133d599f0SMatti Vaittinen // SPDX-License-Identifier: GPL-2.0
233d599f0SMatti Vaittinen /*
333d599f0SMatti Vaittinen * KUnit test for the linear_ranges helper.
433d599f0SMatti Vaittinen *
533d599f0SMatti Vaittinen * Copyright (C) 2020, ROHM Semiconductors.
633d599f0SMatti Vaittinen * Author: Matti Vaittinen <matti.vaittien@fi.rohmeurope.com>
733d599f0SMatti Vaittinen */
833d599f0SMatti Vaittinen #include <kunit/test.h>
933d599f0SMatti Vaittinen
1033d599f0SMatti Vaittinen #include <linux/linear_range.h>
1133d599f0SMatti Vaittinen
1233d599f0SMatti Vaittinen /* First things first. I deeply dislike unit-tests. I have seen all the hell
1333d599f0SMatti Vaittinen * breaking loose when people who think the unit tests are "the silver bullet"
1433d599f0SMatti Vaittinen * to kill bugs get to decide how a company should implement testing strategy...
1533d599f0SMatti Vaittinen *
1633d599f0SMatti Vaittinen * Believe me, it may get _really_ ridiculous. It is tempting to think that
1733d599f0SMatti Vaittinen * walking through all the possible execution branches will nail down 100% of
1833d599f0SMatti Vaittinen * bugs. This may lead to ideas about demands to get certain % of "test
1933d599f0SMatti Vaittinen * coverage" - measured as line coverage. And that is one of the worst things
2033d599f0SMatti Vaittinen * you can do.
2133d599f0SMatti Vaittinen *
2233d599f0SMatti Vaittinen * Ask people to provide line coverage and they do. I've seen clever tools
2333d599f0SMatti Vaittinen * which generate test cases to test the existing functions - and by default
2433d599f0SMatti Vaittinen * these tools expect code to be correct and just generate checks which are
2533d599f0SMatti Vaittinen * passing when ran against current code-base. Run this generator and you'll get
2633d599f0SMatti Vaittinen * tests that do not test code is correct but just verify nothing changes.
2733d599f0SMatti Vaittinen * Problem is that testing working code is pointless. And if it is not
2833d599f0SMatti Vaittinen * working, your test must not assume it is working. You won't catch any bugs
2933d599f0SMatti Vaittinen * by such tests. What you can do is to generate a huge amount of tests.
3033d599f0SMatti Vaittinen * Especially if you were are asked to proivde 100% line-coverage x_x. So what
3133d599f0SMatti Vaittinen * does these tests - which are not finding any bugs now - do?
3233d599f0SMatti Vaittinen *
3333d599f0SMatti Vaittinen * They add inertia to every future development. I think it was Terry Pratchet
3433d599f0SMatti Vaittinen * who wrote someone having same impact as thick syrup has to chronometre.
3533d599f0SMatti Vaittinen * Excessive amount of unit-tests have this effect to development. If you do
3633d599f0SMatti Vaittinen * actually find _any_ bug from code in such environment and try fixing it...
3733d599f0SMatti Vaittinen * ...chances are you also need to fix the test cases. In sunny day you fix one
3833d599f0SMatti Vaittinen * test. But I've done refactoring which resulted 500+ broken tests (which had
3933d599f0SMatti Vaittinen * really zero value other than proving to managers that we do do "quality")...
4033d599f0SMatti Vaittinen *
4133d599f0SMatti Vaittinen * After this being said - there are situations where UTs can be handy. If you
4233d599f0SMatti Vaittinen * have algorithms which take some input and should produce output - then you
4333d599f0SMatti Vaittinen * can implement few, carefully selected simple UT-cases which test this. I've
4433d599f0SMatti Vaittinen * previously used this for example for netlink and device-tree data parsing
4533d599f0SMatti Vaittinen * functions. Feed some data examples to functions and verify the output is as
4633d599f0SMatti Vaittinen * expected. I am not covering all the cases but I will see the logic should be
4733d599f0SMatti Vaittinen * working.
4833d599f0SMatti Vaittinen *
4933d599f0SMatti Vaittinen * Here we also do some minor testing. I don't want to go through all branches
5033d599f0SMatti Vaittinen * or test more or less obvious things - but I want to see the main logic is
5133d599f0SMatti Vaittinen * working. And I definitely don't want to add 500+ test cases that break when
5233d599f0SMatti Vaittinen * some simple fix is done x_x. So - let's only add few, well selected tests
5333d599f0SMatti Vaittinen * which ensure as much logic is good as possible.
