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dma: Use dma-mapping for cache ops and sync after write

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The DMA'd memory area needs cleaned and invalidated after the DMA
write so that any stale cache lines do not mask new data.

Signed-off-by: Andrew Davis <afd@ti.com>
This commit is contained in:
Andrew Davis 2022-10-07 12:11:11 -05:00 committed by Tom Rini
parent fc95f83ec9
commit c8d2fc7517
1 changed files with 13 additions and 4 deletions
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17
drivers/dma/dma-uclass.c
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@ -19,6 +19,7 @@
#include <asm/cache.h>
#include <dm/read.h>
#include <dma-uclass.h>
#include <linux/dma-mapping.h>
#include <dt-structs.h>
#include <errno.h>
@ -235,6 +236,8 @@ int dma_memcpy(void *dst, void *src, size_t len)
{
struct udevice *dev;
const struct dma_ops *ops;
dma_addr_t destination;
dma_addr_t source;
int ret;
ret = dma_get_device(DMA_SUPPORTS_MEM_TO_MEM, &dev);
@ -245,11 +248,17 @@ int dma_memcpy(void *dst, void *src, size_t len)
if (!ops->transfer)
return -ENOSYS;
/* Invalidate the area, so no writeback into the RAM races with DMA */
invalidate_dcache_range((unsigned long)dst, (unsigned long)dst +
roundup(len, ARCH_DMA_MINALIGN));
/* Clean the areas, so no writeback into the RAM races with DMA */
destination = dma_map_single(dst, len, DMA_FROM_DEVICE);
source = dma_map_single(src, len, DMA_TO_DEVICE);
return ops->transfer(dev, DMA_MEM_TO_MEM, dst, src, len);
ret = ops->transfer(dev, DMA_MEM_TO_MEM, dst, src, len);
/* Clean+Invalidate the areas after, so we can see DMA'd data */
dma_unmap_single(destination, len, DMA_FROM_DEVICE);
dma_unmap_single(source, len, DMA_TO_DEVICE);
return ret;
}
UCLASS_DRIVER(dma) = {