arch/m32r/include/asm/system.h

   1 #ifndef _ASM_M32R_SYSTEM_H
   2 #define _ASM_M32R_SYSTEM_H
   3
   4 /*
   5  * This file is subject to the terms and conditions of the GNU General Public
   6  * License.  See the file "COPYING" in the main directory of this archive
   7  * for more details.
   8  *
   9  * Copyright (C) 2001  Hiroyuki Kondo, Hirokazu Takata, and Hitoshi Yamamoto
  10  * Copyright (C) 2004, 2006  Hirokazu Takata <takata at linux-m32r.org>
  11  */
  12
  13 #include <linux/compiler.h>
  14 #include <asm/assembler.h>
  15
  16 #ifdef __KERNEL__
  17
  18 /*
  19  * switch_to(prev, next) should switch from task `prev' to `next'
  20  * `prev' will never be the same as `next'.
  21  *
  22  * `next' and `prev' should be struct task_struct, but it isn't always defined
  23  */
  24
  25 #if defined(CONFIG_FRAME_POINTER) || \
  26         !defined(CONFIG_SCHED_OMIT_FRAME_POINTER)
  27 #define M32R_PUSH_FP "  push fp\n"
  28 #define M32R_POP_FP  "  pop  fp\n"
  29 #else
  30 #define M32R_PUSH_FP ""
  31 #define M32R_POP_FP  ""
  32 #endif
  33
  34 #define switch_to(prev, next, last)  do { \
  35         __asm__ __volatile__ ( \
  36                 "       seth    lr, #high(1f)                           \n" \
  37                 "       or3     lr, lr, #low(1f)                        \n" \
  38                 "       st      lr, @%4  ; store old LR                 \n" \
  39                 "       ld      lr, @%5  ; load new LR                  \n" \
  40                         M32R_PUSH_FP \
  41                 "       st      sp, @%2  ; store old SP                 \n" \
  42                 "       ld      sp, @%3  ; load new SP                  \n" \
  43                 "       push    %1  ; store `prev' on new stack         \n" \
  44                 "       jmp     lr                                      \n" \
  45                 "       .fillinsn                                       \n" \
  46                 "1:                                                     \n" \
  47                 "       pop     %0  ; restore `__last' from new stack   \n" \
  48                         M32R_POP_FP \
  49                 : "=r" (last) \
  50                 : "0" (prev), \
  51                   "r" (&(prev->thread.sp)), "r" (&(next->thread.sp)), \
  52                   "r" (&(prev->thread.lr)), "r" (&(next->thread.lr)) \
  53                 : "memory", "lr" \
  54         ); \
  55 } while(0)
  56
  57 /* Interrupt Control */
  58 #if !defined(CONFIG_CHIP_M32102) && !defined(CONFIG_CHIP_M32104)
  59 #define local_irq_enable() \
  60         __asm__ __volatile__ ("setpsw #0x40 -> nop": : :"memory")
  61 #define local_irq_disable() \
  62         __asm__ __volatile__ ("clrpsw #0x40 -> nop": : :"memory")
  63 #else   /* CONFIG_CHIP_M32102 || CONFIG_CHIP_M32104 */
  64 static inline void local_irq_enable(void)
  65 {
  66         unsigned long tmpreg;
  67         __asm__ __volatile__(
  68                 "mvfc   %0, psw;                \n\t"
  69                 "or3    %0, %0, #0x0040;        \n\t"
  70                 "mvtc   %0, psw;                \n\t"
  71         : "=&r" (tmpreg) : : "cbit", "memory");
  72 }
  73
  74 static inline void local_irq_disable(void)
  75 {
  76         unsigned long tmpreg0, tmpreg1;
  77         __asm__ __volatile__(
  78                 "ld24   %0, #0  ; Use 32-bit insn. \n\t"
  79                 "mvfc   %1, psw ; No interrupt can be accepted here. \n\t"
  80                 "mvtc   %0, psw \n\t"
  81                 "and3   %0, %1, #0xffbf \n\t"
  82                 "mvtc   %0, psw \n\t"
  83         : "=&r" (tmpreg0), "=&r" (tmpreg1) : : "cbit", "memory");
  84 }
  85 #endif  /* CONFIG_CHIP_M32102 || CONFIG_CHIP_M32104 */
  86
  87 #define local_save_flags(x) \
  88         __asm__ __volatile__("mvfc %0,psw" : "=r"(x) : /* no input */)
  89
  90 #define local_irq_restore(x) \
  91         __asm__ __volatile__("mvtc %0,psw" : /* no outputs */ \
  92                 : "r" (x) : "cbit", "memory")
  93
  94 #if !(defined(CONFIG_CHIP_M32102) || defined(CONFIG_CHIP_M32104))
  95 #define local_irq_save(x)                               \
  96         __asm__ __volatile__(                           \
  97                 "mvfc   %0, psw;                \n\t"   \
  98                 "clrpsw #0x40 -> nop;           \n\t"   \
  99                 : "=r" (x) : /* no input */ : "memory")
 100 #else   /* CONFIG_CHIP_M32102 || CONFIG_CHIP_M32104 */
 101 #define local_irq_save(x)                               \
 102         ({                                              \
 103                 unsigned long tmpreg;                   \
 104                 __asm__ __volatile__(                   \
 105                         "ld24   %1, #0 \n\t"            \
 106                         "mvfc   %0, psw \n\t"           \
 107                         "mvtc   %1, psw \n\t"           \
 108                         "and3   %1, %0, #0xffbf \n\t"   \
 109                         "mvtc   %1, psw \n\t"           \
 110                         : "=r" (x), "=&r" (tmpreg)      \
 111                         : : "cbit", "memory");          \
