walnux/arch/arm/src/armv7-a/arm_releasepending.c
2021-03-09 23:18:28 +08:00

127 lines
4 KiB
C

/****************************************************************************
* arch/arm/src/armv7-a/arm_releasepending.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 <sched.h>
#include <debug.h>
#include <nuttx/arch.h>
#include <nuttx/sched.h>
#include "sched/sched.h"
#include "group/group.h"
#include "arm_internal.h"
/****************************************************************************
* Public Functions
****************************************************************************/
/****************************************************************************
* Name: up_release_pending
*
* Description:
* Release and ready-to-run tasks that have collected in the pending task
* list. This can call a context switch if a new task is placed at the
* head of the ready to run list.
*
****************************************************************************/
void up_release_pending(void)
{
struct tcb_s *rtcb = this_task();
sinfo("From TCB=%p\n", rtcb);
/* Merge the g_pendingtasks list into the ready-to-run task list */
if (nxsched_merge_pending())
{
/* The currently active task has changed! We will need to
* switch contexts.
*/
/* Update scheduler parameters */
nxsched_suspend_scheduler(rtcb);
/* Are we operating in interrupt context? */
if (CURRENT_REGS)
{
/* Yes, then we have to do things differently.
* Just copy the CURRENT_REGS into the OLD rtcb.
*/
arm_savestate(rtcb->xcp.regs);
/* Restore the exception context of the rtcb at the (new) head
* of the ready-to-run task list.
*/
rtcb = this_task();
/* Update scheduler parameters */
nxsched_resume_scheduler(rtcb);
/* Then switch contexts. Any necessary address environment
* changes will be made when the interrupt returns.
*/
arm_restorestate(rtcb->xcp.regs);
}
/* Copy the exception context into the TCB of the task that
* was currently active. if arm_saveusercontext returns a non-zero
* value, then this is really the previously running task
* restarting!
*/
else if (!arm_saveusercontext(rtcb->xcp.regs))
{
/* Restore the exception context of the rtcb at the (new) head
* of the ready-to-run task list.
*/
rtcb = this_task();
#ifdef CONFIG_ARCH_ADDRENV
/* Make sure that the address environment for the previously
* running task is closed down gracefully (data caches dump,
* MMU flushed) and set up the address environment for the new
* thread at the head of the ready-to-run list.
*/
group_addrenv(rtcb);
#endif
/* Update scheduler parameters */
nxsched_resume_scheduler(rtcb);
/* Then switch contexts */
arm_fullcontextrestore(rtcb->xcp.regs);
}
}
}