[PATCH -mm 2/3] Documentation: update scatterlist struct description in DMA-API-HOWTO
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From: FUJITA Tomonori on 10 May 2010 23:00 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: FUJITA Tomonori <fujita.tomonori(a)lab.ntt.co.jp> --- Documentation/DMA-API-HOWTO.txt | 17 ++++------------- 1 files changed, 4 insertions(+), 13 deletions(-) diff --git a/Documentation/DMA-API-HOWTO.txt b/Documentation/DMA-API-HOWTO.txt index a38ddad..c3ab456 100644 --- a/Documentation/DMA-API-HOWTO.txt +++ b/Documentation/DMA-API-HOWTO.txt @@ -703,19 +703,10 @@ to "Closing". 1) Struct scatterlist requirements. - Struct scatterlist must contain, at a minimum, the following - members: - - struct page *page; - 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. + Don't invent the architecture specific struct scatterlist; just use + <asm-generic/scatterlist.h>. You need to enable + CONFIG_NEED_SG_DMA_LENGTH if the architecture supports IOMMUs + (including software IOMMU). 2) More to come... -- 1.6.5 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo(a)vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/ |