thunderbolt: Add support for USB4 v2 80 Gb/s link

USB4 v2 bumps the per-lane speed up to 40 Gb/s. Also the lanes are
always bonded which gives 80 Gb/s symmetric link (and 120/40 Gb/s
asymmetric). This updates the speed and width of routers and XDomain
connections to support the Gen 4 link. For now we keep the link as is
even if it is already asymmetric.

While there make tb_port_set_link_width() static.
Signed-off-by: Gil Fine <gil.fine@intel.com>
Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com>

drivers/thunderbolt/dma_test.c

@@ -412,6 +412,7 @@ static void speed_get(const struct dma_test *dt, u64 *val)
 static int speed_validate(u64 val)
 {
 	switch (val) {
+	case 40:
 	case 20:
 	case 10:
 	case 0:
@@ -489,8 +490,11 @@ static void dma_test_check_errors(struct dma_test *dt, int ret)
 	if (!dt->error_code) {
 		if (dt->link_speed && dt->xd->link_speed != dt->link_speed) {
 			dt->error_code = DMA_TEST_SPEED_ERROR;
-		} else if (dt->link_width &&
-			   dt->xd->link_width != dt->link_width) {
+		} else if (dt->link_width) {
+			const struct tb_xdomain *xd = dt->xd;
+
+			if ((dt->link_width == 1 && xd->link_width != TB_LINK_WIDTH_SINGLE) ||
+			    (dt->link_width == 2 && xd->link_width < TB_LINK_WIDTH_DUAL))
 				dt->error_code = DMA_TEST_WIDTH_ERROR;
 		} else if (dt->packets_to_send != dt->packets_sent ||
 			 dt->packets_to_receive != dt->packets_received ||

drivers/thunderbolt/icm.c

@@ -850,7 +850,8 @@ icm_fr_device_connected(struct tb *tb, const struct icm_pkg_header *hdr)
 		sw->security_level = security_level;
 		sw->boot = boot;
 		sw->link_speed = speed_gen3 ? 20 : 10;
-		sw->link_width = dual_lane ? 2 : 1;
+		sw->link_width = dual_lane ? TB_LINK_WIDTH_DUAL :
+					     TB_LINK_WIDTH_SINGLE;
 		sw->rpm = intel_vss_is_rtd3(pkg->ep_name, sizeof(pkg->ep_name));
 
 		if (add_switch(parent_sw, sw))
@@ -1272,7 +1273,8 @@ __icm_tr_device_connected(struct tb *tb, const struct icm_pkg_header *hdr,
 		sw->security_level = security_level;
 		sw->boot = boot;
 		sw->link_speed = speed_gen3 ? 20 : 10;
-		sw->link_width = dual_lane ? 2 : 1;
+		sw->link_width = dual_lane ? TB_LINK_WIDTH_DUAL :
+					     TB_LINK_WIDTH_SINGLE;
 		sw->rpm = force_rtd3;
 		if (!sw->rpm)
 			sw->rpm = intel_vss_is_rtd3(pkg->ep_name,

drivers/thunderbolt/tb.c

@@ -570,7 +570,8 @@ static int tb_available_bandwidth(struct tb *tb, struct tb_port *src_port,
 		usb3_consumed_down = 0;
 	}
 
-	*available_up = *available_down = 40000;
+	/* Maximum possible bandwidth asymmetric Gen 4 link is 120 Gb/s */
+	*available_up = *available_down = 120000;
 
 	/* Find the minimum available bandwidth over all links */
 	tb_for_each_port_on_path(src_port, dst_port, port) {
@@ -581,18 +582,45 @@ static int tb_available_bandwidth(struct tb *tb, struct tb_port *src_port,
 
 		if (tb_is_upstream_port(port)) {
 			link_speed = port->sw->link_speed;
+			/*
+			 * sw->link_width is from upstream perspective
+			 * so we use the opposite for downstream of the
+			 * host router.
+			 */
+			if (port->sw->link_width == TB_LINK_WIDTH_ASYM_TX) {
+				up_bw = link_speed * 3 * 1000;
+				down_bw = link_speed * 1 * 1000;
+			} else if (port->sw->link_width == TB_LINK_WIDTH_ASYM_RX) {
+				up_bw = link_speed * 1 * 1000;
+				down_bw = link_speed * 3 * 1000;
+			} else {
+				up_bw = link_speed * port->sw->link_width * 1000;
+				down_bw = up_bw;
+			}
 		} else {
 			link_speed = tb_port_get_link_speed(port);
 			if (link_speed < 0)
 				return link_speed;
-		}
 
