5 files changed, 387 insertions, 34 deletions

diff --git a/drivers/thunderbolt/lc.c b/drivers/thunderbolt/lc.c
index df56523eb822..bd44d50246d2 100644
--- a/drivers/thunderbolt/lc.c
+++ b/drivers/thunderbolt/lc.c
@@ -205,3 +205,164 @@ bool tb_lc_lane_bonding_possible(struct tb_switch *sw)
 
 	return !!(val & TB_LC_PORT_ATTR_BE);
 }
+
+static int tb_lc_dp_sink_from_port(const struct tb_switch *sw,
+				   struct tb_port *in)
+{
+	struct tb_port *port;
+
+	/* The first DP IN port is sink 0 and second is sink 1 */
+	tb_switch_for_each_port(sw, port) {
+		if (tb_port_is_dpin(port))
+			return in != port;
+	}
+
+	return -EINVAL;
+}
+
+static int tb_lc_dp_sink_available(struct tb_switch *sw, int sink)
+{
+	u32 val, alloc;
+	int ret;
+
+	ret = tb_sw_read(sw, &val, TB_CFG_SWITCH,
+			 sw->cap_lc + TB_LC_SNK_ALLOCATION, 1);
+	if (ret)
+		return ret;
+
+	/*
+	 * Sink is available for CM/SW to use if the allocation valie is
+	 * either 0 or 1.
+	 */
+	if (!sink) {
+		alloc = val & TB_LC_SNK_ALLOCATION_SNK0_MASK;
+		if (!alloc || alloc == TB_LC_SNK_ALLOCATION_SNK0_CM)
+			return 0;
+	} else {
+		alloc = (val & TB_LC_SNK_ALLOCATION_SNK1_MASK) >>
+			TB_LC_SNK_ALLOCATION_SNK1_SHIFT;
+		if (!alloc || alloc == TB_LC_SNK_ALLOCATION_SNK1_CM)
+			return 0;
+	}
+
+	return -EBUSY;
+}
+
+/**
+ * tb_lc_dp_sink_query() - Is DP sink available for DP IN port
+ * @sw: Switch whose DP sink is queried
+ * @in: DP IN port to check
+ *
+ * Queries through LC SNK_ALLOCATION registers whether DP sink is available
+ * for the given DP IN port or not.
+ */
+bool tb_lc_dp_sink_query(struct tb_switch *sw, struct tb_port *in)
+{
+	int sink;
+
+	/*
+	 * For older generations sink is always available as there is no
+	 * allocation mechanism.
+	 */
+	if (sw->generation < 3)
+		return true;
+
+	sink = tb_lc_dp_sink_from_port(sw, in);
+	if (sink < 0)
+		return false;
+
+	return !tb_lc_dp_sink_available(sw, sink);
+}
+
+/**
+ * tb_lc_dp_sink_alloc() - Allocate DP sink
+ * @sw: Switch whose DP sink is allocated
+ * @in: DP IN port the DP sink is allocated for
+ *
+ * Allocate DP sink for @in via LC SNK_ALLOCATION registers. If the
+ * resource is available and allocation is successful returns %0. In all
+ * other cases returs negative errno. In particular %-EBUSY is returned if
+ * the resource was not available.
+ */
+int tb_lc_dp_sink_alloc(struct tb_switch *sw, struct tb_port *in)
+{
+	int ret, sink;
+	u32 val;
+
+	if (sw->generation < 3)
+		return 0;
+
+	sink = tb_lc_dp_sink_from_port(sw, in);
+	if (sink < 0)
+		return sink;
+
+	ret = tb_lc_dp_sink_available(sw, sink);
+	if (ret)
+		return ret;
+
+	ret = tb_sw_read(sw, &val, TB_CFG_SWITCH,
+			 sw->cap_lc + TB_LC_SNK_ALLOCATION, 1);
+	if (ret)
+		return ret;
+
+	if (!sink) {
+		val &= ~TB_LC_SNK_ALLOCATION_SNK0_MASK;
+		val |= TB_LC_SNK_ALLOCATION_SNK0_CM;
+	} else {
+		val &= ~TB_LC_SNK_ALLOCATION_SNK1_MASK;
+		val |= TB_LC_SNK_ALLOCATION_SNK1_CM <<
+			TB_LC_SNK_ALLOCATION_SNK1_SHIFT;
+	}
+
+	ret = tb_sw_write(sw, &val, TB_CFG_SWITCH,
+			  sw->cap_lc + TB_LC_SNK_ALLOCATION, 1);
+
+	if (ret)
+		return ret;
+
+	tb_port_dbg(in, "sink %d allocated\n", sink);
+	return 0;
+}
+
+/**
+ * tb_lc_dp_sink_dealloc() - De-allocate DP sink
+ * @sw: Switch whose DP sink is de-allocated
+ * @in: DP IN port whose DP sink is de-allocated
+ *
+ * De-allocate DP sink from @in using LC SNK_ALLOCATION registers.
+ */
+int tb_lc_dp_sink_dealloc(struct tb_switch *sw, struct tb_port *in)
+{
+	int ret, sink;
+	u32 val;
+
+	if (sw->generation < 3)
+		return 0;
+
+	sink = tb_lc_dp_sink_from_port(sw, in);
+	if (sink < 0)
+		return sink;
+
+	/* Needs to be owned by CM/SW */
+	ret = tb_lc_dp_sink_available(sw, sink);
+	if (ret)
+		return ret;
+
+	ret = tb_sw_read(sw, &val, TB_CFG_SWITCH,
+			 sw->cap_lc + TB_LC_SNK_ALLOCATION, 1);
+	if (ret)
+		return ret;
+
+	if (!sink)
+		val &= ~TB_LC_SNK_ALLOCATION_SNK0_MASK;
+	else
+		val &= ~TB_LC_SNK_ALLOCATION_SNK1_MASK;
+
+	ret = tb_sw_write(sw, &val, TB_CFG_SWITCH,
+			  sw->cap_lc + TB_LC_SNK_ALLOCATION, 1);
+	if (ret)
+		return ret;
+
+	tb_port_dbg(in, "sink %d de-allocated\n", sink);
+	return 0;
+}
diff --git a/drivers/thunderbolt/switch.c b/drivers/thunderbolt/switch.c
index 205045caabdc..3f477df2730a 100644
--- a/drivers/thunderbolt/switch.c
+++ b/drivers/thunderbolt/switch.c
@@ -645,6 +645,7 @@ static int tb_init_port(struct tb_port *port)
 		ida_init(&port->out_hopids);
 	}
 
