Commit | Line | Data |
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989d42e8 | 1 | // SPDX-License-Identifier: GPL-2.0 |
1da177e4 LT |
2 | /* |
3 | * bus.c - bus driver management | |
4 | * | |
5 | * Copyright (c) 2002-3 Patrick Mochel | |
6 | * Copyright (c) 2002-3 Open Source Development Labs | |
e5dd1278 GKH |
7 | * Copyright (c) 2007 Greg Kroah-Hartman <gregkh@suse.de> |
8 | * Copyright (c) 2007 Novell Inc. | |
ccfc901f | 9 | * Copyright (c) 2023 Greg Kroah-Hartman <gregkh@linuxfoundation.org> |
1da177e4 LT |
10 | */ |
11 | ||
765230b5 | 12 | #include <linux/async.h> |
5aee2bf2 | 13 | #include <linux/device/bus.h> |
1da177e4 LT |
14 | #include <linux/device.h> |
15 | #include <linux/module.h> | |
16 | #include <linux/errno.h> | |
5a0e3ad6 | 17 | #include <linux/slab.h> |
1da177e4 LT |
18 | #include <linux/init.h> |
19 | #include <linux/string.h> | |
ca22e56d | 20 | #include <linux/mutex.h> |
63967685 | 21 | #include <linux/sysfs.h> |
1da177e4 LT |
22 | #include "base.h" |
23 | #include "power/power.h" | |
24 | ||
ca22e56d | 25 | /* /sys/devices/system */ |
97ec448a | 26 | static struct kset *system_kset; |
ca22e56d | 27 | |
273afac6 GKH |
28 | /* /sys/bus */ |
29 | static struct kset *bus_kset; | |
30 | ||
1da177e4 | 31 | #define to_bus_attr(_attr) container_of(_attr, struct bus_attribute, attr) |
1da177e4 LT |
32 | |
33 | /* | |
34 | * sysfs bindings for drivers | |
35 | */ | |
36 | ||
37 | #define to_drv_attr(_attr) container_of(_attr, struct driver_attribute, attr) | |
1da177e4 | 38 | |
4f4b3743 DV |
39 | #define DRIVER_ATTR_IGNORE_LOCKDEP(_name, _mode, _show, _store) \ |
40 | struct driver_attribute driver_attr_##_name = \ | |
41 | __ATTR_IGNORE_LOCKDEP(_name, _mode, _show, _store) | |
1da177e4 | 42 | |
b8c5cec2 KS |
43 | static int __must_check bus_rescan_devices_helper(struct device *dev, |
44 | void *data); | |
45 | ||
273afac6 GKH |
46 | /** |
47 | * bus_to_subsys - Turn a struct bus_type into a struct subsys_private | |
48 | * | |
49 | * @bus: pointer to the struct bus_type to look up | |
50 | * | |
51 | * The driver core internals needs to work on the subsys_private structure, not | |
52 | * the external struct bus_type pointer. This function walks the list of | |
53 | * registered busses in the system and finds the matching one and returns the | |
54 | * internal struct subsys_private that relates to that bus. | |
55 | * | |
56 | * Note, the reference count of the return value is INCREMENTED if it is not | |
57 | * NULL. A call to subsys_put() must be done when finished with the pointer in | |
58 | * order for it to be properly freed. | |
59 | */ | |
60 | static struct subsys_private *bus_to_subsys(const struct bus_type *bus) | |
61 | { | |
62 | struct subsys_private *sp = NULL; | |
63 | struct kobject *kobj; | |
64 | ||
e8b812b3 | 65 | if (!bus || !bus_kset) |
273afac6 GKH |
66 | return NULL; |
67 | ||
68 | spin_lock(&bus_kset->list_lock); | |
69 | ||
70 | if (list_empty(&bus_kset->list)) | |
71 | goto done; | |
72 | ||
73 | list_for_each_entry(kobj, &bus_kset->list, entry) { | |
74 | struct kset *kset = container_of(kobj, struct kset, kobj); | |
75 | ||
76 | sp = container_of_const(kset, struct subsys_private, subsys); | |
77 | if (sp->bus == bus) | |
78 | goto done; | |
79 | } | |
80 | sp = NULL; | |
81 | done: | |
82 | sp = subsys_get(sp); | |
83 | spin_unlock(&bus_kset->list_lock); | |
84 | return sp; | |
85 | } | |
86 | ||
38370c4e | 87 | static const struct bus_type *bus_get(const struct bus_type *bus) |
5901d014 | 88 | { |
273afac6 GKH |
89 | struct subsys_private *sp = bus_to_subsys(bus); |
90 | ||
91 | if (sp) | |
c6f7e72a | 92 | return bus; |
c6f7e72a | 93 | return NULL; |
5901d014 GKH |
94 | } |
95 | ||
273afac6 | 96 | static void bus_put(const struct bus_type *bus) |
fc1ede58 | 97 | { |
273afac6 GKH |
98 | struct subsys_private *sp = bus_to_subsys(bus); |
99 | ||
100 | /* two puts are required as the call to bus_to_subsys incremented it again */ | |
101 | subsys_put(sp); | |
102 | subsys_put(sp); | |
fc1ede58 GKH |
103 | } |
104 | ||
4a3ad20c GKH |
105 | static ssize_t drv_attr_show(struct kobject *kobj, struct attribute *attr, |
106 | char *buf) | |
1da177e4 | 107 | { |
4a3ad20c | 108 | struct driver_attribute *drv_attr = to_drv_attr(attr); |
e5dd1278 | 109 | struct driver_private *drv_priv = to_driver(kobj); |
4a0c20bf | 110 | ssize_t ret = -EIO; |
1da177e4 LT |
111 | |
112 | if (drv_attr->show) | |
e5dd1278 | 113 | ret = drv_attr->show(drv_priv->driver, buf); |
1da177e4 LT |
114 | return ret; |
115 | } | |
116 | ||
4a3ad20c GKH |
117 | static ssize_t drv_attr_store(struct kobject *kobj, struct attribute *attr, |
118 | const char *buf, size_t count) | |
1da177e4 | 119 | { |
4a3ad20c | 120 | struct driver_attribute *drv_attr = to_drv_attr(attr); |
e5dd1278 | 121 | struct driver_private *drv_priv = to_driver(kobj); |
4a0c20bf | 122 | ssize_t ret = -EIO; |
1da177e4 LT |
123 | |
124 | if (drv_attr->store) | |
e5dd1278 | 125 | ret = drv_attr->store(drv_priv->driver, buf, count); |
1da177e4 LT |
126 | return ret; |
127 | } | |
128 | ||
52cf25d0 | 129 | static const struct sysfs_ops driver_sysfs_ops = { |
1da177e4 LT |
130 | .show = drv_attr_show, |
131 | .store = drv_attr_store, | |
132 | }; | |
133 | ||
e5dd1278 | 134 | static void driver_release(struct kobject *kobj) |
1da177e4 | 135 | { |
e5dd1278 GKH |
136 | struct driver_private *drv_priv = to_driver(kobj); |
137 | ||
2b3a302a | 138 | pr_debug("driver: '%s': %s\n", kobject_name(kobj), __func__); |
e5dd1278 | 139 | kfree(drv_priv); |
1da177e4 LT |
140 | } |
141 | ||
c83d9ab4 | 142 | static const struct kobj_type driver_ktype = { |
1da177e4 LT |
143 | .sysfs_ops = &driver_sysfs_ops, |
144 | .release = driver_release, | |
145 | }; | |
146 | ||
1da177e4 LT |
147 | /* |
148 | * sysfs bindings for buses | |
149 | */ | |
4a3ad20c GKH |
150 | static ssize_t bus_attr_show(struct kobject *kobj, struct attribute *attr, |
151 | char *buf) | |
1da177e4 | 152 | { |
4a3ad20c | 153 | struct bus_attribute *bus_attr = to_bus_attr(attr); |
6b6e39a6 | 154 | struct subsys_private *subsys_priv = to_subsys_private(kobj); |
1da177e4 LT |
155 | ssize_t ret = 0; |
156 | ||
157 | if (bus_attr->show) | |
6b6e39a6 | 158 | ret = bus_attr->show(subsys_priv->bus, buf); |
1da177e4 LT |
159 | return ret; |
160 | } | |
161 | ||
4a3ad20c GKH |
162 | static ssize_t bus_attr_store(struct kobject *kobj, struct attribute *attr, |
163 | const char *buf, size_t count) | |
1da177e4 | 164 | { |
4a3ad20c | 165 | struct bus_attribute *bus_attr = to_bus_attr(attr); |
6b6e39a6 | 166 | struct subsys_private *subsys_priv = to_subsys_private(kobj); |
1da177e4 LT |
167 | ssize_t ret = 0; |
168 | ||
169 | if (bus_attr->store) | |
6b6e39a6 | 170 | ret = bus_attr->store(subsys_priv->bus, buf, count); |
1da177e4 LT |
