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

2 files changed, 16 insertions, 8 deletions

diff --git a/drivers/gpu/drm/xen/xen_drm_front_gem.c b/drivers/gpu/drm/xen/xen_drm_front_gem.c
index 4f34ef34ba60..74db5a840bed 100644
--- a/drivers/gpu/drm/xen/xen_drm_front_gem.c
+++ b/drivers/gpu/drm/xen/xen_drm_front_gem.c
@@ -290,22 +290,28 @@ int xen_drm_front_gem_mmap(struct file *filp, struct vm_area_struct *vma)
 	return gem_mmap_obj(xen_obj, vma);
 }
 
-void *xen_drm_front_gem_prime_vmap(struct drm_gem_object *gem_obj)
+int xen_drm_front_gem_prime_vmap(struct drm_gem_object *gem_obj, struct dma_buf_map *map)
 {
 	struct xen_gem_object *xen_obj = to_xen_gem_obj(gem_obj);
+	void *vaddr;
 
 	if (!xen_obj->pages)
-		return NULL;
+		return -ENOMEM;
 
 	/* Please see comment in gem_mmap_obj on mapping and attributes. */
-	return vmap(xen_obj->pages, xen_obj->num_pages,
-		    VM_MAP, PAGE_KERNEL);
+	vaddr = vmap(xen_obj->pages, xen_obj->num_pages,
+		     VM_MAP, PAGE_KERNEL);
+	if (!vaddr)
+		return -ENOMEM;
+	dma_buf_map_set_vaddr(map, vaddr);
+
+	return 0;
 }
 
 void xen_drm_front_gem_prime_vunmap(struct drm_gem_object *gem_obj,
-				    void *vaddr)
+				    struct dma_buf_map *map)
 {
-	vunmap(vaddr);
+	vunmap(map->vaddr);
 }
 
 int xen_drm_front_gem_prime_mmap(struct drm_gem_object *gem_obj,
diff --git a/drivers/gpu/drm/xen/xen_drm_front_gem.h b/drivers/gpu/drm/xen/xen_drm_front_gem.h
index a39675fa31b2..a4e67d0a149c 100644
--- a/drivers/gpu/drm/xen/xen_drm_front_gem.h
+++ b/drivers/gpu/drm/xen/xen_drm_front_gem.h
@@ -12,6 +12,7 @@
 #define __XEN_DRM_FRONT_GEM_H
 
 struct dma_buf_attachment;
+struct dma_buf_map;
 struct drm_device;
 struct drm_gem_object;
 struct file;
@@ -34,10 +35,11 @@ void xen_drm_front_gem_free_object_unlocked(struct drm_gem_object *gem_obj);
 
 int xen_drm_front_gem_mmap(struct file *filp, struct vm_area_struct *vma);
 
-void *xen_drm_front_gem_prime_vmap(struct drm_gem_object *gem_obj);
+int xen_drm_front_gem_prime_vmap(struct drm_gem_object *gem_obj,
+				 struct dma_buf_map *map);
 
 void xen_drm_front_gem_prime_vunmap(struct drm_gem_object *gem_obj,
-				    void *vaddr);
+				    struct dma_buf_map *map);
 
 int xen_drm_front_gem_prime_mmap(struct drm_gem_object *gem_obj,
 				 struct vm_area_struct *vma);