xref: /linux/drivers/thunderbolt/debugfs.c (revision 2cd86f02c017bf9733e5cd891381b7d40f6f37ad)
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/bitfield.h>
11 #include <linux/debugfs.h>
12 #include <linux/delay.h>
13 #include <linux/pm_runtime.h>
14 #include <linux/uaccess.h>
15 
16 #include "tb.h"
17 #include "sb_regs.h"
18 
19 #define PORT_CAP_V1_PCIE_LEN	1
20 #define PORT_CAP_V2_PCIE_LEN	2
21 #define PORT_CAP_POWER_LEN	2
22 #define PORT_CAP_LANE_LEN	3
23 #define PORT_CAP_USB3_LEN	5
24 #define PORT_CAP_DP_V1_LEN	9
25 #define PORT_CAP_DP_V2_LEN	14
26 #define PORT_CAP_TMU_V1_LEN	8
27 #define PORT_CAP_TMU_V2_LEN	10
28 #define PORT_CAP_BASIC_LEN	9
29 #define PORT_CAP_USB4_LEN	20
30 
31 #define SWITCH_CAP_TMU_LEN	26
32 #define SWITCH_CAP_BASIC_LEN	27
33 
34 #define PATH_LEN		2
35 
36 #define COUNTER_SET_LEN		3
37 
38 /*
39  * USB4 spec doesn't specify dwell range, the range of 100 ms to 500 ms
40  * probed to give good results.
41  */
42 #define MIN_DWELL_TIME		100 /* ms */
43 #define MAX_DWELL_TIME		500 /* ms */
44 #define DWELL_SAMPLE_INTERVAL	10
45 
46 /* Sideband registers and their sizes as defined in the USB4 spec */
47 struct sb_reg {
48 	unsigned int reg;
49 	unsigned int size;
50 };
51 
52 #define SB_MAX_SIZE		64
53 
54 /* Sideband registers for router */
55 static const struct sb_reg port_sb_regs[] = {
56 	{ USB4_SB_VENDOR_ID, 4 },
57 	{ USB4_SB_PRODUCT_ID, 4 },
58 	{ USB4_SB_DEBUG_CONF, 4 },
59 	{ USB4_SB_DEBUG, 54 },
60 	{ USB4_SB_LRD_TUNING, 4 },
61 	{ USB4_SB_OPCODE, 4 },
62 	{ USB4_SB_METADATA, 4 },
63 	{ USB4_SB_LINK_CONF, 3 },
64 	{ USB4_SB_GEN23_TXFFE, 4 },
65 	{ USB4_SB_GEN4_TXFFE, 4 },
66 	{ USB4_SB_VERSION, 4 },
67 	{ USB4_SB_DATA, 64 },
68 };
69 
70 /* Sideband registers for retimer */
71 static const struct sb_reg retimer_sb_regs[] = {
72 	{ USB4_SB_VENDOR_ID, 4 },
73 	{ USB4_SB_PRODUCT_ID, 4 },
74 	{ USB4_SB_FW_VERSION, 4 },
75 	{ USB4_SB_LRD_TUNING, 4 },
76 	{ USB4_SB_OPCODE, 4 },
77 	{ USB4_SB_METADATA, 4 },
78 	{ USB4_SB_GEN23_TXFFE, 4 },
79 	{ USB4_SB_GEN4_TXFFE, 4 },
80 	{ USB4_SB_VERSION, 4 },
81 	{ USB4_SB_DATA, 64 },
82 };
83 
84 #define DEBUGFS_ATTR(__space, __write)					\
85 static int __space ## _open(struct inode *inode, struct file *file)	\
86 {									\
87 	return single_open(file, __space ## _show, inode->i_private);	\
88 }									\
89 									\
90 static const struct file_operations __space ## _fops = {		\
91 	.owner = THIS_MODULE,						\
92 	.open = __space ## _open,					\
93 	.release = single_release,					\
94 	.read  = seq_read,						\
95 	.write = __write,						\
96 	.llseek = seq_lseek,						\
97 }
98 
99 #define DEBUGFS_ATTR_RO(__space)					\
100 	DEBUGFS_ATTR(__space, NULL)
101 
102 #define DEBUGFS_ATTR_RW(__space)					\
103 	DEBUGFS_ATTR(__space, __space ## _write)
104 
105 static struct dentry *tb_debugfs_root;
106 
107 static void *validate_and_copy_from_user(const void __user *user_buf,
108 					 size_t *count)
109 {
110 	size_t nbytes;
111 	void *buf;
112 
113 	if (!*count)
114 		return ERR_PTR(-EINVAL);
115 
116 	if (!access_ok(user_buf, *count))
117 		return ERR_PTR(-EFAULT);
118 
119 	buf = (void *)get_zeroed_page(GFP_KERNEL);
120 	if (!buf)
121 		return ERR_PTR(-ENOMEM);
122 
123 	nbytes = min_t(size_t, *count, PAGE_SIZE);
124 	if (copy_from_user(buf, user_buf, nbytes)) {
125 		free_page((unsigned long)buf);
126 		return ERR_PTR(-EFAULT);
127 	}
128 
129 	*count = nbytes;
130 	return buf;
131 }
132 
133 static bool parse_line(char **line, u32 *offs, u32 *val, int short_fmt_len,
134 		       int long_fmt_len)
135 {
136 	char *token;
137 	u32 v[5];
138 	int ret;
139 
140 	token = strsep(line, "\n");
141 	if (!token)
142 		return false;
143 
144 	/*
145 	 * For Adapter/Router configuration space:
146 	 * Short format is: offset value\n
147 	 *		    v[0]   v[1]
148 	 * Long format as produced from the read side:
149 	 * offset relative_offset cap_id vs_cap_id value\n
150 	 * v[0]   v[1]            v[2]   v[3]      v[4]
151 	 *
152 	 * For Counter configuration space:
153 	 * Short format is: offset\n
154 	 *		    v[0]
155 	 * Long format as produced from the read side:
156 	 * offset relative_offset counter_id value\n
157 	 * v[0]   v[1]            v[2]       v[3]
158 	 */
159 	ret = sscanf(token, "%i %i %i %i %i", &v[0], &v[1], &v[2], &v[3], &v[4]);
160 	/* In case of Counters, clear counter, "val" content is NA */
161 	if (ret == short_fmt_len) {
162 		*offs = v[0];
163 		*val = v[short_fmt_len - 1];
164 		return true;
165 	} else if (ret == long_fmt_len) {
166 		*offs = v[0];
167 		*val = v[long_fmt_len - 1];
168 		return true;
169 	}
170 
171 	return false;
172 }
173 
174 #if IS_ENABLED(CONFIG_USB4_DEBUGFS_WRITE)
175 static ssize_t regs_write(struct tb_switch *sw, struct tb_port *port,
176 			  const char __user *user_buf, size_t count,
177 			  loff_t *ppos)
178 {
179 	struct tb *tb = sw->tb;
180 	char *line, *buf;
181 	u32 val, offset;
182 	int ret = 0;
183 
184 	buf = validate_and_copy_from_user(user_buf, &count);
185 	if (IS_ERR(buf))
186 		return PTR_ERR(buf);
187 
188 	pm_runtime_get_sync(&sw->dev);
189 
190 	if (mutex_lock_interruptible(&tb->lock)) {
191 		ret = -ERESTARTSYS;
192 		goto out;
193 	}
194 
195 	/* User did hardware changes behind the driver's back */
196 	add_taint(TAINT_USER, LOCKDEP_STILL_OK);
197 
198 	line = buf;
199 	while (parse_line(&line, &offset, &val, 2, 5)) {
200 		if (port)
201 			ret = tb_port_write(port, &val, TB_CFG_PORT, offset, 1);
202 		else
203 			ret = tb_sw_write(sw, &val, TB_CFG_SWITCH, offset, 1);
204 		if (ret)
205 			break;
206 	}
207 
208 	mutex_unlock(&tb->lock);
209 
210 out:
211 	pm_runtime_mark_last_busy(&sw->dev);
212 	pm_runtime_put_autosuspend(&sw->dev);
213 	free_page((unsigned long)buf);
214 
215 	return ret < 0 ? ret : count;
216 }
217 
218 static ssize_t port_regs_write(struct file *file, const char __user *user_buf,
219 			       size_t count, loff_t *ppos)
220 {
221 	struct seq_file *s = file->private_data;
222 	struct tb_port *port = s->private;
223 
224 	return regs_write(port->sw, port, user_buf, count, ppos);
225 }
226 
227 static ssize_t switch_regs_write(struct file *file, const char __user *user_buf,
228 				 size_t count, loff_t *ppos)
229 {
230 	struct seq_file *s = file->private_data;
231 	struct tb_switch *sw = s->private;
232 
233 	return regs_write(sw, NULL, user_buf, count, ppos);
234 }
235 
236 static bool parse_sb_line(char **line, u8 *reg, u8 *data, size_t data_size,
237 			  size_t *bytes_read)
238 {
239 	char *field, *token;
240 	int i;
241 
242 	token = strsep(line, "\n");
243 	if (!token)
244 		return false;
245 
246 	/* Parse the register first */
247 	field = strsep(&token, " ");
248 	if (!field)
249 		return false;
250 	if (kstrtou8(field, 0, reg))
251 		return false;
252 
253 	/* Then the values for the register, up to data_size */
254 	for (i = 0; i < data_size; i++) {
255 		field = strsep(&token, " ");
256 		if (!field)
257 			break;
258 		if (kstrtou8(field, 0, &data[i]))
259 			return false;
260 	}
261 
262 	*bytes_read = i;
263 	return true;
264 }
265 
266 static ssize_t sb_regs_write(struct tb_port *port, const struct sb_reg *sb_regs,
267 			     size_t size, enum usb4_sb_target target, u8 index,
268 			     char *buf, size_t count, loff_t *ppos)
269 {
270 	u8 reg, data[SB_MAX_SIZE];
271 	size_t bytes_read;
272 	char *line = buf;
273 
274 	/* User did hardware changes behind the driver's back */
275 	add_taint(TAINT_USER, LOCKDEP_STILL_OK);
276 
277 	/*
278 	 * For sideband registers we accept:
279 	 * reg b0 b1 b2...\n
280 	 *
281 	 * Here "reg" is the byte offset of the sideband register and "b0"..
282 	 * are the byte values. There can be less byte values than the register
283 	 * size. The leftovers will not be overwritten.