171 | return ret; |
172 | } | |
173 | ||
52cf25d0 | 174 | static const struct sysfs_ops bus_sysfs_ops = { |
1da177e4 LT |
175 | .show = bus_attr_show, |
176 | .store = bus_attr_store, | |
177 | }; | |
178 | ||
0396f286 | 179 | int bus_create_file(const struct bus_type *bus, struct bus_attribute *attr) |
1da177e4 | 180 | { |
0396f286 | 181 | struct subsys_private *sp = bus_to_subsys(bus); |
1da177e4 | 182 | int error; |
0396f286 GKH |
183 | |
184 | if (!sp) | |
185 | return -EINVAL; | |
186 | ||
187 | error = sysfs_create_file(&sp->subsys.kobj, &attr->attr); | |
188 | ||
189 | subsys_put(sp); | |
1da177e4 LT |
190 | return error; |
191 | } | |
4a3ad20c | 192 | EXPORT_SYMBOL_GPL(bus_create_file); |
1da177e4 | 193 | |
0396f286 | 194 | void bus_remove_file(const struct bus_type *bus, struct bus_attribute *attr) |
1da177e4 | 195 | { |
0396f286 GKH |
196 | struct subsys_private *sp = bus_to_subsys(bus); |
197 | ||
198 | if (!sp) | |
199 | return; | |
200 | ||
201 | sysfs_remove_file(&sp->subsys.kobj, &attr->attr); | |
202 | subsys_put(sp); | |
1da177e4 | 203 | } |
4a3ad20c | 204 | EXPORT_SYMBOL_GPL(bus_remove_file); |
1da177e4 | 205 | |
174be70b BVA |
206 | static void bus_release(struct kobject *kobj) |
207 | { | |
371fd7a2 | 208 | struct subsys_private *priv = to_subsys_private(kobj); |
174be70b | 209 | |
37e98d9b | 210 | lockdep_unregister_key(&priv->lock_key); |
174be70b | 211 | kfree(priv); |
174be70b BVA |
212 | } |
213 | ||
c83d9ab4 | 214 | static const struct kobj_type bus_ktype = { |
1da177e4 | 215 | .sysfs_ops = &bus_sysfs_ops, |
174be70b | 216 | .release = bus_release, |
80f03e34 KS |
217 | }; |
218 | ||
c45a88bb | 219 | static int bus_uevent_filter(const struct kobject *kobj) |
80f03e34 | 220 | { |
ee6d3dd4 | 221 | const struct kobj_type *ktype = get_ktype(kobj); |
80f03e34 KS |
222 | |
223 | if (ktype == &bus_ktype) | |
224 | return 1; | |
225 | return 0; | |
226 | } | |
1da177e4 | 227 | |
9cd43611 | 228 | static const struct kset_uevent_ops bus_uevent_ops = { |
80f03e34 | 229 | .filter = bus_uevent_filter, |
1da177e4 LT |
230 | }; |
231 | ||
2b08c8d0 | 232 | /* Manually detach a device from its associated driver. */ |
2581c9cc GKH |
233 | static ssize_t unbind_store(struct device_driver *drv, const char *buf, |
234 | size_t count) | |
151ef38f | 235 | { |
38370c4e | 236 | const struct bus_type *bus = bus_get(drv->bus); |
151ef38f GKH |
237 | struct device *dev; |
238 | int err = -ENODEV; | |
239 | ||
1f9ffc04 | 240 | dev = bus_find_device_by_name(bus, NULL, buf); |
2b08c8d0 | 241 | if (dev && dev->driver == drv) { |
ed88747c | 242 | device_driver_detach(dev); |
151ef38f GKH |
243 | err = count; |
244 | } | |
2b08c8d0 | 245 | put_device(dev); |
fc1ede58 | 246 | bus_put(bus); |
2b08c8d0 | 247 | return err; |
151ef38f | 248 | } |
16b0dd40 | 249 | static DRIVER_ATTR_IGNORE_LOCKDEP(unbind, 0200, NULL, unbind_store); |
151ef38f | 250 | |
afdce75f GKH |
251 | /* |
252 | * Manually attach a device to a driver. | |
253 | * Note: the driver must want to bind to the device, | |
254 | * it is not possible to override the driver's id table. | |
255 | */ | |
2581c9cc GKH |
256 | static ssize_t bind_store(struct device_driver *drv, const char *buf, |
257 | size_t count) | |
afdce75f | 258 | { |
38370c4e | 259 | const struct bus_type *bus = bus_get(drv->bus); |
afdce75f GKH |
260 | struct device *dev; |
261 | int err = -ENODEV; | |
262 | ||
1f9ffc04 | 263 | dev = bus_find_device_by_name(bus, NULL, buf); |
204db60c | 264 | if (dev && driver_match_device(drv, dev)) { |
ed88747c | 265 | err = device_driver_attach(drv, dev); |
ef6dcbdd | 266 | if (!err) { |
4a3ad20c | 267 | /* success */ |
37225401 | 268 | err = count; |
4a3ad20c | 269 | } |
afdce75f | 270 | } |
2b08c8d0 | 271 | put_device(dev); |
fc1ede58 | 272 | bus_put(bus); |
2b08c8d0 | 273 | return err; |
afdce75f | 274 | } |
16b0dd40 | 275 | static DRIVER_ATTR_IGNORE_LOCKDEP(bind, 0200, NULL, bind_store); |
afdce75f | 276 | |
75cff725 | 277 | static ssize_t drivers_autoprobe_show(const struct bus_type *bus, char *buf) |
b8c5cec2 | 278 | { |
a00fdb98 GKH |
279 | struct subsys_private *sp = bus_to_subsys(bus); |
280 | int ret; | |
281 | ||
282 | if (!sp) | |
283 | return -EINVAL; | |
284 | ||
285 | ret = sysfs_emit(buf, "%d\n", sp->drivers_autoprobe); | |
286 | subsys_put(sp); | |
287 | return ret; | |
b8c5cec2 KS |
288 | } |
289 | ||
75cff725 | 290 | static ssize_t drivers_autoprobe_store(const struct bus_type *bus, |
b8c5cec2 KS |
291 | const char *buf, size_t count) |
292 | { | |
a00fdb98 GKH |
293 | struct subsys_private *sp = bus_to_subsys(bus); |
294 | ||
295 | if (!sp) | |
296 | return -EINVAL; | |
297 | ||
b8c5cec2 | 298 | if (buf[0] == '0') |
a00fdb98 | 299 | sp->drivers_autoprobe = 0; |
b8c5cec2 | 300 | else |
a00fdb98 GKH |
301 | sp->drivers_autoprobe = 1; |
302 | ||
303 | subsys_put(sp); | |
b8c5cec2 KS |
304 | return count; |
305 | } | |
306 | ||
75cff725 | 307 | static ssize_t drivers_probe_store(const struct bus_type *bus, |
b8c5cec2 KS |
308 | const char *buf, size_t count) |
309 | { | |
310 | struct device *dev; | |
0372ffb3 | 311 | int err = -EINVAL; |
b8c5cec2 | 312 | |
1f9ffc04 | 313 | dev = bus_find_device_by_name(bus, NULL, buf); |
b8c5cec2 KS |
314 | if (!dev) |
315 | return -ENODEV; | |
0372ffb3 AW |
316 | if (bus_rescan_devices_helper(dev, NULL) == 0) |
317 | err = count; | |
318 | put_device(dev); | |
319 | return err; | |
b8c5cec2 | 320 | } |
151ef38f | 321 | |
4a3ad20c | 322 | static struct device *next_device(struct klist_iter *i) |
465c7a3a | 323 | { |
4a3ad20c | 324 | struct klist_node *n = klist_next(i); |
ae1b4171 GKH |
325 | struct device *dev = NULL; |
326 | struct device_private *dev_prv; | |
327 | ||
328 | if (n) { | |
329 | dev_prv = to_device_private_bus(n); | |
330 | dev = dev_prv->device; | |
331 | } | |
332 | return dev; | |
465c7a3a | 333 | } |
334 | ||
1da177e4 | 335 | /** |
4a3ad20c GKH |
336 | * bus_for_each_dev - device iterator. |
337 | * @bus: bus type. | |
338 | * @start: device to start iterating from. | |
339 | * @data: data for the callback. | |
340 | * @fn: function to be called for each device. | |
1da177e4 | 341 | * |
4a3ad20c GKH |
342 | * Iterate over @bus's list of devices, and call @fn for each, |
343 | * passing it @data. If @start is not NULL, we use that device to | |
344 | * begin iterating from. | |
1da177e4 | 345 | * |
4a3ad20c GKH |
346 | * We check the return of @fn each time. If it returns anything |
347 | * other than 0, we break out and return that value. | |
1da177e4 | 348 | * |
4a3ad20c GKH |
349 | * NOTE: The device that returns a non-zero value is not retained |
350 | * in any way, nor is its refcount incremented. If the caller needs | |
0fa1b0a1 | 351 | * to retain this data, it should do so, and increment the reference |
