From: Andrew Davis <afd@ti.com>
Date: Fri, 7 Oct 2022 17:11:11 +0000 (-0500)
Subject: dma: Use dma-mapping for cache ops and sync after write
X-Git-Url: http://git.dujemihanovic.xyz/?a=commitdiff_plain;h=c8d2fc75171465e19c8583a1ef266b3a7fe49281;p=u-boot.git

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

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>
---

diff --git a/drivers/dma/dma-uclass.c b/drivers/dma/dma-uclass.c
index 012609bb53..70f06f1f09 100644
--- a/drivers/dma/dma-uclass.c
+++ b/drivers/dma/dma-uclass.c
@@ -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) = {