USB: fix usbmon and DMA mapping for scatter-gather URBs
[safe/jmp/linux-2.6] / drivers / usb / host / xhci-ring.c
index 901ce70..c1359ed 100644 (file)
  *   endpoint rings; it generates events on the event ring for these.
  */
 
+#include <linux/scatterlist.h>
+#include <linux/slab.h>
 #include "xhci.h"
 
 /*
  * Returns zero if the TRB isn't in this segment, otherwise it returns the DMA
  * address of the TRB.
  */
-dma_addr_t trb_virt_to_dma(struct xhci_segment *seg,
+dma_addr_t xhci_trb_virt_to_dma(struct xhci_segment *seg,
                union xhci_trb *trb)
 {
-       unsigned int offset;
+       unsigned long segment_offset;
 
-       if (!seg || !trb || (void *) trb < (void *) seg->trbs)
+       if (!seg || !trb || trb < seg->trbs)
                return 0;
-       /* offset in bytes, since these are byte-addressable */
-       offset = (unsigned int) trb - (unsigned int) seg->trbs;
-       /* SEGMENT_SIZE in bytes, trbs are 16-byte aligned */
-       if (offset > SEGMENT_SIZE || (offset % sizeof(*trb)) != 0)
+       /* offset in TRBs */
+       segment_offset = trb - seg->trbs;
+       if (segment_offset > TRBS_PER_SEGMENT)
                return 0;
-       return seg->dma + offset;
+       return seg->dma + (segment_offset * sizeof(*trb));
 }
 
 /* Does this link TRB point to the first segment in a ring,
@@ -111,6 +112,23 @@ static inline int last_trb(struct xhci_hcd *xhci, struct xhci_ring *ring,
                return (trb->link.control & TRB_TYPE_BITMASK) == TRB_TYPE(TRB_LINK);
 }
 
+/* Updates trb to point to the next TRB in the ring, and updates seg if the next
+ * TRB is in a new segment.  This does not skip over link TRBs, and it does not
+ * effect the ring dequeue or enqueue pointers.
+ */
+static void next_trb(struct xhci_hcd *xhci,
+               struct xhci_ring *ring,
+               struct xhci_segment **seg,
+               union xhci_trb **trb)
+{
+       if (last_trb(xhci, ring, *seg, *trb)) {
+               *seg = (*seg)->next;
+               *trb = ((*seg)->trbs);
+       } else {
+               *trb = (*trb)++;
+       }
+}
+
 /*
  * See Cycle bit rules. SW is the consumer for the event ring only.
  * Don't make a ring full of link TRBs.  That would be dumb and this would loop.
@@ -118,6 +136,7 @@ static inline int last_trb(struct xhci_hcd *xhci, struct xhci_ring *ring,
 static void inc_deq(struct xhci_hcd *xhci, struct xhci_ring *ring, bool consumer)
 {
        union xhci_trb *next = ++(ring->dequeue);
+       unsigned long long addr;
 
        ring->deq_updates++;
        /* Update the dequeue pointer further if that was a link TRB or we're at
@@ -127,14 +146,21 @@ static void inc_deq(struct xhci_hcd *xhci, struct xhci_ring *ring, bool consumer
                if (consumer && last_trb_on_last_seg(xhci, ring, ring->deq_seg, next)) {
                        ring->cycle_state = (ring->cycle_state ? 0 : 1);
                        if (!in_interrupt())
-                               xhci_dbg(xhci, "Toggle cycle state for ring 0x%x = %i\n",
-                                               (unsigned int) ring,
+                               xhci_dbg(xhci, "Toggle cycle state for ring %p = %i\n",
+                                               ring,
                                                (unsigned int) ring->cycle_state);
                }
                ring->deq_seg = ring->deq_seg->next;
                ring->dequeue = ring->deq_seg->trbs;
                next = ring->dequeue;
        }
+       addr = (unsigned long long) xhci_trb_virt_to_dma(ring->deq_seg, ring->dequeue);
+       if (ring == xhci->event_ring)
+               xhci_dbg(xhci, "Event ring deq = 0x%llx (DMA)\n", addr);
+       else if (ring == xhci->cmd_ring)
+               xhci_dbg(xhci, "Command ring deq = 0x%llx (DMA)\n", addr);
+       else
+               xhci_dbg(xhci, "Ring deq = 0x%llx (DMA)\n", addr);
 }
 
 /*
@@ -147,13 +173,15 @@ static void inc_deq(struct xhci_hcd *xhci, struct xhci_ring *ring, bool consumer
  * have their chain bit cleared (so that each Link TRB is a separate TD).
  *
  * Section 6.4.4.1 of the 0.95 spec says link TRBs cannot have the chain bit
- * set, but other sections talk about dealing with the chain bit set.
- * Assume section 6.4.4.1 is wrong, and the chain bit can be set in a Link TRB.
+ * set, but other sections talk about dealing with the chain bit set.  This was
+ * fixed in the 0.96 specification errata, but we have to assume that all 0.95
+ * xHCI hardware can't handle the chain bit being cleared on a link TRB.
  */
 static void inc_enq(struct xhci_hcd *xhci, struct xhci_ring *ring, bool consumer)
 {
        u32 chain;
        union xhci_trb *next;
+       unsigned long long addr;
 
        chain = ring->enqueue->generic.field[3] & TRB_CHAIN;
        next = ++(ring->enqueue);
@@ -165,20 +193,27 @@ static void inc_enq(struct xhci_hcd *xhci, struct xhci_ring *ring, bool consumer
        while (last_trb(xhci, ring, ring->enq_seg, next)) {
                if (!consumer) {
                        if (ring != xhci->event_ring) {
+                               /* If we're not dealing with 0.95 hardware,
+                                * carry over the chain bit of the previous TRB
+                                * (which may mean the chain bit is cleared).
+                                */
+                               if (!xhci_link_trb_quirk(xhci)) {
+                                       next->link.control &= ~TRB_CHAIN;
+                                       next->link.control |= chain;
+                               }
                                /* Give this link TRB to the hardware */
+                               wmb();
                                if (next->link.control & TRB_CYCLE)
                                        next->link.control &= (u32) ~TRB_CYCLE;
                                else
                                        next->link.control |= (u32) TRB_CYCLE;
-                               next->link.control &= TRB_CHAIN;
-                               next->link.control |= chain;
                        }
                        /* Toggle the cycle bit after the last ring segment. */
                        if (last_trb_on_last_seg(xhci, ring, ring->enq_seg, next)) {
                                ring->cycle_state = (ring->cycle_state ? 0 : 1);
                                if (!in_interrupt())
-                                       xhci_dbg(xhci, "Toggle cycle state for ring 0x%x = %i\n",
-                                                       (unsigned int) ring,
+                                       xhci_dbg(xhci, "Toggle cycle state for ring %p = %i\n",
+                                                       ring,
                                                        (unsigned int) ring->cycle_state);
                        }
                }
@@ -186,6 +221,13 @@ static void inc_enq(struct xhci_hcd *xhci, struct xhci_ring *ring, bool consumer
                ring->enqueue = ring->enq_seg->trbs;
                next = ring->enqueue;
        }
+       addr = (unsigned long long) xhci_trb_virt_to_dma(ring->enq_seg, ring->enqueue);
+       if (ring == xhci->event_ring)
+               xhci_dbg(xhci, "Event ring enq = 0x%llx (DMA)\n", addr);
+       else if (ring == xhci->cmd_ring)
+               xhci_dbg(xhci, "Command ring enq = 0x%llx (DMA)\n", addr);
+       else
+               xhci_dbg(xhci, "Ring enq = 0x%llx (DMA)\n", addr);
 }
 
 /*
@@ -200,10 +242,27 @@ static int room_on_ring(struct xhci_hcd *xhci, struct xhci_ring *ring,
        int i;
        union xhci_trb *enq = ring->enqueue;
        struct xhci_segment *enq_seg = ring->enq_seg;
+       struct xhci_segment *cur_seg;
+       unsigned int left_on_ring;
 
        /* Check if ring is empty */
-       if (enq == ring->dequeue)
+       if (enq == ring->dequeue) {
+               /* Can't use link trbs */
+               left_on_ring = TRBS_PER_SEGMENT - 1;
+               for (cur_seg = enq_seg->next; cur_seg != enq_seg;
+                               cur_seg = cur_seg->next)
+                       left_on_ring += TRBS_PER_SEGMENT - 1;
+
+               /* Always need one TRB free in the ring. */
+               left_on_ring -= 1;
+               if (num_trbs > left_on_ring) {
+                       xhci_warn(xhci, "Not enough room on ring; "
+                                       "need %u TRBs, %u TRBs left\n",
+                                       num_trbs, left_on_ring);
+                       return 0;
+               }
                return 1;
+       }
        /* Make sure there's an extra empty TRB available */
        for (i = 0; i <= num_trbs; ++i) {
                if (enq == ring->dequeue)
@@ -217,28 +276,30 @@ static int room_on_ring(struct xhci_hcd *xhci, struct xhci_ring *ring,
        return 1;
 }
 
-void set_hc_event_deq(struct xhci_hcd *xhci)
+void xhci_set_hc_event_deq(struct xhci_hcd *xhci)
 {
-       u32 temp;
+       u64 temp;
        dma_addr_t deq;
 
-       deq = trb_virt_to_dma(xhci->event_ring->deq_seg,
+       deq = xhci_trb_virt_to_dma(xhci->event_ring->deq_seg,
                        xhci->event_ring->dequeue);
        if (deq == 0 && !in_interrupt())
                xhci_warn(xhci, "WARN something wrong with SW event ring "
                                "dequeue ptr.\n");
        /* Update HC event ring dequeue pointer */
-       temp = xhci_readl(xhci, &xhci->ir_set->erst_dequeue[0]);
+       temp = xhci_read_64(xhci, &xhci->ir_set->erst_dequeue);
        temp &= ERST_PTR_MASK;
-       if (!in_interrupt())
-               xhci_dbg(xhci, "// Write event ring dequeue pointer\n");
-       xhci_writel(xhci, 0, &xhci->ir_set->erst_dequeue[1]);
-       xhci_writel(xhci, (deq & ~ERST_PTR_MASK) | temp,
-                       &xhci->ir_set->erst_dequeue[0]);
+       /* Don't clear the EHB bit (which is RW1C) because
+        * there might be more events to service.
+        */
+       temp &= ~ERST_EHB;
+       xhci_dbg(xhci, "// Write event ring dequeue pointer, preserving EHB bit\n");
+       xhci_write_64(xhci, ((u64) deq & (u64) ~ERST_PTR_MASK) | temp,
+                       &xhci->ir_set->erst_dequeue);
 }
 
 /* Ring the host controller doorbell after placing a command on the ring */
-void ring_cmd_db(struct xhci_hcd *xhci)
+void xhci_ring_cmd_db(struct xhci_hcd *xhci)
 {
        u32 temp;
 
@@ -249,15 +310,581 @@ void ring_cmd_db(struct xhci_hcd *xhci)
        xhci_readl(xhci, &xhci->dba->doorbell[0]);
 }
 
