xref: /openbmc/linux/drivers/usb/host/xhci-ring.c (revision df2634f43f5106947f3735a0b61a6527a4b278cd)
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 inline 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 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 inline 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->link.control & TRB_TYPE_BITMASK) == TRB_TYPE(TRB_LINK);
117 }
118 
119 static inline int enqueue_is_link_trb(struct xhci_ring *ring)
120 {
121 	struct xhci_link_trb *link = &ring->enqueue->link;
122 	return ((link->control & TRB_TYPE_BITMASK) == TRB_TYPE(TRB_LINK));
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, bool consumer)
147 {
148 	union xhci_trb *next = ++(ring->dequeue);
149 	unsigned long long addr;
150 
151 	ring->deq_updates++;
152 	/* Update the dequeue pointer further if that was a link TRB or we're at
153 	 * the end of an event ring segment (which doesn't have link TRBS)
154 	 */
155 	while (last_trb(xhci, ring, ring->deq_seg, next)) {
156 		if (consumer && last_trb_on_last_seg(xhci, ring, ring->deq_seg, next)) {
157 			ring->cycle_state = (ring->cycle_state ? 0 : 1);
158 			if (!in_interrupt())
159 				xhci_dbg(xhci, "Toggle cycle state for ring %p = %i\n",
160 						ring,
161 						(unsigned int) ring->cycle_state);
162 		}
163 		ring->deq_seg = ring->deq_seg->next;
164 		ring->dequeue = ring->deq_seg->trbs;
165 		next = ring->dequeue;
166 	}
167 	addr = (unsigned long long) xhci_trb_virt_to_dma(ring->deq_seg, ring->dequeue);
168 	if (ring == xhci->event_ring)
169 		xhci_dbg(xhci, "Event ring deq = 0x%llx (DMA)\n", addr);
170 	else if (ring == xhci->cmd_ring)
171 		xhci_dbg(xhci, "Command ring deq = 0x%llx (DMA)\n", addr);
172 	else
173 		xhci_dbg(xhci, "Ring deq = 0x%llx (DMA)\n", addr);
174 }
175 
176 /*
177  * See Cycle bit rules. SW is the consumer for the event ring only.
178  * Don't make a ring full of link TRBs.  That would be dumb and this would loop.
179  *
180  * If we've just enqueued a TRB that is in the middle of a TD (meaning the
181  * chain bit is set), then set the chain bit in all the following link TRBs.
182  * If we've enqueued the last TRB in a TD, make sure the following link TRBs
183  * have their chain bit cleared (so that each Link TRB is a separate TD).
184  *
185  * Section 6.4.4.1 of the 0.95 spec says link TRBs cannot have the chain bit
186  * set, but other sections talk about dealing with the chain bit set.  This was
187  * fixed in the 0.96 specification errata, but we have to assume that all 0.95
188  * xHCI hardware can't handle the chain bit being cleared on a link TRB.
189  *
190  * @more_trbs_coming:	Will you enqueue more TRBs before calling
191  *			prepare_transfer()?
192  */
193 static void inc_enq(struct xhci_hcd *xhci, struct xhci_ring *ring,
194 		bool consumer, bool more_trbs_coming)
195 {
196 	u32 chain;
197 	union xhci_trb *next;
198 	unsigned long long addr;
199 
200 	chain = ring->enqueue->generic.field[3] & TRB_CHAIN;
201 	next = ++(ring->enqueue);
202 
203 	ring->enq_updates++;
204 	/* Update the dequeue pointer further if that was a link TRB or we're at
205 	 * the end of an event ring segment (which doesn't have link TRBS)
206 	 */
207 	while (last_trb(xhci, ring, ring->enq_seg, next)) {
208 		if (!consumer) {
209 			if (ring != xhci->event_ring) {
210 				/*
211 				 * If the caller doesn't plan on enqueueing more
212 				 * TDs before ringing the doorbell, then we
213 				 * don't want to give the link TRB to the
214 				 * hardware just yet.  We'll give the link TRB
215 				 * back in prepare_ring() just before we enqueue
216 				 * the TD at the top of the ring.
217 				 */
218 				if (!chain && !more_trbs_coming)
219 					break;
220 
221 				/* If we're not dealing with 0.95 hardware,
222 				 * carry over the chain bit of the previous TRB
223 				 * (which may mean the chain bit is cleared).
224 				 */
225 				if (!xhci_link_trb_quirk(xhci)) {
226 					next->link.control &= ~TRB_CHAIN;
227 					next->link.control |= chain;
228 				}
229 				/* Give this link TRB to the hardware */
230 				wmb();
231 				next->link.control ^= TRB_CYCLE;
232 			}
233 			/* Toggle the cycle bit after the last ring segment. */
234 			if (last_trb_on_last_seg(xhci, ring, ring->enq_seg, next)) {
235 				ring->cycle_state = (ring->cycle_state ? 0 : 1);
236 				if (!in_interrupt())
237 					xhci_dbg(xhci, "Toggle cycle state for ring %p = %i\n",
238 							ring,
239 							(unsigned int) ring->cycle_state);
240 			}
241 		}
242 		ring->enq_seg = ring->enq_seg->next;
243 		ring->enqueue = ring->enq_seg->trbs;
244 		next = ring->enqueue;
245 	}
246 	addr = (unsigned long long) xhci_trb_virt_to_dma(ring->enq_seg, ring->enqueue);
247 	if (ring == xhci->event_ring)
248 		xhci_dbg(xhci, "Event ring enq = 0x%llx (DMA)\n", addr);
249 	else if (ring == xhci->cmd_ring)
250 		xhci_dbg(xhci, "Command ring enq = 0x%llx (DMA)\n", addr);
251 	else
252 		xhci_dbg(xhci, "Ring enq = 0x%llx (DMA)\n", addr);
253 }
254 
255 /*
256  * Check to see if there's room to enqueue num_trbs on the ring.  See rules
257  * above.
258  * FIXME: this would be simpler and faster if we just kept track of the number
259  * of free TRBs in a ring.
260  */
261 static int room_on_ring(struct xhci_hcd *xhci, struct xhci_ring *ring,
262 		unsigned int num_trbs)
263 {
264 	int i;
265 	union xhci_trb *enq = ring->enqueue;
266 	struct xhci_segment *enq_seg = ring->enq_seg;
267 	struct xhci_segment *cur_seg;
268 	unsigned int left_on_ring;
269 
270 	/* If we are currently pointing to a link TRB, advance the
271 	 * enqueue pointer before checking for space */
272 	while (last_trb(xhci, ring, enq_seg, enq)) {
273 		enq_seg = enq_seg->next;
274 		enq = enq_seg->trbs;
275 	}
276 
277 	/* Check if ring is empty */
278 	if (enq == ring->dequeue) {
279 		/* Can't use link trbs */
280 		left_on_ring = TRBS_PER_SEGMENT - 1;
281 		for (cur_seg = enq_seg->next; cur_seg != enq_seg;
282 				cur_seg = cur_seg->next)
283 			left_on_ring += TRBS_PER_SEGMENT - 1;
284 
285 		/* Always need one TRB free in the ring. */
286 		left_on_ring -= 1;
287 		if (num_trbs > left_on_ring) {
288 			xhci_warn(xhci, "Not enough room on ring; "
289 					"need %u TRBs, %u TRBs left\n",
290 					num_trbs, left_on_ring);
291 			return 0;
292 		}
293 		return 1;
294 	}
295 	/* Make sure there's an extra empty TRB available */
296 	for (i = 0; i <= num_trbs; ++i) {
297 		if (enq == ring->dequeue)
298 			return 0;
299 		enq++;
300 		while (last_trb(xhci, ring, enq_seg, enq)) {
301 			enq_seg = enq_seg->next;
302 			enq = enq_seg->trbs;
303 		}
304 	}
305 	return 1;
306 }
307 
308 /* Ring the host controller doorbell after placing a command on the ring */
309 void xhci_ring_cmd_db(struct xhci_hcd *xhci)
310 {
311 	xhci_dbg(xhci, "// Ding dong!\n");
312 	xhci_writel(xhci, DB_VALUE_HOST, &xhci->dba->doorbell[0]);
313 	/* Flush PCI posted writes */
314 	xhci_readl(xhci, &xhci->dba->doorbell[0]);
315 }
316 
317 void xhci_ring_ep_doorbell(struct xhci_hcd *xhci,
318 		unsigned int slot_id,
319 		unsigned int ep_index,
320 		unsigned int stream_id)
321 {
322 	__u32 __iomem *db_addr = &xhci->dba->doorbell[slot_id];
323 	struct xhci_virt_ep *ep = &xhci->devs[slot_id]->eps[ep_index];
324 	unsigned int ep_state = ep->ep_state;
325 
326 	/* Don't ring the doorbell for this endpoint if there are pending
327 	 * cancellations because we don't want to interrupt processing.
328 	 * We don't want to restart any stream rings if there's a set dequeue
329 	 * pointer command pending because the device can choose to start any
330 	 * stream once the endpoint is on the HW schedule.
331 	 * FIXME - check all the stream rings for pending cancellations.
332 	 */
333 	if ((ep_state & EP_HALT_PENDING) || (ep_state & SET_DEQ_PENDING) ||
334 	    (ep_state & EP_HALTED))
335 		return;
336 	xhci_writel(xhci, DB_VALUE(ep_index, stream_id), db_addr);
337 	/* The CPU has better things to do at this point than wait for a
338 	 * write-posting flush.  It'll get there soon enough.
339 	 */
340 }
341 
342 /* Ring the doorbell for any rings with pending URBs */
343 static void ring_doorbell_for_active_rings(struct xhci_hcd *xhci,
344 		unsigned int slot_id,
345 		unsigned int ep_index)
346 {
347 	unsigned int stream_id;
348 	struct xhci_virt_ep *ep;
349 
350 	ep = &xhci->devs[slot_id]->eps[ep_index];
351 
352 	/* A ring has pending URBs if its TD list is not empty */
353 	if (!(ep->ep_state & EP_HAS_STREAMS)) {
354 		if (!(list_empty(&ep->ring->td_list)))
355 			xhci_ring_ep_doorbell(xhci, slot_id, ep_index, 0);
356 		return;
357 	}
358 
359 	for (stream_id = 1; stream_id < ep->stream_info->num_streams;
360 			stream_id++) {
361 		struct xhci_stream_info *stream_info = ep->stream_info;
362 		if (!list_empty(&stream_info->stream_rings[stream_id]->td_list))
363 			xhci_ring_ep_doorbell(xhci, slot_id, ep_index,
364 						stream_id);
365 	}
366 }
367 
368 /*
369  * Find the segment that trb is in.  Start searching in start_seg.
370  * If we must move past a segment that has a link TRB with a toggle cycle state
371  * bit set, then we will toggle the value pointed at by cycle_state.
372  */
373 static struct xhci_segment *find_trb_seg(
374 		struct xhci_segment *start_seg,
375 		union xhci_trb	*trb, int *cycle_state)
376 {
377 	struct xhci_segment *cur_seg = start_seg;
378 	struct xhci_generic_trb *generic_trb;
379 
380 	while (cur_seg->trbs > trb ||
381 			&cur_seg->trbs[TRBS_PER_SEGMENT - 1] < trb) {
382 		generic_trb = &cur_seg->trbs[TRBS_PER_SEGMENT - 1].generic;
383 		if ((generic_trb->field[3] & TRB_TYPE_BITMASK) ==
384 				TRB_TYPE(TRB_LINK) &&
385 				(generic_trb->field[3] & LINK_TOGGLE))
386 			*cycle_state = ~(*cycle_state) & 0x1;
387 		cur_seg = cur_seg->next;
388 		if (cur_seg == start_seg)
389 			/* Looped over the entire list.  Oops! */
390 			return NULL;
391 	}
392 	return cur_seg;
393 }
394 
395 
396 static struct xhci_ring *xhci_triad_to_transfer_ring(struct xhci_hcd *xhci,
397 		unsigned int slot_id, unsigned int ep_index,
398 		unsigned int stream_id)
399 {
400 	struct xhci_virt_ep *ep;
401 
402 	ep = &xhci->devs[slot_id]->eps[ep_index];
403 	/* Common case: no streams */
404 	if (!(ep->ep_state & EP_HAS_STREAMS))
405 		return ep->ring;
406 
407 	if (stream_id == 0) {
408 		xhci_warn(xhci,
409 				"WARN: Slot ID %u, ep index %u has streams, "
410 				"but URB has no stream ID.\n",
411 				slot_id, ep_index);
412 		return NULL;
413 	}
414 
415 	if (stream_id < ep->stream_info->num_streams)
416 		return ep->stream_info->stream_rings[stream_id];
417 
418 	xhci_warn(xhci,
419 			"WARN: Slot ID %u, ep index %u has "
420 			"stream IDs 1 to %u allocated, "
421 			"but stream ID %u is requested.\n",
422 			slot_id, ep_index,
423 			ep->stream_info->num_streams - 1,
424 			stream_id);
425 	return NULL;
426 }
427 
428 /* Get the right ring for the given URB.
429  * If the endpoint supports streams, boundary check the URB's stream ID.
430  * If the endpoint doesn't support streams, return the singular endpoint ring.
431  */
432 static struct xhci_ring *xhci_urb_to_transfer_ring(struct xhci_hcd *xhci,
433 		struct urb *urb)
434 {
435 	return xhci_triad_to_transfer_ring(xhci, urb->dev->slot_id,
436 		xhci_get_endpoint_index(&urb->ep->desc), urb->stream_id);
437 }
438 
439 /*
440  * Move the xHC's endpoint ring dequeue pointer past cur_td.
441  * Record the new state of the xHC's endpoint ring dequeue segment,
442  * dequeue pointer, and new consumer cycle state in state.
443  * Update our internal representation of the ring's dequeue pointer.
444  *
445  * We do this in three jumps:
446  *  - First we update our new ring state to be the same as when the xHC stopped.
447  *  - Then we traverse the ring to find the segment that contains
448  *    the last TRB in the TD.  We toggle the xHC's new cycle state when we pass
449  *    any link TRBs with the toggle cycle bit set.
450  *  - Finally we move the dequeue state one TRB further, toggling the cycle bit
451  *    if we've moved it past a link TRB with the toggle cycle bit set.
452  */
453 void xhci_find_new_dequeue_state(struct xhci_hcd *xhci,
454 		unsigned int slot_id, unsigned int ep_index,
455 		unsigned int stream_id, struct xhci_td *cur_td,
456 		struct xhci_dequeue_state *state)
457 {
458 	struct xhci_virt_device *dev = xhci->devs[slot_id];
459 	struct xhci_ring *ep_ring;
460 	struct xhci_generic_trb *trb;
461 	struct xhci_ep_ctx *ep_ctx;
462 	dma_addr_t addr;
463 
464 	ep_ring = xhci_triad_to_transfer_ring(xhci, slot_id,
465 			ep_index, stream_id);
466 	if (!ep_ring) {
467 		xhci_warn(xhci, "WARN can't find new dequeue state "
468 				"for invalid stream ID %u.\n",
469 				stream_id);
470 		return;
471 	}
472 	state->new_cycle_state = 0;
473 	xhci_dbg(xhci, "Finding segment containing stopped TRB.\n");
474 	state->new_deq_seg = find_trb_seg(cur_td->start_seg,
475 			dev->eps[ep_index].stopped_trb,
476 			&state->new_cycle_state);
477 	if (!state->new_deq_seg)
478 		BUG();
479 	/* Dig out the cycle state saved by the xHC during the stop ep cmd */
480 	xhci_dbg(xhci, "Finding endpoint context\n");
481 	ep_ctx = xhci_get_ep_ctx(xhci, dev->out_ctx, ep_index);
482 	state->new_cycle_state = 0x1 & ep_ctx->deq;
483 
484 	state->new_deq_ptr = cur_td->last_trb;
485 	xhci_dbg(xhci, "Finding segment containing last TRB in TD.\n");
486 	state->new_deq_seg = find_trb_seg(state->new_deq_seg,
487 			state->new_deq_ptr,
488 			&state->new_cycle_state);
489 	if (!state->new_deq_seg)
490 		BUG();
491 
492 	trb = &state->new_deq_ptr->generic;
493 	if ((trb->field[3] & TRB_TYPE_BITMASK) == TRB_TYPE(TRB_LINK) &&
494 				(trb->field[3] & LINK_TOGGLE))
495 		state->new_cycle_state = ~(state->new_cycle_state) & 0x1;
496 	next_trb(xhci, ep_ring, &state->new_deq_seg, &state->new_deq_ptr);
497 
498 	/* Don't update the ring cycle state for the producer (us). */
499 	xhci_dbg(xhci, "New dequeue segment = %p (virtual)\n",
500 			state->new_deq_seg);
501 	addr = xhci_trb_virt_to_dma(state->new_deq_seg, state->new_deq_ptr);
502 	xhci_dbg(xhci, "New dequeue pointer = 0x%llx (DMA)\n",
503 			(unsigned long long) addr);
504 	xhci_dbg(xhci, "Setting dequeue pointer in internal ring state.\n");
505 	ep_ring->dequeue = state->new_deq_ptr;
506 	ep_ring->deq_seg = state->new_deq_seg;
507 }
508 
509 static void td_to_noop(struct xhci_hcd *xhci, struct xhci_ring *ep_ring,
510 		struct xhci_td *cur_td)
511 {
512 	struct xhci_segment *cur_seg;
513 	union xhci_trb *cur_trb;
514 
515 	for (cur_seg = cur_td->start_seg, cur_trb = cur_td->first_trb;
516 			true;
517 			next_trb(xhci, ep_ring, &cur_seg, &cur_trb)) {
518 		if ((cur_trb->generic.field[3] & TRB_TYPE_BITMASK) ==
519 				TRB_TYPE(TRB_LINK)) {
520 			/* Unchain any chained Link TRBs, but
521 			 * leave the pointers intact.
