[nrf fromlist] tests: drivers: timer: nrf_grtc_timer: Add stress test

Add stress test that randomly starts and aborts multiple timers
from various contexts. Test checks if timers do not expire prematurely.

Upstream PR #: 87944

Signed-off-by: Krzysztof Chruściński <[email protected]>

Author: nordic-krch

tests/drivers/timer/nrf_grtc_timer/boards/nrf54h20dk_nrf54h20_cpuapp.overlay

@@ -2,4 +2,21 @@
 
 &grtc {
 	/delete-property/ child-owned-channels;
+	interrupts = <109 2>;
+};
+
+test_timer: &timer131 {
+	status = "okay";
+	interrupts = <419 1>;
+};
+
+&timer130 {
+	status = "okay";
+	prescaler = <0>;
+};
+
+/ {
+	chosen {
+		zephyr,cpu-load-counter = &timer130;
+	};
 };

tests/drivers/timer/nrf_grtc_timer/boards/nrf54l15dk_nrf54l15_cpuapp.overlay

@@ -0,0 +1,32 @@
+/* SPDX-License-Identifier: Apache-2.0 */
+
+&grtc {
+	interrupts = <228 2>;
+};
+
+test_timer: &timer21 {
+	status = "okay";
+	interrupts = <203 1>;
+};
+
+&timer20 {
+	status = "okay";
+	interrupts = <202 0>;
+};
+
+&timer00 {
+	status = "okay";
+	prescaler = <0>;
+};
+
+/ {
+	chosen {
+		zephyr,cpu-load-counter = &timer00;
+	};
+
+	busy-sim {
+		compatible = "vnd,busy-sim";
+		status = "okay";
+		counter = <&timer20>;
+	};
+};

tests/drivers/timer/nrf_grtc_timer/boards/nrf54l15dk_nrf54l15_cpuflpr.overlay

@@ -0,0 +1,32 @@
+/* SPDX-License-Identifier: Apache-2.0 */
+
+&grtc {
+	/*interrupts = <226 2>;*/
+};
+
+test_timer: &timer21 {
+	status = "okay";
+	/*interrupts = <203 2>;*/
+};
+
+&timer20 {
+	status = "okay";
+	interrupts = <202 0>;
+};
+
+&timer00 {
+	status = "okay";
+	prescaler = <0>;
+};
+
+/ {
+	chosen {
+		zephyr,cpu-load-counter = &timer00;
+	};
+
+	busy-sim {
+		compatible = "vnd,busy-sim";
+		status = "okay";
+		counter = <&timer20>;
+	};
+};

tests/drivers/timer/nrf_grtc_timer/prj.conf

@@ -1,2 +1,8 @@
 CONFIG_ZTEST=y
 CONFIG_NRF_GRTC_TIMER=y
+CONFIG_COUNTER=y
+CONFIG_TEST_RANDOM_GENERATOR=y
+CONFIG_XOSHIRO_RANDOM_GENERATOR=y
+CONFIG_LOG_PRINTK=y
+CONFIG_CPU_LOAD=y
+CONFIG_CPU_LOAD_USE_COUNTER=y

tests/drivers/timer/nrf_grtc_timer/src/main.c

@@ -5,7 +5,15 @@
  */
 #include <zephyr/ztest.h>
 #include <zephyr/drivers/timer/nrf_grtc_timer.h>
+#include <zephyr/drivers/counter.h>
+#include <zephyr/drivers/timer/system_timer.h>
+#include <zephyr/random/random.h>
+#include <zephyr/logging/log.h>
+#include <zephyr/busy_sim.h>
+#include <zephyr/debug/cpu_load.h>
+#include <nrfx_grtc.h>
 #include <hal/nrf_grtc.h>
+LOG_MODULE_REGISTER(test, 1);
 
 #define GRTC_SLEW_TICKS 10
 #define NUMBER_OF_TRIES 2000
@@ -153,4 +161,243 @@ ZTEST(nrf_grtc_timer, test_timer_abort_in_compare_mode)
 	z_nrf_grtc_timer_chan_free(channel);
 }
 
