Re: Question: how to map SCSI data DMA address to virtual address?

[James Bottomley]

On Thu, 2006-03-02 at 17:09 +0000, Christoph Hellwig wrote:
> For each sg list entry do something like:
> 
> 	buffer = kmap_atomic(sg->page, KM_USER0) + sg->offset;
> 	<access buffer>
> 	kunmap_atomic(buffer - sg->offset, KM_USER0);

Remember too that the data might not necessarily be valid without a
flush depending on where it has come from (or where it is going).  See
the dma_sync_sg_for_device/cpu.

James


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