284 	 */
285 	while (parse_sb_line(&line, &reg, data, ARRAY_SIZE(data), &bytes_read)) {
286 		const struct sb_reg *sb_reg;
287 		int ret;
288 
289 		/* At least one byte must be passed */
290 		if (bytes_read < 1)
291 			return -EINVAL;
292 
293 		/* Find the register */
294 		sb_reg = NULL;
295 		for (int i = 0; i < size; i++) {
296 			if (sb_regs[i].reg == reg) {
297 				sb_reg = &sb_regs[i];
298 				break;
299 			}
300 		}
301 
302 		if (!sb_reg)
303 			return -EINVAL;
304 
305 		if (bytes_read > sb_regs->size)
306 			return -E2BIG;
307 
308 		ret = usb4_port_sb_write(port, target, index, sb_reg->reg, data,
309 					 bytes_read);
310 		if (ret)
311 			return ret;
312 	}
313 
314 	return 0;
315 }
316 
317 static ssize_t port_sb_regs_write(struct file *file, const char __user *user_buf,
318 				  size_t count, loff_t *ppos)
319 {
320 	struct seq_file *s = file->private_data;
321 	struct tb_port *port = s->private;
322 	struct tb_switch *sw = port->sw;
323 	struct tb *tb = sw->tb;
324 	char *buf;
325 	int ret;
326 
327 	buf = validate_and_copy_from_user(user_buf, &count);
328 	if (IS_ERR(buf))
329 		return PTR_ERR(buf);
330 
331 	pm_runtime_get_sync(&sw->dev);
332 
333 	if (mutex_lock_interruptible(&tb->lock)) {
334 		ret = -ERESTARTSYS;
335 		goto out;
336 	}
337 
338 	ret = sb_regs_write(port, port_sb_regs, ARRAY_SIZE(port_sb_regs),
339 			    USB4_SB_TARGET_ROUTER, 0, buf, count, ppos);
340 
341 	mutex_unlock(&tb->lock);
342 out:
343 	pm_runtime_mark_last_busy(&sw->dev);
344 	pm_runtime_put_autosuspend(&sw->dev);
345 	free_page((unsigned long)buf);
346 
347 	return ret < 0 ? ret : count;
348 }
349 
350 static ssize_t retimer_sb_regs_write(struct file *file,
351 				     const char __user *user_buf,
352 				     size_t count, loff_t *ppos)
353 {
354 	struct seq_file *s = file->private_data;
355 	struct tb_retimer *rt = s->private;
356 	struct tb *tb = rt->tb;
357 	char *buf;
358 	int ret;
359 
360 	buf = validate_and_copy_from_user(user_buf, &count);
361 	if (IS_ERR(buf))
362 		return PTR_ERR(buf);
363 
364 	pm_runtime_get_sync(&rt->dev);
365 
366 	if (mutex_lock_interruptible(&tb->lock)) {
367 		ret = -ERESTARTSYS;
368 		goto out;
369 	}
370 
371 	ret = sb_regs_write(rt->port, retimer_sb_regs, ARRAY_SIZE(retimer_sb_regs),
372 			    USB4_SB_TARGET_RETIMER, rt->index, buf, count, ppos);
373 
374 	mutex_unlock(&tb->lock);
375 out:
376 	pm_runtime_mark_last_busy(&rt->dev);
377 	pm_runtime_put_autosuspend(&rt->dev);
378 	free_page((unsigned long)buf);
379 
380 	return ret < 0 ? ret : count;
381 }
382 #define DEBUGFS_MODE		0600
383 #else
384 #define port_regs_write		NULL
385 #define switch_regs_write	NULL
386 #define port_sb_regs_write	NULL
387 #define retimer_sb_regs_write	NULL
388 #define DEBUGFS_MODE		0400
389 #endif
390 
391 #if IS_ENABLED(CONFIG_USB4_DEBUGFS_MARGINING)
392 /**
393  * struct tb_margining - Lane margining support
394  * @port: USB4 port through which the margining operations are run
395  * @target: Sideband target
396  * @index: Retimer index if taget is %USB4_SB_TARGET_RETIMER
397  * @dev: Pointer to the device that is the target (USB4 port or retimer)
398  * @caps: Port lane margining capabilities
399  * @results: Last lane margining results
400  * @lanes: %0, %1 or %7 (all)
401  * @min_ber_level: Minimum supported BER level contour value
402  * @max_ber_level: Maximum supported BER level contour value
403  * @ber_level: Current BER level contour value
404  * @voltage_steps: Number of mandatory voltage steps
405  * @max_voltage_offset: Maximum mandatory voltage offset (in mV)
406  * @voltage_steps_optional_range: Number of voltage steps for optional range
407  * @max_voltage_offset_optional_range: Maximum voltage offset for the optional
408  *					range (in mV).
409  * @time_steps: Number of time margin steps
410  * @max_time_offset: Maximum time margin offset (in mUI)
411  * @voltage_time_offset: Offset for voltage / time for software margining
412  * @dwell_time: Dwell time for software margining (in ms)
413  * @error_counter: Error counter operation for software margining
414  * @optional_voltage_offset_range: Enable optional extended voltage range
415  * @software: %true if software margining is used instead of hardware
416  * @time: %true if time margining is used instead of voltage
417  * @right_high: %false if left/low margin test is performed, %true if
418  *		right/high
419  */
420 struct tb_margining {
421 	struct tb_port *port;
422 	enum usb4_sb_target target;
423 	u8 index;
424 	struct device *dev;
425 	u32 caps[2];
426 	u32 results[2];
427 	unsigned int lanes;
428 	unsigned int min_ber_level;
429 	unsigned int max_ber_level;
430 	unsigned int ber_level;
431 	unsigned int voltage_steps;
432 	unsigned int max_voltage_offset;
433 	unsigned int voltage_steps_optional_range;
434 	unsigned int max_voltage_offset_optional_range;
435 	unsigned int time_steps;
436 	unsigned int max_time_offset;
437 	unsigned int voltage_time_offset;
438 	unsigned int dwell_time;
439 	enum usb4_margin_sw_error_counter error_counter;
440 	bool optional_voltage_offset_range;
441 	bool software;
442 	bool time;
443 	bool right_high;
444 };
445 
446 static int margining_modify_error_counter(struct tb_margining *margining,
447 	u32 lanes, enum usb4_margin_sw_error_counter error_counter)
448 {
449 	struct usb4_port_margining_params params = { 0 };
450 	struct tb_port *port = margining->port;
451 	u32 result;
452 
453 	if (error_counter != USB4_MARGIN_SW_ERROR_COUNTER_CLEAR &&
454 	    error_counter != USB4_MARGIN_SW_ERROR_COUNTER_STOP)
455 		return -EOPNOTSUPP;
456 
457 	params.error_counter = error_counter;
458 	params.lanes = lanes;
459 
460 	return usb4_port_sw_margin(port, margining->target, margining->index,
461 				   &params, &result);
462 }
463 
464 static bool supports_software(const struct tb_margining *margining)
465 {
466 	return margining->caps[0] & USB4_MARGIN_CAP_0_MODES_SW;
467 }
468 
469 static bool supports_hardware(const struct tb_margining *margining)
470 {
471 	return margining->caps[0] & USB4_MARGIN_CAP_0_MODES_HW;
472 }
473 
474 static bool both_lanes(const struct tb_margining *margining)
475 {
476 	return margining->caps[0] & USB4_MARGIN_CAP_0_2_LANES;
477 }
478 
479 static unsigned int
480 independent_voltage_margins(const struct tb_margining *margining)
481 {
482 	return FIELD_GET(USB4_MARGIN_CAP_0_VOLTAGE_INDP_MASK, margining->caps[0]);
483 }
484 
485 static bool supports_time(const struct tb_margining *margining)
486 {
487 	return margining->caps[0] & USB4_MARGIN_CAP_0_TIME;
488 }
489 
490 /* Only applicable if supports_time() returns true */
491 static unsigned int
492 independent_time_margins(const struct tb_margining *margining)
493 {
494 	return FIELD_GET(USB4_MARGIN_CAP_1_TIME_INDP_MASK, margining->caps[1]);
495 }
496 
497 static bool
498 supports_optional_voltage_offset_range(const struct tb_margining *margining)
499 {
500 	return margining->caps[0] & USB4_MARGIN_CAP_0_OPT_VOLTAGE_SUPPORT;
501 }
502 
503 static ssize_t
504 margining_ber_level_write(struct file *file, const char __user *user_buf,
505 			   size_t count, loff_t *ppos)
506 {
507 	struct seq_file *s = file->private_data;
508 	struct tb_margining *margining = s->private;
509 	struct tb *tb = margining->port->sw->tb;
510 	unsigned int val;
511 	int ret = 0;
512 	char *buf;
513 
514 	if (mutex_lock_interruptible(&tb->lock))
515 		return -ERESTARTSYS;
516 
517 	if (margining->software) {
518 		ret = -EINVAL;
519 		goto out_unlock;
520 	}
521 
522 	buf = validate_and_copy_from_user(user_buf, &count);
523 	if (IS_ERR(buf)) {
524 		ret = PTR_ERR(buf);
525 		goto out_unlock;
526 	}
527 
528 	buf[count - 1] = '\0';
529 
530 	ret = kstrtouint(buf, 10, &val);
531 	if (ret)
532 		goto out_free;
533 
534 	if (val < margining->min_ber_level ||
535 	    val > margining->max_ber_level) {
536 		ret = -EINVAL;
537 		goto out_free;
538 	}
539 
540 	margining->ber_level = val;
541 
542 out_free:
543 	free_page((unsigned long)buf);
544 out_unlock:
545 	mutex_unlock(&tb->lock);
546 
547 	return ret < 0 ? ret : count;
548 }
549 
550 static void ber_level_show(struct seq_file *s, unsigned int val)
551 {
552 	if (val % 2)
553 		seq_printf(s, "3 * 1e%d (%u)\n", -12 + (val + 1) / 2, val);
554 	else
555 		seq_printf(s, "1e%d (%u)\n", -12 + val / 2, val);
556 }
557 
558 static int margining_ber_level_show(struct seq_file *s, void *not_used)
559 {
560 	const struct tb_margining *margining = s->private;
561 
562 	if (margining->software)
563 		return -EINVAL;
564 	ber_level_show(s, margining->ber_level);
565 	return 0;
566 }
567 DEBUGFS_ATTR_RW(margining_ber_level);
568 
569 static int margining_caps_show(struct seq_file *s, void *not_used)
570 {
571 	struct tb_margining *margining = s->private;
572 	struct tb *tb = margining->port->sw->tb;
573 	u32 cap0, cap1;
