xHCI: set cycle state when allocate rings

In the past all the rings were allocated with cycle state equal to 1.
Now the driver may expand an existing ring, and the new segments shall be
allocated with the same cycle state as the old one.

This affects ring allocation and cached ring re-initialization.

Signed-off-by: Andiry Xu <andiry.xu@amd.com>
Signed-off-by: Sarah Sharp <sarah.a.sharp@linux.intel.com>
Tested-by: Paul Zimmerman <Paul.Zimmerman@synopsys.com>

drivers/usb/host/xhci-mem.c

@@ -34,10 +34,12 @@
  * Section 4.11.1.1:
  * "All components of all Command and Transfer TRBs shall be initialized to '0'"
  */
-static struct xhci_segment *xhci_segment_alloc(struct xhci_hcd *xhci, gfp_t flags)
+static struct xhci_segment *xhci_segment_alloc(struct xhci_hcd *xhci,
+					unsigned int cycle_state, gfp_t flags)
 {
 	struct xhci_segment *seg;
 	dma_addr_t	dma;
+	int		i;
 
 	seg = kzalloc(sizeof *seg, flags);
 	if (!seg)
@@ -50,6 +52,11 @@ static struct xhci_segment *xhci_segment_alloc(struct xhci_hcd *xhci, gfp_t flag
 	}
 
 	memset(seg->trbs, 0, SEGMENT_SIZE);
+	/* If the cycle state is 0, set the cycle bit to 1 for all the TRBs */
+	if (cycle_state == 0) {
+		for (i = 0; i < TRBS_PER_SEGMENT; i++)
+			seg->trbs[i].link.control |= TRB_CYCLE;
+	}
 	seg->dma = dma;
 	seg->next = NULL;
 
@@ -124,7 +131,8 @@ void xhci_ring_free(struct xhci_hcd *xhci, struct xhci_ring *ring)
 	kfree(ring);
 }
 
-static void xhci_initialize_ring_info(struct xhci_ring *ring)
+static void xhci_initialize_ring_info(struct xhci_ring *ring,
+					unsigned int cycle_state)
 {
 	/* The ring is empty, so the enqueue pointer == dequeue pointer */
 	ring->enqueue = ring->first_seg->trbs;
@@ -134,8 +142,11 @@ static void xhci_initialize_ring_info(struct xhci_ring *ring)
 	/* The ring is initialized to 0. The producer must write 1 to the cycle
 	 * bit to handover ownership of the TRB, so PCS = 1.  The consumer must
 	 * compare CCS to the cycle bit to check ownership, so CCS = 1.
+	 *
+	 * New rings are initialized with cycle state equal to 1; if we are
+	 * handling ring expansion, set the cycle state equal to the old ring.
 	 */
-	ring->cycle_state = 1;
+	ring->cycle_state = cycle_state;
 	/* Not necessary for new rings, but needed for re-initialized rings */
 	ring->enq_updates = 0;
 	ring->deq_updates = 0;
@@ -150,11 +161,12 @@ static void xhci_initialize_ring_info(struct xhci_ring *ring)
 /* Allocate segments and link them for a ring */
 static int xhci_alloc_segments_for_ring(struct xhci_hcd *xhci,
 		struct xhci_segment **first, struct xhci_segment **last,
-		unsigned int num_segs, enum xhci_ring_type type, gfp_t flags)
+		unsigned int num_segs, unsigned int cycle_state,
+		enum xhci_ring_type type, gfp_t flags)
 {
 	struct xhci_segment *prev;
 
-	prev = xhci_segment_alloc(xhci, flags);
+	prev = xhci_segment_alloc(xhci, cycle_state, flags);
 	if (!prev)
 		return -ENOMEM;
 	num_segs--;
@@ -163,7 +175,7 @@ static int xhci_alloc_segments_for_ring(struct xhci_hcd *xhci,
 	while (num_segs > 0) {
 		struct xhci_segment	*next;
 
-		next = xhci_segment_alloc(xhci, flags);
+		next = xhci_segment_alloc(xhci, cycle_state, flags);
 		if (!next) {
 			xhci_free_segments_for_ring(xhci, *first);
 			return -ENOMEM;
@@ -187,7 +199,8 @@ static int xhci_alloc_segments_for_ring(struct xhci_hcd *xhci,
  * See section 4.9.1 and figures 15 and 16.
  */
 static struct xhci_ring *xhci_ring_alloc(struct xhci_hcd *xhci,
-		unsigned int num_segs, enum xhci_ring_type type, gfp_t flags)
+		unsigned int num_segs, unsigned int cycle_state,
+		enum xhci_ring_type type, gfp_t flags)
 {
 	struct xhci_ring	*ring;
 	int ret;
@@ -203,7 +216,7 @@ static struct xhci_ring *xhci_ring_alloc(struct xhci_hcd *xhci,
 		return ring;
 
 	ret = xhci_alloc_segments_for_ring(xhci, &ring->first_seg,
-			&ring->last_seg, num_segs, type, flags);
+			&ring->last_seg, num_segs, cycle_state, type, flags);
 	if (ret)
 		goto fail;
 
