| Message ID | 20230518173403.1150549-15-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 06:34:02PM +0100, Catalin Marinas wrote: > If an architecture opted in to DMA bouncing of unaligned kmalloc() > buffers (ARCH_WANT_KMALLOC_DMA_BOUNCE), reduce the minimum kmalloc() > cache alignment below cache-line size to ARCH_KMALLOC_MINALIGN. > > 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> > --- > mm/slab_common.c | 9 ++++++++- > 1 file changed, 8 insertions(+), 1 deletion(-) > > diff --git a/mm/slab_common.c b/mm/slab_common.c > index 7c6475847fdf..84e5a5e435d6 100644 > --- a/mm/slab_common.c > +++ b/mm/slab_common.c > @@ -18,6 +18,7 @@ > #include <linux/uaccess.h> > #include <linux/seq_file.h> > #include <linux/dma-mapping.h> > +#include <linux/swiotlb.h> > #include <linux/proc_fs.h> > #include <linux/debugfs.h> > #include <linux/kasan.h> > @@ -865,7 +866,13 @@ void __init setup_kmalloc_cache_index_table(void) > > static unsigned int __kmalloc_minalign(void) > { > - return dma_get_cache_alignment(); > + int cache_align = dma_get_cache_alignment(); > + > + if (!IS_ENABLED(CONFIG_DMA_BOUNCE_UNALIGNED_KMALLOC) || > + io_tlb_default_mem.nslabs == 0) > + return cache_align; > + > + return ARCH_KMALLOC_MINALIGN; > } This gives a build error if the architecture doesn't select SWIOTLB (I had this done properly in v3 but for some reason I rewrote it here). The fixup is to add #ifdefs. I'll fold this in for v5: diff --git a/mm/slab_common.c b/mm/slab_common.c index 84e5a5e435d6..fe46459a8b77 100644 --- a/mm/slab_common.c +++ b/mm/slab_common.c @@ -864,16 +864,19 @@ void __init setup_kmalloc_cache_index_table(void) } } +#ifdef CONFIG_DMA_BOUNCE_UNALIGNED_KMALLOC static unsigned int __kmalloc_minalign(void) { - int cache_align = dma_get_cache_alignment(); - - if (!IS_ENABLED(CONFIG_DMA_BOUNCE_UNALIGNED_KMALLOC) || - io_tlb_default_mem.nslabs == 0) - return cache_align; - - return ARCH_KMALLOC_MINALIGN; + if (io_tlb_default_mem.nslabs) + return ARCH_KMALLOC_MINALIGN; + return dma_get_cache_alignment(); } +#else +static unsigned int __kmalloc_minalign(void) +{ + return dma_get_cache_alignment(); +} +#endif void __init new_kmalloc_cache(int idx, enum kmalloc_cache_type type, slab_flags_t flags)
diff --git a/mm/slab_common.c b/mm/slab_common.c index 7c6475847fdf..84e5a5e435d6 100644 --- a/mm/slab_common.c +++ b/mm/slab_common.c @@ -18,6 +18,7 @@ #include <linux/uaccess.h> #include <linux/seq_file.h> #include <linux/dma-mapping.h> +#include <linux/swiotlb.h> #include <linux/proc_fs.h> #include <linux/debugfs.h> #include <linux/kasan.h> @@ -865,7 +866,13 @@ void __init setup_kmalloc_cache_index_table(void) static unsigned int __kmalloc_minalign(void) { - return dma_get_cache_alignment(); + int cache_align = dma_get_cache_alignment(); + + if (!IS_ENABLED(CONFIG_DMA_BOUNCE_UNALIGNED_KMALLOC) || + io_tlb_default_mem.nslabs == 0) + return cache_align; + + return ARCH_KMALLOC_MINALIGN; } void __init
If an architecture opted in to DMA bouncing of unaligned kmalloc() buffers (ARCH_WANT_KMALLOC_DMA_BOUNCE), reduce the minimum kmalloc() cache alignment below cache-line size to ARCH_KMALLOC_MINALIGN. 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> --- mm/slab_common.c | 9 ++++++++- 1 file changed, 8 insertions(+), 1 deletion(-)