Re: [PATCH 4/7] drm/ttm: move LRU walk defines into new internal header

[Matthew Brost <matthew.brost@intel.com>]

On Wed, Jul 10, 2024 at 02:42:58PM +0200, Christian König wrote:
> That is something drivers really shouldn't mess with.
> 

Thomas uses this in Xe to implement a shrinker [1]. Seems to need to
remain available for drivers.

Matt

[1] https://patchwork.freedesktop.org/patch/602165/?series=131815&rev=6

> Signed-off-by: Christian König <christian.koenig@amd.com>
> ---
>  drivers/gpu/drm/ttm/ttm_bo.c      |  1 +
>  drivers/gpu/drm/ttm/ttm_bo_util.c |  2 +
>  drivers/gpu/drm/ttm/ttm_bo_util.h | 67 +++++++++++++++++++++++++++++++
>  include/drm/ttm/ttm_bo.h          | 35 ----------------
>  4 files changed, 70 insertions(+), 35 deletions(-)
>  create mode 100644 drivers/gpu/drm/ttm/ttm_bo_util.h
> 
> diff --git a/drivers/gpu/drm/ttm/ttm_bo.c b/drivers/gpu/drm/ttm/ttm_bo.c
> index 0131ec802066..41bee8696e69 100644
> --- a/drivers/gpu/drm/ttm/ttm_bo.c
> +++ b/drivers/gpu/drm/ttm/ttm_bo.c
> @@ -45,6 +45,7 @@
>  #include <linux/dma-resv.h>
>  
>  #include "ttm_module.h"
> +#include "ttm_bo_util.h"
>  
>  static void ttm_bo_mem_space_debug(struct ttm_buffer_object *bo,
>  					struct ttm_placement *placement)
> diff --git a/drivers/gpu/drm/ttm/ttm_bo_util.c b/drivers/gpu/drm/ttm/ttm_bo_util.c
> index 3c07f4712d5c..03e28e3d0d03 100644
> --- a/drivers/gpu/drm/ttm/ttm_bo_util.c
> +++ b/drivers/gpu/drm/ttm/ttm_bo_util.c
> @@ -37,6 +37,8 @@
>  
>  #include <drm/drm_cache.h>
>  
> +#include "ttm_bo_util.h"
> +
>  struct ttm_transfer_obj {
>  	struct ttm_buffer_object base;
>  	struct ttm_buffer_object *bo;
> diff --git a/drivers/gpu/drm/ttm/ttm_bo_util.h b/drivers/gpu/drm/ttm/ttm_bo_util.h
> new file mode 100644
> index 000000000000..c19b50809208
> --- /dev/null
> +++ b/drivers/gpu/drm/ttm/ttm_bo_util.h
> @@ -0,0 +1,67 @@
> +/* SPDX-License-Identifier: GPL-2.0 OR MIT */
> +/**************************************************************************
> + * Copyright 2024 Advanced Micro Devices, Inc.
> + *
> + * Permission is hereby granted, free of charge, to any person obtaining a
> + * copy of this software and associated documentation files (the "Software"),
> + * to deal in the Software without restriction, including without limitation
> + * the rights to use, copy, modify, merge, publish, distribute, sublicense,
> + * and/or sell copies of the Software, and to permit persons to whom the
> + * Software is furnished to do so, subject to the following conditions:
> + *
> + * The above copyright notice and this permission notice shall be included in
> + * all copies or substantial portions of the Software.
> + *
> + * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
> + * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
> + * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
> + * THE COPYRIGHT HOLDER(S) OR AUTHOR(S) BE LIABLE FOR ANY CLAIM, DAMAGES OR
> + * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
> + * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
> + * OTHER DEALINGS IN THE SOFTWARE.
> + *
> + **************************************************************************/
