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USB: xhci: Add tests for TRB address translation.
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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 "xhci.h"
69
70 /*
71  * Returns zero if the TRB isn't in this segment, otherwise it returns the DMA
72  * address of the TRB.
73  */
74 dma_addr_t xhci_trb_virt_to_dma(struct xhci_segment *seg,
75                 union xhci_trb *trb)
76 {
77         unsigned long segment_offset;
78
79         if (!seg || !trb || trb < seg->trbs)
80                 return 0;
81         /* offset in TRBs */
82         segment_offset = trb - seg->trbs;
83         if (segment_offset > TRBS_PER_SEGMENT)
84                 return 0;
85         return seg->dma + (segment_offset * sizeof(*trb));
86 }
87
88 /* Does this link TRB point to the first segment in a ring,
89  * or was the previous TRB the last TRB on the last segment in the ERST?
90  */
91 static inline bool last_trb_on_last_seg(struct xhci_hcd *xhci, struct xhci_ring *ring,
92                 struct xhci_segment *seg, union xhci_trb *trb)
93 {
94         if (ring == xhci->event_ring)
95                 return (trb == &seg->trbs[TRBS_PER_SEGMENT]) &&
96                         (seg->next == xhci->event_ring->first_seg);
97         else
98                 return trb->link.control & LINK_TOGGLE;
99 }
100
101 /* Is this TRB a link TRB or was the last TRB the last TRB in this event ring
102  * segment?  I.e. would the updated event TRB pointer step off the end of the
103  * event seg?
104  */
105 static inline int last_trb(struct xhci_hcd *xhci, struct xhci_ring *ring,
106                 struct xhci_segment *seg, union xhci_trb *trb)
107 {
108         if (ring == xhci->event_ring)
109                 return trb == &seg->trbs[TRBS_PER_SEGMENT];
110         else
111                 return (trb->link.control & TRB_TYPE_BITMASK) == TRB_TYPE(TRB_LINK);
112 }
113
114 /* Updates trb to point to the next TRB in the ring, and updates seg if the next
115  * TRB is in a new segment.  This does not skip over link TRBs, and it does not
116  * effect the ring dequeue or enqueue pointers.
117  */
118 static void next_trb(struct xhci_hcd *xhci,
119                 struct xhci_ring *ring,
120                 struct xhci_segment **seg,
121                 union xhci_trb **trb)
122 {
123         if (last_trb(xhci, ring, *seg, *trb)) {
124                 *seg = (*seg)->next;
125                 *trb = ((*seg)->trbs);
126         } else {
127                 *trb = (*trb)++;
128         }
129 }
130
131 /*
132  * See Cycle bit rules. SW is the consumer for the event ring only.
133  * Don't make a ring full of link TRBs.  That would be dumb and this would loop.
134  */
135 static void inc_deq(struct xhci_hcd *xhci, struct xhci_ring *ring, bool consumer)
136 {
137         union xhci_trb *next = ++(ring->dequeue);
138         unsigned long long addr;
139
140         ring->deq_updates++;
141         /* Update the dequeue pointer further if that was a link TRB or we're at
142          * the end of an event ring segment (which doesn't have link TRBS)
143          */
144         while (last_trb(xhci, ring, ring->deq_seg, next)) {
145                 if (consumer && last_trb_on_last_seg(xhci, ring, ring->deq_seg, next)) {
146                         ring->cycle_state = (ring->cycle_state ? 0 : 1);
147                         if (!in_interrupt())
148                                 xhci_dbg(xhci, "Toggle cycle state for ring %p = %i\n",
149                                                 ring,
150                                                 (unsigned int) ring->cycle_state);
151                 }
152                 ring->deq_seg = ring->deq_seg->next;
153                 ring->dequeue = ring->deq_seg->trbs;
154                 next = ring->dequeue;
155         }
156         addr = (unsigned long long) xhci_trb_virt_to_dma(ring->deq_seg, ring->dequeue);
157         if (ring == xhci->event_ring)
158                 xhci_dbg(xhci, "Event ring deq = 0x%llx (DMA)\n", addr);
159         else if (ring == xhci->cmd_ring)
160                 xhci_dbg(xhci, "Command ring deq = 0x%llx (DMA)\n", addr);
161         else
162                 xhci_dbg(xhci, "Ring deq = 0x%llx (DMA)\n", addr);
163 }
164
165 /*
166  * See Cycle bit rules. SW is the consumer for the event ring only.
167  * Don't make a ring full of link TRBs.  That would be dumb and this would loop.
168  *
169  * If we've just enqueued a TRB that is in the middle of a TD (meaning the
170  * chain bit is set), then set the chain bit in all the following link TRBs.
171  * If we've enqueued the last TRB in a TD, make sure the following link TRBs
172  * have their chain bit cleared (so that each Link TRB is a separate TD).
173  *
174  * Section 6.4.4.1 of the 0.95 spec says link TRBs cannot have the chain bit
175  * set, but other sections talk about dealing with the chain bit set.  This was
176  * fixed in the 0.96 specification errata, but we have to assume that all 0.95
177  * xHCI hardware can't handle the chain bit being cleared on a link TRB.
178  */
179 static void inc_enq(struct xhci_hcd *xhci, struct xhci_ring *ring, bool consumer)
180 {
181         u32 chain;
182         union xhci_trb *next;
183         unsigned long long addr;
184
185         chain = ring->enqueue->generic.field[3] & TRB_CHAIN;
186         next = ++(ring->enqueue);
187
188         ring->enq_updates++;
189         /* Update the dequeue pointer further if that was a link TRB or we're at
190          * the end of an event ring segment (which doesn't have link TRBS)
191          */
192         while (last_trb(xhci, ring, ring->enq_seg, next)) {
193                 if (!consumer) {
194                         if (ring != xhci->event_ring) {
195                                 /* If we're not dealing with 0.95 hardware,
196                                  * carry over the chain bit of the previous TRB
197                                  * (which may mean the chain bit is cleared).
198                                  */
199                                 if (!xhci_link_trb_quirk(xhci)) {
200                                         next->link.control &= ~TRB_CHAIN;
201                                         next->link.control |= chain;
202                                 }
203                                 /* Give this link TRB to the hardware */
204                                 wmb();
205                                 if (next->link.control & TRB_CYCLE)
206                                         next->link.control &= (u32) ~TRB_CYCLE;
207                                 else
208                                         next->link.control |= (u32) TRB_CYCLE;
209                         }
210                         /* Toggle the cycle bit after the last ring segment. */
211                         if (last_trb_on_last_seg(xhci, ring, ring->enq_seg, next)) {
212                                 ring->cycle_state = (ring->cycle_state ? 0 : 1);
213                                 if (!in_interrupt())
214                                         xhci_dbg(xhci, "Toggle cycle state for ring %p = %i\n",
215                                                         ring,
216                                                         (unsigned int) ring->cycle_state);
217                         }
218                 }
219                 ring->enq_seg = ring->enq_seg->next;
220                 ring->enqueue = ring->enq_seg->trbs;
221                 next = ring->enqueue;
222         }
223         addr = (unsigned long long) xhci_trb_virt_to_dma(ring->enq_seg, ring->enqueue);
224         if (ring == xhci->event_ring)
225                 xhci_dbg(xhci, "Event ring enq = 0x%llx (DMA)\n", addr);
226         else if (ring == xhci->cmd_ring)
227                 xhci_dbg(xhci, "Command ring enq = 0x%llx (DMA)\n", addr);
228         else
229                 xhci_dbg(xhci, "Ring enq = 0x%llx (DMA)\n", addr);
230 }
231
232 /*
233  * Check to see if there's room to enqueue num_trbs on the ring.  See rules
234  * above.
235  * FIXME: this would be simpler and faster if we just kept track of the number
236  * of free TRBs in a ring.
237  */
238 static int room_on_ring(struct xhci_hcd *xhci, struct xhci_ring *ring,
239                 unsigned int num_trbs)
240 {
241         int i;
242         union xhci_trb *enq = ring->enqueue;
243         struct xhci_segment *enq_seg = ring->enq_seg;
244
245         /* Check if ring is empty */
246         if (enq == ring->dequeue)
247                 return 1;
248         /* Make sure there's an extra empty TRB available */
249         for (i = 0; i <= num_trbs; ++i) {
250                 if (enq == ring->dequeue)
251                         return 0;
252                 enq++;
253                 while (last_trb(xhci, ring, enq_seg, enq)) {
254                         enq_seg = enq_seg->next;
255                         enq = enq_seg->trbs;
256                 }
257         }
258         return 1;
259 }
260
261 void xhci_set_hc_event_deq(struct xhci_hcd *xhci)
262 {
263         u64 temp;
264         dma_addr_t deq;
265
266         deq = xhci_trb_virt_to_dma(xhci->event_ring->deq_seg,
267                         xhci->event_ring->dequeue);
268         if (deq == 0 && !in_interrupt())
269                 xhci_warn(xhci, "WARN something wrong with SW event ring "
270                                 "dequeue ptr.\n");
271         /* Update HC event ring dequeue pointer */
272         temp = xhci_read_64(xhci, &xhci->ir_set->erst_dequeue);
273         temp &= ERST_PTR_MASK;
274         /* Don't clear the EHB bit (which is RW1C) because
275          * there might be more events to service.
276          */
277         temp &= ~ERST_EHB;
278         xhci_dbg(xhci, "// Write event ring dequeue pointer, preserving EHB bit\n");
279         xhci_write_64(xhci, ((u64) deq & (u64) ~ERST_PTR_MASK) | temp,
280                         &xhci->ir_set->erst_dequeue);
281 }
282
283 /* Ring the host controller doorbell after placing a command on the ring */
284 void xhci_ring_cmd_db(struct xhci_hcd *xhci)
285 {
286         u32 temp;
287
288         xhci_dbg(xhci, "// Ding dong!\n");
289         temp = xhci_readl(xhci, &xhci->dba->doorbell[0]) & DB_MASK;
290         xhci_writel(xhci, temp | DB_TARGET_HOST, &xhci->dba->doorbell[0]);
291         /* Flush PCI posted writes */
292         xhci_readl(xhci, &xhci->dba->doorbell[0]);
293 }
294
295 static void ring_ep_doorbell(struct xhci_hcd *xhci,
296                 unsigned int slot_id,
297                 unsigned int ep_index)
298 {
299         struct xhci_virt_ep *ep;
300         unsigned int ep_state;
301         u32 field;
302         __u32 __iomem *db_addr = &xhci->dba->doorbell[slot_id];
303
304         ep = &xhci->devs[slot_id]->eps[ep_index];
305         ep_state = ep->ep_state;
306         /* Don't ring the doorbell for this endpoint if there are pending
307          * cancellations because the we don't want to interrupt processing.
308          */
309         if (!(ep_state & EP_HALT_PENDING) && !(ep_state & SET_DEQ_PENDING)
310                         && !(ep_state & EP_HALTED)) {
311                 field = xhci_readl(xhci, db_addr) & DB_MASK;
312                 xhci_writel(xhci, field | EPI_TO_DB(ep_index), db_addr);
313                 /* Flush PCI posted writes - FIXME Matthew Wilcox says this
314                  * isn't time-critical and we shouldn't make the CPU wait for
315                  * the flush.
316                  */
317                 xhci_readl(xhci, db_addr);
318         }
319 }
320
321 /*
322  * Find the segment that trb is in.  Start searching in start_seg.
323  * If we must move past a segment that has a link TRB with a toggle cycle state
324  * bit set, then we will toggle the value pointed at by cycle_state.
325  */
326 static struct xhci_segment *find_trb_seg(
327                 struct xhci_segment *start_seg,
328                 union xhci_trb  *trb, int *cycle_state)
329 {
330         struct xhci_segment *cur_seg = start_seg;
331         struct xhci_generic_trb *generic_trb;
332
333         while (cur_seg->trbs > trb ||
334                         &cur_seg->trbs[TRBS_PER_SEGMENT - 1] < trb) {
335                 generic_trb = &cur_seg->trbs[TRBS_PER_SEGMENT - 1].generic;
336                 if (TRB_TYPE(generic_trb->field[3]) == TRB_LINK &&
337                                 (generic_trb->field[3] & LINK_TOGGLE))
338                         *cycle_state = ~(*cycle_state) & 0x1;
339                 cur_seg = cur_seg->next;
340                 if (cur_seg == start_seg)
341                         /* Looped over the entire list.  Oops! */
342                         return 0;
343         }
344         return cur_seg;
345 }
346
347 /*
348  * Move the xHC's endpoint ring dequeue pointer past cur_td.
