xref: /linux/drivers/remoteproc/remoteproc_debugfs.c (revision 2c97b5ae83dca56718774e7b4bf9640f05d11867) 
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * Remote Processor Framework
4  *
5  * Copyright (C) 2011 Texas Instruments, Inc.
6  * Copyright (C) 2011 Google, Inc.
7  *
8  * Ohad Ben-Cohen <ohad@wizery.com>
9  * Mark Grosen <mgrosen@ti.com>
10  * Brian Swetland <swetland@google.com>
11  * Fernando Guzman Lugo <fernando.lugo@ti.com>
12  * Suman Anna <s-anna@ti.com>
13  * Robert Tivy <rtivy@ti.com>
14  * Armando Uribe De Leon <x0095078@ti.com>
15  */
16 
17 #define pr_fmt(fmt)    "%s: " fmt, __func__
18 
19 #include <linux/kernel.h>
20 #include <linux/debugfs.h>
21 #include <linux/remoteproc.h>
22 #include <linux/device.h>
23 #include <linux/uaccess.h>
24 
25 #include "remoteproc_internal.h"
26 
27 /* remoteproc debugfs parent dir */
28 static struct dentry *rproc_dbg;
29 
30 /*
31  * Some remote processors may support dumping trace logs into a shared
32  * memory buffer. We expose this trace buffer using debugfs, so users
33  * can easily tell what's going on remotely.
34  *
35  * We will most probably improve the rproc tracing facilities later on,
36  * but this kind of lightweight and simple mechanism is always good to have,
37  * as it provides very early tracing with little to no dependencies at all.
38  */
39 static ssize_t rproc_trace_read(struct file *filp, char __user *userbuf,
40 				size_t count, loff_t *ppos)
41 {
42 	struct rproc_debug_trace *data = filp->private_data;
43 	struct rproc_mem_entry *trace = &data->trace_mem;
44 	void *va;
45 	char buf[100];
46 	int len;
47 
48 	va = rproc_da_to_va(data->rproc, trace->da, trace->len);
49 
50 	if (!va) {
51 		len = scnprintf(buf, sizeof(buf), "Trace %s not available\n",
52 				trace->name);
53 		va = buf;
54 	} else {
55 		len = strnlen(va, trace->len);
56 	}
57 
58 	return simple_read_from_buffer(userbuf, count, ppos, va, len);
59 }
60 
61 static const struct file_operations trace_rproc_ops = {
62 	.read = rproc_trace_read,
63 	.open = simple_open,
64 	.llseek	= generic_file_llseek,
65 };
66 
67 /* expose the name of the remote processor via debugfs */
68 static ssize_t rproc_name_read(struct file *filp, char __user *userbuf,
69 			       size_t count, loff_t *ppos)
70 {
71 	struct rproc *rproc = filp->private_data;
72 	/* need room for the name, a newline and a terminating null */
73 	char buf[100];
74 	int i;
75 
76 	i = scnprintf(buf, sizeof(buf), "%.98s\n", rproc->name);
77 
78 	return simple_read_from_buffer(userbuf, count, ppos, buf, i);
79 }
80 
81 static const struct file_operations rproc_name_ops = {
82 	.read = rproc_name_read,
83 	.open = simple_open,
84 	.llseek	= generic_file_llseek,
85 };
86 
87 /* expose recovery flag via debugfs */
88 static ssize_t rproc_recovery_read(struct file *filp, char __user *userbuf,
89 				   size_t count, loff_t *ppos)
90 {
91 	struct rproc *rproc = filp->private_data;
92 	char *buf = rproc->recovery_disabled ? "disabled\n" : "enabled\n";
93 
94 	return simple_read_from_buffer(userbuf, count, ppos, buf, strlen(buf));
95 }
96 
97 /*
98  * By writing to the 'recovery' debugfs entry, we control the behavior of the
99  * recovery mechanism dynamically. The default value of this entry is "enabled".
