drivers/usb/host/xhci-ring.c

   1 /*
   2  * xHCI host controller driver
   3  *
   4  * Copyright (C) 2008 Intel Corp.
   5  *
   6  * Author: Sarah Sharp
   7  * Some code borrowed from the Linux EHCI driver.
   8  *
   9  * This program is free software; you can redistribute it and/or modify
  10  * it under the terms of the GNU General Public License version 2 as
  11  * published by the Free Software Foundation.
  12  *
  13  * This program is distributed in the hope that it will be useful, but
  14  * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
  15  * or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  16  * for more details.
  17  *
  18  * You should have received a copy of the GNU General Public License
  19  * along with this program; if not, write to the Free Software Foundation,
  20  * Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  21  */
  22
  23 /*
  24  * Ring initialization rules:
  25  * 1. Each segment is initialized to zero, except for link TRBs.
  26  * 2. Ring cycle state = 0.  This represents Producer Cycle State (PCS) or
  27  *    Consumer Cycle State (CCS), depending on ring function.
  28  * 3. Enqueue pointer = dequeue pointer = address of first TRB in the segment.
  29  *
  30  * Ring behavior rules:
  31  * 1. A ring is empty if enqueue == dequeue.  This means there will always be at
  32  *    least one free TRB in the ring.  This is useful if you want to turn that
  33  *    into a link TRB and expand the ring.
  34  * 2. When incrementing an enqueue or dequeue pointer, if the next TRB is a
  35  *    link TRB, then load the pointer with the address in the link TRB.  If the
  36  *    link TRB had its toggle bit set, you may need to update the ring cycle
  37  *    state (see cycle bit rules).  You may have to do this multiple times
  38  *    until you reach a non-link TRB.
  39  * 3. A ring is full if enqueue++ (for the definition of increment above)
  40  *    equals the dequeue pointer.
  41  *
  42  * Cycle bit rules:
  43  * 1. When a consumer increments a dequeue pointer and encounters a toggle bit
  44  *    in a link TRB, it must toggle the ring cycle state.
  45  * 2. When a producer increments an enqueue pointer and encounters a toggle bit
  46  *    in a link TRB, it must toggle the ring cycle state.
  47  *
  48  * Producer rules:
  49  * 1. Check if ring is full before you enqueue.
  50  * 2. Write the ring cycle state to the cycle bit in the TRB you're enqueuing.
  51  *    Update enqueue pointer between each write (which may update the ring
  52  *    cycle state).
  53  * 3. Notify consumer.  If SW is producer, it rings the doorbell for command
  54  *    and endpoint rings.  If HC is the producer for the event ring,
  55  *    and it generates an interrupt according to interrupt modulation rules.
  56  *
  57  * Consumer rules:
  58  * 1. Check if TRB belongs to you.  If the cycle bit == your ring cycle state,
  59  *    the TRB is owned by the consumer.
  60  * 2. Update dequeue pointer (which may update the ring cycle state) and
  61  *    continue processing TRBs until you reach a TRB which is not owned by you.
  62  * 3. Notify the producer.  SW is the consumer for the event ring, and it
  63  *   updates event ring dequeue pointer.  HC is the consumer for the command and
  64  *   endpoint rings; it generates events on the event ring for these.
  65  */
  66
  67 #include <linux/scatterlist.h>
  68 #include <linux/slab.h>
  69 #include "xhci.h"
  70
  71 /*
  72  * Returns zero if the TRB isn't in this segment, otherwise it returns the DMA
  73  * address of the TRB.
  74  */
  75 dma_addr_t xhci_trb_virt_to_dma(struct xhci_segment *seg,
  76                 union xhci_trb *trb)
  77 {
  78         unsigned long segment_offset;
  79
  80         if (!seg || !trb || trb < seg->trbs)
  81                 return 0;
  82         /* offset in TRBs */
  83         segment_offset = trb - seg->trbs;
  84         if (segment_offset > TRBS_PER_SEGMENT)
  85                 return 0;
  86         return seg->dma + (segment_offset * sizeof(*trb));
  87 }
  88
  89 /* Does this link TRB point to the first segment in a ring,
  90  * or was the previous TRB the last TRB on the last segment in the ERST?
  91  */
  92 static inline bool last_trb_on_last_seg(struct xhci_hcd *xhci, struct xhci_ring *ring,
  93                 struct xhci_segment *seg, union xhci_trb *trb)
  94 {
  95         if (ring == xhci->event_ring)
  96                 return (trb == &seg->trbs[TRBS_PER_SEGMENT]) &&
  97                         (seg->next == xhci->event_ring->first_seg);
  98         else
  99                 return trb->link.control & LINK_TOGGLE;
 100 }
 101
 102 /* Is this TRB a link TRB or was the last TRB the last TRB in this event ring
 103  * segment?  I.e. would the updated event TRB pointer step off the end of the
 104  * event seg?
 105  */
 106 static inline int last_trb(struct xhci_hcd *xhci, struct xhci_ring *ring,
 107                 struct xhci_segment *seg, union xhci_trb *trb)
 108 {
 109         if (ring == xhci->event_ring)
 110                 return trb == &seg->trbs[TRBS_PER_SEGMENT];
 111         else
 112                 return (trb->link.control & TRB_TYPE_BITMASK) == TRB_TYPE(TRB_LINK);
 113 }
 114
 115 static inline int enqueue_is_link_trb(struct xhci_ring *ring)
 116 {
 117         struct xhci_link_trb *link = &ring->enqueue->link;
 118         return ((link->control & TRB_TYPE_BITMASK) == TRB_TYPE(TRB_LINK));
 119 }
 120
 121 /* Updates trb to point to the next TRB in the ring, and updates seg if the next
 122  * TRB is in a new segment.  This does not skip over link TRBs, and it does not
 123  * effect the ring dequeue or enqueue pointers.
 124  */
 125 static void next_trb(struct xhci_hcd *xhci,
 126                 struct xhci_ring *ring,
 127                 struct xhci_segment **seg,
 128                 union xhci_trb **trb)
 129 {
 130         if (last_trb(xhci, ring, *seg, *trb)) {
 131                 *seg = (*seg)->next;
 132                 *trb = ((*seg)->trbs);
 133         } else {
 134                 *trb = (*trb)++;
 135         }
 136 }
 137
 138 /*
 139  * See Cycle bit rules. SW is the consumer for the event ring only.
 140  * Don't make a ring full of link TRBs.  That would be dumb and this would loop.
 141  */
 142 static void inc_deq(struct xhci_hcd *xhci, struct xhci_ring *ring, bool consumer)
 143 {
 144         union xhci_trb *next = ++(ring->dequeue);
 145         unsigned long long addr;
 146
 147         ring->deq_updates++;
 148         /* Update the dequeue pointer further if that was a link TRB or we're at
 149          * the end of an event ring segment (which doesn't have link TRBS)
 150          */
 151         while (last_trb(xhci, ring, ring->deq_seg, next)) {
 152                 if (consumer && last_trb_on_last_seg(xhci, ring, ring->deq_seg, next)) {
 153                         ring->cycle_state = (ring->cycle_state ? 0 : 1);
 154                         if (!in_interrupt())
 155                                 xhci_dbg(xhci, "Toggle cycle state for ring %p = %i\n",
 156                                                 ring,
 157                                                 (unsigned int) ring->cycle_state);
 158                 }
 159                 ring->deq_seg = ring->deq_seg->next;
 160                 ring->dequeue = ring->deq_seg->trbs;
 161                 next = ring->dequeue;
 162         }
 163         addr = (unsigned long long) xhci_trb_virt_to_dma(ring->deq_seg, ring->dequeue);
 164         if (ring == xhci->event_ring)
 165                 xhci_dbg(xhci, "Event ring deq = 0x%llx (DMA)\n", addr);
 166         else if (ring == xhci->cmd_ring)
 167                 xhci_dbg(xhci, "Command ring deq = 0x%llx (DMA)\n", addr);
 168         else
 169                 xhci_dbg(xhci, "Ring deq = 0x%llx (DMA)\n", addr);
 170 }
 171
 172 /*
 173  * See Cycle bit rules. SW is the consumer for the event ring only.
 174  * Don't make a ring full of link TRBs.  That would be dumb and this would loop.
 175  *
 176  * If we've just enqueued a TRB that is in the middle of a TD (meaning the
 177  * chain bit is set), then set the chain bit in all the following link TRBs.
 178  * If we've enqueued the last TRB in a TD, make sure the following link TRBs
 179  * have their chain bit cleared (so that each Link TRB is a separate TD).
 180  *
 181  * Section 6.4.4.1 of the 0.95 spec says link TRBs cannot have the chain bit
 182  * set, but other sections talk about dealing with the chain bit set.  This was
 183  * fixed in the 0.96 specification errata, but we have to assume that all 0.95
 184  * xHCI hardware can't handle the chain bit being cleared on a link TRB.
 185  */
 186 static void inc_enq(struct xhci_hcd *xhci, struct xhci_ring *ring, bool consumer)
 187 {
 188         u32 chain;
 189         union xhci_trb *next;
 190         unsigned long long addr;
 191
 192         chain = ring->enqueue->generic.field[3] & TRB_CHAIN;
 193         next = ++(ring->enqueue);
 194
 195         ring->enq_updates++;
 196         /* Update the dequeue pointer further if that was a link TRB or we're at
 197          * the end of an event ring segment (which doesn't have link TRBS)
 198          */
 199         while (last_trb(xhci, ring, ring->enq_seg, next)) {
 200                 if (!consumer) {
 201                         if (ring != xhci->event_ring) {
 202                                 if (chain) {
 203                                         next->link.control |= TRB_CHAIN;
 204
 205                                         /* Give this link TRB to the hardware */
 206                                         wmb();
 207                                         next->link.control ^= TRB_CYCLE;
 208                                 } else {
 209                                         break;
 210                                 }
 211                         }
 212                         /* Toggle the cycle bit after the last ring segment. */
 213                         if (last_trb_on_last_seg(xhci, ring, ring->enq_seg, next)) {
 214                                 ring->cycle_state = (ring->cycle_state ? 0 : 1);
 215                                 if (!in_interrupt())
 216                                         xhci_dbg(xhci, "Toggle cycle state for ring %p = %i\n",
 217                                                         ring,
 218                                                         (unsigned int) ring->cycle_state);
 219                         }
 220                 }
 221                 ring->enq_seg = ring->enq_seg->next;
 222                 ring->enqueue = ring->enq_seg->trbs;
 223                 next = ring->enqueue;
 224         }
 225         addr = (unsigned long long) xhci_trb_virt_to_dma(ring->enq_seg, ring->enqueue);
 226         if (ring == xhci->event_ring)
 227                 xhci_dbg(xhci, "Event ring enq = 0x%llx (DMA)\n", addr);
 228         else if (ring == xhci->cmd_ring)
 229                 xhci_dbg(xhci, "Command ring enq = 0x%llx (DMA)\n", addr);
 230         else
 231                 xhci_dbg(xhci, "Ring enq = 0x%llx (DMA)\n", addr);
 232 }
 233
 234 /*
 235  * Check to see if there's room to enqueue num_trbs on the ring.  See rules
 236  * above.
 237  * FIXME: this would be simpler and faster if we just kept track of the number
 238  * of free TRBs in a ring.
 239  */
 240 static int room_on_ring(struct xhci_hcd *xhci, struct xhci_ring *ring,
 241                 unsigned int num_trbs)
 242 {
 243         int i;
 244         union xhci_trb *enq = ring->enqueue;
 245         struct xhci_segment *enq_seg = ring->enq_seg;
 246         struct xhci_segment *cur_seg;
 247         unsigned int left_on_ring;
 248
 249         /* If we are currently pointing to a link TRB, advance the
 250          * enqueue pointer before checking for space */
 251         while (last_trb(xhci, ring, enq_seg, enq)) {
 252                 enq_seg = enq_seg->next;
 253                 enq = enq_seg->trbs;
 254         }
 255
 256         /* Check if ring is empty */
 257         if (enq == ring->dequeue) {
 258                 /* Can't use link trbs */
 259                 left_on_ring = TRBS_PER_SEGMENT - 1;
 260                 for (cur_seg = enq_seg->next; cur_seg != enq_seg;
 261                                 cur_seg = cur_seg->next)
 262                         left_on_ring += TRBS_PER_SEGMENT - 1;
 263
 264                 /* Always need one TRB free in the ring. */
 265                 left_on_ring -= 1;
 266                 if (num_trbs > left_on_ring) {
 267                         xhci_warn(xhci, "Not enough room on ring; "
 268                                         "need %u TRBs, %u TRBs left\n",
 269                                         num_trbs, left_on_ring);
 270                         return 0;
 271                 }
 272                 return 1;
 273         }
 274         /* Make sure there's an extra empty TRB available */
 275         for (i = 0; i <= num_trbs; ++i) {
 276                 if (enq == ring->dequeue)
 277                         return 0;
 278                 enq++;
 279                 while (last_trb(xhci, ring, enq_seg, enq)) {
 280                         enq_seg = enq_seg->next;
 281                         enq = enq_seg->trbs;
 282                 }
 283         }
 284         return 1;
 285 }
 286
 287 void xhci_set_hc_event_deq(struct xhci_hcd *xhci)
 288 {
 289         u64 temp;
 290         dma_addr_t deq;
 291
 292         deq = xhci_trb_virt_to_dma(xhci->event_ring->deq_seg,
 293                         xhci->event_ring->dequeue);
 294         if (deq == 0 && !in_interrupt())
 295                 xhci_warn(xhci, "WARN something wrong with SW event ring "
 296                                 "dequeue ptr.\n");
 297         /* Update HC event ring dequeue pointer */
 298         temp = xhci_read_64(xhci, &xhci->ir_set->erst_dequeue);
 299         temp &= ERST_PTR_MASK;
 300         /* Don't clear the EHB bit (which is RW1C) because
 301          * there might be more events to service.
