xref: /linux/drivers/thunderbolt/debugfs.c (revision 87ee9981d1f86ee9b1623a46c7f9e4ac24461fe4)
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/pm_runtime.h>
13 #include <linux/uaccess.h>
14 
15 #include "tb.h"
16 #include "sb_regs.h"
17 
18 #define PORT_CAP_V1_PCIE_LEN	1
19 #define PORT_CAP_V2_PCIE_LEN	2
20 #define PORT_CAP_POWER_LEN	2
21 #define PORT_CAP_LANE_LEN	3
22 #define PORT_CAP_USB3_LEN	5
23 #define PORT_CAP_DP_V1_LEN	9
24 #define PORT_CAP_DP_V2_LEN	14
25 #define PORT_CAP_TMU_V1_LEN	8
26 #define PORT_CAP_TMU_V2_LEN	10
27 #define PORT_CAP_BASIC_LEN	9
28 #define PORT_CAP_USB4_LEN	20
29 
30 #define SWITCH_CAP_TMU_LEN	26
31 #define SWITCH_CAP_BASIC_LEN	27
32 
33 #define PATH_LEN		2
34 
35 #define COUNTER_SET_LEN		3
36 
37 /* Sideband registers and their sizes as defined in the USB4 spec */
38 struct sb_reg {
39 	unsigned int reg;
40 	unsigned int size;
41 };
42 
43 #define SB_MAX_SIZE		64
44 
45 /* Sideband registers for router */
46 static const struct sb_reg port_sb_regs[] = {
47 	{ USB4_SB_VENDOR_ID, 4 },
48 	{ USB4_SB_PRODUCT_ID, 4 },
49 	{ USB4_SB_DEBUG_CONF, 4 },
50 	{ USB4_SB_DEBUG, 54 },
51 	{ USB4_SB_LRD_TUNING, 4 },
52 	{ USB4_SB_OPCODE, 4 },
53 	{ USB4_SB_METADATA, 4 },
54 	{ USB4_SB_LINK_CONF, 3 },
55 	{ USB4_SB_GEN23_TXFFE, 4 },
56 	{ USB4_SB_GEN4_TXFFE, 4 },
57 	{ USB4_SB_VERSION, 4 },
58 	{ USB4_SB_DATA, 64 },
59 };
60 
61 /* Sideband registers for retimer */
62 static const struct sb_reg retimer_sb_regs[] = {
63 	{ USB4_SB_VENDOR_ID, 4 },
64 	{ USB4_SB_PRODUCT_ID, 4 },
65 	{ USB4_SB_FW_VERSION, 4 },
66 	{ USB4_SB_LRD_TUNING, 4 },
67 	{ USB4_SB_OPCODE, 4 },
68 	{ USB4_SB_METADATA, 4 },
69 	{ USB4_SB_GEN23_TXFFE, 4 },
70 	{ USB4_SB_GEN4_TXFFE, 4 },
71 	{ USB4_SB_VERSION, 4 },
72 	{ USB4_SB_DATA, 64 },
73 };
74 
75 #define DEBUGFS_ATTR(__space, __write)					\
76 static int __space ## _open(struct inode *inode, struct file *file)	\
77 {									\
78 	return single_open(file, __space ## _show, inode->i_private);	\
79 }									\
80 									\
81 static const struct file_operations __space ## _fops = {		\
82 	.owner = THIS_MODULE,						\
83 	.open = __space ## _open,					\
84 	.release = single_release,					\
85 	.read  = seq_read,						\
86 	.write = __write,						\
87 	.llseek = seq_lseek,						\
88 }
89 
90 #define DEBUGFS_ATTR_RO(__space)					\
91 	DEBUGFS_ATTR(__space, NULL)
92 
93 #define DEBUGFS_ATTR_RW(__space)					\
94 	DEBUGFS_ATTR(__space, __space ## _write)
95 
96 static struct dentry *tb_debugfs_root;
97 
98 static void *validate_and_copy_from_user(const void __user *user_buf,
99 					 size_t *count)
100 {
101 	size_t nbytes;
102 	void *buf;
103 
104 	if (!*count)
105 		return ERR_PTR(-EINVAL);
106 
107 	if (!access_ok(user_buf, *count))
108 		return ERR_PTR(-EFAULT);
109 
110 	buf = (void *)get_zeroed_page(GFP_KERNEL);
111 	if (!buf)
112 		return ERR_PTR(-ENOMEM);
113 
114 	nbytes = min_t(size_t, *count, PAGE_SIZE);
115 	if (copy_from_user(buf, user_buf, nbytes)) {
116 		free_page((unsigned long)buf);
117 		return ERR_PTR(-EFAULT);
118 	}
119 
120 	*count = nbytes;
121 	return buf;
122 }
123 
124 static bool parse_line(char **line, u32 *offs, u32 *val, int short_fmt_len,
125 		       int long_fmt_len)
126 {
127 	char *token;
128 	u32 v[5];
129 	int ret;
130 
131 	token = strsep(line, "\n");
132 	if (!token)
133 		return false;
134 
135 	/*
136 	 * For Adapter/Router configuration space:
137 	 * Short format is: offset value\n
138 	 *		    v[0]   v[1]
139 	 * Long format as produced from the read side:
140 	 * offset relative_offset cap_id vs_cap_id value\n
141 	 * v[0]   v[1]            v[2]   v[3]      v[4]
142 	 *
143 	 * For Counter configuration space:
144 	 * Short format is: offset\n
145 	 *		    v[0]
146 	 * Long format as produced from the read side:
147 	 * offset relative_offset counter_id value\n
148 	 * v[0]   v[1]            v[2]       v[3]
149 	 */
150 	ret = sscanf(token, "%i %i %i %i %i", &v[0], &v[1], &v[2], &v[3], &v[4]);
151 	/* In case of Counters, clear counter, "val" content is NA */
152 	if (ret == short_fmt_len) {
153 		*offs = v[0];
154 		*val = v[short_fmt_len - 1];
155 		return true;
156 	} else if (ret == long_fmt_len) {
157 		*offs = v[0];
158 		*val = v[long_fmt_len - 1];
159 		return true;
160 	}
161 
162 	return false;
163 }
164 
165 #if IS_ENABLED(CONFIG_USB4_DEBUGFS_WRITE)
166 static ssize_t regs_write(struct tb_switch *sw, struct tb_port *port,
167 			  const char __user *user_buf, size_t count,
168 			  loff_t *ppos)
169 {
170 	struct tb *tb = sw->tb;
171 	char *line, *buf;
172 	u32 val, offset;
173 	int ret = 0;
174 
175 	buf = validate_and_copy_from_user(user_buf, &count);
176 	if (IS_ERR(buf))
177 		return PTR_ERR(buf);
178 
179 	pm_runtime_get_sync(&sw->dev);
180 
181 	if (mutex_lock_interruptible(&tb->lock)) {
182 		ret = -ERESTARTSYS;
183 		goto out;
184 	}
185 
186 	/* User did hardware changes behind the driver's back */
187 	add_taint(TAINT_USER, LOCKDEP_STILL_OK);
188 
189 	line = buf;
190 	while (parse_line(&line, &offset, &val, 2, 5)) {
191 		if (port)
192 			ret = tb_port_write(port, &val, TB_CFG_PORT, offset, 1);
193 		else
194 			ret = tb_sw_write(sw, &val, TB_CFG_SWITCH, offset, 1);
195 		if (ret)
196 			break;
197 	}
198 
199 	mutex_unlock(&tb->lock);
200 
201 out:
202 	pm_runtime_mark_last_busy(&sw->dev);
203 	pm_runtime_put_autosuspend(&sw->dev);
204 	free_page((unsigned long)buf);
205 
206 	return ret < 0 ? ret : count;
207 }
208 
209 static ssize_t port_regs_write(struct file *file, const char __user *user_buf,
210 			       size_t count, loff_t *ppos)
211 {
212 	struct seq_file *s = file->private_data;
213 	struct tb_port *port = s->private;
214 
215 	return regs_write(port->sw, port, user_buf, count, ppos);
216 }
217 
218 static ssize_t switch_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_switch *sw = s->private;
223 
224 	return regs_write(sw, NULL, user_buf, count, ppos);
225 }
226 
227 static bool parse_sb_line(char **line, u8 *reg, u8 *data, size_t data_size,
228 			  size_t *bytes_read)
229 {
230 	char *field, *token;
231 	int i;
232 
233 	token = strsep(line, "\n");
234 	if (!token)
235 		return false;
236 
237 	/* Parse the register first */
238 	field = strsep(&token, " ");
239 	if (!field)
240 		return false;
241 	if (kstrtou8(field, 0, reg))
242 		return false;
243 
244 	/* Then the values for the register, up to data_size */
245 	for (i = 0; i < data_size; i++) {
246 		field = strsep(&token, " ");
247 		if (!field)
248 			break;
249 		if (kstrtou8(field, 0, &data[i]))
250 			return false;
251 	}
252 
253 	*bytes_read = i;
254 	return true;
255 }
256 
257 static ssize_t sb_regs_write(struct tb_port *port, const struct sb_reg *sb_regs,
258 			     size_t size, enum usb4_sb_target target, u8 index,
259 			     char *buf, size_t count, loff_t *ppos)
260 {
261 	u8 reg, data[SB_MAX_SIZE];
262 	size_t bytes_read;
263 	char *line = buf;
264 
265 	/* User did hardware changes behind the driver's back */
266 	add_taint(TAINT_USER, LOCKDEP_STILL_OK);
267 
268 	/*
269 	 * For sideband registers we accept:
270 	 * reg b0 b1 b2...\n
271 	 *
272 	 * Here "reg" is the byte offset of the sideband register and "b0"..