100  *
101  * The 'recovery' debugfs entry supports these commands:
102  *
103  * enabled:	When enabled, the remote processor will be automatically
104  *		recovered whenever it crashes. Moreover, if the remote
105  *		processor crashes while recovery is disabled, it will
106  *		be automatically recovered too as soon as recovery is enabled.
107  *
108  * disabled:	When disabled, a remote processor will remain in a crashed
109  *		state if it crashes. This is useful for debugging purposes;
110  *		without it, debugging a crash is substantially harder.
111  *
112  * recover:	This function will trigger an immediate recovery if the
113  *		remote processor is in a crashed state, without changing
114  *		or checking the recovery state (enabled/disabled).
115  *		This is useful during debugging sessions, when one expects
116  *		additional crashes to happen after enabling recovery. In this
117  *		case, enabling recovery will make it hard to debug subsequent
118  *		crashes, so it's recommended to keep recovery disabled, and
119  *		instead use the "recover" command as needed.
120  */
121 static ssize_t
122 rproc_recovery_write(struct file *filp, const char __user *user_buf,
123 		     size_t count, loff_t *ppos)
124 {
125 	struct rproc *rproc = filp->private_data;
126 	char buf[10];
127 	int ret;
128 
129 	if (count < 1 || count > sizeof(buf))
130 		return -EINVAL;
131 
132 	ret = copy_from_user(buf, user_buf, count);
133 	if (ret)
134 		return -EFAULT;
135 
136 	/* remove end of line */
137 	if (buf[count - 1] == '\n')
138 		buf[count - 1] = '\0';
139 
140 	if (!strncmp(buf, "enabled", count)) {
141 		rproc->recovery_disabled = false;
142 		/* if rproc has crashed, trigger recovery */
143 		if (rproc->state == RPROC_CRASHED)
144 			rproc_trigger_recovery(rproc);
145 	} else if (!strncmp(buf, "disabled", count)) {
146 		rproc->recovery_disabled = true;
147 	} else if (!strncmp(buf, "recover", count)) {
148 		/* if rproc has crashed, trigger recovery */
149 		if (rproc->state == RPROC_CRASHED)
150 			rproc_trigger_recovery(rproc);
151 	}
152 
153 	return count;
154 }
155 
156 static const struct file_operations rproc_recovery_ops = {
157 	.read = rproc_recovery_read,
158 	.write = rproc_recovery_write,
159 	.open = simple_open,
160 	.llseek = generic_file_llseek,
161 };
162 
163 /* expose the crash trigger via debugfs */
164 static ssize_t
165 rproc_crash_write(struct file *filp, const char __user *user_buf,
166 		  size_t count, loff_t *ppos)
167 {
168 	struct rproc *rproc = filp->private_data;
169 	unsigned int type;
170 	int ret;
171 
172 	ret = kstrtouint_from_user(user_buf, count, 0, &type);
173 	if (ret < 0)
174 		return ret;
175 
176 	rproc_report_crash(rproc, type);
177 
178 	return count;
179 }
180 
181 static const struct file_operations rproc_crash_ops = {
182 	.write = rproc_crash_write,
183 	.open = simple_open,
184 	.llseek = generic_file_llseek,
185 };
186 
187 /* Expose resource table content via debugfs */
188 static int rproc_rsc_table_show(struct seq_file *seq, void *p)
189 {
190 	static const char * const types[] = {"carveout", "devmem", "trace", "vdev"};
