drm/panfrost: Align GEM objects GPU VA to 2MB

In order to increase the chances of using 2MB pages, we need to align the
GPU VA mapping to 2MB. Only do this if the object size is 2MB or more.

Cc: Robin Murphy <robin.murphy@arm.com>
Cc: Steven Price <steven.price@arm.com>
Cc: Tomeu Vizoso <tomeu.vizoso@collabora.com>
Signed-off-by: Rob Herring <robh@kernel.org>
Reviewed-by: Tomeu Vizoso <tomeu.vizoso@collabora.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20190610165806.24854-1-robh@kernel.org

drivers/gpu/drm/panfrost/panfrost_gem.c

@@ -52,6 +52,7 @@ struct drm_gem_object *panfrost_gem_create_object(struct drm_device *dev, size_t
 	int ret;
 	struct panfrost_device *pfdev = dev->dev_private;
 	struct panfrost_gem_object *obj;
+	u64 align;
 
 	obj = kzalloc(sizeof(*obj), GFP_KERNEL);
 	if (!obj)
@@ -59,9 +60,12 @@ struct drm_gem_object *panfrost_gem_create_object(struct drm_device *dev, size_t
 
 	obj->base.base.funcs = &panfrost_gem_funcs;
 
+	size = roundup(size, PAGE_SIZE);
+	align = size >= SZ_2M ? SZ_2M >> PAGE_SHIFT : 0;
+
 	spin_lock(&pfdev->mm_lock);
-	ret = drm_mm_insert_node(&pfdev->mm, &obj->node,
-				 roundup(size, PAGE_SIZE) >> PAGE_SHIFT);
+	ret = drm_mm_insert_node_generic(&pfdev->mm, &obj->node,
+					 size >> PAGE_SHIFT, align, 0, 0);
 	spin_unlock(&pfdev->mm_lock);
 	if (ret)
 		goto free_obj;