349  * Record the new state of the xHC's endpoint ring dequeue segment,
350  * dequeue pointer, and new consumer cycle state in state.
351  * Update our internal representation of the ring's dequeue pointer.
352  *
353  * We do this in three jumps:
354  *  - First we update our new ring state to be the same as when the xHC stopped.
355  *  - Then we traverse the ring to find the segment that contains
356  *    the last TRB in the TD.  We toggle the xHC's new cycle state when we pass
357  *    any link TRBs with the toggle cycle bit set.
358  *  - Finally we move the dequeue state one TRB further, toggling the cycle bit
359  *    if we've moved it past a link TRB with the toggle cycle bit set.
360  */
361 void xhci_find_new_dequeue_state(struct xhci_hcd *xhci,
362                 unsigned int slot_id, unsigned int ep_index,
363                 struct xhci_td *cur_td, struct xhci_dequeue_state *state)
364 {
365         struct xhci_virt_device *dev = xhci->devs[slot_id];
366         struct xhci_ring *ep_ring = dev->eps[ep_index].ring;
367         struct xhci_generic_trb *trb;
368         struct xhci_ep_ctx *ep_ctx;
369         dma_addr_t addr;
370
371         state->new_cycle_state = 0;
372         xhci_dbg(xhci, "Finding segment containing stopped TRB.\n");
373         state->new_deq_seg = find_trb_seg(cur_td->start_seg,
374                         dev->eps[ep_index].stopped_trb,
375                         &state->new_cycle_state);
376         if (!state->new_deq_seg)
377                 BUG();
378         /* Dig out the cycle state saved by the xHC during the stop ep cmd */
379         xhci_dbg(xhci, "Finding endpoint context\n");
380         ep_ctx = xhci_get_ep_ctx(xhci, dev->out_ctx, ep_index);
381         state->new_cycle_state = 0x1 & ep_ctx->deq;
382
383         state->new_deq_ptr = cur_td->last_trb;
384         xhci_dbg(xhci, "Finding segment containing last TRB in TD.\n");
385         state->new_deq_seg = find_trb_seg(state->new_deq_seg,
386                         state->new_deq_ptr,
387                         &state->new_cycle_state);
388         if (!state->new_deq_seg)
389                 BUG();
390
391         trb = &state->new_deq_ptr->generic;
392         if (TRB_TYPE(trb->field[3]) == TRB_LINK &&
393                                 (trb->field[3] & LINK_TOGGLE))
394                 state->new_cycle_state = ~(state->new_cycle_state) & 0x1;
395         next_trb(xhci, ep_ring, &state->new_deq_seg, &state->new_deq_ptr);
396
397         /* Don't update the ring cycle state for the producer (us). */
398         xhci_dbg(xhci, "New dequeue segment = %p (virtual)\n",
399                         state->new_deq_seg);
400         addr = xhci_trb_virt_to_dma(state->new_deq_seg, state->new_deq_ptr);
401         xhci_dbg(xhci, "New dequeue pointer = 0x%llx (DMA)\n",
402                         (unsigned long long) addr);
403         xhci_dbg(xhci, "Setting dequeue pointer in internal ring state.\n");
404         ep_ring->dequeue = state->new_deq_ptr;
405         ep_ring->deq_seg = state->new_deq_seg;
406 }
407
408 static void td_to_noop(struct xhci_hcd *xhci, struct xhci_ring *ep_ring,
409                 struct xhci_td *cur_td)
410 {
411         struct xhci_segment *cur_seg;
412         union xhci_trb *cur_trb;
413
414         for (cur_seg = cur_td->start_seg, cur_trb = cur_td->first_trb;
415                         true;
416                         next_trb(xhci, ep_ring, &cur_seg, &cur_trb)) {
417                 if ((cur_trb->generic.field[3] & TRB_TYPE_BITMASK) ==
418                                 TRB_TYPE(TRB_LINK)) {
419                         /* Unchain any chained Link TRBs, but
420                          * leave the pointers intact.
421                          */
422                         cur_trb->generic.field[3] &= ~TRB_CHAIN;
423                         xhci_dbg(xhci, "Cancel (unchain) link TRB\n");
424                         xhci_dbg(xhci, "Address = %p (0x%llx dma); "
425                                         "in seg %p (0x%llx dma)\n",
426                                         cur_trb,
427                                         (unsigned long long)xhci_trb_virt_to_dma(cur_seg, cur_trb),
428                                         cur_seg,
429                                         (unsigned long long)cur_seg->dma);
430                 } else {
431                         cur_trb->generic.field[0] = 0;
432                         cur_trb->generic.field[1] = 0;
433                         cur_trb->generic.field[2] = 0;
434                         /* Preserve only the cycle bit of this TRB */
435                         cur_trb->generic.field[3] &= TRB_CYCLE;
436                         cur_trb->generic.field[3] |= TRB_TYPE(TRB_TR_NOOP);
437                         xhci_dbg(xhci, "Cancel TRB %p (0x%llx dma) "
438                                         "in seg %p (0x%llx dma)\n",
439                                         cur_trb,
440                                         (unsigned long long)xhci_trb_virt_to_dma(cur_seg, cur_trb),
441                                         cur_seg,
442                                         (unsigned long long)cur_seg->dma);
443                 }
444                 if (cur_trb == cur_td->last_trb)
445                         break;
446         }
447 }
448
449 static int queue_set_tr_deq(struct xhci_hcd *xhci, int slot_id,
450                 unsigned int ep_index, struct xhci_segment *deq_seg,
451                 union xhci_trb *deq_ptr, u32 cycle_state);
452
453 void xhci_queue_new_dequeue_state(struct xhci_hcd *xhci,
454                 unsigned int slot_id, unsigned int ep_index,
455                 struct xhci_dequeue_state *deq_state)
456 {
457         struct xhci_virt_ep *ep = &xhci->devs[slot_id]->eps[ep_index];
458
459         xhci_dbg(xhci, "Set TR Deq Ptr cmd, new deq seg = %p (0x%llx dma), "
460                         "new deq ptr = %p (0x%llx dma), new cycle = %u\n",
461                         deq_state->new_deq_seg,
462                         (unsigned long long)deq_state->new_deq_seg->dma,
463                         deq_state->new_deq_ptr,
464                         (unsigned long long)xhci_trb_virt_to_dma(deq_state->new_deq_seg, deq_state->new_deq_ptr),
465                         deq_state->new_cycle_state);
466         queue_set_tr_deq(xhci, slot_id, ep_index,
467                         deq_state->new_deq_seg,
468                         deq_state->new_deq_ptr,
469                         (u32) deq_state->new_cycle_state);
470         /* Stop the TD queueing code from ringing the doorbell until
471          * this command completes.  The HC won't set the dequeue pointer
472          * if the ring is running, and ringing the doorbell starts the
473          * ring running.
474          */
475         ep->ep_state |= SET_DEQ_PENDING;
476 }
477
478 static inline void xhci_stop_watchdog_timer_in_irq(struct xhci_hcd *xhci,
479                 struct xhci_virt_ep *ep)
480 {
481         ep->ep_state &= ~EP_HALT_PENDING;
482         /* Can't del_timer_sync in interrupt, so we attempt to cancel.  If the
483          * timer is running on another CPU, we don't decrement stop_cmds_pending
484          * (since we didn't successfully stop the watchdog timer).
485          */
486         if (del_timer(&ep->stop_cmd_timer))
487                 ep->stop_cmds_pending--;
488 }
489
490 /* Must be called with xhci->lock held in interrupt context */
491 static void xhci_giveback_urb_in_irq(struct xhci_hcd *xhci,
492                 struct xhci_td *cur_td, int status, char *adjective)
493 {
494         struct usb_hcd *hcd = xhci_to_hcd(xhci);
495
496         cur_td->urb->hcpriv = NULL;
497         usb_hcd_unlink_urb_from_ep(hcd, cur_td->urb);
498         xhci_dbg(xhci, "Giveback %s URB %p\n", adjective, cur_td->urb);
499
500         spin_unlock(&xhci->lock);
501         usb_hcd_giveback_urb(hcd, cur_td->urb, status);
502         kfree(cur_td);
503         spin_lock(&xhci->lock);
504         xhci_dbg(xhci, "%s URB given back\n", adjective);
505 }
506
507 /*
508  * When we get a command completion for a Stop Endpoint Command, we need to
509  * unlink any cancelled TDs from the ring.  There are two ways to do that:
510  *
511  *  1. If the HW was in the middle of processing the TD that needs to be
512  *     cancelled, then we must move the ring's dequeue pointer past the last TRB
513  *     in the TD with a Set Dequeue Pointer Command.
514  *  2. Otherwise, we turn all the TRBs in the TD into No-op TRBs (with the chain
515  *     bit cleared) so that the HW will skip over them.
516  */
517 static void handle_stopped_endpoint(struct xhci_hcd *xhci,
518                 union xhci_trb *trb)
519 {
520         unsigned int slot_id;
521         unsigned int ep_index;
522         struct xhci_ring *ep_ring;
523         struct xhci_virt_ep *ep;
524         struct list_head *entry;
525         struct xhci_td *cur_td = 0;
526         struct xhci_td *last_unlinked_td;
527
528         struct xhci_dequeue_state deq_state;
529
530         memset(&deq_state, 0, sizeof(deq_state));
531         slot_id = TRB_TO_SLOT_ID(trb->generic.field[3]);
532         ep_index = TRB_TO_EP_INDEX(trb->generic.field[3]);
533         ep = &xhci->devs[slot_id]->eps[ep_index];
534         ep_ring = ep->ring;
535
536         if (list_empty(&ep->cancelled_td_list)) {
537                 xhci_stop_watchdog_timer_in_irq(xhci, ep);
538                 ring_ep_doorbell(xhci, slot_id, ep_index);
539                 return;
540         }
541
542         /* Fix up the ep ring first, so HW stops executing cancelled TDs.
543          * We have the xHCI lock, so nothing can modify this list until we drop
544          * it.  We're also in the event handler, so we can't get re-interrupted
545          * if another Stop Endpoint command completes
546          */
547         list_for_each(entry, &ep->cancelled_td_list) {
548                 cur_td = list_entry(entry, struct xhci_td, cancelled_td_list);
549                 xhci_dbg(xhci, "Cancelling TD starting at %p, 0x%llx (dma).\n",
550                                 cur_td->first_trb,
551                                 (unsigned long long)xhci_trb_virt_to_dma(cur_td->start_seg, cur_td->first_trb));
552                 /*
553                  * If we stopped on the TD we need to cancel, then we have to
554                  * move the xHC endpoint ring dequeue pointer past this TD.
555                  */
556                 if (cur_td == ep->stopped_td)
557                         xhci_find_new_dequeue_state(xhci, slot_id, ep_index, cur_td,
558                                         &deq_state);
559                 else
560                         td_to_noop(xhci, ep_ring, cur_td);
561                 /*
562                  * The event handler won't see a completion for this TD anymore,
563                  * so remove it from the endpoint ring's TD list.  Keep it in
564                  * the cancelled TD list for URB completion later.
565                  */
566                 list_del(&cur_td->td_list);
567         }
568         last_unlinked_td = cur_td;
569         xhci_stop_watchdog_timer_in_irq(xhci, ep);
570
571         /* If necessary, queue a Set Transfer Ring Dequeue Pointer command */
572         if (deq_state.new_deq_ptr && deq_state.new_deq_seg) {
573                 xhci_queue_new_dequeue_state(xhci,
574                                 slot_id, ep_index, &deq_state);
575                 xhci_ring_cmd_db(xhci);
576         } else {
577                 /* Otherwise just ring the doorbell to restart the ring */
578                 ring_ep_doorbell(xhci, slot_id, ep_index);
579         }
580
581         /*
582          * Drop the lock and complete the URBs in the cancelled TD list.
583          * New TDs to be cancelled might be added to the end of the list before
584          * we can complete all the URBs for the TDs we already unlinked.
