kernel/generic/src/preempt/preemption.c

   1 /*
   2  * Copyright (c) 2005 Jakub Jermar
   3  * All rights reserved.
   4  *
   5  * Redistribution and use in source and binary forms, with or without
   6  * modification, are permitted provided that the following conditions
   7  * are met:
   8  *
   9  * - Redistributions of source code must retain the above copyright
  10  *   notice, this list of conditions and the following disclaimer.
  11  * - Redistributions in binary form must reproduce the above copyright
  12  *   notice, this list of conditions and the following disclaimer in the
  13  *   documentation and/or other materials provided with the distribution.
  14  * - The name of the author may not be used to endorse or promote products
  15  *   derived from this software without specific prior written permission.
  16  *
  17  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
  18  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
  19  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
  20  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
  21  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
  22  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
  23  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
  24  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  25  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
  26  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  27  */
  28
  29 /** @addtogroup generic
  30  * @{
  31  */
  32
  33 /**
  34  * @file        preemption.c
  35  * @brief       Preemption control.
  36  */
  37
  38 #include <preemption.h>
  39 #include <arch.h>
  40 #include <arch/asm.h>
  41 #include <arch/barrier.h>
  42 #include <debug.h>
  43
  44 /** Increment preemption disabled counter. */
  45 void preemption_disable(void)
  46 {
  47         THE->preemption_disabled++;
  48         memory_barrier();
  49 }
  50
  51 /** Decrement preemption disabled counter. */
  52 void preemption_enable(void)
  53 {
  54         ASSERT(THE->preemption_disabled);
  55         memory_barrier();
  56         THE->preemption_disabled--;
  57 }
  58
  59 /** @}
  60  */