160 lines
4.2 KiB
C
160 lines
4.2 KiB
C
/*
|
|
* Copyright (c) 2016 Wind River Systems, Inc.
|
|
*
|
|
* Licensed under the Apache License, Version 2.0 (the "License");
|
|
* you may not use this file except in compliance with the License.
|
|
* You may obtain a copy of the License at
|
|
*
|
|
* http://www.apache.org/licenses/LICENSE-2.0
|
|
*
|
|
* Unless required by applicable law or agreed to in writing, software
|
|
* distributed under the License is distributed on an "AS IS" BASIS,
|
|
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
|
|
* See the License for the specific language governing permissions and
|
|
* limitations under the License.
|
|
*/
|
|
|
|
#include <nanokernel.h>
|
|
#include <kernel_structs.h>
|
|
#include <toolchain.h>
|
|
#include <sections.h>
|
|
#include <drivers/system_timer.h>
|
|
#include <wait_q.h>
|
|
#include <power.h>
|
|
|
|
#if defined(CONFIG_TICKLESS_IDLE)
|
|
/*
|
|
* Idle time must be this value or higher for timer to go into tickless idle
|
|
* state.
|
|
*/
|
|
int32_t _sys_idle_threshold_ticks = CONFIG_TICKLESS_IDLE_THRESH;
|
|
#endif /* CONFIG_TICKLESS_IDLE */
|
|
|
|
#ifdef CONFIG_SYS_POWER_MANAGEMENT
|
|
/*
|
|
* Used to allow _sys_soc_suspend() implementation to control notification
|
|
* of the event that caused exit from kernel idling after pm operations.
|
|
*/
|
|
unsigned char _sys_pm_idle_exit_notify;
|
|
|
|
void __attribute__((weak)) _sys_soc_resume(void)
|
|
{
|
|
}
|
|
|
|
void __attribute__((weak)) _sys_soc_resume_from_deep_sleep(void)
|
|
{
|
|
}
|
|
|
|
/**
|
|
*
|
|
* @brief Indicate that kernel is idling in tickless mode
|
|
*
|
|
* Sets the nanokernel data structure idle field to either a positive value or
|
|
* K_FOREVER.
|
|
*
|
|
* @param ticks the number of ticks to idle
|
|
*
|
|
* @return N/A
|
|
*/
|
|
static void set_kernel_idle_time_in_ticks(int32_t ticks)
|
|
{
|
|
_kernel.idle = ticks;
|
|
}
|
|
#else
|
|
#define set_kernel_idle_time_in_ticks(x) do { } while (0)
|
|
#endif
|
|
|
|
static void _sys_power_save_idle(int32_t ticks __unused)
|
|
{
|
|
#if defined(CONFIG_TICKLESS_IDLE)
|
|
if ((ticks == K_FOREVER) || ticks >= _sys_idle_threshold_ticks) {
|
|
/*
|
|
* Stop generating system timer interrupts until it's time for
|
|
* the next scheduled kernel timer to expire.
|
|
*/
|
|
|
|
_timer_idle_enter(ticks);
|
|
}
|
|
#endif /* CONFIG_TICKLESS_IDLE */
|
|
|
|
set_kernel_idle_time_in_ticks(ticks);
|
|
#if (defined(CONFIG_SYS_POWER_LOW_POWER_STATE) || \
|
|
defined(CONFIG_SYS_POWER_DEEP_SLEEP))
|
|
|
|
_sys_pm_idle_exit_notify = 1;
|
|
|
|
/*
|
|
* Call the suspend hook function of the soc interface to allow
|
|
* entry into a low power state. The function returns
|
|
* SYS_PM_NOT_HANDLED if low power state was not entered, in which
|
|
* case, kernel does normal idle processing.
|
|
*
|
|
* This function is entered with interrupts disabled. If a low power
|
|
* state was entered, then the hook function should enable inerrupts
|
|
* before exiting. This is because the kernel does not do its own idle
|
|
* processing in those cases i.e. skips nano_cpu_idle(). The kernel's
|
|
* idle processing re-enables interrupts which is essential for
|
|
* the kernel's scheduling logic.
|
|
*/
|
|
if (_sys_soc_suspend(ticks) == SYS_PM_NOT_HANDLED) {
|
|
_sys_pm_idle_exit_notify = 0;
|
|
nano_cpu_idle();
|
|
}
|
|
#else
|
|
nano_cpu_idle();
|
|
#endif
|
|
}
|
|
|
|
void _sys_power_save_idle_exit(int32_t ticks)
|
|
{
|
|
#if defined(CONFIG_SYS_POWER_LOW_POWER_STATE)
|
|
/* Some CPU low power states require notification at the ISR
|
|
* to allow any operations that needs to be done before kernel
|
|
* switches task or processes nested interrupts. This can be
|
|
* disabled by calling _sys_soc_pm_idle_exit_notification_disable().
|
|
* Alternatively it can be simply ignored if not required.
|
|
*/
|
|
if (_sys_pm_idle_exit_notify) {
|
|
_sys_soc_resume();
|
|
}
|
|
#endif
|
|
#ifdef CONFIG_TICKLESS_IDLE
|
|
if ((ticks == K_FOREVER) || ticks >= _sys_idle_threshold_ticks) {
|
|
/* Resume normal periodic system timer interrupts */
|
|
|
|
_timer_idle_exit();
|
|
}
|
|
#else
|
|
ARG_UNUSED(ticks);
|
|
#endif /* CONFIG_TICKLESS_IDLE */
|
|
}
|
|
|
|
|
|
#if K_IDLE_PRIO < 0
|
|
#define IDLE_YIELD_IF_COOP() k_yield()
|
|
#else
|
|
#define IDLE_YIELD_IF_COOP() do { } while ((0))
|
|
#endif
|
|
|
|
void idle(void *unused1, void *unused2, void *unused3)
|
|
{
|
|
ARG_UNUSED(unused1);
|
|
ARG_UNUSED(unused2);
|
|
ARG_UNUSED(unused3);
|
|
|
|
#ifdef CONFIG_BOOT_TIME_MEASUREMENT
|
|
/* record timestamp when idling begins */
|
|
|
|
extern uint64_t __idle_tsc;
|
|
|
|
__idle_tsc = _tsc_read();
|
|
#endif
|
|
|
|
for (;;) {
|
|
(void)irq_lock();
|
|
_sys_power_save_idle(_get_next_timeout_expiry());
|
|
|
|
IDLE_YIELD_IF_COOP();
|
|
}
|
|
}
|