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/debugfs.h>
11#include <linux/pm_runtime.h>
12#include <linux/uaccess.h>
13
14#include "tb.h"
15
16#define PORT_CAP_PCIE_LEN	1
17#define PORT_CAP_POWER_LEN	2
18#define PORT_CAP_LANE_LEN	3
19#define PORT_CAP_USB3_LEN	5
20#define PORT_CAP_DP_LEN		8
21#define PORT_CAP_TMU_LEN	8
22#define PORT_CAP_BASIC_LEN	9
23#define PORT_CAP_USB4_LEN	20
24
25#define SWITCH_CAP_TMU_LEN	26
26#define SWITCH_CAP_BASIC_LEN	27
27
28#define PATH_LEN		2
29
30#define COUNTER_SET_LEN		3
31
32#define DEBUGFS_ATTR(__space, __write)					\
33static int __space ## _open(struct inode *inode, struct file *file)	\
34{									\
35	return single_open(file, __space ## _show, inode->i_private);	\
36}									\
37									\
38static const struct file_operations __space ## _fops = {		\
39	.owner = THIS_MODULE,						\
40	.open = __space ## _open,					\
41	.release = single_release,					\
42	.read  = seq_read,						\
43	.write = __write,						\
44	.llseek = seq_lseek,						\
45}
46
47#define DEBUGFS_ATTR_RO(__space)					\
48	DEBUGFS_ATTR(__space, NULL)
49
50#define DEBUGFS_ATTR_RW(__space)					\
51	DEBUGFS_ATTR(__space, __space ## _write)
52
53static struct dentry *tb_debugfs_root;
54
55static void *validate_and_copy_from_user(const void __user *user_buf,
56					 size_t *count)
57{
58	size_t nbytes;
59	void *buf;
60
61	if (!*count)
62		return ERR_PTR(-EINVAL);
63
64	if (!access_ok(user_buf, *count))
65		return ERR_PTR(-EFAULT);
66
67	buf = (void *)get_zeroed_page(GFP_KERNEL);
68	if (!buf)
69		return ERR_PTR(-ENOMEM);
70
71	nbytes = min_t(size_t, *count, PAGE_SIZE);
72	if (copy_from_user(buf, user_buf, nbytes)) {
73		free_page((unsigned long)buf);
74		return ERR_PTR(-EFAULT);
75	}
76
77	*count = nbytes;
78	return buf;
79}
80
81static bool parse_line(char **line, u32 *offs, u32 *val, int short_fmt_len,
82		       int long_fmt_len)
83{
84	char *token;
85	u32 v[5];
86	int ret;
87
88	token = strsep(line, "\n");
89	if (!token)
90		return false;
91
92	/*
93	 * For Adapter/Router configuration space:
94	 * Short format is: offset value\n
95	 *		    v[0]   v[1]
96	 * Long format as produced from the read side:
97	 * offset relative_offset cap_id vs_cap_id value\n
98	 * v[0]   v[1]            v[2]   v[3]      v[4]
99	 *
100	 * For Counter configuration space:
101	 * Short format is: offset\n
102	 *		    v[0]
103	 * Long format as produced from the read side:
104	 * offset relative_offset counter_id value\n
105	 * v[0]   v[1]            v[2]       v[3]
106	 */
107	ret = sscanf(token, "%i %i %i %i %i", &v[0], &v[1], &v[2], &v[3], &v[4]);
108	/* In case of Counters, clear counter, "val" content is NA */
109	if (ret == short_fmt_len) {
110		*offs = v[0];
111		*val = v[short_fmt_len - 1];
112		return true;
113	} else if (ret == long_fmt_len) {
114		*offs = v[0];
115		*val = v[long_fmt_len - 1];
116		return true;
117	}
118
119	return false;
120}
121
122#if IS_ENABLED(CONFIG_USB4_DEBUGFS_WRITE)