 302          */
 303         temp &= ~ERST_EHB;
 304         xhci_dbg(xhci, "// Write event ring dequeue pointer, preserving EHB bit\n");
 305         xhci_write_64(xhci, ((u64) deq & (u64) ~ERST_PTR_MASK) | temp,
 306                         &xhci->ir_set->erst_dequeue);
 307 }
 308
 309 /* Ring the host controller doorbell after placing a command on the ring */
 310 void xhci_ring_cmd_db(struct xhci_hcd *xhci)
 311 {
 312         u32 temp;
 313
 314         xhci_dbg(xhci, "// Ding dong!\n");
 315         temp = xhci_readl(xhci, &xhci->dba->doorbell[0]) & DB_MASK;
 316         xhci_writel(xhci, temp | DB_TARGET_HOST, &xhci->dba->doorbell[0]);
 317         /* Flush PCI posted writes */
 318         xhci_readl(xhci, &xhci->dba->doorbell[0]);
 319 }
 320
 321 static void ring_ep_doorbell(struct xhci_hcd *xhci,
 322                 unsigned int slot_id,
 323                 unsigned int ep_index,
 324                 unsigned int stream_id)
 325 {
 326         struct xhci_virt_ep *ep;
 327         unsigned int ep_state;
 328         u32 field;
 329         __u32 __iomem *db_addr = &xhci->dba->doorbell[slot_id];
 330
 331         ep = &xhci->devs[slot_id]->eps[ep_index];
 332         ep_state = ep->ep_state;
 333         /* Don't ring the doorbell for this endpoint if there are pending
 334          * cancellations because the we don't want to interrupt processing.
 335          * We don't want to restart any stream rings if there's a set dequeue
 336          * pointer command pending because the device can choose to start any
 337          * stream once the endpoint is on the HW schedule.
 338          * FIXME - check all the stream rings for pending cancellations.
 339          */
 340         if (!(ep_state & EP_HALT_PENDING) && !(ep_state & SET_DEQ_PENDING)
 341                         && !(ep_state & EP_HALTED)) {
 342                 field = xhci_readl(xhci, db_addr) & DB_MASK;
 343                 field |= EPI_TO_DB(ep_index) | STREAM_ID_TO_DB(stream_id);
 344                 xhci_writel(xhci, field, db_addr);
 345                 /* Flush PCI posted writes - FIXME Matthew Wilcox says this
 346                  * isn't time-critical and we shouldn't make the CPU wait for
 347                  * the flush.
 348                  */
 349                 xhci_readl(xhci, db_addr);
 350         }
 351 }
 352
 353 /* Ring the doorbell for any rings with pending URBs */
 354 static void ring_doorbell_for_active_rings(struct xhci_hcd *xhci,
 355                 unsigned int slot_id,
 356                 unsigned int ep_index)
 357 {
 358         unsigned int stream_id;
 359         struct xhci_virt_ep *ep;
 360
 361         ep = &xhci->devs[slot_id]->eps[ep_index];
 362
 363         /* A ring has pending URBs if its TD list is not empty */
 364         if (!(ep->ep_state & EP_HAS_STREAMS)) {
 365                 if (!(list_empty(&ep->ring->td_list)))
 366                         ring_ep_doorbell(xhci, slot_id, ep_index, 0);
 367                 return;
 368         }
 369
 370         for (stream_id = 1; stream_id < ep->stream_info->num_streams;
 371                         stream_id++) {
 372                 struct xhci_stream_info *stream_info = ep->stream_info;
 373                 if (!list_empty(&stream_info->stream_rings[stream_id]->td_list))
 374                         ring_ep_doorbell(xhci, slot_id, ep_index, stream_id);
 375         }
 376 }
 377
 378 /*
 379  * Find the segment that trb is in.  Start searching in start_seg.
 380  * If we must move past a segment that has a link TRB with a toggle cycle state
 381  * bit set, then we will toggle the value pointed at by cycle_state.
 382  */
 383 static struct xhci_segment *find_trb_seg(
 384                 struct xhci_segment *start_seg,
 385                 union xhci_trb  *trb, int *cycle_state)
 386 {
 387         struct xhci_segment *cur_seg = start_seg;
 388         struct xhci_generic_trb *generic_trb;
 389
 390         while (cur_seg->trbs > trb ||
 391                         &cur_seg->trbs[TRBS_PER_SEGMENT - 1] < trb) {
 392                 generic_trb = &cur_seg->trbs[TRBS_PER_SEGMENT - 1].generic;
 393                 if ((generic_trb->field[3] & TRB_TYPE_BITMASK) ==
 394                                 TRB_TYPE(TRB_LINK) &&
 395                                 (generic_trb->field[3] & LINK_TOGGLE))
 396                         *cycle_state = ~(*cycle_state) & 0x1;
 397                 cur_seg = cur_seg->next;
 398                 if (cur_seg == start_seg)
 399                         /* Looped over the entire list.  Oops! */
 400                         return NULL;
 401         }
 402         return cur_seg;
 403 }
 404
 405 /*
 406  * Move the xHC's endpoint ring dequeue pointer past cur_td.
 407  * Record the new state of the xHC's endpoint ring dequeue segment,
 408  * dequeue pointer, and new consumer cycle state in state.
 409  * Update our internal representation of the ring's dequeue pointer.
 410  *
 411  * We do this in three jumps:
 412  *  - First we update our new ring state to be the same as when the xHC stopped.
 413  *  - Then we traverse the ring to find the segment that contains
 414  *    the last TRB in the TD.  We toggle the xHC's new cycle state when we pass
 415  *    any link TRBs with the toggle cycle bit set.
 416  *  - Finally we move the dequeue state one TRB further, toggling the cycle bit
 417  *    if we've moved it past a link TRB with the toggle cycle bit set.
 418  */
 419 void xhci_find_new_dequeue_state(struct xhci_hcd *xhci,
 420                 unsigned int slot_id, unsigned int ep_index,
 421                 unsigned int stream_id, struct xhci_td *cur_td,
 422                 struct xhci_dequeue_state *state)
 423 {
 424         struct xhci_virt_device *dev = xhci->devs[slot_id];
 425         struct xhci_ring *ep_ring;
 426         struct xhci_generic_trb *trb;
 427         struct xhci_ep_ctx *ep_ctx;
 428         dma_addr_t addr;
 429
 430         ep_ring = xhci_triad_to_transfer_ring(xhci, slot_id,
 431                         ep_index, stream_id);
 432         if (!ep_ring) {
 433                 xhci_warn(xhci, "WARN can't find new dequeue state "
 434                                 "for invalid stream ID %u.\n",
 435                                 stream_id);
 436                 return;
 437         }
 438         state->new_cycle_state = 0;
 439         xhci_dbg(xhci, "Finding segment containing stopped TRB.\n");
 440         state->new_deq_seg = find_trb_seg(cur_td->start_seg,
 441                         dev->eps[ep_index].stopped_trb,
 442                         &state->new_cycle_state);
 443         if (!state->new_deq_seg)
 444                 BUG();
 445         /* Dig out the cycle state saved by the xHC during the stop ep cmd */
 446         xhci_dbg(xhci, "Finding endpoint context\n");
 447         ep_ctx = xhci_get_ep_ctx(xhci, dev->out_ctx, ep_index);
 448         state->new_cycle_state = 0x1 & ep_ctx->deq;
 449
 450         state->new_deq_ptr = cur_td->last_trb;
 451         xhci_dbg(xhci, "Finding segment containing last TRB in TD.\n");
 452         state->new_deq_seg = find_trb_seg(state->new_deq_seg,
 453                         state->new_deq_ptr,
 454                         &state->new_cycle_state);
 455         if (!state->new_deq_seg)
 456                 BUG();
 457
 458         trb = &state->new_deq_ptr->generic;
 459         if ((trb->field[3] & TRB_TYPE_BITMASK) == TRB_TYPE(TRB_LINK) &&
 460                                 (trb->field[3] & LINK_TOGGLE))
 461                 state->new_cycle_state = ~(state->new_cycle_state) & 0x1;
 462         next_trb(xhci, ep_ring, &state->new_deq_seg, &state->new_deq_ptr);
 463
 464         /* Don't update the ring cycle state for the producer (us). */
 465         xhci_dbg(xhci, "New dequeue segment = %p (virtual)\n",
 466                         state->new_deq_seg);
 467         addr = xhci_trb_virt_to_dma(state->new_deq_seg, state->new_deq_ptr);
 468         xhci_dbg(xhci, "New dequeue pointer = 0x%llx (DMA)\n",
 469                         (unsigned long long) addr);
 470         xhci_dbg(xhci, "Setting dequeue pointer in internal ring state.\n");
 471         ep_ring->dequeue = state->new_deq_ptr;
 472         ep_ring->deq_seg = state->new_deq_seg;
 473 }
 474
 475 static void td_to_noop(struct xhci_hcd *xhci, struct xhci_ring *ep_ring,
 476                 struct xhci_td *cur_td)
 477 {
 478         struct xhci_segment *cur_seg;
 479         union xhci_trb *cur_trb;
 480
 481         for (cur_seg = cur_td->start_seg, cur_trb = cur_td->first_trb;
 482                         true;
 483                         next_trb(xhci, ep_ring, &cur_seg, &cur_trb)) {
 484                 if ((cur_trb->generic.field[3] & TRB_TYPE_BITMASK) ==
 485                                 TRB_TYPE(TRB_LINK)) {
 486                         /* Unchain any chained Link TRBs, but
 487                          * leave the pointers intact.
 488                          */
 489                         cur_trb->generic.field[3] &= ~TRB_CHAIN;
 490                         xhci_dbg(xhci, "Cancel (unchain) link TRB\n");
 491                         xhci_dbg(xhci, "Address = %p (0x%llx dma); "
 492                                         "in seg %p (0x%llx dma)\n",
 493                                         cur_trb,
 494                                         (unsigned long long)xhci_trb_virt_to_dma(cur_seg, cur_trb),
 495                                         cur_seg,
 496                                         (unsigned long long)cur_seg->dma);
 497                 } else {
 498                         cur_trb->generic.field[0] = 0;
 499                         cur_trb->generic.field[1] = 0;
 500                         cur_trb->generic.field[2] = 0;
 501                         /* Preserve only the cycle bit of this TRB */
 502                         cur_trb->generic.field[3] &= TRB_CYCLE;
 503                         cur_trb->generic.field[3] |= TRB_TYPE(TRB_TR_NOOP);
 504                         xhci_dbg(xhci, "Cancel TRB %p (0x%llx dma) "
 505                                         "in seg %p (0x%llx dma)\n",
 506                                         cur_trb,
 507                                         (unsigned long long)xhci_trb_virt_to_dma(cur_seg, cur_trb),
 508                                         cur_seg,
 509                                         (unsigned long long)cur_seg->dma);
 510                 }
 511                 if (cur_trb == cur_td->last_trb)
 512                         break;
 513         }
 514 }
 515
 516 static int queue_set_tr_deq(struct xhci_hcd *xhci, int slot_id,
 517                 unsigned int ep_index, unsigned int stream_id,
 518                 struct xhci_segment *deq_seg,
 519                 union xhci_trb *deq_ptr, u32 cycle_state);
 520
 521 void xhci_queue_new_dequeue_state(struct xhci_hcd *xhci,
 522                 unsigned int slot_id, unsigned int ep_index,
 523                 unsigned int stream_id,
 524                 struct xhci_dequeue_state *deq_state)
 525 {
 526         struct xhci_virt_ep *ep = &xhci->devs[slot_id]->eps[ep_index];
 527
 528         xhci_dbg(xhci, "Set TR Deq Ptr cmd, new deq seg = %p (0x%llx dma), "
 529                         "new deq ptr = %p (0x%llx dma), new cycle = %u\n",
 530                         deq_state->new_deq_seg,
 531                         (unsigned long long)deq_state->new_deq_seg->dma,
 532                         deq_state->new_deq_ptr,
 533                         (unsigned long long)xhci_trb_virt_to_dma(deq_state->new_deq_seg, deq_state->new_deq_ptr),
 534                         deq_state->new_cycle_state);
 535         queue_set_tr_deq(xhci, slot_id, ep_index, stream_id,
 536                         deq_state->new_deq_seg,
 537                         deq_state->new_deq_ptr,
 538                         (u32) deq_state->new_cycle_state);
 539         /* Stop the TD queueing code from ringing the doorbell until
 540          * this command completes.  The HC won't set the dequeue pointer
 541          * if the ring is running, and ringing the doorbell starts the
 542          * ring running.
 543          */
 544         ep->ep_state |= SET_DEQ_PENDING;
 545 }
 546
 547 static inline void xhci_stop_watchdog_timer_in_irq(struct xhci_hcd *xhci,
 548                 struct xhci_virt_ep *ep)
 549 {
 550         ep->ep_state &= ~EP_HALT_PENDING;
 551         /* Can't del_timer_sync in interrupt, so we attempt to cancel.  If the
 552          * timer is running on another CPU, we don't decrement stop_cmds_pending
 553          * (since we didn't successfully stop the watchdog timer).
 554          */
 555         if (del_timer(&ep->stop_cmd_timer))
 556                 ep->stop_cmds_pending--;
 557 }
 558
 559 /* Must be called with xhci->lock held in interrupt context */
 560 static void xhci_giveback_urb_in_irq(struct xhci_hcd *xhci,
 561                 struct xhci_td *cur_td, int status, char *adjective)
 562 {
 563         struct usb_hcd *hcd = xhci_to_hcd(xhci);
 564
 565         cur_td->urb->hcpriv = NULL;
 566         usb_hcd_unlink_urb_from_ep(hcd, cur_td->urb);
 567         xhci_dbg(xhci, "Giveback %s URB %p\n", adjective, cur_td->urb);
 568
 569         spin_unlock(&xhci->lock);
 570         usb_hcd_giveback_urb(hcd, cur_td->urb, status);
 571         kfree(cur_td);
 572         spin_lock(&xhci->lock);
 573         xhci_dbg(xhci, "%s URB given back\n", adjective);
 574 }
 575
 576 /*
 577  * When we get a command completion for a Stop Endpoint Command, we need to
 578  * unlink any cancelled TDs from the ring.  There are two ways to do that:
 579  *
 580  *  1. If the HW was in the middle of processing the TD that needs to be
 581  *     cancelled, then we must move the ring's dequeue pointer past the last TRB
 582  *     in the TD with a Set Dequeue Pointer Command.
 583  *  2. Otherwise, we turn all the TRBs in the TD into No-op TRBs (with the chain
 584  *     bit cleared) so that the HW will skip over them.
