of: overlay: unittest: add tests for overlay notifiers

Add tests for overlay apply and remove notifiers.  Trigger errors
for each of the notifier actions.

These tests will reveal a memory leak problem when a notifier returns
an error for action OF_OVERLAY_POST_APPLY.  The pr_err() message is:

   OF: ERROR: memory leak, expected refcount 1 instead of 3,
   of_node_get()/of_node_put() unbalanced - destroy cset entry: attach
   overlay node /testcase-data/overlay-node/test-bus/test-unittest17

Signed-off-by: Frank Rowand <frank.rowand@sony.com>
Signed-off-by: Rob Herring <robh@kernel.org>
Link: https://lore.kernel.org/r/20220502181742.1402826-3-frowand.list@gmail.com

6 files changed, 85 insertions, 0 deletions

diff --git a/drivers/of/unittest-data/Makefile b/drivers/of/unittest-data/Makefile
index fbded24c608c..d072f3ba3971 100644
--- a/drivers/of/unittest-data/Makefile
+++ b/drivers/of/unittest-data/Makefile
@@ -17,6 +17,11 @@ obj-$(CONFIG_OF_OVERLAY) += overlay.dtb.o \
 			    overlay_12.dtb.o \
 			    overlay_13.dtb.o \
 			    overlay_15.dtb.o \
+			    overlay_16.dtb.o \
+			    overlay_17.dtb.o \
+			    overlay_18.dtb.o \
+			    overlay_19.dtb.o \
+			    overlay_20.dtb.o \
 			    overlay_bad_add_dup_node.dtb.o \
 			    overlay_bad_add_dup_prop.dtb.o \
 			    overlay_bad_phandle.dtb.o \
@@ -75,6 +80,11 @@ apply_static_overlay_1 := overlay_0.dtbo \
 			  overlay_12.dtbo \
 			  overlay_13.dtbo \
 			  overlay_15.dtbo \
+			  overlay_16.dtbo \
+			  overlay_17.dtbo \
+			  overlay_18.dtbo \
+			  overlay_19.dtbo \
+			  overlay_20.dtbo \
 			  overlay_gpio_01.dtbo \
 			  overlay_gpio_02a.dtbo \
 			  overlay_gpio_02b.dtbo \
diff --git a/drivers/of/unittest-data/overlay_16.dts b/drivers/of/unittest-data/overlay_16.dts
new file mode 100644
index 000000000000..80a46dc02581
--- /dev/null
+++ b/drivers/of/unittest-data/overlay_16.dts
@@ -0,0 +1,15 @@
+// SPDX-License-Identifier: GPL-2.0
+/dts-v1/;
+/plugin/;
+
+/* overlay_16 - notify test */
+
+&unittest_test_bus {
+	#address-cells = <1>;
+	#size-cells = <0>;
+
+	test-unittest16 {
+		compatible = "unittest";
+		reg = <16>;
+	};
+};
diff --git a/drivers/of/unittest-data/overlay_17.dts b/drivers/of/unittest-data/overlay_17.dts
new file mode 100644
index 000000000000..5b8a2209177f
--- /dev/null
+++ b/drivers/of/unittest-data/overlay_17.dts
@@ -0,0 +1,15 @@
+// SPDX-License-Identifier: GPL-2.0
+/dts-v1/;
+/plugin/;
+
+/* overlay_17 - notify test */
+
+&unittest_test_bus {
+	#address-cells = <1>;
+	#size-cells = <0>;
+
+	test-unittest17 {
+		compatible = "unittest";
+		reg = <17>;
+	};
+};
diff --git a/drivers/of/unittest-data/overlay_18.dts b/drivers/of/unittest-data/overlay_18.dts
new file mode 100644
index 000000000000..dcddd5f6d301
--- /dev/null
+++ b/drivers/of/unittest-data/overlay_18.dts
@@ -0,0 +1,15 @@
+// SPDX-License-Identifier: GPL-2.0
+/dts-v1/;
+/plugin/;
+
+/* overlay_18 - notify test */
+
+&unittest_test_bus {
+	#address-cells = <1>;
+	#size-cells = <0>;
+
+	test-unittest18 {
+		compatible = "unittest";
+		reg = <18>;
+	};
+};
diff --git a/drivers/of/unittest-data/overlay_19.dts b/drivers/of/unittest-data/overlay_19.dts
new file mode 100644
index 000000000000..32b3ba0b66a3
--- /dev/null
+++ b/drivers/of/unittest-data/overlay_19.dts
@@ -0,0 +1,15 @@
+// SPDX-License-Identifier: GPL-2.0
+/dts-v1/;
+/plugin/;
+
+/* overlay_19 - notify test */
+
+&unittest_test_bus {
+	#address-cells = <1>;
+	#size-cells = <0>;
+
+	test-unittest19 {
+		compatible = "unittest";
+		reg = <19>;
+	};
+};
diff --git a/drivers/of/unittest-data/overlay_20.dts b/drivers/of/unittest-data/overlay_20.dts
new file mode 100644
index 000000000000..d4a4f2f32ec7
--- /dev/null
+++ b/drivers/of/unittest-data/overlay_20.dts
@@ -0,0 +1,15 @@
+// SPDX-License-Identifier: GPL-2.0
+/dts-v1/;
+/plugin/;
+
+/* overlay_20 - notify test */
+
+&unittest_test_bus {
+	#address-cells = <1>;
+	#size-cells = <0>;
+
+	test-unittest20 {
+		compatible = "unittest";
+		reg = <20>;
+	};
+};