5433d599f0SMatti Vaittinen */
5533d599f0SMatti Vaittinen
5633d599f0SMatti Vaittinen /*
5733d599f0SMatti Vaittinen * Test Range 1:
5833d599f0SMatti Vaittinen * selectors: 2 3 4 5 6
5933d599f0SMatti Vaittinen * values (5): 10 20 30 40 50
6033d599f0SMatti Vaittinen *
6133d599f0SMatti Vaittinen * Test Range 2:
6233d599f0SMatti Vaittinen * selectors: 7 8 9 10
6333d599f0SMatti Vaittinen * values (4): 100 150 200 250
6433d599f0SMatti Vaittinen */
6533d599f0SMatti Vaittinen
6633d599f0SMatti Vaittinen #define RANGE1_MIN 10
6733d599f0SMatti Vaittinen #define RANGE1_MIN_SEL 2
6833d599f0SMatti Vaittinen #define RANGE1_STEP 10
6933d599f0SMatti Vaittinen
7033d599f0SMatti Vaittinen /* 2, 3, 4, 5, 6 */
7133d599f0SMatti Vaittinen static const unsigned int range1_sels[] = { RANGE1_MIN_SEL, RANGE1_MIN_SEL + 1,
7233d599f0SMatti Vaittinen RANGE1_MIN_SEL + 2,
7333d599f0SMatti Vaittinen RANGE1_MIN_SEL + 3,
7433d599f0SMatti Vaittinen RANGE1_MIN_SEL + 4 };
7533d599f0SMatti Vaittinen /* 10, 20, 30, 40, 50 */
7633d599f0SMatti Vaittinen static const unsigned int range1_vals[] = { RANGE1_MIN, RANGE1_MIN +
7733d599f0SMatti Vaittinen RANGE1_STEP,
7833d599f0SMatti Vaittinen RANGE1_MIN + RANGE1_STEP * 2,
7933d599f0SMatti Vaittinen RANGE1_MIN + RANGE1_STEP * 3,
8033d599f0SMatti Vaittinen RANGE1_MIN + RANGE1_STEP * 4 };
8133d599f0SMatti Vaittinen
8233d599f0SMatti Vaittinen #define RANGE2_MIN 100
8333d599f0SMatti Vaittinen #define RANGE2_MIN_SEL 7
8433d599f0SMatti Vaittinen #define RANGE2_STEP 50
8533d599f0SMatti Vaittinen
8633d599f0SMatti Vaittinen /* 7, 8, 9, 10 */
8733d599f0SMatti Vaittinen static const unsigned int range2_sels[] = { RANGE2_MIN_SEL, RANGE2_MIN_SEL + 1,
8833d599f0SMatti Vaittinen RANGE2_MIN_SEL + 2,
8933d599f0SMatti Vaittinen RANGE2_MIN_SEL + 3 };
9033d599f0SMatti Vaittinen /* 100, 150, 200, 250 */
9133d599f0SMatti Vaittinen static const unsigned int range2_vals[] = { RANGE2_MIN, RANGE2_MIN +
9233d599f0SMatti Vaittinen RANGE2_STEP,
9333d599f0SMatti Vaittinen RANGE2_MIN + RANGE2_STEP * 2,
9433d599f0SMatti Vaittinen RANGE2_MIN + RANGE2_STEP * 3 };
9533d599f0SMatti Vaittinen
9633d599f0SMatti Vaittinen #define RANGE1_NUM_VALS (ARRAY_SIZE(range1_vals))
9733d599f0SMatti Vaittinen #define RANGE2_NUM_VALS (ARRAY_SIZE(range2_vals))
9833d599f0SMatti Vaittinen #define RANGE_NUM_VALS (RANGE1_NUM_VALS + RANGE2_NUM_VALS)
9933d599f0SMatti Vaittinen
10033d599f0SMatti Vaittinen #define RANGE1_MAX_SEL (RANGE1_MIN_SEL + RANGE1_NUM_VALS - 1)
10133d599f0SMatti Vaittinen #define RANGE1_MAX_VAL (range1_vals[RANGE1_NUM_VALS - 1])
10233d599f0SMatti Vaittinen
10333d599f0SMatti Vaittinen #define RANGE2_MAX_SEL (RANGE2_MIN_SEL + RANGE2_NUM_VALS - 1)
10433d599f0SMatti Vaittinen #define RANGE2_MAX_VAL (range2_vals[RANGE2_NUM_VALS - 1])
10533d599f0SMatti Vaittinen
10633d599f0SMatti Vaittinen #define SMALLEST_SEL RANGE1_MIN_SEL
10733d599f0SMatti Vaittinen #define SMALLEST_VAL RANGE1_MIN
10833d599f0SMatti Vaittinen
10933d599f0SMatti Vaittinen static struct linear_range testr[] = {
110*bc64f30eSMatti Vaittinen LINEAR_RANGE(RANGE1_MIN, RANGE1_MIN_SEL, RANGE1_MAX_SEL, RANGE1_STEP),
