zephyr/arch/posix/core/cpuhalt.c

68 lines
1.9 KiB
C

/*
* Copyright (c) 2011-2015 Wind River Systems, Inc.
* Copyright (c) 2017 Oticon A/S
*
* SPDX-License-Identifier: Apache-2.0
*/
/**
* @file CPU power management code for POSIX
*
* This module provides an implementation of the architecture-specific
* k_cpu_idle() primitive required by the kernel idle loop component.
* It can be called within an implementation of _sys_power_save_idle(),
* which is provided for the kernel by the platform.
*
* The module also provides an implementation of k_cpu_atomic_idle(), which
* atomically re-enables interrupts and enters low power mode.
*
*/
#include "posix_core.h"
#include "posix_soc_if.h"
#include "logging/kernel_event_logger.h"
/**
*
* @brief Power save idle routine for IA-32
*
* This function will be called by the kernel idle loop or possibly within
* an implementation of _sys_power_save_idle in the kernel when the
* '_sys_power_save_flag' variable is non-zero.
*
* This function is just a pass thru to the SOC one
*
* @return N/A
*/
void k_cpu_idle(void)
{
_sys_k_event_logger_enter_sleep();
posix_irq_full_unlock();
posix_halt_cpu();
}
/**
*
* @brief Atomically re-enable interrupts and enter low power mode
*
* INTERNAL
* The requirements for k_cpu_atomic_idle() are as follows:
* 1) The enablement of interrupts and entering a low-power mode needs to be
* atomic, i.e. there should be no period of time where interrupts are
* enabled before the processor enters a low-power mode. See the comments
* in k_lifo_get(), for example, of the race condition that
* occurs if this requirement is not met.
*
* 2) After waking up from the low-power mode, the interrupt lockout state
* must be restored as indicated in the 'imask' input parameter.
*
* This function is just a pass thru to the SOC one
*
* @return N/A
*/
void k_cpu_atomic_idle(unsigned int imask)
{
_sys_k_event_logger_enter_sleep();
posix_atomic_halt_cpu(imask);
}