Merge tag 'thunderbolt-for-v6.3-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/westeri/thunderbolt into usb-next

Mika writes:

thunderbolt: Changes for v6.3 merge window

This includes following Thunderbolt/USB4 changes for the v6.3 merge
window:

  - Add support for DisplayPort bandwidth allocation mode
  - Debug logging improvements
  - Minor cleanups.

All these have been in linux-next with no reported issues.

* tag 'thunderbolt-for-v6.3-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/westeri/thunderbolt:
  thunderbolt: Add missing kernel-doc comment to tb_tunnel_maximum_bandwidth()
  thunderbolt: Handle bandwidth allocation mode enablement notification
  thunderbolt: Add support for DisplayPort bandwidth allocation mode
  thunderbolt: Include the additional DP IN double word in debugfs dump
  thunderbolt: Add functions to support DisplayPort bandwidth allocation mode
  thunderbolt: Increase timeout of DP OUT adapter handshake
  thunderbolt: Take CL states into account when waiting for link to come up
  thunderbolt: Improve debug logging in tb_available_bandwidth()
  thunderbolt: Log DP adapter type
  thunderbolt: Use decimal port number in control and tunnel logs too
  thunderbolt: Refactor tb_acpi_add_link()
  thunderbolt: Use correct type in tb_port_is_clx_enabled() prototype

12 files changed, 1710 insertions, 94 deletions

diff --git a/drivers/thunderbolt/acpi.c b/drivers/thunderbolt/acpi.c
index 317e4f5fdb979..628225deb8fef 100644
--- a/drivers/thunderbolt/acpi.c
+++ b/drivers/thunderbolt/acpi.c
@@ -36,16 +36,13 @@ static acpi_status tb_acpi_add_link(acpi_handle handle, u32 level, void *data,
 	 * We need to do this because the xHCI driver might not yet be
 	 * bound so the USB3 SuperSpeed ports are not yet created.
 	 */
-	dev = acpi_get_first_physical_node(adev);
-	while (!dev) {
-		adev = acpi_dev_parent(adev);
-		if (!adev)
-			break;
+	do {
 		dev = acpi_get_first_physical_node(adev);
-	}
+		if (dev)
+			break;
 
-	if (!dev)
-		goto out_put;
+		adev = acpi_dev_parent(adev);
+	} while (adev);
 
 	/*
 	 * Check that the device is PCIe. This is because USB3
diff --git a/drivers/thunderbolt/ctl.c b/drivers/thunderbolt/ctl.c
index 0c661a706160f..6e7d28e8d81aa 100644
--- a/drivers/thunderbolt/ctl.c
+++ b/drivers/thunderbolt/ctl.c
@@ -230,7 +230,6 @@ static int check_config_address(struct tb_cfg_address addr,
 static struct tb_cfg_result decode_error(const struct ctl_pkg *response)
 {
 	struct cfg_error_pkg *pkg = response->buffer;
-	struct tb_ctl *ctl = response->ctl;
 	struct tb_cfg_result res = { 0 };
 	res.response_route = tb_cfg_get_route(&pkg->header);
 	res.response_port = 0;
@@ -239,13 +238,6 @@ static struct tb_cfg_result decode_error(const struct ctl_pkg *response)
 	if (res.err)
 		return res;
 
-	if (pkg->zero1)
-		tb_ctl_warn(ctl, "pkg->zero1 is %#x\n", pkg->zero1);
-	if (pkg->zero2)
-		tb_ctl_warn(ctl, "pkg->zero2 is %#x\n", pkg->zero2);
-	if (pkg->zero3)
-		tb_ctl_warn(ctl, "pkg->zero3 is %#x\n", pkg->zero3);
-
 	res.err = 1;
 	res.tb_error = pkg->error;
 	res.response_port = pkg->port;
@@ -416,6 +408,7 @@ static int tb_async_error(const struct ctl_pkg *pkg)
 	case TB_CFG_ERROR_LINK_ERROR:
 	case TB_CFG_ERROR_HEC_ERROR_DETECTED:
 	case TB_CFG_ERROR_FLOW_CONTROL_ERROR:
+	case TB_CFG_ERROR_DP_BW:
 		return true;
 
 	default:
@@ -736,6 +729,47 @@ void tb_ctl_stop(struct tb_ctl *ctl)
 /* public interface, commands */
 
 /**
+ * tb_cfg_ack_notification() - Ack notification
+ * @ctl: Control channel to use
+ * @route: Router that originated the event
+ * @error: Pointer to the notification package
+ *
+ * Call this as response for non-plug notification to ack it. Returns
+ * %0 on success or an error code on failure.
+ */
+int tb_cfg_ack_notification(struct tb_ctl *ctl, u64 route,
+			    const struct cfg_error_pkg *error)
+{
+	struct cfg_ack_pkg pkg = {
+		.header = tb_cfg_make_header(route),
+	};
+	const char *name;
+
+	switch (error->error) {
+	case TB_CFG_ERROR_LINK_ERROR:
+		name = "link error";
+		break;
+	case TB_CFG_ERROR_HEC_ERROR_DETECTED:
+		name = "HEC error";
+		break;
+	case TB_CFG_ERROR_FLOW_CONTROL_ERROR:
+		name = "flow control error";
+		break;
+	case TB_CFG_ERROR_DP_BW:
+		name = "DP_BW";
+		break;
+	default:
+		name = "unknown";
+		break;
+	}
+
+	tb_ctl_dbg(ctl, "acking %s (%#x) notification on %llx\n", name,
+		   error->error, route);
+
+	return tb_ctl_tx(ctl, &pkg, sizeof(pkg), TB_CFG_PKG_NOTIFY_ACK);
+}
+
+/**
  * tb_cfg_ack_plug() - Ack hot plug/unplug event
  * @ctl: Control channel to use
  * @route: Router that originated the event
@@ -754,7 +788,7 @@ int tb_cfg_ack_plug(struct tb_ctl *ctl, u64 route, u32 port, bool unplug)
 		.pg = unplug ? TB_CFG_ERROR_PG_HOT_UNPLUG
 			     : TB_CFG_ERROR_PG_HOT_PLUG,
 	};
-	tb_ctl_dbg(ctl, "acking hot %splug event on %llx:%x\n",
+	tb_ctl_dbg(ctl, "acking hot %splug event on %llx:%u\n",
 		   unplug ? "un" : "", route, port);
 	return tb_ctl_tx(ctl, &pkg, sizeof(pkg), TB_CFG_PKG_ERROR);
 }
diff --git a/drivers/thunderbolt/ctl.h b/drivers/thunderbolt/ctl.h
index 7c7d80f96c0c9..eec5c953c743c 100644
--- a/drivers/thunderbolt/ctl.h
+++ b/drivers/thunderbolt/ctl.h
@@ -122,6 +122,8 @@ static inline struct tb_cfg_header tb_cfg_make_header(u64 route)
 	return header;
 }
 
+int tb_cfg_ack_notification(struct tb_ctl *ctl, u64 route,
+			    const struct cfg_error_pkg *error);
 int tb_cfg_ack_plug(struct tb_ctl *ctl, u64 route, u32 port, bool unplug);
 struct tb_cfg_result tb_cfg_reset(struct tb_ctl *ctl, u64 route);
 struct tb_cfg_result tb_cfg_read_raw(struct tb_ctl *ctl, void *buffer,
diff --git a/drivers/thunderbolt/debugfs.c b/drivers/thunderbolt/debugfs.c
index 834bcad42e9fe..4339e706cc3a1 100644
--- a/drivers/thunderbolt/debugfs.c
+++ b/drivers/thunderbolt/debugfs.c
@@ -1159,7 +1159,10 @@ static void port_cap_show(struct tb_port *port, struct seq_file *s,
 		if (tb_port_is_pcie_down(port) || tb_port_is_pcie_up(port)) {
 			length = PORT_CAP_PCIE_LEN;
 		} else if (tb_port_is_dpin(port) || tb_port_is_dpout(port)) {
-			length = PORT_CAP_DP_LEN;
+			if (usb4_dp_port_bw_mode_supported(port))
+				length = PORT_CAP_DP_LEN + 1;
+			else
+				length = PORT_CAP_DP_LEN;
 		} else if (tb_port_is_usb3_down(port) ||
 			   tb_port_is_usb3_up(port)) {
 			length = PORT_CAP_USB3_LEN;
diff --git a/drivers/thunderbolt/switch.c b/drivers/thunderbolt/switch.c
index 363d712aa3643..e1ad1b437291f 100644
--- a/drivers/thunderbolt/switch.c
+++ b/drivers/thunderbolt/switch.c
@@ -513,36 +513,44 @@ int tb_wait_for_port(struct tb_port *port, bool wait_if_unplugged)
 
 	while (retries--) {
 		state = tb_port_state(port);
-		if (state < 0)
-			return state;
-		if (state == TB_PORT_DISABLED) {
+		switch (state) {
+		case TB_PORT_DISABLED:
 			tb_port_dbg(port, "is disabled (state: 0)\n");
 			return 0;
-		}
-		if (state == TB_PORT_UNPLUGGED) {
+
+		case TB_PORT_UNPLUGGED:
 			if (wait_if_unplugged) {
 				/* used during resume */
 				tb_port_dbg(port,
 					    "is unplugged (state: 7), retrying...\n");
 				msleep(100);
-				continue;
+				break;
 			}
 			tb_port_dbg(port, "is unplugged (state: 7)\n");
 			return 0;
-		}
-		if (state == TB_PORT_UP) {
-			tb_port_dbg(port, "is connected, link is up (state: 2)\n");
+
+		case TB_PORT_UP:
+		case TB_PORT_TX_CL0S:
+		case TB_PORT_RX_CL0S:
+		case TB_PORT_CL1:
+		case TB_PORT_CL2:
+			tb_port_dbg(port, "is connected, link is up (state: %d)\n", state);
 			return 1;
+
+		default:
+			if (state < 0)
+				return state;
+
+			/*
+			 * After plug-in the state is TB_PORT_CONNECTING. Give it some
+			 * time.
+			 */
+			tb_port_dbg(port,
+				    "is connected, link is not up (state: %d), retrying...\n",
+				    state);
+			msleep(100);
 		}
 
-		/*
-		 * After plug-in the state is TB_PORT_CONNECTING. Give it some
-		 * time.
-		 */
-		tb_port_dbg(port,
-			    "is connected, link is not up (state: %d), retrying...\n",
-			    state);
-		msleep(100);
 	}
 	tb_port_warn(port,
 		     "failed to reach state TB_PORT_UP. Ignoring port...\n");
diff --git a/drivers/thunderbolt/tb.c b/drivers/thunderbolt/tb.c
index 3f1ab30c4fb15..7bfbc9ca9ba4f 100644
--- a/drivers/thunderbolt/tb.c
+++ b/drivers/thunderbolt/tb.c
@@ -16,7 +16,8 @@
 #include "tb_regs.h"
 #include "tunnel.h"
 
-#define TB_TIMEOUT	100 /* ms */
+#define TB_TIMEOUT	100	/* ms */
+#define MAX_GROUPS	7	/* max Group_ID is 7 */
 
 /**
  * struct tb_cm - Simple Thunderbolt connection manager
@@ -28,12 +29,14 @@
  *		    after cfg has been paused.
  * @remove_work: Work used to remove any unplugged routers after
  *		 runtime resume
+ * @groups: Bandwidth groups used in this domain.
  */
 struct tb_cm {
 	struct list_head tunnel_list;
 	struct list_head dp_resources;
 	bool hotplug_active;
 	struct delayed_work remove_work;
+	struct tb_bandwidth_group groups[MAX_GROUPS];
 };
 
 static inline struct tb *tcm_to_tb(struct tb_cm *tcm)
@@ -49,6 +52,112 @@ struct tb_hotplug_event {
 	bool unplug;
 };
 