522 			 */
523 			cur_trb->generic.field[3] &= ~TRB_CHAIN;
524 			xhci_dbg(xhci, "Cancel (unchain) link TRB\n");
525 			xhci_dbg(xhci, "Address = %p (0x%llx dma); "
526 					"in seg %p (0x%llx dma)\n",
527 					cur_trb,
528 					(unsigned long long)xhci_trb_virt_to_dma(cur_seg, cur_trb),
529 					cur_seg,
530 					(unsigned long long)cur_seg->dma);
531 		} else {
532 			cur_trb->generic.field[0] = 0;
533 			cur_trb->generic.field[1] = 0;
534 			cur_trb->generic.field[2] = 0;
535 			/* Preserve only the cycle bit of this TRB */
536 			cur_trb->generic.field[3] &= TRB_CYCLE;
537 			cur_trb->generic.field[3] |= TRB_TYPE(TRB_TR_NOOP);
538 			xhci_dbg(xhci, "Cancel TRB %p (0x%llx dma) "
539 					"in seg %p (0x%llx dma)\n",
540 					cur_trb,
541 					(unsigned long long)xhci_trb_virt_to_dma(cur_seg, cur_trb),
542 					cur_seg,
543 					(unsigned long long)cur_seg->dma);
544 		}
545 		if (cur_trb == cur_td->last_trb)
546 			break;
547 	}
548 }
549 
550 static int queue_set_tr_deq(struct xhci_hcd *xhci, int slot_id,
551 		unsigned int ep_index, unsigned int stream_id,
552 		struct xhci_segment *deq_seg,
553 		union xhci_trb *deq_ptr, u32 cycle_state);
554 
555 void xhci_queue_new_dequeue_state(struct xhci_hcd *xhci,
556 		unsigned int slot_id, unsigned int ep_index,
557 		unsigned int stream_id,
558 		struct xhci_dequeue_state *deq_state)
559 {
560 	struct xhci_virt_ep *ep = &xhci->devs[slot_id]->eps[ep_index];
561 
562 	xhci_dbg(xhci, "Set TR Deq Ptr cmd, new deq seg = %p (0x%llx dma), "
563 			"new deq ptr = %p (0x%llx dma), new cycle = %u\n",
564 			deq_state->new_deq_seg,
565 			(unsigned long long)deq_state->new_deq_seg->dma,
566 			deq_state->new_deq_ptr,
567 			(unsigned long long)xhci_trb_virt_to_dma(deq_state->new_deq_seg, deq_state->new_deq_ptr),
568 			deq_state->new_cycle_state);
569 	queue_set_tr_deq(xhci, slot_id, ep_index, stream_id,
570 			deq_state->new_deq_seg,
571 			deq_state->new_deq_ptr,
572 			(u32) deq_state->new_cycle_state);
573 	/* Stop the TD queueing code from ringing the doorbell until
574 	 * this command completes.  The HC won't set the dequeue pointer
575 	 * if the ring is running, and ringing the doorbell starts the
576 	 * ring running.
577 	 */
578 	ep->ep_state |= SET_DEQ_PENDING;
579 }
580 
581 static inline void xhci_stop_watchdog_timer_in_irq(struct xhci_hcd *xhci,
582 		struct xhci_virt_ep *ep)
583 {
584 	ep->ep_state &= ~EP_HALT_PENDING;
585 	/* Can't del_timer_sync in interrupt, so we attempt to cancel.  If the
586 	 * timer is running on another CPU, we don't decrement stop_cmds_pending
587 	 * (since we didn't successfully stop the watchdog timer).
588 	 */
589 	if (del_timer(&ep->stop_cmd_timer))
590 		ep->stop_cmds_pending--;
591 }
592 
593 /* Must be called with xhci->lock held in interrupt context */
594 static void xhci_giveback_urb_in_irq(struct xhci_hcd *xhci,
595 		struct xhci_td *cur_td, int status, char *adjective)
596 {
597 	struct usb_hcd *hcd = xhci_to_hcd(xhci);
598 	struct urb	*urb;
599 	struct urb_priv	*urb_priv;
600 
601 	urb = cur_td->urb;
602 	urb_priv = urb->hcpriv;
603 	urb_priv->td_cnt++;
604 
605 	/* Only giveback urb when this is the last td in urb */
606 	if (urb_priv->td_cnt == urb_priv->length) {
607 		usb_hcd_unlink_urb_from_ep(hcd, urb);
608 		xhci_dbg(xhci, "Giveback %s URB %p\n", adjective, urb);
609 
610 		spin_unlock(&xhci->lock);
611 		usb_hcd_giveback_urb(hcd, urb, status);
612 		xhci_urb_free_priv(xhci, urb_priv);
613 		spin_lock(&xhci->lock);
614 		xhci_dbg(xhci, "%s URB given back\n", adjective);
615 	}
616 }
617 
618 /*
619  * When we get a command completion for a Stop Endpoint Command, we need to
620  * unlink any cancelled TDs from the ring.  There are two ways to do that:
621  *
622  *  1. If the HW was in the middle of processing the TD that needs to be
623  *     cancelled, then we must move the ring's dequeue pointer past the last TRB
624  *     in the TD with a Set Dequeue Pointer Command.
625  *  2. Otherwise, we turn all the TRBs in the TD into No-op TRBs (with the chain
626  *     bit cleared) so that the HW will skip over them.
627  */
628 static void handle_stopped_endpoint(struct xhci_hcd *xhci,
629 		union xhci_trb *trb, struct xhci_event_cmd *event)
630 {
631 	unsigned int slot_id;
632 	unsigned int ep_index;
633 	struct xhci_virt_device *virt_dev;
634 	struct xhci_ring *ep_ring;
635 	struct xhci_virt_ep *ep;
636 	struct list_head *entry;
637 	struct xhci_td *cur_td = NULL;
638 	struct xhci_td *last_unlinked_td;
639 
640 	struct xhci_dequeue_state deq_state;
641 
642 	if (unlikely(TRB_TO_SUSPEND_PORT(
643 			xhci->cmd_ring->dequeue->generic.field[3]))) {
644 		slot_id = TRB_TO_SLOT_ID(
645 			xhci->cmd_ring->dequeue->generic.field[3]);
646 		virt_dev = xhci->devs[slot_id];
647 		if (virt_dev)
648 			handle_cmd_in_cmd_wait_list(xhci, virt_dev,
649 				event);
650 		else
651 			xhci_warn(xhci, "Stop endpoint command "
652 				"completion for disabled slot %u\n",
653 				slot_id);
654 		return;
655 	}
656 
657 	memset(&deq_state, 0, sizeof(deq_state));
658 	slot_id = TRB_TO_SLOT_ID(trb->generic.field[3]);
659 	ep_index = TRB_TO_EP_INDEX(trb->generic.field[3]);
660 	ep = &xhci->devs[slot_id]->eps[ep_index];
661 
662 	if (list_empty(&ep->cancelled_td_list)) {
663 		xhci_stop_watchdog_timer_in_irq(xhci, ep);
664 		ring_doorbell_for_active_rings(xhci, slot_id, ep_index);
665 		return;
666 	}
667 
668 	/* Fix up the ep ring first, so HW stops executing cancelled TDs.
669 	 * We have the xHCI lock, so nothing can modify this list until we drop
670 	 * it.  We're also in the event handler, so we can't get re-interrupted
671 	 * if another Stop Endpoint command completes
672 	 */
673 	list_for_each(entry, &ep->cancelled_td_list) {
674 		cur_td = list_entry(entry, struct xhci_td, cancelled_td_list);
675 		xhci_dbg(xhci, "Cancelling TD starting at %p, 0x%llx (dma).\n",
676 				cur_td->first_trb,
677 				(unsigned long long)xhci_trb_virt_to_dma(cur_td->start_seg, cur_td->first_trb));
678 		ep_ring = xhci_urb_to_transfer_ring(xhci, cur_td->urb);
679 		if (!ep_ring) {
680 			/* This shouldn't happen unless a driver is mucking
681 			 * with the stream ID after submission.  This will
682 			 * leave the TD on the hardware ring, and the hardware
683 			 * will try to execute it, and may access a buffer
684 			 * that has already been freed.  In the best case, the
685 			 * hardware will execute it, and the event handler will
686 			 * ignore the completion event for that TD, since it was
687 			 * removed from the td_list for that endpoint.  In
688 			 * short, don't muck with the stream ID after
689 			 * submission.
690 			 */
691 			xhci_warn(xhci, "WARN Cancelled URB %p "
692 					"has invalid stream ID %u.\n",
693 					cur_td->urb,
694 					cur_td->urb->stream_id);
695 			goto remove_finished_td;
696 		}
697 		/*
698 		 * If we stopped on the TD we need to cancel, then we have to
699 		 * move the xHC endpoint ring dequeue pointer past this TD.
700 		 */
701 		if (cur_td == ep->stopped_td)
702 			xhci_find_new_dequeue_state(xhci, slot_id, ep_index,
703 					cur_td->urb->stream_id,
704 					cur_td, &deq_state);
705 		else
706 			td_to_noop(xhci, ep_ring, cur_td);
707 remove_finished_td:
708 		/*
709 		 * The event handler won't see a completion for this TD anymore,
710 		 * so remove it from the endpoint ring's TD list.  Keep it in
711 		 * the cancelled TD list for URB completion later.
712 		 */
713 		list_del(&cur_td->td_list);
714 	}
715 	last_unlinked_td = cur_td;
716 	xhci_stop_watchdog_timer_in_irq(xhci, ep);
717 
718 	/* If necessary, queue a Set Transfer Ring Dequeue Pointer command */
719 	if (deq_state.new_deq_ptr && deq_state.new_deq_seg) {
720 		xhci_queue_new_dequeue_state(xhci,
721 				slot_id, ep_index,
722 				ep->stopped_td->urb->stream_id,
723 				&deq_state);
724 		xhci_ring_cmd_db(xhci);
725 	} else {
726 		/* Otherwise ring the doorbell(s) to restart queued transfers */
727 		ring_doorbell_for_active_rings(xhci, slot_id, ep_index);
728 	}
729 	ep->stopped_td = NULL;
730 	ep->stopped_trb = NULL;
731 
732 	/*
733 	 * Drop the lock and complete the URBs in the cancelled TD list.
734 	 * New TDs to be cancelled might be added to the end of the list before
735 	 * we can complete all the URBs for the TDs we already unlinked.
736 	 * So stop when we've completed the URB for the last TD we unlinked.
737 	 */
738 	do {
739 		cur_td = list_entry(ep->cancelled_td_list.next,
740 				struct xhci_td, cancelled_td_list);
741 		list_del(&cur_td->cancelled_td_list);
742 
743 		/* Clean up the cancelled URB */
744 		/* Doesn't matter what we pass for status, since the core will
745 		 * just overwrite it (because the URB has been unlinked).
746 		 */
747 		xhci_giveback_urb_in_irq(xhci, cur_td, 0, "cancelled");
748 
749 		/* Stop processing the cancelled list if the watchdog timer is
750 		 * running.
751 		 */
752 		if (xhci->xhc_state & XHCI_STATE_DYING)
753 			return;
754 	} while (cur_td != last_unlinked_td);
755 
756 	/* Return to the event handler with xhci->lock re-acquired */
757 }
758 
759 /* Watchdog timer function for when a stop endpoint command fails to complete.
760  * In this case, we assume the host controller is broken or dying or dead.  The
761  * host may still be completing some other events, so we have to be careful to
762  * let the event ring handler and the URB dequeueing/enqueueing functions know
763  * through xhci->state.
764  *
765  * The timer may also fire if the host takes a very long time to respond to the
766  * command, and the stop endpoint command completion handler cannot delete the
767  * timer before the timer function is called.  Another endpoint cancellation may
768  * sneak in before the timer function can grab the lock, and that may queue
769  * another stop endpoint command and add the timer back.  So we cannot use a
770  * simple flag to say whether there is a pending stop endpoint command for a
771  * particular endpoint.
772  *
773  * Instead we use a combination of that flag and a counter for the number of
774  * pending stop endpoint commands.  If the timer is the tail end of the last
775  * stop endpoint command, and the endpoint's command is still pending, we assume
776  * the host is dying.
777  */
778 void xhci_stop_endpoint_command_watchdog(unsigned long arg)
779 {
780 	struct xhci_hcd *xhci;
781 	struct xhci_virt_ep *ep;
782 	struct xhci_virt_ep *temp_ep;
783 	struct xhci_ring *ring;
784 	struct xhci_td *cur_td;
785 	int ret, i, j;
786 
787 	ep = (struct xhci_virt_ep *) arg;
788 	xhci = ep->xhci;
789 
790 	spin_lock(&xhci->lock);
791 
792 	ep->stop_cmds_pending--;
793 	if (xhci->xhc_state & XHCI_STATE_DYING) {
794 		xhci_dbg(xhci, "Stop EP timer ran, but another timer marked "
795 				"xHCI as DYING, exiting.\n");
796 		spin_unlock(&xhci->lock);
797 		return;
798 	}
799 	if (!(ep->stop_cmds_pending == 0 && (ep->ep_state & EP_HALT_PENDING))) {
800 		xhci_dbg(xhci, "Stop EP timer ran, but no command pending, "
801 				"exiting.\n");
802 		spin_unlock(&xhci->lock);
803 		return;
804 	}
805 
806 	xhci_warn(xhci, "xHCI host not responding to stop endpoint command.\n");
807 	xhci_warn(xhci, "Assuming host is dying, halting host.\n");
808 	/* Oops, HC is dead or dying or at least not responding to the stop
809 	 * endpoint command.
810 	 */
811 	xhci->xhc_state |= XHCI_STATE_DYING;
812 	/* Disable interrupts from the host controller and start halting it */
813 	xhci_quiesce(xhci);
814 	spin_unlock(&xhci->lock);
815 
816 	ret = xhci_halt(xhci);
817 
818 	spin_lock(&xhci->lock);
819 	if (ret < 0) {
820 		/* This is bad; the host is not responding to commands and it's
821 		 * not allowing itself to be halted.  At least interrupts are
822 		 * disabled, so we can set HC_STATE_HALT and notify the
823 		 * USB core.  But if we call usb_hc_died(), it will attempt to
824 		 * disconnect all device drivers under this host.  Those
825 		 * disconnect() methods will wait for all URBs to be unlinked,
826 		 * so we must complete them.
827 		 */
828 		xhci_warn(xhci, "Non-responsive xHCI host is not halting.\n");
829 		xhci_warn(xhci, "Completing active URBs anyway.\n");
830 		/* We could turn all TDs on the rings to no-ops.  This won't
831 		 * help if the host has cached part of the ring, and is slow if
832 		 * we want to preserve the cycle bit.  Skip it and hope the host
833 		 * doesn't touch the memory.
834 		 */
835 	}
836 	for (i = 0; i < MAX_HC_SLOTS; i++) {
837 		if (!xhci->devs[i])
838 			continue;
839 		for (j = 0; j < 31; j++) {
840 			temp_ep = &xhci->devs[i]->eps[j];
841 			ring = temp_ep->ring;
842 			if (!ring)
843 				continue;
844 			xhci_dbg(xhci, "Killing URBs for slot ID %u, "
845 					"ep index %u\n", i, j);
846 			while (!list_empty(&ring->td_list)) {
847 				cur_td = list_first_entry(&ring->td_list,
848 						struct xhci_td,
849 						td_list);
850 				list_del(&cur_td->td_list);
851 				if (!list_empty(&cur_td->cancelled_td_list))
852 					list_del(&cur_td->cancelled_td_list);
853 				xhci_giveback_urb_in_irq(xhci, cur_td,
854 						-ESHUTDOWN, "killed");
855 			}
856 			while (!list_empty(&temp_ep->cancelled_td_list)) {
857 				cur_td = list_first_entry(
858 						&temp_ep->cancelled_td_list,
859 						struct xhci_td,
860 						cancelled_td_list);
861 				list_del(&cur_td->cancelled_td_list);
862 				xhci_giveback_urb_in_irq(xhci, cur_td,
863 						-ESHUTDOWN, "killed");
864 			}
865 		}
866 	}
867 	spin_unlock(&xhci->lock);
868 	xhci_to_hcd(xhci)->state = HC_STATE_HALT;
869 	xhci_dbg(xhci, "Calling usb_hc_died()\n");
870 	usb_hc_died(xhci_to_hcd(xhci));
871 	xhci_dbg(xhci, "xHCI host controller is dead.\n");
872 }
873 
874 /*
875  * When we get a completion for a Set Transfer Ring Dequeue Pointer command,
876  * we need to clear the set deq pending flag in the endpoint ring state, so that
877  * the TD queueing code can ring the doorbell again.  We also need to ring the
878  * endpoint doorbell to restart the ring, but only if there aren't more
879  * cancellations pending.
