arch/s390/include/asm/switch_to.h

   1 /*
   2  * Copyright IBM Corp. 1999, 2009
   3  *
   4  * Author(s): Martin Schwidefsky <schwidefsky@de.ibm.com>
   5  */
   6
   7 #ifndef __ASM_SWITCH_TO_H
   8 #define __ASM_SWITCH_TO_H
   9
  10 #include <linux/thread_info.h>
  11 #include <asm/fpu-internal.h>
  12 #include <asm/ptrace.h>
  13
  14 extern struct task_struct *__switch_to(void *, void *);
  15 extern void update_cr_regs(struct task_struct *task);
  16
  17 static inline void save_access_regs(unsigned int *acrs)
  18 {
  19         typedef struct { int _[NUM_ACRS]; } acrstype;
  20
  21         asm volatile("stam 0,15,%0" : "=Q" (*(acrstype *)acrs));
  22 }
  23
  24 static inline void restore_access_regs(unsigned int *acrs)
  25 {
  26         typedef struct { int _[NUM_ACRS]; } acrstype;
  27
  28         asm volatile("lam 0,15,%0" : : "Q" (*(acrstype *)acrs));
  29 }
  30
  31 #define switch_to(prev,next,last) do {                                  \
  32         if (prev->mm) {                                                 \
  33                 save_fpu_regs();                                        \
  34                 save_access_regs(&prev->thread.acrs[0]);                \
  35                 save_ri_cb(prev->thread.ri_cb);                         \
  36         }                                                               \
  37         if (next->mm) {                                                 \
  38                 update_cr_regs(next);                                   \
  39                 set_cpu_flag(CIF_FPU);                                  \
  40                 restore_access_regs(&next->thread.acrs[0]);             \
  41                 restore_ri_cb(next->thread.ri_cb, prev->thread.ri_cb);  \
  42         }                                                               \
  43         prev = __switch_to(prev,next);                                  \
  44 } while (0)
  45
  46 #endif /* __ASM_SWITCH_TO_H */