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  * A coredump-configuration-to-string lookup table, for exposing a
32  * human readable configuration via debugfs. Always keep in sync with
33  * enum rproc_coredump_mechanism
34  */
35 static const char * const rproc_coredump_str[] = {
36 	[RPROC_COREDUMP_DEFAULT]	= "default",
37 	[RPROC_COREDUMP_INLINE]		= "inline",
38 	[RPROC_COREDUMP_DISABLED]	= "disabled",
39 };
40 
41 /* Expose the current coredump configuration via debugfs */
42 static ssize_t rproc_coredump_read(struct file *filp, char __user *userbuf,
43 				   size_t count, loff_t *ppos)
44 {
45 	struct rproc *rproc = filp->private_data;
46 	char buf[20];
47 	int len;
48 
49 	len = scnprintf(buf, sizeof(buf), "%s\n",
50 			rproc_coredump_str[rproc->dump_conf]);
51 
52 	return simple_read_from_buffer(userbuf, count, ppos, buf, len);
53 }
54 
55 /*
56  * By writing to the 'coredump' debugfs entry, we control the behavior of the
57  * coredump mechanism dynamically. The default value of this entry is "default".
58  *
59  * The 'coredump' debugfs entry supports these commands:
60  *
61  * default:	This is the default coredump mechanism. When the remoteproc
62  *		crashes the entire coredump will be copied to a separate buffer
63  *		and exposed to userspace.
64  *
65  * inline:	The coredump will not be copied to a separate buffer and the
66  *		recovery process will have to wait until data is read by
67  *		userspace. But this avoid usage of extra memory.
68  *
69  * disabled:	This will disable coredump. Recovery will proceed without
70  *		collecting any dump.
71  */
72 static ssize_t rproc_coredump_write(struct file *filp,
73 				    const char __user *user_buf, size_t count,
74 				    loff_t *ppos)
75 {
76 	struct rproc *rproc = filp->private_data;
77 	int ret, err = 0;
78 	char buf[20];
79 
80 	if (count > sizeof(buf))
81 		return -EINVAL;
82 
83 	ret = copy_from_user(buf, user_buf, count);
84 	if (ret)
85 		return -EFAULT;
86 
87 	/* remove end of line */
88 	if (buf[count - 1] == '\n')
89 		buf[count - 1] = '\0';
90 
91 	if (rproc->state == RPROC_CRASHED) {
92 		dev_err(&rproc->dev, "can't change coredump configuration\n");
93 		err = -EBUSY;
94 		goto out;
95 	}
96 
97 	if (!strncmp(buf, "disable", count)) {
98 		rproc->dump_conf = RPROC_COREDUMP_DISABLED;
99 	} else if (!strncmp(buf, "inline", count)) {
100 		rproc->dump_conf = RPROC_COREDUMP_INLINE;
101 	} else if (!strncmp(buf, "default", count)) {
102 		rproc->dump_conf = RPROC_COREDUMP_DEFAULT;
103 	} else {
104 		dev_err(&rproc->dev, "Invalid coredump configuration\n");
105 		err = -EINVAL;
106 	}
107 out:
108 	return err ? err : count;
109 }
110 
111 static const struct file_operations rproc_coredump_fops = {
112 	.read = rproc_coredump_read,
113 	.write = rproc_coredump_write,
114 	.open = simple_open,
115 	.llseek = generic_file_llseek,
116 };
117 
118 /*
119  * Some remote processors may support dumping trace logs into a shared
120  * memory buffer. We expose this trace buffer using debugfs, so users
121  * can easily tell what's going on remotely.
122  *
123  * We will most probably improve the rproc tracing facilities later on,
124  * but this kind of lightweight and simple mechanism is always good to have,
125  * as it provides very early tracing with little to no dependencies at all.
