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 <asm/types.h>
  10
  11 /*
  12  *      switch_to() should switch tasks to task nr n, first
  13  */
  14
  15 #define switch_to(prev, next, last) do {                                \
  16  struct task_struct *__last;                                            \
  17  register unsigned long *__ts1 __asm__ ("r1") = &prev->thread.sp;       \
  18  register unsigned long *__ts2 __asm__ ("r2") = &prev->thread.pc;       \
  19  register unsigned long *__ts4 __asm__ ("r4") = (unsigned long *)prev;  \
  20  register unsigned long *__ts5 __asm__ ("r5") = (unsigned long *)next;  \
  21  register unsigned long *__ts6 __asm__ ("r6") = &next->thread.sp;       \
  22  register unsigned long __ts7 __asm__ ("r7") = next->thread.pc;         \
  23  __asm__ __volatile__ (".balign 4\n\t"                                  \
  24                        "stc.l   gbr, @-r15\n\t"                         \
  25                        "sts.l   pr, @-r15\n\t"                          \
  26                        "mov.l   r8, @-r15\n\t"                          \
  27                        "mov.l   r9, @-r15\n\t"                          \
  28                        "mov.l   r10, @-r15\n\t"                         \
  29                        "mov.l   r11, @-r15\n\t"                         \
  30                        "mov.l   r12, @-r15\n\t"                         \
  31                        "mov.l   r13, @-r15\n\t"                         \
  32                        "mov.l   r14, @-r15\n\t"                         \
  33                        "mov.l   r15, @r1        ! save SP\n\t"          \
  34                        "mov.l   @r6, r15        ! change to new stack\n\t" \
  35                        "mova    1f, %0\n\t"                             \
  36                        "mov.l   %0, @r2         ! save PC\n\t"          \
  37                        "mov.l   2f, %0\n\t"                             \
  38                        "jmp     @%0             ! call __switch_to\n\t" \
  39                        " lds    r7, pr          !  with return to new PC\n\t" \
  40                        ".balign 4\n"                                    \
  41                        "2:\n\t"                                         \
  42                        ".long   __switch_to\n"                          \
  43                        "1:\n\t"                                         \
  44                        "mov.l   @r15+, r14\n\t"                         \
  45                        "mov.l   @r15+, r13\n\t"                         \
  46                        "mov.l   @r15+, r12\n\t"                         \
  47                        "mov.l   @r15+, r11\n\t"                         \
  48                        "mov.l   @r15+, r10\n\t"                         \
  49                        "mov.l   @r15+, r9\n\t"                          \
  50                        "mov.l   @r15+, r8\n\t"                          \
  51                        "lds.l   @r15+, pr\n\t"                          \
  52                        "ldc.l   @r15+, gbr\n\t"                         \
  53                        : "=z" (__last)                                  \
  54                        : "r" (__ts1), "r" (__ts2), "r" (__ts4),         \
  55                          "r" (__ts5), "r" (__ts6), "r" (__ts7)          \
  56                        : "r3", "t");                                    \
  57         last = __last;                                                  \
  58 } while (0)
  59
  60 /*
  61  * On SMP systems, when the scheduler does migration-cost autodetection,
  62  * it needs a way to flush as much of the CPU's caches as possible.
  63  *
  64  * TODO: fill this in!
  65  */
  66 static inline void sched_cacheflush(void)
  67 {
  68 }
  69
  70 #ifdef CONFIG_CPU_SH4A
  71 #define __icbi()                        \
  72 {                                       \
  73         unsigned long __addr;           \
  74         __addr = 0xa8000000;            \
  75         __asm__ __volatile__(           \
  76                 "icbi   %0\n\t"         \
  77                 : /* no output */       \
  78                 : "m" (__m(__addr)));   \
  79 }
  80 #endif
  81
  82 static inline unsigned long tas(volatile int *m)
  83 {
  84         unsigned long retval;
  85
  86         __asm__ __volatile__ ("tas.b    @%1\n\t"
  87                               "movt     %0"
  88                               : "=r" (retval): "r" (m): "t", "memory");
  89         return retval;
  90 }
  91
  92 /*
  93  * A brief note on ctrl_barrier(), the control register write barrier.
  94  *
  95  * Legacy SH cores typically require a sequence of 8 nops after
  96  * modification of a control register in order for the changes to take
  97  * effect. On newer cores (like the sh4a and sh5) this is accomplished
  98  * with icbi.
  99  *
 100  * Also note that on sh4a in the icbi case we can forego a synco for the
 101  * write barrier, as it's not necessary for control registers.
 102  *
 103  * Historically we have only done this type of barrier for the MMUCR, but
 104  * it's also necessary for the CCR, so we make it generic here instead.