585          * So stop when we've completed the URB for the last TD we unlinked.
586          */
587         do {
588                 cur_td = list_entry(ep->cancelled_td_list.next,
589                                 struct xhci_td, cancelled_td_list);
590                 list_del(&cur_td->cancelled_td_list);
591
592                 /* Clean up the cancelled URB */
593                 /* Doesn't matter what we pass for status, since the core will
594                  * just overwrite it (because the URB has been unlinked).
595                  */
596                 xhci_giveback_urb_in_irq(xhci, cur_td, 0, "cancelled");
597
598                 /* Stop processing the cancelled list if the watchdog timer is
599                  * running.
600                  */
601                 if (xhci->xhc_state & XHCI_STATE_DYING)
602                         return;
603         } while (cur_td != last_unlinked_td);
604
605         /* Return to the event handler with xhci->lock re-acquired */
606 }
607
608 /* Watchdog timer function for when a stop endpoint command fails to complete.
609  * In this case, we assume the host controller is broken or dying or dead.  The
610  * host may still be completing some other events, so we have to be careful to
611  * let the event ring handler and the URB dequeueing/enqueueing functions know
612  * through xhci->state.
613  *
614  * The timer may also fire if the host takes a very long time to respond to the
615  * command, and the stop endpoint command completion handler cannot delete the
616  * timer before the timer function is called.  Another endpoint cancellation may
617  * sneak in before the timer function can grab the lock, and that may queue
618  * another stop endpoint command and add the timer back.  So we cannot use a
619  * simple flag to say whether there is a pending stop endpoint command for a
620  * particular endpoint.
621  *
622  * Instead we use a combination of that flag and a counter for the number of
623  * pending stop endpoint commands.  If the timer is the tail end of the last
624  * stop endpoint command, and the endpoint's command is still pending, we assume
625  * the host is dying.
626  */
627 void xhci_stop_endpoint_command_watchdog(unsigned long arg)
628 {
629         struct xhci_hcd *xhci;
630         struct xhci_virt_ep *ep;
631         struct xhci_virt_ep *temp_ep;
632         struct xhci_ring *ring;
633         struct xhci_td *cur_td;
634         int ret, i, j;
635
636         ep = (struct xhci_virt_ep *) arg;
637         xhci = ep->xhci;
638
639         spin_lock(&xhci->lock);
640
641         ep->stop_cmds_pending--;
642         if (xhci->xhc_state & XHCI_STATE_DYING) {
643                 xhci_dbg(xhci, "Stop EP timer ran, but another timer marked "
644                                 "xHCI as DYING, exiting.\n");
645                 spin_unlock(&xhci->lock);
646                 return;
647         }
648         if (!(ep->stop_cmds_pending == 0 && (ep->ep_state & EP_HALT_PENDING))) {
649                 xhci_dbg(xhci, "Stop EP timer ran, but no command pending, "
650                                 "exiting.\n");
651                 spin_unlock(&xhci->lock);
652                 return;
653         }
654
655         xhci_warn(xhci, "xHCI host not responding to stop endpoint command.\n");
656         xhci_warn(xhci, "Assuming host is dying, halting host.\n");
657         /* Oops, HC is dead or dying or at least not responding to the stop
658          * endpoint command.
659          */
660         xhci->xhc_state |= XHCI_STATE_DYING;
661         /* Disable interrupts from the host controller and start halting it */
662         xhci_quiesce(xhci);
663         spin_unlock(&xhci->lock);
664
665         ret = xhci_halt(xhci);
666
667         spin_lock(&xhci->lock);
668         if (ret < 0) {
669                 /* This is bad; the host is not responding to commands and it's
670                  * not allowing itself to be halted.  At least interrupts are
671                  * disabled, so we can set HC_STATE_HALT and notify the
672                  * USB core.  But if we call usb_hc_died(), it will attempt to
673                  * disconnect all device drivers under this host.  Those
674                  * disconnect() methods will wait for all URBs to be unlinked,
675                  * so we must complete them.
676                  */
677                 xhci_warn(xhci, "Non-responsive xHCI host is not halting.\n");
678                 xhci_warn(xhci, "Completing active URBs anyway.\n");
679                 /* We could turn all TDs on the rings to no-ops.  This won't
680                  * help if the host has cached part of the ring, and is slow if
681                  * we want to preserve the cycle bit.  Skip it and hope the host
682                  * doesn't touch the memory.
683                  */
684         }
685         for (i = 0; i < MAX_HC_SLOTS; i++) {
686                 if (!xhci->devs[i])
687                         continue;
688                 for (j = 0; j < 31; j++) {
689                         temp_ep = &xhci->devs[i]->eps[j];
690                         ring = temp_ep->ring;
691                         if (!ring)
692                                 continue;
693                         xhci_dbg(xhci, "Killing URBs for slot ID %u, "
694                                         "ep index %u\n", i, j);
695                         while (!list_empty(&ring->td_list)) {
696                                 cur_td = list_first_entry(&ring->td_list,
697                                                 struct xhci_td,
698                                                 td_list);
699                                 list_del(&cur_td->td_list);
700                                 if (!list_empty(&cur_td->cancelled_td_list))
701                                         list_del(&cur_td->cancelled_td_list);
702                                 xhci_giveback_urb_in_irq(xhci, cur_td,
703                                                 -ESHUTDOWN, "killed");
704                         }
705                         while (!list_empty(&temp_ep->cancelled_td_list)) {
706                                 cur_td = list_first_entry(
707                                                 &temp_ep->cancelled_td_list,
708                                                 struct xhci_td,
709                                                 cancelled_td_list);
710                                 list_del(&cur_td->cancelled_td_list);
711                                 xhci_giveback_urb_in_irq(xhci, cur_td,
712                                                 -ESHUTDOWN, "killed");
713                         }
714                 }
715         }
716         spin_unlock(&xhci->lock);
717         xhci_to_hcd(xhci)->state = HC_STATE_HALT;
718         xhci_dbg(xhci, "Calling usb_hc_died()\n");
719         usb_hc_died(xhci_to_hcd(xhci));
720         xhci_dbg(xhci, "xHCI host controller is dead.\n");
721 }
722
723 /*
724  * When we get a completion for a Set Transfer Ring Dequeue Pointer command,
725  * we need to clear the set deq pending flag in the endpoint ring state, so that
726  * the TD queueing code can ring the doorbell again.  We also need to ring the
727  * endpoint doorbell to restart the ring, but only if there aren't more
728  * cancellations pending.
729  */
730 static void handle_set_deq_completion(struct xhci_hcd *xhci,
731                 struct xhci_event_cmd *event,
732                 union xhci_trb *trb)
733 {
734         unsigned int slot_id;
735         unsigned int ep_index;
736         struct xhci_ring *ep_ring;
737         struct xhci_virt_device *dev;
738         struct xhci_ep_ctx *ep_ctx;
739         struct xhci_slot_ctx *slot_ctx;
740
741         slot_id = TRB_TO_SLOT_ID(trb->generic.field[3]);
742         ep_index = TRB_TO_EP_INDEX(trb->generic.field[3]);
743         dev = xhci->devs[slot_id];
744         ep_ring = dev->eps[ep_index].ring;
745         ep_ctx = xhci_get_ep_ctx(xhci, dev->out_ctx, ep_index);
746         slot_ctx = xhci_get_slot_ctx(xhci, dev->out_ctx);
747
748         if (GET_COMP_CODE(event->status) != COMP_SUCCESS) {
749                 unsigned int ep_state;
750                 unsigned int slot_state;
751
752                 switch (GET_COMP_CODE(event->status)) {
753                 case COMP_TRB_ERR:
754                         xhci_warn(xhci, "WARN Set TR Deq Ptr cmd invalid because "
755                                         "of stream ID configuration\n");
756                         break;
757                 case COMP_CTX_STATE:
758                         xhci_warn(xhci, "WARN Set TR Deq Ptr cmd failed due "
759                                         "to incorrect slot or ep state.\n");
760                         ep_state = ep_ctx->ep_info;
761                         ep_state &= EP_STATE_MASK;
762                         slot_state = slot_ctx->dev_state;
763                         slot_state = GET_SLOT_STATE(slot_state);
764                         xhci_dbg(xhci, "Slot state = %u, EP state = %u\n",
765                                         slot_state, ep_state);
766                         break;
767                 case COMP_EBADSLT:
768                         xhci_warn(xhci, "WARN Set TR Deq Ptr cmd failed because "
769                                         "slot %u was not enabled.\n", slot_id);
770                         break;
771                 default:
772                         xhci_warn(xhci, "WARN Set TR Deq Ptr cmd with unknown "
773                                         "completion code of %u.\n",
774                                         GET_COMP_CODE(event->status));
775                         break;
776                 }
777                 /* OK what do we do now?  The endpoint state is hosed, and we
778                  * should never get to this point if the synchronization between
779                  * queueing, and endpoint state are correct.  This might happen
780                  * if the device gets disconnected after we've finished
781                  * cancelling URBs, which might not be an error...
782                  */
783         } else {
784                 xhci_dbg(xhci, "Successful Set TR Deq Ptr cmd, deq = @%08llx\n",
785                                 ep_ctx->deq);
786         }
787
788         dev->eps[ep_index].ep_state &= ~SET_DEQ_PENDING;
789         ring_ep_doorbell(xhci, slot_id, ep_index);
790 }
791
792 static void handle_reset_ep_completion(struct xhci_hcd *xhci,
793                 struct xhci_event_cmd *event,
794                 union xhci_trb *trb)
795 {
796         int slot_id;
797         unsigned int ep_index;
798         struct xhci_ring *ep_ring;
799
800         slot_id = TRB_TO_SLOT_ID(trb->generic.field[3]);
801         ep_index = TRB_TO_EP_INDEX(trb->generic.field[3]);
802         ep_ring = xhci->devs[slot_id]->eps[ep_index].ring;
803         /* This command will only fail if the endpoint wasn't halted,
804          * but we don't care.
805          */
806         xhci_dbg(xhci, "Ignoring reset ep completion code of %u\n",
807                         (unsigned int) GET_COMP_CODE(event->status));
808
809         /* HW with the reset endpoint quirk needs to have a configure endpoint
810          * command complete before the endpoint can be used.  Queue that here
811          * because the HW can't handle two commands being queued in a row.
812          */
813         if (xhci->quirks & XHCI_RESET_EP_QUIRK) {
814                 xhci_dbg(xhci, "Queueing configure endpoint command\n");
815                 xhci_queue_configure_endpoint(xhci,
816                                 xhci->devs[slot_id]->in_ctx->dma, slot_id,
817                                 false);
818                 xhci_ring_cmd_db(xhci);
819         } else {
820                 /* Clear our internal halted state and restart the ring */
821                 xhci->devs[slot_id]->eps[ep_index].ep_state &= ~EP_HALTED;
822                 ring_ep_doorbell(xhci, slot_id, ep_index);
823         }
824 }
825
826 /* Check to see if a command in the device's command queue matches this one.
827  * Signal the completion or free the command, and return 1.  Return 0 if the
828  * completed command isn't at the head of the command list.
