1/* $NetBSD: xenbus.h,v 1.13 2011/12/07 15:47:42 cegger Exp $ */
2/******************************************************************************
3 * xenbus.h
4 *
5 * Talks to Xen Store to figure out what devices we have.
6 *
7 * Copyright (C) 2005 Rusty Russell, IBM Corporation
8 * Copyright (C) 2005 XenSource Ltd.
9 *
10 * This file may be distributed separately from the Linux kernel, or
11 * incorporated into other software packages, subject to the following license:
12 *
13 * Permission is hereby granted, free of charge, to any person obtaining a copy
14 * of this source file (the "Software"), to deal in the Software without
15 * restriction, including without limitation the rights to use, copy, modify,
16 * merge, publish, distribute, sublicense, and/or sell copies of the Software,
17 * and to permit persons to whom the Software is furnished to do so, subject to
18 * the following conditions:
19 *
20 * The above copyright notice and this permission notice shall be included in
21 * all copies or substantial portions of the Software.
22 *
23 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
24 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
25 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
26 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
27 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
28 * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
29 * IN THE SOFTWARE.
30 */
31
32#ifndef _ASM_XEN_XENBUS_H
33#define _ASM_XEN_XENBUS_H
34
35#include <sys/device.h>
36#include <sys/queue.h>
37#include <xen/xen-public/xen.h>
38#include <xen/xen-public/io/xenbus.h>
39#include <xen/xen-public/io/xs_wire.h>
40#include <xen/xen-public/grant_table.h> /* for grant_ref_t */
41
42/* xenbus to hypervisor attach */
43struct xenbus_attach_args {
44 const char *xa_device;
45 int xa_handle;
46};
47
48/* devices to xenbus attach */
49struct xenbusdev_attach_args {
50 const char *xa_type;
51 int xa_id;
52 struct xenbus_device *xa_xbusd;
53};
54
55/* Register callback to watch this node. */
56struct xenbus_watch {
57 SLIST_ENTRY(xenbus_watch) watch_next;
58
59 /* Path being watched. */
60 char *node;
61
62 /* Callback (executed in a process context with no locks held). */
63 void (*xbw_callback)(struct xenbus_watch *,
64 const char **vec, unsigned int len);
65 struct xenbus_device *xbw_dev;
66};
67
68
69/*
70 * A xenbus device. Note that the malloced memory will be larger than
71 * sizeof(xenbus_device) to have the storage for xbusd_path, so xbusd_path
72 * has to be the last entry.
73 */
74typedef enum {
75 XENBUS_FRONTEND_DEVICE,
76 XENBUS_BACKEND_DEVICE
77} xenbusdev_type_t;
78
79struct xenbus_device {
80 SLIST_ENTRY(xenbus_device) xbusd_entries;
81 char *xbusd_otherend; /* the otherend path */
82 int xbusd_otherend_id; /* the otherend's id */
83 /* callback for otherend change */
84 void (*xbusd_otherend_changed)(void *, XenbusState);
85 xenbusdev_type_t xbusd_type;
86 union {
87 struct {
88 device_t f_dev;
89 } f;
90 struct {
91 void *b_cookie; /* private to backend driver */
92 int (*b_detach)(void *);
93 } b;
94 } xbusd_u;
95 int xbusd_has_error;
96 /* for xenbus internal use */
97 struct xenbus_watch xbusd_otherend_watch;
98 const char xbusd_path[1]; /* our path */
99};
100
101/*
102 * frontend devices use the normal autoconf(9) framework to attach.
103 * backend drivers need something more clever because we want the
104 * domain's name or uid in the device's name. Each backend driver registers
105 * to xenbus.
106 */
107
108struct xenbus_backend_driver {
109 SLIST_ENTRY(xenbus_backend_driver) xbakd_entries;
110 int (*xbakd_create) (struct xenbus_device *); /* called for new devs */
111 const char *xbakd_type; /* device type we register for */
112};
113
114void xenbus_backend_register(struct xenbus_backend_driver *);
115
116struct xenbus_transaction;
117
118int xenbus_directory(struct xenbus_transaction *t,
119 const char *dir, const char *node, unsigned int *num,
120 char ***);
121int xenbus_read(struct xenbus_transaction *t,
122 const char *dir, const char *node, unsigned int *len,
123 char **);
124int xenbus_read_ul(struct xenbus_transaction *,
125 const char *, const char *, unsigned long *, int);
126int xenbus_read_ull(struct xenbus_transaction *,
127 const char *, const char *, unsigned long long *, int);
128int xenbus_write(struct xenbus_transaction *t,
129 const char *dir, const char *node, const char *string);
130int xenbus_mkdir(struct xenbus_transaction *t,
131 const char *dir, const char *node);
132int xenbus_exists(struct xenbus_transaction *t,
133 const char *dir, const char *node);
134int xenbus_rm(struct xenbus_transaction *t, const char *dir, const char *node);
135struct xenbus_transaction *xenbus_transaction_start(void);
136int xenbus_transaction_end(struct xenbus_transaction *t, int abort);
137
138/* Single read and scanf: returns -errno or num scanned if > 0. */
139int xenbus_scanf(struct xenbus_transaction *t,
140 const char *dir, const char *node, const char *fmt, ...)
