xref: /linux/drivers/thunderbolt/debugfs.c (revision c1bef05763c94ae284ee2881c03bf0753f8d213a)
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * Debugfs interface
4  *
5  * Copyright (C) 2020, Intel Corporation
6  * Authors: Gil Fine <gil.fine@intel.com>
7  *	    Mika Westerberg <mika.westerberg@linux.intel.com>
8  */
9 
10 #include <linux/array_size.h>
11 #include <linux/bitfield.h>
12 #include <linux/debugfs.h>
13 #include <linux/delay.h>
14 #include <linux/pm_runtime.h>
15 #include <linux/string_choices.h>
16 #include <linux/uaccess.h>
17 
18 #include "tb.h"
19 #include "sb_regs.h"
20 
21 #define PORT_CAP_V1_PCIE_LEN	1
22 #define PORT_CAP_V2_PCIE_LEN	2
23 #define PORT_CAP_POWER_LEN	2
24 #define PORT_CAP_LANE_LEN	3
25 #define PORT_CAP_USB3_LEN	5
26 #define PORT_CAP_DP_V1_LEN	9
27 #define PORT_CAP_DP_V2_LEN	14
28 #define PORT_CAP_TMU_V1_LEN	8
29 #define PORT_CAP_TMU_V2_LEN	10
30 #define PORT_CAP_BASIC_LEN	9
31 #define PORT_CAP_USB4_LEN	20
32 
33 #define SWITCH_CAP_TMU_LEN	26
34 #define SWITCH_CAP_BASIC_LEN	27
35 
36 #define PATH_LEN		2
37 
38 #define COUNTER_SET_LEN		3
39 
40 /*
41  * USB4 spec doesn't specify dwell range, the range of 100 ms to 500 ms
42  * probed to give good results.
43  */
44 #define MIN_DWELL_TIME		100 /* ms */
45 #define MAX_DWELL_TIME		500 /* ms */
46 #define DWELL_SAMPLE_INTERVAL	10
47 
48 enum usb4_margin_cap_voltage_indp {
49 	USB4_MARGIN_CAP_VOLTAGE_INDP_GEN_2_3_MIN,
50 	USB4_MARGIN_CAP_VOLTAGE_INDP_GEN_2_3_HL,
51 	USB4_MARGIN_CAP_VOLTAGE_INDP_GEN_2_3_BOTH,
52 	USB4_MARGIN_CAP_VOLTAGE_INDP_GEN_4_MIN,
53 	USB4_MARGIN_CAP_VOLTAGE_INDP_GEN_4_BOTH,
54 	USB4_MARGIN_CAP_VOLTAGE_INDP_UNKNOWN,
55 };
56 
57 enum usb4_margin_cap_time_indp {
58 	USB4_MARGIN_CAP_TIME_INDP_GEN_2_3_MIN,
59 	USB4_MARGIN_CAP_TIME_INDP_GEN_2_3_LR,
60 	USB4_MARGIN_CAP_TIME_INDP_GEN_2_3_BOTH,
61 	USB4_MARGIN_CAP_TIME_INDP_GEN_4_MIN,
62 	USB4_MARGIN_CAP_TIME_INDP_GEN_4_BOTH,
63 	USB4_MARGIN_CAP_TIME_INDP_UNKNOWN,
64 };
65 
66 /* Sideband registers and their sizes as defined in the USB4 spec */
67 struct sb_reg {
68 	unsigned int reg;
69 	unsigned int size;
70 };
71 
72 #define SB_MAX_SIZE		64
73 
74 /* Sideband registers for router */
75 static const struct sb_reg port_sb_regs[] = {
76 	{ USB4_SB_VENDOR_ID, 4 },
77 	{ USB4_SB_PRODUCT_ID, 4 },
78 	{ USB4_SB_DEBUG_CONF, 4 },
79 	{ USB4_SB_DEBUG, 54 },
80 	{ USB4_SB_LRD_TUNING, 4 },
81 	{ USB4_SB_OPCODE, 4 },
82 	{ USB4_SB_METADATA, 4 },
83 	{ USB4_SB_LINK_CONF, 3 },
84 	{ USB4_SB_GEN23_TXFFE, 4 },
85 	{ USB4_SB_GEN4_TXFFE, 4 },
86 	{ USB4_SB_VERSION, 4 },
87 	{ USB4_SB_DATA, 64 },
88 };
89 
90 /* Sideband registers for retimer */
91 static const struct sb_reg retimer_sb_regs[] = {
92 	{ USB4_SB_VENDOR_ID, 4 },
93 	{ USB4_SB_PRODUCT_ID, 4 },
94 	{ USB4_SB_FW_VERSION, 4 },
95 	{ USB4_SB_LRD_TUNING, 4 },
96 	{ USB4_SB_OPCODE, 4 },
97 	{ USB4_SB_METADATA, 4 },
98 	{ USB4_SB_GEN23_TXFFE, 4 },
99 	{ USB4_SB_GEN4_TXFFE, 4 },
100 	{ USB4_SB_VERSION, 4 },
101 	{ USB4_SB_DATA, 64 },
102 };
103 
104 #define DEBUGFS_ATTR(__space, __write)					\
105 static int __space ## _open(struct inode *inode, struct file *file)	\
106 {									\
107 	return single_open(file, __space ## _show, inode->i_private);	\
108 }									\
109 									\
110 static const struct file_operations __space ## _fops = {		\
111 	.owner = THIS_MODULE,						\
112 	.open = __space ## _open,					\
113 	.release = single_release,					\
114 	.read  = seq_read,						\
115 	.write = __write,						\
116 	.llseek = seq_lseek,						\
117 }
118 
119 #define DEBUGFS_ATTR_RO(__space)					\
120 	DEBUGFS_ATTR(__space, NULL)
121 
122 #define DEBUGFS_ATTR_RW(__space)					\
123 	DEBUGFS_ATTR(__space, __space ## _write)
124 
125 static struct dentry *tb_debugfs_root;
126 
127 static void *validate_and_copy_from_user(const void __user *user_buf,
128 					 size_t *count)
129 {
130 	size_t nbytes;
131 	void *buf;
132 
133 	if (!*count)
134 		return ERR_PTR(-EINVAL);
135 
136 	if (!access_ok(user_buf, *count))
137 		return ERR_PTR(-EFAULT);
138 
139 	buf = (void *)get_zeroed_page(GFP_KERNEL);
140 	if (!buf)
141 		return ERR_PTR(-ENOMEM);
142 
143 	nbytes = min_t(size_t, *count, PAGE_SIZE);
144 	if (copy_from_user(buf, user_buf, nbytes)) {
145 		free_page((unsigned long)buf);
146 		return ERR_PTR(-EFAULT);
147 	}
148 
149 	*count = nbytes;
150 	return buf;
151 }
152 
153 static bool parse_line(char **line, u32 *offs, u32 *val, int short_fmt_len,
154 		       int long_fmt_len)
155 {
156 	char *token;
157 	u32 v[5];
158 	int ret;
159 
160 	token = strsep(line, "\n");
161 	if (!token)
162 		return false;
163 
164 	/*
165 	 * For Adapter/Router configuration space:
166 	 * Short format is: offset value\n
167 	 *		    v[0]   v[1]
168 	 * Long format as produced from the read side:
169 	 * offset relative_offset cap_id vs_cap_id value\n
170 	 * v[0]   v[1]            v[2]   v[3]      v[4]
171 	 *
172 	 * For Path configuration space:
173 	 * Short format is: offset value\n
174 	 *		    v[0]   v[1]
175 	 * Long format as produced from the read side:
176 	 * offset relative_offset in_hop_id value\n
177 	 * v[0]   v[1]            v[2]      v[3]
178 	 *
179 	 * For Counter configuration space:
180 	 * Short format is: offset\n
181 	 *		    v[0]
182 	 * Long format as produced from the read side:
183 	 * offset relative_offset counter_id value\n
184 	 * v[0]   v[1]            v[2]       v[3]
185 	 */
186 	ret = sscanf(token, "%i %i %i %i %i", &v[0], &v[1], &v[2], &v[3], &v[4]);
187 	/* In case of Counters, clear counter, "val" content is NA */
188 	if (ret == short_fmt_len) {
189 		*offs = v[0];
190 		*val = v[short_fmt_len - 1];
191 		return true;
192 	} else if (ret == long_fmt_len) {
193 		*offs = v[0];
194 		*val = v[long_fmt_len - 1];
195 		return true;
196 	}
197 
198 	return false;
199 }
200 
201 #if IS_ENABLED(CONFIG_USB4_DEBUGFS_WRITE)
202 /*
203  * Path registers need to be written in double word pairs and they both must be
204  * read before written. This writes one double word in path config space
205  * following the spec flow.
206  */
207 static int path_write_one(struct tb_port *port, u32 val, u32 offset)
208 {
209 	u32 index = offset % PATH_LEN;
210 	u32 offs = offset - index;
211 	u32 data[PATH_LEN];
212 	int ret;
213 
214 	ret = tb_port_read(port, data, TB_CFG_HOPS, offs, PATH_LEN);
215 	if (ret)
216 		return ret;
217 	data[index] = val;
218 	return tb_port_write(port, data, TB_CFG_HOPS, offs, PATH_LEN);
219 }
220 
221 static ssize_t regs_write(struct tb_switch *sw, struct tb_port *port,
222 			  enum tb_cfg_space space, const char __user *user_buf,
223 			  size_t count, loff_t *ppos)
224 {
225 	int long_fmt_len, ret = 0;
226 	struct tb *tb = sw->tb;
227 	char *line, *buf;
228 	u32 val, offset;
229 
230 	buf = validate_and_copy_from_user(user_buf, &count);
231 	if (IS_ERR(buf))
232 		return PTR_ERR(buf);
233 
234 	pm_runtime_get_sync(&sw->dev);
235 
236 	if (mutex_lock_interruptible(&tb->lock)) {
237 		ret = -ERESTARTSYS;
238 		goto out;
239 	}
240 
241 	/* User did hardware changes behind the driver's back */
242 	add_taint(TAINT_USER, LOCKDEP_STILL_OK);
243 
244 	if (space == TB_CFG_HOPS)
245 		long_fmt_len = 4;
246 	else
247 		long_fmt_len = 5;
248 
249 	line = buf;
250 	while (parse_line(&line, &offset, &val, 2, long_fmt_len)) {
251 		if (port) {
252 			if (space == TB_CFG_HOPS)
253 				ret = path_write_one(port, val, offset);
254 			else
255 				ret = tb_port_write(port, &val, space, offset, 1);
256 		} else {
257 			ret = tb_sw_write(sw, &val, TB_CFG_SWITCH, offset, 1);
258 		}
259 		if (ret)
260 			break;
261 	}
262 
263 	mutex_unlock(&tb->lock);
264 
265 out:
266 	pm_runtime_mark_last_busy(&sw->dev);
267 	pm_runtime_put_autosuspend(&sw->dev);
268 	free_page((unsigned long)buf);
269 
270 	return ret < 0 ? ret : count;
271 }
272 
273 static ssize_t port_regs_write(struct file *file, const char __user *user_buf,
274 			       size_t count, loff_t *ppos)
275 {
276 	struct seq_file *s = file->private_data;
277 	struct tb_port *port = s->private;
278 
279 	return regs_write(port->sw, port, TB_CFG_PORT, user_buf, count, ppos);
280 }
281 
282 static ssize_t path_write(struct file *file, const char __user *user_buf,
283 			  size_t count, loff_t *ppos)
284 {
285 	struct seq_file *s = file->private_data;
286 	struct tb_port *port = s->private;
287 
288 	return regs_write(port->sw, port, TB_CFG_HOPS, user_buf, count, ppos);
289 }
290 
291 static ssize_t switch_regs_write(struct file *file, const char __user *user_buf,
292 				 size_t count, loff_t *ppos)
293 {
294 	struct seq_file *s = file->private_data;
295 	struct tb_switch *sw = s->private;
296 
297 	return regs_write(sw, NULL, TB_CFG_SWITCH, user_buf, count, ppos);
298 }
299 
300 static bool parse_sb_line(char **line, u8 *reg, u8 *data, size_t data_size,
301 			  size_t *bytes_read)
302 {
303 	char *field, *token;
304 	int i;
305 
306 	token = strsep(line, "\n");
307 	if (!token)
308 		return false;
309 
310 	/* Parse the register first */
311 	field = strsep(&token, " ");
312 	if (!field)
313 		return false;
314 	if (kstrtou8(field, 0, reg))
315 		return false;
316 
317 	/* Then the values for the register, up to data_size */
318 	for (i = 0; i < data_size; i++) {
319 		field = strsep(&token, " ");
320 		if (!field)
321 			break;
322 		if (kstrtou8(field, 0, &data[i]))
323 			return false;
324 	}
325 
326 	*bytes_read = i;
327 	return true;
328 }
329 
330 static ssize_t sb_regs_write(struct tb_port *port, const struct sb_reg *sb_regs,
331 			     size_t size, enum usb4_sb_target target, u8 index,
332 			     char *buf, size_t count, loff_t *ppos)
333 {
334 	u8 reg, data[SB_MAX_SIZE];
335 	size_t bytes_read;
336 	char *line = buf;
337 
338 	/* User did hardware changes behind the driver's back */
339 	add_taint(TAINT_USER, LOCKDEP_STILL_OK);
340 
341 	/*
342 	 * For sideband registers we accept:
343 	 * reg b0 b1 b2...\n
344 	 *
345 	 * Here "reg" is the byte offset of the sideband register and "b0"..
