Adding upstream version 6.1.76.upstream/6.1.76

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 1573 insertions, 0 deletions

diff --git a/drivers/thunderbolt/debugfs.c b/drivers/thunderbolt/debugfs.c
new file mode 100644
index 000000000..f691bce5c
--- /dev/null
+++ b/drivers/thunderbolt/debugfs.c
@@ -0,0 +1,1573 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Debugfs interface
+ *
+ * Copyright (C) 2020, Intel Corporation
+ * Authors: Gil Fine <gil.fine@intel.com>
+ *	    Mika Westerberg <mika.westerberg@linux.intel.com>
+ */
+
+#include <linux/debugfs.h>
+#include <linux/pm_runtime.h>
+#include <linux/uaccess.h>
+
+#include "tb.h"
+#include "sb_regs.h"
+
+#define PORT_CAP_PCIE_LEN	1
+#define PORT_CAP_POWER_LEN	2
+#define PORT_CAP_LANE_LEN	3
+#define PORT_CAP_USB3_LEN	5
+#define PORT_CAP_DP_LEN		8
+#define PORT_CAP_TMU_LEN	8
+#define PORT_CAP_BASIC_LEN	9
+#define PORT_CAP_USB4_LEN	20
+
+#define SWITCH_CAP_TMU_LEN	26
+#define SWITCH_CAP_BASIC_LEN	27
+
+#define PATH_LEN		2
+
+#define COUNTER_SET_LEN		3
+
+#define DEBUGFS_ATTR(__space, __write)					\
+static int __space ## _open(struct inode *inode, struct file *file)	\
+{									\
+	return single_open(file, __space ## _show, inode->i_private);	\
+}									\
+									\
+static const struct file_operations __space ## _fops = {		\
+	.owner = THIS_MODULE,						\
+	.open = __space ## _open,					\
+	.release = single_release,					\
+	.read  = seq_read,						\
+	.write = __write,						\
+	.llseek = seq_lseek,						\
+}
+
+#define DEBUGFS_ATTR_RO(__space)					\
+	DEBUGFS_ATTR(__space, NULL)
+
+#define DEBUGFS_ATTR_RW(__space)					\
+	DEBUGFS_ATTR(__space, __space ## _write)
+
+static struct dentry *tb_debugfs_root;
+
+static void *validate_and_copy_from_user(const void __user *user_buf,
+					 size_t *count)
+{
+	size_t nbytes;
+	void *buf;
+
+	if (!*count)
+		return ERR_PTR(-EINVAL);
+
+	if (!access_ok(user_buf, *count))
+		return ERR_PTR(-EFAULT);
+
+	buf = (void *)get_zeroed_page(GFP_KERNEL);
+	if (!buf)
+		return ERR_PTR(-ENOMEM);
+
+	nbytes = min_t(size_t, *count, PAGE_SIZE);
+	if (copy_from_user(buf, user_buf, nbytes)) {
+		free_page((unsigned long)buf);
+		return ERR_PTR(-EFAULT);
+	}
+
+	*count = nbytes;
+	return buf;
+}
+
+static bool parse_line(char **line, u32 *offs, u32 *val, int short_fmt_len,
+		       int long_fmt_len)
+{
+	char *token;
+	u32 v[5];
+	int ret;
+
+	token = strsep(line, "\n");
+	if (!token)
+		return false;
+
+	/*
+	 * For Adapter/Router configuration space:
+	 * Short format is: offset value\n
+	 *		    v[0]   v[1]
+	 * Long format as produced from the read side:
+	 * offset relative_offset cap_id vs_cap_id value\n
+	 * v[0]   v[1]            v[2]   v[3]      v[4]
+	 *
+	 * For Counter configuration space:
+	 * Short format is: offset\n
+	 *		    v[0]
+	 * Long format as produced from the read side:
+	 * offset relative_offset counter_id value\n
+	 * v[0]   v[1]            v[2]       v[3]
+	 */
+	ret = sscanf(token, "%i %i %i %i %i", &v[0], &v[1], &v[2], &v[3], &v[4]);
+	/* In case of Counters, clear counter, "val" content is NA */
+	if (ret == short_fmt_len) {
+		*offs = v[0];
+		*val = v[short_fmt_len - 1];
+		return true;
+	} else if (ret == long_fmt_len) {
+		*offs = v[0];
+		*val = v[long_fmt_len - 1];
+		return true;
+	}
+
+	return false;
+}
+
+#if IS_ENABLED(CONFIG_USB4_DEBUGFS_WRITE)
+static ssize_t regs_write(struct tb_switch *sw, struct tb_port *port,
+			  const char __user *user_buf, size_t count,
+			  loff_t *ppos)
+{
+	struct tb *tb = sw->tb;
+	char *line, *buf;
+	u32 val, offset;
+	int ret = 0;
+
+	buf = validate_and_copy_from_user(user_buf, &count);
+	if (IS_ERR(buf))
+		return PTR_ERR(buf);
+
+	pm_runtime_get_sync(&sw->dev);
+
+	if (mutex_lock_interruptible(&tb->lock)) {
+		ret = -ERESTARTSYS;
+		goto out;
+	}
+
+	/* User did hardware changes behind the driver's back */
+	add_taint(TAINT_USER, LOCKDEP_STILL_OK);
+
+	line = buf;
+	while (parse_line(&line, &offset, &val, 2, 5)) {
+		if (port)
+			ret = tb_port_write(port, &val, TB_CFG_PORT, offset, 1);
+		else
+			ret = tb_sw_write(sw, &val, TB_CFG_SWITCH, offset, 1);
+		if (ret)
+			break;
+	}
+
+	mutex_unlock(&tb->lock);
+
+out:
+	pm_runtime_mark_last_busy(&sw->dev);
+	pm_runtime_put_autosuspend(&sw->dev);
+	free_page((unsigned long)buf);
+
+	return ret < 0 ? ret : count;
+}
+
+static ssize_t port_regs_write(struct file *file, const char __user *user_buf,
+			       size_t count, loff_t *ppos)
+{
+	struct seq_file *s = file->private_data;
+	struct tb_port *port = s->private;
+
+	return regs_write(port->sw, port, user_buf, count, ppos);
+}
+
+static ssize_t switch_regs_write(struct file *file, const char __user *user_buf,
+				 size_t count, loff_t *ppos)
+{
+	struct seq_file *s = file->private_data;
+	struct tb_switch *sw = s->private;
+
+	return regs_write(sw, NULL, user_buf, count, ppos);
+}
+#define DEBUGFS_MODE		0600
+#else
+#define port_regs_write		NULL
+#define switch_regs_write	NULL
