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:
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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
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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 /* XenBus allocations including XenStore data returned to clients. */
55 MALLOC_DECLARE(M_XENBUS);
59 * Path of this device node.
64 * The device type (e.g. vif, vbd).
69 * The state of this device (not the otherend's state).
74 * Domain ID of the other end device.
76 XENBUS_IVAR_OTHEREND_ID,
79 * Path of the other end device.
81 XENBUS_IVAR_OTHEREND_PATH
85 * Simplified accessors for xenbus devices
87 #define XENBUS_ACCESSOR(var, ivar, type) \
88 __BUS_ACCESSOR(xenbus, var, XENBUS, ivar, type)
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 *)
97 * Return the state of a XenBus device.
99 * \param path The root XenStore path for the device.
101 * \return The current state of the device or XenbusStateClosed if no
104 XenbusState xenbus_read_driver_state(const char *path);
107 * Initialize and register a watch on the given path (client suplied storage).
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
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
117 * \param cb_data Client data that can be retrieved from the watch object
118 * during the callback.
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,
133 * Initialize and register a watch at path/path2 in the XenStore.
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
142 * \param cb_data Client data that can be retrieved from the watch object
143 * during the callback.
145 * \return On success, 0. Otherwise an errno value indicating the
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.
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.
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,
163 * Grant access to the given ring_mfn to the peer of the given device.
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.
170 * \return On success, 0. Otherwise an errno value indicating the
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
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.
181 int xenbus_grant_ring(device_t dev, unsigned long ring_mfn, grant_ref_t *refp);
184 * Allocate an event channel for the given XenBus device.
186 * \param dev The device for which to allocate the event channel.
187 * \param port[out] The port identifier for the allocated event channel.
189 * \return On success, 0. Otherwise an errno value indicating the
192 * A successfully allocated event channel should be free'd using
193 * xenbus_free_evtchn().
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.
199 int xenbus_alloc_evtchn(device_t dev, evtchn_port_t *port);
202 * Free an existing event channel.
204 * \param dev The device which allocated this event channel.
205 * \param port The port identifier for the event channel to free.
207 * \return On success, 0. Otherwise an errno value indicating the
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.
214 int xenbus_free_evtchn(device_t dev, evtchn_port_t port);
217 * Record the given errno, along with the given, printf-style, formatted
218 * message in dev's device specific error node in the XenStore.
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
225 void xenbus_dev_error(device_t dev, int err, const char *fmt, ...)
226 __attribute__((format(printf, 3, 4)));
229 * va_list version of xenbus_dev_error().
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.
236 void xenbus_dev_verror(device_t dev, int err, const char *fmt, va_list ap)
237 __attribute__((format(printf, 3, 0)));
240 * Equivalent to xenbus_dev_error(), followed by
241 * xenbus_set_state(dev, XenbusStateClosing).
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
248 void xenbus_dev_fatal(device_t dev, int err, const char *fmt, ...)
249 __attribute__((format(printf, 3, 4)));
252 * va_list version of xenbus_dev_fatal().
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.
259 void xenbus_dev_vfatal(device_t dev, int err, const char *fmt, va_list)
260 __attribute__((format(printf, 3, 0)));
263 * Convert a member of the xenbus_state enum into an ASCII string.
265 * /param state The XenBus state to lookup.
267 * /return A string representing state or, for unrecognized states,
268 * the string "Unknown".
270 const char *xenbus_strstate(enum xenbus_state state);
273 * Return the value of a XenBus device's "online" node within the XenStore.
275 * \param dev The XenBus device to query.
277 * \return The value of the "online" node for the device. If the node
278 * does not exist, 0 (offline) is returned.
280 int xenbus_dev_is_online(device_t dev);
283 * Default callback invoked when a change to the local XenStore sub-tree
284 * for a device is modified.
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.
290 void xenbus_localend_changed(device_t dev, const char *path);
292 #include "xenbus_if.h"
294 #endif /* _XEN_XENBUS_XENBUSVAR_H */