[PATCH v6 11/17] arm64: Allow kmalloc() caches aligned to the smaller cache_line_size()

[Catalin Marinas]

On arm64, ARCH_DMA_MINALIGN is 128, larger than the cache line size on
most of the current platforms (typically 64). Define
ARCH_KMALLOC_MINALIGN to 8 (the default for architectures without their
own ARCH_DMA_MINALIGN) and override dma_get_cache_alignment() to return
cache_line_size(), probed at run-time. The kmalloc() caches will be
limited to the cache line size. This will allow the additional
kmalloc-{64,192} caches on most arm64 platforms.

Signed-off-by: Catalin Marinas <catalin.marinas at arm.com>
Cc: Will Deacon <will at kernel.org>
---
 arch/arm64/include/asm/cache.h | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/arch/arm64/include/asm/cache.h b/arch/arm64/include/asm/cache.h
index a51e6e8f3171..ceb368d33bf4 100644
--- a/arch/arm64/include/asm/cache.h
+++ b/arch/arm64/include/asm/cache.h
@@ -33,6 +33,7 @@
  * the CPU.
  */
 #define ARCH_DMA_MINALIGN	(128)
+#define ARCH_KMALLOC_MINALIGN	(8)
 
 #ifndef __ASSEMBLY__
 
@@ -90,6 +91,8 @@ static inline int cache_line_size_of_cpu(void)
 
 int cache_line_size(void);
 
+#define dma_get_cache_alignment	cache_line_size
+
 /*
  * Read the effective value of CTR_EL0.
  *