273 	 * are the byte values. There can be less byte values than the register
274 	 * size. The leftovers will not be overwritten.
275 	 */
276 	while (parse_sb_line(&line, &reg, data, ARRAY_SIZE(data), &bytes_read)) {
277 		const struct sb_reg *sb_reg;
278 		int ret;
279 
280 		/* At least one byte must be passed */
281 		if (bytes_read < 1)
282 			return -EINVAL;
283 
284 		/* Find the register */
285 		sb_reg = NULL;
286 		for (int i = 0; i < size; i++) {
287 			if (sb_regs[i].reg == reg) {
288 				sb_reg = &sb_regs[i];
289 				break;
290 			}
291 		}
292 
293 		if (!sb_reg)
294 			return -EINVAL;
295 
296 		if (bytes_read > sb_regs->size)
297 			return -E2BIG;
298 
299 		ret = usb4_port_sb_write(port, target, index, sb_reg->reg, data,
300 					 bytes_read);
301 		if (ret)
302 			return ret;
303 	}
304 
305 	return 0;
306 }
307 
308 static ssize_t port_sb_regs_write(struct file *file, const char __user *user_buf,
309 				  size_t count, loff_t *ppos)
310 {
311 	struct seq_file *s = file->private_data;
312 	struct tb_port *port = s->private;
313 	struct tb_switch *sw = port->sw;
314 	struct tb *tb = sw->tb;
315 	char *buf;
316 	int ret;
317 
318 	buf = validate_and_copy_from_user(user_buf, &count);
319 	if (IS_ERR(buf))
320 		return PTR_ERR(buf);
321 
322 	pm_runtime_get_sync(&sw->dev);
323 
324 	if (mutex_lock_interruptible(&tb->lock)) {
325 		ret = -ERESTARTSYS;
326 		goto out;
327 	}
328 
329 	ret = sb_regs_write(port, port_sb_regs, ARRAY_SIZE(port_sb_regs),
330 			    USB4_SB_TARGET_ROUTER, 0, buf, count, ppos);
331 
332 	mutex_unlock(&tb->lock);
333 out:
334 	pm_runtime_mark_last_busy(&sw->dev);
335 	pm_runtime_put_autosuspend(&sw->dev);
336 	free_page((unsigned long)buf);
337 
338 	return ret < 0 ? ret : count;
339 }
340 
341 static ssize_t retimer_sb_regs_write(struct file *file,
342 				     const char __user *user_buf,
343 				     size_t count, loff_t *ppos)
344 {
345 	struct seq_file *s = file->private_data;
346 	struct tb_retimer *rt = s->private;
347 	struct tb *tb = rt->tb;
348 	char *buf;
349 	int ret;
350 
351 	buf = validate_and_copy_from_user(user_buf, &count);
352 	if (IS_ERR(buf))
353 		return PTR_ERR(buf);
354 
355 	pm_runtime_get_sync(&rt->dev);
356 
357 	if (mutex_lock_interruptible(&tb->lock)) {
358 		ret = -ERESTARTSYS;
359 		goto out;
360 	}
361 
362 	ret = sb_regs_write(rt->port, retimer_sb_regs, ARRAY_SIZE(retimer_sb_regs),
363 			    USB4_SB_TARGET_RETIMER, rt->index, buf, count, ppos);
364 
365 	mutex_unlock(&tb->lock);
366 out:
367 	pm_runtime_mark_last_busy(&rt->dev);
368 	pm_runtime_put_autosuspend(&rt->dev);
369 	free_page((unsigned long)buf);
370 
371 	return ret < 0 ? ret : count;
372 }
373 #define DEBUGFS_MODE		0600
374 #else
375 #define port_regs_write		NULL
376 #define switch_regs_write	NULL
377 #define port_sb_regs_write	NULL
378 #define retimer_sb_regs_write	NULL
379 #define DEBUGFS_MODE		0400
380 #endif
381 
382 #if IS_ENABLED(CONFIG_USB4_DEBUGFS_MARGINING)
383 /**
384  * struct tb_margining - Lane margining support
385  * @port: USB4 port through which the margining operations are run
386  * @target: Sideband target
387  * @index: Retimer index if taget is %USB4_SB_TARGET_RETIMER
388  * @dev: Pointer to the device that is the target (USB4 port or retimer)
389  * @caps: Port lane margining capabilities
390  * @results: Last lane margining results
391  * @lanes: %0, %1 or %7 (all)
392  * @min_ber_level: Minimum supported BER level contour value
393  * @max_ber_level: Maximum supported BER level contour value
394  * @ber_level: Current BER level contour value
395  * @voltage_steps: Number of mandatory voltage steps
396  * @max_voltage_offset: Maximum mandatory voltage offset (in mV)
397  * @time_steps: Number of time margin steps
398  * @max_time_offset: Maximum time margin offset (in mUI)
399  * @software: %true if software margining is used instead of hardware
400  * @time: %true if time margining is used instead of voltage
401  * @right_high: %false if left/low margin test is performed, %true if
402  *		right/high
403  */
404 struct tb_margining {
405 	struct tb_port *port;
406 	enum usb4_sb_target target;
407 	u8 index;
408 	struct device *dev;
409 	u32 caps[2];
410 	u32 results[2];
411 	unsigned int lanes;
412 	unsigned int min_ber_level;
413 	unsigned int max_ber_level;
414 	unsigned int ber_level;
415 	unsigned int voltage_steps;
416 	unsigned int max_voltage_offset;
417 	unsigned int time_steps;
418 	unsigned int max_time_offset;
419 	bool software;
420 	bool time;
421 	bool right_high;
422 };
423 
424 static bool supports_software(const struct tb_margining *margining)
425 {
426 	return margining->caps[0] & USB4_MARGIN_CAP_0_MODES_SW;
427 }
428 
429 static bool supports_hardware(const struct tb_margining *margining)
430 {
431 	return margining->caps[0] & USB4_MARGIN_CAP_0_MODES_HW;
432 }
433 
434 static bool both_lanes(const struct tb_margining *margining)
435 {
436 	return margining->caps[0] & USB4_MARGIN_CAP_0_2_LANES;
437 }
438 
439 static unsigned int
440 independent_voltage_margins(const struct tb_margining *margining)
441 {
442 	return FIELD_GET(USB4_MARGIN_CAP_0_VOLTAGE_INDP_MASK, margining->caps[0]);
443 }
444 
445 static bool supports_time(const struct tb_margining *margining)
446 {
447 	return margining->caps[0] & USB4_MARGIN_CAP_0_TIME;
448 }
449 
450 /* Only applicable if supports_time() returns true */
451 static unsigned int
452 independent_time_margins(const struct tb_margining *margining)
453 {
454 	return FIELD_GET(USB4_MARGIN_CAP_1_TIME_INDP_MASK, margining->caps[1]);
455 }
456 
457 static ssize_t
458 margining_ber_level_write(struct file *file, const char __user *user_buf,
459 			   size_t count, loff_t *ppos)
460 {
461 	struct seq_file *s = file->private_data;
462 	struct tb_margining *margining = s->private;
463 	struct tb *tb = margining->port->sw->tb;
464 	unsigned int val;
465 	int ret = 0;
466 	char *buf;
467 
468 	if (mutex_lock_interruptible(&tb->lock))
469 		return -ERESTARTSYS;
470 
471 	if (margining->software) {
472 		ret = -EINVAL;
473 		goto out_unlock;
474 	}
475 
476 	buf = validate_and_copy_from_user(user_buf, &count);
477 	if (IS_ERR(buf)) {
478 		ret = PTR_ERR(buf);
479 		goto out_unlock;
480 	}
481 
482 	buf[count - 1] = '\0';
483 
484 	ret = kstrtouint(buf, 10, &val);
485 	if (ret)
486 		goto out_free;
487 
488 	if (val < margining->min_ber_level ||
489 	    val > margining->max_ber_level) {
490 		ret = -EINVAL;
491 		goto out_free;
492 	}
493 
494 	margining->ber_level = val;
495 
496 out_free:
497 	free_page((unsigned long)buf);
498 out_unlock:
499 	mutex_unlock(&tb->lock);
500 
501 	return ret < 0 ? ret : count;
502 }
503 
504 static void ber_level_show(struct seq_file *s, unsigned int val)
505 {
506 	if (val % 2)
507 		seq_printf(s, "3 * 1e%d (%u)\n", -12 + (val + 1) / 2, val);
508 	else
509 		seq_printf(s, "1e%d (%u)\n", -12 + val / 2, val);
510 }
511 
512 static int margining_ber_level_show(struct seq_file *s, void *not_used)
513 {
514 	const struct tb_margining *margining = s->private;
515 
516 	if (margining->software)
517 		return -EINVAL;
