xref: /linux/drivers/thunderbolt/debugfs.c (revision 6093a688a07da07808f0122f9aa2a3eed250d853)
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 patch 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_regs->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 		return -EINVAL;
960 
961 	scoped_cond_guard(mutex_intr, return -ERESTARTSYS, &tb->lock) {
962 		if (!margining->software)
963 			return -EOPNOTSUPP;
964 
965 		margining->error_counter = error_counter;
966 	}
967 
968 	return count;
969 }
970 
971 static int margining_error_counter_show(struct seq_file *s, void *not_used)
972 {
973 	const struct tb_margining *margining = s->private;
974 	struct tb *tb = margining->port->sw->tb;
975 
976 	scoped_cond_guard(mutex_intr, return -ERESTARTSYS, &tb->lock) {
977 		if (!margining->software)
978 			return -EOPNOTSUPP;
979 
980 		switch (margining->error_counter) {
981 		case USB4_MARGIN_SW_ERROR_COUNTER_NOP:
982 			seq_puts(s, "[nop] clear start stop\n");
983 			break;
984 		case USB4_MARGIN_SW_ERROR_COUNTER_CLEAR:
985 			seq_puts(s, "nop [clear] start stop\n");
986 			break;
987 		case USB4_MARGIN_SW_ERROR_COUNTER_START:
988 			seq_puts(s, "nop clear [start] stop\n");
989 			break;
990 		case USB4_MARGIN_SW_ERROR_COUNTER_STOP:
991 			seq_puts(s, "nop clear start [stop]\n");
992 			break;
993 		}
994 	}
995 
996 	return 0;
997 }
998 DEBUGFS_ATTR_RW(margining_error_counter);
999 
1000 static ssize_t
1001 margining_dwell_time_write(struct file *file, const char __user *user_buf,
1002 			   size_t count, loff_t *ppos)
1003 {
1004 	struct seq_file *s = file->private_data;
1005 	struct tb_margining *margining = s->private;
1006 	struct tb *tb = margining->port->sw->tb;
1007 	unsigned int val;
1008 	int ret;
1009 
1010 	ret = kstrtouint_from_user(user_buf, count, 10, &val);
1011 	if (ret)
1012 		return ret;
1013 
1014 	scoped_cond_guard(mutex_intr, return -ERESTARTSYS, &tb->lock) {
1015 		if (!margining->software)
1016 			return -EOPNOTSUPP;
1017 
1018 		margining->dwell_time = clamp(val, MIN_DWELL_TIME, MAX_DWELL_TIME);
1019 	}
1020 
1021 	return count;
1022 }
1023 
1024 static int margining_dwell_time_show(struct seq_file *s, void *not_used)
1025 {
1026 	struct tb_margining *margining = s->private;
1027 	struct tb *tb = margining->port->sw->tb;
1028 
1029 	scoped_cond_guard(mutex_intr, return -ERESTARTSYS, &tb->lock) {
1030 		if (!margining->software)
1031 			return -EOPNOTSUPP;
1032 
1033 		seq_printf(s, "%d\n", margining->dwell_time);
1034 	}
1035 
1036 	return 0;
1037 }
1038 DEBUGFS_ATTR_RW(margining_dwell_time);
1039 
1040 static ssize_t
1041 margining_optional_voltage_offset_write(struct file *file, const char __user *user_buf,
1042 					size_t count, loff_t *ppos)
1043 {
1044 	struct seq_file *s = file->private_data;
1045 	struct tb_margining *margining = s->private;
1046 	struct tb *tb = margining->port->sw->tb;
1047 	bool val;
1048 	int ret;
1049 
1050 	ret = kstrtobool_from_user(user_buf, count, &val);
1051 	if (ret)
1052 		return ret;
1053 
1054 	scoped_cond_guard(mutex_intr, return -ERESTARTSYS, &tb->lock) {
1055 		margining->optional_voltage_offset_range = val;
1056 	}
1057 
1058 	return count;
1059 }
1060 
1061 static int margining_optional_voltage_offset_show(struct seq_file *s,
1062 						  void *not_used)
1063 {
1064 	struct tb_margining *margining = s->private;
1065 	struct tb *tb = margining->port->sw->tb;
1066 
1067 	scoped_cond_guard(mutex_intr, return -ERESTARTSYS, &tb->lock) {
1068 		seq_printf(s, "%u\n", margining->optional_voltage_offset_range);
1069 	}
1070 
1071 	return 0;
1072 }
1073 DEBUGFS_ATTR_RW(margining_optional_voltage_offset);
1074 
1075 static ssize_t margining_mode_write(struct file *file,
1076 				   const char __user *user_buf,
1077 				   size_t count, loff_t *ppos)
1078 {
1079 	struct seq_file *s = file->private_data;
1080 	struct tb_margining *margining = s->private;
1081 	struct tb *tb = margining->port->sw->tb;
1082 	int ret = 0;
1083 	char *buf;
1084 
1085 	buf = validate_and_copy_from_user(user_buf, &count);
1086 	if (IS_ERR(buf))
1087 		return PTR_ERR(buf);
1088 
1089 	buf[count - 1] = '\0';
1090 
1091 	if (mutex_lock_interruptible(&tb->lock)) {
1092 		ret = -ERESTARTSYS;
1093 		goto out_free;
1094 	}
1095 
1096 	if (!strcmp(buf, "software")) {
1097 		if (supports_software(margining))
1098 			margining->software = true;
1099 		else
1100 			ret = -EINVAL;
1101 	} else if (!strcmp(buf, "hardware")) {
1102 		if (supports_hardware(margining))
1103 			margining->software = false;
1104 		else
1105 			ret = -EINVAL;
1106 	} else {
1107 		ret = -EINVAL;
1108 	}
1109 
1110 	mutex_unlock(&tb->lock);
1111 
1112 out_free:
1113 	free_page((unsigned long)buf);
1114 	return ret ? ret : count;
1115 }
1116 
1117 static int margining_mode_show(struct seq_file *s, void *not_used)
1118 {
1119 	struct tb_margining *margining = s->private;
1120 	struct tb *tb = margining->port->sw->tb;
1121 	const char *space = "";
1122 
1123 	if (mutex_lock_interruptible(&tb->lock))
1124 		return -ERESTARTSYS;
1125 
1126 	if (supports_software(margining)) {
1127 		if (margining->software)
1128 			seq_puts(s, "[software]");
1129 		else
1130 			seq_puts(s, "software");
1131 		space = " ";
1132 	}
1133 	if (supports_hardware(margining)) {
1134 		if (margining->software)
1135 			seq_printf(s, "%shardware", space);
1136 		else
1137 			seq_printf(s, "%s[hardware]", space);
1138 	}
1139 
1140 	mutex_unlock(&tb->lock);
1141 
1142 	seq_puts(s, "\n");
1143 	return 0;
1144 }
1145 DEBUGFS_ATTR_RW(margining_mode);
1146 
1147 static int margining_run_sw(struct tb_margining *margining,
1148 			    struct usb4_port_margining_params *params)
1149 {
1150 	u32 nsamples = margining->dwell_time / DWELL_SAMPLE_INTERVAL;
1151 	int ret, i;
1152 
1153 	ret = usb4_port_sw_margin(margining->port, margining->target, margining->index,
1154 				  params, margining->results);
1155 	if (ret)
1156 		goto out_stop;
1157 
1158 	for (i = 0; i <= nsamples; i++) {
1159 		u32 errors = 0;
1160 
1161 		ret = usb4_port_sw_margin_errors(margining->port, margining->target,
1162 						 margining->index, &margining->results[1]);
1163 		if (ret)
1164 			break;
1165 
1166 		if (margining->lanes == USB4_MARGINING_LANE_RX0)
1167 			errors = FIELD_GET(USB4_MARGIN_SW_ERR_COUNTER_LANE_0_MASK,
1168 					   margining->results[1]);
1169 		else if (margining->lanes == USB4_MARGINING_LANE_RX1)
1170 			errors = FIELD_GET(USB4_MARGIN_SW_ERR_COUNTER_LANE_1_MASK,
1171 					   margining->results[1]);
1172 		else if (margining->lanes == USB4_MARGINING_LANE_RX2)
1173 			errors = FIELD_GET(USB4_MARGIN_SW_ERR_COUNTER_LANE_2_MASK,
1174 					   margining->results[1]);
1175 		else if (margining->lanes == USB4_MARGINING_LANE_ALL)
1176 			errors = margining->results[1];
1177 
1178 		/* Any errors stop the test */
1179 		if (errors)
1180 			break;
1181 
1182 		fsleep(DWELL_SAMPLE_INTERVAL * USEC_PER_MSEC);
1183 	}
1184 
1185 out_stop:
1186 	/*
1187 	 * Stop the counters but don't clear them to allow the
1188 	 * different error counter configurations.
