1 /****************************************************************************** 2 * Copyright (C) 2005 XenSource Ltd 3 * 4 * This file may be distributed separately from the Linux kernel, or 5 * incorporated into other software packages, subject to the following license: 6 * 7 * Permission is hereby granted, free of charge, to any person obtaining a copy 8 * of this source file (the "Software"), to deal in the Software without 9 * restriction, including without limitation the rights to use, copy, modify, 10 * merge, publish, distribute, sublicense, and/or sell copies of the Software, 11 * and to permit persons to whom the Software is furnished to do so, subject to 12 * the following conditions: 13 * 14 * The above copyright notice and this permission notice shall be included in 15 * all copies or substantial portions of the Software. 16 * 17 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR 18 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, 19 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE 20 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER 21 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING 22 * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS 23 * IN THE SOFTWARE. 24 */ 25 26 /** 27 * \file xenbus.c 28 * 29 * \brief Client-facing interface for the Xenbus driver. 30 * 31 * In other words, the interface between the Xenbus and the device-specific 32 * code, be it the frontend or the backend of that driver. 33 */ 34 35 #if 0 36 #define DPRINTK(fmt, args...) \ 37 printk("xenbus_client (%s:%d) " fmt ".\n", __FUNCTION__, __LINE__, ##args) 38 #else 39 #define DPRINTK(fmt, args...) ((void)0) 40 #endif 41 42 #include <sys/cdefs.h> 43 __FBSDID("$FreeBSD$"); 44 45 #include <sys/cdefs.h> 46 #include <sys/param.h> 47 #include <sys/kernel.h> 48 #include <sys/types.h> 49 #include <sys/malloc.h> 50 #include <sys/libkern.h> 51 #include <sys/sbuf.h> 52 53 #include <xen/xen-os.h> 54 #include <xen/hypervisor.h> 55 #include <xen/evtchn.h> 56 #include <xen/gnttab.h> 57 #include <xen/xenbus/xenbusvar.h> 58 59 #include <machine/stdarg.h> 60 61 MALLOC_DEFINE(M_XENBUS, "xenbus", "XenBus Support"); 62 63 /*------------------------- Private Functions --------------------------------*/ 64 /** 65 * \brief Construct the error path corresponding to the given XenBus 66 * device. 67 * 68 * \param dev The XenBus device for which we are constructing an error path. 69 * 70 * \return On success, the contructed error path. Otherwise NULL. 71 * 72 * It is the caller's responsibility to free any returned error path 73 * node using the M_XENBUS malloc type. 74 */ 75 static char * 76 error_path(device_t dev) 77 { 78 char *path_buffer = malloc(strlen("error/") 79 + strlen(xenbus_get_node(dev)) + 1,M_XENBUS, M_WAITOK); 80 81 strcpy(path_buffer, "error/"); 82 strcpy(path_buffer + strlen("error/"), xenbus_get_node(dev)); 83 84 return (path_buffer); 85 } 86 87 /*--------------------------- Public Functions -------------------------------*/ 88 /*-------- API comments for these methods can be found in xenbusvar.h --------*/ 89 const char * 90 xenbus_strstate(XenbusState state) 91 { 92 static const char *const name[] = { 93 [ XenbusStateUnknown ] = "Unknown", 94 [ XenbusStateInitialising ] = "Initialising", 95 [ XenbusStateInitWait ] = "InitWait", 96 [ XenbusStateInitialised ] = "Initialised", 97 [ XenbusStateConnected ] = "Connected", 98 [ XenbusStateClosing ] = "Closing", 99 [ XenbusStateClosed ] = "Closed", 100 }; 101 102 return ((state < (XenbusStateClosed + 1)) ? name[state] : "INVALID"); 103 } 104 105 int 106 xenbus_watch_path(device_t dev, char *path, struct xs_watch *watch, 