/*
 * Copyright (c) 1996, 1998 University of Utah and the Flux Group.
 * All rights reserved.
 * 
 * This file is part of the Flux OSKit.  The OSKit is free software, also known
 * as "open source;" you can redistribute it and/or modify it under the terms
 * of the GNU General Public License (GPL), version 2, as published by the Free
 * Software Foundation (FSF).  To explore alternate licensing terms, contact
 * the University of Utah at csl-dist@cs.utah.edu or +1-801-585-3271.
 * 
 * The OSKit is distributed in the hope that it will be useful, but WITHOUT ANY
 * WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
 * FOR A PARTICULAR PURPOSE.  See the GPL for more details.  You should have
 * received a copy of the GPL along with the OSKit; see the file COPYING.  If
 * not, write to the FSF, 59 Temple Place #330, Boston, MA 02111-1307, USA.
 */

/*
 * Simple address map deallocation routine, similar to what POSIX munmap or
 * Mach vm_deallocate would require.
 */
#include <errno.h>
#include "amm.h"

/*
 * amm_deallocate frees a range of address space.
 * Only AMM_ALLOCATED areas are freed, AMM_RESERVED/FREE regions are skipped.
 *
 * Addr and size define the range.
 *
 * Returns zero on success, error number on failure.
 */
int
amm_deallocate(struct amm *amm, oskit_addr_t addr, oskit_size_t size)
{
	oskit_addr_t saddr, eaddr;
	amm_entry_t *entry;
	int rc;

	saddr = addr;
	eaddr = saddr + size;
	while (saddr < eaddr) {
		/*
		 * Find the next allocated entry and free the portion
		 * covered by our range.
		 */
		entry = amm_find_addr(amm, saddr);
		if ((amm_entry_flags(entry) & AMM_ALLOCATED) == AMM_ALLOCATED) {
			if (eaddr < amm_entry_end(entry))
				size = eaddr - saddr;
			else
				size = amm_entry_end(entry) - saddr;
			rc = amm_modify(amm, saddr, size, AMM_FREE, 0);
			if (rc)
				return rc;
		}
		saddr = amm_entry_end(entry);
	}
	return 0;
}