xen: Stop abusing DT of_dma_configure API

As the removed comments say, these aren't DT based devices.
of_dma_configure() is going to stop allowing a NULL DT node and calling
it will no longer work.

The comment is also now out of date as of commit 9ab91e7c5c51 ("arm64:
default to the direct mapping in get_arch_dma_ops"). Direct mapping
is now the default rather than dma_dummy_ops.

According to Stefano and Oleksandr, the only other part needed is
setting the DMA masks and there's no reason to restrict the masks to
32-bits. So set the masks to 64 bits.

Cc: Robin Murphy <[email protected]>
Cc: Julien Grall <[email protected]>
Cc: Nicolas Saenz Julienne <[email protected]>
Cc: Oleksandr Andrushchenko <[email protected]>
Cc: Boris Ostrovsky <[email protected]>
Cc: Juergen Gross <[email protected]>
Cc: Stefano Stabellini <[email protected]>
Cc: Christoph Hellwig <[email protected]>
Cc: [email protected]
Signed-off-by: Rob Herring <[email protected]>
Acked-by: Oleksandr Andrushchenko <[email protected]>
Reviewed-by: Boris Ostrovsky <[email protected]>
Signed-off-by: Boris Ostrovsky <[email protected]>

1 files changed, 2 insertions, 10 deletions

diff --git a/drivers/gpu/drm/xen/xen_drm_front.c b/drivers/gpu/drm/xen/xen_drm_front.c
index 84aa4d61dc42..3406dfc9a605 100644
--- a/drivers/gpu/drm/xen/xen_drm_front.c
+++ b/drivers/gpu/drm/xen/xen_drm_front.c
@@ -716,17 +716,9 @@ static int xen_drv_probe(struct xenbus_device *xb_dev,
 	struct device *dev = &xb_dev->dev;
 	int ret;
 
-	/*
-	 * The device is not spawn from a device tree, so arch_setup_dma_ops
-	 * is not called, thus leaving the device with dummy DMA ops.
-	 * This makes the device return error on PRIME buffer import, which
-	 * is not correct: to fix this call of_dma_configure() with a NULL
-	 * node to set default DMA ops.
-	 */
-	dev->coherent_dma_mask = DMA_BIT_MASK(32);
-	ret = of_dma_configure(dev, NULL, true);
+	ret = dma_coerce_mask_and_coherent(dev, DMA_BIT_MASK(64));
 	if (ret < 0) {
-		DRM_ERROR("Cannot setup DMA ops, ret %d", ret);
+		DRM_ERROR("Cannot setup DMA mask, ret %d", ret);
 		return ret;
 	}