107 xs_watch_cb_t *callback, uintptr_t callback_data) 108 { 109 int error; 110 111 watch->node = path; 112 watch->callback = callback; 113 watch->callback_data = callback_data; 114 115 error = xs_register_watch(watch); 116 117 if (error) { 118 watch->node = NULL; 119 watch->callback = NULL; 120 xenbus_dev_fatal(dev, error, "adding watch on %s", path); 121 } 122 123 return (error); 124 } 125 126 int 127 xenbus_watch_path2(device_t dev, const char *path, 128 const char *path2, struct xs_watch *watch, 129 xs_watch_cb_t *callback, uintptr_t callback_data) 130 { 131 int error; 132 char *state = malloc(strlen(path) + 1 + strlen(path2) + 1, 133 M_XENBUS, M_WAITOK); 134 135 strcpy(state, path); 136 strcat(state, "/"); 137 strcat(state, path2); 138 139 error = xenbus_watch_path(dev, state, watch, callback, callback_data); 140 if (error) { 141 free(state,M_XENBUS); 142 } 143 144 return (error); 145 } 146 147 void 148 xenbus_dev_verror(device_t dev, int err, const char *fmt, va_list ap) 149 { 150 int ret; 151 unsigned int len; 152 char *printf_buffer = NULL, *path_buffer = NULL; 153 154 #define PRINTF_BUFFER_SIZE 4096 155 printf_buffer = malloc(PRINTF_BUFFER_SIZE,M_XENBUS, M_WAITOK); 156 157 len = sprintf(printf_buffer, "%i ", err); 158 ret = vsnprintf(printf_buffer+len, PRINTF_BUFFER_SIZE-len, fmt, ap); 159 160 KASSERT(len + ret <= PRINTF_BUFFER_SIZE-1, ("xenbus error message too big")); 161 device_printf(dev, "Error %s\n", printf_buffer); 162 path_buffer = error_path(dev); 163 164 if (path_buffer == NULL) { 165 printf("xenbus: failed to write error node for %s (%s)\n", 166 xenbus_get_node(dev), printf_buffer); 167 goto fail; 168 } 169 170 if (xs_write(XST_NIL, path_buffer, "error", printf_buffer) != 0) { 171 printf("xenbus: failed to write error node for %s (%s)\n", 172 xenbus_get_node(dev), printf_buffer); 173 goto fail; 174 } 175 176 fail: 177 if (printf_buffer) 178 free(printf_buffer,M_XENBUS); 179 if (path_buffer) 180 free(path_buffer,M_XENBUS); 181 } 182 183 void 184 xenbus_dev_error(device_t dev, int err, const char *fmt, ...) 185 { 186 va_list ap; 187 188 va_start(ap, fmt); 189 xenbus_dev_verror(dev, err, fmt, ap); 190 va_end(ap); 191 } 192 193 void 194 xenbus_dev_vfatal(device_t dev, int err, const char *fmt, va_list ap) 195 { 196 xenbus_dev_verror(dev, err, fmt, ap); 197 device_printf(dev, "Fatal error. Transitioning to Closing State\n"); 198 xenbus_set_state(dev, XenbusStateClosing); 199 } 200 201 void 202 xenbus_dev_fatal(device_t dev, int err, const char *fmt, ...) 203 { 204 va_list ap; 205 206 va_start(ap, fmt); 207 xenbus_dev_vfatal(dev, err, fmt, ap); 208 va_end(ap); 209 } 210 211 int 212 xenbus_grant_ring(device_t dev, unsigned long ring_mfn, grant_ref_t *refp) 213 { 214 int error; 215 216 error = gnttab_grant_foreign_access( 217 xenbus_get_otherend_id(dev), ring_mfn, 0, refp); 218 if (error) { 219 xenbus_dev_fatal(dev, error, "granting access to ring page"); 220 return (error); 221 } 222 223 return (0); 224 } 225 226 XenbusState 227 xenbus_read_driver_state(const char *path) 228 { 229 XenbusState result; 230 int error; 231 232 error = xs_gather(XST_NIL, path, "state", "%d", &result, NULL); 233 if (error) 234 result = XenbusStateClosed; 235 236 return (result); 237 } 238 239 int 240 xenbus_dev_is_online(device_t dev) 241 { 242 const char *path; 243 int error; 244 int value; 245 246 path = xenbus_get_node(dev); 247 error = xs_gather(XST_NIL, path, "online", "%d", &value, NULL); 248 if (error != 0) { 249 /* Default to not online. */ 250 value = 0; 251 } 252 253 return (value); 254 } 255 256 void 257 xenbus_localend_changed(device_t dev, const char *path) 258 { 259 } 260