35 lines
966 B
C
35 lines
966 B
C
#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->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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struct page *page; /* Location for highmem page, if any */
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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 (0xffffffffUL)
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#endif /* !_ASM_SCATTERLIST_H */
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