oskit/oskit-20020317/lmm/lmm_find_free.c

69 lines
2.0 KiB
C
Executable File

/*
* Copyright (c) 1995, 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.
*/
#include "lmm.h"
void lmm_find_free(lmm_t *lmm, oskit_addr_t *inout_addr,
oskit_size_t *out_size, lmm_flags_t *out_flags)
{
struct lmm_region *reg;
oskit_addr_t start_addr = (*inout_addr + ALIGN_MASK) & ~ALIGN_MASK;
oskit_addr_t lowest_addr = (oskit_addr_t)-1;
oskit_size_t lowest_size = 0;
unsigned lowest_flags = 0;
for (reg = lmm->regions; reg; reg = reg->next)
{
struct lmm_node *node;
if ((reg->nodes == 0)
|| (reg->max <= start_addr)
|| (reg->min > lowest_addr))
continue;
for (node = reg->nodes; node; node = node->next)
{
assert((oskit_addr_t)node >= reg->min);
assert((oskit_addr_t)node < reg->max);
if ((oskit_addr_t)node >= lowest_addr)
break;
if ((oskit_addr_t)node + node->size > start_addr)
{
if ((oskit_addr_t)node > start_addr)
{
lowest_addr = (oskit_addr_t)node;
lowest_size = node->size;
}
else
{
lowest_addr = start_addr;
lowest_size = node->size
- (lowest_addr - (oskit_addr_t)node);
}
lowest_flags = reg->flags;
break;
}
}
}
*inout_addr = lowest_addr;
*out_size = lowest_size;
*out_flags = lowest_flags;
}