 585  */
 586 static void handle_stopped_endpoint(struct xhci_hcd *xhci,
 587                 union xhci_trb *trb)
 588 {
 589         unsigned int slot_id;
 590         unsigned int ep_index;
 591         struct xhci_ring *ep_ring;
 592         struct xhci_virt_ep *ep;
 593         struct list_head *entry;
 594         struct xhci_td *cur_td = NULL;
 595         struct xhci_td *last_unlinked_td;
 596
 597         struct xhci_dequeue_state deq_state;
 598
 599         memset(&deq_state, 0, sizeof(deq_state));
 600         slot_id = TRB_TO_SLOT_ID(trb->generic.field[3]);
 601         ep_index = TRB_TO_EP_INDEX(trb->generic.field[3]);
 602         ep = &xhci->devs[slot_id]->eps[ep_index];
 603
 604         if (list_empty(&ep->cancelled_td_list)) {
 605                 xhci_stop_watchdog_timer_in_irq(xhci, ep);
 606                 ring_doorbell_for_active_rings(xhci, slot_id, ep_index);
 607                 return;
 608         }
 609
 610         /* Fix up the ep ring first, so HW stops executing cancelled TDs.
 611          * We have the xHCI lock, so nothing can modify this list until we drop
 612          * it.  We're also in the event handler, so we can't get re-interrupted
 613          * if another Stop Endpoint command completes
 614          */
 615         list_for_each(entry, &ep->cancelled_td_list) {
 616                 cur_td = list_entry(entry, struct xhci_td, cancelled_td_list);
 617                 xhci_dbg(xhci, "Cancelling TD starting at %p, 0x%llx (dma).\n",
 618                                 cur_td->first_trb,
 619                                 (unsigned long long)xhci_trb_virt_to_dma(cur_td->start_seg, cur_td->first_trb));
 620                 ep_ring = xhci_urb_to_transfer_ring(xhci, cur_td->urb);
 621                 if (!ep_ring) {
 622                         /* This shouldn't happen unless a driver is mucking
 623                          * with the stream ID after submission.  This will
 624                          * leave the TD on the hardware ring, and the hardware
 625                          * will try to execute it, and may access a buffer
 626                          * that has already been freed.  In the best case, the
 627                          * hardware will execute it, and the event handler will
 628                          * ignore the completion event for that TD, since it was
 629                          * removed from the td_list for that endpoint.  In
 630                          * short, don't muck with the stream ID after
 631                          * submission.
 632                          */
 633                         xhci_warn(xhci, "WARN Cancelled URB %p "
 634                                         "has invalid stream ID %u.\n",
 635                                         cur_td->urb,
 636                                         cur_td->urb->stream_id);
 637                         goto remove_finished_td;
 638                 }
 639                 /*
 640                  * If we stopped on the TD we need to cancel, then we have to
 641                  * move the xHC endpoint ring dequeue pointer past this TD.
 642                  */
 643                 if (cur_td == ep->stopped_td)
 644                         xhci_find_new_dequeue_state(xhci, slot_id, ep_index,
 645                                         cur_td->urb->stream_id,
 646                                         cur_td, &deq_state);
 647                 else
 648                         td_to_noop(xhci, ep_ring, cur_td);
 649 remove_finished_td:
 650                 /*
 651                  * The event handler won't see a completion for this TD anymore,
 652                  * so remove it from the endpoint ring's TD list.  Keep it in
 653                  * the cancelled TD list for URB completion later.
 654                  */
 655                 list_del(&cur_td->td_list);
 656         }
 657         last_unlinked_td = cur_td;
 658         xhci_stop_watchdog_timer_in_irq(xhci, ep);
 659
 660         /* If necessary, queue a Set Transfer Ring Dequeue Pointer command */
 661         if (deq_state.new_deq_ptr && deq_state.new_deq_seg) {
 662                 xhci_queue_new_dequeue_state(xhci,
 663                                 slot_id, ep_index,
 664                                 ep->stopped_td->urb->stream_id,
 665                                 &deq_state);
 666                 xhci_ring_cmd_db(xhci);
 667         } else {
 668                 /* Otherwise ring the doorbell(s) to restart queued transfers */
 669                 ring_doorbell_for_active_rings(xhci, slot_id, ep_index);
 670         }
 671         ep->stopped_td = NULL;
 672         ep->stopped_trb = NULL;
 673
 674         /*
 675          * Drop the lock and complete the URBs in the cancelled TD list.
 676          * New TDs to be cancelled might be added to the end of the list before
 677          * we can complete all the URBs for the TDs we already unlinked.
 678          * So stop when we've completed the URB for the last TD we unlinked.
 679          */
 680         do {
 681                 cur_td = list_entry(ep->cancelled_td_list.next,
 682                                 struct xhci_td, cancelled_td_list);
 683                 list_del(&cur_td->cancelled_td_list);
 684
 685                 /* Clean up the cancelled URB */
 686                 /* Doesn't matter what we pass for status, since the core will
 687                  * just overwrite it (because the URB has been unlinked).
 688                  */
 689                 xhci_giveback_urb_in_irq(xhci, cur_td, 0, "cancelled");
 690
 691                 /* Stop processing the cancelled list if the watchdog timer is
 692                  * running.
 693                  */
 694                 if (xhci->xhc_state & XHCI_STATE_DYING)
 695                         return;
 696         } while (cur_td != last_unlinked_td);
 697
 698         /* Return to the event handler with xhci->lock re-acquired */
 699 }
 700
 701 /* Watchdog timer function for when a stop endpoint command fails to complete.
 702  * In this case, we assume the host controller is broken or dying or dead.  The
 703  * host may still be completing some other events, so we have to be careful to
 704  * let the event ring handler and the URB dequeueing/enqueueing functions know
 705  * through xhci->state.
 706  *
 707  * The timer may also fire if the host takes a very long time to respond to the
 708  * command, and the stop endpoint command completion handler cannot delete the
 709  * timer before the timer function is called.  Another endpoint cancellation may
 710  * sneak in before the timer function can grab the lock, and that may queue
 711  * another stop endpoint command and add the timer back.  So we cannot use a
 712  * simple flag to say whether there is a pending stop endpoint command for a
 713  * particular endpoint.
 714  *
 715  * Instead we use a combination of that flag and a counter for the number of
 716  * pending stop endpoint commands.  If the timer is the tail end of the last
 717  * stop endpoint command, and the endpoint's command is still pending, we assume
 718  * the host is dying.
 719  */
 720 void xhci_stop_endpoint_command_watchdog(unsigned long arg)
 721 {
 722         struct xhci_hcd *xhci;
 723         struct xhci_virt_ep *ep;
 724         struct xhci_virt_ep *temp_ep;
 725         struct xhci_ring *ring;
 726         struct xhci_td *cur_td;
 727         int ret, i, j;
 728
 729         ep = (struct xhci_virt_ep *) arg;
 730         xhci = ep->xhci;
 731
 732         spin_lock(&xhci->lock);
 733
 734         ep->stop_cmds_pending--;
 735         if (xhci->xhc_state & XHCI_STATE_DYING) {
 736                 xhci_dbg(xhci, "Stop EP timer ran, but another timer marked "
 737                                 "xHCI as DYING, exiting.\n");
 738                 spin_unlock(&xhci->lock);
 739                 return;
 740         }
 741         if (!(ep->stop_cmds_pending == 0 && (ep->ep_state & EP_HALT_PENDING))) {
 742                 xhci_dbg(xhci, "Stop EP timer ran, but no command pending, "
 743                                 "exiting.\n");
 744                 spin_unlock(&xhci->lock);
 745                 return;
 746         }
 747
 748         xhci_warn(xhci, "xHCI host not responding to stop endpoint command.\n");
 749         xhci_warn(xhci, "Assuming host is dying, halting host.\n");
 750         /* Oops, HC is dead or dying or at least not responding to the stop
 751          * endpoint command.
 752          */
 753         xhci->xhc_state |= XHCI_STATE_DYING;
 754         /* Disable interrupts from the host controller and start halting it */
 755         xhci_quiesce(xhci);
 756         spin_unlock(&xhci->lock);
 757
 758         ret = xhci_halt(xhci);
 759
 760         spin_lock(&xhci->lock);
 761         if (ret < 0) {
 762                 /* This is bad; the host is not responding to commands and it's
 763                  * not allowing itself to be halted.  At least interrupts are
 764                  * disabled, so we can set HC_STATE_HALT and notify the
 765                  * USB core.  But if we call usb_hc_died(), it will attempt to
 766                  * disconnect all device drivers under this host.  Those
 767                  * disconnect() methods will wait for all URBs to be unlinked,
 768                  * so we must complete them.
 769                  */
 770                 xhci_warn(xhci, "Non-responsive xHCI host is not halting.\n");
 771                 xhci_warn(xhci, "Completing active URBs anyway.\n");
 772                 /* We could turn all TDs on the rings to no-ops.  This won't
 773                  * help if the host has cached part of the ring, and is slow if
 774                  * we want to preserve the cycle bit.  Skip it and hope the host
 775                  * doesn't touch the memory.
 776                  */
 777         }
 778         for (i = 0; i < MAX_HC_SLOTS; i++) {
 779                 if (!xhci->devs[i])
 780                         continue;
 781                 for (j = 0; j < 31; j++) {
 782                         temp_ep = &xhci->devs[i]->eps[j];
 783                         ring = temp_ep->ring;
 784                         if (!ring)
 785                                 continue;
 786                         xhci_dbg(xhci, "Killing URBs for slot ID %u, "
 787                                         "ep index %u\n", i, j);
 788                         while (!list_empty(&ring->td_list)) {
 789                                 cur_td = list_first_entry(&ring->td_list,
 790                                                 struct xhci_td,
 791                                                 td_list);
 792                                 list_del(&cur_td->td_list);
 793                                 if (!list_empty(&cur_td->cancelled_td_list))
 794                                         list_del(&cur_td->cancelled_td_list);
 795                                 xhci_giveback_urb_in_irq(xhci, cur_td,
 796                                                 -ESHUTDOWN, "killed");
 797                         }
 798                         while (!list_empty(&temp_ep->cancelled_td_list)) {
 799                                 cur_td = list_first_entry(
 800                                                 &temp_ep->cancelled_td_list,
 801                                                 struct xhci_td,
 802                                                 cancelled_td_list);
 803                                 list_del(&cur_td->cancelled_td_list);
 804                                 xhci_giveback_urb_in_irq(xhci, cur_td,
 805                                                 -ESHUTDOWN, "killed");
 806                         }
 807                 }
 808         }
 809         spin_unlock(&xhci->lock);
 810         xhci_to_hcd(xhci)->state = HC_STATE_HALT;
 811         xhci_dbg(xhci, "Calling usb_hc_died()\n");
 812         usb_hc_died(xhci_to_hcd(xhci));
 813         xhci_dbg(xhci, "xHCI host controller is dead.\n");
 814 }
 815
 816 /*
 817  * When we get a completion for a Set Transfer Ring Dequeue Pointer command,
 818  * we need to clear the set deq pending flag in the endpoint ring state, so that
 819  * the TD queueing code can ring the doorbell again.  We also need to ring the
 820  * endpoint doorbell to restart the ring, but only if there aren't more
 821  * cancellations pending.
 822  */
 823 static void handle_set_deq_completion(struct xhci_hcd *xhci,
 824                 struct xhci_event_cmd *event,
 825                 union xhci_trb *trb)
 826 {
 827         unsigned int slot_id;
 828         unsigned int ep_index;
 829         unsigned int stream_id;
 830         struct xhci_ring *ep_ring;
 831         struct xhci_virt_device *dev;
 832         struct xhci_ep_ctx *ep_ctx;
 833         struct xhci_slot_ctx *slot_ctx;
 834
 835         slot_id = TRB_TO_SLOT_ID(trb->generic.field[3]);
 836         ep_index = TRB_TO_EP_INDEX(trb->generic.field[3]);
 837         stream_id = TRB_TO_STREAM_ID(trb->generic.field[2]);
 838         dev = xhci->devs[slot_id];
 839
 840         ep_ring = xhci_stream_id_to_ring(dev, ep_index, stream_id);
 841         if (!ep_ring) {
 842                 xhci_warn(xhci, "WARN Set TR deq ptr command for "
 843                                 "freed stream ID %u\n",
 844                                 stream_id);
 845                 /* XXX: Harmless??? */
 846                 dev->eps[ep_index].ep_state &= ~SET_DEQ_PENDING;
 847                 return;
 848         }
 849
 850         ep_ctx = xhci_get_ep_ctx(xhci, dev->out_ctx, ep_index);
 851         slot_ctx = xhci_get_slot_ctx(xhci, dev->out_ctx);
 852
 853         if (GET_COMP_CODE(event->status) != COMP_SUCCESS) {
 854                 unsigned int ep_state;
 855                 unsigned int slot_state;
 856
 857                 switch (GET_COMP_CODE(event->status)) {
 858                 case COMP_TRB_ERR:
 859                         xhci_warn(xhci, "WARN Set TR Deq Ptr cmd invalid because "
 860                                         "of stream ID configuration\n");
 861                         break;
 862                 case COMP_CTX_STATE:
 863                         xhci_warn(xhci, "WARN Set TR Deq Ptr cmd failed due "
 864                                         "to incorrect slot or ep state.\n");
 865                         ep_state = ep_ctx->ep_info;
 866                         ep_state &= EP_STATE_MASK;
 867                         slot_state = slot_ctx->dev_state;
 868                         slot_state = GET_SLOT_STATE(slot_state);
 869                         xhci_dbg(xhci, "Slot state = %u, EP state = %u\n",
 870                                         slot_state, ep_state);
 871                         break;
 872                 case COMP_EBADSLT:
 873                         xhci_warn(xhci, "WARN Set TR Deq Ptr cmd failed because "
 874                                         "slot %u was not enabled.\n", slot_id);
 875                         break;
 876                 default:
 877                         xhci_warn(xhci, "WARN Set TR Deq Ptr cmd with unknown "
 878                                         "completion code of %u.\n",
 879                                         GET_COMP_CODE(event->status));
 880                         break;
 881                 }
 882                 /* OK what do we do now?  The endpoint state is hosed, and we
 883                  * should never get to this point if the synchronization between
 884                  * queueing, and endpoint state are correct.  This might happen
 885                  * if the device gets disconnected after we've finished
 886                  * cancelling URBs, which might not be an error...
