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, 38 insertions, 11 deletions

diff --git a/drivers/net/thunderbolt.c b/drivers/net/thunderbolt.c
index ed3743dc62b9..5c9ec91b6e78 100644
--- a/drivers/net/thunderbolt.c
+++ b/drivers/net/thunderbolt.c
@@ -28,7 +28,6 @@
 #define TBNET_LOGOUT_TIMEOUT	100
 
 #define TBNET_RING_SIZE		256
-#define TBNET_LOCAL_PATH	0xf
 #define TBNET_LOGIN_RETRIES	60
 #define TBNET_LOGOUT_RETRIES	5
 #define TBNET_MATCH_FRAGS_ID	BIT(1)
@@ -154,8 +153,8 @@ struct tbnet_ring {
  * @login_sent: ThunderboltIP login message successfully sent
  * @login_received: ThunderboltIP login message received from the remote
  *		    host
- * @transmit_path: HopID the other end needs to use building the
- *		   opposite side path.
+ * @local_transmit_path: HopID we are using to send out packets
+ * @remote_transmit_path: HopID the other end is using to send packets to us
  * @connection_lock: Lock serializing access to @login_sent,
  *		     @login_received and @transmit_path.
  * @login_retries: Number of login retries currently done
@@ -184,7 +183,8 @@ struct tbnet {
 	atomic_t command_id;
 	bool login_sent;
 	bool login_received;
-	u32 transmit_path;
+	int local_transmit_path;
+	int remote_transmit_path;
 	struct mutex connection_lock;
 	int login_retries;
 	struct delayed_work login_work;
@@ -257,7 +257,7 @@ static int tbnet_login_request(struct tbnet *net, u8 sequence)
 			  atomic_inc_return(&net->command_id));
 
 	request.proto_version = TBIP_LOGIN_PROTO_VERSION;
-	request.transmit_path = TBNET_LOCAL_PATH;
+	request.transmit_path = net->local_transmit_path;
 
 	return tb_xdomain_request(xd, &request, sizeof(request),
 				  TB_CFG_PKG_XDOMAIN_RESP, &reply,
@@ -364,10 +364,10 @@ static void tbnet_tear_down(struct tbnet *net, bool send_logout)
 	mutex_lock(&net->connection_lock);
 
 	if (net->login_sent && net->login_received) {
-		int retries = TBNET_LOGOUT_RETRIES;
+		int ret, retries = TBNET_LOGOUT_RETRIES;
 
 		while (send_logout && retries-- > 0) {
-			int ret = tbnet_logout_request(net);
+			ret = tbnet_logout_request(net);
 			if (ret != -ETIMEDOUT)
 				break;
 		}
@@ -377,8 +377,16 @@ static void tbnet_tear_down(struct tbnet *net, bool send_logout)
 		tbnet_free_buffers(&net->rx_ring);
 		tbnet_free_buffers(&net->tx_ring);
 
-		if (tb_xdomain_disable_paths(net->xd))
+		ret = tb_xdomain_disable_paths(net->xd,
+					       net->local_transmit_path,
+					       net->rx_ring.ring->hop,
+					       net->remote_transmit_path,
+					       net->tx_ring.ring->hop);
+		if (ret)
 			netdev_warn(net->dev, "failed to disable DMA paths\n");
+
+		tb_xdomain_release_in_hopid(net->xd, net->remote_transmit_path);
+		net->remote_transmit_path = 0;
 	}
 
 	net->login_retries = 0;
@@ -424,7 +432,7 @@ static int tbnet_handle_packet(const void *buf, size_t size, void *data)
 		if (!ret) {
 			mutex_lock(&net->connection_lock);
 			net->login_received = true;
-			net->transmit_path = pkg->transmit_path;
+			net->remote_transmit_path = pkg->transmit_path;
 
 			/* If we reached the number of max retries or
 			 * previous logout, schedule another round of
@@ -597,12 +605,18 @@ static void tbnet_connected_work(struct work_struct *work)
 	if (!connected)
 		return;
 
+	ret = tb_xdomain_alloc_in_hopid(net->xd, net->remote_transmit_path);
+	if (ret != net->remote_transmit_path) {
+		netdev_err(net->dev, "failed to allocate Rx HopID\n");
+		return;
+	}
+
 	/* Both logins successful so enable the high-speed DMA paths and
 	 * start the network device queue.
 	 */
-	ret = tb_xdomain_enable_paths(net->xd, TBNET_LOCAL_PATH,
+	ret = tb_xdomain_enable_paths(net->xd, net->local_transmit_path,
 				      net->rx_ring.ring->hop,
-				      net->transmit_path,
+				      net->remote_transmit_path,
 				      net->tx_ring.ring->hop);
 	if (ret) {
 		netdev_err(net->dev, "failed to enable DMA paths\n");
@@ -629,6 +643,7 @@ err_free_rx_buffers:
 err_stop_rings:
 	tb_ring_stop(net->rx_ring.ring);
 	tb_ring_stop(net->tx_ring.ring);
+	tb_xdomain_release_in_hopid(net->xd, net->remote_transmit_path);
 }
 
 static void tbnet_login_work(struct work_struct *work)
@@ -851,6 +866,7 @@ static int tbnet_open(struct net_device *dev)
 	struct tb_xdomain *xd = net->xd;
 	u16 sof_mask, eof_mask;
 	struct tb_ring *ring;
+	int hopid;
 
 	netif_carrier_off(dev);
 
@@ -862,6 +878,15 @@ static int tbnet_open(struct net_device *dev)
 	}
 	net->tx_ring.ring = ring;
 
+	hopid = tb_xdomain_alloc_out_hopid(xd, -1);
+	if (hopid < 0) {
+		netdev_err(dev, "failed to allocate Tx HopID\n");
+		tb_ring_free(net->tx_ring.ring);
+		net->tx_ring.ring = NULL;
+		return hopid;
+	}
+	net->local_transmit_path = hopid;
+
 	sof_mask = BIT(TBIP_PDF_FRAME_START);
 	eof_mask = BIT(TBIP_PDF_FRAME_END);
 
@@ -893,6 +918,8 @@ static int tbnet_stop(struct net_device *dev)
 
 	tb_ring_free(net->rx_ring.ring);
 	net->rx_ring.ring = NULL;
+
+	tb_xdomain_release_out_hopid(net->xd, net->local_transmit_path);
 	tb_ring_free(net->tx_ring.ring);
 	net->tx_ring.ring = NULL;