lib/tests: convert test_min_heap module to KUnit

Move lib/test_min_heap.c to lib/tests/min_heap_kunit.c and convert it to
use KUnit.

This change switches the ad-hoc test code to standard KUnit test cases. 
The test data remains the same, but the verification logic is updated to
use KUNIT_EXPECT_* macros.

Also remove CONFIG_TEST_MIN_HEAP from arch/*/configs/* because it is no
longer used.  The new CONFIG_MIN_HEAP_KUNIT_TEST will be automatically
enabled by CONFIG_KUNIT_ALL_TESTS.

The reasons for converting to KUnit are:

1. Standardization:
    Switching from ad-hoc printk-based reporting to the standard
    KTAP format makes it easier for CI systems to parse and report test
    results

2. Better Diagnostics:
    Using KUNIT_EXPECT_* macros automatically provides detailed
    diagnostics on failure.

3. Tooling Integration:
    It allows the test to be managed and executed using standard
    KUnit tools.

Link: https://lkml.kernel.org/r/20251221133516.321846-1-sakamo.ryota@gmail.com
Signed-off-by: Ryota Sakamoto <sakamo.ryota@gmail.com>
Acked-by: Kuan-Wei Chiu <visitorckw@gmail.com>
Cc: Alexander Gordeev <agordeev@linux.ibm.com>
Cc: Christian Borntraeger <borntraeger@linux.ibm.com>
Cc: David Gow <davidgow@google.com>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Heiko Carstens <hca@linux.ibm.com>
Cc: Madhavan Srinivasan <maddy@linux.ibm.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Nicholas Piggin <npiggin@gmail.com>
Cc: Sven Schnelle <svens@linux.ibm.com>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

4 files changed, 79 insertions, 91 deletions

diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug
index 947e62e92da8..3a31bbf53425 100644
--- a/lib/Kconfig.debug
+++ b/lib/Kconfig.debug
@@ -2278,16 +2278,6 @@ config TEST_LIST_SORT
 
 	  If unsure, say N.
 
-config TEST_MIN_HEAP
-	tristate "Min heap test"
-	depends on DEBUG_KERNEL || m
-	help
-	  Enable this to turn on min heap function tests. This test is
-	  executed only once during system boot (so affects only boot time),
-	  or at module load time.
-
-	  If unsure, say N.
-
 config TEST_SORT
 	tristate "Array-based sort test" if !KUNIT_ALL_TESTS
 	depends on KUNIT
@@ -2878,6 +2868,17 @@ config MEMCPY_KUNIT_TEST
 
 	  If unsure, say N.
 
+config MIN_HEAP_KUNIT_TEST
+	tristate "Min heap test" if !KUNIT_ALL_TESTS
+	depends on KUNIT
+	default KUNIT_ALL_TESTS
+	help
+	  This option enables the KUnit test suite for the min heap library
+	  which provides functions for creating and managing min heaps.
+	  The test suite checks the functionality of the min heap library.
+
+	  If unsure, say N
+
 config IS_SIGNED_TYPE_KUNIT_TEST
 	tristate "Test is_signed_type() macro" if !KUNIT_ALL_TESTS
 	depends on KUNIT
diff --git a/lib/Makefile b/lib/Makefile
index 586a9f9b27a9..1f87a174a317 100644
--- a/lib/Makefile
+++ b/lib/Makefile
@@ -75,7 +75,6 @@ obj-$(CONFIG_TEST_UBSAN) += test_ubsan.o
 CFLAGS_test_ubsan.o += $(call cc-disable-warning, unused-but-set-variable)
 UBSAN_SANITIZE_test_ubsan.o := y
 obj-$(CONFIG_TEST_KSTRTOX) += test-kstrtox.o
-obj-$(CONFIG_TEST_MIN_HEAP) += test_min_heap.o
 obj-$(CONFIG_TEST_LKM) += test_module.o
 obj-$(CONFIG_TEST_VMALLOC) += test_vmalloc.o
 obj-$(CONFIG_TEST_RHASHTABLE) += test_rhashtable.o
diff --git a/lib/tests/Makefile b/lib/tests/Makefile
index 9a20608f65f5..088b80d16383 100644
--- a/lib/tests/Makefile
+++ b/lib/tests/Makefile
@@ -33,6 +33,7 @@ CFLAGS_longest_symbol_kunit.o += $(call cc-disable-warning, missing-prototypes)
 obj-$(CONFIG_LONGEST_SYM_KUNIT_TEST) += longest_symbol_kunit.o
 
