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
diff --git a/include/drm/drm_gem.h b/include/drm/drm_gem.h
index c38dd35..5e6daa1 100644
--- a/include/drm/drm_gem.h
+++ b/include/drm/drm_gem.h
@@ -39,6 +39,7 @@
 
 #include <drm/drm_vma_manager.h>
 
+struct dma_buf_map;
 struct drm_gem_object;
 
 /**
@@ -138,7 +139,7 @@ struct drm_gem_object_funcs {
 	 *
 	 * This callback is optional.
 	 */
-	void *(*vmap)(struct drm_gem_object *obj);
+	int (*vmap)(struct drm_gem_object *obj, struct dma_buf_map *map);
 
 	/**
 	 * @vunmap:
@@ -148,7 +149,7 @@ struct drm_gem_object_funcs {
 	 *
 	 * This callback is optional.
 	 */
-	void (*vunmap)(struct drm_gem_object *obj, void *vaddr);
+	void (*vunmap)(struct drm_gem_object *obj, struct dma_buf_map *map);
 
 	/**
 	 * @mmap:
diff --git a/include/drm/drm_gem_cma_helper.h b/include/drm/drm_gem_cma_helper.h
index a064b0d..caf98b9 100644
--- a/include/drm/drm_gem_cma_helper.h
+++ b/include/drm/drm_gem_cma_helper.h
@@ -103,7 +103,7 @@ drm_gem_cma_prime_import_sg_table(struct drm_device *dev,
 				  struct sg_table *sgt);
 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);
+int drm_gem_cma_prime_vmap(struct drm_gem_object *obj, struct dma_buf_map *map);
 
 struct drm_gem_object *
 drm_gem_cma_create_object_default_funcs(struct drm_device *dev, size_t size);
diff --git a/include/drm/drm_gem_shmem_helper.h b/include/drm/drm_gem_shmem_helper.h
index 5381f0c..3449a03 100644
--- a/include/drm/drm_gem_shmem_helper.h
+++ b/include/drm/drm_gem_shmem_helper.h
@@ -113,8 +113,8 @@ int drm_gem_shmem_get_pages(struct drm_gem_shmem_object *shmem);
 void drm_gem_shmem_put_pages(struct drm_gem_shmem_object *shmem);
 int drm_gem_shmem_pin(struct drm_gem_object *obj);
 void drm_gem_shmem_unpin(struct drm_gem_object *obj);
-void *drm_gem_shmem_vmap(struct drm_gem_object *obj);
-void drm_gem_shmem_vunmap(struct drm_gem_object *obj, void *vaddr);
+int drm_gem_shmem_vmap(struct drm_gem_object *obj, struct dma_buf_map *map);
+void drm_gem_shmem_vunmap(struct drm_gem_object *obj, struct dma_buf_map *map);
 
 int drm_gem_shmem_madvise(struct drm_gem_object *obj, int madv);
 
diff --git a/include/drm/drm_gem_vram_helper.h b/include/drm/drm_gem_vram_helper.h
index 128f881..c0d28ba 100644
--- a/include/drm/drm_gem_vram_helper.h
+++ b/include/drm/drm_gem_vram_helper.h
@@ -10,6 +10,7 @@
 #include <drm/ttm/ttm_bo_api.h>
 #include <drm/ttm/ttm_bo_driver.h>
 
+#include <linux/dma-buf-map.h>
 #include <linux/kernel.h> /* for container_of() */
 
 struct drm_mode_create_dumb;
@@ -29,9 +30,8 @@ struct vm_area_struct;
 
 /**
  * struct drm_gem_vram_object - GEM object backed by VRAM
- * @gem:	GEM object
  * @bo:		TTM buffer object
- * @kmap:	Mapping information for @bo
+ * @map:	Mapping information for @bo
  * @placement:	TTM placement information. Supported placements are \
 	%TTM_PL_VRAM and %TTM_PL_SYSTEM
  * @placements:	TTM placement information.
@@ -50,15 +50,15 @@ struct vm_area_struct;
  */
 struct drm_gem_vram_object {
 	struct ttm_buffer_object bo;
-	struct ttm_bo_kmap_obj kmap;
+	struct dma_buf_map map;
 
 	/**
-	 * @kmap_use_count:
+	 * @vmap_use_count:
 	 *
 	 * Reference count on the virtual address.
 	 * The address are un-mapped when the count reaches zero.
 	 */
-	unsigned int kmap_use_count;
+	unsigned int vmap_use_count;
 
 	/* Supported placements are %TTM_PL_VRAM and %TTM_PL_SYSTEM */
 	struct ttm_placement placement;
@@ -97,8 +97,8 @@ u64 drm_gem_vram_mmap_offset(struct drm_gem_vram_object *gbo);
 s64 drm_gem_vram_offset(struct drm_gem_vram_object *gbo);
 int drm_gem_vram_pin(struct drm_gem_vram_object *gbo, unsigned long pl_flag);
 int drm_gem_vram_unpin(struct drm_gem_vram_object *gbo);
-void *drm_gem_vram_vmap(struct drm_gem_vram_object *gbo);
-void drm_gem_vram_vunmap(struct drm_gem_vram_object *gbo, void *vaddr);
+int drm_gem_vram_vmap(struct drm_gem_vram_object *gbo, struct dma_buf_map *map);
+void drm_gem_vram_vunmap(struct drm_gem_vram_object *gbo, struct dma_buf_map *map);
 
 int drm_gem_vram_fill_create_dumb(struct drm_file *file,
 				  struct drm_device *dev,