sun4v/mdesc/init.c

	init.c revision 7c478bd95313f5f23a4c958a745db2134aa03244
/*
 * CDDL HEADER START
 *
 * The contents of this file are subject to the terms of the
 * Common Development and Distribution License, Version 1.0 only
 * (the "License").  You may not use this file except in compliance
 * with the License.
 *
 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
 * or http://www.opensolaris.org/os/licensing.
 * See the License for the specific language governing permissions
 * and limitations under the License.
 *
 * When distributing Covered Code, include this CDDL HEADER in each
 * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
 * If applicable, add the following below this CDDL HEADER, with the
 * fields enclosed by brackets "[]" replaced with your own identifying
 * information: Portions Copyright [yyyy] [name of copyright owner]
 *
 * CDDL HEADER END
 */
/*
 * Copyright 2005 Sun Microsystems, Inc.  All rights reserved.
 * Use is subject to license terms.
 */

#pragma ident   "%Z%%M% %I% %E% SMI"

#include <stdio.h>
#include <unistd.h>
#include <stdlib.h>
#include <sys/types.h>
#include <alloca.h>
#include <sys/stat.h>
#include <malloc.h>
#include <fcntl.h>
#include <syslog.h>
#include <mdesc.h>
#include <string.h>
#include <errno.h>

#define MDESC_PATH  "/devices/pseudo/mdesc@0:mdesc"
#define SIZE    8192

md_t *
mdesc_devinit(void)
{
    int fh;
    uint8_t *bufp = NULL;
    int res;
    int size;
    int offset;
    md_t *mdp;

    fh = open(MDESC_PATH, O_RDONLY, 0);
    if (fh < 0) {
        return (NULL);
    }

    size = SIZE;    /* initial size */
    offset = 0;

    bufp = malloc(size);
    if (NULL == bufp) {
        return (NULL);
    }

        /* OK read until we get a EOF */

    do {
        int len;

        len = size - offset;

        while (len < SIZE) {
            size += SIZE;
            bufp = realloc(bufp, size);
            if (NULL == bufp)
                return (NULL);
            len = size - offset;
        }

        do {
            res = read(fh, bufp+offset, len);
        } while ((res < 0) && (errno == EAGAIN));

        if (res < 0) {
            free(bufp);
            return (NULL);
        }

        offset += res;
    } while (res > 0);

    (void) close(fh);

    bufp = realloc(bufp, offset);
    if (NULL == bufp)
        return (NULL);

    mdp = md_init_intern((uint64_t *)bufp, malloc, free);
    if (NULL == mdp) {
        free(bufp);
        return (NULL);
    }

    return (mdp);
}