+enum test_timer_state {
+	TIMER_IDLE,
+	TIMER_PREPARE,
+	TIMER_ACTIVE
+};
+
+enum test_ctx {
+	TEST_HIGH_PRI,
+	TEST_TIMER_CB,
+	TEST_THREAD
+};
+
+struct test_grtc_timer {
+	struct k_timer timer;
+	uint32_t ticks;
+	uint32_t expire;
+	uint32_t start_cnt;
+	uint32_t expire_cnt;
+	uint32_t abort_cnt;
+	uint32_t exp_expire;
+	int max_late;
+	int min_late;
+	int avg_late;
+	uint32_t early_cnt;
+	enum test_timer_state state;
+};
+
+static atomic_t test_active_cnt;
+static struct test_grtc_timer timers[8];
+static uint32_t test_end;
+static k_tid_t test_tid;
+static volatile bool test_run;
+static uint32_t ctx_cnt[3];
+static const char *const ctx_name[] = { "HIGH PRIO ISR", "TIMER CALLBACK", "THREAD" };
+
+static bool stress_test_action(int ctx, int id)
+{
+	struct test_grtc_timer *timer = &timers[id];
+
+	ctx_cnt[ctx]++;
+	if (timer->state == TIMER_ACTIVE) {
+		/* Aborting soon to expire timers from higher interrupt priority may lead
+		 * to test failures.
+		 */
+		if (ctx == 0 && (k_timer_remaining_get(&timer->timer) < 5)) {
+			return true;
+		}
+
+		if (timer->abort_cnt < timer->expire_cnt / 2) {
+			bool any_active;
+
+			timer->state = TIMER_PREPARE;
+			k_timer_stop(&timer->timer);
+			timer->abort_cnt++;
+			any_active = atomic_dec(&test_active_cnt) > 1;
+			timer->state = TIMER_IDLE;
+
+			return any_active;
+		}
+	} else if (timer->state == TIMER_IDLE) {
+		int ticks = 10 + (sys_rand32_get() & 0x3F);
+		k_timeout_t t = K_TICKS(ticks);
+
+		timer->exp_expire =  k_ticks_to_cyc_floor32(sys_clock_tick_get_32() + ticks);
+		timer->state = TIMER_PREPARE;
+		timer->ticks = ticks;
+		k_timer_start(&timer->timer, t, K_NO_WAIT);
+		atomic_inc(&test_active_cnt);
+		timer->start_cnt++;
+		timer->state = TIMER_ACTIVE;
+	}
+
+	return true;
+}
+
+static void stress_test_actions(int ctx)
+{
+	uint32_t r = sys_rand32_get();
+	int action_cnt = Z_MAX(r & 0x3, 1);
+	int tmr_id = (r >> 8) % ARRAY_SIZE(timers);
+
+	/* Occasionally wake thread context from which timer actions are also executed. */
+	if ((((r >> 2) & 0x3) == 0) || test_active_cnt < 2) {
+		LOG_DBG("ctx:%d thread wakeup", ctx);
+		k_wakeup(test_tid);
+	}
+
+	for (int i = 0; i < action_cnt; i++) {
+		if (stress_test_action(ctx, tmr_id) == false) {
+			stress_test_action(ctx, tmr_id);
+		}
+	}
+}
+
+static void timer_cb(struct k_timer *timer)
+{
+	struct test_grtc_timer *test_timer = CONTAINER_OF(timer, struct test_grtc_timer, timer);
+	uint32_t now = k_cycle_get_32();
+	int diff = now - test_timer->exp_expire;
+
+	atomic_dec(&test_active_cnt);
+	zassert_true(diff >= 0);
+	test_timer->max_late = MAX(diff, test_timer->max_late);
+	test_timer->min_late = MIN(diff, test_timer->min_late);
+
+	if (test_timer->expire_cnt == 0) {
+		test_timer->avg_late = diff;
+	} else {
+		test_timer->avg_late = (test_timer->avg_late * test_timer->expire_cnt + diff) /
+				(test_timer->expire_cnt + 1);
+	}
+
+	test_timer->expire_cnt++;
+	test_timer->state = TIMER_IDLE;
+
+	if (test_run) {
+		stress_test_actions(TEST_TIMER_CB);
+	}
+}
+
+static void counter_set(const struct device *dev, struct counter_alarm_cfg *cfg)