+static void tb_init_bandwidth_groups(struct tb_cm *tcm)
+{
+	int i;
+
+	for (i = 0; i < ARRAY_SIZE(tcm->groups); i++) {
+		struct tb_bandwidth_group *group = &tcm->groups[i];
+
+		group->tb = tcm_to_tb(tcm);
+		group->index = i + 1;
+		INIT_LIST_HEAD(&group->ports);
+	}
+}
+
+static void tb_bandwidth_group_attach_port(struct tb_bandwidth_group *group,
+					   struct tb_port *in)
+{
+	if (!group || WARN_ON(in->group))
+		return;
+
+	in->group = group;
+	list_add_tail(&in->group_list, &group->ports);
+
+	tb_port_dbg(in, "attached to bandwidth group %d\n", group->index);
+}
+
+static struct tb_bandwidth_group *tb_find_free_bandwidth_group(struct tb_cm *tcm)
+{
+	int i;
+
+	for (i = 0; i < ARRAY_SIZE(tcm->groups); i++) {
+		struct tb_bandwidth_group *group = &tcm->groups[i];
+
+		if (list_empty(&group->ports))
+			return group;
+	}
+
+	return NULL;
+}
+
+static struct tb_bandwidth_group *
+tb_attach_bandwidth_group(struct tb_cm *tcm, struct tb_port *in,
+			  struct tb_port *out)
+{
+	struct tb_bandwidth_group *group;
+	struct tb_tunnel *tunnel;
+
+	/*
+	 * Find all DP tunnels that go through all the same USB4 links
+	 * as this one. Because we always setup tunnels the same way we
+	 * can just check for the routers at both ends of the tunnels
+	 * and if they are the same we have a match.
+	 */
+	list_for_each_entry(tunnel, &tcm->tunnel_list, list) {
+		if (!tb_tunnel_is_dp(tunnel))
+			continue;
+
+		if (tunnel->src_port->sw == in->sw &&
+		    tunnel->dst_port->sw == out->sw) {
+			group = tunnel->src_port->group;
+			if (group) {
+				tb_bandwidth_group_attach_port(group, in);
+				return group;
+			}
+		}
+	}
+
+	/* Pick up next available group then */
+	group = tb_find_free_bandwidth_group(tcm);
+	if (group)
+		tb_bandwidth_group_attach_port(group, in);
+	else
+		tb_port_warn(in, "no available bandwidth groups\n");
+
+	return group;
+}
+
+static void tb_discover_bandwidth_group(struct tb_cm *tcm, struct tb_port *in,
+					struct tb_port *out)
+{
+	if (usb4_dp_port_bw_mode_enabled(in)) {
+		int index, i;
+
+		index = usb4_dp_port_group_id(in);
+		for (i = 0; i < ARRAY_SIZE(tcm->groups); i++) {
+			if (tcm->groups[i].index == index) {
+				tb_bandwidth_group_attach_port(&tcm->groups[i], in);
+				return;
+			}
+		}
+	}
+
+	tb_attach_bandwidth_group(tcm, in, out);
+}
+
+static void tb_detach_bandwidth_group(struct tb_port *in)
+{
+	struct tb_bandwidth_group *group = in->group;
+
+	if (group) {
+		in->group = NULL;
+		list_del_init(&in->group_list);
+
+		tb_port_dbg(in, "detached from bandwidth group %d\n", group->index);
+	}
+}
+
 static void tb_handle_hotplug(struct work_struct *work);
 
 static void tb_queue_hotplug(struct tb *tb, u64 route, u8 port, bool unplug)
@@ -193,9 +302,14 @@ static void tb_discover_tunnels(struct tb *tb)
 				parent = tb_switch_parent(parent);
 			}
 		} else if (tb_tunnel_is_dp(tunnel)) {
+			struct tb_port *in = tunnel->src_port;
+			struct tb_port *out = tunnel->dst_port;
+
 			/* Keep the domain from powering down */
-			pm_runtime_get_sync(&tunnel->src_port->sw->dev);
-			pm_runtime_get_sync(&tunnel->dst_port->sw->dev);
+			pm_runtime_get_sync(&in->sw->dev);
+			pm_runtime_get_sync(&out->sw->dev);
+
+			tb_discover_bandwidth_group(tcm, in, out);
 		}
 	}
 }
@@ -350,10 +464,13 @@ static int tb_available_bandwidth(struct tb *tb, struct tb_port *src_port,
 	struct tb_tunnel *tunnel;
 	struct tb_port *port;
 
-	tb_port_dbg(dst_port, "calculating available bandwidth\n");
+	tb_dbg(tb, "calculating available bandwidth between %llx:%u <-> %llx:%u\n",
+	       tb_route(src_port->sw), src_port->port, tb_route(dst_port->sw),
+	       dst_port->port);
 
 	tunnel = tb_find_first_usb3_tunnel(tb, src_port, dst_port);
-	if (tunnel) {
+	if (tunnel && tunnel->src_port != src_port &&
+	    tunnel->dst_port != dst_port) {
 		ret = tb_tunnel_consumed_bandwidth(tunnel, &usb3_consumed_up,
 						   &usb3_consumed_down);
 		if (ret)
@@ -387,7 +504,8 @@ static int tb_available_bandwidth(struct tb *tb, struct tb_port *src_port,
 		up_bw -= up_bw / 10;
 		down_bw = up_bw;
 
-		tb_port_dbg(port, "link total bandwidth %d Mb/s\n", up_bw);
+		tb_port_dbg(port, "link total bandwidth %d/%d Mb/s\n", up_bw,
+			    down_bw);
 
 		/*
 		 * Find all DP tunnels that cross the port and reduce
@@ -396,12 +514,24 @@ static int tb_available_bandwidth(struct tb *tb, struct tb_port *src_port,
 		list_for_each_entry(tunnel, &tcm->tunnel_list, list) {
 			int dp_consumed_up, dp_consumed_down;
 
+			if (tb_tunnel_is_invalid(tunnel))
+				continue;
+
 			if (!tb_tunnel_is_dp(tunnel))
 				continue;
 
 			if (!tb_tunnel_port_on_path(tunnel, port))
 				continue;
 
+			/*
+			 * Ignore the DP tunnel between src_port and
+			 * dst_port because it is the same tunnel and we
+			 * may be re-calculating estimated bandwidth.
+			 */
+			if (tunnel->src_port == src_port &&
+			    tunnel->dst_port == dst_port)
+				continue;
+
 			ret = tb_tunnel_consumed_bandwidth(tunnel,
 							   &dp_consumed_up,
 							   &dp_consumed_down);
@@ -762,6 +892,7 @@ static void tb_deactivate_and_free_tunnel(struct tb_tunnel *tunnel)
 
 	switch (tunnel->type) {
 	case TB_TUNNEL_DP:
+		tb_detach_bandwidth_group(src_port);
 		/*
 		 * In case of DP tunnel make sure the DP IN resource is
 		 * deallocated properly.
@@ -879,6 +1010,99 @@ out:
 	return tb_find_unused_port(sw, TB_TYPE_PCIE_DOWN);
 }
 
+static void
+tb_recalc_estimated_bandwidth_for_group(struct tb_bandwidth_group *group)
+{
+	struct tb_tunnel *first_tunnel;
+	struct tb *tb = group->tb;
+	struct tb_port *in;
+	int ret;
+
+	tb_dbg(tb, "re-calculating bandwidth estimation for group %u\n",
+	       group->index);
+
+	first_tunnel = NULL;
+	list_for_each_entry(in, &group->ports, group_list) {
+		int estimated_bw, estimated_up, estimated_down;
+		struct tb_tunnel *tunnel;
+		struct tb_port *out;
+
+		if (!usb4_dp_port_bw_mode_enabled(in))
+			continue;
+
+		tunnel = tb_find_tunnel(tb, TB_TUNNEL_DP, in, NULL);
+		if (WARN_ON(!tunnel))
+			break;
+
+		if (!first_tunnel) {
+			/*
+			 * Since USB3 bandwidth is shared by all DP
+			 * tunnels under the host router USB4 port, even
+			 * if they do not begin from the host router, we
+			 * can release USB3 bandwidth just once and not
+			 * for each tunnel separately.
+			 */
+			first_tunnel = tunnel;
+			ret = tb_release_unused_usb3_bandwidth(tb,
+				first_tunnel->src_port, first_tunnel->dst_port);
+			if (ret) {
+				tb_port_warn(in,
+					"failed to release unused bandwidth\n");
+				break;
+			}
+		}
+
+		out = tunnel->dst_port;
+		ret = tb_available_bandwidth(tb, in, out, &estimated_up,
+					     &estimated_down);
+		if (ret) {
+			tb_port_warn(in,
+				"failed to re-calculate estimated bandwidth\n");
+			break;
+		}
+
+		/*
+		 * Estimated bandwidth includes:
+		 *  - already allocated bandwidth for the DP tunnel
+		 *  - available bandwidth along the path
+		 *  - bandwidth allocated for USB 3.x but not used.
+		 */
+		tb_port_dbg(in, "re-calculated estimated bandwidth %u/%u Mb/s\n",
+			    estimated_up, estimated_down);
+
+		if (in->sw->config.depth < out->sw->config.depth)
+			estimated_bw = estimated_down;
+		else
+			estimated_bw = estimated_up;
+
+		if (usb4_dp_port_set_estimated_bw(in, estimated_bw))
+			tb_port_warn(in, "failed to update estimated bandwidth\n");
+	}
+
+	if (first_tunnel)
+		tb_reclaim_usb3_bandwidth(tb, first_tunnel->src_port,
+					  first_tunnel->dst_port);
+
+	tb_dbg(tb, "bandwidth estimation for group %u done\n", group->index);
+}
+
+static void tb_recalc_estimated_bandwidth(struct tb *tb)
+{
+	struct tb_cm *tcm = tb_priv(tb);
+	int i;
+
+	tb_dbg(tb, "bandwidth consumption changed, re-calculating estimated bandwidth\n");
+
+	for (i = 0; i < ARRAY_SIZE(tcm->groups); i++) {
+		struct tb_bandwidth_group *group = &tcm->groups[i];
+
+		if (!list_empty(&group->ports))
+			tb_recalc_estimated_bandwidth_for_group(group);
+	}
+
+	tb_dbg(tb, "bandwidth re-calculation done\n");
+}
+
 static struct tb_port *tb_find_dp_out(struct tb *tb, struct tb_port *in)
 {
 	struct tb_port *host_port, *port;
@@ -892,7 +1116,7 @@ static struct tb_port *tb_find_dp_out(struct tb *tb, struct tb_port *in)
 			continue;
 
 		if (tb_port_is_enabled(port)) {
-			tb_port_dbg(port, "in use\n");
+			tb_port_dbg(port, "DP OUT in use\n");
 			continue;
 		}
 
@@ -941,7 +1165,7 @@ static void tb_tunnel_dp(struct tb *tb)
 			continue;
 
 		if (tb_port_is_enabled(port)) {
-			tb_port_dbg(port, "in use\n");
+			tb_port_dbg(port, "DP IN in use\n");
 			continue;
 		}
 
@@ -993,17 +1217,19 @@ static void tb_tunnel_dp(struct tb *tb)
 		goto err_rpm_put;
 	}
 
