Merge tag 'mm-nonmm-stable-2024-11-24-02-05' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm

Pull non-MM updates from Andrew Morton:

 - The series "resource: A couple of cleanups" from Andy Shevchenko
   performs some cleanups in the resource management code

 - The series "Improve the copy of task comm" from Yafang Shao addresses
   possible race-induced overflows in the management of
   task_struct.comm[]

 - The series "Remove unnecessary header includes from
   {tools/}lib/list_sort.c" from Kuan-Wei Chiu adds some cleanups and a
   small fix to the list_sort library code and to its selftest

 - The series "Enhance min heap API with non-inline functions and
   optimizations" also from Kuan-Wei Chiu optimizes and cleans up the
   min_heap library code

 - The series "nilfs2: Finish folio conversion" from Ryusuke Konishi
   finishes off nilfs2's folioification

 - The series "add detect count for hung tasks" from Lance Yang adds
   more userspace visibility into the hung-task detector's activity

 - Apart from that, singelton patches in many places - please see the
   individual changelogs for details

* tag 'mm-nonmm-stable-2024-11-24-02-05' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (71 commits)
  gdb: lx-symbols: do not error out on monolithic build
  kernel/reboot: replace sprintf() with sysfs_emit()
  lib: util_macros_kunit: add kunit test for util_macros.h
  util_macros.h: fix/rework find_closest() macros
  Improve consistency of '#error' directive messages
  ocfs2: fix uninitialized value in ocfs2_file_read_iter()
  hung_task: add docs for hung_task_detect_count
  hung_task: add detect count for hung tasks
  dma-buf: use atomic64_inc_return() in dma_buf_getfile()
  fs/proc/kcore.c: fix coccinelle reported ERROR instances
  resource: avoid unnecessary resource tree walking in __region_intersects()
  ocfs2: remove unused errmsg function and table
  ocfs2: cluster: fix a typo
  lib/scatterlist: use sg_phys() helper
  checkpatch: always parse orig_commit in fixes tag
  nilfs2: convert metadata aops from writepage to writepages
  nilfs2: convert nilfs_recovery_copy_block() to take a folio
  nilfs2: convert nilfs_page_count_clean_buffers() to take a folio
  nilfs2: remove nilfs_writepage
  nilfs2: convert checkpoint file to be folio-based
  ...

10 files changed, 529 insertions, 34 deletions

diff --git a/lib/Kconfig b/lib/Kconfig
index 50d85f38b569..5a318f753b2f 100644
--- a/lib/Kconfig
+++ b/lib/Kconfig
@@ -789,3 +789,9 @@ config POLYNOMIAL
 
 config FIRMWARE_TABLE
 	bool
+
+config UNION_FIND
+	bool
+
+config MIN_HEAP
+	bool
diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug
index 5d9eca035d47..1e37c62e8595 100644
--- a/lib/Kconfig.debug
+++ b/lib/Kconfig.debug
@@ -2269,6 +2269,7 @@ config TEST_LIST_SORT
 config TEST_MIN_HEAP
 	tristate "Min heap test"
 	depends on DEBUG_KERNEL || m
+	select MIN_HEAP
 	help
 	  Enable this to turn on min heap function tests. This test is
 	  executed only once during system boot (so affects only boot time),
@@ -2619,6 +2620,23 @@ config CHECKSUM_KUNIT
 
 	  If unsure, say N.
 
+config UTIL_MACROS_KUNIT
+	tristate "KUnit test util_macros.h functions at runtime" if !KUNIT_ALL_TESTS
+	depends on KUNIT
+	default KUNIT_ALL_TESTS
+	help
+	  Enable this option to test the util_macros.h function at boot.
+
+	  KUnit tests run during boot and output the results to the debug log
+	  in TAP format (http://testanything.org/). Only useful for kernel devs
+	  running the KUnit test harness, and not intended for inclusion into a
+	  production build.
+
+	  For more information on KUnit and unit tests in general please refer
+	  to the KUnit documentation in Documentation/dev-tools/kunit/.
+
+	  If unsure, say N.
+
 config HASH_KUNIT_TEST
 	tristate "KUnit Test for integer hash functions" if !KUNIT_ALL_TESTS
 	depends on KUNIT
@@ -2840,6 +2858,15 @@ config USERCOPY_KUNIT_TEST
 	  on the copy_to/from_user infrastructure, making sure basic
 	  user/kernel boundary testing is working.
 
+config CRC16_KUNIT_TEST
+	tristate "KUnit tests for CRC16"
+	depends on KUNIT
+	default KUNIT_ALL_TESTS
+	select CRC16
+	help
+	  Enable this option to run unit tests for the kernel's CRC16
+	  implementation (<linux/crc16.h>).
+
 config TEST_UDELAY
 	tristate "udelay test driver"
 	help
@@ -2983,6 +3010,22 @@ config TEST_OBJPOOL
 
 	  If unsure, say N.
 