574 
575 	if (mutex_lock_interruptible(&tb->lock))
576 		return -ERESTARTSYS;
577 
578 	/* Dump the raw caps first */
579 	cap0 = margining->caps[0];
580 	seq_printf(s, "0x%08x\n", cap0);
581 	cap1 = margining->caps[1];
582 	seq_printf(s, "0x%08x\n", cap1);
583 
584 	seq_printf(s, "# software margining: %s\n",
585 		   supports_software(margining) ? "yes" : "no");
586 	if (supports_hardware(margining)) {
587 		seq_puts(s, "# hardware margining: yes\n");
588 		seq_puts(s, "# minimum BER level contour: ");
589 		ber_level_show(s, margining->min_ber_level);
590 		seq_puts(s, "# maximum BER level contour: ");
591 		ber_level_show(s, margining->max_ber_level);
592 	} else {
593 		seq_puts(s, "# hardware margining: no\n");
594 	}
595 
596 	seq_printf(s, "# both lanes simultaneously: %s\n",
597 		  both_lanes(margining) ? "yes" : "no");
598 	seq_printf(s, "# voltage margin steps: %u\n",
599 		   margining->voltage_steps);
600 	seq_printf(s, "# maximum voltage offset: %u mV\n",
601 		   margining->max_voltage_offset);
602 	seq_printf(s, "# optional voltage offset range support: %s\n",
603 		   str_yes_no(supports_optional_voltage_offset_range(margining)));
604 	if (supports_optional_voltage_offset_range(margining)) {
605 		seq_printf(s, "# voltage margin steps, optional range: %u\n",
606 			   margining->voltage_steps_optional_range);
607 		seq_printf(s, "# maximum voltage offset, optional range: %u mV\n",
608 			   margining->max_voltage_offset_optional_range);
609 	}
610 
611 	switch (independent_voltage_margins(margining)) {
612 	case USB4_MARGIN_CAP_0_VOLTAGE_MIN:
613 		seq_puts(s, "# returns minimum between high and low voltage margins\n");
614 		break;
615 	case USB4_MARGIN_CAP_0_VOLTAGE_HL:
616 		seq_puts(s, "# returns high or low voltage margin\n");
617 		break;
618 	case USB4_MARGIN_CAP_0_VOLTAGE_BOTH:
619 		seq_puts(s, "# returns both high and low margins\n");
620 		break;
621 	}
622 
623 	if (supports_time(margining)) {
624 		seq_puts(s, "# time margining: yes\n");
625 		seq_printf(s, "# time margining is destructive: %s\n",
626 			   cap1 & USB4_MARGIN_CAP_1_TIME_DESTR ? "yes" : "no");
627 
628 		switch (independent_time_margins(margining)) {
629 		case USB4_MARGIN_CAP_1_TIME_MIN:
630 			seq_puts(s, "# returns minimum between left and right time margins\n");
631 			break;
632 		case USB4_MARGIN_CAP_1_TIME_LR:
633 			seq_puts(s, "# returns left or right margin\n");
634 			break;
635 		case USB4_MARGIN_CAP_1_TIME_BOTH:
636 			seq_puts(s, "# returns both left and right margins\n");
637 			break;
638 		}
639 
640 		seq_printf(s, "# time margin steps: %u\n",
641 			   margining->time_steps);
642 		seq_printf(s, "# maximum time offset: %u mUI\n",
643 			   margining->max_time_offset);
644 	} else {
645 		seq_puts(s, "# time margining: no\n");
646 	}
647 
648 	mutex_unlock(&tb->lock);
649 	return 0;
650 }
651 DEBUGFS_ATTR_RO(margining_caps);
652 
653 static ssize_t
654 margining_lanes_write(struct file *file, const char __user *user_buf,
655 		      size_t count, loff_t *ppos)
656 {
657 	struct seq_file *s = file->private_data;
658 	struct tb_margining *margining = s->private;
659 	struct tb *tb = margining->port->sw->tb;
660 	int ret = 0;
661 	char *buf;
662 
663 	buf = validate_and_copy_from_user(user_buf, &count);
664 	if (IS_ERR(buf))
665 		return PTR_ERR(buf);
666 
667 	buf[count - 1] = '\0';
668 
669 	if (mutex_lock_interruptible(&tb->lock)) {
670 		ret = -ERESTARTSYS;
671 		goto out_free;
672 	}
673 
674 	if (!strcmp(buf, "0")) {
675 		margining->lanes = 0;
676 	} else if (!strcmp(buf, "1")) {
677 		margining->lanes = 1;
678 	} else if (!strcmp(buf, "all")) {
679 		/* Needs to be supported */
680 		if (both_lanes(margining))
681 			margining->lanes = 7;
682 		else
683 			ret = -EINVAL;
684 	} else {
685 		ret = -EINVAL;
686 	}
687 
688 	mutex_unlock(&tb->lock);
689 
690 out_free:
691 	free_page((unsigned long)buf);
692 	return ret < 0 ? ret : count;
693 }
694 
695 static int margining_lanes_show(struct seq_file *s, void *not_used)
696 {
697 	struct tb_margining *margining = s->private;
698 	struct tb *tb = margining->port->sw->tb;
699 	unsigned int lanes;
700 
701 	if (mutex_lock_interruptible(&tb->lock))
702 		return -ERESTARTSYS;
703 
704 	lanes = margining->lanes;
705 	if (both_lanes(margining)) {
706 		if (!lanes)
707 			seq_puts(s, "[0] 1 all\n");
708 		else if (lanes == 1)
709 			seq_puts(s, "0 [1] all\n");
710 		else
711 			seq_puts(s, "0 1 [all]\n");
712 	} else {
713 		if (!lanes)
714 			seq_puts(s, "[0] 1\n");
715 		else
716 			seq_puts(s, "0 [1]\n");
717 	}
718 
719 	mutex_unlock(&tb->lock);
720 	return 0;
721 }
722 DEBUGFS_ATTR_RW(margining_lanes);
723 
724 static ssize_t
725 margining_voltage_time_offset_write(struct file *file,
726 				    const char __user *user_buf,
727 				    size_t count, loff_t *ppos)
728 {
729 	struct seq_file *s = file->private_data;
730 	struct tb_margining *margining = s->private;
731 	struct tb *tb = margining->port->sw->tb;
732 	unsigned int max_margin;
733 	unsigned int val;
734 	int ret;
735 
736 	ret = kstrtouint_from_user(user_buf, count, 10, &val);
737 	if (ret)
738 		return ret;
739 
740 	scoped_cond_guard(mutex_intr, return -ERESTARTSYS, &tb->lock) {
741 		if (!margining->software)
742 			return -EOPNOTSUPP;
743 
744 		if (margining->time)
745 			max_margin = margining->time_steps;
746 		else
747 			if (margining->optional_voltage_offset_range)
748 				max_margin = margining->voltage_steps_optional_range;
749 			else
750 				max_margin = margining->voltage_steps;
751 
752 		margining->voltage_time_offset = clamp(val, 0, max_margin);
753 	}
754 
755 	return count;
756 }
757 
758 static int margining_voltage_time_offset_show(struct seq_file *s,
759 					      void *not_used)
760 {
761 	const struct tb_margining *margining = s->private;
762 	struct tb *tb = margining->port->sw->tb;
763 
764 	scoped_cond_guard(mutex_intr, return -ERESTARTSYS, &tb->lock) {
765 		if (!margining->software)
766 			return -EOPNOTSUPP;
767 
768 		seq_printf(s, "%d\n", margining->voltage_time_offset);
769 	}
770 
771 	return 0;
772 }
773 DEBUGFS_ATTR_RW(margining_voltage_time_offset);
774 
775 static ssize_t
776 margining_error_counter_write(struct file *file, const char __user *user_buf,
777 			      size_t count, loff_t *ppos)
778 {
779 	enum usb4_margin_sw_error_counter error_counter;
780 	struct seq_file *s = file->private_data;
781 	struct tb_margining *margining = s->private;
782 	struct tb *tb = margining->port->sw->tb;
783 	char *buf;
784 
785 	buf = validate_and_copy_from_user(user_buf, &count);
786 	if (IS_ERR(buf))
787 		return PTR_ERR(buf);
788 
789 	buf[count - 1] = '\0';
790 
791 	if (!strcmp(buf, "nop"))
792 		error_counter = USB4_MARGIN_SW_ERROR_COUNTER_NOP;
793 	else if (!strcmp(buf, "clear"))
794 		error_counter = USB4_MARGIN_SW_ERROR_COUNTER_CLEAR;
795 	else if (!strcmp(buf, "start"))
796 		error_counter = USB4_MARGIN_SW_ERROR_COUNTER_START;
797 	else if (!strcmp(buf, "stop"))
798 		error_counter = USB4_MARGIN_SW_ERROR_COUNTER_STOP;
799 	else
800 		return -EINVAL;
801 
802 	scoped_cond_guard(mutex_intr, return -ERESTARTSYS, &tb->lock) {
803 		if (!margining->software)
804 			return -EOPNOTSUPP;
805 
806 		margining->error_counter = error_counter;
807 	}
808 
809 	return count;
810 }
811 
812 static int margining_error_counter_show(struct seq_file *s, void *not_used)
813 {
814 	const struct tb_margining *margining = s->private;
815 	struct tb *tb = margining->port->sw->tb;
816 
817 	scoped_cond_guard(mutex_intr, return -ERESTARTSYS, &tb->lock) {
818 		if (!margining->software)
819 			return -EOPNOTSUPP;
820 
821 		switch (margining->error_counter) {
822 		case USB4_MARGIN_SW_ERROR_COUNTER_NOP:
823 			seq_puts(s, "[nop] clear start stop\n");
824 			break;
825 		case USB4_MARGIN_SW_ERROR_COUNTER_CLEAR:
826 			seq_puts(s, "nop [clear] start stop\n");
827 			break;
828 		case USB4_MARGIN_SW_ERROR_COUNTER_START:
829 			seq_puts(s, "nop clear [start] stop\n");
830 			break;
831 		case USB4_MARGIN_SW_ERROR_COUNTER_STOP:
832 			seq_puts(s, "nop clear start [stop]\n");
833 			break;
834 		}
835 	}
836 
837 	return 0;
838 }
839 DEBUGFS_ATTR_RW(margining_error_counter);
840 
841 static ssize_t
842 margining_dwell_time_write(struct file *file, const char __user *user_buf,
843 			   size_t count, loff_t *ppos)
844 {
845 	struct seq_file *s = file->private_data;
846 	struct tb_margining *margining = s->private;
847 	struct tb *tb = margining->port->sw->tb;
848 	unsigned int val;
849 	int ret;
850 
851 	ret = kstrtouint_from_user(user_buf, count, 10, &val);
852 	if (ret)
853 		return ret;
854 
855 	scoped_cond_guard(mutex_intr, return -ERESTARTSYS, &tb->lock) {
856 		if (!margining->software)
857 			return -EOPNOTSUPP;
858 
859 		margining->dwell_time = clamp(val, MIN_DWELL_TIME, MAX_DWELL_TIME);