880  */
881 static void handle_set_deq_completion(struct xhci_hcd *xhci,
882 		struct xhci_event_cmd *event,
883 		union xhci_trb *trb)
884 {
885 	unsigned int slot_id;
886 	unsigned int ep_index;
887 	unsigned int stream_id;
888 	struct xhci_ring *ep_ring;
889 	struct xhci_virt_device *dev;
890 	struct xhci_ep_ctx *ep_ctx;
891 	struct xhci_slot_ctx *slot_ctx;
892 
893 	slot_id = TRB_TO_SLOT_ID(trb->generic.field[3]);
894 	ep_index = TRB_TO_EP_INDEX(trb->generic.field[3]);
895 	stream_id = TRB_TO_STREAM_ID(trb->generic.field[2]);
896 	dev = xhci->devs[slot_id];
897 
898 	ep_ring = xhci_stream_id_to_ring(dev, ep_index, stream_id);
899 	if (!ep_ring) {
900 		xhci_warn(xhci, "WARN Set TR deq ptr command for "
901 				"freed stream ID %u\n",
902 				stream_id);
903 		/* XXX: Harmless??? */
904 		dev->eps[ep_index].ep_state &= ~SET_DEQ_PENDING;
905 		return;
906 	}
907 
908 	ep_ctx = xhci_get_ep_ctx(xhci, dev->out_ctx, ep_index);
909 	slot_ctx = xhci_get_slot_ctx(xhci, dev->out_ctx);
910 
911 	if (GET_COMP_CODE(event->status) != COMP_SUCCESS) {
912 		unsigned int ep_state;
913 		unsigned int slot_state;
914 
915 		switch (GET_COMP_CODE(event->status)) {
916 		case COMP_TRB_ERR:
917 			xhci_warn(xhci, "WARN Set TR Deq Ptr cmd invalid because "
918 					"of stream ID configuration\n");
919 			break;
920 		case COMP_CTX_STATE:
921 			xhci_warn(xhci, "WARN Set TR Deq Ptr cmd failed due "
922 					"to incorrect slot or ep state.\n");
923 			ep_state = ep_ctx->ep_info;
924 			ep_state &= EP_STATE_MASK;
925 			slot_state = slot_ctx->dev_state;
926 			slot_state = GET_SLOT_STATE(slot_state);
927 			xhci_dbg(xhci, "Slot state = %u, EP state = %u\n",
928 					slot_state, ep_state);
929 			break;
930 		case COMP_EBADSLT:
931 			xhci_warn(xhci, "WARN Set TR Deq Ptr cmd failed because "
932 					"slot %u was not enabled.\n", slot_id);
933 			break;
934 		default:
935 			xhci_warn(xhci, "WARN Set TR Deq Ptr cmd with unknown "
936 					"completion code of %u.\n",
937 					GET_COMP_CODE(event->status));
938 			break;
939 		}
940 		/* OK what do we do now?  The endpoint state is hosed, and we
941 		 * should never get to this point if the synchronization between
942 		 * queueing, and endpoint state are correct.  This might happen
943 		 * if the device gets disconnected after we've finished
944 		 * cancelling URBs, which might not be an error...
945 		 */
946 	} else {
947 		xhci_dbg(xhci, "Successful Set TR Deq Ptr cmd, deq = @%08llx\n",
948 				ep_ctx->deq);
949 	}
950 
951 	dev->eps[ep_index].ep_state &= ~SET_DEQ_PENDING;
952 	/* Restart any rings with pending URBs */
953 	ring_doorbell_for_active_rings(xhci, slot_id, ep_index);
954 }
955 
956 static void handle_reset_ep_completion(struct xhci_hcd *xhci,
957 		struct xhci_event_cmd *event,
958 		union xhci_trb *trb)
959 {
960 	int slot_id;
961 	unsigned int ep_index;
962 
963 	slot_id = TRB_TO_SLOT_ID(trb->generic.field[3]);
964 	ep_index = TRB_TO_EP_INDEX(trb->generic.field[3]);
965 	/* This command will only fail if the endpoint wasn't halted,
966 	 * but we don't care.
967 	 */
968 	xhci_dbg(xhci, "Ignoring reset ep completion code of %u\n",
969 			(unsigned int) GET_COMP_CODE(event->status));
970 
971 	/* HW with the reset endpoint quirk needs to have a configure endpoint
972 	 * command complete before the endpoint can be used.  Queue that here
973 	 * because the HW can't handle two commands being queued in a row.
974 	 */
975 	if (xhci->quirks & XHCI_RESET_EP_QUIRK) {
976 		xhci_dbg(xhci, "Queueing configure endpoint command\n");
977 		xhci_queue_configure_endpoint(xhci,
978 				xhci->devs[slot_id]->in_ctx->dma, slot_id,
979 				false);
980 		xhci_ring_cmd_db(xhci);
981 	} else {
982 		/* Clear our internal halted state and restart the ring(s) */
983 		xhci->devs[slot_id]->eps[ep_index].ep_state &= ~EP_HALTED;
984 		ring_doorbell_for_active_rings(xhci, slot_id, ep_index);
985 	}
986 }
987 
988 /* Check to see if a command in the device's command queue matches this one.
989  * Signal the completion or free the command, and return 1.  Return 0 if the
990  * completed command isn't at the head of the command list.
991  */
992 static int handle_cmd_in_cmd_wait_list(struct xhci_hcd *xhci,
993 		struct xhci_virt_device *virt_dev,
994 		struct xhci_event_cmd *event)
995 {
996 	struct xhci_command *command;
997 
998 	if (list_empty(&virt_dev->cmd_list))
999 		return 0;
1000 
1001 	command = list_entry(virt_dev->cmd_list.next,
1002 			struct xhci_command, cmd_list);
1003 	if (xhci->cmd_ring->dequeue != command->command_trb)
1004 		return 0;
1005 
1006 	command->status =
1007 		GET_COMP_CODE(event->status);
1008 	list_del(&command->cmd_list);
1009 	if (command->completion)
1010 		complete(command->completion);
1011 	else
1012 		xhci_free_command(xhci, command);
1013 	return 1;
1014 }
1015 
1016 static void handle_cmd_completion(struct xhci_hcd *xhci,
1017 		struct xhci_event_cmd *event)
1018 {
1019 	int slot_id = TRB_TO_SLOT_ID(event->flags);
1020 	u64 cmd_dma;
1021 	dma_addr_t cmd_dequeue_dma;
1022 	struct xhci_input_control_ctx *ctrl_ctx;
1023 	struct xhci_virt_device *virt_dev;
1024 	unsigned int ep_index;
1025 	struct xhci_ring *ep_ring;
1026 	unsigned int ep_state;
1027 
1028 	cmd_dma = event->cmd_trb;
1029 	cmd_dequeue_dma = xhci_trb_virt_to_dma(xhci->cmd_ring->deq_seg,
1030 			xhci->cmd_ring->dequeue);
1031 	/* Is the command ring deq ptr out of sync with the deq seg ptr? */
1032 	if (cmd_dequeue_dma == 0) {
1033 		xhci->error_bitmask |= 1 << 4;
1034 		return;
1035 	}
1036 	/* Does the DMA address match our internal dequeue pointer address? */
1037 	if (cmd_dma != (u64) cmd_dequeue_dma) {
1038 		xhci->error_bitmask |= 1 << 5;
1039 		return;
1040 	}
1041 	switch (xhci->cmd_ring->dequeue->generic.field[3] & TRB_TYPE_BITMASK) {
1042 	case TRB_TYPE(TRB_ENABLE_SLOT):
1043 		if (GET_COMP_CODE(event->status) == COMP_SUCCESS)
1044 			xhci->slot_id = slot_id;
1045 		else
1046 			xhci->slot_id = 0;
1047 		complete(&xhci->addr_dev);
1048 		break;
1049 	case TRB_TYPE(TRB_DISABLE_SLOT):
1050 		if (xhci->devs[slot_id])
1051 			xhci_free_virt_device(xhci, slot_id);
1052 		break;
1053 	case TRB_TYPE(TRB_CONFIG_EP):
1054 		virt_dev = xhci->devs[slot_id];
1055 		if (handle_cmd_in_cmd_wait_list(xhci, virt_dev, event))
1056 			break;
1057 		/*
1058 		 * Configure endpoint commands can come from the USB core
1059 		 * configuration or alt setting changes, or because the HW
1060 		 * needed an extra configure endpoint command after a reset
1061 		 * endpoint command or streams were being configured.
1062 		 * If the command was for a halted endpoint, the xHCI driver
1063 		 * is not waiting on the configure endpoint command.
1064 		 */
1065 		ctrl_ctx = xhci_get_input_control_ctx(xhci,
1066 				virt_dev->in_ctx);
1067 		/* Input ctx add_flags are the endpoint index plus one */
1068 		ep_index = xhci_last_valid_endpoint(ctrl_ctx->add_flags) - 1;
1069 		/* A usb_set_interface() call directly after clearing a halted
1070 		 * condition may race on this quirky hardware.  Not worth
1071 		 * worrying about, since this is prototype hardware.  Not sure
1072 		 * if this will work for streams, but streams support was
1073 		 * untested on this prototype.
1074 		 */
1075 		if (xhci->quirks & XHCI_RESET_EP_QUIRK &&
1076 				ep_index != (unsigned int) -1 &&
1077 				ctrl_ctx->add_flags - SLOT_FLAG ==
1078 					ctrl_ctx->drop_flags) {
1079 			ep_ring = xhci->devs[slot_id]->eps[ep_index].ring;
1080 			ep_state = xhci->devs[slot_id]->eps[ep_index].ep_state;
1081 			if (!(ep_state & EP_HALTED))
1082 				goto bandwidth_change;
1083 			xhci_dbg(xhci, "Completed config ep cmd - "
1084 					"last ep index = %d, state = %d\n",
1085 					ep_index, ep_state);
1086 			/* Clear internal halted state and restart ring(s) */
1087 			xhci->devs[slot_id]->eps[ep_index].ep_state &=
1088 				~EP_HALTED;
1089 			ring_doorbell_for_active_rings(xhci, slot_id, ep_index);
1090 			break;
1091 		}
1092 bandwidth_change:
1093 		xhci_dbg(xhci, "Completed config ep cmd\n");
1094 		xhci->devs[slot_id]->cmd_status =
1095 			GET_COMP_CODE(event->status);
1096 		complete(&xhci->devs[slot_id]->cmd_completion);
1097 		break;
1098 	case TRB_TYPE(TRB_EVAL_CONTEXT):
1099 		virt_dev = xhci->devs[slot_id];
1100 		if (handle_cmd_in_cmd_wait_list(xhci, virt_dev, event))
1101 			break;
1102 		xhci->devs[slot_id]->cmd_status = GET_COMP_CODE(event->status);
1103 		complete(&xhci->devs[slot_id]->cmd_completion);
1104 		break;
1105 	case TRB_TYPE(TRB_ADDR_DEV):
1106 		xhci->devs[slot_id]->cmd_status = GET_COMP_CODE(event->status);
1107 		complete(&xhci->addr_dev);
1108 		break;
1109 	case TRB_TYPE(TRB_STOP_RING):
1110 		handle_stopped_endpoint(xhci, xhci->cmd_ring->dequeue, event);
1111 		break;
1112 	case TRB_TYPE(TRB_SET_DEQ):
1113 		handle_set_deq_completion(xhci, event, xhci->cmd_ring->dequeue);
1114 		break;
1115 	case TRB_TYPE(TRB_CMD_NOOP):
1116 		++xhci->noops_handled;
1117 		break;
1118 	case TRB_TYPE(TRB_RESET_EP):
1119 		handle_reset_ep_completion(xhci, event, xhci->cmd_ring->dequeue);
1120 		break;
1121 	case TRB_TYPE(TRB_RESET_DEV):
1122 		xhci_dbg(xhci, "Completed reset device command.\n");
1123 		slot_id = TRB_TO_SLOT_ID(
1124 				xhci->cmd_ring->dequeue->generic.field[3]);
1125 		virt_dev = xhci->devs[slot_id];
1126 		if (virt_dev)
1127 			handle_cmd_in_cmd_wait_list(xhci, virt_dev, event);
1128 		else
1129 			xhci_warn(xhci, "Reset device command completion "
1130 					"for disabled slot %u\n", slot_id);
1131 		break;
1132 	case TRB_TYPE(TRB_NEC_GET_FW):
1133 		if (!(xhci->quirks & XHCI_NEC_HOST)) {
1134 			xhci->error_bitmask |= 1 << 6;
1135 			break;
1136 		}
1137 		xhci_dbg(xhci, "NEC firmware version %2x.%02x\n",
1138 				NEC_FW_MAJOR(event->status),
1139 				NEC_FW_MINOR(event->status));
1140 		break;
1141 	default:
1142 		/* Skip over unknown commands on the event ring */
1143 		xhci->error_bitmask |= 1 << 6;
1144 		break;
1145 	}
1146 	inc_deq(xhci, xhci->cmd_ring, false);
1147 }
1148 
1149 static void handle_vendor_event(struct xhci_hcd *xhci,
1150 		union xhci_trb *event)
1151 {
1152 	u32 trb_type;
1153 
1154 	trb_type = TRB_FIELD_TO_TYPE(event->generic.field[3]);
1155 	xhci_dbg(xhci, "Vendor specific event TRB type = %u\n", trb_type);
1156 	if (trb_type == TRB_NEC_CMD_COMP && (xhci->quirks & XHCI_NEC_HOST))
1157 		handle_cmd_completion(xhci, &event->event_cmd);
1158 }
1159 
1160 static void handle_port_status(struct xhci_hcd *xhci,
1161 		union xhci_trb *event)
1162 {
1163 	struct usb_hcd *hcd = xhci_to_hcd(xhci);
1164 	u32 port_id;
1165 	u32 temp, temp1;
1166 	u32 __iomem *addr;
1167 	int ports;
1168 	int slot_id;
1169 
1170 	/* Port status change events always have a successful completion code */
1171 	if (GET_COMP_CODE(event->generic.field[2]) != COMP_SUCCESS) {
1172 		xhci_warn(xhci, "WARN: xHC returned failed port status event\n");
1173 		xhci->error_bitmask |= 1 << 8;
1174 	}
1175 	port_id = GET_PORT_ID(event->generic.field[0]);
1176 	xhci_dbg(xhci, "Port Status Change Event for port %d\n", port_id);
1177 
1178 	ports = HCS_MAX_PORTS(xhci->hcs_params1);
1179 	if ((port_id <= 0) || (port_id > ports)) {
1180 		xhci_warn(xhci, "Invalid port id %d\n", port_id);
1181 		goto cleanup;
1182 	}
1183 
1184 	addr = &xhci->op_regs->port_status_base + NUM_PORT_REGS * (port_id - 1);
1185 	temp = xhci_readl(xhci, addr);
1186 	if (hcd->state == HC_STATE_SUSPENDED) {
1187 		xhci_dbg(xhci, "resume root hub\n");
1188 		usb_hcd_resume_root_hub(hcd);
1189 	}
1190 
1191 	if ((temp & PORT_PLC) && (temp & PORT_PLS_MASK) == XDEV_RESUME) {
1192 		xhci_dbg(xhci, "port resume event for port %d\n", port_id);
1193 
1194 		temp1 = xhci_readl(xhci, &xhci->op_regs->command);
1195 		if (!(temp1 & CMD_RUN)) {
1196 			xhci_warn(xhci, "xHC is not running.\n");
1197 			goto cleanup;
1198 		}
1199 
1200 		if (DEV_SUPERSPEED(temp)) {
1201 			xhci_dbg(xhci, "resume SS port %d\n", port_id);
1202 			temp = xhci_port_state_to_neutral(temp);
1203 			temp &= ~PORT_PLS_MASK;
1204 			temp |= PORT_LINK_STROBE | XDEV_U0;
1205 			xhci_writel(xhci, temp, addr);
1206 			slot_id = xhci_find_slot_id_by_port(xhci, port_id);
1207 			if (!slot_id) {
1208 				xhci_dbg(xhci, "slot_id is zero\n");
1209 				goto cleanup;
1210 			}
1211 			xhci_ring_device(xhci, slot_id);
1212 			xhci_dbg(xhci, "resume SS port %d finished\n", port_id);
1213 			/* Clear PORT_PLC */
1214 			temp = xhci_readl(xhci, addr);
1215 			temp = xhci_port_state_to_neutral(temp);
1216 			temp |= PORT_PLC;
1217 			xhci_writel(xhci, temp, addr);
1218 		} else {
1219 			xhci_dbg(xhci, "resume HS port %d\n", port_id);
1220 			xhci->resume_done[port_id - 1] = jiffies +
1221 				msecs_to_jiffies(20);
1222 			mod_timer(&hcd->rh_timer,
1223 				  xhci->resume_done[port_id - 1]);
1224 			/* Do the rest in GetPortStatus */
1225 		}
1226 	}
1227 
1228 cleanup:
1229 	/* Update event ring dequeue pointer before dropping the lock */
1230 	inc_deq(xhci, xhci->event_ring, true);
1231 
1232 	spin_unlock(&xhci->lock);
1233 	/* Pass this up to the core */
1234 	usb_hcd_poll_rh_status(xhci_to_hcd(xhci));
1235 	spin_lock(&xhci->lock);
1236 }
1237 
1238 /*
1239  * This TD is defined by the TRBs starting at start_trb in start_seg and ending
1240  * at end_trb, which may be in another segment.  If the suspect DMA address is a
1241  * TRB in this TD, this function returns that TRB's segment.  Otherwise it
1242  * returns 0.
