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4bac07c9 JF |
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> | |
63c9744b | 40 | #include <linux/export.h> |
332f791d | 41 | #include <linux/fs.h> |
4bac07c9 JF |
42 | #include <linux/completion.h> |
43 | #include <linux/init.h> | |
5a0e3ad6 | 44 | #include <linux/slab.h> |
2f69a110 | 45 | #include <linux/semaphore.h> |
4bac07c9 JF |
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> | |
0102e4ef | 50 | #include <xen/interface/event_channel.h> |
4bac07c9 | 51 | |
9cce2914 JG |
52 | #define XENBUS_MAX_RING_GRANT_ORDER 4 |
53 | #define XENBUS_MAX_RING_GRANTS (1U << XENBUS_MAX_RING_GRANT_ORDER) | |
ccc9d90a | 54 | |
4bac07c9 JF |
55 | /* Register callback to watch this node. */ |
56 | struct xenbus_watch | |
57 | { | |
58 | struct list_head list; | |
59 | ||
60 | /* Path being watched. */ | |
61 | const char *node; | |
62 | ||
3dc86ca6 SP |
63 | unsigned int nr_pending; |
64 | ||
fed1755b SP |
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 | ||
4bac07c9 JF |
72 | /* Callback (executed in a process context with no locks held). */ |
73 | void (*callback)(struct xenbus_watch *, | |
5584ea25 | 74 | const char *path, const char *token); |
4bac07c9 JF |
75 | }; |
76 | ||
77 | ||
78 | /* A xenbus device. */ | |
79 | struct xenbus_device { | |
80 | const char *devicetype; | |
81 | const char *nodename; | |
82 | const char *otherend; | |
83 | int otherend_id; | |
84 | struct xenbus_watch otherend_watch; | |
85 | struct device dev; | |
86 | enum xenbus_state state; | |
87 | struct completion down; | |
2abb2746 | 88 | struct work_struct work; |
2f69a110 | 89 | struct semaphore reclaim_sem; |
06f45fe9 JG |
90 | |
91 | /* Event channel based statistics and settings. */ | |
92 | atomic_t event_channels; | |
93 | atomic_t events; | |
94 | atomic_t spurious_events; | |
95 | atomic_t jiffies_eoi_delayed; | |
96 | unsigned int spurious_threshold; | |
4bac07c9 JF |
97 | }; |
98 | ||
99 | static inline struct xenbus_device *to_xenbus_device(struct device *dev) | |
100 | { | |
101 | return container_of(dev, struct xenbus_device, dev); | |
102 | } | |
103 | ||
104 | struct xenbus_device_id | |
105 | { | |
106 | /* .../device/<device_type>/<identifier> */ | |
107 | char devicetype[32]; /* General class of device. */ | |
108 | }; | |
109 | ||
110 | /* A xenbus driver. */ | |
111 | struct xenbus_driver { | |
95afae48 | 112 | const char *name; /* defaults to ids[0].devicetype */ |
4bac07c9 | 113 | const struct xenbus_device_id *ids; |
672b7763 | 114 | bool allow_rebind; /* avoid setting xenstore closed during remove */ |
4bac07c9 JF |
115 | int (*probe)(struct xenbus_device *dev, |
116 | const struct xenbus_device_id *id); | |
117 | void (*otherend_changed)(struct xenbus_device *dev, | |
118 | enum xenbus_state backend_state); | |
119 | int (*remove)(struct xenbus_device *dev); | |
c7853aea | 120 | int (*suspend)(struct xenbus_device *dev); |
4bac07c9 | 121 | int (*resume)(struct xenbus_device *dev); |
df660251 | 122 | int (*uevent)(struct xenbus_device *, struct kobj_uevent_env *); |
4bac07c9 JF |
123 | struct device_driver driver; |
