1 /* $NetBSD: xenbus.h,v 1.9 2008/04/16 18:41:48 cegger Exp $ */ 2 /****************************************************************************** 3 * xenbus.h 4 * 5 * Talks to Xen Store to figure out what devices we have. 6 * 7 * Copyright (C) 2005 Rusty Russell, IBM Corporation 8 * Copyright (C) 2005 XenSource Ltd. 9 * 10 * This file may be distributed separately from the Linux kernel, or 11 * incorporated into other software packages, subject to the following license: 12 * 13 * Permission is hereby granted, free of charge, to any person obtaining a copy 14 * of this source file (the "Software"), to deal in the Software without 15 * restriction, including without limitation the rights to use, copy, modify, 16 * merge, publish, distribute, sublicense, and/or sell copies of the Software, 17 * and to permit persons to whom the Software is furnished to do so, subject to 18 * the following conditions: 19 * 20 * The above copyright notice and this permission notice shall be included in 21 * all copies or substantial portions of the Software. 22 * 23 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR 24 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, 25 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE 26 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER 27 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING 28 * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS 29 * IN THE SOFTWARE. 30 */ 31 32 #ifndef _ASM_XEN_XENBUS_H 33 #define _ASM_XEN_XENBUS_H 34 35 #include <sys/device.h> 36 #include <sys/queue.h> 37 #include <xen/xen3-public/io/xenbus.h> 38 #include <xen/xen3-public/io/xs_wire.h> 39 40 /* xenbus to hypervisor attach */ 41 struct xenbus_attach_args { 42 const char *xa_device; 43 int xa_handle; 44 }; 45 46 /* devices to xenbus attach */ 47 struct xenbusdev_attach_args { 48 const char *xa_type; 49 int xa_id; 50 struct xenbus_device *xa_xbusd; 51 }; 52 53 /* Register callback to watch this node. */ 54 struct xenbus_watch { 55 SLIST_ENTRY(xenbus_watch) watch_next; 56 57 /* Path being watched. */ 58 char *node; 59 60 /* Callback (executed in a process context with no locks held). */ 61 void (*xbw_callback)(struct xenbus_watch *, 62 const char **vec, unsigned int len); 63 struct xenbus_device *xbw_dev; 64 }; 65 66 67 /* 68 * A xenbus device. Note that the malloced memory will be larger than 69 * sizeof(xenbus_device) to have the storage for xbusd_path, so xbusd_path 70 * has to be the last entry. 71 */ 72 typedef enum { 73 XENBUS_FRONTEND_DEVICE, 74 XENBUS_BACKEND_DEVICE 75 } xenbusdev_type_t; 76 77 struct xenbus_device { 78 SLIST_ENTRY(xenbus_device) xbusd_entries; 79 char *xbusd_otherend; /* the otherend path */ 80 int xbusd_otherend_id; /* the otherend's id */ 81 /* callback for otherend change */ 82 void (*xbusd_otherend_changed)(void *, XenbusState); 83 xenbusdev_type_t xbusd_type; 84 union { 85 struct { 86 device_t f_dev; 87 } f; 88 struct { 89 void *b_cookie; /* private to backend driver */ 90 int (*b_detach)(void *); 91 } b; 92 } xbusd_u; 93 int xbusd_has_error; 94 /* for xenbus internal use */ 95 struct xenbus_watch xbusd_otherend_watch; 96 const char xbusd_path[1]; /* our path */ 97 }; 98 99 /* 100 * frontend devices use the normal autoconf(9) framework to attach. 101 * backend drivers need something more clever because we want the 102 * domain's name or uid in the device's name. Each backend driver registers 103 * to xenbus. 104 */ 105 106 struct xenbus_backend_driver { 107 SLIST_ENTRY(xenbus_backend_driver) xbakd_entries; 108 int (*xbakd_create) (struct xenbus_device *); /* called for new devs */ 109 const char *xbakd_type; /* device type we register for */ 110 }; 111 112 void xenbus_backend_register(struct xenbus_backend_driver *); 113 114 struct xenbus_transaction; 115 116 int xenbus_directory(struct xenbus_transaction *t, 117 const char *dir, const char *node, unsigned int *num, 118 char ***); 119 int xenbus_read(struct xenbus_transaction *t, 120 const char *dir, const char *node, unsigned int *len, 121 char **); 122 int xenbus_read_ul(struct xenbus_transaction *, 123 const char *, const char *, unsigned long *, int); 124 int xenbus_read_ull(struct xenbus_transaction *, 125 const char *, const char *, unsigned long long *, int); 126 int xenbus_write(struct xenbus_transaction *t, 127 const char *dir, const char *node, const char *string); 128 int xenbus_mkdir(struct xenbus_transaction *t, 129 const char *dir, const char *node); 130 int xenbus_exists(struct xenbus_transaction *t, 131 const char *dir, const char *node); 132 int xenbus_rm(struct xenbus_transaction *t, const char *dir, const char *node); 133 struct xenbus_transaction *xenbus_transaction_start(void); 134 int xenbus_transaction_end(struct xenbus_transaction *t, int abort); 135 136 /* Single read and scanf: returns -errno or num scanned if > 0. */ 137 int xenbus_scanf(struct xenbus_transaction *t, 138 const char *dir, const char *node, const char *fmt, ...) 