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4bac07c9 JF |
1 | /****************************************************************************** |
2 | * Talks to Xen Store to figure out what devices we have. | |
3 | * | |
4 | * Copyright (C) 2005 Rusty Russell, IBM Corporation | |
5 | * Copyright (C) 2005 Mike Wray, Hewlett-Packard | |
6 | * Copyright (C) 2005, 2006 XenSource Ltd | |
7 | * | |
8 | * This program is free software; you can redistribute it and/or | |
9 | * modify it under the terms of the GNU General Public License version 2 | |
10 | * as published by the Free Software Foundation; or, when distributed | |
11 | * separately from the Linux kernel or incorporated into other | |
12 | * software packages, subject to the following license: | |
13 | * | |
14 | * Permission is hereby granted, free of charge, to any person obtaining a copy | |
15 | * of this source file (the "Software"), to deal in the Software without | |
16 | * restriction, including without limitation the rights to use, copy, modify, | |
17 | * merge, publish, distribute, sublicense, and/or sell copies of the Software, | |
18 | * and to permit persons to whom the Software is furnished to do so, subject to | |
19 | * the following conditions: | |
20 | * | |
21 | * The above copyright notice and this permission notice shall be included in | |
22 | * all copies or substantial portions of the Software. | |
23 | * | |
24 | * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR | |
25 | * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, | |
26 | * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE | |
27 | * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER | |
28 | * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING | |
29 | * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS | |
30 | * IN THE SOFTWARE. | |
31 | */ | |
32 | ||
33 | #define DPRINTK(fmt, args...) \ | |
34 | pr_debug("xenbus_probe (%s:%d) " fmt ".\n", \ | |
35 | __func__, __LINE__, ##args) | |
36 | ||
37 | #include <linux/kernel.h> | |
38 | #include <linux/err.h> | |
39 | #include <linux/string.h> | |
40 | #include <linux/ctype.h> | |
41 | #include <linux/fcntl.h> | |
42 | #include <linux/mm.h> | |
43 | #include <linux/notifier.h> | |
44 | #include <linux/kthread.h> | |
45 | #include <linux/mutex.h> | |
46 | #include <linux/io.h> | |
47 | ||
48 | #include <asm/page.h> | |
49 | #include <asm/pgtable.h> | |
50 | #include <asm/xen/hypervisor.h> | |
51 | #include <xen/xenbus.h> | |
52 | #include <xen/events.h> | |
53 | #include <xen/page.h> | |
54 | ||
55 | #include "xenbus_comms.h" | |
56 | #include "xenbus_probe.h" | |
57 | ||
58 | int xen_store_evtchn; | |
59 | struct xenstore_domain_interface *xen_store_interface; | |
60 | static unsigned long xen_store_mfn; | |
61 | ||
62 | static BLOCKING_NOTIFIER_HEAD(xenstore_chain); | |
63 | ||
64 | static void wait_for_devices(struct xenbus_driver *xendrv); | |
65 | ||
66 | static int xenbus_probe_frontend(const char *type, const char *name); | |
67 | ||
68 | static void xenbus_dev_shutdown(struct device *_dev); | |
69 | ||
70 | /* If something in array of ids matches this device, return it. */ | |
71 | static const struct xenbus_device_id * | |
72 | match_device(const struct xenbus_device_id *arr, struct xenbus_device *dev) | |
73 | { | |
74 | for (; *arr->devicetype != '\0'; arr++) { | |
75 | if (!strcmp(arr->devicetype, dev->devicetype)) | |
76 | return arr; | |
77 | } | |
78 | return NULL; | |
79 | } | |
80 | ||
81 | int xenbus_match(struct device *_dev, struct device_driver *_drv) | |
82 | { | |
83 | struct xenbus_driver *drv = to_xenbus_driver(_drv); | |
84 | ||
85 | if (!drv->ids) | |
86 | return 0; | |
87 | ||
88 | return match_device(drv->ids, to_xenbus_device(_dev)) != NULL; | |
89 | } | |
90 | ||
91 | /* device/<type>/<id> => <type>-<id> */ | |