+config INT_POW_TEST
+	tristate "Integer exponentiation (int_pow) test" if !KUNIT_ALL_TESTS
+	depends on KUNIT
+	default KUNIT_ALL_TESTS
+	help
+	  This option enables the KUnit test suite for the int_pow function,
+	  which performs integer exponentiation. The test suite is designed to
+	  verify that the implementation of int_pow correctly computes the power
+	  of a given base raised to a given exponent.
+
+	  Enabling this option will include tests that check various scenarios
+	  and edge cases to ensure the accuracy and reliability of the exponentiation
+	  function.
+
+	  If unsure, say N
+
 endif # RUNTIME_TESTING_MENU
 
 config ARCH_USE_MEMTEST
@@ -3078,19 +3121,3 @@ config RUST_KERNEL_DOCTESTS
 endmenu # "Rust"
 
 endmenu # Kernel hacking
-
-config INT_POW_TEST
-	tristate "Integer exponentiation (int_pow) test" if !KUNIT_ALL_TESTS
-	depends on KUNIT
-	default KUNIT_ALL_TESTS
-	help
-	  This option enables the KUnit test suite for the int_pow function,
-	  which performs integer exponentiation. The test suite is designed to
-	  verify that the implementation of int_pow correctly computes the power
-	  of a given base raised to a given exponent.
-
-	  Enabling this option will include tests that check various scenarios
-	  and edge cases to ensure the accuracy and reliability of the exponentiation
-	  function.
-
-	  If unsure, say N
diff --git a/lib/Makefile b/lib/Makefile
index b393dd8151e2..8000f2270462 100644
--- a/lib/Makefile
+++ b/lib/Makefile
@@ -35,10 +35,12 @@ lib-y := ctype.o string.o vsprintf.o cmdline.o \
 	 is_single_threaded.o plist.o decompress.o kobject_uevent.o \
 	 earlycpio.o seq_buf.o siphash.o dec_and_lock.o \
 	 nmi_backtrace.o win_minmax.o memcat_p.o \
-	 buildid.o objpool.o union_find.o iomem_copy.o
+	 buildid.o objpool.o iomem_copy.o
 
+lib-$(CONFIG_UNION_FIND) += union_find.o
 lib-$(CONFIG_PRINTK) += dump_stack.o
 lib-$(CONFIG_SMP) += cpumask.o
+lib-$(CONFIG_MIN_HEAP) += min_heap.o
 
 lib-y	+= kobject.o klist.o
 obj-y	+= lockref.o
@@ -371,6 +373,7 @@ obj-$(CONFIG_PLDMFW) += pldmfw/
 CFLAGS_bitfield_kunit.o := $(DISABLE_STRUCTLEAK_PLUGIN)
 obj-$(CONFIG_BITFIELD_KUNIT) += bitfield_kunit.o
 obj-$(CONFIG_CHECKSUM_KUNIT) += checksum_kunit.o
+obj-$(CONFIG_UTIL_MACROS_KUNIT) += util_macros_kunit.o
 obj-$(CONFIG_LIST_KUNIT_TEST) += list-test.o
 obj-$(CONFIG_HASHTABLE_KUNIT_TEST) += hashtable_test.o
 obj-$(CONFIG_LINEAR_RANGES_TEST) += test_linear_ranges.o
@@ -390,6 +393,7 @@ CFLAGS_fortify_kunit.o += $(DISABLE_STRUCTLEAK_PLUGIN)
 obj-$(CONFIG_FORTIFY_KUNIT_TEST) += fortify_kunit.o
 obj-$(CONFIG_SIPHASH_KUNIT_TEST) += siphash_kunit.o
 obj-$(CONFIG_USERCOPY_KUNIT_TEST) += usercopy_kunit.o
+obj-$(CONFIG_CRC16_KUNIT_TEST) += crc16_kunit.o
 