+static void ring_ep_doorbell(struct xhci_hcd *xhci,
+               unsigned int slot_id,
+               unsigned int ep_index)
+{
+       struct xhci_virt_ep *ep;
+       unsigned int ep_state;
+       u32 field;
+       __u32 __iomem *db_addr = &xhci->dba->doorbell[slot_id];
+
+       ep = &xhci->devs[slot_id]->eps[ep_index];
+       ep_state = ep->ep_state;
+       /* Don't ring the doorbell for this endpoint if there are pending
+        * cancellations because the we don't want to interrupt processing.
+        */
+       if (!(ep_state & EP_HALT_PENDING) && !(ep_state & SET_DEQ_PENDING)
+                       && !(ep_state & EP_HALTED)) {
+               field = xhci_readl(xhci, db_addr) & DB_MASK;
+               xhci_writel(xhci, field | EPI_TO_DB(ep_index), db_addr);
+               /* Flush PCI posted writes - FIXME Matthew Wilcox says this
+                * isn't time-critical and we shouldn't make the CPU wait for
+                * the flush.
+                */
+               xhci_readl(xhci, db_addr);
+       }
+}
+
+/*
+ * Find the segment that trb is in.  Start searching in start_seg.
+ * If we must move past a segment that has a link TRB with a toggle cycle state
+ * bit set, then we will toggle the value pointed at by cycle_state.
+ */
+static struct xhci_segment *find_trb_seg(
+               struct xhci_segment *start_seg,
+               union xhci_trb  *trb, int *cycle_state)
+{
+       struct xhci_segment *cur_seg = start_seg;
+       struct xhci_generic_trb *generic_trb;
+
+       while (cur_seg->trbs > trb ||
+                       &cur_seg->trbs[TRBS_PER_SEGMENT - 1] < trb) {
+               generic_trb = &cur_seg->trbs[TRBS_PER_SEGMENT - 1].generic;
+               if (TRB_TYPE(generic_trb->field[3]) == TRB_LINK &&
+                               (generic_trb->field[3] & LINK_TOGGLE))
+                       *cycle_state = ~(*cycle_state) & 0x1;
+               cur_seg = cur_seg->next;
+               if (cur_seg == start_seg)
+                       /* Looped over the entire list.  Oops! */
+                       return 0;
+       }
+       return cur_seg;
+}
+
+/*
+ * Move the xHC's endpoint ring dequeue pointer past cur_td.
+ * Record the new state of the xHC's endpoint ring dequeue segment,
+ * dequeue pointer, and new consumer cycle state in state.
+ * Update our internal representation of the ring's dequeue pointer.
+ *
+ * We do this in three jumps:
+ *  - First we update our new ring state to be the same as when the xHC stopped.
+ *  - Then we traverse the ring to find the segment that contains
+ *    the last TRB in the TD.  We toggle the xHC's new cycle state when we pass
+ *    any link TRBs with the toggle cycle bit set.
+ *  - Finally we move the dequeue state one TRB further, toggling the cycle bit
+ *    if we've moved it past a link TRB with the toggle cycle bit set.
+ */
+void xhci_find_new_dequeue_state(struct xhci_hcd *xhci,
+               unsigned int slot_id, unsigned int ep_index,
+               struct xhci_td *cur_td, struct xhci_dequeue_state *state)
+{
+       struct xhci_virt_device *dev = xhci->devs[slot_id];
+       struct xhci_ring *ep_ring = dev->eps[ep_index].ring;
+       struct xhci_generic_trb *trb;
+       struct xhci_ep_ctx *ep_ctx;
+       dma_addr_t addr;
+
+       state->new_cycle_state = 0;
+       xhci_dbg(xhci, "Finding segment containing stopped TRB.\n");
+       state->new_deq_seg = find_trb_seg(cur_td->start_seg,
+                       dev->eps[ep_index].stopped_trb,
+                       &state->new_cycle_state);
+       if (!state->new_deq_seg)
+               BUG();
+       /* Dig out the cycle state saved by the xHC during the stop ep cmd */
+       xhci_dbg(xhci, "Finding endpoint context\n");
+       ep_ctx = xhci_get_ep_ctx(xhci, dev->out_ctx, ep_index);
+       state->new_cycle_state = 0x1 & ep_ctx->deq;
+
+       state->new_deq_ptr = cur_td->last_trb;
+       xhci_dbg(xhci, "Finding segment containing last TRB in TD.\n");
+       state->new_deq_seg = find_trb_seg(state->new_deq_seg,
+                       state->new_deq_ptr,
+                       &state->new_cycle_state);
+       if (!state->new_deq_seg)
+               BUG();
+
+       trb = &state->new_deq_ptr->generic;
+       if (TRB_TYPE(trb->field[3]) == TRB_LINK &&
+                               (trb->field[3] & LINK_TOGGLE))
+               state->new_cycle_state = ~(state->new_cycle_state) & 0x1;
+       next_trb(xhci, ep_ring, &state->new_deq_seg, &state->new_deq_ptr);
+
+       /* Don't update the ring cycle state for the producer (us). */
+       xhci_dbg(xhci, "New dequeue segment = %p (virtual)\n",
+                       state->new_deq_seg);
+       addr = xhci_trb_virt_to_dma(state->new_deq_seg, state->new_deq_ptr);
+       xhci_dbg(xhci, "New dequeue pointer = 0x%llx (DMA)\n",
+                       (unsigned long long) addr);
+       xhci_dbg(xhci, "Setting dequeue pointer in internal ring state.\n");
+       ep_ring->dequeue = state->new_deq_ptr;
+       ep_ring->deq_seg = state->new_deq_seg;
+}
+
+static void td_to_noop(struct xhci_hcd *xhci, struct xhci_ring *ep_ring,
+               struct xhci_td *cur_td)
+{
+       struct xhci_segment *cur_seg;
+       union xhci_trb *cur_trb;
+
+       for (cur_seg = cur_td->start_seg, cur_trb = cur_td->first_trb;
+                       true;
+                       next_trb(xhci, ep_ring, &cur_seg, &cur_trb)) {
+               if ((cur_trb->generic.field[3] & TRB_TYPE_BITMASK) ==
+                               TRB_TYPE(TRB_LINK)) {
+                       /* Unchain any chained Link TRBs, but
+                        * leave the pointers intact.
+                        */
+                       cur_trb->generic.field[3] &= ~TRB_CHAIN;
+                       xhci_dbg(xhci, "Cancel (unchain) link TRB\n");
+                       xhci_dbg(xhci, "Address = %p (0x%llx dma); "
+                                       "in seg %p (0x%llx dma)\n",
+                                       cur_trb,
+                                       (unsigned long long)xhci_trb_virt_to_dma(cur_seg, cur_trb),
+                                       cur_seg,
+                                       (unsigned long long)cur_seg->dma);
+               } else {
+                       cur_trb->generic.field[0] = 0;
+                       cur_trb->generic.field[1] = 0;
+                       cur_trb->generic.field[2] = 0;
+                       /* Preserve only the cycle bit of this TRB */
+                       cur_trb->generic.field[3] &= TRB_CYCLE;
+                       cur_trb->generic.field[3] |= TRB_TYPE(TRB_TR_NOOP);
+                       xhci_dbg(xhci, "Cancel TRB %p (0x%llx dma) "
+                                       "in seg %p (0x%llx dma)\n",
+                                       cur_trb,
+                                       (unsigned long long)xhci_trb_virt_to_dma(cur_seg, cur_trb),
+                                       cur_seg,
+                                       (unsigned long long)cur_seg->dma);
+               }
+               if (cur_trb == cur_td->last_trb)
+                       break;
+       }
+}
+
+static int queue_set_tr_deq(struct xhci_hcd *xhci, int slot_id,
+               unsigned int ep_index, struct xhci_segment *deq_seg,
+               union xhci_trb *deq_ptr, u32 cycle_state);
+
+void xhci_queue_new_dequeue_state(struct xhci_hcd *xhci,
+               unsigned int slot_id, unsigned int ep_index,
+               struct xhci_dequeue_state *deq_state)
+{
+       struct xhci_virt_ep *ep = &xhci->devs[slot_id]->eps[ep_index];
+
+       xhci_dbg(xhci, "Set TR Deq Ptr cmd, new deq seg = %p (0x%llx dma), "
+                       "new deq ptr = %p (0x%llx dma), new cycle = %u\n",
+                       deq_state->new_deq_seg,
+                       (unsigned long long)deq_state->new_deq_seg->dma,
+                       deq_state->new_deq_ptr,
+                       (unsigned long long)xhci_trb_virt_to_dma(deq_state->new_deq_seg, deq_state->new_deq_ptr),
+                       deq_state->new_cycle_state);
+       queue_set_tr_deq(xhci, slot_id, ep_index,
+                       deq_state->new_deq_seg,
+                       deq_state->new_deq_ptr,
+                       (u32) deq_state->new_cycle_state);
+       /* Stop the TD queueing code from ringing the doorbell until
+        * this command completes.  The HC won't set the dequeue pointer
+        * if the ring is running, and ringing the doorbell starts the
+        * ring running.
+        */
+       ep->ep_state |= SET_DEQ_PENDING;
+}
+
+static inline void xhci_stop_watchdog_timer_in_irq(struct xhci_hcd *xhci,
+               struct xhci_virt_ep *ep)
+{
+       ep->ep_state &= ~EP_HALT_PENDING;
+       /* Can't del_timer_sync in interrupt, so we attempt to cancel.  If the
+        * timer is running on another CPU, we don't decrement stop_cmds_pending
+        * (since we didn't successfully stop the watchdog timer).
+        */
+       if (del_timer(&ep->stop_cmd_timer))
+               ep->stop_cmds_pending--;
+}
+
+/* Must be called with xhci->lock held in interrupt context */
+static void xhci_giveback_urb_in_irq(struct xhci_hcd *xhci,
+               struct xhci_td *cur_td, int status, char *adjective)
+{
+       struct usb_hcd *hcd = xhci_to_hcd(xhci);
+
+       cur_td->urb->hcpriv = NULL;
+       usb_hcd_unlink_urb_from_ep(hcd, cur_td->urb);
+       xhci_dbg(xhci, "Giveback %s URB %p\n", adjective, cur_td->urb);
+
+       spin_unlock(&xhci->lock);
+       usb_hcd_giveback_urb(hcd, cur_td->urb, status);
+       kfree(cur_td);
+       spin_lock(&xhci->lock);
+       xhci_dbg(xhci, "%s URB given back\n", adjective);
+}
+
+/*
+ * When we get a command completion for a Stop Endpoint Command, we need to
+ * unlink any cancelled TDs from the ring.  There are two ways to do that:
+ *
+ *  1. If the HW was in the middle of processing the TD that needs to be
+ *     cancelled, then we must move the ring's dequeue pointer past the last TRB
+ *     in the TD with a Set Dequeue Pointer Command.
+ *  2. Otherwise, we turn all the TRBs in the TD into No-op TRBs (with the chain
+ *     bit cleared) so that the HW will skip over them.
+ */
+static void handle_stopped_endpoint(struct xhci_hcd *xhci,
+               union xhci_trb *trb)
+{
+       unsigned int slot_id;
+       unsigned int ep_index;
+       struct xhci_ring *ep_ring;
+       struct xhci_virt_ep *ep;
+       struct list_head *entry;
+       struct xhci_td *cur_td = 0;
+       struct xhci_td *last_unlinked_td;
+
+       struct xhci_dequeue_state deq_state;
+
+       memset(&deq_state, 0, sizeof(deq_state));
+       slot_id = TRB_TO_SLOT_ID(trb->generic.field[3]);
+       ep_index = TRB_TO_EP_INDEX(trb->generic.field[3]);
+       ep = &xhci->devs[slot_id]->eps[ep_index];
+       ep_ring = ep->ring;
+
+       if (list_empty(&ep->cancelled_td_list)) {
+               xhci_stop_watchdog_timer_in_irq(xhci, ep);
+               ring_ep_doorbell(xhci, slot_id, ep_index);
+               return;
+       }
+
+       /* Fix up the ep ring first, so HW stops executing cancelled TDs.
+        * We have the xHCI lock, so nothing can modify this list until we drop
+        * it.  We're also in the event handler, so we can't get re-interrupted
+        * if another Stop Endpoint command completes
+        */
+       list_for_each(entry, &ep->cancelled_td_list) {
+               cur_td = list_entry(entry, struct xhci_td, cancelled_td_list);
+               xhci_dbg(xhci, "Cancelling TD starting at %p, 0x%llx (dma).\n",
+                               cur_td->first_trb,
+                               (unsigned long long)xhci_trb_virt_to_dma(cur_td->start_seg, cur_td->first_trb));
+               /*
+                * If we stopped on the TD we need to cancel, then we have to
+                * move the xHC endpoint ring dequeue pointer past this TD.
+                */
+               if (cur_td == ep->stopped_td)
+                       xhci_find_new_dequeue_state(xhci, slot_id, ep_index, cur_td,
+                                       &deq_state);
+               else
+                       td_to_noop(xhci, ep_ring, cur_td);
+               /*
+                * The event handler won't see a completion for this TD anymore,
+                * so remove it from the endpoint ring's TD list.  Keep it in
+                * the cancelled TD list for URB completion later.
+                */
+               list_del(&cur_td->td_list);
+       }
+       last_unlinked_td = cur_td;
+       xhci_stop_watchdog_timer_in_irq(xhci, ep);
+
+       /* If necessary, queue a Set Transfer Ring Dequeue Pointer command */
+       if (deq_state.new_deq_ptr && deq_state.new_deq_seg) {
+               xhci_queue_new_dequeue_state(xhci,
+                               slot_id, ep_index, &deq_state);
+               xhci_ring_cmd_db(xhci);
+       } else {
+               /* Otherwise just ring the doorbell to restart the ring */
