Commit | Line | Data |
---|---|---|
1da177e4 LT |
1 | /* |
2 | * drivers/s390/cio/ccwgroup.c | |
3 | * bus driver for ccwgroup | |
1da177e4 LT |
4 | * |
5 | * Copyright (C) 2002 IBM Deutschland Entwicklung GmbH, | |
6 | * IBM Corporation | |
7 | * Author(s): Arnd Bergmann (arndb@de.ibm.com) | |
4ce3b30c | 8 | * Cornelia Huck (cornelia.huck@de.ibm.com) |
1da177e4 LT |
9 | */ |
10 | #include <linux/module.h> | |
11 | #include <linux/errno.h> | |
12 | #include <linux/slab.h> | |
13 | #include <linux/list.h> | |
14 | #include <linux/device.h> | |
15 | #include <linux/init.h> | |
16 | #include <linux/ctype.h> | |
17 | #include <linux/dcache.h> | |
18 | ||
19 | #include <asm/semaphore.h> | |
20 | #include <asm/ccwdev.h> | |
21 | #include <asm/ccwgroup.h> | |
22 | ||
23 | /* In Linux 2.4, we had a channel device layer called "chandev" | |
24 | * that did all sorts of obscure stuff for networking devices. | |
25 | * This is another driver that serves as a replacement for just | |
26 | * one of its functions, namely the translation of single subchannels | |
27 | * to devices that use multiple subchannels. | |
28 | */ | |
29 | ||
30 | /* a device matches a driver if all its slave devices match the same | |
31 | * entry of the driver */ | |
32 | static int | |
33 | ccwgroup_bus_match (struct device * dev, struct device_driver * drv) | |
34 | { | |
35 | struct ccwgroup_device *gdev; | |
36 | struct ccwgroup_driver *gdrv; | |
37 | ||
38 | gdev = container_of(dev, struct ccwgroup_device, dev); | |
39 | gdrv = container_of(drv, struct ccwgroup_driver, driver); | |
40 | ||
41 | if (gdev->creator_id == gdrv->driver_id) | |
42 | return 1; | |
43 | ||
44 | return 0; | |
45 | } | |
46 | static int | |
7eff2e7a | 47 | ccwgroup_uevent (struct device *dev, struct kobj_uevent_env *env) |
1da177e4 LT |
48 | { |
49 | /* TODO */ | |
50 | return 0; | |
51 | } | |
52 | ||
f9ccf456 | 53 | static struct bus_type ccwgroup_bus_type; |
1da177e4 | 54 | |
4d284cac | 55 | static void |
1da177e4 LT |
56 | __ccwgroup_remove_symlinks(struct ccwgroup_device *gdev) |
57 | { | |
58 | int i; | |
59 | char str[8]; | |
60 | ||
61 | for (i = 0; i < gdev->count; i++) { | |
62 | sprintf(str, "cdev%d", i); | |
63 | sysfs_remove_link(&gdev->dev.kobj, str); | |
64 | sysfs_remove_link(&gdev->cdev[i]->dev.kobj, "group_device"); | |
65 | } | |
66 | ||
67 | } | |
68 | ||
69 | /* | |
70 | * Provide an 'ungroup' attribute so the user can remove group devices no | |
71 | * longer needed or accidentially created. Saves memory :) | |
72 | */ | |
d9a9cdfb AS |
73 | static void ccwgroup_ungroup_callback(struct device *dev) |
74 | { | |
75 | struct ccwgroup_device *gdev = to_ccwgroupdev(dev); | |
76 | ||
d76123eb | 77 | mutex_lock(&gdev->reg_mutex); |
d9a9cdfb AS |
78 | __ccwgroup_remove_symlinks(gdev); |
79 | device_unregister(dev); | |
d76123eb | 80 | mutex_unlock(&gdev->reg_mutex); |
d9a9cdfb AS |
81 | } |
82 | ||