 obj-$(CONFIG_GENERIC_LIB_DEVMEM_IS_ALLOWED) += devmem_is_allowed.o
 
diff --git a/lib/crc16_kunit.c b/lib/crc16_kunit.c
new file mode 100644
index 000000000000..0918c98a96d2
--- /dev/null
+++ b/lib/crc16_kunit.c
@@ -0,0 +1,155 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * KUnits tests for CRC16.
+ *
+ * Copyright (C) 2024, LKCAMP
+ * Author: Vinicius Peixoto <vpeixoto@lkcamp.dev>
+ * Author: Fabricio Gasperin <fgasperin@lkcamp.dev>
+ * Author: Enzo Bertoloti <ebertoloti@lkcamp.dev>
+ */
+#include <kunit/test.h>
+#include <linux/crc16.h>
+#include <linux/prandom.h>
+
+#define CRC16_KUNIT_DATA_SIZE 4096
+#define CRC16_KUNIT_TEST_SIZE 100
+#define CRC16_KUNIT_SEED 0x12345678
+
+/**
+ * struct crc16_test - CRC16 test data
+ * @crc: initial input value to CRC16
+ * @start: Start index within the data buffer
+ * @length: Length of the data
+ */
+static struct crc16_test {
+	u16 crc;
+	u16 start;
+	u16 length;
+} tests[CRC16_KUNIT_TEST_SIZE];
+
+u8 data[CRC16_KUNIT_DATA_SIZE];
+
+
+/* Naive implementation of CRC16 for validation purposes */
+static inline u16 _crc16_naive_byte(u16 crc, u8 data)
+{
+	u8 i = 0;
+
+	crc ^= (u16) data;
+	for (i = 0; i < 8; i++) {
+		if (crc & 0x01)
+			crc = (crc >> 1) ^ 0xa001;
+		else
+			crc = crc >> 1;
+	}
+
+	return crc;
+}
+
+
+static inline u16 _crc16_naive(u16 crc, u8 *buffer, size_t len)
+{
+	while (len--)
+		crc = _crc16_naive_byte(crc, *buffer++);
+	return crc;
+}
+
+
+/* Small helper for generating pseudorandom 16-bit data */
+static inline u16 _rand16(void)
+{
+	static u32 rand = CRC16_KUNIT_SEED;
+
+	rand = next_pseudo_random32(rand);
+	return rand & 0xFFFF;
+}
+
+
+static int crc16_init_test_data(struct kunit_suite *suite)
+{
+	size_t i;
+
+	/* Fill the data buffer with random bytes */
+	for (i = 0; i < CRC16_KUNIT_DATA_SIZE; i++)
+		data[i] = _rand16() & 0xFF;
+
+	/* Generate random test data while ensuring the random
+	 * start + length values won't overflow the 4096-byte
+	 * buffer (0x7FF * 2 = 0xFFE < 0x1000)
+	 */
+	for (size_t i = 0; i < CRC16_KUNIT_TEST_SIZE; i++) {
+		tests[i].crc = _rand16();
+		tests[i].start = _rand16() & 0x7FF;
+		tests[i].length = _rand16() & 0x7FF;
+	}
+
+	return 0;
+}
+
+static void crc16_test_empty(struct kunit *test)
+{
+	u16 crc;
+
+	/* The result for empty data should be the same as the
+	 * initial crc
+	 */
+	crc = crc16(0x00, data, 0);
+	KUNIT_EXPECT_EQ(test, crc, 0);
+	crc = crc16(0xFF, data, 0);
+	KUNIT_EXPECT_EQ(test, crc, 0xFF);
+}
+
+static void crc16_test_correctness(struct kunit *test)
+{
+	size_t i;
+	u16 crc, crc_naive;
+
+	for (i = 0; i < CRC16_KUNIT_TEST_SIZE; i++) {
+		/* Compare results with the naive crc16 implementation */
+		crc = crc16(tests[i].crc, data + tests[i].start,
+			    tests[i].length);
+		crc_naive = _crc16_naive(tests[i].crc, data + tests[i].start,
+					 tests[i].length);
+		KUNIT_EXPECT_EQ(test, crc, crc_naive);
+	}
+}
+
+
+static void crc16_test_combine(struct kunit *test)
+{
+	size_t i, j;
+	u16 crc, crc_naive;
+
+	/* Make sure that combining two consecutive crc16 calculations
+	 * yields the same result as calculating the crc16 for the whole thing
+	 */
+	for (i = 0; i < CRC16_KUNIT_TEST_SIZE; i++) {
+		crc_naive = crc16(tests[i].crc, data + tests[i].start, tests[i].length);
+		for (j = 0; j < tests[i].length; j++) {
+			crc = crc16(tests[i].crc, data + tests[i].start, j);
+			crc = crc16(crc, data + tests[i].start + j, tests[i].length - j);
+			KUNIT_EXPECT_EQ(test, crc, crc_naive);
+		}
+	}
+}
+
+
+static struct kunit_case crc16_test_cases[] = {
+	KUNIT_CASE(crc16_test_empty),
+	KUNIT_CASE(crc16_test_combine),
+	KUNIT_CASE(crc16_test_correctness),
+	{},
+};
+
+static struct kunit_suite crc16_test_suite = {
+	.name = "crc16",
+	.test_cases = crc16_test_cases,
+	.suite_init = crc16_init_test_data,
+};
+kunit_test_suite(crc16_test_suite);
+
+MODULE_AUTHOR("Fabricio Gasperin <fgasperin@lkcamp.dev>");
+MODULE_AUTHOR("Vinicius Peixoto <vpeixoto@lkcamp.dev>");
+MODULE_AUTHOR("Enzo Bertoloti <ebertoloti@lkcamp.dev>");
+MODULE_DESCRIPTION("Unit tests for crc16");
+MODULE_LICENSE("GPL");
diff --git a/lib/list-test.c b/lib/list-test.c
index e207c4c98d70..9135cdc1bb39 100644
--- a/lib/list-test.c
+++ b/lib/list-test.c
@@ -412,6 +412,8 @@ static void list_test_list_cut_position(struct kunit *test)
 		KUNIT_EXPECT_PTR_EQ(test, cur, &entries[i]);
 		i++;
 	}
+
+	KUNIT_EXPECT_EQ(test, i, 3);
 }
 
