Platform: goldfish: goldfish_pipe.c: Add DMA support using managed version

Coherent mapping guarantees that the device and CPU are in sync.
Signed-off-by: NShraddha Barke <shraddha.6596@gmail.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/platform/goldfish/goldfish_pipe.c

@@ -57,6 +57,7 @@
 #include <linux/slab.h>
 #include <linux/io.h>
 #include <linux/goldfish.h>
+#include <linux/dma-mapping.h>
 
 /*
  * IMPORTANT: The following constants must match the ones used and defined
@@ -217,17 +218,16 @@ static int valid_batchbuffer_addr(struct goldfish_pipe_dev *dev,
 static int setup_access_params_addr(struct platform_device *pdev,
 					struct goldfish_pipe_dev *dev)
 {
-	u64 paddr;
+	dma_addr_t dma_handle;
 	struct access_params *aps;
 
-	aps = devm_kzalloc(&pdev->dev, sizeof(struct access_params), GFP_KERNEL);
+	aps = dmam_alloc_coherent(&pdev->dev, sizeof(struct access_params),
+				  &dma_handle, GFP_KERNEL);
 	if (!aps)
-		return -1;
+		return -ENOMEM;
 
-	/* FIXME */
-	paddr = __pa(aps);
-	writel((u32)(paddr >> 32), dev->base + PIPE_REG_PARAMS_ADDR_HIGH);
-	writel((u32)paddr, dev->base + PIPE_REG_PARAMS_ADDR_LOW);
+	writel(upper_32_bits(dma_handle), dev->base + PIPE_REG_PARAMS_ADDR_HIGH);
+	writel(lower_32_bits(dma_handle), dev->base + PIPE_REG_PARAMS_ADDR_LOW);
 
 	if (valid_batchbuffer_addr(dev, aps)) {
 		dev->aps = aps;