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/* MN10300 Scatterlist definitions
*
* Copyright (C) 2007 Matsushita Electric Industrial Co., Ltd.
* Copyright (C) 2007 Red Hat, Inc. All Rights Reserved.
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public Licence
* as published by the Free Software Foundation; either version
* 2 of the Licence, or (at your option) any later version.
*/
#ifndef _ASM_SCATTERLIST_H
#define _ASM_SCATTERLIST_H
#include <asm/types.h>
/*
* Drivers must set either ->address or (preferred) page and ->offset
* to indicate where data must be transferred to/from.
*
* Using page is recommended since it handles highmem data as well as
* low mem. ->address is restricted to data which has a virtual mapping, and
* it will go away in the future. Updating to page can be automated very
* easily -- something like
*
* sg->address = some_ptr;
*
* can be rewritten as
*
* sg_set_page(virt_to_page(some_ptr));
* sg->offset = (unsigned long) some_ptr & ~PAGE_MASK;
*
* and that's it. There's no excuse for not highmem enabling YOUR driver. /jens
*/
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 (0x00ffffff)
/*
* 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.
*/
#define sg_dma_address(sg) ((sg)->dma_address)
#define sg_dma_len(sg) ((sg)->length)
#endif /* _ASM_SCATTERLIST_H */
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