1 files changed, 117 insertions, 0 deletions

diff --git a/drivers/usb/musb/musb_host.c b/drivers/usb/musb/musb_host.c
index 51e9e8a38444..8914dec49f01 100644
--- a/drivers/usb/musb/musb_host.c
+++ b/drivers/usb/musb/musb_host.c
@@ -2465,6 +2465,118 @@ static int musb_bus_resume(struct usb_hcd *hcd)
 	return 0;
 }
 
+
+#ifndef CONFIG_MUSB_PIO_ONLY
+
+#define MUSB_USB_DMA_ALIGN 4
+
+struct musb_temp_buffer {
+	void *kmalloc_ptr;
+	void *old_xfer_buffer;
+	u8 data[0];
+};
+
+static void musb_free_temp_buffer(struct urb *urb)
+{
+	enum dma_data_direction dir;
+	struct musb_temp_buffer *temp;
+
+	if (!(urb->transfer_flags & URB_ALIGNED_TEMP_BUFFER))
+		return;
+
+	dir = usb_urb_dir_in(urb) ? DMA_FROM_DEVICE : DMA_TO_DEVICE;
+
+	temp = container_of(urb->transfer_buffer, struct musb_temp_buffer,
+			    data);
+
+	if (dir == DMA_FROM_DEVICE) {
+		memcpy(temp->old_xfer_buffer, temp->data,
+		       urb->transfer_buffer_length);
+	}
+	urb->transfer_buffer = temp->old_xfer_buffer;
+	kfree(temp->kmalloc_ptr);
+
+	urb->transfer_flags &= ~URB_ALIGNED_TEMP_BUFFER;
+}
+
+static int musb_alloc_temp_buffer(struct urb *urb, gfp_t mem_flags)
+{
+	enum dma_data_direction dir;
+	struct musb_temp_buffer *temp;
+	void *kmalloc_ptr;
+	size_t kmalloc_size;
+
+	if (urb->num_sgs || urb->sg ||
+	    urb->transfer_buffer_length == 0 ||
+	    !((uintptr_t)urb->transfer_buffer & (MUSB_USB_DMA_ALIGN - 1)))
+		return 0;
+
+	dir = usb_urb_dir_in(urb) ? DMA_FROM_DEVICE : DMA_TO_DEVICE;
+
+	/* Allocate a buffer with enough padding for alignment */
+	kmalloc_size = urb->transfer_buffer_length +
+		sizeof(struct musb_temp_buffer) + MUSB_USB_DMA_ALIGN - 1;
+
+	kmalloc_ptr = kmalloc(kmalloc_size, mem_flags);
+	if (!kmalloc_ptr)
+		return -ENOMEM;
+
+	/* Position our struct temp_buffer such that data is aligned */
+	temp = PTR_ALIGN(kmalloc_ptr, MUSB_USB_DMA_ALIGN);
+
+
+	temp->kmalloc_ptr = kmalloc_ptr;
+	temp->old_xfer_buffer = urb->transfer_buffer;
+	if (dir == DMA_TO_DEVICE)
+		memcpy(temp->data, urb->transfer_buffer,
+		       urb->transfer_buffer_length);
+	urb->transfer_buffer = temp->data;
+
+	urb->transfer_flags |= URB_ALIGNED_TEMP_BUFFER;
+
+	return 0;
+}
+
+static int musb_map_urb_for_dma(struct usb_hcd *hcd, struct urb *urb,
+				      gfp_t mem_flags)
+{
+	struct musb	*musb = hcd_to_musb(hcd);
+	int ret;
+
+	/*
+	 * The DMA engine in RTL1.8 and above cannot handle
+	 * DMA addresses that are not aligned to a 4 byte boundary.
+	 * For such engine implemented (un)map_urb_for_dma hooks.
+	 * Do not use these hooks for RTL<1.8
+	 */
+	if (musb->hwvers < MUSB_HWVERS_1800)
+		return usb_hcd_map_urb_for_dma(hcd, urb, mem_flags);
+
+	ret = musb_alloc_temp_buffer(urb, mem_flags);
+	if (ret)
+		return ret;
+
+	ret = usb_hcd_map_urb_for_dma(hcd, urb, mem_flags);
+	if (ret)
+		musb_free_temp_buffer(urb);
+
+	return ret;
+}
+
+static void musb_unmap_urb_for_dma(struct usb_hcd *hcd, struct urb *urb)
+{
+	struct musb	*musb = hcd_to_musb(hcd);
+
+	usb_hcd_unmap_urb_for_dma(hcd, urb);
+
+	/* Do not use this hook for RTL<1.8 (see description above) */
+	if (musb->hwvers < MUSB_HWVERS_1800)
+		return;
+
+	musb_free_temp_buffer(urb);
+}
+#endif /* !CONFIG_MUSB_PIO_ONLY */
+
 const struct hc_driver musb_hc_driver = {
 	.description		= "musb-hcd",
 	.product_desc		= "MUSB HDRC host driver",
@@ -2484,6 +2596,11 @@ const struct hc_driver musb_hc_driver = {
 	.urb_dequeue		= musb_urb_dequeue,
 	.endpoint_disable	= musb_h_disable,
 
+#ifndef CONFIG_MUSB_PIO_ONLY
+	.map_urb_for_dma	= musb_map_urb_for_dma,
+	.unmap_urb_for_dma	= musb_unmap_urb_for_dma,
+#endif
+
 	.hub_status_data	= musb_hub_status_data,
 	.hub_control		= musb_hub_control,
 	.bus_suspend		= musb_bus_suspend,