346 	 * are the byte values. There can be less byte values than the register
347 	 * size. The leftovers will not be overwritten.
348 	 */
349 	while (parse_sb_line(&line, &reg, data, ARRAY_SIZE(data), &bytes_read)) {
350 		const struct sb_reg *sb_reg;
351 		int ret;
352 
353 		/* At least one byte must be passed */
354 		if (bytes_read < 1)
355 			return -EINVAL;
356 
357 		/* Find the register */
358 		sb_reg = NULL;
359 		for (int i = 0; i < size; i++) {
360 			if (sb_regs[i].reg == reg) {
361 				sb_reg = &sb_regs[i];
362 				break;
363 			}
364 		}
365 
366 		if (!sb_reg)
367 			return -EINVAL;
368 
369 		if (bytes_read > sb_reg->size)
370 			return -E2BIG;
371 
372 		ret = usb4_port_sb_write(port, target, index, sb_reg->reg, data,
373 					 bytes_read);
374 		if (ret)
375 			return ret;
376 	}
377 
378 	return 0;
379 }
380 
381 static ssize_t port_sb_regs_write(struct file *file, const char __user *user_buf,
382 				  size_t count, loff_t *ppos)
383 {
384 	struct seq_file *s = file->private_data;
385 	struct tb_port *port = s->private;
386 	struct tb_switch *sw = port->sw;
387 	struct tb *tb = sw->tb;
388 	char *buf;
389 	int ret;
390 
391 	buf = validate_and_copy_from_user(user_buf, &count);
392 	if (IS_ERR(buf))
393 		return PTR_ERR(buf);
394 
395 	pm_runtime_get_sync(&sw->dev);
396 
397 	if (mutex_lock_interruptible(&tb->lock)) {
398 		ret = -ERESTARTSYS;
399 		goto out;
400 	}
401 
402 	ret = sb_regs_write(port, port_sb_regs, ARRAY_SIZE(port_sb_regs),
403 			    USB4_SB_TARGET_ROUTER, 0, buf, count, ppos);
404 
405 	mutex_unlock(&tb->lock);
406 out:
407 	pm_runtime_mark_last_busy(&sw->dev);
408 	pm_runtime_put_autosuspend(&sw->dev);
409 	free_page((unsigned long)buf);
410 
411 	return ret < 0 ? ret : count;
412 }
413 
414 static ssize_t retimer_sb_regs_write(struct file *file,
415 				     const char __user *user_buf,
416 				     size_t count, loff_t *ppos)
417 {
418 	struct seq_file *s = file->private_data;
419 	struct tb_retimer *rt = s->private;
420 	struct tb *tb = rt->tb;
421 	char *buf;
422 	int ret;
423 
424 	buf = validate_and_copy_from_user(user_buf, &count);
425 	if (IS_ERR(buf))
426 		return PTR_ERR(buf);
427 
428 	pm_runtime_get_sync(&rt->dev);
429 
430 	if (mutex_lock_interruptible(&tb->lock)) {
431 		ret = -ERESTARTSYS;
432 		goto out;
433 	}
434 
435 	ret = sb_regs_write(rt->port, retimer_sb_regs, ARRAY_SIZE(retimer_sb_regs),
436 			    USB4_SB_TARGET_RETIMER, rt->index, buf, count, ppos);
437 
438 	mutex_unlock(&tb->lock);
439 out:
440 	pm_runtime_mark_last_busy(&rt->dev);
441 	pm_runtime_put_autosuspend(&rt->dev);
442 	free_page((unsigned long)buf);
443 
444 	return ret < 0 ? ret : count;
445 }
446 #define DEBUGFS_MODE		0600
447 #else
448 #define port_regs_write		NULL
449 #define path_write		NULL
450 #define switch_regs_write	NULL
451 #define port_sb_regs_write	NULL
452 #define retimer_sb_regs_write	NULL
453 #define DEBUGFS_MODE		0400
454 #endif
455 
456 #if IS_ENABLED(CONFIG_USB4_DEBUGFS_MARGINING)
457 /**
458  * struct tb_margining - Lane margining support
459  * @port: USB4 port through which the margining operations are run
460  * @target: Sideband target
461  * @index: Retimer index if taget is %USB4_SB_TARGET_RETIMER
462  * @dev: Pointer to the device that is the target (USB4 port or retimer)
463  * @gen: Link generation
464  * @asym_rx: %true% if @port supports asymmetric link with 3 Rx
465  * @caps: Port lane margining capabilities
466  * @results: Last lane margining results
467  * @lanes: %0, %1 or %7 (all)
468  * @min_ber_level: Minimum supported BER level contour value
469  * @max_ber_level: Maximum supported BER level contour value
470  * @ber_level: Current BER level contour value
471  * @voltage_steps: Number of mandatory voltage steps
472  * @max_voltage_offset: Maximum mandatory voltage offset (in mV)
473  * @voltage_steps_optional_range: Number of voltage steps for optional range
474  * @max_voltage_offset_optional_range: Maximum voltage offset for the optional
475  *					range (in mV).
476  * @time_steps: Number of time margin steps
477  * @max_time_offset: Maximum time margin offset (in mUI)
478  * @voltage_time_offset: Offset for voltage / time for software margining
479  * @dwell_time: Dwell time for software margining (in ms)
480  * @error_counter: Error counter operation for software margining
481  * @optional_voltage_offset_range: Enable optional extended voltage range
482  * @software: %true if software margining is used instead of hardware
483  * @time: %true if time margining is used instead of voltage
484  * @right_high: %false if left/low margin test is performed, %true if
485  *		right/high
486  * @upper_eye: %false if the lower PAM3 eye is used, %true if the upper
487  *	       eye is used
488  */
489 struct tb_margining {
490 	struct tb_port *port;
491 	enum usb4_sb_target target;
492 	u8 index;
493 	struct device *dev;
494 	unsigned int gen;
495 	bool asym_rx;
496 	u32 caps[3];
497 	u32 results[3];
498 	enum usb4_margining_lane lanes;
499 	unsigned int min_ber_level;
500 	unsigned int max_ber_level;
501 	unsigned int ber_level;
502 	unsigned int voltage_steps;
503 	unsigned int max_voltage_offset;
504 	unsigned int voltage_steps_optional_range;
505 	unsigned int max_voltage_offset_optional_range;
506 	unsigned int time_steps;
507 	unsigned int max_time_offset;
508 	unsigned int voltage_time_offset;
509 	unsigned int dwell_time;
510 	enum usb4_margin_sw_error_counter error_counter;
511 	bool optional_voltage_offset_range;
512 	bool software;
513 	bool time;
514 	bool right_high;
515 	bool upper_eye;
516 };
517 
518 static int margining_modify_error_counter(struct tb_margining *margining,
519 	u32 lanes, enum usb4_margin_sw_error_counter error_counter)
520 {
521 	struct usb4_port_margining_params params = { 0 };
522 	struct tb_port *port = margining->port;
523 	u32 result;
524 
525 	if (error_counter != USB4_MARGIN_SW_ERROR_COUNTER_CLEAR &&
526 	    error_counter != USB4_MARGIN_SW_ERROR_COUNTER_STOP)
527 		return -EOPNOTSUPP;
528 
529 	params.error_counter = error_counter;
530 	params.lanes = lanes;
531 
532 	return usb4_port_sw_margin(port, margining->target, margining->index,
533 				   &params, &result);
534 }
535 
536 static bool supports_software(const struct tb_margining *margining)
537 {
538 	if (margining->gen < 4)
539 		return margining->caps[0] & USB4_MARGIN_CAP_0_MODES_SW;
540 	return margining->caps[2] & USB4_MARGIN_CAP_2_MODES_SW;
541 }
542 
543 static bool supports_hardware(const struct tb_margining *margining)
544 {
545 	if (margining->gen < 4)
546 		return margining->caps[0] & USB4_MARGIN_CAP_0_MODES_HW;
547 	return margining->caps[2] & USB4_MARGIN_CAP_2_MODES_HW;
548 }
549 
550 static bool all_lanes(const struct tb_margining *margining)
551 {
552 	return margining->caps[0] & USB4_MARGIN_CAP_0_ALL_LANES;
553 }
554 
555 static enum usb4_margin_cap_voltage_indp
556 independent_voltage_margins(const struct tb_margining *margining)
557 {
558 	if (margining->gen < 4) {
559 		switch (FIELD_GET(USB4_MARGIN_CAP_0_VOLTAGE_INDP_MASK, margining->caps[0])) {
560 		case USB4_MARGIN_CAP_0_VOLTAGE_MIN:
561 			return USB4_MARGIN_CAP_VOLTAGE_INDP_GEN_2_3_MIN;
562 		case USB4_MARGIN_CAP_0_VOLTAGE_HL:
563 			return USB4_MARGIN_CAP_VOLTAGE_INDP_GEN_2_3_HL;
564 		case USB4_MARGIN_CAP_1_TIME_BOTH:
565 			return USB4_MARGIN_CAP_VOLTAGE_INDP_GEN_2_3_BOTH;
566 		}
567 	} else {
568 		switch (FIELD_GET(USB4_MARGIN_CAP_2_VOLTAGE_INDP_MASK, margining->caps[2])) {
569 		case USB4_MARGIN_CAP_2_VOLTAGE_MIN:
570 			return USB4_MARGIN_CAP_VOLTAGE_INDP_GEN_4_MIN;
571 		case USB4_MARGIN_CAP_2_VOLTAGE_BOTH:
572 			return USB4_MARGIN_CAP_VOLTAGE_INDP_GEN_4_BOTH;
573 		}
574 	}
575 	return USB4_MARGIN_CAP_VOLTAGE_INDP_UNKNOWN;
576 }
577 
578 static bool supports_time(const struct tb_margining *margining)
579 {
580 	if (margining->gen < 4)
581 		return margining->caps[0] & USB4_MARGIN_CAP_0_TIME;
582 	return margining->caps[2] & USB4_MARGIN_CAP_2_TIME;
583 }
584 
585 /* Only applicable if supports_time() returns true */
586 static enum usb4_margin_cap_time_indp
587 independent_time_margins(const struct tb_margining *margining)
588 {
589 	if (margining->gen < 4) {
590 		switch (FIELD_GET(USB4_MARGIN_CAP_1_TIME_INDP_MASK, margining->caps[1])) {
591 		case USB4_MARGIN_CAP_1_TIME_MIN:
592 			return USB4_MARGIN_CAP_TIME_INDP_GEN_2_3_MIN;
593 		case USB4_MARGIN_CAP_1_TIME_LR:
594 			return USB4_MARGIN_CAP_TIME_INDP_GEN_2_3_LR;
595 		case USB4_MARGIN_CAP_1_TIME_BOTH:
596 			return USB4_MARGIN_CAP_TIME_INDP_GEN_2_3_BOTH;
597 		}
598 	} else {
599 		switch (FIELD_GET(USB4_MARGIN_CAP_2_TIME_INDP_MASK, margining->caps[2])) {
600 		case USB4_MARGIN_CAP_2_TIME_MIN:
601 			return USB4_MARGIN_CAP_TIME_INDP_GEN_4_MIN;
602 		case USB4_MARGIN_CAP_2_TIME_BOTH:
603 			return USB4_MARGIN_CAP_TIME_INDP_GEN_4_BOTH;
604 		}
605 	}
606 	return USB4_MARGIN_CAP_TIME_INDP_UNKNOWN;
607 }
608 
609 static bool
610 supports_optional_voltage_offset_range(const struct tb_margining *margining)
611 {
612 	return margining->caps[0] & USB4_MARGIN_CAP_0_OPT_VOLTAGE_SUPPORT;
613 }
614 
615 static ssize_t
616 margining_ber_level_write(struct file *file, const char __user *user_buf,
617 			   size_t count, loff_t *ppos)
618 {
619 	struct seq_file *s = file->private_data;
620 	struct tb_margining *margining = s->private;
621 	struct tb *tb = margining->port->sw->tb;
622 	unsigned int val;
623 	int ret = 0;
624 	char *buf;
625 
626 	if (mutex_lock_interruptible(&tb->lock))
627 		return -ERESTARTSYS;
628 
