linux-stable/include/asm-ia64/scatterlist.h
Jens Axboe d6ec084200 Add CONFIG_DEBUG_SG sg validation
Add a Kconfig entry which will toggle some sanity checks on the sg
entry and tables.

Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2007-10-22 21:20:03 +02:00

38 lines
985 B
C

#ifndef _ASM_IA64_SCATTERLIST_H
#define _ASM_IA64_SCATTERLIST_H
/*
* Modified 1998-1999, 2001-2002, 2004
* David Mosberger-Tang <davidm@hpl.hp.com>, Hewlett-Packard Co
*/
#include <asm/types.h>
struct scatterlist {
#ifdef CONFIG_DEBUG_SG
unsigned long sg_magic;
#endif
unsigned long page_link;
unsigned int offset;
unsigned int length; /* buffer length */
dma_addr_t dma_address;
unsigned int dma_length;
};
/*
* It used to be that ISA_DMA_THRESHOLD had something to do with the
* DMA-limits of ISA-devices. Nowadays, its only remaining use (apart
* from the aha1542.c driver, which isn't 64-bit clean anyhow) is to
* tell the block-layer (via BLK_BOUNCE_ISA) what the max. physical
* address of a page is that is allocated with GFP_DMA. On IA-64,
* that's 4GB - 1.
*/
#define ISA_DMA_THRESHOLD 0xffffffff
#define sg_dma_len(sg) ((sg)->dma_length)
#define sg_dma_address(sg) ((sg)->dma_address)
#define ARCH_HAS_SG_CHAIN
#endif /* _ASM_IA64_SCATTERLIST_H */