1189 	 */
1190 	margining_modify_error_counter(margining, margining->lanes,
1191 				       USB4_MARGIN_SW_ERROR_COUNTER_STOP);
1192 	return ret;
1193 }
1194 
1195 static int validate_margining(struct tb_margining *margining)
1196 {
1197 	/*
1198 	 * For running on RX2 the link must be asymmetric with 3
1199 	 * receivers. Because this is can change dynamically, check it
1200 	 * here before we start the margining and report back error if
1201 	 * expectations are not met.
1202 	 */
1203 	if (margining->lanes == USB4_MARGINING_LANE_RX2) {
1204 		int ret;
1205 
1206 		ret = tb_port_get_link_width(margining->port);
1207 		if (ret < 0)
1208 			return ret;
1209 		if (ret != TB_LINK_WIDTH_ASYM_RX) {
1210 			tb_port_warn(margining->port, "link is %s expected %s",
1211 				     tb_width_name(ret),
1212 				     tb_width_name(TB_LINK_WIDTH_ASYM_RX));
1213 			return -EINVAL;
1214 		}
1215 	}
1216 
1217 	return 0;
1218 }
1219 
1220 static int margining_run_write(void *data, u64 val)
1221 {
1222 	struct tb_margining *margining = data;
1223 	struct tb_port *port = margining->port;
1224 	struct device *dev = margining->dev;
1225 	struct tb_switch *sw = port->sw;
1226 	struct tb_switch *down_sw;
1227 	struct tb *tb = sw->tb;
1228 	int ret, clx;
1229 
1230 	if (val != 1)
1231 		return -EINVAL;
1232 
1233 	pm_runtime_get_sync(dev);
1234 
1235 	if (mutex_lock_interruptible(&tb->lock)) {
1236 		ret = -ERESTARTSYS;
1237 		goto out_rpm_put;
1238 	}
1239 
1240 	ret = validate_margining(margining);
1241 	if (ret)
1242 		goto out_unlock;
1243 
1244 	if (tb_is_upstream_port(port))
1245 		down_sw = sw;
1246 	else if (port->remote)
1247 		down_sw = port->remote->sw;
1248 	else
1249 		down_sw = NULL;
1250 
1251 	if (down_sw) {
1252 		/*
1253 		 * CL states may interfere with lane margining so
1254 		 * disable them temporarily now.
1255 		 */
1256 		ret = tb_switch_clx_disable(down_sw);
1257 		if (ret < 0) {
1258 			tb_sw_warn(down_sw, "failed to disable CL states\n");
1259 			goto out_unlock;
1260 		}
1261 		clx = ret;
1262 	}
1263 
1264 	/* Clear the results */
1265 	memset(margining->results, 0, sizeof(margining->results));
1266 
1267 	if (margining->software) {
1268 		struct usb4_port_margining_params params = {
1269 			.error_counter = USB4_MARGIN_SW_ERROR_COUNTER_CLEAR,
1270 			.lanes = margining->lanes,
1271 			.time = margining->time,
1272 			.voltage_time_offset = margining->voltage_time_offset,
1273 			.right_high = margining->right_high,
1274 			.upper_eye = margining->upper_eye,
1275 			.optional_voltage_offset_range = margining->optional_voltage_offset_range,
1276 		};
1277 
1278 		tb_port_dbg(port,
1279 			    "running software %s lane margining for %s lanes %u\n",
1280 			    margining->time ? "time" : "voltage", dev_name(dev),
1281 			    margining->lanes);
1282 
1283 		ret = margining_run_sw(margining, &params);
1284 	} else {
1285 		struct usb4_port_margining_params params = {
1286 			.ber_level = margining->ber_level,
1287 			.lanes = margining->lanes,
1288 			.time = margining->time,
1289 			.right_high = margining->right_high,
1290 			.upper_eye = margining->upper_eye,
1291 			.optional_voltage_offset_range = margining->optional_voltage_offset_range,
1292 		};
1293 
1294 		tb_port_dbg(port,
1295 			    "running hardware %s lane margining for %s lanes %u\n",
1296 			    margining->time ? "time" : "voltage", dev_name(dev),
1297 			    margining->lanes);
1298 
1299 		ret = usb4_port_hw_margin(port, margining->target, margining->index, &params,
1300 					  margining->results, ARRAY_SIZE(margining->results));
1301 	}
1302 
1303 	if (down_sw)
1304 		tb_switch_clx_enable(down_sw, clx);
1305 out_unlock:
1306 	mutex_unlock(&tb->lock);
1307 out_rpm_put:
1308 	pm_runtime_mark_last_busy(dev);
1309 	pm_runtime_put_autosuspend(dev);
1310 
1311 	return ret;
1312 }
1313 DEFINE_DEBUGFS_ATTRIBUTE(margining_run_fops, NULL, margining_run_write,
1314 			 "%llu\n");
1315 
1316 static ssize_t margining_results_write(struct file *file,
1317 				       const char __user *user_buf,
1318 				       size_t count, loff_t *ppos)
1319 {
1320 	struct seq_file *s = file->private_data;
1321 	struct tb_margining *margining = s->private;
1322 	struct tb *tb = margining->port->sw->tb;
1323 
1324 	if (mutex_lock_interruptible(&tb->lock))
1325 		return -ERESTARTSYS;
1326 
1327 	/* Just clear the results */
1328 	memset(margining->results, 0, sizeof(margining->results));
1329 
1330 	if (margining->software) {
1331 		/* Clear the error counters */
1332 		margining_modify_error_counter(margining,
1333 					       USB4_MARGINING_LANE_ALL,
1334 					       USB4_MARGIN_SW_ERROR_COUNTER_CLEAR);
1335 	}
1336 
1337 	mutex_unlock(&tb->lock);
1338 	return count;
1339 }
1340 
1341 static void voltage_margin_show(struct seq_file *s,
1342 				const struct tb_margining *margining, u8 val)
1343 {
1344 	unsigned int tmp, voltage;
1345 
1346 	tmp = FIELD_GET(USB4_MARGIN_HW_RES_MARGIN_MASK, val);
1347 	voltage = tmp * margining->max_voltage_offset / margining->voltage_steps;
1348 	seq_printf(s, "%u mV (%u)", voltage, tmp);
1349 	if (val & USB4_MARGIN_HW_RES_EXCEEDS)
1350 		seq_puts(s, " exceeds maximum");
1351 	seq_puts(s, "\n");
1352 	if (margining->optional_voltage_offset_range)
1353 		seq_puts(s, " optional voltage offset range enabled\n");
1354 }
1355 
1356 static void time_margin_show(struct seq_file *s,
1357 			     const struct tb_margining *margining, u8 val)
1358 {
1359 	unsigned int tmp, interval;
1360 
1361 	tmp = FIELD_GET(USB4_MARGIN_HW_RES_MARGIN_MASK, val);
