xenbusvar.h revision 255040
1/****************************************************************************** 2 * Copyright (C) 2005 Rusty Russell, IBM Corporation 3 * Copyright (C) 2005 XenSource Ltd. 4 * 5 * This file may be distributed separately from the Linux kernel, or 6 * incorporated into other software packages, subject to the following license: 7 * 8 * Permission is hereby granted, free of charge, to any person obtaining a copy 9 * of this source file (the "Software"), to deal in the Software without 10 * restriction, including without limitation the rights to use, copy, modify, 11 * merge, publish, distribute, sublicense, and/or sell copies of the Software, 12 * and to permit persons to whom the Software is furnished to do so, subject to 13 * the following conditions: 14 * 15 * The above copyright notice and this permission notice shall be included in 16 * all copies or substantial portions of the Software. 17 * 18 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR 19 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, 20 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE 21 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER 22 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING 23 * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS 24 * IN THE SOFTWARE. 25 * 26 * $FreeBSD: head/sys/xen/xenbus/xenbusvar.h 255040 2013-08-29 19:52:18Z gibbs $ 27 */ 28 29/** 30 * \file xenbusvar.h 31 * 32 * \brief Datastructures and function declarations for usedby device 33 * drivers operating on the XenBus. 34 */ 35 36#ifndef _XEN_XENBUS_XENBUSVAR_H 37#define _XEN_XENBUS_XENBUSVAR_H 38 39#include <sys/queue.h> 40#include <sys/bus.h> 41#include <sys/eventhandler.h> 42#include <sys/malloc.h> 43#include <sys/sbuf.h> 44 45#include <machine/stdarg.h> 46 47#include <xen/xen-os.h> 48#include <xen/interface/grant_table.h> 49#include <xen/interface/io/xenbus.h> 50#include <xen/interface/io/xs_wire.h> 51 52#include <xen/xenstore/xenstorevar.h> 53 54/* XenBus allocations including XenStore data returned to clients. */ 55MALLOC_DECLARE(M_XENBUS); 56 57enum { 58 /** 59 * Path of this device node. 60 */ 61 XENBUS_IVAR_NODE, 62 63 /** 64 * The device type (e.g. vif, vbd). 65 */ 66 XENBUS_IVAR_TYPE, 67 68 /** 69 * The state of this device (not the otherend's state). 70 */ 71 XENBUS_IVAR_STATE, 72 73 /** 74 * Domain ID of the other end device. 75 */ 76 XENBUS_IVAR_OTHEREND_ID, 77 78 /** 79 * Path of the other end device. 80 */ 81 XENBUS_IVAR_OTHEREND_PATH 82}; 83 84/** 85 * Simplified accessors for xenbus devices 86 */ 87#define XENBUS_ACCESSOR(var, ivar, type) \ 88 __BUS_ACCESSOR(xenbus, var, XENBUS, ivar, type) 89 90XENBUS_ACCESSOR(node, NODE, const char *) 91XENBUS_ACCESSOR(type, TYPE, const char *) 92XENBUS_ACCESSOR(state, STATE, enum xenbus_state) 93XENBUS_ACCESSOR(otherend_id, OTHEREND_ID, int) 94XENBUS_ACCESSOR(otherend_path, OTHEREND_PATH, const char *) 95 96/** 97 * Return the state of a XenBus device. 98 * 99 * \param path The root XenStore path for the device. 100 * 101 * \return The current state of the device or XenbusStateClosed if no 102 * state can be read. 103 */ 104XenbusState xenbus_read_driver_state(const char *path); 105 106/** 107 * Return the state of the "other end" (peer) of a XenBus device. 108 * 109 * \param dev The XenBus device whose peer to query. 110 * 111 * \return The current state of the peer device or XenbusStateClosed if no 112 * state can be read. 113 */ 114static inline XenbusState 115xenbus_get_otherend_state(device_t dev) 116{ 117 return (xenbus_read_driver_state(xenbus_get_otherend_path(dev))); 118} 119 120/** 121 * Initialize and register a watch on the given path (client suplied storage). 122 * 123 * \param dev The XenBus device requesting the watch service. 124 * \param path The XenStore path of the object to be watched. The 125 * storage for this string must be stable for the lifetime 126 * of the watch. 127 * \param watch The watch object to use for this request. This object 128 * must be stable for the lifetime of the watch. 129 * \param callback The function to call when XenStore objects at or below 130 * path are modified. 131 * \param cb_data Client data that can be retrieved from the watch object 132 * during the callback. 133 * 134 * \return On success, 0. Otherwise an errno value indicating the 135 * type of failure. 136 * 137 * \note On error, the device 'dev' will be switched to the XenbusStateClosing 138 * state and the returned error is saved in the per-device error node 139 * for dev in the XenStore. 140 */ 141int xenbus_watch_path(device_t dev, char *path, 142 struct xs_watch *watch, 143 xs_watch_cb_t *callback, 144 uintptr_t cb_data); 145 146/** 147 * Initialize and register a watch at path/path2 in the XenStore. 148 * 149 * \param dev The XenBus device requesting the watch service. 