+	INIT_LIST_HEAD(&port->list);
 	return 0;
 
 }
@@ -2333,6 +2334,49 @@ void tb_switch_suspend(struct tb_switch *sw)
 	tb_lc_set_sleep(sw);
 }
 
+/**
+ * tb_switch_query_dp_resource() - Query availability of DP resource
+ * @sw: Switch whose DP resource is queried
+ * @in: DP IN port
+ *
+ * Queries availability of DP resource for DP tunneling using switch
+ * specific means. Returns %true if resource is available.
+ */
+bool tb_switch_query_dp_resource(struct tb_switch *sw, struct tb_port *in)
+{
+	return tb_lc_dp_sink_query(sw, in);
+}
+
+/**
+ * tb_switch_alloc_dp_resource() - Allocate available DP resource
+ * @sw: Switch whose DP resource is allocated
+ * @in: DP IN port
+ *
+ * Allocates DP resource for DP tunneling. The resource must be
+ * available for this to succeed (see tb_switch_query_dp_resource()).
+ * Returns %0 in success and negative errno otherwise.
+ */
+int tb_switch_alloc_dp_resource(struct tb_switch *sw, struct tb_port *in)
+{
+	return tb_lc_dp_sink_alloc(sw, in);
+}
+
+/**
+ * tb_switch_dealloc_dp_resource() - De-allocate DP resource
+ * @sw: Switch whose DP resource is de-allocated
+ * @in: DP IN port
+ *
+ * De-allocates DP resource that was previously allocated for DP
+ * tunneling.
+ */
+void tb_switch_dealloc_dp_resource(struct tb_switch *sw, struct tb_port *in)
+{
+	if (tb_lc_dp_sink_dealloc(sw, in)) {
+		tb_sw_warn(sw, "failed to de-allocate DP resource for port %d\n",
+			   in->port);
+	}
+}
+
 struct tb_sw_lookup {
 	struct tb *tb;
 	u8 link;
diff --git a/drivers/thunderbolt/tb.c b/drivers/thunderbolt/tb.c
index c24b577e049e..8f58b9c3ef07 100644
--- a/drivers/thunderbolt/tb.c
+++ b/drivers/thunderbolt/tb.c
@@ -18,6 +18,7 @@
 /**
  * struct tb_cm - Simple Thunderbolt connection manager
  * @tunnel_list: List of active tunnels
+ * @dp_resources: List of available DP resources for DP tunneling
  * @hotplug_active: tb_handle_hotplug will stop progressing plug
  *		    events and exit if this is not set (it needs to
  *		    acquire the lock one more time). Used to drain wq
@@ -25,6 +26,7 @@
  */
 struct tb_cm {
 	struct list_head tunnel_list;
+	struct list_head dp_resources;
 	bool hotplug_active;
 };
 