860 	}
861 
862 	return count;
863 }
864 
865 static int margining_dwell_time_show(struct seq_file *s, void *not_used)
866 {
867 	struct tb_margining *margining = s->private;
868 	struct tb *tb = margining->port->sw->tb;
869 
870 	scoped_cond_guard(mutex_intr, return -ERESTARTSYS, &tb->lock) {
871 		if (!margining->software)
872 			return -EOPNOTSUPP;
873 
874 		seq_printf(s, "%d\n", margining->dwell_time);
875 	}
876 
877 	return 0;
878 }
879 DEBUGFS_ATTR_RW(margining_dwell_time);
880 
881 static ssize_t
882 margining_optional_voltage_offset_write(struct file *file, const char __user *user_buf,
883 					size_t count, loff_t *ppos)
884 {
885 	struct seq_file *s = file->private_data;
886 	struct tb_margining *margining = s->private;
887 	struct tb *tb = margining->port->sw->tb;
888 	bool val;
889 	int ret;
890 
891 	ret = kstrtobool_from_user(user_buf, count, &val);
892 	if (ret)
893 		return ret;
894 
895 	scoped_cond_guard(mutex_intr, return -ERESTARTSYS, &tb->lock) {
896 		margining->optional_voltage_offset_range = val;
897 	}
898 
899 	return count;
900 }
901 
902 static int margining_optional_voltage_offset_show(struct seq_file *s,
903 						  void *not_used)
904 {
905 	struct tb_margining *margining = s->private;
906 	struct tb *tb = margining->port->sw->tb;
907 
908 	scoped_cond_guard(mutex_intr, return -ERESTARTSYS, &tb->lock) {
909 		seq_printf(s, "%u\n", margining->optional_voltage_offset_range);
910 	}
911 
912 	return 0;
913 }
914 DEBUGFS_ATTR_RW(margining_optional_voltage_offset);
915 
916 static ssize_t margining_mode_write(struct file *file,
917 				   const char __user *user_buf,
918 				   size_t count, loff_t *ppos)
919 {
920 	struct seq_file *s = file->private_data;
921 	struct tb_margining *margining = s->private;
922 	struct tb *tb = margining->port->sw->tb;
923 	int ret = 0;
924 	char *buf;
925 
926 	buf = validate_and_copy_from_user(user_buf, &count);
927 	if (IS_ERR(buf))
928 		return PTR_ERR(buf);
929 
930 	buf[count - 1] = '\0';
931 
932 	if (mutex_lock_interruptible(&tb->lock)) {
933 		ret = -ERESTARTSYS;
934 		goto out_free;
935 	}
936 
937 	if (!strcmp(buf, "software")) {
938 		if (supports_software(margining))
939 			margining->software = true;
940 		else
941 			ret = -EINVAL;
942 	} else if (!strcmp(buf, "hardware")) {
943 		if (supports_hardware(margining))
944 			margining->software = false;
945 		else
946 			ret = -EINVAL;
947 	} else {
948 		ret = -EINVAL;
949 	}
950 
951 	mutex_unlock(&tb->lock);
952 
953 out_free:
954 	free_page((unsigned long)buf);
955 	return ret ? ret : count;
956 }
957 
958 static int margining_mode_show(struct seq_file *s, void *not_used)
959 {
960 	struct tb_margining *margining = s->private;
961 	struct tb *tb = margining->port->sw->tb;
962 	const char *space = "";
963 
964 	if (mutex_lock_interruptible(&tb->lock))
965 		return -ERESTARTSYS;
966 
967 	if (supports_software(margining)) {
968 		if (margining->software)
969 			seq_puts(s, "[software]");
970 		else
971 			seq_puts(s, "software");
972 		space = " ";
973 	}
974 	if (supports_hardware(margining)) {
975 		if (margining->software)
976 			seq_printf(s, "%shardware", space);
977 		else
978 			seq_printf(s, "%s[hardware]", space);
979 	}
980 
981 	mutex_unlock(&tb->lock);
982 
983 	seq_puts(s, "\n");
984 	return 0;
985 }
986 DEBUGFS_ATTR_RW(margining_mode);
987 
988 static int margining_run_sw(struct tb_margining *margining,
989 			    struct usb4_port_margining_params *params)
990 {
991 	u32 nsamples = margining->dwell_time / DWELL_SAMPLE_INTERVAL;
992 	int ret, i;
993 
994 	ret = usb4_port_sw_margin(margining->port, margining->target, margining->index,
995 				  params, margining->results);
996 	if (ret)
997 		goto out_stop;
998 
999 	for (i = 0; i <= nsamples; i++) {
1000 		u32 errors = 0;
1001 
1002 		ret = usb4_port_sw_margin_errors(margining->port, margining->target,
1003 						 margining->index, &margining->results[1]);
1004 		if (ret)
1005 			break;
1006 
1007 		if (margining->lanes == USB4_MARGIN_SW_LANE_0)
1008 			errors = FIELD_GET(USB4_MARGIN_SW_ERR_COUNTER_LANE_0_MASK,
1009 					   margining->results[1]);
1010 		else if (margining->lanes == USB4_MARGIN_SW_LANE_1)
1011 			errors = FIELD_GET(USB4_MARGIN_SW_ERR_COUNTER_LANE_1_MASK,
1012 					   margining->results[1]);
1013 		else if (margining->lanes == USB4_MARGIN_SW_ALL_LANES)
1014 			errors = margining->results[1];
1015 
1016 		/* Any errors stop the test */
1017 		if (errors)
1018 			break;
1019 
1020 		fsleep(DWELL_SAMPLE_INTERVAL * USEC_PER_MSEC);
1021 	}
1022 
1023 out_stop:
1024 	/*
1025 	 * Stop the counters but don't clear them to allow the
1026 	 * different error counter configurations.
1027 	 */
1028 	margining_modify_error_counter(margining, margining->lanes,
1029 				       USB4_MARGIN_SW_ERROR_COUNTER_STOP);
1030 	return ret;
1031 }
1032 
1033 static int margining_run_write(void *data, u64 val)
1034 {
1035 	struct tb_margining *margining = data;
1036 	struct tb_port *port = margining->port;
1037 	struct device *dev = margining->dev;
1038 	struct tb_switch *sw = port->sw;
1039 	struct tb_switch *down_sw;
1040 	struct tb *tb = sw->tb;
1041 	int ret, clx;
1042 
1043 	if (val != 1)
1044 		return -EINVAL;
1045 
1046 	pm_runtime_get_sync(dev);
1047 
1048 	if (mutex_lock_interruptible(&tb->lock)) {
1049 		ret = -ERESTARTSYS;
1050 		goto out_rpm_put;
1051 	}
1052 
1053 	if (tb_is_upstream_port(port))
1054 		down_sw = sw;
1055 	else if (port->remote)
1056 		down_sw = port->remote->sw;
1057 	else
1058 		down_sw = NULL;
1059 
1060 	if (down_sw) {
1061 		/*
1062 		 * CL states may interfere with lane margining so
1063 		 * disable them temporarily now.
1064 		 */
1065 		ret = tb_switch_clx_disable(down_sw);
1066 		if (ret < 0) {
1067 			tb_sw_warn(down_sw, "failed to disable CL states\n");
1068 			goto out_unlock;
1069 		}
1070 		clx = ret;
1071 	}
1072 
1073 	/* Clear the results */
1074 	memset(margining->results, 0, sizeof(margining->results));
1075 
1076 	if (margining->software) {
1077 		struct usb4_port_margining_params params = {
1078 			.error_counter = USB4_MARGIN_SW_ERROR_COUNTER_CLEAR,
1079 			.lanes = margining->lanes,
1080 			.time = margining->time,
1081 			.voltage_time_offset = margining->voltage_time_offset,
1082 			.right_high = margining->right_high,
1083 			.optional_voltage_offset_range = margining->optional_voltage_offset_range,
1084 		};
1085 
1086 		tb_port_dbg(port,
1087 			    "running software %s lane margining for %s lanes %u\n",
1088 			    margining->time ? "time" : "voltage", dev_name(dev),
1089 			    margining->lanes);
1090 
1091 		ret = margining_run_sw(margining, &params);
1092 	} else {
1093 		struct usb4_port_margining_params params = {
1094 			.ber_level = margining->ber_level,
1095 			.lanes = margining->lanes,
1096 			.time = margining->time,
1097 			.right_high = margining->right_high,
1098 			.optional_voltage_offset_range = margining->optional_voltage_offset_range,
1099 		};
1100 
1101 		tb_port_dbg(port,
1102 			    "running hardware %s lane margining for %s lanes %u\n",
1103 			    margining->time ? "time" : "voltage", dev_name(dev),
1104 			    margining->lanes);
1105 
1106 		ret = usb4_port_hw_margin(port, margining->target, margining->index, &params,
1107 					  margining->results);
1108 	}
1109 
1110 	if (down_sw)
1111 		tb_switch_clx_enable(down_sw, clx);
1112 out_unlock:
1113 	mutex_unlock(&tb->lock);
1114 out_rpm_put:
1115 	pm_runtime_mark_last_busy(dev);
1116 	pm_runtime_put_autosuspend(dev);
1117 
1118 	return ret;
1119 }
1120 DEFINE_DEBUGFS_ATTRIBUTE(margining_run_fops, NULL, margining_run_write,
1121 			 "%llu\n");
1122 
1123 static ssize_t margining_results_write(struct file *file,
1124 				       const char __user *user_buf,
1125 				       size_t count, loff_t *ppos)
1126 {
1127 	struct seq_file *s = file->private_data;
1128 	struct tb_margining *margining = s->private;
1129 	struct tb *tb = margining->port->sw->tb;
1130 
1131 	if (mutex_lock_interruptible(&tb->lock))
1132 		return -ERESTARTSYS;
1133 
1134 	/* Just clear the results */
1135 	margining->results[0] = 0;
1136 	margining->results[1] = 0;
1137 
1138 	if (margining->software) {
1139 		/* Clear the error counters */
1140 		margining_modify_error_counter(margining,
1141 					       USB4_MARGIN_SW_ALL_LANES,
1142 					       USB4_MARGIN_SW_ERROR_COUNTER_CLEAR);
1143 	}
1144 
1145 	mutex_unlock(&tb->lock);
1146 	return count;
1147 }
1148 
1149 static void voltage_margin_show(struct seq_file *s,
1150 				const struct tb_margining *margining, u8 val)
1151 {
1152 	unsigned int tmp, voltage;
1153 
1154 	tmp = FIELD_GET(USB4_MARGIN_HW_RES_1_MARGIN_MASK, val);
1155 	voltage = tmp * margining->max_voltage_offset / margining->voltage_steps;
1156 	seq_printf(s, "%u mV (%u)", voltage, tmp);
1157 	if (val & USB4_MARGIN_HW_RES_1_EXCEEDS)