+               ring_ep_doorbell(xhci, slot_id, ep_index);
+       }
+       ep->stopped_td = NULL;
+       ep->stopped_trb = NULL;
+
+       /*
+        * Drop the lock and complete the URBs in the cancelled TD list.
+        * New TDs to be cancelled might be added to the end of the list before
+        * we can complete all the URBs for the TDs we already unlinked.
+        * So stop when we've completed the URB for the last TD we unlinked.
+        */
+       do {
+               cur_td = list_entry(ep->cancelled_td_list.next,
+                               struct xhci_td, cancelled_td_list);
+               list_del(&cur_td->cancelled_td_list);
+
+               /* Clean up the cancelled URB */
+               /* Doesn't matter what we pass for status, since the core will
+                * just overwrite it (because the URB has been unlinked).
+                */
+               xhci_giveback_urb_in_irq(xhci, cur_td, 0, "cancelled");
+
+               /* Stop processing the cancelled list if the watchdog timer is
+                * running.
+                */
+               if (xhci->xhc_state & XHCI_STATE_DYING)
+                       return;
+       } while (cur_td != last_unlinked_td);
+
+       /* Return to the event handler with xhci->lock re-acquired */
+}
+
+/* Watchdog timer function for when a stop endpoint command fails to complete.
+ * In this case, we assume the host controller is broken or dying or dead.  The
+ * host may still be completing some other events, so we have to be careful to
+ * let the event ring handler and the URB dequeueing/enqueueing functions know
+ * through xhci->state.
+ *
+ * The timer may also fire if the host takes a very long time to respond to the
+ * command, and the stop endpoint command completion handler cannot delete the
+ * timer before the timer function is called.  Another endpoint cancellation may
+ * sneak in before the timer function can grab the lock, and that may queue
+ * another stop endpoint command and add the timer back.  So we cannot use a
+ * simple flag to say whether there is a pending stop endpoint command for a
+ * particular endpoint.
+ *
+ * Instead we use a combination of that flag and a counter for the number of
+ * pending stop endpoint commands.  If the timer is the tail end of the last
+ * stop endpoint command, and the endpoint's command is still pending, we assume
+ * the host is dying.
+ */
+void xhci_stop_endpoint_command_watchdog(unsigned long arg)
+{
+       struct xhci_hcd *xhci;
+       struct xhci_virt_ep *ep;
+       struct xhci_virt_ep *temp_ep;
+       struct xhci_ring *ring;
+       struct xhci_td *cur_td;
+       int ret, i, j;
+
+       ep = (struct xhci_virt_ep *) arg;
+       xhci = ep->xhci;
+
+       spin_lock(&xhci->lock);
+
+       ep->stop_cmds_pending--;
+       if (xhci->xhc_state & XHCI_STATE_DYING) {
+               xhci_dbg(xhci, "Stop EP timer ran, but another timer marked "
+                               "xHCI as DYING, exiting.\n");
+               spin_unlock(&xhci->lock);
+               return;
+       }
+       if (!(ep->stop_cmds_pending == 0 && (ep->ep_state & EP_HALT_PENDING))) {
+               xhci_dbg(xhci, "Stop EP timer ran, but no command pending, "
+                               "exiting.\n");
+               spin_unlock(&xhci->lock);
+               return;
+       }
+
+       xhci_warn(xhci, "xHCI host not responding to stop endpoint command.\n");
+       xhci_warn(xhci, "Assuming host is dying, halting host.\n");
+       /* Oops, HC is dead or dying or at least not responding to the stop
+        * endpoint command.
+        */
+       xhci->xhc_state |= XHCI_STATE_DYING;
+       /* Disable interrupts from the host controller and start halting it */
+       xhci_quiesce(xhci);
+       spin_unlock(&xhci->lock);
+
+       ret = xhci_halt(xhci);
+
+       spin_lock(&xhci->lock);
+       if (ret < 0) {
+               /* This is bad; the host is not responding to commands and it's
+                * not allowing itself to be halted.  At least interrupts are
+                * disabled, so we can set HC_STATE_HALT and notify the
+                * USB core.  But if we call usb_hc_died(), it will attempt to
+                * disconnect all device drivers under this host.  Those
+                * disconnect() methods will wait for all URBs to be unlinked,
+                * so we must complete them.
+                */
+               xhci_warn(xhci, "Non-responsive xHCI host is not halting.\n");
+               xhci_warn(xhci, "Completing active URBs anyway.\n");
+               /* We could turn all TDs on the rings to no-ops.  This won't
+                * help if the host has cached part of the ring, and is slow if
+                * we want to preserve the cycle bit.  Skip it and hope the host
+                * doesn't touch the memory.
+                */
+       }
+       for (i = 0; i < MAX_HC_SLOTS; i++) {
+               if (!xhci->devs[i])
+                       continue;
+               for (j = 0; j < 31; j++) {
+                       temp_ep = &xhci->devs[i]->eps[j];
+                       ring = temp_ep->ring;
+                       if (!ring)
+                               continue;
+                       xhci_dbg(xhci, "Killing URBs for slot ID %u, "
+                                       "ep index %u\n", i, j);
+                       while (!list_empty(&ring->td_list)) {
+                               cur_td = list_first_entry(&ring->td_list,
+                                               struct xhci_td,
+                                               td_list);
+                               list_del(&cur_td->td_list);
+                               if (!list_empty(&cur_td->cancelled_td_list))
+                                       list_del(&cur_td->cancelled_td_list);
+                               xhci_giveback_urb_in_irq(xhci, cur_td,
+                                               -ESHUTDOWN, "killed");
+                       }
+                       while (!list_empty(&temp_ep->cancelled_td_list)) {
+                               cur_td = list_first_entry(
+                                               &temp_ep->cancelled_td_list,
+                                               struct xhci_td,
+                                               cancelled_td_list);
+                               list_del(&cur_td->cancelled_td_list);
+                               xhci_giveback_urb_in_irq(xhci, cur_td,
+                                               -ESHUTDOWN, "killed");
+                       }
+               }
+       }
+       spin_unlock(&xhci->lock);
+       xhci_to_hcd(xhci)->state = HC_STATE_HALT;
+       xhci_dbg(xhci, "Calling usb_hc_died()\n");
+       usb_hc_died(xhci_to_hcd(xhci));
+       xhci_dbg(xhci, "xHCI host controller is dead.\n");
+}
+
+/*
+ * When we get a completion for a Set Transfer Ring Dequeue Pointer command,
+ * we need to clear the set deq pending flag in the endpoint ring state, so that
+ * the TD queueing code can ring the doorbell again.  We also need to ring the
+ * endpoint doorbell to restart the ring, but only if there aren't more
+ * cancellations pending.
+ */
+static void handle_set_deq_completion(struct xhci_hcd *xhci,
+               struct xhci_event_cmd *event,
+               union xhci_trb *trb)
+{
+       unsigned int slot_id;
+       unsigned int ep_index;
+       struct xhci_ring *ep_ring;
+       struct xhci_virt_device *dev;
+       struct xhci_ep_ctx *ep_ctx;
+       struct xhci_slot_ctx *slot_ctx;
+
+       slot_id = TRB_TO_SLOT_ID(trb->generic.field[3]);
+       ep_index = TRB_TO_EP_INDEX(trb->generic.field[3]);
+       dev = xhci->devs[slot_id];
+       ep_ring = dev->eps[ep_index].ring;
+       ep_ctx = xhci_get_ep_ctx(xhci, dev->out_ctx, ep_index);
+       slot_ctx = xhci_get_slot_ctx(xhci, dev->out_ctx);
+
+       if (GET_COMP_CODE(event->status) != COMP_SUCCESS) {
+               unsigned int ep_state;
+               unsigned int slot_state;
+
+               switch (GET_COMP_CODE(event->status)) {
+               case COMP_TRB_ERR:
+                       xhci_warn(xhci, "WARN Set TR Deq Ptr cmd invalid because "
+                                       "of stream ID configuration\n");
+                       break;
+               case COMP_CTX_STATE:
+                       xhci_warn(xhci, "WARN Set TR Deq Ptr cmd failed due "
+                                       "to incorrect slot or ep state.\n");
+                       ep_state = ep_ctx->ep_info;
+                       ep_state &= EP_STATE_MASK;
+                       slot_state = slot_ctx->dev_state;
+                       slot_state = GET_SLOT_STATE(slot_state);
+                       xhci_dbg(xhci, "Slot state = %u, EP state = %u\n",
+                                       slot_state, ep_state);
+                       break;
+               case COMP_EBADSLT:
+                       xhci_warn(xhci, "WARN Set TR Deq Ptr cmd failed because "
+                                       "slot %u was not enabled.\n", slot_id);
+                       break;
+               default:
+                       xhci_warn(xhci, "WARN Set TR Deq Ptr cmd with unknown "
+                                       "completion code of %u.\n",
+                                       GET_COMP_CODE(event->status));
+                       break;
+               }
+               /* OK what do we do now?  The endpoint state is hosed, and we
+                * should never get to this point if the synchronization between
+                * queueing, and endpoint state are correct.  This might happen
+                * if the device gets disconnected after we've finished
+                * cancelling URBs, which might not be an error...
+                */
+       } else {
+               xhci_dbg(xhci, "Successful Set TR Deq Ptr cmd, deq = @%08llx\n",
+                               ep_ctx->deq);
+       }
+
+       dev->eps[ep_index].ep_state &= ~SET_DEQ_PENDING;
+       ring_ep_doorbell(xhci, slot_id, ep_index);
+}
+
+static void handle_reset_ep_completion(struct xhci_hcd *xhci,
+               struct xhci_event_cmd *event,
+               union xhci_trb *trb)
+{
+       int slot_id;
+       unsigned int ep_index;
+       struct xhci_ring *ep_ring;
+
+       slot_id = TRB_TO_SLOT_ID(trb->generic.field[3]);
+       ep_index = TRB_TO_EP_INDEX(trb->generic.field[3]);
+       ep_ring = xhci->devs[slot_id]->eps[ep_index].ring;
+       /* This command will only fail if the endpoint wasn't halted,
+        * but we don't care.
+        */
+       xhci_dbg(xhci, "Ignoring reset ep completion code of %u\n",
+                       (unsigned int) GET_COMP_CODE(event->status));
+
+       /* HW with the reset endpoint quirk needs to have a configure endpoint
+        * command complete before the endpoint can be used.  Queue that here
+        * because the HW can't handle two commands being queued in a row.
+        */
+       if (xhci->quirks & XHCI_RESET_EP_QUIRK) {
+               xhci_dbg(xhci, "Queueing configure endpoint command\n");
+               xhci_queue_configure_endpoint(xhci,
+                               xhci->devs[slot_id]->in_ctx->dma, slot_id,
+                               false);
+               xhci_ring_cmd_db(xhci);
+       } else {
+               /* Clear our internal halted state and restart the ring */
+               xhci->devs[slot_id]->eps[ep_index].ep_state &= ~EP_HALTED;
+               ring_ep_doorbell(xhci, slot_id, ep_index);
+       }
+}
+
+/* Check to see if a command in the device's command queue matches this one.
+ * Signal the completion or free the command, and return 1.  Return 0 if the
+ * completed command isn't at the head of the command list.
+ */
+static int handle_cmd_in_cmd_wait_list(struct xhci_hcd *xhci,
+               struct xhci_virt_device *virt_dev,
+               struct xhci_event_cmd *event)
+{
+       struct xhci_command *command;
+
+       if (list_empty(&virt_dev->cmd_list))
+               return 0;
+
+       command = list_entry(virt_dev->cmd_list.next,
+                       struct xhci_command, cmd_list);
+       if (xhci->cmd_ring->dequeue != command->command_trb)
+               return 0;
+
+       command->status =
+               GET_COMP_CODE(event->status);
+       list_del(&command->cmd_list);
+       if (command->completion)
+               complete(command->completion);
+       else
+               xhci_free_command(xhci, command);
+       return 1;
+}
+
 static void handle_cmd_completion(struct xhci_hcd *xhci,
                struct xhci_event_cmd *event)
 {
        int slot_id = TRB_TO_SLOT_ID(event->flags);
        u64 cmd_dma;
        dma_addr_t cmd_dequeue_dma;
+       struct xhci_input_control_ctx *ctrl_ctx;
+       struct xhci_virt_device *virt_dev;
+       unsigned int ep_index;
+       struct xhci_ring *ep_ring;
+       unsigned int ep_state;
 