829  */
830 static int handle_cmd_in_cmd_wait_list(struct xhci_hcd *xhci,
831                 struct xhci_virt_device *virt_dev,
832                 struct xhci_event_cmd *event)
833 {
834         struct xhci_command *command;
835
836         if (list_empty(&virt_dev->cmd_list))
837                 return 0;
838
839         command = list_entry(virt_dev->cmd_list.next,
840                         struct xhci_command, cmd_list);
841         if (xhci->cmd_ring->dequeue != command->command_trb)
842                 return 0;
843
844         command->status =
845                 GET_COMP_CODE(event->status);
846         list_del(&command->cmd_list);
847         if (command->completion)
848                 complete(command->completion);
849         else
850                 xhci_free_command(xhci, command);
851         return 1;
852 }
853
854 static void handle_cmd_completion(struct xhci_hcd *xhci,
855                 struct xhci_event_cmd *event)
856 {
857         int slot_id = TRB_TO_SLOT_ID(event->flags);
858         u64 cmd_dma;
859         dma_addr_t cmd_dequeue_dma;
860         struct xhci_input_control_ctx *ctrl_ctx;
861         struct xhci_virt_device *virt_dev;
862         unsigned int ep_index;
863         struct xhci_ring *ep_ring;
864         unsigned int ep_state;
865
866         cmd_dma = event->cmd_trb;
867         cmd_dequeue_dma = xhci_trb_virt_to_dma(xhci->cmd_ring->deq_seg,
868                         xhci->cmd_ring->dequeue);
869         /* Is the command ring deq ptr out of sync with the deq seg ptr? */
870         if (cmd_dequeue_dma == 0) {
871                 xhci->error_bitmask |= 1 << 4;
872                 return;
873         }
874         /* Does the DMA address match our internal dequeue pointer address? */
875         if (cmd_dma != (u64) cmd_dequeue_dma) {
876                 xhci->error_bitmask |= 1 << 5;
877                 return;
878         }
879         switch (xhci->cmd_ring->dequeue->generic.field[3] & TRB_TYPE_BITMASK) {
880         case TRB_TYPE(TRB_ENABLE_SLOT):
881                 if (GET_COMP_CODE(event->status) == COMP_SUCCESS)
882                         xhci->slot_id = slot_id;
883                 else
884                         xhci->slot_id = 0;
885                 complete(&xhci->addr_dev);
886                 break;
887         case TRB_TYPE(TRB_DISABLE_SLOT):
888                 if (xhci->devs[slot_id])
889                         xhci_free_virt_device(xhci, slot_id);
890                 break;
891         case TRB_TYPE(TRB_CONFIG_EP):
892                 virt_dev = xhci->devs[slot_id];
893                 if (handle_cmd_in_cmd_wait_list(xhci, virt_dev, event))
894                         break;
895                 /*
896                  * Configure endpoint commands can come from the USB core
897                  * configuration or alt setting changes, or because the HW
898                  * needed an extra configure endpoint command after a reset
899                  * endpoint command.  In the latter case, the xHCI driver is
900                  * not waiting on the configure endpoint command.
901                  */
902                 ctrl_ctx = xhci_get_input_control_ctx(xhci,
903                                 virt_dev->in_ctx);
904                 /* Input ctx add_flags are the endpoint index plus one */
905                 ep_index = xhci_last_valid_endpoint(ctrl_ctx->add_flags) - 1;
906                 ep_ring = xhci->devs[slot_id]->eps[ep_index].ring;
907                 if (!ep_ring) {
908                         /* This must have been an initial configure endpoint */
909                         xhci->devs[slot_id]->cmd_status =
910                                 GET_COMP_CODE(event->status);
911                         complete(&xhci->devs[slot_id]->cmd_completion);
912                         break;
913                 }
914                 ep_state = xhci->devs[slot_id]->eps[ep_index].ep_state;
915                 xhci_dbg(xhci, "Completed config ep cmd - last ep index = %d, "
916                                 "state = %d\n", ep_index, ep_state);
917                 if (xhci->quirks & XHCI_RESET_EP_QUIRK &&
918                                 ep_state & EP_HALTED) {
919                         /* Clear our internal halted state and restart ring */
920                         xhci->devs[slot_id]->eps[ep_index].ep_state &=
921                                 ~EP_HALTED;
922                         ring_ep_doorbell(xhci, slot_id, ep_index);
923                 } else {
924                         xhci->devs[slot_id]->cmd_status =
925                                 GET_COMP_CODE(event->status);
926                         complete(&xhci->devs[slot_id]->cmd_completion);
927                 }
928                 break;
929         case TRB_TYPE(TRB_EVAL_CONTEXT):
930                 virt_dev = xhci->devs[slot_id];
931                 if (handle_cmd_in_cmd_wait_list(xhci, virt_dev, event))
932                         break;
933                 xhci->devs[slot_id]->cmd_status = GET_COMP_CODE(event->status);
934                 complete(&xhci->devs[slot_id]->cmd_completion);
935                 break;
936         case TRB_TYPE(TRB_ADDR_DEV):
937                 xhci->devs[slot_id]->cmd_status = GET_COMP_CODE(event->status);
938                 complete(&xhci->addr_dev);
939                 break;
940         case TRB_TYPE(TRB_STOP_RING):
941                 handle_stopped_endpoint(xhci, xhci->cmd_ring->dequeue);
942                 break;
943         case TRB_TYPE(TRB_SET_DEQ):
944                 handle_set_deq_completion(xhci, event, xhci->cmd_ring->dequeue);
945                 break;
946         case TRB_TYPE(TRB_CMD_NOOP):
947                 ++xhci->noops_handled;
948                 break;
949         case TRB_TYPE(TRB_RESET_EP):
950                 handle_reset_ep_completion(xhci, event, xhci->cmd_ring->dequeue);
951                 break;
952         default:
953                 /* Skip over unknown commands on the event ring */
954                 xhci->error_bitmask |= 1 << 6;
955                 break;
956         }
957         inc_deq(xhci, xhci->cmd_ring, false);
958 }
959
960 static void handle_port_status(struct xhci_hcd *xhci,
961                 union xhci_trb *event)
962 {
963         u32 port_id;
964
965         /* Port status change events always have a successful completion code */
966         if (GET_COMP_CODE(event->generic.field[2]) != COMP_SUCCESS) {
967                 xhci_warn(xhci, "WARN: xHC returned failed port status event\n");
968                 xhci->error_bitmask |= 1 << 8;
969         }
970         /* FIXME: core doesn't care about all port link state changes yet */
971         port_id = GET_PORT_ID(event->generic.field[0]);
972         xhci_dbg(xhci, "Port Status Change Event for port %d\n", port_id);
973
974         /* Update event ring dequeue pointer before dropping the lock */
975         inc_deq(xhci, xhci->event_ring, true);
976         xhci_set_hc_event_deq(xhci);
977
978         spin_unlock(&xhci->lock);
979         /* Pass this up to the core */
980         usb_hcd_poll_rh_status(xhci_to_hcd(xhci));
981         spin_lock(&xhci->lock);
982 }
983
984 /*
985  * This TD is defined by the TRBs starting at start_trb in start_seg and ending
986  * at end_trb, which may be in another segment.  If the suspect DMA address is a
987  * TRB in this TD, this function returns that TRB's segment.  Otherwise it
988  * returns 0.
989  */
990 struct xhci_segment *trb_in_td(struct xhci_segment *start_seg,
991                 union xhci_trb  *start_trb,
992                 union xhci_trb  *end_trb,
993                 dma_addr_t      suspect_dma)
994 {
995         dma_addr_t start_dma;
996         dma_addr_t end_seg_dma;
997         dma_addr_t end_trb_dma;
998         struct xhci_segment *cur_seg;
999
1000         start_dma = xhci_trb_virt_to_dma(start_seg, start_trb);
1001         cur_seg = start_seg;
1002
1003         do {
1004                 if (start_dma == 0)
1005                         return 0;
1006                 /* We may get an event for a Link TRB in the middle of a TD */
1007                 end_seg_dma = xhci_trb_virt_to_dma(cur_seg,
1008                                 &cur_seg->trbs[TRBS_PER_SEGMENT - 1]);
1009                 /* If the end TRB isn't in this segment, this is set to 0 */
1010                 end_trb_dma = xhci_trb_virt_to_dma(cur_seg, end_trb);
1011
1012                 if (end_trb_dma > 0) {
1013                         /* The end TRB is in this segment, so suspect should be here */
1014                         if (start_dma <= end_trb_dma) {
1015                                 if (suspect_dma >= start_dma && suspect_dma <= end_trb_dma)
1016                                         return cur_seg;
1017                         } else {
1018                                 /* Case for one segment with
1019                                  * a TD wrapped around to the top
1020                                  */
1021                                 if ((suspect_dma >= start_dma &&
1022                                                         suspect_dma <= end_seg_dma) ||
1023                                                 (suspect_dma >= cur_seg->dma &&
1024                                                  suspect_dma <= end_trb_dma))
1025                                         return cur_seg;
1026                         }
1027                         return 0;
1028                 } else {
1029                         /* Might still be somewhere in this segment */
1030                         if (suspect_dma >= start_dma && suspect_dma <= end_seg_dma)
1031                                 return cur_seg;
1032                 }
1033                 cur_seg = cur_seg->next;
1034                 start_dma = xhci_trb_virt_to_dma(cur_seg, &cur_seg->trbs[0]);
1035         } while (cur_seg != start_seg);
1036
1037         return 0;
1038 }
1039
1040 /*
1041  * If this function returns an error condition, it means it got a Transfer
1042  * event with a corrupted Slot ID, Endpoint ID, or TRB DMA address.
1043  * At this point, the host controller is probably hosed and should be reset.
1044  */
1045 static int handle_tx_event(struct xhci_hcd *xhci,
1046                 struct xhci_transfer_event *event)
1047 {
1048         struct xhci_virt_device *xdev;
1049         struct xhci_virt_ep *ep;
1050         struct xhci_ring *ep_ring;
1051         unsigned int slot_id;
1052         int ep_index;
1053         struct xhci_td *td = 0;
1054         dma_addr_t event_dma;
1055         struct xhci_segment *event_seg;
1056         union xhci_trb *event_trb;
1057         struct urb *urb = 0;
1058         int status = -EINPROGRESS;
1059         struct xhci_ep_ctx *ep_ctx;
1060         u32 trb_comp_code;
1061
1062         xhci_dbg(xhci, "In %s\n", __func__);
1063         slot_id = TRB_TO_SLOT_ID(event->flags);
1064         xdev = xhci->devs[slot_id];
1065         if (!xdev) {
1066                 xhci_err(xhci, "ERROR Transfer event pointed to bad slot\n");
1067                 return -ENODEV;
1068         }
1069
1070         /* Endpoint ID is 1 based, our index is zero based */
1071         ep_index = TRB_TO_EP_ID(event->flags) - 1;
1072         xhci_dbg(xhci, "%s - ep index = %d\n", __func__, ep_index);
1073         ep = &xdev->eps[ep_index];
1074         ep_ring = ep->ring;
1075         ep_ctx = xhci_get_ep_ctx(xhci, xdev->out_ctx, ep_index);
1076         if (!ep_ring || (ep_ctx->ep_info & EP_STATE_MASK) == EP_STATE_DISABLED) {
1077                 xhci_err(xhci, "ERROR Transfer event pointed to disabled endpoint\n");
1078                 return -ENODEV;
1079         }
1080
1081         event_dma = event->buffer;
1082         /* This TRB should be in the TD at the head of this ring's TD list */
1083         xhci_dbg(xhci, "%s - checking for list empty\n", __func__);
1084         if (list_empty(&ep_ring->td_list)) {
1085                 xhci_warn(xhci, "WARN Event TRB for slot %d ep %d with no TDs queued?\n",
1086                                 TRB_TO_SLOT_ID(event->flags), ep_index);
1087                 xhci_dbg(xhci, "Event TRB with TRB type ID %u\n",
1088                                 (unsigned int) (event->flags & TRB_TYPE_BITMASK)>>10);
1089                 xhci_print_trb_offsets(xhci, (union xhci_trb *) event);
1090                 urb = NULL;
1091                 goto cleanup;
1092         }
1093         xhci_dbg(xhci, "%s - getting list entry\n", __func__);
1094         td = list_entry(ep_ring->td_list.next, struct xhci_td, td_list);
1095
1096         /* Is this a TRB in the currently executing TD? */
1097         xhci_dbg(xhci, "%s - looking for TD\n", __func__);
1098         event_seg = trb_in_td(ep_ring->deq_seg, ep_ring->dequeue,
1099                         td->last_trb, event_dma);
1100         xhci_dbg(xhci, "%s - found event_seg = %p\n", __func__, event_seg);
1101         if (!event_seg) {
1102                 /* HC is busted, give up! */
1103                 xhci_err(xhci, "ERROR Transfer event TRB DMA ptr not part of current TD\n");
1104                 return -ESHUTDOWN;
1105         }
1106         event_trb = &event_seg->trbs[(event_dma - event_seg->dma) / sizeof(*event_trb)];
1107         xhci_dbg(xhci, "Event TRB with TRB type ID %u\n",
1108                         (unsigned int) (event->flags & TRB_TYPE_BITMASK)>>10);
1109         xhci_dbg(xhci, "Offset 0x00 (buffer lo) = 0x%x\n",
1110                         lower_32_bits(event->buffer));
1111         xhci_dbg(xhci, "Offset 0x04 (buffer hi) = 0x%x\n",
1112                         upper_32_bits(event->buffer));
1113         xhci_dbg(xhci, "Offset 0x08 (transfer length) = 0x%x\n",
1114                         (unsigned int) event->transfer_len);
1115         xhci_dbg(xhci, "Offset 0x0C (flags) = 0x%x\n",
1116                         (unsigned int) event->flags);
1117
1118         /* Look for common error cases */
1119         trb_comp_code = GET_COMP_CODE(event->transfer_len);
1120         switch (trb_comp_code) {
1121         /* Skip codes that require special handling depending on
1122          * transfer type
1123          */
1124         case COMP_SUCCESS:
1125         case COMP_SHORT_TX:
1126                 break;
1127         case COMP_STOP:
1128                 xhci_dbg(xhci, "Stopped on Transfer TRB\n");
1129                 break;
1130         case COMP_STOP_INVAL:
1131                 xhci_dbg(xhci, "Stopped on No-op or Link TRB\n");
1132                 break;
1133         case COMP_STALL:
1134                 xhci_warn(xhci, "WARN: Stalled endpoint\n");
1135                 ep->ep_state |= EP_HALTED;
1136                 status = -EPIPE;
1137                 break;
1138         case COMP_TRB_ERR:
1139                 xhci_warn(xhci, "WARN: TRB error on endpoint\n");
1140                 status = -EILSEQ;
1141                 break;
1142         case COMP_TX_ERR:
1143                 xhci_warn(xhci, "WARN: transfer error on endpoint\n");
1144                 status = -EPROTO;
1145                 break;
1146         case COMP_BABBLE:
1147                 xhci_warn(xhci, "WARN: babble error on endpoint\n");
1148                 status = -EOVERFLOW;
1149                 break;
1150         case COMP_DB_ERR:
1151                 xhci_warn(xhci, "WARN: HC couldn't access mem fast enough\n");
1152                 status = -ENOSR;
1153                 break;
1154         default:
1155                 xhci_warn(xhci, "ERROR Unknown event condition, HC probably busted\n");
1156                 urb = NULL;
1157                 goto cleanup;
1158         }
1159         /* Now update the urb's actual_length and give back to the core */
1160         /* Was this a control transfer? */
1161         if (usb_endpoint_xfer_control(&td->urb->ep->desc)) {
1162                 xhci_debug_trb(xhci, xhci->event_ring->dequeue);
1163                 switch (trb_comp_code) {
1164                 case COMP_SUCCESS:
1165                         if (event_trb == ep_ring->dequeue) {
1166                                 xhci_warn(xhci, "WARN: Success on ctrl setup TRB without IOC set??\n");
1167                                 status = -ESHUTDOWN;
1168                         } else if (event_trb != td->last_trb) {
1169                                 xhci_warn(xhci, "WARN: Success on ctrl data TRB without IOC set??\n");
1170                                 status = -ESHUTDOWN;
1171                         } else {
1172                                 xhci_dbg(xhci, "Successful control transfer!\n");
1173                                 status = 0;
1174                         }
1175                         break;
1176                 case COMP_SHORT_TX:
1177                         xhci_warn(xhci, "WARN: short transfer on control ep\n");
1178                         if (td->urb->transfer_flags & URB_SHORT_NOT_OK)
1179                                 status = -EREMOTEIO;
1180                         else
1181                                 status = 0;
1182                         break;
1183                 case COMP_BABBLE:
1184                         /* The 0.96 spec says a babbling control endpoint
1185                          * is not halted. The 0.96 spec says it is.  Some HW
1186                          * claims to be 0.95 compliant, but it halts the control
1187                          * endpoint anyway.  Check if a babble halted the
1188                          * endpoint.