+#define DEBUGFS_MODE		0400
+#endif
+
+#if IS_ENABLED(CONFIG_USB4_DEBUGFS_MARGINING)
+/**
+ * struct tb_margining - Lane margining support
+ * @caps: Port lane margining capabilities
+ * @results: Last lane margining results
+ * @lanes: %0, %1 or %7 (all)
+ * @min_ber_level: Minimum supported BER level contour value
+ * @max_ber_level: Maximum supported BER level contour value
+ * @ber_level: Current BER level contour value
+ * @voltage_steps: Number of mandatory voltage steps
+ * @max_voltage_offset: Maximum mandatory voltage offset (in mV)
+ * @time_steps: Number of time margin steps
+ * @max_time_offset: Maximum time margin offset (in mUI)
+ * @software: %true if software margining is used instead of hardware
+ * @time: %true if time margining is used instead of voltage
+ * @right_high: %false if left/low margin test is performed, %true if
+ *		right/high
+ */
+struct tb_margining {
+	u32 caps[2];
+	u32 results[2];
+	unsigned int lanes;
+	unsigned int min_ber_level;
+	unsigned int max_ber_level;
+	unsigned int ber_level;
+	unsigned int voltage_steps;
+	unsigned int max_voltage_offset;
+	unsigned int time_steps;
+	unsigned int max_time_offset;
+	bool software;
+	bool time;
+	bool right_high;
+};
+
+static bool supports_software(const struct usb4_port *usb4)
+{
+	return usb4->margining->caps[0] & USB4_MARGIN_CAP_0_MODES_SW;
+}
+
+static bool supports_hardware(const struct usb4_port *usb4)
+{
+	return usb4->margining->caps[0] & USB4_MARGIN_CAP_0_MODES_HW;
+}
+
+static bool both_lanes(const struct usb4_port *usb4)
+{
+	return usb4->margining->caps[0] & USB4_MARGIN_CAP_0_2_LANES;
+}
+
+static unsigned int independent_voltage_margins(const struct usb4_port *usb4)
+{
+	return (usb4->margining->caps[0] & USB4_MARGIN_CAP_0_VOLTAGE_INDP_MASK) >>
+		USB4_MARGIN_CAP_0_VOLTAGE_INDP_SHIFT;
+}
+
+static bool supports_time(const struct usb4_port *usb4)
+{
+	return usb4->margining->caps[0] & USB4_MARGIN_CAP_0_TIME;
+}
+
+/* Only applicable if supports_time() returns true */
+static unsigned int independent_time_margins(const struct usb4_port *usb4)
+{
+	return (usb4->margining->caps[1] & USB4_MARGIN_CAP_1_TIME_INDP_MASK) >>
+		USB4_MARGIN_CAP_1_TIME_INDP_SHIFT;
+}
+
+static ssize_t
+margining_ber_level_write(struct file *file, const char __user *user_buf,
+			   size_t count, loff_t *ppos)
+{
+	struct seq_file *s = file->private_data;
+	struct tb_port *port = s->private;
+	struct usb4_port *usb4 = port->usb4;
+	struct tb *tb = port->sw->tb;
+	unsigned int val;
+	int ret = 0;
+	char *buf;
+
+	if (mutex_lock_interruptible(&tb->lock))
+		return -ERESTARTSYS;
+
+	if (usb4->margining->software) {
+		ret = -EINVAL;
+		goto out_unlock;
+	}
+
+	buf = validate_and_copy_from_user(user_buf, &count);
+	if (IS_ERR(buf)) {
+		ret = PTR_ERR(buf);
+		goto out_unlock;
+	}
+
+	buf[count - 1] = '\0';
+
+	ret = kstrtouint(buf, 10, &val);
+	if (ret)
+		goto out_free;
+
+	if (val < usb4->margining->min_ber_level ||
+	    val > usb4->margining->max_ber_level) {
+		ret = -EINVAL;
+		goto out_free;
+	}
+
+	usb4->margining->ber_level = val;
+
+out_free:
+	free_page((unsigned long)buf);
+out_unlock:
+	mutex_unlock(&tb->lock);
+
+	return ret < 0 ? ret : count;
+}
+
+static void ber_level_show(struct seq_file *s, unsigned int val)
+{
+	if (val % 2)
+		seq_printf(s, "3 * 1e%d (%u)\n", -12 + (val + 1) / 2, val);
+	else
+		seq_printf(s, "1e%d (%u)\n", -12 + val / 2, val);
+}
+
+static int margining_ber_level_show(struct seq_file *s, void *not_used)
+{
+	struct tb_port *port = s->private;
+	struct usb4_port *usb4 = port->usb4;
+
+	if (usb4->margining->software)
+		return -EINVAL;
+	ber_level_show(s, usb4->margining->ber_level);
+	return 0;
+}
+DEBUGFS_ATTR_RW(margining_ber_level);
+
+static int margining_caps_show(struct seq_file *s, void *not_used)
+{
+	struct tb_port *port = s->private;
+	struct usb4_port *usb4 = port->usb4;
+	struct tb *tb = port->sw->tb;
+	u32 cap0, cap1;
+
+	if (mutex_lock_interruptible(&tb->lock))
+		return -ERESTARTSYS;
+
+	/* Dump the raw caps first */
+	cap0 = usb4->margining->caps[0];
+	seq_printf(s, "0x%08x\n", cap0);
+	cap1 = usb4->margining->caps[1];
+	seq_printf(s, "0x%08x\n", cap1);
+
+	seq_printf(s, "# software margining: %s\n",
+		   supports_software(usb4) ? "yes" : "no");
+	if (supports_hardware(usb4)) {
+		seq_puts(s, "# hardware margining: yes\n");
+		seq_puts(s, "# minimum BER level contour: ");
+		ber_level_show(s, usb4->margining->min_ber_level);
+		seq_puts(s, "# maximum BER level contour: ");
+		ber_level_show(s, usb4->margining->max_ber_level);
+	} else {
+		seq_puts(s, "# hardware margining: no\n");
+	}
+
+	seq_printf(s, "# both lanes simultaneously: %s\n",
+		  both_lanes(usb4) ? "yes" : "no");
+	seq_printf(s, "# voltage margin steps: %u\n",
+		   usb4->margining->voltage_steps);
+	seq_printf(s, "# maximum voltage offset: %u mV\n",
+		   usb4->margining->max_voltage_offset);
+
+	switch (independent_voltage_margins(usb4)) {
+	case USB4_MARGIN_CAP_0_VOLTAGE_MIN:
