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/api.h>
  12 #include <asm/ptrace.h>
  13 #include <asm/guarded_storage.h>
  14
  15 extern struct task_struct *__switch_to(void *, void *);
  16 extern void update_cr_regs(struct task_struct *task);
  17
  18 static inline void save_access_regs(unsigned int *acrs)
  19 {
  20         typedef struct { int _[NUM_ACRS]; } acrstype;
  21
  22         asm volatile("stam 0,15,%0" : "=Q" (*(acrstype *)acrs));
  23 }
  24
  25 static inline void restore_access_regs(unsigned int *acrs)
  26 {
  27         typedef struct { int _[NUM_ACRS]; } acrstype;
  28
  29         asm volatile("lam 0,15,%0" : : "Q" (*(acrstype *)acrs));
  30 }
  31
  32 #define switch_to(prev,next,last) do {                                  \
  33         if (prev->mm) {                                                 \
  34                 save_fpu_regs();                                        \
  35                 save_access_regs(&prev->thread.acrs[0]);                \
  36                 save_ri_cb(prev->thread.ri_cb);                         \
  37                 save_gs_cb(prev->thread.gs_cb);                         \
  38         }                                                               \
  39         if (next->mm) {                                                 \
  40                 update_cr_regs(next);                                   \
  41                 set_cpu_flag(CIF_FPU);                                  \
  42                 restore_access_regs(&next->thread.acrs[0]);             \
  43                 restore_ri_cb(next->thread.ri_cb, prev->thread.ri_cb);  \
  44                 restore_gs_cb(next->thread.gs_cb);                      \
  45         }                                                               \
  46         prev = __switch_to(prev,next);                                  \
  47 } while (0)
  48
  49 #endif /* __ASM_SWITCH_TO_H */