518 	ber_level_show(s, margining->ber_level);
519 	return 0;
520 }
521 DEBUGFS_ATTR_RW(margining_ber_level);
522 
523 static int margining_caps_show(struct seq_file *s, void *not_used)
524 {
525 	struct tb_margining *margining = s->private;
526 	struct tb *tb = margining->port->sw->tb;
527 	u32 cap0, cap1;
528 
529 	if (mutex_lock_interruptible(&tb->lock))
530 		return -ERESTARTSYS;
531 
532 	/* Dump the raw caps first */
533 	cap0 = margining->caps[0];
534 	seq_printf(s, "0x%08x\n", cap0);
535 	cap1 = margining->caps[1];
536 	seq_printf(s, "0x%08x\n", cap1);
537 
538 	seq_printf(s, "# software margining: %s\n",
539 		   supports_software(margining) ? "yes" : "no");
540 	if (supports_hardware(margining)) {
541 		seq_puts(s, "# hardware margining: yes\n");
542 		seq_puts(s, "# minimum BER level contour: ");
543 		ber_level_show(s, margining->min_ber_level);
544 		seq_puts(s, "# maximum BER level contour: ");
545 		ber_level_show(s, margining->max_ber_level);
546 	} else {
547 		seq_puts(s, "# hardware margining: no\n");
548 	}
549 
550 	seq_printf(s, "# both lanes simultaneously: %s\n",
551 		  both_lanes(margining) ? "yes" : "no");
552 	seq_printf(s, "# voltage margin steps: %u\n",
553 		   margining->voltage_steps);
554 	seq_printf(s, "# maximum voltage offset: %u mV\n",
555 		   margining->max_voltage_offset);
556 
557 	switch (independent_voltage_margins(margining)) {
558 	case USB4_MARGIN_CAP_0_VOLTAGE_MIN:
559 		seq_puts(s, "# returns minimum between high and low voltage margins\n");
560 		break;
561 	case USB4_MARGIN_CAP_0_VOLTAGE_HL:
562 		seq_puts(s, "# returns high or low voltage margin\n");
563 		break;
564 	case USB4_MARGIN_CAP_0_VOLTAGE_BOTH:
565 		seq_puts(s, "# returns both high and low margins\n");
566 		break;
567 	}
568 
569 	if (supports_time(margining)) {
570 		seq_puts(s, "# time margining: yes\n");
571 		seq_printf(s, "# time margining is destructive: %s\n",
572 			   cap1 & USB4_MARGIN_CAP_1_TIME_DESTR ? "yes" : "no");
573 
574 		switch (independent_time_margins(margining)) {
575 		case USB4_MARGIN_CAP_1_TIME_MIN:
576 			seq_puts(s, "# returns minimum between left and right time margins\n");
577 			break;
578 		case USB4_MARGIN_CAP_1_TIME_LR:
579 			seq_puts(s, "# returns left or right margin\n");
580 			break;
581 		case USB4_MARGIN_CAP_1_TIME_BOTH:
582 			seq_puts(s, "# returns both left and right margins\n");
583 			break;
584 		}
585 
586 		seq_printf(s, "# time margin steps: %u\n",
587 			   margining->time_steps);
588 		seq_printf(s, "# maximum time offset: %u mUI\n",
589 			   margining->max_time_offset);
590 	} else {
591 		seq_puts(s, "# time margining: no\n");
592 	}
593 
594 	mutex_unlock(&tb->lock);
595 	return 0;
596 }
597 DEBUGFS_ATTR_RO(margining_caps);
598 
599 static ssize_t
600 margining_lanes_write(struct file *file, const char __user *user_buf,
601 		      size_t count, loff_t *ppos)
602 {
603 	struct seq_file *s = file->private_data;
604 	struct tb_margining *margining = s->private;
605 	struct tb *tb = margining->port->sw->tb;
606 	int ret = 0;
607 	char *buf;
608 
609 	buf = validate_and_copy_from_user(user_buf, &count);
610 	if (IS_ERR(buf))
611 		return PTR_ERR(buf);
612 
613 	buf[count - 1] = '\0';
614 
615 	if (mutex_lock_interruptible(&tb->lock)) {
616 		ret = -ERESTARTSYS;
617 		goto out_free;
618 	}
619 
620 	if (!strcmp(buf, "0")) {
621 		margining->lanes = 0;
622 	} else if (!strcmp(buf, "1")) {
623 		margining->lanes = 1;
624 	} else if (!strcmp(buf, "all")) {
625 		/* Needs to be supported */
626 		if (both_lanes(margining))
627 			margining->lanes = 7;
628 		else
629 			ret = -EINVAL;
630 	} else {
631 		ret = -EINVAL;
632 	}
633 
634 	mutex_unlock(&tb->lock);
635 
636 out_free:
637 	free_page((unsigned long)buf);
638 	return ret < 0 ? ret : count;
639 }
640 
641 static int margining_lanes_show(struct seq_file *s, void *not_used)
642 {
643 	struct tb_margining *margining = s->private;
644 	struct tb *tb = margining->port->sw->tb;
645 	unsigned int lanes;
646 
647 	if (mutex_lock_interruptible(&tb->lock))
648 		return -ERESTARTSYS;
649 
650 	lanes = margining->lanes;
651 	if (both_lanes(margining)) {
652 		if (!lanes)
653 			seq_puts(s, "[0] 1 all\n");
654 		else if (lanes == 1)
655 			seq_puts(s, "0 [1] all\n");
656 		else
657 			seq_puts(s, "0 1 [all]\n");
658 	} else {
659 		if (!lanes)
660 			seq_puts(s, "[0] 1\n");
661 		else
662 			seq_puts(s, "0 [1]\n");
663 	}
664 
665 	mutex_unlock(&tb->lock);
666 	return 0;
667 }
668 DEBUGFS_ATTR_RW(margining_lanes);
669 
670 static ssize_t margining_mode_write(struct file *file,
671 				   const char __user *user_buf,
672 				   size_t count, loff_t *ppos)
673 {
674 	struct seq_file *s = file->private_data;
675 	struct tb_margining *margining = s->private;
676 	struct tb *tb = margining->port->sw->tb;
677 	int ret = 0;
678 	char *buf;
679 
680 	buf = validate_and_copy_from_user(user_buf, &count);
681 	if (IS_ERR(buf))
682 		return PTR_ERR(buf);
683 
684 	buf[count - 1] = '\0';
685 
686 	if (mutex_lock_interruptible(&tb->lock)) {
687 		ret = -ERESTARTSYS;
688 		goto out_free;
689 	}
690 
691 	if (!strcmp(buf, "software")) {
692 		if (supports_software(margining))
693 			margining->software = true;
694 		else
695 			ret = -EINVAL;
696 	} else if (!strcmp(buf, "hardware")) {
697 		if (supports_hardware(margining))
698 			margining->software = false;
699 		else
700 			ret = -EINVAL;
701 	} else {
702 		ret = -EINVAL;
703 	}
704 
705 	mutex_unlock(&tb->lock);
706 
707 out_free:
708 	free_page((unsigned long)buf);
709 	return ret ? ret : count;
710 }
711 
712 static int margining_mode_show(struct seq_file *s, void *not_used)
713 {
714 	struct tb_margining *margining = s->private;
715 	struct tb *tb = margining->port->sw->tb;
716 	const char *space = "";
717 
718 	if (mutex_lock_interruptible(&tb->lock))
719 		return -ERESTARTSYS;
720 
721 	if (supports_software(margining)) {
722 		if (margining->software)
723 			seq_puts(s, "[software]");
724 		else
725 			seq_puts(s, "software");
726 		space = " ";
727 	}
728 	if (supports_hardware(margining)) {
729 		if (margining->software)
730 			seq_printf(s, "%shardware", space);
731 		else
732 			seq_printf(s, "%s[hardware]", space);
733 	}
734 
735 	mutex_unlock(&tb->lock);
736 
737 	seq_puts(s, "\n");
738 	return 0;
739 }
740 DEBUGFS_ATTR_RW(margining_mode);
741 
742 static int margining_run_write(void *data, u64 val)
743 {
744 	struct tb_margining *margining = data;
745 	struct tb_port *port = margining->port;
746 	struct device *dev = margining->dev;
747 	struct tb_switch *sw = port->sw;
748 	struct tb_switch *down_sw;
749 	struct tb *tb = sw->tb;
750 	int ret, clx;
751 
752 	if (val != 1)
753 		return -EINVAL;
754 
755 	pm_runtime_get_sync(dev);
756 
757 	if (mutex_lock_interruptible(&tb->lock)) {
758 		ret = -ERESTARTSYS;
759 		goto out_rpm_put;
760 	}
761 
762 	if (tb_is_upstream_port(port))
763 		down_sw = sw;
764 	else if (port->remote)
765 		down_sw = port->remote->sw;
766 	else
767 		down_sw = NULL;
768 
769 	if (down_sw) {
770 		/*
771 		 * CL states may interfere with lane margining so
772 		 * disable them temporarily now.
