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path: root/drivers/usb/host/xhci-ring.c
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Diffstat (limited to 'drivers/usb/host/xhci-ring.c')
-rw-r--r--drivers/usb/host/xhci-ring.c1648
1 files changed, 1648 insertions, 0 deletions
diff --git a/drivers/usb/host/xhci-ring.c b/drivers/usb/host/xhci-ring.c
new file mode 100644
index 000000000000..02d81985c454
--- /dev/null
+++ b/drivers/usb/host/xhci-ring.c
@@ -0,0 +1,1648 @@
+/*
+ * xHCI host controller driver
+ *
+ * Copyright (C) 2008 Intel Corp.
+ *
+ * Author: Sarah Sharp
+ * Some code borrowed from the Linux EHCI driver.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
+ * or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
+ * for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software Foundation,
+ * Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+ */
+
+/*
+ * Ring initialization rules:
+ * 1. Each segment is initialized to zero, except for link TRBs.
+ * 2. Ring cycle state = 0. This represents Producer Cycle State (PCS) or
+ * Consumer Cycle State (CCS), depending on ring function.
+ * 3. Enqueue pointer = dequeue pointer = address of first TRB in the segment.
+ *
+ * Ring behavior rules:
+ * 1. A ring is empty if enqueue == dequeue. This means there will always be at
+ * least one free TRB in the ring. This is useful if you want to turn that
+ * into a link TRB and expand the ring.
+ * 2. When incrementing an enqueue or dequeue pointer, if the next TRB is a
+ * link TRB, then load the pointer with the address in the link TRB. If the
+ * link TRB had its toggle bit set, you may need to update the ring cycle
+ * state (see cycle bit rules). You may have to do this multiple times
+ * until you reach a non-link TRB.
+ * 3. A ring is full if enqueue++ (for the definition of increment above)
+ * equals the dequeue pointer.
+ *
+ * Cycle bit rules:
+ * 1. When a consumer increments a dequeue pointer and encounters a toggle bit
+ * in a link TRB, it must toggle the ring cycle state.
+ * 2. When a producer increments an enqueue pointer and encounters a toggle bit
+ * in a link TRB, it must toggle the ring cycle state.
+ *
+ * Producer rules:
+ * 1. Check if ring is full before you enqueue.
+ * 2. Write the ring cycle state to the cycle bit in the TRB you're enqueuing.
+ * Update enqueue pointer between each write (which may update the ring
+ * cycle state).
+ * 3. Notify consumer. If SW is producer, it rings the doorbell for command
+ * and endpoint rings. If HC is the producer for the event ring,
+ * and it generates an interrupt according to interrupt modulation rules.
+ *
+ * Consumer rules:
+ * 1. Check if TRB belongs to you. If the cycle bit == your ring cycle state,
+ * the TRB is owned by the consumer.
+ * 2. Update dequeue pointer (which may update the ring cycle state) and
+ * continue processing TRBs until you reach a TRB which is not owned by you.
+ * 3. Notify the producer. SW is the consumer for the event ring, and it
+ * updates event ring dequeue pointer. HC is the consumer for the command and
+ * endpoint rings; it generates events on the event ring for these.
+ */
+
+#include <linux/scatterlist.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 xhci_trb_virt_to_dma(struct xhci_segment *seg,
+ union xhci_trb *trb)
+{
+ unsigned long segment_offset;
+
+ if (!seg || !trb || trb < seg->trbs)
+ return 0;
+ /* offset in TRBs */
+ segment_offset = trb - seg->trbs;
+ if (segment_offset > TRBS_PER_SEGMENT)
+ return 0;
+ return seg->dma + (segment_offset * sizeof(*trb));
+}
+
+/* Does this link TRB point to the first segment in a ring,
+ * or was the previous TRB the last TRB on the last segment in the ERST?
