6 files changed, 75 insertions, 17 deletions

diff --git a/drivers/gpu/drm/i915/intel_fb.c b/drivers/gpu/drm/i915/intel_fb.c
index 56ad9df2ccb5..b61966c126d3 100644
--- a/drivers/gpu/drm/i915/intel_fb.c
+++ b/drivers/gpu/drm/i915/intel_fb.c
@@ -238,8 +238,8 @@ int intel_fbdev_destroy(struct drm_device *dev,
 
         drm_framebuffer_cleanup(&ifb->base);
         if (ifb->obj) {
-                drm_gem_object_handle_unreference(ifb->obj);
                 drm_gem_object_unreference(ifb->obj);
+                ifb->obj = NULL;
         }
 
         return 0;
diff --git a/drivers/gpu/drm/nouveau/nouveau_fbcon.c b/drivers/gpu/drm/nouveau/nouveau_fbcon.c
index d2047713dc59..dbd30b2e43fd 100644
--- a/drivers/gpu/drm/nouveau/nouveau_fbcon.c
+++ b/drivers/gpu/drm/nouveau/nouveau_fbcon.c
@@ -352,7 +352,6 @@ nouveau_fbcon_destroy(struct drm_device *dev, struct nouveau_fbdev *nfbdev)
 
         if (nouveau_fb->nvbo) {
                 nouveau_bo_unmap(nouveau_fb->nvbo);
-                drm_gem_object_handle_unreference_unlocked(nouveau_fb->nvbo->gem);
                 drm_gem_object_unreference_unlocked(nouveau_fb->nvbo->gem);
                 nouveau_fb->nvbo = NULL;
         }
diff --git a/drivers/gpu/drm/nouveau/nouveau_notifier.c b/drivers/gpu/drm/nouveau/nouveau_notifier.c
index 3c9964a8fbad..3ec181ff50ce 100644
--- a/drivers/gpu/drm/nouveau/nouveau_notifier.c
+++ b/drivers/gpu/drm/nouveau/nouveau_notifier.c
@@ -79,7 +79,6 @@ nouveau_notifier_takedown_channel(struct nouveau_channel *chan)
         mutex_lock(&dev->struct_mutex);
         nouveau_bo_unpin(chan->notifier_bo);
         mutex_unlock(&dev->struct_mutex);
-        drm_gem_object_handle_unreference_unlocked(chan->notifier_bo->gem);
         drm_gem_object_unreference_unlocked(chan->notifier_bo->gem);
         drm_mm_takedown(&chan->notifier_heap);
 }
diff --git a/drivers/gpu/drm/radeon/radeon_fb.c b/drivers/gpu/drm/radeon/radeon_fb.c
index 9cdf6a35bc2c..40b0c087b592 100644
--- a/drivers/gpu/drm/radeon/radeon_fb.c
+++ b/drivers/gpu/drm/radeon/radeon_fb.c
@@ -97,7 +97,6 @@ static void radeonfb_destroy_pinned_object(struct drm_gem_object *gobj)
                 radeon_bo_unpin(rbo);
                 radeon_bo_unreserve(rbo);
         }
-        drm_gem_object_handle_unreference(gobj);
         drm_gem_object_unreference_unlocked(gobj);
 }
 
diff --git a/drivers/gpu/drm/ttm/ttm_bo.c b/drivers/gpu/drm/ttm/ttm_bo.c
index cb4cf7ef4d1e..db809e034cc4 100644
--- a/drivers/gpu/drm/ttm/ttm_bo.c
+++ b/drivers/gpu/drm/ttm/ttm_bo.c
@@ -442,6 +442,43 @@ 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) {
+                drm_mm_put_block(bo->mem.mm_node);
+                bo->mem.mm_node = NULL;
+        }
+
+        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,
@@ -456,6 +493,7 @@ 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) {
@@ -464,31 +502,52 @@ 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.
+                 */
 
-                ret = ttm_bo_reserve_locked(bo, false, false, false, 0);
-                BUG_ON(ret);
-                if (bo->ttm)
-                        ttm_tt_unbind(bo->ttm);
+                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;
+                }
+
+                put_count = ttm_bo_del_from_lru(bo);
 
                 if (!list_empty(&bo->ddestroy)) {
                         list_del_init(&bo->ddestroy);
                         ++put_count;
                 }
-                if (bo->mem.mm_node) {
-                        drm_mm_put_block(bo->mem.mm_node);
-                        bo->mem.mm_node = NULL;
-                }
-                spin_unlock(&glob->lru_lock);
 
-                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;
diff --git a/include/drm/ttm/ttm_bo_api.h b/include/drm/ttm/ttm_bo_api.h
index 267a86c74e2e..2040e6c4f172 100644
--- a/include/drm/ttm/ttm_bo_api.h
+++ b/include/drm/ttm/ttm_bo_api.h
@@ -246,9 +246,11 @@ struct ttm_buffer_object {
 
         atomic_t reserved;
 
-
         /**
          * Members protected by the bo::lock
+         * In addition, setting sync_obj to anything else
+         * than NULL requires bo::reserved to be held. This allows for
+         * checking NULL while reserved but not holding bo::lock.
          */
 
         void *sync_obj_arg;