123static ssize_t regs_write(struct tb_switch *sw, struct tb_port *port,
124			  const char __user *user_buf, size_t count,
125			  loff_t *ppos)
126{
127	struct tb *tb = sw->tb;
128	char *line, *buf;
129	u32 val, offset;
130	int ret = 0;
131
132	buf = validate_and_copy_from_user(user_buf, &count);
133	if (IS_ERR(buf))
134		return PTR_ERR(buf);
135
136	pm_runtime_get_sync(&sw->dev);
137
138	if (mutex_lock_interruptible(&tb->lock)) {
139		ret = -ERESTARTSYS;
140		goto out;
141	}
142
143	/* User did hardware changes behind the driver's back */
144	add_taint(TAINT_USER, LOCKDEP_STILL_OK);
145
146	line = buf;
147	while (parse_line(&line, &offset, &val, 2, 5)) {
148		if (port)
149			ret = tb_port_write(port, &val, TB_CFG_PORT, offset, 1);
150		else
151			ret = tb_sw_write(sw, &val, TB_CFG_SWITCH, offset, 1);
152		if (ret)
153			break;
154	}
155
156	mutex_unlock(&tb->lock);
157
158out:
159	pm_runtime_mark_last_busy(&sw->dev);
160	pm_runtime_put_autosuspend(&sw->dev);
161	free_page((unsigned long)buf);
162
163	return ret < 0 ? ret : count;
164}
165
166static ssize_t port_regs_write(struct file *file, const char __user *user_buf,
167			       size_t count, loff_t *ppos)
168{
169	struct seq_file *s = file->private_data;
170	struct tb_port *port = s->private;
171
172	return regs_write(port->sw, port, user_buf, count, ppos);
173}
174
175static ssize_t switch_regs_write(struct file *file, const char __user *user_buf,
176				 size_t count, loff_t *ppos)
177{
178	struct seq_file *s = file->private_data;
179	struct tb_switch *sw = s->private;
180
181	return regs_write(sw, NULL, user_buf, count, ppos);
182}
183#define DEBUGFS_MODE		0600
184#else
185#define port_regs_write		NULL
186#define switch_regs_write	NULL
187#define DEBUGFS_MODE		0400
188#endif
189
190static int port_clear_all_counters(struct tb_port *port)
191{
192	u32 *buf;
193	int ret;
194
195	buf = kcalloc(COUNTER_SET_LEN * port->config.max_counters, sizeof(u32),
196		      GFP_KERNEL);
197	if (!buf)
198		return -ENOMEM;
199
200	ret = tb_port_write(port, buf, TB_CFG_COUNTERS, 0,
201			    COUNTER_SET_LEN * port->config.max_counters);
202	kfree(buf);
203
204	return ret;
205}
206
207static ssize_t counters_write(struct file *file, const char __user *user_buf,
208			      size_t count, loff_t *ppos)
209{
210	struct seq_file *s = file->private_data;
211	struct tb_port *port = s->private;
212	struct tb_switch *sw = port->sw;
213	struct tb *tb = port->sw->tb;
214	char *buf;
215	int ret;
216
217	buf = validate_and_copy_from_user(user_buf, &count);
218	if (IS_ERR(buf))
219		return PTR_ERR(buf);
220
221	pm_runtime_get_sync(&sw->dev);
222
223	if (mutex_lock_interruptible(&tb->lock)) {
224		ret = -ERESTARTSYS;
225		goto out;
226	}
227
228	/* If written delimiter only, clear all counters in one shot */
229	if (buf[0] == '\n') {
230		ret = port_clear_all_counters(port);
231	} else  {
232		char *line = buf;
233		u32 val, offset;
234
235		ret = -EINVAL;
236		while (parse_line(&line, &offset, &val, 1, 4)) {
