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1// SPDX-License-Identifier: GPL-2.0-or-later
2/*
3 * vim: noexpandtab ts=8 sts=0 sw=8:
4 *
5 * configfs_example_macros.c - This file is a demonstration module
6 * containing a number of configfs subsystems. It uses the helper
7 * macros defined by configfs.h
8 *
9 * Based on sysfs:
10 * sysfs is Copyright (C) 2001, 2002, 2003 Patrick Mochel
11 *
12 * configfs Copyright (C) 2005 Oracle. All rights reserved.
13 */
14
15#include <linux/init.h>
16#include <linux/module.h>
17#include <linux/slab.h>
18
19#include <linux/configfs.h>
20
21
22
23/*
24 * 01-childless
25 *
26 * This first example is a childless subsystem. It cannot create
27 * any config_items. It just has attributes.
28 *
29 * Note that we are enclosing the configfs_subsystem inside a container.
30 * This is not necessary if a subsystem has no attributes directly
31 * on the subsystem. See the next example, 02-simple-children, for
32 * such a subsystem.
33 */
34
35struct childless {
36 struct configfs_subsystem subsys;
37 int showme;
38 int storeme;
39};
40
41static inline struct childless *to_childless(struct config_item *item)
42{
43 return item ? container_of(to_configfs_subsystem(to_config_group(item)),
44 struct childless, subsys) : NULL;
45}
46
47static ssize_t childless_showme_show(struct config_item *item, char *page)
48{
49 struct childless *childless = to_childless(item);
50 ssize_t pos;
51
52 pos = sprintf(page, "%d\n", childless->showme);
53 childless->showme++;
54
55 return pos;
56}
57
58static ssize_t childless_storeme_show(struct config_item *item, char *page)
59{
60 return sprintf(page, "%d\n", to_childless(item)->storeme);
61}
62
63static ssize_t childless_storeme_store(struct config_item *item,
64 const char *page, size_t count)
65{
66 struct childless *childless = to_childless(item);
67 unsigned long tmp;
68 char *p = (char *) page;
69
70 tmp = simple_strtoul(p, &p, 10);
71 if (!p || (*p && (*p != '\n')))
72 return -EINVAL;
73
74 if (tmp > INT_MAX)
75 return -ERANGE;
76
77 childless->storeme = tmp;
78
79 return count;
80}
81
82static ssize_t childless_description_show(struct config_item *item, char *page)
83{
84 return sprintf(page,
85"[01-childless]\n"
86"\n"
87"The childless subsystem is the simplest possible subsystem in\n"
88"configfs. It does not support the creation of child config_items.\n"
89"It only has a few attributes. In fact, it isn't much different\n"
90"than a directory in /proc.\n");
91}
92
93CONFIGFS_ATTR_RO(childless_, showme);
94CONFIGFS_ATTR(childless_, storeme);
95CONFIGFS_ATTR_RO(childless_, description);
96
97static struct configfs_attribute *childless_attrs[] = {
98 &childless_attr_showme,
99 &childless_attr_storeme,
100 &childless_attr_description,
101 NULL,
102};
103
104static const struct config_item_type childless_type = {
105 .ct_attrs = childless_attrs,
106 .ct_owner = THIS_MODULE,
107};
108
109static struct childless childless_subsys = {
110 .subsys = {
111 .su_group = {
112 .cg_item = {
113 .ci_namebuf = "01-childless",
114 .ci_type = &childless_type,
115 },
116 },
117 },
118};
119
120
121/* ----------------------------------------------------------------- */
122
123/*
124 * 02-simple-children
125 *
126 * This example merely has a simple one-attribute child. Note that
127 * there is no extra attribute structure, as the child's attribute is
128 * known from the get-go. Also, there is no container for the
129 * subsystem, as it has no attributes of its own.
