[PATCH 2/3] drm/amdgpu: Implement new dummy vram manager

[Christian König]

Am 10.05.23 um 00:01 schrieb Alex Deucher:
> From: Rajneesh Bhardwaj <rajneesh.bhardwaj at amd.com>
>
> This adds dummy vram manager to support ASICs that do not have a
> dedicated or carvedout vram domain.

Well that doesn't seem to make much sense. Why we should have that?

Christian.

>
> Reviewed-by: Felix Kuehling <felix.kuehling at amd.com>
> Signed-off-by: Rajneesh Bhardwaj <rajneesh.bhardwaj at amd.com>
> Signed-off-by: Alex Deucher <alexander.deucher at amd.com>
> ---
>   drivers/gpu/drm/amd/amdgpu/amdgpu_vram_mgr.c | 67 ++++++++++++++++++--
>   1 file changed, 60 insertions(+), 7 deletions(-)
>
> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_vram_mgr.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_vram_mgr.c
> index 43d6a9d6a538..89d35d194f2c 100644
> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_vram_mgr.c
> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_vram_mgr.c
> @@ -370,6 +370,45 @@ int amdgpu_vram_mgr_query_page_status(struct amdgpu_vram_mgr *mgr,
>   	return ret;
>   }
>   
> +static void amdgpu_dummy_vram_mgr_debug(struct ttm_resource_manager *man,
> +				  struct drm_printer *printer)
> +{
> +	DRM_DEBUG_DRIVER("Dummy vram mgr debug\n");
> +}
> +
> +static bool amdgpu_dummy_vram_mgr_compatible(struct ttm_resource_manager *man,
> +				       struct ttm_resource *res,
> +				       const struct ttm_place *place,
> +				       size_t size)
> +{
> +	DRM_DEBUG_DRIVER("Dummy vram mgr compatible\n");
> +	return false;
> +}
> +
> +static bool amdgpu_dummy_vram_mgr_intersects(struct ttm_resource_manager *man,
> +				       struct ttm_resource *res,
> +				       const struct ttm_place *place,
> +				       size_t size)
> +{
> +	DRM_DEBUG_DRIVER("Dummy vram mgr intersects\n");
> +	return true;
> +}
> +
> +static void amdgpu_dummy_vram_mgr_del(struct ttm_resource_manager *man,
> +				struct ttm_resource *res)
> +{
> +	DRM_DEBUG_DRIVER("Dummy vram mgr deleted\n");
> +}
> +
> +static int amdgpu_dummy_vram_mgr_new(struct ttm_resource_manager *man,
> +			       struct ttm_buffer_object *tbo,
> +			       const struct ttm_place *place,
> +			       struct ttm_resource **res)
> +{
> +	DRM_DEBUG_DRIVER("Dummy vram mgr new\n");
> +	return -ENOSPC;
> +}
> +
>   /**
>    * amdgpu_vram_mgr_new - allocate new ranges
>    *
> @@ -817,6 +856,14 @@ static void amdgpu_vram_mgr_debug(struct ttm_resource_manager *man,
>   	mutex_unlock(&mgr->lock);
>   }
>   
> +static const struct ttm_resource_manager_func amdgpu_dummy_vram_mgr_func = {
> +	.alloc	= amdgpu_dummy_vram_mgr_new,
> +	.free	= amdgpu_dummy_vram_mgr_del,
> +	.intersects = amdgpu_dummy_vram_mgr_intersects,
> +	.compatible = amdgpu_dummy_vram_mgr_compatible,
> +	.debug	= amdgpu_dummy_vram_mgr_debug
> +};
> +
>   static const struct ttm_resource_manager_func amdgpu_vram_mgr_func = {
>   	.alloc	= amdgpu_vram_mgr_new,
>   	.free	= amdgpu_vram_mgr_del,
> @@ -841,17 +888,22 @@ int amdgpu_vram_mgr_init(struct amdgpu_device *adev)
>   	ttm_resource_manager_init(man, &adev->mman.bdev,
>   				  adev->gmc.real_vram_size);
>   
> -	man->func = &amdgpu_vram_mgr_func;
> -
> -	err = drm_buddy_init(&mgr->mm, man->size, PAGE_SIZE);
> -	if (err)
> -		return err;
> -
>   	mutex_init(&mgr->lock);
>   	INIT_LIST_HEAD(&mgr->reservations_pending);
>   	INIT_LIST_HEAD(&mgr->reserved_pages);
>   	mgr->default_page_size = PAGE_SIZE;
>   
> +	if (!adev->gmc.is_app_apu) {
> +		man->func = &amdgpu_vram_mgr_func;
> +
> +		err = drm_buddy_init(&mgr->mm, man->size, PAGE_SIZE);
> +		if (err)
> +			return err;
> +	} else {
> +		man->func = &amdgpu_dummy_vram_mgr_func;
> +		DRM_INFO("Setup dummy vram mgr\n");
> +	}
> +
>   	ttm_set_driver_manager(&adev->mman.bdev, TTM_PL_VRAM, &mgr->manager);
>   	ttm_resource_manager_set_used(man, true);
>   	return 0;
> @@ -886,7 +938,8 @@ void amdgpu_vram_mgr_fini(struct amdgpu_device *adev)
>   		drm_buddy_free_list(&mgr->mm, &rsv->allocated);
>   		kfree(rsv);
>   	}
> -	drm_buddy_fini(&mgr->mm);
> +	if (!adev->gmc.is_app_apu)
> +		drm_buddy_fini(&mgr->mm);
>   	mutex_unlock(&mgr->lock);
>   
>   	ttm_resource_manager_cleanup(man);