+ */
+static inline bool last_trb_on_last_seg(struct xhci_hcd *xhci, struct xhci_ring *ring,
+ struct xhci_segment *seg, union xhci_trb *trb)
+{
+ if (ring == xhci->event_ring)
+ return (trb == &seg->trbs[TRBS_PER_SEGMENT]) &&
+ (seg->next == xhci->event_ring->first_seg);
+ else
+ return trb->link.control & LINK_TOGGLE;
+}
+
+/* Is this TRB a link TRB or was the last TRB the last TRB in this event ring
+ * segment? I.e. would the updated event TRB pointer step off the end of the
+ * event seg?
+ */
+static inline int last_trb(struct xhci_hcd *xhci, struct xhci_ring *ring,
+ struct xhci_segment *seg, union xhci_trb *trb)
+{
+ if (ring == xhci->event_ring)
+ return trb == &seg->trbs[TRBS_PER_SEGMENT];
+ else
+ 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.
+ */
+static void inc_deq(struct xhci_hcd *xhci, struct xhci_ring *ring, bool consumer)
+{
+ union xhci_trb *next = ++(ring->dequeue);
+
+ ring->deq_updates++;
+ /* Update the dequeue pointer further if that was a link TRB or we're at
+ * the end of an event ring segment (which doesn't have link TRBS)
+ */
+ while (last_trb(xhci, ring, ring->deq_seg, next)) {
+ 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 %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;
+ }
+}
+
+/*
+ * 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.
+ *
+ * If we've just enqueued a TRB that is in the middle of a TD (meaning the
+ * chain bit is set), then set the chain bit in all the following link TRBs.
+ * If we've enqueued the last TRB in a TD, make sure the following link TRBs
+ * 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.
+ */
+static void inc_enq(struct xhci_hcd *xhci, struct xhci_ring *ring, bool consumer)
+{
+ u32 chain;
+ union xhci_trb *next;
+
+ chain = ring->enqueue->generic.field[3] & TRB_CHAIN;
+ next = ++(ring->enqueue);
+
+ ring->enq_updates++;
+ /* Update the dequeue pointer further if that was a link TRB or we're at
+ * the end of an event ring segment (which doesn't have link TRBS)
+ */
+ while (last_trb(xhci, ring, ring->enq_seg, next)) {
+ if (!consumer) {
+ if (ring != xhci->event_ring) {
+ 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;
+ }
+ /* 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 %p = %i\n",
+ ring,
+ (unsigned int) ring->cycle_state);
+ }
+ }
+ ring->enq_seg = ring->enq_seg->next;
+ ring->enqueue = ring->enq_seg->trbs;
+ next = ring->enqueue;
+ }
+}
+
+/*
+ * Check to see if there's room to enqueue num_trbs on the ring. See rules
+ * above.
+ * FIXME: this would be simpler and faster if we just kept track of the number
+ * of free TRBs in a ring.
+ */
+static int room_on_ring(struct xhci_hcd *xhci, struct xhci_ring *ring,
+ unsigned int num_trbs)
+{
+ int i;
+ union xhci_trb *enq = ring->enqueue;
+ struct xhci_segment *enq_seg = ring->enq_seg;
+
+ /* Check if ring is empty */
+ if (enq == ring->dequeue)
+ return 1;
+ /* Make sure there's an extra empty TRB available */
+ for (i = 0; i <= num_trbs; ++i) {
+ if (enq == ring->dequeue)
+ return 0;
+ enq++;
+ while (last_trb(xhci, ring, enq_seg, enq)) {
+ enq_seg = enq_seg->next;
+ enq = enq_seg->trbs;
+ }
+ }
+ return 1;
+}
+
+void xhci_set_hc_event_deq(struct xhci_hcd *xhci)
+{
+ u32 temp;
+ dma_addr_t deq;
+
+ 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 &= 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]);
+}
+
+/* Ring the host controller doorbell after placing a command on the ring */
+void xhci_ring_cmd_db(struct xhci_hcd *xhci)
+{
+ u32 temp;
+
+ xhci_dbg(xhci, "// Ding dong!\n");
+ temp = xhci_readl(xhci, &xhci->dba->doorbell[0]) & DB_MASK;
+ xhci_writel(xhci, temp | DB_TARGET_HOST, &xhci->dba->doorbell[0]);
+ /* Flush PCI posted writes */
+ 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_ring *ep_ring;
+ u32 field;
+ __u32 __iomem *db_addr = &xhci->dba->doorbell[slot_id];
+
+ ep_ring = xhci->devs[slot_id]->ep_rings[ep_index];
+ /* Don't ring the doorbell for this endpoint if there are pending
+ * cancellations because the we don't want to interrupt processing.
