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 #define INVALID_GRANT_HANDLE (~0U) 55 56 /* Register callback to watch this node. */ 57 struct xenbus_watch 58 { 59 struct list_head list; 60 61 /* Path being watched. */ 62 const char *node; 63 64 unsigned int nr_pending; 65 66 /* 67 * Called just before enqueing new event while a spinlock is held. 68 * The event will be discarded if this callback returns false. 69 */ 70 bool (*will_handle)(struct xenbus_watch *, 71 const char *path, const char *token); 72 73 /* Callback (executed in a process context with no locks held). */ 74 void (*callback)(struct xenbus_watch *, 75 const char *path, const char *token); 76 }; 77 78 79 /* A xenbus device. */ 80 struct xenbus_device { 81 const char *devicetype; 82 const char *nodename; 83 const char *otherend; 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 93 static inline struct xenbus_device *to_xenbus_device(struct device *dev) 94 { 95 return container_of(dev, struct xenbus_device, dev); 96 } 97 98 struct xenbus_device_id 99 { 100 /* .../device/<device_type>/<identifier> */ 101 char devicetype[32]; /* General class of device. */ 102 }; 103 104 /* A xenbus driver. */ 105 struct xenbus_driver { 106 const char *name; /* defaults to ids[0].devicetype */ 107 const struct xenbus_device_id *ids; 108 bool allow_rebind; /* avoid setting xenstore closed during remove */ 109 int (*probe)(struct xenbus_device *dev, 110 const struct xenbus_device_id *id); 111 void (*otherend_changed)(struct xenbus_device *dev, 112 enum xenbus_state backend_state); 113 int (*remove)(struct xenbus_device *dev); 114 int (*suspend)(struct xenbus_device *dev); 115 int (*resume)(struct xenbus_device *dev); 116 int (*uevent)(struct xenbus_device *, struct kobj_uevent_env *); 117 struct device_driver driver; 118 int (*read_otherend_details)(struct xenbus_device *dev); 119 int (*is_ready)(struct xenbus_device *dev); 120 void (*reclaim_memory)(struct xenbus_device *dev); 121 }; 122 123 static inline struct xenbus_driver *to_xenbus_driver(struct device_driver *drv) 124 { 125 return container_of(drv, struct xenbus_driver, driver); 126 } 127 128 int __must_check __xenbus_register_frontend(struct xenbus_driver *drv, 129 struct module *owner, 130 const char *mod_name); 131 int __must_check __xenbus_register_backend(struct xenbus_driver *drv, 132 struct module *owner, 133 const char *mod_name); 134 135 #define xenbus_register_frontend(drv) \ 136 __xenbus_register_frontend(drv, THIS_MODULE, KBUILD_MODNAME) 137 #define xenbus_register_backend(drv) \ 138 __xenbus_register_backend(drv, THIS_MODULE, KBUILD_MODNAME) 139 140 void xenbus_unregister_driver(struct xenbus_driver *drv); 141 142 struct xenbus_transaction 143 { 144 u32 id; 145 }; 146 147 /* Nil transaction ID. */ 148 #define XBT_NIL ((struct xenbus_transaction) { 0 }) 149 150 char **xenbus_directory(struct xenbus_transaction t, 151 const char *dir, const char *node, unsigned int *num); 152 void *xenbus_read(struct xenbus_transaction t, 153 const char *dir, const char *node, unsigned int *len); 154 int xenbus_write(struct xenbus_transaction t, 155 const char *dir, const char *node, const char *string); 156 int xenbus_mkdir(struct xenbus_transaction t, 157 const char *dir, const char *node); 158 int xenbus_exists(struct xenbus_transaction t, 159 const char *dir, const char *node); 160 int xenbus_rm(struct xenbus_transaction t, const char *dir, const char *node); 161 int xenbus_transaction_start(struct xenbus_transaction *t); 162 int xenbus_transaction_end(struct xenbus_transaction t, int abort); 163 164 /* Single read and scanf: returns -errno or num scanned if > 0. */ 165 __scanf(4, 5) 166 int xenbus_scanf(struct xenbus_transaction t, 167 const char *dir, const char *node, const char *fmt, ...); 168 169 /* Read an (optional) unsigned value. */ 170 unsigned 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) 175 int 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.*/ 180 int xenbus_gather(struct xenbus_transaction t, const char *dir, ...); 181 182 /* notifer routines for when the xenstore comes up */ 183 extern int xenstored_ready; 184 int register_xenstore_notifier(struct notifier_block *nb); 185 void unregister_xenstore_notifier(struct notifier_block *nb); 186 187 int register_xenbus_watch(struct xenbus_watch *watch); 188 void unregister_xenbus_watch(struct xenbus_watch *watch); 189 void xs_suspend(void); 190 void xs_resume(void); 191 void xs_suspend_cancel(void); 192 193 struct work_struct; 194 195 void xenbus_probe(struct work_struct *); 196 197 #define XENBUS_IS_ERR_READ(str) ({ \ 198 if (!IS_ERR(str) && strlen(str) == 0) { \ 199 kfree(str); \ 200 str = ERR_PTR(-ERANGE); \ 201 } \ 202 IS_ERR(str); \ 203 }) 204 205 #define XENBUS_EXIST_ERR(err) ((err) == -ENOENT || (err) == -ERANGE) 206 207 int xenbus_watch_path(struct xenbus_device *dev, const char *path, 208 struct xenbus_watch *watch, 209 bool (*will_handle)(struct xenbus_watch *, 210 const char *, const char *), 211 void (*callback)(struct xenbus_watch *, 212 const char *, const char *)); 213 __printf(5, 6) 214 int xenbus_watch_pathfmt(struct xenbus_device *dev, struct xenbus_watch *watch, 215 bool (*will_handle)(struct xenbus_watch *, 216 const char *, const char *), 217 void (*callback)(struct xenbus_watch *, 218 const char *, const char *), 219 const char *pathfmt, ...); 220 221 int xenbus_switch_state(struct xenbus_device *dev, enum xenbus_state new_state); 222 int xenbus_grant_ring(struct xenbus_device *dev, void *vaddr, 223 unsigned int nr_pages, grant_ref_t *grefs); 224 int xenbus_map_ring_valloc(struct xenbus_device *dev, grant_ref_t *gnt_refs, 225 unsigned int nr_grefs, void **vaddr); 226 227 int xenbus_unmap_ring_vfree(struct xenbus_device *dev, void *vaddr); 228 229 int xenbus_alloc_evtchn(struct xenbus_device *dev, evtchn_port_t *port); 230 int xenbus_free_evtchn(struct xenbus_device *dev, evtchn_port_t port); 231 232 enum xenbus_state xenbus_read_driver_state(const char *path); 233 234 __printf(3, 4) 235 void xenbus_dev_error(struct xenbus_device *dev, int err, const char *fmt, ...); 236 __printf(3, 4) 237 void xenbus_dev_fatal(struct xenbus_device *dev, int err, const char *fmt, ...); 238 239 const char *xenbus_strstate(enum xenbus_state state); 240 int xenbus_dev_is_online(struct xenbus_device *dev); 241 int xenbus_frontend_closed(struct xenbus_device *dev); 242 243 extern const struct file_operations xen_xenbus_fops; 244 extern struct xenstore_domain_interface *xen_store_interface; 245 extern int xen_store_evtchn; 246 247 #endif /* _XEN_XENBUS_H */ 248