1362 	interval = tmp * margining->max_time_offset / margining->time_steps;
1363 	seq_printf(s, "%u mUI (%u)", interval, tmp);
1364 	if (val & USB4_MARGIN_HW_RES_EXCEEDS)
1365 		seq_puts(s, " exceeds maximum");
1366 	seq_puts(s, "\n");
1367 }
1368 
1369 static u8 margining_hw_result_val(const u32 *results,
1370 				  enum usb4_margining_lane lane,
1371 				  bool right_high)
1372 {
1373 	u32 val;
1374 
1375 	if (lane == USB4_MARGINING_LANE_RX0)
1376 		val = results[1];
1377 	else if (lane == USB4_MARGINING_LANE_RX1)
1378 		val = results[1] >> USB4_MARGIN_HW_RES_LANE_SHIFT;
1379 	else if (lane == USB4_MARGINING_LANE_RX2)
1380 		val = results[2];
1381 	else
1382 		val = 0;
1383 
1384 	return right_high ? val : val >> USB4_MARGIN_HW_RES_LL_SHIFT;
1385 }
1386 
1387 static void margining_hw_result_format(struct seq_file *s,
1388 				       const struct tb_margining *margining,
1389 				       enum usb4_margining_lane lane)
1390 {
1391 	u8 val;
1392 
1393 	if (margining->time) {
1394 		val = margining_hw_result_val(margining->results, lane, true);
1395 		seq_printf(s, "# lane %u right time margin: ", lane);
1396 		time_margin_show(s, margining, val);
1397 		val = margining_hw_result_val(margining->results, lane, false);
1398 		seq_printf(s, "# lane %u left time margin: ", lane);
1399 		time_margin_show(s, margining, val);
1400 	} else {
1401 		val = margining_hw_result_val(margining->results, lane, true);
1402 		seq_printf(s, "# lane %u high voltage margin: ", lane);
1403 		voltage_margin_show(s, margining, val);
1404 		val = margining_hw_result_val(margining->results, lane, false);
1405 		seq_printf(s, "# lane %u low voltage margin: ", lane);
1406 		voltage_margin_show(s, margining, val);
1407 	}
1408 }
1409 
1410 static int margining_results_show(struct seq_file *s, void *not_used)
1411 {
1412 	struct tb_margining *margining = s->private;
1413 	struct tb *tb = margining->port->sw->tb;
1414 
1415 	if (mutex_lock_interruptible(&tb->lock))
1416 		return -ERESTARTSYS;
1417 
1418 	/* Dump the raw results first */
1419 	seq_printf(s, "0x%08x\n", margining->results[0]);
1420 	/* Only the hardware margining has two result dwords */
1421 	if (!margining->software) {
1422 		for (int i = 1; i < ARRAY_SIZE(margining->results); i++)
1423 			seq_printf(s, "0x%08x\n", margining->results[i]);
1424 
1425 		if (margining->lanes == USB4_MARGINING_LANE_ALL) {
1426 			margining_hw_result_format(s, margining,
1427 						   USB4_MARGINING_LANE_RX0);
1428 			margining_hw_result_format(s, margining,
1429 						   USB4_MARGINING_LANE_RX1);
1430 			if (margining->asym_rx)
1431 				margining_hw_result_format(s, margining,
1432 						USB4_MARGINING_LANE_RX2);
1433 		} else {
1434 			margining_hw_result_format(s, margining,
1435 						   margining->lanes);
1436 		}
1437 	} else {
1438 		u32 lane_errors, result;
1439 
1440 		seq_printf(s, "0x%08x\n", margining->results[1]);
1441 
1442 		result = FIELD_GET(USB4_MARGIN_SW_LANES_MASK, margining->results[0]);
1443 		if (result == USB4_MARGINING_LANE_RX0 ||
1444 		    result == USB4_MARGINING_LANE_ALL) {
1445 			lane_errors = FIELD_GET(USB4_MARGIN_SW_ERR_COUNTER_LANE_0_MASK,
1446 						margining->results[1]);
1447 			seq_printf(s, "# lane 0 errors: %u\n", lane_errors);
1448 		}
1449 		if (result == USB4_MARGINING_LANE_RX1 ||
1450 		    result == USB4_MARGINING_LANE_ALL) {
1451 			lane_errors = FIELD_GET(USB4_MARGIN_SW_ERR_COUNTER_LANE_1_MASK,
1452 						margining->results[1]);
1453 			seq_printf(s, "# lane 1 errors: %u\n", lane_errors);
1454 		}
1455 		if (margining->asym_rx &&
1456 		    (result == USB4_MARGINING_LANE_RX2 ||
1457 		     result == USB4_MARGINING_LANE_ALL)) {
1458 			lane_errors = FIELD_GET(USB4_MARGIN_SW_ERR_COUNTER_LANE_2_MASK,
1459 						margining->results[1]);
1460 			seq_printf(s, "# lane 2 errors: %u\n", lane_errors);
1461 		}
1462 	}
1463 
1464 	mutex_unlock(&tb->lock);
1465 	return 0;
1466 }
1467 DEBUGFS_ATTR_RW(margining_results);
1468 
1469 static ssize_t margining_test_write(struct file *file,
1470 				    const char __user *user_buf,
1471 				    size_t count, loff_t *ppos)
1472 {
1473 	struct seq_file *s = file->private_data;
1474 	struct tb_margining *margining = s->private;
1475 	struct tb *tb = margining->port->sw->tb;
1476 	int ret = 0;
1477 	char *buf;
1478 
1479 	buf = validate_and_copy_from_user(user_buf, &count);
1480 	if (IS_ERR(buf))
1481 		return PTR_ERR(buf);
1482 
1483 	buf[count - 1] = '\0';
1484 
1485 	if (mutex_lock_interruptible(&tb->lock)) {
1486 		ret = -ERESTARTSYS;
1487 		goto out_free;
1488 	}
1489 
1490 	if (!strcmp(buf, "time") && supports_time(margining))
1491 		margining->time = true;
1492 	else if (!strcmp(buf, "voltage"))
1493 		margining->time = false;
1494 	else
1495 		ret = -EINVAL;
1496 
1497 	mutex_unlock(&tb->lock);
1498 
1499 out_free:
1500 	free_page((unsigned long)buf);
1501 	return ret ? ret : count;
1502 }
1503 
1504 static int margining_test_show(struct seq_file *s, void *not_used)
1505 {
1506 	struct tb_margining *margining = s->private;
1507 	struct tb *tb = margining->port->sw->tb;
1508 
1509 	if (mutex_lock_interruptible(&tb->lock))
1510 		return -ERESTARTSYS;
1511 
1512 	if (supports_time(margining)) {
1513 		if (margining->time)
1514 			seq_puts(s, "voltage [time]\n");
1515 		else
1516 			seq_puts(s, "[voltage] time\n");
1517 	} else {
1518 		seq_puts(s, "[voltage]\n");
1519 	}
1520 
1521 	mutex_unlock(&tb->lock);
1522 	return 0;
1523 }
1524 DEBUGFS_ATTR_RW(margining_test);
1525 
1526 static ssize_t margining_margin_write(struct file *file,
1527 				    const char __user *user_buf,