-		link_width = port->bonded ? 2 : 1;
+			link_width = tb_port_get_link_width(port);
+			if (link_width < 0)
+				return link_width;
+
+			if (link_width == TB_LINK_WIDTH_ASYM_TX) {
+				up_bw = link_speed * 1 * 1000;
+				down_bw = link_speed * 3 * 1000;
+			} else if (link_width == TB_LINK_WIDTH_ASYM_RX) {
+				up_bw = link_speed * 3 * 1000;
+				down_bw = link_speed * 1 * 1000;
+			} else {
+				up_bw = link_speed * link_width * 1000;
+				down_bw = up_bw;
+			}
+		}
 
-		up_bw = link_speed * link_width * 1000; /* Mb/s */
 		/* Leave 10% guard band */
 		up_bw -= up_bw / 10;
-		down_bw = up_bw;
+		down_bw -= down_bw / 10;
 
 		tb_port_dbg(port, "link total bandwidth %d/%d Mb/s\n", up_bw,
 			    down_bw);

drivers/thunderbolt/tb.h

@@ -135,7 +135,7 @@ struct tb_switch_tmu {
  * @vendor_name: Name of the vendor (or %NULL if not known)
  * @device_name: Name of the device (or %NULL if not known)
  * @link_speed: Speed of the link in Gb/s
- * @link_width: Width of the link (1 or 2)
+ * @link_width: Width of the upstream facing link
  * @link_usb4: Upstream link is USB4
  * @generation: Switch Thunderbolt generation
  * @cap_plug_events: Offset to the plug events capability (%0 if not found)
@@ -173,6 +173,11 @@ struct tb_switch_tmu {
  * switches) you need to have domain lock held.
  *
  * In USB4 terminology this structure represents a router.
+ *
+ * Note @link_width is not the same as whether link is bonded or not.
+ * For Gen 4 links the link is also bonded when it is asymmetric. The
+ * correct way to find out whether the link is bonded or not is to look
+ * @bonded field of the upstream port.
  */
 struct tb_switch {
 	struct device dev;
@@ -188,7 +193,7 @@ struct tb_switch {
 	const char *vendor_name;
 	const char *device_name;
 	unsigned int link_speed;
-	unsigned int link_width;
+	enum tb_link_width link_width;
 	bool link_usb4;
 	unsigned int generation;
 	int cap_plug_events;
@@ -1050,11 +1055,10 @@ static inline bool tb_port_use_credit_allocation(const struct tb_port *port)
 
 int tb_port_get_link_speed(struct tb_port *port);
 int tb_port_get_link_width(struct tb_port *port);
-int tb_port_set_link_width(struct tb_port *port, unsigned int width);
-int tb_port_set_lane_bonding(struct tb_port *port, bool bonding);
+int tb_port_set_link_width(struct tb_port *port, enum tb_link_width width);
 int tb_port_lane_bonding_enable(struct tb_port *port);
 void tb_port_lane_bonding_disable(struct tb_port *port);
-int tb_port_wait_for_link_width(struct tb_port *port, int width,
+int tb_port_wait_for_link_width(struct tb_port *port, unsigned int width_mask,
 				int timeout_msec);
 int tb_port_update_credits(struct tb_port *port);
 

drivers/thunderbolt/tb_regs.h

@@ -346,6 +346,7 @@ struct tb_regs_port_header {
 #define LANE_ADP_CS_1_CURRENT_SPEED_SHIFT	16
 #define LANE_ADP_CS_1_CURRENT_SPEED_GEN2	0x8
 #define LANE_ADP_CS_1_CURRENT_SPEED_GEN3	0x4
+#define LANE_ADP_CS_1_CURRENT_SPEED_GEN4	0x2
 #define LANE_ADP_CS_1_CURRENT_WIDTH_MASK	GENMASK(25, 20)
 #define LANE_ADP_CS_1_CURRENT_WIDTH_SHIFT	20
 #define LANE_ADP_CS_1_PMS			BIT(30)