@@ -56,6 +58,42 @@ static void tb_queue_hotplug(struct tb *tb, u64 route, u8 port, bool unplug)
 
 /* enumeration & hot plug handling */
 
+static void tb_add_dp_resources(struct tb_switch *sw)
+{
+	struct tb_cm *tcm = tb_priv(sw->tb);
+	struct tb_port *port;
+
+	tb_switch_for_each_port(sw, port) {
+		if (!tb_port_is_dpin(port))
+			continue;
+
+		if (!tb_switch_query_dp_resource(sw, port))
+			continue;
+
+		list_add_tail(&port->list, &tcm->dp_resources);
+		tb_port_dbg(port, "DP IN resource available\n");
+	}
+}
+
+static void tb_remove_dp_resources(struct tb_switch *sw)
+{
+	struct tb_cm *tcm = tb_priv(sw->tb);
+	struct tb_port *port, *tmp;
+
+	/* Clear children resources first */
+	tb_switch_for_each_port(sw, port) {
+		if (tb_port_has_remote(port))
+			tb_remove_dp_resources(port->remote->sw);
+	}
+
+	list_for_each_entry_safe(port, tmp, &tcm->dp_resources, list) {
+		if (port->sw == sw) {
+			tb_port_dbg(port, "DP OUT resource unavailable\n");
+			list_del_init(&port->list);
+		}
+	}
+}
+
 static void tb_discover_tunnels(struct tb_switch *sw)
 {
 	struct tb *tb = sw->tb;
@@ -223,8 +261,9 @@ static void tb_scan_port(struct tb_port *port)
 	tb_scan_switch(sw);
 }
 
-static int tb_free_tunnel(struct tb *tb, enum tb_tunnel_type type,
-			  struct tb_port *src_port, struct tb_port *dst_port)
+static struct tb_tunnel *tb_find_tunnel(struct tb *tb, enum tb_tunnel_type type,
+					struct tb_port *src_port,
+					struct tb_port *dst_port)
 {
 	struct tb_cm *tcm = tb_priv(tb);
 	struct tb_tunnel *tunnel;
@@ -233,14 +272,32 @@ static int tb_free_tunnel(struct tb *tb, enum tb_tunnel_type type,
 		if (tunnel->type == type &&
 		    ((src_port && src_port == tunnel->src_port) ||
 		     (dst_port && dst_port == tunnel->dst_port))) {
-			tb_tunnel_deactivate(tunnel);
-			list_del(&tunnel->list);
-			tb_tunnel_free(tunnel);
-			return 0;
+			return tunnel;
 		}
 	}
 
-	return -ENODEV;
+	return NULL;
+}
+
+static void tb_deactivate_and_free_tunnel(struct tb_tunnel *tunnel)
+{
+	if (!tunnel)
+		return;
+
+	tb_tunnel_deactivate(tunnel);
+	list_del(&tunnel->list);
+
+	/*
+	 * In case of DP tunnel make sure the DP IN resource is deallocated
+	 * properly.
+	 */
+	if (tb_tunnel_is_dp(tunnel)) {
+		struct tb_port *in = tunnel->src_port;
+
+		tb_switch_dealloc_dp_resource(in->sw, in);
+	}
+
+	tb_tunnel_free(tunnel);
 }
 