1528 				    size_t count, loff_t *ppos)
1529 {
1530 	struct seq_file *s = file->private_data;
1531 	struct tb_margining *margining = s->private;
1532 	struct tb *tb = margining->port->sw->tb;
1533 	int ret = 0;
1534 	char *buf;
1535 
1536 	buf = validate_and_copy_from_user(user_buf, &count);
1537 	if (IS_ERR(buf))
1538 		return PTR_ERR(buf);
1539 
1540 	buf[count - 1] = '\0';
1541 
1542 	if (mutex_lock_interruptible(&tb->lock)) {
1543 		ret = -ERESTARTSYS;
1544 		goto out_free;
1545 	}
1546 
1547 	if (margining->time) {
1548 		if (!strcmp(buf, "left"))
1549 			margining->right_high = false;
1550 		else if (!strcmp(buf, "right"))
1551 			margining->right_high = true;
1552 		else
1553 			ret = -EINVAL;
1554 	} else {
1555 		if (!strcmp(buf, "low"))
1556 			margining->right_high = false;
1557 		else if (!strcmp(buf, "high"))
1558 			margining->right_high = true;
1559 		else
1560 			ret = -EINVAL;
1561 	}
1562 
1563 	mutex_unlock(&tb->lock);
1564 
1565 out_free:
1566 	free_page((unsigned long)buf);
1567 	return ret ? ret : count;
1568 }
1569 
1570 static int margining_margin_show(struct seq_file *s, void *not_used)
1571 {
1572 	struct tb_margining *margining = s->private;
1573 	struct tb *tb = margining->port->sw->tb;
1574 
1575 	if (mutex_lock_interruptible(&tb->lock))
1576 		return -ERESTARTSYS;
1577 
1578 	if (margining->time) {
1579 		if (margining->right_high)
1580 			seq_puts(s, "left [right]\n");
1581 		else
1582 			seq_puts(s, "[left] right\n");
1583 	} else {
1584 		if (margining->right_high)
1585 			seq_puts(s, "low [high]\n");
1586 		else
1587 			seq_puts(s, "[low] high\n");
1588 	}
1589 
1590 	mutex_unlock(&tb->lock);
1591 	return 0;
1592 }
1593 DEBUGFS_ATTR_RW(margining_margin);
1594 
1595 static ssize_t margining_eye_write(struct file *file,
1596 				   const char __user *user_buf,
1597 				   size_t count, loff_t *ppos)
1598 {
1599 	struct seq_file *s = file->private_data;
1600 	struct tb_port *port = s->private;
1601 	struct usb4_port *usb4 = port->usb4;
1602 	struct tb *tb = port->sw->tb;
1603 	int ret = 0;
1604 	char *buf;
1605 
1606 	buf = validate_and_copy_from_user(user_buf, &count);
1607 	if (IS_ERR(buf))
1608 		return PTR_ERR(buf);
1609 
1610 	buf[count - 1] = '\0';
1611 
1612 	scoped_cond_guard(mutex_intr, ret = -ERESTARTSYS, &tb->lock) {
1613 		if (!strcmp(buf, "lower"))
1614 			usb4->margining->upper_eye = false;
1615 		else if (!strcmp(buf, "upper"))
1616 			usb4->margining->upper_eye = true;
1617 		else
1618 			ret = -EINVAL;
1619 	}
1620 
1621 	free_page((unsigned long)buf);
1622 	return ret ? ret : count;
1623 }
1624 
1625 static int margining_eye_show(struct seq_file *s, void *not_used)
1626 {
1627 	struct tb_port *port = s->private;
1628 	struct usb4_port *usb4 = port->usb4;
1629 	struct tb *tb = port->sw->tb;
1630 
1631 	scoped_guard(mutex_intr, &tb->lock) {
1632 		if (usb4->margining->upper_eye)
1633 			seq_puts(s, "lower [upper]\n");
1634 		else
1635 			seq_puts(s, "[lower] upper\n");
1636 
1637 		return 0;
1638 	}
1639 
1640 	return -ERESTARTSYS;
1641 }
1642 DEBUGFS_ATTR_RW(margining_eye);
1643 
1644 static struct tb_margining *margining_alloc(struct tb_port *port,
1645 					    struct device *dev,
1646 					    enum usb4_sb_target target,
1647 					    u8 index, struct dentry *parent)
1648 {
1649 	struct tb_margining *margining;
1650 	struct dentry *dir;
1651 	unsigned int val;
1652 	int ret;
1653 
1654 	ret = tb_port_get_link_generation(port);
1655 	if (ret < 0) {
1656 		tb_port_warn(port, "failed to read link generation\n");
1657 		return NULL;
1658 	}
1659 
1660 	margining = kzalloc(sizeof(*margining), GFP_KERNEL);
1661 	if (!margining)
1662 		return NULL;
1663 
1664 	margining->port = port;
1665 	margining->target = target;
1666 	margining->index = index;
1667 	margining->dev = dev;
1668 	margining->gen = ret;
1669 	margining->asym_rx = tb_port_width_supported(port, TB_LINK_WIDTH_ASYM_RX);
1670 
1671 	ret = usb4_port_margining_caps(port, target, index, margining->caps,
1672 				       ARRAY_SIZE(margining->caps));
1673 	if (ret) {
1674 		kfree(margining);
1675 		return NULL;
1676 	}
1677 
1678 	/* Set the initial mode */
1679 	if (supports_software(margining))
1680 		margining->software = true;
1681 
1682 	if (margining->gen < 4) {
1683 		val = FIELD_GET(USB4_MARGIN_CAP_0_VOLTAGE_STEPS_MASK, margining->caps[0]);
1684 		margining->voltage_steps = val;
1685 		val = FIELD_GET(USB4_MARGIN_CAP_0_MAX_VOLTAGE_OFFSET_MASK, margining->caps[0]);
1686 		margining->max_voltage_offset = 74 + val * 2;
1687 	} else {
1688 		val = FIELD_GET(USB4_MARGIN_CAP_2_VOLTAGE_STEPS_MASK, margining->caps[2]);
1689 		margining->voltage_steps = val;
1690 		val = FIELD_GET(USB4_MARGIN_CAP_2_MAX_VOLTAGE_OFFSET_MASK, margining->caps[2]);
1691 		margining->max_voltage_offset = 74 + val * 2;
1692 	}
1693 
1694 	if (supports_optional_voltage_offset_range(margining)) {
1695 		val = FIELD_GET(USB4_MARGIN_CAP_0_VOLT_STEPS_OPT_MASK,
1696 				margining->caps[0]);
1697 		margining->voltage_steps_optional_range = val;
1698 		val = FIELD_GET(USB4_MARGIN_CAP_1_MAX_VOLT_OFS_OPT_MASK,
1699 				margining->caps[1]);
1700 		margining->max_voltage_offset_optional_range = 74 + val * 2;
1701 	}
1702 
1703 	if (supports_time(margining)) {
1704 		val = FIELD_GET(USB4_MARGIN_CAP_1_TIME_STEPS_MASK, margining->caps[1]);
1705 		margining->time_steps = val;
1706 		val = FIELD_GET(USB4_MARGIN_CAP_1_TIME_OFFSET_MASK, margining->caps[1]);
1707 		/*
1708 		 * Store it as mUI (milli Unit Interval) because we want
1709 		 * to keep it as integer.
