$OpenBSD: dma_alloc.9,v 1.8 2022/03/31 17:27:23 naddy Exp $
$NetBSD: pool.9,v 1.18 2001/06/21 11:59:01 wiz Exp $
Copyright (c) 2011 Theo de Raadt
All rights reserved.
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.
.Dd $Mdocdate: September 15 2016 $ .Dt DMA_ALLOC 9 .Os .Sh NAME .Nm dma_alloc , .Nm dma_free .Nd DMA-safe memory allocator .Sh SYNOPSIS n sys/types.h n sys/pool.h .Ft void * .Fo dma_alloc .Fa "size_t size" .Fa "int flags" .Fc .Ft void .Fo dma_free .Fa "void *m" .Fa "size_t size" .Fc .Sh DESCRIPTION This allocator provides DMA-safe memory managed using the .Xr pool 9 interface. It is safe to call in most contexts and is typically used for temporary buffers up to 65536 bytes. When buffers are used many times, it may be better to consider using other DMA-safe allocators.
$NetBSD: pool.9,v 1.18 2001/06/21 11:59:01 wiz Exp $
Copyright (c) 2011 Theo de Raadt
All rights reserved.
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.
.Dd $Mdocdate: September 15 2016 $ .Dt DMA_ALLOC 9 .Os .Sh NAME .Nm dma_alloc , .Nm dma_free .Nd DMA-safe memory allocator .Sh SYNOPSIS n sys/types.h n sys/pool.h .Ft void * .Fo dma_alloc .Fa "size_t size" .Fa "int flags" .Fc .Ft void .Fo dma_free .Fa "void *m" .Fa "size_t size" .Fc .Sh DESCRIPTION This allocator provides DMA-safe memory managed using the .Xr pool 9 interface. It is safe to call in most contexts and is typically used for temporary buffers up to 65536 bytes. When buffers are used many times, it may be better to consider using other DMA-safe allocators.
p Interrupt protection is set to .Va IPL_VM using .Xr pool_init 9 .
p The .Ar flags argument is a selection of .Xr pool_get 9 flag arguments.
p The same .Va size argument must be passed to both .Fn dma_alloc and the subsequent .Fn dma_free . Allocations over 65536 will fail. .Sh SEE ALSO .Xr bus_dma 9 , .Xr mbuf 9 , .Xr pool 9 .Sh HISTORY The .Nm interface first appeared in .Ox 4.8 .