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 #define XENBUS_MAX_RING_PAGE_ORDER 4 50 #define XENBUS_MAX_RING_PAGES (1U << XENBUS_MAX_RING_PAGE_ORDER) 51 #define INVALID_GRANT_HANDLE (~0U) 52 53 /* Register callback to watch this node. */ 54 struct xenbus_watch 55 { 56 struct list_head list; 57 58 /* Path being watched. */ 59 const char *node; 60 61 /* Callback (executed in a process context with no locks held). */ 62 void (*callback)(struct xenbus_watch *, 63 const char **vec, unsigned int len); 64 }; 65 66 67 /* A xenbus device. */ 68 struct xenbus_device { 69 const char *devicetype; 70 const char *nodename; 71 const char *otherend; 72 int otherend_id; 73 struct xenbus_watch otherend_watch; 74 struct device dev; 75 enum xenbus_state state; 76 struct completion down; 77 struct work_struct work; 78 }; 79 80 static inline struct xenbus_device *to_xenbus_device(struct device *dev) 81 { 82 return container_of(dev, struct xenbus_device, dev); 83 } 84 85 struct xenbus_device_id 86 { 87 /* .../device/<device_type>/<identifier> */ 88 char devicetype[32]; /* General class of device. */ 89 }; 90 91 /* A xenbus driver. */ 92 struct xenbus_driver { 93 const char *name; /* defaults to ids[0].devicetype */ 94 const struct xenbus_device_id *ids; 95 int (*probe)(struct xenbus_device *dev, 96 const struct xenbus_device_id *id); 97 void (*otherend_changed)(struct xenbus_device *dev, 98 enum xenbus_state backend_state); 99 int (*remove)(struct xenbus_device *dev); 100 int (*suspend)(struct xenbus_device *dev); 101 int (*resume)(struct xenbus_device *dev); 102 int (*uevent)(struct xenbus_device *, struct kobj_uevent_env *); 103 struct device_driver driver; 104 int (*read_otherend_details)(struct xenbus_device *dev); 105 int (*is_ready)(struct xenbus_device *dev); 106 }; 107 108 static inline struct xenbus_driver *to_xenbus_driver(struct device_driver *drv) 109 { 110 return container_of(drv, struct xenbus_driver, driver); 111 } 112 113 int __must_check __xenbus_register_frontend(struct xenbus_driver *drv, 114 struct module *owner, 115 const char *mod_name); 116 int __must_check __xenbus_register_backend(struct xenbus_driver *drv, 117 struct module *owner, 118 const char *mod_name); 119 120 #define xenbus_register_frontend(drv) \ 121 __xenbus_register_frontend(drv, THIS_MODULE, KBUILD_MODNAME) 122 #define xenbus_register_backend(drv) \ 123 __xenbus_register_backend(drv, THIS_MODULE, KBUILD_MODNAME) 124 125 void xenbus_unregister_driver(struct xenbus_driver *drv); 126 127 struct xenbus_transaction 128 { 129 u32 id; 130 }; 131 132 /* Nil transaction ID. */ 133 #define XBT_NIL ((struct xenbus_transaction) { 0 }) 134 135 char **xenbus_directory(struct xenbus_transaction t, 136 const char *dir, const char *node, unsigned int *num); 137 void *xenbus_read(struct xenbus_transaction t, 138 const char *dir, const char *node, unsigned int *len); 139 int xenbus_write(struct xenbus_transaction t, 140 const char *dir, const char *node, const char *string); 141 int xenbus_mkdir(struct xenbus_transaction t, 142 const char *dir, const char *node); 143 int xenbus_exists(struct xenbus_transaction t, 144 const char *dir, const char *node); 145 int xenbus_rm(struct xenbus_transaction t, const char *dir, const char *node); 146 int xenbus_transaction_start(struct xenbus_transaction *t); 147 int xenbus_transaction_end(struct xenbus_transaction t, int abort); 148 149 /* Single read and scanf: returns -errno or num scanned if > 0. */ 150 __scanf(4, 5) 151 int xenbus_scanf(struct xenbus_transaction t, 152 const char *dir, const char *node, const char *fmt, ...); 153 154 /* Single printf and write: returns -errno or 0. */ 155 __printf(4, 5) 156 int xenbus_printf(struct xenbus_transaction t, 157 const char *dir, const char *node, const char *fmt, ...); 158 159 /* Generic read function: NULL-terminated triples of name, 160 * sprintf-style type string, and pointer. Returns 0 or errno.*/ 161 int xenbus_gather(struct xenbus_transaction t, const char *dir, ...); 162 163 /* notifer routines for when the xenstore comes up */ 164 extern int xenstored_ready; 165 int register_xenstore_notifier(struct notifier_block *nb); 166 void unregister_xenstore_notifier(struct notifier_block *nb); 167 168 int register_xenbus_watch(struct xenbus_watch *watch); 169 void unregister_xenbus_watch(struct xenbus_watch *watch); 170 void xs_suspend(void); 171 void xs_resume(void); 172 void xs_suspend_cancel(void); 173 174 /* Used by xenbus_dev to borrow kernel's store connection. */ 175 void *xenbus_dev_request_and_reply(struct xsd_sockmsg *msg); 176 177 struct work_struct; 178 179 /* Prepare for domain suspend: then resume or cancel the suspend. */ 180 void xenbus_suspend(void); 181 void xenbus_resume(void); 182 void xenbus_probe(struct work_struct *); 183 void xenbus_suspend_cancel(void); 184 185 #define XENBUS_IS_ERR_READ(str) ({ \ 186 if (!IS_ERR(str) && strlen(str) == 0) { \ 187 kfree(str); \ 188 str = ERR_PTR(-ERANGE); \ 189 } \ 190 IS_ERR(str); \ 191 }) 192 193 #define XENBUS_EXIST_ERR(err) ((err) == -ENOENT || (err) == -ERANGE) 194 195 int xenbus_watch_path(struct xenbus_device *dev, const char *path, 196 struct xenbus_watch *watch, 197 void (*callback)(struct xenbus_watch *, 198 const char **, unsigned int)); 199 __printf(4, 5) 200 int xenbus_watch_pathfmt(struct xenbus_device *dev, struct xenbus_watch *watch, 201 void (*callback)(struct xenbus_watch *, 202 const char **, unsigned int), 203 const char *pathfmt, ...); 204 205 int xenbus_switch_state(struct xenbus_device *dev, enum xenbus_state new_state); 206 int xenbus_grant_ring(struct xenbus_device *dev, void *vaddr, 207 unsigned int nr_pages, grant_ref_t *grefs); 208 int xenbus_map_ring_valloc(struct xenbus_device *dev, grant_ref_t *gnt_refs, 209 unsigned int nr_grefs, void **vaddr); 210 int xenbus_map_ring(struct xenbus_device *dev, 211 grant_ref_t *gnt_refs, unsigned int nr_grefs, 212 grant_handle_t *handles, unsigned long *vaddrs, 213 bool *leaked); 214 215 int xenbus_unmap_ring_vfree(struct xenbus_device *dev, void *vaddr); 216 int xenbus_unmap_ring(struct xenbus_device *dev, 217 grant_handle_t *handles, unsigned int nr_handles, 218 unsigned long *vaddrs); 219 220 int xenbus_alloc_evtchn(struct xenbus_device *dev, int *port); 221 int xenbus_free_evtchn(struct xenbus_device *dev, int port); 222 223 enum xenbus_state xenbus_read_driver_state(const char *path); 224 225 __printf(3, 4) 226 void xenbus_dev_error(struct xenbus_device *dev, int err, const char *fmt, ...); 227 __printf(3, 4) 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