kernel-ark/include/asm-xtensa/dma.h
Chris Zankel 173d668138 [PATCH] xtensa: remove extra header files
The Xtensa port contained many header files that were never needed.  This
rather lengthy patch removes all those files.  Unfortunately, there were
many dependencies that needed to be updated, so this patch touches quite a
few source files.

Signed-off-by: Chris Zankel <chris@zankel.net>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-12-10 09:55:39 -08:00

62 lines
1.8 KiB
C

/*
* include/asm-xtensa/dma.h
*
* This file is subject to the terms and conditions of the GNU General Public
* License. See the file "COPYING" in the main directory of this archive
* for more details.
*
* Copyright (C) 2003 - 2005 Tensilica Inc.
*/
#ifndef _XTENSA_DMA_H
#define _XTENSA_DMA_H
#include <asm/io.h> /* need byte IO */
/*
* This is only to be defined if we have PC-like DMA.
* By default this is not true on an Xtensa processor,
* however on boards with a PCI bus, such functionality
* might be emulated externally.
*
* NOTE: there still exists driver code that assumes
* this is defined, eg. drivers/sound/soundcard.c (as of 2.4).
*/
#define MAX_DMA_CHANNELS 8
/*
* The maximum virtual address to which DMA transfers
* can be performed on this platform.
*
* NOTE: This is board (platform) specific, not processor-specific!
*
* NOTE: This assumes DMA transfers can only be performed on
* the section of physical memory contiguously mapped in virtual
* space for the kernel. For the Xtensa architecture, this
* means the maximum possible size of this DMA area is
* the size of the statically mapped kernel segment
* (XCHAL_KSEG_{CACHED,BYPASS}_SIZE), ie. 128 MB.
*
* NOTE: When the entire KSEG area is DMA capable, we substract
* one from the max address so that the virt_to_phys() macro
* works correctly on the address (otherwise the address
* enters another area, and virt_to_phys() may not return
* the value desired).
*/
#define MAX_DMA_ADDRESS (PAGE_OFFSET + XCHAL_KIO_SIZE - 1)
/* Reserve and release a DMA channel */
extern int request_dma(unsigned int dmanr, const char * device_id);
extern void free_dma(unsigned int dmanr);
#ifdef CONFIG_PCI
extern int isa_dma_bridge_buggy;
#else
#define isa_dma_bridge_buggy (0)
#endif
#endif