130 */
131
132struct simple_child {
133 struct config_item item;
134 int storeme;
135};
136
137static inline struct simple_child *to_simple_child(struct config_item *item)
138{
139 return item ? container_of(item, struct simple_child, item) : NULL;
140}
141
142static ssize_t simple_child_storeme_show(struct config_item *item, char *page)
143{
144 return sprintf(page, "%d\n", to_simple_child(item)->storeme);
145}
146
147static ssize_t simple_child_storeme_store(struct config_item *item,
148 const char *page, size_t count)
149{
150 struct simple_child *simple_child = to_simple_child(item);
151 unsigned long tmp;
152 char *p = (char *) page;
153
154 tmp = simple_strtoul(p, &p, 10);
155 if (!p || (*p && (*p != '\n')))
156 return -EINVAL;
157
158 if (tmp > INT_MAX)
159 return -ERANGE;
160
161 simple_child->storeme = tmp;
162
163 return count;
164}
165
166CONFIGFS_ATTR(simple_child_, storeme);
167
168static struct configfs_attribute *simple_child_attrs[] = {
169 &simple_child_attr_storeme,
170 NULL,
171};
172
173static void simple_child_release(struct config_item *item)
174{
175 kfree(to_simple_child(item));
176}
177
178static struct configfs_item_operations simple_child_item_ops = {
179 .release = simple_child_release,
180};
181
182static const struct config_item_type simple_child_type = {
183 .ct_item_ops = &simple_child_item_ops,
184 .ct_attrs = simple_child_attrs,
185 .ct_owner = THIS_MODULE,
186};
187
188
189struct simple_children {
190 struct config_group group;
191};
192
193static inline struct simple_children *to_simple_children(struct config_item *item)
194{
195 return item ? container_of(to_config_group(item),
196 struct simple_children, group) : NULL;
197}
198
199static struct config_item *simple_children_make_item(struct config_group *group,
200 const char *name)
201{
202 struct simple_child *simple_child;
203
204 simple_child = kzalloc(sizeof(struct simple_child), GFP_KERNEL);
205 if (!simple_child)
206 return ERR_PTR(-ENOMEM);
207
208 config_item_init_type_name(&simple_child->item, name,
209 &simple_child_type);
210
211 simple_child->storeme = 0;
212
213 return &simple_child->item;
214}
215
216static ssize_t simple_children_description_show(struct config_item *item,
217 char *page)
218{
219 return sprintf(page,
220"[02-simple-children]\n"
221"\n"
222"This subsystem allows the creation of child config_items. These\n"
223"items have only one attribute that is readable and writeable.\n");
224}
225
226CONFIGFS_ATTR_RO(simple_children_, description);
227
228static struct configfs_attribute *simple_children_attrs[] = {
229 &simple_children_attr_description,
230 NULL,
231};
232
233static void simple_children_release(struct config_item *item)
234{
235 kfree(to_simple_children(item));
236}
237
238static struct configfs_item_operations simple_children_item_ops = {
239 .release = simple_children_release,
240};
241
242/*
243 * Note that, since no extra work is required on ->drop_item(),
244 * no ->drop_item() is provided.
245 */
246static struct configfs_group_operations simple_children_group_ops = {
247 .make_item = simple_children_make_item,
248};
249
250static const struct config_item_type simple_children_type = {
251 .ct_item_ops = &simple_children_item_ops,
252 .ct_group_ops = &simple_children_group_ops,
253 .ct_attrs = simple_children_attrs,
254 .ct_owner = THIS_MODULE,
255};
256
257static struct configfs_subsystem simple_children_subsys = {
258 .su_group = {
259 .cg_item = {
260 .ci_namebuf = "02-simple-children",
261 .ci_type = &simple_children_type,
262 },
263 },
264};
265
266
267/* ----------------------------------------------------------------- */
268
269/*
270 * 03-group-children
271 *
272 * This example reuses the simple_children group from above. However,
273 * the simple_children group is not the subsystem itself, it is a
274 * child of the subsystem. Creation of a group in the subsystem creates
275 * a new simple_children group. That group can then have simple_child
276 * children of its own.
277 */
278
279static struct config_group *group_children_make_group(
280 struct config_group *group, const char *name)
281{
282 struct simple_children *simple_children;
283
284 simple_children = kzalloc(sizeof(struct simple_children),
285 GFP_KERNEL);
286 if (!simple_children)
287 return ERR_PTR(-ENOMEM);
288
289 config_group_init_type_name(&simple_children->group, name,
290 &simple_children_type);
291
292 return &simple_children->group;
293}
294
295static ssize_t group_children_description_show(struct config_item *item,
296 char *page)
297{
298 return sprintf(page,
299"[03-group-children]\n"
300"\n"
301"This subsystem allows the creation of child config_groups. These\n"
302"groups are like the subsystem simple-children.\n");
303}
304
305CONFIGFS_ATTR_RO(group_children_, description);
306
307static struct configfs_attribute *group_children_attrs[] = {
308 &group_children_attr_description,
309 NULL,
310};
311
312/*
313 * Note that, since no extra work is required on ->drop_item(),
314 * no ->drop_item() is provided.