1158 		seq_puts(s, " exceeds maximum");
1159 	seq_puts(s, "\n");
1160 	if (margining->optional_voltage_offset_range)
1161 		seq_puts(s, " optional voltage offset range enabled\n");
1162 }
1163 
1164 static void time_margin_show(struct seq_file *s,
1165 			     const struct tb_margining *margining, u8 val)
1166 {
1167 	unsigned int tmp, interval;
1168 
1169 	tmp = FIELD_GET(USB4_MARGIN_HW_RES_1_MARGIN_MASK, val);
1170 	interval = tmp * margining->max_time_offset / margining->time_steps;
1171 	seq_printf(s, "%u mUI (%u)", interval, tmp);
1172 	if (val & USB4_MARGIN_HW_RES_1_EXCEEDS)
1173 		seq_puts(s, " exceeds maximum");
1174 	seq_puts(s, "\n");
1175 }
1176 
1177 static int margining_results_show(struct seq_file *s, void *not_used)
1178 {
1179 	struct tb_margining *margining = s->private;
1180 	struct tb *tb = margining->port->sw->tb;
1181 
1182 	if (mutex_lock_interruptible(&tb->lock))
1183 		return -ERESTARTSYS;
1184 
1185 	/* Dump the raw results first */
1186 	seq_printf(s, "0x%08x\n", margining->results[0]);
1187 	/* Only the hardware margining has two result dwords */
1188 	if (!margining->software) {
1189 		unsigned int val;
1190 
1191 		seq_printf(s, "0x%08x\n", margining->results[1]);
1192 
1193 		if (margining->time) {
1194 			if (!margining->lanes || margining->lanes == 7) {
1195 				val = margining->results[1];
1196 				seq_puts(s, "# lane 0 right time margin: ");
1197 				time_margin_show(s, margining, val);
1198 				val = margining->results[1] >>
1199 					USB4_MARGIN_HW_RES_1_L0_LL_MARGIN_SHIFT;
1200 				seq_puts(s, "# lane 0 left time margin: ");
1201 				time_margin_show(s, margining, val);
1202 			}
1203 			if (margining->lanes == 1 || margining->lanes == 7) {
1204 				val = margining->results[1] >>
1205 					USB4_MARGIN_HW_RES_1_L1_RH_MARGIN_SHIFT;
1206 				seq_puts(s, "# lane 1 right time margin: ");
1207 				time_margin_show(s, margining, val);
1208 				val = margining->results[1] >>
1209 					USB4_MARGIN_HW_RES_1_L1_LL_MARGIN_SHIFT;
1210 				seq_puts(s, "# lane 1 left time margin: ");
1211 				time_margin_show(s, margining, val);
1212 			}
1213 		} else {
1214 			if (!margining->lanes || margining->lanes == 7) {
1215 				val = margining->results[1];
1216 				seq_puts(s, "# lane 0 high voltage margin: ");
1217 				voltage_margin_show(s, margining, val);
1218 				val = margining->results[1] >>
1219 					USB4_MARGIN_HW_RES_1_L0_LL_MARGIN_SHIFT;
1220 				seq_puts(s, "# lane 0 low voltage margin: ");
1221 				voltage_margin_show(s, margining, val);
1222 			}
1223 			if (margining->lanes == 1 || margining->lanes == 7) {
1224 				val = margining->results[1] >>
1225 					USB4_MARGIN_HW_RES_1_L1_RH_MARGIN_SHIFT;
1226 				seq_puts(s, "# lane 1 high voltage margin: ");
1227 				voltage_margin_show(s, margining, val);
1228 				val = margining->results[1] >>
1229 					USB4_MARGIN_HW_RES_1_L1_LL_MARGIN_SHIFT;
1230 				seq_puts(s, "# lane 1 low voltage margin: ");
1231 				voltage_margin_show(s, margining, val);
1232 			}
1233 		}
1234 	} else {
1235 		u32 lane_errors, result;
1236 
1237 		seq_printf(s, "0x%08x\n", margining->results[1]);
1238 		result = FIELD_GET(USB4_MARGIN_SW_LANES_MASK, margining->results[0]);
1239 
1240 		if (result == USB4_MARGIN_SW_LANE_0 ||
1241 		    result == USB4_MARGIN_SW_ALL_LANES) {
1242 			lane_errors = FIELD_GET(USB4_MARGIN_SW_ERR_COUNTER_LANE_0_MASK,
1243 						margining->results[1]);
1244 			seq_printf(s, "# lane 0 errors: %u\n", lane_errors);
1245 		}
1246 		if (result == USB4_MARGIN_SW_LANE_1 ||
1247 		    result == USB4_MARGIN_SW_ALL_LANES) {
1248 			lane_errors = FIELD_GET(USB4_MARGIN_SW_ERR_COUNTER_LANE_1_MASK,
1249 						margining->results[1]);
1250 			seq_printf(s, "# lane 1 errors: %u\n", lane_errors);
1251 		}
1252 	}
1253 
1254 	mutex_unlock(&tb->lock);
1255 	return 0;
1256 }
1257 DEBUGFS_ATTR_RW(margining_results);
1258 
1259 static ssize_t margining_test_write(struct file *file,
1260 				    const char __user *user_buf,
1261 				    size_t count, loff_t *ppos)
1262 {
1263 	struct seq_file *s = file->private_data;
1264 	struct tb_margining *margining = s->private;
1265 	struct tb *tb = margining->port->sw->tb;
1266 	int ret = 0;
1267 	char *buf;
1268 
1269 	buf = validate_and_copy_from_user(user_buf, &count);
1270 	if (IS_ERR(buf))
1271 		return PTR_ERR(buf);
1272 
1273 	buf[count - 1] = '\0';
1274 
1275 	if (mutex_lock_interruptible(&tb->lock)) {
1276 		ret = -ERESTARTSYS;
1277 		goto out_free;
1278 	}
1279 
1280 	if (!strcmp(buf, "time") && supports_time(margining))
1281 		margining->time = true;
1282 	else if (!strcmp(buf, "voltage"))
1283 		margining->time = false;
1284 	else
1285 		ret = -EINVAL;
1286 
1287 	mutex_unlock(&tb->lock);
1288 
1289 out_free:
1290 	free_page((unsigned long)buf);
1291 	return ret ? ret : count;
1292 }
1293 
1294 static int margining_test_show(struct seq_file *s, void *not_used)
1295 {
1296 	struct tb_margining *margining = s->private;
1297 	struct tb *tb = margining->port->sw->tb;
1298 
1299 	if (mutex_lock_interruptible(&tb->lock))
1300 		return -ERESTARTSYS;
1301 
1302 	if (supports_time(margining)) {
1303 		if (margining->time)
1304 			seq_puts(s, "voltage [time]\n");
1305 		else
1306 			seq_puts(s, "[voltage] time\n");
1307 	} else {
1308 		seq_puts(s, "[voltage]\n");
1309 	}
1310 
1311 	mutex_unlock(&tb->lock);
1312 	return 0;
1313 }
1314 DEBUGFS_ATTR_RW(margining_test);
1315 
1316 static ssize_t margining_margin_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 	int ret = 0;
1324 	char *buf;
1325 
1326 	buf = validate_and_copy_from_user(user_buf, &count);
1327 	if (IS_ERR(buf))
1328 		return PTR_ERR(buf);
1329 
1330 	buf[count - 1] = '\0';
1331 
1332 	if (mutex_lock_interruptible(&tb->lock)) {
1333 		ret = -ERESTARTSYS;
1334 		goto out_free;
1335 	}
1336 
1337 	if (margining->time) {
1338 		if (!strcmp(buf, "left"))
1339 			margining->right_high = false;
1340 		else if (!strcmp(buf, "right"))
1341 			margining->right_high = true;
1342 		else
1343 			ret = -EINVAL;
1344 	} else {
1345 		if (!strcmp(buf, "low"))
1346 			margining->right_high = false;
1347 		else if (!strcmp(buf, "high"))
1348 			margining->right_high = true;
1349 		else
1350 			ret = -EINVAL;
1351 	}
1352 
1353 	mutex_unlock(&tb->lock);
1354 
1355 out_free:
1356 	free_page((unsigned long)buf);
1357 	return ret ? ret : count;
1358 }
1359 
1360 static int margining_margin_show(struct seq_file *s, void *not_used)
1361 {
1362 	struct tb_margining *margining = s->private;
1363 	struct tb *tb = margining->port->sw->tb;
1364 
1365 	if (mutex_lock_interruptible(&tb->lock))
1366 		return -ERESTARTSYS;
1367 
1368 	if (margining->time) {
1369 		if (margining->right_high)
1370 			seq_puts(s, "left [right]\n");
1371 		else
1372 			seq_puts(s, "[left] right\n");
1373 	} else {
1374 		if (margining->right_high)
1375 			seq_puts(s, "low [high]\n");
1376 		else
1377 			seq_puts(s, "[low] high\n");
1378 	}
1379 
1380 	mutex_unlock(&tb->lock);
1381 	return 0;
1382 }
1383 DEBUGFS_ATTR_RW(margining_margin);
1384 
1385 static struct tb_margining *margining_alloc(struct tb_port *port,
1386 					    struct device *dev,
1387 					    enum usb4_sb_target target,
1388 					    u8 index, struct dentry *parent)
1389 {
1390 	struct tb_margining *margining;
1391 	struct dentry *dir;
1392 	unsigned int val;
1393 	int ret;
1394 
1395 	margining = kzalloc(sizeof(*margining), GFP_KERNEL);
1396 	if (!margining)
1397 		return NULL;
1398 
1399 	margining->port = port;
1400 	margining->target = target;
1401 	margining->index = index;
1402 	margining->dev = dev;
1403 
1404 	ret = usb4_port_margining_caps(port, target, index, margining->caps);
1405 	if (ret) {
1406 		kfree(margining);
1407 		return NULL;
1408 	}
1409 
1410 	/* Set the initial mode */
1411 	if (supports_software(margining))
1412 		margining->software = true;
1413 
1414 	val = FIELD_GET(USB4_MARGIN_CAP_0_VOLTAGE_STEPS_MASK, margining->caps[0]);
1415 	margining->voltage_steps = val;
1416 	val = FIELD_GET(USB4_MARGIN_CAP_0_MAX_VOLTAGE_OFFSET_MASK, margining->caps[0]);
1417 	margining->max_voltage_offset = 74 + val * 2;
1418 
1419 	if (supports_optional_voltage_offset_range(margining)) {
1420 		val = FIELD_GET(USB4_MARGIN_CAP_0_VOLT_STEPS_OPT_MASK,
1421 				margining->caps[0]);
1422 		margining->voltage_steps_optional_range = val;
1423 		val = FIELD_GET(USB4_MARGIN_CAP_1_MAX_VOLT_OFS_OPT_MASK,
1424 				margining->caps[1]);
1425 		margining->max_voltage_offset_optional_range = 74 + val * 2;
1426 	}
1427 
1428 	if (supports_time(margining)) {
1429 		val = FIELD_GET(USB4_MARGIN_CAP_1_TIME_STEPS_MASK, margining->caps[1]);
1430 		margining->time_steps = val;
1431 		val = FIELD_GET(USB4_MARGIN_CAP_1_TIME_OFFSET_MASK, margining->caps[1]);
1432 		/*
1433 		 * Store it as mUI (milli Unit Interval) because we want
1434 		 * to keep it as integer.