+	if (!tb_attach_bandwidth_group(tcm, in, out))
+		goto err_dealloc_dp;
+
 	/* Make all unused USB3 bandwidth available for the new DP tunnel */
 	ret = tb_release_unused_usb3_bandwidth(tb, in, out);
 	if (ret) {
 		tb_warn(tb, "failed to release unused bandwidth\n");
-		goto err_dealloc_dp;
+		goto err_detach_group;
 	}
 
-	ret = tb_available_bandwidth(tb, in, out, &available_up,
-				     &available_down);
+	ret = tb_available_bandwidth(tb, in, out, &available_up, &available_down);
 	if (ret)
-		goto err_reclaim;
+		goto err_reclaim_usb;
 
 	tb_dbg(tb, "available bandwidth for new DP tunnel %u/%u Mb/s\n",
 	       available_up, available_down);
@@ -1012,7 +1238,7 @@ static void tb_tunnel_dp(struct tb *tb)
 				    available_down);
 	if (!tunnel) {
 		tb_port_dbg(out, "could not allocate DP tunnel\n");
-		goto err_reclaim;
+		goto err_reclaim_usb;
 	}
 
 	if (tb_tunnel_activate(tunnel)) {
@@ -1022,6 +1248,10 @@ static void tb_tunnel_dp(struct tb *tb)
 
 	list_add_tail(&tunnel->list, &tcm->tunnel_list);
 	tb_reclaim_usb3_bandwidth(tb, in, out);
+
+	/* Update the domain with the new bandwidth estimation */
+	tb_recalc_estimated_bandwidth(tb);
+
 	/*
 	 * In case of DP tunnel exists, change host router's 1st children
 	 * TMU mode to HiFi for CL0s to work.
@@ -1032,8 +1262,10 @@ static void tb_tunnel_dp(struct tb *tb)
 
 err_free:
 	tb_tunnel_free(tunnel);
-err_reclaim:
+err_reclaim_usb:
 	tb_reclaim_usb3_bandwidth(tb, in, out);
+err_detach_group:
+	tb_detach_bandwidth_group(in);
 err_dealloc_dp:
 	tb_switch_dealloc_dp_resource(in->sw, in);
 err_rpm_put:
@@ -1066,6 +1298,7 @@ static void tb_dp_resource_unavailable(struct tb *tb, struct tb_port *port)
 	 * See if there is another DP OUT port that can be used for
 	 * to create another tunnel.
 	 */
+	tb_recalc_estimated_bandwidth(tb);
 	tb_tunnel_dp(tb);
 }
 
@@ -1313,6 +1546,7 @@ static void tb_handle_hotplug(struct work_struct *work)
 			if (port->dual_link_port)
 				port->dual_link_port->remote = NULL;
 			/* Maybe we can create another DP tunnel */
+			tb_recalc_estimated_bandwidth(tb);
 			tb_tunnel_dp(tb);
 		} else if (port->xdomain) {
 			struct tb_xdomain *xd = tb_xdomain_get(port->xdomain);
@@ -1370,6 +1604,239 @@ out:
 	kfree(ev);
 }
 
+static int tb_alloc_dp_bandwidth(struct tb_tunnel *tunnel, int *requested_up,
+				 int *requested_down)
+{
+	int allocated_up, allocated_down, available_up, available_down, ret;
+	int requested_up_corrected, requested_down_corrected, granularity;
+	int max_up, max_down, max_up_rounded, max_down_rounded;
+	struct tb *tb = tunnel->tb;
+	struct tb_port *in, *out;
+
+	ret = tb_tunnel_allocated_bandwidth(tunnel, &allocated_up, &allocated_down);
+	if (ret)
+		return ret;
+
+	in = tunnel->src_port;
+	out = tunnel->dst_port;
+
+	tb_port_dbg(in, "bandwidth allocated currently %d/%d Mb/s\n",
+		    allocated_up, allocated_down);
+
+	/*
+	 * If we get rounded up request from graphics side, say HBR2 x 4
+	 * that is 17500 instead of 17280 (this is because of the
+	 * granularity), we allow it too. Here the graphics has already
+	 * negotiated with the DPRX the maximum possible rates (which is
+	 * 17280 in this case).
+	 *
+	 * Since the link cannot go higher than 17280 we use that in our
+	 * calculations but the DP IN adapter Allocated BW write must be
+	 * the same value (17500) otherwise the adapter will mark it as
+	 * failed for graphics.
+	 */
+	ret = tb_tunnel_maximum_bandwidth(tunnel, &max_up, &max_down);
+	if (ret)
+		return ret;
+
+	ret = usb4_dp_port_granularity(in);
+	if (ret < 0)
+		return ret;
+	granularity = ret;
+
+	max_up_rounded = roundup(max_up, granularity);
+	max_down_rounded = roundup(max_down, granularity);
+
+	/*
+	 * This will "fix" the request down to the maximum supported
+	 * rate * lanes if it is at the maximum rounded up level.
+	 */
+	requested_up_corrected = *requested_up;
+	if (requested_up_corrected == max_up_rounded)
+		requested_up_corrected = max_up;
+	else if (requested_up_corrected < 0)
+		requested_up_corrected = 0;
+	requested_down_corrected = *requested_down;
+	if (requested_down_corrected == max_down_rounded)
+		requested_down_corrected = max_down;
+	else if (requested_down_corrected < 0)
+		requested_down_corrected = 0;
+
+	tb_port_dbg(in, "corrected bandwidth request %d/%d Mb/s\n",
+		    requested_up_corrected, requested_down_corrected);
+
+	if ((*requested_up >= 0 && requested_up_corrected > max_up_rounded) ||
+	    (*requested_down >= 0 && requested_down_corrected > max_down_rounded)) {
+		tb_port_dbg(in, "bandwidth request too high (%d/%d Mb/s > %d/%d Mb/s)\n",
+			    requested_up_corrected, requested_down_corrected,
+			    max_up_rounded, max_down_rounded);
+		return -ENOBUFS;
+	}
+
+	if ((*requested_up >= 0 && requested_up_corrected <= allocated_up) ||
+	    (*requested_down >= 0 && requested_down_corrected <= allocated_down)) {
+		/*
+		 * If requested bandwidth is less or equal than what is
+		 * currently allocated to that tunnel we simply change
+		 * the reservation of the tunnel. Since all the tunnels
+		 * going out from the same USB4 port are in the same
+		 * group the released bandwidth will be taken into
+		 * account for the other tunnels automatically below.
+		 */
+		return tb_tunnel_alloc_bandwidth(tunnel, requested_up,
+						 requested_down);
+	}
+
+	/*
+	 * More bandwidth is requested. Release all the potential
+	 * bandwidth from USB3 first.
+	 */
+	ret = tb_release_unused_usb3_bandwidth(tb, in, out);
+	if (ret)
+		return ret;
+
+	/*
+	 * Then go over all tunnels that cross the same USB4 ports (they
+	 * are also in the same group but we use the same function here
+	 * that we use with the normal bandwidth allocation).
+	 */
+	ret = tb_available_bandwidth(tb, in, out, &available_up, &available_down);
+	if (ret)
+		goto reclaim;
+
+	tb_port_dbg(in, "bandwidth available for allocation %d/%d Mb/s\n",
+		    available_up, available_down);
+
+	if ((*requested_up >= 0 && available_up >= requested_up_corrected) ||
+	    (*requested_down >= 0 && available_down >= requested_down_corrected)) {
+		ret = tb_tunnel_alloc_bandwidth(tunnel, requested_up,
+						requested_down);
+	} else {
+		ret = -ENOBUFS;
+	}
+
+reclaim:
+	tb_reclaim_usb3_bandwidth(tb, in, out);
+	return ret;
+}
+
+static void tb_handle_dp_bandwidth_request(struct work_struct *work)
+{
+	struct tb_hotplug_event *ev = container_of(work, typeof(*ev), work);
+	int requested_bw, requested_up, requested_down, ret;
+	struct tb_port *in, *out;
+	struct tb_tunnel *tunnel;
+	struct tb *tb = ev->tb;
+	struct tb_cm *tcm = tb_priv(tb);
+	struct tb_switch *sw;
+
+	pm_runtime_get_sync(&tb->dev);
+
+	mutex_lock(&tb->lock);
+	if (!tcm->hotplug_active)
+		goto unlock;
+
+	sw = tb_switch_find_by_route(tb, ev->route);
+	if (!sw) {
+		tb_warn(tb, "bandwidth request from non-existent router %llx\n",
+			ev->route);
+		goto unlock;
+	}
+
+	in = &sw->ports[ev->port];
+	if (!tb_port_is_dpin(in)) {
+		tb_port_warn(in, "bandwidth request to non-DP IN adapter\n");
+		goto unlock;
+	}
+
+	tb_port_dbg(in, "handling bandwidth allocation request\n");
+
+	if (!usb4_dp_port_bw_mode_enabled(in)) {
+		tb_port_warn(in, "bandwidth allocation mode not enabled\n");
+		goto unlock;
+	}
+
+	ret = usb4_dp_port_requested_bw(in);
+	if (ret < 0) {
+		if (ret == -ENODATA)
+			tb_port_dbg(in, "no bandwidth request active\n");
+		else
+			tb_port_warn(in, "failed to read requested bandwidth\n");
+		goto unlock;
+	}
+	requested_bw = ret;
+
+	tb_port_dbg(in, "requested bandwidth %d Mb/s\n", requested_bw);
+
+	tunnel = tb_find_tunnel(tb, TB_TUNNEL_DP, in, NULL);
+	if (!tunnel) {
+		tb_port_warn(in, "failed to find tunnel\n");
+		goto unlock;
+	}
+
+	out = tunnel->dst_port;
+
+	if (in->sw->config.depth < out->sw->config.depth) {
+		requested_up = -1;
+		requested_down = requested_bw;
+	} else {
+		requested_up = requested_bw;
+		requested_down = -1;
+	}
+
+	ret = tb_alloc_dp_bandwidth(tunnel, &requested_up, &requested_down);
+	if (ret) {
+		if (ret == -ENOBUFS)
+			tb_port_warn(in, "not enough bandwidth available\n");
+		else
+			tb_port_warn(in, "failed to change bandwidth allocation\n");
+	} else {
+		tb_port_dbg(in, "bandwidth allocation changed to %d/%d Mb/s\n",
+			    requested_up, requested_down);
+
+		/* Update other clients about the allocation change */
+		tb_recalc_estimated_bandwidth(tb);
+	}
+
+unlock:
+	mutex_unlock(&tb->lock);
+
+	pm_runtime_mark_last_busy(&tb->dev);
+	pm_runtime_put_autosuspend(&tb->dev);
+}
+
+static void tb_queue_dp_bandwidth_request(struct tb *tb, u64 route, u8 port)
+{
+	struct tb_hotplug_event *ev;
+
+	ev = kmalloc(sizeof(*ev), GFP_KERNEL);
+	if (!ev)
+		return;
+
+	ev->tb = tb;
+	ev->route = route;
+	ev->port = port;
+	INIT_WORK(&ev->work, tb_handle_dp_bandwidth_request);
+	queue_work(tb->wq, &ev->work);
+}
+
+static void tb_handle_notification(struct tb *tb, u64 route,
+				   const struct cfg_error_pkg *error)
+{
+	if (tb_cfg_ack_notification(tb->ctl, route, error))
+		tb_warn(tb, "could not ack notification on %llx\n", route);
+
+	switch (error->error) {
+	case TB_CFG_ERROR_DP_BW:
+		tb_queue_dp_bandwidth_request(tb, route, error->port);
+		break;
+
+	default:
+		/* Ack is enough */
+		return;
+	}
+}
+
 /*
  * tb_schedule_hotplug_handler() - callback function for the control channel
  *
@@ -1379,15 +1846,19 @@ static void tb_handle_event(struct tb *tb, enum tb_cfg_pkg_type type,
 			    const void *buf, size_t size)
 {
 	const struct cfg_event_pkg *pkg = buf;
-	u64 route;
+	u64 route = tb_cfg_get_route(&pkg->header);
 
