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 | |
6d20b035 | 47 | ccwgroup_uevent (struct device *dev, char **envp, int num_envp, char *buffer, |
1da177e4 LT |
48 | int buffer_size) |
49 | { | |
50 | /* TODO */ | |
51 | return 0; | |
52 | } | |
53 | ||
f9ccf456 | 54 | static struct bus_type ccwgroup_bus_type; |
1da177e4 LT |
55 | |
56 | static inline void | |
57 | __ccwgroup_remove_symlinks(struct ccwgroup_device *gdev) | |
58 | { | |
59 | int i; | |
60 | char str[8]; | |
61 | ||
62 | for (i = 0; i < gdev->count; i++) { | |
63 | sprintf(str, "cdev%d", i); | |
64 | sysfs_remove_link(&gdev->dev.kobj, str); | |
65 | sysfs_remove_link(&gdev->cdev[i]->dev.kobj, "group_device"); | |
66 | } | |
67 | ||
68 | } | |
69 | ||
70 | /* | |
71 | * Provide an 'ungroup' attribute so the user can remove group devices no | |
72 | * longer needed or accidentially created. Saves memory :) | |
73 | */ | |
74 | static ssize_t | |
3fd3c0a5 | 75 | ccwgroup_ungroup_store(struct device *dev, struct device_attribute *attr, const char *buf, size_t count) |
1da177e4 LT |
76 | { |
77 | struct ccwgroup_device *gdev; | |
78 | ||
79 | gdev = to_ccwgroupdev(dev); | |
80 | ||
81 | if (gdev->state != CCWGROUP_OFFLINE) | |
82 | return -EINVAL; | |
83 | ||
84 | __ccwgroup_remove_symlinks(gdev); | |
85 | device_unregister(dev); | |
86 | ||
87 | return count; | |
88 | } | |
89 | ||
90 | static DEVICE_ATTR(ungroup, 0200, NULL, ccwgroup_ungroup_store); | |
91 | ||
92 | static void | |
93 | ccwgroup_release (struct device *dev) | |
94 | { | |
95 | struct ccwgroup_device *gdev; | |
96 | int i; | |
97 | ||
98 | gdev = to_ccwgroupdev(dev); | |
99 | ||
100 | for (i = 0; i < gdev->count; i++) { | |
101 | gdev->cdev[i]->dev.driver_data = NULL; | |
102 | put_device(&gdev->cdev[i]->dev); | |
103 | } | |
104 | kfree(gdev); | |
105 | } | |
106 | ||
107 | static inline int | |
108 | __ccwgroup_create_symlinks(struct ccwgroup_device *gdev) | |
109 | { | |
110 | char str[8]; | |
111 | int i, rc; | |
112 | ||
113 | for (i = 0; i < gdev->count; i++) { | |
114 | rc = sysfs_create_link(&gdev->cdev[i]->dev.kobj, &gdev->dev.kobj, | |
115 | "group_device"); | |
116 | if (rc) { | |
117 | for (--i; i >= 0; i--) | |
118 | sysfs_remove_link(&gdev->cdev[i]->dev.kobj, | |
119 | "group_device"); | |
120 | return rc; | |
121 | } | |
122 | } | |
123 | for (i = 0; i < gdev->count; i++) { | |
124 | sprintf(str, "cdev%d", i); | |
125 | rc = sysfs_create_link(&gdev->dev.kobj, &gdev->cdev[i]->dev.kobj, | |
126 | str); | |
127 | if (rc) { | |
128 | for (--i; i >= 0; i--) { | |
129 | sprintf(str, "cdev%d", i); | |
130 | sysfs_remove_link(&gdev->dev.kobj, str); | |
131 | } | |
132 | for (i = 0; i < gdev->count; i++) | |
133 | sysfs_remove_link(&gdev->cdev[i]->dev.kobj, | |
134 | "group_device"); | |
135 | return rc; | |
136 | } | |
137 | } | |
138 | return 0; | |
139 | } | |
140 | ||
141 | /* | |
142 | * try to add a new ccwgroup device for one driver | |
143 | * argc and argv[] are a list of bus_id's of devices | |
144 | * belonging to the driver. | |
145 | */ | |
146 | int | |
147 | ccwgroup_create(struct device *root, | |
148 | unsigned int creator_id, | |
149 | struct ccw_driver *cdrv, | |
150 | int argc, char *argv[]) | |
151 | { | |
152 | struct ccwgroup_device *gdev; | |
153 | int i; | |
154 | int rc; | |