629 	if (margining->software) {
630 		ret = -EINVAL;
631 		goto out_unlock;
632 	}
633 
634 	buf = validate_and_copy_from_user(user_buf, &count);
635 	if (IS_ERR(buf)) {
636 		ret = PTR_ERR(buf);
637 		goto out_unlock;
638 	}
639 
640 	buf[count - 1] = '\0';
641 
642 	ret = kstrtouint(buf, 10, &val);
643 	if (ret)
644 		goto out_free;
645 
646 	if (val < margining->min_ber_level ||
647 	    val > margining->max_ber_level) {
648 		ret = -EINVAL;
649 		goto out_free;
650 	}
651 
652 	margining->ber_level = val;
653 
654 out_free:
655 	free_page((unsigned long)buf);
656 out_unlock:
657 	mutex_unlock(&tb->lock);
658 
659 	return ret < 0 ? ret : count;
660 }
661 
662 static void ber_level_show(struct seq_file *s, unsigned int val)
663 {
664 	if (val % 2)
665 		seq_printf(s, "3 * 1e%d (%u)\n", -12 + (val + 1) / 2, val);
666 	else
667 		seq_printf(s, "1e%d (%u)\n", -12 + val / 2, val);
668 }
669 
670 static int margining_ber_level_show(struct seq_file *s, void *not_used)
671 {
672 	const struct tb_margining *margining = s->private;
673 
674 	if (margining->software)
675 		return -EINVAL;
676 	ber_level_show(s, margining->ber_level);
677 	return 0;
678 }
679 DEBUGFS_ATTR_RW(margining_ber_level);
680 
681 static int margining_caps_show(struct seq_file *s, void *not_used)
682 {
683 	struct tb_margining *margining = s->private;
684 	struct tb *tb = margining->port->sw->tb;
685 	int ret = 0;
686 
687 	if (mutex_lock_interruptible(&tb->lock))
688 		return -ERESTARTSYS;
689 
690 	/* Dump the raw caps first */
691 	for (int i = 0; i < ARRAY_SIZE(margining->caps); i++)
692 		seq_printf(s, "0x%08x\n", margining->caps[i]);
693 
694 	seq_printf(s, "# software margining: %s\n",
695 		   str_yes_no(supports_software(margining)));
696 	if (supports_hardware(margining)) {
697 		seq_puts(s, "# hardware margining: yes\n");
698 		seq_puts(s, "# minimum BER level contour: ");
699 		ber_level_show(s, margining->min_ber_level);
700 		seq_puts(s, "# maximum BER level contour: ");
701 		ber_level_show(s, margining->max_ber_level);
702 	} else {
703 		seq_puts(s, "# hardware margining: no\n");
704 	}
705 
706 	seq_printf(s, "# all lanes simultaneously: %s\n",
707 		  str_yes_no(all_lanes(margining)));
708 	seq_printf(s, "# voltage margin steps: %u\n",
709 		   margining->voltage_steps);
710 	seq_printf(s, "# maximum voltage offset: %u mV\n",
711 		   margining->max_voltage_offset);
712 	seq_printf(s, "# optional voltage offset range support: %s\n",
713 		   str_yes_no(supports_optional_voltage_offset_range(margining)));
714 	if (supports_optional_voltage_offset_range(margining)) {
715 		seq_printf(s, "# voltage margin steps, optional range: %u\n",
716 			   margining->voltage_steps_optional_range);
717 		seq_printf(s, "# maximum voltage offset, optional range: %u mV\n",
718 			   margining->max_voltage_offset_optional_range);
719 	}
720 
721 	switch (independent_voltage_margins(margining)) {
722 	case USB4_MARGIN_CAP_VOLTAGE_INDP_GEN_2_3_MIN:
723 		seq_puts(s, "# returns minimum between high and low voltage margins\n");
724 		break;
725 	case USB4_MARGIN_CAP_VOLTAGE_INDP_GEN_2_3_HL:
726 		seq_puts(s, "# returns high or low voltage margin\n");
727 		break;
728 	case USB4_MARGIN_CAP_VOLTAGE_INDP_GEN_2_3_BOTH:
729 		seq_puts(s, "# returns both high and low margins\n");
730 		break;
731 	case USB4_MARGIN_CAP_VOLTAGE_INDP_GEN_4_MIN:
732 		seq_puts(s, "# returns minimum between high and low voltage margins in both lower and upper eye\n");
733 		break;
734 	case USB4_MARGIN_CAP_VOLTAGE_INDP_GEN_4_BOTH:
735 		seq_puts(s, "# returns both high and low margins of both upper and lower eye\n");
736 		break;
737 	case USB4_MARGIN_CAP_VOLTAGE_INDP_UNKNOWN:
738 		tb_port_warn(margining->port,
739 			     "failed to parse independent voltage margining capabilities\n");
740 		ret = -EIO;
741 		goto out;
742 	}
743 
744 	if (supports_time(margining)) {
745 		seq_puts(s, "# time margining: yes\n");
746 		seq_printf(s, "# time margining is destructive: %s\n",
747 			   str_yes_no(margining->caps[1] & USB4_MARGIN_CAP_1_TIME_DESTR));
748 
749 		switch (independent_time_margins(margining)) {
750 		case USB4_MARGIN_CAP_TIME_INDP_GEN_2_3_MIN:
751 			seq_puts(s, "# returns minimum between left and right time margins\n");
752 			break;
753 		case USB4_MARGIN_CAP_TIME_INDP_GEN_2_3_LR:
754 			seq_puts(s, "# returns left or right margin\n");
755 			break;
756 		case USB4_MARGIN_CAP_TIME_INDP_GEN_2_3_BOTH:
757 			seq_puts(s, "# returns both left and right margins\n");
758 			break;
759 		case USB4_MARGIN_CAP_TIME_INDP_GEN_4_MIN:
760 			seq_puts(s, "# returns minimum between left and right time margins in both lower and upper eye\n");
761 			break;
762 		case USB4_MARGIN_CAP_TIME_INDP_GEN_4_BOTH:
763 			seq_puts(s, "# returns both left and right margins of both upper and lower eye\n");
764 			break;
765 		case USB4_MARGIN_CAP_TIME_INDP_UNKNOWN:
766 			tb_port_warn(margining->port,
767 				     "failed to parse independent time margining capabilities\n");
768 			ret = -EIO;
769 			goto out;
770 		}
771 
772 		seq_printf(s, "# time margin steps: %u\n",
773 			   margining->time_steps);
774 		seq_printf(s, "# maximum time offset: %u mUI\n",
775 			   margining->max_time_offset);
776 	} else {
777 		seq_puts(s, "# time margining: no\n");
778 	}
779 
780 out:
781 	mutex_unlock(&tb->lock);
782 	return ret;
783 }
784 DEBUGFS_ATTR_RO(margining_caps);
785 
786 static const struct {
787 	enum usb4_margining_lane lane;
788 	const char *name;
789 } lane_names[] = {
790 	{
791 		.lane = USB4_MARGINING_LANE_RX0,
792 		.name = "0",
793 	},
794 	{
795 		.lane = USB4_MARGINING_LANE_RX1,
796 		.name = "1",
797 	},
798 	{
799 		.lane = USB4_MARGINING_LANE_RX2,
800 		.name = "2",
801 	},
802 	{
803 		.lane = USB4_MARGINING_LANE_ALL,
804 		.name = "all",
805 	},
806 };
807 
808 static ssize_t
809 margining_lanes_write(struct file *file, const char __user *user_buf,
810 		      size_t count, loff_t *ppos)
811 {
812 	struct seq_file *s = file->private_data;
813 	struct tb_margining *margining = s->private;
814 	struct tb_port *port = margining->port;
815 	struct tb *tb = port->sw->tb;
816 	int lane = -1;
817 	char *buf;
818 
819 	buf = validate_and_copy_from_user(user_buf, &count);
820 	if (IS_ERR(buf))
821 		return PTR_ERR(buf);
822 
823 	buf[count - 1] = '\0';
824 
825 	for (int i = 0; i < ARRAY_SIZE(lane_names); i++) {
826 		if (!strcmp(buf, lane_names[i].name)) {
827 			lane = lane_names[i].lane;
828 			break;
829 		}
830 	}
831 
832 	free_page((unsigned long)buf);
833 
834 	if (lane == -1)
835 		return -EINVAL;
836 
837 	scoped_cond_guard(mutex_intr, return -ERESTARTSYS, &tb->lock) {
838 		if (lane == USB4_MARGINING_LANE_ALL && !all_lanes(margining))
839 			return -EINVAL;
840 		/*
841 		 * Enabling on RX2 requires that it is supported by the
842 		 * USB4 port.
843 		 */
844 		if (lane == USB4_MARGINING_LANE_RX2 && !margining->asym_rx)
845 			return -EINVAL;
846 
847 		margining->lanes = lane;
848 	}
849 
850 	return count;
851 }
852 
853 static int margining_lanes_show(struct seq_file *s, void *not_used)
854 {
855 	struct tb_margining *margining = s->private;
856 	struct tb_port *port = margining->port;
857 	struct tb *tb = port->sw->tb;
858 
859 	scoped_cond_guard(mutex_intr, return -ERESTARTSYS, &tb->lock) {
860 		for (int i = 0; i < ARRAY_SIZE(lane_names); i++) {
861 			if (lane_names[i].lane == USB4_MARGINING_LANE_ALL &&
862 			    !all_lanes(margining))
863 				continue;
864 			if (lane_names[i].lane == USB4_MARGINING_LANE_RX2 &&
865 			    !margining->asym_rx)
866 				continue;
867 
868 			if (i != 0)
869 				seq_putc(s, ' ');
870 
871 			if (lane_names[i].lane == margining->lanes)
872 				seq_printf(s, "[%s]", lane_names[i].name);
873 			else
874 				seq_printf(s, "%s", lane_names[i].name);
875 		}
876 		seq_puts(s, "\n");
877 	}
878 
879 	return 0;
880 }
881 DEBUGFS_ATTR_RW(margining_lanes);
882 
883 static ssize_t
884 margining_voltage_time_offset_write(struct file *file,
885 				    const char __user *user_buf,
886 				    size_t count, loff_t *ppos)
887 {
888 	struct seq_file *s = file->private_data;
889 	struct tb_margining *margining = s->private;
890 	struct tb *tb = margining->port->sw->tb;
891 	unsigned int max_margin;
892 	unsigned int val;
893 	int ret;
894 
895 	ret = kstrtouint_from_user(user_buf, count, 10, &val);
896 	if (ret)
897 		return ret;
898 
899 	scoped_cond_guard(mutex_intr, return -ERESTARTSYS, &tb->lock) {
900 		if (!margining->software)
901 			return -EOPNOTSUPP;
902 
903 		if (margining->time)
904 			max_margin = margining->time_steps;
905 		else
906 			if (margining->optional_voltage_offset_range)
907 				max_margin = margining->voltage_steps_optional_range;
908 			else
909 				max_margin = margining->voltage_steps;
910 
911 		margining->voltage_time_offset = clamp(val, 0, max_margin);
912 	}
913 
914 	return count;
915 }
916 
917 static int margining_voltage_time_offset_show(struct seq_file *s,
918 					      void *not_used)
919 {
920 	const struct tb_margining *margining = s->private;
921 	struct tb *tb = margining->port->sw->tb;
922 
923 	scoped_cond_guard(mutex_intr, return -ERESTARTSYS, &tb->lock) {
924 		if (!margining->software)
925 			return -EOPNOTSUPP;
926 
927 		seq_printf(s, "%d\n", margining->voltage_time_offset);
928 	}
929 
930 	return 0;
931 }
932 DEBUGFS_ATTR_RW(margining_voltage_time_offset);
933 
934 static ssize_t
935 margining_error_counter_write(struct file *file, const char __user *user_buf,
936 			      size_t count, loff_t *ppos)