+		seq_puts(s, "# returns minimum between high and low voltage margins\n");
+		break;
+	case USB4_MARGIN_CAP_0_VOLTAGE_HL:
+		seq_puts(s, "# returns high or low voltage margin\n");
+		break;
+	case USB4_MARGIN_CAP_0_VOLTAGE_BOTH:
+		seq_puts(s, "# returns both high and low margins\n");
+		break;
+	}
+
+	if (supports_time(usb4)) {
+		seq_puts(s, "# time margining: yes\n");
+		seq_printf(s, "# time margining is destructive: %s\n",
+			   cap1 & USB4_MARGIN_CAP_1_TIME_DESTR ? "yes" : "no");
+
+		switch (independent_time_margins(usb4)) {
+		case USB4_MARGIN_CAP_1_TIME_MIN:
+			seq_puts(s, "# returns minimum between left and right time margins\n");
+			break;
+		case USB4_MARGIN_CAP_1_TIME_LR:
+			seq_puts(s, "# returns left or right margin\n");
+			break;
+		case USB4_MARGIN_CAP_1_TIME_BOTH:
+			seq_puts(s, "# returns both left and right margins\n");
+			break;
+		}
+
+		seq_printf(s, "# time margin steps: %u\n",
+			   usb4->margining->time_steps);
+		seq_printf(s, "# maximum time offset: %u mUI\n",
+			   usb4->margining->max_time_offset);
+	} else {
+		seq_puts(s, "# time margining: no\n");
+	}
+
+	mutex_unlock(&tb->lock);
+	return 0;
+}
+DEBUGFS_ATTR_RO(margining_caps);
+
+static ssize_t
+margining_lanes_write(struct file *file, const char __user *user_buf,
+		      size_t count, loff_t *ppos)
+{
+	struct seq_file *s = file->private_data;
+	struct tb_port *port = s->private;
+	struct usb4_port *usb4 = port->usb4;
+	struct tb *tb = port->sw->tb;
+	int ret = 0;
+	char *buf;
+
+	buf = validate_and_copy_from_user(user_buf, &count);
+	if (IS_ERR(buf))
+		return PTR_ERR(buf);
+
+	buf[count - 1] = '\0';
+
+	if (mutex_lock_interruptible(&tb->lock)) {
+		ret = -ERESTARTSYS;
+		goto out_free;
+	}
+
+	if (!strcmp(buf, "0")) {
+		usb4->margining->lanes = 0;
+	} else if (!strcmp(buf, "1")) {
+		usb4->margining->lanes = 1;
+	} else if (!strcmp(buf, "all")) {
+		/* Needs to be supported */
+		if (both_lanes(usb4))
+			usb4->margining->lanes = 7;
+		else
+			ret = -EINVAL;
+	} else {
+		ret = -EINVAL;
+	}
+
+	mutex_unlock(&tb->lock);
+
+out_free:
+	free_page((unsigned long)buf);
+	return ret < 0 ? ret : count;
+}
+
+static int margining_lanes_show(struct seq_file *s, void *not_used)
+{
+	struct tb_port *port = s->private;
+	struct usb4_port *usb4 = port->usb4;
+	struct tb *tb = port->sw->tb;
+	unsigned int lanes;
+
+	if (mutex_lock_interruptible(&tb->lock))
+		return -ERESTARTSYS;
+
+	lanes = usb4->margining->lanes;
+	if (both_lanes(usb4)) {
+		if (!lanes)
+			seq_puts(s, "[0] 1 all\n");
+		else if (lanes == 1)
+			seq_puts(s, "0 [1] all\n");
+		else
+			seq_puts(s, "0 1 [all]\n");
+	} else {
+		if (!lanes)
+			seq_puts(s, "[0] 1\n");
+		else
+			seq_puts(s, "0 [1]\n");
+	}
+
+	mutex_unlock(&tb->lock);
+	return 0;
+}
+DEBUGFS_ATTR_RW(margining_lanes);
+
+static ssize_t margining_mode_write(struct file *file,
+				   const char __user *user_buf,
+				   size_t count, loff_t *ppos)
+{
+	struct seq_file *s = file->private_data;
+	struct tb_port *port = s->private;
+	struct usb4_port *usb4 = port->usb4;
+	struct tb *tb = port->sw->tb;
+	int ret = 0;
+	char *buf;
+
+	buf = validate_and_copy_from_user(user_buf, &count);
+	if (IS_ERR(buf))
+		return PTR_ERR(buf);
+
+	buf[count - 1] = '\0';
+
+	if (mutex_lock_interruptible(&tb->lock)) {
+		ret = -ERESTARTSYS;
+		goto out_free;
+	}
+
+	if (!strcmp(buf, "software")) {
+		if (supports_software(usb4))
+			usb4->margining->software = true;
+		else
+			ret = -EINVAL;
+	} else if (!strcmp(buf, "hardware")) {
+		if (supports_hardware(usb4))
+			usb4->margining->software = false;
+		else
+			ret = -EINVAL;
+	} else {
+		ret = -EINVAL;
+	}
+
+	mutex_unlock(&tb->lock);
+
+out_free:
+	free_page((unsigned long)buf);
+	return ret ? ret : count;
+}
+
+static int margining_mode_show(struct seq_file *s, void *not_used)
+{
+	const struct tb_port *port = s->private;
+	const struct usb4_port *usb4 = port->usb4;
+	struct tb *tb = port->sw->tb;
+	const char *space = "";
+
+	if (mutex_lock_interruptible(&tb->lock))
+		return -ERESTARTSYS;
+
+	if (supports_software(usb4)) {
+		if (usb4->margining->software)
+			seq_puts(s, "[software]");
+		else
+			seq_puts(s, "software");
+		space = " ";
+	}
+	if (supports_hardware(usb4)) {
+		if (usb4->margining->software)
+			seq_printf(s, "%shardware", space);
+		else
+			seq_printf(s, "%s[hardware]", space);
+	}
+
+	mutex_unlock(&tb->lock);
+
+	seq_puts(s, "\n");
+	return 0;
+}
+DEBUGFS_ATTR_RW(margining_mode);
+
+static int margining_run_write(void *data, u64 val)
+{
+	struct tb_port *port = data;
+	struct usb4_port *usb4 = port->usb4;
+	struct tb_switch *sw = port->sw;
+	struct tb_margining *margining;
+	struct tb *tb = sw->tb;
+	int ret;
+
+	if (val != 1)
+		return -EINVAL;
+
+	pm_runtime_get_sync(&sw->dev);
+
+	if (mutex_lock_interruptible(&tb->lock)) {
+		ret = -ERESTARTSYS;
+		goto out_rpm_put;
+	}
+
+	/*
+	 * CL states may interfere with lane margining so inform the user know
+	 * and bail out.