237			ret = tb_port_write(port, &val, TB_CFG_COUNTERS,
238					    offset, 1);
239			if (ret)
240				break;
241		}
242	}
243
244	mutex_unlock(&tb->lock);
245
246out:
247	pm_runtime_mark_last_busy(&sw->dev);
248	pm_runtime_put_autosuspend(&sw->dev);
249	free_page((unsigned long)buf);
250
251	return ret < 0 ? ret : count;
252}
253
254static void cap_show(struct seq_file *s, struct tb_switch *sw,
255		     struct tb_port *port, unsigned int cap, u8 cap_id,
256		     u8 vsec_id, int length)
257{
258	int ret, offset = 0;
259
260	while (length > 0) {
261		int i, dwords = min(length, TB_MAX_CONFIG_RW_LENGTH);
262		u32 data[TB_MAX_CONFIG_RW_LENGTH];
263
264		if (port)
265			ret = tb_port_read(port, data, TB_CFG_PORT, cap + offset,
266					   dwords);
267		else
268			ret = tb_sw_read(sw, data, TB_CFG_SWITCH, cap + offset, dwords);
269		if (ret) {
270			seq_printf(s, "0x%04x <not accessible>\n",
271				   cap + offset);
272			if (dwords > 1)
273				seq_printf(s, "0x%04x ...\n", cap + offset + 1);
274			return;
275		}
276
277		for (i = 0; i < dwords; i++) {
278			seq_printf(s, "0x%04x %4d 0x%02x 0x%02x 0x%08x\n",
279				   cap + offset + i, offset + i,
280				   cap_id, vsec_id, data[i]);
281		}
282
283		length -= dwords;
284		offset += dwords;
285	}
286}
287
288static void port_cap_show(struct tb_port *port, struct seq_file *s,
289			  unsigned int cap)
290{
291	struct tb_cap_any header;
292	u8 vsec_id = 0;
293	size_t length;
294	int ret;
295
296	ret = tb_port_read(port, &header, TB_CFG_PORT, cap, 1);
297	if (ret) {
298		seq_printf(s, "0x%04x <capability read failed>\n", cap);
299		return;
300	}
301
302	switch (header.basic.cap) {
303	case TB_PORT_CAP_PHY:
304		length = PORT_CAP_LANE_LEN;
305		break;
306
307	case TB_PORT_CAP_TIME1:
308		length = PORT_CAP_TMU_LEN;
309		break;
310
311	case TB_PORT_CAP_POWER:
312		length = PORT_CAP_POWER_LEN;
313		break;
314
315	case TB_PORT_CAP_ADAP:
316		if (tb_port_is_pcie_down(port) || tb_port_is_pcie_up(port)) {
317			length = PORT_CAP_PCIE_LEN;
318		} else if (tb_port_is_dpin(port) || tb_port_is_dpout(port)) {
319			length = PORT_CAP_DP_LEN;
320		} else if (tb_port_is_usb3_down(port) ||
321			   tb_port_is_usb3_up(port)) {
322			length = PORT_CAP_USB3_LEN;
323		} else {
324			seq_printf(s, "0x%04x <unsupported capability 0x%02x>\n",
325				   cap, header.basic.cap);
326			return;
327		}
328		break;
329
330	case TB_PORT_CAP_VSE:
331		if (!header.extended_short.length) {
332			ret = tb_port_read(port, (u32 *)&header + 1, TB_CFG_PORT,
333					   cap + 1, 1);
334			if (ret) {
335				seq_printf(s, "0x%04x <capability read failed>\n",
336					   cap + 1);
337				return;
338			}
339			length = header.extended_long.length;
340			vsec_id = header.extended_short.vsec_id;
341		} else {
342			length = header.extended_short.length;
343			vsec_id = header.extended_short.vsec_id;
344			/*
345			 * Ice Lake and Tiger Lake do not implement the
346			 * full length of the capability, only first 32
347			 * dwords so hard-code it here.