937 {
938 	enum usb4_margin_sw_error_counter error_counter;
939 	struct seq_file *s = file->private_data;
940 	struct tb_margining *margining = s->private;
941 	struct tb *tb = margining->port->sw->tb;
942 	char *buf;
943 
944 	buf = validate_and_copy_from_user(user_buf, &count);
945 	if (IS_ERR(buf))
946 		return PTR_ERR(buf);
947 
948 	buf[count - 1] = '\0';
949 
950 	if (!strcmp(buf, "nop"))
951 		error_counter = USB4_MARGIN_SW_ERROR_COUNTER_NOP;
952 	else if (!strcmp(buf, "clear"))
953 		error_counter = USB4_MARGIN_SW_ERROR_COUNTER_CLEAR;
954 	else if (!strcmp(buf, "start"))
955 		error_counter = USB4_MARGIN_SW_ERROR_COUNTER_START;
956 	else if (!strcmp(buf, "stop"))
957 		error_counter = USB4_MARGIN_SW_ERROR_COUNTER_STOP;
958 	else
959 		goto err_free;
960 
961 	free_page((unsigned long)buf);
962 
963 	scoped_cond_guard(mutex_intr, return -ERESTARTSYS, &tb->lock) {
964 		if (!margining->software)
965 			return -EOPNOTSUPP;
966 
967 		margining->error_counter = error_counter;
968 	}
969 
970 	return count;
971 
972 err_free:
973 	free_page((unsigned long)buf);
974 	return -EINVAL;
975 }
976 
977 static int margining_error_counter_show(struct seq_file *s, void *not_used)
978 {
979 	const struct tb_margining *margining = s->private;
980 	struct tb *tb = margining->port->sw->tb;
981 
982 	scoped_cond_guard(mutex_intr, return -ERESTARTSYS, &tb->lock) {
983 		if (!margining->software)
984 			return -EOPNOTSUPP;
985 
986 		switch (margining->error_counter) {
987 		case USB4_MARGIN_SW_ERROR_COUNTER_NOP:
988 			seq_puts(s, "[nop] clear start stop\n");
989 			break;
990 		case USB4_MARGIN_SW_ERROR_COUNTER_CLEAR:
991 			seq_puts(s, "nop [clear] start stop\n");
992 			break;
993 		case USB4_MARGIN_SW_ERROR_COUNTER_START:
994 			seq_puts(s, "nop clear [start] stop\n");
995 			break;
996 		case USB4_MARGIN_SW_ERROR_COUNTER_STOP:
997 			seq_puts(s, "nop clear start [stop]\n");
998 			break;
999 		}
1000 	}
1001 
1002 	return 0;
1003 }
1004 DEBUGFS_ATTR_RW(margining_error_counter);
1005 
1006 static ssize_t
1007 margining_dwell_time_write(struct file *file, const char __user *user_buf,
1008 			   size_t count, loff_t *ppos)
1009 {
1010 	struct seq_file *s = file->private_data;
1011 	struct tb_margining *margining = s->private;
1012 	struct tb *tb = margining->port->sw->tb;
1013 	unsigned int val;
1014 	int ret;
1015 
1016 	ret = kstrtouint_from_user(user_buf, count, 10, &val);
1017 	if (ret)
1018 		return ret;
1019 
1020 	scoped_cond_guard(mutex_intr, return -ERESTARTSYS, &tb->lock) {
1021 		if (!margining->software)
1022 			return -EOPNOTSUPP;
1023 
1024 		margining->dwell_time = clamp(val, MIN_DWELL_TIME, MAX_DWELL_TIME);
1025 	}
1026 
1027 	return count;
1028 }
1029 
1030 static int margining_dwell_time_show(struct seq_file *s, void *not_used)
1031 {
1032 	struct tb_margining *margining = s->private;
1033 	struct tb *tb = margining->port->sw->tb;
1034 
1035 	scoped_cond_guard(mutex_intr, return -ERESTARTSYS, &tb->lock) {
1036 		if (!margining->software)
1037 			return -EOPNOTSUPP;
1038 
1039 		seq_printf(s, "%d\n", margining->dwell_time);
1040 	}
1041 
1042 	return 0;
1043 }
1044 DEBUGFS_ATTR_RW(margining_dwell_time);
1045 
1046 static ssize_t
1047 margining_optional_voltage_offset_write(struct file *file, const char __user *user_buf,
1048 					size_t count, loff_t *ppos)
1049 {
1050 	struct seq_file *s = file->private_data;
1051 	struct tb_margining *margining = s->private;
1052 	struct tb *tb = margining->port->sw->tb;
1053 	bool val;
1054 	int ret;
1055 
1056 	ret = kstrtobool_from_user(user_buf, count, &val);
1057 	if (ret)
1058 		return ret;
1059 
1060 	scoped_cond_guard(mutex_intr, return -ERESTARTSYS, &tb->lock) {
1061 		margining->optional_voltage_offset_range = val;
1062 	}
1063 
1064 	return count;
1065 }
1066 
1067 static int margining_optional_voltage_offset_show(struct seq_file *s,
1068 						  void *not_used)
1069 {
1070 	struct tb_margining *margining = s->private;
1071 	struct tb *tb = margining->port->sw->tb;
1072 
1073 	scoped_cond_guard(mutex_intr, return -ERESTARTSYS, &tb->lock) {
1074 		seq_printf(s, "%u\n", margining->optional_voltage_offset_range);
1075 	}
1076 
1077 	return 0;
1078 }
1079 DEBUGFS_ATTR_RW(margining_optional_voltage_offset);
1080 
1081 static ssize_t margining_mode_write(struct file *file,
1082 				   const char __user *user_buf,
1083 				   size_t count, loff_t *ppos)
1084 {
1085 	struct seq_file *s = file->private_data;
1086 	struct tb_margining *margining = s->private;
1087 	struct tb *tb = margining->port->sw->tb;
1088 	int ret = 0;
1089 	char *buf;
1090 
1091 	buf = validate_and_copy_from_user(user_buf, &count);
1092 	if (IS_ERR(buf))
1093 		return PTR_ERR(buf);
1094 
1095 	buf[count - 1] = '\0';
1096 
1097 	if (mutex_lock_interruptible(&tb->lock)) {
1098 		ret = -ERESTARTSYS;
1099 		goto out_free;
1100 	}
1101 
1102 	if (!strcmp(buf, "software")) {
1103 		if (supports_software(margining))
1104 			margining->software = true;
1105 		else
1106 			ret = -EINVAL;
1107 	} else if (!strcmp(buf, "hardware")) {
1108 		if (supports_hardware(margining))
1109 			margining->software = false;
1110 		else
1111 			ret = -EINVAL;
1112 	} else {
1113 		ret = -EINVAL;
1114 	}
1115 
1116 	mutex_unlock(&tb->lock);
1117 
1118 out_free:
1119 	free_page((unsigned long)buf);
1120 	return ret ? ret : count;
1121 }
1122 
1123 static int margining_mode_show(struct seq_file *s, void *not_used)
1124 {
1125 	struct tb_margining *margining = s->private;
1126 	struct tb *tb = margining->port->sw->tb;
1127 	const char *space = "";
1128 
1129 	if (mutex_lock_interruptible(&tb->lock))
1130 		return -ERESTARTSYS;
1131 
1132 	if (supports_software(margining)) {
1133 		if (margining->software)
1134 			seq_puts(s, "[software]");
1135 		else
1136 			seq_puts(s, "software");
1137 		space = " ";
1138 	}
1139 	if (supports_hardware(margining)) {
1140 		if (margining->software)
1141 			seq_printf(s, "%shardware", space);
1142 		else
1143 			seq_printf(s, "%s[hardware]", space);
1144 	}
1145 
1146 	mutex_unlock(&tb->lock);
1147 
1148 	seq_puts(s, "\n");
1149 	return 0;
1150 }
1151 DEBUGFS_ATTR_RW(margining_mode);
1152 
1153 static int margining_run_sw(struct tb_margining *margining,
1154 			    struct usb4_port_margining_params *params)
1155 {
1156 	u32 nsamples = margining->dwell_time / DWELL_SAMPLE_INTERVAL;
1157 	int ret, i;
1158 
1159 	ret = usb4_port_sw_margin(margining->port, margining->target, margining->index,
1160 				  params, margining->results);
1161 	if (ret)
1162 		goto out_stop;
1163 
1164 	for (i = 0; i <= nsamples; i++) {
1165 		u32 errors = 0;
1166 
1167 		ret = usb4_port_sw_margin_errors(margining->port, margining->target,
1168 						 margining->index, &margining->results[1]);
1169 		if (ret)
1170 			break;
1171 
1172 		if (margining->lanes == USB4_MARGINING_LANE_RX0)
1173 			errors = FIELD_GET(USB4_MARGIN_SW_ERR_COUNTER_LANE_0_MASK,
1174 					   margining->results[1]);
1175 		else if (margining->lanes == USB4_MARGINING_LANE_RX1)
1176 			errors = FIELD_GET(USB4_MARGIN_SW_ERR_COUNTER_LANE_1_MASK,
1177 					   margining->results[1]);
1178 		else if (margining->lanes == USB4_MARGINING_LANE_RX2)
1179 			errors = FIELD_GET(USB4_MARGIN_SW_ERR_COUNTER_LANE_2_MASK,
1180 					   margining->results[1]);
1181 		else if (margining->lanes == USB4_MARGINING_LANE_ALL)
1182 			errors = margining->results[1];
1183 
1184 		/* Any errors stop the test */
1185 		if (errors)
1186 			break;
1187 
1188 		fsleep(DWELL_SAMPLE_INTERVAL * USEC_PER_MSEC);
1189 	}
1190 
1191 out_stop:
1192 	/*
1193 	 * Stop the counters but don't clear them to allow the
1194 	 * different error counter configurations.
1195 	 */
1196 	margining_modify_error_counter(margining, margining->lanes,
1197 				       USB4_MARGIN_SW_ERROR_COUNTER_STOP);
1198 	return ret;
1199 }
1200 
1201 static int validate_margining(struct tb_margining *margining)
1202 {
1203 	/*
1204 	 * For running on RX2 the link must be asymmetric with 3
1205 	 * receivers. Because this can change dynamically, check it
1206 	 * here before we start the margining and report back error if
1207 	 * expectations are not met.
1208 	 */
1209 	if (margining->lanes == USB4_MARGINING_LANE_RX2) {
1210 		int ret;
1211 
1212 		ret = tb_port_get_link_width(margining->port);
1213 		if (ret < 0)
1214 			return ret;
1215 		if (ret != TB_LINK_WIDTH_ASYM_RX) {
1216 			tb_port_warn(margining->port, "link is %s expected %s",
1217 				     tb_width_name(ret),
1218 				     tb_width_name(TB_LINK_WIDTH_ASYM_RX));
1219 			return -EINVAL;
1220 		}
1221 	}
1222 
1223 	return 0;
1224 }
1225 
1226 static int margining_run_write(void *data, u64 val)
1227 {
1228 	struct tb_margining *margining = data;
1229 	struct tb_port *port = margining->port;
1230 	struct device *dev = margining->dev;
1231 	struct tb_switch *sw = port->sw;
1232 	struct tb_switch *down_sw;
1233 	struct tb *tb = sw->tb;
1234 	int ret, clx;
1235 
1236 	if (val != 1)
1237 		return -EINVAL;
1238 
1239 	pm_runtime_get_sync(dev);
1240 
1241 	if (mutex_lock_interruptible(&tb->lock)) {
1242 		ret = -ERESTARTSYS;
1243 		goto out_rpm_put;
1244 	}
1245 
1246 	ret = validate_margining(margining);
1247 	if (ret)
1248 		goto out_unlock;
1249 
1250 	if (tb_is_upstream_port(port))
1251 		down_sw = sw;
1252 	else if (port->remote)
1253 		down_sw = port->remote->sw;
1254 	else
1255 		down_sw = NULL;
1256 
1257 	if (down_sw) {
1258 		/*
1259 		 * CL states may interfere with lane margining so
1260 		 * disable them temporarily now.