141 __attribute__((format(scanf, 4, 5)));
142
143/* Single printf and write: returns -errno or 0. */
144int xenbus_printf(struct xenbus_transaction *t,
145 const char *dir, const char *node, const char *fmt, ...)
146 __attribute__((format(printf, 4, 5)));
147
148/* Generic read function: NULL-terminated triples of name,
149 * sprintf-style type string, and pointer. Returns 0 or errno.*/
150int xenbus_gather(struct xenbus_transaction *t, const char *dir, ...);
151
152/* notifer routines for when the xenstore comes up */
153// XXX int register_xenstore_notifier(struct notifier_block *nb);
154// XXX void unregister_xenstore_notifier(struct notifier_block *nb);
155
156int register_xenbus_watch(struct xenbus_watch *watch);
157void unregister_xenbus_watch(struct xenbus_watch *watch);
158void xs_suspend(void);
159void xs_resume(void);
160
161/* Used by xenbus_dev to borrow kernel's store connection. */
162int xenbus_dev_request_and_reply(struct xsd_sockmsg *msg, void **);
163
164void xenbus_probe(void *);
165
166int xenbus_free_device(struct xenbus_device *);
167
168#define XENBUS_IS_ERR_READ(str) ({ \
169 if (!IS_ERR(str) && strlen(str) == 0) { \
170 kfree(str); \
171 str = ERR_PTR(-ERANGE); \
172 } \
173 IS_ERR(str); \
174})
175
176#define XENBUS_EXIST_ERR(err) ((err) == -ENOENT || (err) == -ERANGE)
177
178
179/**
180 * Register a watch on the given path, using the given xenbus_watch structure
181 * for storage, and the given callback function as the callback. Return 0 on
182 * success, or -errno on error. On success, the given path will be saved as
183 * watch->node, and remains the caller's to free. On error, watch->node will
184 * be NULL, the device will switch to XenbusStateClosing, and the error will
185 * be saved in the store.
186 */
187int xenbus_watch_path(struct xenbus_device *dev, char *path,
188 struct xenbus_watch *watch,
189 void (*callback)(struct xenbus_watch *,
190 const char **, unsigned int));
191
192
193/**
194 * Register a watch on the given path/path2, using the given xenbus_watch
195 * structure for storage, and the given callback function as the callback.
196 * Return 0 on success, or -errno on error. On success, the watched path
197 * (path/path2) will be saved as watch->node, and becomes the caller's to
198 * kfree(). On error, watch->node will be NULL, so the caller has nothing to
199 * free, the device will switch to XenbusStateClosing, and the error will be
200 * saved in the store.
201 */
202int xenbus_watch_path2(struct xenbus_device *dev, const char *path,
203 const char *path2, struct xenbus_watch *watch,
204 void (*callback)(struct xenbus_watch *,
205 const char **, unsigned int));
206
207
208/**
209 * Advertise in the store a change of the given driver to the given new_state.
210 * Perform the change inside the given transaction xbt. xbt may be NULL, in
211 * which case this is performed inside its own transaction. Return 0 on
212 * success, or -errno on error. On error, the device will switch to
213 * XenbusStateClosing, and the error will be saved in the store.
214 */
215int xenbus_switch_state(struct xenbus_device *dev,
216 struct xenbus_transaction *xbt,
217 XenbusState new_state);
218
219
220/**
221 * Grant access to the given ring_mfn to the peer of the given device. Return
222 * 0 on success, or -errno on error. On error, the device will switch to
223 * XenbusStateClosing, and the error will be saved in the store.
224 */
225int xenbus_grant_ring(struct xenbus_device *, paddr_t, grant_ref_t *);
226
227
228/**
229 * Allocate an event channel for the given xenbus_device, assigning the newly
230 * created local port to *port. Return 0 on success, or -errno on error. On
231 * error, the device will switch to XenbusStateClosing, and the error will be
232 * saved in the store.
233 */
234int xenbus_alloc_evtchn(struct xenbus_device *dev, int *port);
235
236
237/**
238 * Return the state of the driver rooted at the given store path, or
239 * XenbusStateClosed if no state can be read.
240 */
241XenbusState xenbus_read_driver_state(const char *path);
242
243
244/***
245 * Report the given negative errno into the store, along with the given
246 * formatted message.
247 */
248void xenbus_dev_error(struct xenbus_device *dev, int err, const char *fmt,
249 ...);
250
251
252/***
253 * Equivalent to xenbus_dev_error(dev, err, fmt, args), followed by
254 * xenbus_switch_state(dev, NULL, XenbusStateClosing) to schedule an orderly
255 * closedown of this driver and its peer.
256 */
257void xenbus_dev_fatal(struct xenbus_device *dev, int err, const char *fmt,
258 ...);
259
260bool xenbus_device_suspend(struct xenbus_device *);
261bool xenbus_device_resume(struct xenbus_device *);
262
263#endif /* _ASM_XEN_XENBUS_H */
264
265/*
266 * Local variables:
267 * c-file-style: "linux"
268 * indent-tabs-mode: t
269 * c-indent-level: 8
270 * c-basic-offset: 8
271 * tab-width: 8
272 * End:
273 */
274