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Commit b02de871 authored by FUJITA Tomonori's avatar FUJITA Tomonori Committed by Linus Torvalds
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Documentation: update scatterlist struct description in DMA-API-HOWTO 



Now we have <asm-generic/scatterlist.h>.  Architectures should use it
instead of inventing the own scatterlist struct.  Let's update the
description.

Signed-off-by: default avatarFUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent 7cdcc8e4

Documentation/DMA-API-HOWTO.txt

+4 −13
Original line number Original line Diff line number Diff line
@@ -703,19 +703,10 @@ to "Closing". 




1) Struct scatterlist requirements.

1) Struct scatterlist requirements.





   Struct scatterlist must contain, at a minimum, the following

   Don't invent the architecture specific struct scatterlist; just use

   members:

   <asm-generic/scatterlist.h>. You need to enable



   CONFIG_NEED_SG_DMA_LENGTH if the architecture supports IOMMUs

	struct page *page;

   (including software IOMMU).

	unsigned int offset;

	unsigned int length;



   The base address is specified by a "page+offset" pair.



   Previous versions of struct scatterlist contained a "void *address"

   field that was sometimes used instead of page+offset.  As of Linux

   2.5., page+offset is always used, and the "address" field has been

   deleted.





2) More to come...

2) More to come...