arch/blackfin/include/asm/switch_to.h

   1 /*
   2  * Copyright 2004-2009 Analog Devices Inc.
   3  *               Tony Kou (tonyko@lineo.ca)
   4  *
   5  * Licensed under the GPL-2 or later
   6  */
   7
   8 #ifndef _BLACKFIN_SWITCH_TO_H
   9 #define _BLACKFIN_SWITCH_TO_H
  10
  11 #define prepare_to_switch()     do { } while(0)
  12
  13 /*
  14  * switch_to(n) should switch tasks to task ptr, first checking that
  15  * ptr isn't the current task, in which case it does nothing.
  16  */
  17
  18 #include <asm/l1layout.h>
  19 #include <asm/mem_map.h>
  20
  21 asmlinkage struct task_struct *resume(struct task_struct *prev, struct task_struct *next);
  22
  23 #ifndef CONFIG_SMP
  24 #define switch_to(prev,next,last) \
  25 do {    \
  26         memcpy (&task_thread_info(prev)->l1_task_info, L1_SCRATCH_TASK_INFO, \
  27                 sizeof *L1_SCRATCH_TASK_INFO); \
  28         memcpy (L1_SCRATCH_TASK_INFO, &task_thread_info(next)->l1_task_info, \
  29                 sizeof *L1_SCRATCH_TASK_INFO); \
  30         (last) = resume (prev, next);   \
  31 } while (0)
  32 #else
  33 #define switch_to(prev, next, last) \
  34 do {    \
  35         (last) = resume(prev, next);   \
  36 } while (0)
  37 #endif
  38
  39 #endif /* _BLACKFIN_SWITCH_TO_H */