linux-kernel - [PATCH 3/3] test_bits: add tests for __GENMASK() and __GENMASK

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Message-Id: <20250322-consolidate-genmask-v1-3-54bfd36c5643@wanadoo.fr>
Date: Sat, 22 Mar 2025 19:39:38 +0900
From: Vincent Mailhol via B4 Relay <devnull+mailhol.vincent.wanadoo.fr@...nel.org>
To: Yury Norov <yury.norov@...il.com>, 
 Lucas De Marchi <lucas.demarchi@...el.com>, 
 Rasmus Villemoes <linux@...musvillemoes.dk>, 
 Jani Nikula <jani.nikula@...ux.intel.com>, 
 Joonas Lahtinen <joonas.lahtinen@...ux.intel.com>, 
 Rodrigo Vivi <rodrigo.vivi@...el.com>, 
 Tvrtko Ursulin <tursulin@...ulin.net>, David Airlie <airlied@...il.com>, 
 Simona Vetter <simona@...ll.ch>, Andrew Morton <akpm@...ux-foundation.org>
Cc: linux-kernel@...r.kernel.org, intel-gfx@...ts.freedesktop.org, 
 dri-devel@...ts.freedesktop.org, Andi Shyti <andi.shyti@...ux.intel.com>, 
 David Laight <David.Laight@...LAB.COM>, 
 Andy Shevchenko <andriy.shevchenko@...ux.intel.com>, 
 Vincent Mailhol <mailhol.vincent@...adoo.fr>
Subject: [PATCH 3/3] test_bits: add tests for __GENMASK() and
 __GENMASK_ULL()

From: Vincent Mailhol <mailhol.vincent@...adoo.fr>

The definitions of GENMASK() and GENMASK_ULL() do not depend any more
on __GENMASK() and __GENMASK_ULL(). Duplicate the existing unit tests
so that __GENMASK{,ULL}() are still covered.

Because __GENMASK() and __GENMASK_ULL() do use GENMASK_INPUT_CHECK(),
drop the TEST_GENMASK_FAILURES negative tests.

It would be good to have a small assembly test case for GENMASK*() in
case somebody decides to unify both in the future. However, I lack
expertise in assembly to do so. Instead add a FIXME message to
highlight the absence of the asm unit test.

Signed-off-by: Vincent Mailhol <mailhol.vincent@...adoo.fr>
Reviewed-by: Lucas De Marchi <lucas.demarchi@...el.com>
---
This patch previously belonged to this series:

  bits: Fixed-type GENMASK_U*() and BIT_U*()
  Link: https://lore.kernel.org/r/20250308-fixed-type-genmasks-v6-0-f59315e73c29@wanadoo.fr

Below changelog also contains the history from the previous series.

Changelog:

  v6 (previous series) -> v1 (new series):

    - Add a message in the commit description to explain why the
      negative tests are dropped.

    - Add Lucas's Reviewed-by tag.

  v5 -> v6:

    - Add a FIXME message to highlight the absence of the asm
      GENMASK*() unit tests.

  v4 -> v5:

    - No changes.

  v3 -> v4:

    - New patch.
---
 lib/test_bits.c | 19 +++++++++++++++++++
 1 file changed, 19 insertions(+)

diff --git a/lib/test_bits.c b/lib/test_bits.c
index 47325b41515fde2c3ed434ed6f4094925c98886b..ab88e50d2edfa2b011f07d50460ac8ea6ff99923 100644
--- a/lib/test_bits.c
+++ b/lib/test_bits.c
@@ -26,6 +26,23 @@ static_assert(assert_type(u16, GENMASK_U16(15, 0)) == U16_MAX);
 static_assert(assert_type(u32, GENMASK_U32(31, 0)) == U32_MAX);
 static_assert(assert_type(u64, GENMASK_U64(63, 0)) == U64_MAX);
 
+/* FIXME: add a test case written in asm for GENMASK() and GENMASK_ULL() */
+
+static void __genmask_test(struct kunit *test)
+{
+	KUNIT_EXPECT_EQ(test, 1ul, __GENMASK(0, 0));
+	KUNIT_EXPECT_EQ(test, 3ul, __GENMASK(1, 0));
+	KUNIT_EXPECT_EQ(test, 6ul, __GENMASK(2, 1));
+	KUNIT_EXPECT_EQ(test, 0xFFFFFFFFul, __GENMASK(31, 0));
+}
+
+static void __genmask_ull_test(struct kunit *test)
+{
+	KUNIT_EXPECT_EQ(test, 1ull, __GENMASK_ULL(0, 0));
+	KUNIT_EXPECT_EQ(test, 3ull, __GENMASK_ULL(1, 0));
+	KUNIT_EXPECT_EQ(test, 0x000000ffffe00000ull, __GENMASK_ULL(39, 21));
+	KUNIT_EXPECT_EQ(test, 0xffffffffffffffffull, __GENMASK_ULL(63, 0));
+}
 
 static void genmask_test(struct kunit *test)
 {
@@ -123,6 +140,8 @@ static void genmask_input_check_test(struct kunit *test)
 
 
 static struct kunit_case bits_test_cases[] = {
+	KUNIT_CASE(__genmask_test),
+	KUNIT_CASE(__genmask_ull_test),
 	KUNIT_CASE(genmask_test),
 	KUNIT_CASE(genmask_ull_test),
 	KUNIT_CASE(genmask_u128_test),

-- 
2.48.1