+ */
+ if (!ep_ring->cancels_pending && !(ep_ring->state & SET_DEQ_PENDING)) {
+ 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;
+}
+
+struct dequeue_state {
+ struct xhci_segment *new_deq_seg;
+ union xhci_trb *new_deq_ptr;
+ int new_cycle_state;
+};
+
+/*
+ * 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.
+ */
+static void find_new_dequeue_state(struct xhci_hcd *xhci,
+ unsigned int slot_id, unsigned int ep_index,
+ struct xhci_td *cur_td, struct dequeue_state *state)
+{
+ struct xhci_virt_device *dev = xhci->devs[slot_id];
+ struct xhci_ring *ep_ring = dev->ep_rings[ep_index];
+ struct xhci_generic_trb *trb;
+
+ state->new_cycle_state = 0;
+ state->new_deq_seg = find_trb_seg(cur_td->start_seg,
+ ep_ring->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 */
+ state->new_cycle_state = 0x1 & dev->out_ctx->ep[ep_index].deq[0];
+
+ state->new_deq_ptr = cur_td->last_trb;
+ 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). */
+ 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);
+
+/*
+ * 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 list_head *entry;
+ struct xhci_td *cur_td = 0;
+ struct xhci_td *last_unlinked_td;
+
+ struct dequeue_state deq_state;
+#ifdef CONFIG_USB_HCD_STAT
+ ktime_t stop_time = ktime_get();
+#endif
+
+ 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_ring = xhci->devs[slot_id]->ep_rings[ep_index];
+
+ if (list_empty(&ep_ring->cancelled_td_list))
+ 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_ring->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_ring->stopped_td)
+ 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);
+ ep_ring->cancels_pending--;
+ }
+ last_unlinked_td = cur_td;
+
+ /* If necessary, queue a Set Transfer Ring Dequeue Pointer command */
+ if (deq_state.new_deq_ptr && deq_state.new_deq_seg) {
+ 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_ring->state |= SET_DEQ_PENDING;
+ xhci_ring_cmd_db(xhci);
+ } else {
+ /* Otherwise just ring the doorbell to restart the ring */
+ ring_ep_doorbell(xhci, slot_id, ep_index);
+ }
+
+ /*
+ * 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_ring->cancelled_td_list.next,
+ struct xhci_td, cancelled_td_list);
+ list_del(&cur_td->cancelled_td_list);
+
+ /* Clean up the cancelled URB */
+#ifdef CONFIG_USB_HCD_STAT
+ hcd_stat_update(xhci->tp_stat, cur_td->urb->actual_length,
+ ktime_sub(stop_time, cur_td->start_time));
+#endif
+ cur_td->urb->hcpriv = NULL;
+ usb_hcd_unlink_urb_from_ep(xhci_to_hcd(xhci), cur_td->urb);
+
+ xhci_dbg(xhci, "Giveback cancelled URB %p\n", cur_td->urb);
+ spin_unlock(&xhci->lock);
+ /* Doesn't matter what we pass for status, since the core will
+ * just overwrite it (because the URB has been unlinked).
