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 * $FreeBSD$
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 * xenbus_get_node
88 * xenbus_get_type
89 * xenbus_get_state
90 * xenbus_get_otherend_id
91 * xenbus_get_otherend_path
92 */
93 #define XENBUS_ACCESSOR(var, ivar, type) \
94 __BUS_ACCESSOR(xenbus, var, XENBUS, ivar, type)
95
96 XENBUS_ACCESSOR(node, NODE, const char *)
97 XENBUS_ACCESSOR(type, TYPE, const char *)
98 XENBUS_ACCESSOR(state, STATE, enum xenbus_state)
99 XENBUS_ACCESSOR(otherend_id, OTHEREND_ID, int)
100 XENBUS_ACCESSOR(otherend_path, OTHEREND_PATH, const char *)
101
102 /**
103 * Return the state of a XenBus device.
104 *
105 * \param path The root XenStore path for the device.
106 *
107 * \return The current state of the device or XenbusStateClosed if no
108 * state can be read.
109 */
110 XenbusState xenbus_read_driver_state(const char *path);
111
112 /**
113 * Return the state of the "other end" (peer) of a XenBus device.
114 *
115 * \param dev The XenBus device whose peer to query.
116 *
117 * \return The current state of the peer device or XenbusStateClosed if no
118 * state can be read.
119 */
120 static inline XenbusState
121 xenbus_get_otherend_state(device_t dev)
122 {
123 return (xenbus_read_driver_state(xenbus_get_otherend_path(dev)));
124 }
125
126 /**
127 * Grant access to the given ring_mfn to the peer of the given device.
128 *
129 * \param dev The device granting access to the ring page.
130 * \param ring_mfn The guest machine page number of the page to grant
131 * peer access rights.
132 * \param refp[out] The grant reference for the page.
133 *
134 * \return On success, 0. Otherwise an errno value indicating the
135 * type of failure.
136 *
137 * A successful call to xenbus_grant_ring should be paired with a call
138 * to gnttab_end_foreign_access() when foregn access to this page is no
139 * longer requried.
140 *
141 * \note On error, \a dev will be switched to the XenbusStateClosing
142 * state and the returned error is saved in the per-device error node
143 * for \a dev in the XenStore.
144 */
145 int xenbus_grant_ring(device_t dev, unsigned long ring_mfn, grant_ref_t *refp);
146
147 /**
148 * Record the given errno, along with the given, printf-style, formatted
149 * message in dev's device specific error node in the XenStore.
150 *
151 * \param dev The device which encountered the error.
152 * \param err The errno value corresponding to the error.
153 * \param fmt Printf format string followed by a variable number of
154 * printf arguments.
155 */
156 void xenbus_dev_error(device_t dev, int err, const char *fmt, ...)
157 __attribute__((format(printf, 3, 4)));
158
159 /**
160 * va_list version of xenbus_dev_error().
161 *
162 * \param dev The device which encountered the error.
163 * \param err The errno value corresponding to the error.
164 * \param fmt Printf format string.
165 * \param ap Va_list of printf arguments.
166 */
167 void xenbus_dev_verror(device_t dev, int err, const char *fmt, va_list ap)
168 __attribute__((format(printf, 3, 0)));
169
170 /**
171 * Equivalent to xenbus_dev_error(), followed by
172 * xenbus_set_state(dev, XenbusStateClosing).
173 *
174 * \param dev The device which encountered the error.
175 * \param err The errno value corresponding to the error.
176 * \param fmt Printf format string followed by a variable number of
177 * printf arguments.
178 */
179 void xenbus_dev_fatal(device_t dev, int err, const char *fmt, ...)
180 __attribute__((format(printf, 3, 4)));
181
182 /**
183 * va_list version of xenbus_dev_fatal().
184 *
185 * \param dev The device which encountered the error.
186 * \param err The errno value corresponding to the error.
187 * \param fmt Printf format string.
188 * \param ap Va_list of printf arguments.
189 */
190 void xenbus_dev_vfatal(device_t dev, int err, const char *fmt, va_list)
191 __attribute__((format(printf, 3, 0)));
192
193 /**
194 * Convert a member of the xenbus_state enum into an ASCII string.
195 *
196 * /param state The XenBus state to lookup.
197 *
198 * /return A string representing state or, for unrecognized states,
199 * the string "Unknown".
200 */
201 const char *xenbus_strstate(enum xenbus_state state);
202
203 /**
204 * Return the value of a XenBus device's "online" node within the XenStore.
205 *
206 * \param dev The XenBus device to query.
207 *
208 * \return The value of the "online" node for the device. If the node
209 * does not exist, 0 (offline) is returned.
210 */
211 int xenbus_dev_is_online(device_t dev);
212
213 /**
214 * Default callback invoked when a change to the local XenStore sub-tree
215 * for a device is modified.
216 *
217 * \param dev The XenBus device whose tree was modified.
218 * \param path The tree relative sub-path to the modified node. The empty
219 * string indicates the root of the tree was destroyed.
220 */
221 void xenbus_localend_changed(device_t dev, const char *path);
222
223 #include "xenbus_if.h"
224
225 #endif /* _XEN_XENBUS_XENBUSVAR_H */
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