124 | int (*read_otherend_details)(struct xenbus_device *dev); | |
1d78d705 | 125 | int (*is_ready)(struct xenbus_device *dev); |
8a105678 | 126 | void (*reclaim_memory)(struct xenbus_device *dev); |
4bac07c9 JF |
127 | }; |
128 | ||
73db144b | 129 | static inline struct xenbus_driver *to_xenbus_driver(struct device_driver *drv) |
4bac07c9 | 130 | { |
73db144b | 131 | return container_of(drv, struct xenbus_driver, driver); |
4bac07c9 JF |
132 | } |
133 | ||
95afae48 DV |
134 | int __must_check __xenbus_register_frontend(struct xenbus_driver *drv, |
135 | struct module *owner, | |
136 | const char *mod_name); | |
137 | int __must_check __xenbus_register_backend(struct xenbus_driver *drv, | |
138 | struct module *owner, | |
139 | const char *mod_name); | |
140 | ||
141 | #define xenbus_register_frontend(drv) \ | |
604b91fe | 142 | __xenbus_register_frontend(drv, THIS_MODULE, KBUILD_MODNAME) |
95afae48 | 143 | #define xenbus_register_backend(drv) \ |
604b91fe | 144 | __xenbus_register_backend(drv, THIS_MODULE, KBUILD_MODNAME) |
4bac07c9 JF |
145 | |
146 | void xenbus_unregister_driver(struct xenbus_driver *drv); | |
147 | ||
148 | struct xenbus_transaction | |
149 | { | |
150 | u32 id; | |
151 | }; | |
152 | ||
153 | /* Nil transaction ID. */ | |
154 | #define XBT_NIL ((struct xenbus_transaction) { 0 }) | |
155 | ||
4bac07c9 JF |
156 | char **xenbus_directory(struct xenbus_transaction t, |
157 | const char *dir, const char *node, unsigned int *num); | |
158 | void *xenbus_read(struct xenbus_transaction t, | |
159 | const char *dir, const char *node, unsigned int *len); | |
160 | int xenbus_write(struct xenbus_transaction t, | |
161 | const char *dir, const char *node, const char *string); | |
162 | int xenbus_mkdir(struct xenbus_transaction t, | |
163 | const char *dir, const char *node); | |
164 | int xenbus_exists(struct xenbus_transaction t, | |
165 | const char *dir, const char *node); | |
166 | int xenbus_rm(struct xenbus_transaction t, const char *dir, const char *node); | |
167 | int xenbus_transaction_start(struct xenbus_transaction *t); | |
168 | int xenbus_transaction_end(struct xenbus_transaction t, int abort); | |
169 | ||
170 | /* Single read and scanf: returns -errno or num scanned if > 0. */ | |
6061d949 | 171 | __scanf(4, 5) |
4bac07c9 | 172 | int xenbus_scanf(struct xenbus_transaction t, |
6061d949 | 173 | const char *dir, const char *node, const char *fmt, ...); |
4bac07c9 | 174 | |
9c53a179 JG |
175 | /* Read an (optional) unsigned value. */ |
176 | unsigned int xenbus_read_unsigned(const char *dir, const char *node, | |
177 | unsigned int default_val); | |
178 | ||
4bac07c9 | 179 | /* Single printf and write: returns -errno or 0. */ |
b9075fa9 | 180 | __printf(4, 5) |
4bac07c9 | 181 | int xenbus_printf(struct xenbus_transaction t, |
b9075fa9 | 182 | const char *dir, const char *node, const char *fmt, ...); |
4bac07c9 JF |
183 | |
184 | /* Generic read function: NULL-terminated triples of name, | |
185 | * sprintf-style type string, and pointer. Returns 0 or errno.*/ | |
186 | int xenbus_gather(struct xenbus_transaction t, const char *dir, ...); | |
