1 /******************************************************************************
2 * Copyright (C) 2005 Rusty Russell, IBM Corporation
3 * Copyright (C) 2005 XenSource Ltd.
5 * This file may be distributed separately from the Linux kernel, or
6 * incorporated into other software packages, subject to the following license:
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
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12 * and to permit persons to whom the Software is furnished to do so, subject to
13 * the following conditions:
15 * The above copyright notice and this permission notice shall be included in
16 * all copies or substantial portions of the Software.
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
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23 * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
32 * \brief Datastructures and function declarations for usedby device
33 * drivers operating on the XenBus.
36 #ifndef _XEN_XENBUS_XENBUSVAR_H
37 #define _XEN_XENBUS_XENBUSVAR_H
39 #include <sys/queue.h>
41 #include <sys/eventhandler.h>
42 #include <sys/malloc.h>
45 #include <machine/stdarg.h>
46 #include <machine/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>
52 #include <xen/xenstore/xenstorevar.h>
54 #include "xenbus_if.h"
56 /* XenBus allocations including XenStore data returned to clients. */
57 MALLOC_DECLARE(M_XENBUS);
61 * Path of this device node.
66 * The device type (e.g. vif, vbd).
71 * The state of this device (not the otherend's state).
76 * Domain ID of the other end device.
78 XENBUS_IVAR_OTHEREND_ID,
81 * Path of the other end device.
83 XENBUS_IVAR_OTHEREND_PATH
87 * Simplified accessors for xenbus devices
89 #define XENBUS_ACCESSOR(var, ivar, type) \
90 __BUS_ACCESSOR(xenbus, var, XENBUS, ivar, type)
92 XENBUS_ACCESSOR(node, NODE, const char *)
93 XENBUS_ACCESSOR(type, TYPE, const char *)
94 XENBUS_ACCESSOR(state, STATE, enum xenbus_state)
95 XENBUS_ACCESSOR(otherend_id, OTHEREND_ID, int)
96 XENBUS_ACCESSOR(otherend_path, OTHEREND_PATH, const char *)
99 * Return the state of a XenBus device.
101 * \param path The root XenStore path for the device.
103 * \return The current state of the device or XenbusStateClosed if no
106 XenbusState xenbus_read_driver_state(const char *path);
109 * Initialize and register a watch on the given path (client suplied storage).
111 * \param dev The XenBus device requesting the watch service.
112 * \param path The XenStore path of the object to be watched. The
113 * storage for this string must be stable for the lifetime
115 * \param watch The watch object to use for this request. This object
116 * must be stable for the lifetime of the watch.
117 * \param callback The function to call when XenStore objects at or below
120 * \return On success, 0. Otherwise an errno value indicating the
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.
127 int xenbus_watch_path(device_t dev, char *path,
128 struct xs_watch *watch,
129 xs_watch_cb_t *callback);
132 * Initialize and register a watch at path/path2 in the XenStore.
134 * \param dev The XenBus device requesting the watch service.
135 * \param path The base XenStore path of the object to be watched.
136 * \param path2 The tail XenStore path of the object to be watched.
137 * \param watch The watch object to use for this request. This object
138 * must be stable for the lifetime of the watch.
139 * \param callback The function to call when XenStore objects at or below
142 * \return On success, 0. Otherwise an errno value indicating the
145 * \note On error, \a dev will be switched to the XenbusStateClosing
146 * state and the returned error is saved in the per-device error node
147 * for \a dev in the XenStore.
149 * Similar to xenbus_watch_path, however the storage for the path to the
150 * watched object is allocated from the heap and filled with "path '/' path2".
151 * Should a call to this function succeed, it is the callers responsibility
152 * to free watch->node using the M_XENBUS malloc type.
154 int xenbus_watch_path2(device_t dev, const char *path,
155 const char *path2, struct xs_watch *watch,
156 xs_watch_cb_t *callback);
159 * Grant access to the given ring_mfn to the peer of the given device.
161 * \param dev The device granting access to the ring page.
162 * \param ring_mfn The guest machine page number of the page to grant
163 * peer access rights.
164 * \param refp[out] The grant reference for the page.
166 * \return On success, 0. Otherwise an errno value indicating the
169 * A successful call to xenbus_grant_ring should be paired with a call
170 * to gnttab_end_foreign_access() when foregn access to this page is no
173 * \note On error, \a dev will be switched to the XenbusStateClosing
174 * state and the returned error is saved in the per-device error node
175 * for \a dev in the XenStore.
177 int xenbus_grant_ring(device_t dev, unsigned long ring_mfn, grant_ref_t *refp);
180 * Allocate an event channel for the given XenBus device.
182 * \param dev The device for which to allocate the event channel.
183 * \param port[out] The port identifier for the allocated event channel.
185 * \return On success, 0. Otherwise an errno value indicating the
188 * A successfully allocated event channel should be free'd using
189 * xenbus_free_evtchn().
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.
195 int xenbus_alloc_evtchn(device_t dev, evtchn_port_t *port);
198 * Free an existing event channel.
200 * \param dev The device which allocated this event channel.
201 * \param port The port identifier for the event channel to free.
203 * \return On success, 0. Otherwise an errno value indicating the
206 * \note On error, \a dev will be switched to the XenbusStateClosing
207 * state and the returned error is saved in the per-device error node
208 * for \a dev in the XenStore.
210 int xenbus_free_evtchn(device_t dev, evtchn_port_t port);
213 * Record the given errno, along with the given, printf-style, formatted
214 * message in dev's device specific error node in the XenStore.
216 * \param dev The device which encountered the error.
217 * \param err The errno value corresponding to the error.
218 * \param fmt Printf format string followed by a variable number of
221 void xenbus_dev_error(device_t dev, int err, const char *fmt, ...)
222 __attribute__((format(printf, 3, 4)));
225 * va_list version of xenbus_dev_error().
227 * \param dev The device which encountered the error.
228 * \param err The errno value corresponding to the error.
229 * \param fmt Printf format string.
230 * \param ap Va_list of printf arguments.
232 void xenbus_dev_verror(device_t dev, int err, const char *fmt, va_list ap)
233 __attribute__((format(printf, 3, 0)));
236 * Equivalent to xenbus_dev_error(), followed by
237 * xenbus_set_state(dev, XenbusStateClosing).
239 * \param dev The device which encountered the error.
240 * \param err The errno value corresponding to the error.
241 * \param fmt Printf format string followed by a variable number of
244 void xenbus_dev_fatal(device_t dev, int err, const char *fmt, ...)
245 __attribute__((format(printf, 3, 4)));
248 * va_list version of xenbus_dev_fatal().
250 * \param dev The device which encountered the error.
251 * \param err The errno value corresponding to the error.
252 * \param fmt Printf format string.
253 * \param ap Va_list of printf arguments.
255 void xenbus_dev_vfatal(device_t dev, int err, const char *fmt, va_list)
256 __attribute__((format(printf, 3, 0)));
259 * Convert a member of the xenbus_state enum into an ASCII string.
261 * /param state The XenBus state to lookup.
263 * /return A string representing state or, for unrecognized states,
264 * the string "Unknown".
266 const char *xenbus_strstate(enum xenbus_state state);
269 * Return the value of a XenBus device's "online" node within the XenStore.
271 * \param dev The XenBus device to query.
273 * \return The value of the "online" node for the device. If the node
274 * does not exist, 0 (offline) is returned.
276 int xenbus_dev_is_online(device_t dev);
278 #endif /* _XEN_XENBUS_XENBUSVAR_H */