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Add group_addrenv() which will be called during context switches in order to change address environments. Not yet hooked in

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Gregory Nutt 2014-08-26 14:57:05 -06:00
parent af22f273d3
commit 582800a04d
1 changed files with 168 additions and 0 deletions
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sched/group/group_addrenv.c Normal file
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/****************************************************************************
* sched/group/group_addrenv.c
*
* Copyright (C) 2014 Gregory Nutt. All rights reserved.
* Author: Gregory Nutt <gnutt@nuttx.org>
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in
* the documentation and/or other materials provided with the
* distribution.
* 3. Neither the name NuttX nor the names of its contributors may be
* used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
* FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
* COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
* BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
* OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
* AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
* ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
* POSSIBILITY OF SUCH DAMAGE.
*
****************************************************************************/
/****************************************************************************
* Included Files
****************************************************************************/
#include <nuttx/config.h>
#include <debug.h>
#include <nuttx/sched.h>
#include "group/group.h"
#ifdef CONFIG_ARCH_ADDRENV
/****************************************************************************
* Pre-processor Definitions
****************************************************************************/
/****************************************************************************
* Public Data
****************************************************************************/
/* This variable holds the group ID of the current task group. This ID is
* zero 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.
*/
gid_t g_gid_current;
/****************************************************************************
* Private Functions
****************************************************************************/
/****************************************************************************
* 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.
*
* 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.
*
* Return 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;
gid_t gid;
int ret;
DEBUGASSERT(tcb && tcb->group);
group = tcb->group;
/* What is the ID of the group of the new thread to run? Use zero if the
* group is a kernel thread.
*/
gid = 0;
if ((tcb->flags & TCB_FLAG_TTYPE_MASK) != TCB_FLAG_TTYPE_KERNEL)
{
gid = group->tg_gid;
}
/* Are we going to change address environments? */
flags = irqsave();
if (gid != g_gid_current)
{
/* Yes.. Is there a current address environment in place? */
if (g_gid_current != 0)
{
/* Find the old group this this ID */
oldgroup = group_findbygid(g_gid_current);
DEBUGASSERT(oldgroup);
if (oldgroup)
{
/* We need to flush the D-Cache and Invalidate the I-Cache for
* the group whose environment is disappearing.
*/
up_addrenv_coherent(&oldgroup->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->addrenv, NULL);
if (ret < 0)
{
bdbg("ERROR: up_addrenv_select failed: %d\n", ret);
}
/* Save the new, current group */
g_gid_current = gid;
}
irqrestore(flags);
return OK;
}
#endif /* CONFIG_ARCH_ADDRENV */