1 /* $NetBSD: xenbus.h,v 1.25 2020/04/25 15:26:17 bouyer 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/bus.h> 37 #include <sys/queue.h> 38 #include <xen/include/public/xen.h> 39 #include <xen/include/public/io/xenbus.h> 40 #include <xen/include/public/io/xs_wire.h> 41 #include <xen/include/public/grant_table.h> /* for grant_ref_t */ 42 43 /* xenbus to hypervisor attach */ 44 struct xenbus_attach_args { 45 const char *xa_device; 46 int xa_handle; 47 bus_dma_tag_t xa_dmat; 48 }; 49 50 /* devices to xenbus attach */ 51 struct xenbusdev_attach_args { 52 const char *xa_type; 53 int xa_id; 54 struct xenbus_device *xa_xbusd; 55 }; 56 57 /* Register callback to watch this node. */ 58 struct xenbus_watch { 59 SLIST_ENTRY(xenbus_watch) watch_next; 60 61 /* Path being watched. */ 62 char *node; 63 size_t node_sz; 64 65 /* Callback (executed in a process context with no locks held). */ 66 void (*xbw_callback)(struct xenbus_watch *, 67 const char **vec, unsigned int len); 68 struct xenbus_device *xbw_dev; 69 }; 70 71 72 /* 73 * A xenbus device. Note that the malloced memory will be larger than 74 * sizeof(xenbus_device) to have the storage for xbusd_path, so xbusd_path 75 * has to be the last entry. 76 */ 77 typedef enum { 78 XENBUS_FRONTEND_DEVICE, 79 XENBUS_BACKEND_DEVICE 80 } xenbusdev_type_t; 81 82 struct xenbus_device { 83 SLIST_ENTRY(xenbus_device) xbusd_entries; 84 char xbusd_otherend[64]; /* the otherend path (size arbitrary) */ 85 int xbusd_otherend_id; /* the otherend's id */ 86 /* callback for otherend change */ 87 void (*xbusd_otherend_changed)(void *, XenbusState); 88 xenbusdev_type_t xbusd_type; 89 union { 90 struct { 91 device_t f_dev; 92 } f; 93 struct { 94 void *b_cookie; /* private to backend driver */ 95 int (*b_detach)(void *); 96 } b; 97 } xbusd_u; 98 int xbusd_has_error; 99 /* for xenbus internal use */ 100 struct xenbus_watch xbusd_otherend_watch; 101 size_t xbusd_sz; /* size of allocated structure */ 102 bus_dma_tag_t xbusd_dmat; 103 const char xbusd_path[1]; /* our path */ 104 }; 105 106 /* 107 * frontend devices use the normal autoconf(9) framework to attach. 108 * backend drivers need something more clever because we want the 109 * domain's name or uid in the device's name. Each backend driver registers 110 * to xenbus. 111 */ 112 113 struct xenbus_backend_driver { 114 SLIST_ENTRY(xenbus_backend_driver) xbakd_entries; 115 int (*xbakd_create) (struct xenbus_device *); /* called for new devs */ 116 const char *xbakd_type; /* device type we register for */ 117 }; 118 119 void xenbus_backend_register(struct xenbus_backend_driver *); 120 121 struct xenbus_transaction; 122 123 int xenbus_directory(struct xenbus_transaction *t, 124 const char *dir, const char *node, unsigned int *num, 125 char ***); 126 void xenbus_directory_free(unsigned int, char **); 127 int xenbus_read(struct xenbus_transaction *, 128 const char *, const char *, char *, size_t); 129 int xenbus_read_ul(struct xenbus_transaction *, 130 const char *, const char *, unsigned long *, int); 131 int xenbus_read_ull(struct xenbus_transaction *, 132 const char *, const char *, unsigned long long *, int); 133 int xenbus_write(struct xenbus_transaction *t, 134 const char *dir, const char *node, const char *string); 135 int xenbus_mkdir(struct xenbus_transaction *t, 136 const char *dir, const char *node); 137 int xenbus_exists(struct xenbus_transaction *t, 138 const char *dir, const char *node); 139 int xenbus_rm(struct xenbus_transaction *t, const char *dir, const char *node); 140 struct xenbus_transaction *xenbus_transaction_start(void); 141 int xenbus_transaction_end(struct xenbus_transaction *t, int abort); 142 143 /* Single printf and write: returns -errno or 0. */ 144 int xenbus_printf(struct xenbus_transaction *t, 145 const char *dir, const char *node, const char *fmt, ...) 