blob: 74a120b6e206ec728093e8c532d2f757722f267f [file] [log] [blame]
Ohad Ben-Cohen6391a702011-10-20 17:24:15 +02001/*
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>
Fernando Guzman Lugo2e37abb2012-09-18 12:26:35 +030031#include <linux/uaccess.h>
32
33#include "remoteproc_internal.h"
Ohad Ben-Cohen6391a702011-10-20 17:24:15 +020034
35/* remoteproc debugfs parent dir */
36static 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 */
47static ssize_t rproc_trace_read(struct file *filp, char __user *userbuf,
48 size_t count, loff_t *ppos)
49{
50 struct rproc_mem_entry *trace = filp->private_data;
51 int len = strnlen(trace->va, trace->len);
52
53 return simple_read_from_buffer(userbuf, count, ppos, trace->va, len);
54}
55
Ohad Ben-Cohen6391a702011-10-20 17:24:15 +020056static const struct file_operations trace_rproc_ops = {
57 .read = rproc_trace_read,
Stephen Boyd234e3402012-04-05 14:25:11 -070058 .open = simple_open,
Ohad Ben-Cohen6391a702011-10-20 17:24:15 +020059 .llseek = generic_file_llseek,
60};
61
62/*
63 * A state-to-string lookup table, for exposing a human readable state
64 * via debugfs. Always keep in sync with enum rproc_state
65 */
66static const char * const rproc_state_string[] = {
67 "offline",
68 "suspended",
69 "running",
70 "crashed",
71 "invalid",
72};
73
74/* expose the state of the remote processor via debugfs */
75static ssize_t rproc_state_read(struct file *filp, char __user *userbuf,
76 size_t count, loff_t *ppos)
77{
78 struct rproc *rproc = filp->private_data;
79 unsigned int state;
80 char buf[30];
81 int i;
82
83 state = rproc->state > RPROC_LAST ? RPROC_LAST : rproc->state;
84
Dan Carpenterae768d52012-09-25 10:02:51 +030085 i = scnprintf(buf, 30, "%.28s (%d)\n", rproc_state_string[state],
Ohad Ben-Cohen6391a702011-10-20 17:24:15 +020086 rproc->state);
87
88 return simple_read_from_buffer(userbuf, count, ppos, buf, i);
89}
90
Lee Jones69e50472016-01-12 12:46:17 +000091static ssize_t rproc_state_write(struct file *filp, const char __user *userbuf,
92 size_t count, loff_t *ppos)
93{
94 struct rproc *rproc = filp->private_data;
95 char buf[10];
96 int ret;
97
98 if (count > sizeof(buf) || count <= 0)
99 return -EINVAL;
100
101 ret = copy_from_user(buf, userbuf, count);
102 if (ret)
103 return -EFAULT;
104
105 if (buf[count - 1] == '\n')
106 buf[count - 1] = '\0';
107
108 if (!strncmp(buf, "start", count)) {
109 ret = rproc_boot(rproc);
110 if (ret) {
111 dev_err(&rproc->dev, "Boot failed: %d\n", ret);
112 return ret;
113 }
114 } else if (!strncmp(buf, "stop", count)) {
115 rproc_shutdown(rproc);
116 } else {
117 dev_err(&rproc->dev, "Unrecognised option: %s\n", buf);
118 return -EINVAL;
119 }
120
121 return count;
122}
123
Ohad Ben-Cohen6391a702011-10-20 17:24:15 +0200124static const struct file_operations rproc_state_ops = {
125 .read = rproc_state_read,
Lee Jones69e50472016-01-12 12:46:17 +0000126 .write = rproc_state_write,
Stephen Boyd234e3402012-04-05 14:25:11 -0700127 .open = simple_open,
Ohad Ben-Cohen6391a702011-10-20 17:24:15 +0200128 .llseek = generic_file_llseek,
129};
130
131/* expose the name of the remote processor via debugfs */
132static ssize_t rproc_name_read(struct file *filp, char __user *userbuf,
133 size_t count, loff_t *ppos)
134{
135 struct rproc *rproc = filp->private_data;
136 /* need room for the name, a newline and a terminating null */
137 char buf[100];
138 int i;
139
Dan Carpenterae768d52012-09-25 10:02:51 +0300140 i = scnprintf(buf, sizeof(buf), "%.98s\n", rproc->name);
Ohad Ben-Cohen6391a702011-10-20 17:24:15 +0200141
142 return simple_read_from_buffer(userbuf, count, ppos, buf, i);
143}
144
145static const struct file_operations rproc_name_ops = {
146 .read = rproc_name_read,
Stephen Boyd234e3402012-04-05 14:25:11 -0700147 .open = simple_open,
Ohad Ben-Cohen6391a702011-10-20 17:24:15 +0200148 .llseek = generic_file_llseek,
149};
150
Fernando Guzman Lugo2e37abb2012-09-18 12:26:35 +0300151/* expose recovery flag via debugfs */
152static ssize_t rproc_recovery_read(struct file *filp, char __user *userbuf,
153 size_t count, loff_t *ppos)
154{
155 struct rproc *rproc = filp->private_data;
156 char *buf = rproc->recovery_disabled ? "disabled\n" : "enabled\n";
157
158 return simple_read_from_buffer(userbuf, count, ppos, buf, strlen(buf));
159}
160
161/*
162 * By writing to the 'recovery' debugfs entry, we control the behavior of the
163 * recovery mechanism dynamically. The default value of this entry is "enabled".
