scatterlist.h

来自「linux 内核源代码」· C头文件 代码 · 共 40 行

/*
 * include/asm-xtensa/scatterlist.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) 2001 - 2005 Tensilica Inc.
 */

#ifndef _XTENSA_SCATTERLIST_H
#define _XTENSA_SCATTERLIST_H

#include <asm/types.h>

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

/*
 * 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)


#define ISA_DMA_THRESHOLD (~0UL)

#endif	/* _XTENSA_SCATTERLIST_H */