-       cmd_dma = (((u64) event->cmd_trb[1]) << 32) + event->cmd_trb[0];
-       cmd_dequeue_dma = trb_virt_to_dma(xhci->cmd_ring->deq_seg,
+       cmd_dma = event->cmd_trb;
+       cmd_dequeue_dma = xhci_trb_virt_to_dma(xhci->cmd_ring->deq_seg,
                        xhci->cmd_ring->dequeue);
        /* Is the command ring deq ptr out of sync with the deq seg ptr? */
        if (cmd_dequeue_dma == 0) {
@@ -281,13 +908,82 @@ static void handle_cmd_completion(struct xhci_hcd *xhci,
                if (xhci->devs[slot_id])
                        xhci_free_virt_device(xhci, slot_id);
                break;
+       case TRB_TYPE(TRB_CONFIG_EP):
+               virt_dev = xhci->devs[slot_id];
+               if (handle_cmd_in_cmd_wait_list(xhci, virt_dev, event))
+                       break;
+               /*
+                * Configure endpoint commands can come from the USB core
+                * configuration or alt setting changes, or because the HW
+                * needed an extra configure endpoint command after a reset
+                * endpoint command.  In the latter case, the xHCI driver is
+                * not waiting on the configure endpoint command.
+                */
+               ctrl_ctx = xhci_get_input_control_ctx(xhci,
+                               virt_dev->in_ctx);
+               /* Input ctx add_flags are the endpoint index plus one */
+               ep_index = xhci_last_valid_endpoint(ctrl_ctx->add_flags) - 1;
+               /* A usb_set_interface() call directly after clearing a halted
+                * condition may race on this quirky hardware.
+                * Not worth worrying about, since this is prototype hardware.
+                */
+               if (xhci->quirks & XHCI_RESET_EP_QUIRK &&
+                               ep_index != (unsigned int) -1 &&
+                               ctrl_ctx->add_flags - SLOT_FLAG ==
+                                       ctrl_ctx->drop_flags) {
+                       ep_ring = xhci->devs[slot_id]->eps[ep_index].ring;
+                       ep_state = xhci->devs[slot_id]->eps[ep_index].ep_state;
+                       if (!(ep_state & EP_HALTED))
+                               goto bandwidth_change;
+                       xhci_dbg(xhci, "Completed config ep cmd - "
+                                       "last ep index = %d, state = %d\n",
+                                       ep_index, ep_state);
+                       /* Clear our internal halted state and restart ring */
+                       xhci->devs[slot_id]->eps[ep_index].ep_state &=
+                               ~EP_HALTED;
+                       ring_ep_doorbell(xhci, slot_id, ep_index);
+                       break;
+               }
+bandwidth_change:
+               xhci_dbg(xhci, "Completed config ep cmd\n");
+               xhci->devs[slot_id]->cmd_status =
+                       GET_COMP_CODE(event->status);
+               complete(&xhci->devs[slot_id]->cmd_completion);
+               break;
+       case TRB_TYPE(TRB_EVAL_CONTEXT):
+               virt_dev = xhci->devs[slot_id];
+               if (handle_cmd_in_cmd_wait_list(xhci, virt_dev, event))
+                       break;
+               xhci->devs[slot_id]->cmd_status = GET_COMP_CODE(event->status);
+               complete(&xhci->devs[slot_id]->cmd_completion);
+               break;
        case TRB_TYPE(TRB_ADDR_DEV):
                xhci->devs[slot_id]->cmd_status = GET_COMP_CODE(event->status);
                complete(&xhci->addr_dev);
                break;
+       case TRB_TYPE(TRB_STOP_RING):
+               handle_stopped_endpoint(xhci, xhci->cmd_ring->dequeue);
+               break;
+       case TRB_TYPE(TRB_SET_DEQ):
+               handle_set_deq_completion(xhci, event, xhci->cmd_ring->dequeue);
+               break;
        case TRB_TYPE(TRB_CMD_NOOP):
                ++xhci->noops_handled;
                break;
+       case TRB_TYPE(TRB_RESET_EP):
+               handle_reset_ep_completion(xhci, event, xhci->cmd_ring->dequeue);
+               break;
+       case TRB_TYPE(TRB_RESET_DEV):
+               xhci_dbg(xhci, "Completed reset device command.\n");
+               slot_id = TRB_TO_SLOT_ID(
+                               xhci->cmd_ring->dequeue->generic.field[3]);
+               virt_dev = xhci->devs[slot_id];
+               if (virt_dev)
+                       handle_cmd_in_cmd_wait_list(xhci, virt_dev, event);
+               else
+                       xhci_warn(xhci, "Reset device command completion "
+                                       "for disabled slot %u\n", slot_id);
+               break;
        default:
                /* Skip over unknown commands on the event ring */
                xhci->error_bitmask |= 1 << 6;
@@ -312,7 +1008,7 @@ static void handle_port_status(struct xhci_hcd *xhci,
 