155 | int del_drvdata; | |
156 | ||
157 | if (argc > 256) /* disallow dumb users */ | |
158 | return -EINVAL; | |
159 | ||
88abaab4 | 160 | gdev = kzalloc(sizeof(*gdev) + argc*sizeof(gdev->cdev[0]), GFP_KERNEL); |
1da177e4 LT |
161 | if (!gdev) |
162 | return -ENOMEM; | |
163 | ||
1da177e4 LT |
164 | atomic_set(&gdev->onoff, 0); |
165 | ||
166 | del_drvdata = 0; | |
167 | for (i = 0; i < argc; i++) { | |
168 | gdev->cdev[i] = get_ccwdev_by_busid(cdrv, argv[i]); | |
169 | ||
170 | /* all devices have to be of the same type in | |
171 | * order to be grouped */ | |
172 | if (!gdev->cdev[i] | |
173 | || gdev->cdev[i]->id.driver_info != | |
174 | gdev->cdev[0]->id.driver_info) { | |
175 | rc = -EINVAL; | |
176 | goto free_dev; | |
177 | } | |
178 | /* Don't allow a device to belong to more than one group. */ | |
179 | if (gdev->cdev[i]->dev.driver_data) { | |
180 | rc = -EINVAL; | |
181 | goto free_dev; | |
182 | } | |
183 | } | |
184 | for (i = 0; i < argc; i++) | |
185 | gdev->cdev[i]->dev.driver_data = gdev; | |
186 | del_drvdata = 1; | |
187 | ||
188 | gdev->creator_id = creator_id; | |
189 | gdev->count = argc; | |
190 | gdev->dev = (struct device ) { | |
191 | .bus = &ccwgroup_bus_type, | |
192 | .parent = root, | |
193 | .release = ccwgroup_release, | |
194 | }; | |
195 | ||
196 | snprintf (gdev->dev.bus_id, BUS_ID_SIZE, "%s", | |
197 | gdev->cdev[0]->dev.bus_id); | |
198 | ||
199 | rc = device_register(&gdev->dev); | |
200 | ||
201 | if (rc) | |
202 | goto free_dev; | |
203 | get_device(&gdev->dev); | |
204 | rc = device_create_file(&gdev->dev, &dev_attr_ungroup); | |
205 | ||
206 | if (rc) { | |
207 | device_unregister(&gdev->dev); | |
208 | goto error; | |
209 | } | |
210 | ||
211 | rc = __ccwgroup_create_symlinks(gdev); | |
212 | if (!rc) { | |
213 | put_device(&gdev->dev); | |
214 | return 0; | |
215 | } | |
216 | device_remove_file(&gdev->dev, &dev_attr_ungroup); | |
217 | device_unregister(&gdev->dev); | |
218 | error: | |
219 | for (i = 0; i < argc; i++) | |
220 | if (gdev->cdev[i]) { | |
221 | put_device(&gdev->cdev[i]->dev); | |
222 | gdev->cdev[i]->dev.driver_data = NULL; | |
223 | } | |
224 | put_device(&gdev->dev); | |
225 | return rc; | |
226 | free_dev: | |
227 | for (i = 0; i < argc; i++) | |
228 | if (gdev->cdev[i]) { | |
229 | put_device(&gdev->cdev[i]->dev); | |
230 | if (del_drvdata) | |
231 | gdev->cdev[i]->dev.driver_data = NULL; | |
232 | } | |
233 | kfree(gdev); | |
234 | return rc; | |
235 | } | |
236 | ||
237 | static int __init | |
238 | init_ccwgroup (void) | |
239 | { | |
240 | return bus_register (&ccwgroup_bus_type); | |
241 | } | |
242 | ||
243 | static void __exit | |
244 | cleanup_ccwgroup (void) | |
245 | { | |
246 | bus_unregister (&ccwgroup_bus_type); | |
247 | } | |
248 | ||
249 | module_init(init_ccwgroup); | |
250 | module_exit(cleanup_ccwgroup); | |
251 | ||
252 | /************************** driver stuff ******************************/ | |
253 | ||
254 | static int | |
255 | ccwgroup_set_online(struct ccwgroup_device *gdev) | |
256 | { | |
257 | struct ccwgroup_driver *gdrv; | |
258 | int ret; | |
259 | ||
973bd993 | 260 | if (atomic_cmpxchg(&gdev->onoff, 0, 1) != 0) |
1da177e4 LT |
261 | return -EAGAIN; |
262 | if (gdev->state == CCWGROUP_ONLINE) { | |
263 | ret = 0; | |
264 | goto out; | |
265 | } | |
