esp-idf/components/freertos/FreeRTOS-Kernel/portable/port_systick.c
Darian Leung 7a4e1fee99 freertos: Fix xTaskIncrementTick()
Previously, xTaskIncrementTick() would always trigger a yield (i.e., return pdTRUE)
when called on core 1. This would mean core 1 would call vTaskSwitchContext() on
every tick, leading to uneccesary CPU overhead.

This commit fixes xTaskIncrementTick() in the following ways:

- Clearly mark IDF additions in xTaskIncrementTick()
- Moved esp_vApplicationTickHook() to be called direclty in xPortSysTickHandler() in order to
  simplify xTaskIncrementTick().
- Only core 0 calls xTaskIncrementTick() in order to simplify the function's logic. Core 0 is
  solely responsible for managing xTickCount and xPendedTicks
- All other cores call xTaskIncrementTickOtherCores() instead which is a simplified version of
  xTaskIncrementTick() and handles the following:
    - Check if core 0 has unblocked a higher priority task to run
    - Check if the current core requires time slicing
    - Call vApplicationTickHook()
2022-07-20 11:31:50 +08:00

194 lines
6.2 KiB
C

/*
* SPDX-FileCopyrightText: 2017-2021 Espressif Systems (Shanghai) CO LTD
*
* SPDX-License-Identifier: Apache-2.0
*/
#include <stdlib.h>
#include <string.h>
#include "FreeRTOS.h"
#include "task.h"
#include "esp_intr_alloc.h"
#include "esp_err.h"
#include "esp_log.h"
#include "sdkconfig.h"
#ifdef CONFIG_FREERTOS_SYSTICK_USES_SYSTIMER
#include "soc/periph_defs.h"
#include "soc/system_reg.h"
#include "hal/systimer_hal.h"
#include "hal/systimer_ll.h"
#endif
#ifdef CONFIG_PM_TRACE
#include "esp_private/pm_trace.h"
#endif //CONFIG_PM_TRACE
BaseType_t xPortSysTickHandler(void);
#ifdef CONFIG_FREERTOS_SYSTICK_USES_CCOUNT
extern void _frxt_tick_timer_init(void);
extern void _xt_tick_divisor_init(void);
#ifdef CONFIG_FREERTOS_CORETIMER_0
#define SYSTICK_INTR_ID (ETS_INTERNAL_TIMER0_INTR_SOURCE+ETS_INTERNAL_INTR_SOURCE_OFF)
#endif
#ifdef CONFIG_FREERTOS_CORETIMER_1
#define SYSTICK_INTR_ID (ETS_INTERNAL_TIMER1_INTR_SOURCE+ETS_INTERNAL_INTR_SOURCE_OFF)
#endif
/**
* @brief Initialize CCONT timer to generate the tick interrupt
*
*/
void vPortSetupTimer(void)
{
/* Init the tick divisor value */
_xt_tick_divisor_init();
_frxt_tick_timer_init();
}
#elif CONFIG_FREERTOS_SYSTICK_USES_SYSTIMER
_Static_assert(SOC_CPU_CORES_NUM <= SOC_SYSTIMER_ALARM_NUM - 1, "the number of cores must match the number of core alarms in SYSTIMER");
void SysTickIsrHandler(void *arg);
static uint32_t s_handled_systicks[portNUM_PROCESSORS] = { 0 };
#define SYSTICK_INTR_ID (ETS_SYSTIMER_TARGET0_EDGE_INTR_SOURCE)
/**
* @brief Set up the systimer peripheral to generate the tick interrupt
*
* Both timer alarms are configured in periodic mode.
* It is done at the same time so SysTicks for both CPUs occur at the same time or very close.
* Shifts a time of triggering interrupts for core 0 and core 1.
*/
void vPortSetupTimer(void)
{
unsigned cpuid = xPortGetCoreID();
#ifdef CONFIG_FREERTOS_CORETIMER_SYSTIMER_LVL3
const unsigned level = ESP_INTR_FLAG_LEVEL3;
#else
const unsigned level = ESP_INTR_FLAG_LEVEL1;
#endif
/* Systimer HAL layer object */
static systimer_hal_context_t systimer_hal;
/* set system timer interrupt vector */
ESP_ERROR_CHECK(esp_intr_alloc(ETS_SYSTIMER_TARGET0_EDGE_INTR_SOURCE + cpuid, ESP_INTR_FLAG_IRAM | level, SysTickIsrHandler, &systimer_hal, NULL));
if (cpuid == 0) {