92 | static int frontend_bus_id(char bus_id[BUS_ID_SIZE], const char *nodename) | |
93 | { | |
94 | nodename = strchr(nodename, '/'); | |
95 | if (!nodename || strlen(nodename + 1) >= BUS_ID_SIZE) { | |
96 | printk(KERN_WARNING "XENBUS: bad frontend %s\n", nodename); | |
97 | return -EINVAL; | |
98 | } | |
99 | ||
100 | strlcpy(bus_id, nodename + 1, BUS_ID_SIZE); | |
101 | if (!strchr(bus_id, '/')) { | |
102 | printk(KERN_WARNING "XENBUS: bus_id %s no slash\n", bus_id); | |
103 | return -EINVAL; | |
104 | } | |
105 | *strchr(bus_id, '/') = '-'; | |
106 | return 0; | |
107 | } | |
108 | ||
109 | ||
110 | static void free_otherend_details(struct xenbus_device *dev) | |
111 | { | |
112 | kfree(dev->otherend); | |
113 | dev->otherend = NULL; | |
114 | } | |
115 | ||
116 | ||
117 | static void free_otherend_watch(struct xenbus_device *dev) | |
118 | { | |
119 | if (dev->otherend_watch.node) { | |
120 | unregister_xenbus_watch(&dev->otherend_watch); | |
121 | kfree(dev->otherend_watch.node); | |
122 | dev->otherend_watch.node = NULL; | |
123 | } | |
124 | } | |
125 | ||
126 | ||
127 | int read_otherend_details(struct xenbus_device *xendev, | |
128 | char *id_node, char *path_node) | |
129 | { | |
130 | int err = xenbus_gather(XBT_NIL, xendev->nodename, | |
131 | id_node, "%i", &xendev->otherend_id, | |
132 | path_node, NULL, &xendev->otherend, | |
133 | NULL); | |
134 | if (err) { | |
135 | xenbus_dev_fatal(xendev, err, | |
136 | "reading other end details from %s", | |
137 | xendev->nodename); | |
138 | return err; | |
139 | } | |
140 | if (strlen(xendev->otherend) == 0 || | |
141 | !xenbus_exists(XBT_NIL, xendev->otherend, "")) { | |
142 | xenbus_dev_fatal(xendev, -ENOENT, | |
143 | "unable to read other end from %s. " | |
144 | "missing or inaccessible.", | |
145 | xendev->nodename); | |
146 | free_otherend_details(xendev); | |
147 | return -ENOENT; | |
148 | } | |
149 | ||
150 | return 0; | |
151 | } | |
152 | ||
153 | ||
154 | static int read_backend_details(struct xenbus_device *xendev) | |
155 | { | |
156 | return read_otherend_details(xendev, "backend-id", "backend"); | |
157 | } | |
158 | ||
159 | ||
160 | /* Bus type for frontend drivers. */ | |
161 | static struct xen_bus_type xenbus_frontend = { | |
162 | .root = "device", | |
163 | .levels = 2, /* device/type/<id> */ | |
164 | .get_bus_id = frontend_bus_id, | |
165 | .probe = xenbus_probe_frontend, | |
166 | .bus = { | |
167 | .name = "xen", | |
168 | .match = xenbus_match, | |
169 | .probe = xenbus_dev_probe, | |
170 | .remove = xenbus_dev_remove, | |
171 | .shutdown = xenbus_dev_shutdown, | |
172 | }, | |
173 | }; | |
174 | ||
175 | static void otherend_changed(struct xenbus_watch *watch, | |
176 | const char **vec, unsigned int len) | |
177 | { | |
178 | struct xenbus_device *dev = | |
179 | container_of(watch, struct xenbus_device, otherend_watch); | |
180 | struct xenbus_driver *drv = to_xenbus_driver(dev->dev.driver); | |
181 | enum xenbus_state state; | |
182 | ||
183 | /* Protect us against watches firing on old details when the otherend | |
184 | details change, say immediately after a resume. */ | |
185 | if (!dev->otherend || | |
186 | strncmp(dev->otherend, vec[XS_WATCH_PATH], | |
187 | strlen(dev->otherend))) { | |
898eb71c JP |
188 | dev_dbg(&dev->dev, "Ignoring watch at %s\n", |
189 | vec[XS_WATCH_PATH]); | |
4bac07c9 JF |
190 | return; |
191 | } | |
192 | ||
193 | state = xenbus_read_driver_state(dev->otherend); | |
194 | ||
898eb71c | 195 | dev_dbg(&dev->dev, "state is %d, (%s), %s, %s\n", |
4bac07c9 JF |
196 | state, xenbus_strstate(state), dev->otherend_watch.node, |
197 | vec[XS_WATCH_PATH]); | |
198 | ||
199 | /* | |
200 | * Ignore xenbus transitions during shutdown. This prevents us doing | |
201 | * work that can fail e.g., when the rootfs is gone. | |
202 | */ | |
203 | if (system_state > SYSTEM_RUNNING) { | |