773 		 */
774 		ret = tb_switch_clx_disable(down_sw);
775 		if (ret < 0) {
776 			tb_sw_warn(down_sw, "failed to disable CL states\n");
777 			goto out_unlock;
778 		}
779 		clx = ret;
780 	}
781 
782 	if (margining->software) {
783 		tb_port_dbg(port,
784 			    "running software %s lane margining for %s lanes %u\n",
785 			    margining->time ? "time" : "voltage", dev_name(dev),
786 			    margining->lanes);
787 		ret = usb4_port_sw_margin(port, margining->target, margining->index,
788 					  margining->lanes, margining->time,
789 					  margining->right_high,
790 					  USB4_MARGIN_SW_COUNTER_CLEAR);
791 		if (ret)
792 			goto out_clx;
793 
794 		ret = usb4_port_sw_margin_errors(port, margining->target,
795 						 margining->index,
796 						 &margining->results[0]);
797 	} else {
798 		tb_port_dbg(port,
799 			    "running hardware %s lane margining for %s lanes %u\n",
800 			    margining->time ? "time" : "voltage", dev_name(dev),
801 			    margining->lanes);
802 		/* Clear the results */
803 		margining->results[0] = 0;
804 		margining->results[1] = 0;
805 		ret = usb4_port_hw_margin(port, margining->target, margining->index,
806 					  margining->lanes, margining->ber_level,
807 					  margining->time, margining->right_high,
808 					  margining->results);
809 	}
810 
811 out_clx:
812 	if (down_sw)
813 		tb_switch_clx_enable(down_sw, clx);
814 out_unlock:
815 	mutex_unlock(&tb->lock);
816 out_rpm_put:
817 	pm_runtime_mark_last_busy(dev);
818 	pm_runtime_put_autosuspend(dev);
819 
820 	return ret;
821 }
822 DEFINE_DEBUGFS_ATTRIBUTE(margining_run_fops, NULL, margining_run_write,
823 			 "%llu\n");
824 
825 static ssize_t margining_results_write(struct file *file,
826 				       const char __user *user_buf,
827 				       size_t count, loff_t *ppos)
828 {
829 	struct seq_file *s = file->private_data;
830 	struct tb_margining *margining = s->private;
831 	struct tb *tb = margining->port->sw->tb;
832 
833 	if (mutex_lock_interruptible(&tb->lock))
834 		return -ERESTARTSYS;
835 
836 	/* Just clear the results */
837 	margining->results[0] = 0;
838 	margining->results[1] = 0;
839 
840 	mutex_unlock(&tb->lock);
841 	return count;
842 }
843 
844 static void voltage_margin_show(struct seq_file *s,
845 				const struct tb_margining *margining, u8 val)
846 {
847 	unsigned int tmp, voltage;
848 
849 	tmp = FIELD_GET(USB4_MARGIN_HW_RES_1_MARGIN_MASK, val);
850 	voltage = tmp * margining->max_voltage_offset / margining->voltage_steps;
851 	seq_printf(s, "%u mV (%u)", voltage, tmp);
852 	if (val & USB4_MARGIN_HW_RES_1_EXCEEDS)
853 		seq_puts(s, " exceeds maximum");
854 	seq_puts(s, "\n");
855 }
856 
857 static void time_margin_show(struct seq_file *s,
858 			     const struct tb_margining *margining, u8 val)
859 {
860 	unsigned int tmp, interval;
861 
862 	tmp = FIELD_GET(USB4_MARGIN_HW_RES_1_MARGIN_MASK, val);
863 	interval = tmp * margining->max_time_offset / margining->time_steps;
864 	seq_printf(s, "%u mUI (%u)", interval, tmp);
865 	if (val & USB4_MARGIN_HW_RES_1_EXCEEDS)
866 		seq_puts(s, " exceeds maximum");
867 	seq_puts(s, "\n");
868 }
869 
870 static int margining_results_show(struct seq_file *s, void *not_used)
871 {
872 	struct tb_margining *margining = s->private;
873 	struct tb *tb = margining->port->sw->tb;
874 
875 	if (mutex_lock_interruptible(&tb->lock))
876 		return -ERESTARTSYS;
877 
878 	/* Dump the raw results first */
879 	seq_printf(s, "0x%08x\n", margining->results[0]);
880 	/* Only the hardware margining has two result dwords */
881 	if (!margining->software) {
882 		unsigned int val;
883 
884 		seq_printf(s, "0x%08x\n", margining->results[1]);
885 
886 		if (margining->time) {
887 			if (!margining->lanes || margining->lanes == 7) {
888 				val = margining->results[1];
889 				seq_puts(s, "# lane 0 right time margin: ");
890 				time_margin_show(s, margining, val);
891 				val = margining->results[1] >>
892 					USB4_MARGIN_HW_RES_1_L0_LL_MARGIN_SHIFT;
893 				seq_puts(s, "# lane 0 left time margin: ");
894 				time_margin_show(s, margining, val);
895 			}
896 			if (margining->lanes == 1 || margining->lanes == 7) {
897 				val = margining->results[1] >>
898 					USB4_MARGIN_HW_RES_1_L1_RH_MARGIN_SHIFT;
899 				seq_puts(s, "# lane 1 right time margin: ");
900 				time_margin_show(s, margining, val);
901 				val = margining->results[1] >>
902 					USB4_MARGIN_HW_RES_1_L1_LL_MARGIN_SHIFT;
903 				seq_puts(s, "# lane 1 left time margin: ");
904 				time_margin_show(s, margining, val);
905 			}
906 		} else {
907 			if (!margining->lanes || margining->lanes == 7) {
908 				val = margining->results[1];
909 				seq_puts(s, "# lane 0 high voltage margin: ");
910 				voltage_margin_show(s, margining, val);
911 				val = margining->results[1] >>
912 					USB4_MARGIN_HW_RES_1_L0_LL_MARGIN_SHIFT;
913 				seq_puts(s, "# lane 0 low voltage margin: ");
914 				voltage_margin_show(s, margining, val);
915 			}
916 			if (margining->lanes == 1 || margining->lanes == 7) {
917 				val = margining->results[1] >>
918 					USB4_MARGIN_HW_RES_1_L1_RH_MARGIN_SHIFT;
919 				seq_puts(s, "# lane 1 high voltage margin: ");
920 				voltage_margin_show(s, margining, val);
921 				val = margining->results[1] >>
922 					USB4_MARGIN_HW_RES_1_L1_LL_MARGIN_SHIFT;
923 				seq_puts(s, "# lane 1 low voltage margin: ");
924 				voltage_margin_show(s, margining, val);
925 			}
926 		}
927 	}
928 
929 	mutex_unlock(&tb->lock);
930 	return 0;
931 }
932 DEBUGFS_ATTR_RW(margining_results);
933 
934 static ssize_t margining_test_write(struct file *file,
935 				    const char __user *user_buf,
936 				    size_t count, loff_t *ppos)
937 {
938 	struct seq_file *s = file->private_data;
939 	struct tb_margining *margining = s->private;
940 	struct tb *tb = margining->port->sw->tb;
941 	int ret = 0;
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 (mutex_lock_interruptible(&tb->lock)) {
951 		ret = -ERESTARTSYS;
952 		goto out_free;
953 	}
954 
955 	if (!strcmp(buf, "time") && supports_time(margining))
956 		margining->time = true;
957 	else if (!strcmp(buf, "voltage"))
958 		margining->time = false;
959 	else
960 		ret = -EINVAL;
961 
962 	mutex_unlock(&tb->lock);
963 
964 out_free:
965 	free_page((unsigned long)buf);
966 	return ret ? ret : count;
967 }
968 
969 static int margining_test_show(struct seq_file *s, void *not_used)
970 {
971 	struct tb_margining *margining = s->private;
972 	struct tb *tb = margining->port->sw->tb;
973 
974 	if (mutex_lock_interruptible(&tb->lock))
975 		return -ERESTARTSYS;
976 
977 	if (supports_time(margining)) {
978 		if (margining->time)
979 			seq_puts(s, "voltage [time]\n");
980 		else
981 			seq_puts(s, "[voltage] time\n");
982 	} else {
983 		seq_puts(s, "[voltage]\n");
984 	}
985 
986 	mutex_unlock(&tb->lock);