348			 */
349			if (!vsec_id &&
350			    (tb_switch_is_ice_lake(port->sw) ||
351			     tb_switch_is_tiger_lake(port->sw)))
352				length = 32;
353		}
354		break;
355
356	case TB_PORT_CAP_USB4:
357		length = PORT_CAP_USB4_LEN;
358		break;
359
360	default:
361		seq_printf(s, "0x%04x <unsupported capability 0x%02x>\n",
362			   cap, header.basic.cap);
363		return;
364	}
365
366	cap_show(s, NULL, port, cap, header.basic.cap, vsec_id, length);
367}
368
369static void port_caps_show(struct tb_port *port, struct seq_file *s)
370{
371	int cap;
372
373	cap = tb_port_next_cap(port, 0);
374	while (cap > 0) {
375		port_cap_show(port, s, cap);
376		cap = tb_port_next_cap(port, cap);
377	}
378}
379
380static int port_basic_regs_show(struct tb_port *port, struct seq_file *s)
381{
382	u32 data[PORT_CAP_BASIC_LEN];
383	int ret, i;
384
385	ret = tb_port_read(port, data, TB_CFG_PORT, 0, ARRAY_SIZE(data));
386	if (ret)
387		return ret;
388
389	for (i = 0; i < ARRAY_SIZE(data); i++)
390		seq_printf(s, "0x%04x %4d 0x00 0x00 0x%08x\n", i, i, data[i]);
391
392	return 0;
393}
394
395static int port_regs_show(struct seq_file *s, void *not_used)
396{
397	struct tb_port *port = s->private;
398	struct tb_switch *sw = port->sw;
399	struct tb *tb = sw->tb;
400	int ret;
401
402	pm_runtime_get_sync(&sw->dev);
403
404	if (mutex_lock_interruptible(&tb->lock)) {
405		ret = -ERESTARTSYS;
406		goto out_rpm_put;
407	}
408
409	seq_puts(s, "# offset relative_offset cap_id vs_cap_id value\n");
410
411	ret = port_basic_regs_show(port, s);
412	if (ret)
413		goto out_unlock;
414
415	port_caps_show(port, s);
416
417out_unlock:
418	mutex_unlock(&tb->lock);
419out_rpm_put:
420	pm_runtime_mark_last_busy(&sw->dev);
421	pm_runtime_put_autosuspend(&sw->dev);
422
423	return ret;
424}
425DEBUGFS_ATTR_RW(port_regs);
426
427static void switch_cap_show(struct tb_switch *sw, struct seq_file *s,
428			    unsigned int cap)
429{
430	struct tb_cap_any header;
431	int ret, length;
432	u8 vsec_id = 0;
433
434	ret = tb_sw_read(sw, &header, TB_CFG_SWITCH, cap, 1);
435	if (ret) {
436		seq_printf(s, "0x%04x <capability read failed>\n", cap);
437		return;
438	}
439
440	if (header.basic.cap == TB_SWITCH_CAP_VSE) {
441		if (!header.extended_short.length) {
442			ret = tb_sw_read(sw, (u32 *)&header + 1, TB_CFG_SWITCH,
443					 cap + 1, 1);
444			if (ret) {
445				seq_printf(s, "0x%04x <capability read failed>\n",
446					   cap + 1);
447				return;
448			}
449			length = header.extended_long.length;
450		} else {
451			length = header.extended_short.length;
452		}
453		vsec_id = header.extended_short.vsec_id;
454	} else {
455		if (header.basic.cap == TB_SWITCH_CAP_TMU) {
456			length = SWITCH_CAP_TMU_LEN;
457		} else  {
458			seq_printf(s, "0x%04x <unknown capability 0x%02x>\n",
459				   cap, header.basic.cap);
460			return;
461		}
462	}
463
464	cap_show(s, sw, NULL, cap, header.basic.cap, vsec_id, length);
465}
466
467static void switch_caps_show(struct tb_switch *sw, struct seq_file *s)
