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/* $OpenBSD: dma_alloc.c,v 1.10 2014/03/28 17:57:11 mpi Exp $ */
/*
* Copyright (c) 2010 Theo de Raadt <deraadt@openbsd.org>
*
* Permission to use, copy, modify, and distribute this software for any
* purpose with or without fee is hereby granted, provided that the above
* copyright notice and this permission notice appear in all copies.
*
* THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
* WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
* MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
* ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
* WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
* ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
* OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
*/
#include <sys/param.h>
#include <sys/pool.h>
#include <uvm/uvm_extern.h>
static __inline int dma_alloc_index(size_t size);
/* Create dma pools from objects sized 2^4 to 2^16 */
#define DMA_PAGE_SHIFT 16
#define DMA_BUCKET_OFFSET 4
static char dmanames[DMA_PAGE_SHIFT - DMA_BUCKET_OFFSET + 1][10];
struct pool dmapools[DMA_PAGE_SHIFT - DMA_BUCKET_OFFSET + 1];
void
dma_alloc_init(void)
{
int i;
for (i = 0; i < nitems(dmapools); i++) {
snprintf(dmanames[i], sizeof(dmanames[0]), "dma%d",
1 << (i + DMA_BUCKET_OFFSET));
pool_init(&dmapools[i], 1 << (i + DMA_BUCKET_OFFSET), 0, 0, 0,
dmanames[i], NULL);
pool_set_constraints(&dmapools[i], &kp_dma_contig);
pool_setipl(&dmapools[i], IPL_VM);
/* XXX need pool_setlowat(&dmapools[i], dmalowat); */
}
}
static __inline int
dma_alloc_index(size_t sz)
{
int b;
for (b = 0; b < nitems(dmapools); b++)
if (sz <= (1 << (b + DMA_BUCKET_OFFSET)))
return (b);
#ifdef DEBUG
printf("dma_alloc/free: object %d too large\n", sz);
#endif
return (-1);
}
void *
dma_alloc(size_t size, int prflags)
{
int pi = dma_alloc_index(size);
if (pi == -1)
return (NULL);
return pool_get(&dmapools[pi], prflags);
}
void
dma_free(void *m, size_t size)
{
int pi = dma_alloc_index(size);
if (pi == -1)
return;
pool_put(&dmapools[pi], m);
}
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