1710 		 */
1711 		margining->max_time_offset = 200 + 10 * val;
1712 	}
1713 
1714 	dir = debugfs_create_dir("margining", parent);
1715 	if (supports_hardware(margining)) {
1716 		val = FIELD_GET(USB4_MARGIN_CAP_1_MIN_BER_MASK, margining->caps[1]);
1717 		margining->min_ber_level = val;
1718 		val = FIELD_GET(USB4_MARGIN_CAP_1_MAX_BER_MASK, margining->caps[1]);
1719 		margining->max_ber_level = val;
1720 
1721 		/* Set the default to minimum */
1722 		margining->ber_level = margining->min_ber_level;
1723 
1724 		debugfs_create_file("ber_level_contour", 0400, dir, margining,
1725 				    &margining_ber_level_fops);
1726 	}
1727 	debugfs_create_file("caps", 0400, dir, margining, &margining_caps_fops);
1728 	debugfs_create_file("lanes", 0600, dir, margining, &margining_lanes_fops);
1729 	debugfs_create_file("mode", 0600, dir, margining, &margining_mode_fops);
1730 	debugfs_create_file("run", 0600, dir, margining, &margining_run_fops);
1731 	debugfs_create_file("results", 0600, dir, margining,
1732 			    &margining_results_fops);
1733 	debugfs_create_file("test", 0600, dir, margining, &margining_test_fops);
1734 	if (independent_voltage_margins(margining) == USB4_MARGIN_CAP_VOLTAGE_INDP_GEN_2_3_HL ||
1735 	    (supports_time(margining) &&
1736 	     independent_time_margins(margining) == USB4_MARGIN_CAP_TIME_INDP_GEN_2_3_LR))
1737 		debugfs_create_file("margin", 0600, dir, margining, &margining_margin_fops);
1738 
1739 	margining->error_counter = USB4_MARGIN_SW_ERROR_COUNTER_CLEAR;
1740 	margining->dwell_time = MIN_DWELL_TIME;
1741 
1742 	if (supports_optional_voltage_offset_range(margining))
1743 		debugfs_create_file("optional_voltage_offset", DEBUGFS_MODE, dir, margining,
1744 				    &margining_optional_voltage_offset_fops);
1745 
1746 	if (supports_software(margining)) {
1747 		debugfs_create_file("voltage_time_offset", DEBUGFS_MODE, dir, margining,
1748 				    &margining_voltage_time_offset_fops);
1749 		debugfs_create_file("error_counter", DEBUGFS_MODE, dir, margining,
1750 				    &margining_error_counter_fops);
1751 		debugfs_create_file("dwell_time", DEBUGFS_MODE, dir, margining,
1752 				    &margining_dwell_time_fops);
1753 	}
1754 
1755 	if (margining->gen >= 4)
1756 		debugfs_create_file("eye", 0600, dir, port, &margining_eye_fops);
1757 
1758 	return margining;
1759 }
1760 
1761 static void margining_port_init(struct tb_port *port)
1762 {
1763 	struct dentry *parent;
1764 	char dir_name[10];
1765 
1766 	if (!port->usb4)
1767 		return;
1768 
1769 	snprintf(dir_name, sizeof(dir_name), "port%d", port->port);
1770 	parent = debugfs_lookup(dir_name, port->sw->debugfs_dir);
1771 	port->usb4->margining = margining_alloc(port, &port->usb4->dev,
1772 						USB4_SB_TARGET_ROUTER, 0,
1773 						parent);
1774 }
1775 
1776 static void margining_port_remove(struct tb_port *port)
1777 {
1778 	struct dentry *parent;
1779 	char dir_name[10];
1780 
1781 	if (!port->usb4)
1782 		return;
1783 
1784 	snprintf(dir_name, sizeof(dir_name), "port%d", port->port);
1785 	parent = debugfs_lookup(dir_name, port->sw->debugfs_dir);
1786 	if (parent)
1787 		debugfs_lookup_and_remove("margining", parent);
1788 
1789 	kfree(port->usb4->margining);
1790 	port->usb4->margining = NULL;
1791 }
1792 
1793 static void margining_switch_init(struct tb_switch *sw)
1794 {
1795 	struct tb_port *upstream, *downstream;
1796 	struct tb_switch *parent_sw;
1797 	u64 route = tb_route(sw);
1798 
1799 	if (!route)
1800 		return;
1801 
1802 	upstream = tb_upstream_port(sw);
1803 	parent_sw = tb_switch_parent(sw);
1804 	downstream = tb_port_at(route, parent_sw);
1805 
1806 	margining_port_init(downstream);
1807 	margining_port_init(upstream);
1808 }
1809 
1810 static void margining_switch_remove(struct tb_switch *sw)
1811 {
1812 	struct tb_port *upstream, *downstream;
1813 	struct tb_switch *parent_sw;
1814 	u64 route = tb_route(sw);
1815 
1816 	if (!route)
1817 		return;
1818 
1819 	upstream = tb_upstream_port(sw);
1820 	parent_sw = tb_switch_parent(sw);
1821 	downstream = tb_port_at(route, parent_sw);
1822 
1823 	margining_port_remove(upstream);
1824 	margining_port_remove(downstream);
1825 }
1826 
1827 static void margining_xdomain_init(struct tb_xdomain *xd)
1828 {
1829 	struct tb_switch *parent_sw;
1830 	struct tb_port *downstream;
1831 
1832 	parent_sw = tb_xdomain_parent(xd);
1833 	downstream = tb_port_at(xd->route, parent_sw);
1834 
1835 	margining_port_init(downstream);
1836 }
1837 
1838 static void margining_xdomain_remove(struct tb_xdomain *xd)
1839 {
1840 	struct tb_switch *parent_sw;
1841 	struct tb_port *downstream;
1842 
1843 	parent_sw = tb_xdomain_parent(xd);
1844 	downstream = tb_port_at(xd->route, parent_sw);
1845 	margining_port_remove(downstream);
1846 }
1847 
1848 static void margining_retimer_init(struct tb_retimer *rt, struct dentry *debugfs_dir)
1849 {
1850 	rt->margining = margining_alloc(rt->port, &rt->dev,
1851 					USB4_SB_TARGET_RETIMER, rt->index,
1852 					debugfs_dir);
1853 }
1854 
1855 static void margining_retimer_remove(struct tb_retimer *rt)
1856 {
1857 	kfree(rt->margining);
1858 	rt->margining = NULL;
1859 }
1860 #else
1861 static inline void margining_switch_init(struct tb_switch *sw) { }
1862 static inline void margining_switch_remove(struct tb_switch *sw) { }
1863 static inline void margining_xdomain_init(struct tb_xdomain *xd) { }
1864 static inline void margining_xdomain_remove(struct tb_xdomain *xd) { }
1865 static inline void margining_retimer_init(struct tb_retimer *rt,
1866 					  struct dentry *debugfs_dir) { }
1867 static inline void margining_retimer_remove(struct tb_retimer *rt) { }
1868 #endif
1869 
1870 static int port_clear_all_counters(struct tb_port *port)
1871 {
1872 	u32 *buf;
1873 	int ret;
1874 
1875 	buf = kcalloc(COUNTER_SET_LEN * port->config.max_counters, sizeof(u32),
1876 		      GFP_KERNEL);
1877 	if (!buf)
1878 		return -ENOMEM;
1879 
1880 	ret = tb_port_write(port, buf, TB_CFG_COUNTERS, 0,
1881 			    COUNTER_SET_LEN * port->config.max_counters);
1882 	kfree(buf);
1883 
1884 	return ret;
1885 }
1886 
1887 static ssize_t counters_write(struct file *file, const char __user *user_buf,
1888 			      size_t count, loff_t *ppos)
1889 {
1890 	struct seq_file *s = file->private_data;
1891 	struct tb_port *port = s->private;
1892 	struct tb_switch *sw = port->sw;
1893 	struct tb *tb = port->sw->tb;
1894 	char *buf;
1895 	int ret;
1896 
1897 	buf = validate_and_copy_from_user(user_buf, &count);
1898 	if (IS_ERR(buf))
1899 		return PTR_ERR(buf);
1900 
1901 	pm_runtime_get_sync(&sw->dev);
1902 
1903 	if (mutex_lock_interruptible(&tb->lock)) {
1904 		ret = -ERESTARTSYS;
1905 		goto out;
1906 	}
1907 
1908 	/* If written delimiter only, clear all counters in one shot */
1909 	if (buf[0] == '\n') {
