1 /*
2  * Remote Processor Framework
3  *
4  * Copyright (C) 2011 Texas Instruments, Inc.
5  * Copyright (C) 2011 Google, Inc.
6  *
7  * Ohad Ben-Cohen <ohad@wizery.com>
8  * Mark Grosen <mgrosen@ti.com>
9  * Brian Swetland <swetland@google.com>
10  * Fernando Guzman Lugo <fernando.lugo@ti.com>
11  * Suman Anna <s-anna@ti.com>
12  * Robert Tivy <rtivy@ti.com>
13  * Armando Uribe De Leon <x0095078@ti.com>
14  *
15  * This program is free software; you can redistribute it and/or
16  * modify it under the terms of the GNU General Public License
17  * version 2 as published by the Free Software Foundation.
18  *
19  * This program is distributed in the hope that it will be useful,
20  * but WITHOUT ANY WARRANTY; without even the implied warranty of
21  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
22  * GNU General Public License for more details.
23  */
24 
25 #define pr_fmt(fmt)    "%s: " fmt, __func__
26 
27 #include <linux/kernel.h>
28 #include <linux/debugfs.h>
29 #include <linux/remoteproc.h>
30 #include <linux/device.h>
31 #include <linux/uaccess.h>
32 
33 #include "remoteproc_internal.h"
34 
35 /* remoteproc debugfs parent dir */
36 static struct dentry *rproc_dbg;
37 
38 /*
39  * Some remote processors may support dumping trace logs into a shared
40  * memory buffer. We expose this trace buffer using debugfs, so users
41  * can easily tell what's going on remotely.
42  *
43  * We will most probably improve the rproc tracing facilities later on,
44  * but this kind of lightweight and simple mechanism is always good to have,
45  * as it provides very early tracing with little to no dependencies at all.
46  */
47 static ssize_t rproc_trace_read(struct file *filp, char __user *userbuf,
48 				size_t count, loff_t *ppos)
49 {
50 	struct rproc_debug_trace *data = filp->private_data;
51 	struct rproc_mem_entry *trace = &data->trace_mem;
52 	void *va;
53 	char buf[100];
54 	int len;
55 
56 	va = rproc_da_to_va(data->rproc, trace->da, trace->len);
57 
58 	if (!va) {
59 		len = scnprintf(buf, sizeof(buf), "Trace %s not available\n",
60 				trace->name);
61 		va = buf;
62 	} else {
63 		len = strnlen(va, trace->len);
64 	}
65 
66 	return simple_read_from_buffer(userbuf, count, ppos, va, len);
67 }
68 
69 static const struct file_operations trace_rproc_ops = {
70 	.read = rproc_trace_read,
71 	.open = simple_open,
72 	.llseek	= generic_file_llseek,
73 };
74 
75 /* expose the name of the remote processor via debugfs */
76 static ssize_t rproc_name_read(struct file *filp, char __user *userbuf,
77 			       size_t count, loff_t *ppos)
78 {
79 	struct rproc *rproc = filp->private_data;
80 	/* need room for the name, a newline and a terminating null */
81 	char buf[100];
82 	int i;
83 
84 	i = scnprintf(buf, sizeof(buf), "%.98s\n", rproc->name);
85 
86 	return simple_read_from_buffer(userbuf, count, ppos, buf, i);
87 }
88 
89 static const struct file_operations rproc_name_ops = {
90 	.read = rproc_name_read,
91 	.open = simple_open,
92 	.llseek	= generic_file_llseek,
93 };
94 
95 /* expose recovery flag via debugfs */
96 static ssize_t rproc_recovery_read(struct file *filp, char __user *userbuf,
97 				   size_t count, loff_t *ppos)
98 {
99 	struct rproc *rproc = filp->private_data;
100 	char *buf = rproc->recovery_disabled ? "disabled\n" : "enabled\n";
101 
102 	return simple_read_from_buffer(userbuf, count, ppos, buf, strlen(buf));
103 }
104 
105 /*
106  * By writing to the 'recovery' debugfs entry, we control the behavior of the
107  * recovery mechanism dynamically. The default value of this entry is "enabled".