 static void list_test_list_cut_before(struct kunit *test)
@@ -440,6 +442,8 @@ static void list_test_list_cut_before(struct kunit *test)
 		KUNIT_EXPECT_PTR_EQ(test, cur, &entries[i]);
 		i++;
 	}
+
+	KUNIT_EXPECT_EQ(test, i, 3);
 }
 
 static void list_test_list_splice(struct kunit *test)
diff --git a/lib/list_sort.c b/lib/list_sort.c
index 0fb59e92ca2d..8d3f623536fe 100644
--- a/lib/list_sort.c
+++ b/lib/list_sort.c
@@ -1,9 +1,6 @@
 // SPDX-License-Identifier: GPL-2.0
-#include <linux/kernel.h>
-#include <linux/bug.h>
 #include <linux/compiler.h>
 #include <linux/export.h>
-#include <linux/string.h>
 #include <linux/list_sort.h>
 #include <linux/list.h>
 
diff --git a/lib/min_heap.c b/lib/min_heap.c
new file mode 100644
index 000000000000..4485372ff3b1
--- /dev/null
+++ b/lib/min_heap.c
@@ -0,0 +1,70 @@
+// SPDX-License-Identifier: GPL-2.0
+#include <linux/export.h>
+#include <linux/min_heap.h>
+
+void __min_heap_init(min_heap_char *heap, void *data, int size)
+{
+	__min_heap_init_inline(heap, data, size);
+}
+EXPORT_SYMBOL(__min_heap_init);
+
+void *__min_heap_peek(struct min_heap_char *heap)
+{
+	return __min_heap_peek_inline(heap);
+}
+EXPORT_SYMBOL(__min_heap_peek);
+
+bool __min_heap_full(min_heap_char *heap)
+{
+	return __min_heap_full_inline(heap);
+}
+EXPORT_SYMBOL(__min_heap_full);
+
+void __min_heap_sift_down(min_heap_char *heap, int pos, size_t elem_size,
+			  const struct min_heap_callbacks *func, void *args)
+{
+	__min_heap_sift_down_inline(heap, pos, elem_size, func, args);
+}
+EXPORT_SYMBOL(__min_heap_sift_down);
+
+void __min_heap_sift_up(min_heap_char *heap, size_t elem_size, size_t idx,
+			const struct min_heap_callbacks *func, void *args)
+{
+	__min_heap_sift_up_inline(heap, elem_size, idx, func, args);
+}
+EXPORT_SYMBOL(__min_heap_sift_up);
+
+void __min_heapify_all(min_heap_char *heap, size_t elem_size,
+		       const struct min_heap_callbacks *func, void *args)
+{
+	__min_heapify_all_inline(heap, elem_size, func, args);
+}
+EXPORT_SYMBOL(__min_heapify_all);
+
+bool __min_heap_pop(min_heap_char *heap, size_t elem_size,
+		    const struct min_heap_callbacks *func, void *args)
+{
+	return __min_heap_pop_inline(heap, elem_size, func, args);
+}
+EXPORT_SYMBOL(__min_heap_pop);
+
+void __min_heap_pop_push(min_heap_char *heap, const void *element, size_t elem_size,
+			 const struct min_heap_callbacks *func, void *args)
+{
+	__min_heap_pop_push_inline(heap, element, elem_size, func, args);
+}
+EXPORT_SYMBOL(__min_heap_pop_push);
+
+bool __min_heap_push(min_heap_char *heap, const void *element, size_t elem_size,
+		     const struct min_heap_callbacks *func, void *args)
+{
+	return __min_heap_push_inline(heap, element, elem_size, func, args);
+}
+EXPORT_SYMBOL(__min_heap_push);
+
+bool __min_heap_del(min_heap_char *heap, size_t elem_size, size_t idx,
+		    const struct min_heap_callbacks *func, void *args)
+{
+	return __min_heap_del_inline(heap, elem_size, idx, func, args);
+}
+EXPORT_SYMBOL(__min_heap_del);
diff --git a/lib/scatterlist.c b/lib/scatterlist.c
index 473b2646f71c..5bb6b8aff232 100644
--- a/lib/scatterlist.c
+++ b/lib/scatterlist.c
@@ -474,14 +474,14 @@ int sg_alloc_append_table_from_pages(struct sg_append_table *sgt_append,
 		return -EOPNOTSUPP;
 
 	if (sgt_append->prv) {
-		unsigned long next_pfn = (page_to_phys(sg_page(sgt_append->prv)) +
-			sgt_append->prv->offset + sgt_append->prv->length) / PAGE_SIZE;
+		unsigned long next_pfn;
 
 		if (WARN_ON(offset))
 			return -EINVAL;
 
 		/* Merge contiguous pages into the last SG */
 		prv_len = sgt_append->prv->length;
+		next_pfn = (sg_phys(sgt_append->prv) + prv_len) / PAGE_SIZE;
 		if (page_to_pfn(pages[0]) == next_pfn) {
 			last_pg = pfn_to_page(next_pfn - 1);
 			while (n_pages && pages_are_mergeable(pages[0], last_pg)) {
diff --git a/lib/test_min_heap.c b/lib/test_min_heap.c
index 64c877e73b64..e6fbb798558b 100644
--- a/lib/test_min_heap.c
+++ b/lib/test_min_heap.c
@@ -23,14 +23,6 @@ static __init bool greater_than(const void *lhs, const void *rhs, void __always_
 	return *(int *)lhs > *(int *)rhs;
 }
 