1243  */
1244 struct xhci_segment *trb_in_td(struct xhci_segment *start_seg,
1245 		union xhci_trb	*start_trb,
1246 		union xhci_trb	*end_trb,
1247 		dma_addr_t	suspect_dma)
1248 {
1249 	dma_addr_t start_dma;
1250 	dma_addr_t end_seg_dma;
1251 	dma_addr_t end_trb_dma;
1252 	struct xhci_segment *cur_seg;
1253 
1254 	start_dma = xhci_trb_virt_to_dma(start_seg, start_trb);
1255 	cur_seg = start_seg;
1256 
1257 	do {
1258 		if (start_dma == 0)
1259 			return NULL;
1260 		/* We may get an event for a Link TRB in the middle of a TD */
1261 		end_seg_dma = xhci_trb_virt_to_dma(cur_seg,
1262 				&cur_seg->trbs[TRBS_PER_SEGMENT - 1]);
1263 		/* If the end TRB isn't in this segment, this is set to 0 */
1264 		end_trb_dma = xhci_trb_virt_to_dma(cur_seg, end_trb);
1265 
1266 		if (end_trb_dma > 0) {
1267 			/* The end TRB is in this segment, so suspect should be here */
1268 			if (start_dma <= end_trb_dma) {
1269 				if (suspect_dma >= start_dma && suspect_dma <= end_trb_dma)
1270 					return cur_seg;
1271 			} else {
1272 				/* Case for one segment with
1273 				 * a TD wrapped around to the top
1274 				 */
1275 				if ((suspect_dma >= start_dma &&
1276 							suspect_dma <= end_seg_dma) ||
1277 						(suspect_dma >= cur_seg->dma &&
1278 						 suspect_dma <= end_trb_dma))
1279 					return cur_seg;
1280 			}
1281 			return NULL;
1282 		} else {
1283 			/* Might still be somewhere in this segment */
1284 			if (suspect_dma >= start_dma && suspect_dma <= end_seg_dma)
1285 				return cur_seg;
1286 		}
1287 		cur_seg = cur_seg->next;
1288 		start_dma = xhci_trb_virt_to_dma(cur_seg, &cur_seg->trbs[0]);
1289 	} while (cur_seg != start_seg);
1290 
1291 	return NULL;
1292 }
1293 
1294 static void xhci_cleanup_halted_endpoint(struct xhci_hcd *xhci,
1295 		unsigned int slot_id, unsigned int ep_index,
1296 		unsigned int stream_id,
1297 		struct xhci_td *td, union xhci_trb *event_trb)
1298 {
1299 	struct xhci_virt_ep *ep = &xhci->devs[slot_id]->eps[ep_index];
1300 	ep->ep_state |= EP_HALTED;
1301 	ep->stopped_td = td;
1302 	ep->stopped_trb = event_trb;
1303 	ep->stopped_stream = stream_id;
1304 
1305 	xhci_queue_reset_ep(xhci, slot_id, ep_index);
1306 	xhci_cleanup_stalled_ring(xhci, td->urb->dev, ep_index);
1307 
1308 	ep->stopped_td = NULL;
1309 	ep->stopped_trb = NULL;
1310 	ep->stopped_stream = 0;
1311 
1312 	xhci_ring_cmd_db(xhci);
1313 }
1314 
1315 /* Check if an error has halted the endpoint ring.  The class driver will
1316  * cleanup the halt for a non-default control endpoint if we indicate a stall.
1317  * However, a babble and other errors also halt the endpoint ring, and the class
1318  * driver won't clear the halt in that case, so we need to issue a Set Transfer
1319  * Ring Dequeue Pointer command manually.
1320  */
1321 static int xhci_requires_manual_halt_cleanup(struct xhci_hcd *xhci,
1322 		struct xhci_ep_ctx *ep_ctx,
1323 		unsigned int trb_comp_code)
1324 {
1325 	/* TRB completion codes that may require a manual halt cleanup */
1326 	if (trb_comp_code == COMP_TX_ERR ||
1327 			trb_comp_code == COMP_BABBLE ||
1328 			trb_comp_code == COMP_SPLIT_ERR)
1329 		/* The 0.96 spec says a babbling control endpoint
1330 		 * is not halted. The 0.96 spec says it is.  Some HW
1331 		 * claims to be 0.95 compliant, but it halts the control
1332 		 * endpoint anyway.  Check if a babble halted the
1333 		 * endpoint.
1334 		 */
1335 		if ((ep_ctx->ep_info & EP_STATE_MASK) == EP_STATE_HALTED)
1336 			return 1;
1337 
1338 	return 0;
1339 }
1340 
1341 int xhci_is_vendor_info_code(struct xhci_hcd *xhci, unsigned int trb_comp_code)
1342 {
1343 	if (trb_comp_code >= 224 && trb_comp_code <= 255) {
1344 		/* Vendor defined "informational" completion code,
1345 		 * treat as not-an-error.
1346 		 */
1347 		xhci_dbg(xhci, "Vendor defined info completion code %u\n",
1348 				trb_comp_code);
1349 		xhci_dbg(xhci, "Treating code as success.\n");
1350 		return 1;
1351 	}
1352 	return 0;
1353 }
1354 
1355 /*
1356  * Finish the td processing, remove the td from td list;
1357  * Return 1 if the urb can be given back.
1358  */
1359 static int finish_td(struct xhci_hcd *xhci, struct xhci_td *td,
1360 	union xhci_trb *event_trb, struct xhci_transfer_event *event,
1361 	struct xhci_virt_ep *ep, int *status, bool skip)
1362 {
1363 	struct xhci_virt_device *xdev;
1364 	struct xhci_ring *ep_ring;
1365 	unsigned int slot_id;
1366 	int ep_index;
1367 	struct urb *urb = NULL;
1368 	struct xhci_ep_ctx *ep_ctx;
1369 	int ret = 0;
1370 	struct urb_priv	*urb_priv;
1371 	u32 trb_comp_code;
1372 
1373 	slot_id = TRB_TO_SLOT_ID(event->flags);
1374 	xdev = xhci->devs[slot_id];
1375 	ep_index = TRB_TO_EP_ID(event->flags) - 1;
1376 	ep_ring = xhci_dma_to_transfer_ring(ep, event->buffer);
1377 	ep_ctx = xhci_get_ep_ctx(xhci, xdev->out_ctx, ep_index);
1378 	trb_comp_code = GET_COMP_CODE(event->transfer_len);
1379 
1380 	if (skip)
1381 		goto td_cleanup;
1382 
1383 	if (trb_comp_code == COMP_STOP_INVAL ||
1384 			trb_comp_code == COMP_STOP) {
1385 		/* The Endpoint Stop Command completion will take care of any
1386 		 * stopped TDs.  A stopped TD may be restarted, so don't update
1387 		 * the ring dequeue pointer or take this TD off any lists yet.
1388 		 */
1389 		ep->stopped_td = td;
1390 		ep->stopped_trb = event_trb;
1391 		return 0;
1392 	} else {
1393 		if (trb_comp_code == COMP_STALL) {
1394 			/* The transfer is completed from the driver's
1395 			 * perspective, but we need to issue a set dequeue
1396 			 * command for this stalled endpoint to move the dequeue
1397 			 * pointer past the TD.  We can't do that here because
1398 			 * the halt condition must be cleared first.  Let the
1399 			 * USB class driver clear the stall later.
1400 			 */
1401 			ep->stopped_td = td;
1402 			ep->stopped_trb = event_trb;
1403 			ep->stopped_stream = ep_ring->stream_id;
1404 		} else if (xhci_requires_manual_halt_cleanup(xhci,
1405 					ep_ctx, trb_comp_code)) {
1406 			/* Other types of errors halt the endpoint, but the
1407 			 * class driver doesn't call usb_reset_endpoint() unless
1408 			 * the error is -EPIPE.  Clear the halted status in the
1409 			 * xHCI hardware manually.
1410 			 */
1411 			xhci_cleanup_halted_endpoint(xhci,
1412 					slot_id, ep_index, ep_ring->stream_id,
1413 					td, event_trb);
1414 		} else {
1415 			/* Update ring dequeue pointer */
1416 			while (ep_ring->dequeue != td->last_trb)
1417 				inc_deq(xhci, ep_ring, false);
1418 			inc_deq(xhci, ep_ring, false);
1419 		}
1420 
1421 td_cleanup:
1422 		/* Clean up the endpoint's TD list */
1423 		urb = td->urb;
1424 		urb_priv = urb->hcpriv;
1425 
1426 		/* Do one last check of the actual transfer length.
1427 		 * If the host controller said we transferred more data than
1428 		 * the buffer length, urb->actual_length will be a very big
1429 		 * number (since it's unsigned).  Play it safe and say we didn't
1430 		 * transfer anything.
1431 		 */
1432 		if (urb->actual_length > urb->transfer_buffer_length) {
1433 			xhci_warn(xhci, "URB transfer length is wrong, "
1434 					"xHC issue? req. len = %u, "
1435 					"act. len = %u\n",
1436 					urb->transfer_buffer_length,
1437 					urb->actual_length);
1438 			urb->actual_length = 0;
1439 			if (td->urb->transfer_flags & URB_SHORT_NOT_OK)
1440 				*status = -EREMOTEIO;
1441 			else
1442 				*status = 0;
1443 		}
1444 		list_del(&td->td_list);
1445 		/* Was this TD slated to be cancelled but completed anyway? */
1446 		if (!list_empty(&td->cancelled_td_list))
1447 			list_del(&td->cancelled_td_list);
1448 
1449 		urb_priv->td_cnt++;
1450 		/* Giveback the urb when all the tds are completed */
1451 		if (urb_priv->td_cnt == urb_priv->length)
1452 			ret = 1;
1453 	}
1454 
1455 	return ret;
1456 }
1457 
1458 /*
1459  * Process control tds, update urb status and actual_length.
1460  */
1461 static int process_ctrl_td(struct xhci_hcd *xhci, struct xhci_td *td,
1462 	union xhci_trb *event_trb, struct xhci_transfer_event *event,
1463 	struct xhci_virt_ep *ep, int *status)
1464 {
1465 	struct xhci_virt_device *xdev;
1466 	struct xhci_ring *ep_ring;
1467 	unsigned int slot_id;
1468 	int ep_index;
1469 	struct xhci_ep_ctx *ep_ctx;
1470 	u32 trb_comp_code;
1471 
1472 	slot_id = TRB_TO_SLOT_ID(event->flags);
1473 	xdev = xhci->devs[slot_id];
1474 	ep_index = TRB_TO_EP_ID(event->flags) - 1;
1475 	ep_ring = xhci_dma_to_transfer_ring(ep, event->buffer);
1476 	ep_ctx = xhci_get_ep_ctx(xhci, xdev->out_ctx, ep_index);
1477 	trb_comp_code = GET_COMP_CODE(event->transfer_len);
1478 
1479 	xhci_debug_trb(xhci, xhci->event_ring->dequeue);
1480 	switch (trb_comp_code) {
1481 	case COMP_SUCCESS:
1482 		if (event_trb == ep_ring->dequeue) {
1483 			xhci_warn(xhci, "WARN: Success on ctrl setup TRB "
1484 					"without IOC set??\n");
1485 			*status = -ESHUTDOWN;
1486 		} else if (event_trb != td->last_trb) {
1487 			xhci_warn(xhci, "WARN: Success on ctrl data TRB "
1488 					"without IOC set??\n");
1489 			*status = -ESHUTDOWN;
1490 		} else {
1491 			xhci_dbg(xhci, "Successful control transfer!\n");
1492 			*status = 0;
1493 		}
1494 		break;
1495 	case COMP_SHORT_TX:
1496 		xhci_warn(xhci, "WARN: short transfer on control ep\n");
1497 		if (td->urb->transfer_flags & URB_SHORT_NOT_OK)
1498 			*status = -EREMOTEIO;
1499 		else
1500 			*status = 0;
1501 		break;
1502 	default:
1503 		if (!xhci_requires_manual_halt_cleanup(xhci,
1504 					ep_ctx, trb_comp_code))
1505 			break;
1506 		xhci_dbg(xhci, "TRB error code %u, "
1507 				"halted endpoint index = %u\n",
1508 				trb_comp_code, ep_index);
1509 		/* else fall through */
1510 	case COMP_STALL:
1511 		/* Did we transfer part of the data (middle) phase? */
1512 		if (event_trb != ep_ring->dequeue &&
1513 				event_trb != td->last_trb)
1514 			td->urb->actual_length =
1515 				td->urb->transfer_buffer_length
1516 				- TRB_LEN(event->transfer_len);
1517 		else
1518 			td->urb->actual_length = 0;
1519 
1520 		xhci_cleanup_halted_endpoint(xhci,
1521 			slot_id, ep_index, 0, td, event_trb);
1522 		return finish_td(xhci, td, event_trb, event, ep, status, true);
1523 	}
1524 	/*
1525 	 * Did we transfer any data, despite the errors that might have
1526 	 * happened?  I.e. did we get past the setup stage?
1527 	 */
1528 	if (event_trb != ep_ring->dequeue) {
1529 		/* The event was for the status stage */
1530 		if (event_trb == td->last_trb) {
1531 			if (td->urb->actual_length != 0) {
1532 				/* Don't overwrite a previously set error code
1533 				 */
1534 				if ((*status == -EINPROGRESS || *status == 0) &&
1535 						(td->urb->transfer_flags
1536 						 & URB_SHORT_NOT_OK))
1537 					/* Did we already see a short data
1538 					 * stage? */
1539 					*status = -EREMOTEIO;
1540 			} else {
1541 				td->urb->actual_length =
1542 					td->urb->transfer_buffer_length;
1543 			}
1544 		} else {
1545 		/* Maybe the event was for the data stage? */
1546 			if (trb_comp_code != COMP_STOP_INVAL) {
1547 				/* We didn't stop on a link TRB in the middle */
1548 				td->urb->actual_length =
1549 					td->urb->transfer_buffer_length -
1550 					TRB_LEN(event->transfer_len);
1551 				xhci_dbg(xhci, "Waiting for status "
1552 						"stage event\n");
1553 				return 0;
1554 			}
1555 		}
1556 	}
1557 
1558 	return finish_td(xhci, td, event_trb, event, ep, status, false);
1559 }
1560 
1561 /*
1562  * Process isochronous tds, update urb packet status and actual_length.
1563  */
1564 static int process_isoc_td(struct xhci_hcd *xhci, struct xhci_td *td,
1565 	union xhci_trb *event_trb, struct xhci_transfer_event *event,
1566 	struct xhci_virt_ep *ep, int *status)
1567 {
1568 	struct xhci_ring *ep_ring;
1569 	struct urb_priv *urb_priv;
1570 	int idx;
1571 	int len = 0;
1572 	int skip_td = 0;
1573 	union xhci_trb *cur_trb;
1574 	struct xhci_segment *cur_seg;
1575 	u32 trb_comp_code;
1576 
1577 	ep_ring = xhci_dma_to_transfer_ring(ep, event->buffer);
1578 	trb_comp_code = GET_COMP_CODE(event->transfer_len);
1579 	urb_priv = td->urb->hcpriv;
1580 	idx = urb_priv->td_cnt;
1581 
1582 	if (ep->skip) {
1583 		/* The transfer is partly done */
1584 		*status = -EXDEV;
1585 		td->urb->iso_frame_desc[idx].status = -EXDEV;
1586 	} else {
1587 		/* handle completion code */
1588 		switch (trb_comp_code) {
1589 		case COMP_SUCCESS:
1590 			td->urb->iso_frame_desc[idx].status = 0;
1591 			xhci_dbg(xhci, "Successful isoc transfer!\n");
1592 			break;
1593 		case COMP_SHORT_TX:
1594 			if (td->urb->transfer_flags & URB_SHORT_NOT_OK)
1595 				td->urb->iso_frame_desc[idx].status =
1596 					 -EREMOTEIO;
1597 			else
1598 				td->urb->iso_frame_desc[idx].status = 0;
1599 			break;
1600 		case COMP_BW_OVER:
1601 			td->urb->iso_frame_desc[idx].status = -ECOMM;
1602 			skip_td = 1;
1603 			break;
1604 		case COMP_BUFF_OVER:
1605 		case COMP_BABBLE:
1606 			td->urb->iso_frame_desc[idx].status = -EOVERFLOW;
1607 			skip_td = 1;
1608 			break;
1609 		case COMP_STALL:
1610 			td->urb->iso_frame_desc[idx].status = -EPROTO;
1611 			skip_td = 1;
1612 			break;
1613 		case COMP_STOP:
1614 		case COMP_STOP_INVAL:
1615 			break;
1616 		default:
1617 			td->urb->iso_frame_desc[idx].status = -1;
1618 			break;
1619 		}
1620 	}
1621 
1622 	/* calc actual length */
1623 	if (ep->skip) {
1624 		td->urb->iso_frame_desc[idx].actual_length = 0;
1625 		/* Update ring dequeue pointer */
1626 		while (ep_ring->dequeue != td->last_trb)
1627 			inc_deq(xhci, ep_ring, false);
1628 		inc_deq(xhci, ep_ring, false);
1629 		return finish_td(xhci, td, event_trb, event, ep, status, true);
1630 	}
1631 
1632 	if (trb_comp_code == COMP_SUCCESS || skip_td == 1) {
1633 		td->urb->iso_frame_desc[idx].actual_length =
1634 			td->urb->iso_frame_desc[idx].length;
1635 		td->urb->actual_length +=
1636 			td->urb->iso_frame_desc[idx].length;
1637 	} else {
1638 		for (cur_trb = ep_ring->dequeue,
1639 		     cur_seg = ep_ring->deq_seg; cur_trb != event_trb;
1640 		     next_trb(xhci, ep_ring, &cur_seg, &cur_trb)) {
1641 			if ((cur_trb->generic.field[3] &
1642 			 TRB_TYPE_BITMASK) != TRB_TYPE(TRB_TR_NOOP) &&
1643 			    (cur_trb->generic.field[3] &
1644 			 TRB_TYPE_BITMASK) != TRB_TYPE(TRB_LINK))
1645 				len +=
1646 				    TRB_LEN(cur_trb->generic.field[2]);
1647 		}
1648 		len += TRB_LEN(cur_trb->generic.field[2]) -
1649 			TRB_LEN(event->transfer_len);
1650 
1651 		if (trb_comp_code != COMP_STOP_INVAL) {
1652 			td->urb->iso_frame_desc[idx].actual_length = len;
1653 			td->urb->actual_length += len;
1654 		}
1655 	}
1656 
1657 	if ((idx == urb_priv->length - 1) && *status == -EINPROGRESS)
1658 		*status = 0;
1659 
1660 	return finish_td(xhci, td, event_trb, event, ep, status, false);
1661 }
1662 
1663 /*
1664  * Process bulk and interrupt tds, update urb status and actual_length.