1910 		ret = port_clear_all_counters(port);
1911 	} else  {
1912 		char *line = buf;
1913 		u32 val, offset;
1914 
1915 		ret = -EINVAL;
1916 		while (parse_line(&line, &offset, &val, 1, 4)) {
1917 			ret = tb_port_write(port, &val, TB_CFG_COUNTERS,
1918 					    offset, 1);
1919 			if (ret)
1920 				break;
1921 		}
1922 	}
1923 
1924 	mutex_unlock(&tb->lock);
1925 
1926 out:
1927 	pm_runtime_mark_last_busy(&sw->dev);
1928 	pm_runtime_put_autosuspend(&sw->dev);
1929 	free_page((unsigned long)buf);
1930 
1931 	return ret < 0 ? ret : count;
1932 }
1933 
1934 static void cap_show_by_dw(struct seq_file *s, struct tb_switch *sw,
1935 			   struct tb_port *port, unsigned int cap,
1936 			   unsigned int offset, u8 cap_id, u8 vsec_id,
1937 			   int dwords)
1938 {
1939 	int i, ret;
1940 	u32 data;
1941 
1942 	for (i = 0; i < dwords; i++) {
1943 		if (port)
1944 			ret = tb_port_read(port, &data, TB_CFG_PORT, cap + offset + i, 1);
1945 		else
1946 			ret = tb_sw_read(sw, &data, TB_CFG_SWITCH, cap + offset + i, 1);
1947 		if (ret) {
1948 			seq_printf(s, "0x%04x <not accessible>\n", cap + offset + i);
1949 			continue;
1950 		}
1951 
1952 		seq_printf(s, "0x%04x %4d 0x%02x 0x%02x 0x%08x\n", cap + offset + i,
1953 			   offset + i, cap_id, vsec_id, data);
1954 	}
1955 }
1956 
1957 static void cap_show(struct seq_file *s, struct tb_switch *sw,
1958 		     struct tb_port *port, unsigned int cap, u8 cap_id,
1959 		     u8 vsec_id, int length)
1960 {
1961 	int ret, offset = 0;
1962 
1963 	while (length > 0) {
1964 		int i, dwords = min(length, TB_MAX_CONFIG_RW_LENGTH);
1965 		u32 data[TB_MAX_CONFIG_RW_LENGTH];
1966 
1967 		if (port)
1968 			ret = tb_port_read(port, data, TB_CFG_PORT, cap + offset,
1969 					   dwords);
1970 		else
1971 			ret = tb_sw_read(sw, data, TB_CFG_SWITCH, cap + offset, dwords);
1972 		if (ret) {
1973 			cap_show_by_dw(s, sw, port, cap, offset, cap_id, vsec_id, length);
1974 			return;
1975 		}
1976 
1977 		for (i = 0; i < dwords; i++) {
1978 			seq_printf(s, "0x%04x %4d 0x%02x 0x%02x 0x%08x\n",
1979 				   cap + offset + i, offset + i,
1980 				   cap_id, vsec_id, data[i]);
1981 		}
1982 
1983 		length -= dwords;
1984 		offset += dwords;
1985 	}
1986 }
1987 
1988 static void port_cap_show(struct tb_port *port, struct seq_file *s,
1989 			  unsigned int cap)
1990 {
1991 	struct tb_cap_any header;
1992 	u8 vsec_id = 0;
1993 	size_t length;
1994 	int ret;
1995 
1996 	ret = tb_port_read(port, &header, TB_CFG_PORT, cap, 1);
1997 	if (ret) {
1998 		seq_printf(s, "0x%04x <capability read failed>\n", cap);
1999 		return;
2000 	}
2001 
2002 	switch (header.basic.cap) {
2003 	case TB_PORT_CAP_PHY:
2004 		length = PORT_CAP_LANE_LEN;
2005 		break;
2006 
2007 	case TB_PORT_CAP_TIME1:
2008 		if (usb4_switch_version(port->sw) < 2)
2009 			length = PORT_CAP_TMU_V1_LEN;
2010 		else
2011 			length = PORT_CAP_TMU_V2_LEN;
2012 		break;
2013 
2014 	case TB_PORT_CAP_POWER:
2015 		length = PORT_CAP_POWER_LEN;
2016 		break;
2017 
2018 	case TB_PORT_CAP_ADAP:
2019 		if (tb_port_is_pcie_down(port) || tb_port_is_pcie_up(port)) {
2020 			if (usb4_switch_version(port->sw) < 2)
2021 				length = PORT_CAP_V1_PCIE_LEN;
2022 			else
2023 				length = PORT_CAP_V2_PCIE_LEN;
2024 		} else if (tb_port_is_dpin(port)) {
2025 			if (usb4_switch_version(port->sw) < 2)
2026 				length = PORT_CAP_DP_V1_LEN;
2027 			else
2028 				length = PORT_CAP_DP_V2_LEN;
2029 		} else if (tb_port_is_dpout(port)) {
2030 			length = PORT_CAP_DP_V1_LEN;
2031 		} else if (tb_port_is_usb3_down(port) ||
2032 			   tb_port_is_usb3_up(port)) {
2033 			length = PORT_CAP_USB3_LEN;
2034 		} else {
2035 			seq_printf(s, "0x%04x <unsupported capability 0x%02x>\n",
2036 				   cap, header.basic.cap);
2037 			return;
2038 		}
2039 		break;
2040 
2041 	case TB_PORT_CAP_VSE:
2042 		if (!header.extended_short.length) {
2043 			ret = tb_port_read(port, (u32 *)&header + 1, TB_CFG_PORT,
2044 					   cap + 1, 1);
2045 			if (ret) {
2046 				seq_printf(s, "0x%04x <capability read failed>\n",
2047 					   cap + 1);
2048 				return;
2049 			}
2050 			length = header.extended_long.length;
2051 			vsec_id = header.extended_short.vsec_id;
2052 		} else {
2053 			length = header.extended_short.length;
2054 			vsec_id = header.extended_short.vsec_id;
2055 		}
2056 		break;
2057 
2058 	case TB_PORT_CAP_USB4:
2059 		length = PORT_CAP_USB4_LEN;
2060 		break;
2061 
2062 	default:
2063 		seq_printf(s, "0x%04x <unsupported capability 0x%02x>\n",
2064 			   cap, header.basic.cap);
2065 		return;
2066 	}
2067 
2068 	cap_show(s, NULL, port, cap, header.basic.cap, vsec_id, length);
2069 }
2070 
2071 static void port_caps_show(struct tb_port *port, struct seq_file *s)
2072 {
2073 	int cap;
2074 
2075 	cap = tb_port_next_cap(port, 0);
2076 	while (cap > 0) {
2077 		port_cap_show(port, s, cap);
2078 		cap = tb_port_next_cap(port, cap);
2079 	}
2080 }
2081 
2082 static int port_basic_regs_show(struct tb_port *port, struct seq_file *s)
2083 {
2084 	u32 data[PORT_CAP_BASIC_LEN];
2085 	int ret, i;
2086 
2087 	ret = tb_port_read(port, data, TB_CFG_PORT, 0, ARRAY_SIZE(data));
2088 	if (ret)
2089 		return ret;
2090 
2091 	for (i = 0; i < ARRAY_SIZE(data); i++)
2092 		seq_printf(s, "0x%04x %4d 0x00 0x00 0x%08x\n", i, i, data[i]);
2093 
2094 	return 0;
2095 }
2096 
2097 static int port_regs_show(struct seq_file *s, void *not_used)
2098 {
2099 	struct tb_port *port = s->private;
2100 	struct tb_switch *sw = port->sw;
2101 	struct tb *tb = sw->tb;
2102 	int ret;
2103 
2104 	pm_runtime_get_sync(&sw->dev);
2105 
2106 	if (mutex_lock_interruptible(&tb->lock)) {
2107 		ret = -ERESTARTSYS;
2108 		goto out_rpm_put;
2109 	}
2110 
2111 	seq_puts(s, "# offset relative_offset cap_id vs_cap_id value\n");
2112 
2113 	ret = port_basic_regs_show(port, s);
2114 	if (ret)
2115 		goto out_unlock;
2116 
2117 	port_caps_show(port, s);
2118 
2119 out_unlock:
2120 	mutex_unlock(&tb->lock);
2121 out_rpm_put:
2122 	pm_runtime_mark_last_busy(&sw->dev);
2123 	pm_runtime_put_autosuspend(&sw->dev);
2124 
2125 	return ret;
2126 }
2127 DEBUGFS_ATTR_RW(port_regs);
2128 
2129 static void switch_cap_show(struct tb_switch *sw, struct seq_file *s,
2130 			    unsigned int cap)
2131 {
2132 	struct tb_cap_any header;
2133 	int ret, length;
2134 	u8 vsec_id = 0;
2135 
2136 	ret = tb_sw_read(sw, &header, TB_CFG_SWITCH, cap, 1);
2137 	if (ret) {
2138 		seq_printf(s, "0x%04x <capability read failed>\n", cap);
2139 		return;
2140 	}
2141 
2142 	if (header.basic.cap == TB_SWITCH_CAP_VSE) {
2143 		if (!header.extended_short.length) {
2144 			ret = tb_sw_read(sw, (u32 *)&header + 1, TB_CFG_SWITCH,
2145 					 cap + 1, 1);
2146 			if (ret) {
2147 				seq_printf(s, "0x%04x <capability read failed>\n",
2148 					   cap + 1);
2149 				return;
2150 			}