204 | struct xen_bus_type *bus = bus; | |
205 | bus = container_of(dev->dev.bus, struct xen_bus_type, bus); | |
206 | /* If we're frontend, drive the state machine to Closed. */ | |
207 | /* This should cause the backend to release our resources. */ | |
208 | if ((bus == &xenbus_frontend) && (state == XenbusStateClosing)) | |
209 | xenbus_frontend_closed(dev); | |
210 | return; | |
211 | } | |
212 | ||
213 | if (drv->otherend_changed) | |
214 | drv->otherend_changed(dev, state); | |
215 | } | |
216 | ||
217 | ||
218 | static int talk_to_otherend(struct xenbus_device *dev) | |
219 | { | |
220 | struct xenbus_driver *drv = to_xenbus_driver(dev->dev.driver); | |
221 | ||
222 | free_otherend_watch(dev); | |
223 | free_otherend_details(dev); | |
224 | ||
225 | return drv->read_otherend_details(dev); | |
226 | } | |
227 | ||
228 | ||
229 | static int watch_otherend(struct xenbus_device *dev) | |
230 | { | |
231 | return xenbus_watch_pathfmt(dev, &dev->otherend_watch, otherend_changed, | |
232 | "%s/%s", dev->otherend, "state"); | |
233 | } | |
234 | ||
235 | ||
236 | int xenbus_dev_probe(struct device *_dev) | |
237 | { | |
238 | struct xenbus_device *dev = to_xenbus_device(_dev); | |
239 | struct xenbus_driver *drv = to_xenbus_driver(_dev->driver); | |
240 | const struct xenbus_device_id *id; | |
241 | int err; | |
242 | ||
243 | DPRINTK("%s", dev->nodename); | |
244 | ||
245 | if (!drv->probe) { | |
246 | err = -ENODEV; | |
247 | goto fail; | |
248 | } | |
249 | ||
250 | id = match_device(drv->ids, dev); | |
251 | if (!id) { | |
252 | err = -ENODEV; | |
253 | goto fail; | |
254 | } | |
255 | ||
256 | err = talk_to_otherend(dev); | |
257 | if (err) { | |
258 | dev_warn(&dev->dev, "talk_to_otherend on %s failed.\n", | |
259 | dev->nodename); | |
260 | return err; | |
261 | } | |
262 | ||
263 | err = drv->probe(dev, id); | |
264 | if (err) | |
265 | goto fail; | |
266 | ||
267 | err = watch_otherend(dev); | |
268 | if (err) { | |
269 | dev_warn(&dev->dev, "watch_otherend on %s failed.\n", | |
270 | dev->nodename); | |
271 | return err; | |
272 | } | |
273 | ||
274 | return 0; | |
275 | fail: | |
276 | xenbus_dev_error(dev, err, "xenbus_dev_probe on %s", dev->nodename); | |
277 | xenbus_switch_state(dev, XenbusStateClosed); | |
278 | return -ENODEV; | |
279 | } | |
280 | ||
281 | int xenbus_dev_remove(struct device *_dev) | |
282 | { | |
283 | struct xenbus_device *dev = to_xenbus_device(_dev); | |
284 | struct xenbus_driver *drv = to_xenbus_driver(_dev->driver); | |
285 | ||
286 | DPRINTK("%s", dev->nodename); | |
287 | ||
288 | free_otherend_watch(dev); | |
289 | free_otherend_details(dev); | |
290 | ||
291 | if (drv->remove) | |
292 | drv->remove(dev); | |
293 | ||
294 | xenbus_switch_state(dev, XenbusStateClosed); | |
295 | return 0; | |
296 | } | |
297 | ||
298 | static void xenbus_dev_shutdown(struct device *_dev) | |
299 | { | |
300 | struct xenbus_device *dev = to_xenbus_device(_dev); | |
301 | unsigned long timeout = 5*HZ; | |
302 | ||
303 | DPRINTK("%s", dev->nodename); | |
304 | ||
305 | get_device(&dev->dev); | |
306 | if (dev->state != XenbusStateConnected) { | |
307 | printk(KERN_INFO "%s: %s: %s != Connected, skipping\n", __func__, | |
308 | dev->nodename, xenbus_strstate(dev->state)); | |
309 | goto out; | |
310 | } | |
311 | xenbus_switch_state(dev, XenbusStateClosing); | |
312 | timeout = wait_for_completion_timeout(&dev->down, timeout); | |
313 | if (!timeout) | |
314 | printk(KERN_INFO "%s: %s timeout closing device\n", | |
315 | __func__, dev->nodename); | |
316 | out: | |
317 | put_device(&dev->dev); | |
318 | } | |
319 | ||
320 | int xenbus_register_driver_common(struct xenbus_driver *drv, | |
321 | struct xen_bus_type *bus, | |
322 | struct module *owner, | |
323 | const char *mod_name) | |
324 | { | |
325 | drv->driver.name = drv->name; | |
