X-Git-Url: https://git.karo-electronics.de/?a=blobdiff_plain;f=Documentation%2FDMA-API-HOWTO.txt;h=d568bc235bc008a215b981bcf303352c54bbda3a;hb=1b68c9596ce17a1e06918ed65fc3d19b92b04aab;hp=3c4e07123e59a6d441319a4f96cbf2730e4fde1c;hpb=83ae170092c8ec4d8a268d93438054e32493ee17;p=karo-tx-linux.git diff --git a/Documentation/DMA-API-HOWTO.txt b/Documentation/DMA-API-HOWTO.txt index 3c4e07123e59..d568bc235bc0 100644 --- a/Documentation/DMA-API-HOWTO.txt +++ b/Documentation/DMA-API-HOWTO.txt @@ -738,17 +738,17 @@ to "Closing". CONFIG_NEED_SG_DMA_LENGTH if the architecture supports IOMMUs (including software IOMMU). -2) ARCH_KMALLOC_MINALIGN +2) ARCH_DMA_MINALIGN Architectures must ensure that kmalloc'ed buffer is DMA-safe. Drivers and subsystems depend on it. If an architecture isn't fully DMA-coherent (i.e. hardware doesn't ensure that data in the CPU cache is identical to data in main memory), - ARCH_KMALLOC_MINALIGN must be set so that the memory allocator + ARCH_DMA_MINALIGN must be set so that the memory allocator makes sure that kmalloc'ed buffer doesn't share a cache line with the others. See arch/arm/include/asm/cache.h as an example. - Note that ARCH_KMALLOC_MINALIGN is about DMA memory alignment + Note that ARCH_DMA_MINALIGN is about DMA memory alignment constraints. You don't need to worry about the architecture data alignment constraints (e.g. the alignment constraints about 64-bit objects).