drm/nouveau: Implement mmap as GEM object function

Moving the driver-specific mmap code into a GEM object function allows
for using DRM helpers for various mmap callbacks.

The GEM object function is provided by GEM TTM helpers. Nouveau's
implementation of verify_access is unused and has been removed. Access
permissions are validated by the DRM helpers.

As a side effect, nouveau_ttm_vm_ops and nouveau_ttm_fault() are now
implemented in nouveau's GEM code.
Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Reviewed-by: Christian König <christian.koenig@amd.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20210525151055.8174-5-tzimmermann@suse.de

drivers/gpu/drm/nouveau/nouveau_bo.c

@@ -1050,15 +1050,6 @@ nouveau_bo_move(struct ttm_buffer_object *bo, bool evict,
 	return ret;
 }
 
-static int
-nouveau_bo_verify_access(struct ttm_buffer_object *bo, struct file *filp)
-{
-	struct nouveau_bo *nvbo = nouveau_bo(bo);
-
-	return drm_vma_node_verify_access(&nvbo->bo.base.vma_node,
-					  filp->private_data);
-}
-
 static void
 nouveau_ttm_io_mem_free_locked(struct nouveau_drm *drm,
 			       struct ttm_resource *reg)
@@ -1331,7 +1322,6 @@ struct ttm_device_funcs nouveau_bo_driver = {
 	.evict_flags = nouveau_bo_evict_flags,
 	.delete_mem_notify = nouveau_bo_delete_mem_notify,
 	.move = nouveau_bo_move,
-	.verify_access = nouveau_bo_verify_access,
 	.io_mem_reserve = &nouveau_ttm_io_mem_reserve,
 	.io_mem_free = &nouveau_ttm_io_mem_free,
 };

drivers/gpu/drm/nouveau/nouveau_drm.c

@@ -1179,7 +1179,7 @@ nouveau_driver_fops = {
 	.open = drm_open,
 	.release = drm_release,
 	.unlocked_ioctl = nouveau_drm_ioctl,
-	.mmap = nouveau_ttm_mmap,
+	.mmap = drm_gem_mmap,
 	.poll = drm_poll,
 	.read = drm_read,
 #if defined(CONFIG_COMPAT)
@@ -1212,6 +1212,7 @@ driver_stub = {
 	.prime_handle_to_fd = drm_gem_prime_handle_to_fd,
 	.prime_fd_to_handle = drm_gem_prime_fd_to_handle,
 	.gem_prime_import_sg_table = nouveau_gem_prime_import_sg_table,
+	.gem_prime_mmap = drm_gem_prime_mmap,
 
 	.dumb_create = nouveau_display_dumb_create,
 	.dumb_map_offset = drm_gem_ttm_dumb_map_offset,

drivers/gpu/drm/nouveau/nouveau_gem.c

@@ -39,6 +39,40 @@
 #include <nvif/class.h>
 #include <nvif/push206e.h>
 
+static vm_fault_t nouveau_ttm_fault(struct vm_fault *vmf)
+{
+	struct vm_area_struct *vma = vmf->vma;
+	struct ttm_buffer_object *bo = vma->vm_private_data;
+	pgprot_t prot;
+	vm_fault_t ret;
+
+	ret = ttm_bo_vm_reserve(bo, vmf);
+	if (ret)
+		return ret;
+
+	ret = nouveau_ttm_fault_reserve_notify(bo);
+	if (ret)
+		goto error_unlock;
+
+	nouveau_bo_del_io_reserve_lru(bo);
+	prot = vm_get_page_prot(vma->vm_flags);
+	ret = ttm_bo_vm_fault_reserved(vmf, prot, TTM_BO_VM_NUM_PREFAULT, 1);
+	nouveau_bo_add_io_reserve_lru(bo);
+	if (ret == VM_FAULT_RETRY && !(vmf->flags & FAULT_FLAG_RETRY_NOWAIT))
+		return ret;
+
+error_unlock:
+	dma_resv_unlock(bo->base.resv);
+	return ret;
+}
+
+static const struct vm_operations_struct nouveau_ttm_vm_ops = {
+	.fault = nouveau_ttm_fault,
+	.open = ttm_bo_vm_open,
+	.close = ttm_bo_vm_close,
+	.access = ttm_bo_vm_access
+};
+
 void
 nouveau_gem_object_del(struct drm_gem_object *gem)
 {
@@ -180,6 +214,8 @@ const struct drm_gem_object_funcs nouveau_gem_object_funcs = {
 	.get_sg_table = nouveau_gem_prime_get_sg_table,
 	.vmap = drm_gem_ttm_vmap,
 	.vunmap = drm_gem_ttm_vunmap,
+	.mmap = drm_gem_ttm_mmap,
+	.vm_ops = &nouveau_ttm_vm_ops,
 };
 
 int

drivers/gpu/drm/nouveau/nouveau_ttm.c

@@ -125,55 +125,6 @@ const struct ttm_resource_manager_func nv04_gart_manager = {
 	.free = nouveau_manager_del,
 };
 
-static vm_fault_t nouveau_ttm_fault(struct vm_fault *vmf)
-{
-	struct vm_area_struct *vma = vmf->vma;
-	struct ttm_buffer_object *bo = vma->vm_private_data;
-	pgprot_t prot;
-	vm_fault_t ret;
-
-	ret = ttm_bo_vm_reserve(bo, vmf);
-	if (ret)
-		return ret;
-
-	ret = nouveau_ttm_fault_reserve_notify(bo);
-	if (ret)
-		goto error_unlock;
-
-	nouveau_bo_del_io_reserve_lru(bo);
-	prot = vm_get_page_prot(vma->vm_flags);
-	ret = ttm_bo_vm_fault_reserved(vmf, prot, TTM_BO_VM_NUM_PREFAULT, 1);
-	nouveau_bo_add_io_reserve_lru(bo);
-	if (ret == VM_FAULT_RETRY && !(vmf->flags & FAULT_FLAG_RETRY_NOWAIT))
-		return ret;
-
-error_unlock:
-	dma_resv_unlock(bo->base.resv);
-	return ret;
-}
-
-static const struct vm_operations_struct nouveau_ttm_vm_ops = {
-	.fault = nouveau_ttm_fault,
-	.open = ttm_bo_vm_open,
-	.close = ttm_bo_vm_close,
-	.access = ttm_bo_vm_access
-};
-
-int
-nouveau_ttm_mmap(struct file *filp, struct vm_area_struct *vma)
-{
-	struct drm_file *file_priv = filp->private_data;
-	struct nouveau_drm *drm = nouveau_drm(file_priv->minor->dev);
-	int ret;
-
-	ret = ttm_bo_mmap(filp, vma, &drm->ttm.bdev);
-	if (ret)
-		return ret;
-
-	vma->vm_ops = &nouveau_ttm_vm_ops;
-	return 0;
-}
-
 static int
 nouveau_ttm_init_host(struct nouveau_drm *drm, u8 kind)
 {

drivers/gpu/drm/nouveau/nouveau_ttm.h

@@ -17,7 +17,6 @@ struct ttm_tt *nouveau_sgdma_create_ttm(struct ttm_buffer_object *bo,
 
 int  nouveau_ttm_init(struct nouveau_drm *drm);
 void nouveau_ttm_fini(struct nouveau_drm *drm);
-int  nouveau_ttm_mmap(struct file *, struct vm_area_struct *);
 
 int  nouveau_ttm_global_init(struct nouveau_drm *);
 void nouveau_ttm_global_release(struct nouveau_drm *);