Messages in this thread | | | Date | Tue, 01 Jul 2003 17:21:36 -0700 (PDT) | Subject | Re: [RFC] block layer support for DMA IOMMU bypass mode II | From | "David S. Miller" <> |
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From: Andi Kleen <ak@suse.de> Date: Wed, 2 Jul 2003 02:22:44 +0200
On Tue, 01 Jul 2003 17:03:23 -0700 (PDT) "David S. Miller" <davem@redhat.com> wrote:
> What do you mean? You map only one 4K chunk, and this is used > for all the sub-1K mappings. How should this work when the 1K mappings are spread all over memory? Maybe I'm missing something but from James description it sounds like the block layer assumes that it can pass in a sglist with arbitary elements and get it back remapped to continuous DMA addresses. It assumes it can pass in an sglist with arbitrary "virtually contiguous" elements and get back a continuous DMA address.
The BIO_VMERGE_BOUNDRY defines the IOMMU page size and therefore what "virtually contiguous" means. - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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