 105  */
 106 #ifdef CONFIG_CPU_SH4A
 107 #define mb()            __asm__ __volatile__ ("synco": : :"memory")
 108 #define rmb()           mb()
 109 #define wmb()           __asm__ __volatile__ ("synco": : :"memory")
 110 #define ctrl_barrier()  __icbi()
 111 #define read_barrier_depends()  do { } while(0)
 112 #else
 113 #define mb()            __asm__ __volatile__ ("": : :"memory")
 114 #define rmb()           mb()
 115 #define wmb()           __asm__ __volatile__ ("": : :"memory")
 116 #define ctrl_barrier()  __asm__ __volatile__ ("nop;nop;nop;nop;nop;nop;nop;nop")
 117 #define read_barrier_depends()  do { } while(0)
 118 #endif
 119
 120 #ifdef CONFIG_SMP
 121 #define smp_mb()        mb()
 122 #define smp_rmb()       rmb()
 123 #define smp_wmb()       wmb()
 124 #define smp_read_barrier_depends()      read_barrier_depends()
 125 #else
 126 #define smp_mb()        barrier()
 127 #define smp_rmb()       barrier()
 128 #define smp_wmb()       barrier()
 129 #define smp_read_barrier_depends()      do { } while(0)
 130 #endif
 131
 132 #define set_mb(var, value) do { xchg(&var, value); } while (0)
 133
 134 /* Interrupt Control */
 135 #ifdef CONFIG_CPU_HAS_SR_RB
 136 static inline void local_irq_enable(void)
 137 {
 138         unsigned long __dummy0, __dummy1;
 139
 140         __asm__ __volatile__("stc       sr, %0\n\t"
 141                              "and       %1, %0\n\t"
 142                              "stc       r6_bank, %1\n\t"
 143                              "or        %1, %0\n\t"
 144                              "ldc       %0, sr"
 145                              : "=&r" (__dummy0), "=r" (__dummy1)
 146                              : "1" (~0x000000f0)
 147                              : "memory");
 148 }
 149 #else
 150 static inline void local_irq_enable(void)
 151 {
 152         unsigned long __dummy0, __dummy1;
 153
 154         __asm__ __volatile__ (
 155                 "stc    sr, %0\n\t"
 156                 "and    %1, %0\n\t"
 157                 "ldc    %0, sr\n\t"
 158                 : "=&r" (__dummy0), "=r" (__dummy1)
 159                 : "1" (~0x000000f0)
 160                 : "memory");
 161 }
 162 #endif
 163
 164 static inline void local_irq_disable(void)
 165 {
 166         unsigned long __dummy;
 167         __asm__ __volatile__("stc       sr, %0\n\t"
 168                              "or        #0xf0, %0\n\t"
 169                              "ldc       %0, sr"
 170                              : "=&z" (__dummy)
 171                              : /* no inputs */
 172                              : "memory");
 173 }
 174
 175 static inline void set_bl_bit(void)
 176 {
 177         unsigned long __dummy0, __dummy1;
 178
 179         __asm__ __volatile__ ("stc      sr, %0\n\t"
 180                              "or        %2, %0\n\t"
 181                              "and       %3, %0\n\t"
 182                              "ldc       %0, sr"
 183                              : "=&r" (__dummy0), "=r" (__dummy1)
 184                              : "r" (0x10000000), "r" (0xffffff0f)
 185                              : "memory");
 186 }
 187
 188 static inline void clear_bl_bit(void)
 189 {
 190         unsigned long __dummy0, __dummy1;
 191
 192         __asm__ __volatile__ ("stc      sr, %0\n\t"
 193                              "and       %2, %0\n\t"
 194                              "ldc       %0, sr"
 195                              : "=&r" (__dummy0), "=r" (__dummy1)
 196                              : "1" (~0x10000000)
 197                              : "memory");
 198 }
 199
 200 #define local_save_flags(x) \
 201         __asm__("stc sr, %0; and #0xf0, %0" : "=&z" (x) :/**/: "memory" )
 202
 203 #define irqs_disabled()                 \
 204 ({                                      \
 205         unsigned long flags;            \
 206         local_save_flags(flags);        \
 207         (flags != 0);                   \
 208 })
 209
 210 static inline unsigned long local_irq_save(void)
 211 {
 212         unsigned long flags, __dummy;
 213
 214         __asm__ __volatile__("stc       sr, %1\n\t"
 215                              "mov       %1, %0\n\t"
 216                              "or        #0xf0, %0\n\t"
 217                              "ldc       %0, sr\n\t"
 218                              "mov       %1, %0\n\t"
 219                              "and       #0xf0, %0"
 220                              : "=&z" (flags), "=&r" (__dummy)
 221                              :/**/
 222                              : "memory" );
 223         return flags;
 224 }
 225
 226 #define local_irq_restore(x) do {                       \
 227         if ((x & 0x000000f0) != 0x000000f0)             \
 228                 local_irq_enable();                     \
 229 } while (0)
 230
 231 /*
 232  * Jump to P2 area.