4a3ad20c | 352 | * count in the supplied callback. |
1da177e4 | 353 | */ |
e0766ea4 | 354 | int bus_for_each_dev(const struct bus_type *bus, struct device *start, |
4a3ad20c | 355 | void *data, int (*fn)(struct device *, void *)) |
1da177e4 | 356 | { |
83b9148d | 357 | struct subsys_private *sp = bus_to_subsys(bus); |
465c7a3a | 358 | struct klist_iter i; |
4a3ad20c | 359 | struct device *dev; |
465c7a3a | 360 | int error = 0; |
1da177e4 | 361 | |
83b9148d | 362 | if (!sp) |
465c7a3a | 363 | return -EINVAL; |
364 | ||
83b9148d | 365 | klist_iter_init_node(&sp->klist_devices, &i, |
7cd9c9bb | 366 | (start ? &start->p->knode_bus : NULL)); |
93ead7c9 | 367 | while (!error && (dev = next_device(&i))) |
7cd9c9bb GKH |
368 | error = fn(dev, data); |
369 | klist_iter_exit(&i); | |
83b9148d | 370 | subsys_put(sp); |
465c7a3a | 371 | return error; |
1da177e4 | 372 | } |
4a3ad20c | 373 | EXPORT_SYMBOL_GPL(bus_for_each_dev); |
1da177e4 | 374 | |
0edb5860 CH |
375 | /** |
376 | * bus_find_device - device iterator for locating a particular device. | |
377 | * @bus: bus type | |
378 | * @start: Device to begin with | |
379 | * @data: Data to pass to match function | |
380 | * @match: Callback function to check device | |
381 | * | |
382 | * This is similar to the bus_for_each_dev() function above, but it | |
383 | * returns a reference to a device that is 'found' for later use, as | |
384 | * determined by the @match callback. | |
385 | * | |
386 | * The callback should return 0 if the device doesn't match and non-zero | |
387 | * if it does. If the callback returns non-zero, this function will | |
388 | * return to the caller and not iterate over any more devices. | |
389 | */ | |
e0766ea4 | 390 | struct device *bus_find_device(const struct bus_type *bus, |
418e3ea1 SP |
391 | struct device *start, const void *data, |
392 | int (*match)(struct device *dev, const void *data)) | |
0edb5860 | 393 | { |
83b9148d | 394 | struct subsys_private *sp = bus_to_subsys(bus); |
0edb5860 CH |
395 | struct klist_iter i; |
396 | struct device *dev; | |
397 | ||
83b9148d | 398 | if (!sp) |
0edb5860 CH |
399 | return NULL; |
400 | ||
83b9148d | 401 | klist_iter_init_node(&sp->klist_devices, &i, |
7cd9c9bb | 402 | (start ? &start->p->knode_bus : NULL)); |
0edb5860 CH |
403 | while ((dev = next_device(&i))) |
404 | if (match(dev, data) && get_device(dev)) | |
405 | break; | |
406 | klist_iter_exit(&i); | |
83b9148d | 407 | subsys_put(sp); |
0edb5860 CH |
408 | return dev; |
409 | } | |
4a3ad20c | 410 | EXPORT_SYMBOL_GPL(bus_find_device); |
38fdac3c | 411 | |
4a3ad20c | 412 | static struct device_driver *next_driver(struct klist_iter *i) |
38fdac3c | 413 | { |
4a3ad20c | 414 | struct klist_node *n = klist_next(i); |
e5dd1278 GKH |
415 | struct driver_private *drv_priv; |
416 | ||
417 | if (n) { | |
418 | drv_priv = container_of(n, struct driver_private, knode_bus); | |
419 | return drv_priv->driver; | |
420 | } | |
421 | return NULL; | |
38fdac3c | 422 | } |
423 | ||
1da177e4 | 424 | /** |
4a3ad20c GKH |
425 | * bus_for_each_drv - driver iterator |
426 | * @bus: bus we're dealing with. | |
427 | * @start: driver to start iterating on. | |
428 | * @data: data to pass to the callback. | |
429 | * @fn: function to call for each driver. | |
1da177e4 | 430 | * |
4a3ad20c GKH |
431 | * This is nearly identical to the device iterator above. |
432 | * We iterate over each driver that belongs to @bus, and call | |
433 | * @fn for each. If @fn returns anything but 0, we break out | |
434 | * and return it. If @start is not NULL, we use it as the head | |
435 | * of the list. | |
1da177e4 | 436 | * |
4a3ad20c GKH |
437 | * NOTE: we don't return the driver that returns a non-zero |
438 | * value, nor do we leave the reference count incremented for that | |
439 | * driver. If the caller needs to know that info, it must set it | |
440 | * in the callback. It must also be sure to increment the refcount | |
441 | * so it doesn't disappear before returning to the caller. | |
1da177e4 | 442 | */ |
e0766ea4 | 443 | int bus_for_each_drv(const struct bus_type *bus, struct device_driver *start, |
4a3ad20c | 444 | void *data, int (*fn)(struct device_driver *, void *)) |
1da177e4 | 445 | { |
83b9148d | 446 | struct subsys_private *sp = bus_to_subsys(bus); |
38fdac3c | 447 | struct klist_iter i; |
4a3ad20c | 448 | struct device_driver *drv; |
38fdac3c | 449 | int error = 0; |
1da177e4 | 450 | |
83b9148d | 451 | if (!sp) |
38fdac3c | 452 | return -EINVAL; |
453 | ||
83b9148d | 454 | klist_iter_init_node(&sp->klist_drivers, &i, |
7cd9c9bb GKH |
455 | start ? &start->p->knode_bus : NULL); |
456 | while ((drv = next_driver(&i)) && !error) | |
457 | error = fn(drv, data); | |
458 | klist_iter_exit(&i); | |
83b9148d | 459 | subsys_put(sp); |
38fdac3c | 460 | return error; |
1da177e4 | 461 | } |
4a3ad20c | 462 | EXPORT_SYMBOL_GPL(bus_for_each_drv); |
1da177e4 | 463 | |
1da177e4 | 464 | /** |
4a3ad20c GKH |
465 | * bus_add_device - add device to bus |
466 | * @dev: device being added | |
1da177e4 | 467 | * |
2023c610 AS |
468 | * - Add device's bus attributes. |
469 | * - Create links to device's bus. | |
4a3ad20c | 470 | * - Add the device to its bus's list of devices. |
1da177e4 | 471 | */ |
4a3ad20c | 472 | int bus_add_device(struct device *dev) |
1da177e4 | 473 | { |
5221b82d GKH |
474 | struct subsys_private *sp = bus_to_subsys(dev->bus); |
475 | int error; | |
1da177e4 | 476 | |
5221b82d GKH |
477 | if (!sp) { |
478 | /* | |
479 | * This is a normal operation for many devices that do not | |
480 | * have a bus assigned to them, just say that all went | |
481 | * well. | |
482 | */ | |
483 | return 0; | |
1da177e4 | 484 | } |
5221b82d GKH |
485 | |
486 | /* | |
487 | * Reference in sp is now incremented and will be dropped when | |
488 | * the device is removed from the bus | |
489 | */ | |
490 | ||
491 | pr_debug("bus: '%s': add device %s\n", sp->bus->name, dev_name(dev)); | |
492 | ||
493 | error = device_add_groups(dev, sp->bus->dev_groups); | |
494 | if (error) | |
495 | goto out_put; | |
496 | ||
497 | error = sysfs_create_link(&sp->devices_kset->kobj, &dev->kobj, dev_name(dev)); | |
498 | if (error) | |
499 | goto out_groups; | |
500 | ||
501 | error = sysfs_create_link(&dev->kobj, &sp->subsys.kobj, "subsystem"); | |
502 | if (error) | |
503 | goto out_subsys; | |
504 | ||
505 | klist_add_tail(&dev->p->knode_bus, &sp->klist_devices); | |
513e7337 CH |
506 | return 0; |
507 | ||
513e7337 | 508 | out_subsys: |
5221b82d | 509 | sysfs_remove_link(&sp->devices_kset->kobj, dev_name(dev)); |
fa6fdb33 | 510 | out_groups: |
5221b82d | 511 | device_remove_groups(dev, sp->bus->dev_groups); |
513e7337 | 512 | out_put: |
5221b82d | 513 | subsys_put(sp); |
1da177e4 LT |
514 | return error; |
515 | } | |
516 | ||
53877d06 | 517 | /** |
