[PATCH v5 2/3] media: uvcvideo: use usb_alloc_noncoherent/usb_free_noncoherent()

[Xu Yang]

This will use USB noncoherent API to alloc/free urb buffers, then
uvc driver needn't to do dma sync operations by itself.

Reviewed-by: Ricardo Ribalda <ribalda@xxxxxxxxxxxx>
Signed-off-by: Xu Yang <xu.yang_2@xxxxxxx>

---
Changes in v5:
 - add Rb tag
Changes in v4:
 - remove uvc_stream_to_dmadev()
Changes in v3:
 - no changes
---
 drivers/media/usb/uvc/uvc_video.c | 61 +++++++------------------------
 1 file changed, 14 insertions(+), 47 deletions(-)

diff --git a/drivers/media/usb/uvc/uvc_video.c b/drivers/media/usb/uvc/uvc_video.c
index e3567aeb0007..a75af314e46b 100644
--- a/drivers/media/usb/uvc/uvc_video.c
+++ b/drivers/media/usb/uvc/uvc_video.c
@@ -1275,20 +1275,6 @@ static inline enum dma_data_direction uvc_stream_dir(
 		return DMA_TO_DEVICE;
 }
 
-static inline struct device *uvc_stream_to_dmadev(struct uvc_streaming *stream)
-{
-	return bus_to_hcd(stream->dev->udev->bus)->self.sysdev;
-}
-
-static int uvc_submit_urb(struct uvc_urb *uvc_urb, gfp_t mem_flags)
-{
-	/* Sync DMA. */
-	dma_sync_sgtable_for_device(uvc_stream_to_dmadev(uvc_urb->stream),
-				    uvc_urb->sgt,
-				    uvc_stream_dir(uvc_urb->stream));
-	return usb_submit_urb(uvc_urb->urb, mem_flags);
-}
-
 /*
  * uvc_video_decode_data_work: Asynchronous memcpy processing
  *
@@ -1310,7 +1296,7 @@ static void uvc_video_copy_data_work(struct work_struct *work)
 		uvc_queue_buffer_release(op->buf);
 	}
 
-	ret = uvc_submit_urb(uvc_urb, GFP_KERNEL);
+	ret = usb_submit_urb(uvc_urb->urb, GFP_KERNEL);
 	if (ret < 0)
 		dev_err(&uvc_urb->stream->intf->dev,
 			"Failed to resubmit video URB (%d).\n", ret);
@@ -1736,12 +1722,6 @@ static void uvc_video_complete(struct urb *urb)
 	/* Re-initialise the URB async work. */
 	uvc_urb->async_operations = 0;
 
-	/* Sync DMA and invalidate vmap range. */
-	dma_sync_sgtable_for_cpu(uvc_stream_to_dmadev(uvc_urb->stream),
-				 uvc_urb->sgt, uvc_stream_dir(stream));
-	invalidate_kernel_vmap_range(uvc_urb->buffer,
-				     uvc_urb->stream->urb_size);
-
 	/*
 	 * Process the URB headers, and optionally queue expensive memcpy tasks
 	 * to be deferred to a work queue.
@@ -1750,7 +1730,7 @@ static void uvc_video_complete(struct urb *urb)
 
 	/* If no async work is needed, resubmit the URB immediately. */
 	if (!uvc_urb->async_operations) {
-		ret = uvc_submit_urb(uvc_urb, GFP_ATOMIC);
+		ret = usb_submit_urb(uvc_urb->urb, GFP_ATOMIC);
 		if (ret < 0)
 			dev_err(&stream->intf->dev,
 				"Failed to resubmit video URB (%d).\n", ret);
@@ -1765,17 +1745,15 @@ static void uvc_video_complete(struct urb *urb)
  */
 static void uvc_free_urb_buffers(struct uvc_streaming *stream)
 {
-	struct device *dma_dev = uvc_stream_to_dmadev(stream);
+	struct usb_device *udev = stream->dev->udev;
 	struct uvc_urb *uvc_urb;
 
 	for_each_uvc_urb(uvc_urb, stream) {
 		if (!uvc_urb->buffer)
 			continue;
 
-		dma_vunmap_noncontiguous(dma_dev, uvc_urb->buffer);
-		dma_free_noncontiguous(dma_dev, stream->urb_size, uvc_urb->sgt,
-				       uvc_stream_dir(stream));
-
+		usb_free_noncoherent(udev, stream->urb_size, uvc_urb->buffer,
+				     uvc_stream_dir(stream), uvc_urb->sgt);
 		uvc_urb->buffer = NULL;
 		uvc_urb->sgt = NULL;
 	}
@@ -1786,26 +1764,13 @@ static void uvc_free_urb_buffers(struct uvc_streaming *stream)
 static bool uvc_alloc_urb_buffer(struct uvc_streaming *stream,
 				 struct uvc_urb *uvc_urb, gfp_t gfp_flags)
 {
-	struct device *dma_dev = uvc_stream_to_dmadev(stream);
-
-	uvc_urb->sgt = dma_alloc_noncontiguous(dma_dev, stream->urb_size,
-					       uvc_stream_dir(stream),
-					       gfp_flags, 0);
-	if (!uvc_urb->sgt)
-		return false;
-	uvc_urb->dma = uvc_urb->sgt->sgl->dma_address;
-
-	uvc_urb->buffer = dma_vmap_noncontiguous(dma_dev, stream->urb_size,
-						 uvc_urb->sgt);
-	if (!uvc_urb->buffer) {
-		dma_free_noncontiguous(dma_dev, stream->urb_size,
-				       uvc_urb->sgt,
-				       uvc_stream_dir(stream));
-		uvc_urb->sgt = NULL;
-		return false;
-	}
+	struct usb_device *udev = stream->dev->udev;
 
-	return true;
+	uvc_urb->buffer = usb_alloc_noncoherent(udev, stream->urb_size,
+						gfp_flags, &uvc_urb->dma,
+						uvc_stream_dir(stream),
+						&uvc_urb->sgt);
+	return !!uvc_urb->buffer;
 }
 
 /*
@@ -1953,6 +1918,7 @@ static int uvc_init_video_isoc(struct uvc_streaming *stream,
 		urb->complete = uvc_video_complete;
 		urb->number_of_packets = npackets;
 		urb->transfer_buffer_length = size;
+		urb->sgt = uvc_urb->sgt;
 
 		for (i = 0; i < npackets; ++i) {
 			urb->iso_frame_desc[i].offset = i * psize;
@@ -2009,6 +1975,7 @@ static int uvc_init_video_bulk(struct uvc_streaming *stream,
 				  size, uvc_video_complete, uvc_urb);
 		urb->transfer_flags = URB_NO_TRANSFER_DMA_MAP;
 		urb->transfer_dma = uvc_urb->dma;
+		urb->sgt = uvc_urb->sgt;
 
 		uvc_urb->urb = urb;
 	}
@@ -2120,7 +2087,7 @@ static int uvc_video_start_transfer(struct uvc_streaming *stream,
 
 	/* Submit the URBs. */
 	for_each_uvc_urb(uvc_urb, stream) {
-		ret = uvc_submit_urb(uvc_urb, gfp_flags);
+		ret = usb_submit_urb(uvc_urb->urb, gfp_flags);
 		if (ret < 0) {
 			dev_err(&stream->intf->dev,
 				"Failed to submit URB %u (%d).\n",
-- 
2.34.1