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. */ 57struct 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. */ 80struct 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 93static inline struct xenbus_device *to_xenbus_device(struct device *dev) 94{ 95 return container_of(dev, struct xenbus_device, dev); 96} 97 98struct xenbus_device_id 99{ 100 /* .../device/<device_type>/<identifier> */ 101 char devicetype[32]; /* General class of device. */ 102}; 103 104/* A xenbus driver. */ 105struct 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 123static inline struct xenbus_driver *to_xenbus_driver(struct device_driver *drv) 124{ 125 return container_of(drv, struct xenbus_driver, driver); 126} 127 128int __must_check __xenbus_register_frontend(struct xenbus_driver *drv, 129 struct module *owner, 130 const char *mod_name); 131int __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 140void xenbus_unregister_driver(struct xenbus_driver *drv); 141 142struct xenbus_transaction 143{ 144 u32 id; 145}; 146 147/* Nil transaction ID. */ 148#define XBT_NIL ((struct xenbus_transaction) { 0 }) 149 150char **xenbus_directory(struct xenbus_transaction t, 151 const char *dir, const char *node, unsigned int *num); 152void *xenbus_read(struct xenbus_transaction t, 153 const char *dir, const char *node, unsigned int *len); 154int xenbus_write(struct xenbus_transaction t, 155 const char *dir, const char *node, const char *string); 156int xenbus_mkdir(struct xenbus_transaction t, 157 const char *dir, const char *node); 158int xenbus_exists(struct xenbus_transaction t, 159 const char *dir, const char *node); 160int xenbus_rm(struct xenbus_transaction t, const char *dir, const char *node); 161int xenbus_transaction_start(struct xenbus_transaction *t); 162int 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) 166int xenbus_scanf(struct xenbus_transaction t, 167 const char *dir, const char *node, const char *fmt, ...); 168 169/* Read an (optional) unsigned value. */ 170unsigned 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) 175int 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.*/ 180int xenbus_gather(struct xenbus_transaction t, const char *dir, ...); 181 182/* notifer routines for when the xenstore comes up */ 183extern int xenstored_ready; 184int register_xenstore_notifier(struct notifier_block *nb); 185void unregister_xenstore_notifier(struct notifier_block *nb); 186 187int register_xenbus_watch(struct xenbus_watch *watch); 188void unregister_xenbus_watch(struct xenbus_watch *watch); 189void xs_suspend(void); 190void xs_resume(void); 191void xs_suspend_cancel(void); 192 193struct work_struct; 194 195#define XENBUS_IS_ERR_READ(str) ({ \ 196 if (!IS_ERR(str) && strlen(str) == 0) { \ 197 kfree(str); \ 198 str = ERR_PTR(-ERANGE); \ 199 } \ 200 IS_ERR(str); \ 201}) 202 203#define XENBUS_EXIST_ERR(err) ((err) == -ENOENT || (err) == -ERANGE) 204 205int xenbus_watch_path(struct xenbus_device *dev, const char *path, 206 struct xenbus_watch *watch, 207 bool (*will_handle)(struct xenbus_watch *, 208 const char *, const char *), 209 void (*callback)(struct xenbus_watch *, 210 const char *, const char *)); 211__printf(5, 6) 212int xenbus_watch_pathfmt(struct xenbus_device *dev, struct xenbus_watch *watch, 213 bool (*will_handle)(struct xenbus_watch *, 214 const char *, const char *), 215 void (*callback)(struct xenbus_watch *, 216 const char *, const char *), 217 const char *pathfmt, ...); 218 219int xenbus_switch_state(struct xenbus_device *dev, enum xenbus_state new_state); 220int xenbus_grant_ring(struct xenbus_device *dev, void *vaddr, 221 unsigned int nr_pages, grant_ref_t *grefs); 222int xenbus_map_ring_valloc(struct xenbus_device *dev, grant_ref_t *gnt_refs, 223 unsigned int nr_grefs, void **vaddr); 224 225int xenbus_unmap_ring_vfree(struct xenbus_device *dev, void *vaddr); 226 227int xenbus_alloc_evtchn(struct xenbus_device *dev, evtchn_port_t *port); 228int xenbus_free_evtchn(struct xenbus_device *dev, evtchn_port_t port); 229 230enum xenbus_state xenbus_read_driver_state(const char *path); 231 232__printf(3, 4) 233void xenbus_dev_error(struct xenbus_device *dev, int err, const char *fmt, ...); 234__printf(3, 4) 235void xenbus_dev_fatal(struct xenbus_device *dev, int err, const char *fmt, ...); 236 237const char *xenbus_strstate(enum xenbus_state state); 238int xenbus_dev_is_online(struct xenbus_device *dev); 239int xenbus_frontend_closed(struct xenbus_device *dev); 240 241extern const struct file_operations xen_xenbus_fops; 242extern struct xenstore_domain_interface *xen_store_interface; 243extern int xen_store_evtchn; 244 245#endif /* _XEN_XENBUS_H */ 246