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6391a706 OBC |
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> | |
2e37abb8 FGL |
31 | #include <linux/uaccess.h> |
32 | ||
33 | #include "remoteproc_internal.h" | |
6391a706 OBC |
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, | |
730f84ce | 48 | size_t count, loff_t *ppos) |
6391a706 OBC |
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 | ||
6391a706 OBC |
56 | static const struct file_operations trace_rproc_ops = { |
57 | .read = rproc_trace_read, | |
234e3405 | 58 | .open = simple_open, |
6391a706 OBC |
59 | .llseek = generic_file_llseek, |
60 | }; | |
61 | ||
6391a706 OBC |
62 | /* expose the name of the remote processor via debugfs */ |
63 | static ssize_t rproc_name_read(struct file *filp, char __user *userbuf, | |
730f84ce | 64 | size_t count, loff_t *ppos) |
6391a706 OBC |
65 | { |
66 | struct rproc *rproc = filp->private_data; | |
67 | /* need room for the name, a newline and a terminating null */ | |
68 | char buf[100]; | |
69 | int i; | |
70 | ||
ae768d5f | 71 | i = scnprintf(buf, sizeof(buf), "%.98s\n", rproc->name); |
6391a706 OBC |
72 | |
73 | return simple_read_from_buffer(userbuf, count, ppos, buf, i); | |
74 | } | |
75 | ||
76 | static const struct file_operations rproc_name_ops = { | |
77 | .read = rproc_name_read, | |
234e3405 | 78 | .open = simple_open, |
6391a706 OBC |
79 | .llseek = generic_file_llseek, |
80 | }; | |
81 | ||
2e37abb8 FGL |
82 | /* expose recovery flag via debugfs */ |
83 | static ssize_t rproc_recovery_read(struct file *filp, char __user *userbuf, | |
84 | size_t count, loff_t *ppos) | |
85 | { | |
86 | struct rproc *rproc = filp->private_data; | |
87 | char *buf = rproc->recovery_disabled ? "disabled\n" : "enabled\n"; | |
88 | ||
89 | return simple_read_from_buffer(userbuf, count, ppos, buf, strlen(buf)); | |
90 | } | |
91 | ||
92 | /* | |
93 | * By writing to the 'recovery' debugfs entry, we control the behavior of the | |
94 | * recovery mechanism dynamically. The default value of this entry is "enabled". | |
95 | * | |
96 | * The 'recovery' debugfs entry supports these commands: | |
97 | * | |
98 | * enabled: When enabled, the remote processor will be automatically | |
99 | * recovered whenever it crashes. Moreover, if the remote | |
100 | * processor crashes while recovery is disabled, it will | |
101 | * be automatically recovered too as soon as recovery is enabled. | |
102 | * | |
103 | * disabled: When disabled, a remote processor will remain in a crashed | |
104 | * state if it crashes. This is useful for debugging purposes; | |
105 | * without it, debugging a crash is substantially harder. | |
106 | * | |
107 | * recover: This function will trigger an immediate recovery if the | |
108 | * remote processor is in a crashed state, without changing | |
109 | * or checking the recovery state (enabled/disabled). | |
110 | * This is useful during debugging sessions, when one expects | |
111 | * additional crashes to happen after enabling recovery. In this | |
112 | * case, enabling recovery will make it hard to debug subsequent | |
113 | * crashes, so it's recommended to keep recovery disabled, and | |
114 | * instead use the "recover" command as needed. | |
115 | */ | |
116 | static ssize_t | |