1665  */
1666 static int process_bulk_intr_td(struct xhci_hcd *xhci, struct xhci_td *td,
1667 	union xhci_trb *event_trb, struct xhci_transfer_event *event,
1668 	struct xhci_virt_ep *ep, int *status)
1669 {
1670 	struct xhci_ring *ep_ring;
1671 	union xhci_trb *cur_trb;
1672 	struct xhci_segment *cur_seg;
1673 	u32 trb_comp_code;
1674 
1675 	ep_ring = xhci_dma_to_transfer_ring(ep, event->buffer);
1676 	trb_comp_code = GET_COMP_CODE(event->transfer_len);
1677 
1678 	switch (trb_comp_code) {
1679 	case COMP_SUCCESS:
1680 		/* Double check that the HW transferred everything. */
1681 		if (event_trb != td->last_trb) {
1682 			xhci_warn(xhci, "WARN Successful completion "
1683 					"on short TX\n");
1684 			if (td->urb->transfer_flags & URB_SHORT_NOT_OK)
1685 				*status = -EREMOTEIO;
1686 			else
1687 				*status = 0;
1688 		} else {
1689 			if (usb_endpoint_xfer_bulk(&td->urb->ep->desc))
1690 				xhci_dbg(xhci, "Successful bulk "
1691 						"transfer!\n");
1692 			else
1693 				xhci_dbg(xhci, "Successful interrupt "
1694 						"transfer!\n");
1695 			*status = 0;
1696 		}
1697 		break;
1698 	case COMP_SHORT_TX:
1699 		if (td->urb->transfer_flags & URB_SHORT_NOT_OK)
1700 			*status = -EREMOTEIO;
1701 		else
1702 			*status = 0;
1703 		break;
1704 	default:
1705 		/* Others already handled above */
1706 		break;
1707 	}
1708 	xhci_dbg(xhci, "ep %#x - asked for %d bytes, "
1709 			"%d bytes untransferred\n",
1710 			td->urb->ep->desc.bEndpointAddress,
1711 			td->urb->transfer_buffer_length,
1712 			TRB_LEN(event->transfer_len));
1713 	/* Fast path - was this the last TRB in the TD for this URB? */
1714 	if (event_trb == td->last_trb) {
1715 		if (TRB_LEN(event->transfer_len) != 0) {
1716 			td->urb->actual_length =
1717 				td->urb->transfer_buffer_length -
1718 				TRB_LEN(event->transfer_len);
1719 			if (td->urb->transfer_buffer_length <
1720 					td->urb->actual_length) {
1721 				xhci_warn(xhci, "HC gave bad length "
1722 						"of %d bytes left\n",
1723 						TRB_LEN(event->transfer_len));
1724 				td->urb->actual_length = 0;
1725 				if (td->urb->transfer_flags & URB_SHORT_NOT_OK)
1726 					*status = -EREMOTEIO;
1727 				else
1728 					*status = 0;
1729 			}
1730 			/* Don't overwrite a previously set error code */
1731 			if (*status == -EINPROGRESS) {
1732 				if (td->urb->transfer_flags & URB_SHORT_NOT_OK)
1733 					*status = -EREMOTEIO;
1734 				else
1735 					*status = 0;
1736 			}
1737 		} else {
1738 			td->urb->actual_length =
1739 				td->urb->transfer_buffer_length;
1740 			/* Ignore a short packet completion if the
1741 			 * untransferred length was zero.
1742 			 */
1743 			if (*status == -EREMOTEIO)
1744 				*status = 0;
1745 		}
1746 	} else {
1747 		/* Slow path - walk the list, starting from the dequeue
1748 		 * pointer, to get the actual length transferred.
1749 		 */
1750 		td->urb->actual_length = 0;
1751 		for (cur_trb = ep_ring->dequeue, cur_seg = ep_ring->deq_seg;
1752 				cur_trb != event_trb;
1753 				next_trb(xhci, ep_ring, &cur_seg, &cur_trb)) {
1754 			if ((cur_trb->generic.field[3] &
1755 			 TRB_TYPE_BITMASK) != TRB_TYPE(TRB_TR_NOOP) &&
1756 			    (cur_trb->generic.field[3] &
1757 			 TRB_TYPE_BITMASK) != TRB_TYPE(TRB_LINK))
1758 				td->urb->actual_length +=
1759 					TRB_LEN(cur_trb->generic.field[2]);
1760 		}
1761 		/* If the ring didn't stop on a Link or No-op TRB, add
1762 		 * in the actual bytes transferred from the Normal TRB
1763 		 */
1764 		if (trb_comp_code != COMP_STOP_INVAL)
1765 			td->urb->actual_length +=
1766 				TRB_LEN(cur_trb->generic.field[2]) -
1767 				TRB_LEN(event->transfer_len);
1768 	}
1769 
1770 	return finish_td(xhci, td, event_trb, event, ep, status, false);
1771 }
1772 
1773 /*
1774  * If this function returns an error condition, it means it got a Transfer
1775  * event with a corrupted Slot ID, Endpoint ID, or TRB DMA address.
1776  * At this point, the host controller is probably hosed and should be reset.
1777  */
1778 static int handle_tx_event(struct xhci_hcd *xhci,
1779 		struct xhci_transfer_event *event)
1780 {
1781 	struct xhci_virt_device *xdev;
1782 	struct xhci_virt_ep *ep;
1783 	struct xhci_ring *ep_ring;
1784 	unsigned int slot_id;
1785 	int ep_index;
1786 	struct xhci_td *td = NULL;
1787 	dma_addr_t event_dma;
1788 	struct xhci_segment *event_seg;
1789 	union xhci_trb *event_trb;
1790 	struct urb *urb = NULL;
1791 	int status = -EINPROGRESS;
1792 	struct urb_priv *urb_priv;
1793 	struct xhci_ep_ctx *ep_ctx;
1794 	u32 trb_comp_code;
1795 	int ret = 0;
1796 
1797 	slot_id = TRB_TO_SLOT_ID(event->flags);
1798 	xdev = xhci->devs[slot_id];
1799 	if (!xdev) {
1800 		xhci_err(xhci, "ERROR Transfer event pointed to bad slot\n");
1801 		return -ENODEV;
1802 	}
1803 
1804 	/* Endpoint ID is 1 based, our index is zero based */
1805 	ep_index = TRB_TO_EP_ID(event->flags) - 1;
1806 	xhci_dbg(xhci, "%s - ep index = %d\n", __func__, ep_index);
1807 	ep = &xdev->eps[ep_index];
1808 	ep_ring = xhci_dma_to_transfer_ring(ep, event->buffer);
1809 	ep_ctx = xhci_get_ep_ctx(xhci, xdev->out_ctx, ep_index);
1810 	if (!ep_ring ||
1811 		(ep_ctx->ep_info & EP_STATE_MASK) == EP_STATE_DISABLED) {
1812 		xhci_err(xhci, "ERROR Transfer event for disabled endpoint "
1813 				"or incorrect stream ring\n");
1814 		return -ENODEV;
1815 	}
1816 
1817 	event_dma = event->buffer;
1818 	trb_comp_code = GET_COMP_CODE(event->transfer_len);
1819 	/* Look for common error cases */
1820 	switch (trb_comp_code) {
1821 	/* Skip codes that require special handling depending on
1822 	 * transfer type
1823 	 */
1824 	case COMP_SUCCESS:
1825 	case COMP_SHORT_TX:
1826 		break;
1827 	case COMP_STOP:
1828 		xhci_dbg(xhci, "Stopped on Transfer TRB\n");
1829 		break;
1830 	case COMP_STOP_INVAL:
1831 		xhci_dbg(xhci, "Stopped on No-op or Link TRB\n");
1832 		break;
1833 	case COMP_STALL:
1834 		xhci_warn(xhci, "WARN: Stalled endpoint\n");
1835 		ep->ep_state |= EP_HALTED;
1836 		status = -EPIPE;
1837 		break;
1838 	case COMP_TRB_ERR:
1839 		xhci_warn(xhci, "WARN: TRB error on endpoint\n");
1840 		status = -EILSEQ;
1841 		break;
1842 	case COMP_SPLIT_ERR:
1843 	case COMP_TX_ERR:
1844 		xhci_warn(xhci, "WARN: transfer error on endpoint\n");
1845 		status = -EPROTO;
1846 		break;
1847 	case COMP_BABBLE:
1848 		xhci_warn(xhci, "WARN: babble error on endpoint\n");
1849 		status = -EOVERFLOW;
1850 		break;
1851 	case COMP_DB_ERR:
1852 		xhci_warn(xhci, "WARN: HC couldn't access mem fast enough\n");
1853 		status = -ENOSR;
1854 		break;
1855 	case COMP_BW_OVER:
1856 		xhci_warn(xhci, "WARN: bandwidth overrun event on endpoint\n");
1857 		break;
1858 	case COMP_BUFF_OVER:
1859 		xhci_warn(xhci, "WARN: buffer overrun event on endpoint\n");
1860 		break;
1861 	case COMP_UNDERRUN:
1862 		/*
1863 		 * When the Isoch ring is empty, the xHC will generate
1864 		 * a Ring Overrun Event for IN Isoch endpoint or Ring
1865 		 * Underrun Event for OUT Isoch endpoint.
1866 		 */
1867 		xhci_dbg(xhci, "underrun event on endpoint\n");
1868 		if (!list_empty(&ep_ring->td_list))
1869 			xhci_dbg(xhci, "Underrun Event for slot %d ep %d "
1870 					"still with TDs queued?\n",
1871 				TRB_TO_SLOT_ID(event->flags), ep_index);
1872 		goto cleanup;
1873 	case COMP_OVERRUN:
1874 		xhci_dbg(xhci, "overrun event on endpoint\n");
1875 		if (!list_empty(&ep_ring->td_list))
1876 			xhci_dbg(xhci, "Overrun Event for slot %d ep %d "
1877 					"still with TDs queued?\n",
1878 				TRB_TO_SLOT_ID(event->flags), ep_index);
1879 		goto cleanup;
1880 	case COMP_MISSED_INT:
1881 		/*
1882 		 * When encounter missed service error, one or more isoc tds
1883 		 * may be missed by xHC.
1884 		 * Set skip flag of the ep_ring; Complete the missed tds as
1885 		 * short transfer when process the ep_ring next time.
1886 		 */
1887 		ep->skip = true;
1888 		xhci_dbg(xhci, "Miss service interval error, set skip flag\n");
1889 		goto cleanup;
1890 	default:
1891 		if (xhci_is_vendor_info_code(xhci, trb_comp_code)) {
1892 			status = 0;
1893 			break;
1894 		}
1895 		xhci_warn(xhci, "ERROR Unknown event condition, HC probably "
1896 				"busted\n");
1897 		goto cleanup;
1898 	}
1899 
1900 	do {
1901 		/* This TRB should be in the TD at the head of this ring's
1902 		 * TD list.
1903 		 */
1904 		if (list_empty(&ep_ring->td_list)) {
1905 			xhci_warn(xhci, "WARN Event TRB for slot %d ep %d "
1906 					"with no TDs queued?\n",
1907 				  TRB_TO_SLOT_ID(event->flags), ep_index);
1908 			xhci_dbg(xhci, "Event TRB with TRB type ID %u\n",
1909 			  (unsigned int) (event->flags & TRB_TYPE_BITMASK)>>10);
1910 			xhci_print_trb_offsets(xhci, (union xhci_trb *) event);
1911 			if (ep->skip) {
1912 				ep->skip = false;
1913 				xhci_dbg(xhci, "td_list is empty while skip "
1914 						"flag set. Clear skip flag.\n");
1915 			}
1916 			ret = 0;
1917 			goto cleanup;
1918 		}
1919 
1920 		td = list_entry(ep_ring->td_list.next, struct xhci_td, td_list);
1921 		/* Is this a TRB in the currently executing TD? */
1922 		event_seg = trb_in_td(ep_ring->deq_seg, ep_ring->dequeue,
1923 				td->last_trb, event_dma);
1924 		if (event_seg && ep->skip) {
1925 			xhci_dbg(xhci, "Found td. Clear skip flag.\n");
1926 			ep->skip = false;
1927 		}
1928 		if (!event_seg &&
1929 		   (!ep->skip || !usb_endpoint_xfer_isoc(&td->urb->ep->desc))) {
1930 			/* HC is busted, give up! */
1931 			xhci_err(xhci, "ERROR Transfer event TRB DMA ptr not "
1932 					"part of current TD\n");
1933 			return -ESHUTDOWN;
1934 		}
1935 
1936 		if (event_seg) {
1937 			event_trb = &event_seg->trbs[(event_dma -
1938 					 event_seg->dma) / sizeof(*event_trb)];
1939 			/*
1940 			 * No-op TRB should not trigger interrupts.
1941 			 * If event_trb is a no-op TRB, it means the
1942 			 * corresponding TD has been cancelled. Just ignore
1943 			 * the TD.
1944 			 */
1945 			if ((event_trb->generic.field[3] & TRB_TYPE_BITMASK)
1946 					 == TRB_TYPE(TRB_TR_NOOP)) {
1947 				xhci_dbg(xhci, "event_trb is a no-op TRB. "
1948 						"Skip it\n");
1949 				goto cleanup;
1950 			}
1951 		}
1952 
1953 		/* Now update the urb's actual_length and give back to
1954 		 * the core
1955 		 */
1956 		if (usb_endpoint_xfer_control(&td->urb->ep->desc))
1957 			ret = process_ctrl_td(xhci, td, event_trb, event, ep,
1958 						 &status);
1959 		else if (usb_endpoint_xfer_isoc(&td->urb->ep->desc))
1960 			ret = process_isoc_td(xhci, td, event_trb, event, ep,
1961 						 &status);
1962 		else
1963 			ret = process_bulk_intr_td(xhci, td, event_trb, event,
1964 						 ep, &status);
1965 
1966 cleanup:
1967 		/*
1968 		 * Do not update event ring dequeue pointer if ep->skip is set.
1969 		 * Will roll back to continue process missed tds.
1970 		 */
1971 		if (trb_comp_code == COMP_MISSED_INT || !ep->skip) {
1972 			inc_deq(xhci, xhci->event_ring, true);
1973 		}
1974 
1975 		if (ret) {
1976 			urb = td->urb;
1977 			urb_priv = urb->hcpriv;
1978 			/* Leave the TD around for the reset endpoint function
1979 			 * to use(but only if it's not a control endpoint,
1980 			 * since we already queued the Set TR dequeue pointer
1981 			 * command for stalled control endpoints).
1982 			 */
1983 			if (usb_endpoint_xfer_control(&urb->ep->desc) ||
1984 				(trb_comp_code != COMP_STALL &&
1985 					trb_comp_code != COMP_BABBLE))
1986 				xhci_urb_free_priv(xhci, urb_priv);
1987 
1988 			usb_hcd_unlink_urb_from_ep(xhci_to_hcd(xhci), urb);
1989 			xhci_dbg(xhci, "Giveback URB %p, len = %d, "
1990 					"status = %d\n",
1991 					urb, urb->actual_length, status);
1992 			spin_unlock(&xhci->lock);
1993 			usb_hcd_giveback_urb(xhci_to_hcd(xhci), urb, status);
1994 			spin_lock(&xhci->lock);
1995 		}
1996 
1997 	/*
1998 	 * If ep->skip is set, it means there are missed tds on the
1999 	 * endpoint ring need to take care of.
2000 	 * Process them as short transfer until reach the td pointed by
2001 	 * the event.
2002 	 */
2003 	} while (ep->skip && trb_comp_code != COMP_MISSED_INT);
2004 
2005 	return 0;
2006 }
2007 
2008 /*
2009  * This function handles all OS-owned events on the event ring.  It may drop
2010  * xhci->lock between event processing (e.g. to pass up port status changes).
2011  */
2012 static void xhci_handle_event(struct xhci_hcd *xhci)
2013 {
2014 	union xhci_trb *event;
2015 	int update_ptrs = 1;
2016 	int ret;
2017 
2018 	xhci_dbg(xhci, "In %s\n", __func__);
2019 	if (!xhci->event_ring || !xhci->event_ring->dequeue) {
2020 		xhci->error_bitmask |= 1 << 1;
2021 		return;
2022 	}
2023 
2024 	event = xhci->event_ring->dequeue;
2025 	/* Does the HC or OS own the TRB? */
2026 	if ((event->event_cmd.flags & TRB_CYCLE) !=
2027 			xhci->event_ring->cycle_state) {
2028 		xhci->error_bitmask |= 1 << 2;
2029 		return;
2030 	}
2031 	xhci_dbg(xhci, "%s - OS owns TRB\n", __func__);
2032 
2033 	/* FIXME: Handle more event types. */
2034 	switch ((event->event_cmd.flags & TRB_TYPE_BITMASK)) {
2035 	case TRB_TYPE(TRB_COMPLETION):
2036 		xhci_dbg(xhci, "%s - calling handle_cmd_completion\n", __func__);
2037 		handle_cmd_completion(xhci, &event->event_cmd);
2038 		xhci_dbg(xhci, "%s - returned from handle_cmd_completion\n", __func__);
2039 		break;
2040 	case TRB_TYPE(TRB_PORT_STATUS):
2041 		xhci_dbg(xhci, "%s - calling handle_port_status\n", __func__);
2042 		handle_port_status(xhci, event);
2043 		xhci_dbg(xhci, "%s - returned from handle_port_status\n", __func__);
2044 		update_ptrs = 0;
2045 		break;
2046 	case TRB_TYPE(TRB_TRANSFER):
2047 		xhci_dbg(xhci, "%s - calling handle_tx_event\n", __func__);
2048 		ret = handle_tx_event(xhci, &event->trans_event);
2049 		xhci_dbg(xhci, "%s - returned from handle_tx_event\n", __func__);
2050 		if (ret < 0)
2051 			xhci->error_bitmask |= 1 << 9;
2052 		else
2053 			update_ptrs = 0;
2054 		break;
2055 	default:
2056 		if ((event->event_cmd.flags & TRB_TYPE_BITMASK) >= TRB_TYPE(48))
2057 			handle_vendor_event(xhci, event);
2058 		else
2059 			xhci->error_bitmask |= 1 << 3;
2060 	}
2061 	/* Any of the above functions may drop and re-acquire the lock, so check
2062 	 * to make sure a watchdog timer didn't mark the host as non-responsive.
