1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * Remote Processor Framework
4 */
5
6#include <linux/remoteproc.h>
7#include <linux/slab.h>
8
9#include "remoteproc_internal.h"
10
11#define to_rproc(d) container_of(d, struct rproc, dev)
12
13static ssize_t recovery_show(struct device *dev,
14 struct device_attribute *attr, char *buf)
15{
16 struct rproc *rproc = to_rproc(dev);
17
18 return sysfs_emit(buf, fmt: "%s", rproc->recovery_disabled ? "disabled\n" : "enabled\n");
19}
20
21/*
22 * By writing to the 'recovery' sysfs entry, we control the behavior of the
23 * recovery mechanism dynamically. The default value of this entry is "enabled".
24 *
25 * The 'recovery' sysfs entry supports these commands:
26 *
27 * enabled: When enabled, the remote processor will be automatically
28 * recovered whenever it crashes. Moreover, if the remote
29 * processor crashes while recovery is disabled, it will
30 * be automatically recovered too as soon as recovery is enabled.
31 *
32 * disabled: When disabled, a remote processor will remain in a crashed
33 * state if it crashes. This is useful for debugging purposes;
34 * without it, debugging a crash is substantially harder.
35 *
36 * recover: This function will trigger an immediate recovery if the
37 * remote processor is in a crashed state, without changing
38 * or checking the recovery state (enabled/disabled).
39 * This is useful during debugging sessions, when one expects
40 * additional crashes to happen after enabling recovery. In this
41 * case, enabling recovery will make it hard to debug subsequent
42 * crashes, so it's recommended to keep recovery disabled, and
43 * instead use the "recover" command as needed.
44 */
45static ssize_t recovery_store(struct device *dev,
46 struct device_attribute *attr,
47 const char *buf, size_t count)
48{
49 struct rproc *rproc = to_rproc(dev);
50
51 if (sysfs_streq(s1: buf, s2: "enabled")) {
52 /* change the flag and begin the recovery process if needed */
53 rproc->recovery_disabled = false;
54 rproc_trigger_recovery(rproc);
55 } else if (sysfs_streq(s1: buf, s2: "disabled")) {
56 rproc->recovery_disabled = true;
57 } else if (sysfs_streq(s1: buf, s2: "recover")) {
58 /* begin the recovery process without changing the flag */
59 rproc_trigger_recovery(rproc);
60 } else {
61 return -EINVAL;
62 }
63
64 return count;
65}
66static DEVICE_ATTR_RW(recovery);
67
68/*
69 * A coredump-configuration-to-string lookup table, for exposing a
70 * human readable configuration via sysfs. Always keep in sync with
71 * enum rproc_coredump_mechanism
72 */
73static const char * const rproc_coredump_str[] = {
74 [RPROC_COREDUMP_DISABLED] = "disabled",
75 [RPROC_COREDUMP_ENABLED] = "enabled",
76 [RPROC_COREDUMP_INLINE] = "inline",
77};
78
79/* Expose the current coredump configuration via debugfs */
80static ssize_t coredump_show(struct device *dev,
81 struct device_attribute *attr, char *buf)
82{
83 struct rproc *rproc = to_rproc(dev);
84
85 return sysfs_emit(buf, fmt: "%s\n", rproc_coredump_str[rproc->dump_conf]);
86}
87
88/*
89 * By writing to the 'coredump' sysfs entry, we control the behavior of the
90 * coredump mechanism dynamically. The default value of this entry is "default".
91 *
92 * The 'coredump' sysfs entry supports these commands:
93 *
94 * disabled: This is the default coredump mechanism. Recovery will proceed
95 * without collecting any dump.
96 *
97 * default: When the remoteproc crashes the entire coredump will be
98 * copied to a separate buffer and exposed to userspace.
99 *
100 * inline: The coredump will not be copied to a separate buffer and the
101 * recovery process will have to wait until data is read by
102 * userspace. But this avoid usage of extra memory.
103 */
104static ssize_t coredump_store(struct device *dev,
105 struct device_attribute *attr,
106 const char *buf, size_t count)
107{
108 struct rproc *rproc = to_rproc(dev);
109
110 if (rproc->state == RPROC_CRASHED) {
111 dev_err(&rproc->dev, "can't change coredump configuration\n");
112 return -EBUSY;
113 }
114
115 if (sysfs_streq(s1: buf, s2: "disabled")) {
116 rproc->dump_conf = RPROC_COREDUMP_DISABLED;
117 } else if (sysfs_streq(s1: buf, s2: "enabled")) {
118 rproc->dump_conf = RPROC_COREDUMP_ENABLED;
119 } else if (sysfs_streq(s1: buf, s2: "inline")) {
120 rproc->dump_conf = RPROC_COREDUMP_INLINE;
121 } else {
122 dev_err(&rproc->dev, "Invalid coredump configuration\n");
123 return -EINVAL;
124 }
125
126 return count;
127}
128static DEVICE_ATTR_RW(coredump);
129
130/* Expose the loaded / running firmware name via sysfs */
131static ssize_t firmware_show(struct device *dev, struct device_attribute *attr,
132 char *buf)
133{
134 struct rproc *rproc = to_rproc(dev);
135 const char *firmware = rproc->firmware;
136
137 /*
138 * If the remote processor has been started by an external
139 * entity we have no idea of what image it is running. As such
140 * simply display a generic string rather then rproc->firmware.