systimer_hal_init(&systimer_hal);
systimer_ll_set_counter_value(systimer_hal.dev, SYSTIMER_LL_COUNTER_OS_TICK, 0);
systimer_ll_apply_counter_value(systimer_hal.dev, SYSTIMER_LL_COUNTER_OS_TICK);
for (cpuid = 0; cpuid < SOC_CPU_CORES_NUM; cpuid++) {
systimer_hal_counter_can_stall_by_cpu(&systimer_hal, SYSTIMER_LL_COUNTER_OS_TICK, cpuid, false);
}
for (cpuid = 0; cpuid < portNUM_PROCESSORS; ++cpuid) {
uint32_t alarm_id = SYSTIMER_LL_ALARM_OS_TICK_CORE0 + cpuid;
/* configure the timer */
systimer_hal_connect_alarm_counter(&systimer_hal, alarm_id, SYSTIMER_LL_COUNTER_OS_TICK);
systimer_hal_set_alarm_period(&systimer_hal, alarm_id, 1000000UL / CONFIG_FREERTOS_HZ);
systimer_hal_select_alarm_mode(&systimer_hal, alarm_id, SYSTIMER_ALARM_MODE_PERIOD);
systimer_hal_counter_can_stall_by_cpu(&systimer_hal, SYSTIMER_LL_COUNTER_OS_TICK, cpuid, true);
if (cpuid == 0) {
systimer_hal_enable_alarm_int(&systimer_hal, alarm_id);
systimer_hal_enable_counter(&systimer_hal, SYSTIMER_LL_COUNTER_OS_TICK);
#ifndef CONFIG_FREERTOS_UNICORE
// SysTick of core 0 and core 1 are shifted by half of period
systimer_hal_counter_value_advance(&systimer_hal, SYSTIMER_LL_COUNTER_OS_TICK, 1000000UL / CONFIG_FREERTOS_HZ / 2);
#endif
}
}
} else {
uint32_t alarm_id = SYSTIMER_LL_ALARM_OS_TICK_CORE0 + cpuid;
systimer_hal_enable_alarm_int(&systimer_hal, alarm_id);
}
}
/**
* @brief Systimer interrupt handler.
*
* The Systimer interrupt for SysTick works in periodic mode no need to calc the next alarm.
* If a timer interrupt is ever serviced more than one tick late, it is necessary to process multiple ticks.
*/
IRAM_ATTR void SysTickIsrHandler(void *arg)
{
uint32_t cpuid = xPortGetCoreID();
systimer_hal_context_t *systimer_hal = (systimer_hal_context_t *)arg;
#ifdef CONFIG_PM_TRACE
ESP_PM_TRACE_ENTER(TICK, cpuid);
#endif
uint32_t alarm_id = SYSTIMER_LL_ALARM_OS_TICK_CORE0 + cpuid;
do {
systimer_ll_clear_alarm_int(systimer_hal->dev, alarm_id);
uint32_t diff = systimer_hal_get_counter_value(systimer_hal, SYSTIMER_LL_COUNTER_OS_TICK) / systimer_ll_get_alarm_period(systimer_hal->dev, alarm_id) - s_handled_systicks[cpuid];
if (diff > 0) {
if (s_handled_systicks[cpuid] == 0) {
s_handled_systicks[cpuid] = diff;
diff = 1;
} else {
s_handled_systicks[cpuid] += diff;
}
do {
xPortSysTickHandler();
} while (--diff);
}
} while (systimer_ll_is_alarm_int_fired(systimer_hal->dev, alarm_id));
#ifdef CONFIG_PM_TRACE
ESP_PM_TRACE_EXIT(TICK, cpuid);
#endif
}
#endif // CONFIG_FREERTOS_SYSTICK_USES_CCOUNT
extern void esp_vApplicationTickHook(void);
/**
* @brief Handler of SysTick
*
* The function is called from:
* - _frxt_timer_int for xtensa with CONFIG_FREERTOS_SYSTICK_USES_CCOUNT
* - SysTickIsrHandler for xtensa with CONFIG_FREERTOS_SYSTICK_USES_SYSTIMER
* - SysTickIsrHandler for riscv
*/
BaseType_t xPortSysTickHandler(void)
{
#if configBENCHMARK
portbenchmarkIntLatency();
#endif //configBENCHMARK
traceISR_ENTER(SYSTICK_INTR_ID);
// Call IDF Tick Hook
esp_vApplicationTickHook();
// Call FreeRTOS Increment tick function
BaseType_t xSwitchRequired;
#if CONFIG_FREERTOS_UNICORE
xSwitchRequired = xTaskIncrementTick();
#else
if (xPortGetCoreID() == 0) {
xSwitchRequired = xTaskIncrementTick();
} else {
xSwitchRequired = xTaskIncrementTickOtherCores();
}
#endif
// Check if yield is required
if (xSwitchRequired != pdFALSE) {
portYIELD_FROM_ISR();
} else {
traceISR_EXIT();
}
return xSwitchRequired;
}