468{
469	int cap;
470
471	cap = tb_switch_next_cap(sw, 0);
472	while (cap > 0) {
473		switch_cap_show(sw, s, cap);
474		cap = tb_switch_next_cap(sw, cap);
475	}
476}
477
478static int switch_basic_regs_show(struct tb_switch *sw, struct seq_file *s)
479{
480	u32 data[SWITCH_CAP_BASIC_LEN];
481	size_t dwords;
482	int ret, i;
483
484	/* Only USB4 has the additional registers */
485	if (tb_switch_is_usb4(sw))
486		dwords = ARRAY_SIZE(data);
487	else
488		dwords = 7;
489
490	ret = tb_sw_read(sw, data, TB_CFG_SWITCH, 0, dwords);
491	if (ret)
492		return ret;
493
494	for (i = 0; i < dwords; i++)
495		seq_printf(s, "0x%04x %4d 0x00 0x00 0x%08x\n", i, i, data[i]);
496
497	return 0;
498}
499
500static int switch_regs_show(struct seq_file *s, void *not_used)
501{
502	struct tb_switch *sw = s->private;
503	struct tb *tb = sw->tb;
504	int ret;
505
506	pm_runtime_get_sync(&sw->dev);
507
508	if (mutex_lock_interruptible(&tb->lock)) {
509		ret = -ERESTARTSYS;
510		goto out_rpm_put;
511	}
512
513	seq_puts(s, "# offset relative_offset cap_id vs_cap_id value\n");
514
515	ret = switch_basic_regs_show(sw, s);
516	if (ret)
517		goto out_unlock;
518
519	switch_caps_show(sw, s);
520
521out_unlock:
522	mutex_unlock(&tb->lock);
523out_rpm_put:
524	pm_runtime_mark_last_busy(&sw->dev);
525	pm_runtime_put_autosuspend(&sw->dev);
526
527	return ret;
528}
529DEBUGFS_ATTR_RW(switch_regs);
530
531static int path_show_one(struct tb_port *port, struct seq_file *s, int hopid)
532{
533	u32 data[PATH_LEN];
534	int ret, i;
535
536	ret = tb_port_read(port, data, TB_CFG_HOPS, hopid * PATH_LEN,
537			   ARRAY_SIZE(data));
538	if (ret) {
539		seq_printf(s, "0x%04x <not accessible>\n", hopid * PATH_LEN);
540		return ret;
541	}
542
543	for (i = 0; i < ARRAY_SIZE(data); i++) {
544		seq_printf(s, "0x%04x %4d 0x%02x 0x%08x\n",
545			   hopid * PATH_LEN + i, i, hopid, data[i]);
546	}
547
548	return 0;
549}
550
551static int path_show(struct seq_file *s, void *not_used)
552{
553	struct tb_port *port = s->private;
554	struct tb_switch *sw = port->sw;
555	struct tb *tb = sw->tb;
556	int start, i, ret = 0;
557
558	pm_runtime_get_sync(&sw->dev);
559
560	if (mutex_lock_interruptible(&tb->lock)) {
561		ret = -ERESTARTSYS;
562		goto out_rpm_put;
563	}
564
565	seq_puts(s, "# offset relative_offset in_hop_id value\n");
566
567	/* NHI and lane adapters have entry for path 0 */
568	if (tb_port_is_null(port) || tb_port_is_nhi(port)) {
569		ret = path_show_one(port, s, 0);
570		if (ret)
571			goto out_unlock;
572	}
573
574	start = tb_port_is_nhi(port) ? 1 : TB_PATH_MIN_HOPID;
575
576	for (i = start; i <= port->config.max_in_hop_id; i++) {
577		ret = path_show_one(port, s, i);
578		if (ret)
579			break;
580	}
581
582out_unlock:
583	mutex_unlock(&tb->lock);
584out_rpm_put:
585	pm_runtime_mark_last_busy(&sw->dev);
586	pm_runtime_put_autosuspend(&sw->dev);
587
588	return ret;
589}
590DEBUGFS_ATTR_RO(path);
591
