1 /******************************************************************************
4 * Talks to Xen Store to figure out what devices we have.
6 * Copyright (C) 2005 Rusty Russell, IBM Corporation
7 * Copyright (C) 2005 XenSource Ltd.
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:
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:
22 * The above copyright notice and this permission notice shall be included in
23 * all copies or substantial portions of the Software.
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
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>
49 #define XENBUS_MAX_RING_GRANT_ORDER 4
50 #define XENBUS_MAX_RING_GRANTS (1U << XENBUS_MAX_RING_GRANT_ORDER)
51 #define INVALID_GRANT_HANDLE (~0U)
53 /* Register callback to watch this node. */
56 struct list_head list
;
58 /* Path being watched. */
61 /* Callback (executed in a process context with no locks held). */
62 void (*callback
)(struct xenbus_watch
*,
63 const char **vec
, unsigned int len
);
67 /* A xenbus device. */
68 struct xenbus_device
{
69 const char *devicetype
;
73 struct xenbus_watch otherend_watch
;
75 enum xenbus_state state
;
76 struct completion down
;
77 struct work_struct work
;
80 static inline struct xenbus_device
*to_xenbus_device(struct device
*dev
)
82 return container_of(dev
, struct xenbus_device
, dev
);
85 struct xenbus_device_id
87 /* .../device/<device_type>/<identifier> */
88 char devicetype
[32]; /* General class of device. */
91 /* A xenbus driver. */
92 struct xenbus_driver
{
93 const char *name
; /* defaults to ids[0].devicetype */
94 const struct xenbus_device_id
*ids
;
95 int (*probe
)(struct xenbus_device
*dev
,
96 const struct xenbus_device_id
*id
);
97 void (*otherend_changed
)(struct xenbus_device
*dev
,
98 enum xenbus_state backend_state
);
99 int (*remove
)(struct xenbus_device
*dev
);
100 int (*suspend
)(struct xenbus_device
*dev
);
101 int (*resume
)(struct xenbus_device
*dev
);
102 int (*uevent
)(struct xenbus_device
*, struct kobj_uevent_env
*);
103 struct device_driver driver
;
104 int (*read_otherend_details
)(struct xenbus_device
*dev
);
105 int (*is_ready
)(struct xenbus_device
*dev
);
108 static inline struct xenbus_driver
*to_xenbus_driver(struct device_driver
*drv
)
110 return container_of(drv
, struct xenbus_driver
, driver
);
113 int __must_check
__xenbus_register_frontend(struct xenbus_driver
*drv
,
114 struct module
*owner
,
115 const char *mod_name
);
116 int __must_check
__xenbus_register_backend(struct xenbus_driver
*drv
,
117 struct module
*owner
,
118 const char *mod_name
);
120 #define xenbus_register_frontend(drv) \
121 __xenbus_register_frontend(drv, THIS_MODULE, KBUILD_MODNAME)
122 #define xenbus_register_backend(drv) \
123 __xenbus_register_backend(drv, THIS_MODULE, KBUILD_MODNAME)
125 void xenbus_unregister_driver(struct xenbus_driver
*drv
);
127 struct xenbus_transaction
132 /* Nil transaction ID. */
133 #define XBT_NIL ((struct xenbus_transaction) { 0 })
135 char **xenbus_directory(struct xenbus_transaction t
,
136 const char *dir
, const char *node
, unsigned int *num
);
137 void *xenbus_read(struct xenbus_transaction t
,
138 const char *dir
, const char *node
, unsigned int *len
);
139 int xenbus_write(struct xenbus_transaction t
,
140 const char *dir
, const char *node
, const char *string
);
141 int xenbus_mkdir(struct xenbus_transaction t
,
142 const char *dir
, const char *node
);
143 int xenbus_exists(struct xenbus_transaction t
,
144 const char *dir
, const char *node
);
145 int xenbus_rm(struct xenbus_transaction t
