Linux Kernel  3.7.1
 All Data Structures Namespaces Files Functions Variables Typedefs Enumerations Enumerator Macros Groups Pages
xenbus.h
Go to the documentation of this file.
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/export.h>
41 #include <linux/completion.h>
42 #include <linux/init.h>
43 #include <linux/slab.h>
44 #include <xen/interface/xen.h>
48 
49 /* Register callback to watch this node. */
51 {
52  struct list_head list;
53 
54  /* Path being watched. */
55  const char *node;
56 
57  /* Callback (executed in a process context with no locks held). */
58  void (*callback)(struct xenbus_watch *,
59  const char **vec, unsigned int len);
60 };
61 
62 
63 /* A xenbus device. */
64 struct xenbus_device {
65  const char *devicetype;
66  const char *nodename;
67  const char *otherend;
70  struct device dev;
72  struct completion down;
73 };
74 
75 static inline struct xenbus_device *to_xenbus_device(struct device *dev)
76 {
77  return container_of(dev, struct xenbus_device, dev);
78 }
79 
81 {
82  /* .../device/<device_type>/<identifier> */
83  char devicetype[32]; /* General class of device. */
84 };
85 
86 /* A xenbus driver. */
87 struct xenbus_driver {
88  const struct xenbus_device_id *ids;
89  int (*probe)(struct xenbus_device *dev,
90  const struct xenbus_device_id *id);
92  enum xenbus_state backend_state);
93  int (*remove)(struct xenbus_device *dev);
95  int (*resume)(struct xenbus_device *dev);
96  int (*uevent)(struct xenbus_device *, struct kobj_uevent_env *);
100 };
101 
102 #define DEFINE_XENBUS_DRIVER(var, drvname, methods...) \
103 struct xenbus_driver var ## _driver = { \
104  .driver.name = drvname + 0 ?: var ## _ids->devicetype, \
105  .driver.owner = THIS_MODULE, \
106  .ids = var ## _ids, ## methods \
107 }
108 
109 static inline struct xenbus_driver *to_xenbus_driver(struct device_driver *drv)
110 {
111  return container_of(drv, struct xenbus_driver, driver);
112 }
113 
116 
117 void xenbus_unregister_driver(struct xenbus_driver *drv);
118 
120 {
122 };
123 
124 /* Nil transaction ID. */
125 #define XBT_NIL ((struct xenbus_transaction) { 0 })
126 
128  const char *dir, const char *node, unsigned int *num);
129 void *xenbus_read(struct xenbus_transaction t,
130  const char *dir, const char *node, unsigned int *len);
132  const char *dir, const char *node, const char *string);
134  const char *dir, const char *node);
136  const char *dir, const char *node);
137 int xenbus_rm(struct xenbus_transaction t, const char *dir, const char *node);
140 
141 /* Single read and scanf: returns -errno or num scanned if > 0. */
142 __scanf(4, 5)
144  const char *dir, const char *node, const char *fmt, ...);
145 
146 /* Single printf and write: returns -errno or 0. */
147 __printf(4, 5)
149  const char *dir, const char *node, const char *fmt, ...);
150 
151 /* Generic read function: NULL-terminated triples of name,
152  * sprintf-style type string, and pointer. Returns 0 or errno.*/
153 int xenbus_gather(struct xenbus_transaction t, const char *dir, ...);
154 
155 /* notifer routines for when the xenstore comes up */
156 extern int xenstored_ready;
159 
162 void xs_suspend(void);
163 void xs_resume(void);
164 void xs_suspend_cancel(void);
165 
166 /* Used by xenbus_dev to borrow kernel's store connection. */
168 
170 
171 /* Prepare for domain suspend: then resume or cancel the suspend. */
172 void xenbus_suspend(void);
173 void xenbus_resume(void);
174 void xenbus_probe(struct work_struct *);
175 void xenbus_suspend_cancel(void);
176 
177 #define XENBUS_IS_ERR_READ(str) ({ \
178  if (!IS_ERR(str) && strlen(str) == 0) { \
179  kfree(str); \
180  str = ERR_PTR(-ERANGE); \
181  } \
182  IS_ERR(str); \
183 })
184 
185 #define XENBUS_EXIST_ERR(err) ((err) == -ENOENT || (err) == -ERANGE)
186 
187 int xenbus_watch_path(struct xenbus_device *dev, const char *path,
188  struct xenbus_watch *watch,
189  void (*callback)(struct xenbus_watch *,
190  const char **, unsigned int));
191 __printf(4, 5)
194  const char **, unsigned int),
195  const char *pathfmt, ...);
196 
198 int xenbus_grant_ring(struct xenbus_device *dev, unsigned long ring_mfn);
200  int gnt_ref, void **vaddr);
201 int xenbus_map_ring(struct xenbus_device *dev, int gnt_ref,
202  grant_handle_t *handle, void *vaddr);
203 
204 int xenbus_unmap_ring_vfree(struct xenbus_device *dev, void *vaddr);
206  grant_handle_t handle, void *vaddr);
207 
209 int xenbus_bind_evtchn(struct xenbus_device *dev, int remote_port, int *port);
210 int xenbus_free_evtchn(struct xenbus_device *dev, int port);
211 
213 
214 __printf(3, 4)
215 void xenbus_dev_error(struct xenbus_device *dev, int err, const char *fmt, ...);
216 __printf(3, 4)
217 void xenbus_dev_fatal(struct xenbus_device *dev, int err, const char *fmt, ...);
218 
222 
223 #endif /* _XEN_XENBUS_H */