LXR linux/arch/avr32/include/asm/switch

   1/*
   2 * Copyright (C) 2004-2006 Atmel Corporation
   3 *
   4 * This program is free software; you can redistribute it and/or modify
   5 * it under the terms of the GNU General Public License version 2 as
   6 * published by the Free Software Foundation.
   7 */
   8#ifndef __ASM_AVR32_SWITCH_TO_H
   9#define __ASM_AVR32_SWITCH_TO_H
  10
  11/*
  12 * Help PathFinder and other Nexus-compliant debuggers keep track of
  13 * the current PID by emitting an Ownership Trace Message each time we
  14 * switch task.
  15 */
  16#ifdef CONFIG_OWNERSHIP_TRACE
  17#include <asm/ocd.h>
  18#define ocd_switch(prev, next)                          \
  19        do {                                            \
  20                ocd_write(PID, prev->pid);              \
  21                ocd_write(PID, next->pid);              \
  22        } while(0)
  23#else
  24#define ocd_switch(prev, next)
  25#endif
  26
  27/*
  28 * switch_to(prev, next, last) should switch from task `prev' to task
  29 * `next'. `prev' will never be the same as `next'.
  30 *
  31 * We just delegate everything to the __switch_to assembly function,
  32 * which is implemented in arch/avr32/kernel/switch_to.S
  33 *
  34 * mb() tells GCC not to cache `current' across this call.
  35 */
  36struct cpu_context;
  37struct task_struct;
  38extern struct task_struct *__switch_to(struct task_struct *,
  39                                       struct cpu_context *,
  40                                       struct cpu_context *);
  41#define switch_to(prev, next, last)                                     \
  42        do {                                                            \
  43                ocd_switch(prev, next);                                 \
  44                last = __switch_to(prev, &prev->thread.cpu_context + 1, \
  45                                   &next->thread.cpu_context);          \
  46        } while (0)
  47
  48
  49#endif /* __ASM_AVR32_SWITCH_TO_H */
  50