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| author | Michael S. Tsirkin <mst@redhat.com> | 2025-12-29 11:53:39 +0300 |
|---|---|---|
| committer | Michael S. Tsirkin <mst@redhat.com> | 2026-01-01 03:27:45 +0300 |
| commit | ca085faabb42c31ee204235facc5a430cb9e78a9 (patch) | |
| tree | 0f92f415a52b2b92cd2e2e7d6906f7cd266477eb /include/linux | |
| parent | f6a15d85498614baf121f7e207e6c55524f175a4 (diff) | |
| download | linux-ca085faabb42c31ee204235facc5a430cb9e78a9.tar.xz | |
dma-mapping: add __dma_from_device_group_begin()/end()
When a structure contains a buffer that DMA writes to alongside fields
that the CPU writes to, cache line sharing between the DMA buffer and
CPU-written fields can cause data corruption on non-cache-coherent
platforms.
Add __dma_from_device_group_begin()/end() annotations to ensure proper
alignment to prevent this:
struct my_device {
spinlock_t lock1;
__dma_from_device_group_begin();
char dma_buffer1[16];
char dma_buffer2[16];
__dma_from_device_group_end();
spinlock_t lock2;
};
Message-ID: <19163086d5e4704c316f18f6da06bc1c72968904.1767601130.git.mst@redhat.com>
Acked-by: Marek Szyprowski <m.szyprowski@samsung.com>
Reviewed-by: Petr Tesarik <ptesarik@suse.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Diffstat (limited to 'include/linux')
| -rw-r--r-- | include/linux/dma-mapping.h | 13 |
1 files changed, 13 insertions, 0 deletions
diff --git a/include/linux/dma-mapping.h b/include/linux/dma-mapping.h index aa36a0d1d9df..29ad2ce700f0 100644 --- a/include/linux/dma-mapping.h +++ b/include/linux/dma-mapping.h @@ -7,6 +7,7 @@ #include <linux/dma-direction.h> #include <linux/scatterlist.h> #include <linux/bug.h> +#include <linux/cache.h> /** * List of possible attributes associated with a DMA mapping. The semantics @@ -703,6 +704,18 @@ static inline int dma_get_cache_alignment(void) } #endif +#ifdef ARCH_HAS_DMA_MINALIGN +#define ____dma_from_device_aligned __aligned(ARCH_DMA_MINALIGN) +#else +#define ____dma_from_device_aligned +#endif +/* Mark start of DMA buffer */ +#define __dma_from_device_group_begin(GROUP) \ + __cacheline_group_begin(GROUP) ____dma_from_device_aligned +/* Mark end of DMA buffer */ +#define __dma_from_device_group_end(GROUP) \ + __cacheline_group_end(GROUP) ____dma_from_device_aligned + static inline void *dmam_alloc_coherent(struct device *dev, size_t size, dma_addr_t *dma_handle, gfp_t gfp) { |