2023c610 AS |
518 | * bus_probe_device - probe drivers for a new device |
519 | * @dev: device to probe | |
53877d06 | 520 | * |
2023c610 | 521 | * - Automatically probe for a driver if the bus allows it. |
53877d06 | 522 | */ |
2023c610 | 523 | void bus_probe_device(struct device *dev) |
53877d06 | 524 | { |
5221b82d | 525 | struct subsys_private *sp = bus_to_subsys(dev->bus); |
ca22e56d | 526 | struct subsys_interface *sif; |
53877d06 | 527 | |
5221b82d | 528 | if (!sp) |
ca22e56d KS |
529 | return; |
530 | ||
5221b82d | 531 | if (sp->drivers_autoprobe) |
765230b5 | 532 | device_initial_probe(dev); |
ca22e56d | 533 | |
5221b82d GKH |
534 | mutex_lock(&sp->mutex); |
535 | list_for_each_entry(sif, &sp->interfaces, node) | |
ca22e56d KS |
536 | if (sif->add_dev) |
537 | sif->add_dev(dev, sif); | |
5221b82d GKH |
538 | mutex_unlock(&sp->mutex); |
539 | subsys_put(sp); | |
53877d06 KS |
540 | } |
541 | ||
1da177e4 | 542 | /** |
4a3ad20c GKH |
543 | * bus_remove_device - remove device from bus |
544 | * @dev: device to be removed | |
1da177e4 | 545 | * |
ca22e56d KS |
546 | * - Remove device from all interfaces. |
547 | * - Remove symlink from bus' directory. | |
4a3ad20c GKH |
548 | * - Delete device from bus's list. |
549 | * - Detach from its driver. | |
550 | * - Drop reference taken in bus_add_device(). | |
1da177e4 | 551 | */ |
4a3ad20c | 552 | void bus_remove_device(struct device *dev) |
1da177e4 | 553 | { |
5221b82d | 554 | struct subsys_private *sp = bus_to_subsys(dev->bus); |
ca22e56d KS |
555 | struct subsys_interface *sif; |
556 | ||
5221b82d | 557 | if (!sp) |
ca22e56d KS |
558 | return; |
559 | ||
5221b82d GKH |
560 | mutex_lock(&sp->mutex); |
561 | list_for_each_entry(sif, &sp->interfaces, node) | |
ca22e56d KS |
562 | if (sif->remove_dev) |
563 | sif->remove_dev(dev, sif); | |
5221b82d | 564 | mutex_unlock(&sp->mutex); |
ca22e56d KS |
565 | |
566 | sysfs_remove_link(&dev->kobj, "subsystem"); | |
5221b82d | 567 | sysfs_remove_link(&sp->devices_kset->kobj, dev_name(dev)); |
fa6fdb33 | 568 | device_remove_groups(dev, dev->bus->dev_groups); |
ca22e56d KS |
569 | if (klist_node_attached(&dev->p->knode_bus)) |
570 | klist_del(&dev->p->knode_bus); | |
571 | ||
572 | pr_debug("bus: '%s': remove device %s\n", | |
573 | dev->bus->name, dev_name(dev)); | |
574 | device_release_driver(dev); | |
5221b82d GKH |
575 | |
576 | /* | |
577 | * Decrement the reference count twice, once for the bus_to_subsys() | |
578 | * call in the start of this function, and the second one from the | |
579 | * reference increment in bus_add_device() | |
580 | */ | |
581 | subsys_put(sp); | |
582 | subsys_put(sp); | |
1da177e4 LT |
583 | } |
584 | ||
f86db396 | 585 | static int __must_check add_bind_files(struct device_driver *drv) |
874c6241 | 586 | { |
f86db396 AM |
587 | int ret; |
588 | ||
589 | ret = driver_create_file(drv, &driver_attr_unbind); | |
590 | if (ret == 0) { | |
591 | ret = driver_create_file(drv, &driver_attr_bind); | |
592 | if (ret) | |
593 | driver_remove_file(drv, &driver_attr_unbind); | |
594 | } | |
595 | return ret; | |
874c6241 GKH |
596 | } |
597 | ||
598 | static void remove_bind_files(struct device_driver *drv) | |
599 | { | |
600 | driver_remove_file(drv, &driver_attr_bind); | |
601 | driver_remove_file(drv, &driver_attr_unbind); | |
602 | } | |
b8c5cec2 | 603 | |
2e7189b6 GKH |
604 | static BUS_ATTR_WO(drivers_probe); |
605 | static BUS_ATTR_RW(drivers_autoprobe); | |
8380770c | 606 | |
4dd1f3f8 | 607 | static int add_probe_files(const struct bus_type *bus) |
b8c5cec2 KS |
608 | { |
609 | int retval; | |
610 | ||
8380770c | 611 | retval = bus_create_file(bus, &bus_attr_drivers_probe); |
b8c5cec2 KS |
612 | if (retval) |
613 | goto out; | |
614 | ||
8380770c | 615 | retval = bus_create_file(bus, &bus_attr_drivers_autoprobe); |
b8c5cec2 | 616 | if (retval) |
8380770c | 617 | bus_remove_file(bus, &bus_attr_drivers_probe); |
b8c5cec2 KS |
618 | out: |
619 | return retval; | |
620 | } | |
621 | ||
4dd1f3f8 | 622 | static void remove_probe_files(const struct bus_type *bus) |
b8c5cec2 | 623 | { |
8380770c KS |
624 | bus_remove_file(bus, &bus_attr_drivers_autoprobe); |
625 | bus_remove_file(bus, &bus_attr_drivers_probe); | |
b8c5cec2 | 626 | } |
1da177e4 | 627 | |
2581c9cc GKH |
628 | static ssize_t uevent_store(struct device_driver *drv, const char *buf, |
629 | size_t count) | |
7ac1cf4a | 630 | { |
df44b479 PR |
631 | int rc; |
632 | ||
633 | rc = kobject_synth_uevent(&drv->p->kobj, buf, count); | |
634 | return rc ? rc : count; | |
7ac1cf4a | 635 | } |
2581c9cc | 636 | static DRIVER_ATTR_WO(uevent); |
7ac1cf4a | 637 | |
1da177e4 | 638 | /** |
4a3ad20c GKH |
639 | * bus_add_driver - Add a driver to the bus. |
640 | * @drv: driver. | |
1da177e4 | 641 | */ |
f86db396 | 642 | int bus_add_driver(struct device_driver *drv) |
1da177e4 | 643 | { |
e4f05682 | 644 | struct subsys_private *sp = bus_to_subsys(drv->bus); |
e5dd1278 | 645 | struct driver_private *priv; |
1da177e4 LT |
646 | int error = 0; |
647 | ||
e4f05682 | 648 | if (!sp) |
4f6e1945 | 649 | return -EINVAL; |
d9fd4d3b | 650 | |
e4f05682 GKH |
651 | /* |
652 | * Reference in sp is now incremented and will be dropped when | |
653 | * the driver is removed from the bus | |
654 | */ | |
655 | pr_debug("bus: '%s': add driver %s\n", sp->bus->name, drv->name); | |
e5dd1278 GKH |
656 | |
657 | priv = kzalloc(sizeof(*priv), GFP_KERNEL); | |
07634464 CH |
658 | if (!priv) { |
659 | error = -ENOMEM; | |
660 | goto out_put_bus; | |
661 | } | |
e5dd1278 GKH |
662 | klist_init(&priv->klist_devices, NULL, NULL); |
663 | priv->driver = drv; | |
664 | drv->p = priv; | |
e4f05682 | 665 | priv->kobj.kset = sp->drivers_kset; |
c8e90d82 GKH |
666 | error = kobject_init_and_add(&priv->kobj, &driver_ktype, NULL, |
667 | "%s", drv->name); | |
dc0afa83 | 668 | if (error) |
07634464 | 669 | goto out_unregister; |
d9fd4d3b | 670 | |
e4f05682 GKH |
671 | klist_add_tail(&priv->knode_bus, &sp->klist_drivers); |
672 | if (sp->drivers_autoprobe) { | |
ef0ff683 AD |
673 | error = driver_attach(drv); |
674 | if (error) | |
310862e5 | 675 | goto out_del_list; |
b8c5cec2 | 676 | } |
d9fd4d3b JG |
677 | module_add_driver(drv->owner, drv); |
678 | ||
7ac1cf4a KS |
679 | error = driver_create_file(drv, &driver_attr_uevent); |
680 | if (error) { | |
681 | printk(KERN_ERR "%s: uevent attr (%s) failed\n", | |
2b3a302a | 682 | __func__, drv->name); |
7ac1cf4a | 683 | } |
e4f05682 | 684 | error = driver_add_groups(drv, sp->bus->drv_groups); |
d9fd4d3b JG |
685 | if (error) { |
686 | /* How the hell do we get out of this pickle? Give up */ | |
4044b2fc | 687 | printk(KERN_ERR "%s: driver_add_groups(%s) failed\n", |
ed0617b5 | 688 | __func__, drv->name); |
e18945b1 | 689 | } |
1a6f2a75 DT |
690 | |
691 | if (!drv->suppress_bind_attrs) { | |