1435 		 */
1436 		margining->max_time_offset = 200 + 10 * val;
1437 	}
1438 
1439 	dir = debugfs_create_dir("margining", parent);
1440 	if (supports_hardware(margining)) {
1441 		val = FIELD_GET(USB4_MARGIN_CAP_1_MIN_BER_MASK, margining->caps[1]);
1442 		margining->min_ber_level = val;
1443 		val = FIELD_GET(USB4_MARGIN_CAP_1_MAX_BER_MASK, margining->caps[1]);
1444 		margining->max_ber_level = val;
1445 
1446 		/* Set the default to minimum */
1447 		margining->ber_level = margining->min_ber_level;
1448 
1449 		debugfs_create_file("ber_level_contour", 0400, dir, margining,
1450 				    &margining_ber_level_fops);
1451 	}
1452 	debugfs_create_file("caps", 0400, dir, margining, &margining_caps_fops);
1453 	debugfs_create_file("lanes", 0600, dir, margining, &margining_lanes_fops);
1454 	debugfs_create_file("mode", 0600, dir, margining, &margining_mode_fops);
1455 	debugfs_create_file("run", 0600, dir, margining, &margining_run_fops);
1456 	debugfs_create_file("results", 0600, dir, margining,
1457 			    &margining_results_fops);
1458 	debugfs_create_file("test", 0600, dir, margining, &margining_test_fops);
1459 	if (independent_voltage_margins(margining) == USB4_MARGIN_CAP_0_VOLTAGE_HL ||
1460 	    (supports_time(margining) &&
1461 	     independent_time_margins(margining) == USB4_MARGIN_CAP_1_TIME_LR))
1462 		debugfs_create_file("margin", 0600, dir, margining,
1463 				    &margining_margin_fops);
1464 
1465 	margining->error_counter = USB4_MARGIN_SW_ERROR_COUNTER_CLEAR;
1466 	margining->dwell_time = MIN_DWELL_TIME;
1467 
1468 	if (supports_optional_voltage_offset_range(margining))
1469 		debugfs_create_file("optional_voltage_offset", DEBUGFS_MODE, dir, margining,
1470 				    &margining_optional_voltage_offset_fops);
1471 
1472 	if (supports_software(margining)) {
1473 		debugfs_create_file("voltage_time_offset", DEBUGFS_MODE, dir, margining,
1474 				    &margining_voltage_time_offset_fops);
1475 		debugfs_create_file("error_counter", DEBUGFS_MODE, dir, margining,
1476 				    &margining_error_counter_fops);
1477 		debugfs_create_file("dwell_time", DEBUGFS_MODE, dir, margining,
1478 				    &margining_dwell_time_fops);
1479 	}
1480 	return margining;
1481 }
1482 
1483 static void margining_port_init(struct tb_port *port)
1484 {
1485 	struct dentry *parent;
1486 	char dir_name[10];
1487 
1488 	if (!port->usb4)
1489 		return;
1490 
1491 	snprintf(dir_name, sizeof(dir_name), "port%d", port->port);
1492 	parent = debugfs_lookup(dir_name, port->sw->debugfs_dir);
1493 	port->usb4->margining = margining_alloc(port, &port->usb4->dev,
1494 						USB4_SB_TARGET_ROUTER, 0,
1495 						parent);
1496 }
1497 
1498 static void margining_port_remove(struct tb_port *port)
1499 {
1500 	struct dentry *parent;
1501 	char dir_name[10];
1502 
1503 	if (!port->usb4)
1504 		return;
1505 
1506 	snprintf(dir_name, sizeof(dir_name), "port%d", port->port);
1507 	parent = debugfs_lookup(dir_name, port->sw->debugfs_dir);
1508 	if (parent)
1509 		debugfs_lookup_and_remove("margining", parent);
1510 
1511 	kfree(port->usb4->margining);
1512 	port->usb4->margining = NULL;
1513 }
1514 
1515 static void margining_switch_init(struct tb_switch *sw)
1516 {
1517 	struct tb_port *upstream, *downstream;
1518 	struct tb_switch *parent_sw;
1519 	u64 route = tb_route(sw);
1520 
1521 	if (!route)
1522 		return;
1523 
1524 	upstream = tb_upstream_port(sw);
1525 	parent_sw = tb_switch_parent(sw);
1526 	downstream = tb_port_at(route, parent_sw);
1527 
1528 	margining_port_init(downstream);
1529 	margining_port_init(upstream);
1530 }
1531 
1532 static void margining_switch_remove(struct tb_switch *sw)
1533 {
1534 	struct tb_port *upstream, *downstream;
1535 	struct tb_switch *parent_sw;
1536 	u64 route = tb_route(sw);
1537 
1538 	if (!route)
1539 		return;
1540 
1541 	upstream = tb_upstream_port(sw);
1542 	parent_sw = tb_switch_parent(sw);
1543 	downstream = tb_port_at(route, parent_sw);
1544 
1545 	margining_port_remove(upstream);
1546 	margining_port_remove(downstream);
1547 }
1548 
1549 static void margining_xdomain_init(struct tb_xdomain *xd)
1550 {
1551 	struct tb_switch *parent_sw;
1552 	struct tb_port *downstream;
1553 
1554 	parent_sw = tb_xdomain_parent(xd);
1555 	downstream = tb_port_at(xd->route, parent_sw);
1556 
1557 	margining_port_init(downstream);
1558 }
1559 
1560 static void margining_xdomain_remove(struct tb_xdomain *xd)
1561 {
1562 	struct tb_switch *parent_sw;
1563 	struct tb_port *downstream;
1564 
1565 	parent_sw = tb_xdomain_parent(xd);
1566 	downstream = tb_port_at(xd->route, parent_sw);
1567 	margining_port_remove(downstream);
1568 }
1569 
1570 static void margining_retimer_init(struct tb_retimer *rt, struct dentry *debugfs_dir)
1571 {
1572 	rt->margining = margining_alloc(rt->port, &rt->dev,
1573 					USB4_SB_TARGET_RETIMER, rt->index,
1574 					debugfs_dir);
1575 }
1576 
1577 static void margining_retimer_remove(struct tb_retimer *rt)
1578 {
1579 	kfree(rt->margining);
1580 	rt->margining = NULL;
1581 }
1582 #else
1583 static inline void margining_switch_init(struct tb_switch *sw) { }
1584 static inline void margining_switch_remove(struct tb_switch *sw) { }
1585 static inline void margining_xdomain_init(struct tb_xdomain *xd) { }
1586 static inline void margining_xdomain_remove(struct tb_xdomain *xd) { }
1587 static inline void margining_retimer_init(struct tb_retimer *rt,
1588 					  struct dentry *debugfs_dir) { }
1589 static inline void margining_retimer_remove(struct tb_retimer *rt) { }
1590 #endif
1591 
1592 static int port_clear_all_counters(struct tb_port *port)
1593 {
1594 	u32 *buf;
1595 	int ret;
1596 
1597 	buf = kcalloc(COUNTER_SET_LEN * port->config.max_counters, sizeof(u32),
1598 		      GFP_KERNEL);
1599 	if (!buf)
1600 		return -ENOMEM;
1601 
1602 	ret = tb_port_write(port, buf, TB_CFG_COUNTERS, 0,
1603 			    COUNTER_SET_LEN * port->config.max_counters);
1604 	kfree(buf);
1605 
1606 	return ret;
1607 }
1608 
1609 static ssize_t counters_write(struct file *file, const char __user *user_buf,
1610 			      size_t count, loff_t *ppos)
1611 {
1612 	struct seq_file *s = file->private_data;
1613 	struct tb_port *port = s->private;
1614 	struct tb_switch *sw = port->sw;
1615 	struct tb *tb = port->sw->tb;
1616 	char *buf;
1617 	int ret;
1618 
1619 	buf = validate_and_copy_from_user(user_buf, &count);
1620 	if (IS_ERR(buf))
1621 		return PTR_ERR(buf);
1622 
1623 	pm_runtime_get_sync(&sw->dev);
1624 
1625 	if (mutex_lock_interruptible(&tb->lock)) {
1626 		ret = -ERESTARTSYS;
1627 		goto out;
1628 	}
1629 
1630 	/* If written delimiter only, clear all counters in one shot */
1631 	if (buf[0] == '\n') {
1632 		ret = port_clear_all_counters(port);
1633 	} else  {
1634 		char *line = buf;
1635 		u32 val, offset;
1636 
1637 		ret = -EINVAL;
1638 		while (parse_line(&line, &offset, &val, 1, 4)) {
1639 			ret = tb_port_write(port, &val, TB_CFG_COUNTERS,
1640 					    offset, 1);
1641 			if (ret)
1642 				break;
1643 		}
1644 	}
1645 
1646 	mutex_unlock(&tb->lock);
1647 
1648 out:
1649 	pm_runtime_mark_last_busy(&sw->dev);
1650 	pm_runtime_put_autosuspend(&sw->dev);
1651 	free_page((unsigned long)buf);
1652 
1653 	return ret < 0 ? ret : count;
1654 }
1655 
1656 static void cap_show_by_dw(struct seq_file *s, struct tb_switch *sw,
1657 			   struct tb_port *port, unsigned int cap,
1658 			   unsigned int offset, u8 cap_id, u8 vsec_id,
1659 			   int dwords)
1660 {
1661 	int i, ret;
1662 	u32 data;
1663 
1664 	for (i = 0; i < dwords; i++) {
1665 		if (port)
1666 			ret = tb_port_read(port, &data, TB_CFG_PORT, cap + offset + i, 1);
1667 		else
1668 			ret = tb_sw_read(sw, &data, TB_CFG_SWITCH, cap + offset + i, 1);
1669 		if (ret) {
1670 			seq_printf(s, "0x%04x <not accessible>\n", cap + offset + i);
1671 			continue;
1672 		}
1673 
1674 		seq_printf(s, "0x%04x %4d 0x%02x 0x%02x 0x%08x\n", cap + offset + i,
1675 			   offset + i, cap_id, vsec_id, data);
1676 	}
1677 }
1678 
1679 static void cap_show(struct seq_file *s, struct tb_switch *sw,
1680 		     struct tb_port *port, unsigned int cap, u8 cap_id,
1681 		     u8 vsec_id, int length)
1682 {
1683 	int ret, offset = 0;
1684 
1685 	while (length > 0) {
