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/completion.h> 41 #include <linux/init.h> 42 #include <xen/interface/xen.h> 43 #include <xen/interface/grant_table.h> 44 #include <xen/interface/io/xenbus.h> 45 #include <xen/interface/io/xs_wire.h> 46 47 /* Register callback to watch this node. */ 48 struct xenbus_watch 49 { 50 struct list_head list; 51 52 /* Path being watched. */ 53 const char *node; 54 55 /* Callback (executed in a process context with no locks held). */ 56 void (*callback)(struct xenbus_watch *, 57 const char **vec, unsigned int len); 58 }; 59 60 61 /* A xenbus device. */ 62 struct xenbus_device { 63 const char *devicetype; 64 const char *nodename; 65 const char *otherend; 66 int otherend_id; 67 struct xenbus_watch otherend_watch; 68 struct device dev; 69 enum xenbus_state state; 70 struct completion down; 71 }; 72 73 static inline struct xenbus_device *to_xenbus_device(struct device *dev) 74 { 75 return container_of(dev, struct xenbus_device, dev); 76 } 77 78 struct xenbus_device_id 79 { 80 /* .../device/<device_type>/<identifier> */ 81 char devicetype[32]; /* General class of device. */ 82 }; 83 84 /* A xenbus driver. */ 85 struct xenbus_driver { 86 char *name; 87 struct module *owner; 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 (*suspend_cancel)(struct xenbus_device *dev); 96 int (*resume)(struct xenbus_device *dev); 97 int (*uevent)(struct xenbus_device *, char **, int, char *, int); 98 struct device_driver driver; 99 int (*read_otherend_details)(struct xenbus_device *dev); 100 }; 101 102 static inline struct xenbus_driver *to_xenbus_driver(struct device_driver *drv) 103 { 104 return container_of(drv, struct xenbus_driver, driver); 105 } 106 107 int __must_check __xenbus_register_frontend(struct xenbus_driver *drv, 108 struct module *owner, 109 const char *mod_name); 110 111 static inline int __must_check 112 xenbus_register_frontend(struct xenbus_driver *drv) 113 { 114 WARN_ON(drv->owner != THIS_MODULE); 115 return __xenbus_register_frontend(drv, THIS_MODULE, KBUILD_MODNAME); 116 } 117 118 int __must_check __xenbus_register_backend(struct xenbus_driver *drv, 119 struct module *owner, 120 const char *mod_name); 121 static inline int __must_check 122 xenbus_register_backend(struct xenbus_driver *drv) 123 { 124 WARN_ON(drv->owner != THIS_MODULE); 125 return __xenbus_register_backend(drv, THIS_MODULE, KBUILD_MODNAME); 126 } 127 128 void xenbus_unregister_driver(struct xenbus_driver *drv); 129 130 struct xenbus_transaction 131 { 132 u32 id; 133 }; 134 135 /* Nil transaction ID. */ 136 #define XBT_NIL ((struct xenbus_transaction) { 0 }) 137 138 int __init xenbus_dev_init(void); 139 140 char **xenbus_directory(struct xenbus_transaction t, 141 const char *dir, const char *node, unsigned int *num); 142 void *xenbus_read(struct xenbus_transaction t, 143 const char *dir, const char *node, unsigned int *len); 144 int xenbus_write(struct xenbus_transaction t, 145 const char *dir, const char *node, const char *string); 146 int xenbus_mkdir(struct xenbus_transaction t, 147 const char *dir, const char *node); 148 int xenbus_exists(struct xenbus_transaction t, 149 const char *dir, const char *node); 150 int xenbus_rm(struct xenbus_transaction t, const char *dir, const char *node); 151 int xenbus_transaction_start(struct xenbus_transaction *t); 152 int xenbus_transaction_end(struct xenbus_transaction t, int abort); 153 154 /* Single read and scanf: returns -errno or num scanned if > 0. */ 155 int xenbus_scanf(struct xenbus_transaction t, 156 const char *dir, const char *node, const char *fmt, ...) 157 __attribute__((format(scanf, 4, 5))); 158 159 /* 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, ...) 162 __attribute__((format(printf, 4, 5))); 163 164 /* Generic read function: NULL-terminated triples of name, 165 * sprintf-style type string, and pointer. Returns 0 or errno.*/ 166 int xenbus_gather(struct xenbus_transaction t, const char *dir, ...); 167 168 /* notifer routines for when the xenstore comes up */ 169 extern int xenstored_ready; 170 int register_xenstore_notifier(struct notifier_block *nb); 171 void unregister_xenstore_notifier(struct notifier_block *nb); 172 173 int register_xenbus_watch(struct xenbus_watch *watch); 174 void unregister_xenbus_watch(struct xenbus_watch *watch); 175 void xs_suspend(void); 176 void xs_resume(void); 177 void xs_suspend_cancel(void); 178 179 /* Used by xenbus_dev to borrow kernel's store connection. */ 180 void *xenbus_dev_request_and_reply(struct xsd_sockmsg *msg); 181 182 struct work_struct; 183 184 /* Prepare for domain suspend: then resume or cancel the suspend. */ 185 void xenbus_suspend(void); 186 void xenbus_resume(void); 187 void xenbus_probe(struct work_struct *); 188 void xenbus_suspend_cancel(void); 189 190 #define XENBUS_IS_ERR_READ(str) ({ \ 191 if (!IS_ERR(str) && strlen(str) == 0) { \ 192 kfree(str); \ 193 str = ERR_PTR(-ERANGE); \ 194 } \ 195 IS_ERR(str); \ 196 }) 197 198 #define XENBUS_EXIST_ERR(err) ((err) == -ENOENT || (err) == -ERANGE) 199 200 int xenbus_watch_path(struct xenbus_device *dev, const char *path, 201 struct xenbus_watch *watch, 202 void (*callback)(struct xenbus_watch *, 203 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, ...) 208 __attribute__ ((format (printf, 4, 5))); 209 210 int xenbus_switch_state(struct xenbus_device *dev, enum xenbus_state new_state); 211 int xenbus_grant_ring(struct xenbus_device *dev, unsigned long ring_mfn); 212 int xenbus_map_ring_valloc(struct xenbus_device *dev, 213 int gnt_ref, void **vaddr); 214 int xenbus_map_ring(struct xenbus_device *dev, int gnt_ref, 215 grant_handle_t *handle, void *vaddr); 216 217 int xenbus_unmap_ring_vfree(struct xenbus_device *dev, void *vaddr); 218 int xenbus_unmap_ring(struct xenbus_device *dev, 219 grant_handle_t handle, void *vaddr); 220 221 int xenbus_alloc_evtchn(struct xenbus_device *dev, int *port); 222 int xenbus_bind_evtchn(struct xenbus_device *dev, int remote_port, int *port); 223 int xenbus_free_evtchn(struct xenbus_device *dev, int port); 224 225 enum xenbus_state xenbus_read_driver_state(const char *path); 226 227 void xenbus_dev_error(struct xenbus_device *dev, int err, const char *fmt, ...); 228 void xenbus_dev_fatal(struct xenbus_device *dev, int err, const char *fmt, ...); 229 230 const char *xenbus_strstate(enum xenbus_state state); 231 int xenbus_dev_is_online(struct xenbus_device *dev); 232 int xenbus_frontend_closed(struct xenbus_device *dev); 233 234 #endif /* _XEN_XENBUS_H */ 235