692 | error = add_bind_files(drv); | |
693 | if (error) { | |
694 | /* Ditto */ | |
695 | printk(KERN_ERR "%s: add_bind_files(%s) failed\n", | |
696 | __func__, drv->name); | |
697 | } | |
1da177e4 | 698 | } |
d9fd4d3b | 699 | |
5c8563d7 | 700 | return 0; |
1a6f2a75 | 701 | |
310862e5 SS |
702 | out_del_list: |
703 | klist_del(&priv->knode_bus); | |
f86db396 | 704 | out_unregister: |
99b28f1b | 705 | kobject_put(&priv->kobj); |
0f9b011d | 706 | /* drv->p is freed in driver_release() */ |
5c8563d7 | 707 | drv->p = NULL; |
f86db396 | 708 | out_put_bus: |
e4f05682 | 709 | subsys_put(sp); |
f86db396 | 710 | return error; |
1da177e4 LT |
711 | } |
712 | ||
1da177e4 | 713 | /** |
4a3ad20c GKH |
714 | * bus_remove_driver - delete driver from bus's knowledge. |
715 | * @drv: driver. | |
1da177e4 | 716 | * |
4a3ad20c GKH |
717 | * Detach the driver from the devices it controls, and remove |
718 | * it from its bus's list of drivers. Finally, we drop the reference | |
719 | * to the bus we took in bus_add_driver(). | |
1da177e4 | 720 | */ |
4a3ad20c | 721 | void bus_remove_driver(struct device_driver *drv) |
1da177e4 | 722 | { |
e4f05682 GKH |
723 | struct subsys_private *sp = bus_to_subsys(drv->bus); |
724 | ||
725 | if (!sp) | |
d9fd4d3b JG |
726 | return; |
727 | ||
e4f05682 GKH |
728 | pr_debug("bus: '%s': remove driver %s\n", sp->bus->name, drv->name); |
729 | ||
1a6f2a75 DT |
730 | if (!drv->suppress_bind_attrs) |
731 | remove_bind_files(drv); | |
e4f05682 | 732 | driver_remove_groups(drv, sp->bus->drv_groups); |
7ac1cf4a | 733 | driver_remove_file(drv, &driver_attr_uevent); |
e5dd1278 | 734 | klist_remove(&drv->p->knode_bus); |
d9fd4d3b JG |
735 | driver_detach(drv); |
736 | module_remove_driver(drv); | |
c10997f6 | 737 | kobject_put(&drv->p->kobj); |
e4f05682 GKH |
738 | |
739 | /* | |
740 | * Decrement the reference count twice, once for the bus_to_subsys() | |
741 | * call in the start of this function, and the second one from the | |
742 | * reference increment in bus_add_driver() | |
743 | */ | |
744 | subsys_put(sp); | |
745 | subsys_put(sp); | |
1da177e4 LT |
746 | } |
747 | ||
1da177e4 | 748 | /* Helper for bus_rescan_devices's iter */ |
f86db396 | 749 | static int __must_check bus_rescan_devices_helper(struct device *dev, |
4a3ad20c | 750 | void *data) |
1da177e4 | 751 | { |
f86db396 AM |
752 | int ret = 0; |
753 | ||
bf74ad5b | 754 | if (!dev->driver) { |
8c97a46a | 755 | if (dev->parent && dev->bus->need_parent_lock) |
8e9394ce | 756 | device_lock(dev->parent); |
f86db396 | 757 | ret = device_attach(dev); |
8c97a46a | 758 | if (dev->parent && dev->bus->need_parent_lock) |
8e9394ce | 759 | device_unlock(dev->parent); |
bf74ad5b | 760 | } |
f86db396 | 761 | return ret < 0 ? ret : 0; |
1da177e4 LT |
762 | } |
763 | ||
1da177e4 | 764 | /** |
23d3d602 GKH |
765 | * bus_rescan_devices - rescan devices on the bus for possible drivers |
766 | * @bus: the bus to scan. | |
1da177e4 | 767 | * |
23d3d602 GKH |
768 | * This function will look for devices on the bus with no driver |
769 | * attached and rescan it against existing drivers to see if it matches | |
770 | * any by calling device_attach() for the unbound devices. | |
1da177e4 | 771 | */ |
9622b9f2 | 772 | int bus_rescan_devices(const struct bus_type *bus) |
1da177e4 | 773 | { |
f86db396 | 774 | return bus_for_each_dev(bus, NULL, NULL, bus_rescan_devices_helper); |
1da177e4 | 775 | } |
4a3ad20c | 776 | EXPORT_SYMBOL_GPL(bus_rescan_devices); |
1da177e4 | 777 | |
e935d5da ME |
778 | /** |
779 | * device_reprobe - remove driver for a device and probe for a new driver | |
780 | * @dev: the device to reprobe | |
781 | * | |
782 | * This function detaches the attached driver (if any) for the given | |
783 | * device and restarts the driver probing process. It is intended | |
784 | * to use if probing criteria changed during a devices lifetime and | |
785 | * driver attachment should change accordingly. | |
786 | */ | |
f86db396 | 787 | int device_reprobe(struct device *dev) |
e935d5da | 788 | { |
ed88747c AD |
789 | if (dev->driver) |
790 | device_driver_detach(dev); | |
f86db396 | 791 | return bus_rescan_devices_helper(dev, NULL); |
e935d5da ME |
792 | } |
793 | EXPORT_SYMBOL_GPL(device_reprobe); | |
1da177e4 | 794 | |
34bb61f9 JB |
795 | static void klist_devices_get(struct klist_node *n) |
796 | { | |
ae1b4171 GKH |
797 | struct device_private *dev_prv = to_device_private_bus(n); |
798 | struct device *dev = dev_prv->device; | |
34bb61f9 JB |
799 | |
800 | get_device(dev); | |
801 | } | |
802 | ||
803 | static void klist_devices_put(struct klist_node *n) | |
804 | { | |
ae1b4171 GKH |
805 | struct device_private *dev_prv = to_device_private_bus(n); |
806 | struct device *dev = dev_prv->device; | |
34bb61f9 JB |
807 | |
808 | put_device(dev); | |
809 | } | |
810 | ||
75cff725 | 811 | static ssize_t bus_uevent_store(const struct bus_type *bus, |
7ac1cf4a KS |
812 | const char *buf, size_t count) |
813 | { | |
a00fdb98 GKH |
814 | struct subsys_private *sp = bus_to_subsys(bus); |
815 | int ret; | |
df44b479 | 816 | |
a00fdb98 GKH |
817 | if (!sp) |
818 | return -EINVAL; | |
819 | ||
820 | ret = kobject_synth_uevent(&sp->subsys.kobj, buf, count); | |
821 | subsys_put(sp); | |
822 | ||
823 | if (ret) | |
824 | return ret; | |
825 | return count; | |
7ac1cf4a | 826 | } |
a4723041 GKH |
827 | /* |
828 | * "open code" the old BUS_ATTR() macro here. We want to use BUS_ATTR_WO() | |
829 | * here, but can not use it as earlier in the file we have | |
830 | * DEVICE_ATTR_WO(uevent), which would cause a clash with the with the store | |
831 | * function name. | |
832 | */ | |
16b0dd40 | 833 | static struct bus_attribute bus_attr_uevent = __ATTR(uevent, 0200, NULL, |
a4723041 | 834 | bus_uevent_store); |
7ac1cf4a | 835 | |
1da177e4 | 836 | /** |
be871b7e | 837 | * bus_register - register a driver-core subsystem |
78d79559 | 838 | * @bus: bus to register |
1da177e4 | 839 | * |
78d79559 | 840 | * Once we have that, we register the bus with the kobject |
4a3ad20c | 841 | * infrastructure, then register the children subsystems it has: |
ca22e56d | 842 | * the devices and drivers that belong to the subsystem. |
1da177e4 | 843 | */ |
00c4a3c4 | 844 | int bus_register(const struct bus_type *bus) |
1da177e4 LT |
845 | { |
846 | int retval; | |
6b6e39a6 | 847 | struct subsys_private *priv; |
3465e2e4 | 848 | struct kobject *bus_kobj; |
37e98d9b | 849 | struct lock_class_key *key; |
c6f7e72a | 850 | |
6b6e39a6 | 851 | priv = kzalloc(sizeof(struct subsys_private), GFP_KERNEL); |
c6f7e72a GKH |
852 | if (!priv) |
853 | return -ENOMEM; | |
854 | ||
855 | priv->bus = bus; | |
1da177e4 | 856 | |
c6f7e72a | 857 | BLOCKING_INIT_NOTIFIER_HEAD(&priv->bus_notifier); |
116af378 | 858 | |
3465e2e4 GKH |
859 | bus_kobj = &priv->subsys.kobj; |
