Merge branch 'ttm-fixes-3.13' of git://people.freedesktop.org/~thomash/linux into drm-fixes

The set_need_resched() removal fix and yet another fix in
ttm_bo_move_memcpy().

* 'ttm-fixes-3.13' of git://people.freedesktop.org/~thomash/linux:
  drm/ttm: Remove set_need_resched from the ttm fault handler
  drm/ttm: Don't move non-existing data

1 files changed, 34 insertions, 1 deletions

diff --git a/drivers/gpu/drm/ttm/ttm_bo.c b/drivers/gpu/drm/ttm/ttm_bo.c
index 8d5a646ebe6a..07e02c4bf5a8 100644
--- a/drivers/gpu/drm/ttm/ttm_bo.c
+++ b/drivers/gpu/drm/ttm/ttm_bo.c
@@ -151,7 +151,7 @@ static void ttm_bo_release_list(struct kref *list_kref)
 	atomic_dec(&bo->glob->bo_count);
 	if (bo->resv == &bo->ttm_resv)
 		reservation_object_fini(&bo->ttm_resv);
-
+	mutex_destroy(&bo->wu_mutex);
 	if (bo->destroy)
 		bo->destroy(bo);
 	else {
@@ -1123,6 +1123,7 @@ int ttm_bo_init(struct ttm_bo_device *bdev,
 	INIT_LIST_HEAD(&bo->ddestroy);
 	INIT_LIST_HEAD(&bo->swap);
 	INIT_LIST_HEAD(&bo->io_reserve_lru);
+	mutex_init(&bo->wu_mutex);
 	bo->bdev = bdev;
 	bo->glob = bdev->glob;
 	bo->type = type;
@@ -1704,3 +1705,35 @@ void ttm_bo_swapout_all(struct ttm_bo_device *bdev)
 		;
 }
 EXPORT_SYMBOL(ttm_bo_swapout_all);
+
+/**
+ * ttm_bo_wait_unreserved - interruptible wait for a buffer object to become
+ * unreserved
+ *
+ * @bo: Pointer to buffer
+ */
+int ttm_bo_wait_unreserved(struct ttm_buffer_object *bo)
+{
+	int ret;
+
+	/*
+	 * In the absense of a wait_unlocked API,
+	 * Use the bo::wu_mutex to avoid triggering livelocks due to
+	 * concurrent use of this function. Note that this use of
+	 * bo::wu_mutex can go away if we change locking order to
+	 * mmap_sem -> bo::reserve.
+	 */
+	ret = mutex_lock_interruptible(&bo->wu_mutex);
+	if (unlikely(ret != 0))
+		return -ERESTARTSYS;
+	if (!ww_mutex_is_locked(&bo->resv->lock))
+		goto out_unlock;
+	ret = ttm_bo_reserve_nolru(bo, true, false, false, NULL);
+	if (unlikely(ret != 0))
+		goto out_unlock;
+	ww_mutex_unlock(&bo->resv->lock);
+
+out_unlock:
+	mutex_unlock(&bo->wu_mutex);
+	return ret;
+}