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/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> 48 49 /* Register callback to watch this node. */ 50 struct xenbus_watch 51 { 52 struct list_head list; 53 54 /* Path being watched. */ 55 const char *node; 56 57 /* Callback (executed in a process context with no locks held). */ 58 void (*callback)(struct xenbus_watch *, 59 const char **vec, unsigned int len); 60 }; 61 62 63 /* A xenbus device. */ 64 struct xenbus_device { 65 const char *devicetype; 66 const char *nodename; 67 const char *otherend; 68 int otherend_id; 69 struct xenbus_watch otherend_watch; 70 struct device dev; 71 enum xenbus_state state; 72 struct completion down; 73 struct work_struct work; 74 }; 75 76 static inline struct xenbus_device *to_xenbus_device(struct device *dev) 77 { 78 return container_of(dev, struct xenbus_device, dev); 79 } 80 81 struct xenbus_device_id 82 { 83 /* .../device/<device_type>/<identifier> */ 84 char devicetype[32]; /* General class of device. */ 85 }; 86 87 /* A xenbus driver. */ 88 struct xenbus_driver { 89 const struct xenbus_device_id *ids; 90 int (*probe)(struct xenbus_device *dev, 91 const struct xenbus_device_id *id); 92 void (*otherend_changed)(struct xenbus_device *dev, 93 enum xenbus_state backend_state); 94 int (*remove)(struct xenbus_device *dev); 95 int (*suspend)(struct xenbus_device *dev); 96 int (*resume)(struct xenbus_device *dev); 97 int (*uevent)(struct xenbus_device *, struct kobj_uevent_env *); 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 #define DEFINE_XENBUS_DRIVER(var, drvname, methods...) \ 104 struct xenbus_driver var ## _driver = { \ 105 .driver.name = drvname + 0 ?: var ## _ids->devicetype, \ 106 .driver.owner = THIS_MODULE, \ 107 .ids = var ## _ids, ## methods \ 108 } 109 110 static inline struct xenbus_driver *to_xenbus_driver(struct device_driver *drv) 111 { 112 return container_of(drv, struct xenbus_driver, driver); 113 } 114 115 int __must_check xenbus_register_frontend(struct xenbus_driver *); 116 int __must_check xenbus_register_backend(struct xenbus_driver *); 117 118 void xenbus_unregister_driver(struct xenbus_driver *drv); 119 120 struct xenbus_transaction 121 { 122 u32 id; 123 }; 124 125 /* Nil transaction ID. */ 126 #define XBT_NIL ((struct xenbus_transaction) { 0 }) 127 128 char **xenbus_directory(struct xenbus_transaction t, 129 const char *dir, const char *node, unsigned int *num); 130 void *xenbus_read(struct xenbus_transaction t, 131 const char *dir, const char *node, unsigned int *len); 132 int xenbus_write(struct xenbus_transaction t, 133 const char *dir, const char *node, const char *string); 134 int xenbus_mkdir(struct xenbus_transaction t, 135 const char *dir, const char *node); 136 int xenbus_exists(struct xenbus_transaction t, 137 const char *dir, const char *node); 138 int xenbus_rm(struct xenbus_transaction t, const char *dir, const char *node); 139 int xenbus_transaction_start(struct xenbus_transaction *t); 140 int xenbus_transaction_end(struct xenbus_transaction t, int abort); 141 142 /* Single read and scanf: returns -errno or num scanned if > 0. */ 143 __scanf(4, 5) 144 int xenbus_scanf(struct xenbus_transaction t, 145 const char *dir, const char *node, const char *fmt, ...); 146 147 /* Single printf and write: returns -errno or 0. */ 148 __printf(4, 5) 149 int xenbus_printf(struct xenbus_transaction t, 150 const char *dir, const char *node, const char *fmt, ...); 151 152 /* Generic read function: NULL-terminated triples of name, 153 * sprintf-style type string, and pointer. Returns 0 or errno.*/ 154 int xenbus_gather(struct xenbus_transaction t, const char *dir, ...); 155 156 /* notifer routines for when the xenstore comes up */ 157 extern int xenstored_ready; 158 int register_xenstore_notifier(struct notifier_block *nb); 159 void unregister_xenstore_notifier(struct notifier_block *nb); 160 161 int register_xenbus_watch(struct xenbus_watch *watch); 162 void unregister_xenbus_watch(struct xenbus_watch *watch); 163 void xs_suspend(void); 164 void xs_resume(void); 165 void xs_suspend_cancel(void); 166 167 /* Used by xenbus_dev to borrow kernel's store connection. */ 168 void *xenbus_dev_request_and_reply(struct xsd_sockmsg *msg); 169 170 struct work_struct; 171 172 /* Prepare for domain suspend: then resume or cancel the suspend. */ 173 void xenbus_suspend(void); 174 void xenbus_resume(void); 175 void xenbus_probe(struct work_struct *); 176 void xenbus_suspend_cancel(void); 177 178 #define XENBUS_IS_ERR_READ(str) ({ \ 179 if (!IS_ERR(str) && strlen(str) == 0) { \ 180 kfree(str); \ 181 str = ERR_PTR(-ERANGE); \ 182 } \ 183 IS_ERR(str); \ 184 }) 185 186 #define XENBUS_EXIST_ERR(err) ((err) == -ENOENT || (err) == -ERANGE) 187 188 int xenbus_watch_path(struct xenbus_device *dev, const char *path, 189 struct xenbus_watch *watch, 190 void (*callback)(struct xenbus_watch *, 191 const char **, unsigned int)); 192 __printf(4, 5) 193 int xenbus_watch_pathfmt(struct xenbus_device *dev, struct xenbus_watch *watch, 194 void (*callback)(struct xenbus_watch *, 195 const char **, unsigned int), 196 const char *pathfmt, ...); 197 198 int xenbus_switch_state(struct xenbus_device *dev, enum xenbus_state new_state); 199 int xenbus_grant_ring(struct xenbus_device *dev, unsigned long ring_mfn); 200 int xenbus_map_ring_valloc(struct xenbus_device *dev, 201 int gnt_ref, void **vaddr); 202 int xenbus_map_ring(struct xenbus_device *dev, int gnt_ref, 203 grant_handle_t *handle, void *vaddr); 204 205 int xenbus_unmap_ring_vfree(struct xenbus_device *dev, void *vaddr); 206 int xenbus_unmap_ring(struct xenbus_device *dev, 207 grant_handle_t handle, void *vaddr); 208 209 int xenbus_alloc_evtchn(struct xenbus_device *dev, int *port); 210 int xenbus_free_evtchn(struct xenbus_device *dev, int port); 211 212 enum xenbus_state xenbus_read_driver_state(const char *path); 213 214 __printf(3, 4) 215 void xenbus_dev_error(struct xenbus_device *dev, int err, const char *fmt, ...); 216 __printf(3, 4) 217 void xenbus_dev_fatal(struct xenbus_device *dev, int err, const char *fmt, ...); 218 219 const char *xenbus_strstate(enum xenbus_state state); 220 int xenbus_dev_is_online(struct xenbus_device *dev); 221 int xenbus_frontend_closed(struct xenbus_device *dev); 222 223 #endif /* _XEN_XENBUS_H */ 224