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 44 #include <sys/param.h> 45 #include <sys/kernel.h> 46 #include <sys/types.h> 47 #include <sys/malloc.h> 48 #include <sys/libkern.h> 49 #include <sys/sbuf.h> 50 #include <sys/stdarg.h> 51 52 #include <xen/xen-os.h> 53 #include <xen/hypervisor.h> 54 #include <xen/evtchn.h> 55 #include <xen/gnttab.h> 56 #include <xen/xenbus/xenbusvar.h> 57 58 MALLOC_DEFINE(M_XENBUS, "xenbus", "XenBus Support"); 59 60 /*------------------------- Private Functions --------------------------------*/ 61 /** 62 * \brief Construct the error path corresponding to the given XenBus 63 * device. 64 * 65 * \param dev The XenBus device for which we are constructing an error path. 66 * 67 * \return On success, the contructed error path. Otherwise NULL. 68 * 69 * It is the caller's responsibility to free any returned error path 70 * node using the M_XENBUS malloc type. 71 */ 72 static char * 73 error_path(device_t dev) 74 { 75 char *path_buffer = malloc(strlen("error/") 76 + strlen(xenbus_get_node(dev)) + 1,M_XENBUS, M_WAITOK); 77 78 strcpy(path_buffer, "error/"); 79 strcpy(path_buffer + strlen("error/"), xenbus_get_node(dev)); 80 81 return (path_buffer); 82 } 83 84 /*--------------------------- Public Functions -------------------------------*/ 85 /*-------- API comments for these methods can be found in xenbusvar.h --------*/ 86 const char * 87 xenbus_strstate(XenbusState state) 88 { 89 static const char *const name[] = { 90 [ XenbusStateUnknown ] = "Unknown", 91 [ XenbusStateInitialising ] = "Initialising", 92 [ XenbusStateInitWait ] = "InitWait", 93 [ XenbusStateInitialised ] = "Initialised", 94 [ XenbusStateConnected ] = "Connected", 95 [ XenbusStateClosing ] = "Closing", 96 [ XenbusStateClosed ] = "Closed", 97 }; 98 99 return ((state < (XenbusStateClosed + 1)) ? name[state] : "INVALID"); 100 } 101 102 void 103 xenbus_dev_verror(device_t dev, int err, const char *fmt, va_list ap) 104 { 105 int ret __diagused; 106 unsigned int len; 107 char *printf_buffer = NULL, *path_buffer = NULL; 108 109 #define PRINTF_BUFFER_SIZE 4096 110 printf_buffer = malloc(PRINTF_BUFFER_SIZE,M_XENBUS, M_WAITOK); 111 112 len = sprintf(printf_buffer, "%i ", err); 113 ret = vsnprintf(printf_buffer+len, PRINTF_BUFFER_SIZE-len, fmt, ap); 114 115 KASSERT(len + ret <= PRINTF_BUFFER_SIZE-1, ("xenbus error message too big")); 116 device_printf(dev, "Error %s\n", printf_buffer); 117 path_buffer = error_path(dev); 118 119 if (path_buffer == NULL) { 120 printf("xenbus: failed to write error node for %s (%s)\n", 121 xenbus_get_node(dev), printf_buffer); 122 goto fail; 123 } 124 125 if (xs_write(XST_NIL, path_buffer, "error", printf_buffer) != 0) { 126 printf("xenbus: failed to write error node for %s (%s)\n", 127 xenbus_get_node(dev), printf_buffer); 128 goto fail; 129 } 130 131 fail: 132 if (printf_buffer) 133 free(printf_buffer,M_XENBUS); 134 if (path_buffer) 135 free(path_buffer,M_XENBUS); 136 } 137 138 void 139 xenbus_dev_error(device_t dev, int err, const char *fmt, ...) 140 { 141 va_list ap; 142 143 va_start(ap, fmt); 144 xenbus_dev_verror(dev, err, fmt, ap); 145 va_end(ap); 146 } 147 148 void 149 xenbus_dev_vfatal(device_t dev, int err, const char *fmt, va_list ap) 150 { 151 xenbus_dev_verror(dev, err, fmt, ap); 152 device_printf(dev, "Fatal error. Transitioning to Closing State\n"); 153 xenbus_set_state(dev, XenbusStateClosing); 154 } 155 156 void 157 xenbus_dev_fatal(device_t dev, int err, const char *fmt, ...) 158 { 159 va_list ap; 160 161 va_start(ap, fmt); 162 xenbus_dev_vfatal(dev, err, fmt, ap); 163 va_end(ap); 164 } 165 166 int 167 xenbus_grant_ring(device_t dev, unsigned long ring_mfn, grant_ref_t *refp) 168 { 169 int error; 170 171 error = gnttab_grant_foreign_access( 172 xenbus_get_otherend_id(dev), ring_mfn, 0, refp); 173 if (error) { 174 xenbus_dev_fatal(dev, error, "granting access to ring page"); 175 return (error); 176 } 177 178 return (0); 179 } 180 181 XenbusState 182 xenbus_read_driver_state(const char *path) 183 { 184 XenbusState result; 185 int error; 186 187 error = xs_gather(XST_NIL, path, "state", "%d", &result, NULL); 188 if (error) 189 result = XenbusStateClosed; 190 191 return (result); 192 } 193 194 int 195 xenbus_dev_is_online(device_t dev) 196 { 197 const char *path; 198 int error; 199 int value; 200 201 path = xenbus_get_node(dev); 202 error = xs_gather(XST_NIL, path, "online", "%d", &value, NULL); 203 if (error != 0) { 204 /* Default to not online. */ 205 value = 0; 206 } 207 208 return (value); 209 } 210 211 void 212 xenbus_localend_changed(device_t dev, const char *path) 213 { 214 } 215