[PATCH 10/10] arm64: Enable dynamic kmalloc() minimum alignment

Catalin Marinas
2022-04-05T14:03:37Z

Define ARCH_KMALLOC_MINALIGN as 64 since this would be the minimum
requirement across most arm64 SoCs. Define arch_kmalloc_minalign()
returning cache_line_size() to set the minimum run-time kmalloc()
alignment for those SoCs with bigger cache lines.

Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will@kernel.org>
---
arch/arm64/include/asm/cache.h | 1 +
arch/arm64/kernel/cacheinfo.c | 7 +++++++
2 files changed, 8 insertions(+)

diff --git a/arch/arm64/include/asm/cache.h b/arch/arm64/include/asm/cache.h
index a074459f8f2f..0bec986c9d51 100644
--- a/arch/arm64/include/asm/cache.h
+++ b/arch/arm64/include/asm/cache.h
@@ -48,6 +48,7 @@
* the CPU.
*/
#define ARCH_DMA_MINALIGN (128)
+#define ARCH_KMALLOC_MINALIGN (64)

#ifdef CONFIG_KASAN_SW_TAGS
#define ARCH_SLAB_MINALIGN (1ULL << KASAN_SHADOW_SCALE_SHIFT)
diff --git a/arch/arm64/kernel/cacheinfo.c b/arch/arm64/kernel/cacheinfo.c
index 587543c6c51c..61211cd597f7 100644
--- a/arch/arm64/kernel/cacheinfo.c
+++ b/arch/arm64/kernel/cacheinfo.c
@@ -97,3 +97,10 @@ int populate_cache_leaves(unsigned int cpu)
}
return 0;
}
+
+#ifndef CONFIG_SLOB
+unsigned int arch_kmalloc_minalign(void)
+{
+ return cache_line_size();
+}
+#endif