139 __attribute__((format(scanf, 4, 5))); 140 141 /* Single printf and write: returns -errno or 0. */ 142 int xenbus_printf(struct xenbus_transaction *t, 143 const char *dir, const char *node, const char *fmt, ...) 144 __attribute__((format(printf, 4, 5))); 145 146 /* Generic read function: NULL-terminated triples of name, 147 * sprintf-style type string, and pointer. Returns 0 or errno.*/ 148 int xenbus_gather(struct xenbus_transaction *t, const char *dir, ...); 149 150 /* notifer routines for when the xenstore comes up */ 151 // XXX int register_xenstore_notifier(struct notifier_block *nb); 152 // XXX void unregister_xenstore_notifier(struct notifier_block *nb); 153 154 int register_xenbus_watch(struct xenbus_watch *watch); 155 void unregister_xenbus_watch(struct xenbus_watch *watch); 156 void xs_suspend(void); 157 void xs_resume(void); 158 159 /* Used by xenbus_dev to borrow kernel's store connection. */ 160 int xenbus_dev_request_and_reply(struct xsd_sockmsg *msg, void **); 161 162 /* Called from xen core code. */ 163 void xenbus_suspend(void); 164 void xenbus_resume(void); 165 166 void xenbus_probe(void *); 167 168 int xenbus_free_device(struct xenbus_device *); 169 170 #define XENBUS_IS_ERR_READ(str) ({ \ 171 if (!IS_ERR(str) && strlen(str) == 0) { \ 172 kfree(str); \ 173 str = ERR_PTR(-ERANGE); \ 174 } \ 175 IS_ERR(str); \ 176 }) 177 178 #define XENBUS_EXIST_ERR(err) ((err) == -ENOENT || (err) == -ERANGE) 179 180 181 /** 182 * Register a watch on the given path, using the given xenbus_watch structure 183 * for storage, and the given callback function as the callback. Return 0 on 184 * success, or -errno on error. On success, the given path will be saved as 185 * watch->node, and remains the caller's to free. On error, watch->node will 186 * be NULL, the device will switch to XenbusStateClosing, and the error will 187 * be saved in the store. 188 */ 189 int xenbus_watch_path(struct xenbus_device *dev, char *path, 190 struct xenbus_watch *watch, 191 void (*callback)(struct xenbus_watch *, 192 const char **, unsigned int)); 193 194 195 /** 196 * Register a watch on the given path/path2, using the given xenbus_watch 197 * structure for storage, and the given callback function as the callback. 198 * Return 0 on success, or -errno on error. On success, the watched path 199 * (path/path2) will be saved as watch->node, and becomes the caller's to 200 * kfree(). On error, watch->node will be NULL, so the caller has nothing to 201 * free, the device will switch to XenbusStateClosing, and the error will be 202 * saved in the store. 203 */ 204 int xenbus_watch_path2(struct xenbus_device *dev, const char *path, 205 const char *path2, struct xenbus_watch *watch, 206 void (*callback)(struct xenbus_watch *, 207 const char **, unsigned int)); 208 209 210 /** 211 * Advertise in the store a change of the given driver to the given new_state. 212 * Perform the change inside the given transaction xbt. xbt may be NULL, in 213 * which case this is performed inside its own transaction. Return 0 on 214 * success, or -errno on error. On error, the device will switch to 215 * XenbusStateClosing, and the error will be saved in the store. 216 */ 217 int xenbus_switch_state(struct xenbus_device *dev, 218 struct xenbus_transaction *xbt, 219 XenbusState new_state); 220 221 222 /** 223 * Grant access to the given ring_mfn to the peer of the given device. Return 224 * 0 on success, or -errno on error. On error, the device will switch to 225 * XenbusStateClosing, and the error will be saved in the store. 226 */ 227 int xenbus_grant_ring(struct xenbus_device *, paddr_t, grant_ref_t *); 228 229 230 /** 231 * Allocate an event channel for the given xenbus_device, assigning the newly 232 * created local port to *port. Return 0 on success, or -errno on error. On 233 * error, the device will switch to XenbusStateClosing, and the error will be 234 * saved in the store. 235 */ 236 int xenbus_alloc_evtchn(struct xenbus_device *dev, int *port); 237 238 239 /** 240 * Return the state of the driver rooted at the given store path, or 241 * XenbusStateClosed if no state can be read. 242 */ 243 XenbusState xenbus_read_driver_state(const char *path); 244 245 246 /*** 247 * Report the given negative errno into the store, along with the given 248 * formatted message. 249 */ 250 void xenbus_dev_error(struct xenbus_device *dev, int err, const char *fmt, 251 ...); 252 253 254 /*** 255 * Equivalent to xenbus_dev_error(dev, err, fmt, args), followed by 256 * xenbus_switch_state(dev, NULL, XenbusStateClosing) to schedule an orderly 257 * closedown of this driver and its peer. 258 */ 259 void xenbus_dev_fatal(struct xenbus_device *dev, int err, const char *fmt, 260 ...); 261 262 263 #endif /* _ASM_XEN_XENBUS_H */ 264 265 /* 266 * Local variables: 267 * c-file-style: "linux" 268 * indent-tabs-mode: t 269 * c-indent-level: 8 270 * c-basic-offset: 8 271 * tab-width: 8 272 * End: 273 */ 274