> +#ifndef _TTM_BO_UTIL_H_
> +#define _TTM_BO_UTIL_H_
> +
> +struct ww_acquire_ctx;
> +
> +struct ttm_buffer_object;
> +struct ttm_operation_ctx;
> +struct ttm_lru_walk;
> +
> +/** struct ttm_lru_walk_ops - Operations for a LRU walk. */
> +struct ttm_lru_walk_ops {
> +	/**
> +	 * process_bo - Process this bo.
> +	 * @walk: struct ttm_lru_walk describing the walk.
> +	 * @bo: A locked and referenced buffer object.
> +	 *
> +	 * Return: Negative error code on error, User-defined positive value
> +	 * (typically, but not always, size of the processed bo) on success.
> +	 * On success, the returned values are summed by the walk and the
> +	 * walk exits when its target is met.
> +	 * 0 also indicates success, -EBUSY means this bo was skipped.
> +	 */
> +	s64 (*process_bo)(struct ttm_lru_walk *walk,
> +			  struct ttm_buffer_object *bo);
> +};
> +
> +/**
> + * struct ttm_lru_walk - Structure describing a LRU walk.
> + */
> +struct ttm_lru_walk {
> +	/** @ops: Pointer to the ops structure. */
> +	const struct ttm_lru_walk_ops *ops;
> +	/** @ctx: Pointer to the struct ttm_operation_ctx. */
> +	struct ttm_operation_ctx *ctx;
> +	/** @ticket: The struct ww_acquire_ctx if any. */
> +	struct ww_acquire_ctx *ticket;
> +	/** @tryock_only: Only use trylock for locking. */
> +	bool trylock_only;
> +};
> +
> +s64 ttm_lru_walk_for_evict(struct ttm_lru_walk *walk, struct ttm_device *bdev,
> +			   struct ttm_resource_manager *man, s64 target);
> +
> +#endif
> diff --git a/include/drm/ttm/ttm_bo.h b/include/drm/ttm/ttm_bo.h
> index d1a732d56259..5f7c967222a2 100644
> --- a/include/drm/ttm/ttm_bo.h
> +++ b/include/drm/ttm/ttm_bo.h
> @@ -194,41 +194,6 @@ struct ttm_operation_ctx {
>  	uint64_t bytes_moved;
>  };
>  
> -struct ttm_lru_walk;
> -
> -/** struct ttm_lru_walk_ops - Operations for a LRU walk. */
> -struct ttm_lru_walk_ops {
> -	/**
> -	 * process_bo - Process this bo.
> -	 * @walk: struct ttm_lru_walk describing the walk.
> -	 * @bo: A locked and referenced buffer object.
> -	 *
> -	 * Return: Negative error code on error, User-defined positive value
> -	 * (typically, but not always, size of the processed bo) on success.
> -	 * On success, the returned values are summed by the walk and the
> -	 * walk exits when its target is met.
> -	 * 0 also indicates success, -EBUSY means this bo was skipped.
> -	 */
> -	s64 (*process_bo)(struct ttm_lru_walk *walk, struct ttm_buffer_object *bo);
> -};
> -
> -/**
> - * struct ttm_lru_walk - Structure describing a LRU walk.
> - */
> -struct ttm_lru_walk {
> -	/** @ops: Pointer to the ops structure. */
> -	const struct ttm_lru_walk_ops *ops;
> -	/** @ctx: Pointer to the struct ttm_operation_ctx. */
> -	struct ttm_operation_ctx *ctx;
> -	/** @ticket: The struct ww_acquire_ctx if any. */
> -	struct ww_acquire_ctx *ticket;
> -	/** @tryock_only: Only use trylock for locking. */
> -	bool trylock_only;
> -};
> -
> -s64 ttm_lru_walk_for_evict(struct ttm_lru_walk *walk, struct ttm_device *bdev,
> -			   struct ttm_resource_manager *man, s64 target);
> -
>  /**
>   * ttm_bo_get - reference a struct ttm_buffer_object
>   *
> -- 
> 2.34.1
>