sos-code-article10/sos/kmalloc.c

115 lines
3.4 KiB
C

/* Copyright (C) 2004 David Decotigny
This program is free software; you can redistribute it and/or
modify it under the terms of the GNU General Public License
as published by the Free Software Foundation; either version 2
of the License, or (at your option) any later version.
This program 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
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program; if not, write to the Free Software
Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307,
USA.
*/
#include <sos/assert.h>
#include <sos/macros.h>
#include "physmem.h"
#include "kmem_vmm.h"
#include "kmem_slab.h"
#include "kmalloc.h"
/* The cache structures for these caches, the object size, their
names, and some number of pages that contain them. They might not
necessarily be powers of 2s. */
static struct {
const char *name;
sos_size_t object_size;
sos_count_t pages_per_slab;
struct sos_kslab_cache *cache;
} kmalloc_cache[] =
{
{ "kmalloc 8B objects", 8, 1 },
{ "kmalloc 16B objects", 16, 1 },
{ "kmalloc 32B objects", 32, 1 },
{ "kmalloc 64B objects", 64, 1 },
{ "kmalloc 128B objects", 128, 1 },
{ "kmalloc 256B objects", 256, 2 },
{ "kmalloc 1024B objects", 1024, 2 },
{ "kmalloc 2048B objects", 2048, 3 },
{ "kmalloc 4096B objects", 4096, 4 },
{ "kmalloc 8192B objects", 8192, 8 },
{ "kmalloc 16384B objects", 16384, 12 },
{ NULL, 0, 0, NULL }
};
sos_ret_t sos_kmalloc_subsystem_setup()
{
int i;
for (i = 0 ; kmalloc_cache[i].object_size != 0 ; i ++)
{
struct sos_kslab_cache *new_cache;
new_cache = sos_kmem_cache_create(kmalloc_cache[i].name,
kmalloc_cache[i].object_size,
kmalloc_cache[i].pages_per_slab,
0,
SOS_KSLAB_CREATE_MAP
);
SOS_ASSERT_FATAL(new_cache != NULL);
kmalloc_cache[i].cache = new_cache;
}
return SOS_OK;
}
sos_vaddr_t sos_kmalloc(sos_size_t size, sos_ui32_t flags)
{
/* Look for a suitable pre-allocated kmalloc cache */
int i;
SOS_ASSERT_FATAL(size > 0);
for (i = 0 ; kmalloc_cache[i].object_size != 0 ; i ++)
{
if (kmalloc_cache[i].object_size >= size)
return sos_kmem_cache_alloc(kmalloc_cache[i].cache,
(flags
& SOS_KMALLOC_ATOMIC)?
SOS_KSLAB_ALLOC_ATOMIC:0);
}
/* none found yet => we directly use the kmem_vmm subsystem to
allocate whole pages */
return sos_kmem_vmm_alloc(SOS_PAGE_ALIGN_SUP(size) / SOS_PAGE_SIZE,
( (flags
& SOS_KMALLOC_ATOMIC)?
SOS_KMEM_VMM_ATOMIC:0)
| SOS_KMEM_VMM_MAP
);
}
sos_ret_t sos_kfree(sos_vaddr_t vaddr)
{
/* The trouble here is that we aren't sure whether this object is a
slab object in a pre-allocated kmalloc cache, or an object
directly allocated as a kmem_vmm region. */
/* We first pretend this object is allocated in a pre-allocated
kmalloc cache */
if (! sos_kmem_cache_free(vaddr))
return SOS_OK; /* Great ! We guessed right ! */
/* Here we're wrong: it appears not to be an object in a
pre-allocated kmalloc cache. So we try to pretend this is a
kmem_vmm area */
return sos_kmem_vmm_free(vaddr);
}