 obj-$(CONFIG_MEMCPY_KUNIT_TEST) += memcpy_kunit.o
+obj-$(CONFIG_MIN_HEAP_KUNIT_TEST) += min_heap_kunit.o
 CFLAGS_overflow_kunit.o = $(call cc-disable-warning, tautological-constant-out-of-range-compare)
 obj-$(CONFIG_OVERFLOW_KUNIT_TEST) += overflow_kunit.o
 obj-$(CONFIG_PRINTF_KUNIT_TEST) += printf_kunit.o
diff --git a/lib/test_min_heap.c b/lib/tests/min_heap_kunit.c
index a9c4a74d3898..9c1122661698 100644
--- a/lib/test_min_heap.c
+++ b/lib/tests/min_heap_kunit.c
@@ -1,60 +1,66 @@
 // SPDX-License-Identifier: GPL-2.0-only
-#define pr_fmt(fmt) "min_heap_test: " fmt
-
 /*
  * Test cases for the min max heap.
  */
 
-#include <linux/log2.h>
+#include <kunit/test.h>
 #include <linux/min_heap.h>
 #include <linux/module.h>
-#include <linux/printk.h>
 #include <linux/random.h>
 
+struct min_heap_test_case {
+	const char *str;
+	bool min_heap;
+};
+
+static struct min_heap_test_case min_heap_cases[] = {
+	{
+		.str = "min",
+		.min_heap = true,
+	},
+	{
+		.str = "max",
+		.min_heap = false,
+	},
+};
+
+KUNIT_ARRAY_PARAM_DESC(min_heap, min_heap_cases, str);
+
 DEFINE_MIN_HEAP(int, min_heap_test);
 
-static __init bool less_than(const void *lhs, const void *rhs, void __always_unused *args)
+static bool less_than(const void *lhs, const void *rhs, void __always_unused *args)
 {
 	return *(int *)lhs < *(int *)rhs;
 }
 
-static __init bool greater_than(const void *lhs, const void *rhs, void __always_unused *args)
+static bool greater_than(const void *lhs, const void *rhs, void __always_unused *args)
 {
 	return *(int *)lhs > *(int *)rhs;
 }
 
-static __init int pop_verify_heap(bool min_heap,
-				struct min_heap_test *heap,
-				const struct min_heap_callbacks *funcs)
+static void pop_verify_heap(struct kunit *test,
+			    bool min_heap,
+			    struct min_heap_test *heap,
+			    const struct min_heap_callbacks *funcs)
 {
 	int *values = heap->data;
-	int err = 0;
 	int last;
 
 	last = values[0];
 	min_heap_pop_inline(heap, funcs, NULL);
 	while (heap->nr > 0) {
-		if (min_heap) {
-			if (last > values[0]) {
-				pr_err("error: expected %d <= %d\n", last,
-					values[0]);
-				err++;
-			}
-		} else {
-			if (last < values[0]) {
-				pr_err("error: expected %d >= %d\n", last,
-					values[0]);
-				err++;
-			}
-		}
+		if (min_heap)
+			KUNIT_EXPECT_LE(test, last, values[0]);
+		else
+			KUNIT_EXPECT_GE(test, last, values[0]);
 		last = values[0];
 		min_heap_pop_inline(heap, funcs, NULL);
 	}
-	return err;
 }
 