860 | retval = kobject_set_name(bus_kobj, "%s", bus->name); | |
1da177e4 LT |
861 | if (retval) |
862 | goto out; | |
863 | ||
3465e2e4 GKH |
864 | bus_kobj->kset = bus_kset; |
865 | bus_kobj->ktype = &bus_ktype; | |
c6f7e72a | 866 | priv->drivers_autoprobe = 1; |
d6b05b84 | 867 | |
c6f7e72a | 868 | retval = kset_register(&priv->subsys); |
1da177e4 LT |
869 | if (retval) |
870 | goto out; | |
871 | ||
7ac1cf4a KS |
872 | retval = bus_create_file(bus, &bus_attr_uevent); |
873 | if (retval) | |
874 | goto bus_uevent_fail; | |
875 | ||
3465e2e4 | 876 | priv->devices_kset = kset_create_and_add("devices", NULL, bus_kobj); |
c6f7e72a | 877 | if (!priv->devices_kset) { |
3d899596 | 878 | retval = -ENOMEM; |
1da177e4 | 879 | goto bus_devices_fail; |
3d899596 | 880 | } |
1da177e4 | 881 | |
3465e2e4 | 882 | priv->drivers_kset = kset_create_and_add("drivers", NULL, bus_kobj); |
c6f7e72a | 883 | if (!priv->drivers_kset) { |
6dcec251 | 884 | retval = -ENOMEM; |
1da177e4 | 885 | goto bus_drivers_fail; |
6dcec251 | 886 | } |
465c7a3a | 887 | |
ca22e56d | 888 | INIT_LIST_HEAD(&priv->interfaces); |
37e98d9b GKH |
889 | key = &priv->lock_key; |
890 | lockdep_register_key(key); | |
ca22e56d | 891 | __mutex_init(&priv->mutex, "subsys mutex", key); |
c6f7e72a GKH |
892 | klist_init(&priv->klist_devices, klist_devices_get, klist_devices_put); |
893 | klist_init(&priv->klist_drivers, NULL, NULL); | |
b8c5cec2 | 894 | |
b8c5cec2 KS |
895 | retval = add_probe_files(bus); |
896 | if (retval) | |
897 | goto bus_probe_files_fail; | |
898 | ||
3465e2e4 | 899 | retval = sysfs_create_groups(bus_kobj, bus->bus_groups); |
12478ba0 GKH |
900 | if (retval) |
901 | goto bus_groups_fail; | |
1da177e4 | 902 | |
7dc72b28 | 903 | pr_debug("bus: '%s': registered\n", bus->name); |
1da177e4 LT |
904 | return 0; |
905 | ||
12478ba0 | 906 | bus_groups_fail: |
b8c5cec2 KS |
907 | remove_probe_files(bus); |
908 | bus_probe_files_fail: | |
3465e2e4 | 909 | kset_unregister(priv->drivers_kset); |
1da177e4 | 910 | bus_drivers_fail: |
3465e2e4 | 911 | kset_unregister(priv->devices_kset); |
1da177e4 | 912 | bus_devices_fail: |
7ac1cf4a KS |
913 | bus_remove_file(bus, &bus_attr_uevent); |
914 | bus_uevent_fail: | |
3465e2e4 | 915 | kset_unregister(&priv->subsys); |
1da177e4 | 916 | out: |
3465e2e4 | 917 | kfree(priv); |
1da177e4 LT |
918 | return retval; |
919 | } | |
be871b7e | 920 | EXPORT_SYMBOL_GPL(bus_register); |
1da177e4 | 921 | |
1da177e4 | 922 | /** |
4a3ad20c GKH |
923 | * bus_unregister - remove a bus from the system |
924 | * @bus: bus. | |
1da177e4 | 925 | * |
4a3ad20c GKH |
926 | * Unregister the child subsystems and the bus itself. |
927 | * Finally, we call bus_put() to release the refcount | |
1da177e4 | 928 | */ |
ad8685d0 | 929 | void bus_unregister(const struct bus_type *bus) |
1da177e4 | 930 | { |
3465e2e4 GKH |
931 | struct subsys_private *sp = bus_to_subsys(bus); |
932 | struct kobject *bus_kobj; | |
933 | ||
934 | if (!sp) | |
935 | return; | |
936 | ||
7dc72b28 | 937 | pr_debug("bus: '%s': unregistering\n", bus->name); |
9cc61e5f GKH |
938 | if (sp->dev_root) |
939 | device_unregister(sp->dev_root); | |
3465e2e4 GKH |
940 | |
941 | bus_kobj = &sp->subsys.kobj; | |
942 | sysfs_remove_groups(bus_kobj, bus->bus_groups); | |
b8c5cec2 | 943 | remove_probe_files(bus); |
7ac1cf4a | 944 | bus_remove_file(bus, &bus_attr_uevent); |
3465e2e4 GKH |
945 | |
946 | kset_unregister(sp->drivers_kset); | |
947 | kset_unregister(sp->devices_kset); | |
948 | kset_unregister(&sp->subsys); | |
949 | subsys_put(sp); | |
1da177e4 | 950 | } |
4a3ad20c | 951 | EXPORT_SYMBOL_GPL(bus_unregister); |
1da177e4 | 952 | |
bc8b7931 | 953 | int bus_register_notifier(const struct bus_type *bus, struct notifier_block *nb) |
116af378 | 954 | { |
32a8121a GKH |
955 | struct subsys_private *sp = bus_to_subsys(bus); |
956 | int retval; | |
957 | ||
958 | if (!sp) | |
959 | return -EINVAL; | |
960 | ||
961 | retval = blocking_notifier_chain_register(&sp->bus_notifier, nb); | |
962 | subsys_put(sp); | |
963 | return retval; | |
116af378 BH |
964 | } |
965 | EXPORT_SYMBOL_GPL(bus_register_notifier); | |
966 | ||
bc8b7931 | 967 | int bus_unregister_notifier(const struct bus_type *bus, struct notifier_block *nb) |
116af378 | 968 | { |
32a8121a GKH |
969 | struct subsys_private *sp = bus_to_subsys(bus); |
970 | int retval; | |
971 | ||
972 | if (!sp) | |
973 | return -EINVAL; | |
974 | retval = blocking_notifier_chain_unregister(&sp->bus_notifier, nb); | |
975 | subsys_put(sp); | |
976 | return retval; | |
116af378 BH |
977 | } |
978 | EXPORT_SYMBOL_GPL(bus_unregister_notifier); | |
979 | ||
ed9f9181 GKH |
980 | void bus_notify(struct device *dev, enum bus_notifier_event value) |
981 | { | |
32a8121a | 982 | struct subsys_private *sp = bus_to_subsys(dev->bus); |
ed9f9181 | 983 | |
32a8121a GKH |
984 | if (!sp) |
985 | return; | |
986 | ||
987 | blocking_notifier_call_chain(&sp->bus_notifier, value, dev); | |
988 | subsys_put(sp); | |
ed9f9181 GKH |
989 | } |
990 | ||
f91482be | 991 | struct kset *bus_get_kset(const struct bus_type *bus) |
0fed80f7 | 992 | { |
beea7892 GKH |
993 | struct subsys_private *sp = bus_to_subsys(bus); |
994 | struct kset *kset; | |
995 | ||
996 | if (!sp) | |
997 | return NULL; | |
998 | ||
999 | kset = &sp->subsys; | |
1000 | subsys_put(sp); | |
1001 | ||
1002 | return kset; | |
0fed80f7 GKH |
1003 | } |
1004 | EXPORT_SYMBOL_GPL(bus_get_kset); | |
1005 | ||
99178b03 | 1006 | /* |
dca25ebd | 1007 | * Yes, this forcibly breaks the klist abstraction temporarily. It |
99178b03 GKH |
1008 | * just wants to sort the klist, not change reference counts and |
1009 | * take/drop locks rapidly in the process. It does all this while | |
1010 | * holding the lock for the list, so objects can't otherwise be | |
1011 | * added/removed while we're swizzling. | |
1012 | */ | |
1013 | static void device_insertion_sort_klist(struct device *a, struct list_head *list, | |
1014 | int (*compare)(const struct device *a, | |
1015 | const struct device *b)) | |
1016 | { | |
99178b03 | 1017 | struct klist_node *n; |
ae1b4171 | 1018 | struct device_private *dev_prv; |
99178b03 GKH |
1019 | struct device *b; |
1020 | ||
4c62785e | 1021 | list_for_each_entry(n, list, n_node) { |
ae1b4171 GKH |
1022 | dev_prv = to_device_private_bus(n); |
1023 | b = dev_prv->device; | |
99178b03 | 1024 | if (compare(a, b) <= 0) { |
ae1b4171 GKH |
1025 | list_move_tail(&a->p->knode_bus.n_node, |
1026 | &b->p->knode_bus.n_node); | |
99178b03 GKH |
1027 | return; |
1028 | } | |
1029 | } | |
ae1b4171 | 1030 | list_move_tail(&a->p->knode_bus.n_node, list); |
99178b03 GKH |
1031 | } |
1032 | ||
1033 | void bus_sort_breadthfirst(struct bus_type *bus, | |
1034 | int (*compare)(const struct device *a, | |
1035 | const struct device *b)) | |