        /* Update event ring dequeue pointer before dropping the lock */
        inc_deq(xhci, xhci->event_ring, true);
-       set_hc_event_deq(xhci);
+       xhci_set_hc_event_deq(xhci);
 
        spin_unlock(&xhci->lock);
        /* Pass this up to the core */
@@ -321,14 +1017,517 @@ static void handle_port_status(struct xhci_hcd *xhci,
 }
 
 /*
+ * This TD is defined by the TRBs starting at start_trb in start_seg and ending
+ * at end_trb, which may be in another segment.  If the suspect DMA address is a
+ * TRB in this TD, this function returns that TRB's segment.  Otherwise it
+ * returns 0.
+ */
+struct xhci_segment *trb_in_td(struct xhci_segment *start_seg,
+               union xhci_trb  *start_trb,
+               union xhci_trb  *end_trb,
+               dma_addr_t      suspect_dma)
+{
+       dma_addr_t start_dma;
+       dma_addr_t end_seg_dma;
+       dma_addr_t end_trb_dma;
+       struct xhci_segment *cur_seg;
+
+       start_dma = xhci_trb_virt_to_dma(start_seg, start_trb);
+       cur_seg = start_seg;
+
+       do {
+               if (start_dma == 0)
+                       return 0;
+               /* We may get an event for a Link TRB in the middle of a TD */
+               end_seg_dma = xhci_trb_virt_to_dma(cur_seg,
+                               &cur_seg->trbs[TRBS_PER_SEGMENT - 1]);
+               /* If the end TRB isn't in this segment, this is set to 0 */
+               end_trb_dma = xhci_trb_virt_to_dma(cur_seg, end_trb);
+
+               if (end_trb_dma > 0) {
+                       /* The end TRB is in this segment, so suspect should be here */
+                       if (start_dma <= end_trb_dma) {
+                               if (suspect_dma >= start_dma && suspect_dma <= end_trb_dma)
+                                       return cur_seg;
+                       } else {
+                               /* Case for one segment with
+                                * a TD wrapped around to the top
+                                */
+                               if ((suspect_dma >= start_dma &&
+                                                       suspect_dma <= end_seg_dma) ||
+                                               (suspect_dma >= cur_seg->dma &&
+                                                suspect_dma <= end_trb_dma))
+                                       return cur_seg;
+                       }
+                       return 0;
+               } else {
+                       /* Might still be somewhere in this segment */
+                       if (suspect_dma >= start_dma && suspect_dma <= end_seg_dma)
+                               return cur_seg;
+               }
+               cur_seg = cur_seg->next;
+               start_dma = xhci_trb_virt_to_dma(cur_seg, &cur_seg->trbs[0]);
+       } while (cur_seg != start_seg);
+
+       return 0;
+}
+
+static void xhci_cleanup_halted_endpoint(struct xhci_hcd *xhci,
+               unsigned int slot_id, unsigned int ep_index,
+               struct xhci_td *td, union xhci_trb *event_trb)
+{
+       struct xhci_virt_ep *ep = &xhci->devs[slot_id]->eps[ep_index];
+       ep->ep_state |= EP_HALTED;
+       ep->stopped_td = td;
+       ep->stopped_trb = event_trb;
+
+       xhci_queue_reset_ep(xhci, slot_id, ep_index);
+       xhci_cleanup_stalled_ring(xhci, td->urb->dev, ep_index);
+
+       ep->stopped_td = NULL;
+       ep->stopped_trb = NULL;
+
+       xhci_ring_cmd_db(xhci);
+}
+
+/* Check if an error has halted the endpoint ring.  The class driver will
+ * cleanup the halt for a non-default control endpoint if we indicate a stall.
+ * However, a babble and other errors also halt the endpoint ring, and the class
+ * driver won't clear the halt in that case, so we need to issue a Set Transfer
+ * Ring Dequeue Pointer command manually.
+ */
+static int xhci_requires_manual_halt_cleanup(struct xhci_hcd *xhci,
+               struct xhci_ep_ctx *ep_ctx,
+               unsigned int trb_comp_code)
+{
+       /* TRB completion codes that may require a manual halt cleanup */
+       if (trb_comp_code == COMP_TX_ERR ||
+                       trb_comp_code == COMP_BABBLE ||
+                       trb_comp_code == COMP_SPLIT_ERR)
+               /* The 0.96 spec says a babbling control endpoint
+                * is not halted. The 0.96 spec says it is.  Some HW
+                * claims to be 0.95 compliant, but it halts the control
+                * endpoint anyway.  Check if a babble halted the
+                * endpoint.
+                */
+               if ((ep_ctx->ep_info & EP_STATE_MASK) == EP_STATE_HALTED)
+                       return 1;
+
+       return 0;
+}
+
+int xhci_is_vendor_info_code(struct xhci_hcd *xhci, unsigned int trb_comp_code)
+{
+       if (trb_comp_code >= 224 && trb_comp_code <= 255) {
+               /* Vendor defined "informational" completion code,
+                * treat as not-an-error.
+                */
+               xhci_dbg(xhci, "Vendor defined info completion code %u\n",
+                               trb_comp_code);
+               xhci_dbg(xhci, "Treating code as success.\n");
+               return 1;
+       }
+       return 0;
+}
+
+/*
+ * If this function returns an error condition, it means it got a Transfer
+ * event with a corrupted Slot ID, Endpoint ID, or TRB DMA address.
+ * At this point, the host controller is probably hosed and should be reset.
+ */
+static int handle_tx_event(struct xhci_hcd *xhci,
+               struct xhci_transfer_event *event)
+{
+       struct xhci_virt_device *xdev;
+       struct xhci_virt_ep *ep;
+       struct xhci_ring *ep_ring;
+       unsigned int slot_id;
+       int ep_index;
+       struct xhci_td *td = 0;
+       dma_addr_t event_dma;
+       struct xhci_segment *event_seg;
+       union xhci_trb *event_trb;
+       struct urb *urb = 0;
+       int status = -EINPROGRESS;
+       struct xhci_ep_ctx *ep_ctx;
+       u32 trb_comp_code;
+
+       xhci_dbg(xhci, "In %s\n", __func__);
+       slot_id = TRB_TO_SLOT_ID(event->flags);
+       xdev = xhci->devs[slot_id];
+       if (!xdev) {
+               xhci_err(xhci, "ERROR Transfer event pointed to bad slot\n");
+               return -ENODEV;
+       }
+
+       /* Endpoint ID is 1 based, our index is zero based */
+       ep_index = TRB_TO_EP_ID(event->flags) - 1;
+       xhci_dbg(xhci, "%s - ep index = %d\n", __func__, ep_index);
+       ep = &xdev->eps[ep_index];
+       ep_ring = ep->ring;
+       ep_ctx = xhci_get_ep_ctx(xhci, xdev->out_ctx, ep_index);
+       if (!ep_ring || (ep_ctx->ep_info & EP_STATE_MASK) == EP_STATE_DISABLED) {
+               xhci_err(xhci, "ERROR Transfer event pointed to disabled endpoint\n");
+               return -ENODEV;
+       }
+
+       event_dma = event->buffer;
+       /* This TRB should be in the TD at the head of this ring's TD list */
+       xhci_dbg(xhci, "%s - checking for list empty\n", __func__);
+       if (list_empty(&ep_ring->td_list)) {
+               xhci_warn(xhci, "WARN Event TRB for slot %d ep %d with no TDs queued?\n",
+                               TRB_TO_SLOT_ID(event->flags), ep_index);
+               xhci_dbg(xhci, "Event TRB with TRB type ID %u\n",
+                               (unsigned int) (event->flags & TRB_TYPE_BITMASK)>>10);
+               xhci_print_trb_offsets(xhci, (union xhci_trb *) event);
+               urb = NULL;
+               goto cleanup;
+       }
+       xhci_dbg(xhci, "%s - getting list entry\n", __func__);
+       td = list_entry(ep_ring->td_list.next, struct xhci_td, td_list);
+
+       /* Is this a TRB in the currently executing TD? */
+       xhci_dbg(xhci, "%s - looking for TD\n", __func__);
+       event_seg = trb_in_td(ep_ring->deq_seg, ep_ring->dequeue,
+                       td->last_trb, event_dma);
+       xhci_dbg(xhci, "%s - found event_seg = %p\n", __func__, event_seg);
+       if (!event_seg) {
+               /* HC is busted, give up! */
+               xhci_err(xhci, "ERROR Transfer event TRB DMA ptr not part of current TD\n");
+               return -ESHUTDOWN;
+       }
+       event_trb = &event_seg->trbs[(event_dma - event_seg->dma) / sizeof(*event_trb)];
+       xhci_dbg(xhci, "Event TRB with TRB type ID %u\n",
+                       (unsigned int) (event->flags & TRB_TYPE_BITMASK)>>10);
+       xhci_dbg(xhci, "Offset 0x00 (buffer lo) = 0x%x\n",
+                       lower_32_bits(event->buffer));
+       xhci_dbg(xhci, "Offset 0x04 (buffer hi) = 0x%x\n",
+                       upper_32_bits(event->buffer));
+       xhci_dbg(xhci, "Offset 0x08 (transfer length) = 0x%x\n",
+                       (unsigned int) event->transfer_len);
+       xhci_dbg(xhci, "Offset 0x0C (flags) = 0x%x\n",
+                       (unsigned int) event->flags);
+
+       /* Look for common error cases */
+       trb_comp_code = GET_COMP_CODE(event->transfer_len);
+       switch (trb_comp_code) {
+       /* Skip codes that require special handling depending on
+        * transfer type
+        */
+       case COMP_SUCCESS:
+       case COMP_SHORT_TX:
+               break;
+       case COMP_STOP:
+               xhci_dbg(xhci, "Stopped on Transfer TRB\n");
+               break;
+       case COMP_STOP_INVAL:
+               xhci_dbg(xhci, "Stopped on No-op or Link TRB\n");
+               break;
+       case COMP_STALL:
+               xhci_warn(xhci, "WARN: Stalled endpoint\n");
+               ep->ep_state |= EP_HALTED;
+               status = -EPIPE;
+               break;
+       case COMP_TRB_ERR:
+               xhci_warn(xhci, "WARN: TRB error on endpoint\n");
+               status = -EILSEQ;
+               break;
+       case COMP_SPLIT_ERR:
+       case COMP_TX_ERR:
+               xhci_warn(xhci, "WARN: transfer error on endpoint\n");
+               status = -EPROTO;
+               break;
+       case COMP_BABBLE:
+               xhci_warn(xhci, "WARN: babble error on endpoint\n");
+               status = -EOVERFLOW;
+               break;
+       case COMP_DB_ERR:
+               xhci_warn(xhci, "WARN: HC couldn't access mem fast enough\n");
+               status = -ENOSR;
+               break;
+       default:
+               if (xhci_is_vendor_info_code(xhci, trb_comp_code)) {
+                       status = 0;
+                       break;
+               }
+               xhci_warn(xhci, "ERROR Unknown event condition, HC probably busted\n");
+               urb = NULL;
+               goto cleanup;
+       }
+       /* Now update the urb's actual_length and give back to the core */
+       /* Was this a control transfer? */
+       if (usb_endpoint_xfer_control(&td->urb->ep->desc)) {
+               xhci_debug_trb(xhci, xhci->event_ring->dequeue);
+               switch (trb_comp_code) {
+               case COMP_SUCCESS:
+                       if (event_trb == ep_ring->dequeue) {
+                               xhci_warn(xhci, "WARN: Success on ctrl setup TRB without IOC set??\n");
+                               status = -ESHUTDOWN;
+                       } else if (event_trb != td->last_trb) {
+                               xhci_warn(xhci, "WARN: Success on ctrl data TRB without IOC set??\n");
+                               status = -ESHUTDOWN;
+                       } else {
+                               xhci_dbg(xhci, "Successful control transfer!\n");
+                               status = 0;
+                       }
+                       break;
+               case COMP_SHORT_TX:
+                       xhci_warn(xhci, "WARN: short transfer on control ep\n");
+                       if (td->urb->transfer_flags & URB_SHORT_NOT_OK)
+                               status = -EREMOTEIO;
+                       else
+                               status = 0;
+                       break;
+
+               default:
+                       if (!xhci_requires_manual_halt_cleanup(xhci,
+                                               ep_ctx, trb_comp_code))
+                               break;
+                       xhci_dbg(xhci, "TRB error code %u, "
+                                       "halted endpoint index = %u\n",
+                                       trb_comp_code, ep_index);
+                       /* else fall through */
+               case COMP_STALL:
+                       /* Did we transfer part of the data (middle) phase? */
+                       if (event_trb != ep_ring->dequeue &&
+                                       event_trb != td->last_trb)
+                               td->urb->actual_length =
+                                       td->urb->transfer_buffer_length
+                                       - TRB_LEN(event->transfer_len);
+                       else
+                               td->urb->actual_length = 0;
+
+                       xhci_cleanup_halted_endpoint(xhci,
+                                       slot_id, ep_index, td, event_trb);
+                       goto td_cleanup;
+               }
+               /*
+                * Did we transfer any data, despite the errors that might have
+                * happened?  I.e. did we get past the setup stage?
+                */
+               if (event_trb != ep_ring->dequeue) {
+                       /* The event was for the status stage */
+                       if (event_trb == td->last_trb) {
+                               if (td->urb->actual_length != 0) {
+                                       /* Don't overwrite a previously set error code */
+                                       if ((status == -EINPROGRESS ||
+                                                               status == 0) &&
+                                                       (td->urb->transfer_flags
+                                                        & URB_SHORT_NOT_OK))
+                                               /* Did we already see a short data stage? */
+                                               status = -EREMOTEIO;
+                               } else {
+                                       td->urb->actual_length =
+                                               td->urb->transfer_buffer_length;
+                               }
+                       } else {
+                       /* Maybe the event was for the data stage? */
+                               if (trb_comp_code != COMP_STOP_INVAL) {
+                                       /* We didn't stop on a link TRB in the middle */
+                                       td->urb->actual_length =
+                                               td->urb->transfer_buffer_length -
+                                               TRB_LEN(event->transfer_len);
+                                       xhci_dbg(xhci, "Waiting for status stage event\n");
+                                       urb = NULL;
+                                       goto cleanup;
+                               }
+                       }
+               }
+       } else {
+               switch (trb_comp_code) {
+               case COMP_SUCCESS:
+                       /* Double check that the HW transferred everything. */
+                       if (event_trb != td->last_trb) {
+                               xhci_warn(xhci, "WARN Successful completion "
+                                               "on short TX\n");
+                               if (td->urb->transfer_flags & URB_SHORT_NOT_OK)
+                                       status = -EREMOTEIO;
+                               else
+                                       status = 0;
+                       } else {
+                               if (usb_endpoint_xfer_bulk(&td->urb->ep->desc))
+                                       xhci_dbg(xhci, "Successful bulk "
+                                                       "transfer!\n");
+                               else
+                                       xhci_dbg(xhci, "Successful interrupt "
+                                                       "transfer!\n");
+                               status = 0;
+                       }
+                       break;
+               case COMP_SHORT_TX:
+                       if (td->urb->transfer_flags & URB_SHORT_NOT_OK)
+                               status = -EREMOTEIO;
+                       else
+                               status = 0;
+                       break;
+               default:
+                       /* Others already handled above */
+                       break;
+               }
+               dev_dbg(&td->urb->dev->dev,
+                               "ep %#x - asked for %d bytes, "
+                               "%d bytes untransferred\n",
+                               td->urb->ep->desc.bEndpointAddress,
+                               td->urb->transfer_buffer_length,
+                               TRB_LEN(event->transfer_len));
+               /* Fast path - was this the last TRB in the TD for this URB? */
+               if (event_trb == td->last_trb) {
+                       if (TRB_LEN(event->transfer_len) != 0) {
+                               td->urb->actual_length =
+                                       td->urb->transfer_buffer_length -
+                                       TRB_LEN(event->transfer_len);
+                               if (td->urb->transfer_buffer_length <
+                                               td->urb->actual_length) {
+                                       xhci_warn(xhci, "HC gave bad length "
+                                                       "of %d bytes left\n",
+                                                       TRB_LEN(event->transfer_len));
+                                       td->urb->actual_length = 0;
+                                       if (td->urb->transfer_flags &
+                                                       URB_SHORT_NOT_OK)
+                                               status = -EREMOTEIO;
+                                       else
+                                               status = 0;
+                               }
+                               /* Don't overwrite a previously set error code */
+                               if (status == -EINPROGRESS) {
+                                       if (td->urb->transfer_flags & URB_SHORT_NOT_OK)
+                                               status = -EREMOTEIO;
+                                       else
+                                               status = 0;
+                               }
+                       } else {
+                               td->urb->actual_length = td->urb->transfer_buffer_length;
+                               /* Ignore a short packet completion if the
+                                * untransferred length was zero.
+                                */
+                               if (status == -EREMOTEIO)
+                                       status = 0;
+                       }
+               } else {
+                       /* Slow path - walk the list, starting from the dequeue
+                        * pointer, to get the actual length transferred.
+                        */
+                       union xhci_trb *cur_trb;
+                       struct xhci_segment *cur_seg;
+
+                       td->urb->actual_length = 0;
+                       for (cur_trb = ep_ring->dequeue, cur_seg = ep_ring->deq_seg;
+                                       cur_trb != event_trb;
+                                       next_trb(xhci, ep_ring, &cur_seg, &cur_trb)) {
+                               if (TRB_TYPE(cur_trb->generic.field[3]) != TRB_TR_NOOP &&
+                                               TRB_TYPE(cur_trb->generic.field[3]) != TRB_LINK)
+                                       td->urb->actual_length +=
+                                               TRB_LEN(cur_trb->generic.field[2]);
+                       }
+                       /* If the ring didn't stop on a Link or No-op TRB, add
+                        * in the actual bytes transferred from the Normal TRB
+                        */
+                       if (trb_comp_code != COMP_STOP_INVAL)
+                               td->urb->actual_length +=
+                                       TRB_LEN(cur_trb->generic.field[2]) -
+                                       TRB_LEN(event->transfer_len);
+               }
+       }
+       if (trb_comp_code == COMP_STOP_INVAL ||
+                       trb_comp_code == COMP_STOP) {
+               /* The Endpoint Stop Command completion will take care of any
+                * stopped TDs.  A stopped TD may be restarted, so don't update
+                * the ring dequeue pointer or take this TD off any lists yet.
+                */
+               ep->stopped_td = td;
+               ep->stopped_trb = event_trb;
+       } else {
+               if (trb_comp_code == COMP_STALL) {
+                       /* The transfer is completed from the driver's
+                        * perspective, but we need to issue a set dequeue
+                        * command for this stalled endpoint to move the dequeue
+                        * pointer past the TD.  We can't do that here because
+                        * the halt condition must be cleared first.  Let the
+                        * USB class driver clear the stall later.
+                        */
+                       ep->stopped_td = td;
+                       ep->stopped_trb = event_trb;
+               } else if (xhci_requires_manual_halt_cleanup(xhci,
+                                       ep_ctx, trb_comp_code)) {
+                       /* Other types of errors halt the endpoint, but the
+                        * class driver doesn't call usb_reset_endpoint() unless
+                        * the error is -EPIPE.  Clear the halted status in the
+                        * xHCI hardware manually.
+                        */
+                       xhci_cleanup_halted_endpoint(xhci,
+                                       slot_id, ep_index, td, event_trb);
+               } else {
+                       /* Update ring dequeue pointer */
+                       while (ep_ring->dequeue != td->last_trb)
+                               inc_deq(xhci, ep_ring, false);
+                       inc_deq(xhci, ep_ring, false);
+               }
+
+td_cleanup:
+               /* Clean up the endpoint's TD list */
+               urb = td->urb;
+               /* Do one last check of the actual transfer length.
+                * If the host controller said we transferred more data than
+                * the buffer length, urb->actual_length will be a very big
+                * number (since it's unsigned).  Play it safe and say we didn't
+                * transfer anything.
+                */
+               if (urb->actual_length > urb->transfer_buffer_length) {
+                       xhci_warn(xhci, "URB transfer length is wrong, "
+                                       "xHC issue? req. len = %u, "
+                                       "act. len = %u\n",
+                                       urb->transfer_buffer_length,
+                                       urb->actual_length);
+                       urb->actual_length = 0;
+                       if (td->urb->transfer_flags & URB_SHORT_NOT_OK)
+                               status = -EREMOTEIO;
+                       else
+                               status = 0;
+               }
+               list_del(&td->td_list);
+               /* Was this TD slated to be cancelled but completed anyway? */
+               if (!list_empty(&td->cancelled_td_list))
+                       list_del(&td->cancelled_td_list);
+
+               /* Leave the TD around for the reset endpoint function to use
+                * (but only if it's not a control endpoint, since we already
+                * queued the Set TR dequeue pointer command for stalled
+                * control endpoints).
+                */
+               if (usb_endpoint_xfer_control(&urb->ep->desc) ||
+                       (trb_comp_code != COMP_STALL &&
+                               trb_comp_code != COMP_BABBLE)) {
+                       kfree(td);
+               }
+               urb->hcpriv = NULL;
+       }
+cleanup:
+       inc_deq(xhci, xhci->event_ring, true);
+       xhci_set_hc_event_deq(xhci);
+
+       /* FIXME for multi-TD URBs (who have buffers bigger than 64MB) */
+       if (urb) {
+               usb_hcd_unlink_urb_from_ep(xhci_to_hcd(xhci), urb);
+               xhci_dbg(xhci, "Giveback URB %p, len = %d, status = %d\n",
+                               urb, urb->actual_length, status);
+               spin_unlock(&xhci->lock);
+               usb_hcd_giveback_urb(xhci_to_hcd(xhci), urb, status);
+               spin_lock(&xhci->lock);
+       }
+       return 0;
+}
+
+/*
  * This function handles all OS-owned events on the event ring.  It may drop
  * xhci->lock between event processing (e.g. to pass up port status changes).
  */
-void handle_event(struct xhci_hcd *xhci)
+void xhci_handle_event(struct xhci_hcd *xhci)
 {
        union xhci_trb *event;
        int update_ptrs = 1;
+       int ret;
 