 887                  */
 888         } else {
 889                 xhci_dbg(xhci, "Successful Set TR Deq Ptr cmd, deq = @%08llx\n",
 890                                 ep_ctx->deq);
 891         }
 892
 893         dev->eps[ep_index].ep_state &= ~SET_DEQ_PENDING;
 894         /* Restart any rings with pending URBs */
 895         ring_doorbell_for_active_rings(xhci, slot_id, ep_index);
 896 }
 897
 898 static void handle_reset_ep_completion(struct xhci_hcd *xhci,
 899                 struct xhci_event_cmd *event,
 900                 union xhci_trb *trb)
 901 {
 902         int slot_id;
 903         unsigned int ep_index;
 904
 905         slot_id = TRB_TO_SLOT_ID(trb->generic.field[3]);
 906         ep_index = TRB_TO_EP_INDEX(trb->generic.field[3]);
 907         /* This command will only fail if the endpoint wasn't halted,
 908          * but we don't care.
 909          */
 910         xhci_dbg(xhci, "Ignoring reset ep completion code of %u\n",
 911                         (unsigned int) GET_COMP_CODE(event->status));
 912
 913         /* HW with the reset endpoint quirk needs to have a configure endpoint
 914          * command complete before the endpoint can be used.  Queue that here
 915          * because the HW can't handle two commands being queued in a row.
 916          */
 917         if (xhci->quirks & XHCI_RESET_EP_QUIRK) {
 918                 xhci_dbg(xhci, "Queueing configure endpoint command\n");
 919                 xhci_queue_configure_endpoint(xhci,
 920                                 xhci->devs[slot_id]->in_ctx->dma, slot_id,
 921                                 false);
 922                 xhci_ring_cmd_db(xhci);
 923         } else {
 924                 /* Clear our internal halted state and restart the ring(s) */
 925                 xhci->devs[slot_id]->eps[ep_index].ep_state &= ~EP_HALTED;
 926                 ring_doorbell_for_active_rings(xhci, slot_id, ep_index);
 927         }
 928 }
 929
 930 /* Check to see if a command in the device's command queue matches this one.
 931  * Signal the completion or free the command, and return 1.  Return 0 if the
 932  * completed command isn't at the head of the command list.
 933  */
 934 static int handle_cmd_in_cmd_wait_list(struct xhci_hcd *xhci,
 935                 struct xhci_virt_device *virt_dev,
 936                 struct xhci_event_cmd *event)
 937 {
 938         struct xhci_command *command;
 939
 940         if (list_empty(&virt_dev->cmd_list))
 941                 return 0;
 942
 943         command = list_entry(virt_dev->cmd_list.next,
 944                         struct xhci_command, cmd_list);
 945         if (xhci->cmd_ring->dequeue != command->command_trb)
 946                 return 0;
 947
 948         command->status =
 949                 GET_COMP_CODE(event->status);
 950         list_del(&command->cmd_list);
 951         if (command->completion)
 952                 complete(command->completion);
 953         else
 954                 xhci_free_command(xhci, command);
 955         return 1;
 956 }
 957
 958 static void handle_cmd_completion(struct xhci_hcd *xhci,
 959                 struct xhci_event_cmd *event)
 960 {
 961         int slot_id = TRB_TO_SLOT_ID(event->flags);
 962         u64 cmd_dma;
 963         dma_addr_t cmd_dequeue_dma;
 964         struct xhci_input_control_ctx *ctrl_ctx;
 965         struct xhci_virt_device *virt_dev;
 966         unsigned int ep_index;
 967         struct xhci_ring *ep_ring;
 968         unsigned int ep_state;
 969
 970         cmd_dma = event->cmd_trb;
 971         cmd_dequeue_dma = xhci_trb_virt_to_dma(xhci->cmd_ring->deq_seg,
 972                         xhci->cmd_ring->dequeue);
 973         /* Is the command ring deq ptr out of sync with the deq seg ptr? */
 974         if (cmd_dequeue_dma == 0) {
 975                 xhci->error_bitmask |= 1 << 4;
 976                 return;
 977         }
 978         /* Does the DMA address match our internal dequeue pointer address? */
 979         if (cmd_dma != (u64) cmd_dequeue_dma) {
 980                 xhci->error_bitmask |= 1 << 5;
 981                 return;
 982         }
 983         switch (xhci->cmd_ring->dequeue->generic.field[3] & TRB_TYPE_BITMASK) {
 984         case TRB_TYPE(TRB_ENABLE_SLOT):
 985                 if (GET_COMP_CODE(event->status) == COMP_SUCCESS)
 986                         xhci->slot_id = slot_id;
 987                 else
 988                         xhci->slot_id = 0;
 989                 complete(&xhci->addr_dev);
 990                 break;
 991         case TRB_TYPE(TRB_DISABLE_SLOT):
 992                 if (xhci->devs[slot_id])
 993                         xhci_free_virt_device(xhci, slot_id);
 994                 break;
 995         case TRB_TYPE(TRB_CONFIG_EP):
 996                 virt_dev = xhci->devs[slot_id];
 997                 if (handle_cmd_in_cmd_wait_list(xhci, virt_dev, event))
 998                         break;
 999                 /*
1000                  * Configure endpoint commands can come from the USB core
1001                  * configuration or alt setting changes, or because the HW
1002                  * needed an extra configure endpoint command after a reset
1003                  * endpoint command or streams were being configured.
1004                  * If the command was for a halted endpoint, the xHCI driver
1005                  * is not waiting on the configure endpoint command.
1006                  */
1007                 ctrl_ctx = xhci_get_input_control_ctx(xhci,
1008                                 virt_dev->in_ctx);
1009                 /* Input ctx add_flags are the endpoint index plus one */
1010                 ep_index = xhci_last_valid_endpoint(ctrl_ctx->add_flags) - 1;
1011                 /* A usb_set_interface() call directly after clearing a halted
1012                  * condition may race on this quirky hardware.  Not worth
1013                  * worrying about, since this is prototype hardware.  Not sure
1014                  * if this will work for streams, but streams support was
1015                  * untested on this prototype.
1016                  */
1017                 if (xhci->quirks & XHCI_RESET_EP_QUIRK &&
1018                                 ep_index != (unsigned int) -1 &&
1019                                 ctrl_ctx->add_flags - SLOT_FLAG ==
1020                                         ctrl_ctx->drop_flags) {
1021                         ep_ring = xhci->devs[slot_id]->eps[ep_index].ring;
1022                         ep_state = xhci->devs[slot_id]->eps[ep_index].ep_state;
1023                         if (!(ep_state & EP_HALTED))
1024                                 goto bandwidth_change;
1025                         xhci_dbg(xhci, "Completed config ep cmd - "
1026                                         "last ep index = %d, state = %d\n",
1027                                         ep_index, ep_state);
1028                         /* Clear internal halted state and restart ring(s) */
1029                         xhci->devs[slot_id]->eps[ep_index].ep_state &=
1030                                 ~EP_HALTED;
1031                         ring_doorbell_for_active_rings(xhci, slot_id, ep_index);
1032                         break;
1033                 }
1034 bandwidth_change:
1035                 xhci_dbg(xhci, "Completed config ep cmd\n");
1036                 xhci->devs[slot_id]->cmd_status =
1037                         GET_COMP_CODE(event->status);
1038                 complete(&xhci->devs[slot_id]->cmd_completion);
1039                 break;
1040         case TRB_TYPE(TRB_EVAL_CONTEXT):
1041                 virt_dev = xhci->devs[slot_id];
1042                 if (handle_cmd_in_cmd_wait_list(xhci, virt_dev, event))
1043                         break;
1044                 xhci->devs[slot_id]->cmd_status = GET_COMP_CODE(event->status);
1045                 complete(&xhci->devs[slot_id]->cmd_completion);
1046                 break;
1047         case TRB_TYPE(TRB_ADDR_DEV):
1048                 xhci->devs[slot_id]->cmd_status = GET_COMP_CODE(event->status);
1049                 complete(&xhci->addr_dev);
1050                 break;
1051         case TRB_TYPE(TRB_STOP_RING):
1052                 handle_stopped_endpoint(xhci, xhci->cmd_ring->dequeue);
1053                 break;
1054         case TRB_TYPE(TRB_SET_DEQ):
1055                 handle_set_deq_completion(xhci, event, xhci->cmd_ring->dequeue);
1056                 break;
1057         case TRB_TYPE(TRB_CMD_NOOP):
1058                 ++xhci->noops_handled;
1059                 break;
1060         case TRB_TYPE(TRB_RESET_EP):
1061                 handle_reset_ep_completion(xhci, event, xhci->cmd_ring->dequeue);
1062                 break;
1063         case TRB_TYPE(TRB_RESET_DEV):
1064                 xhci_dbg(xhci, "Completed reset device command.\n");
1065                 slot_id = TRB_TO_SLOT_ID(
1066                                 xhci->cmd_ring->dequeue->generic.field[3]);
1067                 virt_dev = xhci->devs[slot_id];
1068                 if (virt_dev)
1069                         handle_cmd_in_cmd_wait_list(xhci, virt_dev, event);
1070                 else
1071                         xhci_warn(xhci, "Reset device command completion "
1072                                         "for disabled slot %u\n", slot_id);
1073                 break;
1074         default:
1075                 /* Skip over unknown commands on the event ring */
1076                 xhci->error_bitmask |= 1 << 6;
1077                 break;
1078         }
1079         inc_deq(xhci, xhci->cmd_ring, false);
1080 }
1081
1082 static void handle_port_status(struct xhci_hcd *xhci,
1083                 union xhci_trb *event)
1084 {
1085         u32 port_id;
1086
1087         /* Port status change events always have a successful completion code */
1088         if (GET_COMP_CODE(event->generic.field[2]) != COMP_SUCCESS) {
1089                 xhci_warn(xhci, "WARN: xHC returned failed port status event\n");
1090                 xhci->error_bitmask |= 1 << 8;
1091         }
1092         /* FIXME: core doesn't care about all port link state changes yet */
1093         port_id = GET_PORT_ID(event->generic.field[0]);
1094         xhci_dbg(xhci, "Port Status Change Event for port %d\n", port_id);
1095
1096         /* Update event ring dequeue pointer before dropping the lock */
1097         inc_deq(xhci, xhci->event_ring, true);
1098         xhci_set_hc_event_deq(xhci);
1099
1100         spin_unlock(&xhci->lock);
1101         /* Pass this up to the core */
1102         usb_hcd_poll_rh_status(xhci_to_hcd(xhci));
1103         spin_lock(&xhci->lock);
1104 }
1105
1106 /*
1107  * This TD is defined by the TRBs starting at start_trb in start_seg and ending
1108  * at end_trb, which may be in another segment.  If the suspect DMA address is a
1109  * TRB in this TD, this function returns that TRB's segment.  Otherwise it
1110  * returns 0.
1111  */
1112 struct xhci_segment *trb_in_td(struct xhci_segment *start_seg,
1113                 union xhci_trb  *start_trb,
1114                 union xhci_trb  *end_trb,
1115                 dma_addr_t      suspect_dma)
1116 {
1117         dma_addr_t start_dma;
1118         dma_addr_t end_seg_dma;
1119         dma_addr_t end_trb_dma;
1120         struct xhci_segment *cur_seg;
1121
1122         start_dma = xhci_trb_virt_to_dma(start_seg, start_trb);
1123         cur_seg = start_seg;
1124
1125         do {
1126                 if (start_dma == 0)
1127                         return NULL;
1128                 /* We may get an event for a Link TRB in the middle of a TD */
1129                 end_seg_dma = xhci_trb_virt_to_dma(cur_seg,
1130                                 &cur_seg->trbs[TRBS_PER_SEGMENT - 1]);
1131                 /* If the end TRB isn't in this segment, this is set to 0 */
1132                 end_trb_dma = xhci_trb_virt_to_dma(cur_seg, end_trb);
1133
1134                 if (end_trb_dma > 0) {
1135                         /* The end TRB is in this segment, so suspect should be here */
1136                         if (start_dma <= end_trb_dma) {
1137                                 if (suspect_dma >= start_dma && suspect_dma <= end_trb_dma)
1138                                         return cur_seg;
1139                         } else {
1140                                 /* Case for one segment with
1141                                  * a TD wrapped around to the top
1142                                  */
1143                                 if ((suspect_dma >= start_dma &&
1144                                                         suspect_dma <= end_seg_dma) ||
1145                                                 (suspect_dma >= cur_seg->dma &&
1146                                                  suspect_dma <= end_trb_dma))
1147                                         return cur_seg;
1148                         }
1149                         return NULL;
1150                 } else {
1151                         /* Might still be somewhere in this segment */
1152                         if (suspect_dma >= start_dma && suspect_dma <= end_seg_dma)
1153                                 return cur_seg;
1154                 }
1155                 cur_seg = cur_seg->next;
1156                 start_dma = xhci_trb_virt_to_dma(cur_seg, &cur_seg->trbs[0]);
1157         } while (cur_seg != start_seg);
1158
1159         return NULL;
1160 }
1161
1162 static void xhci_cleanup_halted_endpoint(struct xhci_hcd *xhci,
1163                 unsigned int slot_id, unsigned int ep_index,
1164                 unsigned int stream_id,
1165                 struct xhci_td *td, union xhci_trb *event_trb)
1166 {
1167         struct xhci_virt_ep *ep = &xhci->devs[slot_id]->eps[ep_index];
1168         ep->ep_state |= EP_HALTED;
1169         ep->stopped_td = td;
1170         ep->stopped_trb = event_trb;
1171         ep->stopped_stream = stream_id;
1172
1173         xhci_queue_reset_ep(xhci, slot_id, ep_index);
1174         xhci_cleanup_stalled_ring(xhci, td->urb->dev, ep_index);
1175
1176         ep->stopped_td = NULL;
1177         ep->stopped_trb = NULL;
1178         ep->stopped_stream = 0;
1179
1180         xhci_ring_cmd_db(xhci);
1181 }
1182
1183 /* Check if an error has halted the endpoint ring.  The class driver will
1184  * cleanup the halt for a non-default control endpoint if we indicate a stall.
1185  * However, a babble and other errors also halt the endpoint ring, and the class
1186  * driver won't clear the halt in that case, so we need to issue a Set Transfer
1187  * Ring Dequeue Pointer command manually.
1188  */
1189 static int xhci_requires_manual_halt_cleanup(struct xhci_hcd *xhci,
1190                 struct xhci_ep_ctx *ep_ctx,
1191                 unsigned int trb_comp_code)
1192 {
1193         /* TRB completion codes that may require a manual halt cleanup */
1194         if (trb_comp_code == COMP_TX_ERR ||
1195                         trb_comp_code == COMP_BABBLE ||
1196                         trb_comp_code == COMP_SPLIT_ERR)
1197                 /* The 0.96 spec says a babbling control endpoint
1198                  * is not halted. The 0.96 spec says it is.  Some HW
1199                  * claims to be 0.95 compliant, but it halts the control
1200                  * endpoint anyway.  Check if a babble halted the
1201                  * endpoint.
