arch/avr32/include/asm/switch_to.h

   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 finish_arch_switch(prev)                        \
  19         do {                                            \
  20                 ocd_write(PID, prev->pid);              \
  21                 ocd_write(PID, current->pid);           \
  22         } while(0)
  23 #endif
  24
  25 /*
  26  * switch_to(prev, next, last) should switch from task `prev' to task
  27  * `next'. `prev' will never be the same as `next'.
  28  *
  29  * We just delegate everything to the __switch_to assembly function,
  30  * which is implemented in arch/avr32/kernel/switch_to.S
  31  *
  32  * mb() tells GCC not to cache `current' across this call.
  33  */
  34 struct cpu_context;
  35 struct task_struct;
  36 extern struct task_struct *__switch_to(struct task_struct *,
  37                                        struct cpu_context *,
  38                                        struct cpu_context *);
  39 #define switch_to(prev, next, last)                                     \
  40         do {                                                            \
  41                 last = __switch_to(prev, &prev->thread.cpu_context + 1, \
  42                                    &next->thread.cpu_context);          \
  43         } while (0)
  44
  45
  46 #endif /* __ASM_AVR32_SWITCH_TO_H */