1189                          */
1190                         if (ep_ctx->ep_info != EP_STATE_HALTED)
1191                                 break;
1192                         /* else fall through */
1193                 case COMP_STALL:
1194                         /* Did we transfer part of the data (middle) phase? */
1195                         if (event_trb != ep_ring->dequeue &&
1196                                         event_trb != td->last_trb)
1197                                 td->urb->actual_length =
1198                                         td->urb->transfer_buffer_length
1199                                         - TRB_LEN(event->transfer_len);
1200                         else
1201                                 td->urb->actual_length = 0;
1202
1203                         ep->stopped_td = td;
1204                         ep->stopped_trb = event_trb;
1205                         xhci_queue_reset_ep(xhci, slot_id, ep_index);
1206                         xhci_cleanup_stalled_ring(xhci, td->urb->dev, ep_index);
1207                         xhci_ring_cmd_db(xhci);
1208                         goto td_cleanup;
1209                 default:
1210                         /* Others already handled above */
1211                         break;
1212                 }
1213                 /*
1214                  * Did we transfer any data, despite the errors that might have
1215                  * happened?  I.e. did we get past the setup stage?
1216                  */
1217                 if (event_trb != ep_ring->dequeue) {
1218                         /* The event was for the status stage */
1219                         if (event_trb == td->last_trb) {
1220                                 if (td->urb->actual_length != 0) {
1221                                         /* Don't overwrite a previously set error code */
1222                                         if ((status == -EINPROGRESS ||
1223                                                                 status == 0) &&
1224                                                         (td->urb->transfer_flags
1225                                                          & URB_SHORT_NOT_OK))
1226                                                 /* Did we already see a short data stage? */
1227                                                 status = -EREMOTEIO;
1228                                 } else {
1229                                         td->urb->actual_length =
1230                                                 td->urb->transfer_buffer_length;
1231                                 }
1232                         } else {
1233                         /* Maybe the event was for the data stage? */
1234                                 if (trb_comp_code != COMP_STOP_INVAL) {
1235                                         /* We didn't stop on a link TRB in the middle */
1236                                         td->urb->actual_length =
1237                                                 td->urb->transfer_buffer_length -
1238                                                 TRB_LEN(event->transfer_len);
1239                                         xhci_dbg(xhci, "Waiting for status stage event\n");
1240                                         urb = NULL;
1241                                         goto cleanup;
1242                                 }
1243                         }
1244                 }
1245         } else {
1246                 switch (trb_comp_code) {
1247                 case COMP_SUCCESS:
1248                         /* Double check that the HW transferred everything. */
1249                         if (event_trb != td->last_trb) {
1250                                 xhci_warn(xhci, "WARN Successful completion "
1251                                                 "on short TX\n");
1252                                 if (td->urb->transfer_flags & URB_SHORT_NOT_OK)
1253                                         status = -EREMOTEIO;
1254                                 else
1255                                         status = 0;
1256                         } else {
1257                                 if (usb_endpoint_xfer_bulk(&td->urb->ep->desc))
1258                                         xhci_dbg(xhci, "Successful bulk "
1259                                                         "transfer!\n");
1260                                 else
1261                                         xhci_dbg(xhci, "Successful interrupt "
1262                                                         "transfer!\n");
1263                                 status = 0;
1264                         }
1265                         break;
1266                 case COMP_SHORT_TX:
1267                         if (td->urb->transfer_flags & URB_SHORT_NOT_OK)
1268                                 status = -EREMOTEIO;
1269                         else
1270                                 status = 0;
1271                         break;
1272                 default:
1273                         /* Others already handled above */
1274                         break;
1275                 }
1276                 dev_dbg(&td->urb->dev->dev,
1277                                 "ep %#x - asked for %d bytes, "
1278                                 "%d bytes untransferred\n",
1279                                 td->urb->ep->desc.bEndpointAddress,
1280                                 td->urb->transfer_buffer_length,
1281                                 TRB_LEN(event->transfer_len));
1282                 /* Fast path - was this the last TRB in the TD for this URB? */
1283                 if (event_trb == td->last_trb) {
1284                         if (TRB_LEN(event->transfer_len) != 0) {
1285                                 td->urb->actual_length =
1286                                         td->urb->transfer_buffer_length -
1287                                         TRB_LEN(event->transfer_len);
1288                                 if (td->urb->transfer_buffer_length <
1289                                                 td->urb->actual_length) {
1290                                         xhci_warn(xhci, "HC gave bad length "
1291                                                         "of %d bytes left\n",
1292                                                         TRB_LEN(event->transfer_len));
1293                                         td->urb->actual_length = 0;
1294                                         if (td->urb->transfer_flags &
1295                                                         URB_SHORT_NOT_OK)
1296                                                 status = -EREMOTEIO;
1297                                         else
1298                                                 status = 0;
1299                                 }
1300                                 /* Don't overwrite a previously set error code */
1301                                 if (status == -EINPROGRESS) {
1302                                         if (td->urb->transfer_flags & URB_SHORT_NOT_OK)
1303                                                 status = -EREMOTEIO;
1304                                         else
1305                                                 status = 0;
1306                                 }
1307                         } else {
1308                                 td->urb->actual_length = td->urb->transfer_buffer_length;
1309                                 /* Ignore a short packet completion if the
1310                                  * untransferred length was zero.
1311                                  */
1312                                 if (status == -EREMOTEIO)
1313                                         status = 0;
1314                         }
1315                 } else {
1316                         /* Slow path - walk the list, starting from the dequeue
1317                          * pointer, to get the actual length transferred.
1318                          */
1319                         union xhci_trb *cur_trb;
1320                         struct xhci_segment *cur_seg;
1321
1322                         td->urb->actual_length = 0;
1323                         for (cur_trb = ep_ring->dequeue, cur_seg = ep_ring->deq_seg;
1324                                         cur_trb != event_trb;
1325                                         next_trb(xhci, ep_ring, &cur_seg, &cur_trb)) {
1326                                 if (TRB_TYPE(cur_trb->generic.field[3]) != TRB_TR_NOOP &&
1327                                                 TRB_TYPE(cur_trb->generic.field[3]) != TRB_LINK)
1328                                         td->urb->actual_length +=
1329                                                 TRB_LEN(cur_trb->generic.field[2]);
1330                         }
1331                         /* If the ring didn't stop on a Link or No-op TRB, add
1332                          * in the actual bytes transferred from the Normal TRB
1333                          */
1334                         if (trb_comp_code != COMP_STOP_INVAL)
1335                                 td->urb->actual_length +=
1336                                         TRB_LEN(cur_trb->generic.field[2]) -
1337                                         TRB_LEN(event->transfer_len);
1338                 }
1339         }
1340         if (trb_comp_code == COMP_STOP_INVAL ||
1341                         trb_comp_code == COMP_STOP) {
1342                 /* The Endpoint Stop Command completion will take care of any
1343                  * stopped TDs.  A stopped TD may be restarted, so don't update
1344                  * the ring dequeue pointer or take this TD off any lists yet.
1345                  */
1346                 ep->stopped_td = td;
1347                 ep->stopped_trb = event_trb;
1348         } else {
1349                 if (trb_comp_code == COMP_STALL ||
1350                                 trb_comp_code == COMP_BABBLE) {
1351                         /* The transfer is completed from the driver's
1352                          * perspective, but we need to issue a set dequeue
1353                          * command for this stalled endpoint to move the dequeue
1354                          * pointer past the TD.  We can't do that here because
1355                          * the halt condition must be cleared first.
1356                          */
1357                         ep->stopped_td = td;
1358                         ep->stopped_trb = event_trb;
1359                 } else {
1360                         /* Update ring dequeue pointer */
1361                         while (ep_ring->dequeue != td->last_trb)
1362                                 inc_deq(xhci, ep_ring, false);
1363                         inc_deq(xhci, ep_ring, false);
1364                 }
1365
1366 td_cleanup:
1367                 /* Clean up the endpoint's TD list */
1368                 urb = td->urb;
1369                 /* Do one last check of the actual transfer length.
1370                  * If the host controller said we transferred more data than
1371                  * the buffer length, urb->actual_length will be a very big
1372                  * number (since it's unsigned).  Play it safe and say we didn't
1373                  * transfer anything.
