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Commit ce00f7fe authored by FUJITA Tomonori's avatar FUJITA Tomonori Committed by Linus Torvalds
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Documentation: DMA-API-HOWTO.txt: rename ARCH_KMALLOC_MINALIGN to ARCH_DMA_MINALIGN 



ARCH_KMALLOC_MINALIGN was renamed to ARCH_DMA_MINALIGN (the commit
a6eb9fe1).

ARCH_DMA_MINALIGN must be defined instead of ARCH_KMALLOC_MINALIGN to
ensure that kmalloc'ed buffer is DMA-safe.

Signed-off-by: default avatarFUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent b171aa27

Documentation/DMA-API-HOWTO.txt

+3 −3
Original line number Diff line number Diff line
@@ -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).