987 	return 0;
988 }
989 DEBUGFS_ATTR_RW(margining_test);
990 
991 static ssize_t margining_margin_write(struct file *file,
992 				    const char __user *user_buf,
993 				    size_t count, loff_t *ppos)
994 {
995 	struct seq_file *s = file->private_data;
996 	struct tb_margining *margining = s->private;
997 	struct tb *tb = margining->port->sw->tb;
998 	int ret = 0;
999 	char *buf;
1000 
1001 	buf = validate_and_copy_from_user(user_buf, &count);
1002 	if (IS_ERR(buf))
1003 		return PTR_ERR(buf);
1004 
1005 	buf[count - 1] = '\0';
1006 
1007 	if (mutex_lock_interruptible(&tb->lock)) {
1008 		ret = -ERESTARTSYS;
1009 		goto out_free;
1010 	}
1011 
1012 	if (margining->time) {
1013 		if (!strcmp(buf, "left"))
1014 			margining->right_high = false;
1015 		else if (!strcmp(buf, "right"))
1016 			margining->right_high = true;
1017 		else
1018 			ret = -EINVAL;
1019 	} else {
1020 		if (!strcmp(buf, "low"))
1021 			margining->right_high = false;
1022 		else if (!strcmp(buf, "high"))
1023 			margining->right_high = true;
1024 		else
1025 			ret = -EINVAL;
1026 	}
1027 
1028 	mutex_unlock(&tb->lock);
1029 
1030 out_free:
1031 	free_page((unsigned long)buf);
1032 	return ret ? ret : count;
1033 }
1034 
1035 static int margining_margin_show(struct seq_file *s, void *not_used)
1036 {
1037 	struct tb_margining *margining = s->private;
1038 	struct tb *tb = margining->port->sw->tb;
1039 
1040 	if (mutex_lock_interruptible(&tb->lock))
1041 		return -ERESTARTSYS;
1042 
1043 	if (margining->time) {
1044 		if (margining->right_high)
1045 			seq_puts(s, "left [right]\n");
1046 		else
1047 			seq_puts(s, "[left] right\n");
1048 	} else {
1049 		if (margining->right_high)
1050 			seq_puts(s, "low [high]\n");
1051 		else
1052 			seq_puts(s, "[low] high\n");
1053 	}
1054 
1055 	mutex_unlock(&tb->lock);
1056 	return 0;
1057 }
1058 DEBUGFS_ATTR_RW(margining_margin);
1059 
1060 static struct tb_margining *margining_alloc(struct tb_port *port,
1061 					    struct device *dev,
1062 					    enum usb4_sb_target target,
1063 					    u8 index, struct dentry *parent)
1064 {
1065 	struct tb_margining *margining;
1066 	struct dentry *dir;
1067 	unsigned int val;
1068 	int ret;
1069 
1070 	margining = kzalloc(sizeof(*margining), GFP_KERNEL);
1071 	if (!margining)
1072 		return NULL;
1073 
1074 	margining->port = port;
1075 	margining->target = target;
1076 	margining->index = index;
1077 	margining->dev = dev;
1078 
1079 	ret = usb4_port_margining_caps(port, target, index, margining->caps);
1080 	if (ret) {
1081 		kfree(margining);
1082 		return NULL;
1083 	}
1084 
1085 	/* Set the initial mode */
1086 	if (supports_software(margining))
1087 		margining->software = true;
1088 
1089 	val = FIELD_GET(USB4_MARGIN_CAP_0_VOLTAGE_STEPS_MASK, margining->caps[0]);
1090 	margining->voltage_steps = val;
1091 	val = FIELD_GET(USB4_MARGIN_CAP_0_MAX_VOLTAGE_OFFSET_MASK, margining->caps[0]);
1092 	margining->max_voltage_offset = 74 + val * 2;
1093 
1094 	if (supports_time(margining)) {
1095 		val = FIELD_GET(USB4_MARGIN_CAP_1_TIME_STEPS_MASK, margining->caps[1]);
1096 		margining->time_steps = val;
1097 		val = FIELD_GET(USB4_MARGIN_CAP_1_TIME_OFFSET_MASK, margining->caps[1]);
1098 		/*
1099 		 * Store it as mUI (milli Unit Interval) because we want
1100 		 * to keep it as integer.
1101 		 */
1102 		margining->max_time_offset = 200 + 10 * val;
1103 	}
1104 
1105 	dir = debugfs_create_dir("margining", parent);
1106 	if (supports_hardware(margining)) {
1107 		val = FIELD_GET(USB4_MARGIN_CAP_1_MIN_BER_MASK, margining->caps[1]);
1108 		margining->min_ber_level = val;
1109 		val = FIELD_GET(USB4_MARGIN_CAP_1_MAX_BER_MASK, margining->caps[1]);
1110 		margining->max_ber_level = val;
1111 
1112 		/* Set the default to minimum */
1113 		margining->ber_level = margining->min_ber_level;
1114 
1115 		debugfs_create_file("ber_level_contour", 0400, dir, margining,
1116 				    &margining_ber_level_fops);
1117 	}
1118 	debugfs_create_file("caps", 0400, dir, margining, &margining_caps_fops);
1119 	debugfs_create_file("lanes", 0600, dir, margining, &margining_lanes_fops);
1120 	debugfs_create_file("mode", 0600, dir, margining, &margining_mode_fops);
1121 	debugfs_create_file("run", 0600, dir, margining, &margining_run_fops);
1122 	debugfs_create_file("results", 0600, dir, margining,
1123 			    &margining_results_fops);
1124 	debugfs_create_file("test", 0600, dir, margining, &margining_test_fops);
1125 	if (independent_voltage_margins(margining) == USB4_MARGIN_CAP_0_VOLTAGE_HL ||
1126 	    (supports_time(margining) &&
1127 	     independent_time_margins(margining) == USB4_MARGIN_CAP_1_TIME_LR))
1128 		debugfs_create_file("margin", 0600, dir, margining,
1129 				    &margining_margin_fops);
1130 	return margining;
1131 }
1132 
1133 static void margining_port_init(struct tb_port *port)
1134 {
1135 	struct dentry *parent;
1136 	char dir_name[10];
1137 
1138 	if (!port->usb4)
1139 		return;
1140 
1141 	snprintf(dir_name, sizeof(dir_name), "port%d", port->port);
1142 	parent = debugfs_lookup(dir_name, port->sw->debugfs_dir);
1143 	port->usb4->margining = margining_alloc(port, &port->usb4->dev,
1144 						USB4_SB_TARGET_ROUTER, 0,
1145 						parent);
1146 }
1147 
1148 static void margining_port_remove(struct tb_port *port)
1149 {
1150 	struct dentry *parent;
1151 	char dir_name[10];
1152 
1153 	if (!port->usb4)
1154 		return;
1155 
1156 	snprintf(dir_name, sizeof(dir_name), "port%d", port->port);
1157 	parent = debugfs_lookup(dir_name, port->sw->debugfs_dir);
1158 	if (parent)
1159 		debugfs_lookup_and_remove("margining", parent);
1160 
1161 	kfree(port->usb4->margining);
1162 	port->usb4->margining = NULL;
1163 }
1164 
1165 static void margining_switch_init(struct tb_switch *sw)
1166 {
1167 	struct tb_port *upstream, *downstream;
1168 	struct tb_switch *parent_sw;
1169 	u64 route = tb_route(sw);
1170 
1171 	if (!route)
1172 		return;
1173 
1174 	upstream = tb_upstream_port(sw);
1175 	parent_sw = tb_switch_parent(sw);
1176 	downstream = tb_port_at(route, parent_sw);
1177 
1178 	margining_port_init(downstream);
1179 	margining_port_init(upstream);
1180 }
1181 
1182 static void margining_switch_remove(struct tb_switch *sw)
1183 {
1184 	struct tb_port *upstream, *downstream;
1185 	struct tb_switch *parent_sw;
1186 	u64 route = tb_route(sw);
1187 
1188 	if (!route)
1189 		return;
1190 
1191 	upstream = tb_upstream_port(sw);
1192 	parent_sw = tb_switch_parent(sw);
1193 	downstream = tb_port_at(route, parent_sw);
1194 
1195 	margining_port_remove(upstream);
1196 	margining_port_remove(downstream);
1197 }
1198 
1199 static void margining_xdomain_init(struct tb_xdomain *xd)
1200 {
1201 	struct tb_switch *parent_sw;
1202 	struct tb_port *downstream;
1203 
1204 	parent_sw = tb_xdomain_parent(xd);