1686 		int i, dwords = min(length, TB_MAX_CONFIG_RW_LENGTH);
1687 		u32 data[TB_MAX_CONFIG_RW_LENGTH];
1688 
1689 		if (port)
1690 			ret = tb_port_read(port, data, TB_CFG_PORT, cap + offset,
1691 					   dwords);
1692 		else
1693 			ret = tb_sw_read(sw, data, TB_CFG_SWITCH, cap + offset, dwords);
1694 		if (ret) {
1695 			cap_show_by_dw(s, sw, port, cap, offset, cap_id, vsec_id, length);
1696 			return;
1697 		}
1698 
1699 		for (i = 0; i < dwords; i++) {
1700 			seq_printf(s, "0x%04x %4d 0x%02x 0x%02x 0x%08x\n",
1701 				   cap + offset + i, offset + i,
1702 				   cap_id, vsec_id, data[i]);
1703 		}
1704 
1705 		length -= dwords;
1706 		offset += dwords;
1707 	}
1708 }
1709 
1710 static void port_cap_show(struct tb_port *port, struct seq_file *s,
1711 			  unsigned int cap)
1712 {
1713 	struct tb_cap_any header;
1714 	u8 vsec_id = 0;
1715 	size_t length;
1716 	int ret;
1717 
1718 	ret = tb_port_read(port, &header, TB_CFG_PORT, cap, 1);
1719 	if (ret) {
1720 		seq_printf(s, "0x%04x <capability read failed>\n", cap);
1721 		return;
1722 	}
1723 
1724 	switch (header.basic.cap) {
1725 	case TB_PORT_CAP_PHY:
1726 		length = PORT_CAP_LANE_LEN;
1727 		break;
1728 
1729 	case TB_PORT_CAP_TIME1:
1730 		if (usb4_switch_version(port->sw) < 2)
1731 			length = PORT_CAP_TMU_V1_LEN;
1732 		else
1733 			length = PORT_CAP_TMU_V2_LEN;
1734 		break;
1735 
1736 	case TB_PORT_CAP_POWER:
1737 		length = PORT_CAP_POWER_LEN;
1738 		break;
1739 
1740 	case TB_PORT_CAP_ADAP:
1741 		if (tb_port_is_pcie_down(port) || tb_port_is_pcie_up(port)) {
1742 			if (usb4_switch_version(port->sw) < 2)
1743 				length = PORT_CAP_V1_PCIE_LEN;
1744 			else
1745 				length = PORT_CAP_V2_PCIE_LEN;
1746 		} else if (tb_port_is_dpin(port)) {
1747 			if (usb4_switch_version(port->sw) < 2)
1748 				length = PORT_CAP_DP_V1_LEN;
1749 			else
1750 				length = PORT_CAP_DP_V2_LEN;
1751 		} else if (tb_port_is_dpout(port)) {
1752 			length = PORT_CAP_DP_V1_LEN;
1753 		} else if (tb_port_is_usb3_down(port) ||
1754 			   tb_port_is_usb3_up(port)) {
1755 			length = PORT_CAP_USB3_LEN;
1756 		} else {
1757 			seq_printf(s, "0x%04x <unsupported capability 0x%02x>\n",
1758 				   cap, header.basic.cap);
1759 			return;
1760 		}
1761 		break;
1762 
1763 	case TB_PORT_CAP_VSE:
1764 		if (!header.extended_short.length) {
1765 			ret = tb_port_read(port, (u32 *)&header + 1, TB_CFG_PORT,
1766 					   cap + 1, 1);
1767 			if (ret) {
1768 				seq_printf(s, "0x%04x <capability read failed>\n",
1769 					   cap + 1);
1770 				return;
1771 			}
1772 			length = header.extended_long.length;
1773 			vsec_id = header.extended_short.vsec_id;
1774 		} else {
1775 			length = header.extended_short.length;
1776 			vsec_id = header.extended_short.vsec_id;
1777 		}
1778 		break;
1779 
1780 	case TB_PORT_CAP_USB4:
1781 		length = PORT_CAP_USB4_LEN;
1782 		break;
1783 
1784 	default:
1785 		seq_printf(s, "0x%04x <unsupported capability 0x%02x>\n",
1786 			   cap, header.basic.cap);
1787 		return;
1788 	}
1789 
1790 	cap_show(s, NULL, port, cap, header.basic.cap, vsec_id, length);
1791 }
1792 
1793 static void port_caps_show(struct tb_port *port, struct seq_file *s)
1794 {
1795 	int cap;
1796 
1797 	cap = tb_port_next_cap(port, 0);
1798 	while (cap > 0) {
1799 		port_cap_show(port, s, cap);
1800 		cap = tb_port_next_cap(port, cap);
1801 	}
1802 }
1803 
1804 static int port_basic_regs_show(struct tb_port *port, struct seq_file *s)
1805 {
1806 	u32 data[PORT_CAP_BASIC_LEN];
1807 	int ret, i;
1808 
1809 	ret = tb_port_read(port, data, TB_CFG_PORT, 0, ARRAY_SIZE(data));
1810 	if (ret)
1811 		return ret;
1812 
1813 	for (i = 0; i < ARRAY_SIZE(data); i++)
1814 		seq_printf(s, "0x%04x %4d 0x00 0x00 0x%08x\n", i, i, data[i]);
1815 
1816 	return 0;
1817 }
1818 
1819 static int port_regs_show(struct seq_file *s, void *not_used)
1820 {
1821 	struct tb_port *port = s->private;
1822 	struct tb_switch *sw = port->sw;
1823 	struct tb *tb = sw->tb;
1824 	int ret;
1825 
1826 	pm_runtime_get_sync(&sw->dev);
1827 
1828 	if (mutex_lock_interruptible(&tb->lock)) {
1829 		ret = -ERESTARTSYS;
1830 		goto out_rpm_put;
1831 	}
1832 
1833 	seq_puts(s, "# offset relative_offset cap_id vs_cap_id value\n");
1834 
1835 	ret = port_basic_regs_show(port, s);
1836 	if (ret)
1837 		goto out_unlock;
1838 
1839 	port_caps_show(port, s);
1840 
1841 out_unlock:
1842 	mutex_unlock(&tb->lock);
1843 out_rpm_put:
1844 	pm_runtime_mark_last_busy(&sw->dev);
1845 	pm_runtime_put_autosuspend(&sw->dev);
1846 
1847 	return ret;
1848 }
1849 DEBUGFS_ATTR_RW(port_regs);
1850 
1851 static void switch_cap_show(struct tb_switch *sw, struct seq_file *s,
1852 			    unsigned int cap)
1853 {
1854 	struct tb_cap_any header;
1855 	int ret, length;
1856 	u8 vsec_id = 0;
1857 
1858 	ret = tb_sw_read(sw, &header, TB_CFG_SWITCH, cap, 1);
1859 	if (ret) {
1860 		seq_printf(s, "0x%04x <capability read failed>\n", cap);
1861 		return;
1862 	}
1863 
1864 	if (header.basic.cap == TB_SWITCH_CAP_VSE) {
1865 		if (!header.extended_short.length) {
1866 			ret = tb_sw_read(sw, (u32 *)&header + 1, TB_CFG_SWITCH,
1867 					 cap + 1, 1);
1868 			if (ret) {
1869 				seq_printf(s, "0x%04x <capability read failed>\n",
1870 					   cap + 1);
1871 				return;
1872 			}
1873 			length = header.extended_long.length;
1874 		} else {
1875 			length = header.extended_short.length;
1876 		}
1877 		vsec_id = header.extended_short.vsec_id;
1878 	} else {
1879 		if (header.basic.cap == TB_SWITCH_CAP_TMU) {
1880 			length = SWITCH_CAP_TMU_LEN;
1881 		} else  {
1882 			seq_printf(s, "0x%04x <unknown capability 0x%02x>\n",
1883 				   cap, header.basic.cap);
1884 			return;
1885 		}
1886 	}
1887 
1888 	cap_show(s, sw, NULL, cap, header.basic.cap, vsec_id, length);
1889 }
1890 
1891 static void switch_caps_show(struct tb_switch *sw, struct seq_file *s)
1892 {
1893 	int cap;
1894 
1895 	cap = tb_switch_next_cap(sw, 0);
1896 	while (cap > 0) {
1897 		switch_cap_show(sw, s, cap);
1898 		cap = tb_switch_next_cap(sw, cap);
1899 	}
1900 }
1901 
1902 static int switch_basic_regs_show(struct tb_switch *sw, struct seq_file *s)
1903 {
1904 	u32 data[SWITCH_CAP_BASIC_LEN];
1905 	size_t dwords;
1906 	int ret, i;
1907 
1908 	/* Only USB4 has the additional registers */
1909 	if (tb_switch_is_usb4(sw))
1910 		dwords = ARRAY_SIZE(data);
1911 	else
1912 		dwords = 5;
1913 
1914 	ret = tb_sw_read(sw, data, TB_CFG_SWITCH, 0, dwords);
1915 	if (ret)
1916 		return ret;
1917 
1918 	for (i = 0; i < dwords; i++)
1919 		seq_printf(s, "0x%04x %4d 0x00 0x00 0x%08x\n", i, i, data[i]);
1920 
1921 	return 0;
1922 }
1923 
1924 static int switch_regs_show(struct seq_file *s, void *not_used)
1925 {
1926 	struct tb_switch *sw = s->private;
1927 	struct tb *tb = sw->tb;
1928 	int ret;
1929 
1930 	pm_runtime_get_sync(&sw->dev);
1931 
1932 	if (mutex_lock_interruptible(&tb->lock)) {
1933 		ret = -ERESTARTSYS;
1934 		goto out_rpm_put;
1935 	}
1936 
1937 	seq_puts(s, "# offset relative_offset cap_id vs_cap_id value\n");
1938 
1939 	ret = switch_basic_regs_show(sw, s);
1940 	if (ret)
1941 		goto out_unlock;
1942 
1943 	switch_caps_show(sw, s);
1944 
1945 out_unlock:
1946 	mutex_unlock(&tb->lock);
1947 out_rpm_put:
1948 	pm_runtime_mark_last_busy(&sw->dev);
1949 	pm_runtime_put_autosuspend(&sw->dev);
1950 
1951 	return ret;
1952 }
1953 DEBUGFS_ATTR_RW(switch_regs);
1954 
1955 static int path_show_one(struct tb_port *port, struct seq_file *s, int hopid)
1956 {
1957 	u32 data[PATH_LEN];
1958 	int ret, i;
1959 
1960 	ret = tb_port_read(port, data, TB_CFG_HOPS, hopid * PATH_LEN,
1961 			   ARRAY_SIZE(data));
1962 	if (ret) {
1963 		seq_printf(s, "0x%04x <not accessible>\n", hopid * PATH_LEN);
1964 		return ret;
1965 	}
1966 
1967 	for (i = 0; i < ARRAY_SIZE(data); i++) {
1968 		seq_printf(s, "0x%04x %4d 0x%02x 0x%08x\n",
1969 			   hopid * PATH_LEN + i, i, hopid, data[i]);
1970 	}
1971 
1972 	return 0;
1973 }
1974 
1975 static int path_show(struct seq_file *s, void *not_used)
1976 {
1977 	struct tb_port *port = s->private;
1978 	struct tb_switch *sw = port->sw;
1979 	struct tb *tb = sw->tb;
1980 	int start, i, ret = 0;
1981 
1982 	pm_runtime_get_sync(&sw->dev);
1983 
1984 	if (mutex_lock_interruptible(&tb->lock)) {
1985 		ret = -ERESTARTSYS;
