drm/cma-helper: Remove empty drm_gem_cma_prime_vunmap()

The function drm_gem_cma_prime_vunmap() is empty. Remove it before
changing the interface to use struct drm_buf_map.
Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Reviewed-by: Christian König <christian.koenig@amd.com>
Tested-by: Sam Ravnborg <sam@ravnborg.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20201103093015.1063-3-tzimmermann@suse.de

drivers/gpu/drm/drm_gem_cma_helper.c

@@ -537,23 +537,6 @@ void *drm_gem_cma_prime_vmap(struct drm_gem_object *obj)
 }
 EXPORT_SYMBOL_GPL(drm_gem_cma_prime_vmap);
 
-/**
- * drm_gem_cma_prime_vunmap - unmap a CMA GEM object from the kernel's virtual
- *     address space
- * @obj: GEM object
- * @vaddr: kernel virtual address where the CMA GEM object was mapped
- *
- * This function removes a buffer exported via DRM PRIME from the kernel's
- * virtual address space. This is a no-op because CMA buffers cannot be
- * unmapped from kernel space. Drivers using the CMA helpers should set this
- * as their &drm_gem_object_funcs.vunmap callback.
- */
-void drm_gem_cma_prime_vunmap(struct drm_gem_object *obj, void *vaddr)
-{
-	/* Nothing to do */
-}
-EXPORT_SYMBOL_GPL(drm_gem_cma_prime_vunmap);
-
 static const struct drm_gem_object_funcs drm_gem_cma_default_funcs = {
 	.free = drm_gem_cma_free_object,
 	.print_info = drm_gem_cma_print_info,

drivers/gpu/drm/vc4/vc4_bo.c

@@ -387,7 +387,6 @@ static const struct drm_gem_object_funcs vc4_gem_object_funcs = {
 	.export = vc4_prime_export,
 	.get_sg_table = drm_gem_cma_prime_get_sg_table,
 	.vmap = vc4_prime_vmap,
-	.vunmap = drm_gem_cma_prime_vunmap,
 	.vm_ops = &vc4_vm_ops,
 };
 

include/drm/drm_gem_cma_helper.h

@@ -104,7 +104,6 @@ drm_gem_cma_prime_import_sg_table(struct drm_device *dev,
 int drm_gem_cma_prime_mmap(struct drm_gem_object *obj,
 			   struct vm_area_struct *vma);
 void *drm_gem_cma_prime_vmap(struct drm_gem_object *obj);
-void drm_gem_cma_prime_vunmap(struct drm_gem_object *obj, void *vaddr);
 
 struct drm_gem_object *
 drm_gem_cma_create_object_default_funcs(struct drm_device *dev, size_t size);