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/*
* 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 2004 Sun Microsystems, Inc. All rights reserved.
* Use is subject to license terms.
*/
#pragma ident "@(#)vmem_stand.c 1.4 05/06/08 SMI"
/*
* Standalone-specific vmem routines
*
* The standalone allocator operates on a pre-existing blob of memory, the
* location and dimensions of which are set using vmem_stand_setsize(). We
* then hand out CHUNKSIZE-sized pieces of this blob, until we run out.
*/
#define DEF_CHUNKSIZE (64 * 1024) /* 64K */
#define DEF_NREGIONS 2
#include <errno.h>
#include <limits.h>
#include <sys/sysmacros.h>
#include <sys/mman.h>
#include <unistd.h>
#include <strings.h>
#include "vmem_base.h"
#include "misc.h"
static vmem_t *stand_heap;
static size_t stand_chunksize;
typedef struct stand_region {
caddr_t sr_base;
caddr_t sr_curtop;
size_t sr_left;
} stand_region_t;
static stand_region_t stand_regions[DEF_NREGIONS];
static int stand_nregions;
extern void membar_producer(void);
void
vmem_stand_init(void)
{
stand_chunksize = MAX(DEF_CHUNKSIZE, pagesize);
stand_nregions = 0;
}
int
vmem_stand_add(caddr_t base, size_t len)
{
stand_region_t *sr = &stand_regions[stand_nregions];
ASSERT(pagesize != 0);
if (stand_nregions == DEF_NREGIONS) {
errno = ENOSPC;
return (-1); /* we don't have room -- throw it back */
}
/*
* We guarantee that only one call to `vmem_stand_add' will be
* active at a time, but we can't ensure that the allocator won't be
* in use while this function is being called. As such, we have to
* ensure that sr is populated and visible to other processors before
* allowing the allocator to access the new region.
*/
sr->sr_base = base;
sr->sr_curtop = (caddr_t)P2ROUNDUP((ulong_t)base, stand_chunksize);
sr->sr_left = P2ALIGN(len - (size_t)(sr->sr_curtop - sr->sr_base),
stand_chunksize);
membar_producer();
stand_nregions++;
return (0);
}
static void *
stand_parent_alloc(vmem_t *src, size_t size, int vmflags)
{
int old_errno = errno;
stand_region_t *sr;
size_t chksize;
void *ret;
int i;
if ((ret = vmem_alloc(src, size, VM_NOSLEEP)) != NULL) {
errno = old_errno;
return (ret);
}
/* We need to allocate another chunk */
chksize = roundup(size, stand_chunksize);
for (sr = stand_regions, i = 0; i < stand_nregions; i++, sr++) {
if (sr->sr_left >= chksize)
break;
}
if (i == stand_nregions) {
/*
* We don't have enough in any of our regions to satisfy the
* request.
*/
errno = old_errno;
return (NULL);
}
if ((ret = _vmem_extend_alloc(src, sr->sr_curtop, chksize, size,
vmflags)) == NULL) {
errno = old_errno;
return (NULL);
}
bzero(sr->sr_curtop, chksize);
sr->sr_curtop += chksize;
sr->sr_left -= chksize;
return (ret);
}
vmem_t *
vmem_stand_arena(vmem_alloc_t **a_out, vmem_free_t **f_out)
{
ASSERT(stand_nregions == 1);
stand_heap = vmem_init("stand_parent", stand_chunksize,
stand_parent_alloc, vmem_free,
"stand_heap", NULL, 0, pagesize, vmem_alloc, vmem_free);
if (a_out != NULL)
*a_out = vmem_alloc;
if (f_out != NULL)
*f_out = vmem_free;
return (stand_heap);
}
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