+       xhci_dbg(xhci, "In %s\n", __func__);
        if (!xhci->event_ring || !xhci->event_ring->dequeue) {
                xhci->error_bitmask |= 1 << 1;
                return;
@@ -341,29 +1540,53 @@ void handle_event(struct xhci_hcd *xhci)
                xhci->error_bitmask |= 1 << 2;
                return;
        }
+       xhci_dbg(xhci, "%s - OS owns TRB\n", __func__);
 
        /* FIXME: Handle more event types. */
        switch ((event->event_cmd.flags & TRB_TYPE_BITMASK)) {
        case TRB_TYPE(TRB_COMPLETION):
+               xhci_dbg(xhci, "%s - calling handle_cmd_completion\n", __func__);
                handle_cmd_completion(xhci, &event->event_cmd);
+               xhci_dbg(xhci, "%s - returned from handle_cmd_completion\n", __func__);
                break;
        case TRB_TYPE(TRB_PORT_STATUS):
+               xhci_dbg(xhci, "%s - calling handle_port_status\n", __func__);
                handle_port_status(xhci, event);
+               xhci_dbg(xhci, "%s - returned from handle_port_status\n", __func__);
                update_ptrs = 0;
                break;
+       case TRB_TYPE(TRB_TRANSFER):
+               xhci_dbg(xhci, "%s - calling handle_tx_event\n", __func__);
+               ret = handle_tx_event(xhci, &event->trans_event);
+               xhci_dbg(xhci, "%s - returned from handle_tx_event\n", __func__);
+               if (ret < 0)
+                       xhci->error_bitmask |= 1 << 9;
+               else
+                       update_ptrs = 0;
+               break;
        default:
                xhci->error_bitmask |= 1 << 3;
        }
+       /* Any of the above functions may drop and re-acquire the lock, so check
+        * to make sure a watchdog timer didn't mark the host as non-responsive.
+        */
+       if (xhci->xhc_state & XHCI_STATE_DYING) {
+               xhci_dbg(xhci, "xHCI host dying, returning from "
+                               "event handler.\n");
+               return;
+       }
 
        if (update_ptrs) {
                /* Update SW and HC event ring dequeue pointer */
                inc_deq(xhci, xhci->event_ring, true);
-               set_hc_event_deq(xhci);
+               xhci_set_hc_event_deq(xhci);
        }
        /* Are there more items on the event ring? */
-       handle_event(xhci);
+       xhci_handle_event(xhci);
 }
 
+/****          Endpoint Ring Operations        ****/
+
 /*
  * Generic function for queueing a TRB on a ring.
  * The caller must have checked to make sure there's room on the ring.
@@ -382,12 +1605,584 @@ static void queue_trb(struct xhci_hcd *xhci, struct xhci_ring *ring,
        inc_enq(xhci, ring, consumer);
 }
 
