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: releng/9.0/sys/xen/xenbus/xenbusvar.h 222975 2011-06-11 04:59:01Z gibbs $
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 #include <machine/xen/xen-os.h>
47
48 #include <xen/interface/grant_table.h>
49 #include <xen/interface/io/xenbus.h>
50 #include <xen/interface/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 #define XENBUS_ACCESSOR(var, ivar, type) \
88 __BUS_ACCESSOR(xenbus, var, XENBUS, ivar, type)
89
90 XENBUS_ACCESSOR(node, NODE, const char *)
91 XENBUS_ACCESSOR(type, TYPE, const char *)
92 XENBUS_ACCESSOR(state, STATE, enum xenbus_state)
93 XENBUS_ACCESSOR(otherend_id, OTHEREND_ID, int)
94 XENBUS_ACCESSOR(otherend_path, OTHEREND_PATH, const char *)
95
96 /**
97 * Return the state of a XenBus device.
98 *
99 * \param path The root XenStore path for the device.
100 *
101 * \return The current state of the device or XenbusStateClosed if no
102 * state can be read.
103 */
104 XenbusState xenbus_read_driver_state(const char *path);
105
106 /**
107 * Initialize and register a watch on the given path (client suplied storage).
108 *
109 * \param dev The XenBus device requesting the watch service.
110 * \param path The XenStore path of the object to be watched. The
111 * storage for this string must be stable for the lifetime
112 * of the watch.
113 * \param watch The watch object to use for this request. This object
114 * must be stable for the lifetime of the watch.
115 * \param callback The function to call when XenStore objects at or below
116 * path are modified.
117 * \param cb_data Client data that can be retrieved from the watch object
118 * during the callback.
119 *
120 * \return On success, 0. Otherwise an errno value indicating the
121 * type of failure.
122 *
123 * \note On error, the device 'dev' will be switched to the XenbusStateClosing
124 * state and the returned error is saved in the per-device error node
125 * for dev in the XenStore.
126 */
127 int xenbus_watch_path(device_t dev, char *path,
128 struct xs_watch *watch,
129 xs_watch_cb_t *callback,
130 uintptr_t cb_data);
131
132 /**
133 * Initialize and register a watch at path/path2 in the XenStore.
134 *
135 * \param dev The XenBus device requesting the watch service.
136 * \param path The base XenStore path of the object to be watched.
137 * \param path2 The tail XenStore path of the object to be watched.
138 * \param watch The watch object to use for this request. This object
139 * must be stable for the lifetime of the watch.
140 * \param callback The function to call when XenStore objects at or below
141 * path are modified.
142 * \param cb_data Client data that can be retrieved from the watch object
143 * during the callback.
144 *
145 * \return On success, 0. Otherwise an errno value indicating the
146 * type of failure.
147 *
148 * \note On error, \a dev will be switched to the XenbusStateClosing
149 * state and the returned error is saved in the per-device error node
150 * for \a dev in the XenStore.
151 *
152 * Similar to xenbus_watch_path, however the storage for the path to the
153 * watched object is allocated from the heap and filled with "path '/' path2".
154 * Should a call to this function succeed, it is the callers responsibility
155 * to free watch->node using the M_XENBUS malloc type.
156 */
157 int xenbus_watch_path2(device_t dev, const char *path,
158 const char *path2, struct xs_watch *watch,
159 xs_watch_cb_t *callback,
160 uintptr_t cb_data);
161
162 /**
163 * Grant access to the given ring_mfn to the peer of the given device.
164 *
165 * \param dev The device granting access to the ring page.
166 * \param ring_mfn The guest machine page number of the page to grant
167 * peer access rights.
168 * \param refp[out] The grant reference for the page.
169 *
170 * \return On success, 0. Otherwise an errno value indicating the
171 * type of failure.
172 *
173 * A successful call to xenbus_grant_ring should be paired with a call
174 * to gnttab_end_foreign_access() when foregn access to this page is no
175 * longer requried.
176 *
177 * \note On error, \a dev will be switched to the XenbusStateClosing
178 * state and the returned error is saved in the per-device error node
179 * for \a dev in the XenStore.