108  *
109  * The 'recovery' debugfs entry supports these commands:
110  *
111  * enabled:	When enabled, the remote processor will be automatically
112  *		recovered whenever it crashes. Moreover, if the remote
113  *		processor crashes while recovery is disabled, it will
114  *		be automatically recovered too as soon as recovery is enabled.
115  *
116  * disabled:	When disabled, a remote processor will remain in a crashed
117  *		state if it crashes. This is useful for debugging purposes;
118  *		without it, debugging a crash is substantially harder.
119  *
120  * recover:	This function will trigger an immediate recovery if the
121  *		remote processor is in a crashed state, without changing
122  *		or checking the recovery state (enabled/disabled).
123  *		This is useful during debugging sessions, when one expects
124  *		additional crashes to happen after enabling recovery. In this
125  *		case, enabling recovery will make it hard to debug subsequent
126  *		crashes, so it's recommended to keep recovery disabled, and
127  *		instead use the "recover" command as needed.
128  */
129 static ssize_t
130 rproc_recovery_write(struct file *filp, const char __user *user_buf,
131 		     size_t count, loff_t *ppos)
132 {
133 	struct rproc *rproc = filp->private_data;
134 	char buf[10];
135 	int ret;
136 
137 	if (count < 1 || count > sizeof(buf))
138 		return -EINVAL;
139 
140 	ret = copy_from_user(buf, user_buf, count);
141 	if (ret)
142 		return -EFAULT;
143 
144 	/* remove end of line */
145 	if (buf[count - 1] == '\n')
146 		buf[count - 1] = '\0';
147 
148 	if (!strncmp(buf, "enabled", count)) {
149 		rproc->recovery_disabled = false;
150 		/* if rproc has crashed, trigger recovery */
151 		if (rproc->state == RPROC_CRASHED)
152 			rproc_trigger_recovery(rproc);
153 	} else if (!strncmp(buf, "disabled", count)) {
154 		rproc->recovery_disabled = true;
155 	} else if (!strncmp(buf, "recover", count)) {
156 		/* if rproc has crashed, trigger recovery */
157 		if (rproc->state == RPROC_CRASHED)
158 			rproc_trigger_recovery(rproc);
159 	}
160 
161 	return count;
162 }
163 
164 static const struct file_operations rproc_recovery_ops = {
165 	.read = rproc_recovery_read,
166 	.write = rproc_recovery_write,
167 	.open = simple_open,
168 	.llseek = generic_file_llseek,
169 };
170 
171 /* expose the crash trigger via debugfs */
172 static ssize_t
173 rproc_crash_write(struct file *filp, const char __user *user_buf,
174 		  size_t count, loff_t *ppos)
175 {
176 	struct rproc *rproc = filp->private_data;
177 	unsigned int type;
178 	int ret;
179 
180 	ret = kstrtouint_from_user(user_buf, count, 0, &type);
181 	if (ret < 0)
182 		return ret;
183 
184 	rproc_report_crash(rproc, type);
185 
186 	return count;
187 }
188 
189 static const struct file_operations rproc_crash_ops = {
190 	.write = rproc_crash_write,
191 	.open = simple_open,
192 	.llseek = generic_file_llseek,
193 };
194 
195 /* Expose resource table content via debugfs */
196 static int rproc_rsc_table_show(struct seq_file *seq, void *p)
197 {
198 	static const char * const types[] = {"carveout", "devmem", "trace", "vdev"};
