, start_trb);
3731 	return 0;
3732 cleanup:
3733 	/* Clean up a partially enqueued isoc transfer. */
3734 
3735 	for (i--; i >= 0; i--)
3736 		list_del_init(&urb_priv->td[i]->td_list);
3737 
3738 	/* Use the first TD as a temporary variable to turn the TDs we've queued
3739 	 * into No-ops with a software-owned cycle bit. That way the hardware
3740 	 * won't accidentally start executing bogus TDs when we partially
3741 	 * overwrite them.  td->first_trb and td->start_seg are already set.
3742 	 */
3743 	urb_priv->td[0]->last_trb = ep_ring->enqueue;
3744 	/* Every TRB except the first & last will have its cycle bit flipped. */
3745 	td_to_noop(xhci, ep_ring, urb_priv->td[0], true);
3746 
3747 	/* Reset the ring enqueue back to the first TRB and its cycle bit. */
3748 	ep_ring->enqueue = urb_priv->td[0]->first_trb;
3749 	ep_ring->enq_seg = urb_priv->td[0]->start_seg;
3750 	ep_ring->cycle_state = start_cycle;
3751 	ep_ring->num_trbs_free = ep_ring->num_trbs_free_temp;
3752 	usb_hcd_unlink_urb_from_ep(bus_to_hcd(urb->dev->bus), urb);
3753 	return ret;
3754 }
3755 
3756 /*
3757  * Check transfer ring to guarantee there is enough room for the urb.
3758  * Update ISO URB start_frame and interval.
3759  * Update interval as xhci_queue_intr_tx does. Just use xhci frame_index to
3760  * update the urb->start_frame by now.
3761  * Always assume URB_ISO_ASAP set, and NEVER use urb->start_frame as input.
3762  */
3763 int xhci_queue_isoc_tx_prepare(struct xhci_hcd *xhci, gfp_t mem_flags,
3764 		struct urb *urb, int slot_id, unsigned int ep_index)
3765 {
3766 	struct xhci_virt_device *xdev;
3767 	struct xhci_ring *ep_ring;
3768 	struct xhci_ep_ctx *ep_ctx;
3769 	int start_frame;
3770 	int xhci_interval;
3771 	int ep_interval;
3772 	int num_tds, num_trbs, i;
3773 	int ret;
3774 
3775 	xdev = xhci->devs[slot_id];
3776 	ep_ring = xdev->eps[ep_index].ring;
3777 	ep_ctx = xhci_get_ep_ctx(xhci, xdev->out_ctx, ep_index);
3778 
3779 	num_trbs = 0;
3780 	num_tds = urb->number_of_packets;
3781 	for (i = 0; i < num_tds; i++)
3782 		num_trbs += count_isoc_trbs_needed(xhci, urb, i);
3783 
3784 	/* Check the ring to guarantee there is enough room for the whole urb.
3785 	 * Do not insert any td of the urb to the ring if the check failed.
3786 	 */
3787 	ret = prepare_ring(xhci, ep_ring, le32_to_cpu(ep_ctx->ep_info) & EP_STATE_MASK,
3788 			   num_trbs, mem_flags);
3789 	if (ret)
3790 		return ret;
3791 
3792 	start_frame = xhci_readl(xhci, &xhci->run_regs->microframe_index);
3793 	start_frame &= 0x3fff;
3794 
3795 	urb->start_frame = start_frame;
3796 	if (urb->dev->speed == USB_SPEED_LOW ||
3797 			urb->dev->speed == USB_SPEED_FULL)
3798 		urb->start_frame >>= 3;
3799 
3800 	xhci_interval = EP_INTERVAL_TO_UFRAMES(le32_to_cpu(ep_ctx->ep_info));
3801 	ep_interval = urb->interval;
3802 	/* Convert to microframes */
3803 	if (urb->dev->speed == USB_SPEED_LOW ||
3804 			urb->dev->speed == USB_SPEED_FULL)
3805 		ep_interval *= 8;
3806 	/* FIXME change this to a warning and a suggestion to use the new API
3807 	 * to set the polling interval (once the API is added).