2063 	 */
2064 	if (xhci->xhc_state & XHCI_STATE_DYING) {
2065 		xhci_dbg(xhci, "xHCI host dying, returning from "
2066 				"event handler.\n");
2067 		return;
2068 	}
2069 
2070 	if (update_ptrs)
2071 		/* Update SW event ring dequeue pointer */
2072 		inc_deq(xhci, xhci->event_ring, true);
2073 
2074 	/* Are there more items on the event ring? */
2075 	xhci_handle_event(xhci);
2076 }
2077 
2078 /*
2079  * xHCI spec says we can get an interrupt, and if the HC has an error condition,
2080  * we might get bad data out of the event ring.  Section 4.10.2.7 has a list of
2081  * indicators of an event TRB error, but we check the status *first* to be safe.
2082  */
2083 irqreturn_t xhci_irq(struct usb_hcd *hcd)
2084 {
2085 	struct xhci_hcd *xhci = hcd_to_xhci(hcd);
2086 	u32 status;
2087 	union xhci_trb *trb;
2088 	u64 temp_64;
2089 	union xhci_trb *event_ring_deq;
2090 	dma_addr_t deq;
2091 
2092 	spin_lock(&xhci->lock);
2093 	trb = xhci->event_ring->dequeue;
2094 	/* Check if the xHC generated the interrupt, or the irq is shared */
2095 	status = xhci_readl(xhci, &xhci->op_regs->status);
2096 	if (status == 0xffffffff)
2097 		goto hw_died;
2098 
2099 	if (!(status & STS_EINT)) {
2100 		spin_unlock(&xhci->lock);
2101 		return IRQ_NONE;
2102 	}
2103 	xhci_dbg(xhci, "op reg status = %08x\n", status);
2104 	xhci_dbg(xhci, "Event ring dequeue ptr:\n");
2105 	xhci_dbg(xhci, "@%llx %08x %08x %08x %08x\n",
2106 			(unsigned long long)
2107 			xhci_trb_virt_to_dma(xhci->event_ring->deq_seg, trb),
2108 			lower_32_bits(trb->link.segment_ptr),
2109 			upper_32_bits(trb->link.segment_ptr),
2110 			(unsigned int) trb->link.intr_target,
2111 			(unsigned int) trb->link.control);
2112 
2113 	if (status & STS_FATAL) {
2114 		xhci_warn(xhci, "WARNING: Host System Error\n");
2115 		xhci_halt(xhci);
2116 hw_died:
2117 		xhci_to_hcd(xhci)->state = HC_STATE_HALT;
2118 		spin_unlock(&xhci->lock);
2119 		return -ESHUTDOWN;
2120 	}
2121 
2122 	/*
2123 	 * Clear the op reg interrupt status first,
2124 	 * so we can receive interrupts from other MSI-X interrupters.
2125 	 * Write 1 to clear the interrupt status.
2126 	 */
2127 	status |= STS_EINT;
2128 	xhci_writel(xhci, status, &xhci->op_regs->status);
2129 	/* FIXME when MSI-X is supported and there are multiple vectors */
2130 	/* Clear the MSI-X event interrupt status */
2131 
2132 	if (hcd->irq != -1) {
2133 		u32 irq_pending;
2134 		/* Acknowledge the PCI interrupt */
2135 		irq_pending = xhci_readl(xhci, &xhci->ir_set->irq_pending);
2136 		irq_pending |= 0x3;
2137 		xhci_writel(xhci, irq_pending, &xhci->ir_set->irq_pending);
2138 	}
2139 
2140 	if (xhci->xhc_state & XHCI_STATE_DYING) {
2141 		xhci_dbg(xhci, "xHCI dying, ignoring interrupt. "
2142 				"Shouldn't IRQs be disabled?\n");
2143 		/* Clear the event handler busy flag (RW1C);
2144 		 * the event ring should be empty.
2145 		 */
2146 		temp_64 = xhci_read_64(xhci, &xhci->ir_set->erst_dequeue);
2147 		xhci_write_64(xhci, temp_64 | ERST_EHB,
2148 				&xhci->ir_set->erst_dequeue);
2149 		spin_unlock(&xhci->lock);
2150 
2151 		return IRQ_HANDLED;
2152 	}
2153 
2154 	event_ring_deq = xhci->event_ring->dequeue;
2155 	/* FIXME this should be a delayed service routine
2156 	 * that clears the EHB.
2157 	 */
2158 	xhci_handle_event(xhci);
2159 
2160 	temp_64 = xhci_read_64(xhci, &xhci->ir_set->erst_dequeue);
2161 	/* If necessary, update the HW's version of the event ring deq ptr. */
2162 	if (event_ring_deq != xhci->event_ring->dequeue) {
2163 		deq = xhci_trb_virt_to_dma(xhci->event_ring->deq_seg,
2164 				xhci->event_ring->dequeue);
2165 		if (deq == 0)
2166 			xhci_warn(xhci, "WARN something wrong with SW event "
2167 					"ring dequeue ptr.\n");
2168 		/* Update HC event ring dequeue pointer */
2169 		temp_64 &= ERST_PTR_MASK;
2170 		temp_64 |= ((u64) deq & (u64) ~ERST_PTR_MASK);
2171 	}
2172 
2173 	/* Clear the event handler busy flag (RW1C); event ring is empty. */
2174 	temp_64 |= ERST_EHB;
2175 	xhci_write_64(xhci, temp_64, &xhci->ir_set->erst_dequeue);
2176 
2177 	spin_unlock(&xhci->lock);
2178 
2179 	return IRQ_HANDLED;
2180 }
2181 
2182 irqreturn_t xhci_msi_irq(int irq, struct usb_hcd *hcd)
2183 {
2184 	irqreturn_t ret;
2185 
2186 	set_bit(HCD_FLAG_SAW_IRQ, &hcd->flags);
2187 
2188 	ret = xhci_irq(hcd);
2189 
2190 	return ret;
2191 }
2192 
2193 /****		Endpoint Ring Operations	****/
2194 
2195 /*
2196  * Generic function for queueing a TRB on a ring.
2197  * The caller must have checked to make sure there's room on the ring.
2198  *
2199  * @more_trbs_coming:	Will you enqueue more TRBs before calling
2200  *			prepare_transfer()?
2201  */
2202 static void queue_trb(struct xhci_hcd *xhci, struct xhci_ring *ring,
2203 		bool consumer, bool more_trbs_coming,
2204 		u32 field1, u32 field2, u32 field3, u32 field4)
2205 {
2206 	struct xhci_generic_trb *trb;
2207 
2208 	trb = &ring->enqueue->generic;
2209 	trb->field[0] = field1;
2210 	trb->field[1] = field2;
2211 	trb->field[2] = field3;
2212 	trb->field[3] = field4;
2213 	inc_enq(xhci, ring, consumer, more_trbs_coming);
2214 }
2215 
2216 /*
2217  * Does various checks on the endpoint ring, and makes it ready to queue num_trbs.
2218  * FIXME allocate segments if the ring is full.
2219  */
2220 static int prepare_ring(struct xhci_hcd *xhci, struct xhci_ring *ep_ring,
2221 		u32 ep_state, unsigned int num_trbs, gfp_t mem_flags)
2222 {
2223 	/* Make sure the endpoint has been added to xHC schedule */
2224 	xhci_dbg(xhci, "Endpoint state = 0x%x\n", ep_state);
2225 	switch (ep_state) {
2226 	case EP_STATE_DISABLED:
2227 		/*
2228 		 * USB core changed config/interfaces without notifying us,
2229 		 * or hardware is reporting the wrong state.
2230 		 */
2231 		xhci_warn(xhci, "WARN urb submitted to disabled ep\n");
2232 		return -ENOENT;
2233 	case EP_STATE_ERROR:
2234 		xhci_warn(xhci, "WARN waiting for error on ep to be cleared\n");
2235 		/* FIXME event handling code for error needs to clear it */
2236 		/* XXX not sure if this should be -ENOENT or not */
2237 		return -EINVAL;
2238 	case EP_STATE_HALTED:
2239 		xhci_dbg(xhci, "WARN halted endpoint, queueing URB anyway.\n");
2240 	case EP_STATE_STOPPED:
2241 	case EP_STATE_RUNNING:
2242 		break;
2243 	default:
2244 		xhci_err(xhci, "ERROR unknown endpoint state for ep\n");
2245 		/*
2246 		 * FIXME issue Configure Endpoint command to try to get the HC
2247 		 * back into a known state.
2248 		 */
2249 		return -EINVAL;
2250 	}
2251 	if (!room_on_ring(xhci, ep_ring, num_trbs)) {
2252 		/* FIXME allocate more room */
2253 		xhci_err(xhci, "ERROR no room on ep ring\n");
2254 		return -ENOMEM;
2255 	}
2256 
2257 	if (enqueue_is_link_trb(ep_ring)) {
2258 		struct xhci_ring *ring = ep_ring;
2259 		union xhci_trb *next;
2260 
2261 		xhci_dbg(xhci, "prepare_ring: pointing to link trb\n");
2262 		next = ring->enqueue;
2263 
2264 		while (last_trb(xhci, ring, ring->enq_seg, next)) {
2265 
2266 			/* If we're not dealing with 0.95 hardware,
2267 			 * clear the chain bit.
2268 			 */
2269 			if (!xhci_link_trb_quirk(xhci))
2270 				next->link.control &= ~TRB_CHAIN;
2271 			else
2272 				next->link.control |= TRB_CHAIN;
2273 
2274 			wmb();
2275 			next->link.control ^= (u32) TRB_CYCLE;
2276 
2277 			/* Toggle the cycle bit after the last ring segment. */
2278 			if (last_trb_on_last_seg(xhci, ring, ring->enq_seg, next)) {
2279 				ring->cycle_state = (ring->cycle_state ? 0 : 1);
2280 				if (!in_interrupt()) {
2281 					xhci_dbg(xhci, "queue_trb: Toggle cycle "
2282 						"state for ring %p = %i\n",
2283 						ring, (unsigned int)ring->cycle_state);
2284 				}
2285 			}
2286 			ring->enq_seg = ring->enq_seg->next;
2287 			ring->enqueue = ring->enq_seg->trbs;
2288 			next = ring->enqueue;
2289 		}
2290 	}
2291 
2292 	return 0;
2293 }
2294 
2295 static int prepare_transfer(struct xhci_hcd *xhci,
2296 		struct xhci_virt_device *xdev,
2297 		unsigned int ep_index,
2298 		unsigned int stream_id,
2299 		unsigned int num_trbs,
2300 		struct urb *urb,
2301 		unsigned int td_index,
2302 		gfp_t mem_flags)
2303 {
2304 	int ret;
2305 	struct urb_priv *urb_priv;
2306 	struct xhci_td	*td;
2307 	struct xhci_ring *ep_ring;
2308 	struct xhci_ep_ctx *ep_ctx = xhci_get_ep_ctx(xhci, xdev->out_ctx, ep_index);
2309 
2310 	ep_ring = xhci_stream_id_to_ring(xdev, ep_index, stream_id);
2311 	if (!ep_ring) {
2312 		xhci_dbg(xhci, "Can't prepare ring for bad stream ID %u\n",
2313 				stream_id);
2314 		return -EINVAL;
2315 	}
2316 
2317 	ret = prepare_ring(xhci, ep_ring,
2318 			ep_ctx->ep_info & EP_STATE_MASK,
2319 			num_trbs, mem_flags);
2320 	if (ret)
2321 		return ret;
2322 
2323 	urb_priv = urb->hcpriv;
2324 	td = urb_priv->td[td_index];
2325 
2326 	INIT_LIST_HEAD(&td->td_list);
2327 	INIT_LIST_HEAD(&td->cancelled_td_list);
2328 
2329 	if (td_index == 0) {
2330 		ret = usb_hcd_link_urb_to_ep(xhci_to_hcd(xhci), urb);
2331 		if (unlikely(ret)) {
2332 			xhci_urb_free_priv(xhci, urb_priv);
2333 			urb->hcpriv = NULL;
2334 			return ret;
2335 		}
2336 	}
2337 
2338 	td->urb = urb;
2339 	/* Add this TD to the tail of the endpoint ring's TD list */
2340 	list_add_tail(&td->td_list, &ep_ring->td_list);
2341 	td->start_seg = ep_ring->enq_seg;
2342 	td->first_trb = ep_ring->enqueue;
2343 
2344 	urb_priv->td[td_index] = td;
2345 
2346 	return 0;
2347 }
2348 
2349 static unsigned int count_sg_trbs_needed(struct xhci_hcd *xhci, struct urb *urb)
2350 {
2351 	int num_sgs, num_trbs, running_total, temp, i;
2352 	struct scatterlist *sg;
2353 
2354 	sg = NULL;
2355 	num_sgs = urb->num_sgs;
2356 	temp = urb->transfer_buffer_length;
2357 
2358 	xhci_dbg(xhci, "count sg list trbs: \n");
2359 	num_trbs = 0;
2360 	for_each_sg(urb->sg, sg, num_sgs, i) {
2361 		unsigned int previous_total_trbs = num_trbs;
2362 		unsigned int len = sg_dma_len(sg);
2363 
2364 		/* Scatter gather list entries may cross 64KB boundaries */
2365 		running_total = TRB_MAX_BUFF_SIZE -
2366 			(sg_dma_address(sg) & ((1 << TRB_MAX_BUFF_SHIFT) - 1));
2367 		if (running_total != 0)
2368 			num_trbs++;
2369 
2370 		/* How many more 64KB chunks to transfer, how many more TRBs? */
2371 		while (running_total < sg_dma_len(sg)) {
2372 			num_trbs++;
2373 			running_total += TRB_MAX_BUFF_SIZE;
2374 		}
2375 		xhci_dbg(xhci, " sg #%d: dma = %#llx, len = %#x (%d), num_trbs = %d\n",
2376 				i, (unsigned long long)sg_dma_address(sg),
2377 				len, len, num_trbs - previous_total_trbs);
2378 
2379 		len = min_t(int, len, temp);
2380 		temp -= len;
2381 		if (temp == 0)
2382 			break;
2383 	}
2384 	xhci_dbg(xhci, "\n");
2385 	if (!in_interrupt())
2386 		xhci_dbg(xhci, "ep %#x - urb len = %d, sglist used, "
2387 				"num_trbs = %d\n",
2388 				urb->ep->desc.bEndpointAddress,
2389 				urb->transfer_buffer_length,
2390 				num_trbs);
2391 	return num_trbs;
2392 }
2393 
2394 static void check_trb_math(struct urb *urb, int num_trbs, int running_total)
2395 {
2396 	if (num_trbs != 0)
2397 		dev_dbg(&urb->dev->dev, "%s - ep %#x - Miscalculated number of "
2398 				"TRBs, %d left\n", __func__,
2399 				urb->ep->desc.bEndpointAddress, num_trbs);
2400 	if (running_total != urb->transfer_buffer_length)
2401 		dev_dbg(&urb->dev->dev, "%s - ep %#x - Miscalculated tx length, "
2402 				"queued %#x (%d), asked for %#x (%d)\n",
2403 				__func__,
2404 				urb->ep->desc.bEndpointAddress,
2405 				running_total, running_total,
2406 				urb->transfer_buffer_length,
2407 				urb->transfer_buffer_length);
2408 }
2409 
2410 static void giveback_first_trb(struct xhci_hcd *xhci, int slot_id,
2411 		unsigned int ep_index, unsigned int stream_id, int start_cycle,
2412 		struct xhci_generic_trb *start_trb)
2413 {
2414 	/*
2415 	 * Pass all the TRBs to the hardware at once and make sure this write
2416 	 * isn't reordered.
2417 	 */
2418 	wmb();
2419 	if (start_cycle)
2420 		start_trb->field[3] |= start_cycle;
2421 	else
2422 		start_trb->field[3] &= ~0x1;
2423 	xhci_ring_ep_doorbell(xhci, slot_id, ep_index, stream_id);
2424 }
2425 
2426 /*
2427  * xHCI uses normal TRBs for both bulk and interrupt.  When the interrupt
2428  * endpoint is to be serviced, the xHC will consume (at most) one TD.  A TD
2429  * (comprised of sg list entries) can take several service intervals to
2430  * transmit.
2431  */
2432 int xhci_queue_intr_tx(struct xhci_hcd *xhci, gfp_t mem_flags,
2433 		struct urb *urb, int slot_id, unsigned int ep_index)
2434 {
2435 	struct xhci_ep_ctx *ep_ctx = xhci_get_ep_ctx(xhci,
2436 			xhci->devs[slot_id]->out_ctx, ep_index);
2437 	int xhci_interval;
2438 	int ep_interval;
2439 
2440 	xhci_interval = EP_INTERVAL_TO_UFRAMES(ep_ctx->ep_info);
2441 	ep_interval = urb->interval;
2442 	/* Convert to microframes */
2443 	if (urb->dev->speed == USB_SPEED_LOW ||
2444 			urb->dev->speed == USB_SPEED_FULL)
2445 		ep_interval *= 8;
2446 	/* FIXME change this to a warning and a suggestion to use the new API
2447 	 * to set the polling interval (once the API is added).
2448 	 */
2449 	if (xhci_interval != ep_interval) {
2450 		if (printk_ratelimit())
2451 			dev_dbg(&urb->dev->dev, "Driver uses different interval"
2452 					" (%d microframe%s) than xHCI "
2453 					"(%d microframe%s)\n",
2454 					ep_interval,
2455 					ep_interval == 1 ? "" : "s",
2456 					xhci_interval,
2457 					xhci_interval == 1 ? "" : "s");
2458 		urb->interval = xhci_interval;
2459 		/* Convert back to frames for LS/FS devices */
2460 		if (urb->dev->speed == USB_SPEED_LOW ||
2461 				urb->dev->speed == USB_SPEED_FULL)
2462 			urb->interval /= 8;
2463 	}
2464 	return xhci_queue_bulk_tx(xhci, GFP_ATOMIC, urb, slot_id, ep_index);
2465 }
2466 
2467 /*
2468  * The TD size is the number of bytes remaining in the TD (including this TRB),
2469  * right shifted by 10.