592static int counter_set_regs_show(struct tb_port *port, struct seq_file *s,
593				 int counter)
594{
595	u32 data[COUNTER_SET_LEN];
596	int ret, i;
597
598	ret = tb_port_read(port, data, TB_CFG_COUNTERS,
599			   counter * COUNTER_SET_LEN, ARRAY_SIZE(data));
600	if (ret) {
601		seq_printf(s, "0x%04x <not accessible>\n",
602			   counter * COUNTER_SET_LEN);
603		return ret;
604	}
605
606	for (i = 0; i < ARRAY_SIZE(data); i++) {
607		seq_printf(s, "0x%04x %4d 0x%02x 0x%08x\n",
608			   counter * COUNTER_SET_LEN + i, i, counter, data[i]);
609	}
610
611	return 0;
612}
613
614static int counters_show(struct seq_file *s, void *not_used)
615{
616	struct tb_port *port = s->private;
617	struct tb_switch *sw = port->sw;
618	struct tb *tb = sw->tb;
619	int i, ret = 0;
620
621	pm_runtime_get_sync(&sw->dev);
622
623	if (mutex_lock_interruptible(&tb->lock)) {
624		ret = -ERESTARTSYS;
625		goto out;
626	}
627
628	seq_puts(s, "# offset relative_offset counter_id value\n");
629
630	for (i = 0; i < port->config.max_counters; i++) {
631		ret = counter_set_regs_show(port, s, i);
632		if (ret)
633			break;
634	}
635
636	mutex_unlock(&tb->lock);
637
638out:
639	pm_runtime_mark_last_busy(&sw->dev);
640	pm_runtime_put_autosuspend(&sw->dev);
641
642	return ret;
643}
644DEBUGFS_ATTR_RW(counters);
645
646/**
647 * tb_switch_debugfs_init() - Add debugfs entries for router
648 * @sw: Pointer to the router
649 *
650 * Adds debugfs directories and files for given router.
651 */
652void tb_switch_debugfs_init(struct tb_switch *sw)
653{
654	struct dentry *debugfs_dir;
655	struct tb_port *port;
656
657	debugfs_dir = debugfs_create_dir(dev_name(&sw->dev), tb_debugfs_root);
658	sw->debugfs_dir = debugfs_dir;
659	debugfs_create_file("regs", DEBUGFS_MODE, debugfs_dir, sw,
660			    &switch_regs_fops);
661
662	tb_switch_for_each_port(sw, port) {
663		struct dentry *debugfs_dir;
664		char dir_name[10];
665
666		if (port->disabled)
667			continue;
668		if (port->config.type == TB_TYPE_INACTIVE)
669			continue;
670
671		snprintf(dir_name, sizeof(dir_name), "port%d", port->port);
672		debugfs_dir = debugfs_create_dir(dir_name, sw->debugfs_dir);
673		debugfs_create_file("regs", DEBUGFS_MODE, debugfs_dir,
674				    port, &port_regs_fops);
675		debugfs_create_file("path", 0400, debugfs_dir, port,
676				    &path_fops);
677		if (port->config.counters_support)
678			debugfs_create_file("counters", 0600, debugfs_dir, port,
679					    &counters_fops);
680	}
681}
682
683/**
684 * tb_switch_debugfs_remove() - Remove all router debugfs entries
685 * @sw: Pointer to the router
686 *
687 * Removes all previously added debugfs entries under this router.
688 */
689void tb_switch_debugfs_remove(struct tb_switch *sw)
690{
691	debugfs_remove_recursive(sw->debugfs_dir);
692}
693
694void tb_debugfs_init(void)
695{
696	tb_debugfs_root = debugfs_create_dir("thunderbolt", NULL);
697}
698
699void tb_debugfs_exit(void)
700{
701	debugfs_remove_recursive(tb_debugfs_root);
702}
703