-/* Generic function for queueing a command TRB on the command ring */
-static int queue_command(struct xhci_hcd *xhci, u32 field1, u32 field2, u32 field3, u32 field4)
+/*
+ * Does various checks on the endpoint ring, and makes it ready to queue num_trbs.
+ * FIXME allocate segments if the ring is full.
+ */
+static int prepare_ring(struct xhci_hcd *xhci, struct xhci_ring *ep_ring,
+               u32 ep_state, unsigned int num_trbs, gfp_t mem_flags)
 {
-       if (!room_on_ring(xhci, xhci->cmd_ring, 1)) {
+       /* Make sure the endpoint has been added to xHC schedule */
+       xhci_dbg(xhci, "Endpoint state = 0x%x\n", ep_state);
+       switch (ep_state) {
+       case EP_STATE_DISABLED:
+               /*
+                * USB core changed config/interfaces without notifying us,
+                * or hardware is reporting the wrong state.
+                */
+               xhci_warn(xhci, "WARN urb submitted to disabled ep\n");
+               return -ENOENT;
+       case EP_STATE_ERROR:
+               xhci_warn(xhci, "WARN waiting for error on ep to be cleared\n");
+               /* FIXME event handling code for error needs to clear it */
+               /* XXX not sure if this should be -ENOENT or not */
+               return -EINVAL;
+       case EP_STATE_HALTED:
+               xhci_dbg(xhci, "WARN halted endpoint, queueing URB anyway.\n");
+       case EP_STATE_STOPPED:
+       case EP_STATE_RUNNING:
+               break;
+       default:
+               xhci_err(xhci, "ERROR unknown endpoint state for ep\n");
+               /*
+                * FIXME issue Configure Endpoint command to try to get the HC
+                * back into a known state.
+                */
+               return -EINVAL;
+       }
+       if (!room_on_ring(xhci, ep_ring, num_trbs)) {
+               /* FIXME allocate more room */
+               xhci_err(xhci, "ERROR no room on ep ring\n");
+               return -ENOMEM;
+       }
+       return 0;
+}
+
+static int prepare_transfer(struct xhci_hcd *xhci,
+               struct xhci_virt_device *xdev,
+               unsigned int ep_index,
+               unsigned int num_trbs,
+               struct urb *urb,
+               struct xhci_td **td,
+               gfp_t mem_flags)
+{
+       int ret;
+       struct xhci_ep_ctx *ep_ctx = xhci_get_ep_ctx(xhci, xdev->out_ctx, ep_index);
+       ret = prepare_ring(xhci, xdev->eps[ep_index].ring,
+                       ep_ctx->ep_info & EP_STATE_MASK,
+                       num_trbs, mem_flags);
+       if (ret)
+               return ret;
+       *td = kzalloc(sizeof(struct xhci_td), mem_flags);
+       if (!*td)
+               return -ENOMEM;
+       INIT_LIST_HEAD(&(*td)->td_list);
+       INIT_LIST_HEAD(&(*td)->cancelled_td_list);
+
+       ret = usb_hcd_link_urb_to_ep(xhci_to_hcd(xhci), urb);
+       if (unlikely(ret)) {
+               kfree(*td);
+               return ret;
+       }
+
+       (*td)->urb = urb;
+       urb->hcpriv = (void *) (*td);
+       /* Add this TD to the tail of the endpoint ring's TD list */
+       list_add_tail(&(*td)->td_list, &xdev->eps[ep_index].ring->td_list);
+       (*td)->start_seg = xdev->eps[ep_index].ring->enq_seg;
+       (*td)->first_trb = xdev->eps[ep_index].ring->enqueue;
+
+       return 0;
+}
+
+static unsigned int count_sg_trbs_needed(struct xhci_hcd *xhci, struct urb *urb)
+{
+       int num_sgs, num_trbs, running_total, temp, i;
+       struct scatterlist *sg;
+
+       sg = NULL;
+       num_sgs = urb->num_sgs;
+       temp = urb->transfer_buffer_length;
+
+       xhci_dbg(xhci, "count sg list trbs: \n");
+       num_trbs = 0;
+       for_each_sg(urb->sg->sg, sg, num_sgs, i) {
+               unsigned int previous_total_trbs = num_trbs;
+               unsigned int len = sg_dma_len(sg);
+
+               /* Scatter gather list entries may cross 64KB boundaries */
+               running_total = TRB_MAX_BUFF_SIZE -
+                       (sg_dma_address(sg) & ((1 << TRB_MAX_BUFF_SHIFT) - 1));
+               if (running_total != 0)
+                       num_trbs++;
+
+               /* How many more 64KB chunks to transfer, how many more TRBs? */
+               while (running_total < sg_dma_len(sg)) {
+                       num_trbs++;
+                       running_total += TRB_MAX_BUFF_SIZE;
+               }
+               xhci_dbg(xhci, " sg #%d: dma = %#llx, len = %#x (%d), num_trbs = %d\n",
+                               i, (unsigned long long)sg_dma_address(sg),
+                               len, len, num_trbs - previous_total_trbs);
+
+               len = min_t(int, len, temp);
+               temp -= len;
+               if (temp == 0)
+                       break;
+       }
+       xhci_dbg(xhci, "\n");
+       if (!in_interrupt())
+               dev_dbg(&urb->dev->dev, "ep %#x - urb len = %d, sglist used, num_trbs = %d\n",
+                               urb->ep->desc.bEndpointAddress,
+                               urb->transfer_buffer_length,
+                               num_trbs);
+       return num_trbs;
+}
+
+static void check_trb_math(struct urb *urb, int num_trbs, int running_total)
+{
+       if (num_trbs != 0)
+               dev_dbg(&urb->dev->dev, "%s - ep %#x - Miscalculated number of "
+                               "TRBs, %d left\n", __func__,
+                               urb->ep->desc.bEndpointAddress, num_trbs);
+       if (running_total != urb->transfer_buffer_length)
+               dev_dbg(&urb->dev->dev, "%s - ep %#x - Miscalculated tx length, "
+                               "queued %#x (%d), asked for %#x (%d)\n",
+                               __func__,
+                               urb->ep->desc.bEndpointAddress,
+                               running_total, running_total,
+                               urb->transfer_buffer_length,
+                               urb->transfer_buffer_length);
+}
+
+static void giveback_first_trb(struct xhci_hcd *xhci, int slot_id,
+               unsigned int ep_index, int start_cycle,
+               struct xhci_generic_trb *start_trb, struct xhci_td *td)
+{
+       /*
+        * Pass all the TRBs to the hardware at once and make sure this write
+        * isn't reordered.
+        */
+       wmb();
+       start_trb->field[3] |= start_cycle;
+       ring_ep_doorbell(xhci, slot_id, ep_index);
+}
+
+/*
+ * xHCI uses normal TRBs for both bulk and interrupt.  When the interrupt
+ * endpoint is to be serviced, the xHC will consume (at most) one TD.  A TD
+ * (comprised of sg list entries) can take several service intervals to
+ * transmit.
+ */
+int xhci_queue_intr_tx(struct xhci_hcd *xhci, gfp_t mem_flags,
+               struct urb *urb, int slot_id, unsigned int ep_index)
+{
+       struct xhci_ep_ctx *ep_ctx = xhci_get_ep_ctx(xhci,
+                       xhci->devs[slot_id]->out_ctx, ep_index);
+       int xhci_interval;
+       int ep_interval;
+
+       xhci_interval = EP_INTERVAL_TO_UFRAMES(ep_ctx->ep_info);
+       ep_interval = urb->interval;
+       /* Convert to microframes */
+       if (urb->dev->speed == USB_SPEED_LOW ||
+                       urb->dev->speed == USB_SPEED_FULL)
+               ep_interval *= 8;
+       /* FIXME change this to a warning and a suggestion to use the new API
+        * to set the polling interval (once the API is added).
+        */
+       if (xhci_interval != ep_interval) {
+               if (!printk_ratelimit())
+                       dev_dbg(&urb->dev->dev, "Driver uses different interval"
+                                       " (%d microframe%s) than xHCI "
+                                       "(%d microframe%s)\n",
+                                       ep_interval,
+                                       ep_interval == 1 ? "" : "s",
+                                       xhci_interval,
+                                       xhci_interval == 1 ? "" : "s");
+               urb->interval = xhci_interval;
+               /* Convert back to frames for LS/FS devices */
+               if (urb->dev->speed == USB_SPEED_LOW ||
+                               urb->dev->speed == USB_SPEED_FULL)
+                       urb->interval /= 8;
+       }
+       return xhci_queue_bulk_tx(xhci, GFP_ATOMIC, urb, slot_id, ep_index);
+}
+
+/*
+ * The TD size is the number of bytes remaining in the TD (including this TRB),
+ * right shifted by 10.
+ * It must fit in bits 21:17, so it can't be bigger than 31.
+ */
+static u32 xhci_td_remainder(unsigned int remainder)
+{
+       u32 max = (1 << (21 - 17 + 1)) - 1;
+
+       if ((remainder >> 10) >= max)
+               return max << 17;
+       else
+               return (remainder >> 10) << 17;
+}
+
+static int queue_bulk_sg_tx(struct xhci_hcd *xhci, gfp_t mem_flags,
+               struct urb *urb, int slot_id, unsigned int ep_index)
+{
+       struct xhci_ring *ep_ring;
+       unsigned int num_trbs;
+       struct xhci_td *td;
+       struct scatterlist *sg;
+       int num_sgs;
+       int trb_buff_len, this_sg_len, running_total;
+       bool first_trb;
+       u64 addr;
+
+       struct xhci_generic_trb *start_trb;
+       int start_cycle;
+
+       ep_ring = xhci->devs[slot_id]->eps[ep_index].ring;
+       num_trbs = count_sg_trbs_needed(xhci, urb);
+       num_sgs = urb->num_sgs;
+
+       trb_buff_len = prepare_transfer(xhci, xhci->devs[slot_id],
+                       ep_index, num_trbs, urb, &td, mem_flags);
+       if (trb_buff_len < 0)
+               return trb_buff_len;
+       /*
+        * Don't give the first TRB to the hardware (by toggling the cycle bit)
+        * until we've finished creating all the other TRBs.  The ring's cycle
+        * state may change as we enqueue the other TRBs, so save it too.
+        */
+       start_trb = &ep_ring->enqueue->generic;
+       start_cycle = ep_ring->cycle_state;
+
+       running_total = 0;
+       /*
+        * How much data is in the first TRB?
+        *
+        * There are three forces at work for TRB buffer pointers and lengths:
+        * 1. We don't want to walk off the end of this sg-list entry buffer.
+        * 2. The transfer length that the driver requested may be smaller than
+        *    the amount of memory allocated for this scatter-gather list.
+        * 3. TRBs buffers can't cross 64KB boundaries.
+        */
+       sg = urb->sg->sg;
+       addr = (u64) sg_dma_address(sg);
+       this_sg_len = sg_dma_len(sg);
+       trb_buff_len = TRB_MAX_BUFF_SIZE -
+               (addr & ((1 << TRB_MAX_BUFF_SHIFT) - 1));
+       trb_buff_len = min_t(int, trb_buff_len, this_sg_len);
+       if (trb_buff_len > urb->transfer_buffer_length)
+               trb_buff_len = urb->transfer_buffer_length;
+       xhci_dbg(xhci, "First length to xfer from 1st sglist entry = %u\n",
+                       trb_buff_len);
+
+       first_trb = true;
+       /* Queue the first TRB, even if it's zero-length */
+       do {
+               u32 field = 0;
+               u32 length_field = 0;
+               u32 remainder = 0;
+
+               /* Don't change the cycle bit of the first TRB until later */
+               if (first_trb)
+                       first_trb = false;
+               else
+                       field |= ep_ring->cycle_state;
+
+               /* Chain all the TRBs together; clear the chain bit in the last
+                * TRB to indicate it's the last TRB in the chain.
+                */
+               if (num_trbs > 1) {
+                       field |= TRB_CHAIN;
+               } else {
+                       /* FIXME - add check for ZERO_PACKET flag before this */
+                       td->last_trb = ep_ring->enqueue;
+                       field |= TRB_IOC;
+               }
+               xhci_dbg(xhci, " sg entry: dma = %#x, len = %#x (%d), "
+                               "64KB boundary at %#x, end dma = %#x\n",
+                               (unsigned int) addr, trb_buff_len, trb_buff_len,
+                               (unsigned int) (addr + TRB_MAX_BUFF_SIZE) & ~(TRB_MAX_BUFF_SIZE - 1),
+                               (unsigned int) addr + trb_buff_len);
+               if (TRB_MAX_BUFF_SIZE -
+                               (addr & ((1 << TRB_MAX_BUFF_SHIFT) - 1)) < trb_buff_len) {
+                       xhci_warn(xhci, "WARN: sg dma xfer crosses 64KB boundaries!\n");
+                       xhci_dbg(xhci, "Next boundary at %#x, end dma = %#x\n",
+                                       (unsigned int) (addr + TRB_MAX_BUFF_SIZE) & ~(TRB_MAX_BUFF_SIZE - 1),
+                                       (unsigned int) addr + trb_buff_len);
+               }
+               remainder = xhci_td_remainder(urb->transfer_buffer_length -
+                               running_total) ;
+               length_field = TRB_LEN(trb_buff_len) |
+                       remainder |
+                       TRB_INTR_TARGET(0);
+               queue_trb(xhci, ep_ring, false,
+                               lower_32_bits(addr),
+                               upper_32_bits(addr),
+                               length_field,
+                               /* We always want to know if the TRB was short,
+                                * or we won't get an event when it completes.
+                                * (Unless we use event data TRBs, which are a
+                                * waste of space and HC resources.)
+                                */
+                               field | TRB_ISP | TRB_TYPE(TRB_NORMAL));
+               --num_trbs;
+               running_total += trb_buff_len;
+
+               /* Calculate length for next transfer --
+                * Are we done queueing all the TRBs for this sg entry?
+                */
+               this_sg_len -= trb_buff_len;
+               if (this_sg_len == 0) {
+                       --num_sgs;
+                       if (num_sgs == 0)
+                               break;
+                       sg = sg_next(sg);
+                       addr = (u64) sg_dma_address(sg);
+                       this_sg_len = sg_dma_len(sg);
+               } else {
+                       addr += trb_buff_len;
+               }
+
+               trb_buff_len = TRB_MAX_BUFF_SIZE -
+                       (addr & ((1 << TRB_MAX_BUFF_SHIFT) - 1));
+               trb_buff_len = min_t(int, trb_buff_len, this_sg_len);
+               if (running_total + trb_buff_len > urb->transfer_buffer_length)
+                       trb_buff_len =
+                               urb->transfer_buffer_length - running_total;
+       } while (running_total < urb->transfer_buffer_length);
+
+       check_trb_math(urb, num_trbs, running_total);
+       giveback_first_trb(xhci, slot_id, ep_index, start_cycle, start_trb, td);
+       return 0;
+}
+
+/* This is very similar to what ehci-q.c qtd_fill() does */
+int xhci_queue_bulk_tx(struct xhci_hcd *xhci, gfp_t mem_flags,
+               struct urb *urb, int slot_id, unsigned int ep_index)
+{
+       struct xhci_ring *ep_ring;
+       struct xhci_td *td;
+       int num_trbs;
+       struct xhci_generic_trb *start_trb;
+       bool first_trb;
+       int start_cycle;
+       u32 field, length_field;
+
+       int running_total, trb_buff_len, ret;
+       u64 addr;
+
+       if (urb->num_sgs)
+               return queue_bulk_sg_tx(xhci, mem_flags, urb, slot_id, ep_index);
+
+       ep_ring = xhci->devs[slot_id]->eps[ep_index].ring;
+
+       num_trbs = 0;
+       /* How much data is (potentially) left before the 64KB boundary? */
+       running_total = TRB_MAX_BUFF_SIZE -
+               (urb->transfer_dma & ((1 << TRB_MAX_BUFF_SHIFT) - 1));
+
+       /* If there's some data on this 64KB chunk, or we have to send a
+        * zero-length transfer, we need at least one TRB
+        */
+       if (running_total != 0 || urb->transfer_buffer_length == 0)
+               num_trbs++;
+       /* How many more 64KB chunks to transfer, how many more TRBs? */
+       while (running_total < urb->transfer_buffer_length) {
+               num_trbs++;
+               running_total += TRB_MAX_BUFF_SIZE;
+       }
+       /* FIXME: this doesn't deal with URB_ZERO_PACKET - need one more */
+
+       if (!in_interrupt())
+               dev_dbg(&urb->dev->dev, "ep %#x - urb len = %#x (%d), addr = %#llx, num_trbs = %d\n",
+                               urb->ep->desc.bEndpointAddress,
+                               urb->transfer_buffer_length,
+                               urb->transfer_buffer_length,
+                               (unsigned long long)urb->transfer_dma,
+                               num_trbs);
+
+       ret = prepare_transfer(xhci, xhci->devs[slot_id], ep_index,
+                       num_trbs, urb, &td, mem_flags);
+       if (ret < 0)
+               return ret;
+
+       /*
+        * Don't give the first TRB to the hardware (by toggling the cycle bit)
+        * until we've finished creating all the other TRBs.  The ring's cycle
+        * state may change as we enqueue the other TRBs, so save it too.
+        */
+       start_trb = &ep_ring->enqueue->generic;
+       start_cycle = ep_ring->cycle_state;
+
+       running_total = 0;
+       /* How much data is in the first TRB? */
+       addr = (u64) urb->transfer_dma;
+       trb_buff_len = TRB_MAX_BUFF_SIZE -
+               (urb->transfer_dma & ((1 << TRB_MAX_BUFF_SHIFT) - 1));
+       if (urb->transfer_buffer_length < trb_buff_len)
+               trb_buff_len = urb->transfer_buffer_length;
+
+       first_trb = true;
+
+       /* Queue the first TRB, even if it's zero-length */
+       do {
+               u32 remainder = 0;
+               field = 0;
+
+               /* Don't change the cycle bit of the first TRB until later */
+               if (first_trb)
+                       first_trb = false;
+               else
+                       field |= ep_ring->cycle_state;
+
+               /* Chain all the TRBs together; clear the chain bit in the last
+                * TRB to indicate it's the last TRB in the chain.
+                */
+               if (num_trbs > 1) {
+                       field |= TRB_CHAIN;
+               } else {
+                       /* FIXME - add check for ZERO_PACKET flag before this */
+                       td->last_trb = ep_ring->enqueue;
+                       field |= TRB_IOC;
+               }
+               remainder = xhci_td_remainder(urb->transfer_buffer_length -
+                               running_total);
+               length_field = TRB_LEN(trb_buff_len) |
+                       remainder |
+                       TRB_INTR_TARGET(0);
+               queue_trb(xhci, ep_ring, false,
+                               lower_32_bits(addr),
+                               upper_32_bits(addr),
+                               length_field,
+                               /* We always want to know if the TRB was short,
+                                * or we won't get an event when it completes.
+                                * (Unless we use event data TRBs, which are a
+                                * waste of space and HC resources.)
+                                */
+                               field | TRB_ISP | TRB_TYPE(TRB_NORMAL));
+               --num_trbs;
+               running_total += trb_buff_len;
+
+               /* Calculate length for next transfer */
+               addr += trb_buff_len;
+               trb_buff_len = urb->transfer_buffer_length - running_total;
+               if (trb_buff_len > TRB_MAX_BUFF_SIZE)
+                       trb_buff_len = TRB_MAX_BUFF_SIZE;
+       } while (running_total < urb->transfer_buffer_length);
+
+       check_trb_math(urb, num_trbs, running_total);
+       giveback_first_trb(xhci, slot_id, ep_index, start_cycle, start_trb, td);
+       return 0;
+}
+
+/* Caller must have locked xhci->lock */
+int xhci_queue_ctrl_tx(struct xhci_hcd *xhci, gfp_t mem_flags,
+               struct urb *urb, int slot_id, unsigned int ep_index)
+{
+       struct xhci_ring *ep_ring;
+       int num_trbs;
+       int ret;
+       struct usb_ctrlrequest *setup;
+       struct xhci_generic_trb *start_trb;
+       int start_cycle;
+       u32 field, length_field;
+       struct xhci_td *td;
+
+       ep_ring = xhci->devs[slot_id]->eps[ep_index].ring;
+
+       /*
+        * Need to copy setup packet into setup TRB, so we can't use the setup
+        * DMA address.
+        */
+       if (!urb->setup_packet)
+               return -EINVAL;
+
+       if (!in_interrupt())
+               xhci_dbg(xhci, "Queueing ctrl tx for slot id %d, ep %d\n",
+                               slot_id, ep_index);
+       /* 1 TRB for setup, 1 for status */
+       num_trbs = 2;
+       /*
+        * Don't need to check if we need additional event data and normal TRBs,
+        * since data in control transfers will never get bigger than 16MB
+        * XXX: can we get a buffer that crosses 64KB boundaries?
+        */
+       if (urb->transfer_buffer_length > 0)
+               num_trbs++;
+       ret = prepare_transfer(xhci, xhci->devs[slot_id], ep_index, num_trbs,
+                       urb, &td, mem_flags);
+       if (ret < 0)
+               return ret;
+
+       /*
+        * Don't give the first TRB to the hardware (by toggling the cycle bit)
+        * until we've finished creating all the other TRBs.  The ring's cycle
+        * state may change as we enqueue the other TRBs, so save it too.
+        */
+       start_trb = &ep_ring->enqueue->generic;
+       start_cycle = ep_ring->cycle_state;
+
+       /* Queue setup TRB - see section 6.4.1.2.1 */
+       /* FIXME better way to translate setup_packet into two u32 fields? */
+       setup = (struct usb_ctrlrequest *) urb->setup_packet;
+       queue_trb(xhci, ep_ring, false,
+                       /* FIXME endianness is probably going to bite my ass here. */
+                       setup->bRequestType | setup->bRequest << 8 | setup->wValue << 16,
+                       setup->wIndex | setup->wLength << 16,
+                       TRB_LEN(8) | TRB_INTR_TARGET(0),
+                       /* Immediate data in pointer */
+                       TRB_IDT | TRB_TYPE(TRB_SETUP));
+
+       /* If there's data, queue data TRBs */
+       field = 0;
+       length_field = TRB_LEN(urb->transfer_buffer_length) |
+               xhci_td_remainder(urb->transfer_buffer_length) |
+               TRB_INTR_TARGET(0);
+       if (urb->transfer_buffer_length > 0) {
+               if (setup->bRequestType & USB_DIR_IN)
+                       field |= TRB_DIR_IN;
+               queue_trb(xhci, ep_ring, false,
+                               lower_32_bits(urb->transfer_dma),
+                               upper_32_bits(urb->transfer_dma),
+                               length_field,
+                               /* Event on short tx */
+                               field | TRB_ISP | TRB_TYPE(TRB_DATA) | ep_ring->cycle_state);
+       }
+
+       /* Save the DMA address of the last TRB in the TD */
+       td->last_trb = ep_ring->enqueue;
+
+       /* Queue status TRB - see Table 7 and sections 4.11.2.2 and 6.4.1.2.3 */
+       /* If the device sent data, the status stage is an OUT transfer */
+       if (urb->transfer_buffer_length > 0 && setup->bRequestType & USB_DIR_IN)
+               field = 0;
+       else
+               field = TRB_DIR_IN;
+       queue_trb(xhci, ep_ring, false,
+                       0,
+                       0,
+                       TRB_INTR_TARGET(0),
+                       /* Event on completion */
+                       field | TRB_IOC | TRB_TYPE(TRB_STATUS) | ep_ring->cycle_state);
+
+       giveback_first_trb(xhci, slot_id, ep_index, start_cycle, start_trb, td);
+       return 0;
+}
+
+/****          Command Ring Operations         ****/
+
+/* Generic function for queueing a command TRB on the command ring.
+ * Check to make sure there's room on the command ring for one command TRB.
+ * Also check that there's room reserved for commands that must not fail.
+ * If this is a command that must not fail, meaning command_must_succeed = TRUE,
+ * then only check for the number of reserved spots.
+ * Don't decrement xhci->cmd_ring_reserved_trbs after we've queued the TRB
+ * because the command event handler may want to resubmit a failed command.
+ */
+static int queue_command(struct xhci_hcd *xhci, u32 field1, u32 field2,
+               u32 field3, u32 field4, bool command_must_succeed)
+{
+       int reserved_trbs = xhci->cmd_ring_reserved_trbs;
+       if (!command_must_succeed)
+               reserved_trbs++;
+
+       if (!room_on_ring(xhci, xhci->cmd_ring, reserved_trbs)) {
                if (!in_interrupt())
                        xhci_err(xhci, "ERR: No room for command on command ring\n");
+               if (command_must_succeed)
+                       xhci_err(xhci, "ERR: Reserved TRB counting for "
+                                       "unfailable commands failed.\n");
                return -ENOMEM;
        }
        queue_trb(xhci, xhci->cmd_ring, false, field1, field2, field3,
@@ -398,31 +2193,108 @@ static int queue_command(struct xhci_hcd *xhci, u32 field1, u32 field2, u32 fiel
 /* Queue a no-op command on the command ring */
 static int queue_cmd_noop(struct xhci_hcd *xhci)
 {
-       return queue_command(xhci, 0, 0, 0, TRB_TYPE(TRB_CMD_NOOP));
+       return queue_command(xhci, 0, 0, 0, TRB_TYPE(TRB_CMD_NOOP), false);
 }
 
