[PATCH] drm/amdgpu: unpack dma_fence_chain containers during sync

[Christian König]

Ping, Pierre/Marek does this change works as expected?

Regards,
Christian.

Am 18.11.20 um 14:20 schrieb Christian König:
> This allows for optimizing the CPU round trip away.
>
> Signed-off-by: Christian König <christian.koenig at amd.com>
> ---
>   drivers/gpu/drm/amd/amdgpu/amdgpu_cs.c   |  2 +-
>   drivers/gpu/drm/amd/amdgpu/amdgpu_sync.c | 27 ++++++++++++++++++++++++
>   drivers/gpu/drm/amd/amdgpu/amdgpu_sync.h |  1 +
>   3 files changed, 29 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_cs.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_cs.c
> index 79342976fa76..68f9a4adf5d2 100644
> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_cs.c
> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_cs.c
> @@ -1014,7 +1014,7 @@ static int amdgpu_syncobj_lookup_and_add_to_sync(struct amdgpu_cs_parser *p,
>   		return r;
>   	}
>   
> -	r = amdgpu_sync_fence(&p->job->sync, fence);
> +	r = amdgpu_sync_fence_chain(&p->job->sync, fence);
>   	dma_fence_put(fence);
>   
>   	return r;
> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_sync.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_sync.c
> index 8ea6c49529e7..d0d64af06f54 100644
> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_sync.c
> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_sync.c
> @@ -28,6 +28,8 @@
>    *    Christian König <christian.koenig at amd.com>
>    */
>   
> +#include <linux/dma-fence-chain.h>
> +
>   #include "amdgpu.h"
>   #include "amdgpu_trace.h"
>   #include "amdgpu_amdkfd.h"
> @@ -169,6 +171,31 @@ int amdgpu_sync_fence(struct amdgpu_sync *sync, struct dma_fence *f)
>   	return 0;
>   }
>   
> +/**
> + * amdgpu_sync_fence_chain - unpack dma_fence_chain and sync
> + *
> + * @sync: sync object to add fence to
> + * @f: potential dma_fence_chain to sync to.
> + *
> + * Add the fences inside the chain to the sync object.
> + */
> +int amdgpu_sync_fence_chain(struct amdgpu_sync *sync, struct dma_fence *f)
> +{
> +	int r;
> +
> +	dma_fence_chain_for_each(f, f) {
> +		if (dma_fence_is_signaled(f))
> +			continue;
> +
> +		r = amdgpu_sync_fence(sync, f);
> +		if (r) {
> +			dma_fence_put(f);
> +			return r;
> +		}
> +	}
> +	return 0;
> +}
> +
>   /**
>    * amdgpu_sync_vm_fence - remember to sync to this VM fence
>    *
> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_sync.h b/drivers/gpu/drm/amd/amdgpu/amdgpu_sync.h
> index 7c0fe20c470d..b142175b65b6 100644
> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_sync.h
> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_sync.h
> @@ -48,6 +48,7 @@ struct amdgpu_sync {
>   
>   void amdgpu_sync_create(struct amdgpu_sync *sync);
>   int amdgpu_sync_fence(struct amdgpu_sync *sync, struct dma_fence *f);
> +int amdgpu_sync_fence_chain(struct amdgpu_sync *sync, struct dma_fence *f);
>   int amdgpu_sync_vm_fence(struct amdgpu_sync *sync, struct dma_fence *fence);
>   int amdgpu_sync_resv(struct amdgpu_device *adev, struct amdgpu_sync *sync,
>   		     struct dma_resv *resv, enum amdgpu_sync_mode mode,