315 */
316static struct configfs_group_operations group_children_group_ops = {
317 .make_group = group_children_make_group,
318};
319
320static const struct config_item_type group_children_type = {
321 .ct_group_ops = &group_children_group_ops,
322 .ct_attrs = group_children_attrs,
323 .ct_owner = THIS_MODULE,
324};
325
326static struct configfs_subsystem group_children_subsys = {
327 .su_group = {
328 .cg_item = {
329 .ci_namebuf = "03-group-children",
330 .ci_type = &group_children_type,
331 },
332 },
333};
334
335/* ----------------------------------------------------------------- */
336
337/*
338 * We're now done with our subsystem definitions.
339 * For convenience in this module, here's a list of them all. It
340 * allows the init function to easily register them. Most modules
341 * will only have one subsystem, and will only call register_subsystem
342 * on it directly.
343 */
344static struct configfs_subsystem *example_subsys[] = {
345 &childless_subsys.subsys,
346 &simple_children_subsys,
347 &group_children_subsys,
348 NULL,
349};
350
351static int __init configfs_example_init(void)
352{
353 int ret;
354 int i;
355 struct configfs_subsystem *subsys;
356
357 for (i = 0; example_subsys[i]; i++) {
358 subsys = example_subsys[i];
359
360 config_group_init(&subsys->su_group);
361 mutex_init(&subsys->su_mutex);
362 ret = configfs_register_subsystem(subsys);
363 if (ret) {
364 printk(KERN_ERR "Error %d while registering subsystem %s\n",
365 ret,
366 subsys->su_group.cg_item.ci_namebuf);
367 goto out_unregister;
368 }
369 }
370
371 return 0;
372
373out_unregister:
374 for (i--; i >= 0; i--)
375 configfs_unregister_subsystem(example_subsys[i]);
376
377 return ret;
378}
379
380static void __exit configfs_example_exit(void)
381{
382 int i;
383
384 for (i = 0; example_subsys[i]; i++)
385 configfs_unregister_subsystem(example_subsys[i]);
386}
387
388module_init(configfs_example_init);
389module_exit(configfs_example_exit);
390MODULE_LICENSE("GPL");
1/*
2 * vim: noexpandtab ts=8 sts=0 sw=8:
3 *
4 * configfs_example_macros.c - This file is a demonstration module
5 * containing a number of configfs subsystems. It uses the helper
6 * macros defined by configfs.h
7 *
8 * This program is free software; you can redistribute it and/or
9 * modify it under the terms of the GNU General Public
10 * License as published by the Free Software Foundation; either
11 * version 2 of the License, or (at your option) any later version.
12 *
13 * This program is distributed in the hope that it will be useful,
14 * but WITHOUT ANY WARRANTY; without even the implied warranty of
15 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
16 * General Public License for more details.
17 *
18 * You should have received a copy of the GNU General Public
19 * License along with this program; if not, write to the
20 * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
21 * Boston, MA 021110-1307, USA.
22 *
23 * Based on sysfs:
24 * sysfs is Copyright (C) 2001, 2002, 2003 Patrick Mochel
25 *
26 * configfs Copyright (C) 2005 Oracle. All rights reserved.
27 */
28
29#include <linux/init.h>
30#include <linux/module.h>
31#include <linux/slab.h>
32
33#include <linux/configfs.h>
34
35
36
37/*
38 * 01-childless
39 *
40 * This first example is a childless subsystem. It cannot create
41 * any config_items. It just has attributes.
42 *
43 * Note that we are enclosing the configfs_subsystem inside a container.
44 * This is not necessary if a subsystem has no attributes directly
45 * on the subsystem. See the next example, 02-simple-children, for
46 * such a subsystem.
