Linux kernel mirror (for testing)
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linux
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/fs.h>
42#include <linux/completion.h>
43#include <linux/init.h>
44#include <linux/slab.h>
45#include <linux/semaphore.h>
46#include <xen/interface/xen.h>
47#include <xen/interface/grant_table.h>
48#include <xen/interface/io/xenbus.h>
49#include <xen/interface/io/xs_wire.h>
50#include <xen/interface/event_channel.h>
51
52#define XENBUS_MAX_RING_GRANT_ORDER 4
53#define XENBUS_MAX_RING_GRANTS (1U << XENBUS_MAX_RING_GRANT_ORDER)
54
55/* Register callback to watch this node. */
56struct xenbus_watch
57{
58 struct list_head list;
59
60 /* Path being watched. */
61 const char *node;
62
63 unsigned int nr_pending;
64
65 /*
66 * Called just before enqueing new event while a spinlock is held.
67 * The event will be discarded if this callback returns false.
68 */
69 bool (*will_handle)(struct xenbus_watch *,
70 const char *path, const char *token);
71
72 /* Callback (executed in a process context with no locks held). */
73 void (*callback)(struct xenbus_watch *,
74 const char *path, const char *token);
75};
76
77
78/* A xenbus device. */
79struct xenbus_device {
80 const char *devicetype;
81 const char *nodename;
82 const char *otherend;
83 bool vanished;
84 int otherend_id;
85 struct xenbus_watch otherend_watch;
86 struct device dev;
87 enum xenbus_state state;
88 struct completion down;
89 struct work_struct work;
90 struct semaphore reclaim_sem;
91
92 /* Event channel based statistics and settings. */
93 atomic_t event_channels;
94 atomic_t events;
95 atomic_t spurious_events;
96 atomic_t jiffies_eoi_delayed;
97 unsigned int spurious_threshold;
98};
99
100#define to_xenbus_device(__dev) container_of_const(__dev, struct xenbus_device, dev)
101
102struct xenbus_device_id
103{
104 /* .../device/<device_type>/<identifier> */
105 char devicetype[32]; /* General class of device. */
106};
107
108/* A xenbus driver. */
109struct xenbus_driver {
110 const char *name; /* defaults to ids[0].devicetype */
111 const struct xenbus_device_id *ids;
112 bool allow_rebind; /* avoid setting xenstore closed during remove */
113 bool not_essential; /* is not mandatory for boot progress */
114 int (*probe)(struct xenbus_device *dev,
115 const struct xenbus_device_id *id);
116 void (*otherend_changed)(struct xenbus_device *dev,
117 enum xenbus_state backend_state);
118 void (*remove)(struct xenbus_device *dev);
119 int (*suspend)(struct xenbus_device *dev);
120 int (*resume)(struct xenbus_device *dev);
121 int (*uevent)(const struct xenbus_device *, struct kobj_uevent_env *);
122 struct device_driver driver;
123 int (*read_otherend_details)(struct xenbus_device *dev);
124 int (*is_ready)(struct xenbus_device *dev);
125 void (*reclaim_memory)(struct xenbus_device *dev);
126};
127
128#define to_xenbus_driver(__drv) container_of_const(__drv, struct xenbus_driver, driver)
129
130int __must_check __xenbus_register_frontend(struct xenbus_driver *drv,
131 struct module *owner,
132 const char *mod_name);
133int __must_check __xenbus_register_backend(struct xenbus_driver *drv,
134 struct module *owner,
135 const char *mod_name);
136
137#define xenbus_register_frontend(drv) \
138 __xenbus_register_frontend(drv, THIS_MODULE, KBUILD_MODNAME)
139#define xenbus_register_backend(drv) \
140 __xenbus_register_backend(drv, THIS_MODULE, KBUILD_MODNAME)
141
142void xenbus_unregister_driver(struct xenbus_driver *drv);
143
144struct xenbus_transaction
145{
146 u32 id;
147};
148
149/* Nil transaction ID. */
150#define XBT_NIL ((struct xenbus_transaction) { 0 })
151
152char **xenbus_directory(struct xenbus_transaction t,
153 const char *dir, const char *node, unsigned int *num);
154void *xenbus_read(struct xenbus_transaction t,
