thunderbolt: Allow multiple DMA tunnels over a single XDomain connection

Currently we have had an artificial limitation of a single DMA tunnel
per XDomain connection. However, hardware wise there is no such limit
and software based connection manager can take advantage of all the DMA
rings available on the host to establish tunnels.

For this reason make the tb_xdomain_[enable|disable]_paths() to take the
DMA ring and HopID as parameter instead of storing them in the struct
tb_xdomain. We also add API functions to allocate input and output
HopIDs of the XDomain connection that the service drivers can use
instead of hard-coding.

Also convert the two existing service drivers over to this API.

Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com>

1 files changed, 71 insertions, 11 deletions

diff --git a/drivers/thunderbolt/tunnel.c b/drivers/thunderbolt/tunnel.c
index 2e7ec037a73e..e1979bed7146 100644
--- a/drivers/thunderbolt/tunnel.c
+++ b/drivers/thunderbolt/tunnel.c
@@ -815,28 +815,28 @@ static void tb_dma_init_path(struct tb_path *path, unsigned int efc, u32 credits
  * @tb: Pointer to the domain structure
  * @nhi: Host controller port
  * @dst: Destination null port which the other domain is connected to
- * @transmit_ring: NHI ring number used to send packets towards the
- *		   other domain. Set to %0 if TX path is not needed.
  * @transmit_path: HopID used for transmitting packets
- * @receive_ring: NHI ring number used to receive packets from the
- *		  other domain. Set to %0 if RX path is not needed.
+ * @transmit_ring: NHI ring number used to send packets towards the
+ *		   other domain. Set to %-1 if TX path is not needed.
  * @receive_path: HopID used for receiving packets
+ * @receive_ring: NHI ring number used to receive packets from the
+ *		  other domain. Set to %-1 if RX path is not needed.
  *
  * Return: Returns a tb_tunnel on success or NULL on failure.
  */
 struct tb_tunnel *tb_tunnel_alloc_dma(struct tb *tb, struct tb_port *nhi,
-				      struct tb_port *dst, int transmit_ring,
-				      int transmit_path, int receive_ring,
-				      int receive_path)
+				      struct tb_port *dst, int transmit_path,
+				      int transmit_ring, int receive_path,
+				      int receive_ring)
 {
 	struct tb_tunnel *tunnel;
 	size_t npaths = 0, i = 0;
 	struct tb_path *path;
 	u32 credits;
 
-	if (receive_ring)
+	if (receive_ring > 0)
 		npaths++;
-	if (transmit_ring)
+	if (transmit_ring > 0)
 		npaths++;
 
 	if (WARN_ON(!npaths))
@@ -851,7 +851,7 @@ struct tb_tunnel *tb_tunnel_alloc_dma(struct tb *tb, struct tb_port *nhi,
 
 	credits = tb_dma_credits(nhi);
 
-	if (receive_ring) {
+	if (receive_ring > 0) {
 		path = tb_path_alloc(tb, dst, receive_path, nhi, receive_ring, 0,
 				     "DMA RX");
 		if (!path) {
@@ -862,7 +862,7 @@ struct tb_tunnel *tb_tunnel_alloc_dma(struct tb *tb, struct tb_port *nhi,
 		tunnel->paths[i++] = path;
 	}
 
-	if (transmit_ring) {
+	if (transmit_ring > 0) {
 		path = tb_path_alloc(tb, nhi, transmit_ring, dst, transmit_path, 0,
 				     "DMA TX");
 		if (!path) {
@@ -876,6 +876,66 @@ struct tb_tunnel *tb_tunnel_alloc_dma(struct tb *tb, struct tb_port *nhi,
 	return tunnel;
 }
 
+/**
+ * tb_tunnel_match_dma() - Match DMA tunnel
+ * @tunnel: Tunnel to match
+ * @transmit_path: HopID used for transmitting packets. Pass %-1 to ignore.
+ * @transmit_ring: NHI ring number used to send packets towards the
+ *		   other domain. Pass %-1 to ignore.
+ * @receive_path: HopID used for receiving packets. Pass %-1 to ignore.
+ * @receive_ring: NHI ring number used to receive packets from the
+ *		  other domain. Pass %-1 to ignore.
+ *
+ * This function can be used to match specific DMA tunnel, if there are
+ * multiple DMA tunnels going through the same XDomain connection.
+ * Returns true if there is match and false otherwise.
+ */
+bool tb_tunnel_match_dma(const struct tb_tunnel *tunnel, int transmit_path,
+			 int transmit_ring, int receive_path, int receive_ring)
+{
+	const struct tb_path *tx_path = NULL, *rx_path = NULL;
+	int i;
+
+	if (!receive_ring || !transmit_ring)
+		return false;
+
+	for (i = 0; i < tunnel->npaths; i++) {
+		const struct tb_path *path = tunnel->paths[i];
+
+		if (!path)
+			continue;
+
+		if (tb_port_is_nhi(path->hops[0].in_port))
+			tx_path = path;
+		else if (tb_port_is_nhi(path->hops[path->path_length - 1].out_port))
+			rx_path = path;
+	}
+
+	if (transmit_ring > 0 || transmit_path > 0) {
+		if (!tx_path)
+			return false;
+		if (transmit_ring > 0 &&
+		    (tx_path->hops[0].in_hop_index != transmit_ring))
+			return false;
+		if (transmit_path > 0 &&
+		    (tx_path->hops[tx_path->path_length - 1].next_hop_index != transmit_path))
+			return false;
+	}
+
+	if (receive_ring > 0 || receive_path > 0) {
+		if (!rx_path)
+			return false;
+		if (receive_path > 0 &&
+		    (rx_path->hops[0].in_hop_index != receive_path))
+			return false;
+		if (receive_ring > 0 &&
+		    (rx_path->hops[rx_path->path_length - 1].next_hop_index != receive_ring))
+			return false;
+	}
+
+	return true;
+}
+
 static int tb_usb3_max_link_rate(struct tb_port *up, struct tb_port *down)
 {
 	int ret, up_max_rate, down_max_rate;