111*bc64f30eSMatti Vaittinen LINEAR_RANGE(RANGE2_MIN, RANGE2_MIN_SEL, RANGE2_MAX_SEL, RANGE2_STEP),
11233d599f0SMatti Vaittinen };
11333d599f0SMatti Vaittinen
range_test_get_value(struct kunit * test)11433d599f0SMatti Vaittinen static void range_test_get_value(struct kunit *test)
11533d599f0SMatti Vaittinen {
11633d599f0SMatti Vaittinen int ret, i;
11733d599f0SMatti Vaittinen unsigned int sel, val;
11833d599f0SMatti Vaittinen
11933d599f0SMatti Vaittinen for (i = 0; i < RANGE1_NUM_VALS; i++) {
12033d599f0SMatti Vaittinen sel = range1_sels[i];
12133d599f0SMatti Vaittinen ret = linear_range_get_value_array(&testr[0], 2, sel, &val);
12233d599f0SMatti Vaittinen KUNIT_EXPECT_EQ(test, 0, ret);
12333d599f0SMatti Vaittinen KUNIT_EXPECT_EQ(test, val, range1_vals[i]);
12433d599f0SMatti Vaittinen }
12533d599f0SMatti Vaittinen for (i = 0; i < RANGE2_NUM_VALS; i++) {
12633d599f0SMatti Vaittinen sel = range2_sels[i];
12733d599f0SMatti Vaittinen ret = linear_range_get_value_array(&testr[0], 2, sel, &val);
12833d599f0SMatti Vaittinen KUNIT_EXPECT_EQ(test, 0, ret);
12933d599f0SMatti Vaittinen KUNIT_EXPECT_EQ(test, val, range2_vals[i]);
13033d599f0SMatti Vaittinen }
13133d599f0SMatti Vaittinen ret = linear_range_get_value_array(&testr[0], 2, sel + 1, &val);
13233d599f0SMatti Vaittinen KUNIT_EXPECT_NE(test, 0, ret);
13333d599f0SMatti Vaittinen }
13433d599f0SMatti Vaittinen
range_test_get_selector_high(struct kunit * test)13533d599f0SMatti Vaittinen static void range_test_get_selector_high(struct kunit *test)
13633d599f0SMatti Vaittinen {
13733d599f0SMatti Vaittinen int ret, i;
13833d599f0SMatti Vaittinen unsigned int sel;
13933d599f0SMatti Vaittinen bool found;
14033d599f0SMatti Vaittinen
14133d599f0SMatti Vaittinen for (i = 0; i < RANGE1_NUM_VALS; i++) {
14233d599f0SMatti Vaittinen ret = linear_range_get_selector_high(&testr[0], range1_vals[i],
14333d599f0SMatti Vaittinen &sel, &found);
14433d599f0SMatti Vaittinen KUNIT_EXPECT_EQ(test, 0, ret);
14533d599f0SMatti Vaittinen KUNIT_EXPECT_EQ(test, sel, range1_sels[i]);
14633d599f0SMatti Vaittinen KUNIT_EXPECT_TRUE(test, found);
14733d599f0SMatti Vaittinen }
14833d599f0SMatti Vaittinen
14933d599f0SMatti Vaittinen ret = linear_range_get_selector_high(&testr[0], RANGE1_MAX_VAL + 1,
15033d599f0SMatti Vaittinen &sel, &found);
15133d599f0SMatti Vaittinen KUNIT_EXPECT_LE(test, ret, 0);
15233d599f0SMatti Vaittinen
15333d599f0SMatti Vaittinen ret = linear_range_get_selector_high(&testr[0], RANGE1_MIN - 1,
15433d599f0SMatti Vaittinen &sel, &found);
15533d599f0SMatti Vaittinen KUNIT_EXPECT_EQ(test, 0, ret);
15633d599f0SMatti Vaittinen KUNIT_EXPECT_FALSE(test, found);
15733d599f0SMatti Vaittinen KUNIT_EXPECT_EQ(test, sel, range1_sels[0]);
15833d599f0SMatti Vaittinen }
15933d599f0SMatti Vaittinen
range_test_get_value_amount(struct kunit * test)16033d599f0SMatti Vaittinen static void range_test_get_value_amount(struct kunit *test)
16133d599f0SMatti Vaittinen {
16233d599f0SMatti Vaittinen int ret;
16333d599f0SMatti Vaittinen