266 | if (!gdev->dev.driver) { | |
267 | ret = -EINVAL; | |
268 | goto out; | |
269 | } | |
270 | gdrv = to_ccwgroupdrv (gdev->dev.driver); | |
a0016408 | 271 | if ((ret = gdrv->set_online ? gdrv->set_online(gdev) : 0)) |
1da177e4 LT |
272 | goto out; |
273 | ||
274 | gdev->state = CCWGROUP_ONLINE; | |
275 | out: | |
276 | atomic_set(&gdev->onoff, 0); | |
277 | return ret; | |
278 | } | |
279 | ||
280 | static int | |
281 | ccwgroup_set_offline(struct ccwgroup_device *gdev) | |
282 | { | |
283 | struct ccwgroup_driver *gdrv; | |
284 | int ret; | |
285 | ||
973bd993 | 286 | if (atomic_cmpxchg(&gdev->onoff, 0, 1) != 0) |
1da177e4 LT |
287 | return -EAGAIN; |
288 | if (gdev->state == CCWGROUP_OFFLINE) { | |
289 | ret = 0; | |
290 | goto out; | |
291 | } | |
292 | if (!gdev->dev.driver) { | |
293 | ret = -EINVAL; | |
294 | goto out; | |
295 | } | |
296 | gdrv = to_ccwgroupdrv (gdev->dev.driver); | |
a0016408 | 297 | if ((ret = gdrv->set_offline ? gdrv->set_offline(gdev) : 0)) |
1da177e4 LT |
298 | goto out; |
299 | ||
300 | gdev->state = CCWGROUP_OFFLINE; | |
301 | out: | |
302 | atomic_set(&gdev->onoff, 0); | |
303 | return ret; | |
304 | } | |
305 | ||
306 | static ssize_t | |
3fd3c0a5 | 307 | ccwgroup_online_store (struct device *dev, struct device_attribute *attr, const char *buf, size_t count) |
1da177e4 LT |
308 | { |
309 | struct ccwgroup_device *gdev; | |
310 | struct ccwgroup_driver *gdrv; | |
311 | unsigned int value; | |
312 | int ret; | |
313 | ||
314 | gdev = to_ccwgroupdev(dev); | |
315 | if (!dev->driver) | |
316 | return count; | |
317 | ||
318 | gdrv = to_ccwgroupdrv (gdev->dev.driver); | |
319 | if (!try_module_get(gdrv->owner)) | |
320 | return -EINVAL; | |
321 | ||
d2c993d8 | 322 | value = simple_strtoul(buf, NULL, 0); |
1da177e4 LT |
323 | ret = count; |
324 | if (value == 1) | |
325 | ccwgroup_set_online(gdev); | |
326 | else if (value == 0) | |
327 | ccwgroup_set_offline(gdev); | |
328 | else | |
329 | ret = -EINVAL; | |
330 | module_put(gdrv->owner); | |
331 | return ret; | |
332 | } | |
333 | ||
334 | static ssize_t | |
3fd3c0a5 | 335 | ccwgroup_online_show (struct device *dev, struct device_attribute *attr, char *buf) |
1da177e4 LT |
336 | { |
337 | int online; | |
338 | ||
339 | online = (to_ccwgroupdev(dev)->state == CCWGROUP_ONLINE); | |
340 | ||
341 | return sprintf(buf, online ? "1\n" : "0\n"); | |
342 | } | |
343 | ||
344 | static DEVICE_ATTR(online, 0644, ccwgroup_online_show, ccwgroup_online_store); | |
345 | ||
346 | static int | |
347 | ccwgroup_probe (struct device *dev) | |
348 | { | |
349 | struct ccwgroup_device *gdev; | |
350 | struct ccwgroup_driver *gdrv; | |
351 | ||
352 | int ret; | |
353 | ||
354 | gdev = to_ccwgroupdev(dev); | |
355 | gdrv = to_ccwgroupdrv(dev->driver); | |
356 | ||
357 | if ((ret = device_create_file(dev, &dev_attr_online))) | |
358 | return ret; | |
359 | ||
360 | pr_debug("%s: device %s\n", __func__, gdev->dev.bus_id); | |
361 | ret = gdrv->probe ? gdrv->probe(gdev) : -ENODEV; | |
362 | if (ret) | |
363 | device_remove_file(dev, &dev_attr_online); | |
364 | ||
365 | return ret; | |
366 | } | |
367 | ||
368 | static int | |
369 | ccwgroup_remove (struct device *dev) | |
370 | { | |
371 | struct ccwgroup_device *gdev; | |
372 | struct ccwgroup_driver *gdrv; | |
373 | ||