1986 		goto out_rpm_put;
1987 	}
1988 
1989 	seq_puts(s, "# offset relative_offset in_hop_id value\n");
1990 
1991 	/* NHI and lane adapters have entry for path 0 */
1992 	if (tb_port_is_null(port) || tb_port_is_nhi(port)) {
1993 		ret = path_show_one(port, s, 0);
1994 		if (ret)
1995 			goto out_unlock;
1996 	}
1997 
1998 	start = tb_port_is_nhi(port) ? 1 : TB_PATH_MIN_HOPID;
1999 
2000 	for (i = start; i <= port->config.max_in_hop_id; i++) {
2001 		ret = path_show_one(port, s, i);
2002 		if (ret)
2003 			break;
2004 	}
2005 
2006 out_unlock:
2007 	mutex_unlock(&tb->lock);
2008 out_rpm_put:
2009 	pm_runtime_mark_last_busy(&sw->dev);
2010 	pm_runtime_put_autosuspend(&sw->dev);
2011 
2012 	return ret;
2013 }
2014 DEBUGFS_ATTR_RO(path);
2015 
2016 static int counter_set_regs_show(struct tb_port *port, struct seq_file *s,
2017 				 int counter)
2018 {
2019 	u32 data[COUNTER_SET_LEN];
2020 	int ret, i;
2021 
2022 	ret = tb_port_read(port, data, TB_CFG_COUNTERS,
2023 			   counter * COUNTER_SET_LEN, ARRAY_SIZE(data));
2024 	if (ret) {
2025 		seq_printf(s, "0x%04x <not accessible>\n",
2026 			   counter * COUNTER_SET_LEN);
2027 		return ret;
2028 	}
2029 
2030 	for (i = 0; i < ARRAY_SIZE(data); i++) {
2031 		seq_printf(s, "0x%04x %4d 0x%02x 0x%08x\n",
2032 			   counter * COUNTER_SET_LEN + i, i, counter, data[i]);
2033 	}
2034 
2035 	return 0;
2036 }
2037 
2038 static int counters_show(struct seq_file *s, void *not_used)
2039 {
2040 	struct tb_port *port = s->private;
2041 	struct tb_switch *sw = port->sw;
2042 	struct tb *tb = sw->tb;
2043 	int i, ret = 0;
2044 
2045 	pm_runtime_get_sync(&sw->dev);
2046 
2047 	if (mutex_lock_interruptible(&tb->lock)) {
2048 		ret = -ERESTARTSYS;
2049 		goto out;
2050 	}
2051 
2052 	seq_puts(s, "# offset relative_offset counter_id value\n");
2053 
2054 	for (i = 0; i < port->config.max_counters; i++) {
2055 		ret = counter_set_regs_show(port, s, i);
2056 		if (ret)
2057 			break;
2058 	}
2059 
2060 	mutex_unlock(&tb->lock);
2061 
2062 out:
2063 	pm_runtime_mark_last_busy(&sw->dev);
2064 	pm_runtime_put_autosuspend(&sw->dev);
2065 
2066 	return ret;
2067 }
2068 DEBUGFS_ATTR_RW(counters);
2069 
2070 static int sb_regs_show(struct tb_port *port, const struct sb_reg *sb_regs,
2071 			size_t size, enum usb4_sb_target target, u8 index,
2072 			struct seq_file *s)
2073 {
2074 	int ret, i;
2075 
2076 	seq_puts(s, "# register value\n");
2077 
2078 	for (i = 0; i < size; i++) {
2079 		const struct sb_reg *regs = &sb_regs[i];
2080 		u8 data[64];
2081 		int j;
2082 
2083 		memset(data, 0, sizeof(data));
2084 		ret = usb4_port_sb_read(port, target, index, regs->reg, data,
2085 					regs->size);
2086 		if (ret)
2087 			return ret;
2088 
2089 		seq_printf(s, "0x%02x", regs->reg);
2090 		for (j = 0; j < regs->size; j++)
2091 			seq_printf(s, " 0x%02x", data[j]);
2092 		seq_puts(s, "\n");
2093 	}
2094 
2095 	return 0;
2096 }
2097 
2098 static int port_sb_regs_show(struct seq_file *s, void *not_used)
2099 {
2100 	struct tb_port *port = s->private;
2101 	struct tb_switch *sw = port->sw;
2102 	struct tb *tb = sw->tb;
2103 	int ret;
2104 
2105 	pm_runtime_get_sync(&sw->dev);
2106 
2107 	if (mutex_lock_interruptible(&tb->lock)) {
2108 		ret = -ERESTARTSYS;
2109 		goto out_rpm_put;
2110 	}
2111 
2112 	ret = sb_regs_show(port, port_sb_regs, ARRAY_SIZE(port_sb_regs),
2113 			   USB4_SB_TARGET_ROUTER, 0, s);
2114 
2115 	mutex_unlock(&tb->lock);
2116 out_rpm_put:
2117 	pm_runtime_mark_last_busy(&sw->dev);
2118 	pm_runtime_put_autosuspend(&sw->dev);
2119 
2120 	return ret;
2121 }
2122 DEBUGFS_ATTR_RW(port_sb_regs);
2123 
2124 /**
2125  * tb_switch_debugfs_init() - Add debugfs entries for router
2126  * @sw: Pointer to the router
2127  *
2128  * Adds debugfs directories and files for given router.
2129  */
2130 void tb_switch_debugfs_init(struct tb_switch *sw)
2131 {
2132 	struct dentry *debugfs_dir;
2133 	struct tb_port *port;
2134 
2135 	debugfs_dir = debugfs_create_dir(dev_name(&sw->dev), tb_debugfs_root);
2136 	sw->debugfs_dir = debugfs_dir;
2137 	debugfs_create_file("regs", DEBUGFS_MODE, debugfs_dir, sw,
2138 			    &switch_regs_fops);
2139 
2140 	tb_switch_for_each_port(sw, port) {
2141 		struct dentry *debugfs_dir;
2142 		char dir_name[10];
2143 
2144 		if (port->disabled)
2145 			continue;
2146 		if (port->config.type == TB_TYPE_INACTIVE)
2147 			continue;
2148 
2149 		snprintf(dir_name, sizeof(dir_name), "port%d", port->port);
2150 		debugfs_dir = debugfs_create_dir(dir_name, sw->debugfs_dir);
2151 		debugfs_create_file("regs", DEBUGFS_MODE, debugfs_dir,
2152 				    port, &port_regs_fops);
2153 		debugfs_create_file("path", 0400, debugfs_dir, port,
2154 				    &path_fops);
2155 		if (port->config.counters_support)
2156 			debugfs_create_file("counters", 0600, debugfs_dir, port,
2157 					    &counters_fops);
2158 		if (port->usb4)
2159 			debugfs_create_file("sb_regs", DEBUGFS_MODE, debugfs_dir,
2160 					    port, &port_sb_regs_fops);
2161 	}
2162 
2163 	margining_switch_init(sw);
2164 }
2165 
2166 /**
2167  * tb_switch_debugfs_remove() - Remove all router debugfs entries
2168  * @sw: Pointer to the router
2169  *
2170  * Removes all previously added debugfs entries under this router.
2171  */
2172 void tb_switch_debugfs_remove(struct tb_switch *sw)
2173 {
2174 	margining_switch_remove(sw);
2175 	debugfs_remove_recursive(sw->debugfs_dir);
2176 }
2177 
2178 void tb_xdomain_debugfs_init(struct tb_xdomain *xd)
2179 {
2180 	margining_xdomain_init(xd);
2181 }
2182 
2183 void tb_xdomain_debugfs_remove(struct tb_xdomain *xd)
2184 {
2185 	margining_xdomain_remove(xd);
2186 }
2187 
2188 /**
2189  * tb_service_debugfs_init() - Add debugfs directory for service
2190  * @svc: Thunderbolt service pointer
2191  *
2192  * Adds debugfs directory for service.
2193  */
2194 void tb_service_debugfs_init(struct tb_service *svc)
2195 {
2196 	svc->debugfs_dir = debugfs_create_dir(dev_name(&svc->dev),
2197 					      tb_debugfs_root);
2198 }
2199 
2200 /**
2201  * tb_service_debugfs_remove() - Remove service debugfs directory
2202  * @svc: Thunderbolt service pointer
2203  *
2204  * Removes the previously created debugfs directory for @svc.
2205  */
2206 void tb_service_debugfs_remove(struct tb_service *svc)
2207 {
2208 	debugfs_remove_recursive(svc->debugfs_dir);
2209 	svc->debugfs_dir = NULL;
2210 }
2211 
2212 static int retimer_sb_regs_show(struct seq_file *s, void *not_used)
2213 {
2214 	struct tb_retimer *rt = s->private;
2215 	struct tb *tb = rt->tb;
2216 	int ret;
2217 
2218 	pm_runtime_get_sync(&rt->dev);
2219 
2220 	if (mutex_lock_interruptible(&tb->lock)) {
2221 		ret = -ERESTARTSYS;
2222 		goto out_rpm_put;
2223 	}
2224 
2225 	ret = sb_regs_show(rt->port, retimer_sb_regs, ARRAY_SIZE(retimer_sb_regs),
2226 			   USB4_SB_TARGET_RETIMER, rt->index, s);
2227 
2228 	mutex_unlock(&tb->lock);
2229 out_rpm_put:
2230 	pm_runtime_mark_last_busy(&rt->dev);
2231 	pm_runtime_put_autosuspend(&rt->dev);
2232 
2233 	return ret;
2234 }
2235 DEBUGFS_ATTR_RW(retimer_sb_regs);
2236 
2237 /**
2238  * tb_retimer_debugfs_init() - Add debugfs directory for retimer
2239  * @rt: Pointer to retimer structure
2240  *
2241  * Adds and populates retimer debugfs directory.
2242  */
2243 void tb_retimer_debugfs_init(struct tb_retimer *rt)
2244 {
2245 	struct dentry *debugfs_dir;
2246 
2247 	debugfs_dir = debugfs_create_dir(dev_name(&rt->dev), tb_debugfs_root);
2248 	debugfs_create_file("sb_regs", DEBUGFS_MODE, debugfs_dir, rt,
2249 			    &retimer_sb_regs_fops);
2250 	margining_retimer_init(rt, debugfs_dir);
2251 }
2252 
2253 /**
2254  * tb_retimer_debugfs_remove() - Remove retimer debugfs directory
2255  * @rt: Pointer to retimer structure
2256  *
2257  * Removes the retimer debugfs directory along with its contents.
2258  */
2259 void tb_retimer_debugfs_remove(struct tb_retimer *rt)
2260 {
2261 	debugfs_lookup_and_remove(dev_name(&rt->dev), tb_debugfs_root);
2262 	margining_retimer_remove(rt);
2263 }
2264 
2265 void tb_debugfs_init(void)
2266 {
2267 	tb_debugfs_root = debugfs_create_dir("thunderbolt", NULL);
2268 }
2269 
2270 void tb_debugfs_exit(void)
2271 {
2272 	debugfs_remove_recursive(tb_debugfs_root);
2273 }
2274