| /* |
| * Copyright (c) 2012-2014 Wind River Systems, Inc. |
| * |
| * SPDX-License-Identifier: Apache-2.0 |
| */ |
| |
| /** |
| * @file |
| * |
| * @brief measure time from ISR to a rescheduled thread |
| * |
| * This file contains test that measures time to switch from an interrupt |
| * handler to executing a thread after rescheduling. In other words, execution |
| * after interrupt handler resume in a different thread than the one which got |
| * interrupted. |
| */ |
| |
| #include <zephyr/kernel.h> |
| #include <zephyr/irq_offload.h> |
| |
| #include "utils.h" |
| |
| static timing_t timestamp_start; |
| static timing_t timestamp_end; |
| static struct k_work work; |
| |
| K_SEM_DEFINE(INTSEMA, 0, 1); |
| K_SEM_DEFINE(WORKSEMA, 0, 1); |
| |
| /** |
| * |
| * @brief Test ISR used to measure best case interrupt latency |
| * |
| * The interrupt handler gets the second timestamp. |
| * |
| */ |
| static void latency_test_isr(const void *unused) |
| { |
| ARG_UNUSED(unused); |
| |
| k_work_submit(&work); |
| timestamp_start = timing_counter_get(); |
| } |
| |
| static void worker(struct k_work *item) |
| { |
| (void)item; |
| |
| timestamp_end = timing_counter_get(); |
| k_sem_give(&WORKSEMA); |
| } |
| |
| /** |
| * |
| * @brief Software interrupt generating thread |
| * |
| * Lower priority thread that, when it starts, it waits for a semaphore. When |
| * it gets it, released by the main thread, sets up the interrupt handler and |
| * generates the software interrupt |
| * |
| * @return 0 on success |
| */ |
| void int_thread(void) |
| { |
| k_sem_take(&INTSEMA, K_FOREVER); |
| irq_offload(latency_test_isr, NULL); |
| k_thread_suspend(k_current_get()); |
| } |
| |
| K_THREAD_DEFINE(int_thread_id, 512, (k_thread_entry_t)int_thread, NULL, NULL, |
| NULL, 11, 0, 0); |
| |
| /** |
| * |
| * @brief The test main function |
| * |
| * @return 0 on success |
| */ |
| int int_to_thread_evt(void) |
| { |
| uint32_t diff; |
| |
| k_work_init(&work, worker); |
| |
| timing_start(); |
| TICK_SYNCH(); |
| k_sem_give(&INTSEMA); |
| k_sem_take(&WORKSEMA, K_FOREVER); |
| timing_stop(); |
| |
| diff = timing_cycles_get(×tamp_start, ×tamp_end); |
| |
| PRINT_STATS("Time from ISR to executing a different thread", diff) |
| |
| return 0; |
| } |