+ */
+ usb_hcd_giveback_urb(xhci_to_hcd(xhci), cur_td->urb, 0);
+ kfree(cur_td);
+
+ spin_lock(&xhci->lock);
+ } while (cur_td != last_unlinked_td);
+
+ /* Return to the event handler with xhci->lock re-acquired */
+}
+
+/*
+ * 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;
+
+ 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->ep_rings[ep_index];
+
+ 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 = dev->out_ctx->ep[ep_index].ep_info;
+ ep_state &= EP_STATE_MASK;
+ slot_state = dev->out_ctx->slot.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[0] = 0x%x, "
+ "deq[1] = 0x%x.\n",
+ dev->out_ctx->ep[ep_index].deq[0],
+ dev->out_ctx->ep[ep_index].deq[1]);
+ }
+
+ ep_ring->state &= ~SET_DEQ_PENDING;
+ ring_ep_doorbell(xhci, slot_id, ep_index);
+}
+
+
+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;
+
+ cmd_dma = (((u64) event->cmd_trb[1]) << 32) + event->cmd_trb[0];
+ 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) {
+ xhci->error_bitmask |= 1 << 4;
+ return;
+ }
+ /* Does the DMA address match our internal dequeue pointer address? */
+ if (cmd_dma != (u64) cmd_dequeue_dma) {
+ xhci->error_bitmask |= 1 << 5;
+ return;
+ }
+ switch (xhci->cmd_ring->dequeue->generic.field[3] & TRB_TYPE_BITMASK) {
+ case TRB_TYPE(TRB_ENABLE_SLOT):
+ if (GET_COMP_CODE(event->status) == COMP_SUCCESS)
+ xhci->slot_id = slot_id;
+ else
+ xhci->slot_id = 0;
+ complete(&xhci->addr_dev);
+ break;
+ case TRB_TYPE(TRB_DISABLE_SLOT):
+ if (xhci->devs[slot_id])
+ xhci_free_virt_device(xhci, slot_id);
+ break;
+ case TRB_TYPE(TRB_CONFIG_EP):
+ 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;
+ default:
+ /* Skip over unknown commands on the event ring */
+ xhci->error_bitmask |= 1 << 6;
+ break;
+ }
+ inc_deq(xhci, xhci->cmd_ring, false);
+}
+
+static void handle_port_status(struct xhci_hcd *xhci,
+ union xhci_trb *event)
+{
+ u32 port_id;
+
+ /* Port status change events always have a successful completion code */
+ if (GET_COMP_CODE(event->generic.field[2]) != COMP_SUCCESS) {
+ xhci_warn(xhci, "WARN: xHC returned failed port status event\n");
+ xhci->error_bitmask |= 1 << 8;
+ }
+ /* FIXME: core doesn't care about all port link state changes yet */
+ port_id = GET_PORT_ID(event->generic.field[0]);
+ xhci_dbg(xhci, "Port Status Change Event for port %d\n", port_id);
+
+ /* Update event ring dequeue pointer before dropping the lock */
+ inc_deq(xhci, xhci->event_ring, true);
+ xhci_set_hc_event_deq(xhci);
+
+ spin_unlock(&xhci->lock);
+ /* Pass this up to the core */
+ usb_hcd_poll_rh_status(xhci_to_hcd(xhci));
+ spin_lock(&xhci->lock);
+}
+
+/*
+ * 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.
+ */
+static 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 {
+ /* 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,
+ &start_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 (1);
+
+}
+
+/*
+ * 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_ring *ep_ring;
+ 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;
+
+ xdev = xhci->devs[TRB_TO_SLOT_ID(event->flags)];
+ 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;
+ ep_ring = xdev->ep_rings[ep_index];
+ if (!ep_ring || (xdev->out_ctx->ep[ep_index].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[0];
+ if (event->buffer[1] != 0)
+ xhci_warn(xhci, "WARN ignoring upper 32-bits of 64-bit TRB dma address\n");
+
+ /* This TRB should be in the TD at the head of this ring's TD list */
+ 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;
+ }
+ td = list_entry(ep_ring->td_list.next, struct xhci_td, td_list);
+
+ /* Is this a TRB in the currently executing TD? */
+ event_seg = trb_in_td(ep_ring->deq_seg, ep_ring->dequeue,