-static __init void swap_ints(void *lhs, void *rhs, void __always_unused *args)
-{
-	int temp = *(int *)lhs;
-
-	*(int *)lhs = *(int *)rhs;
-	*(int *)rhs = temp;
-}
-
 static __init int pop_verify_heap(bool min_heap,
 				struct min_heap_test *heap,
 				const struct min_heap_callbacks *funcs)
@@ -72,7 +64,7 @@ static __init int test_heapify_all(bool min_heap)
 	};
 	struct min_heap_callbacks funcs = {
 		.less = min_heap ? less_than : greater_than,
-		.swp = swap_ints,
+		.swp = NULL,
 	};
 	int i, err;
 
@@ -104,7 +96,7 @@ static __init int test_heap_push(bool min_heap)
 	};
 	struct min_heap_callbacks funcs = {
 		.less = min_heap ? less_than : greater_than,
-		.swp = swap_ints,
+		.swp = NULL,
 	};
 	int i, temp, err;
 
@@ -136,7 +128,7 @@ static __init int test_heap_pop_push(bool min_heap)
 	};
 	struct min_heap_callbacks funcs = {
 		.less = min_heap ? less_than : greater_than,
-		.swp = swap_ints,
+		.swp = NULL,
 	};
 	int i, temp, err;
 
@@ -175,7 +167,7 @@ static __init int test_heap_del(bool min_heap)
 	heap.nr = ARRAY_SIZE(values);
 	struct min_heap_callbacks funcs = {
 		.less = min_heap ? less_than : greater_than,
-		.swp = swap_ints,
+		.swp = NULL,
 	};
 	int i, err;
 
