Re: [PATCH 6/6] of: Add KUnit test to confirm DTB is loaded

[David Gow]

On Sat, 13 Jan 2024 at 04:07, Stephen Boyd <sboyd@xxxxxxxxxx> wrote:
>
> 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>
> ---

I won't pretend to be a devicetree expert, but this looks good to me
from a KUnit point of view, and passes comfortably here.

checkpatch seems to have one complaint about the kconfig help text.
Personally, I think the brief description is fine.

Reviewed-by: David Gow <davidgow@xxxxxxxxxx>

Cheers,
-- David

>  drivers/of/.kunitconfig |  3 ++
>  drivers/of/Kconfig      |  9 ++++
>  drivers/of/Makefile     |  2 +
>  drivers/of/of_test.c    | 98 +++++++++++++++++++++++++++++++++++++++++
>  4 files changed, 112 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 9628e48baa15..a527ba8451d9 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 DTB 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.
> +

FYI:
WARNING: please write a help paragraph that fully describes the config symbol
#111: FILE: drivers/of/Kconfig:40:

>  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..7609ad3081b9
> --- /dev/null
> +++ b/drivers/of/of_test.c
> @@ -0,0 +1,98 @@
> +// 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 "/" exists.
> + */
> +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 live DTB is loaded.
> + */
> +static struct kunit_suite dtb_suite = {
> +       .name = "dtb",
> +       .test_cases = dtb_test_cases,
> +};
> +
> +/*
> + * Test that calling of_have_populated_dt() returns false when
> + * the OF_EMPTY_ROOT flag isn't set.
> + */
> +static void of_have_populated_dt_false_when_flag_set(struct kunit *test)
> +{
> +       bool was_set;
> +
> +       KUNIT_ASSERT_NOT_ERR_OR_NULL(test, of_root);
> +
> +       was_set = of_node_test_and_set_flag(of_root, OF_EMPTY_ROOT);
> +       KUNIT_EXPECT_FALSE(test, of_have_populated_dt());
> +
> +       if (!was_set)
> +               of_node_clear_flag(of_root, OF_EMPTY_ROOT);
> +}
> +
> +/*
> + * Test that calling of_have_populated_dt() returns false when
> + * the OF_EMPTY_ROOT flag isn't set.
> + */
> +static void of_have_populated_dt_true_when_flag_clear(struct kunit *test)
> +{
> +       bool was_set;
> +
> +       KUNIT_ASSERT_NOT_ERR_OR_NULL(test, of_root);
> +
> +       was_set = of_node_check_flag(of_root, OF_EMPTY_ROOT);
> +       of_node_set_flag(of_root, OF_EMPTY_ROOT);
> +       KUNIT_EXPECT_FALSE(test, of_have_populated_dt());
> +
> +       if (was_set)
> +               of_node_set_flag(of_root, OF_EMPTY_ROOT);
> +}
> +
> +static struct kunit_case of_have_populated_dt_test_cases[] = {
> +       KUNIT_CASE(of_have_populated_dt_false_when_flag_set),
> +       KUNIT_CASE(of_have_populated_dt_true_when_flag_clear),
> +       {}
> +};
> +
> +/*
> + * Test suite to confirm behavior of of_have_populated_dt().
> + */
> +static struct kunit_suite of_have_populated_dt_suite = {
> +       .name = "of_have_populated_dt",
> +       .test_cases = of_have_populated_dt_test_cases,
> +};
> +
> +kunit_test_suites(
> +       &dtb_suite,
> +       &of_have_populated_dt_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
>

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