xenbusvar.h revision 185605
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 file may be distributed separately from the Linux kernel, or 10 * incorporated into other software packages, subject to the following license: 11 * 12 * Permission is hereby granted, free of charge, to any person obtaining a copy 13 * of this source file (the "Software"), to deal in the Software without 14 * restriction, including without limitation the rights to use, copy, modify, 15 * merge, publish, distribute, sublicense, and/or sell copies of the Software, 16 * and to permit persons to whom the Software is furnished to do so, subject to 17 * the following conditions: 18 * 19 * The above copyright notice and this permission notice shall be included in 20 * all copies or substantial portions of the Software. 21 * 22 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR 23 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, 24 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE 25 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER 26 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING 27 * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS 28 * IN THE SOFTWARE. 29 * 30 * $FreeBSD: head/sys/xen/xenbus/xenbusvar.h 185605 2008-12-04 07:59:05Z kmacy $ 31 */ 32 33#ifndef _XEN_XENBUS_XENBUSVAR_H 34#define _XEN_XENBUS_XENBUSVAR_H 35 36#include <sys/queue.h> 37#include <sys/bus.h> 38#include <sys/eventhandler.h> 39#include <machine/xen/xen-os.h> 40#include <xen/interface/io/xenbus.h> 41#include <xen/interface/io/xs_wire.h> 42 43#include "xenbus_if.h" 44 45enum { 46 /* 47 * Path of this device node. 48 */ 49 XENBUS_IVAR_NODE, 50 51 /* 52 * The device type (e.g. vif, vbd). 53 */ 54 XENBUS_IVAR_TYPE, 55 56 /* 57 * The state of this device (not the otherend's state). 58 */ 59 XENBUS_IVAR_STATE, 60 61 /* 62 * Domain ID of the other end device. 63 */ 64 XENBUS_IVAR_OTHEREND_ID, 65 66 /* 67 * Path of the other end device. 68 */ 69 XENBUS_IVAR_OTHEREND_PATH 70}; 71 72/* 73 * Simplified accessors for xenbus devices 74 */ 75#define XENBUS_ACCESSOR(var, ivar, type) \ 76 __BUS_ACCESSOR(xenbus, var, XENBUS, ivar, type) 77 78XENBUS_ACCESSOR(node, NODE, const char *) 79XENBUS_ACCESSOR(type, TYPE, const char *) 80XENBUS_ACCESSOR(state, STATE, enum xenbus_state) 81XENBUS_ACCESSOR(otherend_id, OTHEREND_ID, int) 82XENBUS_ACCESSOR(otherend_path, OTHEREND_PATH, const char *) 83 84/* Register callback to watch this node. */ 85struct xenbus_watch 86{ 87 LIST_ENTRY(xenbus_watch) list; 88 89 /* Path being watched. */ 90 char *node; 91 92 /* Callback (executed in a process context with no locks held). */ 93 void (*callback)(struct xenbus_watch *, 94 const char **vec, unsigned int len); 95}; 96 97typedef int (*xenstore_event_handler_t)(void *); 98 99struct xenbus_transaction 100{ 101 uint32_t id; 102}; 103 104#define XBT_NIL ((struct xenbus_transaction) { 0 }) 105 106char **xenbus_directory(struct xenbus_transaction t, 107 const char *dir, const char *node, unsigned int *num); 108void *xenbus_read(struct xenbus_transaction t, 109 const char *dir, const char *node, unsigned int *len); 110int xenbus_write(struct xenbus_transaction t, 111 const char *dir, const char *node, const char *string); 112int xenbus_mkdir(struct xenbus_transaction t, 113 const char *dir, const char *node); 114int xenbus_exists(struct xenbus_transaction t, 115 const char *dir, const char *node); 116int xenbus_rm(struct xenbus_transaction t, const char *dir, const char *node); 117int xenbus_transaction_start(struct xenbus_transaction *t); 118int xenbus_transaction_end(struct xenbus_transaction t, int abort); 119 120/* Single read and scanf: returns -errno or num scanned if > 0. */ 121int xenbus_scanf(struct xenbus_transaction t, 122 const char *dir, const char *node, const char *fmt, ...) 123 __attribute__((format(scanf, 4, 5))); 124 125/* Single printf and write: returns -errno or 0. */ 126int xenbus_printf(struct xenbus_transaction t, 127 const char *dir, const char *node, const char *fmt, ...) 128 __attribute__((format(printf, 4, 5))); 129 130/* Generic read function: NULL-terminated triples of name, 131 * sprintf-style type string, and pointer. Returns 0 or errno.