diff --git a/lib/util_macros_kunit.c b/lib/util_macros_kunit.c
new file mode 100644
index 000000000000..94cc9f0de50a
--- /dev/null
+++ b/lib/util_macros_kunit.c
@@ -0,0 +1,240 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * Test cases for bitfield helpers.
+ */
+
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+
+#include <kunit/test.h>
+#include <linux/util_macros.h>
+
+#define FIND_CLOSEST_RANGE_CHECK(from, to, array, exp_idx)		\
+{									\
+	int i;								\
+	for (i = from; i <= to; i++) {					\
+		int found = find_closest(i, array, ARRAY_SIZE(array));	\
+		KUNIT_ASSERT_EQ(ctx, exp_idx, found);			\
+	}								\
+}
+
+static void test_find_closest(struct kunit *ctx)
+{
+	/* This will test a few arrays that are found in drivers */
+	static const int ina226_avg_tab[] = { 1, 4, 16, 64, 128, 256, 512, 1024 };
+	static const unsigned int ad7616_oversampling_avail[] = {
+		1, 2, 4, 8, 16, 32, 64, 128,
+	};
+	static u32 wd_timeout_table[] = { 2, 4, 6, 8, 16, 32, 48, 64 };
+	static int array_prog1a[] = { 1, 2, 3, 4, 5 };
+	static u32 array_prog1b[] = { 2, 3, 4, 5, 6 };
+	static int array_prog1mix[] = { -2, -1, 0, 1, 2 };
+	static int array_prog2a[] = { 1, 3, 5, 7 };
+	static u32 array_prog2b[] = { 2, 4, 6, 8 };
+	static int array_prog3a[] = { 1, 4, 7, 10 };
+	static u32 array_prog3b[] = { 2, 5, 8, 11 };
+	static int array_prog4a[] = { 1, 5, 9, 13 };
+	static u32 array_prog4b[] = { 2, 6, 10, 14 };
+
+	FIND_CLOSEST_RANGE_CHECK(-3, 2, ina226_avg_tab, 0);
+	FIND_CLOSEST_RANGE_CHECK(3, 10, ina226_avg_tab, 1);
+	FIND_CLOSEST_RANGE_CHECK(11, 40, ina226_avg_tab, 2);
+	FIND_CLOSEST_RANGE_CHECK(41, 96, ina226_avg_tab, 3);
+	FIND_CLOSEST_RANGE_CHECK(97, 192, ina226_avg_tab, 4);
+	FIND_CLOSEST_RANGE_CHECK(193, 384, ina226_avg_tab, 5);
+	FIND_CLOSEST_RANGE_CHECK(385, 768, ina226_avg_tab, 6);
+	FIND_CLOSEST_RANGE_CHECK(769, 2048, ina226_avg_tab, 7);
+
+	/* The array that found the bug that caused this kunit to exist */
+	FIND_CLOSEST_RANGE_CHECK(-3, 1, ad7616_oversampling_avail, 0);
+	FIND_CLOSEST_RANGE_CHECK(2, 3, ad7616_oversampling_avail, 1);
+	FIND_CLOSEST_RANGE_CHECK(4, 6, ad7616_oversampling_avail, 2);
+	FIND_CLOSEST_RANGE_CHECK(7, 12, ad7616_oversampling_avail, 3);
+	FIND_CLOSEST_RANGE_CHECK(13, 24, ad7616_oversampling_avail, 4);
+	FIND_CLOSEST_RANGE_CHECK(25, 48, ad7616_oversampling_avail, 5);
+	FIND_CLOSEST_RANGE_CHECK(49, 96, ad7616_oversampling_avail, 6);
+	FIND_CLOSEST_RANGE_CHECK(97, 256, ad7616_oversampling_avail, 7);
+
+	FIND_CLOSEST_RANGE_CHECK(-3, 3, wd_timeout_table, 0);
+	FIND_CLOSEST_RANGE_CHECK(4, 5, wd_timeout_table, 1);
+	FIND_CLOSEST_RANGE_CHECK(6, 7, wd_timeout_table, 2);
+	FIND_CLOSEST_RANGE_CHECK(8, 12, wd_timeout_table, 3);
+	FIND_CLOSEST_RANGE_CHECK(13, 24, wd_timeout_table, 4);
+	FIND_CLOSEST_RANGE_CHECK(25, 40, wd_timeout_table, 5);
+	FIND_CLOSEST_RANGE_CHECK(41, 56, wd_timeout_table, 6);
+	FIND_CLOSEST_RANGE_CHECK(57, 128, wd_timeout_table, 7);
+
+	/* One could argue that find_closest() should not be used for monotonic
+	 * arrays (like 1,2,3,4,5), but even so, it should work as long as the
+	 * array is sorted ascending. */
+	FIND_CLOSEST_RANGE_CHECK(-3, 1, array_prog1a, 0);
+	FIND_CLOSEST_RANGE_CHECK(2, 2, array_prog1a, 1);
+	FIND_CLOSEST_RANGE_CHECK(3, 3, array_prog1a, 2);
+	FIND_CLOSEST_RANGE_CHECK(4, 4, array_prog1a, 3);
+	FIND_CLOSEST_RANGE_CHECK(5, 8, array_prog1a, 4);
+
+	FIND_CLOSEST_RANGE_CHECK(-3, 2, array_prog1b, 0);
+	FIND_CLOSEST_RANGE_CHECK(3, 3, array_prog1b, 1);
+	FIND_CLOSEST_RANGE_CHECK(4, 4, array_prog1b, 2);
+	FIND_CLOSEST_RANGE_CHECK(5, 5, array_prog1b, 3);