1205 	downstream = tb_port_at(xd->route, parent_sw);
1206 
1207 	margining_port_init(downstream);
1208 }
1209 
1210 static void margining_xdomain_remove(struct tb_xdomain *xd)
1211 {
1212 	struct tb_switch *parent_sw;
1213 	struct tb_port *downstream;
1214 
1215 	parent_sw = tb_xdomain_parent(xd);
1216 	downstream = tb_port_at(xd->route, parent_sw);
1217 	margining_port_remove(downstream);
1218 }
1219 
1220 static void margining_retimer_init(struct tb_retimer *rt, struct dentry *debugfs_dir)
1221 {
1222 	rt->margining = margining_alloc(rt->port, &rt->dev,
1223 					USB4_SB_TARGET_RETIMER, rt->index,
1224 					debugfs_dir);
1225 }
1226 
1227 static void margining_retimer_remove(struct tb_retimer *rt)
1228 {
1229 	kfree(rt->margining);
1230 	rt->margining = NULL;
1231 }
1232 #else
1233 static inline void margining_switch_init(struct tb_switch *sw) { }
1234 static inline void margining_switch_remove(struct tb_switch *sw) { }
1235 static inline void margining_xdomain_init(struct tb_xdomain *xd) { }
1236 static inline void margining_xdomain_remove(struct tb_xdomain *xd) { }
1237 static inline void margining_retimer_init(struct tb_retimer *rt,
1238 					  struct dentry *debugfs_dir) { }
1239 static inline void margining_retimer_remove(struct tb_retimer *rt) { }
1240 #endif
1241 
1242 static int port_clear_all_counters(struct tb_port *port)
1243 {
1244 	u32 *buf;
1245 	int ret;
1246 
1247 	buf = kcalloc(COUNTER_SET_LEN * port->config.max_counters, sizeof(u32),
1248 		      GFP_KERNEL);
1249 	if (!buf)
1250 		return -ENOMEM;
1251 
1252 	ret = tb_port_write(port, buf, TB_CFG_COUNTERS, 0,
1253 			    COUNTER_SET_LEN * port->config.max_counters);
1254 	kfree(buf);
1255 
1256 	return ret;
1257 }
1258 
1259 static ssize_t counters_write(struct file *file, const char __user *user_buf,
1260 			      size_t count, loff_t *ppos)
1261 {
1262 	struct seq_file *s = file->private_data;
1263 	struct tb_port *port = s->private;
1264 	struct tb_switch *sw = port->sw;
1265 	struct tb *tb = port->sw->tb;
1266 	char *buf;
1267 	int ret;
1268 
1269 	buf = validate_and_copy_from_user(user_buf, &count);
1270 	if (IS_ERR(buf))
1271 		return PTR_ERR(buf);
1272 
1273 	pm_runtime_get_sync(&sw->dev);
1274 
1275 	if (mutex_lock_interruptible(&tb->lock)) {
1276 		ret = -ERESTARTSYS;
1277 		goto out;
1278 	}
1279 
1280 	/* If written delimiter only, clear all counters in one shot */
1281 	if (buf[0] == '\n') {
1282 		ret = port_clear_all_counters(port);
1283 	} else  {
1284 		char *line = buf;
1285 		u32 val, offset;
1286 
1287 		ret = -EINVAL;
1288 		while (parse_line(&line, &offset, &val, 1, 4)) {
1289 			ret = tb_port_write(port, &val, TB_CFG_COUNTERS,
1290 					    offset, 1);
1291 			if (ret)
1292 				break;
1293 		}
1294 	}
1295 
1296 	mutex_unlock(&tb->lock);
1297 
1298 out:
1299 	pm_runtime_mark_last_busy(&sw->dev);
1300 	pm_runtime_put_autosuspend(&sw->dev);
1301 	free_page((unsigned long)buf);
1302 
1303 	return ret < 0 ? ret : count;
1304 }
1305 
1306 static void cap_show_by_dw(struct seq_file *s, struct tb_switch *sw,
1307 			   struct tb_port *port, unsigned int cap,
1308 			   unsigned int offset, u8 cap_id, u8 vsec_id,
1309 			   int dwords)
1310 {
1311 	int i, ret;
1312 	u32 data;
1313 
1314 	for (i = 0; i < dwords; i++) {
1315 		if (port)
1316 			ret = tb_port_read(port, &data, TB_CFG_PORT, cap + offset + i, 1);
1317 		else
1318 			ret = tb_sw_read(sw, &data, TB_CFG_SWITCH, cap + offset + i, 1);
1319 		if (ret) {
1320 			seq_printf(s, "0x%04x <not accessible>\n", cap + offset + i);
1321 			continue;
1322 		}
1323 
1324 		seq_printf(s, "0x%04x %4d 0x%02x 0x%02x 0x%08x\n", cap + offset + i,
1325 			   offset + i, cap_id, vsec_id, data);
1326 	}
1327 }
1328 
1329 static void cap_show(struct seq_file *s, struct tb_switch *sw,
1330 		     struct tb_port *port, unsigned int cap, u8 cap_id,
1331 		     u8 vsec_id, int length)
1332 {
1333 	int ret, offset = 0;
1334 
1335 	while (length > 0) {
1336 		int i, dwords = min(length, TB_MAX_CONFIG_RW_LENGTH);
1337 		u32 data[TB_MAX_CONFIG_RW_LENGTH];
1338 
1339 		if (port)
1340 			ret = tb_port_read(port, data, TB_CFG_PORT, cap + offset,
1341 					   dwords);
1342 		else
1343 			ret = tb_sw_read(sw, data, TB_CFG_SWITCH, cap + offset, dwords);
1344 		if (ret) {
1345 			cap_show_by_dw(s, sw, port, cap, offset, cap_id, vsec_id, length);
1346 			return;
1347 		}
1348 
1349 		for (i = 0; i < dwords; i++) {
1350 			seq_printf(s, "0x%04x %4d 0x%02x 0x%02x 0x%08x\n",
1351 				   cap + offset + i, offset + i,
1352 				   cap_id, vsec_id, data[i]);
1353 		}
1354 
1355 		length -= dwords;
1356 		offset += dwords;
1357 	}
1358 }
1359 
1360 static void port_cap_show(struct tb_port *port, struct seq_file *s,
1361 			  unsigned int cap)
1362 {
1363 	struct tb_cap_any header;
1364 	u8 vsec_id = 0;
1365 	size_t length;
1366 	int ret;
1367 
1368 	ret = tb_port_read(port, &header, TB_CFG_PORT, cap, 1);
1369 	if (ret) {
1370 		seq_printf(s, "0x%04x <capability read failed>\n", cap);
1371 		return;
1372 	}
1373 
1374 	switch (header.basic.cap) {
1375 	case TB_PORT_CAP_PHY:
1376 		length = PORT_CAP_LANE_LEN;
1377 		break;
1378 
1379 	case TB_PORT_CAP_TIME1:
1380 		if (usb4_switch_version(port->sw) < 2)
1381 			length = PORT_CAP_TMU_V1_LEN;
1382 		else
1383 			length = PORT_CAP_TMU_V2_LEN;
1384 		break;
1385 
1386 	case TB_PORT_CAP_POWER:
1387 		length = PORT_CAP_POWER_LEN;
1388 		break;
1389 
1390 	case TB_PORT_CAP_ADAP:
1391 		if (tb_port_is_pcie_down(port) || tb_port_is_pcie_up(port)) {
1392 			if (usb4_switch_version(port->sw) < 2)
1393 				length = PORT_CAP_V1_PCIE_LEN;
1394 			else
1395 				length = PORT_CAP_V2_PCIE_LEN;
1396 		} else if (tb_port_is_dpin(port)) {
1397 			if (usb4_switch_version(port->sw) < 2)
1398 				length = PORT_CAP_DP_V1_LEN;
1399 			else
1400 				length = PORT_CAP_DP_V2_LEN;
1401 		} else if (tb_port_is_dpout(port)) {
1402 			length = PORT_CAP_DP_V1_LEN;
1403 		} else if (tb_port_is_usb3_down(port) ||
1404 			   tb_port_is_usb3_up(port)) {
1405 			length = PORT_CAP_USB3_LEN;
1406 		} else {
1407 			seq_printf(s, "0x%04x <unsupported capability 0x%02x>\n",
1408 				   cap, header.basic.cap);
1409 			return;
1410 		}
1411 		break;
1412 
1413 	case TB_PORT_CAP_VSE:
1414 		if (!header.extended_short.length) {
1415 			ret = tb_port_read(port, (u32 *)&header + 1, TB_CFG_PORT,
1416 					   cap + 1, 1);
1417 			if (ret) {
1418 				seq_printf(s, "0x%04x <capability read failed>\n",
1419 					   cap + 1);
1420 				return;
1421 			}
1422 			length = header.extended_long.length;
1423 			vsec_id = header.extended_short.vsec_id;
1424 		} else {
1425 			length = header.extended_short.length;
1426 			vsec_id = header.extended_short.vsec_id;
1427 		}
1428 		break;
1429 
1430 	case TB_PORT_CAP_USB4:
1431 		length = PORT_CAP_USB4_LEN;