1202                  */
1203                 if ((ep_ctx->ep_info & EP_STATE_MASK) == EP_STATE_HALTED)
1204                         return 1;
1205
1206         return 0;
1207 }
1208
1209 int xhci_is_vendor_info_code(struct xhci_hcd *xhci, unsigned int trb_comp_code)
1210 {
1211         if (trb_comp_code >= 224 && trb_comp_code <= 255) {
1212                 /* Vendor defined "informational" completion code,
1213                  * treat as not-an-error.
1214                  */
1215                 xhci_dbg(xhci, "Vendor defined info completion code %u\n",
1216                                 trb_comp_code);
1217                 xhci_dbg(xhci, "Treating code as success.\n");
1218                 return 1;
1219         }
1220         return 0;
1221 }
1222
1223 /*
1224  * If this function returns an error condition, it means it got a Transfer
1225  * event with a corrupted Slot ID, Endpoint ID, or TRB DMA address.
1226  * At this point, the host controller is probably hosed and should be reset.
1227  */
1228 static int handle_tx_event(struct xhci_hcd *xhci,
1229                 struct xhci_transfer_event *event)
1230 {
1231         struct xhci_virt_device *xdev;
1232         struct xhci_virt_ep *ep;
1233         struct xhci_ring *ep_ring;
1234         unsigned int slot_id;
1235         int ep_index;
1236         struct xhci_td *td = NULL;
1237         dma_addr_t event_dma;
1238         struct xhci_segment *event_seg;
1239         union xhci_trb *event_trb;
1240         struct urb *urb = NULL;
1241         int status = -EINPROGRESS;
1242         struct xhci_ep_ctx *ep_ctx;
1243         u32 trb_comp_code;
1244
1245         xhci_dbg(xhci, "In %s\n", __func__);
1246         slot_id = TRB_TO_SLOT_ID(event->flags);
1247         xdev = xhci->devs[slot_id];
1248         if (!xdev) {
1249                 xhci_err(xhci, "ERROR Transfer event pointed to bad slot\n");
1250                 return -ENODEV;
1251         }
1252
1253         /* Endpoint ID is 1 based, our index is zero based */
1254         ep_index = TRB_TO_EP_ID(event->flags) - 1;
1255         xhci_dbg(xhci, "%s - ep index = %d\n", __func__, ep_index);
1256         ep = &xdev->eps[ep_index];
1257         ep_ring = xhci_dma_to_transfer_ring(ep, event->buffer);
1258         ep_ctx = xhci_get_ep_ctx(xhci, xdev->out_ctx, ep_index);
1259         if (!ep_ring || (ep_ctx->ep_info & EP_STATE_MASK) == EP_STATE_DISABLED) {
1260                 xhci_err(xhci, "ERROR Transfer event for disabled endpoint "
1261                                 "or incorrect stream ring\n");
1262                 return -ENODEV;
1263         }
1264
1265         event_dma = event->buffer;
1266         /* This TRB should be in the TD at the head of this ring's TD list */
1267         xhci_dbg(xhci, "%s - checking for list empty\n", __func__);
1268         if (list_empty(&ep_ring->td_list)) {
1269                 xhci_warn(xhci, "WARN Event TRB for slot %d ep %d with no TDs queued?\n",
1270                                 TRB_TO_SLOT_ID(event->flags), ep_index);
1271                 xhci_dbg(xhci, "Event TRB with TRB type ID %u\n",
1272                                 (unsigned int) (event->flags & TRB_TYPE_BITMASK)>>10);
1273                 xhci_print_trb_offsets(xhci, (union xhci_trb *) event);
1274                 urb = NULL;
1275                 goto cleanup;
1276         }
1277         xhci_dbg(xhci, "%s - getting list entry\n", __func__);
1278         td = list_entry(ep_ring->td_list.next, struct xhci_td, td_list);
1279
1280         /* Is this a TRB in the currently executing TD? */
1281         xhci_dbg(xhci, "%s - looking for TD\n", __func__);
1282         event_seg = trb_in_td(ep_ring->deq_seg, ep_ring->dequeue,
1283                         td->last_trb, event_dma);
1284         xhci_dbg(xhci, "%s - found event_seg = %p\n", __func__, event_seg);
1285         if (!event_seg) {
1286                 /* HC is busted, give up! */
1287                 xhci_err(xhci, "ERROR Transfer event TRB DMA ptr not part of current TD\n");
1288                 return -ESHUTDOWN;
1289         }
1290         event_trb = &event_seg->trbs[(event_dma - event_seg->dma) / sizeof(*event_trb)];
1291         xhci_dbg(xhci, "Event TRB with TRB type ID %u\n",
1292                         (unsigned int) (event->flags & TRB_TYPE_BITMASK)>>10);
1293         xhci_dbg(xhci, "Offset 0x00 (buffer lo) = 0x%x\n",
1294                         lower_32_bits(event->buffer));
1295         xhci_dbg(xhci, "Offset 0x04 (buffer hi) = 0x%x\n",
1296                         upper_32_bits(event->buffer));
1297         xhci_dbg(xhci, "Offset 0x08 (transfer length) = 0x%x\n",
1298                         (unsigned int) event->transfer_len);
1299         xhci_dbg(xhci, "Offset 0x0C (flags) = 0x%x\n",
1300                         (unsigned int) event->flags);
1301
1302         /* Look for common error cases */
1303         trb_comp_code = GET_COMP_CODE(event->transfer_len);
1304         switch (trb_comp_code) {
1305         /* Skip codes that require special handling depending on
1306          * transfer type
1307          */
1308         case COMP_SUCCESS:
1309         case COMP_SHORT_TX:
1310                 break;
1311         case COMP_STOP:
1312                 xhci_dbg(xhci, "Stopped on Transfer TRB\n");
1313                 break;
1314         case COMP_STOP_INVAL:
1315                 xhci_dbg(xhci, "Stopped on No-op or Link TRB\n");
1316                 break;
1317         case COMP_STALL:
1318                 xhci_warn(xhci, "WARN: Stalled endpoint\n");
1319                 ep->ep_state |= EP_HALTED;
1320                 status = -EPIPE;
1321                 break;
1322         case COMP_TRB_ERR:
1323                 xhci_warn(xhci, "WARN: TRB error on endpoint\n");
1324                 status = -EILSEQ;
1325                 break;
1326         case COMP_SPLIT_ERR:
1327         case COMP_TX_ERR:
1328                 xhci_warn(xhci, "WARN: transfer error on endpoint\n");
1329                 status = -EPROTO;
1330                 break;
1331         case COMP_BABBLE:
1332                 xhci_warn(xhci, "WARN: babble error on endpoint\n");
1333                 status = -EOVERFLOW;
1334                 break;
1335         case COMP_DB_ERR:
1336                 xhci_warn(xhci, "WARN: HC couldn't access mem fast enough\n");
1337                 status = -ENOSR;
1338                 break;
1339         default:
1340                 if (xhci_is_vendor_info_code(xhci, trb_comp_code)) {
1341                         status = 0;
1342                         break;
1343                 }
1344                 xhci_warn(xhci, "ERROR Unknown event condition, HC probably busted\n");
1345                 urb = NULL;
1346                 goto cleanup;
1347         }
1348         /* Now update the urb's actual_length and give back to the core */
1349         /* Was this a control transfer? */
1350         if (usb_endpoint_xfer_control(&td->urb->ep->desc)) {
1351                 xhci_debug_trb(xhci, xhci->event_ring->dequeue);
1352                 switch (trb_comp_code) {
1353                 case COMP_SUCCESS:
1354                         if (event_trb == ep_ring->dequeue) {
1355                                 xhci_warn(xhci, "WARN: Success on ctrl setup TRB without IOC set??\n");
1356                                 status = -ESHUTDOWN;
1357                         } else if (event_trb != td->last_trb) {
1358                                 xhci_warn(xhci, "WARN: Success on ctrl data TRB without IOC set??\n");
1359                                 status = -ESHUTDOWN;
1360                         } else {
1361                                 xhci_dbg(xhci, "Successful control transfer!\n");
1362                                 status = 0;
1363                         }
1364                         break;
1365                 case COMP_SHORT_TX:
1366                         xhci_warn(xhci, "WARN: short transfer on control ep\n");
1367                         if (td->urb->transfer_flags & URB_SHORT_NOT_OK)
1368                                 status = -EREMOTEIO;
1369                         else
1370                                 status = 0;
1371                         break;
1372
1373                 default:
1374                         if (!xhci_requires_manual_halt_cleanup(xhci,
1375                                                 ep_ctx, trb_comp_code))
1376                                 break;
1377                         xhci_dbg(xhci, "TRB error code %u, "
1378                                         "halted endpoint index = %u\n",
1379                                         trb_comp_code, ep_index);
1380                         /* else fall through */
1381                 case COMP_STALL:
1382                         /* Did we transfer part of the data (middle) phase? */
1383                         if (event_trb != ep_ring->dequeue &&
1384                                         event_trb != td->last_trb)
1385                                 td->urb->actual_length =
1386                                         td->urb->transfer_buffer_length
1387                                         - TRB_LEN(event->transfer_len);
1388                         else
1389                                 td->urb->actual_length = 0;
1390
1391                         xhci_cleanup_halted_endpoint(xhci,
1392                                         slot_id, ep_index, 0, td, event_trb);
1393                         goto td_cleanup;
1394                 }
1395                 /*
1396                  * Did we transfer any data, despite the errors that might have
1397                  * happened?  I.e. did we get past the setup stage?
1398                  */
1399                 if (event_trb != ep_ring->dequeue) {
1400                         /* The event was for the status stage */
1401                         if (event_trb == td->last_trb) {
1402                                 if (td->urb->actual_length != 0) {
1403                                         /* Don't overwrite a previously set error code */
1404                                         if ((status == -EINPROGRESS ||
1405                                                                 status == 0) &&
1406                                                         (td->urb->transfer_flags
1407                                                          & URB_SHORT_NOT_OK))
1408                                                 /* Did we already see a short data stage? */
1409                                                 status = -EREMOTEIO;
1410                                 } else {
1411                                         td->urb->actual_length =
1412                                                 td->urb->transfer_buffer_length;
1413                                 }
1414                         } else {
1415                         /* Maybe the event was for the data stage? */
1416                                 if (trb_comp_code != COMP_STOP_INVAL) {
1417                                         /* We didn't stop on a link TRB in the middle */
1418                                         td->urb->actual_length =
1419                                                 td->urb->transfer_buffer_length -
1420                                                 TRB_LEN(event->transfer_len);
1421                                         xhci_dbg(xhci, "Waiting for status stage event\n");
1422                                         urb = NULL;
1423                                         goto cleanup;
1424                                 }
1425                         }
1426                 }
1427         } else {
1428                 switch (trb_comp_code) {
1429                 case COMP_SUCCESS:
1430                         /* Double check that the HW transferred everything. */
1431                         if (event_trb != td->last_trb) {
1432                                 xhci_warn(xhci, "WARN Successful completion "
1433                                                 "on short TX\n");
1434                                 if (td->urb->transfer_flags & URB_SHORT_NOT_OK)
1435                                         status = -EREMOTEIO;
1436                                 else
1437                                         status = 0;
1438                         } else {
1439                                 if (usb_endpoint_xfer_bulk(&td->urb->ep->desc))
1440                                         xhci_dbg(xhci, "Successful bulk "
1441                                                         "transfer!\n");
1442                                 else
1443                                         xhci_dbg(xhci, "Successful interrupt "
1444                                                         "transfer!\n");
1445                                 status = 0;
1446                         }
1447                         break;
1448                 case COMP_SHORT_TX:
1449                         if (td->urb->transfer_flags & URB_SHORT_NOT_OK)
1450                                 status = -EREMOTEIO;
1451                         else
1452                                 status = 0;
1453                         break;
1454                 default:
1455                         /* Others already handled above */
1456                         break;
1457                 }
1458                 dev_dbg(&td->urb->dev->dev,
1459                                 "ep %#x - asked for %d bytes, "
1460                                 "%d bytes untransferred\n",
1461                                 td->urb->ep->desc.bEndpointAddress,
1462                                 td->urb->transfer_buffer_length,
1463                                 TRB_LEN(event->transfer_len));
1464                 /* Fast path - was this the last TRB in the TD for this URB? */
1465                 if (event_trb == td->last_trb) {
1466                         if (TRB_LEN(event->transfer_len) != 0) {
1467                                 td->urb->actual_length =
1468                                         td->urb->transfer_buffer_length -
1469                                         TRB_LEN(event->transfer_len);
1470                                 if (td->urb->transfer_buffer_length <
1471                                                 td->urb->actual_length) {
1472                                         xhci_warn(xhci, "HC gave bad length "
1473                                                         "of %d bytes left\n",
1474                                                         TRB_LEN(event->transfer_len));
1475                                         td->urb->actual_length = 0;
1476                                         if (td->urb->transfer_flags &
1477                                                         URB_SHORT_NOT_OK)
1478                                                 status = -EREMOTEIO;
1479                                         else
1480                                                 status = 0;
1481                                 }
1482                                 /* Don't overwrite a previously set error code */
1483                                 if (status == -EINPROGRESS) {
1484                                         if (td->urb->transfer_flags & URB_SHORT_NOT_OK)
1485                                                 status = -EREMOTEIO;
1486                                         else
1487                                                 status = 0;
1488                                 }
1489                         } else {
1490                                 td->urb->actual_length = td->urb->transfer_buffer_length;
1491                                 /* Ignore a short packet completion if the
1492                                  * untransferred length was zero.
1493                                  */
1494                                 if (status == -EREMOTEIO)
1495                                         status = 0;
1496                         }
1497                 } else {
1498                         /* Slow path - walk the list, starting from the dequeue
1499                          * pointer, to get the actual length transferred.
