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path: root/drivers/gpu/drm/ttm/ttm_bo.c
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Diffstat (limited to 'drivers/gpu/drm/ttm/ttm_bo.c')
-rw-r--r--drivers/gpu/drm/ttm/ttm_bo.c35
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 8d5a646ebe6..07e02c4bf5a 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;
+}