+	 */
+	if (tb_port_is_clx_enabled(port, TB_CL1 | TB_CL2)) {
+		tb_port_warn(port,
+			     "CL states are enabled, Disable them with clx=0 and re-connect\n");
+		ret = -EINVAL;
+		goto out_unlock;
+	}
+
+	margining = usb4->margining;
+
+	if (margining->software) {
+		tb_port_dbg(port, "running software %s lane margining for lanes %u\n",
+			    margining->time ? "time" : "voltage", margining->lanes);
+		ret = usb4_port_sw_margin(port, margining->lanes, margining->time,
+					  margining->right_high,
+					  USB4_MARGIN_SW_COUNTER_CLEAR);
+		if (ret)
+			goto out_unlock;
+
+		ret = usb4_port_sw_margin_errors(port, &margining->results[0]);
+	} else {
+		tb_port_dbg(port, "running hardware %s lane margining for lanes %u\n",
+			    margining->time ? "time" : "voltage", margining->lanes);
+		/* Clear the results */
+		margining->results[0] = 0;
+		margining->results[1] = 0;
+		ret = usb4_port_hw_margin(port, margining->lanes,
+					  margining->ber_level, margining->time,
+					  margining->right_high, margining->results);
+	}
+
+out_unlock:
+	mutex_unlock(&tb->lock);
+out_rpm_put:
+	pm_runtime_mark_last_busy(&sw->dev);
+	pm_runtime_put_autosuspend(&sw->dev);
+
+	return ret;
+}
+DEFINE_DEBUGFS_ATTRIBUTE(margining_run_fops, NULL, margining_run_write,
+			 "%llu\n");
+
+static ssize_t margining_results_write(struct file *file,
+				       const char __user *user_buf,
+				       size_t count, loff_t *ppos)
+{
+	struct seq_file *s = file->private_data;
+	struct tb_port *port = s->private;
+	struct usb4_port *usb4 = port->usb4;
+	struct tb *tb = port->sw->tb;
+
+	if (mutex_lock_interruptible(&tb->lock))
+		return -ERESTARTSYS;
+
+	/* Just clear the results */
+	usb4->margining->results[0] = 0;
+	usb4->margining->results[1] = 0;
+
+	mutex_unlock(&tb->lock);
+	return count;
+}
+
+static void voltage_margin_show(struct seq_file *s,
+				const struct tb_margining *margining, u8 val)
+{
+	unsigned int tmp, voltage;
+
+	tmp = val & USB4_MARGIN_HW_RES_1_MARGIN_MASK;
+	voltage = tmp * margining->max_voltage_offset / margining->voltage_steps;
+	seq_printf(s, "%u mV (%u)", voltage, tmp);
+	if (val & USB4_MARGIN_HW_RES_1_EXCEEDS)
+		seq_puts(s, " exceeds maximum");
+	seq_puts(s, "\n");
+}
+
+static void time_margin_show(struct seq_file *s,
+			     const struct tb_margining *margining, u8 val)
+{
+	unsigned int tmp, interval;
+
+	tmp = val & USB4_MARGIN_HW_RES_1_MARGIN_MASK;
+	interval = tmp * margining->max_time_offset / margining->time_steps;
+	seq_printf(s, "%u mUI (%u)", interval, tmp);
+	if (val & USB4_MARGIN_HW_RES_1_EXCEEDS)
+		seq_puts(s, " exceeds maximum");
+	seq_puts(s, "\n");
+}
+
+static int margining_results_show(struct seq_file *s, void *not_used)
+{
+	struct tb_port *port = s->private;
+	struct usb4_port *usb4 = port->usb4;
+	struct tb_margining *margining;
+	struct tb *tb = port->sw->tb;
+
+	if (mutex_lock_interruptible(&tb->lock))
+		return -ERESTARTSYS;
+
+	margining = usb4->margining;
+	/* Dump the raw results first */
+	seq_printf(s, "0x%08x\n", margining->results[0]);
+	/* Only the hardware margining has two result dwords */
+	if (!margining->software) {
+		unsigned int val;
+
+		seq_printf(s, "0x%08x\n", margining->results[1]);
+
+		if (margining->time) {
+			if (!margining->lanes || margining->lanes == 7) {
+				val = margining->results[1];
+				seq_puts(s, "# lane 0 right time margin: ");
+				time_margin_show(s, margining, val);
+				val = margining->results[1] >>
+					USB4_MARGIN_HW_RES_1_L0_LL_MARGIN_SHIFT;
+				seq_puts(s, "# lane 0 left time margin: ");
+				time_margin_show(s, margining, val);
+			}
+			if (margining->lanes == 1 || margining->lanes == 7) {
+				val = margining->results[1] >>
+					USB4_MARGIN_HW_RES_1_L1_RH_MARGIN_SHIFT;
+				seq_puts(s, "# lane 1 right time margin: ");
+				time_margin_show(s, margining, val);
+				val = margining->results[1] >>
+					USB4_MARGIN_HW_RES_1_L1_LL_MARGIN_SHIFT;
+				seq_puts(s, "# lane 1 left time margin: ");
+				time_margin_show(s, margining, val);
+			}
+		} else {
+			if (!margining->lanes || margining->lanes == 7) {
+				val = margining->results[1];
+				seq_puts(s, "# lane 0 high voltage margin: ");
+				voltage_margin_show(s, margining, val);
+				val = margining->results[1] >>
+					USB4_MARGIN_HW_RES_1_L0_LL_MARGIN_SHIFT;
+				seq_puts(s, "# lane 0 low voltage margin: ");
+				voltage_margin_show(s, margining, val);
+			}
+			if (margining->lanes == 1 || margining->lanes == 7) {
+				val = margining->results[1] >>
+					USB4_MARGIN_HW_RES_1_L1_RH_MARGIN_SHIFT;
+				seq_puts(s, "# lane 1 high voltage margin: ");
+				voltage_margin_show(s, margining, val);
