1 files changed, 97 insertions, 0 deletions
diff --git a/drivers/gpu/drm/qxl/qxl_fence.c b/drivers/gpu/drm/qxl/qxl_fence.c
new file mode 100644
index 00000000000..63c6715ad38
--- /dev/null
+++ b/drivers/gpu/drm/qxl/qxl_fence.c
@@ -0,0 +1,97 @@
+/*
+ * Copyright 2013 Red Hat Inc.
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a
+ * copy of this software and associated documentation files (the "Software"),
+ * to deal in the Software without restriction, including without limitation
+ * the rights to use, copy, modify, merge, publish, distribute, sublicense,
+ * and/or sell copies of the Software, and to permit persons to whom the
+ * Software is furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
+ * THE COPYRIGHT HOLDER(S) OR AUTHOR(S) BE LIABLE FOR ANY CLAIM, DAMAGES OR
+ * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
+ * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
+ * OTHER DEALINGS IN THE SOFTWARE.
+ *
+ * Authors: Dave Airlie
+ *          Alon Levy
+ */
+
+
+#include "qxl_drv.h"
+
+/* QXL fencing-
+
+   When we submit operations to the GPU we pass a release reference to the GPU
+   with them, the release reference is then added to the release ring when
+   the GPU is finished with that particular operation and has removed it from
+   its tree.
+
+   So we have can have multiple outstanding non linear fences per object.
+
+   From a TTM POV we only care if the object has any outstanding releases on
+   it.
+
+   we wait until all outstanding releases are processeed.
+
+   sync object is just a list of release ids that represent that fence on
+   that buffer.
+
+   we just add new releases onto the sync object attached to the object.
+
+   This currently uses a radix tree to store the list of release ids.
+
+   For some reason every so often qxl hw fails to release, things go wrong.
+*/
+
+
+int qxl_fence_add_release(struct qxl_fence *qfence, uint32_t rel_id)
+{
+	struct qxl_bo *bo = container_of(qfence, struct qxl_bo, fence);
+
+	spin_lock(&bo->tbo.bdev->fence_lock);
+	radix_tree_insert(&qfence->tree, rel_id, qfence);
+	qfence->num_active_releases++;
+	spin_unlock(&bo->tbo.bdev->fence_lock);
+	return 0;
+}
+
+int qxl_fence_remove_release(struct qxl_fence *qfence, uint32_t rel_id)
+{
+	void *ret;
+	int retval = 0;
+	struct qxl_bo *bo = container_of(qfence, struct qxl_bo, fence);
+
+	spin_lock(&bo->tbo.bdev->fence_lock);
+
+	ret = radix_tree_delete(&qfence->tree, rel_id);
+	if (ret == qfence)
+		qfence->num_active_releases--;
+	else {
+		DRM_DEBUG("didn't find fence in radix tree for %d\n", rel_id);
+		retval = -ENOENT;
+	}
+	spin_unlock(&bo->tbo.bdev->fence_lock);
+	return retval;
+}
+
+
+int qxl_fence_init(struct qxl_device *qdev, struct qxl_fence *qfence)
+{
+	qfence->qdev = qdev;
+	qfence->num_active_releases = 0;
+	INIT_RADIX_TREE(&qfence->tree, GFP_ATOMIC);
+	return 0;
+}
+
+void qxl_fence_fini(struct qxl_fence *qfence)
+{
+	kfree(qfence->release_ids);
+	qfence->num_active_releases = 0;
+}