, const char *dir
, const char *node
);
146 int xenbus_transaction_start(struct xenbus_transaction
*t
);
147 int xenbus_transaction_end(struct xenbus_transaction t
, int abort
);
149 /* Single read and scanf: returns -errno or num scanned if > 0. */
151 int xenbus_scanf(struct xenbus_transaction t
,
152 const char *dir
, const char *node
, const char *fmt
, ...);
154 /* Read an (optional) unsigned value. */
155 unsigned int xenbus_read_unsigned(const char *dir
, const char *node
,
156 unsigned int default_val
);
158 /* Single printf and write: returns -errno or 0. */
160 int xenbus_printf(struct xenbus_transaction t
,
161 const char *dir
, const char *node
, const char *fmt
, ...);
163 /* Generic read function: NULL-terminated triples of name,
164 * sprintf-style type string, and pointer. Returns 0 or errno.*/
165 int xenbus_gather(struct xenbus_transaction t
, const char *dir
, ...);
167 /* notifer routines for when the xenstore comes up */
168 extern int xenstored_ready
;
169 int register_xenstore_notifier(struct notifier_block
*nb
);
170 void unregister_xenstore_notifier(struct notifier_block
*nb
);
172 int register_xenbus_watch(struct xenbus_watch
*watch
);
173 void unregister_xenbus_watch(struct xenbus_watch
*watch
);
174 void xs_suspend(void);
175 void xs_resume(void);
176 void xs_suspend_cancel(void);
178 /* Used by xenbus_dev to borrow kernel's store connection. */
179 void *xenbus_dev_request_and_reply(struct xsd_sockmsg
*msg
);
183 /* Prepare for domain suspend: then resume or cancel the suspend. */
184 void xenbus_suspend(void);
185 void xenbus_resume(void);
186 void xenbus_probe(struct work_struct
*);
187 void xenbus_suspend_cancel(void);
189 #define XENBUS_IS_ERR_READ(str) ({ \
190 if (!IS_ERR(str) && strlen(str) == 0) { \
192 str = ERR_PTR(-ERANGE); \
197 #define XENBUS_EXIST_ERR(err) ((err) == -ENOENT || (err) == -ERANGE)
199 int xenbus_watch_path(struct xenbus_device
*dev
, const char *path
,
200 struct xenbus_watch
*watch
,
201 void (*callback
)(struct xenbus_watch
*,
202 const char **, unsigned int));
204 int xenbus_watch_pathfmt(struct xenbus_device
*dev
, struct xenbus_watch
*watch
,
205 void (*callback
)(struct xenbus_watch
*,
206 const char **, unsigned int),
207 const char *pathfmt
, ...);
209 int xenbus_switch_state(struct xenbus_device
*dev
, enum xenbus_state new_state
);
210 int xenbus_grant_ring(struct xenbus_device
*dev
, void *vaddr
,
211 unsigned int nr_pages
, grant_ref_t
*grefs
);
212 int xenbus_map_ring_valloc(struct xenbus_device
*dev
, grant_ref_t
*gnt_refs
,
213 unsigned int nr_grefs
, void **vaddr
);
214 int xenbus_map_ring(struct xenbus_device
*dev
,
215 grant_ref_t
*gnt_refs
, unsigned int nr_grefs
,
216 grant_handle_t
*handles
, unsigned long *vaddrs
,
219 int xenbus_unmap_ring_vfree(struct xenbus_device
*dev
, void *vaddr
);
220 int xenbus_unmap_ring(struct xenbus_device
*dev
,
221 grant_handle_t
*handles
, unsigned int nr_handles
,
222 unsigned long *vaddrs
);
224 int xenbus_alloc_evtchn(struct xenbus_device
*dev
, int *port
);
225 int xenbus_free_evtchn(struct xenbus_device
*dev
, int port
);
227 enum xenbus_state
xenbus_read_driver_state(const char *path
);
230 void xenbus_dev_error(struct xenbus_device
*dev
, int err
, const char *fmt
, ...);
232 void xenbus_dev_fatal(struct xenbus_device
*dev
, int err
, const char *fmt
, ...);
234 const char *xenbus_strstate(enum xenbus_state state
);
235 int xenbus_dev_is_online(struct xenbus_device
*dev
);
236 int xenbus_frontend_closed(struct xenbus_device
*dev
);
238 #endif /* _XEN_XENBUS_H */