[PATCH] lib: add basic KUnit test for lib/math
From: Daniel Latypov
Date: Mon Oct 19 2020 - 18:46:19 EST
Add basic test coverage for files that don't require any config options:
* gcd.c
* lcm.c
* int_sqrt.c
* reciprocal_div.c
(Ignored int_pow.c since it's a simple textbook algorithm.)
These tests aren't particularly interesting, but
* they're chosen as easy to understand examples of how to write tests
* provides a place to add tests for any new files in this dir
* written so adding new test cases to cover edge cases should be easy
Signed-off-by: Daniel Latypov <dlatypov@xxxxxxxxxx>
---
lib/math/Kconfig | 5 ++
lib/math/Makefile | 2 +
lib/math/math_test.c | 197 +++++++++++++++++++++++++++++++++++++++++++
3 files changed, 204 insertions(+)
create mode 100644 lib/math/math_test.c
diff --git a/lib/math/Kconfig b/lib/math/Kconfig
index f19bc9734fa7..6ba8680439c1 100644
--- a/lib/math/Kconfig
+++ b/lib/math/Kconfig
@@ -15,3 +15,8 @@ config PRIME_NUMBERS
config RATIONAL
bool
+
+config MATH_KUNIT_TEST
+ tristate "KUnit test for lib/math" if !KUNIT_ALL_TESTS
+ default KUNIT_ALL_TESTS
+ depends on KUNIT
diff --git a/lib/math/Makefile b/lib/math/Makefile
index be6909e943bd..fba6fe90f50b 100644
--- a/lib/math/Makefile
+++ b/lib/math/Makefile
@@ -4,3 +4,5 @@ obj-y += div64.o gcd.o lcm.o int_pow.o int_sqrt.o reciprocal_div.o
obj-$(CONFIG_CORDIC) += cordic.o
obj-$(CONFIG_PRIME_NUMBERS) += prime_numbers.o
obj-$(CONFIG_RATIONAL) += rational.o
+
+obj-$(CONFIG_MATH_KUNIT_TEST) += math_test.o
diff --git a/lib/math/math_test.c b/lib/math/math_test.c
new file mode 100644
index 000000000000..6f4681ea7c72
--- /dev/null
+++ b/lib/math/math_test.c
@@ -0,0 +1,197 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Simple KUnit suite for math helper funcs that are always enabled.
+ *
+ * Copyright (C) 2020, Google LLC.
+ * Author: Daniel Latypov <dlatypov@xxxxxxxxxx>
+ */
+
+#include <kunit/test.h>
+#include <linux/gcd.h>
+#include <linux/kernel.h>
+#include <linux/lcm.h>
+#include <linux/reciprocal_div.h>
+
+/* Generic test case for unsigned long inputs. */
+struct test_case {
+ unsigned long a, b;
+ unsigned long result;
+};
+
+static void gcd_test(struct kunit *test)
+{
+ const char *message_fmt = "gcd(%lu, %lu)";
+ int i;
+
+ struct test_case test_cases[] = {
+ {
+ .a = 0, .b = 1,
+ .result = 1,
+ },
+ {
+ .a = 2, .b = 2,
+ .result = 2,
+ },
+ {
+ .a = 2, .b = 4,
+ .result = 2,
+ },
+ {
+ .a = 3, .b = 5,
+ .result = 1,
+ },
+ {
+ .a = 3*9, .b = 3*5,
+ .result = 3,
+ },
+ {
+ .a = 3*5*7, .b = 3*5*11,
+ .result = 15,
+ },
+ {
+ .a = (1 << 21) - 1,
+ .b = (1 << 22) - 1,
+ .result = 1,
+ },
+ };
+
