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56 lines
1.7 KiB
C
56 lines
1.7 KiB
C
/* MN10300 Scatterlist definitions
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*
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* Copyright (C) 2007 Matsushita Electric Industrial Co., Ltd.
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* Copyright (C) 2007 Red Hat, Inc. All Rights Reserved.
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*
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* This program is free software; you can redistribute it and/or
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* modify it under the terms of the GNU General Public Licence
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* as published by the Free Software Foundation; either version
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* 2 of the Licence, or (at your option) any later version.
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*/
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#ifndef _ASM_SCATTERLIST_H
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#define _ASM_SCATTERLIST_H
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#include <asm/types.h>
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/*
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* Drivers must set either ->address or (preferred) page and ->offset
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* to indicate where data must be transferred to/from.
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*
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* Using page is recommended since it handles highmem data as well as
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* low mem. ->address is restricted to data which has a virtual mapping, and
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* it will go away in the future. Updating to page can be automated very
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* easily -- something like
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*
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* sg->address = some_ptr;
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*
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* can be rewritten as
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*
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* sg_set_page(virt_to_page(some_ptr));
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* sg->offset = (unsigned long) some_ptr & ~PAGE_MASK;
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*
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* and that's it. There's no excuse for not highmem enabling YOUR driver. /jens
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*/
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struct scatterlist {
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#ifdef CONFIG_DEBUG_SG
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unsigned long sg_magic;
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#endif
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unsigned long page_link;
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unsigned int offset; /* for highmem, page offset */
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dma_addr_t dma_address;
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unsigned int length;
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};
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#define ISA_DMA_THRESHOLD (0x00ffffff)
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/*
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* These macros should be used after a pci_map_sg call has been done
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* to get bus addresses of each of the SG entries and their lengths.
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* You should only work with the number of sg entries pci_map_sg
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* returns.
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*/
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#define sg_dma_address(sg) ((sg)->dma_address)
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#define sg_dma_len(sg) ((sg)->length)
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#endif /* _ASM_SCATTERLIST_H */
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