*/ 132int xenbus_gather(struct xenbus_transaction t, const char *dir, ...); 133 134/* notifer routines for when the xenstore comes up */ 135int register_xenstore_notifier(xenstore_event_handler_t func, void *arg, int priority); 136#if 0 137void unregister_xenstore_notifier(); 138#endif 139int register_xenbus_watch(struct xenbus_watch *watch); 140void unregister_xenbus_watch(struct xenbus_watch *watch); 141void xs_suspend(void); 142void xs_resume(void); 143 144/* Used by xenbus_dev to borrow kernel's store connection. */ 145void *xenbus_dev_request_and_reply(struct xsd_sockmsg *msg); 146 147#define XENBUS_IS_ERR_READ(str) ({ \ 148 if (!IS_ERR(str) && strlen(str) == 0) { \ 149 free(str, M_DEVBUF); \ 150 str = ERR_PTR(-ERANGE); \ 151 } \ 152 IS_ERR(str); \ 153}) 154 155#define XENBUS_EXIST_ERR(err) ((err) == -ENOENT || (err) == -ERANGE) 156 157/** 158 * Register a watch on the given path, using the given xenbus_watch structure 159 * for storage, and the given callback function as the callback. Return 0 on 160 * success, or -errno on error. On success, the given path will be saved as 161 * watch->node, and remains the caller's to free. On error, watch->node will 162 * be NULL, the device will switch to XenbusStateClosing, and the error will 163 * be saved in the store. 164 */ 165int xenbus_watch_path(device_t dev, char *path, 166 struct xenbus_watch *watch, 167 void (*callback)(struct xenbus_watch *, 168 const char **, unsigned int)); 169 170 171/** 172 * Register a watch on the given path/path2, using the given xenbus_watch 173 * structure for storage, and the given callback function as the callback. 174 * Return 0 on success, or -errno on error. On success, the watched path 175 * (path/path2) will be saved as watch->node, and becomes the caller's to 176 * kfree(). On error, watch->node will be NULL, so the caller has nothing to 177 * free, the device will switch to XenbusStateClosing, and the error will be 178 * saved in the store. 179 */ 180int xenbus_watch_path2(device_t dev, const char *path, 181 const char *path2, struct xenbus_watch *watch, 182 void (*callback)(struct xenbus_watch *, 183 const char **, unsigned int)); 184 185 186/** 187 * Advertise in the store a change of the given driver to the given new_state. 188 * which case this is performed inside its own transaction. Return 0 on 189 * success, or -errno on error. On error, the device will switch to 190 * XenbusStateClosing, and the error will be saved in the store. 191 */ 192int xenbus_switch_state(device_t dev, 193 XenbusState new_state); 194 195 196/** 197 * Grant access to the given ring_mfn to the peer of the given device. Return 198 * 0 on success, or -errno on error. On error, the device will switch to 199 * XenbusStateClosing, and the error will be saved in the store. 200 */ 201int xenbus_grant_ring(device_t dev, unsigned long ring_mfn); 202 203 204/** 205 * Allocate an event channel for the given xenbus_device, assigning the newly 206 * created local port to *port. Return 0 on success, or -errno on error. On 207 * error, the device will switch to XenbusStateClosing, and the error will be 208 * saved in the store. 209 */ 210int xenbus_alloc_evtchn(device_t dev, int *port); 211 212 213/** 214 * Free an existing event channel. Returns 0 on success or -errno on error. 215 */ 216int xenbus_free_evtchn(device_t dev, int port); 217 218 219/** 220 * Return the state of the driver rooted at the given store path, or 221 * XenbusStateClosed if no state can be read. 222 */ 223XenbusState xenbus_read_driver_state(const char *path); 224 225 226/*** 227 * Report the given negative errno into the store, along with the given 228 * formatted message. 229 */ 230void xenbus_dev_error(device_t dev, int err, const char *fmt, 231 ...); 232 233 234/*** 235 * Equivalent to xenbus_dev_error(dev, err, fmt, args), followed by 236 * xenbus_switch_state(dev, NULL, XenbusStateClosing) to schedule an orderly 237 * closedown of this driver and its peer. 238 */ 239void xenbus_dev_fatal(device_t dev, int err, const char *fmt, 240 ...); 241 242int xenbus_dev_init(void); 243 244const char *xenbus_strstate(enum xenbus_state state); 245int xenbus_dev_is_online(device_t dev); 246int xenbus_frontend_closed(device_t dev); 247 248#endif /* _XEN_XENBUS_XENBUSVAR_H */ 249