+				val = margining->results[1] >>
+					USB4_MARGIN_HW_RES_1_L1_LL_MARGIN_SHIFT;
+				seq_puts(s, "# lane 1 low voltage margin: ");
+				voltage_margin_show(s, margining, val);
+			}
+		}
+	}
+
+	mutex_unlock(&tb->lock);
+	return 0;
+}
+DEBUGFS_ATTR_RW(margining_results);
+
+static ssize_t margining_test_write(struct file *file,
+				    const char __user *user_buf,
+				    size_t count, loff_t *ppos)
+{
+	struct seq_file *s = file->private_data;
+	struct tb_port *port = s->private;
+	struct usb4_port *usb4 = port->usb4;
+	struct tb *tb = port->sw->tb;
+	int ret = 0;
+	char *buf;
+
+	buf = validate_and_copy_from_user(user_buf, &count);
+	if (IS_ERR(buf))
+		return PTR_ERR(buf);
+
+	buf[count - 1] = '\0';
+
+	if (mutex_lock_interruptible(&tb->lock)) {
+		ret = -ERESTARTSYS;
+		goto out_free;
+	}
+
+	if (!strcmp(buf, "time") && supports_time(usb4))
+		usb4->margining->time = true;
+	else if (!strcmp(buf, "voltage"))
+		usb4->margining->time = false;
+	else
+		ret = -EINVAL;
+
+	mutex_unlock(&tb->lock);
+
+out_free:
+	free_page((unsigned long)buf);
+	return ret ? ret : count;
+}
+
+static int margining_test_show(struct seq_file *s, void *not_used)
+{
+	struct tb_port *port = s->private;
+	struct usb4_port *usb4 = port->usb4;
+	struct tb *tb = port->sw->tb;
+
+	if (mutex_lock_interruptible(&tb->lock))
+		return -ERESTARTSYS;
+
+	if (supports_time(usb4)) {
+		if (usb4->margining->time)
+			seq_puts(s, "voltage [time]\n");
+		else
+			seq_puts(s, "[voltage] time\n");
+	} else {
+		seq_puts(s, "[voltage]\n");
+	}
+
+	mutex_unlock(&tb->lock);
+	return 0;
+}
+DEBUGFS_ATTR_RW(margining_test);
+
+static ssize_t margining_margin_write(struct file *file,
+				    const char __user *user_buf,
+				    size_t count, loff_t *ppos)
+{
+	struct seq_file *s = file->private_data;
+	struct tb_port *port = s->private;
+	struct usb4_port *usb4 = port->usb4;
+	struct tb *tb = port->sw->tb;
+	int ret = 0;
+	char *buf;
+
+	buf = validate_and_copy_from_user(user_buf, &count);
+	if (IS_ERR(buf))
+		return PTR_ERR(buf);
+
+	buf[count - 1] = '\0';
+
+	if (mutex_lock_interruptible(&tb->lock)) {
+		ret = -ERESTARTSYS;
+		goto out_free;
+	}
+
+	if (usb4->margining->time) {
+		if (!strcmp(buf, "left"))
+			usb4->margining->right_high = false;
+		else if (!strcmp(buf, "right"))
+			usb4->margining->right_high = true;
+		else
+			ret = -EINVAL;
+	} else {
+		if (!strcmp(buf, "low"))
+			usb4->margining->right_high = false;
+		else if (!strcmp(buf, "high"))
+			usb4->margining->right_high = true;
+		else
+			ret = -EINVAL;
+	}
+
+	mutex_unlock(&tb->lock);
+
+out_free:
+	free_page((unsigned long)buf);
+	return ret ? ret : count;
+}
+
+static int margining_margin_show(struct seq_file *s, void *not_used)
+{
+	struct tb_port *port = s->private;
+	struct usb4_port *usb4 = port->usb4;
+	struct tb *tb = port->sw->tb;
+
+	if (mutex_lock_interruptible(&tb->lock))
+		return -ERESTARTSYS;
+
+	if (usb4->margining->time) {
+		if (usb4->margining->right_high)
+			seq_puts(s, "left [right]\n");
+		else
+			seq_puts(s, "[left] right\n");
+	} else {
+		if (usb4->margining->right_high)
+			seq_puts(s, "low [high]\n");
+		else
+			seq_puts(s, "[low] high\n");
+	}
+
+	mutex_unlock(&tb->lock);
+	return 0;
+}
+DEBUGFS_ATTR_RW(margining_margin);
+
+static void margining_port_init(struct tb_port *port)
+{
+	struct tb_margining *margining;
+	struct dentry *dir, *parent;
+	struct usb4_port *usb4;
+	char dir_name[10];
+	unsigned int val;
+	int ret;
+
+	usb4 = port->usb4;
+	if (!usb4)
+		return;
+
+	snprintf(dir_name, sizeof(dir_name), "port%d", port->port);
+	parent = debugfs_lookup(dir_name, port->sw->debugfs_dir);
+
+	margining = kzalloc(sizeof(*margining), GFP_KERNEL);
+	if (!margining)
+		return;
+
+	ret = usb4_port_margining_caps(port, margining->caps);
+	if (ret) {
+		kfree(margining);
+		return;
+	}
+
+	usb4->margining = margining;
+
+	/* Set the initial mode */
+	if (supports_software(usb4))
+		margining->software = true;
+
+	val = (margining->caps[0] & USB4_MARGIN_CAP_0_VOLTAGE_STEPS_MASK) >>
+		USB4_MARGIN_CAP_0_VOLTAGE_STEPS_SHIFT;
+	margining->voltage_steps = val;
+	val = (margining->caps[0] & USB4_MARGIN_CAP_0_MAX_VOLTAGE_OFFSET_MASK) >>
+		USB4_MARGIN_CAP_0_MAX_VOLTAGE_OFFSET_SHIFT;
+	margining->max_voltage_offset = 74 + val * 2;
+
+	if (supports_time(usb4)) {
+		val = (margining->caps[1] & USB4_MARGIN_CAP_1_TIME_STEPS_MASK) >>
+			USB4_MARGIN_CAP_1_TIME_STEPS_SHIFT;
+		margining->time_steps = val;
+		val = (margining->caps[1] & USB4_MARGIN_CAP_1_TIME_OFFSET_MASK) >>
+			USB4_MARGIN_CAP_1_TIME_OFFSET_SHIFT;
+		/*
+		 * Store it as mUI (milli Unit Interval) because we want
+		 * to keep it as integer.