3808 	 */
3809 	if (xhci_interval != ep_interval) {
3810 		if (printk_ratelimit())
3811 			dev_dbg(&urb->dev->dev, "Driver uses different interval"
3812 					" (%d microframe%s) than xHCI "
3813 					"(%d microframe%s)\n",
3814 					ep_interval,
3815 					ep_interval == 1 ? "" : "s",
3816 					xhci_interval,
3817 					xhci_interval == 1 ? "" : "s");
3818 		urb->interval = xhci_interval;
3819 		/* Convert back to frames for LS/FS devices */
3820 		if (urb->dev->speed == USB_SPEED_LOW ||
3821 				urb->dev->speed == USB_SPEED_FULL)
3822 			urb->interval /= 8;
3823 	}
3824 	ep_ring->num_trbs_free_temp = ep_ring->num_trbs_free;
3825 
3826 	return xhci_queue_isoc_tx(xhci, mem_flags, urb, slot_id, ep_index);
3827 }
3828 
3829 /****		Command Ring Operations		****/
3830 
3831 /* Generic function for queueing a command TRB on the command ring.
3832  * Check to make sure there's room on the command ring for one command TRB.
3833  * Also check that there's room reserved for commands that must not fail.
3834  * If this is a command that must not fail, meaning command_must_succeed = TRUE,
3835  * then only check for the number of reserved spots.
3836  * Don't decrement xhci->cmd_ring_reserved_trbs after we've queued the TRB
3837  * because the command event handler may want to resubmit a failed command.
3838  */
3839 static int queue_command(struct xhci_hcd *xhci, u32 field1, u32 field2,
3840 		u32 field3, u32 field4, bool command_must_succeed)
3841 {
3842 	int reserved_trbs = xhci->cmd_ring_reserved_trbs;
3843 	int ret;
3844 
3845 	if (!command_must_succeed)
3846 		reserved_trbs++;
3847 
3848 	ret = prepare_ring(xhci, xhci->cmd_ring, EP_STATE_RUNNING,
3849 			reserved_trbs, GFP_ATOMIC);
3850 	if (ret < 0) {
3851 		xhci_err(xhci, "ERR: No room for command on command ring\n");
3852 		if (command_must_succeed)
3853 			xhci_err(xhci, "ERR: Reserved TRB counting for "
3854 					"unfailable commands failed.\n");
3855 		return ret;
3856 	}
3857 	queue_trb(xhci, xhci->cmd_ring, false, field1, field2, field3,
3858 			field4 | xhci->cmd_ring->cycle_state);
3859 	return 0;
3860 }
3861 
3862 /* Queue a slot enable or disable request on the command ring */
3863 int xhci_queue_slot_control(struct xhci_hcd *xhci, u32 trb_type, u32 slot_id)
3864 {
3865 	return queue_command(xhci, 0, 0, 0,
3866 			TRB_TYPE(trb_type) | SLOT_ID_FOR_TRB(slot_id), false);
3867 }
3868 
3869 /* Queue an address device command TRB */
3870 int xhci_queue_address_device(struct xhci_hcd *xhci, dma_addr_t in_ctx_ptr,
3871 		u32 slot_id)
3872 {
3873 	return queue_command(xhci, lower_32_bits(in_ctx_ptr),
3874 			upper_32_bits(in_ctx_ptr), 0,
3875 			TRB_TYPE(TRB_ADDR_DEV) | SLOT_ID_FOR_TRB(slot_id),
3876 			false);
3877 }
3878 
3879 int xhci_queue_vendor_command(struct xhci_hcd *xhci,
3880 		u32 field1, u32 field2, u32 field3, u32 field4)
3881 {
3882 	return queue_command(xhci, field1, field2, field3, field4, false);
3883 }
3884 
3885 /* Queue a reset device command TRB */
3886 int xhci_queue_reset_device(struct xhci_hcd *xhci, u32 slot_id)
3887 {
3888 	return queue_command(xhci, 0, 0, 0,
3889 			TRB_TYPE(TRB_RESET_DEV) | SLOT_ID_FOR_TRB(slot_id),
3890 			false);
3891 }
3892 
3893 /* Queue a configure endpoint command TRB */
3894 int xhci_queue_configure_endpoint(struct xhci_hcd *xhci, dma_addr_t in_ctx_ptr,
3895 		u32 slot_id, bool command_must_succeed)
3896 {
3897 	return queue_command(xhci, lower_32_bits(in_ctx_ptr),
3898 			upper_32_bits(in_ctx_ptr), 0,
3899 			TRB_TYPE(TRB_CONFIG_EP) | SLOT_ID_FOR_TRB(slot_id),
3900 			command_must_succeed);
3901 }
3902 
3903 /* Queue an evaluate context command TRB */
3904 int xhci_queue_evaluate_context(struct xhci_hcd *xhci, dma_addr_t in_ctx_ptr,
3905 		u32 slot_id, bool command_must_succeed)
3906 {
3907 	return queue_command(xhci, lower_32_bits(in_ctx_ptr),
3908 			upper_32_bits(in_ctx_ptr), 0,
3909 			TRB_TYPE(TRB_EVAL_CONTEXT) | SLOT_ID_FOR_TRB(slot_id),
3910 			command_must_succeed);
3911 }
3912 
3913 /*
3914  * Suspend is set to indicate "Stop Endpoint Command" is being issued to stop
3915  * activity on an endpoint that is about to be suspended.