191 	struct rproc *rproc = seq->private;
192 	struct resource_table *table = rproc->table_ptr;
193 	struct fw_rsc_carveout *c;
194 	struct fw_rsc_devmem *d;
195 	struct fw_rsc_trace *t;
196 	struct fw_rsc_vdev *v;
197 	int i, j;
198 
199 	if (!table) {
200 		seq_puts(seq, "No resource table found\n");
201 		return 0;
202 	}
203 
204 	for (i = 0; i < table->num; i++) {
205 		int offset = table->offset[i];
206 		struct fw_rsc_hdr *hdr = (void *)table + offset;
207 		void *rsc = (void *)hdr + sizeof(*hdr);
208 
209 		switch (hdr->type) {
210 		case RSC_CARVEOUT:
211 			c = rsc;
212 			seq_printf(seq, "Entry %d is of type %s\n", i, types[hdr->type]);
213 			seq_printf(seq, "  Device Address 0x%x\n", c->da);
214 			seq_printf(seq, "  Physical Address 0x%x\n", c->pa);
215 			seq_printf(seq, "  Length 0x%x Bytes\n", c->len);
216 			seq_printf(seq, "  Flags 0x%x\n", c->flags);
217 			seq_printf(seq, "  Reserved (should be zero) [%d]\n", c->reserved);
218 			seq_printf(seq, "  Name %s\n\n", c->name);
219 			break;
220 		case RSC_DEVMEM:
221 			d = rsc;
222 			seq_printf(seq, "Entry %d is of type %s\n", i, types[hdr->type]);
223 			seq_printf(seq, "  Device Address 0x%x\n", d->da);
224 			seq_printf(seq, "  Physical Address 0x%x\n", d->pa);
225 			seq_printf(seq, "  Length 0x%x Bytes\n", d->len);
226 			seq_printf(seq, "  Flags 0x%x\n", d->flags);
227 			seq_printf(seq, "  Reserved (should be zero) [%d]\n", d->reserved);
228 			seq_printf(seq, "  Name %s\n\n", d->name);
229 			break;
230 		case RSC_TRACE:
231 			t = rsc;
232 			seq_printf(seq, "Entry %d is of type %s\n", i, types[hdr->type]);
233 			seq_printf(seq, "  Device Address 0x%x\n", t->da);
234 			seq_printf(seq, "  Length 0x%x Bytes\n", t->len);
235 			seq_printf(seq, "  Reserved (should be zero) [%d]\n", t->reserved);
236 			seq_printf(seq, "  Name %s\n\n", t->name);
237 			break;
238 		case RSC_VDEV:
239 			v = rsc;
240 			seq_printf(seq, "Entry %d is of type %s\n", i, types[hdr->type]);
241 
242 			seq_printf(seq, "  ID %d\n", v->id);
243 			seq_printf(seq, "  Notify ID %d\n", v->notifyid);
244 			seq_printf(seq, "  Device features 0x%x\n", v->dfeatures);
245 			seq_printf(seq, "  Guest features 0x%x\n", v->gfeatures);
246 			seq_printf(seq, "  Config length 0x%x\n", v->config_len);
247 			seq_printf(seq, "  Status 0x%x\n", v->status);
248 			seq_printf(seq, "  Number of vrings %d\n", v->num_of_vrings);
249 			seq_printf(seq, "  Reserved (should be zero) [%d][%d]\n\n",
250 				   v->reserved[0], v->reserved[1]);
251 
252 			for (j = 0; j < v->num_of_vrings; j++) {
253 				seq_printf(seq, "  Vring %d\n", j);
254 				seq_printf(seq, "    Device Address 0x%x\n", v->vring[j].da);
255 				seq_printf(seq, "    Alignment %d\n", v->vring[j].align);
256 				seq_printf(seq, "    Number of buffers %d\n", v->vring[j].num);
257 				seq_printf(seq, "    Notify ID %d\n", v->vring[j].notifyid);
258 				seq_printf(seq, "    Physical Address 0x%x\n\n",
259 					   v->vring[j].pa);
260 			}
261 			break;
262 		default:
263 			seq_printf(seq, "Unknown resource type found: %d [hdr: %pK]\n",
264 				   hdr->type, hdr);
265 			break;
266 		}
267 	}
