drm: exynos: use common helper for a scatterlist contiguity check

Use common helper for checking the contiguity of the imported dma-buf.
Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com>
Reviewed-by: Andrzej Hajda <a.hajda@samsung.com>
Acked-by : Inki Dae <inki.dae@samsung.com>

drivers/gpu/drm/exynos/exynos_drm_gem.c

@@ -431,28 +431,11 @@ exynos_drm_gem_prime_import_sg_table(struct drm_device *dev,
 {
 	struct exynos_drm_gem *exynos_gem;
 
-	if (sgt->nents < 1)
-		return ERR_PTR(-EINVAL);
-
-	/*
-	 * Check if the provided buffer has been mapped as contiguous
-	 * into DMA address space.
-	 */
-	if (sgt->nents > 1) {
-		dma_addr_t next_addr = sg_dma_address(sgt->sgl);
-		struct scatterlist *s;
-		unsigned int i;
-
-		for_each_sg(sgt->sgl, s, sgt->nents, i) {
-			if (!sg_dma_len(s))
-				break;
-			if (sg_dma_address(s) != next_addr) {
+	/* check if the entries in the sg_table are contiguous */
+	if (drm_prime_get_contiguous_size(sgt) < attach->dmabuf->size) {
 		DRM_ERROR("buffer chunks must be mapped contiguously");
 		return ERR_PTR(-EINVAL);
 	}
-			next_addr = sg_dma_address(s) + sg_dma_len(s);
-		}
-	}
 
 	exynos_gem = exynos_drm_gem_init(dev, attach->dmabuf->size);
 	if (IS_ERR(exynos_gem))