18dabf473e
Change the page member of the scatterlist structure to be an unsigned long, and encode more stuff in the lower bits: - Bits 0 and 1 zero: this is a normal sg entry. Next sg entry is located at sg + 1. - Bit 0 set: this is a chain entry, the next real entry is at ->page_link with the two low bits masked off. - Bit 1 set: this is the final entry in the sg entry. sg_next() will return NULL when passed such an entry. It's thus important that sg table users use the proper accessors to get and set the page member. Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
27 lines
743 B
C
27 lines
743 B
C
#ifndef _BLACKFIN_SCATTERLIST_H
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#define _BLACKFIN_SCATTERLIST_H
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#include <linux/mm.h>
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struct scatterlist {
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unsigned long page_link;
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unsigned int 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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/*
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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, or alternatively stop on the first sg_dma_len(sg) which
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* is 0.
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*/
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#define sg_address(sg) (page_address((sg)->page) + (sg)->offset)
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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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#define ISA_DMA_THRESHOLD (0xffffffff)
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#endif /* !(_BLACKFIN_SCATTERLIST_H) */
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