1261 		 */
1262 		ret = tb_switch_clx_disable(down_sw);
1263 		if (ret < 0) {
1264 			tb_sw_warn(down_sw, "failed to disable CL states\n");
1265 			goto out_unlock;
1266 		}
1267 		clx = ret;
1268 	}
1269 
1270 	/* Clear the results */
1271 	memset(margining->results, 0, sizeof(margining->results));
1272 
1273 	if (margining->software) {
1274 		struct usb4_port_margining_params params = {
1275 			.error_counter = USB4_MARGIN_SW_ERROR_COUNTER_CLEAR,
1276 			.lanes = margining->lanes,
1277 			.time = margining->time,
1278 			.voltage_time_offset = margining->voltage_time_offset,
1279 			.right_high = margining->right_high,
1280 			.upper_eye = margining->upper_eye,
1281 			.optional_voltage_offset_range = margining->optional_voltage_offset_range,
1282 		};
1283 
1284 		tb_port_dbg(port,
1285 			    "running software %s lane margining for %s lanes %u\n",
1286 			    margining->time ? "time" : "voltage", dev_name(dev),
1287 			    margining->lanes);
1288 
1289 		ret = margining_run_sw(margining, &params);
1290 	} else {
1291 		struct usb4_port_margining_params params = {
1292 			.ber_level = margining->ber_level,
1293 			.lanes = margining->lanes,
1294 			.time = margining->time,
1295 			.right_high = margining->right_high,
1296 			.upper_eye = margining->upper_eye,
1297 			.optional_voltage_offset_range = margining->optional_voltage_offset_range,
1298 		};
1299 
1300 		tb_port_dbg(port,
1301 			    "running hardware %s lane margining for %s lanes %u\n",
1302 			    margining->time ? "time" : "voltage", dev_name(dev),
1303 			    margining->lanes);
1304 
1305 		ret = usb4_port_hw_margin(port, margining->target, margining->index, &params,
1306 					  margining->results, ARRAY_SIZE(margining->results));
1307 	}
1308 
1309 	if (down_sw)
1310 		tb_switch_clx_enable(down_sw, clx);
1311 out_unlock:
1312 	mutex_unlock(&tb->lock);
1313 out_rpm_put:
1314 	pm_runtime_mark_last_busy(dev);
1315 	pm_runtime_put_autosuspend(dev);
1316 
1317 	return ret;
1318 }
1319 DEFINE_DEBUGFS_ATTRIBUTE(margining_run_fops, NULL, margining_run_write,
1320 			 "%llu\n");
1321 
1322 static ssize_t margining_results_write(struct file *file,
1323 				       const char __user *user_buf,
1324 				       size_t count, loff_t *ppos)
1325 {
1326 	struct seq_file *s = file->private_data;
1327 	struct tb_margining *margining = s->private;
1328 	struct tb *tb = margining->port->sw->tb;
1329 
1330 	if (mutex_lock_interruptible(&tb->lock))
1331 		return -ERESTARTSYS;
1332 
1333 	/* Just clear the results */
1334 	memset(margining->results, 0, sizeof(margining->results));
1335 
1336 	if (margining->software) {
1337 		/* Clear the error counters */
1338 		margining_modify_error_counter(margining,
1339 					       USB4_MARGINING_LANE_ALL,
1340 					       USB4_MARGIN_SW_ERROR_COUNTER_CLEAR);
1341 	}
1342 
1343 	mutex_unlock(&tb->lock);
1344 	return count;
1345 }
1346 
1347 static void voltage_margin_show(struct seq_file *s,
1348 				const struct tb_margining *margining, u8 val)
1349 {
1350 	unsigned int tmp, voltage;
1351 
1352 	tmp = FIELD_GET(USB4_MARGIN_HW_RES_MARGIN_MASK, val);
1353 	voltage = tmp * margining->max_voltage_offset / margining->voltage_steps;
1354 	seq_printf(s, "%u mV (%u)", voltage, tmp);
1355 	if (val & USB4_MARGIN_HW_RES_EXCEEDS)
1356 		seq_puts(s, " exceeds maximum");
1357 	seq_puts(s, "\n");
1358 	if (margining->optional_voltage_offset_range)
1359 		seq_puts(s, " optional voltage offset range enabled\n");
1360 }
1361 
1362 static void time_margin_show(struct seq_file *s,
1363 			     const struct tb_margining *margining, u8 val)
1364 {
1365 	unsigned int tmp, interval;
1366 
1367 	tmp = FIELD_GET(USB4_MARGIN_HW_RES_MARGIN_MASK, val);
1368 	interval = tmp * margining->max_time_offset / margining->time_steps;
1369 	seq_printf(s, "%u mUI (%u)", interval, tmp);
1370 	if (val & USB4_MARGIN_HW_RES_EXCEEDS)
1371 		seq_puts(s, " exceeds maximum");
1372 	seq_puts(s, "\n");
1373 }
1374 
1375 static u8 margining_hw_result_val(const u32 *results,
1376 				  enum usb4_margining_lane lane,
1377 				  bool right_high)
1378 {
1379 	u32 val;
1380 
1381 	if (lane == USB4_MARGINING_LANE_RX0)
1382 		val = results[1];
1383 	else if (lane == USB4_MARGINING_LANE_RX1)
1384 		val = results[1] >> USB4_MARGIN_HW_RES_LANE_SHIFT;
1385 	else if (lane == USB4_MARGINING_LANE_RX2)
1386 		val = results[2];
1387 	else
1388 		val = 0;
1389 
1390 	return right_high ? val : val >> USB4_MARGIN_HW_RES_LL_SHIFT;
1391 }
1392 
1393 static void margining_hw_result_format(struct seq_file *s,
1394 				       const struct tb_margining *margining,
1395 				       enum usb4_margining_lane lane)
1396 {
1397 	u8 val;
1398 
1399 	if (margining->time) {
1400 		val = margining_hw_result_val(margining->results, lane, true);
1401 		seq_printf(s, "# lane %u right time margin: ", lane);
1402 		time_margin_show(s, margining, val);
1403 		val = margining_hw_result_val(margining->results, lane, false);
1404 		seq_printf(s, "# lane %u left time margin: ", lane);
1405 		time_margin_show(s, margining, val);
1406 	} else {
1407 		val = margining_hw_result_val(margining->results, lane, true);
1408 		seq_printf(s, "# lane %u high voltage margin: ", lane);
1409 		voltage_margin_show(s, margining, val);
1410 		val = margining_hw_result_val(margining->results, lane, false);
1411 		seq_printf(s, "# lane %u low voltage margin: ", lane);
1412 		voltage_margin_show(s, margining, val);
1413 	}
1414 }
1415 
1416 static int margining_results_show(struct seq_file *s, void *not_used)
1417 {
1418 	struct tb_margining *margining = s->private;
1419 	struct tb *tb = margining->port->sw->tb;
1420 
1421 	if (mutex_lock_interruptible(&tb->lock))
1422 		return -ERESTARTSYS;
1423 
1424 	/* Dump the raw results first */
1425 	seq_printf(s, "0x%08x\n", margining->results[0]);
1426 	/* Only the hardware margining has two result dwords */
1427 	if (!margining->software) {
1428 		for (int i = 1; i < ARRAY_SIZE(margining->results); i++)
1429 			seq_printf(s, "0x%08x\n", margining->results[i]);
1430 
1431 		if (margining->lanes == USB4_MARGINING_LANE_ALL) {
1432 			margining_hw_result_format(s, margining,
1433 						   USB4_MARGINING_LANE_RX0);
1434 			margining_hw_result_format(s, margining,
1435 						   USB4_MARGINING_LANE_RX1);
1436 			if (margining->asym_rx)
1437 				margining_hw_result_format(s, margining,
1438 						USB4_MARGINING_LANE_RX2);
1439 		} else {
1440 			margining_hw_result_format(s, margining,
1441 						   margining->lanes);
1442 		}
1443 	} else {
1444 		u32 lane_errors, result;
1445 
1446 		seq_printf(s, "0x%08x\n", margining->results[1]);
1447 
1448 		result = FIELD_GET(USB4_MARGIN_SW_LANES_MASK, margining->results[0]);
1449 		if (result == USB4_MARGINING_LANE_RX0 ||
1450 		    result == USB4_MARGINING_LANE_ALL) {
1451 			lane_errors = FIELD_GET(USB4_MARGIN_SW_ERR_COUNTER_LANE_0_MASK,
1452 						margining->results[1]);
1453 			seq_printf(s, "# lane 0 errors: %u\n", lane_errors);
1454 		}
1455 		if (result == USB4_MARGINING_LANE_RX1 ||
1456 		    result == USB4_MARGINING_LANE_ALL) {
1457 			lane_errors = FIELD_GET(USB4_MARGIN_SW_ERR_COUNTER_LANE_1_MASK,
1458 						margining->results[1]);
1459 			seq_printf(s, "# lane 1 errors: %u\n", lane_errors);
1460 		}
1461 		if (margining->asym_rx &&
1462 		    (result == USB4_MARGINING_LANE_RX2 ||
1463 		     result == USB4_MARGINING_LANE_ALL)) {
1464 			lane_errors = FIELD_GET(USB4_MARGIN_SW_ERR_COUNTER_LANE_2_MASK,
1465 						margining->results[1]);
1466 			seq_printf(s, "# lane 2 errors: %u\n", lane_errors);
1467 		}
1468 	}
1469 
1470 	mutex_unlock(&tb->lock);
1471 	return 0;
1472 }
1473 DEBUGFS_ATTR_RW(margining_results);
1474 
1475 static ssize_t margining_test_write(struct file *file,
1476 				    const char __user *user_buf,
1477 				    size_t count, loff_t *ppos)
1478 {
1479 	struct seq_file *s = file->private_data;
1480 	struct tb_margining *margining = s->private;
1481 	struct tb *tb = margining->port->sw->tb;
1482 	int ret = 0;
1483 	char *buf;
1484 
1485 	buf = validate_and_copy_from_user(user_buf, &count);
1486 	if (IS_ERR(buf))
1487 		return PTR_ERR(buf);
1488 
1489 	buf[count - 1] = '\0';
1490 
1491 	if (mutex_lock_interruptible(&tb->lock)) {
1492 		ret = -ERESTARTSYS;
1493 		goto out_free;
1494 	}
1495 
1496 	if (!strcmp(buf, "time") && supports_time(margining))
1497 		margining->time = true;
1498 	else if (!strcmp(buf, "voltage"))
1499 		margining->time = false;
1500 	else
1501 		ret = -EINVAL;
1502 
1503 	mutex_unlock(&tb->lock);
1504 
1505 out_free:
1506 	free_page((unsigned long)buf);
1507 	return ret ? ret : count;
1508 }
1509 
1510 static int margining_test_show(struct seq_file *s, void *not_used)
1511 {
1512 	struct tb_margining *margining = s->private;
1513 	struct tb *tb = margining->port->sw->tb;
1514 
1515 	if (mutex_lock_interruptible(&tb->lock))
1516 		return -ERESTARTSYS;
1517 
1518 	if (supports_time(margining)) {
1519 		if (margining->time)
1520 			seq_puts(s, "voltage [time]\n");
1521 		else
1522 			seq_puts(s, "[voltage] time\n");
1523 	} else {
1524 		seq_puts(s, "[voltage]\n");
1525 	}
1526 
1527 	mutex_unlock(&tb->lock);
1528 	return 0;
1529 }
1530 DEBUGFS_ATTR_RW(margining_test);
1531 
1532 static ssize_t margining_margin_write(struct file *file,
1533 				    const char __user *user_buf,
1534 				    size_t count, loff_t *ppos)
1535 {
1536 	struct seq_file *s = file->private_data;
1537 	struct tb_margining *margining = s->private;
1538 	struct tb *tb = margining->port->sw->tb;
1539 	int ret = 0;
1540 	char *buf;
1541 
1542 	buf = validate_and_copy_from_user(user_buf, &count);
1543 	if (IS_ERR(buf))
1544 		return PTR_ERR(buf);
1545 
1546 	buf[count - 1] = '\0';
1547 
1548 	if (mutex_lock_interruptible(&tb->lock)) {
1549 		ret = -ERESTARTSYS;
1550 		goto out_free;
1551 	}
1552 
1553 	if (margining->time) {
1554 		if (!strcmp(buf, "left"))
1555 			margining->right_high = false;
1556 		else if (!strcmp(buf, "right"))