1432 		break;
1433 
1434 	default:
1435 		seq_printf(s, "0x%04x <unsupported capability 0x%02x>\n",
1436 			   cap, header.basic.cap);
1437 		return;
1438 	}
1439 
1440 	cap_show(s, NULL, port, cap, header.basic.cap, vsec_id, length);
1441 }
1442 
1443 static void port_caps_show(struct tb_port *port, struct seq_file *s)
1444 {
1445 	int cap;
1446 
1447 	cap = tb_port_next_cap(port, 0);
1448 	while (cap > 0) {
1449 		port_cap_show(port, s, cap);
1450 		cap = tb_port_next_cap(port, cap);
1451 	}
1452 }
1453 
1454 static int port_basic_regs_show(struct tb_port *port, struct seq_file *s)
1455 {
1456 	u32 data[PORT_CAP_BASIC_LEN];
1457 	int ret, i;
1458 
1459 	ret = tb_port_read(port, data, TB_CFG_PORT, 0, ARRAY_SIZE(data));
1460 	if (ret)
1461 		return ret;
1462 
1463 	for (i = 0; i < ARRAY_SIZE(data); i++)
1464 		seq_printf(s, "0x%04x %4d 0x00 0x00 0x%08x\n", i, i, data[i]);
1465 
1466 	return 0;
1467 }
1468 
1469 static int port_regs_show(struct seq_file *s, void *not_used)
1470 {
1471 	struct tb_port *port = s->private;
1472 	struct tb_switch *sw = port->sw;
1473 	struct tb *tb = sw->tb;
1474 	int ret;
1475 
1476 	pm_runtime_get_sync(&sw->dev);
1477 
1478 	if (mutex_lock_interruptible(&tb->lock)) {
1479 		ret = -ERESTARTSYS;
1480 		goto out_rpm_put;
1481 	}
1482 
1483 	seq_puts(s, "# offset relative_offset cap_id vs_cap_id value\n");
1484 
1485 	ret = port_basic_regs_show(port, s);
1486 	if (ret)
1487 		goto out_unlock;
1488 
1489 	port_caps_show(port, s);
1490 
1491 out_unlock:
1492 	mutex_unlock(&tb->lock);
1493 out_rpm_put:
1494 	pm_runtime_mark_last_busy(&sw->dev);
1495 	pm_runtime_put_autosuspend(&sw->dev);
1496 
1497 	return ret;
1498 }
1499 DEBUGFS_ATTR_RW(port_regs);
1500 
1501 static void switch_cap_show(struct tb_switch *sw, struct seq_file *s,
1502 			    unsigned int cap)
1503 {
1504 	struct tb_cap_any header;
1505 	int ret, length;
1506 	u8 vsec_id = 0;
1507 
1508 	ret = tb_sw_read(sw, &header, TB_CFG_SWITCH, cap, 1);
1509 	if (ret) {
1510 		seq_printf(s, "0x%04x <capability read failed>\n", cap);
1511 		return;
1512 	}
1513 
1514 	if (header.basic.cap == TB_SWITCH_CAP_VSE) {
1515 		if (!header.extended_short.length) {
1516 			ret = tb_sw_read(sw, (u32 *)&header + 1, TB_CFG_SWITCH,
1517 					 cap + 1, 1);
1518 			if (ret) {
1519 				seq_printf(s, "0x%04x <capability read failed>\n",
1520 					   cap + 1);
1521 				return;
1522 			}
1523 			length = header.extended_long.length;
1524 		} else {
1525 			length = header.extended_short.length;
1526 		}
1527 		vsec_id = header.extended_short.vsec_id;
1528 	} else {
1529 		if (header.basic.cap == TB_SWITCH_CAP_TMU) {
1530 			length = SWITCH_CAP_TMU_LEN;
1531 		} else  {
1532 			seq_printf(s, "0x%04x <unknown capability 0x%02x>\n",
1533 				   cap, header.basic.cap);
1534 			return;
1535 		}
1536 	}
1537 
1538 	cap_show(s, sw, NULL, cap, header.basic.cap, vsec_id, length);
1539 }
1540 
1541 static void switch_caps_show(struct tb_switch *sw, struct seq_file *s)
1542 {
1543 	int cap;
1544 
1545 	cap = tb_switch_next_cap(sw, 0);
1546 	while (cap > 0) {
1547 		switch_cap_show(sw, s, cap);
1548 		cap = tb_switch_next_cap(sw, cap);
1549 	}
1550 }
1551 
1552 static int switch_basic_regs_show(struct tb_switch *sw, struct seq_file *s)
1553 {
1554 	u32 data[SWITCH_CAP_BASIC_LEN];
1555 	size_t dwords;
1556 	int ret, i;
1557 
1558 	/* Only USB4 has the additional registers */
1559 	if (tb_switch_is_usb4(sw))
1560 		dwords = ARRAY_SIZE(data);
1561 	else
1562 		dwords = 5;
1563 
1564 	ret = tb_sw_read(sw, data, TB_CFG_SWITCH, 0, dwords);
1565 	if (ret)
1566 		return ret;
1567 
1568 	for (i = 0; i < dwords; i++)
1569 		seq_printf(s, "0x%04x %4d 0x00 0x00 0x%08x\n", i, i, data[i]);
1570 
1571 	return 0;
1572 }
1573 
1574 static int switch_regs_show(struct seq_file *s, void *not_used)
1575 {
1576 	struct tb_switch *sw = s->private;
1577 	struct tb *tb = sw->tb;
1578 	int ret;
1579 
1580 	pm_runtime_get_sync(&sw->dev);
1581 
1582 	if (mutex_lock_interruptible(&tb->lock)) {
1583 		ret = -ERESTARTSYS;
1584 		goto out_rpm_put;
1585 	}
1586 
1587 	seq_puts(s, "# offset relative_offset cap_id vs_cap_id value\n");
1588 
1589 	ret = switch_basic_regs_show(sw, s);
1590 	if (ret)
1591 		goto out_unlock;
1592 
1593 	switch_caps_show(sw, s);
1594 
1595 out_unlock:
1596 	mutex_unlock(&tb->lock);
1597 out_rpm_put:
1598 	pm_runtime_mark_last_busy(&sw->dev);
1599 	pm_runtime_put_autosuspend(&sw->dev);
1600 
1601 	return ret;
1602 }
1603 DEBUGFS_ATTR_RW(switch_regs);
1604 
1605 static int path_show_one(struct tb_port *port, struct seq_file *s, int hopid)
1606 {
1607 	u32 data[PATH_LEN];
1608 	int ret, i;
1609 
1610 	ret = tb_port_read(port, data, TB_CFG_HOPS, hopid * PATH_LEN,
1611 			   ARRAY_SIZE(data));
1612 	if (ret) {
1613 		seq_printf(s, "0x%04x <not accessible>\n", hopid * PATH_LEN);
1614 		return ret;
1615 	}
1616 
1617 	for (i = 0; i < ARRAY_SIZE(data); i++) {
1618 		seq_printf(s, "0x%04x %4d 0x%02x 0x%08x\n",
1619 			   hopid * PATH_LEN + i, i, hopid, data[i]);
1620 	}
1621 
1622 	return 0;
1623 }
1624 
1625 static int path_show(struct seq_file *s, void *not_used)
1626 {
1627 	struct tb_port *port = s->private;
1628 	struct tb_switch *sw = port->sw;
1629 	struct tb *tb = sw->tb;
1630 	int start, i, ret = 0;
1631 
1632 	pm_runtime_get_sync(&sw->dev);
1633 
1634 	if (mutex_lock_interruptible(&tb->lock)) {
1635 		ret = -ERESTARTSYS;
1636 		goto out_rpm_put;
1637 	}
1638 
1639 	seq_puts(s, "# offset relative_offset in_hop_id value\n");
1640 
1641 	/* NHI and lane adapters have entry for path 0 */
1642 	if (tb_port_is_null(port) || tb_port_is_nhi(port)) {
1643 		ret = path_show_one(port, s, 0);
1644 		if (ret)
1645 			goto out_unlock;
1646 	}
1647 
1648 	start = tb_port_is_nhi(port) ? 1 : TB_PATH_MIN_HOPID;
1649 
1650 	for (i = start; i <= port->config.max_in_hop_id; i++) {
1651 		ret = path_show_one(port, s, i);
1652 		if (ret)
1653 			break;
1654 	}
1655 
1656 out_unlock:
1657 	mutex_unlock(&tb->lock);
1658 out_rpm_put:
1659 	pm_runtime_mark_last_busy(&sw->dev);
1660 	pm_runtime_put_autosuspend(&sw->dev);
1661 
1662 	return ret;
1663 }
1664 DEBUGFS_ATTR_RO(path);
1665 
1666 static int counter_set_regs_show(struct tb_port *port, struct seq_file *s,
1667 				 int counter)
1668 {
1669 	u32 data[COUNTER_SET_LEN];
1670 	int ret, i;
1671 
1672 	ret = tb_port_read(port, data, TB_CFG_COUNTERS,
1673 			   counter * COUNTER_SET_LEN, ARRAY_SIZE(data));
1674 	if (ret) {
1675 		seq_printf(s, "0x%04x <not accessible>\n",
1676 			   counter * COUNTER_SET_LEN);
1677 		return ret;
1678 	}
1679 
1680 	for (i = 0; i < ARRAY_SIZE(data); i++) {
1681 		seq_printf(s, "0x%04x %4d 0x%02x 0x%08x\n",
1682 			   counter * COUNTER_SET_LEN + i, i, counter, data[i]);
1683 	}
1684 
1685 	return 0;
1686 }
1687 
