| /* |
| * Copyright (c) 2012-2014 Wind River Systems, Inc. |
| * Copyright (c) 2017 Intel Corporation. |
| * |
| * SPDX-License-Identifier: Apache-2.0 |
| */ |
| |
| /** |
| * @file measure time from ISR back to interrupted thread |
| * |
| * This file contains test that measures time to switch from the interrupt |
| * handler back to the interrupted thread. |
| */ |
| |
| #include "timestamp.h" |
| #include "utils.h" |
| |
| #include <arch/cpu.h> |
| #include <irq_offload.h> |
| |
| static volatile int flag_var; |
| |
| static u32_t timestamp; |
| |
| /** |
| * |
| * @brief Test ISR used to measure best case interrupt latency |
| * |
| * The interrupt handler gets the second timestamp. |
| * |
| * @return N/A |
| */ |
| static void latency_test_isr(void *unused) |
| { |
| ARG_UNUSED(unused); |
| |
| flag_var = 1; |
| timestamp = TIME_STAMP_DELTA_GET(0); |
| } |
| |
| /** |
| * |
| * @brief Interrupt preparation function |
| * |
| * Function makes all the test preparations: registers the interrupt handler, |
| * gets the first timestamp and invokes the software interrupt. |
| * |
| * @return N/A |
| */ |
| static void make_int(void) |
| { |
| flag_var = 0; |
| irq_offload(latency_test_isr, NULL); |
| if (flag_var != 1) { |
| PRINT_FORMAT(" Flag variable has not changed. FAILED\n"); |
| } else { |
| timestamp = TIME_STAMP_DELTA_GET(timestamp); |
| } |
| } |
| |
| /** |
| * |
| * @brief The test main function |
| * |
| * @return 0 on success |
| */ |
| int int_to_thread(void) |
| { |
| PRINT_FORMAT(" 1 - Measure time to switch from ISR back to" |
| " interrupted thread"); |
| TICK_SYNCH(); |
| make_int(); |
| if (flag_var == 1) { |
| PRINT_FORMAT(" switching time is %u tcs = %u nsec", |
| timestamp, SYS_CLOCK_HW_CYCLES_TO_NS(timestamp)); |
| } |
| return 0; |
| } |