arch/arm/include/asm/switch_to.h

   1 #ifndef __ASM_ARM_SWITCH_TO_H
   2 #define __ASM_ARM_SWITCH_TO_H
   3
   4 #include <linux/thread_info.h>
   5
   6 /*
   7  * For v7 SMP cores running a preemptible kernel we may be pre-empted
   8  * during a TLB maintenance operation, so execute an inner-shareable dsb
   9  * to ensure that the maintenance completes in case we migrate to another
  10  * CPU.
  11  */
  12 #if defined(CONFIG_PREEMPT) && defined(CONFIG_SMP) && defined(CONFIG_CPU_V7)
  13 #define __complete_pending_tlbi()       dsb(ish)
  14 #else
  15 #define __complete_pending_tlbi()
  16 #endif
  17
  18 /*
  19  * switch_to(prev, next) should switch from task `prev' to `next'
  20  * `prev' will never be the same as `next'.  schedule() itself
  21  * contains the memory barrier to tell GCC not to cache `current'.
  22  */
  23 extern struct task_struct *__switch_to(struct task_struct *, struct thread_info *, struct thread_info *);
  24
  25 #define switch_to(prev,next,last)                                       \
  26 do {                                                                    \
  27         __complete_pending_tlbi();                                      \
  28         last = __switch_to(prev,task_thread_info(prev), task_thread_info(next));        \
  29 } while (0)
  30
  31 #endif /* __ASM_ARM_SWITCH_TO_H */