1 /******************************************************************************
2 * Copyright (C) 2005 XenSource Ltd
4 * This file may be distributed separately from the Linux kernel, or
5 * incorporated into other software packages, subject to the following license:
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11 * and to permit persons to whom the Software is furnished to do so, subject to
12 * the following conditions:
14 * The above copyright notice and this permission notice shall be included in
15 * all copies or substantial portions of the Software.
17 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
18 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
19 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
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29 * \brief Client-facing interface for the Xenbus driver.
31 * In other words, the interface between the Xenbus and the device-specific
32 * code, be it the frontend or the backend of that driver.
36 #define DPRINTK(fmt, args...) \
37 printk("xenbus_client (%s:%d) " fmt ".\n", __FUNCTION__, __LINE__, ##args)
39 #define DPRINTK(fmt, args...) ((void)0)
42 #include <sys/cdefs.h>
43 __FBSDID("$FreeBSD$");
45 #include <sys/cdefs.h>
46 #include <sys/param.h>
47 #include <sys/kernel.h>
48 #include <sys/types.h>
49 #include <sys/malloc.h>
50 #include <sys/libkern.h>
53 #include <machine/xen/xen-os.h>
54 #include <xen/hypervisor.h>
55 #include <xen/evtchn.h>
56 #include <xen/gnttab.h>
57 #include <xen/xenbus/xenbusvar.h>
58 #include <machine/stdarg.h>
60 MALLOC_DEFINE(M_XENBUS, "xenbus", "XenBus Support");
62 /*------------------------- Private Functions --------------------------------*/
64 * \brief Construct the error path corresponding to the given XenBus
67 * \param dev The XenBus device for which we are constructing an error path.
69 * \return On success, the contructed error path. Otherwise NULL.
71 * It is the caller's responsibility to free any returned error path
72 * node using the M_XENBUS malloc type.
75 error_path(device_t dev)
77 char *path_buffer = malloc(strlen("error/")
78 + strlen(xenbus_get_node(dev)) + 1,M_XENBUS, M_WAITOK);
80 strcpy(path_buffer, "error/");
81 strcpy(path_buffer + strlen("error/"), xenbus_get_node(dev));
86 /*--------------------------- Public Functions -------------------------------*/
87 /*-------- API comments for these methods can be found in xenbusvar.h --------*/
89 xenbus_strstate(XenbusState state)
91 static const char *const name[] = {
92 [ XenbusStateUnknown ] = "Unknown",
93 [ XenbusStateInitialising ] = "Initialising",
94 [ XenbusStateInitWait ] = "InitWait",
95 [ XenbusStateInitialised ] = "Initialised",
96 [ XenbusStateConnected ] = "Connected",
97 [ XenbusStateClosing ] = "Closing",
98 [ XenbusStateClosed ] = "Closed",
101 return ((state < (XenbusStateClosed + 1)) ? name[state] : "INVALID");
105 xenbus_watch_path(device_t dev, char *path, struct xs_watch *watch,
106 xs_watch_cb_t *callback, uintptr_t callback_data)
111 watch->callback = callback;
112 watch->callback_data = callback_data;
114 error = xs_register_watch(watch);
118 watch->callback = NULL;
119 xenbus_dev_fatal(dev, error, "adding watch on %s", path);
126 xenbus_watch_path2(device_t dev, const char *path,
127 const char *path2, struct xs_watch *watch,
128 xs_watch_cb_t *callback, uintptr_t callback_data)
131 char *state = malloc(strlen(path) + 1 + strlen(path2) + 1,
136 strcat(state, path2);
138 error = xenbus_watch_path(dev, state, watch, callback, callback_data);
140 free(state,M_XENBUS);
147 xenbus_dev_verror(device_t dev, int err, const char *fmt, va_list ap)
151 char *printf_buffer = NULL, *path_buffer = NULL;
153 #define PRINTF_BUFFER_SIZE 4096
154 printf_buffer = malloc(PRINTF_BUFFER_SIZE,M_XENBUS, M_WAITOK);
156 len = sprintf(printf_buffer, "%i ", err);
157 ret = vsnprintf(printf_buffer+len, PRINTF_BUFFER_SIZE-len, fmt, ap);
159 KASSERT(len + ret <= PRINTF_BUFFER_SIZE-1, ("xenbus error message too big"));
160 device_printf(dev, "Error %s\n", printf_buffer);
161 path_buffer = error_path(dev);
163 if (path_buffer == NULL) {
164 printf("xenbus: failed to write error node for %s (%s)\n",
165 xenbus_get_node(dev), printf_buffer);
169 if (xs_write(XST_NIL, path_buffer, "error", printf_buffer) != 0) {
170 printf("xenbus: failed to write error node for %s (%s)\n",
171 xenbus_get_node(dev), printf_buffer);
177 free(printf_buffer,M_XENBUS);
179 free(path_buffer,M_XENBUS);
183 xenbus_dev_error(device_t dev, int err, const char *fmt, ...)
188 xenbus_dev_verror(dev, err, fmt, ap);
193 xenbus_dev_vfatal(device_t dev, int err, const char *fmt, va_list ap)
195 xenbus_dev_verror(dev, err, fmt, ap);
196 device_printf(dev, "Fatal error. Transitioning to Closing State\n");
197 xenbus_set_state(dev, XenbusStateClosing);
201 xenbus_dev_fatal(device_t dev, int err, const char *fmt, ...)
206 xenbus_dev_vfatal(dev, err, fmt, ap);
211 xenbus_grant_ring(device_t dev, unsigned long ring_mfn, grant_ref_t *refp)
215 error = gnttab_grant_foreign_access(
216 xenbus_get_otherend_id(dev), ring_mfn, 0, refp);
218 xenbus_dev_fatal(dev, error, "granting access to ring page");
226 xenbus_alloc_evtchn(device_t dev, evtchn_port_t *port)
228 struct evtchn_alloc_unbound alloc_unbound;
231 alloc_unbound.dom = DOMID_SELF;
232 alloc_unbound.remote_dom = xenbus_get_otherend_id(dev);
234 err = HYPERVISOR_event_channel_op(EVTCHNOP_alloc_unbound,
238 xenbus_dev_fatal(dev, -err, "allocating event channel");
241 *port = alloc_unbound.port;
246 xenbus_free_evtchn(device_t dev, evtchn_port_t port)
248 struct evtchn_close close;
253 err = HYPERVISOR_event_channel_op(EVTCHNOP_close, &close);
255 xenbus_dev_error(dev, -err, "freeing event channel %d", port);
262 xenbus_read_driver_state(const char *path)
267 error = xs_gather(XST_NIL, path, "state", "%d", &result, NULL);
269 result = XenbusStateClosed;
275 xenbus_dev_is_online(device_t dev)
281 path = xenbus_get_node(dev);
282 error = xs_gather(XST_NIL, path, "online", "%d", &value, NULL);
284 /* Default to not online. */
292 xenbus_localend_changed(device_t dev, const char *path)