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
  12 extern struct task_struct *__switch_to(void *, void *);
  13 extern void update_per_regs(struct task_struct *task);
  14
  15 static inline void save_fp_regs(s390_fp_regs *fpregs)
  16 {
  17         asm volatile(
  18                 "       std     0,%O0+8(%R0)\n"
  19                 "       std     2,%O0+24(%R0)\n"
  20                 "       std     4,%O0+40(%R0)\n"
  21                 "       std     6,%O0+56(%R0)"
  22                 : "=Q" (*fpregs) : "Q" (*fpregs));
  23         if (!MACHINE_HAS_IEEE)
  24                 return;
  25         asm volatile(
  26                 "       stfpc   %0\n"
  27                 "       std     1,%O0+16(%R0)\n"
  28                 "       std     3,%O0+32(%R0)\n"
  29                 "       std     5,%O0+48(%R0)\n"
  30                 "       std     7,%O0+64(%R0)\n"
  31                 "       std     8,%O0+72(%R0)\n"
  32                 "       std     9,%O0+80(%R0)\n"
  33                 "       std     10,%O0+88(%R0)\n"
  34                 "       std     11,%O0+96(%R0)\n"
  35                 "       std     12,%O0+104(%R0)\n"
  36                 "       std     13,%O0+112(%R0)\n"
  37                 "       std     14,%O0+120(%R0)\n"
  38                 "       std     15,%O0+128(%R0)\n"
  39                 : "=Q" (*fpregs) : "Q" (*fpregs));
  40 }
  41
  42 static inline void restore_fp_regs(s390_fp_regs *fpregs)
  43 {
  44         asm volatile(
  45                 "       ld      0,%O0+8(%R0)\n"
  46                 "       ld      2,%O0+24(%R0)\n"
  47                 "       ld      4,%O0+40(%R0)\n"
  48                 "       ld      6,%O0+56(%R0)"
  49                 : : "Q" (*fpregs));
  50         if (!MACHINE_HAS_IEEE)
  51                 return;
  52         asm volatile(
  53                 "       lfpc    %0\n"
  54                 "       ld      1,%O0+16(%R0)\n"
  55                 "       ld      3,%O0+32(%R0)\n"
  56                 "       ld      5,%O0+48(%R0)\n"
  57                 "       ld      7,%O0+64(%R0)\n"
  58                 "       ld      8,%O0+72(%R0)\n"
  59                 "       ld      9,%O0+80(%R0)\n"
  60                 "       ld      10,%O0+88(%R0)\n"
  61                 "       ld      11,%O0+96(%R0)\n"
  62                 "       ld      12,%O0+104(%R0)\n"
  63                 "       ld      13,%O0+112(%R0)\n"
  64                 "       ld      14,%O0+120(%R0)\n"
  65                 "       ld      15,%O0+128(%R0)\n"
  66                 : : "Q" (*fpregs));
  67 }
  68
  69 static inline void save_access_regs(unsigned int *acrs)
  70 {
  71         asm volatile("stam 0,15,%0" : "=Q" (*acrs));
  72 }
  73
  74 static inline void restore_access_regs(unsigned int *acrs)
  75 {
  76         asm volatile("lam 0,15,%0" : : "Q" (*acrs));
  77 }
  78
  79 #define switch_to(prev,next,last) do {                                  \
  80         if (prev->mm) {                                                 \
  81                 save_fp_regs(&prev->thread.fp_regs);                    \
  82                 save_access_regs(&prev->thread.acrs[0]);                \
  83         }                                                               \
  84         if (next->mm) {                                                 \
  85                 restore_fp_regs(&next->thread.fp_regs);                 \
  86                 restore_access_regs(&next->thread.acrs[0]);             \
  87                 update_per_regs(next);                                  \
  88         }                                                               \
  89         prev = __switch_to(prev,next);                                  \
  90 } while (0)
  91
  92 #define finish_arch_switch(prev) do {                                        \
  93         set_fs(current->thread.mm_segment);                                  \
  94 } while (0)
  95
  96 #endif /* __ASM_SWITCH_TO_H */