xref: /freebsd/sys/cam/ctl/ctl_backend.c (revision 9a14aa017b21c292740c00ee098195cd46642730)
1 /*-
2  * Copyright (c) 2003 Silicon Graphics International Corp.
3  * All rights reserved.
4  *
5  * Redistribution and use in source and binary forms, with or without
6  * modification, are permitted provided that the following conditions
7  * are met:
8  * 1. Redistributions of source code must retain the above copyright
9  *    notice, this list of conditions, and the following disclaimer,
10  *    without modification.
11  * 2. Redistributions in binary form must reproduce at minimum a disclaimer
12  *    substantially similar to the "NO WARRANTY" disclaimer below
13  *    ("Disclaimer") and any redistribution must be conditioned upon
14  *    including a substantially similar Disclaimer requirement for further
15  *    binary redistribution.
16  *
17  * NO WARRANTY
18  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
19  * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
20  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR
21  * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
22  * HOLDERS OR CONTRIBUTORS BE LIABLE FOR SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
23  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
24  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
25  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
26  * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
27  * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
28  * POSSIBILITY OF SUCH DAMAGES.
29  *
30  * $Id: //depot/users/kenm/FreeBSD-test2/sys/cam/ctl/ctl_backend.c#3 $
31  */
32 /*
33  * CTL backend driver registration routines
34  *
35  * Author: Ken Merry <ken@FreeBSD.org>
36  */
37 
38 #include <sys/cdefs.h>
39 __FBSDID("$FreeBSD$");
40 
41 #include <sys/param.h>
42 #include <sys/systm.h>
43 #include <sys/kernel.h>
44 #include <sys/types.h>
45 #include <sys/malloc.h>
46 #include <sys/lock.h>
47 #include <sys/mutex.h>
48 #include <sys/condvar.h>
49 #include <sys/queue.h>
50 
51 #include <cam/scsi/scsi_all.h>
52 #include <cam/scsi/scsi_da.h>
53 #include <cam/ctl/ctl_io.h>
54 #include <cam/ctl/ctl.h>
55 #include <cam/ctl/ctl_frontend.h>
56 #include <cam/ctl/ctl_backend.h>
57 #include <cam/ctl/ctl_frontend_internal.h>
58 #include <cam/ctl/ctl_ioctl.h>
59 #include <cam/ctl/ctl_ha.h>
60 #include <cam/ctl/ctl_private.h>
61 #include <cam/ctl/ctl_debug.h>
62 
63 extern struct ctl_softc *control_softc;
64 
65 int
66 ctl_backend_register(struct ctl_backend_driver *be)
67 {
68 	struct ctl_softc *ctl_softc;
69 	struct ctl_backend_driver *be_tmp;
70 
71 	ctl_softc = control_softc;
72 
73 	mtx_lock(&ctl_softc->ctl_lock);
74 	/*
75 	 * Sanity check, make sure this isn't a duplicate registration.
76 	 */
77 	STAILQ_FOREACH(be_tmp, &ctl_softc->be_list, links) {
78 		if (strcmp(be_tmp->name, be->name) == 0) {
79 			mtx_unlock(&ctl_softc->ctl_lock);
80 			return (-1);
81 		}
82 	}
83 	mtx_unlock(&ctl_softc->ctl_lock);
84 
85 	/*
86 	 * Call the backend's initialization routine.
87 	 */
88 	be->init();
89 
90 	mtx_lock(&ctl_softc->ctl_lock);
91 
92 	STAILQ_INSERT_TAIL(&ctl_softc->be_list, be, links);
93 
94 	ctl_softc->num_backends++;
95 
96 	/*
97 	 * Don't want to increment the usage count for internal consumers,
98 	 * we won't be able to unload otherwise.
99 	 */
100 	/* XXX KDM find a substitute for this? */
101 #if 0
102 	if ((be->flags & CTL_BE_FLAG_INTERNAL) == 0)
103 		MOD_INC_USE_COUNT;
104 #endif
105 
106 #ifdef CS_BE_CONFIG_MOVE_DONE_IS_NOT_USED
107 	be->config_move_done = ctl_config_move_done;
108 #endif
109 	/* XXX KDM fix this! */
110 	be->num_luns = 0;
111 #if 0
112 	atomic_set(&be->num_luns, 0);
113 #endif
114 
115 	mtx_unlock(&ctl_softc->ctl_lock);
116 
117 	return (0);
118 }
119 
120 int
121 ctl_backend_deregister(struct ctl_backend_driver *be)
122 {
123 	struct ctl_softc *ctl_softc;
124 
125 	ctl_softc = control_softc;
126 
127 	mtx_lock(&ctl_softc->ctl_lock);
128 
129 #if 0
130 	if (atomic_read(&be->num_luns) != 0) {
131 #endif
132 	/* XXX KDM fix this! */
133 	if (be->num_luns != 0) {
134 		mtx_unlock(&ctl_softc->ctl_lock);
135 		return (-1);
136 	}
137 
138 	STAILQ_REMOVE(&ctl_softc->be_list, be, ctl_backend_driver, links);
139 
140 	ctl_softc->num_backends--;
141 
142 	/* XXX KDM find a substitute for this? */
143 #if 0
144 	if ((be->flags & CTL_BE_FLAG_INTERNAL) == 0)
145 		MOD_DEC_USE_COUNT;
146 #endif
147 
148 	mtx_unlock(&ctl_softc->ctl_lock);
149 
150 	return (0);
151 }
152 
153 struct ctl_backend_driver *
154 ctl_backend_find(char *backend_name)
155 {
156 	struct ctl_softc *ctl_softc;
157 	struct ctl_backend_driver *be_tmp;
158 
159 	ctl_softc = control_softc;
160 
161 	mtx_lock(&ctl_softc->ctl_lock);
162 
163 	STAILQ_FOREACH(be_tmp, &ctl_softc->be_list, links) {
164 		if (strcmp(be_tmp->name, backend_name) == 0) {
165 			mtx_unlock(&ctl_softc->ctl_lock);
166 			return (be_tmp);
167 		}
168 	}
169 
170 	mtx_unlock(&ctl_softc->ctl_lock);
171 
172 	return (NULL);
173 }
174 
175 /*
176  * vim: ts=8
177  */
178