199 	struct rproc *rproc = seq->private;
200 	struct resource_table *table = rproc->table_ptr;
201 	struct fw_rsc_carveout *c;
202 	struct fw_rsc_devmem *d;
203 	struct fw_rsc_trace *t;
204 	struct fw_rsc_vdev *v;
205 	int i, j;
206 
207 	if (!table) {
208 		seq_puts(seq, "No resource table found\n");
209 		return 0;
210 	}
211 
212 	for (i = 0; i < table->num; i++) {
213 		int offset = table->offset[i];
214 		struct fw_rsc_hdr *hdr = (void *)table + offset;
215 		void *rsc = (void *)hdr + sizeof(*hdr);
216 
217 		switch (hdr->type) {
218 		case RSC_CARVEOUT:
219 			c = rsc;
220 			seq_printf(seq, "Entry %d is of type %s\n", i, types[hdr->type]);
221 			seq_printf(seq, "  Device Address 0x%x\n", c->da);
222 			seq_printf(seq, "  Physical Address 0x%x\n", c->pa);
223 			seq_printf(seq, "  Length 0x%x Bytes\n", c->len);
224 			seq_printf(seq, "  Flags 0x%x\n", c->flags);
225 			seq_printf(seq, "  Reserved (should be zero) [%d]\n", c->reserved);
226 			seq_printf(seq, "  Name %s\n\n", c->name);
227 			break;
228 		case RSC_DEVMEM:
229 			d = rsc;
230 			seq_printf(seq, "Entry %d is of type %s\n", i, types[hdr->type]);
231 			seq_printf(seq, "  Device Address 0x%x\n", d->da);
232 			seq_printf(seq, "  Physical Address 0x%x\n", d->pa);
233 			seq_printf(seq, "  Length 0x%x Bytes\n", d->len);
234 			seq_printf(seq, "  Flags 0x%x\n", d->flags);
235 			seq_printf(seq, "  Reserved (should be zero) [%d]\n", d->reserved);
236 			seq_printf(seq, "  Name %s\n\n", d->name);
237 			break;
238 		case RSC_TRACE:
239 			t = rsc;
240 			seq_printf(seq, "Entry %d is of type %s\n", i, types[hdr->type]);
241 			seq_printf(seq, "  Device Address 0x%x\n", t->da);
242 			seq_printf(seq, "  Length 0x%x Bytes\n", t->len);
243 			seq_printf(seq, "  Reserved (should be zero) [%d]\n", t->reserved);
244 			seq_printf(seq, "  Name %s\n\n", t->name);
245 			break;
246 		case RSC_VDEV:
247 			v = rsc;
248 			seq_printf(seq, "Entry %d is of type %s\n", i, types[hdr->type]);
249 
250 			seq_printf(seq, "  ID %d\n", v->id);
251 			seq_printf(seq, "  Notify ID %d\n", v->notifyid);
252 			seq_printf(seq, "  Device features 0x%x\n", v->dfeatures);
253 			seq_printf(seq, "  Guest features 0x%x\n", v->gfeatures);
254 			seq_printf(seq, "  Config length 0x%x\n", v->config_len);
255 			seq_printf(seq, "  Status 0x%x\n", v->status);
256 			seq_printf(seq, "  Number of vrings %d\n", v->num_of_vrings);
257 			seq_printf(seq, "  Reserved (should be zero) [%d][%d]\n\n",
258 				   v->reserved[0], v->reserved[1]);
259 
260 			for (j = 0; j < v->num_of_vrings; j++) {
261 				seq_printf(seq, "  Vring %d\n", j);
262 				seq_printf(seq, "    Device Address 0x%x\n", v->vring[j].da);
263 				seq_printf(seq, "    Alignment %d\n", v->vring[j].align);
264 				seq_printf(seq, "    Number of buffers %d\n", v->vring[j].num);
265 				seq_printf(seq, "    Notify ID %d\n", v->vring[j].notifyid);
266 				seq_printf(seq, "    Physical Address 0x%x\n\n",
267 					   v->vring[j].pa);
268 			}
269 			break;
270 		default:
271 			seq_printf(seq, "Unknown resource type found: %d [hdr: %pK]\n",
272 				   hdr->type, hdr);
273 			break;
274 		}
275 	}
276 
277 	return 0;
278 }
279 
