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>
45 #include <xen/interface/grant_table.h>
46 #include <xen/interface/io/xenbus.h>
47 #include <xen/interface/io/xs_wire.h>
48
49 /* Register callback to watch this node. */
50 struct xenbus_watch
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;
68 int otherend_id;
69 struct xenbus_watch otherend_watch;
70 struct device dev;
71 enum xenbus_state state;
72 struct completion down;
73 };
74
to_xenbus_device(struct device * dev)75 static inline struct xenbus_device *to_xenbus_device(struct device *dev)
76 {
77 return container_of(dev, struct xenbus_device, dev);
78 }
79
80 struct xenbus_device_id
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);
91 void (*otherend_changed)(struct xenbus_device *dev,
92 enum xenbus_state backend_state);
93 int (*remove)(struct xenbus_device *dev);
94 int (*suspend)(struct xenbus_device *dev);
95 int (*resume)(struct xenbus_device *dev);
96 int (*uevent)(struct xenbus_device *, struct kobj_uevent_env *);
97 struct device_driver driver;
98 int (*read_otherend_details)(struct xenbus_device *dev);
99 int (*is_ready)(struct xenbus_device *dev);
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
to_xenbus_driver(struct device_driver * drv)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
114 int __must_check xenbus_register_frontend(struct xenbus_driver *);
115 int __must_check xenbus_register_backend(struct xenbus_driver *);
116
117 void xenbus_unregister_driver(struct xenbus_driver *drv);
118
119 struct xenbus_transaction
120 {
121 u32 id;
122 };
123
124 /* Nil transaction ID. */
125 #define XBT_NIL ((struct xenbus_transaction) { 0 })
126
127 char **xenbus_directory(struct xenbus_transaction t,
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);
131 int xenbus_write(struct xenbus_transaction t,
132 const char *dir, const char *node, const char *string);
133 int xenbus_mkdir(struct xenbus_transaction t,
134 const char *dir, const char *node);
135 int xenbus_exists(struct xenbus_transaction t,
136 const char *dir, const char *node);
137 int xenbus_rm(struct xenbus_transaction t, const char *dir, const char *node);
138 int xenbus_transaction_start(struct xenbus_transaction *t);
139 int xenbus_transaction_end(struct xenbus_transaction t, int abort);
140
141 /* Single read and scanf: returns -errno or num scanned if > 0. */
142 __scanf(4, 5)
143 int xenbus_scanf(struct xenbus_transaction t,
144 const char *dir, const char *node, const char *fmt, ...);
145
146 /* Single printf and write: returns -errno or 0. */
147 __printf(4, 5)
148 int xenbus_printf(struct xenbus_transaction t,
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;
157 int register_xenstore_notifier(struct notifier_block *nb);
158 void unregister_xenstore_notifier(struct notifier_block *nb);
159
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);
165
166 /* Used by xenbus_dev to borrow kernel's store connection. */
167 void *xenbus_dev_request_and_reply(struct xsd_sockmsg *msg);
168
169 struct work_struct;
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)
192 int xenbus_watch_pathfmt(struct xenbus_device *dev, struct xenbus_watch *watch,
193 void (*callback)(struct xenbus_watch *,
194 const char **, unsigned int),
195 const char *pathfmt, ...);
196
197 int xenbus_switch_state(struct xenbus_device *dev, enum xenbus_state new_state);
198 int xenbus_grant_ring(struct xenbus_device *dev, unsigned long ring_mfn);
199 int xenbus_map_ring_valloc(struct xenbus_device *dev,
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);
205 int xenbus_unmap_ring(struct xenbus_device *dev,
206 grant_handle_t handle, void *vaddr);
207
208 int xenbus_alloc_evtchn(struct xenbus_device *dev, int *port);
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
212 enum xenbus_state xenbus_read_driver_state(const char *path);
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
219 const char *xenbus_strstate(enum xenbus_state state);
220 int xenbus_dev_is_online(struct xenbus_device *dev);
221 int xenbus_frontend_closed(struct xenbus_device *dev);
222
223 #endif /* _XEN_XENBUS_H */
224