+	FIND_CLOSEST_RANGE_CHECK(6, 8, array_prog1b, 4);
+
+	FIND_CLOSEST_RANGE_CHECK(-4, -2, array_prog1mix, 0);
+	FIND_CLOSEST_RANGE_CHECK(-1, -1, array_prog1mix, 1);
+	FIND_CLOSEST_RANGE_CHECK(0, 0, array_prog1mix, 2);
+	FIND_CLOSEST_RANGE_CHECK(1, 1, array_prog1mix, 3);
+	FIND_CLOSEST_RANGE_CHECK(2, 5, array_prog1mix, 4);
+
+	FIND_CLOSEST_RANGE_CHECK(-3, 2, array_prog2a, 0);
+	FIND_CLOSEST_RANGE_CHECK(3, 4, array_prog2a, 1);
+	FIND_CLOSEST_RANGE_CHECK(5, 6, array_prog2a, 2);
+	FIND_CLOSEST_RANGE_CHECK(7, 10, array_prog2a, 3);
+
+	FIND_CLOSEST_RANGE_CHECK(-3, 3, array_prog2b, 0);
+	FIND_CLOSEST_RANGE_CHECK(4, 5, array_prog2b, 1);
+	FIND_CLOSEST_RANGE_CHECK(6, 7, array_prog2b, 2);
+	FIND_CLOSEST_RANGE_CHECK(8, 10, array_prog2b, 3);
+
+	FIND_CLOSEST_RANGE_CHECK(-3, 2, array_prog3a, 0);
+	FIND_CLOSEST_RANGE_CHECK(3, 5, array_prog3a, 1);
+	FIND_CLOSEST_RANGE_CHECK(6, 8, array_prog3a, 2);
+	FIND_CLOSEST_RANGE_CHECK(9, 20, array_prog3a, 3);
+
+	FIND_CLOSEST_RANGE_CHECK(-3, 3, array_prog3b, 0);
+	FIND_CLOSEST_RANGE_CHECK(4, 6, array_prog3b, 1);
+	FIND_CLOSEST_RANGE_CHECK(7, 9, array_prog3b, 2);
+	FIND_CLOSEST_RANGE_CHECK(10, 20, array_prog3b, 3);
+
+	FIND_CLOSEST_RANGE_CHECK(-3, 3, array_prog4a, 0);
+	FIND_CLOSEST_RANGE_CHECK(4, 7, array_prog4a, 1);
+	FIND_CLOSEST_RANGE_CHECK(8, 11, array_prog4a, 2);
+	FIND_CLOSEST_RANGE_CHECK(12, 20, array_prog4a, 3);
+
+	FIND_CLOSEST_RANGE_CHECK(-3, 4, array_prog4b, 0);
+	FIND_CLOSEST_RANGE_CHECK(5, 8, array_prog4b, 1);
+	FIND_CLOSEST_RANGE_CHECK(9, 12, array_prog4b, 2);
+	FIND_CLOSEST_RANGE_CHECK(13, 20, array_prog4b, 3);
+}
+
+#define FIND_CLOSEST_DESC_RANGE_CHECK(from, to, array, exp_idx)	\
+{									\
+	int i;								\
+	for (i = from; i <= to; i++) {					\
+		int found = find_closest_descending(i, array,		\
+						ARRAY_SIZE(array));	\
+		KUNIT_ASSERT_EQ(ctx, exp_idx, found);			\
+	}								\
+}
+
+static void test_find_closest_descending(struct kunit *ctx)
+{
+	/* Same arrays as 'test_find_closest' but reversed */
+	static const int ina226_avg_tab[] = { 1024, 512, 256, 128, 64, 16, 4, 1 };
+	static const unsigned int ad7616_oversampling_avail[] = {
+		128, 64, 32, 16, 8, 4, 2, 1
+	};
+	static u32 wd_timeout_table[] = { 64, 48, 32, 16, 8, 6, 4, 2 };
+	static int array_prog1a[] = { 5, 4, 3, 2, 1 };
+	static u32 array_prog1b[] = { 6, 5, 4, 3, 2 };
+	static int array_prog1mix[] = { 2, 1, 0, -1, -2 };
+	static int array_prog2a[] = { 7, 5, 3, 1 };
+	static u32 array_prog2b[] = { 8, 6, 4, 2 };
+	static int array_prog3a[] = { 10, 7, 4, 1 };
+	static u32 array_prog3b[] = { 11, 8, 5, 2 };
+	static int array_prog4a[] = { 13, 9, 5, 1 };
+	static u32 array_prog4b[] = { 14, 10, 6, 2 };
+
+	FIND_CLOSEST_DESC_RANGE_CHECK(-3, 2, ina226_avg_tab, 7);
+	FIND_CLOSEST_DESC_RANGE_CHECK(3, 10, ina226_avg_tab, 6);
+	FIND_CLOSEST_DESC_RANGE_CHECK(11, 40, ina226_avg_tab, 5);
+	FIND_CLOSEST_DESC_RANGE_CHECK(41, 96, ina226_avg_tab, 4);
+	FIND_CLOSEST_DESC_RANGE_CHECK(97, 192, ina226_avg_tab, 3);
+	FIND_CLOSEST_DESC_RANGE_CHECK(193, 384, ina226_avg_tab, 2);
+	FIND_CLOSEST_DESC_RANGE_CHECK(385, 768, ina226_avg_tab, 1);
+	FIND_CLOSEST_DESC_RANGE_CHECK(769, 2048, ina226_avg_tab, 0);
+
+	FIND_CLOSEST_DESC_RANGE_CHECK(-3, 1, ad7616_oversampling_avail, 7);
+	FIND_CLOSEST_DESC_RANGE_CHECK(2, 3, ad7616_oversampling_avail, 6);
+	FIND_CLOSEST_DESC_RANGE_CHECK(4, 6, ad7616_oversampling_avail, 5);
+	FIND_CLOSEST_DESC_RANGE_CHECK(7, 12, ad7616_oversampling_avail, 4);
+	FIND_CLOSEST_DESC_RANGE_CHECK(13, 24, ad7616_oversampling_avail, 3);
+	FIND_CLOSEST_DESC_RANGE_CHECK(25, 48, ad7616_oversampling_avail, 2);
