include/asm-sh/system.h

   1 #ifndef __ASM_SH_SYSTEM_H
   2 #define __ASM_SH_SYSTEM_H
   3
   4 /*
   5  * Copyright (C) 1999, 2000  Niibe Yutaka  &  Kaz Kojima
   6  * Copyright (C) 2002 Paul Mundt
   7  */
   8
   9 #include <linux/irqflags.h>
  10 #include <linux/compiler.h>
  11 #include <asm/types.h>
  12
  13 /*
  14  *      switch_to() should switch tasks to task nr n, first
  15  */
  16
  17 #define switch_to(prev, next, last) do {                                \
  18  struct task_struct *__last;                                            \
  19  register unsigned long *__ts1 __asm__ ("r1") = &prev->thread.sp;       \
  20  register unsigned long *__ts2 __asm__ ("r2") = &prev->thread.pc;       \
  21  register unsigned long *__ts4 __asm__ ("r4") = (unsigned long *)prev;  \
  22  register unsigned long *__ts5 __asm__ ("r5") = (unsigned long *)next;  \
  23  register unsigned long *__ts6 __asm__ ("r6") = &next->thread.sp;       \
  24  register unsigned long __ts7 __asm__ ("r7") = next->thread.pc;         \
  25  __asm__ __volatile__ (".balign 4\n\t"                                  \
  26                        "stc.l   gbr, @-r15\n\t"                         \
  27                        "sts.l   pr, @-r15\n\t"                          \
  28                        "mov.l   r8, @-r15\n\t"                          \
  29                        "mov.l   r9, @-r15\n\t"                          \
  30                        "mov.l   r10, @-r15\n\t"                         \
  31                        "mov.l   r11, @-r15\n\t"                         \
  32                        "mov.l   r12, @-r15\n\t"                         \
  33                        "mov.l   r13, @-r15\n\t"                         \
  34                        "mov.l   r14, @-r15\n\t"                         \
  35                        "mov.l   r15, @r1        ! save SP\n\t"          \
  36                        "mov.l   @r6, r15        ! change to new stack\n\t" \
  37                        "mova    1f, %0\n\t"                             \
  38                        "mov.l   %0, @r2         ! save PC\n\t"          \
  39                        "mov.l   2f, %0\n\t"                             \
  40                        "jmp     @%0             ! call __switch_to\n\t" \
  41                        " lds    r7, pr          !  with return to new PC\n\t" \
  42                        ".balign 4\n"                                    \
  43                        "2:\n\t"                                         \
  44                        ".long   __switch_to\n"                          \
  45                        "1:\n\t"                                         \
  46                        "mov.l   @r15+, r14\n\t"                         \
  47                        "mov.l   @r15+, r13\n\t"                         \
  48                        "mov.l   @r15+, r12\n\t"                         \
  49                        "mov.l   @r15+, r11\n\t"                         \
  50                        "mov.l   @r15+, r10\n\t"                         \
  51                        "mov.l   @r15+, r9\n\t"                          \
  52                        "mov.l   @r15+, r8\n\t"                          \
  53                        "lds.l   @r15+, pr\n\t"                          \
  54                        "ldc.l   @r15+, gbr\n\t"                         \
  55                        : "=z" (__last)                                  \
  56                        : "r" (__ts1), "r" (__ts2), "r" (__ts4),         \
  57                          "r" (__ts5), "r" (__ts6), "r" (__ts7)          \
  58                        : "r3", "t");                                    \
  59         last = __last;                                                  \
  60 } while (0)
  61
  62 /*
  63  * On SMP systems, when the scheduler does migration-cost autodetection,
  64  * it needs a way to flush as much of the CPU's caches as possible.
  65  *
  66  * TODO: fill this in!
  67  */
  68 static inline void sched_cacheflush(void)
  69 {
  70 }
  71
  72 #ifdef CONFIG_CPU_SH4A
  73 #define __icbi()                        \
  74 {                                       \
  75         unsigned long __addr;           \
  76         __addr = 0xa8000000;            \
  77         __asm__ __volatile__(           \
  78                 "icbi   %0\n\t"         \
  79                 : /* no output */       \
  80                 : "m" (__m(__addr)));   \
  81 }
  82 #endif
  83
  84 static inline unsigned long tas(volatile int *m)
  85 {
  86         unsigned long retval;
  87
  88         __asm__ __volatile__ ("tas.b    @%1\n\t"
  89                               "movt     %0"
  90                               : "=r" (retval): "r" (m): "t", "memory");
  91         return retval;
  92 }
  93
  94 /*
  95  * A brief note on ctrl_barrier(), the control register write barrier.
  96  *
  97  * Legacy SH cores typically require a sequence of 8 nops after
  98  * modification of a control register in order for the changes to take
  99  * effect. On newer cores (like the sh4a and sh5) this is accomplished
 100  * with icbi.
 101  *
 102  * Also note that on sh4a in the icbi case we can forego a synco for the
 103  * write barrier, as it's not necessary for control registers.
 104  *
 105  * Historically we have only done this type of barrier for the MMUCR, but
 106  * it's also necessary for the CCR, so we make it generic here instead.
