drm/ttm: Remove set_need_resched from the ttm fault handler

[~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 8d5a646ebe6ae9ef0a924145885ce897d1260e1b..07e02c4bf5a8e0def00e120a14b5ada2d1cfaa97 100644 (file)
--- 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;
+}