-	if (type != TB_CFG_PKG_EVENT) {
+	switch (type) {
+	case TB_CFG_PKG_ERROR:
+		tb_handle_notification(tb, route, (const struct cfg_error_pkg *)buf);
+		return;
+	case TB_CFG_PKG_EVENT:
+		break;
+	default:
 		tb_warn(tb, "unexpected event %#x, ignoring\n", type);
 		return;
 	}
 
-	route = tb_cfg_get_route(&pkg->header);
-
 	if (tb_cfg_ack_plug(tb->ctl, route, pkg->port, pkg->unplug)) {
 		tb_warn(tb, "could not ack plug event on %llx:%x\n", route,
 			pkg->port);
@@ -1817,6 +2288,7 @@ struct tb *tb_probe(struct tb_nhi *nhi)
 	INIT_LIST_HEAD(&tcm->tunnel_list);
 	INIT_LIST_HEAD(&tcm->dp_resources);
 	INIT_DELAYED_WORK(&tcm->remove_work, tb_remove_work);
+	tb_init_bandwidth_groups(tcm);
 
 	tb_dbg(tb, "using software connection manager\n");
 
diff --git a/drivers/thunderbolt/tb.h b/drivers/thunderbolt/tb.h
index f9786976f5ecf..2953cf38c29ed 100644
--- a/drivers/thunderbolt/tb.h
+++ b/drivers/thunderbolt/tb.h
@@ -224,6 +224,23 @@ struct tb_switch {
 };
 
 /**
+ * struct tb_bandwidth_group - Bandwidth management group
+ * @tb: Pointer to the domain the group belongs to
+ * @index: Index of the group (aka Group_ID). Valid values %1-%7
+ * @ports: DP IN adapters belonging to this group are linked here
+ *
+ * Any tunnel that requires isochronous bandwidth (that's DP for now) is
+ * attached to a bandwidth group. All tunnels going through the same
+ * USB4 links share the same group and can dynamically distribute the
+ * bandwidth within the group.
+ */
+struct tb_bandwidth_group {
+	struct tb *tb;
+	int index;
+	struct list_head ports;
+};
+
+/**
  * struct tb_port - a thunderbolt port, part of a tb_switch
  * @config: Cached port configuration read from registers
  * @sw: Switch the port belongs to
@@ -247,6 +264,9 @@ struct tb_switch {
  * @ctl_credits: Buffers reserved for control path
  * @dma_credits: Number of credits allocated for DMA tunneling for all
  *		 DMA paths through this port.
+ * @group: Bandwidth allocation group the adapter is assigned to. Only
+ *	   used for DP IN adapters for now.
+ * @group_list: The adapter is linked to the group's list of ports through this
  *
  * In USB4 terminology this structure represents an adapter (protocol or
  * lane adapter).
@@ -272,6 +292,8 @@ struct tb_port {
 	unsigned int total_credits;
 	unsigned int ctl_credits;
 	unsigned int dma_credits;
+	struct tb_bandwidth_group *group;
+	struct list_head group_list;
 };
 
 /**
@@ -1047,7 +1069,7 @@ void tb_port_lane_bonding_disable(struct tb_port *port);
 int tb_port_wait_for_link_width(struct tb_port *port, int width,
 				int timeout_msec);
 int tb_port_update_credits(struct tb_port *port);
-bool tb_port_is_clx_enabled(struct tb_port *port, enum tb_clx clx);
+bool tb_port_is_clx_enabled(struct tb_port *port, unsigned int clx);
 
 int tb_switch_find_vse_cap(struct tb_switch *sw, enum tb_switch_vse_cap vsec);
 int tb_switch_find_cap(struct tb_switch *sw, enum tb_switch_cap cap);
@@ -1238,6 +1260,21 @@ int usb4_usb3_port_allocate_bandwidth(struct tb_port *port, int *upstream_bw,
 int usb4_usb3_port_release_bandwidth(struct tb_port *port, int *upstream_bw,
 				     int *downstream_bw);
 
+int usb4_dp_port_set_cm_id(struct tb_port *port, int cm_id);
+bool usb4_dp_port_bw_mode_supported(struct tb_port *port);
+bool usb4_dp_port_bw_mode_enabled(struct tb_port *port);
+int usb4_dp_port_set_cm_bw_mode_supported(struct tb_port *port, bool supported);
+int usb4_dp_port_group_id(struct tb_port *port);
+int usb4_dp_port_set_group_id(struct tb_port *port, int group_id);
+int usb4_dp_port_nrd(struct tb_port *port, int *rate, int *lanes);
+int usb4_dp_port_set_nrd(struct tb_port *port, int rate, int lanes);
+int usb4_dp_port_granularity(struct tb_port *port);
+int usb4_dp_port_set_granularity(struct tb_port *port, int granularity);
+int usb4_dp_port_set_estimated_bw(struct tb_port *port, int bw);
+int usb4_dp_port_allocated_bw(struct tb_port *port);
+int usb4_dp_port_allocate_bw(struct tb_port *port, int bw);
+int usb4_dp_port_requested_bw(struct tb_port *port);
+
 static inline bool tb_is_usb4_port_device(const struct device *dev)
 {
 	return dev->type == &usb4_port_device_type;
diff --git a/drivers/thunderbolt/tb_msgs.h b/drivers/thunderbolt/tb_msgs.h
index 33c4c7aed56da..3234bff078995 100644
--- a/drivers/thunderbolt/tb_msgs.h
+++ b/drivers/thunderbolt/tb_msgs.h
@@ -29,6 +29,7 @@ enum tb_cfg_error {
 	TB_CFG_ERROR_HEC_ERROR_DETECTED = 12,
 	TB_CFG_ERROR_FLOW_CONTROL_ERROR = 13,
 	TB_CFG_ERROR_LOCK = 15,
+	TB_CFG_ERROR_DP_BW = 32,
 };
 
 /* common header */
@@ -64,14 +65,16 @@ struct cfg_write_pkg {
 /* TB_CFG_PKG_ERROR */
 struct cfg_error_pkg {
 	struct tb_cfg_header header;
-	enum tb_cfg_error error:4;
-	u32 zero1:4;
+	enum tb_cfg_error error:8;
 	u32 port:6;
-	u32 zero2:2; /* Both should be zero, still they are different fields. */
-	u32 zero3:14;
+	u32 reserved:16;
 	u32 pg:2;
 } __packed;
 
+struct cfg_ack_pkg {
+	struct tb_cfg_header header;
+};
+
 #define TB_CFG_ERROR_PG_HOT_PLUG	0x2
 #define TB_CFG_ERROR_PG_HOT_UNPLUG	0x3
 
diff --git a/drivers/thunderbolt/tb_regs.h b/drivers/thunderbolt/tb_regs.h
index 3c38b0cb8f74e..2636423748cdd 100644
--- a/drivers/thunderbolt/tb_regs.h
+++ b/drivers/thunderbolt/tb_regs.h
@@ -50,6 +50,10 @@ enum tb_port_state {
 	TB_PORT_DISABLED	= 0, /* tb_cap_phy.disable == 1 */
 	TB_PORT_CONNECTING	= 1, /* retry */
 	TB_PORT_UP		= 2,
+	TB_PORT_TX_CL0S		= 3,
+	TB_PORT_RX_CL0S		= 4,
+	TB_PORT_CL1		= 5,
+	TB_PORT_CL2		= 6,
 	TB_PORT_UNPLUGGED	= 7,
 };
 
@@ -381,15 +385,42 @@ struct tb_regs_port_header {
 #define ADP_DP_CS_1_AUX_RX_HOPID_MASK		GENMASK(21, 11)
 #define ADP_DP_CS_1_AUX_RX_HOPID_SHIFT		11
 #define ADP_DP_CS_2				0x02
+#define ADP_DP_CS_2_NRD_MLC_MASK		GENMASK(2, 0)
 #define ADP_DP_CS_2_HDP				BIT(6)
+#define ADP_DP_CS_2_NRD_MLR_MASK		GENMASK(9, 7)
+#define ADP_DP_CS_2_NRD_MLR_SHIFT		7
+#define ADP_DP_CS_2_CA				BIT(10)
+#define ADP_DP_CS_2_GR_MASK			GENMASK(12, 11)
+#define ADP_DP_CS_2_GR_SHIFT			11
+#define ADP_DP_CS_2_GR_0_25G			0x0
+#define ADP_DP_CS_2_GR_0_5G			0x1
+#define ADP_DP_CS_2_GR_1G			0x2
+#define ADP_DP_CS_2_GROUP_ID_MASK		GENMASK(15, 13)
+#define ADP_DP_CS_2_GROUP_ID_SHIFT		13
+#define ADP_DP_CS_2_CM_ID_MASK			GENMASK(19, 16)
+#define ADP_DP_CS_2_CM_ID_SHIFT			16
+#define ADP_DP_CS_2_CMMS			BIT(20)
+#define ADP_DP_CS_2_ESTIMATED_BW_MASK		GENMASK(31, 24)
+#define ADP_DP_CS_2_ESTIMATED_BW_SHIFT		24
 #define ADP_DP_CS_3				0x03
 #define ADP_DP_CS_3_HDPC			BIT(9)
 #define DP_LOCAL_CAP				0x04
 #define DP_REMOTE_CAP				0x05
+/* For DP IN adapter */
+#define DP_STATUS				0x06
+#define DP_STATUS_ALLOCATED_BW_MASK		GENMASK(31, 24)
+#define DP_STATUS_ALLOCATED_BW_SHIFT		24
+/* For DP OUT adapter */
 #define DP_STATUS_CTRL				0x06
 #define DP_STATUS_CTRL_CMHS			BIT(25)
 #define DP_STATUS_CTRL_UF			BIT(26)
 #define DP_COMMON_CAP				0x07
+/* Only if DP IN supports BW allocation mode */
+#define ADP_DP_CS_8				0x08
+#define ADP_DP_CS_8_REQUESTED_BW_MASK		GENMASK(7, 0)
+#define ADP_DP_CS_8_DPME			BIT(30)
+#define ADP_DP_CS_8_DR				BIT(31)
+
 /*
  * DP_COMMON_CAP offsets work also for DP_LOCAL_CAP and DP_REMOTE_CAP
  * with exception of DPRX done.
@@ -406,7 +437,12 @@ struct tb_regs_port_header {
 #define DP_COMMON_CAP_2_LANES			0x1
 #define DP_COMMON_CAP_4_LANES			0x2
 #define DP_COMMON_CAP_LTTPR_NS			BIT(27)
+#define DP_COMMON_CAP_BW_MODE			BIT(28)
 #define DP_COMMON_CAP_DPRX_DONE			BIT(31)
+/* Only present if DP IN supports BW allocation mode */
+#define ADP_DP_CS_8				0x08
+#define ADP_DP_CS_8_DPME			BIT(30)
+#define ADP_DP_CS_8_DR				BIT(31)
 
 /* PCIe adapter registers */
 #define ADP_PCIE_CS_0				0x00
diff --git a/drivers/thunderbolt/tunnel.c b/drivers/thunderbolt/tunnel.c
index 1fc3c29b24f83..9099ae73e78f3 100644
--- a/drivers/thunderbolt/tunnel.c
+++ b/drivers/thunderbolt/tunnel.c
@@ -9,6 +9,7 @@
 #include <linux/delay.h>
 #include <linux/slab.h>
 #include <linux/list.h>
+#include <linux/ktime.h>
 