2470  * It must fit in bits 21:17, so it can't be bigger than 31.
2471  */
2472 static u32 xhci_td_remainder(unsigned int remainder)
2473 {
2474 	u32 max = (1 << (21 - 17 + 1)) - 1;
2475 
2476 	if ((remainder >> 10) >= max)
2477 		return max << 17;
2478 	else
2479 		return (remainder >> 10) << 17;
2480 }
2481 
2482 static int queue_bulk_sg_tx(struct xhci_hcd *xhci, gfp_t mem_flags,
2483 		struct urb *urb, int slot_id, unsigned int ep_index)
2484 {
2485 	struct xhci_ring *ep_ring;
2486 	unsigned int num_trbs;
2487 	struct urb_priv *urb_priv;
2488 	struct xhci_td *td;
2489 	struct scatterlist *sg;
2490 	int num_sgs;
2491 	int trb_buff_len, this_sg_len, running_total;
2492 	bool first_trb;
2493 	u64 addr;
2494 	bool more_trbs_coming;
2495 
2496 	struct xhci_generic_trb *start_trb;
2497 	int start_cycle;
2498 
2499 	ep_ring = xhci_urb_to_transfer_ring(xhci, urb);
2500 	if (!ep_ring)
2501 		return -EINVAL;
2502 
2503 	num_trbs = count_sg_trbs_needed(xhci, urb);
2504 	num_sgs = urb->num_sgs;
2505 
2506 	trb_buff_len = prepare_transfer(xhci, xhci->devs[slot_id],
2507 			ep_index, urb->stream_id,
2508 			num_trbs, urb, 0, mem_flags);
2509 	if (trb_buff_len < 0)
2510 		return trb_buff_len;
2511 
2512 	urb_priv = urb->hcpriv;
2513 	td = urb_priv->td[0];
2514 
2515 	/*
2516 	 * Don't give the first TRB to the hardware (by toggling the cycle bit)
2517 	 * until we've finished creating all the other TRBs.  The ring's cycle
2518 	 * state may change as we enqueue the other TRBs, so save it too.
2519 	 */
2520 	start_trb = &ep_ring->enqueue->generic;
2521 	start_cycle = ep_ring->cycle_state;
2522 
2523 	running_total = 0;
2524 	/*
2525 	 * How much data is in the first TRB?
2526 	 *
2527 	 * There are three forces at work for TRB buffer pointers and lengths:
2528 	 * 1. We don't want to walk off the end of this sg-list entry buffer.
2529 	 * 2. The transfer length that the driver requested may be smaller than
2530 	 *    the amount of memory allocated for this scatter-gather list.
2531 	 * 3. TRBs buffers can't cross 64KB boundaries.
2532 	 */
2533 	sg = urb->sg;
2534 	addr = (u64) sg_dma_address(sg);
2535 	this_sg_len = sg_dma_len(sg);
2536 	trb_buff_len = TRB_MAX_BUFF_SIZE -
2537 		(addr & ((1 << TRB_MAX_BUFF_SHIFT) - 1));
2538 	trb_buff_len = min_t(int, trb_buff_len, this_sg_len);
2539 	if (trb_buff_len > urb->transfer_buffer_length)
2540 		trb_buff_len = urb->transfer_buffer_length;
2541 	xhci_dbg(xhci, "First length to xfer from 1st sglist entry = %u\n",
2542 			trb_buff_len);
2543 
2544 	first_trb = true;
2545 	/* Queue the first TRB, even if it's zero-length */
2546 	do {
2547 		u32 field = 0;
2548 		u32 length_field = 0;
2549 		u32 remainder = 0;
2550 
2551 		/* Don't change the cycle bit of the first TRB until later */
2552 		if (first_trb) {
2553 			first_trb = false;
2554 			if (start_cycle == 0)
2555 				field |= 0x1;
2556 		} else
2557 			field |= ep_ring->cycle_state;
2558 
2559 		/* Chain all the TRBs together; clear the chain bit in the last
2560 		 * TRB to indicate it's the last TRB in the chain.
2561 		 */
2562 		if (num_trbs > 1) {
2563 			field |= TRB_CHAIN;
2564 		} else {
2565 			/* FIXME - add check for ZERO_PACKET flag before this */
2566 			td->last_trb = ep_ring->enqueue;
2567 			field |= TRB_IOC;
2568 		}
2569 		xhci_dbg(xhci, " sg entry: dma = %#x, len = %#x (%d), "
2570 				"64KB boundary at %#x, end dma = %#x\n",
2571 				(unsigned int) addr, trb_buff_len, trb_buff_len,
2572 				(unsigned int) (addr + TRB_MAX_BUFF_SIZE) & ~(TRB_MAX_BUFF_SIZE - 1),
2573 				(unsigned int) addr + trb_buff_len);
2574 		if (TRB_MAX_BUFF_SIZE -
2575 				(addr & ((1 << TRB_MAX_BUFF_SHIFT) - 1)) < trb_buff_len) {
2576 			xhci_warn(xhci, "WARN: sg dma xfer crosses 64KB boundaries!\n");
2577 			xhci_dbg(xhci, "Next boundary at %#x, end dma = %#x\n",
2578 					(unsigned int) (addr + TRB_MAX_BUFF_SIZE) & ~(TRB_MAX_BUFF_SIZE - 1),
2579 					(unsigned int) addr + trb_buff_len);
2580 		}
2581 		remainder = xhci_td_remainder(urb->transfer_buffer_length -
2582 				running_total) ;
2583 		length_field = TRB_LEN(trb_buff_len) |
2584 			remainder |
2585 			TRB_INTR_TARGET(0);
2586 		if (num_trbs > 1)
2587 			more_trbs_coming = true;
2588 		else
2589 			more_trbs_coming = false;
2590 		queue_trb(xhci, ep_ring, false, more_trbs_coming,
2591 				lower_32_bits(addr),
2592 				upper_32_bits(addr),
2593 				length_field,
2594 				/* We always want to know if the TRB was short,
2595 				 * or we won't get an event when it completes.
2596 				 * (Unless we use event data TRBs, which are a
2597 				 * waste of space and HC resources.)
2598 				 */
2599 				field | TRB_ISP | TRB_TYPE(TRB_NORMAL));
2600 		--num_trbs;
2601 		running_total += trb_buff_len;
2602 
2603 		/* Calculate length for next transfer --
2604 		 * Are we done queueing all the TRBs for this sg entry?
2605 		 */
2606 		this_sg_len -= trb_buff_len;
2607 		if (this_sg_len == 0) {
2608 			--num_sgs;
2609 			if (num_sgs == 0)
2610 				break;
2611 			sg = sg_next(sg);
2612 			addr = (u64) sg_dma_address(sg);
2613 			this_sg_len = sg_dma_len(sg);
2614 		} else {
2615 			addr += trb_buff_len;
2616 		}
2617 
2618 		trb_buff_len = TRB_MAX_BUFF_SIZE -
2619 			(addr & ((1 << TRB_MAX_BUFF_SHIFT) - 1));
2620 		trb_buff_len = min_t(int, trb_buff_len, this_sg_len);
2621 		if (running_total + trb_buff_len > urb->transfer_buffer_length)
2622 			trb_buff_len =
2623 				urb->transfer_buffer_length - running_total;
2624 	} while (running_total < urb->transfer_buffer_length);
2625 
2626 	check_trb_math(urb, num_trbs, running_total);
2627 	giveback_first_trb(xhci, slot_id, ep_index, urb->stream_id,
2628 			start_cycle, start_trb);
2629 	return 0;
2630 }
2631 
2632 /* This is very similar to what ehci-q.c qtd_fill() does */
2633 int xhci_queue_bulk_tx(struct xhci_hcd *xhci, gfp_t mem_flags,
2634 		struct urb *urb, int slot_id, unsigned int ep_index)
2635 {
2636 	struct xhci_ring *ep_ring;
2637 	struct urb_priv *urb_priv;
2638 	struct xhci_td *td;
2639 	int num_trbs;
2640 	struct xhci_generic_trb *start_trb;
2641 	bool first_trb;
2642 	bool more_trbs_coming;
2643 	int start_cycle;
2644 	u32 field, length_field;
2645 
2646 	int running_total, trb_buff_len, ret;
2647 	u64 addr;
2648 
2649 	if (urb->num_sgs)
2650 		return queue_bulk_sg_tx(xhci, mem_flags, urb, slot_id, ep_index);
2651 
2652 	ep_ring = xhci_urb_to_transfer_ring(xhci, urb);
2653 	if (!ep_ring)
2654 		return -EINVAL;
2655 
2656 	num_trbs = 0;
2657 	/* How much data is (potentially) left before the 64KB boundary? */
2658 	running_total = TRB_MAX_BUFF_SIZE -
2659 		(urb->transfer_dma & ((1 << TRB_MAX_BUFF_SHIFT) - 1));
2660 
2661 	/* If there's some data on this 64KB chunk, or we have to send a
2662 	 * zero-length transfer, we need at least one TRB
2663 	 */
2664 	if (running_total != 0 || urb->transfer_buffer_length == 0)
2665 		num_trbs++;
2666 	/* How many more 64KB chunks to transfer, how many more TRBs? */
2667 	while (running_total < urb->transfer_buffer_length) {
2668 		num_trbs++;
2669 		running_total += TRB_MAX_BUFF_SIZE;
2670 	}
2671 	/* FIXME: this doesn't deal with URB_ZERO_PACKET - need one more */
2672 
2673 	if (!in_interrupt())
2674 		xhci_dbg(xhci, "ep %#x - urb len = %#x (%d), "
2675 				"addr = %#llx, num_trbs = %d\n",
2676 				urb->ep->desc.bEndpointAddress,
2677 				urb->transfer_buffer_length,
2678 				urb->transfer_buffer_length,
2679 				(unsigned long long)urb->transfer_dma,
2680 				num_trbs);
2681 
2682 	ret = prepare_transfer(xhci, xhci->devs[slot_id],
2683 			ep_index, urb->stream_id,
2684 			num_trbs, urb, 0, mem_flags);
2685 	if (ret < 0)
2686 		return ret;
2687 
2688 	urb_priv = urb->hcpriv;
2689 	td = urb_priv->td[0];
2690 
2691 	/*
2692 	 * Don't give the first TRB to the hardware (by toggling the cycle bit)
2693 	 * until we've finished creating all the other TRBs.  The ring's cycle
2694 	 * state may change as we enqueue the other TRBs, so save it too.
2695 	 */
2696 	start_trb = &ep_ring->enqueue->generic;
2697 	start_cycle = ep_ring->cycle_state;
2698 
2699 	running_total = 0;
2700 	/* How much data is in the first TRB? */
2701 	addr = (u64) urb->transfer_dma;
2702 	trb_buff_len = TRB_MAX_BUFF_SIZE -
2703 		(urb->transfer_dma & ((1 << TRB_MAX_BUFF_SHIFT) - 1));
2704 	if (urb->transfer_buffer_length < trb_buff_len)
2705 		trb_buff_len = urb->transfer_buffer_length;
2706 
2707 	first_trb = true;
2708 
2709 	/* Queue the first TRB, even if it's zero-length */
2710 	do {
2711 		u32 remainder = 0;
2712 		field = 0;
2713 
2714 		/* Don't change the cycle bit of the first TRB until later */
2715 		if (first_trb) {
2716 			first_trb = false;
2717 			if (start_cycle == 0)
2718 				field |= 0x1;
2719 		} else
2720 			field |= ep_ring->cycle_state;
2721 
2722 		/* Chain all the TRBs together; clear the chain bit in the last
2723 		 * TRB to indicate it's the last TRB in the chain.
2724 		 */
2725 		if (num_trbs > 1) {
2726 			field |= TRB_CHAIN;
2727 		} else {
2728 			/* FIXME - add check for ZERO_PACKET flag before this */
2729 			td->last_trb = ep_ring->enqueue;
2730 			field |= TRB_IOC;
2731 		}
2732 		remainder = xhci_td_remainder(urb->transfer_buffer_length -
2733 				running_total);
2734 		length_field = TRB_LEN(trb_buff_len) |
2735 			remainder |
2736 			TRB_INTR_TARGET(0);
2737 		if (num_trbs > 1)
2738 			more_trbs_coming = true;
2739 		else
2740 			more_trbs_coming = false;
2741 		queue_trb(xhci, ep_ring, false, more_trbs_coming,
2742 				lower_32_bits(addr),
2743 				upper_32_bits(addr),
2744 				length_field,
2745 				/* We always want to know if the TRB was short,
2746 				 * or we won't get an event when it completes.
2747 				 * (Unless we use event data TRBs, which are a
2748 				 * waste of space and HC resources.)
2749 				 */
2750 				field | TRB_ISP | TRB_TYPE(TRB_NORMAL));
2751 		--num_trbs;
2752 		running_total += trb_buff_len;
2753 
2754 		/* Calculate length for next transfer */
2755 		addr += trb_buff_len;
2756 		trb_buff_len = urb->transfer_buffer_length - running_total;
2757 		if (trb_buff_len > TRB_MAX_BUFF_SIZE)
2758 			trb_buff_len = TRB_MAX_BUFF_SIZE;
2759 	} while (running_total < urb->transfer_buffer_length);
2760 
2761 	check_trb_math(urb, num_trbs, running_total);
2762 	giveback_first_trb(xhci, slot_id, ep_index, urb->stream_id,
2763 			start_cycle, start_trb);
2764 	return 0;
2765 }
2766 
2767 /* Caller must have locked xhci->lock */
2768 int xhci_queue_ctrl_tx(struct xhci_hcd *xhci, gfp_t mem_flags,
2769 		struct urb *urb, int slot_id, unsigned int ep_index)
2770 {
2771 	struct xhci_ring *ep_ring;
2772 	int num_trbs;
2773 	int ret;
2774 	struct usb_ctrlrequest *setup;
2775 	struct xhci_generic_trb *start_trb;
2776 	int start_cycle;
2777 	u32 field, length_field;
2778 	struct urb_priv *urb_priv;
2779 	struct xhci_td *td;
2780 
2781 	ep_ring = xhci_urb_to_transfer_ring(xhci, urb);
2782 	if (!ep_ring)
2783 		return -EINVAL;
2784 
2785 	/*
2786 	 * Need to copy setup packet into setup TRB, so we can't use the setup
2787 	 * DMA address.
2788 	 */
2789 	if (!urb->setup_packet)
2790 		return -EINVAL;
2791 
2792 	if (!in_interrupt())
2793 		xhci_dbg(xhci, "Queueing ctrl tx for slot id %d, ep %d\n",
2794 				slot_id, ep_index);
2795 	/* 1 TRB for setup, 1 for status */
2796 	num_trbs = 2;
2797 	/*
2798 	 * Don't need to check if we need additional event data and normal TRBs,
2799 	 * since data in control transfers will never get bigger than 16MB
2800 	 * XXX: can we get a buffer that crosses 64KB boundaries?
2801 	 */
2802 	if (urb->transfer_buffer_length > 0)
2803 		num_trbs++;
2804 	ret = prepare_transfer(xhci, xhci->devs[slot_id],
2805 			ep_index, urb->stream_id,
2806 			num_trbs, urb, 0, mem_flags);
2807 	if (ret < 0)
2808 		return ret;
2809 
2810 	urb_priv = urb->hcpriv;
2811 	td = urb_priv->td[0];
2812 
2813 	/*
2814 	 * Don't give the first TRB to the hardware (by toggling the cycle bit)
2815 	 * until we've finished creating all the other TRBs.  The ring's cycle
2816 	 * state may change as we enqueue the other TRBs, so save it too.
