From 4ab5f8ec7d71aea5fe13a48248242130f84ac6bb Mon Sep 17 00:00:00 2001 From: Catalin Marinas Date: Mon, 12 Jun 2023 16:31:45 +0100 Subject: mm/slab: decouple ARCH_KMALLOC_MINALIGN from ARCH_DMA_MINALIGN Patch series "mm, dma, arm64: Reduce ARCH_KMALLOC_MINALIGN to 8", v7. A series reducing the kmalloc() minimum alignment on arm64 to 8 (from 128). This patch (of 17): In preparation for supporting a kmalloc() minimum alignment smaller than the arch DMA alignment, decouple the two definitions. This requires that either the kmalloc() caches are aligned to a (run-time) cache-line size or the DMA API bounces unaligned kmalloc() allocations. Subsequent patches will implement both options. 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. Architectures opting in to a smaller ARCH_KMALLOC_MINALIGN will need to define its value in the arch headers. Since ARCH_DMA_MINALIGN is now always defined, adjust the #ifdef in dma_get_cache_alignment() so that there is no change for architectures not requiring a minimum DMA alignment. Link: https://lkml.kernel.org/r/20230612153201.554742-1-catalin.marinas@arm.com Link: https://lkml.kernel.org/r/20230612153201.554742-2-catalin.marinas@arm.com Signed-off-by: Catalin Marinas Tested-by: Isaac J. Manjarres Cc: Vlastimil Babka Cc: Christoph Hellwig Cc: Robin Murphy Cc: Alasdair Kergon Cc: Ard Biesheuvel Cc: Arnd Bergmann Cc: Daniel Vetter Cc: Greg Kroah-Hartman Cc: Herbert Xu Cc: Joerg Roedel Cc: Jonathan Cameron Cc: Marc Zyngier Cc: Mark Brown Cc: Mike Snitzer Cc: Rafael J. Wysocki Cc: Saravana Kannan Cc: Will Deacon Cc: Jerry Snitselaar Cc: Jonathan Cameron Cc: Lars-Peter Clausen Cc: Logan Gunthorpe Signed-off-by: Andrew Morton --- include/linux/cache.h | 6 ++++++ include/linux/dma-mapping.h | 3 ++- include/linux/slab.h | 14 ++++++++++---- 3 files changed, 18 insertions(+), 5 deletions(-) diff --git a/include/linux/cache.h b/include/linux/cache.h index 5da1bbd96154..9900d20b76c2 100644 --- a/include/linux/cache.h +++ b/include/linux/cache.h @@ -98,4 +98,10 @@ struct cacheline_padding { #define CACHELINE_PADDING(name) #endif +#ifdef ARCH_DMA_MINALIGN +#define ARCH_HAS_DMA_MINALIGN +#else +#define ARCH_DMA_MINALIGN __alignof__(unsigned long long) +#endif + #endif /* __LINUX_CACHE_H */ diff --git a/include/linux/dma-mapping.h b/include/linux/dma-mapping.h index 0ee20b764000..a50375331eac 100644 --- a/include/linux/dma-mapping.h +++ b/include/linux/dma-mapping.h @@ -2,6 +2,7 @@ #ifndef _LINUX_DMA_MAPPING_H #define _LINUX_DMA_MAPPING_H +#include #include #include #include @@ -545,7 +546,7 @@ static inline int dma_set_min_align_mask(struct device *dev, static inline int dma_get_cache_alignment(void) { -#ifdef ARCH_DMA_MINALIGN +#ifdef ARCH_HAS_DMA_MINALIGN return ARCH_DMA_MINALIGN; #endif return 1; diff --git a/include/linux/slab.h b/include/linux/slab.h index 6b3e155b70bf..ca53425e9b32 100644 --- a/include/linux/slab.h +++ b/include/linux/slab.h @@ -12,6 +12,7 @@ #ifndef _LINUX_SLAB_H #define _LINUX_SLAB_H +#include #include #include #include @@ -235,12 +236,17 @@ void kmem_dump_obj(void *object); * alignment larger than the alignment of a 64-bit integer. * Setting ARCH_DMA_MINALIGN in arch headers allows that. */ -#if defined(ARCH_DMA_MINALIGN) && ARCH_DMA_MINALIGN > 8 +#ifdef ARCH_HAS_DMA_MINALIGN +#if 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 +#endif + +#ifndef ARCH_KMALLOC_MINALIGN #define ARCH_KMALLOC_MINALIGN __alignof__(unsigned long long) +#elif ARCH_KMALLOC_MINALIGN > 8 +#define KMALLOC_MIN_SIZE ARCH_KMALLOC_MINALIGN +#define KMALLOC_SHIFT_LOW ilog2(KMALLOC_MIN_SIZE) #endif /* -- cgit v1.2.3