126  */
127 static ssize_t rproc_trace_read(struct file *filp, char __user *userbuf,
128 				size_t count, loff_t *ppos)
129 {
130 	struct rproc_debug_trace *data = filp->private_data;
131 	struct rproc_mem_entry *trace = &data->trace_mem;
132 	void *va;
133 	char buf[100];
134 	int len;
135 
136 	va = rproc_da_to_va(data->rproc, trace->da, trace->len);
137 
138 	if (!va) {
139 		len = scnprintf(buf, sizeof(buf), "Trace %s not available\n",
140 				trace->name);
141 		va = buf;
142 	} else {
143 		len = strnlen(va, trace->len);
144 	}
145 
146 	return simple_read_from_buffer(userbuf, count, ppos, va, len);
147 }
148 
149 static const struct file_operations trace_rproc_ops = {
150 	.read = rproc_trace_read,
151 	.open = simple_open,
152 	.llseek	= generic_file_llseek,
153 };
154 
155 /* expose the name of the remote processor via debugfs */
156 static ssize_t rproc_name_read(struct file *filp, char __user *userbuf,
157 			       size_t count, loff_t *ppos)
158 {
159 	struct rproc *rproc = filp->private_data;
160 	/* need room for the name, a newline and a terminating null */
161 	char buf[100];
162 	int i;
163 
164 	i = scnprintf(buf, sizeof(buf), "%.98s\n", rproc->name);
165 
166 	return simple_read_from_buffer(userbuf, count, ppos, buf, i);
167 }
168 
169 static const struct file_operations rproc_name_ops = {
170 	.read = rproc_name_read,
171 	.open = simple_open,
172 	.llseek	= generic_file_llseek,
173 };
174 
175 /* expose recovery flag via debugfs */
176 static ssize_t rproc_recovery_read(struct file *filp, char __user *userbuf,
177 				   size_t count, loff_t *ppos)
178 {
179 	struct rproc *rproc = filp->private_data;
180 	char *buf = rproc->recovery_disabled ? "disabled\n" : "enabled\n";
181 
182 	return simple_read_from_buffer(userbuf, count, ppos, buf, strlen(buf));
183 }
184 
185 /*
186  * By writing to the 'recovery' debugfs entry, we control the behavior of the
187  * recovery mechanism dynamically. The default value of this entry is "enabled".
188  *
189  * The 'recovery' debugfs entry supports these commands:
190  *
191  * enabled:	When enabled, the remote processor will be automatically
192  *		recovered whenever it crashes. Moreover, if the remote
193  *		processor crashes while recovery is disabled, it will
194  *		be automatically recovered too as soon as recovery is enabled.
195  *
196  * disabled:	When disabled, a remote processor will remain in a crashed
197  *		state if it crashes. This is useful for debugging purposes;
198  *		without it, debugging a crash is substantially harder.
199  *
200  * recover:	This function will trigger an immediate recovery if the
201  *		remote processor is in a crashed state, without changing
202  *		or checking the recovery state (enabled/disabled).
203  *		This is useful during debugging sessions, when one expects
204  *		additional crashes to happen after enabling recovery. In this
205  *		case, enabling recovery will make it hard to debug subsequent
206  *		crashes, so it's recommended to keep recovery disabled, and
207  *		instead use the "recover" command as needed.
208  */
209 static ssize_t
210 rproc_recovery_write(struct file *filp, const char __user *user_buf,
211 		     size_t count, loff_t *ppos)
212 {
213 	struct rproc *rproc = filp->private_data;
214 	char buf[10];
215 	int ret;
216 
217 	if (count < 1 || count > sizeof(buf))
218 		return -EINVAL;
219 
220 	ret = copy_from_user(buf, user_buf, count);
221 	if (ret)
222 		return -EFAULT;
223 
224 	/* remove end of line */
225 	if (buf[count - 1] == '\n')
226 		buf[count - 1] = '\0';
227 
228 	if (!strncmp(buf, "enabled", count)) {