47 */
48
49struct childless {
50 struct configfs_subsystem subsys;
51 int showme;
52 int storeme;
53};
54
55static inline struct childless *to_childless(struct config_item *item)
56{
57 return item ? container_of(to_configfs_subsystem(to_config_group(item)),
58 struct childless, subsys) : NULL;
59}
60
61static ssize_t childless_showme_show(struct config_item *item, char *page)
62{
63 struct childless *childless = to_childless(item);
64 ssize_t pos;
65
66 pos = sprintf(page, "%d\n", childless->showme);
67 childless->showme++;
68
69 return pos;
70}
71
72static ssize_t childless_storeme_show(struct config_item *item, char *page)
73{
74 return sprintf(page, "%d\n", to_childless(item)->storeme);
75}
76
77static ssize_t childless_storeme_store(struct config_item *item,
78 const char *page, size_t count)
79{
80 struct childless *childless = to_childless(item);
81 unsigned long tmp;
82 char *p = (char *) page;
83
84 tmp = simple_strtoul(p, &p, 10);
85 if (!p || (*p && (*p != '\n')))
86 return -EINVAL;
87
88 if (tmp > INT_MAX)
89 return -ERANGE;
90
91 childless->storeme = tmp;
92
93 return count;
94}
95
96static ssize_t childless_description_show(struct config_item *item, char *page)
97{
98 return sprintf(page,
99"[01-childless]\n"
100"\n"
101"The childless subsystem is the simplest possible subsystem in\n"
102"configfs. It does not support the creation of child config_items.\n"
103"It only has a few attributes. In fact, it isn't much different\n"
104"than a directory in /proc.\n");
105}
106
107CONFIGFS_ATTR_RO(childless_, showme);
108CONFIGFS_ATTR(childless_, storeme);
109CONFIGFS_ATTR_RO(childless_, description);
110
111static struct configfs_attribute *childless_attrs[] = {
112 &childless_attr_showme,
113 &childless_attr_storeme,
114 &childless_attr_description,
115 NULL,
116};
117
118static struct config_item_type childless_type = {
119 .ct_attrs = childless_attrs,
120 .ct_owner = THIS_MODULE,
121};
122
123static struct childless childless_subsys = {
124 .subsys = {
125 .su_group = {
126 .cg_item = {
127 .ci_namebuf = "01-childless",
128 .ci_type = &childless_type,
129 },
130 },
131 },
132};
133
134
135/* ----------------------------------------------------------------- */
136
137/*
138 * 02-simple-children
139 *
140 * This example merely has a simple one-attribute child. Note that
141 * there is no extra attribute structure, as the child's attribute is
142 * known from the get-go. Also, there is no container for the
143 * subsystem, as it has no attributes of its own.
144 */
145
146struct simple_child {
147 struct config_item item;
148 int storeme;
149};
150
151static inline struct simple_child *to_simple_child(struct config_item *item)
152{
153 return item ? container_of(item, struct simple_child, item) : NULL;
154}
155
156static ssize_t simple_child_storeme_show(struct config_item *item, char *page)
157{
158 return sprintf(page, "%d\n", to_simple_child(item)->storeme);
159}
160
161static ssize_t simple_child_storeme_store(struct config_item *item,
162 const char *page, size_t count)
163{
164 struct simple_child *simple_child = to_simple_child(item);
165 unsigned long tmp;
166 char *p = (char *) page;
167
168 tmp = simple_strtoul(p, &p, 10);
169 if (!p || (*p && (*p != '\n')))
170 return -EINVAL;
171
172 if (tmp > INT_MAX)
173 return -ERANGE;
174
175 simple_child->storeme = tmp;
176
177 return count;
178}
179
180CONFIGFS_ATTR(simple_child_, storeme);
181
182static struct configfs_attribute *simple_child_attrs[] = {
183 &simple_child_attr_storeme,
184 NULL,
185};
186
187static void simple_child_release(struct config_item *item)
188{
189 kfree(to_simple_child(item));
190}
191
192static struct configfs_item_operations simple_child_item_ops = {
193 .release = simple_child_release,
194};
195
196static struct config_item_type simple_child_type = {
197 .ct_item_ops = &simple_child_item_ops,
198 .ct_attrs = simple_child_attrs,
199 .ct_owner = THIS_MODULE,
200};
201
202
203struct simple_children {
204 struct config_group group;
205};
206
207static inline struct simple_children *to_simple_children(struct config_item *item)
208{
209 return item ? container_of(to_config_group(item),
210 struct simple_children, group) : NULL;
211}
212
213static struct config_item *simple_children_make_item(struct config_group *group,
214 const char *name)
215{
216 struct simple_child *simple_child;
217
218 simple_child = kzalloc(sizeof(struct simple_child), GFP_KERNEL);
219 if (!simple_child)
220 return ERR_PTR(-ENOMEM);
221
222 config_item_init_type_name(&simple_child->item, name,
223 &simple_child_type);
224
225 simple_child->storeme = 0;
226
227 return &simple_child->item;
228}
229
230static ssize_t simple_children_description_show(struct config_item *item,
231 char *page)
232{
233 return sprintf(page,
234"[02-simple-children]\n"
235"\n"
236"This subsystem allows the creation of child config_items. These\n"
237"items have only one attribute that is readable and writeable.\n");
238}
239
240CONFIGFS_ATTR_RO(simple_children_, description);
241
242static struct configfs_attribute *simple_children_attrs[] = {
243 &simple_children_attr_description,
244 NULL,
245};
246
247static void simple_children_release(struct config_item *item)
248{
249 kfree(to_simple_children(item));
250}
251
252static struct configfs_item_operations simple_children_item_ops = {
253 .release = simple_children_release,
254};
255
256/*
257 * Note that, since no extra work is required on ->drop_item(),
258 * no ->drop_item() is provided.