2151 			length = header.extended_long.length;
2152 		} else {
2153 			length = header.extended_short.length;
2154 		}
2155 		vsec_id = header.extended_short.vsec_id;
2156 	} else {
2157 		if (header.basic.cap == TB_SWITCH_CAP_TMU) {
2158 			length = SWITCH_CAP_TMU_LEN;
2159 		} else  {
2160 			seq_printf(s, "0x%04x <unknown capability 0x%02x>\n",
2161 				   cap, header.basic.cap);
2162 			return;
2163 		}
2164 	}
2165 
2166 	cap_show(s, sw, NULL, cap, header.basic.cap, vsec_id, length);
2167 }
2168 
2169 static void switch_caps_show(struct tb_switch *sw, struct seq_file *s)
2170 {
2171 	int cap;
2172 
2173 	cap = tb_switch_next_cap(sw, 0);
2174 	while (cap > 0) {
2175 		switch_cap_show(sw, s, cap);
2176 		cap = tb_switch_next_cap(sw, cap);
2177 	}
2178 }
2179 
2180 static int switch_basic_regs_show(struct tb_switch *sw, struct seq_file *s)
2181 {
2182 	u32 data[SWITCH_CAP_BASIC_LEN];
2183 	size_t dwords;
2184 	int ret, i;
2185 
2186 	/* Only USB4 has the additional registers */
2187 	if (tb_switch_is_usb4(sw))
2188 		dwords = ARRAY_SIZE(data);
2189 	else
2190 		dwords = 5;
2191 
2192 	ret = tb_sw_read(sw, data, TB_CFG_SWITCH, 0, dwords);
2193 	if (ret)
2194 		return ret;
2195 
2196 	for (i = 0; i < dwords; i++)
2197 		seq_printf(s, "0x%04x %4d 0x00 0x00 0x%08x\n", i, i, data[i]);
2198 
2199 	return 0;
2200 }
2201 
2202 static int switch_regs_show(struct seq_file *s, void *not_used)
2203 {
2204 	struct tb_switch *sw = s->private;
2205 	struct tb *tb = sw->tb;
2206 	int ret;
2207 
2208 	pm_runtime_get_sync(&sw->dev);
2209 
2210 	if (mutex_lock_interruptible(&tb->lock)) {
2211 		ret = -ERESTARTSYS;
2212 		goto out_rpm_put;
2213 	}
2214 
2215 	seq_puts(s, "# offset relative_offset cap_id vs_cap_id value\n");
2216 
2217 	ret = switch_basic_regs_show(sw, s);
2218 	if (ret)
2219 		goto out_unlock;
2220 
2221 	switch_caps_show(sw, s);
2222 
2223 out_unlock:
2224 	mutex_unlock(&tb->lock);
2225 out_rpm_put:
2226 	pm_runtime_mark_last_busy(&sw->dev);
2227 	pm_runtime_put_autosuspend(&sw->dev);
2228 
2229 	return ret;
2230 }
2231 DEBUGFS_ATTR_RW(switch_regs);
2232 
2233 static int path_show_one(struct tb_port *port, struct seq_file *s, int hopid)
2234 {
2235 	u32 data[PATH_LEN];
2236 	int ret, i;
2237 
2238 	ret = tb_port_read(port, data, TB_CFG_HOPS, hopid * PATH_LEN,
2239 			   ARRAY_SIZE(data));
2240 	if (ret) {
2241 		seq_printf(s, "0x%04x <not accessible>\n", hopid * PATH_LEN);
2242 		return ret;
2243 	}
2244 
2245 	for (i = 0; i < ARRAY_SIZE(data); i++) {
2246 		seq_printf(s, "0x%04x %4d 0x%02x 0x%08x\n",
2247 			   hopid * PATH_LEN + i, i, hopid, data[i]);
2248 	}
2249 
2250 	return 0;
2251 }
2252 
2253 static int path_show(struct seq_file *s, void *not_used)
2254 {
2255 	struct tb_port *port = s->private;
2256 	struct tb_switch *sw = port->sw;
2257 	struct tb *tb = sw->tb;
2258 	int start, i, ret = 0;
2259 
2260 	pm_runtime_get_sync(&sw->dev);
2261 
2262 	if (mutex_lock_interruptible(&tb->lock)) {
2263 		ret = -ERESTARTSYS;
2264 		goto out_rpm_put;
2265 	}
2266 
2267 	seq_puts(s, "# offset relative_offset in_hop_id value\n");
2268 
2269 	/* NHI and lane adapters have entry for path 0 */
2270 	if (tb_port_is_null(port) || tb_port_is_nhi(port)) {
2271 		ret = path_show_one(port, s, 0);
2272 		if (ret)
2273 			goto out_unlock;
2274 	}
2275 
2276 	start = tb_port_is_nhi(port) ? 1 : TB_PATH_MIN_HOPID;
2277 
2278 	for (i = start; i <= port->config.max_in_hop_id; i++) {
2279 		ret = path_show_one(port, s, i);
2280 		if (ret)
2281 			break;
2282 	}
2283 
2284 out_unlock:
2285 	mutex_unlock(&tb->lock);
2286 out_rpm_put:
2287 	pm_runtime_mark_last_busy(&sw->dev);
2288 	pm_runtime_put_autosuspend(&sw->dev);
2289 
2290 	return ret;
2291 }
2292 DEBUGFS_ATTR_RW(path);
2293 
2294 static int counter_set_regs_show(struct tb_port *port, struct seq_file *s,
2295 				 int counter)
2296 {
2297 	u32 data[COUNTER_SET_LEN];
2298 	int ret, i;
2299 
2300 	ret = tb_port_read(port, data, TB_CFG_COUNTERS,
2301 			   counter * COUNTER_SET_LEN, ARRAY_SIZE(data));
2302 	if (ret) {
2303 		seq_printf(s, "0x%04x <not accessible>\n",
2304 			   counter * COUNTER_SET_LEN);
2305 		return ret;
2306 	}
2307 
2308 	for (i = 0; i < ARRAY_SIZE(data); i++) {
2309 		seq_printf(s, "0x%04x %4d 0x%02x 0x%08x\n",
2310 			   counter * COUNTER_SET_LEN + i, i, counter, data[i]);
2311 	}
2312 
2313 	return 0;
2314 }
2315 
2316 static int counters_show(struct seq_file *s, void *not_used)
2317 {
2318 	struct tb_port *port = s->private;
2319 	struct tb_switch *sw = port->sw;
2320 	struct tb *tb = sw->tb;
2321 	int i, ret = 0;
2322 
2323 	pm_runtime_get_sync(&sw->dev);
2324 
2325 	if (mutex_lock_interruptible(&tb->lock)) {
2326 		ret = -ERESTARTSYS;
2327 		goto out;
2328 	}
2329 
2330 	seq_puts(s, "# offset relative_offset counter_id value\n");
2331 
2332 	for (i = 0; i < port->config.max_counters; i++) {
2333 		ret = counter_set_regs_show(port, s, i);
2334 		if (ret)
2335 			break;
2336 	}
2337 
2338 	mutex_unlock(&tb->lock);
2339 
2340 out:
2341 	pm_runtime_mark_last_busy(&sw->dev);
2342 	pm_runtime_put_autosuspend(&sw->dev);
2343 
2344 	return ret;
2345 }
2346 DEBUGFS_ATTR_RW(counters);
2347 
2348 static int sb_regs_show(struct tb_port *port, const struct sb_reg *sb_regs,
2349 			size_t size, enum usb4_sb_target target, u8 index,
2350 			struct seq_file *s)
2351 {
2352 	int ret, i;
2353 
2354 	seq_puts(s, "# register value\n");
2355 
2356 	for (i = 0; i < size; i++) {
2357 		const struct sb_reg *regs = &sb_regs[i];
2358 		u8 data[64];
2359 		int j;
2360 
2361 		memset(data, 0, sizeof(data));
2362 		ret = usb4_port_sb_read(port, target, index, regs->reg, data,
2363 					regs->size);
2364 		if (ret)
2365 			return ret;
2366 
2367 		seq_printf(s, "0x%02x", regs->reg);
2368 		for (j = 0; j < regs->size; j++)
2369 			seq_printf(s, " 0x%02x", data[j]);
2370 		seq_puts(s, "\n");
2371 	}
2372 
2373 	return 0;
2374 }
2375 
2376 static int port_sb_regs_show(struct seq_file *s, void *not_used)
2377 {
2378 	struct tb_port *port = s->private;
2379 	struct tb_switch *sw = port->sw;
2380 	struct tb *tb = sw->tb;
2381 	int ret;
2382 
2383 	pm_runtime_get_sync(&sw->dev);
2384 
2385 	if (mutex_lock_interruptible(&tb->lock)) {
2386 		ret = -ERESTARTSYS;
2387 		goto out_rpm_put;
2388 	}
2389 
2390 	ret = sb_regs_show(port, port_sb_regs, ARRAY_SIZE(port_sb_regs),
2391 			   USB4_SB_TARGET_ROUTER, 0, s);
2392 
2393 	mutex_unlock(&tb->lock);
2394 out_rpm_put:
2395 	pm_runtime_mark_last_busy(&sw->dev);
2396 	pm_runtime_put_autosuspend(&sw->dev);
2397 
2398 	return ret;
2399 }
2400 DEBUGFS_ATTR_RW(port_sb_regs);
2401 
2402 /**
2403  * tb_switch_debugfs_init() - Add debugfs entries for router
2404  * @sw: Pointer to the router
2405  *
2406  * Adds debugfs directories and files for given router.