326 | drv->driver.bus = &bus->bus; | |
327 | drv->driver.owner = owner; | |
328 | drv->driver.mod_name = mod_name; | |
329 | ||
330 | return driver_register(&drv->driver); | |
331 | } | |
332 | ||
333 | int __xenbus_register_frontend(struct xenbus_driver *drv, | |
334 | struct module *owner, const char *mod_name) | |
335 | { | |
336 | int ret; | |
337 | ||
338 | drv->read_otherend_details = read_backend_details; | |
339 | ||
340 | ret = xenbus_register_driver_common(drv, &xenbus_frontend, | |
341 | owner, mod_name); | |
342 | if (ret) | |
343 | return ret; | |
344 | ||
345 | /* If this driver is loaded as a module wait for devices to attach. */ | |
346 | wait_for_devices(drv); | |
347 | ||
348 | return 0; | |
349 | } | |
350 | EXPORT_SYMBOL_GPL(__xenbus_register_frontend); | |
351 | ||
352 | void xenbus_unregister_driver(struct xenbus_driver *drv) | |
353 | { | |
354 | driver_unregister(&drv->driver); | |
355 | } | |
356 | EXPORT_SYMBOL_GPL(xenbus_unregister_driver); | |
357 | ||
358 | struct xb_find_info | |
359 | { | |
360 | struct xenbus_device *dev; | |
361 | const char *nodename; | |
362 | }; | |
363 | ||
364 | static int cmp_dev(struct device *dev, void *data) | |
365 | { | |
366 | struct xenbus_device *xendev = to_xenbus_device(dev); | |
367 | struct xb_find_info *info = data; | |
368 | ||
369 | if (!strcmp(xendev->nodename, info->nodename)) { | |
370 | info->dev = xendev; | |
371 | get_device(dev); | |
372 | return 1; | |
373 | } | |
374 | return 0; | |
375 | } | |
376 | ||
377 | struct xenbus_device *xenbus_device_find(const char *nodename, | |
378 | struct bus_type *bus) | |
379 | { | |
380 | struct xb_find_info info = { .dev = NULL, .nodename = nodename }; | |
381 | ||
382 | bus_for_each_dev(bus, NULL, &info, cmp_dev); | |
383 | return info.dev; | |
384 | } | |
385 | ||
386 | static int cleanup_dev(struct device *dev, void *data) | |
387 | { | |
388 | struct xenbus_device *xendev = to_xenbus_device(dev); | |
389 | struct xb_find_info *info = data; | |
390 | int len = strlen(info->nodename); | |
391 | ||
392 | DPRINTK("%s", info->nodename); | |
393 | ||
394 | /* Match the info->nodename path, or any subdirectory of that path. */ | |
395 | if (strncmp(xendev->nodename, info->nodename, len)) | |
396 | return 0; | |
397 | ||
398 | /* If the node name is longer, ensure it really is a subdirectory. */ | |
399 | if ((strlen(xendev->nodename) > len) && (xendev->nodename[len] != '/')) | |
400 | return 0; | |
401 | ||
402 | info->dev = xendev; | |
403 | get_device(dev); | |
404 | return 1; | |
405 | } | |
406 | ||
407 | static void xenbus_cleanup_devices(const char *path, struct bus_type *bus) | |
408 | { | |
409 | struct xb_find_info info = { .nodename = path }; | |
410 | ||
411 | do { | |
412 | info.dev = NULL; | |
413 | bus_for_each_dev(bus, NULL, &info, cleanup_dev); | |
414 | if (info.dev) { | |
415 | device_unregister(&info.dev->dev); | |
416 | put_device(&info.dev->dev); | |
417 | } | |
418 | } while (info.dev); | |
419 | } | |
420 | ||
421 | static void xenbus_dev_release(struct device *dev) | |
422 | { | |
423 | if (dev) | |
424 | kfree(to_xenbus_device(dev)); | |
425 | } | |
426 | ||
427 | static ssize_t xendev_show_nodename(struct device *dev, | |
428 | struct device_attribute *attr, char *buf) | |
429 | { | |
430 | return sprintf(buf, "%s\n", to_xenbus_device(dev)->nodename); | |
431 | } | |
432 | DEVICE_ATTR(nodename, S_IRUSR | S_IRGRP | S_IROTH, xendev_show_nodename, NULL); | |
433 | ||
434 | static ssize_t xendev_show_devtype(struct device *dev, | |
435 | struct device_attribute *attr, char *buf) | |
436 | { | |
437 | return sprintf(buf, "%s\n", to_xenbus_device(dev)->devicetype); | |
438 | } | |
439 | DEVICE_ATTR(devtype, S_IRUSR | S_IRGRP | S_IROTH, xendev_show_devtype, NULL); | |
440 | ||
441 | ||
442 | int xenbus_probe_node(struct xen_bus_type *bus, | |
