xref: /illumos-gate/usr/src/cmd/picl/plugins/sun4v/mdesc/init.c (revision d48be21240dfd051b689384ce2b23479d757f2d8)
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 (the "License").
6  * You may not use this file except in compliance with the License.
7  *
8  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
9  * or http://www.opensolaris.org/os/licensing.
10  * See the License for the specific language governing permissions
11  * and limitations under the License.
12  *
13  * When distributing Covered Code, include this CDDL HEADER in each
14  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
15  * If applicable, add the following below this CDDL HEADER, with the
16  * fields enclosed by brackets "[]" replaced with your own identifying
17  * information: Portions Copyright [yyyy] [name of copyright owner]
18  *
19  * CDDL HEADER END
20  */
21 
22 /*
23  * Copyright 2007 Sun Microsystems, Inc.  All rights reserved.
24  * Use is subject to license terms.
25  */
26 
27 #include <stdio.h>
28 #include <unistd.h>
29 #include <stdlib.h>
30 #include <sys/types.h>
31 #include <alloca.h>
32 #include <sys/stat.h>
33 #include <malloc.h>
34 #include <fcntl.h>
35 #include <syslog.h>
36 #include <mdesc.h>
37 #include <string.h>
38 #include <errno.h>
39 
40 #define	MDESC_PATH	"/devices/pseudo/mdesc@0:mdesc"
41 
42 static void mdesc_free(void *bufp, size_t size);
43 uint64_t *md_bufp;
44 
45 md_t *
46 mdesc_devinit(void)
47 {
48 	int fd;
49 	md_t *mdp;
50 	size_t size;
51 
52 	/*
53 	 * We haven't finished using the previous MD/PRI info.
54 	 */
55 	if (md_bufp != NULL)
56 		return (NULL);
57 
58 	do {
59 		if ((fd = open(MDESC_PATH, O_RDONLY, 0)) < 0)
60 			break;
61 
62 		if (ioctl(fd, MDESCIOCGSZ, &size) < 0)
63 			break;
64 		if ((md_bufp = (uint64_t *)malloc(size)) == NULL) {
65 			(void) close(fd);
66 			break;
67 		}
68 
69 		/*
70 		 * A partial read is as bad as a failed read.
71 		 */
72 		if (read(fd, md_bufp, size) != size) {
73 			free(md_bufp);
74 			md_bufp = NULL;
75 		}
76 
77 		(void) close(fd);
78 	/*LINTED: E_CONSTANT_CONDITION */
79 	} while (0);
80 
81 	if (md_bufp) {
82 		mdp = md_init_intern(md_bufp, malloc, mdesc_free);
83 		if (mdp == NULL) {
84 			free(md_bufp);
85 			md_bufp = NULL;
86 		}
87 	} else
88 		mdp = NULL;
89 
90 	return (mdp);
91 }
92 
93 /*ARGSUSED*/
94 void
95 mdesc_free(void *bufp, size_t size)
96 {
97 	if (bufp)
98 		free(bufp);
99 }
100 
101 void
102 mdesc_devfini(md_t *mdp)
103 {
104 	if (mdp)
105 		(void) md_fini(mdp);
106 
107 	if (md_bufp)
108 		free(md_bufp);
109 	md_bufp = NULL;
110 }
111