From: Tien Fong Chee <tien.fong.c...@intel.com>
This new DMA class function enables DMA being used for initializing
a range of destination such as memory to zeros. This is quite useful to
help accelerating the performance in scrubbing memory when ECC is enabled.
Signed-off-by: Tien Fong Chee <tien.fong.c...@intel.com>
---
drivers/dma/dma-uclass.c | 15 +++++++++++++++
include/dma.h | 12 ++++++++++++
2 files changed, 27 insertions(+)
diff --git a/drivers/dma/dma-uclass.c b/drivers/dma/dma-uclass.c
index a33f7d5..cb83c24 100644
--- a/drivers/dma/dma-uclass.c
+++ b/drivers/dma/dma-uclass.c
@@ -61,6 +61,21 @@ int dma_memcpy(void *dst, void *src, size_t len)
return ops->transfer(dev, DMA_MEM_TO_MEM, dst, src, len);
}
+int dma_memcpy_zeroes(struct udevice *dev, void *dst, size_t len)
+{
+ const struct dma_ops *ops;
+
+ ops = device_get_ops(dev);
+ if (!ops->transfer_zeroes)
+ 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));
+
+ return ops->transfer_zeroes(dev, dst, len);
+}
+
UCLASS_DRIVER(dma) = {
.id = UCLASS_DMA,
.name = "dma",
diff --git a/include/dma.h b/include/dma.h
index 50e9652..6bad2264 100644
--- a/include/dma.h
+++ b/include/dma.h
@@ -46,6 +46,7 @@ struct dma_ops {
*/
int (*transfer)(struct udevice *dev, int direction, void *dst,
void *src, size_t len);
+ int (*transfer_zeroes)(struct udevice *dev, void *dst, size_t len);
};
/*
@@ -82,4 +83,15 @@ int dma_get_device(u32 transfer_type, struct udevice **devp);
*/
int dma_memcpy(void *dst, void *src, size_t len);
+/*
+ * dma_memcpy_zeroes - Fill up destination with zeros through DMA.
+ *
+ * @dev: The DMA device
+ * @dst: destination pointer
+ * @len: length to be copied with zero
+ * @return: on successful transfer returns zero.
+ * on failure returns error code.
+ */
+int dma_memcpy_zeroes(struct udevice *dev, void *dst, size_t len);
+
#endif /* _DMA_H_ */
--
2.2.0
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