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