116 lines
3.0 KiB
C
116 lines
3.0 KiB
C
/*
|
|
* CDDL HEADER START
|
|
*
|
|
* The contents of this file are subject to the terms of the
|
|
* Common Development and Distribution License (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 2006 Sun Microsystems, Inc. All rights reserved.
|
|
* Use is subject to license terms.
|
|
*/
|
|
|
|
#include <sys/isa_defs.h>
|
|
#include <sys/nvpair.h>
|
|
#include <sys/sysmacros.h>
|
|
|
|
/*
|
|
* This allocator is very simple.
|
|
* - it uses a pre-allocated buffer for memory allocations.
|
|
* - it does _not_ free memory in the pre-allocated buffer.
|
|
*
|
|
* The reason for the selected implementation is simplicity.
|
|
* This allocator is designed for the usage in interrupt context when
|
|
* the caller may not wait for free memory.
|
|
*/
|
|
|
|
/* pre-allocated buffer for memory allocations */
|
|
typedef struct nvbuf {
|
|
uintptr_t nvb_buf; /* address of pre-allocated buffer */
|
|
uintptr_t nvb_lim; /* limit address in the buffer */
|
|
uintptr_t nvb_cur; /* current address in the buffer */
|
|
} nvbuf_t;
|
|
|
|
/*
|
|
* Initialize the pre-allocated buffer allocator. The caller needs to supply
|
|
*
|
|
* buf address of pre-allocated buffer
|
|
* bufsz size of pre-allocated buffer
|
|
*
|
|
* nv_fixed_init() calculates the remaining members of nvbuf_t.
|
|
*/
|
|
static int
|
|
nv_fixed_init(nv_alloc_t *nva, va_list valist)
|
|
{
|
|
uintptr_t base = va_arg(valist, uintptr_t);
|
|
uintptr_t lim = base + va_arg(valist, size_t);
|
|
nvbuf_t *nvb = (nvbuf_t *)P2ROUNDUP(base, sizeof (uintptr_t));
|
|
|
|
if (base == 0 || (uintptr_t)&nvb[1] > lim)
|
|
return (EINVAL);
|
|
|
|
nvb->nvb_buf = (uintptr_t)&nvb[0];
|
|
nvb->nvb_cur = (uintptr_t)&nvb[1];
|
|
nvb->nvb_lim = lim;
|
|
nva->nva_arg = nvb;
|
|
|
|
return (0);
|
|
}
|
|
|
|
static void *
|
|
nv_fixed_alloc(nv_alloc_t *nva, size_t size)
|
|
{
|
|
nvbuf_t *nvb = nva->nva_arg;
|
|
uintptr_t new = nvb->nvb_cur;
|
|
|
|
if (size == 0 || new + size > nvb->nvb_lim)
|
|
return (NULL);
|
|
|
|
nvb->nvb_cur = P2ROUNDUP(new + size, sizeof (uintptr_t));
|
|
|
|
return ((void *)new);
|
|
}
|
|
|
|
static void
|
|
nv_fixed_free(nv_alloc_t *nva, void *buf, size_t size)
|
|
{
|
|
/* don't free memory in the pre-allocated buffer */
|
|
(void) nva, (void) buf, (void) size;
|
|
}
|
|
|
|
static void
|
|
nv_fixed_reset(nv_alloc_t *nva)
|
|
{
|
|
nvbuf_t *nvb = nva->nva_arg;
|
|
|
|
nvb->nvb_cur = (uintptr_t)&nvb[1];
|
|
}
|
|
|
|
static const nv_alloc_ops_t nv_fixed_ops_def = {
|
|
.nv_ao_init = nv_fixed_init,
|
|
.nv_ao_fini = NULL,
|
|
.nv_ao_alloc = nv_fixed_alloc,
|
|
.nv_ao_free = nv_fixed_free,
|
|
.nv_ao_reset = nv_fixed_reset
|
|
};
|
|
|
|
const nv_alloc_ops_t *const nv_fixed_ops = &nv_fixed_ops_def;
|
|
|
|
#if defined(_KERNEL)
|
|
EXPORT_SYMBOL(nv_fixed_ops);
|
|
#endif
|