 107  */
 108 #ifdef CONFIG_CPU_SH4A
 109 #define mb()            __asm__ __volatile__ ("synco": : :"memory")
 110 #define rmb()           mb()
 111 #define wmb()           __asm__ __volatile__ ("synco": : :"memory")
 112 #define ctrl_barrier()  __icbi()
 113 #define read_barrier_depends()  do { } while(0)
 114 #else
 115 #define mb()            __asm__ __volatile__ ("": : :"memory")
 116 #define rmb()           mb()
 117 #define wmb()           __asm__ __volatile__ ("": : :"memory")
 118 #define ctrl_barrier()  __asm__ __volatile__ ("nop;nop;nop;nop;nop;nop;nop;nop")
 119 #define read_barrier_depends()  do { } while(0)
 120 #endif
 121
 122 #ifdef CONFIG_SMP
 123 #define smp_mb()        mb()
 124 #define smp_rmb()       rmb()
 125 #define smp_wmb()       wmb()
 126 #define smp_read_barrier_depends()      read_barrier_depends()
 127 #else
 128 #define smp_mb()        barrier()
 129 #define smp_rmb()       barrier()
 130 #define smp_wmb()       barrier()
 131 #define smp_read_barrier_depends()      do { } while(0)
 132 #endif
 133
 134 #define set_mb(var, value) do { xchg(&var, value); } while (0)
 135
 136 /*
 137  * Jump to P2 area.
 138  * When handling TLB or caches, we need to do it from P2 area.
 139  */
 140 #define jump_to_P2()                    \
 141 do {                                    \
 142         unsigned long __dummy;          \
 143         __asm__ __volatile__(           \
 144                 "mov.l  1f, %0\n\t"     \
 145                 "or     %1, %0\n\t"     \
 146                 "jmp    @%0\n\t"        \
 147                 " nop\n\t"              \
 148                 ".balign 4\n"           \
 149                 "1:     .long 2f\n"     \
 150                 "2:"                    \
 151                 : "=&r" (__dummy)       \
 152                 : "r" (0x20000000));    \
 153 } while (0)
 154
 155 /*
 156  * Back to P1 area.
 157  */
 158 #define back_to_P1()                                    \
 159 do {                                                    \
 160         unsigned long __dummy;                          \
 161         ctrl_barrier();                                 \
 162         __asm__ __volatile__(                           \
 163                 "mov.l  1f, %0\n\t"                     \
 164                 "jmp    @%0\n\t"                        \
 165                 " nop\n\t"                              \
 166                 ".balign 4\n"                           \
 167                 "1:     .long 2f\n"                     \
 168                 "2:"                                    \
 169                 : "=&r" (__dummy));                     \
 170 } while (0)
 171
 172 static inline unsigned long xchg_u32(volatile u32 *m, unsigned long val)
 173 {
 174         unsigned long flags, retval;
 175
 176         local_irq_save(flags);
 177         retval = *m;
 178         *m = val;
 179         local_irq_restore(flags);
 180         return retval;
 181 }
 182
 183 static inline unsigned long xchg_u8(volatile u8 *m, unsigned long val)
 184 {
 185         unsigned long flags, retval;
 186
 187         local_irq_save(flags);
 188         retval = *m;
 189         *m = val & 0xff;
 190         local_irq_restore(flags);
 191         return retval;
 192 }
 193
 194 extern void __xchg_called_with_bad_pointer(void);
 195
 196 #define __xchg(ptr, x, size)                            \
 197 ({                                                      \
 198         unsigned long __xchg__res;                      \
 199         volatile void *__xchg_ptr = (ptr);              \
 200         switch (size) {                                 \
 201         case 4:                                         \
 202                 __xchg__res = xchg_u32(__xchg_ptr, x);  \
 203                 break;                                  \
 204         case 1:                                         \
 205                 __xchg__res = xchg_u8(__xchg_ptr, x);   \
 206                 break;                                  \
 207         default:                                        \
 208                 __xchg_called_with_bad_pointer();       \
 209                 __xchg__res = x;                        \
 210                 break;                                  \
 211         }                                               \
 212                                                         \
 213         __xchg__res;                                    \
 214 })
 215
 216 #define xchg(ptr,x)     \
 217         ((__typeof__(*(ptr)))__xchg((ptr),(unsigned long)(x), sizeof(*(ptr))))
 218
 219 static inline unsigned long __cmpxchg_u32(volatile int * m, unsigned long old,
 220         unsigned long new)
 221 {
 222         __u32 retval;
 223         unsigned long flags;
 224
 225         local_irq_save(flags);
 226         retval = *m;
 227         if (retval == old)
 228                 *m = new;
 229         local_irq_restore(flags);       /* implies memory barrier  */
 230         return retval;
 231 }
 232
 233 /* This function doesn't exist, so you'll get a linker error
 234  * if something tries to do an invalid cmpxchg(). */
 235 extern void __cmpxchg_called_with_bad_pointer(void);
 236
 237 #define __HAVE_ARCH_CMPXCHG 1
 238
 239 static inline unsigned long __cmpxchg(volatile void * ptr, unsigned long old,
 240                 unsigned long new, int size)
 241 {
 242         switch (size) {
 243         case 4:
 244                 return __cmpxchg_u32(ptr, old, new);
 245         }
 246         __cmpxchg_called_with_bad_pointer();
 247         return old;
 248 }
 249
 250 #define cmpxchg(ptr,o,n)                                                 \
 251   ({                                                                     \
 252      __typeof__(*(ptr)) _o_ = (o);                                       \
 253      __typeof__(*(ptr)) _n_ = (n);                                       \
 254      (__typeof__(*(ptr))) __cmpxchg((ptr), (unsigned long)_o_,           \
 255                                     (unsigned long)_n_, sizeof(*(ptr))); \
 256   })
 257
 258 extern void *set_exception_table_vec(unsigned int vec, void *handler);
 259
 260 static inline void *set_exception_table_evt(unsigned int evt, void *handler)
 261 {
 262         return set_exception_table_vec(evt >> 5, handler);
 263 }
 264
 265 /* XXX
 266  * disable hlt during certain critical i/o operations
 267  */
 268 #define HAVE_DISABLE_HLT
 269 void disable_hlt(void);
 270 void enable_hlt(void);
 271
 272 #define arch_align_stack(x) (x)
 273
 274 #endif