+		 */
+		margining->max_time_offset = 200 + 10 * val;
+	}
+
+	dir = debugfs_create_dir("margining", parent);
+	if (supports_hardware(usb4)) {
+		val = (margining->caps[1] & USB4_MARGIN_CAP_1_MIN_BER_MASK) >>
+			USB4_MARGIN_CAP_1_MIN_BER_SHIFT;
+		margining->min_ber_level = val;
+		val = (margining->caps[1] & USB4_MARGIN_CAP_1_MAX_BER_MASK) >>
+			USB4_MARGIN_CAP_1_MAX_BER_SHIFT;
+		margining->max_ber_level = val;
+
+		/* Set the default to minimum */
+		margining->ber_level = margining->min_ber_level;
+
+		debugfs_create_file("ber_level_contour", 0400, dir, port,
+				    &margining_ber_level_fops);
+	}
+	debugfs_create_file("caps", 0400, dir, port, &margining_caps_fops);
+	debugfs_create_file("lanes", 0600, dir, port, &margining_lanes_fops);
+	debugfs_create_file("mode", 0600, dir, port, &margining_mode_fops);
+	debugfs_create_file("run", 0600, dir, port, &margining_run_fops);
+	debugfs_create_file("results", 0600, dir, port, &margining_results_fops);
+	debugfs_create_file("test", 0600, dir, port, &margining_test_fops);
+	if (independent_voltage_margins(usb4) ||
+	    (supports_time(usb4) && independent_time_margins(usb4)))
+		debugfs_create_file("margin", 0600, dir, port, &margining_margin_fops);
+}
+
+static void margining_port_remove(struct tb_port *port)
+{
+	struct dentry *parent;
+	char dir_name[10];
+
+	if (!port->usb4)
+		return;
+
+	snprintf(dir_name, sizeof(dir_name), "port%d", port->port);
+	parent = debugfs_lookup(dir_name, port->sw->debugfs_dir);
+	if (parent)
+		debugfs_lookup_and_remove("margining", parent);
+
+	kfree(port->usb4->margining);
+	port->usb4->margining = NULL;
+}
+
+static void margining_switch_init(struct tb_switch *sw)
+{
+	struct tb_port *upstream, *downstream;
+	struct tb_switch *parent_sw;
+	u64 route = tb_route(sw);
+
+	if (!route)
+		return;
+
+	upstream = tb_upstream_port(sw);
+	parent_sw = tb_switch_parent(sw);
+	downstream = tb_port_at(route, parent_sw);
+
+	margining_port_init(downstream);
+	margining_port_init(upstream);
+}
+
+static void margining_switch_remove(struct tb_switch *sw)
+{
+	struct tb_port *upstream, *downstream;
+	struct tb_switch *parent_sw;
+	u64 route = tb_route(sw);
+
+	if (!route)
+		return;
+
+	upstream = tb_upstream_port(sw);
+	parent_sw = tb_switch_parent(sw);
+	downstream = tb_port_at(route, parent_sw);
+
+	margining_port_remove(upstream);
+	margining_port_remove(downstream);
+}
+
+static void margining_xdomain_init(struct tb_xdomain *xd)
+{
+	struct tb_switch *parent_sw;
+	struct tb_port *downstream;
+
+	parent_sw = tb_xdomain_parent(xd);
+	downstream = tb_port_at(xd->route, parent_sw);
+
+	margining_port_init(downstream);
+}
+
+static void margining_xdomain_remove(struct tb_xdomain *xd)
+{
+	struct tb_switch *parent_sw;
+	struct tb_port *downstream;
+
+	parent_sw = tb_xdomain_parent(xd);
+	downstream = tb_port_at(xd->route, parent_sw);
+	margining_port_remove(downstream);
+}
+#else
+static inline void margining_switch_init(struct tb_switch *sw) { }
+static inline void margining_switch_remove(struct tb_switch *sw) { }
+static inline void margining_xdomain_init(struct tb_xdomain *xd) { }
+static inline void margining_xdomain_remove(struct tb_xdomain *xd) { }
+#endif
+
+static int port_clear_all_counters(struct tb_port *port)
+{
+	u32 *buf;
+	int ret;
+
+	buf = kcalloc(COUNTER_SET_LEN * port->config.max_counters, sizeof(u32),
+		      GFP_KERNEL);
+	if (!buf)
+		return -ENOMEM;
+
+	ret = tb_port_write(port, buf, TB_CFG_COUNTERS, 0,
+			    COUNTER_SET_LEN * port->config.max_counters);
+	kfree(buf);
+
+	return ret;
+}
+
+static ssize_t counters_write(struct file *file, const char __user *user_buf,
+			      size_t count, loff_t *ppos)
+{
+	struct seq_file *s = file->private_data;
+	struct tb_port *port = s->private;
+	struct tb_switch *sw = port->sw;
+	struct tb *tb = port->sw->tb;
+	char *buf;
+	int ret;
+
+	buf = validate_and_copy_from_user(user_buf, &count);
+	if (IS_ERR(buf))
+		return PTR_ERR(buf);
+
+	pm_runtime_get_sync(&sw->dev);
+
+	if (mutex_lock_interruptible(&tb->lock)) {
+		ret = -ERESTARTSYS;
+		goto out;
+	}
+
+	/* If written delimiter only, clear all counters in one shot */
+	if (buf[0] == '\n') {
+		ret = port_clear_all_counters(port);
+	} else  {
+		char *line = buf;
+		u32 val, offset;
+
+		ret = -EINVAL;
+		while (parse_line(&line, &offset, &val, 1, 4)) {
+			ret = tb_port_write(port, &val, TB_CFG_COUNTERS,
+					    offset, 1);
+			if (ret)
+				break;
+		}
+	}
+
+	mutex_unlock(&tb->lock);
+
+out:
+	pm_runtime_mark_last_busy(&sw->dev);
+	pm_runtime_put_autosuspend(&sw->dev);
+	free_page((unsigned long)buf);
+
+	return ret < 0 ? ret : count;
+}
+
+static void cap_show_by_dw(struct seq_file *s, struct tb_switch *sw,
+			   struct tb_port *port, unsigned int cap,
+			   unsigned int offset, u8 cap_id, u8 vsec_id,
+			   int dwords)
+{
+	int i, ret;
+	u32 data;
+
+	for (i = 0; i < dwords; i++) {
+		if (port)
+			ret = tb_port_read(port, &data, TB_CFG_PORT, cap + offset + i, 1);
+		else
+			ret = tb_sw_read(sw, &data, TB_CFG_SWITCH, cap + offset + i, 1);
+		if (ret) {
+			seq_printf(s, "0x%04x <not accessible>\n", cap + offset + i);
+			continue;
+		}
+
+		seq_printf(s, "0x%04x %4d 0x%02x 0x%02x 0x%08x\n", cap + offset + i,
+			   offset + i, cap_id, vsec_id, data);
+	}
+}
+
+static void cap_show(struct seq_file *s, struct tb_switch *sw,
+		     struct tb_port *port, unsigned int cap, u8 cap_id,
+		     u8 vsec_id, int length)
+{
