drm/tegra: Add PRIME support

Implement very basic PRIME support. This currently only works with
buffers that are contiguous in memory and will refuse to import any
physically non-contiguous buffers.

Signed-off-by: Thierry Reding <treding@nvidia.com>
diff --git a/drivers/gpu/drm/tegra/gem.h b/drivers/gpu/drm/tegra/gem.h
index 007e0be..ffd4f792 100644
--- a/drivers/gpu/drm/tegra/gem.h
+++ b/drivers/gpu/drm/tegra/gem.h
@@ -31,6 +31,7 @@
 	struct drm_gem_object gem;
 	struct host1x_bo base;
 	unsigned long flags;
+	struct sg_table *sgt;
 	dma_addr_t paddr;
 	void *vaddr;
 };
@@ -57,4 +58,10 @@
 
 extern const struct vm_operations_struct tegra_bo_vm_ops;
 
+struct dma_buf *tegra_gem_prime_export(struct drm_device *drm,
+				       struct drm_gem_object *gem,
+				       int flags);
+struct drm_gem_object *tegra_gem_prime_import(struct drm_device *drm,
+					      struct dma_buf *buf);
+
 #endif