 #include "tunnel.h"
 #include "tb.h"
@@ -44,12 +45,17 @@
 /* Minimum number of credits for DMA path */
 #define TB_MIN_DMA_CREDITS		1U
 
+static bool bw_alloc_mode = true;
+module_param(bw_alloc_mode, bool, 0444);
+MODULE_PARM_DESC(bw_alloc_mode,
+		 "enable bandwidth allocation mode if supported (default: true)");
+
 static const char * const tb_tunnel_names[] = { "PCI", "DP", "DMA", "USB3" };
 
 #define __TB_TUNNEL_PRINT(level, tunnel, fmt, arg...)                   \
 	do {                                                            \
 		struct tb_tunnel *__tunnel = (tunnel);                  \
-		level(__tunnel->tb, "%llx:%x <-> %llx:%x (%s): " fmt,   \
+		level(__tunnel->tb, "%llx:%u <-> %llx:%u (%s): " fmt,   \
 		      tb_route(__tunnel->src_port->sw),                 \
 		      __tunnel->src_port->port,                         \
 		      tb_route(__tunnel->dst_port->sw),                 \
@@ -339,9 +345,10 @@ static bool tb_dp_is_usb4(const struct tb_switch *sw)
 	return tb_switch_is_usb4(sw) || tb_switch_is_titan_ridge(sw);
 }
 
-static int tb_dp_cm_handshake(struct tb_port *in, struct tb_port *out)
+static int tb_dp_cm_handshake(struct tb_port *in, struct tb_port *out,
+			      int timeout_msec)
 {
-	int timeout = 10;
+	ktime_t timeout = ktime_add_ms(ktime_get(), timeout_msec);
 	u32 val;
 	int ret;
 
@@ -368,8 +375,8 @@ static int tb_dp_cm_handshake(struct tb_port *in, struct tb_port *out)
 			return ret;
 		if (!(val & DP_STATUS_CTRL_CMHS))
 			return 0;
-		usleep_range(10, 100);
-	} while (timeout--);
+		usleep_range(100, 150);
+	} while (ktime_before(ktime_get(), timeout));
 
 	return -ETIMEDOUT;
 }
@@ -519,7 +526,7 @@ static int tb_dp_xchg_caps(struct tb_tunnel *tunnel)
 	 * Perform connection manager handshake between IN and OUT ports
 	 * before capabilities exchange can take place.
 	 */
-	ret = tb_dp_cm_handshake(in, out);
+	ret = tb_dp_cm_handshake(in, out, 1500);
 	if (ret)
 		return ret;
 
@@ -597,6 +604,133 @@ static int tb_dp_xchg_caps(struct tb_tunnel *tunnel)
 			     in->cap_adap + DP_REMOTE_CAP, 1);
 }
 
+static int tb_dp_bw_alloc_mode_enable(struct tb_tunnel *tunnel)
+{
+	int ret, estimated_bw, granularity, tmp;
+	struct tb_port *out = tunnel->dst_port;
+	struct tb_port *in = tunnel->src_port;
+	u32 out_dp_cap, out_rate, out_lanes;
+	u32 in_dp_cap, in_rate, in_lanes;
+	u32 rate, lanes;
+
+	if (!bw_alloc_mode)
+		return 0;
+
+	ret = usb4_dp_port_set_cm_bw_mode_supported(in, true);
+	if (ret)
+		return ret;
+
+	ret = usb4_dp_port_set_group_id(in, in->group->index);
+	if (ret)
+		return ret;
+
+	/*
+	 * Get the non-reduced rate and lanes based on the lowest
+	 * capability of both adapters.
+	 */
+	ret = tb_port_read(in, &in_dp_cap, TB_CFG_PORT,
+			   in->cap_adap + DP_LOCAL_CAP, 1);
+	if (ret)
+		return ret;
+
+	ret = tb_port_read(out, &out_dp_cap, TB_CFG_PORT,
+			   out->cap_adap + DP_LOCAL_CAP, 1);
+	if (ret)
+		return ret;
+
+	in_rate = tb_dp_cap_get_rate(in_dp_cap);
+	in_lanes = tb_dp_cap_get_lanes(in_dp_cap);
+	out_rate = tb_dp_cap_get_rate(out_dp_cap);
+	out_lanes = tb_dp_cap_get_lanes(out_dp_cap);
+
+	rate = min(in_rate, out_rate);
+	lanes = min(in_lanes, out_lanes);
+	tmp = tb_dp_bandwidth(rate, lanes);
+
+	tb_port_dbg(in, "non-reduced bandwidth %u Mb/s x%u = %u Mb/s\n", rate,
+		    lanes, tmp);
+
+	ret = usb4_dp_port_set_nrd(in, rate, lanes);
+	if (ret)
+		return ret;
+
+	for (granularity = 250; tmp / granularity > 255 && granularity <= 1000;
+	     granularity *= 2)
+		;
+
+	tb_port_dbg(in, "granularity %d Mb/s\n", granularity);
+
+	/*
+	 * Returns -EINVAL if granularity above is outside of the
+	 * accepted ranges.
+	 */
+	ret = usb4_dp_port_set_granularity(in, granularity);
+	if (ret)
+		return ret;
+
+	/*
+	 * Bandwidth estimation is pretty much what we have in
+	 * max_up/down fields. For discovery we just read what the
+	 * estimation was set to.
+	 */
+	if (in->sw->config.depth < out->sw->config.depth)
+		estimated_bw = tunnel->max_down;
+	else
+		estimated_bw = tunnel->max_up;
+
+	tb_port_dbg(in, "estimated bandwidth %d Mb/s\n", estimated_bw);
+
+	ret = usb4_dp_port_set_estimated_bw(in, estimated_bw);
+	if (ret)
+		return ret;
+
+	/* Initial allocation should be 0 according the spec */
+	ret = usb4_dp_port_allocate_bw(in, 0);
+	if (ret)
+		return ret;
+
+	tb_port_dbg(in, "bandwidth allocation mode enabled\n");
+	return 0;
+}
+
+static int tb_dp_init(struct tb_tunnel *tunnel)
+{
+	struct tb_port *in = tunnel->src_port;
+	struct tb_switch *sw = in->sw;
+	struct tb *tb = in->sw->tb;
+	int ret;
+
+	ret = tb_dp_xchg_caps(tunnel);
+	if (ret)
+		return ret;
+
+	if (!tb_switch_is_usb4(sw))
+		return 0;
+
+	if (!usb4_dp_port_bw_mode_supported(in))
+		return 0;
+
+	tb_port_dbg(in, "bandwidth allocation mode supported\n");
+
+	ret = usb4_dp_port_set_cm_id(in, tb->index);
+	if (ret)
+		return ret;
+
+	return tb_dp_bw_alloc_mode_enable(tunnel);
+}
+
+static void tb_dp_deinit(struct tb_tunnel *tunnel)
+{
+	struct tb_port *in = tunnel->src_port;
+
+	if (!usb4_dp_port_bw_mode_supported(in))
+		return;
+	if (usb4_dp_port_bw_mode_enabled(in)) {
+		usb4_dp_port_set_cm_bw_mode_supported(in, false);
+		tb_port_dbg(in, "bandwidth allocation mode disabled\n");
+	}
+}
+
 static int tb_dp_activate(struct tb_tunnel *tunnel, bool active)
 {
 	int ret;
@@ -634,49 +768,275 @@ static int tb_dp_activate(struct tb_tunnel *tunnel, bool active)
 	return 0;
 }
 
+/* max_bw is rounded up to next granularity */
+static int tb_dp_nrd_bandwidth(struct tb_tunnel *tunnel, int *max_bw)
+{
+	struct tb_port *in = tunnel->src_port;
+	int ret, rate, lanes, nrd_bw;
+
+	ret = usb4_dp_port_nrd(in, &rate, &lanes);
+	if (ret)
+		return ret;
+
+	nrd_bw = tb_dp_bandwidth(rate, lanes);
+
+	if (max_bw) {
+		ret = usb4_dp_port_granularity(in);
+		if (ret < 0)
+			return ret;
+		*max_bw = roundup(nrd_bw, ret);
+	}
+
+	return nrd_bw;
+}
+
+static int tb_dp_bw_mode_consumed_bandwidth(struct tb_tunnel *tunnel,
+					    int *consumed_up, int *consumed_down)
+{
+	struct tb_port *out = tunnel->dst_port;
+	struct tb_port *in = tunnel->src_port;
+	int ret, allocated_bw, max_bw;
+
+	if (!usb4_dp_port_bw_mode_enabled(in))
+		return -EOPNOTSUPP;
+
+	if (!tunnel->bw_mode)
+		return -EOPNOTSUPP;
+
+	/* Read what was allocated previously if any */
+	ret = usb4_dp_port_allocated_bw(in);
+	if (ret < 0)
+		return ret;
+	allocated_bw = ret;
+
+	ret = tb_dp_nrd_bandwidth(tunnel, &max_bw);
+	if (ret < 0)
+		return ret;
+	if (allocated_bw == max_bw)
+		allocated_bw = ret;
+
+	tb_port_dbg(in, "consumed bandwidth through allocation mode %d Mb/s\n",
+		    allocated_bw);
+
+	if (in->sw->config.depth < out->sw->config.depth) {
+		*consumed_up = 0;
+		*consumed_down = allocated_bw;
+	} else {
+		*consumed_up = allocated_bw;
+		*consumed_down = 0;
+	}
+
+	return 0;
+}
+
+static int tb_dp_allocated_bandwidth(struct tb_tunnel *tunnel, int *allocated_up,
+				     int *allocated_down)
+{
+	struct tb_port *out = tunnel->dst_port;
+	struct tb_port *in = tunnel->src_port;
+
+	/*
+	 * If we have already set the allocated bandwidth then use that.
+	 * Otherwise we read it from the DPRX.
+	 */
+	if (usb4_dp_port_bw_mode_enabled(in) && tunnel->bw_mode) {
+		int ret, allocated_bw, max_bw;
+
+		ret = usb4_dp_port_allocated_bw(in);
+		if (ret < 0)
+			return ret;
+		allocated_bw = ret;
+
+		ret = tb_dp_nrd_bandwidth(tunnel, &max_bw);
+		if (ret < 0)
+			return ret;
+		if (allocated_bw == max_bw)
+			allocated_bw = ret;
+
+		if (in->sw->config.depth < out->sw->config.depth) {
+			*allocated_up = 0;
+			*allocated_down = allocated_bw;
+		} else {
+			*allocated_up = allocated_bw;
+			*allocated_down = 0;
+		}
+		return 0;
+	}
+
+	return tunnel->consumed_bandwidth(tunnel, allocated_up,
+					  allocated_down);
+}
+
+static int tb_dp_alloc_bandwidth(struct tb_tunnel *tunnel, int *alloc_up,
+				 int *alloc_down)
+{
+	struct tb_port *out = tunnel->dst_port;
+	struct tb_port *in = tunnel->src_port;
+	int max_bw, ret, tmp;
+
+	if (!usb4_dp_port_bw_mode_enabled(in))
+		return -EOPNOTSUPP;
+
+	ret = tb_dp_nrd_bandwidth(tunnel, &max_bw);
+	if (ret < 0)
+		return ret;
+
+	if (in->sw->config.depth < out->sw->config.depth) {
+		tmp = min(*alloc_down, max_bw);
+		ret = usb4_dp_port_allocate_bw(in, tmp);
+		if (ret)
+			return ret;
+		*alloc_down = tmp;
+		*alloc_up = 0;
+	} else {
+		tmp = min(*alloc_up, max_bw);
+		ret = usb4_dp_port_allocate_bw(in, tmp);
+		if (ret)
+			return ret;
+		*alloc_down = 0;
+		*alloc_up = tmp;
+	}
+
+	/* Now we can use BW mode registers to figure out the bandwidth */
+	/* TODO: need to handle discovery too */
+	tunnel->bw_mode = true;
+	return 0;
+}
+
+static int tb_dp_read_dprx(struct tb_tunnel *tunnel, u32 *rate, u32 *lanes,
+			   int timeout_msec)
+{
+	ktime_t timeout = ktime_add_ms(ktime_get(), timeout_msec);
+	struct tb_port *in = tunnel->src_port;
+
+	/*
+	 * Wait for DPRX done. Normally it should be already set for
+	 * active tunnel.
+	 */
+	do {
+		u32 val;
+		int ret;
+
+		ret = tb_port_read(in, &val, TB_CFG_PORT,
+				   in->cap_adap + DP_COMMON_CAP, 1);
+		if (ret)
+			return ret;
+
+		if (val & DP_COMMON_CAP_DPRX_DONE) {
+			*rate = tb_dp_cap_get_rate(val);
+			*lanes = tb_dp_cap_get_lanes(val);
+
+			tb_port_dbg(in, "consumed bandwidth through DPRX %d Mb/s\n",
+				    tb_dp_bandwidth(*rate, *lanes));
+			return 0;
+		}
+		usleep_range(100, 150);
+	} while (ktime_before(ktime_get(), timeout));
+
+	return -ETIMEDOUT;
+}
+
+/* Read cap from tunnel DP IN */
+static int tb_dp_read_cap(struct tb_tunnel *tunnel, unsigned int cap, u32 *rate,
+			  u32 *lanes)
+{
+	struct tb_port *in = tunnel->src_port;
+	u32 val;
+	int ret;
+
+	switch (cap) {
+	case DP_LOCAL_CAP:
+	case DP_REMOTE_CAP:
+		break;
+
+	default:
+		tb_tunnel_WARN(tunnel, "invalid capability index %#x\n", cap);
+		return -EINVAL;
+	}
+
+	/*
+	 * Read from the copied remote cap so that we take into account
+	 * if capabilities were reduced during exchange.
+	 */
+	ret = tb_port_read(in, &val, TB_CFG_PORT, in->cap_adap + cap, 1);
+	if (ret)
+		return ret;
+
+	*rate = tb_dp_cap_get_rate(val);
+	*lanes = tb_dp_cap_get_lanes(val);
+
+	tb_port_dbg(in, "bandwidth from %#x capability %d Mb/s\n", cap,
+		    tb_dp_bandwidth(*rate, *lanes));
+	return 0;
+}
+
+static int tb_dp_maximum_bandwidth(struct tb_tunnel *tunnel, int *max_up,
+				   int *max_down)
+{
+	struct tb_port *in = tunnel->src_port;
+	u32 rate, lanes;
+	int ret;
+
+	/*
+	 * DP IN adapter DP_LOCAL_CAP gets updated to the lowest AUX read
+	 * parameter values so this so we can use this to determine the
+	 * maximum possible bandwidth over this link.
+	 */
+	ret = tb_dp_read_cap(tunnel, DP_LOCAL_CAP, &rate, &lanes);
+	if (ret)
+		return ret;
+
+	if (in->sw->config.depth < tunnel->dst_port->sw->config.depth) {
+		*max_up = 0;
+		*max_down = tb_dp_bandwidth(rate, lanes);
+	} else {
+		*max_up = tb_dp_bandwidth(rate, lanes);
+		*max_down = 0;
+	}
+
+	return 0;
+}
+
 static int tb_dp_consumed_bandwidth(struct tb_tunnel *tunnel, int *consumed_up,
 				    int *consumed_down)
 {
 	struct tb_port *in = tunnel->src_port;
 	const struct tb_switch *sw = in->sw;
-	u32 val, rate = 0, lanes = 0;
+	u32 rate = 0, lanes = 0;
 	int ret;
 
