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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.
*/
#include <sys/vmem.h>
#include <sys/kmem.h>
#include <sys/param.h>
#include <sys/sysmacros.h>
#include <sys/cmn_err.h>
#include <vm/seg_kmem.h>
static vmem_t *id32_arena;
static kmem_cache_t *id32_cache;
#define ID32_BITS 5
#define ID32_ALIGN (1 << ID32_BITS)
#define ID32_MOD (ID32_ALIGN - 1)
#if defined(__amd64)
/*
* For amd64 the 32 bit id is the offset of the entry in the arena.
*/
extern char *heap_core_base;
#define ID32_ENCODE(x) (((x) - (uintptr_t)heap_core_base) | \
((((x) - (uintptr_t)heap_core_base) % ID32_MOD)) + 1)
#define ID32_DECODE(x) (P2ALIGN((x), (uintptr_t)ID32_ALIGN) + \
(uintptr_t)heap_core_base)
#define ID32_VALID(x) (ID32_ENCODE(ID32_DECODE(x)) == (x))
#else /* __amd64 */
/*
* All other architectures use the 32 bit pointer value for the 32 bit id.
*/
#define ID32_ENCODE(x) (((x) | ((x) % ID32_MOD)) + 1)
#define ID32_DECODE(x) P2ALIGN((x), ID32_ALIGN)
#define ID32_VALID(x) (ID32_ENCODE(ID32_DECODE(x)) == (x))
#endif /* __amd64 */
void
id32_init(void)
{
id32_arena = vmem_create("id32", NULL, 0, PAGESIZE,
segkmem_alloc, segkmem_free, heap32_arena, 0, VM_SLEEP);
id32_cache = kmem_cache_create("id32_cache", ID32_ALIGN, ID32_ALIGN,
NULL, NULL, NULL, NULL, id32_arena, 0);
}
/*
* Return a 32-bit identifier for the specified pointer.
*/
uint32_t
id32_alloc(void *ptr, int kmflag)
{
void **hent = kmem_cache_alloc(id32_cache, kmflag);
uintptr_t id;
if (hent == NULL)
return (0);
*hent = ptr;
id = ID32_ENCODE((uintptr_t)hent);
ASSERT64(id <= UINT32_MAX);
return ((uint32_t)id);
}
/*
* Free a 32-bit ID.
*/
void
id32_free(uint32_t id)
{
if (!ID32_VALID(id)) {
cmn_err(CE_WARN, "id32_free(%x): bad ID rejected\n", id);
return;
}
kmem_cache_free(id32_cache, (void *)(uintptr_t)ID32_DECODE(id));
}
/*
* Return the pointer described by a 32-bit ID, or NULL if the ID is bad.
*/
void *
id32_lookup(uint32_t id)
{
if (!ID32_VALID(id)) {
cmn_err(CE_WARN, "id32_lookup(%x): bad ID rejected\n", id);
return (NULL);
}
return (((void **)(uintptr_t)ID32_DECODE(id))[0]);
}
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