drivers/thunderbolt/xdomain.c

@@ -1290,13 +1290,16 @@ static int tb_xdomain_link_state_change(struct tb_xdomain *xd,
 
 static int tb_xdomain_bond_lanes_uuid_high(struct tb_xdomain *xd)
 {
+	unsigned int width, width_mask;
 	struct tb_port *port;
-	int ret, width;
+	int ret;
 
 	if (xd->target_link_width == LANE_ADP_CS_1_TARGET_WIDTH_SINGLE) {
-		width = 1;
+		width = TB_LINK_WIDTH_SINGLE;
+		width_mask = width;
 	} else if (xd->target_link_width == LANE_ADP_CS_1_TARGET_WIDTH_DUAL) {
-		width = 2;
+		width = TB_LINK_WIDTH_DUAL;
+		width_mask = width | TB_LINK_WIDTH_ASYM_TX | TB_LINK_WIDTH_ASYM_RX;
 	} else {
 		if (xd->state_retries-- > 0) {
 			dev_dbg(&xd->dev,
@@ -1328,15 +1331,16 @@ static int tb_xdomain_bond_lanes_uuid_high(struct tb_xdomain *xd)
 		return ret;
 	}
 
-	ret = tb_port_wait_for_link_width(port, width, XDOMAIN_BONDING_TIMEOUT);
+	ret = tb_port_wait_for_link_width(port, width_mask,
+					  XDOMAIN_BONDING_TIMEOUT);
 	if (ret) {
 		dev_warn(&xd->dev, "error waiting for link width to become %d\n",
-			 width);
+			 width_mask);
 		return ret;
 	}
 
-	port->bonded = width == 2;
-	port->dual_link_port->bonded = width == 2;
+	port->bonded = width > TB_LINK_WIDTH_SINGLE;
+	port->dual_link_port->bonded = width > TB_LINK_WIDTH_SINGLE;
 
 	tb_port_update_credits(port);
 	tb_xdomain_update_link_attributes(xd);
@@ -1735,16 +1739,57 @@ static ssize_t speed_show(struct device *dev, struct device_attribute *attr,
 static DEVICE_ATTR(rx_speed, 0444, speed_show, NULL);
 static DEVICE_ATTR(tx_speed, 0444, speed_show, NULL);
 
-static ssize_t lanes_show(struct device *dev, struct device_attribute *attr,
+static ssize_t rx_lanes_show(struct device *dev, struct device_attribute *attr,
 			     char *buf)
 {
 	struct tb_xdomain *xd = container_of(dev, struct tb_xdomain, dev);
+	unsigned int width;
 
-	return sysfs_emit(buf, "%u\n", xd->link_width);
+	switch (xd->link_width) {
+	case TB_LINK_WIDTH_SINGLE:
+	case TB_LINK_WIDTH_ASYM_RX:
+		width = 1;
+		break;
+	case TB_LINK_WIDTH_DUAL:
+		width = 2;
+		break;
+	case TB_LINK_WIDTH_ASYM_TX:
+		width = 3;
+		break;
+	default:
+		WARN_ON_ONCE(1);
+		return -EINVAL;
+	}
+
+	return sysfs_emit(buf, "%u\n", width);
 }
+static DEVICE_ATTR(rx_lanes, 0444, rx_lanes_show, NULL);
 
-static DEVICE_ATTR(rx_lanes, 0444, lanes_show, NULL);
-static DEVICE_ATTR(tx_lanes, 0444, lanes_show, NULL);
+static ssize_t tx_lanes_show(struct device *dev, struct device_attribute *attr,
+			     char *buf)
+{
+	struct tb_xdomain *xd = container_of(dev, struct tb_xdomain, dev);
+	unsigned int width;
+
+	switch (xd->link_width) {
+	case TB_LINK_WIDTH_SINGLE:
+	case TB_LINK_WIDTH_ASYM_TX:
+		width = 1;
+		break;
+	case TB_LINK_WIDTH_DUAL:
+		width = 2;
+		break;
+	case TB_LINK_WIDTH_ASYM_RX:
+		width = 3;
+		break;
+	default:
+		WARN_ON_ONCE(1);
+		return -EINVAL;
+	}
+
+	return sysfs_emit(buf, "%u\n", width);
+}
+static DEVICE_ATTR(tx_lanes, 0444, tx_lanes_show, NULL);
 
 static struct attribute *xdomain_attrs[] = {
 	&dev_attr_device.attr,
@@ -1974,6 +2019,7 @@ void tb_xdomain_remove(struct tb_xdomain *xd)
  */
 int tb_xdomain_lane_bonding_enable(struct tb_xdomain *xd)
 {
+	unsigned int width_mask;
 	struct tb_port *port;
 	int ret;
 
