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 <contrib/xen/grant_table.h> 49 #include <contrib/xen/io/xenbus.h> 50 #include <contrib/xen/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 * Grant access to the given ring_mfn to the peer of the given device. 128 * 129 * \param dev The device granting access to the ring page. 130 * \param ring_mfn The guest machine page number of the page to grant 131 * peer access rights. 132 * \param refp[out] The grant reference for the page. 133 * 134 * \return On success, 0. Otherwise an errno value indicating the 135 * type of failure. 136 * 137 * A successful call to xenbus_grant_ring should be paired with a call 138 * to gnttab_end_foreign_access() when foregn access to this page is no 139 * longer requried. 140 * 141 * \note On error, \a dev will be switched to the XenbusStateClosing 142 * state and the returned error is saved in the per-device error node 143 * for \a dev in the XenStore. 144 */ 145 int xenbus_grant_ring(device_t dev, unsigned long ring_mfn, grant_ref_t *refp); 146 147 /** 148 * Record the given errno, along with the given, printf-style, formatted 149 * message in dev's device specific error node in the XenStore. 150 * 151 * \param dev The device which encountered the error. 152 * \param err The errno value corresponding to the error. 153 * \param fmt Printf format string followed by a variable number of 154 * printf arguments. 155 */ 156 void xenbus_dev_error(device_t dev, int err, const char *fmt, ...) 157 __attribute__((format(printf, 3, 4))); 158 159 /** 160 * va_list version of xenbus_dev_error(). 161 * 162 * \param dev The device which encountered the error. 163 * \param err The errno value corresponding to the error. 164 * \param fmt Printf format string. 165 * \param ap Va_list of printf arguments. 166 */ 167 void xenbus_dev_verror(device_t dev, int err, const char *fmt, va_list ap) 168 __attribute__((format(printf, 3, 0))); 169 170 /** 171 * Equivalent to xenbus_dev_error(), followed by 172 * xenbus_set_state(dev, XenbusStateClosing). 173 * 174 * \param dev The device which encountered the error. 175 * \param err The errno value corresponding to the error. 176 * \param fmt Printf format string followed by a variable number of 177 * printf arguments. 178 */ 179 void xenbus_dev_fatal(device_t dev, int err, const char *fmt, ...) 180 __attribute__((format(printf, 3, 4))); 181 182 /** 183 * va_list version of xenbus_dev_fatal(). 184 * 185 * \param dev The device which encountered the error. 186 * \param err The errno value corresponding to the error. 187 * \param fmt Printf format string. 188 * \param ap Va_list of printf arguments. 189 */ 190 void xenbus_dev_vfatal(device_t dev, int err, const char *fmt, va_list) 191 __attribute__((format(printf, 3, 0))); 192 193 /** 194 * Convert a member of the xenbus_state enum into an ASCII string. 195 * 196 * /param state The XenBus state to lookup. 197 * 198 * /return A string representing state or, for unrecognized states, 199 * the string "Unknown". 200 */ 201 const char *xenbus_strstate(enum xenbus_state state); 202 203 /** 204 * Return the value of a XenBus device's "online" node within the XenStore. 205 * 206 * \param dev The XenBus device to query. 207 * 208 * \return The value of the "online" node for the device. If the node 209 * does not exist, 0 (offline) is returned. 210 */ 211 int xenbus_dev_is_online(device_t dev); 212 213 /** 214 * Default callback invoked when a change to the local XenStore sub-tree 215 * for a device is modified. 216 * 217 * \param dev The XenBus device whose tree was modified. 218 * \param path The tree relative sub-path to the modified node. The empty 219 * string indicates the root of the tree was destroyed. 220 */ 221 void xenbus_localend_changed(device_t dev, const char *path); 222 223 #include "xenbus_if.h" 224 225 #endif /* _XEN_XENBUS_XENBUSVAR_H */ 226