1036 | { | |
b5aaecb8 | 1037 | struct subsys_private *sp = bus_to_subsys(bus); |
99178b03 | 1038 | LIST_HEAD(sorted_devices); |
4c62785e | 1039 | struct klist_node *n, *tmp; |
ae1b4171 | 1040 | struct device_private *dev_prv; |
99178b03 GKH |
1041 | struct device *dev; |
1042 | struct klist *device_klist; | |
1043 | ||
b5aaecb8 GKH |
1044 | if (!sp) |
1045 | return; | |
1046 | device_klist = &sp->klist_devices; | |
99178b03 GKH |
1047 | |
1048 | spin_lock(&device_klist->k_lock); | |
4c62785e | 1049 | list_for_each_entry_safe(n, tmp, &device_klist->k_list, n_node) { |
ae1b4171 GKH |
1050 | dev_prv = to_device_private_bus(n); |
1051 | dev = dev_prv->device; | |
99178b03 GKH |
1052 | device_insertion_sort_klist(dev, &sorted_devices, compare); |
1053 | } | |
1054 | list_splice(&sorted_devices, &device_klist->k_list); | |
1055 | spin_unlock(&device_klist->k_lock); | |
b5aaecb8 | 1056 | subsys_put(sp); |
99178b03 GKH |
1057 | } |
1058 | EXPORT_SYMBOL_GPL(bus_sort_breadthfirst); | |
1059 | ||
b0a8a59a GKH |
1060 | struct subsys_dev_iter { |
1061 | struct klist_iter ki; | |
1062 | const struct device_type *type; | |
1063 | }; | |
1064 | ||
ca22e56d KS |
1065 | /** |
1066 | * subsys_dev_iter_init - initialize subsys device iterator | |
1067 | * @iter: subsys iterator to initialize | |
adac0375 | 1068 | * @sp: the subsys private (i.e. bus) we wanna iterate over |
ca22e56d KS |
1069 | * @start: the device to start iterating from, if any |
1070 | * @type: device_type of the devices to iterate over, NULL for all | |
1071 | * | |
1072 | * Initialize subsys iterator @iter such that it iterates over devices | |
1073 | * of @subsys. If @start is set, the list iteration will start there, | |
1074 | * otherwise if it is NULL, the iteration starts at the beginning of | |
1075 | * the list. | |
1076 | */ | |
adac0375 | 1077 | static void subsys_dev_iter_init(struct subsys_dev_iter *iter, struct subsys_private *sp, |
2e45fc55 | 1078 | struct device *start, const struct device_type *type) |
ca22e56d KS |
1079 | { |
1080 | struct klist_node *start_knode = NULL; | |
1081 | ||
1082 | if (start) | |
1083 | start_knode = &start->p->knode_bus; | |
adac0375 | 1084 | klist_iter_init_node(&sp->klist_devices, &iter->ki, start_knode); |
7cd9c9bb | 1085 | iter->type = type; |
ca22e56d | 1086 | } |
ca22e56d KS |
1087 | |
1088 | /** | |
1089 | * subsys_dev_iter_next - iterate to the next device | |
1090 | * @iter: subsys iterator to proceed | |
1091 | * | |
1092 | * Proceed @iter to the next device and return it. Returns NULL if | |
1093 | * iteration is complete. | |
1094 | * | |
1095 | * The returned device is referenced and won't be released till | |
1096 | * iterator is proceed to the next device or exited. The caller is | |
1097 | * free to do whatever it wants to do with the device including | |
1098 | * calling back into subsys code. | |
1099 | */ | |
38cdadef | 1100 | static struct device *subsys_dev_iter_next(struct subsys_dev_iter *iter) |
ca22e56d KS |
1101 | { |
1102 | struct klist_node *knode; | |
1103 | struct device *dev; | |
1104 | ||
1105 | for (;;) { | |
1106 | knode = klist_next(&iter->ki); | |
1107 | if (!knode) | |
1108 | return NULL; | |
371fd7a2 | 1109 | dev = to_device_private_bus(knode)->device; |
ca22e56d KS |
1110 | if (!iter->type || iter->type == dev->type) |
1111 | return dev; | |
1112 | } | |
1113 | } | |
ca22e56d KS |
1114 | |
1115 | /** | |
1116 | * subsys_dev_iter_exit - finish iteration | |
1117 | * @iter: subsys iterator to finish | |
1118 | * | |
1119 | * Finish an iteration. Always call this function after iteration is | |
1120 | * complete whether the iteration ran till the end or not. | |
1121 | */ | |
af6d0743 | 1122 | static void subsys_dev_iter_exit(struct subsys_dev_iter *iter) |
ca22e56d KS |
1123 | { |
1124 | klist_iter_exit(&iter->ki); | |
1125 | } | |
ca22e56d KS |
1126 | |
1127 | int subsys_interface_register(struct subsys_interface *sif) | |
1128 | { | |
adac0375 | 1129 | struct subsys_private *sp; |
ca22e56d KS |
1130 | struct subsys_dev_iter iter; |
1131 | struct device *dev; | |
1132 | ||
1133 | if (!sif || !sif->subsys) | |
1134 | return -ENODEV; | |
1135 | ||
adac0375 GKH |
1136 | sp = bus_to_subsys(sif->subsys); |
1137 | if (!sp) | |
ca22e56d KS |
1138 | return -EINVAL; |
1139 | ||
adac0375 GKH |
1140 | /* |
1141 | * Reference in sp is now incremented and will be dropped when | |
1142 | * the interface is removed from the bus | |
1143 | */ | |
1144 | ||
1145 | mutex_lock(&sp->mutex); | |
1146 | list_add_tail(&sif->node, &sp->interfaces); | |
ca22e56d | 1147 | if (sif->add_dev) { |
adac0375 | 1148 | subsys_dev_iter_init(&iter, sp, NULL, NULL); |
ca22e56d KS |
1149 | while ((dev = subsys_dev_iter_next(&iter))) |
1150 | sif->add_dev(dev, sif); | |
1151 | subsys_dev_iter_exit(&iter); | |
1152 | } | |
adac0375 | 1153 | mutex_unlock(&sp->mutex); |
ca22e56d KS |
1154 | |
1155 | return 0; | |
1156 | } | |
1157 | EXPORT_SYMBOL_GPL(subsys_interface_register); | |
1158 | ||
1159 | void subsys_interface_unregister(struct subsys_interface *sif) | |
1160 | { | |
adac0375 | 1161 | struct subsys_private *sp; |
ca22e56d KS |
1162 | struct subsys_dev_iter iter; |
1163 | struct device *dev; | |
1164 | ||
2b31594a | 1165 | if (!sif || !sif->subsys) |
ca22e56d KS |
1166 | return; |
1167 | ||
adac0375 GKH |
1168 | sp = bus_to_subsys(sif->subsys); |
1169 | if (!sp) | |
1170 | return; | |
2b31594a | 1171 | |
adac0375 | 1172 | mutex_lock(&sp->mutex); |
ca22e56d KS |
1173 | list_del_init(&sif->node); |
1174 | if (sif->remove_dev) { | |
adac0375 | 1175 | subsys_dev_iter_init(&iter, sp, NULL, NULL); |
ca22e56d KS |
1176 | while ((dev = subsys_dev_iter_next(&iter))) |
1177 | sif->remove_dev(dev, sif); | |
1178 | subsys_dev_iter_exit(&iter); | |
1179 | } | |
adac0375 | 1180 | mutex_unlock(&sp->mutex); |
ca22e56d | 1181 | |
adac0375 GKH |
1182 | /* |
1183 | * Decrement the reference count twice, once for the bus_to_subsys() | |
1184 | * call in the start of this function, and the second one from the | |
1185 | * reference increment in subsys_interface_register() | |
1186 | */ | |
1187 | subsys_put(sp); | |
1188 | subsys_put(sp); | |
ca22e56d KS |
1189 | } |
1190 | EXPORT_SYMBOL_GPL(subsys_interface_unregister); | |
1191 | ||
1192 | static void system_root_device_release(struct device *dev) | |
1193 | { | |
1194 | kfree(dev); | |
1195 | } | |
d73ce004 TH |
1196 | |
1197 | static int subsys_register(struct bus_type *subsys, | |
1198 | const struct attribute_group **groups, | |
1199 | struct kobject *parent_of_root) | |
ca22e56d | 1200 | { |
9cc61e5f | 1201 | struct subsys_private *sp; |
ca22e56d KS |
1202 | struct device *dev; |
1203 | int err; | |
1204 | ||
1205 | err = bus_register(subsys); | |
1206 | if (err < 0) | |
1207 | return err; | |
1208 | ||
