From: Alex Sierra alex.sierra@amd.com
[why] To support svm bo eviction mechanism.
[how] If the BO crated has AMDGPU_AMDKFD_CREATE_SVM_BO flag set, enable_signal callback will be called inside amdgpu_evict_flags. This also causes gutting of the BO by removing all placements, so that TTM won't actually do an eviction. Instead it will discard the memory held by the BO. This is needed for HMM migration to user mode system memory pages.
Signed-off-by: Alex Sierra alex.sierra@amd.com Signed-off-by: Felix Kuehling Felix.Kuehling@amd.com --- drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c | 14 ++++++++++++++ 1 file changed, 14 insertions(+)
diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c index aca5a29f6d2a..2d80eb3fa571 100644 --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c @@ -111,6 +111,20 @@ static void amdgpu_evict_flags(struct ttm_buffer_object *bo, }
abo = ttm_to_amdgpu_bo(bo); + if (abo->flags & AMDGPU_AMDKFD_CREATE_SVM_BO) { + struct dma_fence *fence; + struct dma_resv *resv = &bo->base._resv; + + rcu_read_lock(); + fence = rcu_dereference(resv->fence_excl); + if (fence && !fence->ops->signaled) + dma_fence_enable_sw_signaling(fence); + + placement->num_placement = 0; + placement->num_busy_placement = 0; + rcu_read_unlock(); + return; + } switch (bo->mem.mem_type) { case AMDGPU_PL_GDS: case AMDGPU_PL_GWS: