usr/src/cmd/picl/plugins/sun4v/mdesc/init.c

   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         free(bufp);
  98 }
  99
 100 void
 101 mdesc_devfini(md_t *mdp)
 102 {
 103         if (mdp)
 104                 (void) md_fini(mdp);
 105
 106         free(md_bufp);
 107         md_bufp = NULL;
 108 }