187 | ||
188 | /* notifer routines for when the xenstore comes up */ | |
189 | extern int xenstored_ready; | |
190 | int register_xenstore_notifier(struct notifier_block *nb); | |
191 | void unregister_xenstore_notifier(struct notifier_block *nb); | |
192 | ||
193 | int register_xenbus_watch(struct xenbus_watch *watch); | |
194 | void unregister_xenbus_watch(struct xenbus_watch *watch); | |
195 | void xs_suspend(void); | |
196 | void xs_resume(void); | |
197 | void xs_suspend_cancel(void); | |
198 | ||
4bac07c9 JF |
199 | struct work_struct; |
200 | ||
4bac07c9 JF |
201 | #define XENBUS_IS_ERR_READ(str) ({ \ |
202 | if (!IS_ERR(str) && strlen(str) == 0) { \ | |
203 | kfree(str); \ | |
204 | str = ERR_PTR(-ERANGE); \ | |
205 | } \ | |
206 | IS_ERR(str); \ | |
207 | }) | |
208 | ||
209 | #define XENBUS_EXIST_ERR(err) ((err) == -ENOENT || (err) == -ERANGE) | |
210 | ||
211 | int xenbus_watch_path(struct xenbus_device *dev, const char *path, | |
212 | struct xenbus_watch *watch, | |
2e85d32b SP |
213 | bool (*will_handle)(struct xenbus_watch *, |
214 | const char *, const char *), | |
4bac07c9 | 215 | void (*callback)(struct xenbus_watch *, |
5584ea25 | 216 | const char *, const char *)); |
2e85d32b | 217 | __printf(5, 6) |
4bac07c9 | 218 | int xenbus_watch_pathfmt(struct xenbus_device *dev, struct xenbus_watch *watch, |
2e85d32b SP |
219 | bool (*will_handle)(struct xenbus_watch *, |
220 | const char *, const char *), | |
4bac07c9 | 221 | void (*callback)(struct xenbus_watch *, |
5584ea25 | 222 | const char *, const char *), |
b9075fa9 | 223 | const char *pathfmt, ...); |
4bac07c9 JF |
224 | |
225 | int xenbus_switch_state(struct xenbus_device *dev, enum xenbus_state new_state); | |
ccc9d90a WL |
226 | int xenbus_grant_ring(struct xenbus_device *dev, void *vaddr, |
227 | unsigned int nr_pages, grant_ref_t *grefs); | |
228 | int xenbus_map_ring_valloc(struct xenbus_device *dev, grant_ref_t *gnt_refs, | |
229 | unsigned int nr_grefs, void **vaddr); | |
4bac07c9 JF |
230 | |
231 | int xenbus_unmap_ring_vfree(struct xenbus_device *dev, void *vaddr); | |
4bac07c9 | 232 | |
0102e4ef YY |
233 | int xenbus_alloc_evtchn(struct xenbus_device *dev, evtchn_port_t *port); |
234 | int xenbus_free_evtchn(struct xenbus_device *dev, evtchn_port_t port); | |
4bac07c9 JF |
235 | |
236 | enum xenbus_state xenbus_read_driver_state(const char *path); | |
237 | ||
b9075fa9 | 238 | __printf(3, 4) |
4bac07c9 | 239 | void xenbus_dev_error(struct xenbus_device *dev, int err, const char *fmt, ...); |
b9075fa9 | 240 | __printf(3, 4) |
4bac07c9 JF |
241 | void xenbus_dev_fatal(struct xenbus_device *dev, int err, const char *fmt, ...); |
242 | ||
243 | const char *xenbus_strstate(enum xenbus_state state); | |
244 | int xenbus_dev_is_online(struct xenbus_device *dev); | |
245 | int xenbus_frontend_closed(struct xenbus_device *dev); | |
246 | ||
332f791d JG |
247 | extern const struct file_operations xen_xenbus_fops; |
248 | extern struct xenstore_domain_interface *xen_store_interface; | |
249 | extern int xen_store_evtchn; | |
250 | ||
4bac07c9 | 251 | #endif /* _XEN_XENBUS_H */ |