arch/sh/include/asm/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  * from linux kernel code.
   9  */
  10
  11 #include <asm/irqflags.h>
  12 #include <asm/types.h>
  13
  14 /*
  15  *      switch_to() should switch tasks to task nr n, first
  16  */
  17
  18 #define switch_to(prev, next, last) do {                                \
  19  struct task_struct *__last;                                            \
  20  register unsigned long *__ts1 __asm__ ("r1") = &prev->thread.sp;       \
  21  register unsigned long *__ts2 __asm__ ("r2") = &prev->thread.pc;       \
  22  register unsigned long *__ts4 __asm__ ("r4") = (unsigned long *)prev;  \
  23  register unsigned long *__ts5 __asm__ ("r5") = (unsigned long *)next;  \
  24  register unsigned long *__ts6 __asm__ ("r6") = &next->thread.sp;       \
  25  register unsigned long __ts7 __asm__ ("r7") = next->thread.pc;         \
  26  __asm__ __volatile__ (".balign 4\n\t"                                  \
  27                        "stc.l   gbr, @-r15\n\t"                         \
  28                        "sts.l   pr, @-r15\n\t"                          \
  29                        "mov.l   r8, @-r15\n\t"                          \
  30                        "mov.l   r9, @-r15\n\t"                          \
  31                        "mov.l   r10, @-r15\n\t"                         \
  32                        "mov.l   r11, @-r15\n\t"                         \
  33                        "mov.l   r12, @-r15\n\t"                         \
  34                        "mov.l   r13, @-r15\n\t"                         \
  35                        "mov.l   r14, @-r15\n\t"                         \
  36                        "mov.l   r15, @r1        ! save SP\n\t"          \
  37                        "mov.l   @r6, r15        ! change to new stack\n\t" \
  38                        "mova    1f, %0\n\t"                             \
  39                        "mov.l   %0, @r2         ! save PC\n\t"          \
  40                        "mov.l   2f, %0\n\t"                             \
  41                        "jmp     @%0             ! call __switch_to\n\t" \
  42                        " lds    r7, pr          !  with return to new PC\n\t" \
  43                        ".balign 4\n"                                    \
  44                        "2:\n\t"                                         \
  45                        ".long   __switch_to\n"                          \
  46                        "1:\n\t"                                         \
  47                        "mov.l   @r15+, r14\n\t"                         \
  48                        "mov.l   @r15+, r13\n\t"                         \
  49                        "mov.l   @r15+, r12\n\t"                         \
  50                        "mov.l   @r15+, r11\n\t"                         \
  51                        "mov.l   @r15+, r10\n\t"                         \
  52                        "mov.l   @r15+, r9\n\t"                          \
  53                        "mov.l   @r15+, r8\n\t"                          \
  54                        "lds.l   @r15+, pr\n\t"                          \
  55                        "ldc.l   @r15+, gbr\n\t"                         \
  56                        : "=z" (__last)                                  \
  57                        : "r" (__ts1), "r" (__ts2), "r" (__ts4),         \
  58                          "r" (__ts5), "r" (__ts6), "r" (__ts7)          \
  59                        : "r3", "t");                                    \
  60         last = __last;                                                  \
  61 } while (0)
  62
  63 /*
  64  * On SMP systems, when the scheduler does migration-cost autodetection,
  65  * it needs a way to flush as much of the CPU's caches as possible.
  66  *
  67  * TODO: fill this in!
  68  */
  69 static inline void sched_cacheflush(void)
  70 {
  71 }
  72
  73 #ifdef CONFIG_CPU_SH4A
  74 #define __icbi()                        \
  75 {                                       \
  76         unsigned long __addr;           \
  77         __addr = 0xa8000000;            \
  78         __asm__ __volatile__(           \
  79                 "icbi   %0\n\t"         \
  80                 : /* no output */       \
  81                 : "m" (__m(__addr)));   \
  82 }
  83 #endif
  84
  85 static inline unsigned long tas(volatile int *m)
  86 {
  87         unsigned long retval;
  88
  89         __asm__ __volatile__ ("tas.b    @%1\n\t"
  90                               "movt     %0"
  91                               : "=r" (retval): "r" (m): "t", "memory");
  92         return retval;
  93 }
  94
  95 /*
  96  * A brief note on ctrl_barrier(), the control register write barrier.
  97  *
  98  * Legacy SH cores typically require a sequence of 8 nops after
  99  * modification of a control register in order for the changes to take
 100  * effect. On newer cores (like the sh4a and sh5) this is accomplished
 101  * with icbi.
 102  *
 103  * Also note that on sh4a in the icbi case we can forego a synco for the
 104  * write barrier, as it's not necessary for control registers.
 105  *
 106  * Historically we have only done this type of barrier for the MMUCR, but
 107  * it's also necessary for the CCR, so we make it generic here instead.
 108  */
 109 #ifdef CONFIG_CPU_SH4A
 110 #define mb()            __asm__ __volatile__ ("synco": : :"memory")
 111 #define rmb()           mb()
 112 #define wmb()           __asm__ __volatile__ ("synco": : :"memory")
 113 #define ctrl_barrier()  __icbi()
 114 #define read_barrier_depends()  do { } while(0)
 115 #else
 116 #define mb()            __asm__ __volatile__ ("": : :"memory")
 117 #define rmb()           mb()
 118 #define wmb()           __asm__ __volatile__ ("": : :"memory")
 119 #define ctrl_barrier()  __asm__ __volatile__ ("nop;nop;nop;nop;nop;nop;nop;nop")
 120 #define read_barrier_depends()  do { } while(0)
 121 #endif
 122
 123 #ifdef CONFIG_SMP
 124 #define smp_mb()        mb()
 125 #define smp_rmb()       rmb()
 126 #define smp_wmb()       wmb()
 127 #define smp_read_barrier_depends()      read_barrier_depends()
 128 #else
 129 #define smp_mb()        barrier()
 130 #define smp_rmb()       barrier()
 131 #define smp_wmb()       barrier()
 132 #define smp_read_barrier_depends()      do { } while(0)
 133 #endif
 134
 135 #define set_mb(var, value) do { xchg(&var, value); } while (0)
 136
 137 /*
 138  * Jump to P2 area.
