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

["Christian König" <ckoenig.leichtzumerken@gmail.com>]

Am 10.07.24 um 20:19 schrieb Matthew Brost:
> 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.

No, that is exactly what I try to prevent with that.

This is an internally thing of TTM and drivers should never use it directly.

Regards,
Christian.

>
> 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
>>