drm/ttm: replace dma_resv object on deleted BOs v3

When non-imported BOs are resurrected for delayed delete we replace
the dma_resv object to allow for easy reclaiming of the resources.

v2: move that to ttm_bo_individualize_resv
v3: add a comment to explain what's going on

Signed-off-by: Christian König <christian.koenig@amd.com>
Reviewed-by: xinhui pan <xinhui.pan@amd.com>
Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: https://patchwork.freedesktop.org/patch/352927/

diff --git a/drivers/gpu/drm/ttm/ttm_bo.c b/drivers/gpu/drm/ttm/ttm_bo.c
index 28fd91ca6806cd2e497669c992abc76a8d934ea8..6688599def4b02c4b0b486cc1e280eab51061a02 100644 (file)
--- a/drivers/gpu/drm/ttm/ttm_bo.c
+++ b/drivers/gpu/drm/ttm/ttm_bo.c
@@ -393,6 +393,18 @@ static int ttm_bo_individualize_resv(struct ttm_buffer_object *bo)
 
        r = dma_resv_copy_fences(&bo->base._resv, bo->base.resv);
        dma_resv_unlock(&bo->base._resv);
+       if (r)
+               return r;
+
+       if (bo->type != ttm_bo_type_sg) {
+               /* This works because the BO is about to be destroyed and nobody
+                * reference it any more. The only tricky case is the trylock on
+                * the resv object while holding the lru_lock.
+                */
+               spin_lock(&ttm_bo_glob.lru_lock);
+               bo->base.resv = &bo->base._resv;
+               spin_unlock(&ttm_bo_glob.lru_lock);
+       }
 
        return r;
 }
@@ -720,7 +732,7 @@ static bool ttm_bo_evict_swapout_allowable(struct ttm_buffer_object *bo,
 
        if (bo->base.resv == ctx->resv) {
                dma_resv_assert_held(bo->base.resv);
-               if (ctx->flags & TTM_OPT_FLAG_ALLOW_RES_EVICT || bo->deleted)
+               if (ctx->flags & TTM_OPT_FLAG_ALLOW_RES_EVICT)
                        ret = true;
                *locked = false;
                if (busy)