150 * \param path The base XenStore path of the object to be watched. 151 * \param path2 The tail XenStore path of the object to be watched. 152 * \param watch The watch object to use for this request. This object 153 * must be stable for the lifetime of the watch. 154 * \param callback The function to call when XenStore objects at or below 155 * path are modified. 156 * \param cb_data Client data that can be retrieved from the watch object 157 * during the callback. 158 * 159 * \return On success, 0. Otherwise an errno value indicating the 160 * type of failure. 161 * 162 * \note On error, \a dev will be switched to the XenbusStateClosing 163 * state and the returned error is saved in the per-device error node 164 * for \a dev in the XenStore. 165 * 166 * Similar to xenbus_watch_path, however the storage for the path to the 167 * watched object is allocated from the heap and filled with "path '/' path2". 168 * Should a call to this function succeed, it is the callers responsibility 169 * to free watch->node using the M_XENBUS malloc type. 170 */ 171int xenbus_watch_path2(device_t dev, const char *path, 172 const char *path2, struct xs_watch *watch, 173 xs_watch_cb_t *callback, 174 uintptr_t cb_data); 175 176/** 177 * Grant access to the given ring_mfn to the peer of the given device. 178 * 179 * \param dev The device granting access to the ring page. 180 * \param ring_mfn The guest machine page number of the page to grant 181 * peer access rights. 182 * \param refp[out] The grant reference for the page. 183 * 184 * \return On success, 0. Otherwise an errno value indicating the 185 * type of failure. 186 * 187 * A successful call to xenbus_grant_ring should be paired with a call 188 * to gnttab_end_foreign_access() when foregn access to this page is no 189 * longer requried. 190 * 191 * \note On error, \a dev will be switched to the XenbusStateClosing 192 * state and the returned error is saved in the per-device error node 193 * for \a dev in the XenStore. 194 */ 195int xenbus_grant_ring(device_t dev, unsigned long ring_mfn, grant_ref_t *refp); 196 197/** 198 * Record the given errno, along with the given, printf-style, formatted 199 * message in dev's device specific error node in the XenStore. 200 * 201 * \param dev The device which encountered the error. 202 * \param err The errno value corresponding to the error. 203 * \param fmt Printf format string followed by a variable number of 204 * printf arguments. 205 */ 206void xenbus_dev_error(device_t dev, int err, const char *fmt, ...) 207 __attribute__((format(printf, 3, 4))); 208 209/** 210 * va_list version of xenbus_dev_error(). 211 * 212 * \param dev The device which encountered the error. 213 * \param err The errno value corresponding to the error. 214 * \param fmt Printf format string. 215 * \param ap Va_list of printf arguments. 216 */ 217void xenbus_dev_verror(device_t dev, int err, const char *fmt, va_list ap) 218 __attribute__((format(printf, 3, 0))); 219 220/** 221 * Equivalent to xenbus_dev_error(), followed by 222 * xenbus_set_state(dev, XenbusStateClosing). 223 * 224 * \param dev The device which encountered the error. 225 * \param err The errno value corresponding to the error. 226 * \param fmt Printf format string followed by a variable number of 227 * printf arguments. 228 */ 229void xenbus_dev_fatal(device_t dev, int err, const char *fmt, ...) 230 __attribute__((format(printf, 3, 4))); 231 232/** 233 * va_list version of xenbus_dev_fatal(). 234 * 235 * \param dev The device which encountered the error. 236 * \param err The errno value corresponding to the error. 237 * \param fmt Printf format string. 238 * \param ap Va_list of printf arguments. 239 */ 240void xenbus_dev_vfatal(device_t dev, int err, const char *fmt, va_list) 241 __attribute__((format(printf, 3, 0))); 242 243/** 244 * Convert a member of the xenbus_state enum into an ASCII string. 245 * 246 * /param state The XenBus state to lookup. 247 * 248 * /return A string representing state or, for unrecognized states, 249 * the string "Unknown". 250 */ 251const char *xenbus_strstate(enum xenbus_state state); 252 253/** 254 * Return the value of a XenBus device's "online" node within the XenStore. 255 * 256 * \param dev The XenBus device to query. 257 * 258 * \return The value of the "online" node for the device. If the node 259 * does not exist, 0 (offline) is returned. 260 */ 261int xenbus_dev_is_online(device_t dev); 262 263/** 264 * Default callback invoked when a change to the local XenStore sub-tree 265 * for a device is modified. 266 * 267 * \param dev The XenBus device whose tree was modified. 268 * \param path The tree relative sub-path to the modified node. The empty 269 * string indicates the root of the tree was destroyed. 270 */ 271void xenbus_localend_changed(device_t dev, const char *path); 272 273#include "xenbus_if.h" 274 275#endif /* _XEN_XENBUS_XENBUSVAR_H */ 276