229 		/* change the flag and begin the recovery process if needed */
230 		rproc->recovery_disabled = false;
231 		rproc_trigger_recovery(rproc);
232 	} else if (!strncmp(buf, "disabled", count)) {
233 		rproc->recovery_disabled = true;
234 	} else if (!strncmp(buf, "recover", count)) {
235 		/* begin the recovery process without changing the flag */
236 		rproc_trigger_recovery(rproc);
237 	} else {
238 		return -EINVAL;
239 	}
240 
241 	return count;
242 }
243 
244 static const struct file_operations rproc_recovery_ops = {
245 	.read = rproc_recovery_read,
246 	.write = rproc_recovery_write,
247 	.open = simple_open,
248 	.llseek = generic_file_llseek,
249 };
250 
251 /* expose the crash trigger via debugfs */
252 static ssize_t
253 rproc_crash_write(struct file *filp, const char __user *user_buf,
254 		  size_t count, loff_t *ppos)
255 {
256 	struct rproc *rproc = filp->private_data;
257 	unsigned int type;
258 	int ret;
259 
260 	ret = kstrtouint_from_user(user_buf, count, 0, &type);
261 	if (ret < 0)
262 		return ret;
263 
264 	rproc_report_crash(rproc, type);
265 
266 	return count;
267 }
268 
269 static const struct file_operations rproc_crash_ops = {
270 	.write = rproc_crash_write,
271 	.open = simple_open,
272 	.llseek = generic_file_llseek,
273 };
274 
275 /* Expose resource table content via debugfs */
276 static int rproc_rsc_table_show(struct seq_file *seq, void *p)
277 {
278 	static const char * const types[] = {"carveout", "devmem", "trace", "vdev"};
279 	struct rproc *rproc = seq->private;
280 	struct resource_table *table = rproc->table_ptr;
281 	struct fw_rsc_carveout *c;
282 	struct fw_rsc_devmem *d;
283 	struct fw_rsc_trace *t;
284 	struct fw_rsc_vdev *v;
285 	int i, j;
286 
287 	if (!table) {
288 		seq_puts(seq, "No resource table found\n");
289 		return 0;
290 	}
291 
292 	for (i = 0; i < table->num; i++) {
293 		int offset = table->offset[i];
294 		struct fw_rsc_hdr *hdr = (void *)table + offset;
295 		void *rsc = (void *)hdr + sizeof(*hdr);
296 
297 		switch (hdr->type) {
298 		case RSC_CARVEOUT:
299 			c = rsc;
300 			seq_printf(seq, "Entry %d is of type %s\n", i, types[hdr->type]);
301 			seq_printf(seq, "  Device Address 0x%x\n", c->da);
302 			seq_printf(seq, "  Physical Address 0x%x\n", c->pa);
303 			seq_printf(seq, "  Length 0x%x Bytes\n", c->len);
304 			seq_printf(seq, "  Flags 0x%x\n", c->flags);
305 			seq_printf(seq, "  Reserved (should be zero) [%d]\n", c->reserved);
306 			seq_printf(seq, "  Name %s\n\n", c->name);
307 			break;
308 		case RSC_DEVMEM:
309 			d = rsc;
310 			seq_printf(seq, "Entry %d is of type %s\n", i, types[hdr->type]);
311 			seq_printf(seq, "  Device Address 0x%x\n", d->da);
312 			seq_printf(seq, "  Physical Address 0x%x\n", d->pa);
313 			seq_printf(seq, "  Length 0x%x Bytes\n", d->len);
314 			seq_printf(seq, "  Flags 0x%x\n", d->flags);
315 			seq_printf(seq, "  Reserved (should be zero) [%d]\n", d->reserved);
316 			seq_printf(seq, "  Name %s\n\n", d->name);
317 			break;
318 		case RSC_TRACE:
319 			t = rsc;
320 			seq_printf(seq, "Entry %d is of type %s\n", i, types[hdr->type]);
321 			seq_printf(seq, "  Device Address 0x%x\n", t->da);
322 			seq_printf(seq, "  Length 0x%x Bytes\n", t->len);
323 			seq_printf(seq, "  Reserved (should be zero) [%d]\n", t->reserved);
324 			seq_printf(seq, "  Name %s\n\n", t->name);
325 			break;
326 		case RSC_VDEV:
327 			v = rsc;
328 			seq_printf(seq, "Entry %d is of type %s\n", i, types[hdr->type]);
329 
330 			seq_printf(seq, "  ID %d\n", v->id);
331 			seq_printf(seq, "  Notify ID %d\n", v->notifyid);
332 			seq_printf(seq, "  Device features 0x%x\n", v->dfeatures);
