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| author | FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp> | 2010-08-14 16:36:17 +0900 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2010-08-14 11:56:46 -0700 |
| commit | ce00f7feb0a497b4280e1efe16e03728ed292687 (patch) | |
| tree | 43f643b31bb7208e62bba3d1d64549421d83a1be /Documentation/DMA-API-HOWTO.txt | |
| parent | b171aa27700c78511086a759383b033949c9d7f0 (diff) | |
| download | lwn-ce00f7feb0a497b4280e1efe16e03728ed292687.tar.gz lwn-ce00f7feb0a497b4280e1efe16e03728ed292687.zip | |
Documentation: DMA-API-HOWTO.txt: rename ARCH_KMALLOC_MINALIGN to ARCH_DMA_MINALIGN
ARCH_KMALLOC_MINALIGN was renamed to ARCH_DMA_MINALIGN (the commit
a6eb9fe105d5de0053b261148cee56c94b4720ca).
ARCH_DMA_MINALIGN must be defined instead of ARCH_KMALLOC_MINALIGN to
ensure that kmalloc'ed buffer is DMA-safe.
Signed-off-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'Documentation/DMA-API-HOWTO.txt')
| -rw-r--r-- | Documentation/DMA-API-HOWTO.txt | 6 |
1 files changed, 3 insertions, 3 deletions
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). |