2407  */
2408 void tb_switch_debugfs_init(struct tb_switch *sw)
2409 {
2410 	struct dentry *debugfs_dir;
2411 	struct tb_port *port;
2412 
2413 	debugfs_dir = debugfs_create_dir(dev_name(&sw->dev), tb_debugfs_root);
2414 	sw->debugfs_dir = debugfs_dir;
2415 	debugfs_create_file("regs", DEBUGFS_MODE, debugfs_dir, sw,
2416 			    &switch_regs_fops);
2417 	if (sw->drom)
2418 		debugfs_create_blob("drom", 0400, debugfs_dir, &sw->drom_blob);
2419 
2420 	tb_switch_for_each_port(sw, port) {
2421 		struct dentry *debugfs_dir;
2422 		char dir_name[10];
2423 
2424 		if (port->disabled)
2425 			continue;
2426 		if (port->config.type == TB_TYPE_INACTIVE)
2427 			continue;
2428 
2429 		snprintf(dir_name, sizeof(dir_name), "port%d", port->port);
2430 		debugfs_dir = debugfs_create_dir(dir_name, sw->debugfs_dir);
2431 		debugfs_create_file("regs", DEBUGFS_MODE, debugfs_dir,
2432 				    port, &port_regs_fops);
2433 		debugfs_create_file("path", 0400, debugfs_dir, port,
2434 				    &path_fops);
2435 		if (port->config.counters_support)
2436 			debugfs_create_file("counters", 0600, debugfs_dir, port,
2437 					    &counters_fops);
2438 		if (port->usb4)
2439 			debugfs_create_file("sb_regs", DEBUGFS_MODE, debugfs_dir,
2440 					    port, &port_sb_regs_fops);
2441 	}
2442 
2443 	margining_switch_init(sw);
2444 }
2445 
2446 /**
2447  * tb_switch_debugfs_remove() - Remove all router debugfs entries
2448  * @sw: Pointer to the router
2449  *
2450  * Removes all previously added debugfs entries under this router.
2451  */
2452 void tb_switch_debugfs_remove(struct tb_switch *sw)
2453 {
2454 	margining_switch_remove(sw);
2455 	debugfs_remove_recursive(sw->debugfs_dir);
2456 }
2457 
2458 void tb_xdomain_debugfs_init(struct tb_xdomain *xd)
2459 {
2460 	margining_xdomain_init(xd);
2461 }
2462 
2463 void tb_xdomain_debugfs_remove(struct tb_xdomain *xd)
2464 {
2465 	margining_xdomain_remove(xd);
2466 }
2467 
2468 /**
2469  * tb_service_debugfs_init() - Add debugfs directory for service
2470  * @svc: Thunderbolt service pointer
2471  *
2472  * Adds debugfs directory for service.
2473  */
2474 void tb_service_debugfs_init(struct tb_service *svc)
2475 {
2476 	svc->debugfs_dir = debugfs_create_dir(dev_name(&svc->dev),
2477 					      tb_debugfs_root);
2478 }
2479 
2480 /**
2481  * tb_service_debugfs_remove() - Remove service debugfs directory
2482  * @svc: Thunderbolt service pointer
2483  *
2484  * Removes the previously created debugfs directory for @svc.
2485  */
2486 void tb_service_debugfs_remove(struct tb_service *svc)
2487 {
2488 	debugfs_remove_recursive(svc->debugfs_dir);
2489 	svc->debugfs_dir = NULL;
2490 }
2491 
2492 static int retimer_sb_regs_show(struct seq_file *s, void *not_used)
2493 {
2494 	struct tb_retimer *rt = s->private;
2495 	struct tb *tb = rt->tb;
2496 	int ret;
2497 
2498 	pm_runtime_get_sync(&rt->dev);
2499 
2500 	if (mutex_lock_interruptible(&tb->lock)) {
2501 		ret = -ERESTARTSYS;
2502 		goto out_rpm_put;
2503 	}
2504 
2505 	ret = sb_regs_show(rt->port, retimer_sb_regs, ARRAY_SIZE(retimer_sb_regs),
2506 			   USB4_SB_TARGET_RETIMER, rt->index, s);
2507 
2508 	mutex_unlock(&tb->lock);
2509 out_rpm_put:
2510 	pm_runtime_mark_last_busy(&rt->dev);
2511 	pm_runtime_put_autosuspend(&rt->dev);
2512 
2513 	return ret;
2514 }
2515 DEBUGFS_ATTR_RW(retimer_sb_regs);
2516 
2517 /**
2518  * tb_retimer_debugfs_init() - Add debugfs directory for retimer
2519  * @rt: Pointer to retimer structure
2520  *
2521  * Adds and populates retimer debugfs directory.
2522  */
2523 void tb_retimer_debugfs_init(struct tb_retimer *rt)
2524 {
2525 	struct dentry *debugfs_dir;
2526 
2527 	debugfs_dir = debugfs_create_dir(dev_name(&rt->dev), tb_debugfs_root);
2528 	debugfs_create_file("sb_regs", DEBUGFS_MODE, debugfs_dir, rt,
2529 			    &retimer_sb_regs_fops);
2530 	margining_retimer_init(rt, debugfs_dir);
2531 }
2532 
2533 /**
2534  * tb_retimer_debugfs_remove() - Remove retimer debugfs directory
2535  * @rt: Pointer to retimer structure
2536  *
2537  * Removes the retimer debugfs directory along with its contents.
2538  */
2539 void tb_retimer_debugfs_remove(struct tb_retimer *rt)
2540 {
2541 	debugfs_lookup_and_remove(dev_name(&rt->dev), tb_debugfs_root);
2542 	margining_retimer_remove(rt);
2543 }
2544 
2545 void tb_debugfs_init(void)
2546 {
2547 	tb_debugfs_root = debugfs_create_dir("thunderbolt", NULL);
2548 }
2549 
2550 void tb_debugfs_exit(void)
2551 {
2552 	debugfs_remove_recursive(tb_debugfs_root);
2553 }
2554