1557 			margining->right_high = true;
1558 		else
1559 			ret = -EINVAL;
1560 	} else {
1561 		if (!strcmp(buf, "low"))
1562 			margining->right_high = false;
1563 		else if (!strcmp(buf, "high"))
1564 			margining->right_high = true;
1565 		else
1566 			ret = -EINVAL;
1567 	}
1568 
1569 	mutex_unlock(&tb->lock);
1570 
1571 out_free:
1572 	free_page((unsigned long)buf);
1573 	return ret ? ret : count;
1574 }
1575 
1576 static int margining_margin_show(struct seq_file *s, void *not_used)
1577 {
1578 	struct tb_margining *margining = s->private;
1579 	struct tb *tb = margining->port->sw->tb;
1580 
1581 	if (mutex_lock_interruptible(&tb->lock))
1582 		return -ERESTARTSYS;
1583 
1584 	if (margining->time) {
1585 		if (margining->right_high)
1586 			seq_puts(s, "left [right]\n");
1587 		else
1588 			seq_puts(s, "[left] right\n");
1589 	} else {
1590 		if (margining->right_high)
1591 			seq_puts(s, "low [high]\n");
1592 		else
1593 			seq_puts(s, "[low] high\n");
1594 	}
1595 
1596 	mutex_unlock(&tb->lock);
1597 	return 0;
1598 }
1599 DEBUGFS_ATTR_RW(margining_margin);
1600 
1601 static ssize_t margining_eye_write(struct file *file,
1602 				   const char __user *user_buf,
1603 				   size_t count, loff_t *ppos)
1604 {
1605 	struct seq_file *s = file->private_data;
1606 	struct tb_port *port = s->private;
1607 	struct usb4_port *usb4 = port->usb4;
1608 	struct tb *tb = port->sw->tb;
1609 	int ret = 0;
1610 	char *buf;
1611 
1612 	buf = validate_and_copy_from_user(user_buf, &count);
1613 	if (IS_ERR(buf))
1614 		return PTR_ERR(buf);
1615 
1616 	buf[count - 1] = '\0';
1617 
1618 	scoped_cond_guard(mutex_intr, ret = -ERESTARTSYS, &tb->lock) {
1619 		if (!strcmp(buf, "lower"))
1620 			usb4->margining->upper_eye = false;
1621 		else if (!strcmp(buf, "upper"))
1622 			usb4->margining->upper_eye = true;
1623 		else
1624 			ret = -EINVAL;
1625 	}
1626 
1627 	free_page((unsigned long)buf);
1628 	return ret ? ret : count;
1629 }
1630 
1631 static int margining_eye_show(struct seq_file *s, void *not_used)
1632 {
1633 	struct tb_port *port = s->private;
1634 	struct usb4_port *usb4 = port->usb4;
1635 	struct tb *tb = port->sw->tb;
1636 
1637 	scoped_guard(mutex_intr, &tb->lock) {
1638 		if (usb4->margining->upper_eye)
1639 			seq_puts(s, "lower [upper]\n");
1640 		else
1641 			seq_puts(s, "[lower] upper\n");
1642 
1643 		return 0;
1644 	}
1645 
1646 	return -ERESTARTSYS;
1647 }
1648 DEBUGFS_ATTR_RW(margining_eye);
1649 
1650 static struct tb_margining *margining_alloc(struct tb_port *port,
1651 					    struct device *dev,
1652 					    enum usb4_sb_target target,
1653 					    u8 index, struct dentry *parent)
1654 {
1655 	struct tb_margining *margining;
1656 	struct dentry *dir;
1657 	unsigned int val;
1658 	int ret;
1659 
1660 	ret = tb_port_get_link_generation(port);
1661 	if (ret < 0) {
1662 		tb_port_warn(port, "failed to read link generation\n");
1663 		return NULL;
1664 	}
1665 
1666 	margining = kzalloc_obj(*margining);
1667 	if (!margining)
1668 		return NULL;
1669 
1670 	margining->port = port;
1671 	margining->target = target;
1672 	margining->index = index;
1673 	margining->dev = dev;
1674 	margining->gen = ret;
1675 	margining->asym_rx = tb_port_width_supported(port, TB_LINK_WIDTH_ASYM_RX);
1676 
1677 	ret = usb4_port_margining_caps(port, target, index, margining->caps,
1678 				       ARRAY_SIZE(margining->caps));
1679 	if (ret) {
1680 		kfree(margining);
1681 		return NULL;
1682 	}
1683 
1684 	/* Set the initial mode */
1685 	if (supports_software(margining))
1686 		margining->software = true;
1687 
1688 	if (margining->gen < 4) {
1689 		val = FIELD_GET(USB4_MARGIN_CAP_0_VOLTAGE_STEPS_MASK, margining->caps[0]);
1690 		margining->voltage_steps = val;
1691 		val = FIELD_GET(USB4_MARGIN_CAP_0_MAX_VOLTAGE_OFFSET_MASK, margining->caps[0]);
1692 		margining->max_voltage_offset = 74 + val * 2;
1693 	} else {
1694 		val = FIELD_GET(USB4_MARGIN_CAP_2_VOLTAGE_STEPS_MASK, margining->caps[2]);
1695 		margining->voltage_steps = val;
1696 		val = FIELD_GET(USB4_MARGIN_CAP_2_MAX_VOLTAGE_OFFSET_MASK, margining->caps[2]);
1697 		margining->max_voltage_offset = 74 + val * 2;
1698 	}
1699 
1700 	if (supports_optional_voltage_offset_range(margining)) {
1701 		val = FIELD_GET(USB4_MARGIN_CAP_0_VOLT_STEPS_OPT_MASK,
1702 				margining->caps[0]);
1703 		margining->voltage_steps_optional_range = val;
1704 		val = FIELD_GET(USB4_MARGIN_CAP_1_MAX_VOLT_OFS_OPT_MASK,
1705 				margining->caps[1]);
1706 		margining->max_voltage_offset_optional_range = 74 + val * 2;
1707 	}
1708 
1709 	if (supports_time(margining)) {
1710 		val = FIELD_GET(USB4_MARGIN_CAP_1_TIME_STEPS_MASK, margining->caps[1]);
1711 		margining->time_steps = val;
1712 		val = FIELD_GET(USB4_MARGIN_CAP_1_TIME_OFFSET_MASK, margining->caps[1]);
1713 		/*
1714 		 * Store it as mUI (milli Unit Interval) because we want
1715 		 * to keep it as integer.
1716 		 */
1717 		margining->max_time_offset = 200 + 10 * val;
1718 	}
1719 
1720 	dir = debugfs_create_dir("margining", parent);
1721 	if (supports_hardware(margining)) {
1722 		val = FIELD_GET(USB4_MARGIN_CAP_1_MIN_BER_MASK, margining->caps[1]);
1723 		margining->min_ber_level = val;
1724 		val = FIELD_GET(USB4_MARGIN_CAP_1_MAX_BER_MASK, margining->caps[1]);
1725 		margining->max_ber_level = val;
1726 
1727 		/* Set the default to minimum */
1728 		margining->ber_level = margining->min_ber_level;
1729 
1730 		debugfs_create_file("ber_level_contour", 0400, dir, margining,
1731 				    &margining_ber_level_fops);
1732 	}
1733 	debugfs_create_file("caps", 0400, dir, margining, &margining_caps_fops);
1734 	debugfs_create_file("lanes", 0600, dir, margining, &margining_lanes_fops);
1735 	debugfs_create_file("mode", 0600, dir, margining, &margining_mode_fops);
1736 	debugfs_create_file("run", 0600, dir, margining, &margining_run_fops);
1737 	debugfs_create_file("results", 0600, dir, margining,
1738 			    &margining_results_fops);
1739 	debugfs_create_file("test", 0600, dir, margining, &margining_test_fops);
1740 	if (independent_voltage_margins(margining) == USB4_MARGIN_CAP_VOLTAGE_INDP_GEN_2_3_HL ||
1741 	    (supports_time(margining) &&
1742 	     independent_time_margins(margining) == USB4_MARGIN_CAP_TIME_INDP_GEN_2_3_LR))
1743 		debugfs_create_file("margin", 0600, dir, margining, &margining_margin_fops);
1744 
1745 	margining->error_counter = USB4_MARGIN_SW_ERROR_COUNTER_CLEAR;
1746 	margining->dwell_time = MIN_DWELL_TIME;
1747 
1748 	if (supports_optional_voltage_offset_range(margining))
1749 		debugfs_create_file("optional_voltage_offset", DEBUGFS_MODE, dir, margining,
1750 				    &margining_optional_voltage_offset_fops);
1751 
1752 	if (supports_software(margining)) {
1753 		debugfs_create_file("voltage_time_offset", DEBUGFS_MODE, dir, margining,
1754 				    &margining_voltage_time_offset_fops);
1755 		debugfs_create_file("error_counter", DEBUGFS_MODE, dir, margining,
1756 				    &margining_error_counter_fops);
1757 		debugfs_create_file("dwell_time", DEBUGFS_MODE, dir, margining,
1758 				    &margining_dwell_time_fops);
1759 	}
1760 
1761 	if (margining->gen >= 4)
1762 		debugfs_create_file("eye", 0600, dir, port, &margining_eye_fops);
1763 
1764 	return margining;
1765 }
1766 
1767 static void margining_port_init(struct tb_port *port)
1768 {
1769 	struct dentry *parent;
1770 	char dir_name[10];
1771 
1772 	if (!port->usb4)
1773 		return;
1774 
1775 	snprintf(dir_name, sizeof(dir_name), "port%d", port->port);
1776 	parent = debugfs_lookup(dir_name, port->sw->debugfs_dir);
1777 	port->usb4->margining = margining_alloc(port, &port->usb4->dev,
1778 						USB4_SB_TARGET_ROUTER, 0,
1779 						parent);
1780 }
1781 
1782 static void margining_port_remove(struct tb_port *port)
1783 {
1784 	struct dentry *parent;
1785 	char dir_name[10];
1786 
1787 	if (!port->usb4)
1788 		return;
1789 	if (!port->usb4->margining)
1790 		return;
1791 
1792 	snprintf(dir_name, sizeof(dir_name), "port%d", port->port);
1793 	parent = debugfs_lookup(dir_name, port->sw->debugfs_dir);
1794 	if (parent)
1795 		debugfs_lookup_and_remove("margining", parent);
1796 
1797 	kfree(port->usb4->margining);
1798 	port->usb4->margining = NULL;
1799 }
1800 
1801 static void margining_switch_init(struct tb_switch *sw)
1802 {
1803 	struct tb_port *upstream, *downstream;
1804 	struct tb_switch *parent_sw;
1805 	u64 route = tb_route(sw);
1806 
1807 	if (!route)
1808 		return;
1809 
1810 	upstream = tb_upstream_port(sw);
1811 	parent_sw = tb_switch_parent(sw);
1812 	downstream = tb_port_at(route, parent_sw);
1813 
1814 	margining_port_init(downstream);
1815 	margining_port_init(upstream);
1816 }
1817 
1818 static void margining_switch_remove(struct tb_switch *sw)
1819 {
1820 	struct tb_port *upstream, *downstream;
1821 	struct tb_switch *parent_sw;
1822 	u64 route = tb_route(sw);
1823 
1824 	if (!route)
1825 		return;
1826 
1827 	upstream = tb_upstream_port(sw);
1828 	parent_sw = tb_switch_parent(sw);
1829 	downstream = tb_port_at(route, parent_sw);
1830 
1831 	margining_port_remove(upstream);
1832 	margining_port_remove(downstream);
1833 }
1834 
1835 static void margining_xdomain_init(struct tb_xdomain *xd)
1836 {
1837 	struct tb_switch *parent_sw;
1838 	struct tb_port *downstream;
1839 
1840 	parent_sw = tb_xdomain_parent(xd);
1841 	downstream = tb_port_at(xd->route, parent_sw);
1842 
1843 	margining_port_init(downstream);
1844 }
1845 
1846 static void margining_xdomain_remove(struct tb_xdomain *xd)
1847 {
1848 	struct tb_switch *parent_sw;
1849 	struct tb_port *downstream;
1850 
1851 	parent_sw = tb_xdomain_parent(xd);
1852 	downstream = tb_port_at(xd->route, parent_sw);
1853 	margining_port_remove(downstream);
1854 }
1855 
1856 static void margining_retimer_init(struct tb_retimer *rt, struct dentry *debugfs_dir)
1857 {
1858 	rt->margining = margining_alloc(rt->port, &rt->dev,
1859 					USB4_SB_TARGET_RETIMER, rt->index,
1860 					debugfs_dir);
1861 }
1862 