9cc61e5f GKH |
1209 | sp = bus_to_subsys(subsys); |
1210 | if (!sp) { | |
1211 | err = -EINVAL; | |
1212 | goto err_sp; | |
1213 | } | |
1214 | ||
ca22e56d KS |
1215 | dev = kzalloc(sizeof(struct device), GFP_KERNEL); |
1216 | if (!dev) { | |
1217 | err = -ENOMEM; | |
1218 | goto err_dev; | |
1219 | } | |
1220 | ||
1221 | err = dev_set_name(dev, "%s", subsys->name); | |
1222 | if (err < 0) | |
1223 | goto err_name; | |
1224 | ||
d73ce004 | 1225 | dev->kobj.parent = parent_of_root; |
ca22e56d KS |
1226 | dev->groups = groups; |
1227 | dev->release = system_root_device_release; | |
1228 | ||
1229 | err = device_register(dev); | |
1230 | if (err < 0) | |
1231 | goto err_dev_reg; | |
1232 | ||
9cc61e5f GKH |
1233 | sp->dev_root = dev; |
1234 | subsys_put(sp); | |
ca22e56d KS |
1235 | return 0; |
1236 | ||
1237 | err_dev_reg: | |
1238 | put_device(dev); | |
1239 | dev = NULL; | |
1240 | err_name: | |
1241 | kfree(dev); | |
1242 | err_dev: | |
9cc61e5f GKH |
1243 | subsys_put(sp); |
1244 | err_sp: | |
ca22e56d KS |
1245 | bus_unregister(subsys); |
1246 | return err; | |
1247 | } | |
d73ce004 TH |
1248 | |
1249 | /** | |
1250 | * subsys_system_register - register a subsystem at /sys/devices/system/ | |
1251 | * @subsys: system subsystem | |
1252 | * @groups: default attributes for the root device | |
1253 | * | |
1254 | * All 'system' subsystems have a /sys/devices/system/<name> root device | |
1255 | * with the name of the subsystem. The root device can carry subsystem- | |
1256 | * wide attributes. All registered devices are below this single root | |
1257 | * device and are named after the subsystem with a simple enumeration | |
e227867f | 1258 | * number appended. The registered devices are not explicitly named; |
d73ce004 TH |
1259 | * only 'id' in the device needs to be set. |
1260 | * | |
1261 | * Do not use this interface for anything new, it exists for compatibility | |
1262 | * with bad ideas only. New subsystems should use plain subsystems; and | |
1263 | * add the subsystem-wide attributes should be added to the subsystem | |
1264 | * directory itself and not some create fake root-device placed in | |
1265 | * /sys/devices/system/<name>. | |
1266 | */ | |
1267 | int subsys_system_register(struct bus_type *subsys, | |
1268 | const struct attribute_group **groups) | |
1269 | { | |
1270 | return subsys_register(subsys, groups, &system_kset->kobj); | |
1271 | } | |
ca22e56d KS |
1272 | EXPORT_SYMBOL_GPL(subsys_system_register); |
1273 | ||
d73ce004 TH |
1274 | /** |
1275 | * subsys_virtual_register - register a subsystem at /sys/devices/virtual/ | |
1276 | * @subsys: virtual subsystem | |
1277 | * @groups: default attributes for the root device | |
1278 | * | |
1279 | * All 'virtual' subsystems have a /sys/devices/system/<name> root device | |
1280 | * with the name of the subystem. The root device can carry subsystem-wide | |
1281 | * attributes. All registered devices are below this single root device. | |
1282 | * There's no restriction on device naming. This is for kernel software | |
1283 | * constructs which need sysfs interface. | |
1284 | */ | |
1285 | int subsys_virtual_register(struct bus_type *subsys, | |
1286 | const struct attribute_group **groups) | |
1287 | { | |
1288 | struct kobject *virtual_dir; | |
1289 | ||
1290 | virtual_dir = virtual_device_parent(NULL); | |
1291 | if (!virtual_dir) | |
1292 | return -ENOMEM; | |
1293 | ||
1294 | return subsys_register(subsys, groups, virtual_dir); | |
1295 | } | |
1c04fc35 | 1296 | EXPORT_SYMBOL_GPL(subsys_virtual_register); |
d73ce004 | 1297 | |
adc18506 GKH |
1298 | /** |
1299 | * driver_find - locate driver on a bus by its name. | |
1300 | * @name: name of the driver. | |
1301 | * @bus: bus to scan for the driver. | |
1302 | * | |
1303 | * Call kset_find_obj() to iterate over list of drivers on | |
1304 | * a bus to find driver by name. Return driver if found. | |
1305 | * | |
1306 | * This routine provides no locking to prevent the driver it returns | |
1307 | * from being unregistered or unloaded while the caller is using it. | |
1308 | * The caller is responsible for preventing this. | |
1309 | */ | |
7c06be04 | 1310 | struct device_driver *driver_find(const char *name, const struct bus_type *bus) |
adc18506 | 1311 | { |
fb451966 GKH |
1312 | struct subsys_private *sp = bus_to_subsys(bus); |
1313 | struct kobject *k; | |
adc18506 GKH |
1314 | struct driver_private *priv; |
1315 | ||
fb451966 GKH |
1316 | if (!sp) |
1317 | return NULL; | |
1318 | ||
1319 | k = kset_find_obj(sp->drivers_kset, name); | |
1320 | subsys_put(sp); | |
1321 | if (!k) | |
1322 | return NULL; | |
1323 | ||
1324 | priv = to_driver(k); | |
1325 | ||
1326 | /* Drop reference added by kset_find_obj() */ | |
1327 | kobject_put(k); | |
1328 | return priv->driver; | |
adc18506 GKH |
1329 | } |
1330 | EXPORT_SYMBOL_GPL(driver_find); | |
1331 | ||
63b823d7 GKH |
1332 | /* |
1333 | * Warning, the value could go to "removed" instantly after calling this function, so be very | |
1334 | * careful when calling it... | |
1335 | */ | |
1336 | bool bus_is_registered(const struct bus_type *bus) | |
1337 | { | |
1338 | struct subsys_private *sp = bus_to_subsys(bus); | |
1339 | bool is_initialized = false; | |
1340 | ||
1341 | if (sp) { | |
1342 | is_initialized = true; | |
1343 | subsys_put(sp); | |
1344 | } | |
1345 | return is_initialized; | |
1346 | } | |
1347 | ||
8c99377e GKH |
1348 | /** |
1349 | * bus_get_dev_root - return a pointer to the "device root" of a bus | |
1350 | * @bus: bus to return the device root of. | |
1351 | * | |
1352 | * If a bus has a "device root" structure, return it, WITH THE REFERENCE | |
1353 | * COUNT INCREMENTED. | |
1354 | * | |
1355 | * Note, when finished with the device, a call to put_device() is required. | |
1356 | * | |
1357 | * If the device root is not present (or bus is not a valid pointer), NULL | |
1358 | * will be returned. | |
1359 | */ | |
1360 | struct device *bus_get_dev_root(const struct bus_type *bus) | |
1361 | { | |
9cc61e5f GKH |
1362 | struct subsys_private *sp = bus_to_subsys(bus); |
1363 | struct device *dev_root; | |
1364 | ||
1365 | if (!sp) | |
1366 | return NULL; | |
1367 | ||
1368 | dev_root = get_device(sp->dev_root); | |
1369 | subsys_put(sp); | |
1370 | return dev_root; | |
8c99377e GKH |
1371 | } |
1372 | EXPORT_SYMBOL_GPL(bus_get_dev_root); | |
1373 | ||
1da177e4 LT |
1374 | int __init buses_init(void) |
1375 | { | |
59a54833 GKH |
1376 | bus_kset = kset_create_and_add("bus", &bus_uevent_ops, NULL); |
1377 | if (!bus_kset) | |
1378 | return -ENOMEM; | |
ca22e56d KS |
1379 | |
1380 | system_kset = kset_create_and_add("system", NULL, &devices_kset->kobj); | |
1381 | if (!system_kset) | |
1382 | return -ENOMEM; | |
1383 | ||
59a54833 | 1384 | return 0; |
1da177e4 | 1385 | } |