drm/gem: Use struct dma_buf_map in GEM vmap ops and convert GEM backends

This patch replaces the vmap/vunmap's use of raw pointers in GEM object
functions with instances of struct dma_buf_map. GEM backends are
converted as well. For most of them, this simply changes the returned type.

TTM-based drivers now return information about the location of the memory,
either system or I/O memory. GEM VRAM helpers and qxl now use ttm_bo_vmap()
et al. Amdgpu, nouveau and radeon use drm_gem_ttm_vmap() et al instead of
implementing their own vmap callbacks.

v7:
	* init QXL cursor to mapped BO buffer (kernel test robot)
v5:
	* update vkms after switch to shmem
v4:
	* use ttm_bo_vmap(), drm_gem_ttm_vmap(), et al. (Daniel, Christian)
	* fix a trailing { in drm_gem_vmap()
	* remove several empty functions instead of converting them (Daniel)
	* comment uses of raw pointers with a TODO (Daniel)
	* TODO list: convert more helpers to use struct dma_buf_map

Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Acked-by: Christian König <christian.koenig@amd.com>
Tested-by: Sam Ravnborg <sam@ravnborg.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20201103093015.1063-7-tzimmermann@suse.de

1 files changed, 7 insertions, 3 deletions

diff --git a/drivers/gpu/drm/drm_gem_cma_helper.c b/drivers/gpu/drm/drm_gem_cma_helper.c
index d527485ea0b7..b57e3e9222f0 100644
--- a/drivers/gpu/drm/drm_gem_cma_helper.c
+++ b/drivers/gpu/drm/drm_gem_cma_helper.c
@@ -519,6 +519,8 @@ EXPORT_SYMBOL_GPL(drm_gem_cma_prime_mmap);
  * drm_gem_cma_prime_vmap - map a CMA GEM object into the kernel's virtual
  *     address space
  * @obj: GEM object
+ * @map: Returns the kernel virtual address of the CMA GEM object's backing
+ *       store.
  *
  * This function maps a buffer exported via DRM PRIME into the kernel's
  * virtual address space. Since the CMA buffers are already mapped into the
@@ -527,13 +529,15 @@ EXPORT_SYMBOL_GPL(drm_gem_cma_prime_mmap);
  * driver's &drm_gem_object_funcs.vmap callback.
  *
  * Returns:
- * The kernel virtual address of the CMA GEM object's backing store.
+ * 0 on success, or a negative error code otherwise.
  */
-void *drm_gem_cma_prime_vmap(struct drm_gem_object *obj)
+int drm_gem_cma_prime_vmap(struct drm_gem_object *obj, struct dma_buf_map *map)
 {
 	struct drm_gem_cma_object *cma_obj = to_drm_gem_cma_obj(obj);
 
-	return cma_obj->vaddr;
+	dma_buf_map_set_vaddr(map, cma_obj->vaddr);
+
+	return 0;
 }
 EXPORT_SYMBOL_GPL(drm_gem_cma_prime_vmap);