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 * $FreeBSD$ 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. */ 55 MALLOC_DECLARE(M_XENBUS); 56 57 enum { 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 * xenbus_get_node 88 * xenbus_get_type 89 * xenbus_get_state 90 * xenbus_get_otherend_id 91 * xenbus_get_otherend_path 92 */ 93 #define XENBUS_ACCESSOR(var, ivar, type) \ 94 __BUS_ACCESSOR(xenbus, var, XENBUS, ivar, type) 95 96 XENBUS_ACCESSOR(node, NODE, const char *) 97 XENBUS_ACCESSOR(type, TYPE, const char *) 98 XENBUS_ACCESSOR(state, STATE, enum xenbus_state) 99 XENBUS_ACCESSOR(otherend_id, OTHEREND_ID, int) 100 XENBUS_ACCESSOR(otherend_path, OTHEREND_PATH, const char *) 101 102 /** 103 * Return the state of a XenBus device. 104 * 105 * \param path The root XenStore path for the device. 106 * 107 * \return The current state of the device or XenbusStateClosed if no 108 * state can be read. 109 */ 110 XenbusState xenbus_read_driver_state(const char *path); 111 112 /** 113 * Return the state of the "other end" (peer) of a XenBus device. 114 * 115 * \param dev The XenBus device whose peer to query. 116 * 117 * \return The current state of the peer device or XenbusStateClosed if no 118 * state can be read. 119 */ 120 static inline XenbusState 121 xenbus_get_otherend_state(device_t dev) 122 { 123 return (xenbus_read_driver_state(xenbus_get_otherend_path(dev))); 124 } 125 126 /** 127 * Initialize and register a watch on the given path (client suplied storage). 128 * 129 * \param dev The XenBus device requesting the watch service. 130 * \param path The XenStore path of the object to be watched. The 131 * storage for this string must be stable for the lifetime 132 * of the watch. 133 * \param watch The watch object to use for this request. This object 134 * must be stable for the lifetime of the watch. 135 * \param callback The function to call when XenStore objects at or below 136 * path are modified. 137 * \param cb_data Client data that can be retrieved from the watch object 138 * during the callback. 139 * 140 * \return On success, 0. Otherwise an errno value indicating the 141 * type of failure. 142 * 143 * \note On error, the device 'dev' will be switched to the XenbusStateClosing 144 * state and the returned error is saved in the per-device error node 145 * for dev in the XenStore. 146 */ 147 int xenbus_watch_path(device_t dev, char *path, 148 struct xs_watch *watch, 149 xs_watch_cb_t *callback, 150 uintptr_t cb_data); 151 152 /** 153 * Initialize and register a watch at path/path2 in the XenStore. 154 * 155 * \param dev The XenBus device requesting the watch service. 156 * \param path The base XenStore path of the object to be watched. 157 * \param path2 The tail XenStore path of the object to be watched. 158 * \param watch The watch object to use for this request. This object 159 * must be stable for the lifetime of the watch. 160 * \param callback The function to call when XenStore objects at or below 161 * path are modified. 162 * \param cb_data Client data that can be retrieved from the watch object 163 * during the callback. 164 * 165 * \return On success, 0. Otherwise an errno value indicating the 166 * type of failure. 167 * 168 * \note On error, \a dev will be switched to the XenbusStateClosing 169 * state and the returned error is saved in the per-device error node 170 * for \a dev in the XenStore. 171 * 172 * Similar to xenbus_watch_path, however the storage for the path to the 173 * watched object is allocated from the heap and filled with "path '/' path2". 174 * Should a call to this function succeed, it is the callers responsibility 175 * to free watch->node using the M_XENBUS malloc type. 176 */ 177 int xenbus_watch_path2(device_t dev, const char *path, 178 const char *path2, struct xs_watch *watch, 179 xs_watch_cb_t *callback, 180 uintptr_t cb_data); 181 182 /** 183 * Grant access to the given ring_mfn to the peer of the given device. 184 * 185 * \param dev The device granting access to the ring page. 186 * \param ring_mfn The guest machine page number of the page to grant 187 * peer access rights. 188 * \param refp[out] The grant reference for the page. 189 * 190 * \return On success, 0. Otherwise an errno value indicating the 191 * type of failure. 192 * 193 * A successful call to xenbus_grant_ring should be paired with a call 194 * to gnttab_end_foreign_access() when foregn access to this page is no 195 * longer requried. 196 * 197 * \note On error, \a dev will be switched to the XenbusStateClosing 198 * state and the returned error is saved in the per-device error node 199 * for \a dev in the XenStore. 200 */ 201 int xenbus_grant_ring(device_t dev, unsigned long ring_mfn, grant_ref_t *refp); 202 203 /** 204 * Record the given errno, along with the given, printf-style, formatted 205 * message in dev's device specific error node in the XenStore. 206 * 207 * \param dev The device which encountered the error. 208 * \param err The errno value corresponding to the error. 209 * \param fmt Printf format string followed by a variable number of 210 * printf arguments. 211 */ 212 void xenbus_dev_error(device_t dev, int err, const char *fmt, ...) 213 __attribute__((format(printf, 3, 4))); 214 215 /** 216 * va_list version of xenbus_dev_error(). 217 * 218 * \param dev The device which encountered the error. 219 * \param err The errno value corresponding to the error. 220 * \param fmt Printf format string. 221 * \param ap Va_list of printf arguments. 222 */ 223 void xenbus_dev_verror(device_t dev, int err, const char *fmt, va_list ap) 224 __attribute__((format(printf, 3, 0))); 225 226 /** 227 * Equivalent to xenbus_dev_error(), followed by 228 * xenbus_set_state(dev, XenbusStateClosing). 229 * 230 * \param dev The device which encountered the error. 231 * \param err The errno value corresponding to the error. 232 * \param fmt Printf format string followed by a variable number of 233 * printf arguments. 234 */ 235 void xenbus_dev_fatal(device_t dev, int err, const char *fmt, ...) 236 __attribute__((format(printf, 3, 4))); 237 238 /** 239 * va_list version of xenbus_dev_fatal(). 240 * 241 * \param dev The device which encountered the error. 242 * \param err The errno value corresponding to the error. 243 * \param fmt Printf format string. 244 * \param ap Va_list of printf arguments. 245 */ 246 void xenbus_dev_vfatal(device_t dev, int err, const char *fmt, va_list) 247 __attribute__((format(printf, 3, 0))); 248 249 /** 250 * Convert a member of the xenbus_state enum into an ASCII string. 251 * 252 * /param state The XenBus state to lookup. 253 * 254 * /return A string representing state or, for unrecognized states, 255 * the string "Unknown". 256 */ 257 const char *xenbus_strstate(enum xenbus_state state); 258 259 /** 260 * Return the value of a XenBus device's "online" node within the XenStore. 261 * 262 * \param dev The XenBus device to query. 263 * 264 * \return The value of the "online" node for the device. If the node 265 * does not exist, 0 (offline) is returned. 266 */ 267 int xenbus_dev_is_online(device_t dev); 268 269 /** 270 * Default callback invoked when a change to the local XenStore sub-tree 271 * for a device is modified. 272 * 273 * \param dev The XenBus device whose tree was modified. 274 * \param path The tree relative sub-path to the modified node. The empty 275 * string indicates the root of the tree was destroyed. 276 */ 277 void xenbus_localend_changed(device_t dev, const char *path); 278 279 #include "xenbus_if.h" 280 281 #endif /* _XEN_XENBUS_XENBUSVAR_H */ 282