diff options
Diffstat (limited to 'drivers/usb/host/xhci-ring.c')
-rw-r--r-- | drivers/usb/host/xhci-ring.c | 491 |
1 files changed, 458 insertions, 33 deletions
diff --git a/drivers/usb/host/xhci-ring.c b/drivers/usb/host/xhci-ring.c index c948288042e2..f967a6df83c7 100644 --- a/drivers/usb/host/xhci-ring.c +++ b/drivers/usb/host/xhci-ring.c @@ -112,6 +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. @@ -250,6 +267,344 @@ 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_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; +} + +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 = 0x%x (0x%x dma); " + "in seg 0x%x (0x%x dma)\n", + (unsigned int) cur_trb, + trb_virt_to_dma(cur_seg, cur_trb), + (unsigned int) cur_seg, + 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 0x%x (0x%x dma) " + "in seg 0x%x (0x%x dma)\n", + (unsigned int) cur_trb, + trb_virt_to_dma(cur_seg, cur_trb), + (unsigned int) cur_seg, + 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 0x%x, 0x%x (dma).\n", + (unsigned int) cur_td->first_trb, + 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 = 0x%x (0x%x dma), " + "new deq ptr = 0x%x (0x%x dma), new cycle = %u\n", + (unsigned int) deq_state.new_deq_seg, + deq_state.new_deq_seg->dma, + (unsigned int) deq_state.new_deq_ptr, + 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; + 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 0x%x\n", + (unsigned int) 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) { @@ -290,6 +645,12 @@ static void handle_cmd_completion(struct xhci_hcd *xhci, 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; @@ -346,11 +707,9 @@ static struct xhci_segment *trb_in_td( cur_seg = start_seg; do { - /* - * Last TRB is a link TRB (unless we start inserting links in - * the middle, FIXME if you do) - */ - end_seg_dma = trb_virt_to_dma(cur_seg, &start_seg->trbs[TRBS_PER_SEGMENT - 2]); + /* We may get an event for a Link TRB in the middle of a TD */ + end_seg_dma = 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 = trb_virt_to_dma(cur_seg, end_trb); @@ -396,7 +755,7 @@ static int handle_tx_event(struct xhci_hcd *xhci, dma_addr_t event_dma; struct xhci_segment *event_seg; union xhci_trb *event_trb; - struct urb *urb; + struct urb *urb = 0; int status = -EINPROGRESS; xdev = xhci->devs[TRB_TO_SLOT_ID(event->flags)]; @@ -457,6 +816,12 @@ static int handle_tx_event(struct xhci_hcd *xhci, 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; @@ -510,11 +875,15 @@ static int handle_tx_event(struct xhci_hcd *xhci, 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; + td->urb->actual_length = + td->urb->transfer_buffer_length; } else { - /* The event was for the data stage */ - td->urb->actual_length = td->urb->transfer_buffer_length - - TRB_LEN(event->transfer_len); + /* 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 { @@ -573,29 +942,55 @@ static int handle_tx_event(struct xhci_hcd *xhci, status = 0; } } else { - /* Slow path - walk the list, starting from the first - * TRB to get the actual length transferred + /* 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; - while (ep_ring->dequeue != event_trb) { - td->urb->actual_length += TRB_LEN(ep_ring->dequeue->generic.field[2]); - inc_deq(xhci, ep_ring, false); + 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]); } - td->urb->actual_length += TRB_LEN(ep_ring->dequeue->generic.field[2]) - - TRB_LEN(event->transfer_len); - + /* 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); } } - /* Update ring dequeue pointer */ - while (ep_ring->dequeue != td->last_trb) + /* 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); - inc_deq(xhci, ep_ring, false); - /* Clean up the endpoint's TD list */ - urb = td->urb; - list_del(&td->td_list); - kfree(td); - urb->hcpriv = NULL; + /* 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); set_hc_event_deq(xhci); @@ -744,6 +1139,7 @@ int xhci_prepare_transfer(struct xhci_hcd *xhci, 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)) { @@ -755,6 +1151,8 @@ int xhci_prepare_transfer(struct xhci_hcd *xhci, 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; } @@ -823,19 +1221,13 @@ 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) { - u32 field; - /* * Pass all the TRBs to the hardware at once and make sure this write * isn't reordered. */ wmb(); start_trb->field[3] |= start_cycle; - field = xhci_readl(xhci, &xhci->dba->doorbell[slot_id]) & DB_MASK; - xhci_writel(xhci, field | EPI_TO_DB(ep_index), - &xhci->dba->doorbell[slot_id]); - /* Flush PCI posted writes */ - xhci_readl(xhci, &xhci->dba->doorbell[slot_id]); + ring_ep_doorbell(xhci, slot_id, ep_index); } int queue_bulk_sg_tx(struct xhci_hcd *xhci, gfp_t mem_flags, @@ -1221,3 +1613,36 @@ int queue_configure_endpoint(struct xhci_hcd *xhci, dma_addr_t in_ctx_ptr, u32 s return queue_command(xhci, in_ctx_ptr, 0, 0, TRB_TYPE(TRB_CONFIG_EP) | SLOT_ID_FOR_TRB(slot_id)); } + +int 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 = 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 = 0x%x, deq pt = 0x%x\n", + (unsigned int) deq_seg, + (unsigned int) deq_ptr); + return queue_command(xhci, (u32) addr | cycle_state, 0, 0, + trb_slot_id | trb_ep_index | type); +} |