[PATCH v2 7/7] of: Add KUnit test to confirm DTB is loaded

From: Stephen Boyd
Date: Mon Jan 29 2024 - 19:47:00 EST


Add a KUnit test that confirms a DTB has been loaded, i.e. there is a
root node, and that the of_have_populated_dt() API works properly.

Cc: Rob Herring <robh+dt@xxxxxxxxxx>
Cc: Frank Rowand <frowand.list@xxxxxxxxx>
Cc: David Gow <davidgow@xxxxxxxxxx>
Cc: Brendan Higgins <brendan.higgins@xxxxxxxxx>
Signed-off-by: Stephen Boyd <sboyd@xxxxxxxxxx>
---
drivers/of/.kunitconfig | 3 +++
drivers/of/Kconfig | 9 ++++++++
drivers/of/Makefile | 2 ++
drivers/of/of_test.c | 48 +++++++++++++++++++++++++++++++++++++++++
4 files changed, 62 insertions(+)
create mode 100644 drivers/of/.kunitconfig
create mode 100644 drivers/of/of_test.c

diff --git a/drivers/of/.kunitconfig b/drivers/of/.kunitconfig
new file mode 100644
index 000000000000..5a8fee11978c
--- /dev/null
+++ b/drivers/of/.kunitconfig
@@ -0,0 +1,3 @@
+CONFIG_KUNIT=y
+CONFIG_OF=y
+CONFIG_OF_KUNIT_TEST=y
diff --git a/drivers/of/Kconfig b/drivers/of/Kconfig
index 17733285b415..53d1b5dd89e8 100644
--- a/drivers/of/Kconfig
+++ b/drivers/of/Kconfig
@@ -37,6 +37,15 @@ config OF_UNITTEST

If unsure, say N here. This option is not safe to enable.

+config OF_KUNIT_TEST
+ tristate "Devicetree KUnit Test" if !KUNIT_ALL_TESTS
+ depends on KUNIT
+ default KUNIT_ALL_TESTS
+ help
+ This option builds KUnit unit tests for device tree infrastructure.
+
+ If unsure, say N here, but this option is safe to enable.
+
config OF_ALL_DTBS
bool "Build all Device Tree Blobs"
depends on COMPILE_TEST
diff --git a/drivers/of/Makefile b/drivers/of/Makefile
index df305348d1cb..251d33532148 100644
--- a/drivers/of/Makefile
+++ b/drivers/of/Makefile
@@ -19,4 +19,6 @@ obj-y += kexec.o
endif
endif

+obj-$(CONFIG_OF_KUNIT_TEST) += of_test.o
+
obj-$(CONFIG_OF_UNITTEST) += unittest-data/
diff --git a/drivers/of/of_test.c b/drivers/of/of_test.c
new file mode 100644
index 000000000000..71a767b42b43
--- /dev/null
+++ b/drivers/of/of_test.c
@@ -0,0 +1,48 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * KUnit tests for OF APIs
+ */
+#include <linux/module.h>
+#include <linux/of.h>
+
+#include <kunit/test.h>
+
+/*
+ * Test that the root node "/" can be found by path.
+ */
+static void dtb_root_node_found_by_path(struct kunit *test)
+{
+ struct device_node *np;
+
+ np = of_find_node_by_path("/");
+ KUNIT_EXPECT_NOT_ERR_OR_NULL(test, np);
+ of_node_put(np);
+}
+
+/*
+ * Test that the 'of_root' global variable is always populated when DT code is
+ * enabled.
+ */
+static void dtb_root_node_populates_of_root(struct kunit *test)
+{
+ KUNIT_EXPECT_NOT_ERR_OR_NULL(test, of_root);
+}
+
+static struct kunit_case dtb_test_cases[] = {
+ KUNIT_CASE(dtb_root_node_found_by_path),
+ KUNIT_CASE(dtb_root_node_populates_of_root),
+ {}
+};
+
+/*
+ * Test suite to confirm a DTB is loaded.
+ */
+static struct kunit_suite dtb_suite = {
+ .name = "dtb",
+ .test_cases = dtb_test_cases,
+};
+
+kunit_test_suites(
+ &dtb_suite,
+);
+MODULE_LICENSE("GPL");
--
https://git.kernel.org/pub/scm/linux/kernel/git/clk/linux.git/
https://git.kernel.org/pub/scm/linux/kernel/git/sboyd/spmi.git