1 /*
2 * CDDL HEADER START
3 *
4 * The contents of this file are subject to the terms of the
5 * Common Development and Distribution License, Version 1.0 only
6 * (the "License"). You may not use this file except in compliance
7 * with the License.
8 *
9 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
10 * or http://www.opensolaris.org/os/licensing.
11 * See the License for the specific language governing permissions
12 * and limitations under the License.
13 *
14 * When distributing Covered Code, include this CDDL HEADER in each
15 * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
16 * If applicable, add the following below this CDDL HEADER, with the
17 * fields enclosed by brackets "[]" replaced with your own identifying
18 * information: Portions Copyright [yyyy] [name of copyright owner]
19 *
20 * CDDL HEADER END
21 */
22 /*
23 * Copyright 2003 Sun Microsystems, Inc. All rights reserved.
24 * Use is subject to license terms.
25 */
26
27 #pragma ident "%Z%%M% %I% %E% SMI"
28
29 #include <sys/conf.h>
30 #include <sys/sysmacros.h>
31 #include <sys/async.h>
32
33 static bus_func_desc_t *bfd_list = NULL; /* list of busfunc descriptors */
34 kmutex_t bfd_lock; /* lock protecting bfd_list */
35
36 /*
37 * Register a new bus function. We expect this function to be called from a
38 * driver attach or detach routine, so we can safely perform a sleeping
39 * allocation here. We just insert the new element at the head of the list.
40 * For more information on bus_func semantics, refer to sun4u/sys/async.h.
41 */
42 void
bus_func_register(int type,busfunc_t func,void * arg)43 bus_func_register(int type, busfunc_t func, void *arg)
44 {
45 bus_func_desc_t *bfd = kmem_alloc(sizeof (bus_func_desc_t), KM_SLEEP);
46
47 bfd->bf_type = type;
48 bfd->bf_func = func;
49 bfd->bf_arg = arg;
50
51 mutex_enter(&bfd_lock);
52 bfd->bf_next = bfd_list;
53 bfd_list = bfd;
54 mutex_exit(&bfd_lock);
55 }
56
57 /*
58 * Unregister the specified bus function. We only delete an element that
59 * exactly matches the specified (type, func, arg) tuple. We expect this
60 * function to only be called from driver detach context.
61 */
62 void
bus_func_unregister(int type,busfunc_t func,void * arg)63 bus_func_unregister(int type, busfunc_t func, void *arg)
64 {
65 bus_func_desc_t *bfd, **pp;
66
67 mutex_enter(&bfd_lock);
68 pp = &bfd_list;
69
70 for (bfd = bfd_list; bfd != NULL; bfd = bfd->bf_next) {
71 if (bfd->bf_type == type && bfd->bf_func == func &&
72 bfd->bf_arg == arg) {
73 *pp = bfd->bf_next;
74 break;
75 }
76 pp = &bfd->bf_next;
77 }
78
79 mutex_exit(&bfd_lock);
80
81 if (bfd != NULL)
82 kmem_free(bfd, sizeof (bus_func_desc_t));
83 }
84
85 /*
86 * Invoke the registered bus functions of the specified type. We return the
87 * maximum of the result values (e.g. BF_FATAL if any call returned BF_FATAL).
88 * This function assumes that (1) the BF_* constants are defined so that the
89 * most fatal error has the highest numerical value, and (2) that the bf_func
90 * callbacks obey the rules described in async.h.
91 */
92 uint_t
bus_func_invoke(int type)93 bus_func_invoke(int type)
94 {
95 bus_func_desc_t *bfd;
96 uint_t err = BF_NONE;
97
98 mutex_enter(&bfd_lock);
99
100 for (bfd = bfd_list; bfd != NULL; bfd = bfd->bf_next) {
101 if (bfd->bf_type == type) {
102 uint_t status = bfd->bf_func(bfd->bf_arg);
103 err = MAX(err, status);
104 }
105 }
106
107 mutex_exit(&bfd_lock);
108 return (err);
109 }
110