@@ -213,7 +226,7 @@ static struct xhci_ring *xhci_ring_alloc(struct xhci_hcd *xhci,
 		ring->last_seg->trbs[TRBS_PER_SEGMENT - 1].link.control |=
 			cpu_to_le32(LINK_TOGGLE);
 	}
-	xhci_initialize_ring_info(ring);
+	xhci_initialize_ring_info(ring, cycle_state);
 	return ring;
 
 fail:
@@ -249,18 +262,25 @@ void xhci_free_or_cache_endpoint_ring(struct xhci_hcd *xhci,
  * pointers to the beginning of the ring.
  */
 static void xhci_reinit_cached_ring(struct xhci_hcd *xhci,
-			struct xhci_ring *ring, enum xhci_ring_type type)
+			struct xhci_ring *ring, unsigned int cycle_state,
+			enum xhci_ring_type type)
 {
 	struct xhci_segment	*seg = ring->first_seg;
+	int i;
+
 	do {
 		memset(seg->trbs, 0,
 				sizeof(union xhci_trb)*TRBS_PER_SEGMENT);
+		if (cycle_state == 0) {
+			for (i = 0; i < TRBS_PER_SEGMENT; i++)
+				seg->trbs[i].link.control |= TRB_CYCLE;
+		}
 		/* All endpoint rings have link TRBs */
 		xhci_link_segments(xhci, seg, seg->next, type);
 		seg = seg->next;
 	} while (seg != ring->first_seg);
 	ring->type = type;
-	xhci_initialize_ring_info(ring);
+	xhci_initialize_ring_info(ring, cycle_state);
 	/* td list should be empty since all URBs have been cancelled,
 	 * but just in case...
 	 */
@@ -561,7 +581,7 @@ struct xhci_stream_info *xhci_alloc_stream_info(struct xhci_hcd *xhci,
 	 */
 	for (cur_stream = 1; cur_stream < num_streams; cur_stream++) {
 		stream_info->stream_rings[cur_stream] =
-			xhci_ring_alloc(xhci, 1, TYPE_STREAM, mem_flags);
+			xhci_ring_alloc(xhci, 1, 1, TYPE_STREAM, mem_flags);
 		cur_ring = stream_info->stream_rings[cur_stream];
 		if (!cur_ring)
 			goto cleanup_rings;
@@ -895,7 +915,7 @@ int xhci_alloc_virt_device(struct xhci_hcd *xhci, int slot_id,
 	}
 
 	/* Allocate endpoint 0 ring */
-	dev->eps[0].ring = xhci_ring_alloc(xhci, 1, TYPE_CTRL, flags);
+	dev->eps[0].ring = xhci_ring_alloc(xhci, 1, 1, TYPE_CTRL, flags);
 	if (!dev->eps[0].ring)
 		goto fail;
 
@@ -1349,10 +1369,10 @@ int xhci_endpoint_init(struct xhci_hcd *xhci,
 	 */
 	if (usb_endpoint_xfer_isoc(&ep->desc))
 		virt_dev->eps[ep_index].new_ring =
-			xhci_ring_alloc(xhci, 8, type, mem_flags);
+			xhci_ring_alloc(xhci, 8, 1, type, mem_flags);
 	else
 		virt_dev->eps[ep_index].new_ring =
-			xhci_ring_alloc(xhci, 1, type, mem_flags);
+			xhci_ring_alloc(xhci, 1, 1, type, mem_flags);
 	if (!virt_dev->eps[ep_index].new_ring) {
 		/* Attempt to use the ring cache */
 		if (virt_dev->num_rings_cached == 0)
@@ -1362,7 +1382,7 @@ int xhci_endpoint_init(struct xhci_hcd *xhci,
 		virt_dev->ring_cache[virt_dev->num_rings_cached] = NULL;
 		virt_dev->num_rings_cached--;
 		xhci_reinit_cached_ring(xhci, virt_dev->eps[ep_index].new_ring,
-					type);
+					1, type);
 	}
 	virt_dev->eps[ep_index].skip = false;
 	ep_ring = virt_dev->eps[ep_index].new_ring;
@@ -2270,7 +2290,7 @@ int xhci_mem_init(struct xhci_hcd *xhci, gfp_t flags)
 		goto fail;
 
 	/* Set up the command ring to have one segments for now. */
-	xhci->cmd_ring = xhci_ring_alloc(xhci, 1, TYPE_COMMAND, flags);
+	xhci->cmd_ring = xhci_ring_alloc(xhci, 1, 1, TYPE_COMMAND, flags);
 	if (!xhci->cmd_ring)
 		goto fail;
 	xhci_dbg(xhci, "Allocated command ring at %p\n", xhci->cmd_ring);
@@ -2301,7 +2321,7 @@ int xhci_mem_init(struct xhci_hcd *xhci, gfp_t flags)
 	 * the event ring segment table (ERST).  Section 4.9.3.
 	 */
 	xhci_dbg(xhci, "// Allocating event ring\n");
-	xhci->event_ring = xhci_ring_alloc(xhci, ERST_NUM_SEGS, TYPE_EVENT,
+	xhci->event_ring = xhci_ring_alloc(xhci, ERST_NUM_SEGS, 1, TYPE_EVENT,
 						flags);
 	if (!xhci->event_ring)
 		goto fail;