180 */
181 int xenbus_grant_ring(device_t dev, unsigned long ring_mfn, grant_ref_t *refp);
182
183 /**
184 * Allocate an event channel for the given XenBus device.
185 *
186 * \param dev The device for which to allocate the event channel.
187 * \param port[out] The port identifier for the allocated event channel.
188 *
189 * \return On success, 0. Otherwise an errno value indicating the
190 * type of failure.
191 *
192 * A successfully allocated event channel should be free'd using
193 * xenbus_free_evtchn().
194 *
195 * \note On error, \a dev will be switched to the XenbusStateClosing
196 * state and the returned error is saved in the per-device error node
197 * for \a dev in the XenStore.
198 */
199 int xenbus_alloc_evtchn(device_t dev, evtchn_port_t *port);
200
201 /**
202 * Free an existing event channel.
203 *
204 * \param dev The device which allocated this event channel.
205 * \param port The port identifier for the event channel to free.
206 *
207 * \return On success, 0. Otherwise an errno value indicating the
208 * type of failure.
209 *
210 * \note On error, \a dev will be switched to the XenbusStateClosing
211 * state and the returned error is saved in the per-device error node
212 * for \a dev in the XenStore.
213 */
214 int xenbus_free_evtchn(device_t dev, evtchn_port_t port);
215
216 /**
217 * Record the given errno, along with the given, printf-style, formatted
218 * message in dev's device specific error node in the XenStore.
219 *
220 * \param dev The device which encountered the error.
221 * \param err The errno value corresponding to the error.
222 * \param fmt Printf format string followed by a variable number of
223 * printf arguments.
224 */
225 void xenbus_dev_error(device_t dev, int err, const char *fmt, ...)
226 __attribute__((format(printf, 3, 4)));
227
228 /**
229 * va_list version of xenbus_dev_error().
230 *
231 * \param dev The device which encountered the error.
232 * \param err The errno value corresponding to the error.
233 * \param fmt Printf format string.
234 * \param ap Va_list of printf arguments.
235 */
236 void xenbus_dev_verror(device_t dev, int err, const char *fmt, va_list ap)
237 __attribute__((format(printf, 3, 0)));
238
239 /**
240 * Equivalent to xenbus_dev_error(), followed by
241 * xenbus_set_state(dev, XenbusStateClosing).
242 *
243 * \param dev The device which encountered the error.
244 * \param err The errno value corresponding to the error.
245 * \param fmt Printf format string followed by a variable number of
246 * printf arguments.
247 */
248 void xenbus_dev_fatal(device_t dev, int err, const char *fmt, ...)
249 __attribute__((format(printf, 3, 4)));
250
251 /**
252 * va_list version of xenbus_dev_fatal().
253 *
254 * \param dev The device which encountered the error.
255 * \param err The errno value corresponding to the error.
256 * \param fmt Printf format string.
257 * \param ap Va_list of printf arguments.
258 */
259 void xenbus_dev_vfatal(device_t dev, int err, const char *fmt, va_list)
260 __attribute__((format(printf, 3, 0)));
261
262 /**
263 * Convert a member of the xenbus_state enum into an ASCII string.
264 *
265 * /param state The XenBus state to lookup.
266 *
267 * /return A string representing state or, for unrecognized states,
268 * the string "Unknown".
269 */
270 const char *xenbus_strstate(enum xenbus_state state);
271
272 /**
273 * Return the value of a XenBus device's "online" node within the XenStore.
274 *
275 * \param dev The XenBus device to query.
276 *
277 * \return The value of the "online" node for the device. If the node
278 * does not exist, 0 (offline) is returned.
279 */
280 int xenbus_dev_is_online(device_t dev);
281
282 /**
283 * Default callback invoked when a change to the local XenStore sub-tree
284 * for a device is modified.
285 *
286 * \param dev The XenBus device whose tree was modified.
287 * \param path The tree relative sub-path to the modified node. The empty
288 * string indicates the root of the tree was destroyed.
289 */
290 void xenbus_localend_changed(device_t dev, const char *path);
291
292 #include "xenbus_if.h"
293
294 #endif /* _XEN_XENBUS_XENBUSVAR_H */
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