1da177e4 | 83 | static ssize_t |
3fd3c0a5 | 84 | ccwgroup_ungroup_store(struct device *dev, struct device_attribute *attr, const char *buf, size_t count) |
1da177e4 LT |
85 | { |
86 | struct ccwgroup_device *gdev; | |
d9a9cdfb | 87 | int rc; |
1da177e4 LT |
88 | |
89 | gdev = to_ccwgroupdev(dev); | |
90 | ||
91 | if (gdev->state != CCWGROUP_OFFLINE) | |
92 | return -EINVAL; | |
93 | ||
d9a9cdfb AS |
94 | /* Note that we cannot unregister the device from one of its |
95 | * attribute methods, so we have to use this roundabout approach. | |
96 | */ | |
97 | rc = device_schedule_callback(dev, ccwgroup_ungroup_callback); | |
98 | if (rc) | |
99 | count = rc; | |
1da177e4 LT |
100 | return count; |
101 | } | |
102 | ||
103 | static DEVICE_ATTR(ungroup, 0200, NULL, ccwgroup_ungroup_store); | |
104 | ||
105 | static void | |
106 | ccwgroup_release (struct device *dev) | |
107 | { | |
108 | struct ccwgroup_device *gdev; | |
109 | int i; | |
110 | ||
111 | gdev = to_ccwgroupdev(dev); | |
112 | ||
113 | for (i = 0; i < gdev->count; i++) { | |
114 | gdev->cdev[i]->dev.driver_data = NULL; | |
115 | put_device(&gdev->cdev[i]->dev); | |
116 | } | |
117 | kfree(gdev); | |
118 | } | |
119 | ||
4d284cac | 120 | static int |
1da177e4 LT |
121 | __ccwgroup_create_symlinks(struct ccwgroup_device *gdev) |
122 | { | |
123 | char str[8]; | |
124 | int i, rc; | |
125 | ||
126 | for (i = 0; i < gdev->count; i++) { | |
127 | rc = sysfs_create_link(&gdev->cdev[i]->dev.kobj, &gdev->dev.kobj, | |
128 | "group_device"); | |
129 | if (rc) { | |
130 | for (--i; i >= 0; i--) | |
131 | sysfs_remove_link(&gdev->cdev[i]->dev.kobj, | |
132 | "group_device"); | |
133 | return rc; | |
134 | } | |
135 | } | |
136 | for (i = 0; i < gdev->count; i++) { | |
137 | sprintf(str, "cdev%d", i); | |
138 | rc = sysfs_create_link(&gdev->dev.kobj, &gdev->cdev[i]->dev.kobj, | |
139 | str); | |
140 | if (rc) { | |
141 | for (--i; i >= 0; i--) { | |
142 | sprintf(str, "cdev%d", i); | |
143 | sysfs_remove_link(&gdev->dev.kobj, str); | |
144 | } | |
145 | for (i = 0; i < gdev->count; i++) | |
146 | sysfs_remove_link(&gdev->cdev[i]->dev.kobj, | |
147 | "group_device"); | |
148 | return rc; | |
149 | } | |
150 | } | |
151 | return 0; | |
152 | } | |
153 | ||
b2ffd8e9 CH |
154 | /** |
155 | * ccwgroup_create() - create and register a ccw group device | |
156 | * @root: parent device for the new device | |
157 | * @creator_id: identifier of creating driver | |
158 | * @cdrv: ccw driver of slave devices | |
159 | * @argc: number of slave devices | |
160 | * @argv: bus ids of slave devices | |
161 | * | |
162 | * Create and register a new ccw group device as a child of @root. Slave | |
163 | * devices are obtained from the list of bus ids given in @argv[] and must all | |
164 | * belong to @cdrv. | |
165 | * Returns: | |
166 | * %0 on success and an error code on failure. | |
167 | * Context: | |
168 | * non-atomic | |