+ td->last_trb, event_dma);
+ 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[0]) = 0x%x\n",
+ (unsigned int) event->buffer[0]);
+ xhci_dbg(xhci, "Offset 0x04 (buffer[0]) = 0x%x\n",
+ (unsigned int) event->buffer[1]);
+ 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 */
+ switch (GET_COMP_CODE(event->transfer_len)) {
+ /* 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");
+ status = -EPIPE;
+ break;
+ case COMP_TRB_ERR:
+ xhci_warn(xhci, "WARN: TRB error on endpoint\n");
+ status = -EILSEQ;
+ break;
+ case COMP_TX_ERR:
+ xhci_warn(xhci, "WARN: transfer error on endpoint\n");
+ status = -EPROTO;
+ break;
+ case COMP_DB_ERR:
+ xhci_warn(xhci, "WARN: HC couldn't access mem fast enough\n");
+ status = -ENOSR;
+ break;
+ default:
+ 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 (GET_COMP_CODE(event->transfer_len)) {
+ 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");
+ status = -EREMOTEIO;
+ break;
+ default:
+ /* Others already handled above */
+ break;
+ }
+ /*
+ * 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) {
+ td->urb->actual_length =
+ td->urb->transfer_buffer_length;
+ } else {
+ /* Maybe the event was for the data stage? */
+ if (GET_COMP_CODE(event->transfer_len) != 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);
+ }
+ }
+ } else {
+ switch (GET_COMP_CODE(event->transfer_len)) {
+ 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 {
+ xhci_dbg(xhci, "Successful bulk 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->actual_length < 0) {
+ 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;
+ } else {
+ td->urb->actual_length = td->urb->transfer_buffer_length;
+ /* Ignore a short packet completion if the
+ * untransferred length was zero.
+ */
+ 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 (GET_COMP_CODE(event->transfer_len) != COMP_STOP_INVAL)
+ td->urb->actual_length +=
+ TRB_LEN(cur_trb->generic.field[2]) -
+ TRB_LEN(event->transfer_len);
+ }
+ }
+ /* 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.
+ */
+ if (GET_COMP_CODE(event->transfer_len) == COMP_STOP_INVAL ||
+ GET_COMP_CODE(event->transfer_len) == COMP_STOP) {
+ ep_ring->stopped_td = td;
+ ep_ring->stopped_trb = 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);
+
+ /* Clean up the endpoint's TD list */
+ urb = td->urb;
+ 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);
+ ep_ring->cancels_pending--;
+ }
+ 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);
+ 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 xhci_handle_event(struct xhci_hcd *xhci)
+{
+ union xhci_trb *event;
+ int update_ptrs = 1;
+ int ret;
+
+ if (!xhci->event_ring || !xhci->event_ring->dequeue) {
+ xhci->error_bitmask |= 1 << 1;
+ return;
+ }
+
+ event = xhci->event_ring->dequeue;
+ /* Does the HC or OS own the TRB? */
+ if ((event->event_cmd.flags & TRB_CYCLE) !=
+ xhci->event_ring->cycle_state) {
+ xhci->error_bitmask |= 1 << 2;
+ return;
+ }
+
+ /* FIXME: Handle more event types. */
+ switch ((event->event_cmd.flags & TRB_TYPE_BITMASK)) {
+ case TRB_TYPE(TRB_COMPLETION):
+ handle_cmd_completion(xhci, &event->event_cmd);
+ break;
+ case TRB_TYPE(TRB_PORT_STATUS):
+ handle_port_status(xhci, event);
+ update_ptrs = 0;
+ break;
+ case TRB_TYPE(TRB_TRANSFER):
+ ret = handle_tx_event(xhci, &event->trans_event);
+ if (ret < 0)
+ xhci->error_bitmask |= 1 << 9;
+ else
+ update_ptrs = 0;
+ break;
+ default:
+ xhci->error_bitmask |= 1 << 3;
+ }
+
+ if (update_ptrs) {
+ /* Update SW and HC event ring dequeue pointer */
+ inc_deq(xhci, xhci->event_ring, true);
+ xhci_set_hc_event_deq(xhci);
+ }
+ /* Are there more items on the event ring? */
+ 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.