146 __attribute__((format(printf, 4, 5))); 147 148 /* notifer routines for when the xenstore comes up */ 149 // XXX int register_xenstore_notifier(struct notifier_block *nb); 150 // XXX void unregister_xenstore_notifier(struct notifier_block *nb); 151 152 int register_xenbus_watch(struct xenbus_watch *watch); 153 void unregister_xenbus_watch(struct xenbus_watch *watch); 154 void xs_suspend(void); 155 void xs_resume(void); 156 157 /* Used by xenbus_dev to borrow kernel's store connection. */ 158 int xenbus_dev_request_and_reply(struct xsd_sockmsg *msg, void **); 159 void xenbus_dev_reply_free(struct xsd_sockmsg *msg, void *); 160 161 void xenbus_probe(void *); 162 163 int xenbus_free_device(struct xenbus_device *); 164 165 #define XENBUS_IS_ERR_READ(str) ({ \ 166 if (!IS_ERR(str) && strlen(str) == 0) { \ 167 kfree(str); \ 168 str = ERR_PTR(-ERANGE); \ 169 } \ 170 IS_ERR(str); \ 171 }) 172 173 #define XENBUS_EXIST_ERR(err) ((err) == -ENOENT || (err) == -ERANGE) 174 175 176 /** 177 * Register a watch on the given path/path2, using the given xenbus_watch 178 * structure for storage, and the given callback function as the callback. 179 * Return 0 on success, or -errno on error. On success, the watched path 180 * (path/path2) will be saved as watch->node, and becomes the caller's to 181 * kfree(). On error, watch->node will be NULL, so the caller has nothing to 182 * free, the device will switch to XenbusStateClosing, and the error will be 183 * saved in the store. 184 */ 185 int xenbus_watch_path2(struct xenbus_device *dev, const char *path, 186 const char *path2, struct xenbus_watch *watch, 187 void (*callback)(struct xenbus_watch *, 188 const char **, unsigned int)); 189 190 /* Unregister the watch, and free associated internal structures. */ 191 void xenbus_unwatch_path(struct xenbus_watch *); 192 193 /** 194 * Advertise in the store a change of the given driver to the given new_state. 195 * Perform the change inside the given transaction xbt. xbt may be NULL, in 196 * which case this is performed inside its own transaction. Return 0 on 197 * success, or -errno on error. On error, the device will switch to 198 * XenbusStateClosing, and the error will be saved in the store. 199 */ 200 int xenbus_switch_state(struct xenbus_device *dev, 201 struct xenbus_transaction *xbt, 202 XenbusState new_state); 203 204 205 /** 206 * Grant access to the given ring_mfn to the peer of the given device. Return 207 * 0 on success, or -errno on error. On error, the device will switch to 208 * XenbusStateClosing, and the error will be saved in the store. 209 */ 210 int xenbus_grant_ring(struct xenbus_device *, paddr_t, grant_ref_t *); 211 212 213 /** 214 * Allocate an event channel for the given xenbus_device, assigning the newly 215 * created local port to *port. Return 0 on success, or -errno on error. On 216 * error, the device will switch to XenbusStateClosing, and the error will be 217 * saved in the store. 218 */ 219 int xenbus_alloc_evtchn(struct xenbus_device *dev, int *port); 220 221 222 /** 223 * Return the state of the driver rooted at the given store path, or 224 * XenbusStateClosed if no state can be read. 225 */ 226 XenbusState xenbus_read_driver_state(const char *path); 227 228 229 /*** 230 * Report the given negative errno into the store, along with the given 231 * formatted message. 232 */ 233 void xenbus_dev_error(struct xenbus_device *dev, int err, const char *fmt, 234 ...); 235 236 237 /*** 238 * Equivalent to xenbus_dev_error(dev, err, fmt, args), followed by 239 * xenbus_switch_state(dev, NULL, XenbusStateClosing) to schedule an orderly 240 * closedown of this driver and its peer. 241 */ 242 void xenbus_dev_fatal(struct xenbus_device *dev, int err, const char *fmt, 243 ...); 244 245 bool xenbus_device_suspend(struct xenbus_device *); 246 bool xenbus_device_resume(struct xenbus_device *); 247 248 #endif /* _ASM_XEN_XENBUS_H */ 249 250 /* 251 * Local variables: 252 * c-file-style: "linux" 253 * indent-tabs-mode: t 254 * c-indent-level: 8 255 * c-basic-offset: 8 256 * tab-width: 8 257 * End: 258 */ 259
Indexes created Sun Sep 21 20:09:37 GMT 2025