+ for (i = 0; i < ARRAY_SIZE(test_cases); ++i) {
+ KUNIT_EXPECT_EQ_MSG(test, test_cases[i].result,
+ gcd(test_cases[i].a, test_cases[i].b),
+ message_fmt, test_cases[i].a,
+ test_cases[i].b);
+
+ /* gcd(a,b) == gcd(b,a) */
+ KUNIT_EXPECT_EQ_MSG(test, test_cases[i].result,
+ gcd(test_cases[i].b, test_cases[i].a),
+ message_fmt, test_cases[i].b,
+ test_cases[i].a);
+ }
+}
+
+static void lcm_test(struct kunit *test)
+{
+ const char *message_fmt = "lcm(%lu, %lu)";
+ int i;
+
+ struct test_case test_cases[] = {
+ {
+ .a = 0, .b = 1,
+ .result = 0,
+ },
+ {
+ .a = 1, .b = 2,
+ .result = 2,
+ },
+ {
+ .a = 2, .b = 2,
+ .result = 2,
+ },
+ {
+ .a = 3*5, .b = 3*7,
+ .result = 3*5*7,
+ },
+ };
+
+ for (i = 0; i < ARRAY_SIZE(test_cases); ++i) {
+ KUNIT_EXPECT_EQ_MSG(test, test_cases[i].result,
+ lcm(test_cases[i].a, test_cases[i].b),
+ message_fmt, test_cases[i].a,
+ test_cases[i].b);
+
+ /* lcm(a,b) == lcm(b,a) */
+ KUNIT_EXPECT_EQ_MSG(test, test_cases[i].result,
+ lcm(test_cases[i].b, test_cases[i].a),
+ message_fmt, test_cases[i].b,
+ test_cases[i].a);
+ }
+}
+
+static void int_sqrt_test(struct kunit *test)
+{
+ const char *message_fmt = "sqrt(%lu)";
+ int i;
+
+ struct test_case test_cases[] = {
+ {
+ .a = 0,
+ .result = 0,
+ },
+ {
+ .a = 1,
+ .result = 1,
+ },
+ {
+ .a = 4,
+ .result = 2,
+ },
+ {
+ .a = 5,
+ .result = 2,
+ },
+ {
+ .a = 8,
+ .result = 2,
+ },
+ {
+ .a = 1UL >> 32,
+ .result = 1UL >> 16,
+ },
+ };
+
+ for (i = 0; i < ARRAY_SIZE(test_cases); ++i) {
+ KUNIT_EXPECT_EQ_MSG(test, int_sqrt(test_cases[i].a),
+ test_cases[i].result, message_fmt,
+ test_cases[i].a);
+ }
+}
+
+struct reciprocal_test_case {
+ u32 a, b;
+ u32 result;
+};
+
+static void reciprocal_div_test(struct kunit *test)
+{
+ int i;
+ struct reciprocal_value rv;
+ struct reciprocal_test_case test_cases[] = {
+ {
+ .a = 0, .b = 1,
+ .result = 0,
+ },
+ {
+ .a = 42, .b = 20,
+ .result = 2,
+ },
+ {
+ .a = (1<<16), .b = (1<<14),
+ .result = 1<<2,
+ },
+ };
+
+ for (i = 0; i < ARRAY_SIZE(test_cases); ++i) {
+ rv = reciprocal_value(test_cases[i].b);
+ KUNIT_EXPECT_EQ_MSG(test, test_cases[i].result,
+ reciprocal_divide(test_cases[i].a, rv),
+ "reciprocal_divide(%u, %u)",
+ test_cases[i].a, test_cases[i].b);
+ }
+}
+
+static struct kunit_case math_test_cases[] = {
+ KUNIT_CASE(gcd_test),
+ KUNIT_CASE(lcm_test),
+ KUNIT_CASE(int_sqrt_test),
+ KUNIT_CASE(reciprocal_div_test),
+ {}
+};
+
+static struct kunit_suite math_test_suite = {
+ .name = "lib-math",
+ .test_cases = math_test_cases,
+};
+
+kunit_test_suites(&math_test_suite);
+
+MODULE_LICENSE("GPL v2");
base-commit: 7cf726a59435301046250c42131554d9ccc566b8
--
2.29.0.rc1.297.gfa9743e501-goog