 	if (tb_dp_is_usb4(sw)) {
-		int timeout = 20;
-
 		/*
-		 * Wait for DPRX done. Normally it should be already set
-		 * for active tunnel.
+		 * On USB4 routers check if the bandwidth allocation
+		 * mode is enabled first and then read the bandwidth
+		 * through those registers.
 		 */
-		do {
-			ret = tb_port_read(in, &val, TB_CFG_PORT,
-					   in->cap_adap + DP_COMMON_CAP, 1);
-			if (ret)
+		ret = tb_dp_bw_mode_consumed_bandwidth(tunnel, consumed_up,
+						       consumed_down);
+		if (ret < 0) {
+			if (ret != -EOPNOTSUPP)
 				return ret;
-
-			if (val & DP_COMMON_CAP_DPRX_DONE) {
-				rate = tb_dp_cap_get_rate(val);
-				lanes = tb_dp_cap_get_lanes(val);
-				break;
-			}
-			msleep(250);
-		} while (timeout--);
-
-		if (!timeout)
-			return -ETIMEDOUT;
-	} else if (sw->generation >= 2) {
+		} else if (!ret) {
+			return 0;
+		}
 		/*
-		 * Read from the copied remote cap so that we take into
-		 * account if capabilities were reduced during exchange.
+		 * Then see if the DPRX negotiation is ready and if yes
+		 * return that bandwidth (it may be smaller than the
+		 * reduced one). Otherwise return the remote (possibly
+		 * reduced) caps.
 		 */
-		ret = tb_port_read(in, &val, TB_CFG_PORT,
-				   in->cap_adap + DP_REMOTE_CAP, 1);
+		ret = tb_dp_read_dprx(tunnel, &rate, &lanes, 150);
+		if (ret) {
+			if (ret == -ETIMEDOUT)
+				ret = tb_dp_read_cap(tunnel, DP_REMOTE_CAP,
+						     &rate, &lanes);
+			if (ret)
+				return ret;
+		}
+	} else if (sw->generation >= 2) {
+		ret = tb_dp_read_cap(tunnel, DP_REMOTE_CAP, &rate, &lanes);
 		if (ret)
 			return ret;
-
-		rate = tb_dp_cap_get_rate(val);
-		lanes = tb_dp_cap_get_lanes(val);
 	} else {
 		/* No bandwidth management for legacy devices  */
 		*consumed_up = 0;
@@ -798,8 +1158,12 @@ struct tb_tunnel *tb_tunnel_discover_dp(struct tb *tb, struct tb_port *in,
 	if (!tunnel)
 		return NULL;
 
-	tunnel->init = tb_dp_xchg_caps;
+	tunnel->init = tb_dp_init;
+	tunnel->deinit = tb_dp_deinit;
 	tunnel->activate = tb_dp_activate;
+	tunnel->maximum_bandwidth = tb_dp_maximum_bandwidth;
+	tunnel->allocated_bandwidth = tb_dp_allocated_bandwidth;
+	tunnel->alloc_bandwidth = tb_dp_alloc_bandwidth;
 	tunnel->consumed_bandwidth = tb_dp_consumed_bandwidth;
 	tunnel->src_port = in;
 
@@ -887,8 +1251,12 @@ struct tb_tunnel *tb_tunnel_alloc_dp(struct tb *tb, struct tb_port *in,
 	if (!tunnel)
 		return NULL;
 
-	tunnel->init = tb_dp_xchg_caps;
+	tunnel->init = tb_dp_init;
+	tunnel->deinit = tb_dp_deinit;
 	tunnel->activate = tb_dp_activate;
+	tunnel->maximum_bandwidth = tb_dp_maximum_bandwidth;
+	tunnel->allocated_bandwidth = tb_dp_allocated_bandwidth;
+	tunnel->alloc_bandwidth = tb_dp_alloc_bandwidth;
 	tunnel->consumed_bandwidth = tb_dp_consumed_bandwidth;
 	tunnel->src_port = in;
 	tunnel->dst_port = out;
@@ -1714,6 +2082,72 @@ static bool tb_tunnel_is_active(const struct tb_tunnel *tunnel)
 }
 
 /**
+ * tb_tunnel_maximum_bandwidth() - Return maximum possible bandwidth
+ * @tunnel: Tunnel to check
+ * @max_up: Maximum upstream bandwidth in Mb/s
+ * @max_down: Maximum downstream bandwidth in Mb/s
+ *
+ * Returns maximum possible bandwidth this tunnel can go if not limited
+ * by other bandwidth clients. If the tunnel does not support this
+ * returns %-EOPNOTSUPP.
+ */
+int tb_tunnel_maximum_bandwidth(struct tb_tunnel *tunnel, int *max_up,
+				int *max_down)
+{
+	if (!tb_tunnel_is_active(tunnel))
+		return -EINVAL;
+
+	if (tunnel->maximum_bandwidth)
+		return tunnel->maximum_bandwidth(tunnel, max_up, max_down);
+	return -EOPNOTSUPP;
+}
+
+/**
+ * tb_tunnel_allocated_bandwidth() - Return bandwidth allocated for the tunnel
+ * @tunnel: Tunnel to check
+ * @allocated_up: Currently allocated upstream bandwidth in Mb/s is stored here
+ * @allocated_down: Currently allocated downstream bandwidth in Mb/s is
+ *		    stored here
+ *
+ * Returns the bandwidth allocated for the tunnel. This may be higher
+ * than what the tunnel actually consumes.
+ */
+int tb_tunnel_allocated_bandwidth(struct tb_tunnel *tunnel, int *allocated_up,
+				  int *allocated_down)
+{
+	if (!tb_tunnel_is_active(tunnel))
+		return -EINVAL;
+
+	if (tunnel->allocated_bandwidth)
+		return tunnel->allocated_bandwidth(tunnel, allocated_up,
+						   allocated_down);
+	return -EOPNOTSUPP;
+}
+
+/**
+ * tb_tunnel_alloc_bandwidth() - Change tunnel bandwidth allocation
+ * @tunnel: Tunnel whose bandwidth allocation to change
+ * @alloc_up: New upstream bandwidth in Mb/s
+ * @alloc_down: New downstream bandwidth in Mb/s
+ *
+ * Tries to change tunnel bandwidth allocation. If succeeds returns %0
+ * and updates @alloc_up and @alloc_down to that was actually allocated
+ * (it may not be the same as passed originally). Returns negative errno
+ * in case of failure.
+ */
+int tb_tunnel_alloc_bandwidth(struct tb_tunnel *tunnel, int *alloc_up,
+			      int *alloc_down)
+{
+	if (!tb_tunnel_is_active(tunnel))
+		return -EINVAL;
+
+	if (tunnel->alloc_bandwidth)
+		return tunnel->alloc_bandwidth(tunnel, alloc_up, alloc_down);
+
+	return -EOPNOTSUPP;
+}
+
+/**
  * tb_tunnel_consumed_bandwidth() - Return bandwidth consumed by the tunnel
  * @tunnel: Tunnel to check
  * @consumed_up: Consumed bandwidth in Mb/s from @dst_port to @src_port.
diff --git a/drivers/thunderbolt/tunnel.h b/drivers/thunderbolt/tunnel.h
index bb4d1f1d6d0b0..bf690f7beeeeb 100644
--- a/drivers/thunderbolt/tunnel.h
+++ b/drivers/thunderbolt/tunnel.h
@@ -29,6 +29,9 @@ enum tb_tunnel_type {
  * @init: Optional tunnel specific initialization
  * @deinit: Optional tunnel specific de-initialization
  * @activate: Optional tunnel specific activation/deactivation
+ * @maximum_bandwidth: Returns maximum possible bandwidth for this tunnel
+ * @allocated_bandwidth: Return how much bandwidth is allocated for the tunnel
+ * @alloc_bandwidth: Change tunnel bandwidth allocation
  * @consumed_bandwidth: Return how much bandwidth the tunnel consumes
  * @release_unused_bandwidth: Release all unused bandwidth
  * @reclaim_available_bandwidth: Reclaim back available bandwidth
@@ -40,6 +43,8 @@ enum tb_tunnel_type {
  *	      Only set if the bandwidth needs to be limited.
  * @allocated_up: Allocated upstream bandwidth (only for USB3)
  * @allocated_down: Allocated downstream bandwidth (only for USB3)
+ * @bw_mode: DP bandwidth allocation mode registers can be used to
+ *	     determine consumed and allocated bandwidth
  */
 struct tb_tunnel {
 	struct tb *tb;
@@ -50,6 +55,12 @@ struct tb_tunnel {
 	int (*init)(struct tb_tunnel *tunnel);
 	void (*deinit)(struct tb_tunnel *tunnel);
 	int (*activate)(struct tb_tunnel *tunnel, bool activate);
+	int (*maximum_bandwidth)(struct tb_tunnel *tunnel, int *max_up,
+				 int *max_down);
+	int (*allocated_bandwidth)(struct tb_tunnel *tunnel, int *allocated_up,
+				   int *allocated_down);
+	int (*alloc_bandwidth)(struct tb_tunnel *tunnel, int *alloc_up,
+			       int *alloc_down);
 	int (*consumed_bandwidth)(struct tb_tunnel *tunnel, int *consumed_up,
 				  int *consumed_down);
 	int (*release_unused_bandwidth)(struct tb_tunnel *tunnel);
@@ -62,6 +73,7 @@ struct tb_tunnel {
 	int max_down;
 	int allocated_up;
 	int allocated_down;
+	bool bw_mode;
 };
 
