/* 
 * Copyright (c) 1996 The University of Utah and
 * the Computer Systems Laboratory at the University of Utah (CSL).
 * All rights reserved.
 *
 * Permission to use, copy, modify and distribute this software is hereby
 * granted provided that (1) source code retains these copyright, permission,
 * and disclaimer notices, and (2) redistributions including binaries
 * reproduce the notices in supporting documentation, and (3) all advertising
 * materials mentioning features or use of this software display the following
 * acknowledgement: ``This product includes software developed by the
 * Computer Systems Laboratory at the University of Utah.''
 *
 * THE UNIVERSITY OF UTAH AND CSL ALLOW FREE USE OF THIS SOFTWARE IN ITS "AS
 * IS" CONDITION.  THE UNIVERSITY OF UTAH AND CSL DISCLAIM ANY LIABILITY OF
 * ANY KIND FOR ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE.
 *
 * CSL requests users of this software to return to csl-dist@cs.utah.edu any
 * improvements that they make and grant CSL redistribution rights.
 */

#include <stddef.h>
#include "malloc_internal.h"

void *_memalign(size_t alignment, size_t size)
{
	unsigned shift;
	size_t *chunk;

	/* Find the alignment shift in bits.  XXX use proc_ops.h  */
	for (shift = 0; (1 << shift) < alignment; shift++);

	/*
	 * Allocate a chunk of LMM memory with the specified alignment shift
	 * and an offset such that the memory block we return will be aligned
	 * after we add our size field to the beginning of it.
	 */
	size += sizeof(size_t);

	malloc_lmm_begin();
	chunk = lmm_alloc_aligned(&malloc_lmm, size, 0, shift,
		(1 << shift) - sizeof(size_t));
	malloc_lmm_end();

	if (!chunk)
		return NULL;

	*chunk = size;
	return chunk+1;
}