259 */
260static struct configfs_group_operations simple_children_group_ops = {
261 .make_item = simple_children_make_item,
262};
263
264static struct config_item_type simple_children_type = {
265 .ct_item_ops = &simple_children_item_ops,
266 .ct_group_ops = &simple_children_group_ops,
267 .ct_attrs = simple_children_attrs,
268 .ct_owner = THIS_MODULE,
269};
270
271static struct configfs_subsystem simple_children_subsys = {
272 .su_group = {
273 .cg_item = {
274 .ci_namebuf = "02-simple-children",
275 .ci_type = &simple_children_type,
276 },
277 },
278};
279
280
281/* ----------------------------------------------------------------- */
282
283/*
284 * 03-group-children
285 *
286 * This example reuses the simple_children group from above. However,
287 * the simple_children group is not the subsystem itself, it is a
288 * child of the subsystem. Creation of a group in the subsystem creates
289 * a new simple_children group. That group can then have simple_child
290 * children of its own.
291 */
292
293static struct config_group *group_children_make_group(
294 struct config_group *group, const char *name)
295{
296 struct simple_children *simple_children;
297
298 simple_children = kzalloc(sizeof(struct simple_children),
299 GFP_KERNEL);
300 if (!simple_children)
301 return ERR_PTR(-ENOMEM);
302
303 config_group_init_type_name(&simple_children->group, name,
304 &simple_children_type);
305
306 return &simple_children->group;
307}
308
309static ssize_t group_children_description_show(struct config_item *item,
310 char *page)
311{
312 return sprintf(page,
313"[03-group-children]\n"
314"\n"
315"This subsystem allows the creation of child config_groups. These\n"
316"groups are like the subsystem simple-children.\n");
317}
318
319CONFIGFS_ATTR_RO(group_children_, description);
320
321static struct configfs_attribute *group_children_attrs[] = {
322 &group_children_attr_description,
323 NULL,
324};
325
326/*
327 * Note that, since no extra work is required on ->drop_item(),
328 * no ->drop_item() is provided.
329 */
330static struct configfs_group_operations group_children_group_ops = {
331 .make_group = group_children_make_group,
332};
333
334static struct config_item_type group_children_type = {
335 .ct_group_ops = &group_children_group_ops,
336 .ct_attrs = group_children_attrs,
337 .ct_owner = THIS_MODULE,
338};
339
340static struct configfs_subsystem group_children_subsys = {
341 .su_group = {
342 .cg_item = {
343 .ci_namebuf = "03-group-children",
344 .ci_type = &group_children_type,
345 },
346 },
347};
348
349/* ----------------------------------------------------------------- */
350
351/*
352 * We're now done with our subsystem definitions.
353 * For convenience in this module, here's a list of them all. It
354 * allows the init function to easily register them. Most modules
355 * will only have one subsystem, and will only call register_subsystem
356 * on it directly.
357 */
358static struct configfs_subsystem *example_subsys[] = {
359 &childless_subsys.subsys,
360 &simple_children_subsys,
361 &group_children_subsys,
362 NULL,
363};
364
365static int __init configfs_example_init(void)
366{
367 int ret;
368 int i;
369 struct configfs_subsystem *subsys;
370
371 for (i = 0; example_subsys[i]; i++) {
372 subsys = example_subsys[i];
373
374 config_group_init(&subsys->su_group);
375 mutex_init(&subsys->su_mutex);
376 ret = configfs_register_subsystem(subsys);
377 if (ret) {
378 printk(KERN_ERR "Error %d while registering subsystem %s\n",
379 ret,
380 subsys->su_group.cg_item.ci_namebuf);
381 goto out_unregister;
382 }
383 }
384
385 return 0;
386
387out_unregister:
388 for (i--; i >= 0; i--)
389 configfs_unregister_subsystem(example_subsys[i]);
390
391 return ret;
392}
393
394static void __exit configfs_example_exit(void)
395{
396 int i;
397
398 for (i = 0; example_subsys[i]; i++)
399 configfs_unregister_subsystem(example_subsys[i]);
400}
401
402module_init(configfs_example_init);
403module_exit(configfs_example_exit);
404MODULE_LICENSE("GPL");