incubator-nuttx/sched/group/group_addrenv.c

156 lines
4.7 KiB
C

/****************************************************************************
* sched/group/group_addrenv.c
*
* 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 <assert.h>
#include <debug.h>
#include <nuttx/irq.h>
#include <nuttx/sched.h>
#include "sched/sched.h"
#include "group/group.h"
#ifdef CONFIG_ARCH_ADDRENV
/****************************************************************************
* Public Data
****************************************************************************/
/* This variable holds the current task group. This pointer is NULL
* if the current task is a kernel thread that has no address environment
* (other than the kernel context).
*
* This must only be accessed with interrupts disabled.
*/
FAR struct task_group_s *g_group_current[CONFIG_SMP_NCPUS];
/****************************************************************************
* Public Functions
****************************************************************************/
/****************************************************************************
* Name: group_addrenv
*
* Description:
* Instantiate the group address environment for the current thread at the
* the head of the ready to run list.
*
* This function is called from platform-specific code after any context
* switch (i.e., after any change in the thread at the head of the
* ready-to-run list). This function will change the address environment
* if the new thread is part of a different task group.
*
* Input Parameters:
* tcb - The TCB of thread that needs an address environment. This should
* be the TCB at the head of the ready-to-run list, but that is not
* enough.
*
* Returned Value:
* Zero (OK) is returned on success. A negated errno value is returned on
* any failure.
*
* Assumptions:
* This function should only be called within critical OS sections with
* interrupts disabled. Interrupts are disabled internally just to be
* certain, however.
*
****************************************************************************/
int group_addrenv(FAR struct tcb_s *tcb)
{
FAR struct task_group_s *group;
FAR struct task_group_s *oldgroup;
irqstate_t flags;
int cpu;
int ret;
/* NULL for the tcb means to use the TCB of the task at the head of the
* ready to run list.
*/
if (!tcb)
{
tcb = this_task();
}
DEBUGASSERT(tcb && tcb->group);
group = tcb->group;
/* Does the group have an address environment? */
if ((group->tg_flags & GROUP_FLAG_ADDRENV) == 0)
{
/* No... just return perhaps leaving a different address environment
* intact.
*/
return OK;
}
/* Are we going to change address environments? */
flags = enter_critical_section();
cpu = this_cpu();
oldgroup = g_group_current[cpu];
if (group != oldgroup)
{
/* Yes.. Is there a current address environment in place? */
if (oldgroup)
{
/* We need to flush the D-Cache and Invalidate the I-Cache for
* the group whose environment is disappearing.
*/
DEBUGASSERT((oldgroup->tg_flags & GROUP_FLAG_ADDRENV) != 0);
up_addrenv_coherent(&oldgroup->tg_addrenv);
}
/* Instantiate the new address environment (removing the old
* environment in the process). For the case of kernel threads,
* the old mappings will be removed and no new mappings will be
* instantiated.
*/
ret = up_addrenv_select(&group->tg_addrenv, NULL);
if (ret < 0)
{
berr("ERROR: up_addrenv_select failed: %d\n", ret);
}
/* Save the new, current group */
g_group_current[cpu] = group;
}
leave_critical_section(flags);
return OK;
}
#endif /* CONFIG_ARCH_ADDRENV */