dwc2: Add dcache support

This adds dcache support for dwc2. The DMA buffers must be DMA aligned and
is flushed for outgoing transactions before starting transfer. For
ingoing transactions it is invalidated after the transfer has finished.

Signed-off-by: Alexander Stein <alexanders83@web.de>
Acked-by: Stephen Warren <swarren@wwwdotorg.org>
[trini: Update to apply again on top of DM patches]
Signed-off-by: Tom Rini <trini@konsulko.com>

drivers/usb/host/dwc2.c

@@ -27,8 +27,8 @@
 
 struct dwc2_priv {
 #ifdef CONFIG_DM_USB
-	uint8_t aligned_buffer[DWC2_DATA_BUF_SIZE] __aligned(8);
-	uint8_t status_buffer[DWC2_STATUS_BUF_SIZE] __aligned(8);
+	uint8_t aligned_buffer[DWC2_DATA_BUF_SIZE] __aligned(ARCH_DMA_MINALIGN);
+	uint8_t status_buffer[DWC2_STATUS_BUF_SIZE] __aligned(ARCH_DMA_MINALIGN);
 #else
 	uint8_t *aligned_buffer;
 	uint8_t *status_buffer;
@@ -39,9 +39,11 @@ struct dwc2_priv {
 };
 
 #ifndef CONFIG_DM_USB
-/* We need doubleword-aligned buffers for DMA transfers */
-DEFINE_ALIGN_BUFFER(uint8_t, aligned_buffer_addr, DWC2_DATA_BUF_SIZE, 8);
-DEFINE_ALIGN_BUFFER(uint8_t, status_buffer_addr, DWC2_STATUS_BUF_SIZE, 8);
+/* We need cacheline-aligned buffers for DMA transfers and dcache support */
+DEFINE_ALIGN_BUFFER(uint8_t, aligned_buffer_addr, DWC2_DATA_BUF_SIZE,
+		ARCH_DMA_MINALIGN);
+DEFINE_ALIGN_BUFFER(uint8_t, status_buffer_addr, DWC2_STATUS_BUF_SIZE,
+		ARCH_DMA_MINALIGN);
 
 static struct dwc2_priv local;
 #endif
@@ -821,8 +823,11 @@ int chunk_msg(struct dwc2_priv *priv, struct usb_device *dev,
 		       &hc_regs->hctsiz);
 
 		if (!in) {
-			memcpy(priv->aligned_buffer, (char *)buffer + done,
-			       len);
+			memcpy(priv->aligned_buffer, (char *)buffer + done, len);
+
+			flush_dcache_range((unsigned long)priv->aligned_buffer,
+				(unsigned long)((void *)priv->aligned_buffer +
+				roundup(len, ARCH_DMA_MINALIGN)));
 		}
 
 		writel(phys_to_bus((unsigned long)priv->aligned_buffer),
@@ -840,6 +845,11 @@ int chunk_msg(struct dwc2_priv *priv, struct usb_device *dev,
 
 		if (in) {
 			xfer_len -= sub;
+
+			invalidate_dcache_range((unsigned long)priv->aligned_buffer,
+				(unsigned long)((void *)priv->aligned_buffer +
+				roundup(xfer_len, ARCH_DMA_MINALIGN)));
+
 			memcpy(buffer + done, priv->aligned_buffer, xfer_len);
 			if (sub)
 				stop_transfer = 1;