1da177e4 | 169 | */ |
b2ffd8e9 CH |
170 | int ccwgroup_create(struct device *root, unsigned int creator_id, |
171 | struct ccw_driver *cdrv, int argc, char *argv[]) | |
1da177e4 LT |
172 | { |
173 | struct ccwgroup_device *gdev; | |
174 | int i; | |
175 | int rc; | |
1da177e4 LT |
176 | |
177 | if (argc > 256) /* disallow dumb users */ | |
178 | return -EINVAL; | |
179 | ||
88abaab4 | 180 | gdev = kzalloc(sizeof(*gdev) + argc*sizeof(gdev->cdev[0]), GFP_KERNEL); |
1da177e4 LT |
181 | if (!gdev) |
182 | return -ENOMEM; | |
183 | ||
1da177e4 | 184 | atomic_set(&gdev->onoff, 0); |
d76123eb CH |
185 | mutex_init(&gdev->reg_mutex); |
186 | mutex_lock(&gdev->reg_mutex); | |
1da177e4 LT |
187 | for (i = 0; i < argc; i++) { |
188 | gdev->cdev[i] = get_ccwdev_by_busid(cdrv, argv[i]); | |
189 | ||
190 | /* all devices have to be of the same type in | |
191 | * order to be grouped */ | |
192 | if (!gdev->cdev[i] | |
193 | || gdev->cdev[i]->id.driver_info != | |
194 | gdev->cdev[0]->id.driver_info) { | |
195 | rc = -EINVAL; | |
d76123eb | 196 | goto error; |
1da177e4 LT |
197 | } |
198 | /* Don't allow a device to belong to more than one group. */ | |
199 | if (gdev->cdev[i]->dev.driver_data) { | |
200 | rc = -EINVAL; | |
d76123eb | 201 | goto error; |
1da177e4 | 202 | } |
1da177e4 | 203 | gdev->cdev[i]->dev.driver_data = gdev; |
17088229 | 204 | } |
1da177e4 LT |
205 | |
206 | gdev->creator_id = creator_id; | |
207 | gdev->count = argc; | |
292888c8 HC |
208 | gdev->dev.bus = &ccwgroup_bus_type; |
209 | gdev->dev.parent = root; | |
210 | gdev->dev.release = ccwgroup_release; | |
1da177e4 LT |
211 | |
212 | snprintf (gdev->dev.bus_id, BUS_ID_SIZE, "%s", | |
213 | gdev->cdev[0]->dev.bus_id); | |
214 | ||
215 | rc = device_register(&gdev->dev); | |
1da177e4 | 216 | if (rc) |
d76123eb | 217 | goto error; |
1da177e4 LT |
218 | get_device(&gdev->dev); |
219 | rc = device_create_file(&gdev->dev, &dev_attr_ungroup); | |
220 | ||
221 | if (rc) { | |
222 | device_unregister(&gdev->dev); | |
223 | goto error; | |
224 | } | |
225 | ||
226 | rc = __ccwgroup_create_symlinks(gdev); | |
227 | if (!rc) { | |
d76123eb | 228 | mutex_unlock(&gdev->reg_mutex); |
1da177e4 LT |
229 | put_device(&gdev->dev); |
230 | return 0; | |
231 | } | |
232 | device_remove_file(&gdev->dev, &dev_attr_ungroup); | |
233 | device_unregister(&gdev->dev); | |
234 | error: | |
1da177e4 LT |
235 | for (i = 0; i < argc; i++) |
236 | if (gdev->cdev[i]) { | |
17088229 | 237 | if (gdev->cdev[i]->dev.driver_data == gdev) |
1da177e4 | 238 | gdev->cdev[i]->dev.driver_data = NULL; |
17088229 | 239 | put_device(&gdev->cdev[i]->dev); |
1da177e4 | 240 | } |
d76123eb CH |
241 | mutex_unlock(&gdev->reg_mutex); |
242 | put_device(&gdev->dev); | |
1da177e4 LT |
243 | return rc; |
244 | } | |
245 | ||
246 | static int __init | |
247 | init_ccwgroup (void) | |
248 | { | |
249 | return bus_register (&ccwgroup_bus_type); | |