117 | rproc_recovery_write(struct file *filp, const char __user *user_buf, | |
118 | size_t count, loff_t *ppos) | |
119 | { | |
120 | struct rproc *rproc = filp->private_data; | |
121 | char buf[10]; | |
122 | int ret; | |
123 | ||
92792e48 | 124 | if (count < 1 || count > sizeof(buf)) |
47fff9fd | 125 | return -EINVAL; |
2e37abb8 FGL |
126 | |
127 | ret = copy_from_user(buf, user_buf, count); | |
128 | if (ret) | |
bec109a4 | 129 | return -EFAULT; |
2e37abb8 FGL |
130 | |
131 | /* remove end of line */ | |
132 | if (buf[count - 1] == '\n') | |
133 | buf[count - 1] = '\0'; | |
134 | ||
135 | if (!strncmp(buf, "enabled", count)) { | |
136 | rproc->recovery_disabled = false; | |
137 | /* if rproc has crashed, trigger recovery */ | |
138 | if (rproc->state == RPROC_CRASHED) | |
139 | rproc_trigger_recovery(rproc); | |
140 | } else if (!strncmp(buf, "disabled", count)) { | |
141 | rproc->recovery_disabled = true; | |
142 | } else if (!strncmp(buf, "recover", count)) { | |
143 | /* if rproc has crashed, trigger recovery */ | |
144 | if (rproc->state == RPROC_CRASHED) | |
145 | rproc_trigger_recovery(rproc); | |
146 | } | |
147 | ||
148 | return count; | |
149 | } | |
150 | ||
151 | static const struct file_operations rproc_recovery_ops = { | |
152 | .read = rproc_recovery_read, | |
153 | .write = rproc_recovery_write, | |
154 | .open = simple_open, | |
155 | .llseek = generic_file_llseek, | |
156 | }; | |
157 | ||
6391a706 OBC |
158 | void rproc_remove_trace_file(struct dentry *tfile) |
159 | { | |
160 | debugfs_remove(tfile); | |
161 | } | |
162 | ||
163 | struct dentry *rproc_create_trace_file(const char *name, struct rproc *rproc, | |
730f84ce | 164 | struct rproc_mem_entry *trace) |
6391a706 OBC |
165 | { |
166 | struct dentry *tfile; | |
167 | ||
730f84ce AS |
168 | tfile = debugfs_create_file(name, 0400, rproc->dbg_dir, trace, |
169 | &trace_rproc_ops); | |
6391a706 | 170 | if (!tfile) { |
b5ab5e24 | 171 | dev_err(&rproc->dev, "failed to create debugfs trace entry\n"); |
6391a706 OBC |
172 | return NULL; |
173 | } | |
174 | ||
175 | return tfile; | |
176 | } | |
177 | ||
178 | void rproc_delete_debug_dir(struct rproc *rproc) | |
179 | { | |
180 | if (!rproc->dbg_dir) | |
181 | return; | |
182 | ||
183 | debugfs_remove_recursive(rproc->dbg_dir); | |
184 | } | |
185 | ||
186 | void rproc_create_debug_dir(struct rproc *rproc) | |
187 | { | |
b5ab5e24 | 188 | struct device *dev = &rproc->dev; |
6391a706 OBC |
189 | |
190 | if (!rproc_dbg) | |
191 | return; | |
192 | ||
193 | rproc->dbg_dir = debugfs_create_dir(dev_name(dev), rproc_dbg); | |
194 | if (!rproc->dbg_dir) | |
195 | return; | |
196 | ||
197 | debugfs_create_file("name", 0400, rproc->dbg_dir, | |
730f84ce | 198 | rproc, &rproc_name_ops); |
2e37abb8 | 199 | debugfs_create_file("recovery", 0400, rproc->dbg_dir, |
730f84ce | 200 | rproc, &rproc_recovery_ops); |
6391a706 OBC |
201 | } |
202 | ||
203 | void __init rproc_init_debugfs(void) | |
204 | { | |
205 | if (debugfs_initialized()) { | |
206 | rproc_dbg = debugfs_create_dir(KBUILD_MODNAME, NULL); | |
207 | if (!rproc_dbg) | |
208 | pr_err("can't create debugfs dir\n"); | |
209 | } | |
210 | } | |
211 | ||
212 | void __exit rproc_exit_debugfs(void) | |
213 | { | |
57971159 | 214 | debugfs_remove(rproc_dbg); |
6391a706 | 215 | } |