268 
269 	return 0;
270 }
271 
272 static int rproc_rsc_table_open(struct inode *inode, struct file *file)
273 {
274 	return single_open(file, rproc_rsc_table_show, inode->i_private);
275 }
276 
277 static const struct file_operations rproc_rsc_table_ops = {
278 	.open		= rproc_rsc_table_open,
279 	.read		= seq_read,
280 	.llseek		= seq_lseek,
281 	.release	= single_release,
282 };
283 
284 /* Expose carveout content via debugfs */
285 static int rproc_carveouts_show(struct seq_file *seq, void *p)
286 {
287 	struct rproc *rproc = seq->private;
288 	struct rproc_mem_entry *carveout;
289 
290 	list_for_each_entry(carveout, &rproc->carveouts, node) {
291 		seq_puts(seq, "Carveout memory entry:\n");
292 		seq_printf(seq, "\tName: %s\n", carveout->name);
293 		seq_printf(seq, "\tVirtual address: %pK\n", carveout->va);
294 		seq_printf(seq, "\tDMA address: %pad\n", &carveout->dma);
295 		seq_printf(seq, "\tDevice address: 0x%x\n", carveout->da);
296 		seq_printf(seq, "\tLength: 0x%x Bytes\n\n", carveout->len);
297 	}
298 
299 	return 0;
300 }
301 
302 static int rproc_carveouts_open(struct inode *inode, struct file *file)
303 {
304 	return single_open(file, rproc_carveouts_show, inode->i_private);
305 }
306 
307 static const struct file_operations rproc_carveouts_ops = {
308 	.open		= rproc_carveouts_open,
309 	.read		= seq_read,
310 	.llseek		= seq_lseek,
311 	.release	= single_release,
312 };
313 
314 void rproc_remove_trace_file(struct dentry *tfile)
315 {
316 	debugfs_remove(tfile);
317 }
318 
319 struct dentry *rproc_create_trace_file(const char *name, struct rproc *rproc,
320 				       struct rproc_debug_trace *trace)
321 {
322 	struct dentry *tfile;
323 
324 	tfile = debugfs_create_file(name, 0400, rproc->dbg_dir, trace,
325 				    &trace_rproc_ops);
326 	if (!tfile) {
327 		dev_err(&rproc->dev, "failed to create debugfs trace entry\n");
328 		return NULL;
329 	}
330 
331 	return tfile;
332 }
333 
334 void rproc_delete_debug_dir(struct rproc *rproc)
335 {
336 	debugfs_remove_recursive(rproc->dbg_dir);
337 }
338 
339 void rproc_create_debug_dir(struct rproc *rproc)
340 {
341 	struct device *dev = &rproc->dev;
342 
343 	if (!rproc_dbg)
344 		return;
345 
346 	rproc->dbg_dir = debugfs_create_dir(dev_name(dev), rproc_dbg);
347 	if (!rproc->dbg_dir)
348 		return;
349 
350 	debugfs_create_file("name", 0400, rproc->dbg_dir,
351 			    rproc, &rproc_name_ops);
352 	debugfs_create_file("recovery", 0400, rproc->dbg_dir,
353 			    rproc, &rproc_recovery_ops);
354 	debugfs_create_file("crash", 0200, rproc->dbg_dir,
355 			    rproc, &rproc_crash_ops);
356 	debugfs_create_file("resource_table", 0400, rproc->dbg_dir,
357 			    rproc, &rproc_rsc_table_ops);
358 	debugfs_create_file("carveout_memories", 0400, rproc->dbg_dir,
359 			    rproc, &rproc_carveouts_ops);
360 }
361 
362 void __init rproc_init_debugfs(void)
363 {
364 	if (debugfs_initialized()) {
365 		rproc_dbg = debugfs_create_dir(KBUILD_MODNAME, NULL);
366 		if (!rproc_dbg)
367 			pr_err("can't create debugfs dir\n");
368 	}
369 }
370 
371 void __exit rproc_exit_debugfs(void)
372 {
373 	debugfs_remove(rproc_dbg);
374 }
375