250 | } | |
251 | ||
252 | static void __exit | |
253 | cleanup_ccwgroup (void) | |
254 | { | |
255 | bus_unregister (&ccwgroup_bus_type); | |
256 | } | |
257 | ||
258 | module_init(init_ccwgroup); | |
259 | module_exit(cleanup_ccwgroup); | |
260 | ||
261 | /************************** driver stuff ******************************/ | |
262 | ||
263 | static int | |
264 | ccwgroup_set_online(struct ccwgroup_device *gdev) | |
265 | { | |
266 | struct ccwgroup_driver *gdrv; | |
267 | int ret; | |
268 | ||
973bd993 | 269 | if (atomic_cmpxchg(&gdev->onoff, 0, 1) != 0) |
1da177e4 LT |
270 | return -EAGAIN; |
271 | if (gdev->state == CCWGROUP_ONLINE) { | |
272 | ret = 0; | |
273 | goto out; | |
274 | } | |
275 | if (!gdev->dev.driver) { | |
276 | ret = -EINVAL; | |
277 | goto out; | |
278 | } | |
279 | gdrv = to_ccwgroupdrv (gdev->dev.driver); | |
a0016408 | 280 | if ((ret = gdrv->set_online ? gdrv->set_online(gdev) : 0)) |
1da177e4 LT |
281 | goto out; |
282 | ||
283 | gdev->state = CCWGROUP_ONLINE; | |
284 | out: | |
285 | atomic_set(&gdev->onoff, 0); | |
286 | return ret; | |
287 | } | |
288 | ||
289 | static int | |
290 | ccwgroup_set_offline(struct ccwgroup_device *gdev) | |
291 | { | |
292 | struct ccwgroup_driver *gdrv; | |
293 | int ret; | |
294 | ||
973bd993 | 295 | if (atomic_cmpxchg(&gdev->onoff, 0, 1) != 0) |
1da177e4 LT |
296 | return -EAGAIN; |
297 | if (gdev->state == CCWGROUP_OFFLINE) { | |
298 | ret = 0; | |
299 | goto out; | |
300 | } | |
301 | if (!gdev->dev.driver) { | |
302 | ret = -EINVAL; | |
303 | goto out; | |
304 | } | |
305 | gdrv = to_ccwgroupdrv (gdev->dev.driver); | |
a0016408 | 306 | if ((ret = gdrv->set_offline ? gdrv->set_offline(gdev) : 0)) |
1da177e4 LT |
307 | goto out; |
308 | ||
309 | gdev->state = CCWGROUP_OFFLINE; | |
310 | out: | |
311 | atomic_set(&gdev->onoff, 0); | |
312 | return ret; | |
313 | } | |
314 | ||
315 | static ssize_t | |
3fd3c0a5 | 316 | ccwgroup_online_store (struct device *dev, struct device_attribute *attr, const char *buf, size_t count) |
1da177e4 LT |
317 | { |
318 | struct ccwgroup_device *gdev; | |
319 | struct ccwgroup_driver *gdrv; | |
320 | unsigned int value; | |
321 | int ret; | |
322 | ||
323 | gdev = to_ccwgroupdev(dev); | |
324 | if (!dev->driver) | |
325 | return count; | |
326 | ||
327 | gdrv = to_ccwgroupdrv (gdev->dev.driver); | |
328 | if (!try_module_get(gdrv->owner)) | |
329 | return -EINVAL; | |
330 | ||
d2c993d8 | 331 | value = simple_strtoul(buf, NULL, 0); |
1da177e4 LT |
332 | ret = count; |
333 | if (value == 1) | |
334 | ccwgroup_set_online(gdev); | |
335 | else if (value == 0) | |
336 | ccwgroup_set_offline(gdev); | |
337 | else | |
338 | ret = -EINVAL; | |
339 | module_put(gdrv->owner); | |
340 | return ret; | |
341 | } | |
342 | ||
343 | static ssize_t | |
3fd3c0a5 | 344 | ccwgroup_online_show (struct device *dev, struct device_attribute *attr, char *buf) |
1da177e4 LT |