374 | gdev = to_ccwgroupdev(dev); | |
375 | gdrv = to_ccwgroupdrv(dev->driver); | |
376 | ||
377 | pr_debug("%s: device %s\n", __func__, gdev->dev.bus_id); | |
378 | ||
379 | device_remove_file(dev, &dev_attr_online); | |
380 | ||
381 | if (gdrv && gdrv->remove) | |
382 | gdrv->remove(gdev); | |
383 | return 0; | |
384 | } | |
385 | ||
f9ccf456 RK |
386 | static struct bus_type ccwgroup_bus_type = { |
387 | .name = "ccwgroup", | |
388 | .match = ccwgroup_bus_match, | |
389 | .uevent = ccwgroup_uevent, | |
390 | .probe = ccwgroup_probe, | |
391 | .remove = ccwgroup_remove, | |
392 | }; | |
393 | ||
1da177e4 LT |
394 | int |
395 | ccwgroup_driver_register (struct ccwgroup_driver *cdriver) | |
396 | { | |
397 | /* register our new driver with the core */ | |
398 | cdriver->driver = (struct device_driver) { | |
399 | .bus = &ccwgroup_bus_type, | |
400 | .name = cdriver->name, | |
1da177e4 LT |
401 | }; |
402 | ||
403 | return driver_register(&cdriver->driver); | |
404 | } | |
405 | ||
b0744bd2 | 406 | static int |
887ab599 | 407 | __ccwgroup_match_all(struct device *dev, void *data) |
1da177e4 | 408 | { |
887ab599 | 409 | return 1; |
1da177e4 LT |
410 | } |
411 | ||
412 | void | |
413 | ccwgroup_driver_unregister (struct ccwgroup_driver *cdriver) | |
414 | { | |
887ab599 CH |
415 | struct device *dev; |
416 | ||
1da177e4 LT |
417 | /* We don't want ccwgroup devices to live longer than their driver. */ |
418 | get_driver(&cdriver->driver); | |
887ab599 CH |
419 | while ((dev = driver_find_device(&cdriver->driver, NULL, NULL, |
420 | __ccwgroup_match_all))) { | |
421 | __ccwgroup_remove_symlinks(to_ccwgroupdev(dev)); | |
422 | device_unregister(dev); | |
423 | put_device(dev); | |
424 | } | |
1da177e4 LT |
425 | put_driver(&cdriver->driver); |
426 | driver_unregister(&cdriver->driver); | |
427 | } | |
428 | ||
429 | int | |
430 | ccwgroup_probe_ccwdev(struct ccw_device *cdev) | |
431 | { | |
432 | return 0; | |
433 | } | |
434 | ||
435 | static inline struct ccwgroup_device * | |
436 | __ccwgroup_get_gdev_by_cdev(struct ccw_device *cdev) | |
437 | { | |
438 | struct ccwgroup_device *gdev; | |
439 | ||
440 | if (cdev->dev.driver_data) { | |
441 | gdev = (struct ccwgroup_device *)cdev->dev.driver_data; | |
442 | if (get_device(&gdev->dev)) { | |
d305ef5d | 443 | if (device_is_registered(&gdev->dev)) |
1da177e4 LT |
444 | return gdev; |
445 | put_device(&gdev->dev); | |
446 | } | |
447 | return NULL; | |
448 | } | |
449 | return NULL; | |
450 | } | |
451 | ||
452 | void | |
453 | ccwgroup_remove_ccwdev(struct ccw_device *cdev) | |
454 | { | |
455 | struct ccwgroup_device *gdev; | |
456 | ||
457 | /* Ignore offlining errors, device is gone anyway. */ | |
458 | ccw_device_set_offline(cdev); | |
459 | /* If one of its devices is gone, the whole group is done for. */ | |
460 | gdev = __ccwgroup_get_gdev_by_cdev(cdev); | |
461 | if (gdev) { | |
462 | __ccwgroup_remove_symlinks(gdev); | |
463 | device_unregister(&gdev->dev); | |
464 | put_device(&gdev->dev); | |
465 | } | |
466 | } | |
467 | ||
468 | MODULE_LICENSE("GPL"); | |
469 | EXPORT_SYMBOL(ccwgroup_driver_register); | |
470 | EXPORT_SYMBOL(ccwgroup_driver_unregister); | |
471 | EXPORT_SYMBOL(ccwgroup_create); | |
472 | EXPORT_SYMBOL(ccwgroup_probe_ccwdev); | |
473 | EXPORT_SYMBOL(ccwgroup_remove_ccwdev); |