tests: Add lib/timestamp-test test case

Signed-off-by: Jakub Czapiga <jacz@semihalf.com>
Change-Id: I39abfc644fef085cef2175086a0e45a040b244de
Reviewed-on: https://review.coreboot.org/c/coreboot/+/46968
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Paul Fagerburg <pfagerburg@chromium.org>
diff --git a/tests/lib/timestamp-test.c b/tests/lib/timestamp-test.c
new file mode 100644
index 0000000..8dc103d
--- /dev/null
+++ b/tests/lib/timestamp-test.c
@@ -0,0 +1,138 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+
+#include "../lib/timestamp.c"
+#include <commonlib/bsd/helpers.h>
+#include <tests/test.h>
+#include "stubs/timestamp.h"
+
+/* Timestamp region definition */
+#define TIMESTAMP_REGION_SIZE (1 * KiB)
+TEST_REGION(timestamp, TIMESTAMP_REGION_SIZE);
+
+void test_timestamp_init(void **state)
+{
+	timestamp_init(1000);
+
+	assert_non_null(glob_ts_table);
+}
+
+void test_timestamp_add(void **state)
+{
+	const int base_multipler = 2000;
+	const int timestamp_base = 1000;
+	struct timestamp_entry *entry;
+	int i;
+
+	timestamp_init(timestamp_base);
+
+	timestamp_add(TS_START_ROMSTAGE, base_multipler);
+
+	assert_int_equal(1, glob_ts_table->num_entries);
+
+	entry = &glob_ts_table->entries[0];
+	assert_int_equal(1, entry->entry_id);
+	assert_int_equal(base_multipler - timestamp_base, /* Added timestamp reduced by base */
+			entry->entry_stamp);
+
+	/* Add few timestamps to check if all of them will be added properly */
+	for (i = 1; i < 10; ++i)
+		timestamp_add(i + 1, base_multipler * (i + 1));
+
+	assert_int_equal(10, glob_ts_table->num_entries);
+
+	for (i = 0; i < 10; ++i) {
+		entry = &glob_ts_table->entries[i];
+		assert_int_equal(i + 1, entry->entry_id);
+		assert_int_equal(base_multipler * (i + 1) - timestamp_base,
+				 entry->entry_stamp);
+	}
+}
+
+void test_timestamp_add_now(void **state)
+{
+	const int base_multipler = 2000;
+	const int timestamp_base = 1000;
+	struct timestamp_entry *entry;
+
+	/* Initialize with base timestamp of 1000.
+	 * This value will be subtracted from each timestamp
+	 * when adding it.
+	 */
+	timestamp_init(timestamp_base);
+
+	dummy_timestamp_set(base_multipler);
+
+	timestamp_add_now(TS_START_ROMSTAGE);
+
+	assert_int_equal(1, glob_ts_table->num_entries);
+
+	entry = &glob_ts_table->entries[0];
+
+	assert_int_equal(1, entry->entry_id);
+	assert_int_equal(base_multipler - timestamp_base, /* Added timestamp reduced by base */
+			entry->entry_stamp);
+}
+
+void test_timestamp_rescale_table(void **state)
+{
+	const int base_multipler = 1000;
+	int i;
+
+	timestamp_init(0);
+
+	/* Add few timestamps to check if all of them will be rescaled properly */
+	for (i = 1; i <= 10; ++i)
+		timestamp_add(i, base_multipler * i);
+
+	/* Check if all entries were added to table */
+	assert_int_equal(10, glob_ts_table->num_entries);
+
+	timestamp_rescale_table(2, 4);
+
+	/* Check if there is the same number of entries */
+	assert_int_equal(10, glob_ts_table->num_entries);
+
+	for (i = 0; i < glob_ts_table->num_entries; ++i)
+		assert_int_equal(base_multipler * (i + 1) / 4 * 2,
+				 glob_ts_table->entries[i].entry_stamp);
+}
+
+void test_get_us_since_boot(void **state)
+{
+	const int base_multipler = 10000;
+	const int timestamp_base = 1000;
+	const int freq_base = 100;
+
+	timestamp_init(timestamp_base);
+	dummy_timestamp_set(base_multipler);
+	dummy_timestamp_tick_freq_mhz_set(freq_base);
+	/* There is a need to update this field manually, because cbmem hooks are not used. */
+	glob_ts_table->tick_freq_mhz = freq_base;
+
+	assert_int_equal((base_multipler - timestamp_base) / freq_base, get_us_since_boot());
+}
+
+int setup_timestamp_and_freq(void **state)
+{
+	dummy_timestamp_set(0);
+	dummy_timestamp_tick_freq_mhz_set(1);
+
+	return 0;
+}
+
+int main(void)
+{
+	const struct CMUnitTest tests[] = {
+		cmocka_unit_test_setup(test_timestamp_init, setup_timestamp_and_freq),
+		cmocka_unit_test_setup(test_timestamp_add, setup_timestamp_and_freq),
+		cmocka_unit_test_setup(test_timestamp_add_now, setup_timestamp_and_freq),
+		cmocka_unit_test_setup(test_timestamp_rescale_table, setup_timestamp_and_freq),
+		cmocka_unit_test_setup(test_get_us_since_boot, setup_timestamp_and_freq),
+	};
+
+#if CONFIG(COLLECT_TIMESTAMPS)
+	return cmocka_run_group_tests(tests, NULL, NULL);
+#else
+	return 0;
+#endif
+}