-static __init int test_heapify_all(bool min_heap)
+static void test_heapify_all(struct kunit *test)
 {
+	const struct min_heap_test_case *params = test->param_value;
 	int values[] = { 3, 1, 2, 4, 0x8000000, 0x7FFFFFF, 0,
 			 -3, -1, -2, -4, 0x8000000, 0x7FFFFFF };
 	struct min_heap_test heap = {
@@ -63,15 +69,14 @@ static __init int test_heapify_all(bool min_heap)
 		.size =  ARRAY_SIZE(values),
 	};
 	struct min_heap_callbacks funcs = {
-		.less = min_heap ? less_than : greater_than,
+		.less = params->min_heap ? less_than : greater_than,
 		.swp = NULL,
 	};
-	int i, err;
+	int i;
 
 	/* Test with known set of values. */
 	min_heapify_all_inline(&heap, &funcs, NULL);
-	err = pop_verify_heap(min_heap, &heap, &funcs);
-
+	pop_verify_heap(test, params->min_heap, &heap, &funcs);
 
 	/* Test with randomly generated values. */
 	heap.nr = ARRAY_SIZE(values);
@@ -79,13 +84,12 @@ static __init int test_heapify_all(bool min_heap)
 		values[i] = get_random_u32();
 
 	min_heapify_all_inline(&heap, &funcs, NULL);
-	err += pop_verify_heap(min_heap, &heap, &funcs);
-
-	return err;
+	pop_verify_heap(test, params->min_heap, &heap, &funcs);
 }
 
-static __init int test_heap_push(bool min_heap)
+static void test_heap_push(struct kunit *test)
 {
+	const struct min_heap_test_case *params = test->param_value;
 	const int data[] = { 3, 1, 2, 4, 0x80000000, 0x7FFFFFFF, 0,
 			     -3, -1, -2, -4, 0x80000000, 0x7FFFFFFF };
 	int values[ARRAY_SIZE(data)];
@@ -95,29 +99,28 @@ static __init int test_heap_push(bool min_heap)
 		.size =  ARRAY_SIZE(values),
 	};
 	struct min_heap_callbacks funcs = {
-		.less = min_heap ? less_than : greater_than,
+		.less = params->min_heap ? less_than : greater_than,
 		.swp = NULL,
 	};
-	int i, temp, err;
+	int i, temp;
 
 	/* Test with known set of values copied from data. */
 	for (i = 0; i < ARRAY_SIZE(data); i++)
 		min_heap_push_inline(&heap, &data[i], &funcs, NULL);
 
-	err = pop_verify_heap(min_heap, &heap, &funcs);
+	pop_verify_heap(test, params->min_heap, &heap, &funcs);
 
 	/* Test with randomly generated values. */
 	while (heap.nr < heap.size) {
 		temp = get_random_u32();
 		min_heap_push_inline(&heap, &temp, &funcs, NULL);
 	}
-	err += pop_verify_heap(min_heap, &heap, &funcs);
-
-	return err;
+	pop_verify_heap(test, params->min_heap, &heap, &funcs);
 }
 
-static __init int test_heap_pop_push(bool min_heap)
+static void test_heap_pop_push(struct kunit *test)
 {
+	const struct min_heap_test_case *params = test->param_value;
 	const int data[] = { 3, 1, 2, 4, 0x80000000, 0x7FFFFFFF, 0,
 			     -3, -1, -2, -4, 0x80000000, 0x7FFFFFFF };
 	int values[ARRAY_SIZE(data)];
@@ -127,13 +130,13 @@ static __init int test_heap_pop_push(bool min_heap)
 		.size =  ARRAY_SIZE(values),
 	};
 	struct min_heap_callbacks funcs = {
-		.less = min_heap ? less_than : greater_than,
+		.less = params->min_heap ? less_than : greater_than,
 		.swp = NULL,
 	};
-	int i, temp, err;
+	int i, temp;
 
 	/* Fill values with data to pop and replace. */
-	temp = min_heap ? 0x80000000 : 0x7FFFFFFF;
+	temp = params->min_heap ? 0x80000000 : 0x7FFFFFFF;
 	for (i = 0; i < ARRAY_SIZE(data); i++)
 		min_heap_push_inline(&heap, &temp, &funcs, NULL);
 
@@ -141,7 +144,7 @@ static __init int test_heap_pop_push(bool min_heap)
 	for (i = 0; i < ARRAY_SIZE(data); i++)
 		min_heap_pop_push_inline(&heap, &data[i], &funcs, NULL);
 
