ia64/xen-unstable

view linux-2.6-xen-sparse/include/xen/xenbus.h @ 13835:1e56ac73b9b9

linux: Allow xenbus_strstate() to be used from modules.

The function is referenced by a number of DPRINTK()-s. Also, properly
const-ify it.

Signed-off-by: Jan Beulich <jbeulich@novell.com>
author kfraser@localhost.localdomain
date Fri Feb 02 16:04:11 2007 +0000 (2007-02-02)
parents f89126a59073
children ed4311db1cf6
line source
1 /******************************************************************************
2 * xenbus.h
3 *
4 * Talks to Xen Store to figure out what devices we have.
5 *
6 * Copyright (C) 2005 Rusty Russell, IBM Corporation
7 * Copyright (C) 2005 XenSource Ltd.
8 *
9 * This program is free software; you can redistribute it and/or
10 * modify it under the terms of the GNU General Public License version 2
11 * as published by the Free Software Foundation; or, when distributed
12 * separately from the Linux kernel or incorporated into other
13 * software packages, subject to the following license:
14 *
15 * Permission is hereby granted, free of charge, to any person obtaining a copy
16 * of this source file (the "Software"), to deal in the Software without
17 * restriction, including without limitation the rights to use, copy, modify,
18 * merge, publish, distribute, sublicense, and/or sell copies of the Software,
19 * and to permit persons to whom the Software is furnished to do so, subject to
20 * the following conditions:
21 *
22 * The above copyright notice and this permission notice shall be included in
23 * all copies or substantial portions of the Software.
24 *
25 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
26 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
27 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
28 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
29 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
30 * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
31 * IN THE SOFTWARE.
32 */
34 #ifndef _XEN_XENBUS_H
35 #define _XEN_XENBUS_H
37 #include <linux/device.h>
38 #include <linux/notifier.h>
39 #include <linux/mutex.h>
40 #include <linux/completion.h>
41 #include <linux/init.h>
42 #include <xen/interface/xen.h>
43 #include <xen/interface/grant_table.h>
44 #include <xen/interface/io/xenbus.h>
45 #include <xen/interface/io/xs_wire.h>
47 /* Register callback to watch this node. */
48 struct xenbus_watch
49 {
50 struct list_head list;
52 /* Path being watched. */
53 const char *node;
55 /* Callback (executed in a process context with no locks held). */
56 void (*callback)(struct xenbus_watch *,
57 const char **vec, unsigned int len);
59 /* See XBWF_ definitions below. */
60 unsigned long flags;
61 };
63 /*
64 * Execute callback in its own kthread. Useful if the callback is long
65 * running or heavily serialised, to avoid taking out the main xenwatch thread
66 * for a long period of time (or even unwittingly causing a deadlock).
67 */
68 #define XBWF_new_thread 1
70 /* A xenbus device. */
71 struct xenbus_device {
72 const char *devicetype;
73 const char *nodename;
74 const char *otherend;
75 int otherend_id;
76 struct xenbus_watch otherend_watch;
77 struct device dev;
78 enum xenbus_state state;
79 struct completion down;
80 };
82 static inline struct xenbus_device *to_xenbus_device(struct device *dev)
83 {
84 return container_of(dev, struct xenbus_device, dev);
85 }
87 struct xenbus_device_id
88 {
89 /* .../device/<device_type>/<identifier> */
90 char devicetype[32]; /* General class of device. */
91 };
93 /* A xenbus driver. */
94 struct xenbus_driver {
95 char *name;
96 struct module *owner;
97 const struct xenbus_device_id *ids;
98 int (*probe)(struct xenbus_device *dev,
99 const struct xenbus_device_id *id);
100 void (*otherend_changed)(struct xenbus_device *dev,
101 enum xenbus_state backend_state);
102 int (*remove)(struct xenbus_device *dev);