333 			seq_printf(seq, "  Guest features 0x%x\n", v->gfeatures);
334 			seq_printf(seq, "  Config length 0x%x\n", v->config_len);
335 			seq_printf(seq, "  Status 0x%x\n", v->status);
336 			seq_printf(seq, "  Number of vrings %d\n", v->num_of_vrings);
337 			seq_printf(seq, "  Reserved (should be zero) [%d][%d]\n\n",
338 				   v->reserved[0], v->reserved[1]);
339 
340 			for (j = 0; j < v->num_of_vrings; j++) {
341 				seq_printf(seq, "  Vring %d\n", j);
342 				seq_printf(seq, "    Device Address 0x%x\n", v->vring[j].da);
343 				seq_printf(seq, "    Alignment %d\n", v->vring[j].align);
344 				seq_printf(seq, "    Number of buffers %d\n", v->vring[j].num);
345 				seq_printf(seq, "    Notify ID %d\n", v->vring[j].notifyid);
346 				seq_printf(seq, "    Physical Address 0x%x\n\n",
347 					   v->vring[j].pa);
348 			}
349 			break;
350 		default:
351 			seq_printf(seq, "Unknown resource type found: %d [hdr: %pK]\n",
352 				   hdr->type, hdr);
353 			break;
354 		}
355 	}
356 
357 	return 0;
358 }
359 
360 DEFINE_SHOW_ATTRIBUTE(rproc_rsc_table);
361 
362 /* Expose carveout content via debugfs */
363 static int rproc_carveouts_show(struct seq_file *seq, void *p)
364 {
365 	struct rproc *rproc = seq->private;
366 	struct rproc_mem_entry *carveout;
367 
368 	list_for_each_entry(carveout, &rproc->carveouts, node) {
369 		seq_puts(seq, "Carveout memory entry:\n");
370 		seq_printf(seq, "\tName: %s\n", carveout->name);
371 		seq_printf(seq, "\tVirtual address: %pK\n", carveout->va);
372 		seq_printf(seq, "\tDMA address: %pad\n", &carveout->dma);
373 		seq_printf(seq, "\tDevice address: 0x%x\n", carveout->da);
374 		seq_printf(seq, "\tLength: 0x%zx Bytes\n\n", carveout->len);
375 	}
376 
377 	return 0;
378 }
379 
380 DEFINE_SHOW_ATTRIBUTE(rproc_carveouts);
381 
382 void rproc_remove_trace_file(struct dentry *tfile)
383 {
384 	debugfs_remove(tfile);
385 }
386 
387 struct dentry *rproc_create_trace_file(const char *name, struct rproc *rproc,
388 				       struct rproc_debug_trace *trace)
389 {
390 	struct dentry *tfile;
391 
392 	tfile = debugfs_create_file(name, 0400, rproc->dbg_dir, trace,
393 				    &trace_rproc_ops);
394 	if (!tfile) {
395 		dev_err(&rproc->dev, "failed to create debugfs trace entry\n");
396 		return NULL;
397 	}
398 
399 	return tfile;
400 }
401 
402 void rproc_delete_debug_dir(struct rproc *rproc)
403 {
404 	debugfs_remove_recursive(rproc->dbg_dir);
405 }
406 
407 void rproc_create_debug_dir(struct rproc *rproc)
408 {
409 	struct device *dev = &rproc->dev;
410 
411 	if (!rproc_dbg)
412 		return;
413 
414 	rproc->dbg_dir = debugfs_create_dir(dev_name(dev), rproc_dbg);
415 	if (!rproc->dbg_dir)
416 		return;
417 
418 	debugfs_create_file("name", 0400, rproc->dbg_dir,
419 			    rproc, &rproc_name_ops);
420 	debugfs_create_file("recovery", 0600, rproc->dbg_dir,
421 			    rproc, &rproc_recovery_ops);
422 	debugfs_create_file("crash", 0200, rproc->dbg_dir,
423 			    rproc, &rproc_crash_ops);
424 	debugfs_create_file("resource_table", 0400, rproc->dbg_dir,
425 			    rproc, &rproc_rsc_table_fops);
426 	debugfs_create_file("carveout_memories", 0400, rproc->dbg_dir,
427 			    rproc, &rproc_carveouts_fops);
428 	debugfs_create_file("coredump", 0600, rproc->dbg_dir,
429 			    rproc, &rproc_coredump_fops);
430 }
431 
432 void __init rproc_init_debugfs(void)
433 {
434 	if (debugfs_initialized()) {
435 		rproc_dbg = debugfs_create_dir(KBUILD_MODNAME, NULL);
436 		if (!rproc_dbg)
437 			pr_err("can't create debugfs dir\n");
438 	}
439 }
440 
441 void __exit rproc_exit_debugfs(void)
442 {
443 	debugfs_remove(rproc_dbg);
444 }
445