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/ptrace.h>
  12
  13 extern struct task_struct *__switch_to(void *, void *);
  14 extern void update_cr_regs(struct task_struct *task);
  15
  16 static inline int test_fp_ctl(u32 fpc)
  17 {
  18         u32 orig_fpc;
  19         int rc;
  20
  21         if (!MACHINE_HAS_IEEE)
  22                 return 0;
  23
  24         asm volatile(
  25                 "       efpc    %1\n"
  26                 "       sfpc    %2\n"
  27                 "0:     sfpc    %1\n"
  28                 "       la      %0,0\n"
  29                 "1:\n"
  30                 EX_TABLE(0b,1b)
  31                 : "=d" (rc), "=d" (orig_fpc)
  32                 : "d" (fpc), "0" (-EINVAL));
  33         return rc;
  34 }
  35
  36 static inline void save_fp_ctl(u32 *fpc)
  37 {
  38         if (!MACHINE_HAS_IEEE)
  39                 return;
  40
  41         asm volatile(
  42                 "       stfpc   %0\n"
  43                 : "+Q" (*fpc));
  44 }
  45
  46 static inline int restore_fp_ctl(u32 *fpc)
  47 {
  48         int rc;
  49
  50         if (!MACHINE_HAS_IEEE)
  51                 return 0;
  52
  53         asm volatile(
  54                 "0:     lfpc    %1\n"
  55                 "       la      %0,0\n"
  56                 "1:\n"
  57                 EX_TABLE(0b,1b)
  58                 : "=d" (rc) : "Q" (*fpc), "0" (-EINVAL));
  59         return rc;
  60 }
  61
  62 static inline void save_fp_regs(freg_t *fprs)
  63 {
  64         asm volatile("std 0,%0" : "=Q" (fprs[0]));
  65         asm volatile("std 2,%0" : "=Q" (fprs[2]));
  66         asm volatile("std 4,%0" : "=Q" (fprs[4]));
  67         asm volatile("std 6,%0" : "=Q" (fprs[6]));
  68         if (!MACHINE_HAS_IEEE)
  69                 return;
  70         asm volatile("std 1,%0" : "=Q" (fprs[1]));
  71         asm volatile("std 3,%0" : "=Q" (fprs[3]));
  72         asm volatile("std 5,%0" : "=Q" (fprs[5]));
  73         asm volatile("std 7,%0" : "=Q" (fprs[7]));
  74         asm volatile("std 8,%0" : "=Q" (fprs[8]));
  75         asm volatile("std 9,%0" : "=Q" (fprs[9]));
  76         asm volatile("std 10,%0" : "=Q" (fprs[10]));
  77         asm volatile("std 11,%0" : "=Q" (fprs[11]));
  78         asm volatile("std 12,%0" : "=Q" (fprs[12]));
  79         asm volatile("std 13,%0" : "=Q" (fprs[13]));
  80         asm volatile("std 14,%0" : "=Q" (fprs[14]));
  81         asm volatile("std 15,%0" : "=Q" (fprs[15]));
  82 }
  83
  84 static inline void restore_fp_regs(freg_t *fprs)
  85 {
  86         asm volatile("ld 0,%0" : : "Q" (fprs[0]));
  87         asm volatile("ld 2,%0" : : "Q" (fprs[2]));
  88         asm volatile("ld 4,%0" : : "Q" (fprs[4]));
  89         asm volatile("ld 6,%0" : : "Q" (fprs[6]));
  90         if (!MACHINE_HAS_IEEE)
  91                 return;
  92         asm volatile("ld 1,%0" : : "Q" (fprs[1]));
  93         asm volatile("ld 3,%0" : : "Q" (fprs[3]));
  94         asm volatile("ld 5,%0" : : "Q" (fprs[5]));
  95         asm volatile("ld 7,%0" : : "Q" (fprs[7]));
  96         asm volatile("ld 8,%0" : : "Q" (fprs[8]));
  97         asm volatile("ld 9,%0" : : "Q" (fprs[9]));
  98         asm volatile("ld 10,%0" : : "Q" (fprs[10]));
  99         asm volatile("ld 11,%0" : : "Q" (fprs[11]));
 100         asm volatile("ld 12,%0" : : "Q" (fprs[12]));
 101         asm volatile("ld 13,%0" : : "Q" (fprs[13]));
 102         asm volatile("ld 14,%0" : : "Q" (fprs[14]));
 103         asm volatile("ld 15,%0" : : "Q" (fprs[15]));
 104 }
 105
 106 static inline void save_access_regs(unsigned int *acrs)
 107 {
 108         typedef struct { int _[NUM_ACRS]; } acrstype;
 109
 110         asm volatile("stam 0,15,%0" : "=Q" (*(acrstype *)acrs));
 111 }
 112
 113 static inline void restore_access_regs(unsigned int *acrs)
 114 {
 115         typedef struct { int _[NUM_ACRS]; } acrstype;
 116
 117         asm volatile("lam 0,15,%0" : : "Q" (*(acrstype *)acrs));
 118 }
 119
 120 #define switch_to(prev,next,last) do {                                  \
 121         if (prev->mm) {                                                 \
 122                 save_fp_ctl(&prev->thread.fp_regs.fpc);                 \
 123                 save_fp_regs(prev->thread.fp_regs.fprs);                \
 124                 save_access_regs(&prev->thread.acrs[0]);                \
 125                 save_ri_cb(prev->thread.ri_cb);                         \
 126         }                                                               \
 127         if (next->mm) {                                                 \
 128                 restore_fp_ctl(&next->thread.fp_regs.fpc);              \
 129                 restore_fp_regs(next->thread.fp_regs.fprs);             \
 130                 restore_access_regs(&next->thread.acrs[0]);             \
 131                 restore_ri_cb(next->thread.ri_cb, prev->thread.ri_cb);  \
 132                 update_cr_regs(next);                                   \
 133         }                                                               \
 134         prev = __switch_to(prev,next);                                  \
 135 } while (0)
 136
 137 #define finish_arch_switch(prev) do {                                        \
 138         set_fs(current->thread.mm_segment);                                  \
 139 } while (0)
 140
 141 #endif /* __ASM_SWITCH_TO_H */