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>
diff --git a/Documentation/DMA-API-HOWTO.txt b/Documentation/DMA-API-HOWTO.txt
index 3c4e071..d568bc2 100644
--- a/Documentation/DMA-API-HOWTO.txt
+++ b/Documentation/DMA-API-HOWTO.txt
@@ -738,17 +738,17 @@
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).