+	FIND_CLOSEST_DESC_RANGE_CHECK(49, 96, ad7616_oversampling_avail, 1);
+	FIND_CLOSEST_DESC_RANGE_CHECK(97, 256, ad7616_oversampling_avail, 0);
+
+	FIND_CLOSEST_DESC_RANGE_CHECK(-3, 3, wd_timeout_table, 7);
+	FIND_CLOSEST_DESC_RANGE_CHECK(4, 5, wd_timeout_table, 6);
+	FIND_CLOSEST_DESC_RANGE_CHECK(6, 7, wd_timeout_table, 5);
+	FIND_CLOSEST_DESC_RANGE_CHECK(8, 12, wd_timeout_table, 4);
+	FIND_CLOSEST_DESC_RANGE_CHECK(13, 24, wd_timeout_table, 3);
+	FIND_CLOSEST_DESC_RANGE_CHECK(25, 40, wd_timeout_table, 2);
+	FIND_CLOSEST_DESC_RANGE_CHECK(41, 56, wd_timeout_table, 1);
+	FIND_CLOSEST_DESC_RANGE_CHECK(57, 128, wd_timeout_table, 0);
+
+	/* One could argue that find_closest_descending() should not be used
+	 * for monotonic arrays (like 5,4,3,2,1), but even so, it should still
+	 * it should work as long as the array is sorted descending. */
+	FIND_CLOSEST_DESC_RANGE_CHECK(-3, 1, array_prog1a, 4);
+	FIND_CLOSEST_DESC_RANGE_CHECK(2, 2, array_prog1a, 3);
+	FIND_CLOSEST_DESC_RANGE_CHECK(3, 3, array_prog1a, 2);
+	FIND_CLOSEST_DESC_RANGE_CHECK(4, 4, array_prog1a, 1);
+	FIND_CLOSEST_DESC_RANGE_CHECK(5, 8, array_prog1a, 0);
+
+	FIND_CLOSEST_DESC_RANGE_CHECK(-3, 2, array_prog1b, 4);
+	FIND_CLOSEST_DESC_RANGE_CHECK(3, 3, array_prog1b, 3);
+	FIND_CLOSEST_DESC_RANGE_CHECK(4, 4, array_prog1b, 2);
+	FIND_CLOSEST_DESC_RANGE_CHECK(5, 5, array_prog1b, 1);
+	FIND_CLOSEST_DESC_RANGE_CHECK(6, 8, array_prog1b, 0);
+
+	FIND_CLOSEST_DESC_RANGE_CHECK(-4, -2, array_prog1mix, 4);
+	FIND_CLOSEST_DESC_RANGE_CHECK(-1, -1, array_prog1mix, 3);
+	FIND_CLOSEST_DESC_RANGE_CHECK(0, 0, array_prog1mix, 2);
+	FIND_CLOSEST_DESC_RANGE_CHECK(1, 1, array_prog1mix, 1);
+	FIND_CLOSEST_DESC_RANGE_CHECK(2, 5, array_prog1mix, 0);
+
+	FIND_CLOSEST_DESC_RANGE_CHECK(-3, 2, array_prog2a, 3);
+	FIND_CLOSEST_DESC_RANGE_CHECK(3, 4, array_prog2a, 2);
+	FIND_CLOSEST_DESC_RANGE_CHECK(5, 6, array_prog2a, 1);
+	FIND_CLOSEST_DESC_RANGE_CHECK(7, 10, array_prog2a, 0);
+
+	FIND_CLOSEST_DESC_RANGE_CHECK(-3, 3, array_prog2b, 3);
+	FIND_CLOSEST_DESC_RANGE_CHECK(4, 5, array_prog2b, 2);
+	FIND_CLOSEST_DESC_RANGE_CHECK(6, 7, array_prog2b, 1);
+	FIND_CLOSEST_DESC_RANGE_CHECK(8, 10, array_prog2b, 0);
+
+	FIND_CLOSEST_DESC_RANGE_CHECK(-3, 2, array_prog3a, 3);
+	FIND_CLOSEST_DESC_RANGE_CHECK(3, 5, array_prog3a, 2);
+	FIND_CLOSEST_DESC_RANGE_CHECK(6, 8, array_prog3a, 1);
+	FIND_CLOSEST_DESC_RANGE_CHECK(9, 20, array_prog3a, 0);
+
+	FIND_CLOSEST_DESC_RANGE_CHECK(-3, 3, array_prog3b, 3);
+	FIND_CLOSEST_DESC_RANGE_CHECK(4, 6, array_prog3b, 2);
+	FIND_CLOSEST_DESC_RANGE_CHECK(7, 9, array_prog3b, 1);
+	FIND_CLOSEST_DESC_RANGE_CHECK(10, 20, array_prog3b, 0);
+
+	FIND_CLOSEST_DESC_RANGE_CHECK(-3, 3, array_prog4a, 3);
+	FIND_CLOSEST_DESC_RANGE_CHECK(4, 7, array_prog4a, 2);
+	FIND_CLOSEST_DESC_RANGE_CHECK(8, 11, array_prog4a, 1);
+	FIND_CLOSEST_DESC_RANGE_CHECK(12, 20, array_prog4a, 0);
+
+	FIND_CLOSEST_DESC_RANGE_CHECK(-3, 4, array_prog4b, 3);
+	FIND_CLOSEST_DESC_RANGE_CHECK(5, 8, array_prog4b, 2);
+	FIND_CLOSEST_DESC_RANGE_CHECK(9, 12, array_prog4b, 1);
+	FIND_CLOSEST_DESC_RANGE_CHECK(13, 20, array_prog4b, 0);
+}
+
+static struct kunit_case __refdata util_macros_test_cases[] = {
+	KUNIT_CASE(test_find_closest),
+	KUNIT_CASE(test_find_closest_descending),
+	{}
+};
+
+static struct kunit_suite util_macros_test_suite = {
+	.name = "util_macros.h",
+	.test_cases = util_macros_test_cases,
+};
+
+kunit_test_suites(&util_macros_test_suite);
+
+MODULE_AUTHOR("Alexandru Ardelean <aardelean@baylibre.com>");
+MODULE_DESCRIPTION("Test cases for util_macros.h helpers");
+MODULE_LICENSE("GPL");