345 | { |
346 | int online; | |
347 | ||
348 | online = (to_ccwgroupdev(dev)->state == CCWGROUP_ONLINE); | |
349 | ||
350 | return sprintf(buf, online ? "1\n" : "0\n"); | |
351 | } | |
352 | ||
353 | static DEVICE_ATTR(online, 0644, ccwgroup_online_show, ccwgroup_online_store); | |
354 | ||
355 | static int | |
356 | ccwgroup_probe (struct device *dev) | |
357 | { | |
358 | struct ccwgroup_device *gdev; | |
359 | struct ccwgroup_driver *gdrv; | |
360 | ||
361 | int ret; | |
362 | ||
363 | gdev = to_ccwgroupdev(dev); | |
364 | gdrv = to_ccwgroupdrv(dev->driver); | |
365 | ||
366 | if ((ret = device_create_file(dev, &dev_attr_online))) | |
367 | return ret; | |
368 | ||
1da177e4 LT |
369 | ret = gdrv->probe ? gdrv->probe(gdev) : -ENODEV; |
370 | if (ret) | |
371 | device_remove_file(dev, &dev_attr_online); | |
372 | ||
373 | return ret; | |
374 | } | |
375 | ||
376 | static int | |
377 | ccwgroup_remove (struct device *dev) | |
378 | { | |
379 | struct ccwgroup_device *gdev; | |
380 | struct ccwgroup_driver *gdrv; | |
381 | ||
382 | gdev = to_ccwgroupdev(dev); | |
383 | gdrv = to_ccwgroupdrv(dev->driver); | |
384 | ||
1da177e4 LT |
385 | device_remove_file(dev, &dev_attr_online); |
386 | ||
387 | if (gdrv && gdrv->remove) | |
388 | gdrv->remove(gdev); | |
389 | return 0; | |
390 | } | |
391 | ||
f9ccf456 RK |
392 | static struct bus_type ccwgroup_bus_type = { |
393 | .name = "ccwgroup", | |
394 | .match = ccwgroup_bus_match, | |
395 | .uevent = ccwgroup_uevent, | |
396 | .probe = ccwgroup_probe, | |
397 | .remove = ccwgroup_remove, | |
398 | }; | |
399 | ||
b2ffd8e9 CH |
400 | /** |
401 | * ccwgroup_driver_register() - register a ccw group driver | |
402 | * @cdriver: driver to be registered | |
403 | * | |
404 | * This function is mainly a wrapper around driver_register(). | |
405 | */ | |
406 | int ccwgroup_driver_register(struct ccwgroup_driver *cdriver) | |
1da177e4 LT |
407 | { |
408 | /* register our new driver with the core */ | |
292888c8 HC |
409 | cdriver->driver.bus = &ccwgroup_bus_type; |
410 | cdriver->driver.name = cdriver->name; | |
1da177e4 LT |
411 | |
412 | return driver_register(&cdriver->driver); | |
413 | } | |
414 | ||
b0744bd2 | 415 | static int |
887ab599 | 416 | __ccwgroup_match_all(struct device *dev, void *data) |
1da177e4 | 417 | { |
887ab599 | 418 | return 1; |
1da177e4 LT |
419 | } |
420 | ||
b2ffd8e9 CH |
421 | /** |
422 | * ccwgroup_driver_unregister() - deregister a ccw group driver | |
423 | * @cdriver: driver to be deregistered | |
424 | * | |
425 | * This function is mainly a wrapper around driver_unregister(). | |
426 | */ | |
427 | void ccwgroup_driver_unregister(struct ccwgroup_driver *cdriver) | |
1da177e4 | 428 | { |
887ab599 CH |
429 | struct device *dev; |
430 | ||
1da177e4 LT |
431 | /* We don't want ccwgroup devices to live longer than their driver. */ |
432 | get_driver(&cdriver->driver); | |
887ab599 CH |