2817 	 */
2818 	start_trb = &ep_ring->enqueue->generic;
2819 	start_cycle = ep_ring->cycle_state;
2820 
2821 	/* Queue setup TRB - see section 6.4.1.2.1 */
2822 	/* FIXME better way to translate setup_packet into two u32 fields? */
2823 	setup = (struct usb_ctrlrequest *) urb->setup_packet;
2824 	field = 0;
2825 	field |= TRB_IDT | TRB_TYPE(TRB_SETUP);
2826 	if (start_cycle == 0)
2827 		field |= 0x1;
2828 	queue_trb(xhci, ep_ring, false, true,
2829 			/* FIXME endianness is probably going to bite my ass here. */
2830 			setup->bRequestType | setup->bRequest << 8 | setup->wValue << 16,
2831 			setup->wIndex | setup->wLength << 16,
2832 			TRB_LEN(8) | TRB_INTR_TARGET(0),
2833 			/* Immediate data in pointer */
2834 			field);
2835 
2836 	/* If there's data, queue data TRBs */
2837 	field = 0;
2838 	length_field = TRB_LEN(urb->transfer_buffer_length) |
2839 		xhci_td_remainder(urb->transfer_buffer_length) |
2840 		TRB_INTR_TARGET(0);
2841 	if (urb->transfer_buffer_length > 0) {
2842 		if (setup->bRequestType & USB_DIR_IN)
2843 			field |= TRB_DIR_IN;
2844 		queue_trb(xhci, ep_ring, false, true,
2845 				lower_32_bits(urb->transfer_dma),
2846 				upper_32_bits(urb->transfer_dma),
2847 				length_field,
2848 				/* Event on short tx */
2849 				field | TRB_ISP | TRB_TYPE(TRB_DATA) | ep_ring->cycle_state);
2850 	}
2851 
2852 	/* Save the DMA address of the last TRB in the TD */
2853 	td->last_trb = ep_ring->enqueue;
2854 
2855 	/* Queue status TRB - see Table 7 and sections 4.11.2.2 and 6.4.1.2.3 */
2856 	/* If the device sent data, the status stage is an OUT transfer */
2857 	if (urb->transfer_buffer_length > 0 && setup->bRequestType & USB_DIR_IN)
2858 		field = 0;
2859 	else
2860 		field = TRB_DIR_IN;
2861 	queue_trb(xhci, ep_ring, false, false,
2862 			0,
2863 			0,
2864 			TRB_INTR_TARGET(0),
2865 			/* Event on completion */
2866 			field | TRB_IOC | TRB_TYPE(TRB_STATUS) | ep_ring->cycle_state);
2867 
2868 	giveback_first_trb(xhci, slot_id, ep_index, 0,
2869 			start_cycle, start_trb);
2870 	return 0;
2871 }
2872 
2873 static int count_isoc_trbs_needed(struct xhci_hcd *xhci,
2874 		struct urb *urb, int i)
2875 {
2876 	int num_trbs = 0;
2877 	u64 addr, td_len, running_total;
2878 
2879 	addr = (u64) (urb->transfer_dma + urb->iso_frame_desc[i].offset);
2880 	td_len = urb->iso_frame_desc[i].length;
2881 
2882 	running_total = TRB_MAX_BUFF_SIZE -
2883 			(addr & ((1 << TRB_MAX_BUFF_SHIFT) - 1));
2884 	if (running_total != 0)
2885 		num_trbs++;
2886 
2887 	while (running_total < td_len) {
2888 		num_trbs++;
2889 		running_total += TRB_MAX_BUFF_SIZE;
2890 	}
2891 
2892 	return num_trbs;
2893 }
2894 
2895 /* This is for isoc transfer */
2896 static int xhci_queue_isoc_tx(struct xhci_hcd *xhci, gfp_t mem_flags,
2897 		struct urb *urb, int slot_id, unsigned int ep_index)
2898 {
2899 	struct xhci_ring *ep_ring;
2900 	struct urb_priv *urb_priv;
2901 	struct xhci_td *td;
2902 	int num_tds, trbs_per_td;
2903 	struct xhci_generic_trb *start_trb;
2904 	bool first_trb;
2905 	int start_cycle;
2906 	u32 field, length_field;
2907 	int running_total, trb_buff_len, td_len, td_remain_len, ret;
2908 	u64 start_addr, addr;
2909 	int i, j;
2910 	bool more_trbs_coming;
2911 
2912 	ep_ring = xhci->devs[slot_id]->eps[ep_index].ring;
2913 
2914 	num_tds = urb->number_of_packets;
2915 	if (num_tds < 1) {
2916 		xhci_dbg(xhci, "Isoc URB with zero packets?\n");
2917 		return -EINVAL;
2918 	}
2919 
2920 	if (!in_interrupt())
2921 		xhci_dbg(xhci, "ep %#x - urb len = %#x (%d),"
2922 				" addr = %#llx, num_tds = %d\n",
2923 				urb->ep->desc.bEndpointAddress,
2924 				urb->transfer_buffer_length,
2925 				urb->transfer_buffer_length,
2926 				(unsigned long long)urb->transfer_dma,
2927 				num_tds);
2928 
2929 	start_addr = (u64) urb->transfer_dma;
2930 	start_trb = &ep_ring->enqueue->generic;
2931 	start_cycle = ep_ring->cycle_state;
2932 
2933 	/* Queue the first TRB, even if it's zero-length */
2934 	for (i = 0; i < num_tds; i++) {
2935 		first_trb = true;
2936 
2937 		running_total = 0;
2938 		addr = start_addr + urb->iso_frame_desc[i].offset;
2939 		td_len = urb->iso_frame_desc[i].length;
2940 		td_remain_len = td_len;
2941 
2942 		trbs_per_td = count_isoc_trbs_needed(xhci, urb, i);
2943 
2944 		ret = prepare_transfer(xhci, xhci->devs[slot_id], ep_index,
2945 				urb->stream_id, trbs_per_td, urb, i, mem_flags);
2946 		if (ret < 0)
2947 			return ret;
2948 
2949 		urb_priv = urb->hcpriv;
2950 		td = urb_priv->td[i];
2951 
2952 		for (j = 0; j < trbs_per_td; j++) {
2953 			u32 remainder = 0;
2954 			field = 0;
2955 
2956 			if (first_trb) {
2957 				/* Queue the isoc TRB */
2958 				field |= TRB_TYPE(TRB_ISOC);
2959 				/* Assume URB_ISO_ASAP is set */
2960 				field |= TRB_SIA;
2961 				if (i == 0) {
2962 					if (start_cycle == 0)
2963 						field |= 0x1;
2964 				} else
2965 					field |= ep_ring->cycle_state;
2966 				first_trb = false;
2967 			} else {
2968 				/* Queue other normal TRBs */
2969 				field |= TRB_TYPE(TRB_NORMAL);
2970 				field |= ep_ring->cycle_state;
2971 			}
2972 
2973 			/* Chain all the TRBs together; clear the chain bit in
2974 			 * the last TRB to indicate it's the last TRB in the
2975 			 * chain.
2976 			 */
2977 			if (j < trbs_per_td - 1) {
2978 				field |= TRB_CHAIN;
2979 				more_trbs_coming = true;
2980 			} else {
2981 				td->last_trb = ep_ring->enqueue;
2982 				field |= TRB_IOC;
2983 				more_trbs_coming = false;
2984 			}
2985 
2986 			/* Calculate TRB length */
2987 			trb_buff_len = TRB_MAX_BUFF_SIZE -
2988 				(addr & ((1 << TRB_MAX_BUFF_SHIFT) - 1));
2989 			if (trb_buff_len > td_remain_len)
2990 				trb_buff_len = td_remain_len;
2991 
2992 			remainder = xhci_td_remainder(td_len - running_total);
2993 			length_field = TRB_LEN(trb_buff_len) |
2994 				remainder |
2995 				TRB_INTR_TARGET(0);
2996 			queue_trb(xhci, ep_ring, false, more_trbs_coming,
2997 				lower_32_bits(addr),
2998 				upper_32_bits(addr),
2999 				length_field,
3000 				/* We always want to know if the TRB was short,
3001 				 * or we won't get an event when it completes.
3002 				 * (Unless we use event data TRBs, which are a
3003 				 * waste of space and HC resources.)
3004 				 */
3005 				field | TRB_ISP);
3006 			running_total += trb_buff_len;
3007 
3008 			addr += trb_buff_len;
3009 			td_remain_len -= trb_buff_len;
3010 		}
3011 
3012 		/* Check TD length */
3013 		if (running_total != td_len) {
3014 			xhci_err(xhci, "ISOC TD length unmatch\n");
3015 			return -EINVAL;
3016 		}
3017 	}
3018 
3019 	giveback_first_trb(xhci, slot_id, ep_index, urb->stream_id,
3020 			start_cycle, start_trb);
3021 	return 0;
3022 }
3023 
3024 /*
3025  * Check transfer ring to guarantee there is enough room for the urb.
3026  * Update ISO URB start_frame and interval.
3027  * Update interval as xhci_queue_intr_tx does. Just use xhci frame_index to
3028  * update the urb->start_frame by now.
3029  * Always assume URB_ISO_ASAP set, and NEVER use urb->start_frame as input.
3030  */
3031 int xhci_queue_isoc_tx_prepare(struct xhci_hcd *xhci, gfp_t mem_flags,
3032 		struct urb *urb, int slot_id, unsigned int ep_index)
3033 {
3034 	struct xhci_virt_device *xdev;
3035 	struct xhci_ring *ep_ring;
3036 	struct xhci_ep_ctx *ep_ctx;
3037 	int start_frame;
3038 	int xhci_interval;
3039 	int ep_interval;
3040 	int num_tds, num_trbs, i;
3041 	int ret;
3042 
3043 	xdev = xhci->devs[slot_id];
3044 	ep_ring = xdev->eps[ep_index].ring;
3045 	ep_ctx = xhci_get_ep_ctx(xhci, xdev->out_ctx, ep_index);
3046 
3047 	num_trbs = 0;
3048 	num_tds = urb->number_of_packets;
3049 	for (i = 0; i < num_tds; i++)
3050 		num_trbs += count_isoc_trbs_needed(xhci, urb, i);
3051 
3052 	/* Check the ring to guarantee there is enough room for the whole urb.
3053 	 * Do not insert any td of the urb to the ring if the check failed.
3054 	 */
3055 	ret = prepare_ring(xhci, ep_ring, ep_ctx->ep_info & EP_STATE_MASK,
3056 				num_trbs, mem_flags);
3057 	if (ret)
3058 		return ret;
3059 
3060 	start_frame = xhci_readl(xhci, &xhci->run_regs->microframe_index);
3061 	start_frame &= 0x3fff;
3062 
3063 	urb->start_frame = start_frame;
3064 	if (urb->dev->speed == USB_SPEED_LOW ||
3065 			urb->dev->speed == USB_SPEED_FULL)
3066 		urb->start_frame >>= 3;
3067 
3068 	xhci_interval = EP_INTERVAL_TO_UFRAMES(ep_ctx->ep_info);
3069 	ep_interval = urb->interval;
3070 	/* Convert to microframes */
3071 	if (urb->dev->speed == USB_SPEED_LOW ||
3072 			urb->dev->speed == USB_SPEED_FULL)
3073 		ep_interval *= 8;
3074 	/* FIXME change this to a warning and a suggestion to use the new API
3075 	 * to set the polling interval (once the API is added).
3076 	 */
3077 	if (xhci_interval != ep_interval) {
3078 		if (printk_ratelimit())
3079 			dev_dbg(&urb->dev->dev, "Driver uses different interval"
3080 					" (%d microframe%s) than xHCI "
3081 					"(%d microframe%s)\n",
3082 					ep_interval,
3083 					ep_interval == 1 ? "" : "s",
3084 					xhci_interval,
3085 					xhci_interval == 1 ? "" : "s");
3086 		urb->interval = xhci_interval;
3087 		/* Convert back to frames for LS/FS devices */
3088 		if (urb->dev->speed == USB_SPEED_LOW ||
3089 				urb->dev->speed == USB_SPEED_FULL)
3090 			urb->interval /= 8;
3091 	}
3092 	return xhci_queue_isoc_tx(xhci, GFP_ATOMIC, urb, slot_id, ep_index);
3093 }
3094 
3095 /****		Command Ring Operations		****/
3096 
3097 /* Generic function for queueing a command TRB on the command ring.
3098  * Check to make sure there's room on the command ring for one command TRB.
3099  * Also check that there's room reserved for commands that must not fail.
3100  * If this is a command that must not fail, meaning command_must_succeed = TRUE,
3101  * then only check for the number of reserved spots.
3102  * Don't decrement xhci->cmd_ring_reserved_trbs after we've queued the TRB
3103  * because the command event handler may want to resubmit a failed command.
3104  */
3105 static int queue_command(struct xhci_hcd *xhci, u32 field1, u32 field2,
3106 		u32 field3, u32 field4, bool command_must_succeed)
3107 {
3108 	int reserved_trbs = xhci->cmd_ring_reserved_trbs;
3109 	int ret;
3110 
3111 	if (!command_must_succeed)
3112 		reserved_trbs++;
3113 
3114 	ret = prepare_ring(xhci, xhci->cmd_ring, EP_STATE_RUNNING,
3115 			reserved_trbs, GFP_ATOMIC);
3116 	if (ret < 0) {
3117 		xhci_err(xhci, "ERR: No room for command on command ring\n");
3118 		if (command_must_succeed)
3119 			xhci_err(xhci, "ERR: Reserved TRB counting for "
3120 					"unfailable commands failed.\n");
3121 		return ret;
3122 	}
3123 	queue_trb(xhci, xhci->cmd_ring, false, false, field1, field2, field3,
3124 			field4 | xhci->cmd_ring->cycle_state);
3125 	return 0;
3126 }
3127 
3128 /* Queue a no-op command on the command ring */
3129 static int queue_cmd_noop(struct xhci_hcd *xhci)
3130 {
3131 	return queue_command(xhci, 0, 0, 0, TRB_TYPE(TRB_CMD_NOOP), false);
3132 }
3133 
3134 /*
3135  * Place a no-op command on the command ring to test the command and
3136  * event ring.
3137  */
3138 void *xhci_setup_one_noop(struct xhci_hcd *xhci)
3139 {
3140 	if (queue_cmd_noop(xhci) < 0)
3141 		return NULL;
3142 	xhci->noops_submitted++;
3143 	return xhci_ring_cmd_db;
3144 }
3145 
3146 /* Queue a slot enable or disable request on the command ring */
3147 int xhci_queue_slot_control(struct xhci_hcd *xhci, u32 trb_type, u32 slot_id)
3148 {
3149 	return queue_command(xhci, 0, 0, 0,
3150 			TRB_TYPE(trb_type) | SLOT_ID_FOR_TRB(slot_id), false);
3151 }
3152 
3153 /* Queue an address device command TRB */
3154 int xhci_queue_address_device(struct xhci_hcd *xhci, dma_addr_t in_ctx_ptr,
3155 		u32 slot_id)
3156 {
3157 	return queue_command(xhci, lower_32_bits(in_ctx_ptr),
3158 			upper_32_bits(in_ctx_ptr), 0,
3159 			TRB_TYPE(TRB_ADDR_DEV) | SLOT_ID_FOR_TRB(slot_id),
3160 			false);
3161 }
3162 
3163 int xhci_queue_vendor_command(struct xhci_hcd *xhci,
3164 		u32 field1, u32 field2, u32 field3, u32 field4)
3165 {
3166 	return queue_command(xhci, field1, field2, field3, field4, false);
3167 }
3168 
3169 /* Queue a reset device command TRB */
3170 int xhci_queue_reset_device(struct xhci_hcd *xhci, u32 slot_id)
3171 {
3172 	return queue_command(xhci, 0, 0, 0,
3173 			TRB_TYPE(TRB_RESET_DEV) | SLOT_ID_FOR_TRB(slot_id),
3174 			false);
3175 }
3176 
3177 /* Queue a configure endpoint command TRB */
3178 int xhci_queue_configure_endpoint(struct xhci_hcd *xhci, dma_addr_t in_ctx_ptr,
3179 		u32 slot_id, bool command_must_succeed)
3180 {
3181 	return queue_command(xhci, lower_32_bits(in_ctx_ptr),
3182 			upper_32_bits(in_ctx_ptr), 0,
3183 			TRB_TYPE(TRB_CONFIG_EP) | SLOT_ID_FOR_TRB(slot_id),
3184 			command_must_succeed);
3185 }
3186 
3187 /* Queue an evaluate context command TRB */
3188 int xhci_queue_evaluate_context(struct xhci_hcd *xhci, dma_addr_t in_ctx_ptr,
3189 		u32 slot_id)
3190 {
3191 	return queue_command(xhci, lower_32_bits(in_ctx_ptr),
3192 			upper_32_bits(in_ctx_ptr), 0,
3193 			TRB_TYPE(TRB_EVAL_CONTEXT) | SLOT_ID_FOR_TRB(slot_id),
3194 			false);
3195 }
3196 
3197 /*
3198  * Suspend is set to indicate "Stop Endpoint Command" is being issued to stop
3199  * activity on an endpoint that is about to be suspended.
3200  */
3201 int xhci_queue_stop_endpoint(struct xhci_hcd *xhci, int slot_id,
3202 		unsigned int ep_index, int suspend)
3203 {
3204 	u32 trb_slot_id = SLOT_ID_FOR_TRB(slot_id);
3205 	u32 trb_ep_index = EP_ID_FOR_TRB(ep_index);
3206 	u32 type = TRB_TYPE(TRB_STOP_RING);
3207 	u32 trb_suspend = SUSPEND_PORT_FOR_TRB(suspend);
3208 
3209 	return queue_command(xhci, 0, 0, 0,
3210 			trb_slot_id | trb_ep_index | type | trb_suspend, false);
3211 }
3212 
3213 /* Set Transfer Ring Dequeue Pointer command.
3214  * This should not be used for endpoints that have streams enabled.
3215  */
3216 static int queue_set_tr_deq(struct xhci_hcd *xhci, int slot_id,
3217 		unsigned int ep_index, unsigned int stream_id,
3218 		struct xhci_segment *deq_seg,
3219 		union xhci_trb *deq_ptr, u32 cycle_state)
3220 {
3221 	dma_addr_t addr;
3222 	u32 trb_slot_id = SLOT_ID_FOR_TRB(slot_id);
3223 	u32 trb_ep_index = EP_ID_FOR_TRB(ep_index);
3224 	u32 trb_stream_id = STREAM_ID_FOR_TRB(stream_id);
3225 	u32 type = TRB_TYPE(TRB_SET_DEQ);
3226 
3227 	addr = xhci_trb_virt_to_dma(deq_seg, deq_ptr);
3228 	if (addr == 0) {
3229 		xhci_warn(xhci, "WARN Cannot submit Set TR Deq Ptr\n");
3230 		xhci_warn(xhci, "WARN deq seg = %p, deq pt = %p\n",
3231 				deq_seg, deq_ptr);
3232 		return 0;
3233 	}
3234 	return queue_command(xhci, lower_32_bits(addr) | cycle_state,
3235 			upper_32_bits(addr), trb_stream_id,
3236 			trb_slot_id | trb_ep_index | type, false);
3237 }
3238 
3239 int xhci_queue_reset_ep(struct xhci_hcd *xhci, int slot_id,
3240 		unsigned int ep_index)
3241 {
3242 	u32 trb_slot_id = SLOT_ID_FOR_TRB(slot_id);
3243 	u32 trb_ep_index = EP_ID_FOR_TRB(ep_index);
3244 	u32 type = TRB_TYPE(TRB_RESET_EP);
3245 
3246 	return queue_command(xhci, 0, 0, 0, trb_slot_id | trb_ep_index | type,
3247 			false);
3248 }
3249