// 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");