433 | while ((dev = driver_find_device(&cdriver->driver, NULL, NULL, |
434 | __ccwgroup_match_all))) { | |
d76123eb CH |
435 | struct ccwgroup_device *gdev = to_ccwgroupdev(dev); |
436 | ||
437 | mutex_lock(&gdev->reg_mutex); | |
438 | __ccwgroup_remove_symlinks(gdev); | |
887ab599 | 439 | device_unregister(dev); |
d76123eb | 440 | mutex_unlock(&gdev->reg_mutex); |
887ab599 CH |
441 | put_device(dev); |
442 | } | |
1da177e4 LT |
443 | put_driver(&cdriver->driver); |
444 | driver_unregister(&cdriver->driver); | |
445 | } | |
446 | ||
b2ffd8e9 CH |
447 | /** |
448 | * ccwgroup_probe_ccwdev() - probe function for slave devices | |
449 | * @cdev: ccw device to be probed | |
450 | * | |
451 | * This is a dummy probe function for ccw devices that are slave devices in | |
452 | * a ccw group device. | |
453 | * Returns: | |
454 | * always %0 | |
455 | */ | |
456 | int ccwgroup_probe_ccwdev(struct ccw_device *cdev) | |
1da177e4 LT |
457 | { |
458 | return 0; | |
459 | } | |
460 | ||
4d284cac | 461 | static struct ccwgroup_device * |
1da177e4 LT |
462 | __ccwgroup_get_gdev_by_cdev(struct ccw_device *cdev) |
463 | { | |
464 | struct ccwgroup_device *gdev; | |
465 | ||
466 | if (cdev->dev.driver_data) { | |
467 | gdev = (struct ccwgroup_device *)cdev->dev.driver_data; | |
468 | if (get_device(&gdev->dev)) { | |
d76123eb | 469 | mutex_lock(&gdev->reg_mutex); |
d305ef5d | 470 | if (device_is_registered(&gdev->dev)) |
1da177e4 | 471 | return gdev; |
d76123eb | 472 | mutex_unlock(&gdev->reg_mutex); |
1da177e4 LT |
473 | put_device(&gdev->dev); |
474 | } | |
475 | return NULL; | |
476 | } | |
477 | return NULL; | |
478 | } | |
479 | ||
b2ffd8e9 CH |
480 | /** |
481 | * ccwgroup_remove_ccwdev() - remove function for slave devices | |
482 | * @cdev: ccw device to be removed | |
483 | * | |
484 | * This is a remove function for ccw devices that are slave devices in a ccw | |
485 | * group device. It sets the ccw device offline and also deregisters the | |
486 | * embedding ccw group device. | |
487 | */ | |
488 | void ccwgroup_remove_ccwdev(struct ccw_device *cdev) | |
1da177e4 LT |
489 | { |
490 | struct ccwgroup_device *gdev; | |
491 | ||
492 | /* Ignore offlining errors, device is gone anyway. */ | |
493 | ccw_device_set_offline(cdev); | |
494 | /* If one of its devices is gone, the whole group is done for. */ | |
495 | gdev = __ccwgroup_get_gdev_by_cdev(cdev); | |
496 | if (gdev) { | |
497 | __ccwgroup_remove_symlinks(gdev); | |
498 | device_unregister(&gdev->dev); | |
d76123eb | 499 | mutex_unlock(&gdev->reg_mutex); |
1da177e4 LT |
500 | put_device(&gdev->dev); |
501 | } | |
502 | } | |
503 | ||
504 | MODULE_LICENSE("GPL"); | |
505 | EXPORT_SYMBOL(ccwgroup_driver_register); | |
506 | EXPORT_SYMBOL(ccwgroup_driver_unregister); | |
507 | EXPORT_SYMBOL(ccwgroup_create); | |
508 | EXPORT_SYMBOL(ccwgroup_probe_ccwdev); | |
509 | EXPORT_SYMBOL(ccwgroup_remove_ccwdev); |