 139  * When handling TLB or caches, we need to do it from P2 area.
 140  */
 141 #define jump_to_P2()                    \
 142 do {                                    \
 143         unsigned long __dummy;          \
 144         __asm__ __volatile__(           \
 145                 "mov.l  1f, %0\n\t"     \
 146                 "or     %1, %0\n\t"     \
 147                 "jmp    @%0\n\t"        \
 148                 " nop\n\t"              \
 149                 ".balign 4\n"           \
 150                 "1:     .long 2f\n"     \
 151                 "2:"                    \
 152                 : "=&r" (__dummy)       \
 153                 : "r" (0x20000000));    \
 154 } while (0)
 155
 156 /*
 157  * Back to P1 area.
 158  */
 159 #define back_to_P1()                                    \
 160 do {                                                    \
 161         unsigned long __dummy;                          \
 162         ctrl_barrier();                                 \
 163         __asm__ __volatile__(                           \
 164                 "mov.l  1f, %0\n\t"                     \
 165                 "jmp    @%0\n\t"                        \
 166                 " nop\n\t"                              \
 167                 ".balign 4\n"                           \
 168                 "1:     .long 2f\n"                     \
 169                 "2:"                                    \
 170                 : "=&r" (__dummy));                     \
 171 } while (0)
 172
 173 static inline unsigned long xchg_u32(volatile u32 *m, unsigned long val)
 174 {
 175         unsigned long flags, retval;
 176
 177         local_irq_save(flags);
 178         retval = *m;
 179         *m = val;
 180         local_irq_restore(flags);
 181         return retval;
 182 }
 183
 184 static inline unsigned long xchg_u8(volatile u8 *m, unsigned long val)
 185 {
 186         unsigned long flags, retval;
 187
 188         local_irq_save(flags);
 189         retval = *m;
 190         *m = val & 0xff;
 191         local_irq_restore(flags);
 192         return retval;
 193 }
 194
 195 extern void __xchg_called_with_bad_pointer(void);
 196
 197 #define __xchg(ptr, x, size)                            \
 198 ({                                                      \
 199         unsigned long __xchg__res;                      \
 200         volatile void *__xchg_ptr = (ptr);              \
 201         switch (size) {                                 \
 202         case 4:                                         \
 203                 __xchg__res = xchg_u32(__xchg_ptr, x);  \
 204                 break;                                  \
 205         case 1:                                         \
 206                 __xchg__res = xchg_u8(__xchg_ptr, x);   \
 207                 break;                                  \
 208         default:                                        \
 209                 __xchg_called_with_bad_pointer();       \
 210                 __xchg__res = x;                        \
 211                 break;                                  \
 212         }                                               \
 213                                                         \
 214         __xchg__res;                                    \
 215 })
 216
 217 #define xchg(ptr,x)     \
 218         ((__typeof__(*(ptr)))__xchg((ptr),(unsigned long)(x), sizeof(*(ptr))))
 219
 220 static inline unsigned long __cmpxchg_u32(volatile int * m, unsigned long old,
 221         unsigned long new)
 222 {
 223         __u32 retval;
 224         unsigned long flags;
 225
 226         local_irq_save(flags);
 227         retval = *m;
 228         if (retval == old)
 229                 *m = new;
 230         local_irq_restore(flags);       /* implies memory barrier  */
 231         return retval;
 232 }
 233
 234 /* This function doesn't exist, so you'll get a linker error
 235  * if something tries to do an invalid cmpxchg(). */
 236 extern void __cmpxchg_called_with_bad_pointer(void);
 237
 238 #define __HAVE_ARCH_CMPXCHG 1
 239
 240 static inline unsigned long __cmpxchg(volatile void * ptr, unsigned long old,
 241                 unsigned long new, int size)
 242 {
 243         switch (size) {
 244         case 4:
 245                 return __cmpxchg_u32(ptr, old, new);
 246         }
 247         __cmpxchg_called_with_bad_pointer();
 248         return old;
 249 }
 250
 251 #define cmpxchg(ptr,o,n)                                                 \
 252   ({                                                                     \
 253      __typeof__(*(ptr)) _o_ = (o);                                       \
 254      __typeof__(*(ptr)) _n_ = (n);                                       \
 255      (__typeof__(*(ptr))) __cmpxchg((ptr), (unsigned long)_o_,           \
 256                                     (unsigned long)_n_, sizeof(*(ptr))); \
 257   })
 258
 259 extern void *set_exception_table_vec(unsigned int vec, void *handler);
 260
 261 static inline void *set_exception_table_evt(unsigned int evt, void *handler)
 262 {
 263         return set_exception_table_vec(evt >> 5, handler);
 264 }
 265
 266 /* XXX
 267  * disable hlt during certain critical i/o operations
 268  */
 269 #define HAVE_DISABLE_HLT
 270 void disable_hlt(void);
 271 void enable_hlt(void);
 272
 273 #define arch_align_stack(x) (x)
 274
 275 static inline void trigger_address_error(void)
 276 {
 277         set_bl_bit();
 278         __asm__ __volatile__ (
 279                 "mov.l @%1, %0"
 280                 :
 281                 : "r" (0x10000000), "r" (0x80000001)
 282         );
 283 }
 284
 285 #endif