 /*
  * Place a no-op command on the command ring to test the command and
  * event ring.
  */
-void *setup_one_noop(struct xhci_hcd *xhci)
+void *xhci_setup_one_noop(struct xhci_hcd *xhci)
 {
        if (queue_cmd_noop(xhci) < 0)
                return NULL;
        xhci->noops_submitted++;
-       return ring_cmd_db;
+       return xhci_ring_cmd_db;
 }
 
 /* Queue a slot enable or disable request on the command ring */
-int queue_slot_control(struct xhci_hcd *xhci, u32 trb_type, u32 slot_id)
+int xhci_queue_slot_control(struct xhci_hcd *xhci, u32 trb_type, u32 slot_id)
 {
        return queue_command(xhci, 0, 0, 0,
-                       TRB_TYPE(trb_type) | SLOT_ID_FOR_TRB(slot_id));
+                       TRB_TYPE(trb_type) | SLOT_ID_FOR_TRB(slot_id), false);
 }
 
 /* Queue an address device command TRB */
-int queue_address_device(struct xhci_hcd *xhci, dma_addr_t in_ctx_ptr, u32 slot_id)
+int xhci_queue_address_device(struct xhci_hcd *xhci, dma_addr_t in_ctx_ptr,
+               u32 slot_id)
+{
+       return queue_command(xhci, lower_32_bits(in_ctx_ptr),
+                       upper_32_bits(in_ctx_ptr), 0,
+                       TRB_TYPE(TRB_ADDR_DEV) | SLOT_ID_FOR_TRB(slot_id),
+                       false);
+}
+
+/* Queue a reset device command TRB */
+int xhci_queue_reset_device(struct xhci_hcd *xhci, u32 slot_id)
+{
+       return queue_command(xhci, 0, 0, 0,
+                       TRB_TYPE(TRB_RESET_DEV) | SLOT_ID_FOR_TRB(slot_id),
+                       false);
+}
+
+/* Queue a configure endpoint command TRB */
+int xhci_queue_configure_endpoint(struct xhci_hcd *xhci, dma_addr_t in_ctx_ptr,
+               u32 slot_id, bool command_must_succeed)
+{
+       return queue_command(xhci, lower_32_bits(in_ctx_ptr),
+                       upper_32_bits(in_ctx_ptr), 0,
+                       TRB_TYPE(TRB_CONFIG_EP) | SLOT_ID_FOR_TRB(slot_id),
+                       command_must_succeed);
+}
+
+/* Queue an evaluate context command TRB */
+int xhci_queue_evaluate_context(struct xhci_hcd *xhci, dma_addr_t in_ctx_ptr,
+               u32 slot_id)
+{
+       return queue_command(xhci, lower_32_bits(in_ctx_ptr),
+                       upper_32_bits(in_ctx_ptr), 0,
+                       TRB_TYPE(TRB_EVAL_CONTEXT) | SLOT_ID_FOR_TRB(slot_id),
+                       false);
+}
+
+int xhci_queue_stop_endpoint(struct xhci_hcd *xhci, int slot_id,
+               unsigned int ep_index)
+{
+       u32 trb_slot_id = SLOT_ID_FOR_TRB(slot_id);
+       u32 trb_ep_index = EP_ID_FOR_TRB(ep_index);
+       u32 type = TRB_TYPE(TRB_STOP_RING);
+
+       return queue_command(xhci, 0, 0, 0,
+                       trb_slot_id | trb_ep_index | type, false);
+}
+
+/* Set Transfer Ring Dequeue Pointer command.
+ * This should not be used for endpoints that have streams enabled.
+ */
+static int queue_set_tr_deq(struct xhci_hcd *xhci, int slot_id,
+               unsigned int ep_index, struct xhci_segment *deq_seg,
+               union xhci_trb *deq_ptr, u32 cycle_state)
+{
+       dma_addr_t addr;
+       u32 trb_slot_id = SLOT_ID_FOR_TRB(slot_id);
+       u32 trb_ep_index = EP_ID_FOR_TRB(ep_index);
+       u32 type = TRB_TYPE(TRB_SET_DEQ);
+
+       addr = xhci_trb_virt_to_dma(deq_seg, deq_ptr);
+       if (addr == 0) {
+               xhci_warn(xhci, "WARN Cannot submit Set TR Deq Ptr\n");
+               xhci_warn(xhci, "WARN deq seg = %p, deq pt = %p\n",
+                               deq_seg, deq_ptr);
+               return 0;
+       }
+       return queue_command(xhci, lower_32_bits(addr) | cycle_state,
+                       upper_32_bits(addr), 0,
+                       trb_slot_id | trb_ep_index | type, false);
+}
+
+int xhci_queue_reset_ep(struct xhci_hcd *xhci, int slot_id,
+               unsigned int ep_index)
 {
-       return queue_command(xhci, in_ctx_ptr, 0, 0,
-                       TRB_TYPE(TRB_ADDR_DEV) | SLOT_ID_FOR_TRB(slot_id));
+       u32 trb_slot_id = SLOT_ID_FOR_TRB(slot_id);
+       u32 trb_ep_index = EP_ID_FOR_TRB(ep_index);
+       u32 type = TRB_TYPE(TRB_RESET_EP);
+
+       return queue_command(xhci, 0, 0, 0, trb_slot_id | trb_ep_index | type,
+                       false);
 }