155 const char *dir, const char *node, unsigned int *len);
156int xenbus_write(struct xenbus_transaction t,
157 const char *dir, const char *node, const char *string);
158int xenbus_exists(struct xenbus_transaction t,
159 const char *dir, const char *node);
160int xenbus_rm(struct xenbus_transaction t, const char *dir, const char *node);
161int xenbus_transaction_start(struct xenbus_transaction *t);
162int xenbus_transaction_end(struct xenbus_transaction t, bool abort);
163
164/* Single read and scanf: returns -errno or num scanned if > 0. */
165__scanf(4, 5)
166int xenbus_scanf(struct xenbus_transaction t,
167 const char *dir, const char *node, const char *fmt, ...);
168
169/* Read an (optional) unsigned value. */
170unsigned int xenbus_read_unsigned(const char *dir, const char *node,
171 unsigned int default_val);
172
173/* Single printf and write: returns -errno or 0. */
174__printf(4, 5)
175int xenbus_printf(struct xenbus_transaction t,
176 const char *dir, const char *node, const char *fmt, ...);
177
178/* Generic read function: NULL-terminated triples of name,
179 * sprintf-style type string, and pointer. Returns 0 or errno.*/
180int xenbus_gather(struct xenbus_transaction t, const char *dir, ...);
181
182/* notifier routines for when the xenstore comes up */
183extern int xenstored_ready;
184int register_xenstore_notifier(struct notifier_block *nb);
185void unregister_xenstore_notifier(struct notifier_block *nb);
186
187int register_xenbus_watch(struct xenbus_watch *watch);
188void unregister_xenbus_watch(struct xenbus_watch *watch);
189void xs_suspend(void);
190void xs_resume(void);
191void xs_suspend_cancel(void);
192
193struct work_struct;
194
195#define XENBUS_IS_ERR_READ(str) ({ \
196 if (!IS_ERR(str) && strlen(str) == 0) { \
197 kfree(str); \
198 str = ERR_PTR(-ERANGE); \
199 } \
200 IS_ERR(str); \
201})
202
203#define XENBUS_EXIST_ERR(err) ((err) == -ENOENT || (err) == -ERANGE)
204
205int xenbus_watch_path(struct xenbus_device *dev, const char *path,
206 struct xenbus_watch *watch,
207 bool (*will_handle)(struct xenbus_watch *,
208 const char *, const char *),
209 void (*callback)(struct xenbus_watch *,
210 const char *, const char *));
211__printf(5, 6)
212int xenbus_watch_pathfmt(struct xenbus_device *dev, struct xenbus_watch *watch,
213 bool (*will_handle)(struct xenbus_watch *,
214 const char *, const char *),
215 void (*callback)(struct xenbus_watch *,
216 const char *, const char *),
217 const char *pathfmt, ...);
218
219int xenbus_switch_state(struct xenbus_device *dev, enum xenbus_state new_state);
220int xenbus_setup_ring(struct xenbus_device *dev, gfp_t gfp, void **vaddr,
221 unsigned int nr_pages, grant_ref_t *grefs);
222void xenbus_teardown_ring(void **vaddr, unsigned int nr_pages,
223 grant_ref_t *grefs);
224int xenbus_map_ring_valloc(struct xenbus_device *dev, grant_ref_t *gnt_refs,
225 unsigned int nr_grefs, void **vaddr);
226
227int xenbus_unmap_ring_vfree(struct xenbus_device *dev, void *vaddr);
228
229int xenbus_alloc_evtchn(struct xenbus_device *dev, evtchn_port_t *port);
230int xenbus_free_evtchn(struct xenbus_device *dev, evtchn_port_t port);
231
232enum xenbus_state xenbus_read_driver_state(const struct xenbus_device *dev,
233 const char *path);
234
235__printf(3, 4)
236void xenbus_dev_error(struct xenbus_device *dev, int err, const char *fmt, ...);
237__printf(3, 4)
238void xenbus_dev_fatal(struct xenbus_device *dev, int err, const char *fmt, ...);
239
240const char *xenbus_strstate(enum xenbus_state state);
241int xenbus_dev_is_online(struct xenbus_device *dev);
242int xenbus_frontend_closed(struct xenbus_device *dev);
243
244extern const struct file_operations xen_xenbus_fops;
245extern struct xenstore_domain_interface *xen_store_interface;
246extern int xen_store_evtchn;
247
248#endif /* _XEN_XENBUS_H */