443 | const char *type, | |
444 | const char *nodename) | |
445 | { | |
446 | int err; | |
447 | struct xenbus_device *xendev; | |
448 | size_t stringlen; | |
449 | char *tmpstring; | |
450 | ||
451 | enum xenbus_state state = xenbus_read_driver_state(nodename); | |
452 | ||
453 | if (state != XenbusStateInitialising) { | |
454 | /* Device is not new, so ignore it. This can happen if a | |
455 | device is going away after switching to Closed. */ | |
456 | return 0; | |
457 | } | |
458 | ||
459 | stringlen = strlen(nodename) + 1 + strlen(type) + 1; | |
460 | xendev = kzalloc(sizeof(*xendev) + stringlen, GFP_KERNEL); | |
461 | if (!xendev) | |
462 | return -ENOMEM; | |
463 | ||
464 | xendev->state = XenbusStateInitialising; | |
465 | ||
466 | /* Copy the strings into the extra space. */ | |
467 | ||
468 | tmpstring = (char *)(xendev + 1); | |
469 | strcpy(tmpstring, nodename); | |
470 | xendev->nodename = tmpstring; | |
471 | ||
472 | tmpstring += strlen(tmpstring) + 1; | |
473 | strcpy(tmpstring, type); | |
474 | xendev->devicetype = tmpstring; | |
475 | init_completion(&xendev->down); | |
476 | ||
477 | xendev->dev.bus = &bus->bus; | |
478 | xendev->dev.release = xenbus_dev_release; | |
479 | ||
480 | err = bus->get_bus_id(xendev->dev.bus_id, xendev->nodename); | |
481 | if (err) | |
482 | goto fail; | |
483 | ||
484 | /* Register with generic device framework. */ | |
485 | err = device_register(&xendev->dev); | |
486 | if (err) | |
487 | goto fail; | |
488 | ||
489 | err = device_create_file(&xendev->dev, &dev_attr_nodename); | |
490 | if (err) | |
491 | goto fail_unregister; | |
492 | ||
493 | err = device_create_file(&xendev->dev, &dev_attr_devtype); | |
494 | if (err) | |
495 | goto fail_remove_file; | |
496 | ||
497 | return 0; | |
498 | fail_remove_file: | |
499 | device_remove_file(&xendev->dev, &dev_attr_nodename); | |
500 | fail_unregister: | |
501 | device_unregister(&xendev->dev); | |
502 | fail: | |
503 | kfree(xendev); | |
504 | return err; | |
505 | } | |
506 | ||
507 | /* device/<typename>/<name> */ | |
508 | static int xenbus_probe_frontend(const char *type, const char *name) | |
509 | { | |
510 | char *nodename; | |
511 | int err; | |
512 | ||
513 | nodename = kasprintf(GFP_KERNEL, "%s/%s/%s", | |
514 | xenbus_frontend.root, type, name); | |
515 | if (!nodename) | |
516 | return -ENOMEM; | |
517 | ||
518 | DPRINTK("%s", nodename); | |
519 | ||
520 | err = xenbus_probe_node(&xenbus_frontend, type, nodename); | |
521 | kfree(nodename); | |
522 | return err; | |
523 | } | |
524 | ||
525 | static int xenbus_probe_device_type(struct xen_bus_type *bus, const char *type) | |
526 | { | |
527 | int err = 0; | |
528 | char **dir; | |
529 | unsigned int dir_n = 0; | |
530 | int i; | |
531 | ||
532 | dir = xenbus_directory(XBT_NIL, bus->root, type, &dir_n); | |
533 | if (IS_ERR(dir)) | |
534 | return PTR_ERR(dir); | |
535 | ||
536 | for (i = 0; i < dir_n; i++) { | |
537 | err = bus->probe(type, dir[i]); | |
538 | if (err) | |
539 | break; | |
540 | } | |
541 | kfree(dir); | |
542 | return err; | |
543 | } | |
544 | ||
545 | int xenbus_probe_devices(struct xen_bus_type *bus) | |
546 | { | |
547 | int err = 0; | |
548 | char **dir; | |
549 | unsigned int i, dir_n; | |
550 | ||
551 | dir = xenbus_directory(XBT_NIL, bus->root, "", &dir_n); | |
552 | if (IS_ERR(dir)) | |
553 | return PTR_ERR(dir); | |
554 | ||
555 | for (i = 0; i < dir_n; i++) { | |
556 | err = xenbus_probe_device_type(bus, dir[i]); | |
557 | if (err) | |
558 | break; | |
559 | } | |
560 | kfree(dir); | |
561 | return err; | |
562 | } | |
563 | ||
564 | static unsigned int char_count(const char *str, char c) | |
565 | { | |
566 | unsigned int i, ret = 0; | |
567 | ||
568 | for (i = 0; str[i]; i++) | |
569 | if (str[i] == c) | |
570 | ret++; | |
571 | return ret; | |
572 | } | |
