• Mario Kleiner's avatar
    drm/amdgpu: Attach exclusive fence to prime exported bo's. (v5) · d039fc37
    Mario Kleiner authored
    commit 8e94a46c upstream.
    
    External clients which import our bo's wait only
    for exclusive dmabuf-fences, not on shared ones,
    ditto for bo's which we import from external
    providers and write to.
    
    Therefore attach exclusive fences on prime shared buffers
    if our exported buffer gets imported by an external
    client, or if we import a buffer from an external
    exporter.
    
    See discussion in thread:
    https://lists.freedesktop.org/archives/dri-devel/2016-October/122370.html
    
    Prime export tested on Intel iGPU + AMD Tonga dGPU as
    DRI3/Present Prime render offload, and with the Tonga
    standalone as primary gpu.
    
    v2: Add a wait for all shared fences before prime export,
        as suggested by Christian Koenig.
    
    v3: - Mark buffer prime_exported in amdgpu_gem_prime_pin,
        so we only use the exclusive fence when exporting a
        bo to external clients like a separate iGPU, but not
        when exporting/importing from/to ourselves as part of
        regular DRI3 fd passing.
    
        - Propagate failure of reservation_object_wait_rcu back
        to caller.
    
    v4: - Switch to a prime_shared_count counter instead of a
          flag, which gets in/decremented on prime_pin/unpin, so
          we can switch back to shared fences if all clients
          detach from our exported bo.
    
        - Also switch to exclusive fence for prime imported bo's.
    
    v5: - Drop lret, instead use int ret -> long ret, as proposed
          by Christian.
    
    Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=95472
    Tested-by: Mike Lothian <mike@fireburn.co.uk> (v1)
    Signed-off-by: default avatarMario Kleiner <mario.kleiner.de@gmail.com>
    Reviewed-by: Christian König <christian.koenig@amd.com>.
    Cc: Christian König <christian.koenig@amd.com>
    Cc: Michel Dänzer <michel.daenzer@amd.com>
    Signed-off-by: default avatarAlex Deucher <alexander.deucher@amd.com>
    Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
    d039fc37
amdgpu.h 72.1 KB