 /**
@@ -253,11 +310,8 @@ static void tb_free_invalid_tunnels(struct tb *tb)
 	struct tb_tunnel *n;
 
 	list_for_each_entry_safe(tunnel, n, &tcm->tunnel_list, list) {
-		if (tb_tunnel_is_invalid(tunnel)) {
-			tb_tunnel_deactivate(tunnel);
-			list_del(&tunnel->list);
-			tb_tunnel_free(tunnel);
-		}
+		if (tb_tunnel_is_invalid(tunnel))
+			tb_deactivate_and_free_tunnel(tunnel);
 	}
 }
 
@@ -273,6 +327,7 @@ static void tb_free_unplugged_children(struct tb_switch *sw)
 			continue;
 
 		if (port->remote->sw->is_unplugged) {
+			tb_remove_dp_resources(port->remote->sw);
 			tb_switch_lane_bonding_disable(port->remote->sw);
 			tb_switch_remove(port->remote->sw);
 			port->remote = NULL;
@@ -367,42 +422,112 @@ out:
 	return tb_find_unused_port(sw, TB_TYPE_PCIE_DOWN);
 }
 
-static int tb_tunnel_dp(struct tb *tb, struct tb_port *out)
+static void tb_tunnel_dp(struct tb *tb)
 {
 	struct tb_cm *tcm = tb_priv(tb);
-	struct tb_switch *sw = out->sw;
+	struct tb_port *port, *in, *out;
 	struct tb_tunnel *tunnel;
-	struct tb_port *in;
 
-	if (tb_port_is_enabled(out))
-		return 0;
+	/*
+	 * Find pair of inactive DP IN and DP OUT adapters and then
+	 * establish a DP tunnel between them.
+	 */
+	tb_dbg(tb, "looking for DP IN <-> DP OUT pairs:\n");
+
+	in = NULL;
+	out = NULL;
+	list_for_each_entry(port, &tcm->dp_resources, list) {
+		if (tb_port_is_enabled(port)) {
+			tb_port_dbg(port, "in use\n");
+			continue;
+		}
 
-	do {
-		sw = tb_to_switch(sw->dev.parent);
-		if (!sw)
-			return 0;
-		in = tb_find_unused_port(sw, TB_TYPE_DP_HDMI_IN);
-	} while (!in);
+		tb_port_dbg(port, "available\n");
+
+		if (!in && tb_port_is_dpin(port))
+			in = port;
+		else if (!out && tb_port_is_dpout(port))
+			out = port;
+	}
+
+	if (!in) {
+		tb_dbg(tb, "no suitable DP IN adapter available, not tunneling\n");
+		return;
+	}
+	if (!out) {
+		tb_dbg(tb, "no suitable DP OUT adapter available, not tunneling\n");
+		return;
+	}
+
+	if (tb_switch_alloc_dp_resource(in->sw, in)) {
+		tb_port_dbg(in, "no resource available for DP IN, not tunneling\n");
+		return;
+	}
 
 	tunnel = tb_tunnel_alloc_dp(tb, in, out);
 	if (!tunnel) {
-		tb_port_dbg(out, "DP tunnel allocation failed\n");
-		return -ENOMEM;
+		tb_port_dbg(out, "could not allocate DP tunnel\n");
+		goto dealloc_dp;
 	}
 
 	if (tb_tunnel_activate(tunnel)) {
 		tb_port_info(out, "DP tunnel activation failed, aborting\n");
 		tb_tunnel_free(tunnel);
-		return -EIO;
+		goto dealloc_dp;
 	}
 
 	list_add_tail(&tunnel->list, &tcm->tunnel_list);
-	return 0;
+	return;
+
+dealloc_dp:
+	tb_switch_dealloc_dp_resource(in->sw, in);
 }
 
