123456789101112131415161718192021222324252627282930313233343536373839404142434445464748495051525354555657585960616263646566676869707172737475767778798081828384858687888990919293949596979899100101102103104105106107108109110111112113114115116117118119120121122123124125126127128129130131132133134135136137138139140141142143144145146147148149150151152153154155156157158159160161162163164165166167168169170171172173174175176177178 |
- /****************************************************************************
- * sched/group/group_addrenv.c
- *
- * Copyright (C) 2014, 2016 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/irq.h>
- #include <nuttx/sched.h>
- #include "sched/sched.h"
- #include "group/group.h"
- #ifdef CONFIG_ARCH_ADDRENV
- /****************************************************************************
- * 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;
- /****************************************************************************
- * 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;
- gid_t gid;
- 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;
- }
- /* Get the ID of the group that needs the address environment */
- gid = group->tg_gid;
- DEBUGASSERT(gid != 0);
- /* Are we going to change address environments? */
- flags = enter_critical_section();
- if (gid != g_gid_current)
- {
- /* Yes.. Is there a current address environment in place? */
- if (g_gid_current != 0)
- {
- /* Find the old group with this ID. */
- oldgroup = group_findbygid(g_gid_current);
- DEBUGASSERT(oldgroup &&
- (oldgroup->tg_flags & GROUP_FLAG_ADDRENV) != 0);
- 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->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_gid_current = gid;
- }
- leave_critical_section(flags);
- return OK;
- }
- #endif /* CONFIG_ARCH_ADDRENV */
|