1374                  */
1375                 if (urb->actual_length > urb->transfer_buffer_length) {
1376                         xhci_warn(xhci, "URB transfer length is wrong, "
1377                                         "xHC issue? req. len = %u, "
1378                                         "act. len = %u\n",
1379                                         urb->transfer_buffer_length,
1380                                         urb->actual_length);
1381                         urb->actual_length = 0;
1382                         if (td->urb->transfer_flags & URB_SHORT_NOT_OK)
1383                                 status = -EREMOTEIO;
1384                         else
1385                                 status = 0;
1386                 }
1387                 list_del(&td->td_list);
1388                 /* Was this TD slated to be cancelled but completed anyway? */
1389                 if (!list_empty(&td->cancelled_td_list))
1390                         list_del(&td->cancelled_td_list);
1391
1392                 /* Leave the TD around for the reset endpoint function to use
1393                  * (but only if it's not a control endpoint, since we already
1394                  * queued the Set TR dequeue pointer command for stalled
1395                  * control endpoints).
1396                  */
1397                 if (usb_endpoint_xfer_control(&urb->ep->desc) ||
1398                         (trb_comp_code != COMP_STALL &&
1399                                 trb_comp_code != COMP_BABBLE)) {
1400                         kfree(td);
1401                 }
1402                 urb->hcpriv = NULL;
1403         }
1404 cleanup:
1405         inc_deq(xhci, xhci->event_ring, true);
1406         xhci_set_hc_event_deq(xhci);
1407
1408         /* FIXME for multi-TD URBs (who have buffers bigger than 64MB) */
1409         if (urb) {
1410                 usb_hcd_unlink_urb_from_ep(xhci_to_hcd(xhci), urb);
1411                 xhci_dbg(xhci, "Giveback URB %p, len = %d, status = %d\n",
1412                                 urb, urb->actual_length, status);
1413                 spin_unlock(&xhci->lock);
1414                 usb_hcd_giveback_urb(xhci_to_hcd(xhci), urb, status);
1415                 spin_lock(&xhci->lock);
1416         }
1417         return 0;
1418 }
1419
1420 /*
1421  * This function handles all OS-owned events on the event ring.  It may drop
1422  * xhci->lock between event processing (e.g. to pass up port status changes).
1423  */
1424 void xhci_handle_event(struct xhci_hcd *xhci)
1425 {
1426         union xhci_trb *event;
1427         int update_ptrs = 1;
1428         int ret;
1429
1430         xhci_dbg(xhci, "In %s\n", __func__);
1431         if (!xhci->event_ring || !xhci->event_ring->dequeue) {
1432                 xhci->error_bitmask |= 1 << 1;
1433                 return;
1434         }
1435
1436         event = xhci->event_ring->dequeue;
1437         /* Does the HC or OS own the TRB? */
1438         if ((event->event_cmd.flags & TRB_CYCLE) !=
1439                         xhci->event_ring->cycle_state) {
1440                 xhci->error_bitmask |= 1 << 2;
1441                 return;
1442         }
1443         xhci_dbg(xhci, "%s - OS owns TRB\n", __func__);
1444
1445         /* FIXME: Handle more event types. */
1446         switch ((event->event_cmd.flags & TRB_TYPE_BITMASK)) {
1447         case TRB_TYPE(TRB_COMPLETION):
1448                 xhci_dbg(xhci, "%s - calling handle_cmd_completion\n", __func__);
1449                 handle_cmd_completion(xhci, &event->event_cmd);
1450                 xhci_dbg(xhci, "%s - returned from handle_cmd_completion\n", __func__);
1451                 break;
1452         case TRB_TYPE(TRB_PORT_STATUS):
1453                 xhci_dbg(xhci, "%s - calling handle_port_status\n", __func__);
1454                 handle_port_status(xhci, event);
1455                 xhci_dbg(xhci, "%s - returned from handle_port_status\n", __func__);
1456                 update_ptrs = 0;
1457                 break;
1458         case TRB_TYPE(TRB_TRANSFER):
1459                 xhci_dbg(xhci, "%s - calling handle_tx_event\n", __func__);
1460                 ret = handle_tx_event(xhci, &event->trans_event);
1461                 xhci_dbg(xhci, "%s - returned from handle_tx_event\n", __func__);
1462                 if (ret < 0)
1463                         xhci->error_bitmask |= 1 << 9;
1464                 else
1465                         update_ptrs = 0;
1466                 break;
1467         default:
1468                 xhci->error_bitmask |= 1 << 3;
1469         }
1470         /* Any of the above functions may drop and re-acquire the lock, so check
1471          * to make sure a watchdog timer didn't mark the host as non-responsive.
1472          */
1473         if (xhci->xhc_state & XHCI_STATE_DYING) {
1474                 xhci_dbg(xhci, "xHCI host dying, returning from "
1475                                 "event handler.\n");
1476                 return;
1477         }
1478
1479         if (update_ptrs) {
1480                 /* Update SW and HC event ring dequeue pointer */
1481                 inc_deq(xhci, xhci->event_ring, true);
1482                 xhci_set_hc_event_deq(xhci);
1483         }
1484         /* Are there more items on the event ring? */
1485         xhci_handle_event(xhci);
1486 }
1487
1488 /****           Endpoint Ring Operations        ****/
1489
1490 /*
1491  * Generic function for queueing a TRB on a ring.
1492  * The caller must have checked to make sure there's room on the ring.
1493  */
1494 static void queue_trb(struct xhci_hcd *xhci, struct xhci_ring *ring,
1495                 bool consumer,
1496                 u32 field1, u32 field2, u32 field3, u32 field4)
1497 {
1498         struct xhci_generic_trb *trb;
1499
1500         trb = &ring->enqueue->generic;
1501         trb->field[0] = field1;
1502         trb->field[1] = field2;
1503         trb->field[2] = field3;
1504         trb->field[3] = field4;
1505         inc_enq(xhci, ring, consumer);
1506 }
1507
1508 /*
1509  * Does various checks on the endpoint ring, and makes it ready to queue num_trbs.
1510  * FIXME allocate segments if the ring is full.
1511  */
1512 static int prepare_ring(struct xhci_hcd *xhci, struct xhci_ring *ep_ring,
1513                 u32 ep_state, unsigned int num_trbs, gfp_t mem_flags)
1514 {
1515         /* Make sure the endpoint has been added to xHC schedule */
1516         xhci_dbg(xhci, "Endpoint state = 0x%x\n", ep_state);
1517         switch (ep_state) {
1518         case EP_STATE_DISABLED:
1519                 /*
1520                  * USB core changed config/interfaces without notifying us,
1521                  * or hardware is reporting the wrong state.
1522                  */
1523                 xhci_warn(xhci, "WARN urb submitted to disabled ep\n");
1524                 return -ENOENT;
1525         case EP_STATE_ERROR:
1526                 xhci_warn(xhci, "WARN waiting for error on ep to be cleared\n");
1527                 /* FIXME event handling code for error needs to clear it */
1528                 /* XXX not sure if this should be -ENOENT or not */
1529                 return -EINVAL;
1530         case EP_STATE_HALTED:
1531                 xhci_dbg(xhci, "WARN halted endpoint, queueing URB anyway.\n");
1532         case EP_STATE_STOPPED:
1533         case EP_STATE_RUNNING:
1534                 break;
1535         default:
1536                 xhci_err(xhci, "ERROR unknown endpoint state for ep\n");
1537                 /*
1538                  * FIXME issue Configure Endpoint command to try to get the HC
1539                  * back into a known state.
1540                  */
1541                 return -EINVAL;
1542         }
1543         if (!room_on_ring(xhci, ep_ring, num_trbs)) {
1544                 /* FIXME allocate more room */
1545                 xhci_err(xhci, "ERROR no room on ep ring\n");
1546                 return -ENOMEM;
1547         }
1548         return 0;
1549 }
1550
1551 static int prepare_transfer(struct xhci_hcd *xhci,
1552                 struct xhci_virt_device *xdev,
1553                 unsigned int ep_index,
1554                 unsigned int num_trbs,
1555                 struct urb *urb,
1556                 struct xhci_td **td,
1557                 gfp_t mem_flags)
1558 {
1559         int ret;
1560         struct xhci_ep_ctx *ep_ctx = xhci_get_ep_ctx(xhci, xdev->out_ctx, ep_index);
1561         ret = prepare_ring(xhci, xdev->eps[ep_index].ring,
1562                         ep_ctx->ep_info & EP_STATE_MASK,
1563                         num_trbs, mem_flags);
1564         if (ret)
1565                 return ret;
1566         *td = kzalloc(sizeof(struct xhci_td), mem_flags);
1567         if (!*td)
1568                 return -ENOMEM;
1569         INIT_LIST_HEAD(&(*td)->td_list);
1570         INIT_LIST_HEAD(&(*td)->cancelled_td_list);
1571
1572         ret = usb_hcd_link_urb_to_ep(xhci_to_hcd(xhci), urb);
1573         if (unlikely(ret)) {
1574                 kfree(*td);
1575                 return ret;
1576         }
1577
1578         (*td)->urb = urb;
1579         urb->hcpriv = (void *) (*td);
1580         /* Add this TD to the tail of the endpoint ring's TD list */
1581         list_add_tail(&(*td)->td_list, &xdev->eps[ep_index].ring->td_list);
1582         (*td)->start_seg = xdev->eps[ep_index].ring->enq_seg;
1583         (*td)->first_trb = xdev->eps[ep_index].ring->enqueue;
1584
1585         return 0;
1586 }
1587
1588 static unsigned int count_sg_trbs_needed(struct xhci_hcd *xhci, struct urb *urb)
1589 {
1590         int num_sgs, num_trbs, running_total, temp, i;
1591         struct scatterlist *sg;
1592
1593         sg = NULL;
1594         num_sgs = urb->num_sgs;
1595         temp = urb->transfer_buffer_length;
1596
1597         xhci_dbg(xhci, "count sg list trbs: \n");
1598         num_trbs = 0;
1599         for_each_sg(urb->sg->sg, sg, num_sgs, i) {
1600                 unsigned int previous_total_trbs = num_trbs;
1601                 unsigned int len = sg_dma_len(sg);
1602
1603                 /* Scatter gather list entries may cross 64KB boundaries */
1604                 running_total = TRB_MAX_BUFF_SIZE -
1605                         (sg_dma_address(sg) & ((1 << TRB_MAX_BUFF_SHIFT) - 1));
1606                 if (running_total != 0)
1607                         num_trbs++;
1608
1609                 /* How many more 64KB chunks to transfer, how many more TRBs? */
1610                 while (running_total < sg_dma_len(sg)) {
1611                         num_trbs++;
1612                         running_total += TRB_MAX_BUFF_SIZE;
1613                 }
1614                 xhci_dbg(xhci, " sg #%d: dma = %#llx, len = %#x (%d), num_trbs = %d\n",
1615                                 i, (unsigned long long)sg_dma_address(sg),
1616                                 len, len, num_trbs - previous_total_trbs);
1617
1618                 len = min_t(int, len, temp);
1619                 temp -= len;
1620                 if (temp == 0)
1621                         break;
1622         }
1623         xhci_dbg(xhci, "\n");
1624         if (!in_interrupt())
1625                 dev_dbg(&urb->dev->dev, "ep %#x - urb len = %d, sglist used, num_trbs = %d\n",
1626                                 urb->ep->desc.bEndpointAddress,
1627                                 urb->transfer_buffer_length,
1628                                 num_trbs);
1629         return num_trbs;
1630 }
1631
1632 static void check_trb_math(struct urb *urb, int num_trbs, int running_total)
1633 {
1634         if (num_trbs != 0)
1635                 dev_dbg(&urb->dev->dev, "%s - ep %#x - Miscalculated number of "
1636                                 "TRBs, %d left\n", __func__,
1637                                 urb->ep->desc.bEndpointAddress, num_trbs);
1638         if (running_total != urb->transfer_buffer_length)
1639                 dev_dbg(&urb->dev->dev, "%s - ep %#x - Miscalculated tx length, "
1640                                 "queued %#x (%d), asked for %#x (%d)\n",
1641                                 __func__,
1642                                 urb->ep->desc.bEndpointAddress,
1643                                 running_total, running_total,
1644                                 urb->transfer_buffer_length,
1645                                 urb->transfer_buffer_length);
1646 }
1647
1648 static void giveback_first_trb(struct xhci_hcd *xhci, int slot_id,
1649                 unsigned int ep_index, int start_cycle,
1650                 struct xhci_generic_trb *start_trb, struct xhci_td *td)
1651 {
1652         /*
1653          * Pass all the TRBs to the hardware at once and make sure this write
1654          * isn't reordered.
