xref: /minix3/lib/libc/gen/getpagesize.c (revision f14fb602092e015ff630df58e17c2a9cd57d29b3)
1*f14fb602SLionel Sambuc /*	$NetBSD: getpagesize.c,v 1.11 2012/06/24 15:26:03 christos Exp $	*/
22fe8fb19SBen Gras 
32fe8fb19SBen Gras /*
42fe8fb19SBen Gras  * Copyright (c) 1989, 1993
52fe8fb19SBen Gras  *	The Regents of the University of California.  All rights reserved.
62fe8fb19SBen Gras  *
72fe8fb19SBen Gras  * Redistribution and use in source and binary forms, with or without
82fe8fb19SBen Gras  * modification, are permitted provided that the following conditions
92fe8fb19SBen Gras  * are met:
102fe8fb19SBen Gras  * 1. Redistributions of source code must retain the above copyright
112fe8fb19SBen Gras  *    notice, this list of conditions and the following disclaimer.
122fe8fb19SBen Gras  * 2. Redistributions in binary form must reproduce the above copyright
132fe8fb19SBen Gras  *    notice, this list of conditions and the following disclaimer in the
142fe8fb19SBen Gras  *    documentation and/or other materials provided with the distribution.
152fe8fb19SBen Gras  * 3. Neither the name of the University nor the names of its contributors
162fe8fb19SBen Gras  *    may be used to endorse or promote products derived from this software
172fe8fb19SBen Gras  *    without specific prior written permission.
182fe8fb19SBen Gras  *
192fe8fb19SBen Gras  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
202fe8fb19SBen Gras  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
212fe8fb19SBen Gras  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
222fe8fb19SBen Gras  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
232fe8fb19SBen Gras  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
242fe8fb19SBen Gras  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
252fe8fb19SBen Gras  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
262fe8fb19SBen Gras  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
272fe8fb19SBen Gras  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
282fe8fb19SBen Gras  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
292fe8fb19SBen Gras  * SUCH DAMAGE.
302fe8fb19SBen Gras  */
312fe8fb19SBen Gras 
322fe8fb19SBen Gras #include <sys/cdefs.h>
332fe8fb19SBen Gras #if defined(LIBC_SCCS) && !defined(lint)
342fe8fb19SBen Gras #if 0
352fe8fb19SBen Gras static char sccsid[] = "@(#)getpagesize.c	8.1 (Berkeley) 6/4/93";
362fe8fb19SBen Gras #else
37*f14fb602SLionel Sambuc __RCSID("$NetBSD: getpagesize.c,v 1.11 2012/06/24 15:26:03 christos Exp $");
382fe8fb19SBen Gras #endif
392fe8fb19SBen Gras #endif /* LIBC_SCCS and not lint */
402fe8fb19SBen Gras 
412fe8fb19SBen Gras #include "namespace.h"
422fe8fb19SBen Gras #include <sys/param.h>
432fe8fb19SBen Gras #include <sys/sysctl.h>
442fe8fb19SBen Gras #include <assert.h>
452fe8fb19SBen Gras #include <unistd.h>
462fe8fb19SBen Gras 
472fe8fb19SBen Gras #ifdef __weak_alias
__weak_alias(getpagesize,_getpagesize)482fe8fb19SBen Gras __weak_alias(getpagesize,_getpagesize)
492fe8fb19SBen Gras #endif
502fe8fb19SBen Gras 
512fe8fb19SBen Gras int
52*f14fb602SLionel Sambuc getpagesize(void)
532fe8fb19SBen Gras {
542fe8fb19SBen Gras 	static int pagsz;
552fe8fb19SBen Gras 
562fe8fb19SBen Gras 	if (pagsz == 0) {
572fe8fb19SBen Gras 		int mib[2];
582fe8fb19SBen Gras 		size_t size;
592fe8fb19SBen Gras 
602fe8fb19SBen Gras 		mib[0] = CTL_HW;
612fe8fb19SBen Gras 		mib[1] = HW_PAGESIZE;
622fe8fb19SBen Gras 		size = sizeof pagsz;
632fe8fb19SBen Gras 		if (sysctl(mib, 2, &pagsz, &size, NULL, 0) == -1)
642fe8fb19SBen Gras 			return (-1);
652fe8fb19SBen Gras 		_DIAGASSERT(pagsz);
662fe8fb19SBen Gras 	}
672fe8fb19SBen Gras 	return (pagsz);
682fe8fb19SBen Gras }
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