 233  * When handling TLB or caches, we need to do it from P2 area.
 234  */
 235 #define jump_to_P2()                    \
 236 do {                                    \
 237         unsigned long __dummy;          \
 238         __asm__ __volatile__(           \
 239                 "mov.l  1f, %0\n\t"     \
 240                 "or     %1, %0\n\t"     \
 241                 "jmp    @%0\n\t"        \
 242                 " nop\n\t"              \
 243                 ".balign 4\n"           \
 244                 "1:     .long 2f\n"     \
 245                 "2:"                    \
 246                 : "=&r" (__dummy)       \
 247                 : "r" (0x20000000));    \
 248 } while (0)
 249
 250 /*
 251  * Back to P1 area.
 252  */
 253 #define back_to_P1()                                    \
 254 do {                                                    \
 255         unsigned long __dummy;                          \
 256         ctrl_barrier();                                 \
 257         __asm__ __volatile__(                           \
 258                 "mov.l  1f, %0\n\t"                     \
 259                 "jmp    @%0\n\t"                        \
 260                 " nop\n\t"                              \
 261                 ".balign 4\n"                           \
 262                 "1:     .long 2f\n"                     \
 263                 "2:"                                    \
 264                 : "=&r" (__dummy));                     \
 265 } while (0)
 266
 267 /* For spinlocks etc */
 268 #define local_irq_save(x)       x = local_irq_save()
 269
 270 static inline unsigned long xchg_u32(volatile u32 *m, unsigned long val)
 271 {
 272         unsigned long flags, retval;
 273
 274         local_irq_save(flags);
 275         retval = *m;
 276         *m = val;
 277         local_irq_restore(flags);
 278         return retval;
 279 }
 280
 281 static inline unsigned long xchg_u8(volatile u8 *m, unsigned long val)
 282 {
 283         unsigned long flags, retval;
 284
 285         local_irq_save(flags);
 286         retval = *m;
 287         *m = val & 0xff;
 288         local_irq_restore(flags);
 289         return retval;
 290 }
 291
 292 extern void __xchg_called_with_bad_pointer(void);
 293
 294 #define __xchg(ptr, x, size)                            \
 295 ({                                                      \
 296         unsigned long __xchg__res;                      \
 297         volatile void *__xchg_ptr = (ptr);              \
 298         switch (size) {                                 \
 299         case 4:                                         \
 300                 __xchg__res = xchg_u32(__xchg_ptr, x);  \
 301                 break;                                  \
 302         case 1:                                         \
 303                 __xchg__res = xchg_u8(__xchg_ptr, x);   \
 304                 break;                                  \
 305         default:                                        \
 306                 __xchg_called_with_bad_pointer();       \
 307                 __xchg__res = x;                        \
 308                 break;                                  \
 309         }                                               \
 310                                                         \
 311         __xchg__res;                                    \
 312 })
 313
 314 #define xchg(ptr,x)     \
 315         ((__typeof__(*(ptr)))__xchg((ptr),(unsigned long)(x), sizeof(*(ptr))))
 316
 317 static inline unsigned long __cmpxchg_u32(volatile int * m, unsigned long old,
 318         unsigned long new)
 319 {
 320         __u32 retval;
 321         unsigned long flags;
 322
 323         local_irq_save(flags);
 324         retval = *m;
 325         if (retval == old)
 326                 *m = new;
 327         local_irq_restore(flags);       /* implies memory barrier  */
 328         return retval;
 329 }
 330
 331 /* This function doesn't exist, so you'll get a linker error
 332  * if something tries to do an invalid cmpxchg(). */
 333 extern void __cmpxchg_called_with_bad_pointer(void);
 334
 335 #define __HAVE_ARCH_CMPXCHG 1
 336
 337 static inline unsigned long __cmpxchg(volatile void * ptr, unsigned long old,
 338                 unsigned long new, int size)
 339 {
 340         switch (size) {
 341         case 4:
 342                 return __cmpxchg_u32(ptr, old, new);
 343         }
 344         __cmpxchg_called_with_bad_pointer();
 345         return old;
 346 }
 347
 348 #define cmpxchg(ptr,o,n)                                                 \
 349   ({                                                                     \
 350      __typeof__(*(ptr)) _o_ = (o);                                       \
 351      __typeof__(*(ptr)) _n_ = (n);                                       \
 352      (__typeof__(*(ptr))) __cmpxchg((ptr), (unsigned long)_o_,           \
 353                                     (unsigned long)_n_, sizeof(*(ptr))); \
 354   })
 355
 356 /* XXX
 357  * disable hlt during certain critical i/o operations
 358  */
 359 #define HAVE_DISABLE_HLT
 360 void disable_hlt(void);
 361 void enable_hlt(void);
 362
 363 #define arch_align_stack(x) (x)
 364
 365 #endif