[PATCH v5 1/5] drm/ttm: add new api ttm_device_prepare_hibernation()

[Mario Limonciello]

On 7/9/2025 6:05 AM, Samuel Zhang wrote:
> This new api is used for hibernation to move GTT BOs to shmem after
> VRAM eviction. shmem will be flushed to swap disk later to reduce
> the system memory usage for hibernation.
> 
> Signed-off-by: Samuel Zhang <guoqing.zhang at amd.com>
> Reviewed-by: Christian König <christian.koenig at amd.com>
> ---
>   drivers/gpu/drm/ttm/ttm_device.c | 23 +++++++++++++++++++++++
>   include/drm/ttm/ttm_device.h     |  1 +
>   2 files changed, 24 insertions(+)
> 
> diff --git a/drivers/gpu/drm/ttm/ttm_device.c b/drivers/gpu/drm/ttm/ttm_device.c
> index 02e797fd1891..9c9ab1903919 100644
> --- a/drivers/gpu/drm/ttm/ttm_device.c
> +++ b/drivers/gpu/drm/ttm/ttm_device.c
> @@ -123,6 +123,29 @@ static int ttm_global_init(void)
>   	return ret;
>   }
>   
> +/**
> + * ttm_device_prepare_hibernation - move GTT BOs to shmem for hibernation.
> + *
> + * @bdev: A pointer to a struct ttm_device to prepare hibernation for.
> + *
> + * Return: 0 on success, negative number on failure.
> + */
> +int ttm_device_prepare_hibernation(struct ttm_device *bdev)
> +{
> +	struct ttm_operation_ctx ctx = {
> +		.interruptible = false,
> +		.no_wait_gpu = false,
> +		.force_alloc = true

On linux-next (next-20250709):

drivers/gpu/drm/ttm/ttm_device.c: In function 
‘ttm_device_prepare_hibernation’:
drivers/gpu/drm/ttm/ttm_device.c:140:18: error: ‘struct 
ttm_operation_ctx’ has no member named ‘force_alloc’
   140 |                 .force_alloc = true
       |                  ^~~~~~~~~~~

> +	};
> +	int ret;
> +
> +	do {
> +		ret = ttm_device_swapout(bdev, &ctx, GFP_KERNEL);
> +	} while (ret > 0);
> +	return ret;
> +}
> +EXPORT_SYMBOL(ttm_device_prepare_hibernation);
> +
>   /*
>    * A buffer object shrink method that tries to swap out the first
>    * buffer object on the global::swap_lru list.
> diff --git a/include/drm/ttm/ttm_device.h b/include/drm/ttm/ttm_device.h
> index 39b8636b1845..592b5f802859 100644
> --- a/include/drm/ttm/ttm_device.h
> +++ b/include/drm/ttm/ttm_device.h
> @@ -272,6 +272,7 @@ struct ttm_device {
>   int ttm_global_swapout(struct ttm_operation_ctx *ctx, gfp_t gfp_flags);
>   int ttm_device_swapout(struct ttm_device *bdev, struct ttm_operation_ctx *ctx,
>   		       gfp_t gfp_flags);
> +int ttm_device_prepare_hibernation(struct ttm_device *bdev);
>   
>   static inline struct ttm_resource_manager *
>   ttm_manager_type(struct ttm_device *bdev, int mem_type)