+{
+	int err;
+	uint32_t us = 150 + (sys_rand32_get() & 0x3F);
+
+	cfg->ticks = counter_us_to_ticks(dev, us);
+	err = counter_set_channel_alarm(dev, 0, cfg);
+	zassert_equal(err, 0);
+}
+
+static void counter_cb(const struct device *dev, uint8_t chan_id, uint32_t ticks, void *user_data)
+{
+	struct counter_alarm_cfg *config = user_data;
+
+	if (test_run) {
+		stress_test_actions(TEST_HIGH_PRI);
+		counter_set(dev, config);
+	}
+}
+
+static void report_progress(uint32_t start, uint32_t end)
+{
+	static uint32_t next_report;
+	static uint32_t step;
+	static uint32_t progress;
+
+	if (next_report == 0) {
+		step = (end - start) / 10;
+		next_report = start + step;
+	}
+
+	if (k_uptime_get_32() > next_report) {
+		next_report += step;
+		progress += 10;
+		printk("%d%%\r", progress);
+	}
+}
+
+static void grtc_stress_test(bool busy_sim_en)
+{
+	static struct counter_alarm_cfg alarm_cfg;
+#if DT_NODE_EXISTS(DT_NODELABEL(test_timer)) && DT_NODE_HAS_STATUS(DT_NODELABEL(test_timer), okay)
+	const struct device *const counter_dev = DEVICE_DT_GET(DT_NODELABEL(test_timer));
+#else
+	const struct device *const counter_dev = NULL;
+#endif
+	uint32_t test_ms = 5000;
+	uint32_t test_start = k_uptime_get_32();
+	uint32_t load;
+
+	test_end = k_cycle_get_32() + k_ms_to_cyc_floor32(test_ms);
+	test_tid = k_current_get();
+
+	for (size_t i = 0; i < ARRAY_SIZE(timers); i++) {
+		k_timer_init(&timers[i].timer, timer_cb, NULL);
+	}
+
+	if (IS_ENABLED(CONFIG_CPU_LOAD)) {
+		(void)cpu_load_get(true);
+	}
+
+	if (counter_dev) {
+		counter_start(counter_dev);
+	}
+
+	alarm_cfg.callback = counter_cb;
+	alarm_cfg.user_data = &alarm_cfg;
+	test_run = true;
+
+	if (counter_dev) {
+		counter_set(counter_dev, &alarm_cfg);
+	}
+
+	if (busy_sim_en) {
+		busy_sim_start(500, 200, 1000, 400, NULL);
+	}
+
+	LOG_DBG("Starting test, will end at %d", test_end);
+	while (k_cycle_get_32() < test_end) {
+		report_progress(test_start, test_start + test_ms);
+		stress_test_actions(TEST_THREAD);
+		k_sleep(K_MSEC(test_ms));
+	}
+
+	load = IS_ENABLED(CONFIG_CPU_LOAD) ? cpu_load_get(true) : 0;
+
+	test_run = false;
+	k_msleep(50);
+
+	for (size_t i = 0; i < ARRAY_SIZE(timers); i++) {
+		zassert_equal(timers[i].state, TIMER_IDLE, "Unexpected timer %d state:%d",
+				i, timers[i].state);
+		TC_PRINT("Timer%d (%p)\r\n\tstart_cnt:%d abort_cnt:%d expire_cnt:%d\n",
+			i, &timers[i], timers[i].start_cnt, timers[i].abort_cnt,
+			timers[i].expire_cnt);
+		TC_PRINT("\tavarage late:%d ticks, max late:%d, min late:%d early:%d\n",
+				timers[i].avg_late, timers[i].max_late, timers[i].min_late,
+				timers[i].early_cnt);
+	}
+
+	for (size_t i = 0; i < ARRAY_SIZE(ctx_cnt); i++) {
+		TC_PRINT("Context: %s executed %d times\n", ctx_name[i], ctx_cnt[i]);
+	}
+	TC_PRINT("CPU load during test:%d.%d\n", load / 10, load % 10);
+
+	if (busy_sim_en) {
+		busy_sim_stop();
+	}
+
+	if (counter_dev) {
+		counter_stop(counter_dev);
+	}
+}
+
+ZTEST(nrf_grtc_timer, test_stress)
+{
+	grtc_stress_test(false);
+}
+
 ZTEST_SUITE(nrf_grtc_timer, NULL, NULL, NULL, NULL, NULL);