1655          */
1656         wmb();
1657         start_trb->field[3] |= start_cycle;
1658         ring_ep_doorbell(xhci, slot_id, ep_index);
1659 }
1660
1661 /*
1662  * xHCI uses normal TRBs for both bulk and interrupt.  When the interrupt
1663  * endpoint is to be serviced, the xHC will consume (at most) one TD.  A TD
1664  * (comprised of sg list entries) can take several service intervals to
1665  * transmit.
1666  */
1667 int xhci_queue_intr_tx(struct xhci_hcd *xhci, gfp_t mem_flags,
1668                 struct urb *urb, int slot_id, unsigned int ep_index)
1669 {
1670         struct xhci_ep_ctx *ep_ctx = xhci_get_ep_ctx(xhci,
1671                         xhci->devs[slot_id]->out_ctx, ep_index);
1672         int xhci_interval;
1673         int ep_interval;
1674
1675         xhci_interval = EP_INTERVAL_TO_UFRAMES(ep_ctx->ep_info);
1676         ep_interval = urb->interval;
1677         /* Convert to microframes */
1678         if (urb->dev->speed == USB_SPEED_LOW ||
1679                         urb->dev->speed == USB_SPEED_FULL)
1680                 ep_interval *= 8;
1681         /* FIXME change this to a warning and a suggestion to use the new API
1682          * to set the polling interval (once the API is added).
1683          */
1684         if (xhci_interval != ep_interval) {
1685                 if (!printk_ratelimit())
1686                         dev_dbg(&urb->dev->dev, "Driver uses different interval"
1687                                         " (%d microframe%s) than xHCI "
1688                                         "(%d microframe%s)\n",
1689                                         ep_interval,
1690                                         ep_interval == 1 ? "" : "s",
1691                                         xhci_interval,
1692                                         xhci_interval == 1 ? "" : "s");
1693                 urb->interval = xhci_interval;
1694                 /* Convert back to frames for LS/FS devices */
1695                 if (urb->dev->speed == USB_SPEED_LOW ||
1696                                 urb->dev->speed == USB_SPEED_FULL)
1697                         urb->interval /= 8;
1698         }
1699         return xhci_queue_bulk_tx(xhci, GFP_ATOMIC, urb, slot_id, ep_index);
1700 }
1701
1702 static int queue_bulk_sg_tx(struct xhci_hcd *xhci, gfp_t mem_flags,
1703                 struct urb *urb, int slot_id, unsigned int ep_index)
1704 {
1705         struct xhci_ring *ep_ring;
1706         unsigned int num_trbs;
1707         struct xhci_td *td;
1708         struct scatterlist *sg;
1709         int num_sgs;
1710         int trb_buff_len, this_sg_len, running_total;
1711         bool first_trb;
1712         u64 addr;
1713
1714         struct xhci_generic_trb *start_trb;
1715         int start_cycle;
1716
1717         ep_ring = xhci->devs[slot_id]->eps[ep_index].ring;
1718         num_trbs = count_sg_trbs_needed(xhci, urb);
1719         num_sgs = urb->num_sgs;
1720
1721         trb_buff_len = prepare_transfer(xhci, xhci->devs[slot_id],
1722                         ep_index, num_trbs, urb, &td, mem_flags);
1723         if (trb_buff_len < 0)
1724                 return trb_buff_len;
1725         /*
1726          * Don't give the first TRB to the hardware (by toggling the cycle bit)
1727          * until we've finished creating all the other TRBs.  The ring's cycle
1728          * state may change as we enqueue the other TRBs, so save it too.
1729          */
1730         start_trb = &ep_ring->enqueue->generic;
1731         start_cycle = ep_ring->cycle_state;
1732
1733         running_total = 0;
1734         /*
1735          * How much data is in the first TRB?
1736          *
1737          * There are three forces at work for TRB buffer pointers and lengths:
1738          * 1. We don't want to walk off the end of this sg-list entry buffer.
1739          * 2. The transfer length that the driver requested may be smaller than
1740          *    the amount of memory allocated for this scatter-gather list.
1741          * 3. TRBs buffers can't cross 64KB boundaries.
1742          */
1743         sg = urb->sg->sg;
1744         addr = (u64) sg_dma_address(sg);
1745         this_sg_len = sg_dma_len(sg);
1746         trb_buff_len = TRB_MAX_BUFF_SIZE -
1747                 (addr & ((1 << TRB_MAX_BUFF_SHIFT) - 1));
1748         trb_buff_len = min_t(int, trb_buff_len, this_sg_len);
1749         if (trb_buff_len > urb->transfer_buffer_length)
1750                 trb_buff_len = urb->transfer_buffer_length;
1751         xhci_dbg(xhci, "First length to xfer from 1st sglist entry = %u\n",
1752                         trb_buff_len);
1753
1754         first_trb = true;
1755         /* Queue the first TRB, even if it's zero-length */
1756         do {
1757                 u32 field = 0;
1758                 u32 length_field = 0;
1759
1760                 /* Don't change the cycle bit of the first TRB until later */
1761                 if (first_trb)
1762                         first_trb = false;
1763                 else
1764                         field |= ep_ring->cycle_state;
1765
1766                 /* Chain all the TRBs together; clear the chain bit in the last
1767                  * TRB to indicate it's the last TRB in the chain.
1768                  */
1769                 if (num_trbs > 1) {
1770                         field |= TRB_CHAIN;
1771                 } else {
1772                         /* FIXME - add check for ZERO_PACKET flag before this */
1773                         td->last_trb = ep_ring->enqueue;
1774                         field |= TRB_IOC;
1775                 }
1776                 xhci_dbg(xhci, " sg entry: dma = %#x, len = %#x (%d), "
1777                                 "64KB boundary at %#x, end dma = %#x\n",
1778                                 (unsigned int) addr, trb_buff_len, trb_buff_len,
1779                                 (unsigned int) (addr + TRB_MAX_BUFF_SIZE) & ~(TRB_MAX_BUFF_SIZE - 1),
1780                                 (unsigned int) addr + trb_buff_len);
1781                 if (TRB_MAX_BUFF_SIZE -
1782                                 (addr & ((1 << TRB_MAX_BUFF_SHIFT) - 1)) < trb_buff_len) {
1783                         xhci_warn(xhci, "WARN: sg dma xfer crosses 64KB boundaries!\n");
1784                         xhci_dbg(xhci, "Next boundary at %#x, end dma = %#x\n",
1785                                         (unsigned int) (addr + TRB_MAX_BUFF_SIZE) & ~(TRB_MAX_BUFF_SIZE - 1),
1786                                         (unsigned int) addr + trb_buff_len);
1787                 }
1788                 length_field = TRB_LEN(trb_buff_len) |
1789                         TD_REMAINDER(urb->transfer_buffer_length - running_total) |
1790                         TRB_INTR_TARGET(0);
1791                 queue_trb(xhci, ep_ring, false,
1792                                 lower_32_bits(addr),
1793                                 upper_32_bits(addr),
1794                                 length_field,
1795                                 /* We always want to know if the TRB was short,
1796                                  * or we won't get an event when it completes.
1797                                  * (Unless we use event data TRBs, which are a
1798                                  * waste of space and HC resources.)
1799                                  */
1800                                 field | TRB_ISP | TRB_TYPE(TRB_NORMAL));
1801                 --num_trbs;
1802                 running_total += trb_buff_len;
1803
1804                 /* Calculate length for next transfer --
1805                  * Are we done queueing all the TRBs for this sg entry?
1806                  */
1807                 this_sg_len -= trb_buff_len;
1808                 if (this_sg_len == 0) {
1809                         --num_sgs;
1810                         if (num_sgs == 0)
1811                                 break;
1812                         sg = sg_next(sg);
1813                         addr = (u64) sg_dma_address(sg);
1814                         this_sg_len = sg_dma_len(sg);
1815                 } else {
1816                         addr += trb_buff_len;
1817                 }
1818
1819                 trb_buff_len = TRB_MAX_BUFF_SIZE -
1820                         (addr & ((1 << TRB_MAX_BUFF_SHIFT) - 1));
1821                 trb_buff_len = min_t(int, trb_buff_len, this_sg_len);
1822                 if (running_total + trb_buff_len > urb->transfer_buffer_length)
1823                         trb_buff_len =
1824                                 urb->transfer_buffer_length - running_total;
1825         } while (running_total < urb->transfer_buffer_length);
1826
1827         check_trb_math(urb, num_trbs, running_total);
1828         giveback_first_trb(xhci, slot_id, ep_index, start_cycle, start_trb, td);
1829         return 0;
1830 }
1831
1832 /* This is very similar to what ehci-q.c qtd_fill() does */
1833 int xhci_queue_bulk_tx(struct xhci_hcd *xhci, gfp_t mem_flags,
1834                 struct urb *urb, int slot_id, unsigned int ep_index)
1835 {
1836         struct xhci_ring *ep_ring;
1837         struct xhci_td *td;
1838         int num_trbs;
1839         struct xhci_generic_trb *start_trb;
1840         bool first_trb;
1841         int start_cycle;
1842         u32 field, length_field;
1843
1844         int running_total, trb_buff_len, ret;
1845         u64 addr;
1846
1847         if (urb->sg)
1848                 return queue_bulk_sg_tx(xhci, mem_flags, urb, slot_id, ep_index);
1849
1850         ep_ring = xhci->devs[slot_id]->eps[ep_index].ring;
1851
1852         num_trbs = 0;
1853         /* How much data is (potentially) left before the 64KB boundary? */
1854         running_total = TRB_MAX_BUFF_SIZE -
1855                 (urb->transfer_dma & ((1 << TRB_MAX_BUFF_SHIFT) - 1));
1856
1857         /* If there's some data on this 64KB chunk, or we have to send a
1858          * zero-length transfer, we need at least one TRB
1859          */
1860         if (running_total != 0 || urb->transfer_buffer_length == 0)
1861                 num_trbs++;
1862         /* How many more 64KB chunks to transfer, how many more TRBs? */
1863         while (running_total < urb->transfer_buffer_length) {
1864                 num_trbs++;
1865                 running_total += TRB_MAX_BUFF_SIZE;
1866         }
1867         /* FIXME: this doesn't deal with URB_ZERO_PACKET - need one more */
1868
1869         if (!in_interrupt())
1870                 dev_dbg(&urb->dev->dev, "ep %#x - urb len = %#x (%d), addr = %#llx, num_trbs = %d\n",
1871                                 urb->ep->desc.bEndpointAddress,
1872                                 urb->transfer_buffer_length,
1873                                 urb->transfer_buffer_length,
1874                                 (unsigned long long)urb->transfer_dma,
1875                                 num_trbs);
1876
1877         ret = prepare_transfer(xhci, xhci->devs[slot_id], ep_index,
1878                         num_trbs, urb, &td, mem_flags);
1879         if (ret < 0)
1880                 return ret;
1881
1882         /*
1883          * Don't give the first TRB to the hardware (by toggling the cycle bit)
1884          * until we've finished creating all the other TRBs.  The ring's cycle
1885          * state may change as we enqueue the other TRBs, so save it too.
1886          */
1887         start_trb = &ep_ring->enqueue->generic;
1888         start_cycle = ep_ring->cycle_state;
1889
1890         running_total = 0;
1891         /* How much data is in the first TRB? */
1892         addr = (u64) urb->transfer_dma;
1893         trb_buff_len = TRB_MAX_BUFF_SIZE -
1894                 (urb->transfer_dma & ((1 << TRB_MAX_BUFF_SHIFT) - 1));
1895         if (urb->transfer_buffer_length < trb_buff_len)
1896                 trb_buff_len = urb->transfer_buffer_length;
1897
1898         first_trb = true;
1899
1900         /* Queue the first TRB, even if it's zero-length */
1901         do {
1902                 field = 0;
1903
1904                 /* Don't change the cycle bit of the first TRB until later */
1905                 if (first_trb)
1906                         first_trb = false;
1907                 else
1908                         field |= ep_ring->cycle_state;
1909
1910                 /* Chain all the TRBs together; clear the chain bit in the last
1911                  * TRB to indicate it's the last TRB in the chain.
