Re: [PATCH v3 2/8] ttm: turn ttm_bo_device.vma_manager into a pointer

["Koenig, Christian" <Christian.Koenig@amd.com>]

Am 08.08.19 um 11:36 schrieb Gerd Hoffmann:
> Rename the embedded struct vma_offset_manager, it is named _vma_manager
> now.  ttm_bo_device.vma_manager is a pointer now, pointing to the
> embedded ttm_bo_device._vma_manager by default.
>
> Add ttm_bo_device_init_with_vma_manager() function which allows to
> initialize ttm with a different vma manager.

Can't we go down the route of completely removing the vma_manager from 
TTM? ttm_bo_mmap() would get the BO as parameter instead.

That would also make the verify_access callback completely superfluous 
and looks like a good step into the right direction of de-midlayering.

Christian.

>
> Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
> ---
>   include/drm/ttm/ttm_bo_driver.h | 11 +++++++++--
>   drivers/gpu/drm/ttm/ttm_bo.c    | 29 +++++++++++++++++++++--------
>   drivers/gpu/drm/ttm/ttm_bo_vm.c |  6 +++---
>   3 files changed, 33 insertions(+), 13 deletions(-)
>
> diff --git a/include/drm/ttm/ttm_bo_driver.h b/include/drm/ttm/ttm_bo_driver.h
> index 3f1935c19a66..2f84d6bcd1a7 100644
> --- a/include/drm/ttm/ttm_bo_driver.h
> +++ b/include/drm/ttm/ttm_bo_driver.h
> @@ -441,7 +441,8 @@ extern struct ttm_bo_global {
>    *
>    * @driver: Pointer to a struct ttm_bo_driver struct setup by the driver.
>    * @man: An array of mem_type_managers.
> - * @vma_manager: Address space manager
> + * @vma_manager: Address space manager (pointer)
> + * @_vma_manager: Address space manager (enbedded)
>    * lru_lock: Spinlock that protects the buffer+device lru lists and
>    * ddestroy lists.
>    * @dev_mapping: A pointer to the struct address_space representing the
> @@ -464,7 +465,8 @@ struct ttm_bo_device {
>   	/*
>   	 * Protected by internal locks.
>   	 */
> -	struct drm_vma_offset_manager vma_manager;
> +	struct drm_vma_offset_manager *vma_manager;
> +	struct drm_vma_offset_manager _vma_manager;
>   
>   	/*
>   	 * Protected by the global:lru lock.
> @@ -597,6 +599,11 @@ int ttm_bo_device_init(struct ttm_bo_device *bdev,
>   		       struct ttm_bo_driver *driver,
>   		       struct address_space *mapping,
>   		       bool need_dma32);
> +int ttm_bo_device_init_with_vma_manager(struct ttm_bo_device *bdev,
> +					struct ttm_bo_driver *driver,
> +					struct address_space *mapping,
> +					struct drm_vma_offset_manager *vma_manager,
> +					bool need_dma32);
>   
>   /**
>    * ttm_bo_unmap_virtual
> diff --git a/drivers/gpu/drm/ttm/ttm_bo.c b/drivers/gpu/drm/ttm/ttm_bo.c
> index 10a861a1690c..0ed1a1182962 100644
> --- a/drivers/gpu/drm/ttm/ttm_bo.c
> +++ b/drivers/gpu/drm/ttm/ttm_bo.c
> @@ -672,7 +672,7 @@ static void ttm_bo_release(struct kref *kref)
>   	struct ttm_bo_device *bdev = bo->bdev;
>   	struct ttm_mem_type_manager *man = &bdev->man[bo->mem.mem_type];
>   
> -	drm_vma_offset_remove(&bdev->vma_manager, &bo->base.vma_node);
> +	drm_vma_offset_remove(bdev->vma_manager, &bo->base.vma_node);
>   	ttm_mem_io_lock(man, false);
>   	ttm_mem_io_free_vm(bo);
>   	ttm_mem_io_unlock(man);
> @@ -1353,7 +1353,7 @@ int ttm_bo_init_reserved(struct ttm_bo_device *bdev,
