1 /* $NetBSD: dmover_session.c,v 1.5 2008/01/04 21:17:52 ad Exp $ */
2
3 /*
4 * Copyright (c) 2002 Wasabi Systems, Inc.
5 * All rights reserved.
6 *
7 * Written by Jason R. Thorpe for Wasabi Systems, Inc.
8 *
9 * Redistribution and use in source and binary forms, with or without
10 * modification, are permitted provided that the following conditions
11 * are met:
12 * 1. Redistributions of source code must retain the above copyright
13 * notice, this list of conditions and the following disclaimer.
14 * 2. Redistributions in binary form must reproduce the above copyright
15 * notice, this list of conditions and the following disclaimer in the
16 * documentation and/or other materials provided with the distribution.
17 * 3. All advertising materials mentioning features or use of this software
18 * must display the following acknowledgement:
19 * This product includes software developed for the NetBSD Project by
20 * Wasabi Systems, Inc.
21 * 4. The name of Wasabi Systems, Inc. may not be used to endorse
22 * or promote products derived from this software without specific prior
23 * written permission.
24 *
25 * THIS SOFTWARE IS PROVIDED BY WASABI SYSTEMS, INC. ``AS IS'' AND
26 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
27 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
28 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL WASABI SYSTEMS, INC
29 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
30 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
31 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
32 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
33 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
34 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
35 * POSSIBILITY OF SUCH DAMAGE.
36 */
37
38 /*
39 * dmover_session.c: Session management functions for dmover-api.
40 */
41
42 #include <sys/cdefs.h>
43 __KERNEL_RCSID(0, "$NetBSD: dmover_session.c,v 1.5 2008/01/04 21:17:52 ad Exp $");
44
45 #include <sys/param.h>
46 #include <sys/simplelock.h>
47 #include <sys/pool.h>
48 #include <sys/systm.h>
49 #include <sys/malloc.h>
50
51 #include <dev/dmover/dmovervar.h>
52
53 struct pool dmover_session_pool;
54
55 static int initialized;
56 static struct simplelock initialized_slock = SIMPLELOCK_INITIALIZER;
57
58 void
59 dmover_session_initialize(void)
60 {
61
62 simple_lock(&initialized_slock);
63 if (__predict_true(initialized == 0)) {
64 pool_init(&dmover_session_pool, sizeof(struct dmover_session),
65 0, 0, 0, "dmses", &pool_allocator_nointr, IPL_NONE);
66 initialized = 1;
67 }
68 simple_unlock(&initialized_slock);
69 }
70
71 /*
72 * dmover_session_create: [client interface function]
73 *
74 * Create a dmover session.
75 */
76 int
77 dmover_session_create(const char *type, struct dmover_session **dsesp)
78 {
79 struct dmover_session *dses;
80 int error;
81
82 if (__predict_false(initialized == 0)) {
83 simple_lock(&initialized_slock);
84 error = initialized ? 0 : ENXIO;
85 simple_unlock(&initialized_slock);
86
87 if (error)
88 return (error);
89 }
90
91 dses = pool_get(&dmover_session_pool, PR_NOWAIT);
92 if (__predict_false(dses == NULL))
93 return (ENOMEM);
94
95 /* Allocate a back-end to the session. */
96 error = dmover_backend_alloc(dses, type);
97 if (__predict_false(error)) {
98 pool_put(&dmover_session_pool, dses);
99 return (error);
100 }
101
102 TAILQ_INIT(&dses->__dses_pendreqs);
103 dses->__dses_npendreqs = 0;
104
105 *dsesp = dses;
106 return (0);
107 }
108
109 /*
110 * dmover_session_destroy: [client interface function]
111 *
112 * Tear down a dmover session.
113 */
114 void
115 dmover_session_destroy(struct dmover_session *dses)
116 {
117
118 #ifdef DIAGNOSTIC
119 if (__predict_false(initialized == 0)) {
120 int croak;
121
122 simple_lock(&initialized_slock);
123 croak = (initialized == 0);
124 simple_unlock(&initialized_slock);
125
126 if (croak)
127 panic("dmover_session_destroy: not initialized");
128 }
129 #endif
130
131 /* XXX */
132 if (dses->__dses_npendreqs)
133 panic("dmover_session_destroy");
134
135 dmover_backend_release(dses);
136 pool_put(&dmover_session_pool, dses);
137 }
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