summaryrefslogtreecommitdiff
path: root/include/asm-generic/scatterlist.h
blob: 8b9454496a7c901edd8723586a98981916faeac8 (plain) (blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
#ifndef __ASM_GENERIC_SCATTERLIST_H
#define __ASM_GENERIC_SCATTERLIST_H

#include <linux/types.h>

struct scatterlist {
#ifdef CONFIG_DEBUG_SG
	unsigned long	sg_magic;
#endif
	unsigned long	page_link;
	unsigned int	offset;
	unsigned int	length;
	dma_addr_t	dma_address;
	unsigned int	dma_length;
};

/*
 * These macros should be used after a dma_map_sg call has been done
 * to get bus addresses of each of the SG entries and their lengths.
 * You should only work with the number of sg entries pci_map_sg
 * returns, or alternatively stop on the first sg_dma_len(sg) which
 * is 0.
 */
#define sg_dma_address(sg)	((sg)->dma_address)
#ifndef sg_dma_len
/*
 * Normally, you have an iommu on 64 bit machines, but not on 32 bit
 * machines. Architectures that are differnt should override this.
 */
#if __BITS_PER_LONG == 64
#define sg_dma_len(sg)		((sg)->dma_length)
#else
#define sg_dma_len(sg)		((sg)->length)
#endif /* 64 bit */
#endif /* sg_dma_len */

#ifndef ISA_DMA_THRESHOLD
#define ISA_DMA_THRESHOLD	(~0UL)
#endif

#define ARCH_HAS_SG_CHAIN

#endif /* __ASM_GENERIC_SCATTERLIST_H */