drm/ttm: add ttm_bo_reserve_slowpath

[~andy/linux] / drivers / gpu / drm / ttm / ttm_bo.c

diff --git a/drivers/gpu/drm/ttm/ttm_bo.c b/drivers/gpu/drm/ttm/ttm_bo.c
index e8e4814b12957b26bf5e08f3ad51814d3c192fa7..4dd6f9e77a7d213f98fa2ef0569270e0baf19b50 100644 (file)
--- a/drivers/gpu/drm/ttm/ttm_bo.c
+++ b/drivers/gpu/drm/ttm/ttm_bo.c
@@ -310,6 +310,53 @@ int ttm_bo_reserve(struct ttm_buffer_object *bo,
        return ret;
 }
 
+int ttm_bo_reserve_slowpath_nolru(struct ttm_buffer_object *bo,
+                                 bool interruptible, uint32_t sequence)
+{
+       bool wake_up = false;
+       int ret;
+
+       while (unlikely(atomic_xchg(&bo->reserved, 1) != 0)) {
+               WARN_ON(bo->seq_valid && sequence == bo->val_seq);
+
+               ret = ttm_bo_wait_unreserved(bo, interruptible);
+
+               if (unlikely(ret))
+                       return ret;
+       }
+
+       if ((bo->val_seq - sequence < (1 << 31)) || !bo->seq_valid)
+               wake_up = true;
+
+       /**
+        * Wake up waiters that may need to recheck for deadlock,
+        * if we decreased the sequence number.
+        */
+       bo->val_seq = sequence;
+       bo->seq_valid = true;
+       if (wake_up)
+               wake_up_all(&bo->event_queue);
+
+       return 0;
+}
+
+int ttm_bo_reserve_slowpath(struct ttm_buffer_object *bo,
+                           bool interruptible, uint32_t sequence)
+{
+       struct ttm_bo_global *glob = bo->glob;
+       int put_count, ret;
+
+       ret = ttm_bo_reserve_slowpath_nolru(bo, interruptible, sequence);
+       if (likely(!ret)) {
+               spin_lock(&glob->lru_lock);
+               put_count = ttm_bo_del_from_lru(bo);
+               spin_unlock(&glob->lru_lock);
+               ttm_bo_list_ref_sub(bo, put_count, true);
+       }
+       return ret;
+}
+EXPORT_SYMBOL(ttm_bo_reserve_slowpath);
+
 void ttm_bo_unreserve_locked(struct ttm_buffer_object *bo)
 {
        ttm_bo_add_to_lru(bo);