linux-kernel - [PATCH v7 4/5] test_bits: add tests for GENMASK

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Message-Id: <20250322-fixed-type-genmasks-v7-4-da380ff1c5b9@wanadoo.fr>
Date: Sat, 22 Mar 2025 18:23:15 +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 v7 4/5] test_bits: add tests for GENMASK_U*()

From: Lucas De Marchi <lucas.demarchi@...el.com>

Add some additional tests in lib/test_bits.c to cover the
expected/non-expected values of the fixed-type GENMASK_U*() macros.

Also check that the result value matches the expected type. Since
those are known at build time, use static_assert() instead of normal
kunit tests.

Signed-off-by: Lucas De Marchi <lucas.demarchi@...el.com>
Signed-off-by: Vincent Mailhol <mailhol.vincent@...adoo.fr>
---
Changelog:

  v6 -> v7:
  v5 -> v6:

    - No changes.

  v4 -> v5:

    - Revert v4 change. GENMASK_U8()/GENMASK_U16() are now back to
      u8/u16.

  v3 -> v4:

    - Adjust the type of GENMASK_U8()/GENMASK_U16() from u8/u16 to
      unsigned int.

    - Reorder the tests to match the order in which the macros are
      declared in bits.h.
---
 lib/test_bits.c | 20 ++++++++++++++++++++
 1 file changed, 20 insertions(+)

diff --git a/lib/test_bits.c b/lib/test_bits.c
index c7b38d91e1f16d42b7ca92e62fbd6c19b37e76a0..f443476f3265c463c1219b13c1ef9663d238d58b 100644
--- a/lib/test_bits.c
+++ b/lib/test_bits.c
@@ -5,6 +5,16 @@
 
 #include <kunit/test.h>
 #include <linux/bits.h>
+#include <linux/types.h>
+
+#define assert_type(t, x) _Generic(x, t: x, default: 0)
+
+static_assert(assert_type(unsigned long, GENMASK(31, 0)) == U32_MAX);
+static_assert(assert_type(unsigned long long, GENMASK_ULL(63, 0)) == U64_MAX);
+static_assert(assert_type(u8, GENMASK_U8(7, 0)) == U8_MAX);
+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);
 
 
 static void genmask_test(struct kunit *test)
@@ -14,11 +24,21 @@ static void genmask_test(struct kunit *test)
 	KUNIT_EXPECT_EQ(test, 6ul, GENMASK(2, 1));
 	KUNIT_EXPECT_EQ(test, 0xFFFFFFFFul, GENMASK(31, 0));
 
+	KUNIT_EXPECT_EQ(test, 1u, GENMASK_U8(0, 0));
+	KUNIT_EXPECT_EQ(test, 3u, GENMASK_U16(1, 0));
+	KUNIT_EXPECT_EQ(test, 0x10000, GENMASK_U32(16, 16));
+
 #ifdef TEST_GENMASK_FAILURES
 	/* these should fail compilation */
 	GENMASK(0, 1);
 	GENMASK(0, 10);
 	GENMASK(9, 10);
+
+	GENMASK_U32(0, 31);
+	GENMASK_U64(64, 0);
+	GENMASK_U32(32, 0);
+	GENMASK_U16(16, 0);
+	GENMASK_U8(8, 0);
 #endif
 
 

-- 
2.48.1