164 *
165 * The 'recovery' debugfs entry supports these commands:
166 *
167 * enabled: When enabled, the remote processor will be automatically
168 * recovered whenever it crashes. Moreover, if the remote
169 * processor crashes while recovery is disabled, it will
170 * be automatically recovered too as soon as recovery is enabled.
171 *
172 * disabled: When disabled, a remote processor will remain in a crashed
173 * state if it crashes. This is useful for debugging purposes;
174 * without it, debugging a crash is substantially harder.
175 *
176 * recover: This function will trigger an immediate recovery if the
177 * remote processor is in a crashed state, without changing
178 * or checking the recovery state (enabled/disabled).
179 * This is useful during debugging sessions, when one expects
180 * additional crashes to happen after enabling recovery. In this
181 * case, enabling recovery will make it hard to debug subsequent
182 * crashes, so it's recommended to keep recovery disabled, and
183 * instead use the "recover" command as needed.
184 */
185static ssize_t
186rproc_recovery_write(struct file *filp, const char __user *user_buf,
187 size_t count, loff_t *ppos)
188{
189 struct rproc *rproc = filp->private_data;
190 char buf[10];
191 int ret;
192
Arnd Bergmann92792e42015-11-20 18:26:07 +0100193 if (count < 1 || count > sizeof(buf))
Lee Jones47fff9f2016-01-12 12:46:15 +0000194 return -EINVAL;
Fernando Guzman Lugo2e37abb2012-09-18 12:26:35 +0300195
196 ret = copy_from_user(buf, user_buf, count);
197 if (ret)
Dan Carpenterbec109a2012-09-25 10:05:33 +0300198 return -EFAULT;
Fernando Guzman Lugo2e37abb2012-09-18 12:26:35 +0300199
200 /* remove end of line */
201 if (buf[count - 1] == '\n')
202 buf[count - 1] = '\0';
203
204 if (!strncmp(buf, "enabled", count)) {
205 rproc->recovery_disabled = false;
206 /* if rproc has crashed, trigger recovery */
207 if (rproc->state == RPROC_CRASHED)
208 rproc_trigger_recovery(rproc);
209 } else if (!strncmp(buf, "disabled", count)) {
210 rproc->recovery_disabled = true;
211 } else if (!strncmp(buf, "recover", count)) {
212 /* if rproc has crashed, trigger recovery */
213 if (rproc->state == RPROC_CRASHED)
214 rproc_trigger_recovery(rproc);
215 }
216
217 return count;
218}
219
220static const struct file_operations rproc_recovery_ops = {
221 .read = rproc_recovery_read,
222 .write = rproc_recovery_write,
223 .open = simple_open,
224 .llseek = generic_file_llseek,
225};
226
Ohad Ben-Cohen6391a702011-10-20 17:24:15 +0200227void rproc_remove_trace_file(struct dentry *tfile)
228{
229 debugfs_remove(tfile);
230}
231
232struct dentry *rproc_create_trace_file(const char *name, struct rproc *rproc,
233 struct rproc_mem_entry *trace)
234{
235 struct dentry *tfile;
236
237 tfile = debugfs_create_file(name, 0400, rproc->dbg_dir,
238 trace, &trace_rproc_ops);
239 if (!tfile) {
Ohad Ben-Cohenb5ab5e22012-05-30 22:01:25 +0300240 dev_err(&rproc->dev, "failed to create debugfs trace entry\n");
Ohad Ben-Cohen6391a702011-10-20 17:24:15 +0200241 return NULL;
242 }
243
244 return tfile;
245}
246
247void rproc_delete_debug_dir(struct rproc *rproc)
248{
249 if (!rproc->dbg_dir)
250 return;
251
252 debugfs_remove_recursive(rproc->dbg_dir);
253}
254
255void rproc_create_debug_dir(struct rproc *rproc)
256{
Ohad Ben-Cohenb5ab5e22012-05-30 22:01:25 +0300257 struct device *dev = &rproc->dev;
Ohad Ben-Cohen6391a702011-10-20 17:24:15 +0200258
259 if (!rproc_dbg)
260 return;
261
262 rproc->dbg_dir = debugfs_create_dir(dev_name(dev), rproc_dbg);
263 if (!rproc->dbg_dir)
264 return;
265
266 debugfs_create_file("name", 0400, rproc->dbg_dir,
267 rproc, &rproc_name_ops);
268 debugfs_create_file("state", 0400, rproc->dbg_dir,
269 rproc, &rproc_state_ops);
Fernando Guzman Lugo2e37abb2012-09-18 12:26:35 +0300270 debugfs_create_file("recovery", 0400, rproc->dbg_dir,
271 rproc, &rproc_recovery_ops);
Ohad Ben-Cohen6391a702011-10-20 17:24:15 +0200272}
273
274void __init rproc_init_debugfs(void)
275{
276 if (debugfs_initialized()) {
277 rproc_dbg = debugfs_create_dir(KBUILD_MODNAME, NULL);
278 if (!rproc_dbg)
279 pr_err("can't create debugfs dir\n");
280 }
281}
282
283void __exit rproc_exit_debugfs(void)
284{
Suman Anna57971152013-06-30 11:33:05 +0300285 debugfs_remove(rproc_dbg);
Ohad Ben-Cohen6391a702011-10-20 17:24:15 +0200286}