xhci: remove obsolete dequeue pointer moving code

xhci_find_new_dequeue_state() and xhci_queue_new_dequeue_state() are no
longer used afer introducing the move_dequeue_past_td() function.

also remove struct xhci_dequeue_state as its no longer used.
Signed-off-by: NMathias Nyman <mathias.nyman@linux.intel.com>
Link: https://lore.kernel.org/r/20210129130044.206855-26-mathias.nyman@linux.intel.comSigned-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/usb/host/xhci-ring.c

@@ -551,123 +551,6 @@ static u64 xhci_get_hw_deq(struct xhci_hcd *xhci, struct xhci_virt_device *vdev,
 	return le64_to_cpu(ep_ctx->deq);
 }
 
-/*
- * 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, stream id, 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.
- *
- * Some of the uses of xhci_generic_trb are grotty, but if they're done
- * with correct __le32 accesses they should work fine.  Only users of this are
- * in here.
- */
-void xhci_find_new_dequeue_state(struct xhci_hcd *xhci,
-		unsigned int slot_id, unsigned int ep_index,
-		unsigned int stream_id, struct xhci_td *cur_td,
-		struct xhci_dequeue_state *state)
-{
-	struct xhci_virt_device *dev = xhci->devs[slot_id];
-	struct xhci_virt_ep *ep = &dev->eps[ep_index];
-	struct xhci_ring *ep_ring;
-	struct xhci_segment *new_seg;
-	union xhci_trb *new_deq;
-	dma_addr_t addr;
-	u64 hw_dequeue;
-	bool cycle_found = false;
-	bool td_last_trb_found = false;
-
-	ep_ring = xhci_triad_to_transfer_ring(xhci, slot_id,
-			ep_index, stream_id);
-	if (!ep_ring) {
-		xhci_warn(xhci, "WARN can't find new dequeue state "
-				"for invalid stream ID %u.\n",
-				stream_id);
-		return;
-	}
-	/*
-	 * A cancelled TD can complete with a stall if HW cached the trb.
-	 * In this case driver can't find cur_td, but if the ring is empty we
-	 * can move the dequeue pointer to the current enqueue position.
-	 */
-	if (!cur_td) {
-		if (list_empty(&ep_ring->td_list)) {
-			state->new_deq_seg = ep_ring->enq_seg;
-			state->new_deq_ptr = ep_ring->enqueue;
-			state->new_cycle_state = ep_ring->cycle_state;
-			goto done;
-		} else {
-			xhci_warn(xhci, "Can't find new dequeue state, missing cur_td\n");
-			return;
-		}
-	}
-
-	/* Dig out the cycle state saved by the xHC during the stop ep cmd */
-	xhci_dbg_trace(xhci, trace_xhci_dbg_cancel_urb,
-			"Finding endpoint context");
-
-	hw_dequeue = xhci_get_hw_deq(xhci, dev, ep_index, stream_id);
-	new_seg = ep_ring->deq_seg;
-	new_deq = ep_ring->dequeue;
-	state->new_cycle_state = hw_dequeue & 0x1;
-	state->stream_id = stream_id;
-
-	/*
-	 * We want to find the pointer, segment and cycle state of the new trb
-	 * (the one after current TD's last_trb). We know the cycle state at
-	 * hw_dequeue, so walk the ring until both hw_dequeue and last_trb are
-	 * found.
-	 */
-	do {
-		if (!cycle_found && xhci_trb_virt_to_dma(new_seg, new_deq)
-		    == (dma_addr_t)(hw_dequeue & ~0xf)) {
-			cycle_found = true;
-			if (td_last_trb_found)
-				break;
-		}
-		if (new_deq == cur_td->last_trb)
-			td_last_trb_found = true;
-
-		if (cycle_found && trb_is_link(new_deq) &&
-		    link_trb_toggles_cycle(new_deq))
-			state->new_cycle_state ^= 0x1;
-
-		next_trb(xhci, ep_ring, &new_seg, &new_deq);
-
-		/* Search wrapped around, bail out */
-		if (new_deq == ep->ring->dequeue) {
-			xhci_err(xhci, "Error: Failed finding new dequeue state\n");
-			state->new_deq_seg = NULL;
-			state->new_deq_ptr = NULL;
-			return;
-		}
-
-	} while (!cycle_found || !td_last_trb_found);
-
-	state->new_deq_seg = new_seg;
-	state->new_deq_ptr = new_deq;
-
-done:
-	/* Don't update the ring cycle state for the producer (us). */
-	xhci_dbg_trace(xhci, trace_xhci_dbg_cancel_urb,
-			"Cycle state = 0x%x", state->new_cycle_state);
-
-	xhci_dbg_trace(xhci, trace_xhci_dbg_cancel_urb,
-			"New dequeue segment = %p (virtual)",
-			state->new_deq_seg);
-	addr = xhci_trb_virt_to_dma(state->new_deq_seg, state->new_deq_ptr);
-	xhci_dbg_trace(xhci, trace_xhci_dbg_cancel_urb,
-			"New dequeue pointer = 0x%llx (DMA)",
-			(unsigned long long) addr);
-}
-
 static int xhci_move_dequeue_past_td(struct xhci_hcd *xhci,
 				unsigned int slot_id, unsigned int ep_index,
 				unsigned int stream_id, struct xhci_td *td)
@@ -4418,71 +4301,6 @@ int xhci_queue_stop_endpoint(struct xhci_hcd *xhci, struct xhci_command *cmd,
 			trb_slot_id | trb_ep_index | type | trb_suspend, false);
 }
 