+	int ret, offset = 0;
+
+	while (length > 0) {
+		int i, dwords = min(length, TB_MAX_CONFIG_RW_LENGTH);
+		u32 data[TB_MAX_CONFIG_RW_LENGTH];
+
+		if (port)
+			ret = tb_port_read(port, data, TB_CFG_PORT, cap + offset,
+					   dwords);
+		else
+			ret = tb_sw_read(sw, data, TB_CFG_SWITCH, cap + offset, dwords);
+		if (ret) {
+			cap_show_by_dw(s, sw, port, cap, offset, cap_id, vsec_id, length);
+			return;
+		}
+
+		for (i = 0; i < dwords; i++) {
+			seq_printf(s, "0x%04x %4d 0x%02x 0x%02x 0x%08x\n",
+				   cap + offset + i, offset + i,
+				   cap_id, vsec_id, data[i]);
+		}
+
+		length -= dwords;
+		offset += dwords;
+	}
+}
+
+static void port_cap_show(struct tb_port *port, struct seq_file *s,
+			  unsigned int cap)
+{
+	struct tb_cap_any header;
+	u8 vsec_id = 0;
+	size_t length;
+	int ret;
+
+	ret = tb_port_read(port, &header, TB_CFG_PORT, cap, 1);
+	if (ret) {
+		seq_printf(s, "0x%04x <capability read failed>\n", cap);
+		return;
+	}
+
+	switch (header.basic.cap) {
+	case TB_PORT_CAP_PHY:
+		length = PORT_CAP_LANE_LEN;
+		break;
+
+	case TB_PORT_CAP_TIME1:
+		length = PORT_CAP_TMU_LEN;
+		break;
+
+	case TB_PORT_CAP_POWER:
+		length = PORT_CAP_POWER_LEN;
+		break;
+
+	case TB_PORT_CAP_ADAP:
+		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;
+		} else if (tb_port_is_usb3_down(port) ||
+			   tb_port_is_usb3_up(port)) {
+			length = PORT_CAP_USB3_LEN;
+		} else {
+			seq_printf(s, "0x%04x <unsupported capability 0x%02x>\n",
+				   cap, header.basic.cap);
+			return;
+		}
+		break;
+
+	case TB_PORT_CAP_VSE:
+		if (!header.extended_short.length) {
+			ret = tb_port_read(port, (u32 *)&header + 1, TB_CFG_PORT,
+					   cap + 1, 1);
+			if (ret) {
+				seq_printf(s, "0x%04x <capability read failed>\n",
+					   cap + 1);
+				return;
+			}
+			length = header.extended_long.length;
+			vsec_id = header.extended_short.vsec_id;
+		} else {
+			length = header.extended_short.length;
+			vsec_id = header.extended_short.vsec_id;
+		}
+		break;
+
+	case TB_PORT_CAP_USB4:
+		length = PORT_CAP_USB4_LEN;
+		break;
+
+	default:
+		seq_printf(s, "0x%04x <unsupported capability 0x%02x>\n",
+			   cap, header.basic.cap);
+		return;
+	}
+
+	cap_show(s, NULL, port, cap, header.basic.cap, vsec_id, length);
+}
+
+static void port_caps_show(struct tb_port *port, struct seq_file *s)
+{
+	int cap;
+
+	cap = tb_port_next_cap(port, 0);
+	while (cap > 0) {
+		port_cap_show(port, s, cap);
+		cap = tb_port_next_cap(port, cap);
+	}
+}
+
+static int port_basic_regs_show(struct tb_port *port, struct seq_file *s)
+{
+	u32 data[PORT_CAP_BASIC_LEN];
+	int ret, i;
+
+	ret = tb_port_read(port, data, TB_CFG_PORT, 0, ARRAY_SIZE(data));
+	if (ret)
+		return ret;
+
+	for (i = 0; i < ARRAY_SIZE(data); i++)
+		seq_printf(s, "0x%04x %4d 0x00 0x00 0x%08x\n", i, i, data[i]);
+
+	return 0;
+}
+
+static int port_regs_show(struct seq_file *s, void *not_used)
+{
+	struct tb_port *port = s->private;
+	struct tb_switch *sw = port->sw;
+	struct tb *tb = sw->tb;
+	int ret;
+
+	pm_runtime_get_sync(&sw->dev);
+
+	if (mutex_lock_interruptible(&tb->lock)) {
+		ret = -ERESTARTSYS;
+		goto out_rpm_put;
+	}
+
+	seq_puts(s, "# offset relative_offset cap_id vs_cap_id value\n");
+
+	ret = port_basic_regs_show(port, s);
+	if (ret)
+		goto out_unlock;
+
+	port_caps_show(port, s);
+
+out_unlock:
+	mutex_unlock(&tb->lock);
+out_rpm_put:
+	pm_runtime_mark_last_busy(&sw->dev);
+	pm_runtime_put_autosuspend(&sw->dev);
+
+	return ret;
+}
+DEBUGFS_ATTR_RW(port_regs);
+
+static void switch_cap_show(struct tb_switch *sw, struct seq_file *s,
+			    unsigned int cap)
+{
+	struct tb_cap_any header;
+	int ret, length;
+	u8 vsec_id = 0;
+
+	ret = tb_sw_read(sw, &header, TB_CFG_SWITCH, cap, 1);
+	if (ret) {
+		seq_printf(s, "0x%04x <capability read failed>\n", cap);
+		return;
+	}
+
+	if (header.basic.cap == TB_SWITCH_CAP_VSE) {
+		if (!header.extended_short.length) {
+			ret = tb_sw_read(sw, (u32 *)&header + 1, TB_CFG_SWITCH,
+					 cap + 1, 1);
+			if (ret) {
+				seq_printf(s, "0x%04x <capability read failed>\n",
+					   cap + 1);
+				return;
+			}
+			length = header.extended_long.length;
+		} else {
+			length = header.extended_short.length;
+		}
+		vsec_id = header.extended_short.vsec_id;
+	} else {
+		if (header.basic.cap == TB_SWITCH_CAP_TMU) {
+			length = SWITCH_CAP_TMU_LEN;
+		} else  {
+			seq_printf(s, "0x%04x <unknown capability 0x%02x>\n",
+				   cap, header.basic.cap);
+			return;
+		}
+	}
+
+	cap_show(s, sw, NULL, cap, header.basic.cap, vsec_id, length);
+}
+
+static void switch_caps_show(struct tb_switch *sw, struct seq_file *s)
+{
+	int cap;
+
+	cap = tb_switch_next_cap(sw, 0);
+	while (cap > 0) {
+		switch_cap_show(sw, s, cap);
+		cap = tb_switch_next_cap(sw, cap);
+	}
+}
+
+static int switch_basic_regs_show(struct tb_switch *sw, struct seq_file *s)
+{
+	u32 data[SWITCH_CAP_BASIC_LEN];
+	size_t dwords;
+	int ret, i;
+
+	/* Only USB4 has the additional registers */
+	if (tb_switch_is_usb4(sw))
+		dwords = ARRAY_SIZE(data);
+	else
+		dwords = 7;
+
+	ret = tb_sw_read(sw, data, TB_CFG_SWITCH, 0, dwords);
+	if (ret)
+		return ret;
+
+	for (i = 0; i < dwords; i++)
+		seq_printf(s, "0x%04x %4d 0x00 0x00 0x%08x\n", i, i, data[i]);
+
+	return 0;
+}
+
+static int switch_regs_show(struct seq_file *s, void *not_used)
+{
+	struct tb_switch *sw = s->private;
+	struct tb *tb = sw->tb;
+	int ret;
+
+	pm_runtime_get_sync(&sw->dev);
+
+	if (mutex_lock_interruptible(&tb->lock)) {
