diff options
author | FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp> | 2010-08-14 03:36:17 -0400 |
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committer | Linus Torvalds <torvalds@linux-foundation.org> | 2010-08-14 14:56:46 -0400 |
commit | ce00f7feb0a497b4280e1efe16e03728ed292687 (patch) | |
tree | 43f643b31bb7208e62bba3d1d64549421d83a1be /Documentation | |
parent | b171aa27700c78511086a759383b033949c9d7f0 (diff) |
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')
-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". | |||
738 | CONFIG_NEED_SG_DMA_LENGTH if the architecture supports IOMMUs | 738 | CONFIG_NEED_SG_DMA_LENGTH if the architecture supports IOMMUs |
739 | (including software IOMMU). | 739 | (including software IOMMU). |
740 | 740 | ||
741 | 2) ARCH_KMALLOC_MINALIGN | 741 | 2) ARCH_DMA_MINALIGN |
742 | 742 | ||
743 | Architectures must ensure that kmalloc'ed buffer is | 743 | Architectures must ensure that kmalloc'ed buffer is |
744 | DMA-safe. Drivers and subsystems depend on it. If an architecture | 744 | DMA-safe. Drivers and subsystems depend on it. If an architecture |
745 | isn't fully DMA-coherent (i.e. hardware doesn't ensure that data in | 745 | isn't fully DMA-coherent (i.e. hardware doesn't ensure that data in |
746 | the CPU cache is identical to data in main memory), | 746 | the CPU cache is identical to data in main memory), |
747 | ARCH_KMALLOC_MINALIGN must be set so that the memory allocator | 747 | ARCH_DMA_MINALIGN must be set so that the memory allocator |
748 | makes sure that kmalloc'ed buffer doesn't share a cache line with | 748 | makes sure that kmalloc'ed buffer doesn't share a cache line with |
749 | the others. See arch/arm/include/asm/cache.h as an example. | 749 | the others. See arch/arm/include/asm/cache.h as an example. |
750 | 750 | ||
751 | Note that ARCH_KMALLOC_MINALIGN is about DMA memory alignment | 751 | Note that ARCH_DMA_MINALIGN is about DMA memory alignment |
752 | constraints. You don't need to worry about the architecture data | 752 | constraints. You don't need to worry about the architecture data |
753 | alignment constraints (e.g. the alignment constraints about 64-bit | 753 | alignment constraints (e.g. the alignment constraints about 64-bit |
754 | objects). | 754 | objects). |