16433d599f0SMatti Vaittinen ret = linear_range_values_in_range_array(&testr[0], 2);
16533d599f0SMatti Vaittinen KUNIT_EXPECT_EQ(test, (int)RANGE_NUM_VALS, ret);
16633d599f0SMatti Vaittinen }
16733d599f0SMatti Vaittinen
range_test_get_selector_low(struct kunit * test)16833d599f0SMatti Vaittinen static void range_test_get_selector_low(struct kunit *test)
16933d599f0SMatti Vaittinen {
17033d599f0SMatti Vaittinen int i, ret;
17133d599f0SMatti Vaittinen unsigned int sel;
17233d599f0SMatti Vaittinen bool found;
17333d599f0SMatti Vaittinen
17433d599f0SMatti Vaittinen for (i = 0; i < RANGE1_NUM_VALS; i++) {
17533d599f0SMatti Vaittinen ret = linear_range_get_selector_low_array(&testr[0], 2,
17633d599f0SMatti Vaittinen range1_vals[i], &sel,
17733d599f0SMatti Vaittinen &found);
17833d599f0SMatti Vaittinen KUNIT_EXPECT_EQ(test, 0, ret);
17933d599f0SMatti Vaittinen KUNIT_EXPECT_EQ(test, sel, range1_sels[i]);
18033d599f0SMatti Vaittinen KUNIT_EXPECT_TRUE(test, found);
18133d599f0SMatti Vaittinen }
18233d599f0SMatti Vaittinen for (i = 0; i < RANGE2_NUM_VALS; i++) {
18333d599f0SMatti Vaittinen ret = linear_range_get_selector_low_array(&testr[0], 2,
18433d599f0SMatti Vaittinen range2_vals[i], &sel,
18533d599f0SMatti Vaittinen &found);
18633d599f0SMatti Vaittinen KUNIT_EXPECT_EQ(test, 0, ret);
18733d599f0SMatti Vaittinen KUNIT_EXPECT_EQ(test, sel, range2_sels[i]);
18833d599f0SMatti Vaittinen KUNIT_EXPECT_TRUE(test, found);
18933d599f0SMatti Vaittinen }
19033d599f0SMatti Vaittinen
19133d599f0SMatti Vaittinen /*
19233d599f0SMatti Vaittinen * Seek value greater than range max => get_selector_*_low should
19333d599f0SMatti Vaittinen * return Ok - but set found to false as value is not in range
19433d599f0SMatti Vaittinen */
19533d599f0SMatti Vaittinen ret = linear_range_get_selector_low_array(&testr[0], 2,
19633d599f0SMatti Vaittinen range2_vals[RANGE2_NUM_VALS - 1] + 1,
19733d599f0SMatti Vaittinen &sel, &found);
19833d599f0SMatti Vaittinen
19933d599f0SMatti Vaittinen KUNIT_EXPECT_EQ(test, 0, ret);
20033d599f0SMatti Vaittinen KUNIT_EXPECT_EQ(test, sel, range2_sels[RANGE2_NUM_VALS - 1]);
20133d599f0SMatti Vaittinen KUNIT_EXPECT_FALSE(test, found);
20233d599f0SMatti Vaittinen }
20333d599f0SMatti Vaittinen
20433d599f0SMatti Vaittinen static struct kunit_case range_test_cases[] = {
20533d599f0SMatti Vaittinen KUNIT_CASE(range_test_get_value_amount),
20633d599f0SMatti Vaittinen KUNIT_CASE(range_test_get_selector_high),
20733d599f0SMatti Vaittinen KUNIT_CASE(range_test_get_selector_low),
20833d599f0SMatti Vaittinen KUNIT_CASE(range_test_get_value),
20933d599f0SMatti Vaittinen {},
21033d599f0SMatti Vaittinen };
21133d599f0SMatti Vaittinen
21233d599f0SMatti Vaittinen static struct kunit_suite range_test_module = {
21333d599f0SMatti Vaittinen .name = "linear-ranges-test",
21433d599f0SMatti Vaittinen .test_cases = range_test_cases,
21533d599f0SMatti Vaittinen };
21633d599f0SMatti Vaittinen
21733d599f0SMatti Vaittinen kunit_test_suites(&range_test_module);
21833d599f0SMatti Vaittinen
21933d599f0SMatti Vaittinen MODULE_LICENSE("GPL");
220