1500                          */
1501                         union xhci_trb *cur_trb;
1502                         struct xhci_segment *cur_seg;
1503
1504                         td->urb->actual_length = 0;
1505                         for (cur_trb = ep_ring->dequeue, cur_seg = ep_ring->deq_seg;
1506                                         cur_trb != event_trb;
1507                                         next_trb(xhci, ep_ring, &cur_seg, &cur_trb)) {
1508                                 if ((cur_trb->generic.field[3] &
1509                                  TRB_TYPE_BITMASK) != TRB_TYPE(TRB_TR_NOOP) &&
1510                                     (cur_trb->generic.field[3] &
1511                                  TRB_TYPE_BITMASK) != TRB_TYPE(TRB_LINK))
1512                                         td->urb->actual_length +=
1513                                                 TRB_LEN(cur_trb->generic.field[2]);
1514                         }
1515                         /* If the ring didn't stop on a Link or No-op TRB, add
1516                          * in the actual bytes transferred from the Normal TRB
1517                          */
1518                         if (trb_comp_code != COMP_STOP_INVAL)
1519                                 td->urb->actual_length +=
1520                                         TRB_LEN(cur_trb->generic.field[2]) -
1521                                         TRB_LEN(event->transfer_len);
1522                 }
1523         }
1524         if (trb_comp_code == COMP_STOP_INVAL ||
1525                         trb_comp_code == COMP_STOP) {
1526                 /* The Endpoint Stop Command completion will take care of any
1527                  * stopped TDs.  A stopped TD may be restarted, so don't update
1528                  * the ring dequeue pointer or take this TD off any lists yet.
1529                  */
1530                 ep->stopped_td = td;
1531                 ep->stopped_trb = event_trb;
1532         } else {
1533                 if (trb_comp_code == COMP_STALL) {
1534                         /* The transfer is completed from the driver's
1535                          * perspective, but we need to issue a set dequeue
1536                          * command for this stalled endpoint to move the dequeue
1537                          * pointer past the TD.  We can't do that here because
1538                          * the halt condition must be cleared first.  Let the
1539                          * USB class driver clear the stall later.
1540                          */
1541                         ep->stopped_td = td;
1542                         ep->stopped_trb = event_trb;
1543                         ep->stopped_stream = ep_ring->stream_id;
1544                 } else if (xhci_requires_manual_halt_cleanup(xhci,
1545                                         ep_ctx, trb_comp_code)) {
1546                         /* Other types of errors halt the endpoint, but the
1547                          * class driver doesn't call usb_reset_endpoint() unless
1548                          * the error is -EPIPE.  Clear the halted status in the
1549                          * xHCI hardware manually.
1550                          */
1551                         xhci_cleanup_halted_endpoint(xhci,
1552                                         slot_id, ep_index, ep_ring->stream_id, td, event_trb);
1553                 } else {
1554                         /* Update ring dequeue pointer */
1555                         while (ep_ring->dequeue != td->last_trb)
1556                                 inc_deq(xhci, ep_ring, false);
1557                         inc_deq(xhci, ep_ring, false);
1558                 }
1559
1560 td_cleanup:
1561                 /* Clean up the endpoint's TD list */
1562                 urb = td->urb;
1563                 /* Do one last check of the actual transfer length.
1564                  * If the host controller said we transferred more data than
1565                  * the buffer length, urb->actual_length will be a very big
1566                  * number (since it's unsigned).  Play it safe and say we didn't
1567                  * transfer anything.
1568                  */
1569                 if (urb->actual_length > urb->transfer_buffer_length) {
1570                         xhci_warn(xhci, "URB transfer length is wrong, "
1571                                         "xHC issue? req. len = %u, "
1572                                         "act. len = %u\n",
1573                                         urb->transfer_buffer_length,
1574                                         urb->actual_length);
1575                         urb->actual_length = 0;
1576                         if (td->urb->transfer_flags & URB_SHORT_NOT_OK)
1577                                 status = -EREMOTEIO;
1578                         else
1579                                 status = 0;
1580                 }
1581                 list_del(&td->td_list);
1582                 /* Was this TD slated to be cancelled but completed anyway? */
1583                 if (!list_empty(&td->cancelled_td_list))
1584                         list_del(&td->cancelled_td_list);
1585
1586                 /* Leave the TD around for the reset endpoint function to use
1587                  * (but only if it's not a control endpoint, since we already
1588                  * queued the Set TR dequeue pointer command for stalled
1589                  * control endpoints).
1590                  */
1591                 if (usb_endpoint_xfer_control(&urb->ep->desc) ||
1592                         (trb_comp_code != COMP_STALL &&
1593                                 trb_comp_code != COMP_BABBLE)) {
1594                         kfree(td);
1595                 }
1596                 urb->hcpriv = NULL;
1597         }
1598 cleanup:
1599         inc_deq(xhci, xhci->event_ring, true);
1600         xhci_set_hc_event_deq(xhci);
1601
1602         /* FIXME for multi-TD URBs (who have buffers bigger than 64MB) */
1603         if (urb) {
1604                 usb_hcd_unlink_urb_from_ep(xhci_to_hcd(xhci), urb);
1605                 xhci_dbg(xhci, "Giveback URB %p, len = %d, status = %d\n",
1606                                 urb, urb->actual_length, status);
1607                 spin_unlock(&xhci->lock);
1608                 usb_hcd_giveback_urb(xhci_to_hcd(xhci), urb, status);
1609                 spin_lock(&xhci->lock);
1610         }
1611         return 0;
1612 }
1613
1614 /*
1615  * This function handles all OS-owned events on the event ring.  It may drop
1616  * xhci->lock between event processing (e.g. to pass up port status changes).
1617  */
1618 void xhci_handle_event(struct xhci_hcd *xhci)
1619 {
1620         union xhci_trb *event;
1621         int update_ptrs = 1;
1622         int ret;
1623
1624         xhci_dbg(xhci, "In %s\n", __func__);
1625         if (!xhci->event_ring || !xhci->event_ring->dequeue) {
1626                 xhci->error_bitmask |= 1 << 1;
1627                 return;
1628         }
1629
1630         event = xhci->event_ring->dequeue;
1631         /* Does the HC or OS own the TRB? */
1632         if ((event->event_cmd.flags & TRB_CYCLE) !=
1633                         xhci->event_ring->cycle_state) {
1634                 xhci->error_bitmask |= 1 << 2;
1635                 return;
1636         }
1637         xhci_dbg(xhci, "%s - OS owns TRB\n", __func__);
1638
1639         /* FIXME: Handle more event types. */
1640         switch ((event->event_cmd.flags & TRB_TYPE_BITMASK)) {
1641         case TRB_TYPE(TRB_COMPLETION):
1642                 xhci_dbg(xhci, "%s - calling handle_cmd_completion\n", __func__);
1643                 handle_cmd_completion(xhci, &event->event_cmd);
1644                 xhci_dbg(xhci, "%s - returned from handle_cmd_completion\n", __func__);
1645                 break;
1646         case TRB_TYPE(TRB_PORT_STATUS):
1647                 xhci_dbg(xhci, "%s - calling handle_port_status\n", __func__);
1648                 handle_port_status(xhci, event);
1649                 xhci_dbg(xhci, "%s - returned from handle_port_status\n", __func__);
1650                 update_ptrs = 0;
1651                 break;
1652         case TRB_TYPE(TRB_TRANSFER):
1653                 xhci_dbg(xhci, "%s - calling handle_tx_event\n", __func__);
1654                 ret = handle_tx_event(xhci, &event->trans_event);
1655                 xhci_dbg(xhci, "%s - returned from handle_tx_event\n", __func__);
1656                 if (ret < 0)
1657                         xhci->error_bitmask |= 1 << 9;
1658                 else
1659                         update_ptrs = 0;
1660                 break;
1661         default:
1662                 xhci->error_bitmask |= 1 << 3;
1663         }
1664         /* Any of the above functions may drop and re-acquire the lock, so check
1665          * to make sure a watchdog timer didn't mark the host as non-responsive.
1666          */
1667         if (xhci->xhc_state & XHCI_STATE_DYING) {
1668                 xhci_dbg(xhci, "xHCI host dying, returning from "
1669                                 "event handler.\n");
1670                 return;
1671         }
1672
1673         if (update_ptrs) {
1674                 /* Update SW and HC event ring dequeue pointer */
1675                 inc_deq(xhci, xhci->event_ring, true);
1676                 xhci_set_hc_event_deq(xhci);
1677         }
1678         /* Are there more items on the event ring? */
1679         xhci_handle_event(xhci);
1680 }
1681
1682 /****           Endpoint Ring Operations        ****/
1683
1684 /*
1685  * Generic function for queueing a TRB on a ring.
1686  * The caller must have checked to make sure there's room on the ring.
1687  */
1688 static void queue_trb(struct xhci_hcd *xhci, struct xhci_ring *ring,
1689                 bool consumer,
1690                 u32 field1, u32 field2, u32 field3, u32 field4)
1691 {
1692         struct xhci_generic_trb *trb;
1693
1694         trb = &ring->enqueue->generic;
1695         trb->field[0] = field1;
1696         trb->field[1] = field2;
1697         trb->field[2] = field3;
1698         trb->field[3] = field4;
1699         inc_enq(xhci, ring, consumer);
1700 }
1701
1702 /*
1703  * Does various checks on the endpoint ring, and makes it ready to queue num_trbs.
1704  * FIXME allocate segments if the ring is full.
1705  */
1706 static int prepare_ring(struct xhci_hcd *xhci, struct xhci_ring *ep_ring,
1707                 u32 ep_state, unsigned int num_trbs, gfp_t mem_flags)
1708 {
1709         /* Make sure the endpoint has been added to xHC schedule */
1710         xhci_dbg(xhci, "Endpoint state = 0x%x\n", ep_state);
1711         switch (ep_state) {
1712         case EP_STATE_DISABLED:
1713                 /*
1714                  * USB core changed config/interfaces without notifying us,
1715                  * or hardware is reporting the wrong state.
1716                  */
1717                 xhci_warn(xhci, "WARN urb submitted to disabled ep\n");
1718                 return -ENOENT;
1719         case EP_STATE_ERROR:
1720                 xhci_warn(xhci, "WARN waiting for error on ep to be cleared\n");
1721                 /* FIXME event handling code for error needs to clear it */
1722                 /* XXX not sure if this should be -ENOENT or not */
1723                 return -EINVAL;
1724         case EP_STATE_HALTED:
1725                 xhci_dbg(xhci, "WARN halted endpoint, queueing URB anyway.\n");
1726         case EP_STATE_STOPPED:
1727         case EP_STATE_RUNNING:
1728                 break;
1729         default:
1730                 xhci_err(xhci, "ERROR unknown endpoint state for ep\n");
1731                 /*
1732                  * FIXME issue Configure Endpoint command to try to get the HC
1733                  * back into a known state.
1734                  */
1735                 return -EINVAL;
1736         }
1737         if (!room_on_ring(xhci, ep_ring, num_trbs)) {
1738                 /* FIXME allocate more room */
1739                 xhci_err(xhci, "ERROR no room on ep ring\n");
1740                 return -ENOMEM;
1741         }
1742
1743         if (enqueue_is_link_trb(ep_ring)) {
1744                 struct xhci_ring *ring = ep_ring;
1745                 union xhci_trb *next;
1746
1747                 xhci_dbg(xhci, "prepare_ring: pointing to link trb\n");
1748                 next = ring->enqueue;
1749
1750                 while (last_trb(xhci, ring, ring->enq_seg, next)) {
1751
1752                         /* If we're not dealing with 0.95 hardware,
1753                          * clear the chain bit.
1754                          */
1755                         if (!xhci_link_trb_quirk(xhci))
1756                                 next->link.control &= ~TRB_CHAIN;
1757                         else
1758                                 next->link.control |= TRB_CHAIN;
1759
1760                         wmb();
1761                         next->link.control ^= (u32) TRB_CYCLE;
1762
1763                         /* Toggle the cycle bit after the last ring segment. */
1764                         if (last_trb_on_last_seg(xhci, ring, ring->enq_seg, next)) {
1765                                 ring->cycle_state = (ring->cycle_state ? 0 : 1);
1766                                 if (!in_interrupt()) {
1767                                         xhci_dbg(xhci, "queue_trb: Toggle cycle "
1768                                                 "state for ring %p = %i\n",
1769                                                 ring, (unsigned int)ring->cycle_state);
1770                                 }
1771                         }
1772                         ring->enq_seg = ring->enq_seg->next;
1773                         ring->enqueue = ring->enq_seg->trbs;
1774                         next = ring->enqueue;
1775                 }
1776         }
1777
1778         return 0;
1779 }
1780
1781 static int prepare_transfer(struct xhci_hcd *xhci,
1782                 struct xhci_virt_device *xdev,
1783                 unsigned int ep_index,
1784                 unsigned int stream_id,
1785                 unsigned int num_trbs,
1786                 struct urb *urb,
1787                 struct xhci_td **td,
1788                 gfp_t mem_flags)
1789 {
1790         int ret;
1791         struct xhci_ring *ep_ring;
1792         struct xhci_ep_ctx *ep_ctx = xhci_get_ep_ctx(xhci, xdev->out_ctx, ep_index);
1793
1794         ep_ring = xhci_stream_id_to_ring(xdev, ep_index, stream_id);
1795         if (!ep_ring) {
1796                 xhci_dbg(xhci, "Can't prepare ring for bad stream ID %u\n",
1797                                 stream_id);
1798                 return -EINVAL;
1799         }
1800
1801         ret = prepare_ring(xhci, ep_ring,
1802                         ep_ctx->ep_info & EP_STATE_MASK,
1803                         num_trbs, mem_flags);
1804         if (ret)
1805                 return ret;
1806         *td = kzalloc(sizeof(struct xhci_td), mem_flags);
1807         if (!*td)
1808                 return -ENOMEM;
1809         INIT_LIST_HEAD(&(*td)->td_list);
1810         INIT_LIST_HEAD(&(*td)->cancelled_td_list);
1811
1812         ret = usb_hcd_link_urb_to_ep(xhci_to_hcd(xhci), urb);
1813         if (unlikely(ret)) {
1814                 kfree(*td);
1815                 return ret;
1816         }
1817
1818         (*td)->urb = urb;
1819         urb->hcpriv = (void *) (*td);
1820         /* Add this TD to the tail of the endpoint ring's TD list */
1821         list_add_tail(&(*td)->td_list, &ep_ring->td_list);
1822         (*td)->start_seg = ep_ring->enq_seg;
1823         (*td)->first_trb = ep_ring->enqueue;
1824
1825         return 0;
1826 }
1827
1828 static unsigned int count_sg_trbs_needed(struct xhci_hcd *xhci, struct urb *urb)
1829 {
1830         int num_sgs, num_trbs, running_total, temp, i;
1831         struct scatterlist *sg;
1832
1833         sg = NULL;
1834         num_sgs = urb->num_sgs;
1835         temp = urb->transfer_buffer_length;
1836
1837         xhci_dbg(xhci, "count sg list trbs: \n");
1838         num_trbs = 0;
1839         for_each_sg(urb->sg, sg, num_sgs, i) {
1840                 unsigned int previous_total_trbs = num_trbs;
1841                 unsigned int len = sg_dma_len(sg);
1842
1843                 /* Scatter gather list entries may cross 64KB boundaries */
1844                 running_total = TRB_MAX_BUFF_SIZE -
1845                         (sg_dma_address(sg) & ((1 << TRB_MAX_BUFF_SHIFT) - 1));
1846                 if (running_total != 0)
1847                         num_trbs++;
1848
1849                 /* How many more 64KB chunks to transfer, how many more TRBs? */
1850                 while (running_total < sg_dma_len(sg)) {
1851                         num_trbs++;
1852                         running_total += TRB_MAX_BUFF_SIZE;
1853                 }
1854                 xhci_dbg(xhci, " sg #%d: dma = %#llx, len = %#x (%d), num_trbs = %d\n",
1855                                 i, (unsigned long long)sg_dma_address(sg),
1856                                 len, len, num_trbs - previous_total_trbs);
1857
1858                 len = min_t(int, len, temp);
1859                 temp -= len;
1860                 if (temp == 0)
1861                         break;
1862         }
1863         xhci_dbg(xhci, "\n");
1864         if (!in_interrupt())
1865                 dev_dbg(&urb->dev->dev, "ep %#x - urb len = %d, sglist used, num_trbs = %d\n",
1866                                 urb->ep->desc.bEndpointAddress,
1867                                 urb->transfer_buffer_length,
1868                                 num_trbs);
1869         return num_trbs;
1870 }
1871
1872 static void check_trb_math(struct urb *urb, int num_trbs, int running_total)
1873 {
1874         if (num_trbs != 0)
1875                 dev_dbg(&urb->dev->dev, "%s - ep %#x - Miscalculated number of "
1876                                 "TRBs, %d left\n", __func__,
1877                                 urb->ep->desc.bEndpointAddress, num_trbs);
1878         if (running_total != urb->transfer_buffer_length)
1879                 dev_dbg(&urb->dev->dev, "%s - ep %#x - Miscalculated tx length, "
1880                                 "queued %#x (%d), asked for %#x (%d)\n",
1881                                 __func__,
1882                                 urb->ep->desc.bEndpointAddress,
1883                                 running_total, running_total,
1884                                 urb->transfer_buffer_length,
1885                                 urb->transfer_buffer_length);
1886 }
1887
1888 static void giveback_first_trb(struct xhci_hcd *xhci, int slot_id,
1889                 unsigned int ep_index, unsigned int stream_id, int start_cycle,
1890                 struct xhci_generic_trb *start_trb, struct xhci_td *td)
1891 {
1892         /*
1893          * Pass all the TRBs to the hardware at once and make sure this write
1894          * isn't reordered.