 struct tb_tunnel *tb_tunnel_discover_pci(struct tb *tb, struct tb_port *down,
@@ -92,6 +104,12 @@ void tb_tunnel_deactivate(struct tb_tunnel *tunnel);
 bool tb_tunnel_is_invalid(struct tb_tunnel *tunnel);
 bool tb_tunnel_port_on_path(const struct tb_tunnel *tunnel,
 			    const struct tb_port *port);
+int tb_tunnel_maximum_bandwidth(struct tb_tunnel *tunnel, int *max_up,
+				int *max_down);
+int tb_tunnel_allocated_bandwidth(struct tb_tunnel *tunnel, int *allocated_up,
+				  int *allocated_down);
+int tb_tunnel_alloc_bandwidth(struct tb_tunnel *tunnel, int *alloc_up,
+			      int *alloc_down);
 int tb_tunnel_consumed_bandwidth(struct tb_tunnel *tunnel, int *consumed_up,
 				 int *consumed_down);
 int tb_tunnel_release_unused_bandwidth(struct tb_tunnel *tunnel);
diff --git a/drivers/thunderbolt/usb4.c b/drivers/thunderbolt/usb4.c
index 2ed50fcbcca7a..1e5e9c147a310 100644
--- a/drivers/thunderbolt/usb4.c
+++ b/drivers/thunderbolt/usb4.c
@@ -2186,3 +2186,575 @@ err_request:
 	usb4_usb3_port_clear_cm_request(port);
 	return ret;
 }
+
+static bool is_usb4_dpin(const struct tb_port *port)
+{
+	if (!tb_port_is_dpin(port))
+		return false;
+	if (!tb_switch_is_usb4(port->sw))
+		return false;
+	return true;
+}
+
+/**
+ * usb4_dp_port_set_cm_id() - Assign CM ID to the DP IN adapter
+ * @port: DP IN adapter
+ * @cm_id: CM ID to assign
+ *
+ * Sets CM ID for the @port. Returns %0 on success and negative errno
+ * otherwise. Speficially returns %-EOPNOTSUPP if the @port does not
+ * support this.
+ */
+int usb4_dp_port_set_cm_id(struct tb_port *port, int cm_id)
+{
+	u32 val;
+	int ret;
+
+	if (!is_usb4_dpin(port))
+		return -EOPNOTSUPP;
+
+	ret = tb_port_read(port, &val, TB_CFG_PORT,
+			   port->cap_adap + ADP_DP_CS_2, 1);
+	if (ret)
+		return ret;
+
+	val &= ~ADP_DP_CS_2_CM_ID_MASK;
+	val |= cm_id << ADP_DP_CS_2_CM_ID_SHIFT;
+
+	return tb_port_write(port, &val, TB_CFG_PORT,
+			     port->cap_adap + ADP_DP_CS_2, 1);
+}
+
+/**
+ * usb4_dp_port_bw_mode_supported() - Is the bandwidth allocation mode supported
+ * @port: DP IN adapter to check
+ *
+ * Can be called to any DP IN adapter. Returns true if the adapter
+ * supports USB4 bandwidth allocation mode, false otherwise.
+ */
+bool usb4_dp_port_bw_mode_supported(struct tb_port *port)
+{
+	int ret;
+	u32 val;
+
+	if (!is_usb4_dpin(port))
+		return false;
+
+	ret = tb_port_read(port, &val, TB_CFG_PORT,
+			   port->cap_adap + DP_LOCAL_CAP, 1);
+	if (ret)
+		return false;
+
+	return !!(val & DP_COMMON_CAP_BW_MODE);
+}
+
+/**
+ * usb4_dp_port_bw_mode_enabled() - Is the bandwidth allocation mode enabled
+ * @port: DP IN adapter to check
+ *
+ * Can be called to any DP IN adapter. Returns true if the bandwidth
+ * allocation mode has been enabled, false otherwise.
+ */
+bool usb4_dp_port_bw_mode_enabled(struct tb_port *port)
+{
+	int ret;
+	u32 val;
+
+	if (!is_usb4_dpin(port))
+		return false;
+
+	ret = tb_port_read(port, &val, TB_CFG_PORT,
+			   port->cap_adap + ADP_DP_CS_8, 1);
+	if (ret)
+		return false;
+
+	return !!(val & ADP_DP_CS_8_DPME);
+}
+
+/**
+ * usb4_dp_port_set_cm_bw_mode_supported() - Set/clear CM support for bandwidth allocation mode
+ * @port: DP IN adapter
+ * @supported: Does the CM support bandwidth allocation mode
+ *
+ * Can be called to any DP IN adapter. Sets or clears the CM support bit
+ * of the DP IN adapter. Returns %0 in success and negative errno
+ * otherwise. Specifically returns %-OPNOTSUPP if the passed in adapter
+ * does not support this.
+ */
+int usb4_dp_port_set_cm_bw_mode_supported(struct tb_port *port, bool supported)
+{
+	u32 val;
+	int ret;
+
+	if (!is_usb4_dpin(port))
+		return -EOPNOTSUPP;
+
+	ret = tb_port_read(port, &val, TB_CFG_PORT,
+			   port->cap_adap + ADP_DP_CS_2, 1);
+	if (ret)
+		return ret;
+
+	if (supported)
+		val |= ADP_DP_CS_2_CMMS;
+	else
+		val &= ~ADP_DP_CS_2_CMMS;
+
+	return tb_port_write(port, &val, TB_CFG_PORT,
+			     port->cap_adap + ADP_DP_CS_2, 1);
+}
+
+/**
+ * usb4_dp_port_group_id() - Return Group ID assigned for the adapter
+ * @port: DP IN adapter
+ *
+ * Reads bandwidth allocation Group ID from the DP IN adapter and
+ * returns it. If the adapter does not support setting Group_ID
+ * %-EOPNOTSUPP is returned.
+ */
+int usb4_dp_port_group_id(struct tb_port *port)
+{
+	u32 val;
+	int ret;
+
+	if (!is_usb4_dpin(port))
+		return -EOPNOTSUPP;
+
+	ret = tb_port_read(port, &val, TB_CFG_PORT,
+			   port->cap_adap + ADP_DP_CS_2, 1);
+	if (ret)
+		return ret;
+
+	return (val & ADP_DP_CS_2_GROUP_ID_MASK) >> ADP_DP_CS_2_GROUP_ID_SHIFT;
+}
+
+/**
+ * usb4_dp_port_set_group_id() - Set adapter Group ID
+ * @port: DP IN adapter
+ * @group_id: Group ID for the adapter
+ *
+ * Sets bandwidth allocation mode Group ID for the DP IN adapter.
+ * Returns %0 in case of success and negative errno otherwise.
+ * Specifically returns %-EOPNOTSUPP if the adapter does not support
+ * this.
+ */
+int usb4_dp_port_set_group_id(struct tb_port *port, int group_id)
+{
+	u32 val;
+	int ret;
+
+	if (!is_usb4_dpin(port))
+		return -EOPNOTSUPP;
+
+	ret = tb_port_read(port, &val, TB_CFG_PORT,
+			   port->cap_adap + ADP_DP_CS_2, 1);
+	if (ret)
+		return ret;
+
+	val &= ~ADP_DP_CS_2_GROUP_ID_MASK;
+	val |= group_id << ADP_DP_CS_2_GROUP_ID_SHIFT;
+
+	return tb_port_write(port, &val, TB_CFG_PORT,
+			     port->cap_adap + ADP_DP_CS_2, 1);
+}
+
+/**
+ * usb4_dp_port_nrd() - Read non-reduced rate and lanes
+ * @port: DP IN adapter
+ * @rate: Non-reduced rate in Mb/s is placed here
+ * @lanes: Non-reduced lanes are placed here
+ *
+ * Reads the non-reduced rate and lanes from the DP IN adapter. Returns
+ * %0 in success and negative errno otherwise. Specifically returns
+ * %-EOPNOTSUPP if the adapter does not support this.
+ */
+int usb4_dp_port_nrd(struct tb_port *port, int *rate, int *lanes)
+{
+	u32 val, tmp;
+	int ret;
+
+	if (!is_usb4_dpin(port))
+		return -EOPNOTSUPP;
+
+	ret = tb_port_read(port, &val, TB_CFG_PORT,
+			   port->cap_adap + ADP_DP_CS_2, 1);
+	if (ret)
+		return ret;
+
+	tmp = (val & ADP_DP_CS_2_NRD_MLR_MASK) >> ADP_DP_CS_2_NRD_MLR_SHIFT;
+	switch (tmp) {
+	case DP_COMMON_CAP_RATE_RBR:
+		*rate = 1620;
+		break;
+	case DP_COMMON_CAP_RATE_HBR:
+		*rate = 2700;
+		break;
+	case DP_COMMON_CAP_RATE_HBR2:
+		*rate = 5400;
+		break;
+	case DP_COMMON_CAP_RATE_HBR3:
+		*rate = 8100;
+		break;
+	}
+
+	tmp = val & ADP_DP_CS_2_NRD_MLC_MASK;
+	switch (tmp) {
+	case DP_COMMON_CAP_1_LANE:
+		*lanes = 1;
+		break;
+	case DP_COMMON_CAP_2_LANES:
+		*lanes = 2;
+		break;
+	case DP_COMMON_CAP_4_LANES:
+		*lanes = 4;
+		break;
+	}
+
+	return 0;
+}
+
+/**
+ * usb4_dp_port_set_nrd() - Set non-reduced rate and lanes
+ * @port: DP IN adapter
+ * @rate: Non-reduced rate in Mb/s
+ * @lanes: Non-reduced lanes
+ *
+ * Before the capabilities reduction this function can be used to set
+ * the non-reduced values for the DP IN adapter. Returns %0 in success
+ * and negative errno otherwise. If the adapter does not support this
+ * %-EOPNOTSUPP is returned.
+ */
+int usb4_dp_port_set_nrd(struct tb_port *port, int rate, int lanes)
+{
+	u32 val;
+	int ret;
+
+	if (!is_usb4_dpin(port))
+		return -EOPNOTSUPP;
+
+	ret = tb_port_read(port, &val, TB_CFG_PORT,
+			   port->cap_adap + ADP_DP_CS_2, 1);
+	if (ret)
+		return ret;
+
+	val &= ~ADP_DP_CS_2_NRD_MLR_MASK;
+
+	switch (rate) {
+	case 1620:
+		break;
+	case 2700:
+		val |= (DP_COMMON_CAP_RATE_HBR << ADP_DP_CS_2_NRD_MLR_SHIFT)
+			& ADP_DP_CS_2_NRD_MLR_MASK;
+		break;
+	case 5400:
