scatterlist.h

来自「linux 内核源代码」· C头文件 代码 · 共 28 行

#ifndef __ASM_SH_SCATTERLIST_H
#define __ASM_SH_SCATTERLIST_H

#include <asm/types.h>

struct scatterlist {
#ifdef CONFIG_DEBUG_SG
    unsigned long sg_magic;
#endif
    unsigned long page_link;
    unsigned int offset;/* for highmem, page offset */
    dma_addr_t dma_address;
    unsigned int length;
};

#define ISA_DMA_THRESHOLD (0x1fffffff)

/* These macros should be used after a pci_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)
#define sg_dma_len(sg)		((sg)->length)

#endif /* !(__ASM_SH_SCATTERLIST_H) */