3916  */
3917 int xhci_queue_stop_endpoint(struct xhci_hcd *xhci, int slot_id,
3918 		unsigned int ep_index, int suspend)
3919 {
3920 	u32 trb_slot_id = SLOT_ID_FOR_TRB(slot_id);
3921 	u32 trb_ep_index = EP_ID_FOR_TRB(ep_index);
3922 	u32 type = TRB_TYPE(TRB_STOP_RING);
3923 	u32 trb_suspend = SUSPEND_PORT_FOR_TRB(suspend);
3924 
3925 	return queue_command(xhci, 0, 0, 0,
3926 			trb_slot_id | trb_ep_index | type | trb_suspend, false);
3927 }
3928 
3929 /* Set Transfer Ring Dequeue Pointer command.
3930  * This should not be used for endpoints that have streams enabled.
3931  */
3932 static int queue_set_tr_deq(struct xhci_hcd *xhci, int slot_id,
3933 		unsigned int ep_index, unsigned int stream_id,
3934 		struct xhci_segment *deq_seg,
3935 		union xhci_trb *deq_ptr, u32 cycle_state)
3936 {
3937 	dma_addr_t addr;
3938 	u32 trb_slot_id = SLOT_ID_FOR_TRB(slot_id);
3939 	u32 trb_ep_index = EP_ID_FOR_TRB(ep_index);
3940 	u32 trb_stream_id = STREAM_ID_FOR_TRB(stream_id);
3941 	u32 type = TRB_TYPE(TRB_SET_DEQ);
3942 	struct xhci_virt_ep *ep;
3943 
3944 	addr = xhci_trb_virt_to_dma(deq_seg, deq_ptr);
3945 	if (addr == 0) {
3946 		xhci_warn(xhci, "WARN Cannot submit Set TR Deq Ptr\n");
3947 		xhci_warn(xhci, "WARN deq seg = %p, deq pt = %p\n",
3948 				deq_seg, deq_ptr);
3949 		return 0;
3950 	}
3951 	ep = &xhci->devs[slot_id]->eps[ep_index];
3952 	if ((ep->ep_state & SET_DEQ_PENDING)) {
3953 		xhci_warn(xhci, "WARN Cannot submit Set TR Deq Ptr\n");
3954 		xhci_warn(xhci, "A Set TR Deq Ptr command is pending.\n");
3955 		return 0;
3956 	}
3957 	ep->queued_deq_seg = deq_seg;
3958 	ep->queued_deq_ptr = deq_ptr;
3959 	return queue_command(xhci, lower_32_bits(addr) | cycle_state,
3960 			upper_32_bits(addr), trb_stream_id,
3961 			trb_slot_id | trb_ep_index | type, false);
3962 }
3963 
3964 int xhci_queue_reset_ep(struct xhci_hcd *xhci, int slot_id,
3965 		unsigned int ep_index)
3966 {
3967 	u32 trb_slot_id = SLOT_ID_FOR_TRB(slot_id);
3968 	u32 trb_ep_index = EP_ID_FOR_TRB(ep_index);
3969 	u32 type = TRB_TYPE(TRB_RESET_EP);
3970 
3971 	return queue_command(xhci, 0, 0, 0, trb_slot_id | trb_ep_index | type,
3972 			false);
3973 }
3974