-static void tb_teardown_dp(struct tb *tb, struct tb_port *out)
+static void tb_dp_resource_unavailable(struct tb *tb, struct tb_port *port)
 {
-	tb_free_tunnel(tb, TB_TUNNEL_DP, NULL, out);
+	struct tb_port *in, *out;
+	struct tb_tunnel *tunnel;
+
+	if (tb_port_is_dpin(port)) {
+		tb_port_dbg(port, "DP IN resource unavailable\n");
+		in = port;
+		out = NULL;
+	} else {
+		tb_port_dbg(port, "DP OUT resource unavailable\n");
+		in = NULL;
+		out = port;
+	}
+
+	tunnel = tb_find_tunnel(tb, TB_TUNNEL_DP, in, out);
+	tb_deactivate_and_free_tunnel(tunnel);
+	list_del_init(&port->list);
+
+	/*
+	 * See if there is another DP OUT port that can be used for
+	 * to create another tunnel.
+	 */
+	tb_tunnel_dp(tb);
+}
+
+static void tb_dp_resource_available(struct tb *tb, struct tb_port *port)
+{
+	struct tb_cm *tcm = tb_priv(tb);
+	struct tb_port *p;
+
+	if (tb_port_is_enabled(port))
+		return;
+
+	list_for_each_entry(p, &tcm->dp_resources, list) {
+		if (p == port)
+			return;
+	}
+
+	tb_port_dbg(port, "DP %s resource available\n",
+		    tb_port_is_dpin(port) ? "IN" : "OUT");
+	list_add_tail(&port->list, &tcm->dp_resources);
+
+	/* Look for suitable DP IN <-> DP OUT pairs now */
+	tb_tunnel_dp(tb);
 }
 
 static int tb_tunnel_pci(struct tb *tb, struct tb_switch *sw)
@@ -477,6 +602,7 @@ static int tb_approve_xdomain_paths(struct tb *tb, struct tb_xdomain *xd)
 static void __tb_disconnect_xdomain_paths(struct tb *tb, struct tb_xdomain *xd)
 {
 	struct tb_port *dst_port;
+	struct tb_tunnel *tunnel;
 	struct tb_switch *sw;
 
 	sw = tb_to_switch(xd->dev.parent);
@@ -487,7 +613,8 @@ static void __tb_disconnect_xdomain_paths(struct tb *tb, struct tb_xdomain *xd)
 	 * case of cable disconnect) so it is fine if we cannot find it
 	 * here anymore.
 	 */
-	tb_free_tunnel(tb, TB_TUNNEL_DMA, NULL, dst_port);
+	tunnel = tb_find_tunnel(tb, TB_TUNNEL_DMA, NULL, dst_port);
+	tb_deactivate_and_free_tunnel(tunnel);
 }
 
 static int tb_disconnect_xdomain_paths(struct tb *tb, struct tb_xdomain *xd)
@@ -542,11 +669,14 @@ static void tb_handle_hotplug(struct work_struct *work)
 			tb_port_dbg(port, "switch unplugged\n");
 			tb_sw_set_unplugged(port->remote->sw);
 			tb_free_invalid_tunnels(tb);
+			tb_remove_dp_resources(port->remote->sw);
 			tb_switch_lane_bonding_disable(port->remote->sw);
 			tb_switch_remove(port->remote->sw);
 			port->remote = NULL;
 			if (port->dual_link_port)
 				port->dual_link_port->remote = NULL;
+			/* Maybe we can create another DP tunnel */
+			tb_tunnel_dp(tb);
 		} else if (port->xdomain) {
 			struct tb_xdomain *xd = tb_xdomain_get(port->xdomain);
 
@@ -563,8 +693,8 @@ static void tb_handle_hotplug(struct work_struct *work)
 			port->xdomain = NULL;
 			__tb_disconnect_xdomain_paths(tb, xd);
 			tb_xdomain_put(xd);
-		} else if (tb_port_is_dpout(port)) {
-			tb_teardown_dp(tb, port);
+		} else if (tb_port_is_dpout(port) || tb_port_is_dpin(port)) {
+			tb_dp_resource_unavailable(tb, port);
 		} else {
 			tb_port_dbg(port,
 				   "got unplug event for disconnected port, ignoring\n");
@@ -577,8 +707,8 @@ static void tb_handle_hotplug(struct work_struct *work)
 			tb_scan_port(port);
 			if (!port->remote)
 				tb_port_dbg(port, "hotplug: no switch found\n");
-		} else if (tb_port_is_dpout(port)) {
-			tb_tunnel_dp(tb, port);
+		} else if (tb_port_is_dpout(port) || tb_port_is_dpin(port)) {
+			tb_dp_resource_available(tb, port);
 		}
 	}
 
