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).