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 int (*is_ready)(struct xenbus_device *dev); 101 }; 102 103 static inline struct xenbus_driver *to_xenbus_driver(struct device_driver *drv) 104 { 105 return container_of(drv, struct xenbus_driver, driver); 106 } 107 108 int __must_check __xenbus_register_frontend(struct xenbus_driver *drv, 109 struct module *owner, 110 const char *mod_name); 111 112 static inline int __must_check 113 xenbus_register_frontend(struct xenbus_driver *drv) 114 { 115 WARN_ON(drv->owner != THIS_MODULE); 116 return __xenbus_register_frontend(drv, THIS_MODULE, KBUILD_MODNAME); 117 } 118 119 int __must_check __xenbus_register_backend(struct xenbus_driver *drv, 120 struct module *owner, 121 const char *mod_name); 122 static inline int __must_check 123 xenbus_register_backend(struct xenbus_driver *drv) 124 { 125 WARN_ON(drv->owner != THIS_MODULE); 126 return __xenbus_register_backend(drv, THIS_MODULE, KBUILD_MODNAME); 127 } 128 129 void xenbus_unregister_driver(struct xenbus_driver *drv); 130 131 struct xenbus_transaction 132 { 133 u32 id; 134 }; 135 136 /* Nil transaction ID. */ 137 #define XBT_NIL ((struct xenbus_transaction) { 0 }) 138 139 int __init xenbus_dev_init(void); 140 141 char **xenbus_directory(struct xenbus_transaction t, 142 const char *dir, const char *node, unsigned int *num); 143 void *xenbus_read(struct xenbus_transaction t, 144 const char *dir, const char *node, unsigned int *len); 145 int xenbus_write(struct xenbus_transaction t, 146 const char *dir, const char *node, const char *string); 147 int xenbus_mkdir(struct xenbus_transaction t, 148 const char *dir, const char *node); 149 int xenbus_exists(struct xenbus_transaction t, 150 const char *dir, const char *node); 151 int xenbus_rm(struct xenbus_transaction t, const char *dir, const char *node); 152 int xenbus_transaction_start(struct xenbus_transaction *t); 153 int xenbus_transaction_end(struct xenbus_transaction t, int abort); 154 155 /* Single read and scanf: returns -errno or num scanned if > 0. */ 156 int xenbus_scanf(struct xenbus_transaction t, 157 const char *dir, const char *node, const char *fmt, ...) 158 __attribute__((format(scanf, 4, 5))); 159 160 /* Single printf and write: returns -errno or 0. */ 161 int xenbus_printf(struct xenbus_transaction t, 162 const char *dir, const char *node, const char *fmt, ...) 163 __attribute__((format(printf, 4, 5))); 164 165 /* Generic read function: NULL-terminated triples of name, 166 * sprintf-style type string, and pointer. Returns 0 or errno.*/ 167 int xenbus_gather(struct xenbus_transaction t, const char *dir, ...); 168 169 /* notifer routines for when the xenstore comes up */ 170 extern int xenstored_ready; 171 int register_xenstore_notifier(struct notifier_block *nb); 172 void unregister_xenstore_notifier(struct notifier_block *nb); 173 174 int register_xenbus_watch(struct xenbus_watch *watch); 175 void unregister_xenbus_watch(struct xenbus_watch *watch); 176 void xs_suspend(void); 177 void xs_resume(void); 178 void xs_suspend_cancel(void); 179 180 /* Used by xenbus_dev to borrow kernel's store connection. */ 181 void *xenbus_dev_request_and_reply(struct xsd_sockmsg *msg); 182 183 struct work_struct; 184 185 /* Prepare for domain suspend: then resume or cancel the suspend. */ 186 void xenbus_suspend(void); 187 void xenbus_resume(void); 188 void xenbus_probe(struct work_struct *); 189 void xenbus_suspend_cancel(void); 190 191 #define XENBUS_IS_ERR_READ(str) ({ \ 192 if (!IS_ERR(str) && strlen(str) == 0) { \ 193 kfree(str); \ 194 str = ERR_PTR(-ERANGE); \ 195 } \ 196 IS_ERR(str); \ 197 }) 198 199 #define XENBUS_EXIST_ERR(err) ((err) == -ENOENT || (err) == -ERANGE) 200 201 int xenbus_watch_path(struct xenbus_device *dev, const char *path, 202 struct xenbus_watch *watch, 203 void (*callback)(struct xenbus_watch *, 204 const char **, unsigned int)); 205 int xenbus_watch_pathfmt(struct xenbus_device *dev, struct xenbus_watch *watch, 206 void (*callback)(struct xenbus_watch *, 207 const char **, unsigned int), 208 const char *pathfmt, ...) 209 __attribute__ ((format (printf, 4, 5))); 210 211 int xenbus_switch_state(struct xenbus_device *dev, enum xenbus_state new_state); 212 int xenbus_grant_ring(struct xenbus_device *dev, unsigned long ring_mfn); 213 int xenbus_map_ring_valloc(struct xenbus_device *dev, 214 int gnt_ref, void **vaddr); 215 int xenbus_map_ring(struct xenbus_device *dev, int gnt_ref, 216 grant_handle_t *handle, void *vaddr); 217 218 int xenbus_unmap_ring_vfree(struct xenbus_device *dev, void *vaddr); 219 int xenbus_unmap_ring(struct xenbus_device *dev, 220 grant_handle_t handle, void *vaddr); 221 222 int xenbus_alloc_evtchn(struct xenbus_device *dev, int *port); 223 int xenbus_bind_evtchn(struct xenbus_device *dev, int remote_port, int *port); 224 int xenbus_free_evtchn(struct xenbus_device *dev, int port); 225 226 enum xenbus_state xenbus_read_driver_state(const char *path); 227 228 void xenbus_dev_error(struct xenbus_device *dev, int err, const char *fmt, ...); 229 void xenbus_dev_fatal(struct xenbus_device *dev, int err, const char *fmt, ...); 230 231 const char *xenbus_strstate(enum xenbus_state state); 232 int xenbus_dev_is_online(struct xenbus_device *dev); 233 int xenbus_frontend_closed(struct xenbus_device *dev); 234 235 #endif /* _XEN_XENBUS_H */ 236