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| author | Stephen Boyd <sboyd@kernel.org> | 2024-07-18 23:05:01 +0200 |
|---|---|---|
| committer | Stephen Boyd <sboyd@kernel.org> | 2024-07-30 00:33:12 +0200 |
| commit | 6774e90f3146818c284b805b16ecdc144dda1c60 (patch) | |
| tree | f41741a8a52b457c681c77f2235d2d90ef1513d7 /Documentation/dev-tools | |
| parent | of/platform: Allow overlays to create platform devices from the root node (diff) | |
| download | linux-6774e90f3146818c284b805b16ecdc144dda1c60.tar.xz linux-6774e90f3146818c284b805b16ecdc144dda1c60.zip | |
of: Add test managed wrappers for of_overlay_apply()/of_node_put()
Add test managed wrappers for of_overlay_apply() that automatically
removes the overlay when the test is finished. This API is intended for
use by KUnit tests that test code which relies on 'struct device_node's
and of_*() APIs.
KUnit tests will call of_overlay_apply_kunit() to load an overlay that's
been built into the kernel image. When the test is complete, the overlay
will be removed.
This has a few benefits:
1) It keeps the tests hermetic because the overlay is removed when the
test is complete. Tests won't even be aware that an overlay was
loaded in another test.
2) The overlay code can live right next to the unit test that loads it.
The overlay and the unit test can be compiled into one kernel module
if desired.
3) We can test different device tree configurations by loading
different overlays. The overlays can be written for a specific test,
and there can be many of them loaded per-test without needing to jam
all possible combinations into one DTB.
4) It also allows KUnit to test device tree dependent code on any
architecture, not just UML. This allows KUnit tests to test
architecture specific device tree code.
There are some potential pitfalls though. Test authors need to be
careful to not overwrite properties in the live tree. The easiest way to
do this is to add and remove nodes with a 'kunit-' prefix, almost
guaranteeing that the same node won't be present in the tree loaded at
boot.
Suggested-by: Rob Herring <robh@kernel.org>
Cc: Rob Herring <robh@kernel.org>
Cc: Saravana Kannan <saravanak@google.com>
Reviewed-by: Rob Herring (Arm) <robh@kernel.org>
Reviewed-by: David Gow <davidgow@google.com>
Signed-off-by: Stephen Boyd <sboyd@kernel.org>
Link: https://lore.kernel.org/r/20240718210513.3801024-3-sboyd@kernel.org
Diffstat (limited to 'Documentation/dev-tools')
| -rw-r--r-- | Documentation/dev-tools/kunit/api/index.rst | 11 | ||||
| -rw-r--r-- | Documentation/dev-tools/kunit/api/of.rst | 13 |
2 files changed, 24 insertions, 0 deletions
diff --git a/Documentation/dev-tools/kunit/api/index.rst b/Documentation/dev-tools/kunit/api/index.rst index 2d8f756aab56..282befa17edf 100644 --- a/Documentation/dev-tools/kunit/api/index.rst +++ b/Documentation/dev-tools/kunit/api/index.rst @@ -9,11 +9,15 @@ API Reference test resource functionredirection + of This page documents the KUnit kernel testing API. It is divided into the following sections: +Core KUnit API +============== + Documentation/dev-tools/kunit/api/test.rst - Documents all of the standard testing API @@ -25,3 +29,10 @@ Documentation/dev-tools/kunit/api/resource.rst Documentation/dev-tools/kunit/api/functionredirection.rst - Documents the KUnit Function Redirection API + +Driver KUnit API +================ + +Documentation/dev-tools/kunit/api/of.rst + + - Documents the KUnit device tree (OF) API diff --git a/Documentation/dev-tools/kunit/api/of.rst b/Documentation/dev-tools/kunit/api/of.rst new file mode 100644 index 000000000000..cb4193dcddbb --- /dev/null +++ b/Documentation/dev-tools/kunit/api/of.rst @@ -0,0 +1,13 @@ +.. SPDX-License-Identifier: GPL-2.0 + +==================== +Device Tree (OF) API +==================== + +The KUnit device tree API is used to test device tree (of_*) dependent code. + +.. kernel-doc:: include/kunit/of.h + :internal: + +.. kernel-doc:: drivers/of/of_kunit_helpers.c + :export: |