@@ -1997,7 +2043,12 @@ int tb_xdomain_lane_bonding_enable(struct tb_xdomain *xd)
 		return ret;
 	}
 
-	ret = tb_port_wait_for_link_width(port, 2, XDOMAIN_BONDING_TIMEOUT);
+	/* Any of the widths are all bonded */
+	width_mask = TB_LINK_WIDTH_DUAL | TB_LINK_WIDTH_ASYM_TX |
+		     TB_LINK_WIDTH_ASYM_RX;
+
+	ret = tb_port_wait_for_link_width(port, width_mask,
+					  XDOMAIN_BONDING_TIMEOUT);
 	if (ret) {
 		tb_port_warn(port, "failed to enable lane bonding\n");
 		return ret;
@@ -2024,8 +2075,11 @@ void tb_xdomain_lane_bonding_disable(struct tb_xdomain *xd)
 
 	port = tb_xdomain_downstream_port(xd);
 	if (port->dual_link_port) {
+		int ret;
+
 		tb_port_lane_bonding_disable(port);
-		if (tb_port_wait_for_link_width(port, 1, 100) == -ETIMEDOUT)
+		ret = tb_port_wait_for_link_width(port, TB_LINK_WIDTH_SINGLE, 100);
+		if (ret == -ETIMEDOUT)
 			tb_port_warn(port, "timeout disabling lane bonding\n");
 		tb_port_disable(port->dual_link_port);
 		tb_port_update_credits(port);

include/linux/thunderbolt.h

@@ -171,6 +171,20 @@ struct tb_property *tb_property_get_next(struct tb_property_dir *dir,
 int tb_register_property_dir(const char *key, struct tb_property_dir *dir);
 void tb_unregister_property_dir(const char *key, struct tb_property_dir *dir);
 
+/**
+ * enum tb_link_width - Thunderbolt/USB4 link width
+ * @TB_LINK_WIDTH_SINGLE: Single lane link
+ * @TB_LINK_WIDTH_DUAL: Dual lane symmetric link
+ * @TB_LINK_WIDTH_ASYM_TX: Dual lane asymmetric Gen 4 link with 3 trasmitters
+ * @TB_LINK_WIDTH_ASYM_RX: Dual lane asymmetric Gen 4 link with 3 receivers
+ */
+enum tb_link_width {
+	TB_LINK_WIDTH_SINGLE = BIT(0),
+	TB_LINK_WIDTH_DUAL = BIT(1),
+	TB_LINK_WIDTH_ASYM_TX = BIT(2),
+	TB_LINK_WIDTH_ASYM_RX = BIT(3),
+};
+
 /**
  * struct tb_xdomain - Cross-domain (XDomain) connection
  * @dev: XDomain device
@@ -186,7 +200,7 @@ void tb_unregister_property_dir(const char *key, struct tb_property_dir *dir);
  * @vendor_name: Name of the vendor (or %NULL if not known)
  * @device_name: Name of the device (or %NULL if not known)
  * @link_speed: Speed of the link in Gb/s
- * @link_width: Width of the link (1 or 2)
+ * @link_width: Width of the downstream facing link
  * @link_usb4: Downstream link is USB4
  * @is_unplugged: The XDomain is unplugged
  * @needs_uuid: If the XDomain does not have @remote_uuid it will be
@@ -234,7 +248,7 @@ struct tb_xdomain {
 	const char *vendor_name;
 	const char *device_name;
 	unsigned int link_speed;
-	unsigned int link_width;
+	enum tb_link_width link_width;
 	bool link_usb4;
 	bool is_unplugged;
 	bool needs_uuid;