+ */
+static void queue_trb(struct xhci_hcd *xhci, struct xhci_ring *ring,
+ bool consumer,
+ u32 field1, u32 field2, u32 field3, u32 field4)
+{
+ struct xhci_generic_trb *trb;
+
+ trb = &ring->enqueue->generic;
+ trb->field[0] = field1;
+ trb->field[1] = field2;
+ trb->field[2] = field3;
+ trb->field[3] = field4;
+ inc_enq(xhci, ring, consumer);
+}
+
+/*
+ * 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)
+{
+ /* 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_HALTED:
+ case EP_STATE_ERROR:
+ xhci_warn(xhci, "WARN waiting for halt or 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_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;
+
+ ret = prepare_ring(xhci, xdev->ep_rings[ep_index],
+ xdev->out_ctx->ep[ep_index].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->ep_rings[ep_index]->td_list);
+ (*td)->start_seg = xdev->ep_rings[ep_index]->enq_seg;
+ (*td)->first_trb = xdev->ep_rings[ep_index]->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);
+}
+
+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]->ep_rings[ep_index];
+ 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;
+
+ /* 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);
+ }
+ queue_trb(xhci, ep_ring, false,
+ (u32) addr,
+ (u32) ((u64) addr >> 32),
+ TRB_LEN(trb_buff_len) | TRB_INTR_TARGET(0),
+ /* 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;
+
+ int running_total, trb_buff_len, ret;
+ u64 addr;
+
+ if (urb->sg)
+ return queue_bulk_sg_tx(xhci, mem_flags, urb, slot_id, ep_index);
+
+ ep_ring = xhci->devs[slot_id]->ep_rings[ep_index];
+
+ 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 {
+ 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;
+ }
+ queue_trb(xhci, ep_ring, false,
+ (u32) addr,
+ (u32) ((u64) addr >> 32),
+ TRB_LEN(trb_buff_len) | TRB_INTR_TARGET(0),
+ /* 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;
+ struct xhci_td *td;
+
+ ep_ring = xhci->devs[slot_id]->ep_rings[ep_index];
+
+ /*
+ * 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;
+ 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),
+ TRB_LEN(urb->transfer_buffer_length) | TRB_INTR_TARGET(0),
+ /* 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 */
+static int queue_command(struct xhci_hcd *xhci, u32 field1, u32 field2, u32 field3, u32 field4)
+{
+ if (!room_on_ring(xhci, xhci->cmd_ring, 1)) {
+ if (!in_interrupt())
+ xhci_err(xhci, "ERR: No room for command on command ring\n");
+ return -ENOMEM;
+ }
+ queue_trb(xhci, xhci->cmd_ring, false, field1, field2, field3,
+ field4 | xhci->cmd_ring->cycle_state);
+ return 0;
+}
+
+/* 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));
+}
+
+/*
+ * Place a no-op command on the command ring to test the command and
+ * event ring.
+ */
+void *xhci_setup_one_noop(struct xhci_hcd *xhci)
+{
+ if (queue_cmd_noop(xhci) < 0)
+ return NULL;
+ xhci->noops_submitted++;
+ return xhci_ring_cmd_db;
+}
+
+/* Queue a slot enable or disable request on the command ring */
+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));
+}
+
+/* Queue an address device command TRB */
+int xhci_queue_address_device(struct xhci_hcd *xhci, dma_addr_t in_ctx_ptr,
+ u32 slot_id)
+{
+ return queue_command(xhci, in_ctx_ptr, 0, 0,
+ TRB_TYPE(TRB_ADDR_DEV) | SLOT_ID_FOR_TRB(slot_id));
+}
+
+/* Queue a configure endpoint command TRB */
+int xhci_queue_configure_endpoint(struct xhci_hcd *xhci, dma_addr_t in_ctx_ptr,
+ u32 slot_id)
+{
+ return queue_command(xhci, in_ctx_ptr, 0, 0,
+ TRB_TYPE(TRB_CONFIG_EP) | SLOT_ID_FOR_TRB(slot_id));
+}
+
+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);
+}
+
+/* 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 queue_command(xhci, (u32) addr | cycle_state, 0, 0,
+ trb_slot_id | trb_ep_index | type);
+}