@@ -691,6 +821,8 @@ static int tb_start(struct tb *tb)
 	tb_scan_switch(tb->root_switch);
 	/* Find out tunnels created by the boot firmware */
 	tb_discover_tunnels(tb->root_switch);
+	/* Add DP IN resources for the root switch */
+	tb_add_dp_resources(tb->root_switch);
 	/* Make the discovered switches available to the userspace */
 	device_for_each_child(&tb->root_switch->dev, NULL,
 			      tb_scan_finalize_switch);
@@ -820,6 +952,7 @@ struct tb *tb_probe(struct tb_nhi *nhi)
 
 	tcm = tb_priv(tb);
 	INIT_LIST_HEAD(&tcm->tunnel_list);
+	INIT_LIST_HEAD(&tcm->dp_resources);
 
 	return tb;
 }
diff --git a/drivers/thunderbolt/tb.h b/drivers/thunderbolt/tb.h
index 3d7b2202d248..5311e6e3f3df 100644
--- a/drivers/thunderbolt/tb.h
+++ b/drivers/thunderbolt/tb.h
@@ -137,6 +137,7 @@ struct tb_switch {
  * @link_nr: Is this primary or secondary port on the dual_link.
  * @in_hopids: Currently allocated input HopIDs
  * @out_hopids: Currently allocated output HopIDs
+ * @list: Used to link ports to DP resources list
  */
 struct tb_port {
 	struct tb_regs_port_header config;
@@ -152,6 +153,7 @@ struct tb_port {
 	u8 link_nr:1;
 	struct ida in_hopids;
 	struct ida out_hopids;
+	struct list_head list;
 };
 
 /**
@@ -650,6 +652,10 @@ static inline bool tb_switch_is_icm(const struct tb_switch *sw)
 int tb_switch_lane_bonding_enable(struct tb_switch *sw);
 void tb_switch_lane_bonding_disable(struct tb_switch *sw);
 
+bool tb_switch_query_dp_resource(struct tb_switch *sw, struct tb_port *in);
+int tb_switch_alloc_dp_resource(struct tb_switch *sw, struct tb_port *in);
+void tb_switch_dealloc_dp_resource(struct tb_switch *sw, struct tb_port *in);
+
 int tb_wait_for_port(struct tb_port *port, bool wait_if_unplugged);
 int tb_port_add_nfc_credits(struct tb_port *port, int credits);
 int tb_port_set_initial_credits(struct tb_port *port, u32 credits);
@@ -694,6 +700,9 @@ int tb_lc_configure_link(struct tb_switch *sw);
 void tb_lc_unconfigure_link(struct tb_switch *sw);
 int tb_lc_set_sleep(struct tb_switch *sw);
 bool tb_lc_lane_bonding_possible(struct tb_switch *sw);
+bool tb_lc_dp_sink_query(struct tb_switch *sw, struct tb_port *in);
+int tb_lc_dp_sink_alloc(struct tb_switch *sw, struct tb_port *in);
+int tb_lc_dp_sink_dealloc(struct tb_switch *sw, struct tb_port *in);
 
 static inline int tb_route_length(u64 route)
 {
diff --git a/drivers/thunderbolt/tb_regs.h b/drivers/thunderbolt/tb_regs.h
index 8d11b4a2d552..aec35e61cc14 100644
--- a/drivers/thunderbolt/tb_regs.h
+++ b/drivers/thunderbolt/tb_regs.h
@@ -295,6 +295,12 @@ struct tb_regs_hop {
 #define TB_LC_DESC_PORT_SIZE_SHIFT	16
 #define TB_LC_DESC_PORT_SIZE_MASK	GENMASK(27, 16)
 #define TB_LC_FUSE			0x03
+#define TB_LC_SNK_ALLOCATION		0x10
+#define TB_LC_SNK_ALLOCATION_SNK0_MASK	GENMASK(3, 0)
+#define TB_LC_SNK_ALLOCATION_SNK0_CM	0x1
+#define TB_LC_SNK_ALLOCATION_SNK1_SHIFT	4
+#define TB_LC_SNK_ALLOCATION_SNK1_MASK	GENMASK(7, 4)
+#define TB_LC_SNK_ALLOCATION_SNK1_CM	0x1
 
 /* Link controller registers */
 #define TB_LC_PORT_ATTR			0x8d