+		ret = -ERESTARTSYS;
+		goto out_rpm_put;
+	}
+
+	seq_puts(s, "# offset relative_offset cap_id vs_cap_id value\n");
+
+	ret = switch_basic_regs_show(sw, s);
+	if (ret)
+		goto out_unlock;
+
+	switch_caps_show(sw, s);
+
+out_unlock:
+	mutex_unlock(&tb->lock);
+out_rpm_put:
+	pm_runtime_mark_last_busy(&sw->dev);
+	pm_runtime_put_autosuspend(&sw->dev);
+
+	return ret;
+}
+DEBUGFS_ATTR_RW(switch_regs);
+
+static int path_show_one(struct tb_port *port, struct seq_file *s, int hopid)
+{
+	u32 data[PATH_LEN];
+	int ret, i;
+
+	ret = tb_port_read(port, data, TB_CFG_HOPS, hopid * PATH_LEN,
+			   ARRAY_SIZE(data));
+	if (ret) {
+		seq_printf(s, "0x%04x <not accessible>\n", hopid * PATH_LEN);
+		return ret;
+	}
+
+	for (i = 0; i < ARRAY_SIZE(data); i++) {
+		seq_printf(s, "0x%04x %4d 0x%02x 0x%08x\n",
+			   hopid * PATH_LEN + i, i, hopid, data[i]);
+	}
+
+	return 0;
+}
+
+static int path_show(struct seq_file *s, void *not_used)
+{
+	struct tb_port *port = s->private;
+	struct tb_switch *sw = port->sw;
+	struct tb *tb = sw->tb;
+	int start, i, ret = 0;
+
+	pm_runtime_get_sync(&sw->dev);
+
+	if (mutex_lock_interruptible(&tb->lock)) {
+		ret = -ERESTARTSYS;
+		goto out_rpm_put;
+	}
+
+	seq_puts(s, "# offset relative_offset in_hop_id value\n");
+
+	/* NHI and lane adapters have entry for path 0 */
+	if (tb_port_is_null(port) || tb_port_is_nhi(port)) {
+		ret = path_show_one(port, s, 0);
+		if (ret)
+			goto out_unlock;
+	}
+
+	start = tb_port_is_nhi(port) ? 1 : TB_PATH_MIN_HOPID;
+
+	for (i = start; i <= port->config.max_in_hop_id; i++) {
+		ret = path_show_one(port, s, i);
+		if (ret)
+			break;
+	}
+
+out_unlock:
+	mutex_unlock(&tb->lock);
+out_rpm_put:
+	pm_runtime_mark_last_busy(&sw->dev);
+	pm_runtime_put_autosuspend(&sw->dev);
+
+	return ret;
+}
+DEBUGFS_ATTR_RO(path);
+
+static int counter_set_regs_show(struct tb_port *port, struct seq_file *s,
+				 int counter)
+{
+	u32 data[COUNTER_SET_LEN];
+	int ret, i;
+
+	ret = tb_port_read(port, data, TB_CFG_COUNTERS,
+			   counter * COUNTER_SET_LEN, ARRAY_SIZE(data));
+	if (ret) {
+		seq_printf(s, "0x%04x <not accessible>\n",
+			   counter * COUNTER_SET_LEN);
+		return ret;
+	}
+
+	for (i = 0; i < ARRAY_SIZE(data); i++) {
+		seq_printf(s, "0x%04x %4d 0x%02x 0x%08x\n",
+			   counter * COUNTER_SET_LEN + i, i, counter, data[i]);
+	}
+
+	return 0;
+}
+
+static int counters_show(struct seq_file *s, void *not_used)
+{
+	struct tb_port *port = s->private;
+	struct tb_switch *sw = port->sw;
+	struct tb *tb = sw->tb;
+	int i, ret = 0;
+
+	pm_runtime_get_sync(&sw->dev);
+
+	if (mutex_lock_interruptible(&tb->lock)) {
+		ret = -ERESTARTSYS;
+		goto out;
+	}
+
+	seq_puts(s, "# offset relative_offset counter_id value\n");
+
+	for (i = 0; i < port->config.max_counters; i++) {
+		ret = counter_set_regs_show(port, s, i);
+		if (ret)
+			break;
+	}
+
+	mutex_unlock(&tb->lock);
+
+out:
+	pm_runtime_mark_last_busy(&sw->dev);
+	pm_runtime_put_autosuspend(&sw->dev);
+
+	return ret;
+}
+DEBUGFS_ATTR_RW(counters);
+
+/**
+ * tb_switch_debugfs_init() - Add debugfs entries for router
+ * @sw: Pointer to the router
+ *
+ * Adds debugfs directories and files for given router.
+ */
+void tb_switch_debugfs_init(struct tb_switch *sw)
+{
+	struct dentry *debugfs_dir;
+	struct tb_port *port;
+
+	debugfs_dir = debugfs_create_dir(dev_name(&sw->dev), tb_debugfs_root);
+	sw->debugfs_dir = debugfs_dir;
+	debugfs_create_file("regs", DEBUGFS_MODE, debugfs_dir, sw,
+			    &switch_regs_fops);
+
+	tb_switch_for_each_port(sw, port) {
+		struct dentry *debugfs_dir;
+		char dir_name[10];
+
+		if (port->disabled)
+			continue;
+		if (port->config.type == TB_TYPE_INACTIVE)
+			continue;
+
+		snprintf(dir_name, sizeof(dir_name), "port%d", port->port);
+		debugfs_dir = debugfs_create_dir(dir_name, sw->debugfs_dir);
+		debugfs_create_file("regs", DEBUGFS_MODE, debugfs_dir,
+				    port, &port_regs_fops);
+		debugfs_create_file("path", 0400, debugfs_dir, port,
+				    &path_fops);
+		if (port->config.counters_support)
+			debugfs_create_file("counters", 0600, debugfs_dir, port,
+					    &counters_fops);
+	}
+
+	margining_switch_init(sw);
+}
+
+/**
+ * tb_switch_debugfs_remove() - Remove all router debugfs entries
+ * @sw: Pointer to the router
+ *
+ * Removes all previously added debugfs entries under this router.
+ */
+void tb_switch_debugfs_remove(struct tb_switch *sw)
+{
+	margining_switch_remove(sw);
+	debugfs_remove_recursive(sw->debugfs_dir);
+}
+
+void tb_xdomain_debugfs_init(struct tb_xdomain *xd)
+{
+	margining_xdomain_init(xd);
+}
+
+void tb_xdomain_debugfs_remove(struct tb_xdomain *xd)
+{
+	margining_xdomain_remove(xd);
+}
+
+/**
+ * tb_service_debugfs_init() - Add debugfs directory for service
+ * @svc: Thunderbolt service pointer
+ *
+ * Adds debugfs directory for service.
+ */
+void tb_service_debugfs_init(struct tb_service *svc)
+{
+	svc->debugfs_dir = debugfs_create_dir(dev_name(&svc->dev),
+					      tb_debugfs_root);
+}
+
+/**
+ * tb_service_debugfs_remove() - Remove service debugfs directory
+ * @svc: Thunderbolt service pointer
+ *
+ * Removes the previously created debugfs directory for @svc.
+ */
+void tb_service_debugfs_remove(struct tb_service *svc)
+{
+	debugfs_remove_recursive(svc->debugfs_dir);
+	svc->debugfs_dir = NULL;
+}
+
+void tb_debugfs_init(void)
+{
+	tb_debugfs_root = debugfs_create_dir("thunderbolt", NULL);
+}
+
+void tb_debugfs_exit(void)
+{
+	debugfs_remove_recursive(tb_debugfs_root);
+}