1863 static void margining_retimer_remove(struct tb_retimer *rt)
1864 {
1865 	kfree(rt->margining);
1866 	rt->margining = NULL;
1867 }
1868 #else
1869 static inline void margining_switch_init(struct tb_switch *sw) { }
1870 static inline void margining_switch_remove(struct tb_switch *sw) { }
1871 static inline void margining_xdomain_init(struct tb_xdomain *xd) { }
1872 static inline void margining_xdomain_remove(struct tb_xdomain *xd) { }
1873 static inline void margining_retimer_init(struct tb_retimer *rt,
1874 					  struct dentry *debugfs_dir) { }
1875 static inline void margining_retimer_remove(struct tb_retimer *rt) { }
1876 #endif
1877 
1878 static int port_clear_all_counters(struct tb_port *port)
1879 {
1880 	u32 *buf;
1881 	int ret;
1882 
1883 	buf = kcalloc(COUNTER_SET_LEN * port->config.max_counters, sizeof(u32),
1884 		      GFP_KERNEL);
1885 	if (!buf)
1886 		return -ENOMEM;
1887 
1888 	ret = tb_port_write(port, buf, TB_CFG_COUNTERS, 0,
1889 			    COUNTER_SET_LEN * port->config.max_counters);
1890 	kfree(buf);
1891 
1892 	return ret;
1893 }
1894 
1895 static ssize_t counters_write(struct file *file, const char __user *user_buf,
1896 			      size_t count, loff_t *ppos)
1897 {
1898 	struct seq_file *s = file->private_data;
1899 	struct tb_port *port = s->private;
1900 	struct tb_switch *sw = port->sw;
1901 	struct tb *tb = port->sw->tb;
1902 	char *buf;
1903 	int ret;
1904 
1905 	buf = validate_and_copy_from_user(user_buf, &count);
1906 	if (IS_ERR(buf))
1907 		return PTR_ERR(buf);
1908 
1909 	pm_runtime_get_sync(&sw->dev);
1910 
1911 	if (mutex_lock_interruptible(&tb->lock)) {
1912 		ret = -ERESTARTSYS;
1913 		goto out;
1914 	}
1915 
1916 	/* If written delimiter only, clear all counters in one shot */
1917 	if (buf[0] == '\n') {
1918 		ret = port_clear_all_counters(port);
1919 	} else  {
1920 		char *line = buf;
1921 		u32 val, offset;
1922 
1923 		ret = -EINVAL;
1924 		while (parse_line(&line, &offset, &val, 1, 4)) {
1925 			ret = tb_port_write(port, &val, TB_CFG_COUNTERS,
1926 					    offset, 1);
1927 			if (ret)
1928 				break;
1929 		}
1930 	}
1931 
1932 	mutex_unlock(&tb->lock);
1933 
1934 out:
1935 	pm_runtime_mark_last_busy(&sw->dev);
1936 	pm_runtime_put_autosuspend(&sw->dev);
1937 	free_page((unsigned long)buf);
1938 
1939 	return ret < 0 ? ret : count;
1940 }
1941 
1942 static void cap_show_by_dw(struct seq_file *s, struct tb_switch *sw,
1943 			   struct tb_port *port, unsigned int cap,
1944 			   unsigned int offset, u8 cap_id, u8 vsec_id,
1945 			   int dwords)
1946 {
1947 	int i, ret;
1948 	u32 data;
1949 
1950 	for (i = 0; i < dwords; i++) {
1951 		if (port)
1952 			ret = tb_port_read(port, &data, TB_CFG_PORT, cap + offset + i, 1);
1953 		else
1954 			ret = tb_sw_read(sw, &data, TB_CFG_SWITCH, cap + offset + i, 1);
1955 		if (ret) {
1956 			seq_printf(s, "0x%04x <not accessible>\n", cap + offset + i);
1957 			continue;
1958 		}
1959 
1960 		seq_printf(s, "0x%04x %4d 0x%02x 0x%02x 0x%08x\n", cap + offset + i,
1961 			   offset + i, cap_id, vsec_id, data);
1962 	}
1963 }
1964 
1965 static void cap_show(struct seq_file *s, struct tb_switch *sw,
1966 		     struct tb_port *port, unsigned int cap, u8 cap_id,
1967 		     u8 vsec_id, int length)
1968 {
1969 	int ret, offset = 0;
1970 
1971 	while (length > 0) {
1972 		int i, dwords = min(length, TB_MAX_CONFIG_RW_LENGTH);
1973 		u32 data[TB_MAX_CONFIG_RW_LENGTH];
1974 
1975 		if (port)
1976 			ret = tb_port_read(port, data, TB_CFG_PORT, cap + offset,
1977 					   dwords);
1978 		else
1979 			ret = tb_sw_read(sw, data, TB_CFG_SWITCH, cap + offset, dwords);
1980 		if (ret) {
1981 			cap_show_by_dw(s, sw, port, cap, offset, cap_id, vsec_id, length);
1982 			return;
1983 		}
1984 
1985 		for (i = 0; i < dwords; i++) {
1986 			seq_printf(s, "0x%04x %4d 0x%02x 0x%02x 0x%08x\n",
1987 				   cap + offset + i, offset + i,
1988 				   cap_id, vsec_id, data[i]);
1989 		}
1990 
1991 		length -= dwords;
1992 		offset += dwords;
1993 	}
1994 }
1995 
1996 static void port_cap_show(struct tb_port *port, struct seq_file *s,
1997 			  unsigned int cap)
1998 {
1999 	struct tb_cap_any header;
2000 	u8 vsec_id = 0;
2001 	size_t length;
2002 	int ret;
2003 
2004 	ret = tb_port_read(port, &header, TB_CFG_PORT, cap, 1);
2005 	if (ret) {
2006 		seq_printf(s, "0x%04x <capability read failed>\n", cap);
2007 		return;
2008 	}
2009 
2010 	switch (header.basic.cap) {
2011 	case TB_PORT_CAP_PHY:
2012 		length = PORT_CAP_LANE_LEN;
2013 		break;
2014 
2015 	case TB_PORT_CAP_TIME1:
2016 		if (usb4_switch_version(port->sw) < 2)
2017 			length = PORT_CAP_TMU_V1_LEN;
2018 		else
2019 			length = PORT_CAP_TMU_V2_LEN;
2020 		break;
2021 
2022 	case TB_PORT_CAP_POWER:
2023 		length = PORT_CAP_POWER_LEN;
2024 		break;
2025 
2026 	case TB_PORT_CAP_ADAP:
2027 		if (tb_port_is_pcie_down(port) || tb_port_is_pcie_up(port)) {
2028 			if (usb4_switch_version(port->sw) < 2)
2029 				length = PORT_CAP_V1_PCIE_LEN;
2030 			else
2031 				length = PORT_CAP_V2_PCIE_LEN;
2032 		} else if (tb_port_is_dpin(port)) {
2033 			if (usb4_switch_version(port->sw) < 2)
2034 				length = PORT_CAP_DP_V1_LEN;
2035 			else
2036 				length = PORT_CAP_DP_V2_LEN;
2037 		} else if (tb_port_is_dpout(port)) {
2038 			length = PORT_CAP_DP_V1_LEN;
2039 		} else if (tb_port_is_usb3_down(port) ||
2040 			   tb_port_is_usb3_up(port)) {
2041 			length = PORT_CAP_USB3_LEN;
2042 		} else {
2043 			seq_printf(s, "0x%04x <unsupported capability 0x%02x>\n",
2044 				   cap, header.basic.cap);
2045 			return;
2046 		}
2047 		break;
2048 
2049 	case TB_PORT_CAP_VSE:
2050 		if (!header.extended_short.length) {
2051 			ret = tb_port_read(port, (u32 *)&header + 1, TB_CFG_PORT,
2052 					   cap + 1, 1);
2053 			if (ret) {
2054 				seq_printf(s, "0x%04x <capability read failed>\n",
2055 					   cap + 1);
2056 				return;
2057 			}
2058 			length = header.extended_long.length;
2059 			vsec_id = header.extended_short.vsec_id;
2060 		} else {
2061 			length = header.extended_short.length;
2062 			vsec_id = header.extended_short.vsec_id;
2063 		}
2064 		break;
2065 
2066 	case TB_PORT_CAP_USB4:
2067 		length = PORT_CAP_USB4_LEN;
2068 		break;
2069 
2070 	default:
2071 		seq_printf(s, "0x%04x <unsupported capability 0x%02x>\n",
2072 			   cap, header.basic.cap);
2073 		return;
2074 	}
2075 
2076 	cap_show(s, NULL, port, cap, header.basic.cap, vsec_id, length);
2077 }
2078 
2079 static void port_caps_show(struct tb_port *port, struct seq_file *s)
2080 {
2081 	int cap;
2082 
2083 	cap = tb_port_next_cap(port, 0);
2084 	while (cap > 0) {
2085 		port_cap_show(port, s, cap);
2086 		cap = tb_port_next_cap(port, cap);
2087 	}
2088 }
2089 
2090 static int port_basic_regs_show(struct tb_port *port, struct seq_file *s)
2091 {
2092 	u32 data[PORT_CAP_BASIC_LEN];
2093 	int ret, i;
2094 
2095 	ret = tb_port_read(port, data, TB_CFG_PORT, 0, ARRAY_SIZE(data));
2096 	if (ret)
2097 		return ret;
2098 
2099 	for (i = 0; i < ARRAY_SIZE(data); i++)
2100 		seq_printf(s, "0x%04x %4d 0x00 0x00 0x%08x\n", i, i, data[i]);
2101 
2102 	return 0;
2103 }
2104 
2105 static int port_regs_show(struct seq_file *s, void *not_used)
2106 {
2107 	struct tb_port *port = s->private;
2108 	struct tb_switch *sw = port->sw;
2109 	struct tb *tb = sw->tb;
2110 	int ret;
2111 
2112 	pm_runtime_get_sync(&sw->dev);
2113 
2114 	if (mutex_lock_interruptible(&tb->lock)) {
2115 		ret = -ERESTARTSYS;
2116 		goto out_rpm_put;
2117 	}
2118 
2119 	seq_puts(s, "# offset relative_offset cap_id vs_cap_id value\n");
2120 
2121 	ret = port_basic_regs_show(port, s);
2122 	if (ret)
2123 		goto out_unlock;
2124 
2125 	port_caps_show(port, s);
2126 
2127 out_unlock:
2128 	mutex_unlock(&tb->lock);
2129 out_rpm_put:
2130 	pm_runtime_mark_last_busy(&sw->dev);
2131 	pm_runtime_put_autosuspend(&sw->dev);
2132 
2133 	return ret;
2134 }
2135 DEBUGFS_ATTR_RW(port_regs);
2136 
2137 static void switch_cap_show(struct tb_switch *sw, struct seq_file *s,
2138 			    unsigned int cap)
2139 {
2140 	struct tb_cap_any header;
2141 	int ret, length;
2142 	u8 vsec_id = 0;
2143 
2144 	ret = tb_sw_read(sw, &header, TB_CFG_SWITCH, cap, 1);
2145 	if (ret) {
2146 		seq_printf(s, "0x%04x <capability read failed>\n", cap);
2147 		return;
2148 	}
2149 
2150 	if (header.basic.cap == TB_SWITCH_CAP_VSE) {
2151 		if (!header.extended_short.length) {
2152 			ret = tb_sw_read(sw, (u32 *)&header + 1, TB_CFG_SWITCH,
2153 					 cap + 1, 1);
2154 			if (ret) {
2155 				seq_printf(s, "0x%04x <capability read failed>\n",
2156 					   cap + 1);
2157 				return;
2158 			}
2159 			length = header.extended_long.length;
2160 		} else {
2161 			length = header.extended_short.length;
2162 		}
2163 		vsec_id = header.extended_short.vsec_id;
2164 	} else {
2165 		if (header.basic.cap == TB_SWITCH_CAP_TMU) {
2166 			length = SWITCH_CAP_TMU_LEN;
2167 		} else  {
2168 			seq_printf(s, "0x%04x <unknown capability 0x%02x>\n",
2169 				   cap, header.basic.cap);
2170 			return;
2171 		}
2172 	}
2173 
2174 	cap_show(s, sw, NULL, cap, header.basic.cap, vsec_id, length);
2175 }
2176 
2177 static void switch_caps_show(struct tb_switch *sw, struct seq_file *s)
2178 {
2179 	int cap;
2180 
2181 	cap = tb_switch_next_cap(sw, 0);
2182 	while (cap > 0) {
2183 		switch_cap_show(sw, s, cap);
2184 		cap = tb_switch_next_cap(sw, cap);
2185 	}
2186 }
2187 
2188 static int switch_basic_regs_show(struct tb_switch *sw, struct seq_file *s)
2189 {
2190 	u32 data[SWITCH_CAP_BASIC_LEN];
2191 	size_t dwords;
2192 	int ret, i;
2193 
2194 	/* Only USB4 has the additional registers */
2195 	if (tb_switch_is_usb4(sw))
2196 		dwords = ARRAY_SIZE(data);
2197 	else
2198 		dwords = 5;
2199 
2200 	ret = tb_sw_read(sw, data, TB_CFG_SWITCH, 0, dwords);
2201 	if (ret)
2202 		return ret;
2203 
2204 	for (i = 0; i < dwords; i++)
2205 		seq_printf(s, "0x%04x %4d 0x00 0x00 0x%08x\n", i, i, data[i]);
2206 
2207 	return 0;
2208 }
2209 
2210 static int switch_regs_show(struct seq_file *s, void *not_used)
