Commit 5c9dd72d authored by Stephen Boyd's avatar Stephen Boyd
Browse files

of: Add a KUnit test for overlays and test managed APIs 



Test the KUnit test managed overlay APIs. Confirm that platform devices
are created and destroyed properly. This provides us confidence that the
test managed APIs work correctly and can be relied upon to provide tests
with fake platform devices and device nodes via overlays compiled into
the kernel image.

Cc: Rob Herring <robh@kernel.org>
Cc: Saravana Kannan <saravanak@google.com>
Cc: Daniel Latypov <dlatypov@google.com>
Cc: Brendan Higgins <brendan.higgins@linux.dev>
Reviewed-by: default avatarDavid Gow <davidgow@google.com>
Cc: Rae Moar <rmoar@google.com>
Reviewed-by: default avatarRob Herring (Arm) <robh@kernel.org>
Signed-off-by: default avatarStephen Boyd <sboyd@kernel.org>
Link: https://lore.kernel.org/r/20240718210513.3801024-5-sboyd@kernel.org
parent 7fc616c8

drivers/of/.kunitconfig

+1 −0
Original line number Diff line number Diff line 
CONFIG_KUNIT=y

CONFIG_OF=y

CONFIG_OF_KUNIT_TEST=y

CONFIG_OF_OVERLAY_KUNIT_TEST=y

drivers/of/Kconfig

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@@ -107,6 +107,16 @@ config OF_OVERLAY 
	  While this option is selected automatically when needed, you can

	  enable it manually to improve device tree unit test coverage.



config OF_OVERLAY_KUNIT_TEST

	tristate "Device Tree overlay KUnit tests" if !KUNIT_ALL_TESTS

	depends on KUNIT

	default KUNIT_ALL_TESTS

	select OF_OVERLAY

	help

	  This option builds KUnit unit tests for the device tree overlay code.



	  If unsure, say N here, but this option is safe to enable.



config OF_NUMA

	bool

drivers/of/Makefile

+2 −0
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@@ -21,5 +21,7 @@ endif 


obj-$(CONFIG_KUNIT) += of_kunit_helpers.o

obj-$(CONFIG_OF_KUNIT_TEST) += of_test.o

obj-$(CONFIG_OF_OVERLAY_KUNIT_TEST) += overlay-test.o

overlay-test-y := overlay_test.o kunit_overlay_test.dtbo.o



obj-$(CONFIG_OF_UNITTEST) += unittest-data/

drivers/of/kunit_overlay_test.dtso

0 → 100644
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// SPDX-License-Identifier: GPL-2.0

/dts-v1/;

/plugin/;



&{/} {

	kunit-test {

		compatible = "test,empty";

	};

};

drivers/of/overlay_test.c

0 → 100644
+115 −0
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// SPDX-License-Identifier: GPL-2.0

/*

 * KUnit tests for device tree overlays

 */

#include <linux/device/bus.h>

#include <linux/kconfig.h>

#include <linux/of.h>

#include <linux/of_platform.h>

#include <linux/platform_device.h>



#include <kunit/of.h>

#include <kunit/test.h>



static const char * const kunit_node_name = "kunit-test";

static const char * const kunit_compatible = "test,empty";



/* Test that of_overlay_apply_kunit() adds a node to the live tree */

static void of_overlay_apply_kunit_apply(struct kunit *test)

{

	struct device_node *np;



	KUNIT_ASSERT_EQ(test, 0,

			of_overlay_apply_kunit(test, kunit_overlay_test));



	np = of_find_node_by_name(NULL, kunit_node_name);

	KUNIT_EXPECT_NOT_ERR_OR_NULL(test, np);

	of_node_put(np);

}



/*

 * Test that of_overlay_apply_kunit() creates platform devices with the

 * expected device_node

 */

static void of_overlay_apply_kunit_platform_device(struct kunit *test)

{

	struct platform_device *pdev;

	struct device_node *np;



	KUNIT_ASSERT_EQ(test, 0,

			of_overlay_apply_kunit(test, kunit_overlay_test));



	np = of_find_node_by_name(NULL, kunit_node_name);

	of_node_put_kunit(test, np);

	KUNIT_ASSERT_NOT_ERR_OR_NULL(test, np);



	pdev = of_find_device_by_node(np);

	KUNIT_EXPECT_NOT_ERR_OR_NULL(test, pdev);

	if (pdev)

		put_device(&pdev->dev);

}



static int of_overlay_bus_match_compatible(struct device *dev, const void *data)

{

	return of_device_is_compatible(dev->of_node, data);

}



/* Test that of_overlay_apply_kunit() cleans up after the test is finished */

static void of_overlay_apply_kunit_cleanup(struct kunit *test)

{

	struct kunit fake;

	struct platform_device *pdev;

	struct device *dev;

	struct device_node *np;



	if (!IS_ENABLED(CONFIG_OF_EARLY_FLATTREE))

		kunit_skip(test, "requires CONFIG_OF_EARLY_FLATTREE for root node");



	kunit_init_test(&fake, "fake test", NULL);

	KUNIT_ASSERT_EQ(test, fake.status, KUNIT_SUCCESS);



	KUNIT_ASSERT_EQ(test, 0,

			of_overlay_apply_kunit(&fake, kunit_overlay_test));



	np = of_find_node_by_name(NULL, kunit_node_name);

	KUNIT_ASSERT_NOT_ERR_OR_NULL(test, np);

	of_node_put_kunit(test, np);



	pdev = of_find_device_by_node(np);

	KUNIT_ASSERT_NOT_ERR_OR_NULL(test, pdev);

	put_device(&pdev->dev); /* Not derefing 'pdev' after this */



	/* Remove overlay */

	kunit_cleanup(&fake);



	/* The node and device should be removed */

	np = of_find_node_by_name(NULL, kunit_node_name);

	KUNIT_EXPECT_PTR_EQ(test, NULL, np);

	of_node_put(np);



	dev = bus_find_device(&platform_bus_type, NULL, kunit_compatible,

			      of_overlay_bus_match_compatible);

	KUNIT_EXPECT_PTR_EQ(test, NULL, dev);

	put_device(dev);

}



static struct kunit_case of_overlay_apply_kunit_test_cases[] = {

	KUNIT_CASE(of_overlay_apply_kunit_apply),

	KUNIT_CASE(of_overlay_apply_kunit_platform_device),

	KUNIT_CASE(of_overlay_apply_kunit_cleanup),

	{}

};



/*

 * Test suite for test managed device tree overlays.

 */

static struct kunit_suite of_overlay_apply_kunit_suite = {

	.name = "of_overlay_apply_kunit",

	.test_cases = of_overlay_apply_kunit_test_cases,

};



kunit_test_suites(

	&of_overlay_apply_kunit_suite,

);

MODULE_LICENSE("GPL");

MODULE_DESCRIPTION("KUnit tests for device tree overlays");