280 static int rproc_rsc_table_open(struct inode *inode, struct file *file)
281 {
282 	return single_open(file, rproc_rsc_table_show, inode->i_private);
283 }
284 
285 static const struct file_operations rproc_rsc_table_ops = {
286 	.open		= rproc_rsc_table_open,
287 	.read		= seq_read,
288 	.llseek		= seq_lseek,
289 	.release	= single_release,
290 };
291 
292 /* Expose carveout content via debugfs */
293 static int rproc_carveouts_show(struct seq_file *seq, void *p)
294 {
295 	struct rproc *rproc = seq->private;
296 	struct rproc_mem_entry *carveout;
297 
298 	list_for_each_entry(carveout, &rproc->carveouts, node) {
299 		seq_puts(seq, "Carveout memory entry:\n");
300 		seq_printf(seq, "\tName: %s\n", carveout->name);
301 		seq_printf(seq, "\tVirtual address: %pK\n", carveout->va);
302 		seq_printf(seq, "\tDMA address: %pad\n", &carveout->dma);
303 		seq_printf(seq, "\tDevice address: 0x%x\n", carveout->da);
304 		seq_printf(seq, "\tLength: 0x%x Bytes\n\n", carveout->len);
305 	}
306 
307 	return 0;
308 }
309 
310 static int rproc_carveouts_open(struct inode *inode, struct file *file)
311 {
312 	return single_open(file, rproc_carveouts_show, inode->i_private);
313 }
314 
315 static const struct file_operations rproc_carveouts_ops = {
316 	.open		= rproc_carveouts_open,
317 	.read		= seq_read,
318 	.llseek		= seq_lseek,
319 	.release	= single_release,
320 };
321 
322 void rproc_remove_trace_file(struct dentry *tfile)
323 {
324 	debugfs_remove(tfile);
325 }
326 
327 struct dentry *rproc_create_trace_file(const char *name, struct rproc *rproc,
328 				       struct rproc_debug_trace *trace)
329 {
330 	struct dentry *tfile;
331 
332 	tfile = debugfs_create_file(name, 0400, rproc->dbg_dir, trace,
333 				    &trace_rproc_ops);
334 	if (!tfile) {
335 		dev_err(&rproc->dev, "failed to create debugfs trace entry\n");
336 		return NULL;
337 	}
338 
339 	return tfile;
340 }
341 
342 void rproc_delete_debug_dir(struct rproc *rproc)
343 {
344 	if (!rproc->dbg_dir)
345 		return;
346 
347 	debugfs_remove_recursive(rproc->dbg_dir);
348 }
349 
350 void rproc_create_debug_dir(struct rproc *rproc)
351 {
352 	struct device *dev = &rproc->dev;
353 
354 	if (!rproc_dbg)
355 		return;
356 
357 	rproc->dbg_dir = debugfs_create_dir(dev_name(dev), rproc_dbg);
358 	if (!rproc->dbg_dir)
359 		return;
360 
361 	debugfs_create_file("name", 0400, rproc->dbg_dir,
362 			    rproc, &rproc_name_ops);
363 	debugfs_create_file("recovery", 0400, rproc->dbg_dir,
364 			    rproc, &rproc_recovery_ops);
365 	debugfs_create_file("crash", 0200, rproc->dbg_dir,
366 			    rproc, &rproc_crash_ops);
367 	debugfs_create_file("resource_table", 0400, rproc->dbg_dir,
368 			    rproc, &rproc_rsc_table_ops);
369 	debugfs_create_file("carveout_memories", 0400, rproc->dbg_dir,
370 			    rproc, &rproc_carveouts_ops);
371 }
372 
373 void __init rproc_init_debugfs(void)
374 {
375 	if (debugfs_initialized()) {
376 		rproc_dbg = debugfs_create_dir(KBUILD_MODNAME, NULL);
377 		if (!rproc_dbg)
378 			pr_err("can't create debugfs dir\n");
379 	}
380 }
381 
382 void __exit rproc_exit_debugfs(void)
383 {
384 	debugfs_remove(rproc_dbg);
385 }
386