1688 static int counters_show(struct seq_file *s, void *not_used)
1689 {
1690 	struct tb_port *port = s->private;
1691 	struct tb_switch *sw = port->sw;
1692 	struct tb *tb = sw->tb;
1693 	int i, ret = 0;
1694 
1695 	pm_runtime_get_sync(&sw->dev);
1696 
1697 	if (mutex_lock_interruptible(&tb->lock)) {
1698 		ret = -ERESTARTSYS;
1699 		goto out;
1700 	}
1701 
1702 	seq_puts(s, "# offset relative_offset counter_id value\n");
1703 
1704 	for (i = 0; i < port->config.max_counters; i++) {
1705 		ret = counter_set_regs_show(port, s, i);
1706 		if (ret)
1707 			break;
1708 	}
1709 
1710 	mutex_unlock(&tb->lock);
1711 
1712 out:
1713 	pm_runtime_mark_last_busy(&sw->dev);
1714 	pm_runtime_put_autosuspend(&sw->dev);
1715 
1716 	return ret;
1717 }
1718 DEBUGFS_ATTR_RW(counters);
1719 
1720 static int sb_regs_show(struct tb_port *port, const struct sb_reg *sb_regs,
1721 			size_t size, enum usb4_sb_target target, u8 index,
1722 			struct seq_file *s)
1723 {
1724 	int ret, i;
1725 
1726 	seq_puts(s, "# register value\n");
1727 
1728 	for (i = 0; i < size; i++) {
1729 		const struct sb_reg *regs = &sb_regs[i];
1730 		u8 data[64];
1731 		int j;
1732 
1733 		memset(data, 0, sizeof(data));
1734 		ret = usb4_port_sb_read(port, target, index, regs->reg, data,
1735 					regs->size);
1736 		if (ret)
1737 			return ret;
1738 
1739 		seq_printf(s, "0x%02x", regs->reg);
1740 		for (j = 0; j < regs->size; j++)
1741 			seq_printf(s, " 0x%02x", data[j]);
1742 		seq_puts(s, "\n");
1743 	}
1744 
1745 	return 0;
1746 }
1747 
1748 static int port_sb_regs_show(struct seq_file *s, void *not_used)
1749 {
1750 	struct tb_port *port = s->private;
1751 	struct tb_switch *sw = port->sw;
1752 	struct tb *tb = sw->tb;
1753 	int ret;
1754 
1755 	pm_runtime_get_sync(&sw->dev);
1756 
1757 	if (mutex_lock_interruptible(&tb->lock)) {
1758 		ret = -ERESTARTSYS;
1759 		goto out_rpm_put;
1760 	}
1761 
1762 	ret = sb_regs_show(port, port_sb_regs, ARRAY_SIZE(port_sb_regs),
1763 			   USB4_SB_TARGET_ROUTER, 0, s);
1764 
1765 	mutex_unlock(&tb->lock);
1766 out_rpm_put:
1767 	pm_runtime_mark_last_busy(&sw->dev);
1768 	pm_runtime_put_autosuspend(&sw->dev);
1769 
1770 	return ret;
1771 }
1772 DEBUGFS_ATTR_RW(port_sb_regs);
1773 
1774 /**
1775  * tb_switch_debugfs_init() - Add debugfs entries for router
1776  * @sw: Pointer to the router
1777  *
1778  * Adds debugfs directories and files for given router.
1779  */
1780 void tb_switch_debugfs_init(struct tb_switch *sw)
1781 {
1782 	struct dentry *debugfs_dir;
1783 	struct tb_port *port;
1784 
1785 	debugfs_dir = debugfs_create_dir(dev_name(&sw->dev), tb_debugfs_root);
1786 	sw->debugfs_dir = debugfs_dir;
1787 	debugfs_create_file("regs", DEBUGFS_MODE, debugfs_dir, sw,
1788 			    &switch_regs_fops);
1789 
1790 	tb_switch_for_each_port(sw, port) {
1791 		struct dentry *debugfs_dir;
1792 		char dir_name[10];
1793 
1794 		if (port->disabled)
1795 			continue;
1796 		if (port->config.type == TB_TYPE_INACTIVE)
1797 			continue;
1798 
1799 		snprintf(dir_name, sizeof(dir_name), "port%d", port->port);
1800 		debugfs_dir = debugfs_create_dir(dir_name, sw->debugfs_dir);
1801 		debugfs_create_file("regs", DEBUGFS_MODE, debugfs_dir,
1802 				    port, &port_regs_fops);
1803 		debugfs_create_file("path", 0400, debugfs_dir, port,
1804 				    &path_fops);
1805 		if (port->config.counters_support)
1806 			debugfs_create_file("counters", 0600, debugfs_dir, port,
1807 					    &counters_fops);
1808 		if (port->usb4)
1809 			debugfs_create_file("sb_regs", DEBUGFS_MODE, debugfs_dir,
1810 					    port, &port_sb_regs_fops);
1811 	}
1812 
1813 	margining_switch_init(sw);
1814 }
1815 
1816 /**
1817  * tb_switch_debugfs_remove() - Remove all router debugfs entries
1818  * @sw: Pointer to the router
1819  *
1820  * Removes all previously added debugfs entries under this router.
1821  */
1822 void tb_switch_debugfs_remove(struct tb_switch *sw)
1823 {
1824 	margining_switch_remove(sw);
1825 	debugfs_remove_recursive(sw->debugfs_dir);
1826 }
1827 
1828 void tb_xdomain_debugfs_init(struct tb_xdomain *xd)
1829 {
1830 	margining_xdomain_init(xd);
1831 }
1832 
1833 void tb_xdomain_debugfs_remove(struct tb_xdomain *xd)
1834 {
1835 	margining_xdomain_remove(xd);
1836 }
1837 
1838 /**
1839  * tb_service_debugfs_init() - Add debugfs directory for service
1840  * @svc: Thunderbolt service pointer
1841  *
1842  * Adds debugfs directory for service.
1843  */
1844 void tb_service_debugfs_init(struct tb_service *svc)
1845 {
1846 	svc->debugfs_dir = debugfs_create_dir(dev_name(&svc->dev),
1847 					      tb_debugfs_root);
1848 }
1849 
1850 /**
1851  * tb_service_debugfs_remove() - Remove service debugfs directory
1852  * @svc: Thunderbolt service pointer
1853  *
1854  * Removes the previously created debugfs directory for @svc.
1855  */
1856 void tb_service_debugfs_remove(struct tb_service *svc)
1857 {
1858 	debugfs_remove_recursive(svc->debugfs_dir);
1859 	svc->debugfs_dir = NULL;
1860 }
1861 
1862 static int retimer_sb_regs_show(struct seq_file *s, void *not_used)
1863 {
1864 	struct tb_retimer *rt = s->private;
1865 	struct tb *tb = rt->tb;
1866 	int ret;
1867 
1868 	pm_runtime_get_sync(&rt->dev);
1869 
1870 	if (mutex_lock_interruptible(&tb->lock)) {
1871 		ret = -ERESTARTSYS;
1872 		goto out_rpm_put;
1873 	}
1874 
1875 	ret = sb_regs_show(rt->port, retimer_sb_regs, ARRAY_SIZE(retimer_sb_regs),
1876 			   USB4_SB_TARGET_RETIMER, rt->index, s);
1877 
1878 	mutex_unlock(&tb->lock);
1879 out_rpm_put:
1880 	pm_runtime_mark_last_busy(&rt->dev);
1881 	pm_runtime_put_autosuspend(&rt->dev);
1882 
1883 	return ret;
1884 }
1885 DEBUGFS_ATTR_RW(retimer_sb_regs);
1886 
1887 /**
1888  * tb_retimer_debugfs_init() - Add debugfs directory for retimer
1889  * @rt: Pointer to retimer structure
1890  *
1891  * Adds and populates retimer debugfs directory.
1892  */
1893 void tb_retimer_debugfs_init(struct tb_retimer *rt)
1894 {
1895 	struct dentry *debugfs_dir;
1896 
1897 	debugfs_dir = debugfs_create_dir(dev_name(&rt->dev), tb_debugfs_root);
1898 	debugfs_create_file("sb_regs", DEBUGFS_MODE, debugfs_dir, rt,
1899 			    &retimer_sb_regs_fops);
1900 	margining_retimer_init(rt, debugfs_dir);
1901 }
1902 
1903 /**
1904  * tb_retimer_debugfs_remove() - Remove retimer debugfs directory
1905  * @rt: Pointer to retimer structure
1906  *
1907  * Removes the retimer debugfs directory along with its contents.
1908  */
1909 void tb_retimer_debugfs_remove(struct tb_retimer *rt)
1910 {
1911 	debugfs_lookup_and_remove(dev_name(&rt->dev), tb_debugfs_root);
1912 	margining_retimer_remove(rt);
1913 }
1914 
1915 void tb_debugfs_init(void)
1916 {
1917 	tb_debugfs_root = debugfs_create_dir("thunderbolt", NULL);
1918 }
1919 
1920 void tb_debugfs_exit(void)
1921 {
1922 	debugfs_remove_recursive(tb_debugfs_root);
1923 }
1924