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@xxxxxxx>
Reviewed-by: Vlastimil Babka <vbabka@xxxxxxx>
Cc: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
Cc: Christoph Hellwig <hch@xxxxxx>
Cc: Robin Murphy <robin.murphy@xxxxxxx>
Tested-by: Isaac J. Manjarres <isaacmanjarres@xxxxxxxxxx>
---
mm/slab_common.c | 5 +++++
1 file changed, 5 insertions(+)
diff --git a/mm/slab_common.c b/mm/slab_common.c
index 7c6475847fdf..43c008165f56 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>
@@ -865,6 +866,10 @@ void __init setup_kmalloc_cache_index_table(void)
static unsigned int __kmalloc_minalign(void)
{
+#ifdef CONFIG_DMA_BOUNCE_UNALIGNED_KMALLOC
+ if (io_tlb_default_mem.nslabs)
+ return ARCH_KMALLOC_MINALIGN;
+#endif
return dma_get_cache_alignment();
}