1895          */
1896         wmb();
1897         start_trb->field[3] |= start_cycle;
1898         ring_ep_doorbell(xhci, slot_id, ep_index, stream_id);
1899 }
1900
1901 /*
1902  * xHCI uses normal TRBs for both bulk and interrupt.  When the interrupt
1903  * endpoint is to be serviced, the xHC will consume (at most) one TD.  A TD
1904  * (comprised of sg list entries) can take several service intervals to
1905  * transmit.
1906  */
1907 int xhci_queue_intr_tx(struct xhci_hcd *xhci, gfp_t mem_flags,
1908                 struct urb *urb, int slot_id, unsigned int ep_index)
1909 {
1910         struct xhci_ep_ctx *ep_ctx = xhci_get_ep_ctx(xhci,
1911                         xhci->devs[slot_id]->out_ctx, ep_index);
1912         int xhci_interval;
1913         int ep_interval;
1914
1915         xhci_interval = EP_INTERVAL_TO_UFRAMES(ep_ctx->ep_info);
1916         ep_interval = urb->interval;
1917         /* Convert to microframes */
1918         if (urb->dev->speed == USB_SPEED_LOW ||
1919                         urb->dev->speed == USB_SPEED_FULL)
1920                 ep_interval *= 8;
1921         /* FIXME change this to a warning and a suggestion to use the new API
1922          * to set the polling interval (once the API is added).
1923          */
1924         if (xhci_interval != ep_interval) {
1925                 if (!printk_ratelimit())
1926                         dev_dbg(&urb->dev->dev, "Driver uses different interval"
1927                                         " (%d microframe%s) than xHCI "
1928                                         "(%d microframe%s)\n",
1929                                         ep_interval,
1930                                         ep_interval == 1 ? "" : "s",
1931                                         xhci_interval,
1932                                         xhci_interval == 1 ? "" : "s");
1933                 urb->interval = xhci_interval;
1934                 /* Convert back to frames for LS/FS devices */
1935                 if (urb->dev->speed == USB_SPEED_LOW ||
1936                                 urb->dev->speed == USB_SPEED_FULL)
1937                         urb->interval /= 8;
1938         }
1939         return xhci_queue_bulk_tx(xhci, GFP_ATOMIC, urb, slot_id, ep_index);
1940 }
1941
1942 /*
1943  * The TD size is the number of bytes remaining in the TD (including this TRB),
1944  * right shifted by 10.
1945  * It must fit in bits 21:17, so it can't be bigger than 31.
1946  */
1947 static u32 xhci_td_remainder(unsigned int remainder)
1948 {
1949         u32 max = (1 << (21 - 17 + 1)) - 1;
1950
1951         if ((remainder >> 10) >= max)
1952                 return max << 17;
1953         else
1954                 return (remainder >> 10) << 17;
1955 }
1956
1957 static int queue_bulk_sg_tx(struct xhci_hcd *xhci, gfp_t mem_flags,
1958                 struct urb *urb, int slot_id, unsigned int ep_index)
1959 {
1960         struct xhci_ring *ep_ring;
1961         unsigned int num_trbs;
1962         struct xhci_td *td;
1963         struct scatterlist *sg;
1964         int num_sgs;
1965         int trb_buff_len, this_sg_len, running_total;
1966         bool first_trb;
1967         u64 addr;
1968
1969         struct xhci_generic_trb *start_trb;
1970         int start_cycle;
1971
1972         ep_ring = xhci_urb_to_transfer_ring(xhci, urb);
1973         if (!ep_ring)
1974                 return -EINVAL;
1975
1976         num_trbs = count_sg_trbs_needed(xhci, urb);
1977         num_sgs = urb->num_sgs;
1978
1979         trb_buff_len = prepare_transfer(xhci, xhci->devs[slot_id],
1980                         ep_index, urb->stream_id,
1981                         num_trbs, urb, &td, mem_flags);
1982         if (trb_buff_len < 0)
1983                 return trb_buff_len;
1984         /*
1985          * Don't give the first TRB to the hardware (by toggling the cycle bit)
1986          * until we've finished creating all the other TRBs.  The ring's cycle
1987          * state may change as we enqueue the other TRBs, so save it too.
1988          */
1989         start_trb = &ep_ring->enqueue->generic;
1990         start_cycle = ep_ring->cycle_state;
1991
1992         running_total = 0;
1993         /*
1994          * How much data is in the first TRB?
1995          *
1996          * There are three forces at work for TRB buffer pointers and lengths:
1997          * 1. We don't want to walk off the end of this sg-list entry buffer.
1998          * 2. The transfer length that the driver requested may be smaller than
1999          *    the amount of memory allocated for this scatter-gather list.
2000          * 3. TRBs buffers can't cross 64KB boundaries.
2001          */
2002         sg = urb->sg;
2003         addr = (u64) sg_dma_address(sg);
2004         this_sg_len = sg_dma_len(sg);
2005         trb_buff_len = TRB_MAX_BUFF_SIZE -
2006                 (addr & ((1 << TRB_MAX_BUFF_SHIFT) - 1));
2007         trb_buff_len = min_t(int, trb_buff_len, this_sg_len);
2008         if (trb_buff_len > urb->transfer_buffer_length)
2009                 trb_buff_len = urb->transfer_buffer_length;
2010         xhci_dbg(xhci, "First length to xfer from 1st sglist entry = %u\n",
2011                         trb_buff_len);
2012
2013         first_trb = true;
2014         /* Queue the first TRB, even if it's zero-length */
2015         do {
2016                 u32 field = 0;
2017                 u32 length_field = 0;
2018                 u32 remainder = 0;
2019
2020                 /* Don't change the cycle bit of the first TRB until later */
2021                 if (first_trb)
2022                         first_trb = false;
2023                 else
2024                         field |= ep_ring->cycle_state;
2025
2026                 /* Chain all the TRBs together; clear the chain bit in the last
2027                  * TRB to indicate it's the last TRB in the chain.
2028                  */
2029                 if (num_trbs > 1) {
2030                         field |= TRB_CHAIN;
2031                 } else {
2032                         /* FIXME - add check for ZERO_PACKET flag before this */
2033                         td->last_trb = ep_ring->enqueue;
2034                         field |= TRB_IOC;
2035                 }
2036                 xhci_dbg(xhci, " sg entry: dma = %#x, len = %#x (%d), "
2037                                 "64KB boundary at %#x, end dma = %#x\n",
2038                                 (unsigned int) addr, trb_buff_len, trb_buff_len,
2039                                 (unsigned int) (addr + TRB_MAX_BUFF_SIZE) & ~(TRB_MAX_BUFF_SIZE - 1),
2040                                 (unsigned int) addr + trb_buff_len);
2041                 if (TRB_MAX_BUFF_SIZE -
2042                                 (addr & ((1 << TRB_MAX_BUFF_SHIFT) - 1)) < trb_buff_len) {
2043                         xhci_warn(xhci, "WARN: sg dma xfer crosses 64KB boundaries!\n");
2044                         xhci_dbg(xhci, "Next boundary at %#x, end dma = %#x\n",
2045                                         (unsigned int) (addr + TRB_MAX_BUFF_SIZE) & ~(TRB_MAX_BUFF_SIZE - 1),
2046                                         (unsigned int) addr + trb_buff_len);
2047                 }
2048                 remainder = xhci_td_remainder(urb->transfer_buffer_length -
2049                                 running_total) ;
2050                 length_field = TRB_LEN(trb_buff_len) |
2051                         remainder |
2052                         TRB_INTR_TARGET(0);
2053                 queue_trb(xhci, ep_ring, false,
2054                                 lower_32_bits(addr),
2055                                 upper_32_bits(addr),
2056                                 length_field,
2057                                 /* We always want to know if the TRB was short,
2058                                  * or we won't get an event when it completes.
2059                                  * (Unless we use event data TRBs, which are a
2060                                  * waste of space and HC resources.)
2061                                  */
2062                                 field | TRB_ISP | TRB_TYPE(TRB_NORMAL));
2063                 --num_trbs;
2064                 running_total += trb_buff_len;
2065
2066                 /* Calculate length for next transfer --
2067                  * Are we done queueing all the TRBs for this sg entry?
2068                  */
2069                 this_sg_len -= trb_buff_len;
2070                 if (this_sg_len == 0) {
2071                         --num_sgs;
2072                         if (num_sgs == 0)
2073                                 break;
2074                         sg = sg_next(sg);
2075                         addr = (u64) sg_dma_address(sg);
2076                         this_sg_len = sg_dma_len(sg);
2077                 } else {
2078                         addr += trb_buff_len;
2079                 }
2080
2081                 trb_buff_len = TRB_MAX_BUFF_SIZE -
2082                         (addr & ((1 << TRB_MAX_BUFF_SHIFT) - 1));
2083                 trb_buff_len = min_t(int, trb_buff_len, this_sg_len);
2084                 if (running_total + trb_buff_len > urb->transfer_buffer_length)
2085                         trb_buff_len =
2086                                 urb->transfer_buffer_length - running_total;
2087         } while (running_total < urb->transfer_buffer_length);
2088
2089         check_trb_math(urb, num_trbs, running_total);
2090         giveback_first_trb(xhci, slot_id, ep_index, urb->stream_id,
2091                         start_cycle, start_trb, td);
2092         return 0;
2093 }
2094
2095 /* This is very similar to what ehci-q.c qtd_fill() does */
2096 int xhci_queue_bulk_tx(struct xhci_hcd *xhci, gfp_t mem_flags,
2097                 struct urb *urb, int slot_id, unsigned int ep_index)
2098 {
2099         struct xhci_ring *ep_ring;
2100         struct xhci_td *td;
2101         int num_trbs;
2102         struct xhci_generic_trb *start_trb;
2103         bool first_trb;
2104         int start_cycle;
2105         u32 field, length_field;
2106
2107         int running_total, trb_buff_len, ret;
2108         u64 addr;
2109
2110         if (urb->num_sgs)
2111                 return queue_bulk_sg_tx(xhci, mem_flags, urb, slot_id, ep_index);
2112
2113         ep_ring = xhci_urb_to_transfer_ring(xhci, urb);
2114         if (!ep_ring)
2115                 return -EINVAL;
2116
2117         num_trbs = 0;
2118         /* How much data is (potentially) left before the 64KB boundary? */
2119         running_total = TRB_MAX_BUFF_SIZE -
2120                 (urb->transfer_dma & ((1 << TRB_MAX_BUFF_SHIFT) - 1));
2121
2122         /* If there's some data on this 64KB chunk, or we have to send a
2123          * zero-length transfer, we need at least one TRB
2124          */
2125         if (running_total != 0 || urb->transfer_buffer_length == 0)
2126                 num_trbs++;
2127         /* How many more 64KB chunks to transfer, how many more TRBs? */
2128         while (running_total < urb->transfer_buffer_length) {
2129                 num_trbs++;
2130                 running_total += TRB_MAX_BUFF_SIZE;
2131         }
2132         /* FIXME: this doesn't deal with URB_ZERO_PACKET - need one more */
2133
2134         if (!in_interrupt())
2135                 dev_dbg(&urb->dev->dev, "ep %#x - urb len = %#x (%d), addr = %#llx, num_trbs = %d\n",
2136                                 urb->ep->desc.bEndpointAddress,
2137                                 urb->transfer_buffer_length,
2138                                 urb->transfer_buffer_length,
2139                                 (unsigned long long)urb->transfer_dma,
2140                                 num_trbs);
2141
2142         ret = prepare_transfer(xhci, xhci->devs[slot_id],
2143                         ep_index, urb->stream_id,
2144                         num_trbs, urb, &td, mem_flags);
2145         if (ret < 0)
2146                 return ret;
2147
2148         /*
2149          * Don't give the first TRB to the hardware (by toggling the cycle bit)
2150          * until we've finished creating all the other TRBs.  The ring's cycle
2151          * state may change as we enqueue the other TRBs, so save it too.
