[RFC 0/2] DMA-mapping & IOMMU - physically contiguous allocations

From: Marek Szyprowski
Date: Mon Oct 15 2012 - 10:04:03 EST


Hello,

Some devices, which have IOMMU, for some use cases might require to
allocate a buffers for DMA which is contiguous in physical memory. Such
use cases appears for example in DRM subsystem when one wants to improve
performance or use secure buffer protection.

I would like to ask if adding a new attribute, as proposed in this RFC
is a good idea? I feel that it might be an attribute just for a single
driver, but I would like to know your opinion. Should we look for other
solution?

Best regards
--
Marek Szyprowski
Samsung Poland R&D Center


Marek Szyprowski (2):
common: DMA-mapping: add DMA_ATTR_FORCE_CONTIGUOUS attribute
ARM: dma-mapping: add support for DMA_ATTR_FORCE_CONTIGUOUS attribute

Documentation/DMA-attributes.txt | 9 +++++++++
arch/arm/mm/dma-mapping.c | 41 ++++++++++++++++++++++++++++++--------
include/linux/dma-attrs.h | 1 +
3 files changed, 43 insertions(+), 8 deletions(-)

--
1.7.9.5

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