103 int (*suspend)(struct xenbus_device *dev);
104 int (*suspend_cancel)(struct xenbus_device *dev);
105 int (*resume)(struct xenbus_device *dev);
106 int (*uevent)(struct xenbus_device *, char **, int, char *, int);
107 struct device_driver driver;
108 int (*read_otherend_details)(struct xenbus_device *dev);
109 };
111 static inline struct xenbus_driver *to_xenbus_driver(struct device_driver *drv)
112 {
113 return container_of(drv, struct xenbus_driver, driver);
114 }
116 int xenbus_register_frontend(struct xenbus_driver *drv);
117 int xenbus_register_backend(struct xenbus_driver *drv);
118 void xenbus_unregister_driver(struct xenbus_driver *drv);
120 struct xenbus_transaction
121 {
122 u32 id;
123 };
125 /* Nil transaction ID. */
126 #define XBT_NIL ((struct xenbus_transaction) { 0 })
128 char **xenbus_directory(struct xenbus_transaction t,
129 const char *dir, const char *node, unsigned int *num);
130 void *xenbus_read(struct xenbus_transaction t,
131 const char *dir, const char *node, unsigned int *len);
132 int xenbus_write(struct xenbus_transaction t,
133 const char *dir, const char *node, const char *string);
134 int xenbus_mkdir(struct xenbus_transaction t,
135 const char *dir, const char *node);
136 int xenbus_exists(struct xenbus_transaction t,
137 const char *dir, const char *node);
138 int xenbus_rm(struct xenbus_transaction t, const char *dir, const char *node);
139 int xenbus_transaction_start(struct xenbus_transaction *t);
140 int xenbus_transaction_end(struct xenbus_transaction t, int abort);
142 /* Single read and scanf: returns -errno or num scanned if > 0. */
143 int xenbus_scanf(struct xenbus_transaction t,
144 const char *dir, const char *node, const char *fmt, ...)
145 __attribute__((format(scanf, 4, 5)));
147 /* Single printf and write: returns -errno or 0. */
148 int xenbus_printf(struct xenbus_transaction t,
149 const char *dir, const char *node, const char *fmt, ...)
150 __attribute__((format(printf, 4, 5)));
152 /* Generic read function: NULL-terminated triples of name,
153 * sprintf-style type string, and pointer. Returns 0 or errno.*/
154 int xenbus_gather(struct xenbus_transaction t, const char *dir, ...);
156 /* notifer routines for when the xenstore comes up */
157 int register_xenstore_notifier(struct notifier_block *nb);
158 void unregister_xenstore_notifier(struct notifier_block *nb);
160 int register_xenbus_watch(struct xenbus_watch *watch);
161 void unregister_xenbus_watch(struct xenbus_watch *watch);
162 void xs_suspend(void);
163 void xs_resume(void);
164 void xs_suspend_cancel(void);
166 /* Used by xenbus_dev to borrow kernel's store connection. */
167 void *xenbus_dev_request_and_reply(struct xsd_sockmsg *msg);
169 /* Prepare for domain suspend: then resume or cancel the suspend. */
170 void xenbus_suspend(void);
171 void xenbus_resume(void);
172 void xenbus_suspend_cancel(void);
174 #define XENBUS_IS_ERR_READ(str) ({ \
175 if (!IS_ERR(str) && strlen(str) == 0) { \
176 kfree(str); \
177 str = ERR_PTR(-ERANGE); \
178 } \
179 IS_ERR(str); \
180 })
182 #define XENBUS_EXIST_ERR(err) ((err) == -ENOENT || (err) == -ERANGE)
185 /**
186 * Register a watch on the given path, using the given xenbus_watch structure
187 * for storage, and the given callback function as the callback. Return 0 on
188 * success, or -errno on error. On success, the given path will be saved as
189 * watch->node, and remains the caller's to free. On error, watch->node will
190 * be NULL, the device will switch to XenbusStateClosing, and the error will
191 * be saved in the store.
192 */
193 int xenbus_watch_path(struct xenbus_device *dev, const char *path,
194 struct xenbus_watch *watch,
195 void (*callback)(struct xenbus_watch *,
196 const char **, unsigned int));
199 /**
200 * Register a watch on the given path/path2, using the given xenbus_watch
201 * structure for storage, and the given callback function as the callback.
