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:
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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 * Return the state of the "other end" (peer) of a XenBus device.
109 * \param dev The XenBus device whose peer to query.
111 * \return The current state of the peer device or XenbusStateClosed if no
114 static inline XenbusState
115 xenbus_get_otherend_state(device_t dev)
117 return (xenbus_read_driver_state(xenbus_get_otherend_path(dev)));
121 * Initialize and register a watch on the given path (client suplied storage).
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
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
131 * \param cb_data Client data that can be retrieved from the watch object
132 * during the callback.
134 * \return On success, 0. Otherwise an errno value indicating the
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.
141 int xenbus_watch_path(device_t dev, char *path,
142 struct xs_watch *watch,
143 xs_watch_cb_t *callback,
147 * Initialize and register a watch at path/path2 in the XenStore.
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
156 * \param cb_data Client data that can be retrieved from the watch object
157 * during the callback.
159 * \return On success, 0. Otherwise an errno value indicating the
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.
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.
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,
177 * Grant access to the given ring_mfn to the peer of the given device.
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.
184 * \return On success, 0. Otherwise an errno value indicating the
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
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_grant_ring(device_t dev, unsigned long ring_mfn, grant_ref_t *refp);
198 * Allocate an event channel for the given XenBus device.
200 * \param dev The device for which to allocate the event channel.
201 * \param port[out] The port identifier for the allocated event channel.
203 * \return On success, 0. Otherwise an errno value indicating the
206 * A successfully allocated event channel should be free'd using
207 * xenbus_free_evtchn().
209 * \note On error, \a dev will be switched to the XenbusStateClosing
210 * state and the returned error is saved in the per-device error node
211 * for \a dev in the XenStore.
213 int xenbus_alloc_evtchn(device_t dev, evtchn_port_t *port);
216 * Free an existing event channel.
218 * \param dev The device which allocated this event channel.
219 * \param port The port identifier for the event channel to free.
221 * \return On success, 0. Otherwise an errno value indicating the
224 * \note On error, \a dev will be switched to the XenbusStateClosing
225 * state and the returned error is saved in the per-device error node
226 * for \a dev in the XenStore.
228 int xenbus_free_evtchn(device_t dev, evtchn_port_t port);
231 * Record the given errno, along with the given, printf-style, formatted
232 * message in dev's device specific error node in the XenStore.
234 * \param dev The device which encountered the error.
235 * \param err The errno value corresponding to the error.
236 * \param fmt Printf format string followed by a variable number of
239 void xenbus_dev_error(device_t dev, int err, const char *fmt, ...)
240 __attribute__((format(printf, 3, 4)));
243 * va_list version of xenbus_dev_error().
245 * \param dev The device which encountered the error.
246 * \param err The errno value corresponding to the error.
247 * \param fmt Printf format string.
248 * \param ap Va_list of printf arguments.
250 void xenbus_dev_verror(device_t dev, int err, const char *fmt, va_list ap)
251 __attribute__((format(printf, 3, 0)));
254 * Equivalent to xenbus_dev_error(), followed by
255 * xenbus_set_state(dev, XenbusStateClosing).
257 * \param dev The device which encountered the error.
258 * \param err The errno value corresponding to the error.
259 * \param fmt Printf format string followed by a variable number of
262 void xenbus_dev_fatal(device_t dev, int err, const char *fmt, ...)
263 __attribute__((format(printf, 3, 4)));
266 * va_list version of xenbus_dev_fatal().
268 * \param dev The device which encountered the error.
269 * \param err The errno value corresponding to the error.
270 * \param fmt Printf format string.
271 * \param ap Va_list of printf arguments.
273 void xenbus_dev_vfatal(device_t dev, int err, const char *fmt, va_list)
274 __attribute__((format(printf, 3, 0)));
277 * Convert a member of the xenbus_state enum into an ASCII string.
279 * /param state The XenBus state to lookup.
281 * /return A string representing state or, for unrecognized states,
282 * the string "Unknown".
284 const char *xenbus_strstate(enum xenbus_state state);
287 * Return the value of a XenBus device's "online" node within the XenStore.
289 * \param dev The XenBus device to query.
291 * \return The value of the "online" node for the device. If the node
292 * does not exist, 0 (offline) is returned.
294 int xenbus_dev_is_online(device_t dev);
297 * Default callback invoked when a change to the local XenStore sub-tree
298 * for a device is modified.
300 * \param dev The XenBus device whose tree was modified.
301 * \param path The tree relative sub-path to the modified node. The empty
302 * string indicates the root of the tree was destroyed.
304 void xenbus_localend_changed(device_t dev, const char *path);
306 #include "xenbus_if.h"
308 #endif /* _XEN_XENBUS_XENBUSVAR_H */