1 files changed, 70 insertions, 9 deletions

diff --git a/drivers/gpu/drm/ttm/ttm_bo.c b/drivers/gpu/drm/ttm/ttm_bo.c
index af7b57a47fbc..1e9bb2156dcf 100644
--- a/drivers/gpu/drm/ttm/ttm_bo.c
+++ b/drivers/gpu/drm/ttm/ttm_bo.c
@@ -439,6 +439,42 @@ out_err:
 }
 
 /**
+ * Call bo::reserved and with the lru lock held.
+ * Will release GPU memory type usage on destruction.
+ * This is the place to put in driver specific hooks.
+ * Will release the bo::reserved lock and the
+ * lru lock on exit.
+ */
+
+static void ttm_bo_cleanup_memtype_use(struct ttm_buffer_object *bo)
+{
+        struct ttm_bo_global *glob = bo->glob;
+
+        if (bo->ttm) {
+
+                /**
+                 * Release the lru_lock, since we don't want to have
+                 * an atomic requirement on ttm_tt[unbind|destroy].
+                 */
+
+                spin_unlock(&glob->lru_lock);
+                ttm_tt_unbind(bo->ttm);
+                ttm_tt_destroy(bo->ttm);
+                bo->ttm = NULL;
+                spin_lock(&glob->lru_lock);
+        }
+
+        if (bo->mem.mm_node) {
+                ttm_bo_mem_put(bo, &bo->mem);
+        }
+
+        atomic_set(&bo->reserved, 0);
+        wake_up_all(&bo->event_queue);
+        spin_unlock(&glob->lru_lock);
+}
+
+
+/**
  * If bo idle, remove from delayed- and lru lists, and unref.
  * If not idle, and already on delayed list, do nothing.
  * If not idle, and not on delayed list, put on delayed list,
@@ -453,6 +489,7 @@ static int ttm_bo_cleanup_refs(struct ttm_buffer_object *bo, bool remove_all)
         int ret;
 
         spin_lock(&bo->lock);
+retry:
         (void) ttm_bo_wait(bo, false, false, !remove_all);
 
         if (!bo->sync_obj) {
@@ -461,28 +498,52 @@ static int ttm_bo_cleanup_refs(struct ttm_buffer_object *bo, bool remove_all)
                 spin_unlock(&bo->lock);
 
                 spin_lock(&glob->lru_lock);
-                put_count = ttm_bo_del_from_lru(bo);
+                ret = ttm_bo_reserve_locked(bo, false, !remove_all, false, 0);
+
+                /**
+                 * Someone else has the object reserved. Bail and retry.
+                 */
+
+                if (unlikely(ret == -EBUSY)) {
+                        spin_unlock(&glob->lru_lock);
+                        spin_lock(&bo->lock);
+                        goto requeue;
+                }
+
+                /**
+                 * We can re-check for sync object without taking
+                 * the bo::lock since setting the sync object requires
+                 * also bo::reserved. A busy object at this point may
+                 * be caused by another thread starting an accelerated
+                 * eviction.
+                 */
+
+                if (unlikely(bo->sync_obj)) {
+                        atomic_set(&bo->reserved, 0);
+                        wake_up_all(&bo->event_queue);
+                        spin_unlock(&glob->lru_lock);
+                        spin_lock(&bo->lock);
+                        if (remove_all)
+                                goto retry;
+                        else
+                                goto requeue;
+                }
 
-                ret = ttm_bo_reserve_locked(bo, false, false, false, 0);
-                BUG_ON(ret);
-                if (bo->ttm)
-                        ttm_tt_unbind(bo->ttm);
+                put_count = ttm_bo_del_from_lru(bo);
 
                 if (!list_empty(&bo->ddestroy)) {
                         list_del_init(&bo->ddestroy);
                         ++put_count;
                 }
-                spin_unlock(&glob->lru_lock);
-                ttm_bo_mem_put(bo, &bo->mem);
 
-                atomic_set(&bo->reserved, 0);
+                ttm_bo_cleanup_memtype_use(bo);
 
                 while (put_count--)
                         kref_put(&bo->list_kref, ttm_bo_ref_bug);
 
                 return 0;
         }
-
+requeue:
         spin_lock(&glob->lru_lock);
         if (list_empty(&bo->ddestroy)) {
                 void *sync_obj = bo->sync_obj;