>   	 */
>   	if (bo->type == ttm_bo_type_device ||
>   	    bo->type == ttm_bo_type_sg)
> -		ret = drm_vma_offset_add(&bdev->vma_manager, &bo->base.vma_node,
> +		ret = drm_vma_offset_add(bdev->vma_manager, &bo->base.vma_node,
>   					 bo->mem.num_pages);
>   
>   	/* passed reservation objects should already be locked,
> @@ -1704,7 +1704,7 @@ int ttm_bo_device_release(struct ttm_bo_device *bdev)
>   			pr_debug("Swap list %d was clean\n", i);
>   	spin_unlock(&glob->lru_lock);
>   
> -	drm_vma_offset_manager_destroy(&bdev->vma_manager);
> +	drm_vma_offset_manager_destroy(&bdev->_vma_manager);
>   
>   	if (!ret)
>   		ttm_bo_global_release();
> @@ -1713,10 +1713,11 @@ int ttm_bo_device_release(struct ttm_bo_device *bdev)
>   }
>   EXPORT_SYMBOL(ttm_bo_device_release);
>   
> -int ttm_bo_device_init(struct ttm_bo_device *bdev,
> -		       struct ttm_bo_driver *driver,
> -		       struct address_space *mapping,
> -		       bool need_dma32)
> +int ttm_bo_device_init_with_vma_manager(struct ttm_bo_device *bdev,
> +					struct ttm_bo_driver *driver,
> +					struct address_space *mapping,
> +					struct drm_vma_offset_manager *vma_manager,
> +					bool need_dma32)
>   {
>   	struct ttm_bo_global *glob = &ttm_bo_glob;
>   	int ret;
> @@ -1737,7 +1738,8 @@ int ttm_bo_device_init(struct ttm_bo_device *bdev,
>   	if (unlikely(ret != 0))
>   		goto out_no_sys;
>   
> -	drm_vma_offset_manager_init(&bdev->vma_manager,
> +	bdev->vma_manager = vma_manager;
> +	drm_vma_offset_manager_init(&bdev->_vma_manager,
>   				    DRM_FILE_PAGE_OFFSET_START,
>   				    DRM_FILE_PAGE_OFFSET_SIZE);
>   	INIT_DELAYED_WORK(&bdev->wq, ttm_bo_delayed_workqueue);
> @@ -1754,6 +1756,17 @@ int ttm_bo_device_init(struct ttm_bo_device *bdev,
>   	ttm_bo_global_release();
>   	return ret;
>   }
> +EXPORT_SYMBOL(ttm_bo_device_init_with_vma_manager);
> +
> +int ttm_bo_device_init(struct ttm_bo_device *bdev,
> +		       struct ttm_bo_driver *driver,
> +		       struct address_space *mapping,
> +		       bool need_dma32)
> +{
> +	return ttm_bo_device_init_with_vma_manager(bdev, driver, mapping,
> +						   &bdev->_vma_manager,
> +						   need_dma32);
> +}
>   EXPORT_SYMBOL(ttm_bo_device_init);
>   
>   /*
> diff --git a/drivers/gpu/drm/ttm/ttm_bo_vm.c b/drivers/gpu/drm/ttm/ttm_bo_vm.c
> index 85f5bcbe0c76..d4eecde8d050 100644
> --- a/drivers/gpu/drm/ttm/ttm_bo_vm.c
> +++ b/drivers/gpu/drm/ttm/ttm_bo_vm.c
> @@ -409,16 +409,16 @@ static struct ttm_buffer_object *ttm_bo_vm_lookup(struct ttm_bo_device *bdev,
>   	struct drm_vma_offset_node *node;
>   	struct ttm_buffer_object *bo = NULL;
>   
> -	drm_vma_offset_lock_lookup(&bdev->vma_manager);
> +	drm_vma_offset_lock_lookup(bdev->vma_manager);
>   
> -	node = drm_vma_offset_lookup_locked(&bdev->vma_manager, offset, pages);
> +	node = drm_vma_offset_lookup_locked(bdev->vma_manager, offset, pages);
>   	if (likely(node)) {
>   		bo = container_of(node, struct ttm_buffer_object,
>   				  base.vma_node);
>   		bo = ttm_bo_get_unless_zero(bo);
>   	}
>   
> -	drm_vma_offset_unlock_lookup(&bdev->vma_manager);
> +	drm_vma_offset_unlock_lookup(bdev->vma_manager);
>   
>   	if (!bo)
>   		pr_err("Could not find buffer object to map\n");