573 | ||
574 | static int strsep_len(const char *str, char c, unsigned int len) | |
575 | { | |
576 | unsigned int i; | |
577 | ||
578 | for (i = 0; str[i]; i++) | |
579 | if (str[i] == c) { | |
580 | if (len == 0) | |
581 | return i; | |
582 | len--; | |
583 | } | |
584 | return (len == 0) ? i : -ERANGE; | |
585 | } | |
586 | ||
587 | void xenbus_dev_changed(const char *node, struct xen_bus_type *bus) | |
588 | { | |
589 | int exists, rootlen; | |
590 | struct xenbus_device *dev; | |
591 | char type[BUS_ID_SIZE]; | |
592 | const char *p, *root; | |
593 | ||
594 | if (char_count(node, '/') < 2) | |
595 | return; | |
596 | ||
597 | exists = xenbus_exists(XBT_NIL, node, ""); | |
598 | if (!exists) { | |
599 | xenbus_cleanup_devices(node, &bus->bus); | |
600 | return; | |
601 | } | |
602 | ||
603 | /* backend/<type>/... or device/<type>/... */ | |
604 | p = strchr(node, '/') + 1; | |
605 | snprintf(type, BUS_ID_SIZE, "%.*s", (int)strcspn(p, "/"), p); | |
606 | type[BUS_ID_SIZE-1] = '\0'; | |
607 | ||
608 | rootlen = strsep_len(node, '/', bus->levels); | |
609 | if (rootlen < 0) | |
610 | return; | |
611 | root = kasprintf(GFP_KERNEL, "%.*s", rootlen, node); | |
612 | if (!root) | |
613 | return; | |
614 | ||
615 | dev = xenbus_device_find(root, &bus->bus); | |
616 | if (!dev) | |
617 | xenbus_probe_node(bus, type, root); | |
618 | else | |
619 | put_device(&dev->dev); | |
620 | ||
621 | kfree(root); | |
622 | } | |
623 | ||
624 | static void frontend_changed(struct xenbus_watch *watch, | |
625 | const char **vec, unsigned int len) | |
626 | { | |
627 | DPRINTK(""); | |
628 | ||
629 | xenbus_dev_changed(vec[XS_WATCH_PATH], &xenbus_frontend); | |
630 | } | |
631 | ||
632 | /* We watch for devices appearing and vanishing. */ | |
633 | static struct xenbus_watch fe_watch = { | |
634 | .node = "device", | |
635 | .callback = frontend_changed, | |
636 | }; | |
637 | ||
638 | static int suspend_dev(struct device *dev, void *data) | |
639 | { | |
640 | int err = 0; | |
641 | struct xenbus_driver *drv; | |
642 | struct xenbus_device *xdev; | |
643 | ||
644 | DPRINTK(""); | |
645 | ||
646 | if (dev->driver == NULL) | |
647 | return 0; | |
648 | drv = to_xenbus_driver(dev->driver); | |
649 | xdev = container_of(dev, struct xenbus_device, dev); | |
650 | if (drv->suspend) | |
651 | err = drv->suspend(xdev); | |
652 | if (err) | |
653 | printk(KERN_WARNING | |
654 | "xenbus: suspend %s failed: %i\n", dev->bus_id, err); | |
655 | return 0; | |
656 | } | |
657 | ||
658 | static int suspend_cancel_dev(struct device *dev, void *data) | |
659 | { | |
660 | int err = 0; | |
661 | struct xenbus_driver *drv; | |
662 | struct xenbus_device *xdev; | |
663 | ||
664 | DPRINTK(""); | |
665 | ||
666 | if (dev->driver == NULL) | |
667 | return 0; | |
668 | drv = to_xenbus_driver(dev->driver); | |
669 | xdev = container_of(dev, struct xenbus_device, dev); | |
670 | if (drv->suspend_cancel) | |
671 | err = drv->suspend_cancel(xdev); | |
672 | if (err) | |
673 | printk(KERN_WARNING | |
674 | "xenbus: suspend_cancel %s failed: %i\n", | |
675 | dev->bus_id, err); | |
676 | return 0; | |
677 | } | |
678 | ||
679 | static int resume_dev(struct device *dev, void *data) | |
680 | { | |
681 | int err; | |
682 | struct xenbus_driver *drv; | |
683 | struct xenbus_device *xdev; | |
684 | ||
685 | DPRINTK(""); | |
686 | ||
687 | if (dev->driver == NULL) | |
688 | return 0; | |
689 | ||
690 | drv = to_xenbus_driver(dev->driver); | |
691 | xdev = container_of(dev, struct xenbus_device, dev); | |
692 | ||
693 | err = talk_to_otherend(xdev); | |
694 | if (err) { | |
695 | printk(KERN_WARNING | |
696 | "xenbus: resume (talk_to_otherend) %s failed: %i\n", | |
697 | dev->bus_id, err); | |
698 | return err; | |
699 | } | |
700 | ||
701 | xdev->state = XenbusStateInitialising; | |
702 | ||
703 | if (drv->resume) { | |