1912                  */
1913                 if (num_trbs > 1) {
1914                         field |= TRB_CHAIN;
1915                 } else {
1916                         /* FIXME - add check for ZERO_PACKET flag before this */
1917                         td->last_trb = ep_ring->enqueue;
1918                         field |= TRB_IOC;
1919                 }
1920                 length_field = TRB_LEN(trb_buff_len) |
1921                         TD_REMAINDER(urb->transfer_buffer_length - running_total) |
1922                         TRB_INTR_TARGET(0);
1923                 queue_trb(xhci, ep_ring, false,
1924                                 lower_32_bits(addr),
1925                                 upper_32_bits(addr),
1926                                 length_field,
1927                                 /* We always want to know if the TRB was short,
1928                                  * or we won't get an event when it completes.
1929                                  * (Unless we use event data TRBs, which are a
1930                                  * waste of space and HC resources.)
1931                                  */
1932                                 field | TRB_ISP | TRB_TYPE(TRB_NORMAL));
1933                 --num_trbs;
1934                 running_total += trb_buff_len;
1935
1936                 /* Calculate length for next transfer */
1937                 addr += trb_buff_len;
1938                 trb_buff_len = urb->transfer_buffer_length - running_total;
1939                 if (trb_buff_len > TRB_MAX_BUFF_SIZE)
1940                         trb_buff_len = TRB_MAX_BUFF_SIZE;
1941         } while (running_total < urb->transfer_buffer_length);
1942
1943         check_trb_math(urb, num_trbs, running_total);
1944         giveback_first_trb(xhci, slot_id, ep_index, start_cycle, start_trb, td);
1945         return 0;
1946 }
1947
1948 /* Caller must have locked xhci->lock */
1949 int xhci_queue_ctrl_tx(struct xhci_hcd *xhci, gfp_t mem_flags,
1950                 struct urb *urb, int slot_id, unsigned int ep_index)
1951 {
1952         struct xhci_ring *ep_ring;
1953         int num_trbs;
1954         int ret;
1955         struct usb_ctrlrequest *setup;
1956         struct xhci_generic_trb *start_trb;
1957         int start_cycle;
1958         u32 field, length_field;
1959         struct xhci_td *td;
1960
1961         ep_ring = xhci->devs[slot_id]->eps[ep_index].ring;
1962
1963         /*
1964          * Need to copy setup packet into setup TRB, so we can't use the setup
1965          * DMA address.
1966          */
1967         if (!urb->setup_packet)
1968                 return -EINVAL;
1969
1970         if (!in_interrupt())
1971                 xhci_dbg(xhci, "Queueing ctrl tx for slot id %d, ep %d\n",
1972                                 slot_id, ep_index);
1973         /* 1 TRB for setup, 1 for status */
1974         num_trbs = 2;
1975         /*
1976          * Don't need to check if we need additional event data and normal TRBs,
1977          * since data in control transfers will never get bigger than 16MB
1978          * XXX: can we get a buffer that crosses 64KB boundaries?
1979          */
1980         if (urb->transfer_buffer_length > 0)
1981                 num_trbs++;
1982         ret = prepare_transfer(xhci, xhci->devs[slot_id], ep_index, num_trbs,
1983                         urb, &td, mem_flags);
1984         if (ret < 0)
1985                 return ret;
1986
1987         /*
1988          * Don't give the first TRB to the hardware (by toggling the cycle bit)
1989          * until we've finished creating all the other TRBs.  The ring's cycle
1990          * state may change as we enqueue the other TRBs, so save it too.
1991          */
1992         start_trb = &ep_ring->enqueue->generic;
1993         start_cycle = ep_ring->cycle_state;
1994
1995         /* Queue setup TRB - see section 6.4.1.2.1 */
1996         /* FIXME better way to translate setup_packet into two u32 fields? */
1997         setup = (struct usb_ctrlrequest *) urb->setup_packet;
1998         queue_trb(xhci, ep_ring, false,
1999                         /* FIXME endianness is probably going to bite my ass here. */
2000                         setup->bRequestType | setup->bRequest << 8 | setup->wValue << 16,
2001                         setup->wIndex | setup->wLength << 16,
2002                         TRB_LEN(8) | TRB_INTR_TARGET(0),
2003                         /* Immediate data in pointer */
2004                         TRB_IDT | TRB_TYPE(TRB_SETUP));
2005
2006         /* If there's data, queue data TRBs */
2007         field = 0;
2008         length_field = TRB_LEN(urb->transfer_buffer_length) |
2009                 TD_REMAINDER(urb->transfer_buffer_length) |
2010                 TRB_INTR_TARGET(0);
2011         if (urb->transfer_buffer_length > 0) {
2012                 if (setup->bRequestType & USB_DIR_IN)
2013                         field |= TRB_DIR_IN;
2014                 queue_trb(xhci, ep_ring, false,
2015                                 lower_32_bits(urb->transfer_dma),
2016                                 upper_32_bits(urb->transfer_dma),
2017                                 length_field,
2018                                 /* Event on short tx */
2019                                 field | TRB_ISP | TRB_TYPE(TRB_DATA) | ep_ring->cycle_state);
2020         }
2021
2022         /* Save the DMA address of the last TRB in the TD */
2023         td->last_trb = ep_ring->enqueue;
2024
2025         /* Queue status TRB - see Table 7 and sections 4.11.2.2 and 6.4.1.2.3 */
2026         /* If the device sent data, the status stage is an OUT transfer */
2027         if (urb->transfer_buffer_length > 0 && setup->bRequestType & USB_DIR_IN)
2028                 field = 0;
2029         else
2030                 field = TRB_DIR_IN;
2031         queue_trb(xhci, ep_ring, false,
2032                         0,
2033                         0,
2034                         TRB_INTR_TARGET(0),
2035                         /* Event on completion */
2036                         field | TRB_IOC | TRB_TYPE(TRB_STATUS) | ep_ring->cycle_state);
2037
2038         giveback_first_trb(xhci, slot_id, ep_index, start_cycle, start_trb, td);
2039         return 0;
2040 }
2041
2042 /****           Command Ring Operations         ****/
2043
2044 /* Generic function for queueing a command TRB on the command ring.
2045  * Check to make sure there's room on the command ring for one command TRB.
2046  * Also check that there's room reserved for commands that must not fail.
2047  * If this is a command that must not fail, meaning command_must_succeed = TRUE,
2048  * then only check for the number of reserved spots.
2049  * Don't decrement xhci->cmd_ring_reserved_trbs after we've queued the TRB
2050  * because the command event handler may want to resubmit a failed command.
2051  */
2052 static int queue_command(struct xhci_hcd *xhci, u32 field1, u32 field2,
2053                 u32 field3, u32 field4, bool command_must_succeed)
2054 {
2055         int reserved_trbs = xhci->cmd_ring_reserved_trbs;
2056         if (!command_must_succeed)
2057                 reserved_trbs++;
2058
2059         if (!room_on_ring(xhci, xhci->cmd_ring, reserved_trbs)) {
2060                 if (!in_interrupt())
2061                         xhci_err(xhci, "ERR: No room for command on command ring\n");
2062                 if (command_must_succeed)
2063                         xhci_err(xhci, "ERR: Reserved TRB counting for "
2064                                         "unfailable commands failed.\n");
2065                 return -ENOMEM;
2066         }
2067         queue_trb(xhci, xhci->cmd_ring, false, field1, field2, field3,
2068                         field4 | xhci->cmd_ring->cycle_state);
2069         return 0;
2070 }
2071
2072 /* Queue a no-op command on the command ring */
2073 static int queue_cmd_noop(struct xhci_hcd *xhci)
2074 {
2075         return queue_command(xhci, 0, 0, 0, TRB_TYPE(TRB_CMD_NOOP), false);
2076 }
2077
2078 /*
2079  * Place a no-op command on the command ring to test the command and
2080  * event ring.
2081  */
2082 void *xhci_setup_one_noop(struct xhci_hcd *xhci)
2083 {
2084         if (queue_cmd_noop(xhci) < 0)
2085                 return NULL;
2086         xhci->noops_submitted++;
2087         return xhci_ring_cmd_db;
2088 }
2089
2090 /* Queue a slot enable or disable request on the command ring */
2091 int xhci_queue_slot_control(struct xhci_hcd *xhci, u32 trb_type, u32 slot_id)
2092 {
2093         return queue_command(xhci, 0, 0, 0,
2094                         TRB_TYPE(trb_type) | SLOT_ID_FOR_TRB(slot_id), false);
2095 }
2096
2097 /* Queue an address device command TRB */
2098 int xhci_queue_address_device(struct xhci_hcd *xhci, dma_addr_t in_ctx_ptr,
2099                 u32 slot_id)
2100 {
2101         return queue_command(xhci, lower_32_bits(in_ctx_ptr),
2102                         upper_32_bits(in_ctx_ptr), 0,
2103                         TRB_TYPE(TRB_ADDR_DEV) | SLOT_ID_FOR_TRB(slot_id),
2104                         false);
2105 }
2106
2107 /* Queue a configure endpoint command TRB */
2108 int xhci_queue_configure_endpoint(struct xhci_hcd *xhci, dma_addr_t in_ctx_ptr,
2109                 u32 slot_id, bool command_must_succeed)
2110 {
2111         return queue_command(xhci, lower_32_bits(in_ctx_ptr),
2112                         upper_32_bits(in_ctx_ptr), 0,
2113                         TRB_TYPE(TRB_CONFIG_EP) | SLOT_ID_FOR_TRB(slot_id),
2114                         command_must_succeed);
2115 }
2116
2117 /* Queue an evaluate context command TRB */
2118 int xhci_queue_evaluate_context(struct xhci_hcd *xhci, dma_addr_t in_ctx_ptr,
2119                 u32 slot_id)
2120 {
2121         return queue_command(xhci, lower_32_bits(in_ctx_ptr),
2122                         upper_32_bits(in_ctx_ptr), 0,
2123                         TRB_TYPE(TRB_EVAL_CONTEXT) | SLOT_ID_FOR_TRB(slot_id),
2124                         false);
2125 }
2126
2127 int xhci_queue_stop_endpoint(struct xhci_hcd *xhci, int slot_id,
2128                 unsigned int ep_index)
2129 {
2130         u32 trb_slot_id = SLOT_ID_FOR_TRB(slot_id);
2131         u32 trb_ep_index = EP_ID_FOR_TRB(ep_index);
2132         u32 type = TRB_TYPE(TRB_STOP_RING);
2133
2134         return queue_command(xhci, 0, 0, 0,
2135                         trb_slot_id | trb_ep_index | type, false);
2136 }
2137
2138 /* Set Transfer Ring Dequeue Pointer command.
2139  * This should not be used for endpoints that have streams enabled.
2140  */
2141 static int queue_set_tr_deq(struct xhci_hcd *xhci, int slot_id,
2142                 unsigned int ep_index, struct xhci_segment *deq_seg,
2143                 union xhci_trb *deq_ptr, u32 cycle_state)
2144 {
2145         dma_addr_t addr;
2146         u32 trb_slot_id = SLOT_ID_FOR_TRB(slot_id);
2147         u32 trb_ep_index = EP_ID_FOR_TRB(ep_index);
2148         u32 type = TRB_TYPE(TRB_SET_DEQ);
2149
2150         addr = xhci_trb_virt_to_dma(deq_seg, deq_ptr);
2151         if (addr == 0) {
2152                 xhci_warn(xhci, "WARN Cannot submit Set TR Deq Ptr\n");
2153                 xhci_warn(xhci, "WARN deq seg = %p, deq pt = %p\n",
2154                                 deq_seg, deq_ptr);
2155                 return 0;
2156         }
2157         return queue_command(xhci, lower_32_bits(addr) | cycle_state,
2158                         upper_32_bits(addr), 0,
2159                         trb_slot_id | trb_ep_index | type, false);
2160 }
2161
2162 int xhci_queue_reset_ep(struct xhci_hcd *xhci, int slot_id,
2163                 unsigned int ep_index)
2164 {
2165         u32 trb_slot_id = SLOT_ID_FOR_TRB(slot_id);
2166         u32 trb_ep_index = EP_ID_FOR_TRB(ep_index);
2167         u32 type = TRB_TYPE(TRB_RESET_EP);
2168
2169         return queue_command(xhci, 0, 0, 0, trb_slot_id | trb_ep_index | type,
2170                         false);
2171 }