source: trunk/packages/xen-3.1/xen-3.1/linux-2.6-xen-sparse/include/xen/xenbus.h @ 34

Last change on this file since 34 was 34, checked in by hartmans, 18 years ago

Add xen and xen-common

File size: 10.6 KB
Line 
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 */
33
34#ifndef _XEN_XENBUS_H
35#define _XEN_XENBUS_H
36
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>
46
47/* Register callback to watch this node. */
48struct xenbus_watch
49{
50        struct list_head list;
51
52        /* Path being watched. */
53        const char *node;
54
55        /* Callback (executed in a process context with no locks held). */
56        void (*callback)(struct xenbus_watch *,
57                         const char **vec, unsigned int len);
58
59        /* See XBWF_ definitions below. */
60        unsigned long flags;
61};
62
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
69
70/* A xenbus device. */
71struct 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};
81
82static inline struct xenbus_device *to_xenbus_device(struct device *dev)
83{
84        return container_of(dev, struct xenbus_device, dev);
85}
86
87struct xenbus_device_id
88{
89        /* .../device/<device_type>/<identifier> */
90        char devicetype[32];    /* General class of device. */
91};
92
93/* A xenbus driver. */
94struct 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};
110
111static inline struct xenbus_driver *to_xenbus_driver(struct device_driver *drv)
112{
113        return container_of(drv, struct xenbus_driver, driver);
114}
115
116int xenbus_register_frontend(struct xenbus_driver *drv);
117int xenbus_register_backend(struct xenbus_driver *drv);
118void xenbus_unregister_driver(struct xenbus_driver *drv);
119
120struct xenbus_transaction
121{
122        u32 id;
123};
124
125/* Nil transaction ID. */
126#define XBT_NIL ((struct xenbus_transaction) { 0 })
127
128char **xenbus_directory(struct xenbus_transaction t,
129                        const char *dir, const char *node, unsigned int *num);
130void *xenbus_read(struct xenbus_transaction t,
131                  const char *dir, const char *node, unsigned int *len);
132int xenbus_write(struct xenbus_transaction t,
133                 const char *dir, const char *node, const char *string);
134int xenbus_mkdir(struct xenbus_transaction t,
135                 const char *dir, const char *node);
136int xenbus_exists(struct xenbus_transaction t,
137                  const char *dir, const char *node);
138int xenbus_rm(struct xenbus_transaction t, const char *dir, const char *node);
139int xenbus_transaction_start(struct xenbus_transaction *t);
140int xenbus_transaction_end(struct xenbus_transaction t, int abort);
141
142/* Single read and scanf: returns -errno or num scanned if > 0. */
143int xenbus_scanf(struct xenbus_transaction t,
144                 const char *dir, const char *node, const char *fmt, ...)
145        __attribute__((format(scanf, 4, 5)));
146
147/* Single printf and write: returns -errno or 0. */
148int xenbus_printf(struct xenbus_transaction t,
149                  const char *dir, const char *node, const char *fmt, ...)
150        __attribute__((format(printf, 4, 5)));
151
152/* Generic read function: NULL-terminated triples of name,
153 * sprintf-style type string, and pointer. Returns 0 or errno.*/
154int xenbus_gather(struct xenbus_transaction t, const char *dir, ...);
155
156/* notifer routines for when the xenstore comes up */
157int register_xenstore_notifier(struct notifier_block *nb);
158void unregister_xenstore_notifier(struct notifier_block *nb);
159
160int register_xenbus_watch(struct xenbus_watch *watch);
161void unregister_xenbus_watch(struct xenbus_watch *watch);
162void xs_suspend(void);
163void xs_resume(void);
164void xs_suspend_cancel(void);
165
166/* Used by xenbus_dev to borrow kernel's store connection. */
167void *xenbus_dev_request_and_reply(struct xsd_sockmsg *msg);
168
169/* Prepare for domain suspend: then resume or cancel the suspend. */
170void xenbus_suspend(void);
171void xenbus_resume(void);
172void xenbus_suspend_cancel(void);
173
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})
181
182#define XENBUS_EXIST_ERR(err) ((err) == -ENOENT || (err) == -ERANGE)
183
184
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 */
193int 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));
197
198
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 */
208int 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));
212
213
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 */
219int xenbus_switch_state(struct xenbus_device *dev, enum xenbus_state new_state);
220
221
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 */
227int xenbus_grant_ring(struct xenbus_device *dev, unsigned long ring_mfn);
228
229
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 */
240struct vm_struct *xenbus_map_ring_valloc(struct xenbus_device *dev,
241                                         int gnt_ref);
242int xenbus_map_ring(struct xenbus_device *dev, int gnt_ref,
243                           grant_handle_t *handle, void *vaddr);
244
245
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 */
253int xenbus_unmap_ring_vfree(struct xenbus_device *dev, struct vm_struct *);
254int xenbus_unmap_ring(struct xenbus_device *dev,
255                      grant_handle_t handle, void *vaddr);
256
257
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 */
264int xenbus_alloc_evtchn(struct xenbus_device *dev, int *port);
265
266
267/**
268 * Free an existing event channel. Returns 0 on success or -errno on error.
269 */
270int xenbus_free_evtchn(struct xenbus_device *dev, int port);
271
272
273/**
274 * Return the state of the driver rooted at the given store path, or
275 * XenbusStateUnknown if no state can be read.
276 */
277enum xenbus_state xenbus_read_driver_state(const char *path);
278
279
280/***
281 * Report the given negative errno into the store, along with the given
282 * formatted message.
283 */
284void xenbus_dev_error(struct xenbus_device *dev, int err, const char *fmt,
285                      ...);
286
287
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 */
293void xenbus_dev_fatal(struct xenbus_device *dev, int err, const char *fmt,
294                      ...);
295
296int xenbus_dev_init(void);
297
298const char *xenbus_strstate(enum xenbus_state state);
299int xenbus_dev_is_online(struct xenbus_device *dev);
300int xenbus_frontend_closed(struct xenbus_device *dev);
301
302#endif /* _XEN_XENBUS_H */
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