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/10.1/sys/xen/xenbus/xenbusvar.h 255040 2013-08-29 19:52:18Z 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
47 #include <xen/xen-os.h>
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 * Return the state of the "other end" (peer) of a XenBus device.
108 *
109 * \param dev The XenBus device whose peer to query.
110 *
111 * \return The current state of the peer device or XenbusStateClosed if no
112 * state can be read.
113 */
114 static inline XenbusState
115 xenbus_get_otherend_state(device_t dev)
116 {
117 return (xenbus_read_driver_state(xenbus_get_otherend_path(dev)));
118 }
119
120 /**
121 * Initialize and register a watch on the given path (client suplied storage).
122 *
123 * \param dev The XenBus device requesting the watch service.
124 * \param path The XenStore path of the object to be watched. The
125 * storage for this string must be stable for the lifetime
126 * of the watch.
127 * \param watch The watch object to use for this request. This object
128 * must be stable for the lifetime of the watch.
129 * \param callback The function to call when XenStore objects at or below
130 * path are modified.
131 * \param cb_data Client data that can be retrieved from the watch object
132 * during the callback.
133 *
134 * \return On success, 0. Otherwise an errno value indicating the
135 * type of failure.
136 *
137 * \note On error, the device 'dev' will be switched to the XenbusStateClosing
138 * state and the returned error is saved in the per-device error node
139 * for dev in the XenStore.
140 */
141 int xenbus_watch_path(device_t dev, char *path,
142 struct xs_watch *watch,
143 xs_watch_cb_t *callback,
144 uintptr_t cb_data);
145
146 /**
147 * Initialize and register a watch at path/path2 in the XenStore.
148 *
149 * \param dev The XenBus device requesting the watch service.
150 * \param path The base XenStore path of the object to be watched.
151 * \param path2 The tail XenStore path of the object to be watched.
152 * \param watch The watch object to use for this request. This object
153 * must be stable for the lifetime of the watch.
154 * \param callback The function to call when XenStore objects at or below
155 * path are modified.
156 * \param cb_data Client data that can be retrieved from the watch object
157 * during the callback.
158 *
159 * \return On success, 0. Otherwise an errno value indicating the
160 * type of failure.
161 *
162 * \note On error, \a dev will be switched to the XenbusStateClosing
163 * state and the returned error is saved in the per-device error node
164 * for \a dev in the XenStore.
165 *
166 * Similar to xenbus_watch_path, however the storage for the path to the
167 * watched object is allocated from the heap and filled with "path '/' path2".
168 * Should a call to this function succeed, it is the callers responsibility
169 * to free watch->node using the M_XENBUS malloc type.
170 */
171 int xenbus_watch_path2(device_t dev, const char *path,
172 const char *path2, struct xs_watch *watch,
173 xs_watch_cb_t *callback,
174 uintptr_t cb_data);
175
176 /**
177 * Grant access to the given ring_mfn to the peer of the given device.
178 *
179 * \param dev The device granting access to the ring page.
180 * \param ring_mfn The guest machine page number of the page to grant
181 * peer access rights.
182 * \param refp[out] The grant reference for the page.
183 *
184 * \return On success, 0. Otherwise an errno value indicating the
185 * type of failure.
186 *
187 * A successful call to xenbus_grant_ring should be paired with a call
188 * to gnttab_end_foreign_access() when foregn access to this page is no
189 * longer requried.
190 *
191 * \note On error, \a dev will be switched to the XenbusStateClosing
192 * state and the returned error is saved in the per-device error node
193 * for \a dev in the XenStore.
194 */
195 int xenbus_grant_ring(device_t dev, unsigned long ring_mfn, grant_ref_t *refp);
196
197 /**
198 * Record the given errno, along with the given, printf-style, formatted
199 * message in dev's device specific error node in the XenStore.
200 *
201 * \param dev The device which encountered the error.
202 * \param err The errno value corresponding to the error.
203 * \param fmt Printf format string followed by a variable number of
204 * printf arguments.
205 */
206 void xenbus_dev_error(device_t dev, int err, const char *fmt, ...)
207 __attribute__((format(printf, 3, 4)));
208
209 /**
210 * va_list version of xenbus_dev_error().
211 *
212 * \param dev The device which encountered the error.
213 * \param err The errno value corresponding to the error.
214 * \param fmt Printf format string.
215 * \param ap Va_list of printf arguments.
216 */
217 void xenbus_dev_verror(device_t dev, int err, const char *fmt, va_list ap)
218 __attribute__((format(printf, 3, 0)));
219
220 /**
221 * Equivalent to xenbus_dev_error(), followed by
222 * xenbus_set_state(dev, XenbusStateClosing).
223 *
224 * \param dev The device which encountered the error.
225 * \param err The errno value corresponding to the error.
226 * \param fmt Printf format string followed by a variable number of
227 * printf arguments.
228 */
229 void xenbus_dev_fatal(device_t dev, int err, const char *fmt, ...)
230 __attribute__((format(printf, 3, 4)));
231
232 /**
233 * va_list version of xenbus_dev_fatal().
234 *
235 * \param dev The device which encountered the error.
236 * \param err The errno value corresponding to the error.
237 * \param fmt Printf format string.
238 * \param ap Va_list of printf arguments.
239 */
240 void xenbus_dev_vfatal(device_t dev, int err, const char *fmt, va_list)
241 __attribute__((format(printf, 3, 0)));
242
243 /**
244 * Convert a member of the xenbus_state enum into an ASCII string.
245 *
246 * /param state The XenBus state to lookup.
247 *
248 * /return A string representing state or, for unrecognized states,
249 * the string "Unknown".
250 */
251 const char *xenbus_strstate(enum xenbus_state state);
252
253 /**
254 * Return the value of a XenBus device's "online" node within the XenStore.
255 *
256 * \param dev The XenBus device to query.
257 *
258 * \return The value of the "online" node for the device. If the node
259 * does not exist, 0 (offline) is returned.
260 */
261 int xenbus_dev_is_online(device_t dev);
262
263 /**
264 * Default callback invoked when a change to the local XenStore sub-tree
265 * for a device is modified.
266 *
267 * \param dev The XenBus device whose tree was modified.
268 * \param path The tree relative sub-path to the modified node. The empty
269 * string indicates the root of the tree was destroyed.
270 */
271 void xenbus_localend_changed(device_t dev, const char *path);
272
273 #include "xenbus_if.h"
274
275 #endif /* _XEN_XENBUS_XENBUSVAR_H */
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