In preparation for supporting a dynamic kmalloc() minimum alignment, allow architectures to define ARCH_KMALLOC_MINALIGN independently of ARCH_DMA_MINALIGN. In addition, always define ARCH_DMA_MINALIGN even if an architecture does not override it. After this patch, ARCH_DMA_MINALIGN is expected to be used in static alignment annotations and defined by an architecture to be the maximum alignment for all supported configurations/SoCs in a single Image. ARCH_KMALLOC_MINALIGN, if different, is the minimum alignment guaranteed by kmalloc(). Signed-off-by: Catalin Marinas <catalin.marinas@xxxxxxx> Cc: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- include/linux/slab.h | 23 ++++++++++++++++++----- 1 file changed, 18 insertions(+), 5 deletions(-) diff --git a/include/linux/slab.h b/include/linux/slab.h index 373b3ef99f4e..d58211bdeceb 100644 --- a/include/linux/slab.h +++ b/include/linux/slab.h @@ -187,17 +187,30 @@ bool kmem_valid_obj(void *object); void kmem_dump_obj(void *object); #endif +/* + * slob does not support independent control of ARCH_KMALLOC_MINALIGN and + * ARCH_DMA_MINALIGN. + */ +#ifdef CONFIG_SLOB +#undef ARCH_KMALLOC_MINALIGN +#endif + /* * Some archs want to perform DMA into kmalloc caches and need a guaranteed * alignment larger than the alignment of a 64-bit integer. - * Setting ARCH_KMALLOC_MINALIGN in arch headers allows that. + * Setting ARCH_DMA_MINALIGN in arch headers allows that. */ -#if defined(ARCH_DMA_MINALIGN) && ARCH_DMA_MINALIGN > 8 +#ifndef ARCH_DMA_MINALIGN +#define ARCH_DMA_MINALIGN __alignof__(unsigned long long) +#elif ARCH_DMA_MINALIGN > 8 && !defined(ARCH_KMALLOC_MINALIGN) #define ARCH_KMALLOC_MINALIGN ARCH_DMA_MINALIGN -#define KMALLOC_MIN_SIZE ARCH_DMA_MINALIGN -#define KMALLOC_SHIFT_LOW ilog2(ARCH_DMA_MINALIGN) -#else +#endif + +#ifndef ARCH_KMALLOC_MINALIGN #define ARCH_KMALLOC_MINALIGN __alignof__(unsigned long long) +#else +#define KMALLOC_MIN_SIZE ARCH_KMALLOC_MINALIGN +#define KMALLOC_SHIFT_LOW ilog2(KMALLOC_MIN_SIZE) #endif /*