704 | err = drv->resume(xdev); | |
705 | if (err) { | |
706 | printk(KERN_WARNING | |
707 | "xenbus: resume %s failed: %i\n", | |
708 | dev->bus_id, err); | |
709 | return err; | |
710 | } | |
711 | } | |
712 | ||
713 | err = watch_otherend(xdev); | |
714 | if (err) { | |
715 | printk(KERN_WARNING | |
716 | "xenbus_probe: resume (watch_otherend) %s failed: " | |
717 | "%d.\n", dev->bus_id, err); | |
718 | return err; | |
719 | } | |
720 | ||
721 | return 0; | |
722 | } | |
723 | ||
724 | void xenbus_suspend(void) | |
725 | { | |
726 | DPRINTK(""); | |
727 | ||
728 | bus_for_each_dev(&xenbus_frontend.bus, NULL, NULL, suspend_dev); | |
729 | xenbus_backend_suspend(suspend_dev); | |
730 | xs_suspend(); | |
731 | } | |
732 | EXPORT_SYMBOL_GPL(xenbus_suspend); | |
733 | ||
734 | void xenbus_resume(void) | |
735 | { | |
736 | xb_init_comms(); | |
737 | xs_resume(); | |
738 | bus_for_each_dev(&xenbus_frontend.bus, NULL, NULL, resume_dev); | |
739 | xenbus_backend_resume(resume_dev); | |
740 | } | |
741 | EXPORT_SYMBOL_GPL(xenbus_resume); | |
742 | ||
743 | void xenbus_suspend_cancel(void) | |
744 | { | |
745 | xs_suspend_cancel(); | |
746 | bus_for_each_dev(&xenbus_frontend.bus, NULL, NULL, suspend_cancel_dev); | |
747 | xenbus_backend_resume(suspend_cancel_dev); | |
748 | } | |
749 | EXPORT_SYMBOL_GPL(xenbus_suspend_cancel); | |
750 | ||
751 | /* A flag to determine if xenstored is 'ready' (i.e. has started) */ | |
752 | int xenstored_ready = 0; | |
753 | ||
754 | ||
755 | int register_xenstore_notifier(struct notifier_block *nb) | |
756 | { | |
757 | int ret = 0; | |
758 | ||
759 | if (xenstored_ready > 0) | |
760 | ret = nb->notifier_call(nb, 0, NULL); | |
761 | else | |
762 | blocking_notifier_chain_register(&xenstore_chain, nb); | |
763 | ||
764 | return ret; | |
765 | } | |
766 | EXPORT_SYMBOL_GPL(register_xenstore_notifier); | |
767 | ||
768 | void unregister_xenstore_notifier(struct notifier_block *nb) | |
769 | { | |
770 | blocking_notifier_chain_unregister(&xenstore_chain, nb); | |
771 | } | |
772 | EXPORT_SYMBOL_GPL(unregister_xenstore_notifier); | |
773 | ||
774 | void xenbus_probe(struct work_struct *unused) | |
775 | { | |
776 | BUG_ON((xenstored_ready <= 0)); | |
777 | ||
778 | /* Enumerate devices in xenstore and watch for changes. */ | |
779 | xenbus_probe_devices(&xenbus_frontend); | |
780 | register_xenbus_watch(&fe_watch); | |
781 | xenbus_backend_probe_and_watch(); | |
782 | ||
783 | /* Notify others that xenstore is up */ | |
784 | blocking_notifier_call_chain(&xenstore_chain, 0, NULL); | |
785 | } | |
786 | ||
787 | static int __init xenbus_probe_init(void) | |
788 | { | |
789 | int err = 0; | |
790 | ||
791 | DPRINTK(""); | |
792 | ||
793 | err = -ENODEV; | |
794 | if (!is_running_on_xen()) | |
795 | goto out_error; | |
796 | ||
797 | /* Register ourselves with the kernel bus subsystem */ | |
798 | err = bus_register(&xenbus_frontend.bus); | |
799 | if (err) | |
800 | goto out_error; | |
801 | ||
802 | err = xenbus_backend_bus_register(); | |
803 | if (err) | |
804 | goto out_unreg_front; | |
805 | ||
806 | /* | |
807 | * Domain0 doesn't have a store_evtchn or store_mfn yet. | |
808 | */ | |
809 | if (is_initial_xendomain()) { | |
810 | /* dom0 not yet supported */ | |
811 | } else { | |
812 | xenstored_ready = 1; | |
813 | xen_store_evtchn = xen_start_info->store_evtchn; | |
814 | xen_store_mfn = xen_start_info->store_mfn; | |
815 | } | |
816 | xen_store_interface = mfn_to_virt(xen_store_mfn); | |
817 | ||
818 | /* Initialize the interface to xenstore. */ | |
819 | err = xs_init(); | |
820 | if (err) { | |
821 | printk(KERN_WARNING | |
822 | "XENBUS: Error initializing xenstore comms: %i\n", err); | |
823 | goto out_unreg_back; | |
824 | } | |
825 | ||
826 | if (!is_initial_xendomain()) | |
827 | xenbus_probe(NULL); | |
828 | ||
829 | return 0; | |
