drm/ttm: use RCU in ttm_bo_flush_all_fences

This allows it to call the function without the lock held.

Signed-off-by: Christian König <christian.koenig@amd.com>
Reviewed-by: xinhui pan <xinhui.pan@amd.com>
Link: https://patchwork.freedesktop.org/patch/352742/

diff --git a/drivers/gpu/drm/ttm/ttm_bo.c b/drivers/gpu/drm/ttm/ttm_bo.c
index c1104c8..e12fc2c 100644 (file)
--- a/drivers/gpu/drm/ttm/ttm_bo.c
+++ b/drivers/gpu/drm/ttm/ttm_bo.c
@@ -429,22 +429,24 @@ static int ttm_bo_individualize_resv(struct ttm_buffer_object *bo)
 
 static void ttm_bo_flush_all_fences(struct ttm_buffer_object *bo)
 {
+       struct dma_resv *resv = &bo->base._resv;
        struct dma_resv_list *fobj;
        struct dma_fence *fence;
        int i;
 
-       fobj = dma_resv_get_list(&bo->base._resv);
-       fence = dma_resv_get_excl(&bo->base._resv);
+       rcu_read_lock();
+       fobj = rcu_dereference(resv->fence);
+       fence = rcu_dereference(resv->fence_excl);
        if (fence && !fence->ops->signaled)
                dma_fence_enable_sw_signaling(fence);
 
        for (i = 0; fobj && i < fobj->shared_count; ++i) {
-               fence = rcu_dereference_protected(fobj->shared[i],
-                                       dma_resv_held(bo->base.resv));
+               fence = rcu_dereference(fobj->shared[i]);
 
                if (!fence->ops->signaled)
                        dma_fence_enable_sw_signaling(fence);
        }
+       rcu_read_unlock();
 }
 
 static void ttm_bo_cleanup_refs_or_queue(struct ttm_buffer_object *bo)