| Message ID | 20230518173403.1150549-2-catalin.marinas@arm.com (mailing list archive) |
|---|---|
| State | New |
| Headers | show |
| Series | mm, dma, arm64: Reduce ARCH_KMALLOC_MINALIGN to 8 | expand |
On Thu, May 18, 2023 at 06:33:49PM +0100, Catalin Marinas wrote: > diff --git a/include/linux/slab.h b/include/linux/slab.h > index 6b3e155b70bf..3f76e7c53ada 100644 > --- a/include/linux/slab.h > +++ b/include/linux/slab.h > @@ -235,14 +235,24 @@ 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_DMA_MINALIGN > +#define 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) > +#endif > #else > +#define ARCH_DMA_MINALIGN __alignof__(unsigned long long) > +#endif > + > +#ifndef ARCH_KMALLOC_MINALIGN > #define ARCH_KMALLOC_MINALIGN __alignof__(unsigned long long) > #endif > > +#if ARCH_KMALLOC_MINALIGN > 8 > +#define KMALLOC_MIN_SIZE ARCH_KMALLOC_MINALIGN > +#define KMALLOC_SHIFT_LOW ilog2(KMALLOC_MIN_SIZE) > +#endif And another fixup here (reported by the test robot; I pushed the fixups to the git branch): diff --git a/include/linux/slab.h b/include/linux/slab.h index 3f76e7c53ada..50dcf9cfbf62 100644 --- a/include/linux/slab.h +++ b/include/linux/slab.h @@ -246,9 +246,7 @@ void kmem_dump_obj(void *object); #ifndef ARCH_KMALLOC_MINALIGN #define ARCH_KMALLOC_MINALIGN __alignof__(unsigned long long) -#endif - -#if ARCH_KMALLOC_MINALIGN > 8 +#elif ARCH_KMALLOC_MINALIGN > 8 #define KMALLOC_MIN_SIZE ARCH_KMALLOC_MINALIGN #define KMALLOC_SHIFT_LOW ilog2(KMALLOC_MIN_SIZE) #endif
diff --git a/include/linux/dma-mapping.h b/include/linux/dma-mapping.h index 0ee20b764000..3288a1339271 100644 --- a/include/linux/dma-mapping.h +++ b/include/linux/dma-mapping.h @@ -545,7 +545,7 @@ 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..3f76e7c53ada 100644 --- a/include/linux/slab.h +++ b/include/linux/slab.h @@ -235,14 +235,24 @@ 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_DMA_MINALIGN +#define 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) +#endif #else +#define ARCH_DMA_MINALIGN __alignof__(unsigned long long) +#endif + +#ifndef ARCH_KMALLOC_MINALIGN #define ARCH_KMALLOC_MINALIGN __alignof__(unsigned long long) #endif +#if ARCH_KMALLOC_MINALIGN > 8 +#define KMALLOC_MIN_SIZE ARCH_KMALLOC_MINALIGN +#define KMALLOC_SHIFT_LOW ilog2(KMALLOC_MIN_SIZE) +#endif + /* * Setting ARCH_SLAB_MINALIGN in arch headers allows a different alignment. * Intended for arches that get misalignment faults even for 64 bit integer
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. Signed-off-by: Catalin Marinas <catalin.marinas@arm.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Christoph Hellwig <hch@lst.de> Cc: Robin Murphy <robin.murphy@arm.com> --- include/linux/dma-mapping.h | 2 +- include/linux/slab.h | 16 +++++++++++++--- 2 files changed, 14 insertions(+), 4 deletions(-)