incubator-nuttx/sched/init/nx_smpstart.c

138 lines
3.9 KiB
C

/****************************************************************************
* sched/init/nx_smpstart.c
*
* SPDX-License-Identifier: Apache-2.0
*
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership. The
* ASF licenses this file to you 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.
*
****************************************************************************/
/****************************************************************************
* Included Files
****************************************************************************/
#include <nuttx/config.h>
#include <sys/types.h>
#include <stdio.h>
#include <assert.h>
#include <debug.h>
#include <nuttx/arch.h>
#include <nuttx/kmalloc.h>
#include <nuttx/sched.h>
#include <nuttx/sched_note.h>
#include "group/group.h"
#include "sched/sched.h"
#include "init/init.h"
#ifdef CONFIG_SMP
/****************************************************************************
* Public Functions
****************************************************************************/
/****************************************************************************
* Name: nx_idle_trampoline
*
* Description:
* This is the common start-up logic for the IDLE task for CPUs 1 through
* (CONFIG_SMP_NCPUS-1). Having a start-up function such as this for the
* IDLE is not really an architectural necessity. It is used only for
* symmetry with how other threads are started (see nxtask_start() and
* pthread_start()).
*
* Input Parameters:
* None.
*
* Returned Value:
* This function does not return.
*
****************************************************************************/
void nx_idle_trampoline(void)
{
#ifdef CONFIG_SCHED_INSTRUMENTATION_SWITCH
FAR struct tcb_s *tcb = this_task();
/* Announce that the IDLE task has started */
sched_note_start(tcb);
#endif
/* Enter the IDLE loop */
sinfo("CPU%d: Beginning Idle Loop\n", this_cpu());
for (; ; )
{
/* Perform any processor-specific idle state operations */
up_idle();
}
}
/****************************************************************************
* Name: nx_smp_start
*
* Description:
* In an SMP configuration, only one CPU is initially active (CPU 0).
* System initialization occurs on that single thread. At the completion
* of the initialization of the OS, just before beginning normal
* multitasking, the additional CPUs would be started by calling this
* function.
*
* Input Parameters:
* None
*
* Returned Value:
* Zero on success; a negated errno value on failure.
*
* Assumption:
* Runs before the full initialization sequence has completed. Runs after
* all OS facilities are set up, but before multi-tasking has been started.
*
****************************************************************************/
int nx_smp_start(void)
{
int ret;
int cpu;
/* Flush dcache before start other CPUs. */
up_flush_dcache_all();
/* Start all of the other CPUs. CPU0 is already running. */
for (cpu = 1; cpu < CONFIG_SMP_NCPUS; cpu++)
{
/* Start the CPU */
ret = up_cpu_start(cpu);
if (ret < 0)
{
serr("ERROR: Failed to start CPU%d: %d\n", cpu, ret);
return ret;
}
}
return OK;
}
#endif /* CONFIG_SMP */