-/* Set Transfer Ring Dequeue Pointer command */
-void xhci_queue_new_dequeue_state(struct xhci_hcd *xhci,
-		unsigned int slot_id, unsigned int ep_index,
-		struct xhci_dequeue_state *deq_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 trb_stream_id = STREAM_ID_FOR_TRB(deq_state->stream_id);
-	u32 trb_sct = 0;
-	u32 type = TRB_TYPE(TRB_SET_DEQ);
-	struct xhci_virt_ep *ep;
-	struct xhci_command *cmd;
-	int ret;
-
-	xhci_dbg_trace(xhci, trace_xhci_dbg_cancel_urb,
-		"Set TR Deq Ptr cmd, new deq seg = %p (0x%llx dma), new deq ptr = %p (0x%llx dma), new cycle = %u",
-		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);
-
-	addr = xhci_trb_virt_to_dma(deq_state->new_deq_seg,
-				    deq_state->new_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_state->new_deq_seg, deq_state->new_deq_ptr);
-		return;
-	}
-	ep = &xhci->devs[slot_id]->eps[ep_index];
-	if ((ep->ep_state & SET_DEQ_PENDING)) {
-		xhci_warn(xhci, "WARN Cannot submit Set TR Deq Ptr\n");
-		xhci_warn(xhci, "A Set TR Deq Ptr command is pending.\n");
-		return;
-	}
-
-	/* This function gets called from contexts where it cannot sleep */
-	cmd = xhci_alloc_command(xhci, false, GFP_ATOMIC);
-	if (!cmd)
-		return;
-
-	ep->queued_deq_seg = deq_state->new_deq_seg;
-	ep->queued_deq_ptr = deq_state->new_deq_ptr;
-	if (deq_state->stream_id)
-		trb_sct = SCT_FOR_TRB(SCT_PRI_TR);
-	ret = queue_command(xhci, cmd,
-		lower_32_bits(addr) | trb_sct | deq_state->new_cycle_state,
-		upper_32_bits(addr), trb_stream_id,
-		trb_slot_id | trb_ep_index | type, false);
-	if (ret < 0) {
-		xhci_free_command(xhci, cmd);
-		return;
-	}
-
-	/* 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;
-}
-
 int xhci_queue_reset_ep(struct xhci_hcd *xhci, struct xhci_command *cmd,
 			int slot_id, unsigned int ep_index,
 			enum xhci_ep_reset_type reset_type)

drivers/usb/host/xhci.h

@@ -1571,13 +1571,6 @@ struct xhci_cd {
 	union xhci_trb		*cmd_trb;
 };
 
-struct xhci_dequeue_state {
-	struct xhci_segment *new_deq_seg;
-	union xhci_trb *new_deq_ptr;
-	int new_cycle_state;
-	unsigned int stream_id;
-};
-
 enum xhci_ring_type {
 	TYPE_CTRL = 0,
 	TYPE_ISOC,
@@ -2132,13 +2125,6 @@ int xhci_queue_reset_ep(struct xhci_hcd *xhci, struct xhci_command *cmd,
 		enum xhci_ep_reset_type reset_type);
 int xhci_queue_reset_device(struct xhci_hcd *xhci, struct xhci_command *cmd,
 		u32 slot_id);
-void xhci_find_new_dequeue_state(struct xhci_hcd *xhci,
-		unsigned int slot_id, unsigned int ep_index,
-		unsigned int stream_id, struct xhci_td *cur_td,
-		struct xhci_dequeue_state *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);
 void xhci_cleanup_stalled_ring(struct xhci_hcd *xhci, unsigned int slot_id,
 			       unsigned int ep_index, unsigned int stream_id,
 			       struct xhci_td *td);