2152          */
2153         start_trb = &ep_ring->enqueue->generic;
2154         start_cycle = ep_ring->cycle_state;
2155
2156         running_total = 0;
2157         /* How much data is in the first TRB? */
2158         addr = (u64) urb->transfer_dma;
2159         trb_buff_len = TRB_MAX_BUFF_SIZE -
2160                 (urb->transfer_dma & ((1 << TRB_MAX_BUFF_SHIFT) - 1));
2161         if (urb->transfer_buffer_length < trb_buff_len)
2162                 trb_buff_len = urb->transfer_buffer_length;
2163
2164         first_trb = true;
2165
2166         /* Queue the first TRB, even if it's zero-length */
2167         do {
2168                 u32 remainder = 0;
2169                 field = 0;
2170
2171                 /* Don't change the cycle bit of the first TRB until later */
2172                 if (first_trb)
2173                         first_trb = false;
2174                 else
2175                         field |= ep_ring->cycle_state;
2176
2177                 /* Chain all the TRBs together; clear the chain bit in the last
2178                  * TRB to indicate it's the last TRB in the chain.
2179                  */
2180                 if (num_trbs > 1) {
2181                         field |= TRB_CHAIN;
2182                 } else {
2183                         /* FIXME - add check for ZERO_PACKET flag before this */
2184                         td->last_trb = ep_ring->enqueue;
2185                         field |= TRB_IOC;
2186                 }
2187                 remainder = xhci_td_remainder(urb->transfer_buffer_length -
2188                                 running_total);
2189                 length_field = TRB_LEN(trb_buff_len) |
2190                         remainder |
2191                         TRB_INTR_TARGET(0);
2192                 queue_trb(xhci, ep_ring, false,
2193                                 lower_32_bits(addr),
2194                                 upper_32_bits(addr),
2195                                 length_field,
2196                                 /* We always want to know if the TRB was short,
2197                                  * or we won't get an event when it completes.
2198                                  * (Unless we use event data TRBs, which are a
2199                                  * waste of space and HC resources.)
2200                                  */
2201                                 field | TRB_ISP | TRB_TYPE(TRB_NORMAL));
2202                 --num_trbs;
2203                 running_total += trb_buff_len;
2204
2205                 /* Calculate length for next transfer */
2206                 addr += trb_buff_len;
2207                 trb_buff_len = urb->transfer_buffer_length - running_total;
2208                 if (trb_buff_len > TRB_MAX_BUFF_SIZE)
2209                         trb_buff_len = TRB_MAX_BUFF_SIZE;
2210         } while (running_total < urb->transfer_buffer_length);
2211
2212         check_trb_math(urb, num_trbs, running_total);
2213         giveback_first_trb(xhci, slot_id, ep_index, urb->stream_id,
2214                         start_cycle, start_trb, td);
2215         return 0;
2216 }
2217
2218 /* Caller must have locked xhci->lock */
2219 int xhci_queue_ctrl_tx(struct xhci_hcd *xhci, gfp_t mem_flags,
2220                 struct urb *urb, int slot_id, unsigned int ep_index)
2221 {
2222         struct xhci_ring *ep_ring;
2223         int num_trbs;
2224         int ret;
2225         struct usb_ctrlrequest *setup;
2226         struct xhci_generic_trb *start_trb;
2227         int start_cycle;
2228         u32 field, length_field;
2229         struct xhci_td *td;
2230
2231         ep_ring = xhci_urb_to_transfer_ring(xhci, urb);
2232         if (!ep_ring)
2233                 return -EINVAL;
2234
2235         /*
2236          * Need to copy setup packet into setup TRB, so we can't use the setup
2237          * DMA address.
2238          */
2239         if (!urb->setup_packet)
2240                 return -EINVAL;
2241
2242         if (!in_interrupt())
2243                 xhci_dbg(xhci, "Queueing ctrl tx for slot id %d, ep %d\n",
2244                                 slot_id, ep_index);
2245         /* 1 TRB for setup, 1 for status */
2246         num_trbs = 2;
2247         /*
2248          * Don't need to check if we need additional event data and normal TRBs,
2249          * since data in control transfers will never get bigger than 16MB
2250          * XXX: can we get a buffer that crosses 64KB boundaries?
2251          */
2252         if (urb->transfer_buffer_length > 0)
2253                 num_trbs++;
2254         ret = prepare_transfer(xhci, xhci->devs[slot_id],
2255                         ep_index, urb->stream_id,
2256                         num_trbs, urb, &td, mem_flags);
2257         if (ret < 0)
2258                 return ret;
2259
2260         /*
2261          * Don't give the first TRB to the hardware (by toggling the cycle bit)
2262          * until we've finished creating all the other TRBs.  The ring's cycle
2263          * state may change as we enqueue the other TRBs, so save it too.
2264          */
2265         start_trb = &ep_ring->enqueue->generic;
2266         start_cycle = ep_ring->cycle_state;
2267
2268         /* Queue setup TRB - see section 6.4.1.2.1 */
2269         /* FIXME better way to translate setup_packet into two u32 fields? */
2270         setup = (struct usb_ctrlrequest *) urb->setup_packet;
2271         queue_trb(xhci, ep_ring, false,
2272                         /* FIXME endianness is probably going to bite my ass here. */
2273                         setup->bRequestType | setup->bRequest << 8 | setup->wValue << 16,
2274                         setup->wIndex | setup->wLength << 16,
2275                         TRB_LEN(8) | TRB_INTR_TARGET(0),
2276                         /* Immediate data in pointer */
2277                         TRB_IDT | TRB_TYPE(TRB_SETUP));
2278
2279         /* If there's data, queue data TRBs */
2280         field = 0;
2281         length_field = TRB_LEN(urb->transfer_buffer_length) |
2282                 xhci_td_remainder(urb->transfer_buffer_length) |
2283                 TRB_INTR_TARGET(0);
2284         if (urb->transfer_buffer_length > 0) {
2285                 if (setup->bRequestType & USB_DIR_IN)
2286                         field |= TRB_DIR_IN;
2287                 queue_trb(xhci, ep_ring, false,
2288                                 lower_32_bits(urb->transfer_dma),
2289                                 upper_32_bits(urb->transfer_dma),
2290                                 length_field,
2291                                 /* Event on short tx */
2292                                 field | TRB_ISP | TRB_TYPE(TRB_DATA) | ep_ring->cycle_state);
2293         }
2294
2295         /* Save the DMA address of the last TRB in the TD */
2296         td->last_trb = ep_ring->enqueue;
2297
2298         /* Queue status TRB - see Table 7 and sections 4.11.2.2 and 6.4.1.2.3 */
2299         /* If the device sent data, the status stage is an OUT transfer */
2300         if (urb->transfer_buffer_length > 0 && setup->bRequestType & USB_DIR_IN)
2301                 field = 0;
2302         else
2303                 field = TRB_DIR_IN;
2304         queue_trb(xhci, ep_ring, false,
2305                         0,
2306                         0,
2307                         TRB_INTR_TARGET(0),
2308                         /* Event on completion */
2309                         field | TRB_IOC | TRB_TYPE(TRB_STATUS) | ep_ring->cycle_state);
2310
2311         giveback_first_trb(xhci, slot_id, ep_index, 0,
2312                         start_cycle, start_trb, td);
2313         return 0;
2314 }
2315
2316 /****           Command Ring Operations         ****/
2317
2318 /* Generic function for queueing a command TRB on the command ring.
2319  * Check to make sure there's room on the command ring for one command TRB.
2320  * Also check that there's room reserved for commands that must not fail.
2321  * If this is a command that must not fail, meaning command_must_succeed = TRUE,
2322  * then only check for the number of reserved spots.
2323  * Don't decrement xhci->cmd_ring_reserved_trbs after we've queued the TRB
2324  * because the command event handler may want to resubmit a failed command.
2325  */
2326 static int queue_command(struct xhci_hcd *xhci, u32 field1, u32 field2,
2327                 u32 field3, u32 field4, bool command_must_succeed)
2328 {
2329         int reserved_trbs = xhci->cmd_ring_reserved_trbs;
2330         if (!command_must_succeed)
2331                 reserved_trbs++;
2332
2333         if (!room_on_ring(xhci, xhci->cmd_ring, reserved_trbs)) {
2334                 if (!in_interrupt())
2335                         xhci_err(xhci, "ERR: No room for command on command ring\n");
2336                 if (command_must_succeed)
2337                         xhci_err(xhci, "ERR: Reserved TRB counting for "
2338                                         "unfailable commands failed.\n");
2339                 return -ENOMEM;
2340         }
2341         queue_trb(xhci, xhci->cmd_ring, false, field1, field2, field3,
2342                         field4 | xhci->cmd_ring->cycle_state);
2343         return 0;
2344 }
2345
2346 /* Queue a no-op command on the command ring */
2347 static int queue_cmd_noop(struct xhci_hcd *xhci)
2348 {
2349         return queue_command(xhci, 0, 0, 0, TRB_TYPE(TRB_CMD_NOOP), false);
2350 }
2351
2352 /*
2353  * Place a no-op command on the command ring to test the command and
2354  * event ring.
2355  */
2356 void *xhci_setup_one_noop(struct xhci_hcd *xhci)
2357 {
2358         if (queue_cmd_noop(xhci) < 0)
2359                 return NULL;
2360         xhci->noops_submitted++;
2361         return xhci_ring_cmd_db;
2362 }
2363
2364 /* Queue a slot enable or disable request on the command ring */
2365 int xhci_queue_slot_control(struct xhci_hcd *xhci, u32 trb_type, u32 slot_id)
2366 {
2367         return queue_command(xhci, 0, 0, 0,
2368                         TRB_TYPE(trb_type) | SLOT_ID_FOR_TRB(slot_id), false);
2369 }
2370
2371 /* Queue an address device command TRB */
2372 int xhci_queue_address_device(struct xhci_hcd *xhci, dma_addr_t in_ctx_ptr,
2373                 u32 slot_id)
2374 {
2375         return queue_command(xhci, lower_32_bits(in_ctx_ptr),
2376                         upper_32_bits(in_ctx_ptr), 0,
2377                         TRB_TYPE(TRB_ADDR_DEV) | SLOT_ID_FOR_TRB(slot_id),
2378                         false);
2379 }
2380
2381 /* Queue a reset device command TRB */
2382 int xhci_queue_reset_device(struct xhci_hcd *xhci, u32 slot_id)
2383 {
2384         return queue_command(xhci, 0, 0, 0,
2385                         TRB_TYPE(TRB_RESET_DEV) | SLOT_ID_FOR_TRB(slot_id),
2386                         false);
2387 }
2388
2389 /* Queue a configure endpoint command TRB */
2390 int xhci_queue_configure_endpoint(struct xhci_hcd *xhci, dma_addr_t in_ctx_ptr,
2391                 u32 slot_id, bool command_must_succeed)
2392 {
2393         return queue_command(xhci, lower_32_bits(in_ctx_ptr),
2394                         upper_32_bits(in_ctx_ptr), 0,
2395                         TRB_TYPE(TRB_CONFIG_EP) | SLOT_ID_FOR_TRB(slot_id),
2396                         command_must_succeed);
2397 }
2398
2399 /* Queue an evaluate context command TRB */
2400 int xhci_queue_evaluate_context(struct xhci_hcd *xhci, dma_addr_t in_ctx_ptr,
2401                 u32 slot_id)
2402 {
2403         return queue_command(xhci, lower_32_bits(in_ctx_ptr),
2404                         upper_32_bits(in_ctx_ptr), 0,
2405                         TRB_TYPE(TRB_EVAL_CONTEXT) | SLOT_ID_FOR_TRB(slot_id),
2406                         false);
2407 }
2408
2409 int xhci_queue_stop_endpoint(struct xhci_hcd *xhci, int slot_id,
2410                 unsigned int ep_index)
2411 {
2412         u32 trb_slot_id = SLOT_ID_FOR_TRB(slot_id);
2413         u32 trb_ep_index = EP_ID_FOR_TRB(ep_index);
2414         u32 type = TRB_TYPE(TRB_STOP_RING);
2415
2416         return queue_command(xhci, 0, 0, 0,
2417                         trb_slot_id | trb_ep_index | type, false);
2418 }
2419
2420 /* Set Transfer Ring Dequeue Pointer command.
2421  * This should not be used for endpoints that have streams enabled.
2422  */
2423 static int queue_set_tr_deq(struct xhci_hcd *xhci, int slot_id,
2424                 unsigned int ep_index, unsigned int stream_id,
2425                 struct xhci_segment *deq_seg,
2426                 union xhci_trb *deq_ptr, u32 cycle_state)
2427 {
2428         dma_addr_t addr;
2429         u32 trb_slot_id = SLOT_ID_FOR_TRB(slot_id);
2430         u32 trb_ep_index = EP_ID_FOR_TRB(ep_index);
2431         u32 trb_stream_id = STREAM_ID_FOR_TRB(stream_id);
2432         u32 type = TRB_TYPE(TRB_SET_DEQ);
2433
2434         addr = xhci_trb_virt_to_dma(deq_seg, deq_ptr);
2435         if (addr == 0) {
2436                 xhci_warn(xhci, "WARN Cannot submit Set TR Deq Ptr\n");
2437                 xhci_warn(xhci, "WARN deq seg = %p, deq pt = %p\n",
2438                                 deq_seg, deq_ptr);
2439                 return 0;
2440         }
2441         return queue_command(xhci, lower_32_bits(addr) | cycle_state,
2442                         upper_32_bits(addr), trb_stream_id,
2443                         trb_slot_id | trb_ep_index | type, false);
2444 }
2445
2446 int xhci_queue_reset_ep(struct xhci_hcd *xhci, int slot_id,
2447                 unsigned int ep_index)
2448 {
2449         u32 trb_slot_id = SLOT_ID_FOR_TRB(slot_id);
2450         u32 trb_ep_index = EP_ID_FOR_TRB(ep_index);
2451         u32 type = TRB_TYPE(TRB_RESET_EP);
2452
2453         return queue_command(xhci, 0, 0, 0, trb_slot_id | trb_ep_index | type,
2454                         false);
2455 }