141 */
142 if (rproc->state == RPROC_ATTACHED)
143 firmware = "unknown";
144
145 return sprintf(buf, fmt: "%s\n", firmware);
146}
147
148/* Change firmware name via sysfs */
149static ssize_t firmware_store(struct device *dev,
150 struct device_attribute *attr,
151 const char *buf, size_t count)
152{
153 struct rproc *rproc = to_rproc(dev);
154 int err;
155
156 err = rproc_set_firmware(rproc, fw_name: buf);
157
158 return err ? err : count;
159}
160static DEVICE_ATTR_RW(firmware);
161
162/*
163 * A state-to-string lookup table, for exposing a human readable state
164 * via sysfs. Always keep in sync with enum rproc_state
165 */
166static const char * const rproc_state_string[] = {
167 [RPROC_OFFLINE] = "offline",
168 [RPROC_SUSPENDED] = "suspended",
169 [RPROC_RUNNING] = "running",
170 [RPROC_CRASHED] = "crashed",
171 [RPROC_DELETED] = "deleted",
172 [RPROC_ATTACHED] = "attached",
173 [RPROC_DETACHED] = "detached",
174 [RPROC_LAST] = "invalid",
175};
176
177/* Expose the state of the remote processor via sysfs */
178static ssize_t state_show(struct device *dev, struct device_attribute *attr,
179 char *buf)
180{
181 struct rproc *rproc = to_rproc(dev);
182 unsigned int state;
183
184 state = rproc->state > RPROC_LAST ? RPROC_LAST : rproc->state;
185 return sprintf(buf, fmt: "%s\n", rproc_state_string[state]);
186}
187
188/* Change remote processor state via sysfs */
189static ssize_t state_store(struct device *dev,
190 struct device_attribute *attr,
191 const char *buf, size_t count)
192{
193 struct rproc *rproc = to_rproc(dev);
194 int ret = 0;
195
196 if (sysfs_streq(s1: buf, s2: "start")) {
197 ret = rproc_boot(rproc);
198 if (ret)
199 dev_err(&rproc->dev, "Boot failed: %d\n", ret);
200 } else if (sysfs_streq(s1: buf, s2: "stop")) {
201 ret = rproc_shutdown(rproc);
202 } else if (sysfs_streq(s1: buf, s2: "detach")) {
203 ret = rproc_detach(rproc);
204 } else {
205 dev_err(&rproc->dev, "Unrecognised option: %s\n", buf);
206 ret = -EINVAL;
207 }
208 return ret ? ret : count;
209}
210static DEVICE_ATTR_RW(state);
211
212/* Expose the name of the remote processor via sysfs */
213static ssize_t name_show(struct device *dev, struct device_attribute *attr,
214 char *buf)
215{
216 struct rproc *rproc = to_rproc(dev);
217
218 return sprintf(buf, fmt: "%s\n", rproc->name);
219}
220static DEVICE_ATTR_RO(name);
221
222static umode_t rproc_is_visible(struct kobject *kobj, struct attribute *attr,
223 int n)
224{
225 struct device *dev = kobj_to_dev(kobj);
226 struct rproc *rproc = to_rproc(dev);
227 umode_t mode = attr->mode;
228
229 if (rproc->sysfs_read_only && (attr == &dev_attr_recovery.attr ||
230 attr == &dev_attr_firmware.attr ||
231 attr == &dev_attr_state.attr ||
232 attr == &dev_attr_coredump.attr))
233 mode = 0444;
234
235 return mode;
236}
237
238static struct attribute *rproc_attrs[] = {
239 &dev_attr_coredump.attr,
240 &dev_attr_recovery.attr,
241 &dev_attr_firmware.attr,
242 &dev_attr_state.attr,
243 &dev_attr_name.attr,
244 NULL
245};
246
247static const struct attribute_group rproc_devgroup = {
248 .attrs = rproc_attrs,
249 .is_visible = rproc_is_visible,
250};
251
252static const struct attribute_group *rproc_devgroups[] = {
253 &rproc_devgroup,
254 NULL
255};
256
257struct class rproc_class = {
258 .name = "remoteproc",
259 .dev_groups = rproc_devgroups,
260};
261
262int __init rproc_init_sysfs(void)
263{
264 /* create remoteproc device class for sysfs */
265 int err = class_register(class: &rproc_class);
266
267 if (err)
268 pr_err("remoteproc: unable to register class\n");
269 return err;
270}
271
272void __exit rproc_exit_sysfs(void)
273{
274 class_unregister(class: &rproc_class);
275}
276

source code of linux/drivers/remoteproc/remoteproc_sysfs.c