202 * Return 0 on success, or -errno on error. On success, the watched path
203 * (path/path2) will be saved as watch->node, and becomes the caller's to
204 * kfree(). On error, watch->node will be NULL, so the caller has nothing to
205 * free, the device will switch to XenbusStateClosing, and the error will be
206 * saved in the store.
207 */
208 int xenbus_watch_path2(struct xenbus_device *dev, const char *path,
209 const char *path2, struct xenbus_watch *watch,
210 void (*callback)(struct xenbus_watch *,
211 const char **, unsigned int));
214 /**
215 * Advertise in the store a change of the given driver to the given new_state.
216 * Return 0 on success, or -errno on error. On error, the device will switch
217 * to XenbusStateClosing, and the error will be saved in the store.
218 */
219 int xenbus_switch_state(struct xenbus_device *dev, enum xenbus_state new_state);
222 /**
223 * Grant access to the given ring_mfn to the peer of the given device. Return
224 * 0 on success, or -errno on error. On error, the device will switch to
225 * XenbusStateClosing, and the error will be saved in the store.
226 */
227 int xenbus_grant_ring(struct xenbus_device *dev, unsigned long ring_mfn);
230 /**
231 * Map a page of memory into this domain from another domain's grant table.
232 * xenbus_map_ring_valloc allocates a page of virtual address space, maps the
233 * page to that address, and sets *vaddr to that address.
234 * xenbus_map_ring does not allocate the virtual address space (you must do
235 * this yourself!). It only maps in the page to the specified address.
236 * Returns 0 on success, and GNTST_* (see xen/include/interface/grant_table.h)
237 * or -ENOMEM on error. If an error is returned, device will switch to
238 * XenbusStateClosing and the error message will be saved in XenStore.
239 */
240 struct vm_struct *xenbus_map_ring_valloc(struct xenbus_device *dev,
241 int gnt_ref);
242 int xenbus_map_ring(struct xenbus_device *dev, int gnt_ref,
243 grant_handle_t *handle, void *vaddr);
246 /**
247 * Unmap a page of memory in this domain that was imported from another domain.
248 * Use xenbus_unmap_ring_vfree if you mapped in your memory with
249 * xenbus_map_ring_valloc (it will free the virtual address space).
250 * Returns 0 on success and returns GNTST_* on error
251 * (see xen/include/interface/grant_table.h).
252 */
253 int xenbus_unmap_ring_vfree(struct xenbus_device *dev, struct vm_struct *);
254 int xenbus_unmap_ring(struct xenbus_device *dev,
255 grant_handle_t handle, void *vaddr);
258 /**
259 * Allocate an event channel for the given xenbus_device, assigning the newly
260 * created local port to *port. Return 0 on success, or -errno on error. On
261 * error, the device will switch to XenbusStateClosing, and the error will be
262 * saved in the store.
263 */
264 int xenbus_alloc_evtchn(struct xenbus_device *dev, int *port);
267 /**
268 * Free an existing event channel. Returns 0 on success or -errno on error.
269 */
270 int xenbus_free_evtchn(struct xenbus_device *dev, int port);
273 /**
274 * Return the state of the driver rooted at the given store path, or
275 * XenbusStateUnknown if no state can be read.
276 */
277 enum xenbus_state xenbus_read_driver_state(const char *path);
280 /***
281 * Report the given negative errno into the store, along with the given
282 * formatted message.
283 */
284 void xenbus_dev_error(struct xenbus_device *dev, int err, const char *fmt,
285 ...);
288 /***
289 * Equivalent to xenbus_dev_error(dev, err, fmt, args), followed by
290 * xenbus_switch_state(dev, NULL, XenbusStateClosing) to schedule an orderly
291 * closedown of this driver and its peer.
292 */
293 void xenbus_dev_fatal(struct xenbus_device *dev, int err, const char *fmt,
294 ...);
296 int __init xenbus_dev_init(void);
298 const char *xenbus_strstate(enum xenbus_state state);
299 int xenbus_dev_is_online(struct xenbus_device *dev);
300 int xenbus_frontend_closed(struct xenbus_device *dev);
302 #endif /* _XEN_XENBUS_H */