blob: da4e71d870cd1c0850d3a214b16c832d53910d5a [file] [log] [blame]
/*
* 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;
}