2211 {
2212 	struct tb_switch *sw = s->private;
2213 	struct tb *tb = sw->tb;
2214 	int ret;
2215 
2216 	pm_runtime_get_sync(&sw->dev);
2217 
2218 	if (mutex_lock_interruptible(&tb->lock)) {
2219 		ret = -ERESTARTSYS;
2220 		goto out_rpm_put;
2221 	}
2222 
2223 	seq_puts(s, "# offset relative_offset cap_id vs_cap_id value\n");
2224 
2225 	ret = switch_basic_regs_show(sw, s);
2226 	if (ret)
2227 		goto out_unlock;
2228 
2229 	switch_caps_show(sw, s);
2230 
2231 out_unlock:
2232 	mutex_unlock(&tb->lock);
2233 out_rpm_put:
2234 	pm_runtime_mark_last_busy(&sw->dev);
2235 	pm_runtime_put_autosuspend(&sw->dev);
2236 
2237 	return ret;
2238 }
2239 DEBUGFS_ATTR_RW(switch_regs);
2240 
2241 static int path_show_one(struct tb_port *port, struct seq_file *s, int hopid)
2242 {
2243 	u32 data[PATH_LEN];
2244 	int ret, i;
2245 
2246 	ret = tb_port_read(port, data, TB_CFG_HOPS, hopid * PATH_LEN,
2247 			   ARRAY_SIZE(data));
2248 	if (ret) {
2249 		seq_printf(s, "0x%04x <not accessible>\n", hopid * PATH_LEN);
2250 		return ret;
2251 	}
2252 
2253 	for (i = 0; i < ARRAY_SIZE(data); i++) {
2254 		seq_printf(s, "0x%04x %4d 0x%02x 0x%08x\n",
2255 			   hopid * PATH_LEN + i, i, hopid, data[i]);
2256 	}
2257 
2258 	return 0;
2259 }
2260 
2261 static int path_show(struct seq_file *s, void *not_used)
2262 {
2263 	struct tb_port *port = s->private;
2264 	struct tb_switch *sw = port->sw;
2265 	struct tb *tb = sw->tb;
2266 	int start, i, ret = 0;
2267 
2268 	pm_runtime_get_sync(&sw->dev);
2269 
2270 	if (mutex_lock_interruptible(&tb->lock)) {
2271 		ret = -ERESTARTSYS;
2272 		goto out_rpm_put;
2273 	}
2274 
2275 	seq_puts(s, "# offset relative_offset in_hop_id value\n");
2276 
2277 	/* NHI and lane adapters have entry for path 0 */
2278 	if (tb_port_is_null(port) || tb_port_is_nhi(port)) {
2279 		ret = path_show_one(port, s, 0);
2280 		if (ret)
2281 			goto out_unlock;
2282 	}
2283 
2284 	start = tb_port_is_nhi(port) ? 1 : TB_PATH_MIN_HOPID;
2285 
2286 	for (i = start; i <= port->config.max_in_hop_id; i++) {
2287 		ret = path_show_one(port, s, i);
2288 		if (ret)
2289 			break;
2290 	}
2291 
2292 out_unlock:
2293 	mutex_unlock(&tb->lock);
2294 out_rpm_put:
2295 	pm_runtime_mark_last_busy(&sw->dev);
2296 	pm_runtime_put_autosuspend(&sw->dev);
2297 
2298 	return ret;
2299 }
2300 DEBUGFS_ATTR_RW(path);
2301 
2302 static int counter_set_regs_show(struct tb_port *port, struct seq_file *s,
2303 				 int counter)
2304 {
2305 	u32 data[COUNTER_SET_LEN];
2306 	int ret, i;
2307 
2308 	ret = tb_port_read(port, data, TB_CFG_COUNTERS,
2309 			   counter * COUNTER_SET_LEN, ARRAY_SIZE(data));
2310 	if (ret) {
2311 		seq_printf(s, "0x%04x <not accessible>\n",
2312 			   counter * COUNTER_SET_LEN);
2313 		return ret;
2314 	}
2315 
2316 	for (i = 0; i < ARRAY_SIZE(data); i++) {
2317 		seq_printf(s, "0x%04x %4d 0x%02x 0x%08x\n",
2318 			   counter * COUNTER_SET_LEN + i, i, counter, data[i]);
2319 	}
2320 
2321 	return 0;
2322 }
2323 
2324 static int counters_show(struct seq_file *s, void *not_used)
2325 {
2326 	struct tb_port *port = s->private;
2327 	struct tb_switch *sw = port->sw;
2328 	struct tb *tb = sw->tb;
2329 	int i, ret = 0;
2330 
2331 	pm_runtime_get_sync(&sw->dev);
2332 
2333 	if (mutex_lock_interruptible(&tb->lock)) {
2334 		ret = -ERESTARTSYS;
2335 		goto out;
2336 	}
2337 
2338 	seq_puts(s, "# offset relative_offset counter_id value\n");
2339 
2340 	for (i = 0; i < port->config.max_counters; i++) {
2341 		ret = counter_set_regs_show(port, s, i);
2342 		if (ret)
2343 			break;
2344 	}
2345 
2346 	mutex_unlock(&tb->lock);
2347 
2348 out:
2349 	pm_runtime_mark_last_busy(&sw->dev);
2350 	pm_runtime_put_autosuspend(&sw->dev);
2351 
2352 	return ret;
2353 }
2354 DEBUGFS_ATTR_RW(counters);
2355 
2356 static int sb_regs_show(struct tb_port *port, const struct sb_reg *sb_regs,
2357 			size_t size, enum usb4_sb_target target, u8 index,
2358 			struct seq_file *s)
2359 {
2360 	int ret, i;
2361 
2362 	seq_puts(s, "# register value\n");
2363 
2364 	for (i = 0; i < size; i++) {
2365 		const struct sb_reg *regs = &sb_regs[i];
2366 		u8 data[64];
2367 		int j;
2368 
2369 		memset(data, 0, sizeof(data));
2370 		ret = usb4_port_sb_read(port, target, index, regs->reg, data,
2371 					regs->size);
2372 		if (ret) {
2373 			seq_printf(s, "0x%02x <not accessible>\n", regs->reg);
2374 			continue;
2375 		}
2376 
2377 		seq_printf(s, "0x%02x", regs->reg);
2378 		for (j = 0; j < regs->size; j++)
2379 			seq_printf(s, " 0x%02x", data[j]);
2380 		seq_puts(s, "\n");
2381 	}
2382 
2383 	return 0;
2384 }
2385 
2386 static int port_sb_regs_show(struct seq_file *s, void *not_used)
2387 {
2388 	struct tb_port *port = s->private;
2389 	struct tb_switch *sw = port->sw;
2390 	struct tb *tb = sw->tb;
2391 	int ret;
2392 
2393 	pm_runtime_get_sync(&sw->dev);
2394 
2395 	if (mutex_lock_interruptible(&tb->lock)) {
2396 		ret = -ERESTARTSYS;
2397 		goto out_rpm_put;
2398 	}
2399 
2400 	ret = sb_regs_show(port, port_sb_regs, ARRAY_SIZE(port_sb_regs),
2401 			   USB4_SB_TARGET_ROUTER, 0, s);
2402 
2403 	mutex_unlock(&tb->lock);
2404 out_rpm_put:
2405 	pm_runtime_mark_last_busy(&sw->dev);
2406 	pm_runtime_put_autosuspend(&sw->dev);
2407 
2408 	return ret;
2409 }
2410 DEBUGFS_ATTR_RW(port_sb_regs);
2411 
2412 /**
2413  * tb_switch_debugfs_init() - Add debugfs entries for router
2414  * @sw: Pointer to the router
2415  *
2416  * Adds debugfs directories and files for given router.
2417  */
2418 void tb_switch_debugfs_init(struct tb_switch *sw)
2419 {
2420 	struct dentry *debugfs_dir;
2421 	struct tb_port *port;
2422 
2423 	debugfs_dir = debugfs_create_dir(dev_name(&sw->dev), tb_debugfs_root);
2424 	sw->debugfs_dir = debugfs_dir;
2425 	debugfs_create_file("regs", DEBUGFS_MODE, debugfs_dir, sw,
2426 			    &switch_regs_fops);
2427 	if (sw->drom)
2428 		debugfs_create_blob("drom", 0400, debugfs_dir, &sw->drom_blob);
2429 
2430 	tb_switch_for_each_port(sw, port) {
2431 		struct dentry *debugfs_dir;
2432 		char dir_name[10];
2433 
2434 		if (port->disabled)
2435 			continue;
2436 		if (port->config.type == TB_TYPE_INACTIVE)
2437 			continue;
2438 
2439 		snprintf(dir_name, sizeof(dir_name), "port%d", port->port);
2440 		debugfs_dir = debugfs_create_dir(dir_name, sw->debugfs_dir);
2441 		debugfs_create_file("regs", DEBUGFS_MODE, debugfs_dir,
2442 				    port, &port_regs_fops);
2443 		debugfs_create_file("path", 0400, debugfs_dir, port,
2444 				    &path_fops);
2445 		if (port->config.counters_support)
2446 			debugfs_create_file("counters", 0600, debugfs_dir, port,
2447 					    &counters_fops);
2448 		if (port->usb4)
2449 			debugfs_create_file("sb_regs", DEBUGFS_MODE, debugfs_dir,
2450 					    port, &port_sb_regs_fops);
2451 	}
2452 
2453 	margining_switch_init(sw);
2454 }
2455 
2456 /**
2457  * tb_switch_debugfs_remove() - Remove all router debugfs entries
2458  * @sw: Pointer to the router
2459  *
2460  * Removes all previously added debugfs entries under this router.
2461  */
2462 void tb_switch_debugfs_remove(struct tb_switch *sw)
2463 {
2464 	margining_switch_remove(sw);
2465 	debugfs_remove_recursive(sw->debugfs_dir);
2466 }
2467 
2468 void tb_xdomain_debugfs_init(struct tb_xdomain *xd)
2469 {
2470 	margining_xdomain_init(xd);
2471 }
2472 
2473 void tb_xdomain_debugfs_remove(struct tb_xdomain *xd)
2474 {
2475 	margining_xdomain_remove(xd);
2476 }
2477 
2478 /**
2479  * tb_service_debugfs_init() - Add debugfs directory for service
2480  * @svc: Thunderbolt service pointer
2481  *
2482  * Adds debugfs directory for service.
2483  */
2484 void tb_service_debugfs_init(struct tb_service *svc)
2485 {
2486 	svc->debugfs_dir = debugfs_create_dir(dev_name(&svc->dev),
2487 					      tb_debugfs_root);
2488 }
2489 
2490 /**
2491  * tb_service_debugfs_remove() - Remove service debugfs directory
2492  * @svc: Thunderbolt service pointer
2493  *
2494  * Removes the previously created debugfs directory for @svc.
2495  */
2496 void tb_service_debugfs_remove(struct tb_service *svc)
2497 {
2498 	debugfs_remove_recursive(svc->debugfs_dir);
2499 	svc->debugfs_dir = NULL;
2500 }
2501 
2502 static int retimer_sb_regs_show(struct seq_file *s, void *not_used)
2503 {
2504 	struct tb_retimer *rt = s->private;
2505 	struct tb *tb = rt->tb;
2506 	int ret;
2507 
2508 	pm_runtime_get_sync(&rt->dev);
2509 
2510 	if (mutex_lock_interruptible(&tb->lock)) {
2511 		ret = -ERESTARTSYS;
2512 		goto out_rpm_put;
2513 	}
2514 
2515 	ret = sb_regs_show(rt->port, retimer_sb_regs, ARRAY_SIZE(retimer_sb_regs),
2516 			   USB4_SB_TARGET_RETIMER, rt->index, s);
2517 
2518 	mutex_unlock(&tb->lock);
2519 out_rpm_put:
2520 	pm_runtime_mark_last_busy(&rt->dev);
2521 	pm_runtime_put_autosuspend(&rt->dev);
2522 
2523 	return ret;
2524 }
2525 DEBUGFS_ATTR_RW(retimer_sb_regs);
2526 
2527 /**
2528  * tb_retimer_debugfs_init() - Add debugfs directory for retimer
2529  * @rt: Pointer to retimer structure
2530  *
2531  * Adds and populates retimer debugfs directory.
2532  */
2533 void tb_retimer_debugfs_init(struct tb_retimer *rt)
2534 {
2535 	struct dentry *debugfs_dir;
2536 
2537 	debugfs_dir = debugfs_create_dir(dev_name(&rt->dev), tb_debugfs_root);
2538 	debugfs_create_file("sb_regs", DEBUGFS_MODE, debugfs_dir, rt,
2539 			    &retimer_sb_regs_fops);
2540 	margining_retimer_init(rt, debugfs_dir);
2541 }
2542 
2543 /**
2544  * tb_retimer_debugfs_remove() - Remove retimer debugfs directory
2545  * @rt: Pointer to retimer structure
2546  *
2547  * Removes the retimer debugfs directory along with its contents.
2548  */
2549 void tb_retimer_debugfs_remove(struct tb_retimer *rt)
2550 {
2551 	debugfs_lookup_and_remove(dev_name(&rt->dev), tb_debugfs_root);
2552 	margining_retimer_remove(rt);
2553 }
2554 
2555 void tb_debugfs_init(void)
2556 {
2557 	tb_debugfs_root = debugfs_create_dir("thunderbolt", NULL);
2558 }
2559 
2560 void tb_debugfs_exit(void)
2561 {
2562 	debugfs_remove_recursive(tb_debugfs_root);
2563 }
2564