-	err = pop_verify_heap(min_heap, &heap, &funcs);
+	pop_verify_heap(test, params->min_heap, &heap, &funcs);
 
 	heap.nr = 0;
 	for (i = 0; i < ARRAY_SIZE(data); i++)
@@ -152,13 +155,12 @@ static __init int test_heap_pop_push(bool min_heap)
 		temp = get_random_u32();
 		min_heap_pop_push_inline(&heap, &temp, &funcs, NULL);
 	}
-	err += pop_verify_heap(min_heap, &heap, &funcs);
-
-	return err;
+	pop_verify_heap(test, params->min_heap, &heap, &funcs);
 }
 
-static __init int test_heap_del(bool min_heap)
+static void test_heap_del(struct kunit *test)
 {
+	const struct min_heap_test_case *params = test->param_value;
 	int values[] = { 3, 1, 2, 4, 0x8000000, 0x7FFFFFF, 0,
 			 -3, -1, -2, -4, 0x8000000, 0x7FFFFFF };
 	struct min_heap_test heap;
@@ -166,17 +168,16 @@ static __init int test_heap_del(bool min_heap)
 	min_heap_init_inline(&heap, values, ARRAY_SIZE(values));
 	heap.nr = ARRAY_SIZE(values);
 	struct min_heap_callbacks funcs = {
-		.less = min_heap ? less_than : greater_than,
+		.less = params->min_heap ? less_than : greater_than,
 		.swp = NULL,
 	};
-	int i, err;
+	int i;
 
 	/* Test with known set of values. */
 	min_heapify_all_inline(&heap, &funcs, NULL);
 	for (i = 0; i < ARRAY_SIZE(values) / 2; i++)
 		min_heap_del_inline(&heap, get_random_u32() % heap.nr, &funcs, NULL);
-	err = pop_verify_heap(min_heap, &heap, &funcs);
-
+	pop_verify_heap(test, params->min_heap, &heap, &funcs);
 
 	/* Test with randomly generated values. */
 	heap.nr = ARRAY_SIZE(values);
@@ -186,37 +187,23 @@ static __init int test_heap_del(bool min_heap)
 
 	for (i = 0; i < ARRAY_SIZE(values) / 2; i++)
 		min_heap_del_inline(&heap, get_random_u32() % heap.nr, &funcs, NULL);
-	err += pop_verify_heap(min_heap, &heap, &funcs);
-
-	return err;
+	pop_verify_heap(test, params->min_heap, &heap, &funcs);
 }
 
-static int __init test_min_heap_init(void)
-{
-	int err = 0;
-
-	err += test_heapify_all(true);
-	err += test_heapify_all(false);
-	err += test_heap_push(true);
-	err += test_heap_push(false);
-	err += test_heap_pop_push(true);
-	err += test_heap_pop_push(false);
-	err += test_heap_del(true);
-	err += test_heap_del(false);
-	if (err) {
-		pr_err("test failed with %d errors\n", err);
-		return -EINVAL;
-	}
-	pr_info("test passed\n");
-	return 0;
-}
-module_init(test_min_heap_init);
+static struct kunit_case min_heap_test_cases[] = {
+	KUNIT_CASE_PARAM(test_heapify_all, min_heap_gen_params),
+	KUNIT_CASE_PARAM(test_heap_push, min_heap_gen_params),
+	KUNIT_CASE_PARAM(test_heap_pop_push, min_heap_gen_params),
+	KUNIT_CASE_PARAM(test_heap_del, min_heap_gen_params),
+	{},
+};
 
-static void __exit test_min_heap_exit(void)
-{
-	/* do nothing */
-}
-module_exit(test_min_heap_exit);
+static struct kunit_suite min_heap_test_suite = {
+	.name = "min_heap",
+	.test_cases = min_heap_test_cases,
+};
+
+kunit_test_suite(min_heap_test_suite);
 
 MODULE_DESCRIPTION("Test cases for the min max heap");
 MODULE_LICENSE("GPL");