Re: [PATCH v1 16/20] drm/amdgpu: give ttm entities access to all the sdma scheds

["Christian König" <christian.koenig@amd.com>]

On 11/4/25 09:35, Pierre-Eric Pelloux-Prayer wrote:
> Signed-off-by: Pierre-Eric Pelloux-Prayer <pierre-eric.pelloux-prayer@amd.com>
> ---
>  drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c | 23 ++++++++++-------------
>  drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.h |  1 +
>  2 files changed, 11 insertions(+), 13 deletions(-)
> 
> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c
> index 47eaab9350ae..d88bdb2ac083 100644
> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c
> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c
> @@ -2187,8 +2187,8 @@ u32 amdgpu_ttm_set_buffer_funcs_status(struct amdgpu_device *adev, bool enable)
>  	u32 num_clear_entities, num_move_entities;
>  	u32 windows, w;
>  
> -	num_clear_entities = adev->sdma.num_instances;
> -	num_move_entities = MIN(adev->sdma.num_instances, TTM_FENCES_MAX_SLOT_COUNT);
> +	num_clear_entities = MIN(adev->mman.num_buffer_funcs_rings, TTM_FENCES_MAX_SLOT_COUNT);
> +	num_move_entities = MIN(adev->mman.num_buffer_funcs_rings, TTM_FENCES_MAX_SLOT_COUNT);
>  	man->pipelined_eviction.n_fences = num_move_entities;
>  	windows = adev->gmc.is_app_apu ? 0 : (2 * num_move_entities + num_clear_entities);
>  
> @@ -2197,13 +2197,8 @@ u32 amdgpu_ttm_set_buffer_funcs_status(struct amdgpu_device *adev, bool enable)
>  		return windows;
>  
>  	if (enable) {
> -		struct amdgpu_ring *ring;
> -		struct drm_gpu_scheduler *sched;
> -
> -		ring = adev->mman.buffer_funcs_rings[0];
> -		sched = &ring->sched;
>  		r = drm_sched_entity_init(&adev->mman.default_entity.base,
> -					  DRM_SCHED_PRIORITY_KERNEL, &sched,
> +					  DRM_SCHED_PRIORITY_KERNEL, adev->mman.scheds,
>  					  1, NULL);
>  		if (r) {
>  			dev_err(adev->dev, "Failed setting up entity (%d)\n",
> @@ -2215,8 +2210,8 @@ u32 amdgpu_ttm_set_buffer_funcs_status(struct amdgpu_device *adev, bool enable)
>  		atomic_set(&adev->mman.next_move_entity, 0);
>  		for (i = 0; i < num_move_entities; i++) {
>  			r = drm_sched_entity_init(&adev->mman.move_entities[i].base,
> -						  DRM_SCHED_PRIORITY_NORMAL, &sched,
> -						  1, NULL);
> +						  DRM_SCHED_PRIORITY_NORMAL, adev->mman.scheds,
> +						  adev->mman.num_buffer_funcs_rings, NULL);
>  			if (r) {
>  				dev_err(adev->dev,
>  					"Failed setting up TTM BO move entities (%d)\n",
> @@ -2238,8 +2233,8 @@ u32 amdgpu_ttm_set_buffer_funcs_status(struct amdgpu_device *adev, bool enable)
>  
>  		for (i = 0; i < num_clear_entities; i++) {
>  			r = drm_sched_entity_init(&adev->mman.clear_entities[i].base,
> -						  DRM_SCHED_PRIORITY_NORMAL, &sched,
> -						  1, NULL);
> +						  DRM_SCHED_PRIORITY_NORMAL, adev->mman.scheds,
> +						  adev->mman.num_buffer_funcs_rings, NULL);
>  			if (r) {
>  				for (j = 0; j < num_move_entities; j++)
>  					drm_sched_entity_destroy(
> @@ -2650,8 +2645,10 @@ void amdgpu_sdma_set_buffer_funcs_rings(struct amdgpu_device *adev)
>  	struct amdgpu_vmhub *hub = &adev->vmhub[AMDGPU_GFXHUB(0)];
>  	int i;
>  
> -	for (i = 0; i < adev->sdma.num_instances; i++)
> +	for (i = 0; i < adev->sdma.num_instances; i++) {
>  		adev->mman.buffer_funcs_rings[i] = &adev->sdma.instance[i].ring;
> +		adev->mman.scheds[i] = &adev->sdma.instance[i].ring.sched;
> +	}
>  
>  	adev->mman.num_buffer_funcs_rings = hub->sdma_invalidation_workaround ?
>  		1 : adev->sdma.num_instances;
> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.h b/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.h
> index d7fee371b814..c059a3d52b57 100644
> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.h
> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.h
> @@ -68,6 +68,7 @@ struct amdgpu_mman {
>  	const struct amdgpu_buffer_funcs	*buffer_funcs;
>  	struct amdgpu_ring			*buffer_funcs_rings[AMDGPU_MAX_RINGS];
>  	u32					num_buffer_funcs_rings;
> +	struct drm_gpu_scheduler		*scheds[AMDGPU_MAX_RINGS];

That looks like you are duplicating the data of buffer_funcs_rings. Why?

Regards,
Christian.

>  	bool					buffer_funcs_enabled;
>  
>  	struct mutex				gtt_window_lock;