830 | ||
831 | out_unreg_back: | |
832 | xenbus_backend_bus_unregister(); | |
833 | ||
834 | out_unreg_front: | |
835 | bus_unregister(&xenbus_frontend.bus); | |
836 | ||
837 | out_error: | |
838 | return err; | |
839 | } | |
840 | ||
841 | postcore_initcall(xenbus_probe_init); | |
842 | ||
843 | MODULE_LICENSE("GPL"); | |
844 | ||
845 | static int is_disconnected_device(struct device *dev, void *data) | |
846 | { | |
847 | struct xenbus_device *xendev = to_xenbus_device(dev); | |
848 | struct device_driver *drv = data; | |
849 | ||
850 | /* | |
851 | * A device with no driver will never connect. We care only about | |
852 | * devices which should currently be in the process of connecting. | |
853 | */ | |
854 | if (!dev->driver) | |
855 | return 0; | |
856 | ||
857 | /* Is this search limited to a particular driver? */ | |
858 | if (drv && (dev->driver != drv)) | |
859 | return 0; | |
860 | ||
861 | return (xendev->state != XenbusStateConnected); | |
862 | } | |
863 | ||
864 | static int exists_disconnected_device(struct device_driver *drv) | |
865 | { | |
866 | return bus_for_each_dev(&xenbus_frontend.bus, NULL, drv, | |
867 | is_disconnected_device); | |
868 | } | |
869 | ||
870 | static int print_device_status(struct device *dev, void *data) | |
871 | { | |
872 | struct xenbus_device *xendev = to_xenbus_device(dev); | |
873 | struct device_driver *drv = data; | |
874 | ||
875 | /* Is this operation limited to a particular driver? */ | |
876 | if (drv && (dev->driver != drv)) | |
877 | return 0; | |
878 | ||
879 | if (!dev->driver) { | |
880 | /* Information only: is this too noisy? */ | |
881 | printk(KERN_INFO "XENBUS: Device with no driver: %s\n", | |
882 | xendev->nodename); | |
883 | } else if (xendev->state != XenbusStateConnected) { | |
884 | printk(KERN_WARNING "XENBUS: Timeout connecting " | |
885 | "to device: %s (state %d)\n", | |
886 | xendev->nodename, xendev->state); | |
887 | } | |
888 | ||
889 | return 0; | |
890 | } | |
891 | ||
892 | /* We only wait for device setup after most initcalls have run. */ | |
893 | static int ready_to_wait_for_devices; | |
894 | ||
895 | /* | |
896 | * On a 10 second timeout, wait for all devices currently configured. We need | |
897 | * to do this to guarantee that the filesystems and / or network devices | |
898 | * needed for boot are available, before we can allow the boot to proceed. | |
899 | * | |
900 | * This needs to be on a late_initcall, to happen after the frontend device | |
901 | * drivers have been initialised, but before the root fs is mounted. | |
902 | * | |
903 | * A possible improvement here would be to have the tools add a per-device | |
904 | * flag to the store entry, indicating whether it is needed at boot time. | |
905 | * This would allow people who knew what they were doing to accelerate their | |
906 | * boot slightly, but of course needs tools or manual intervention to set up | |
907 | * those flags correctly. | |
908 | */ | |
909 | static void wait_for_devices(struct xenbus_driver *xendrv) | |
910 | { | |
911 | unsigned long timeout = jiffies + 10*HZ; | |
912 | struct device_driver *drv = xendrv ? &xendrv->driver : NULL; | |
913 | ||
914 | if (!ready_to_wait_for_devices || !is_running_on_xen()) | |
915 | return; | |
916 | ||
917 | while (exists_disconnected_device(drv)) { | |
918 | if (time_after(jiffies, timeout)) | |
919 | break; | |
920 | schedule_timeout_interruptible(HZ/10); | |
921 | } | |
922 | ||
923 | bus_for_each_dev(&xenbus_frontend.bus, NULL, drv, | |
924 | print_device_status); | |
925 | } | |
926 | ||
927 | #ifndef MODULE | |
928 | static int __init boot_wait_for_devices(void) | |
929 | { | |
930 | ready_to_wait_for_devices = 1; | |
931 | wait_for_devices(NULL); | |
932 | return 0; | |
933 | } | |
934 | ||
935 | late_initcall(boot_wait_for_devices); | |
936 | #endif |