+		val |= (DP_COMMON_CAP_RATE_HBR2 << ADP_DP_CS_2_NRD_MLR_SHIFT)
+			& ADP_DP_CS_2_NRD_MLR_MASK;
+		break;
+	case 8100:
+		val |= (DP_COMMON_CAP_RATE_HBR3 << ADP_DP_CS_2_NRD_MLR_SHIFT)
+			& ADP_DP_CS_2_NRD_MLR_MASK;
+		break;
+	default:
+		return -EINVAL;
+	}
+
+	val &= ~ADP_DP_CS_2_NRD_MLC_MASK;
+
+	switch (lanes) {
+	case 1:
+		break;
+	case 2:
+		val |= DP_COMMON_CAP_2_LANES;
+		break;
+	case 4:
+		val |= DP_COMMON_CAP_4_LANES;
+		break;
+	default:
+		return -EINVAL;
+	}
+
+	return tb_port_write(port, &val, TB_CFG_PORT,
+			     port->cap_adap + ADP_DP_CS_2, 1);
+}
+
+/**
+ * usb4_dp_port_granularity() - Return granularity for the bandwidth values
+ * @port: DP IN adapter
+ *
+ * Reads the programmed granularity from @port. If the DP IN adapter does
+ * not support bandwidth allocation mode returns %-EOPNOTSUPP and negative
+ * errno in other error cases.
+ */
+int usb4_dp_port_granularity(struct tb_port *port)
+{
+	u32 val;
+	int ret;
+
+	if (!is_usb4_dpin(port))
+		return -EOPNOTSUPP;
+
+	ret = tb_port_read(port, &val, TB_CFG_PORT,
+			   port->cap_adap + ADP_DP_CS_2, 1);
+	if (ret)
+		return ret;
+
+	val &= ADP_DP_CS_2_GR_MASK;
+	val >>= ADP_DP_CS_2_GR_SHIFT;
+
+	switch (val) {
+	case ADP_DP_CS_2_GR_0_25G:
+		return 250;
+	case ADP_DP_CS_2_GR_0_5G:
+		return 500;
+	case ADP_DP_CS_2_GR_1G:
+		return 1000;
+	}
+
+	return -EINVAL;
+}
+
+/**
+ * usb4_dp_port_set_granularity() - Set granularity for the bandwidth values
+ * @port: DP IN adapter
+ * @granularity: Granularity in Mb/s. Supported values: 1000, 500 and 250.
+ *
+ * Sets the granularity used with the estimated, allocated and requested
+ * bandwidth. Returns %0 in success and negative errno otherwise. If the
+ * adapter does not support this %-EOPNOTSUPP is returned.
+ */
+int usb4_dp_port_set_granularity(struct tb_port *port, int granularity)
+{
+	u32 val;
+	int ret;
+
+	if (!is_usb4_dpin(port))
+		return -EOPNOTSUPP;
+
+	ret = tb_port_read(port, &val, TB_CFG_PORT,
+			   port->cap_adap + ADP_DP_CS_2, 1);
+	if (ret)
+		return ret;
+
+	val &= ~ADP_DP_CS_2_GR_MASK;
+
+	switch (granularity) {
+	case 250:
+		val |= ADP_DP_CS_2_GR_0_25G << ADP_DP_CS_2_GR_SHIFT;
+		break;
+	case 500:
+		val |= ADP_DP_CS_2_GR_0_5G << ADP_DP_CS_2_GR_SHIFT;
+		break;
+	case 1000:
+		val |= ADP_DP_CS_2_GR_1G << ADP_DP_CS_2_GR_SHIFT;
+		break;
+	default:
+		return -EINVAL;
+	}
+
+	return tb_port_write(port, &val, TB_CFG_PORT,
+			     port->cap_adap + ADP_DP_CS_2, 1);
+}
+
+/**
+ * usb4_dp_port_set_estimated_bw() - Set estimated bandwidth
+ * @port: DP IN adapter
+ * @bw: Estimated bandwidth in Mb/s.
+ *
+ * Sets the estimated bandwidth to @bw. Set the granularity by calling
+ * usb4_dp_port_set_granularity() before calling this. The @bw is round
+ * down to the closest granularity multiplier. Returns %0 in success
+ * and negative errno otherwise. Specifically returns %-EOPNOTSUPP if
+ * the adapter does not support this.
+ */
+int usb4_dp_port_set_estimated_bw(struct tb_port *port, int bw)
+{
+	u32 val, granularity;
+	int ret;
+
+	if (!is_usb4_dpin(port))
+		return -EOPNOTSUPP;
+
+	ret = usb4_dp_port_granularity(port);
+	if (ret < 0)
+		return ret;
+	granularity = ret;
+
+	ret = tb_port_read(port, &val, TB_CFG_PORT,
+			   port->cap_adap + ADP_DP_CS_2, 1);
+	if (ret)
+		return ret;
+
+	val &= ~ADP_DP_CS_2_ESTIMATED_BW_MASK;
+	val |= (bw / granularity) << ADP_DP_CS_2_ESTIMATED_BW_SHIFT;
+
+	return tb_port_write(port, &val, TB_CFG_PORT,
+			     port->cap_adap + ADP_DP_CS_2, 1);
+}
+
+/**
+ * usb4_dp_port_allocated_bw() - Return allocated bandwidth
+ * @port: DP IN adapter
+ *
+ * Reads and returns allocated bandwidth for @port in Mb/s (taking into
+ * account the programmed granularity). Returns negative errno in case
+ * of error.
+ */
+int usb4_dp_port_allocated_bw(struct tb_port *port)
+{
+	u32 val, granularity;
+	int ret;
+
+	if (!is_usb4_dpin(port))
+		return -EOPNOTSUPP;
+
+	ret = usb4_dp_port_granularity(port);
+	if (ret < 0)
+		return ret;
+	granularity = ret;
+
+	ret = tb_port_read(port, &val, TB_CFG_PORT,
+			   port->cap_adap + DP_STATUS, 1);
+	if (ret)
+		return ret;
+
+	val &= DP_STATUS_ALLOCATED_BW_MASK;
+	val >>= DP_STATUS_ALLOCATED_BW_SHIFT;
+
+	return val * granularity;
+}
+
+static int __usb4_dp_port_set_cm_ack(struct tb_port *port, bool ack)
+{
+	u32 val;
+	int ret;
+
+	ret = tb_port_read(port, &val, TB_CFG_PORT,
+			   port->cap_adap + ADP_DP_CS_2, 1);
+	if (ret)
+		return ret;
+
+	if (ack)
+		val |= ADP_DP_CS_2_CA;
+	else
+		val &= ~ADP_DP_CS_2_CA;
+
+	return tb_port_write(port, &val, TB_CFG_PORT,
+			     port->cap_adap + ADP_DP_CS_2, 1);
+}
+
+static inline int usb4_dp_port_set_cm_ack(struct tb_port *port)
+{
+	return __usb4_dp_port_set_cm_ack(port, true);
+}
+
+static int usb4_dp_port_wait_and_clear_cm_ack(struct tb_port *port,
+					      int timeout_msec)
+{
+	ktime_t end;
+	u32 val;
+	int ret;
+
+	ret = __usb4_dp_port_set_cm_ack(port, false);
+	if (ret)
+		return ret;
+
+	end = ktime_add_ms(ktime_get(), timeout_msec);
+	do {
+		ret = tb_port_read(port, &val, TB_CFG_PORT,
+				   port->cap_adap + ADP_DP_CS_8, 1);
+		if (ret)
+			return ret;
+
+		if (!(val & ADP_DP_CS_8_DR))
+			break;
+
+		usleep_range(50, 100);
+	} while (ktime_before(ktime_get(), end));
+
+	if (val & ADP_DP_CS_8_DR)
+		return -ETIMEDOUT;
+
+	ret = tb_port_read(port, &val, TB_CFG_PORT,
+			   port->cap_adap + ADP_DP_CS_2, 1);
+	if (ret)
+		return ret;
+
+	val &= ~ADP_DP_CS_2_CA;
+	return tb_port_write(port, &val, TB_CFG_PORT,
+			     port->cap_adap + ADP_DP_CS_2, 1);
+}
+
+/**
+ * usb4_dp_port_allocate_bw() - Set allocated bandwidth
+ * @port: DP IN adapter
+ * @bw: New allocated bandwidth in Mb/s
+ *
+ * Communicates the new allocated bandwidth with the DPCD (graphics
+ * driver). Takes into account the programmed granularity. Returns %0 in
+ * success and negative errno in case of error.
+ */
+int usb4_dp_port_allocate_bw(struct tb_port *port, int bw)
+{
+	u32 val, granularity;
+	int ret;
+
+	if (!is_usb4_dpin(port))
+		return -EOPNOTSUPP;
+
+	ret = usb4_dp_port_granularity(port);
+	if (ret < 0)
+		return ret;
+	granularity = ret;
+
+	ret = tb_port_read(port, &val, TB_CFG_PORT,
+			   port->cap_adap + DP_STATUS, 1);
+	if (ret)
+		return ret;
+
+	val &= ~DP_STATUS_ALLOCATED_BW_MASK;
+	val |= (bw / granularity) << DP_STATUS_ALLOCATED_BW_SHIFT;
+
+	ret = tb_port_write(port, &val, TB_CFG_PORT,
+			    port->cap_adap + DP_STATUS, 1);
+	if (ret)
+		return ret;
+
+	ret = usb4_dp_port_set_cm_ack(port);
+	if (ret)
+		return ret;
+
+	return usb4_dp_port_wait_and_clear_cm_ack(port, 500);
+}
+
+/**
+ * usb4_dp_port_requested_bw() - Read requested bandwidth
+ * @port: DP IN adapter
+ *
+ * Reads the DPCD (graphics driver) requested bandwidth and returns it
+ * in Mb/s. Takes the programmed granularity into account. In case of
+ * error returns negative errno. Specifically returns %-EOPNOTSUPP if
+ * the adapter does not support bandwidth allocation mode, and %ENODATA
+ * if there is no active bandwidth request from the graphics driver.
+ */
+int usb4_dp_port_requested_bw(struct tb_port *port)
+{
+	u32 val, granularity;
+	int ret;
+
+	if (!is_usb4_dpin(port))
+		return -EOPNOTSUPP;
+
+	ret = usb4_dp_port_granularity(port);
+	if (ret < 0)
+		return ret;
+	granularity = ret;
+
+	ret = tb_port_read(port, &val, TB_CFG_PORT,
+			   port->cap_adap + ADP_DP_CS_8, 1);
+	if (ret)
+		return ret;
+
+	if (!(val & ADP_DP_CS_8_DR))
+		return -ENODATA;
+
+	return (val & ADP_DP_CS_8_REQUESTED_BW_MASK) * granularity;
+}