 112         })
 113 #endif  /* CONFIG_CHIP_M32102 || CONFIG_CHIP_M32104 */
 114
 115 #define irqs_disabled()                                 \
 116         ({                                              \
 117                 unsigned long flags;                    \
 118                 local_save_flags(flags);                \
 119                 !(flags & 0x40);                        \
 120         })
 121
 122 #define nop()   __asm__ __volatile__ ("nop" : : )
 123
 124 #define xchg(ptr, x)                                                    \
 125         ((__typeof__(*(ptr)))__xchg((unsigned long)(x), (ptr), sizeof(*(ptr))))
 126 #define xchg_local(ptr, x)                                              \
 127         ((__typeof__(*(ptr)))__xchg_local((unsigned long)(x), (ptr),    \
 128                         sizeof(*(ptr))))
 129
 130 extern void  __xchg_called_with_bad_pointer(void);
 131
 132 #ifdef CONFIG_CHIP_M32700_TS1
 133 #define DCACHE_CLEAR(reg0, reg1, addr)                          \
 134         "seth   "reg1", #high(dcache_dummy);            \n\t"   \
 135         "or3    "reg1", "reg1", #low(dcache_dummy);     \n\t"   \
 136         "lock   "reg0", @"reg1";                        \n\t"   \
 137         "add3   "reg0", "addr", #0x1000;                \n\t"   \
 138         "ld     "reg0", @"reg0";                        \n\t"   \
 139         "add3   "reg0", "addr", #0x2000;                \n\t"   \
 140         "ld     "reg0", @"reg0";                        \n\t"   \
 141         "unlock "reg0", @"reg1";                        \n\t"
 142         /* FIXME: This workaround code cannot handle kernel modules
 143          * correctly under SMP environment.
 144          */
 145 #else   /* CONFIG_CHIP_M32700_TS1 */
 146 #define DCACHE_CLEAR(reg0, reg1, addr)
 147 #endif  /* CONFIG_CHIP_M32700_TS1 */
 148
 149 static __always_inline unsigned long
 150 __xchg(unsigned long x, volatile void *ptr, int size)
 151 {
 152         unsigned long flags;
 153         unsigned long tmp = 0;
 154
 155         local_irq_save(flags);
 156
 157         switch (size) {
 158 #ifndef CONFIG_SMP
 159         case 1:
 160                 __asm__ __volatile__ (
 161                         "ldb    %0, @%2 \n\t"
 162                         "stb    %1, @%2 \n\t"
 163                         : "=&r" (tmp) : "r" (x), "r" (ptr) : "memory");
 164                 break;
 165         case 2:
 166                 __asm__ __volatile__ (
 167                         "ldh    %0, @%2 \n\t"
 168                         "sth    %1, @%2 \n\t"
 169                         : "=&r" (tmp) : "r" (x), "r" (ptr) : "memory");
 170                 break;
 171         case 4:
 172                 __asm__ __volatile__ (
 173                         "ld     %0, @%2 \n\t"
 174                         "st     %1, @%2 \n\t"
 175                         : "=&r" (tmp) : "r" (x), "r" (ptr) : "memory");
 176                 break;
 177 #else  /* CONFIG_SMP */
 178         case 4:
 179                 __asm__ __volatile__ (
 180                         DCACHE_CLEAR("%0", "r4", "%2")
 181                         "lock   %0, @%2;        \n\t"
 182                         "unlock %1, @%2;        \n\t"
 183                         : "=&r" (tmp) : "r" (x), "r" (ptr)
 184                         : "memory"
 185 #ifdef CONFIG_CHIP_M32700_TS1
 186                         , "r4"
 187 #endif  /* CONFIG_CHIP_M32700_TS1 */
 188                 );
 189                 break;
 190 #endif  /* CONFIG_SMP */
 191         default:
 192                 __xchg_called_with_bad_pointer();
 193         }
 194
 195         local_irq_restore(flags);
 196
 197         return (tmp);
 198 }
 199
 200 static __always_inline unsigned long
 201 __xchg_local(unsigned long x, volatile void *ptr, int size)
 202 {
 203         unsigned long flags;
 204         unsigned long tmp = 0;
 205
 206         local_irq_save(flags);
 207
 208         switch (size) {
 209         case 1:
 210                 __asm__ __volatile__ (
 211                         "ldb    %0, @%2 \n\t"
 212                         "stb    %1, @%2 \n\t"
 213                         : "=&r" (tmp) : "r" (x), "r" (ptr) : "memory");
 214                 break;
 215         case 2:
 216                 __asm__ __volatile__ (
 217                         "ldh    %0, @%2 \n\t"
 218                         "sth    %1, @%2 \n\t"
 219                         : "=&r" (tmp) : "r" (x), "r" (ptr) : "memory");
 220                 break;
 221         case 4:
 222                 __asm__ __volatile__ (
 223                         "ld     %0, @%2 \n\t"
 224                         "st     %1, @%2 \n\t"
 225                         : "=&r" (tmp) : "r" (x), "r" (ptr) : "memory");
 226                 break;
 227         default:
 228                 __xchg_called_with_bad_pointer();
 229         }
 230
 231         local_irq_restore(flags);
 232
 233         return (tmp);
 234 }
 235
 236 #define __HAVE_ARCH_CMPXCHG     1
 237
 238 static inline unsigned long
 239 __cmpxchg_u32(volatile unsigned int *p, unsigned int old, unsigned int new)
 240 {
 241         unsigned long flags;
 242         unsigned int retval;
 243
 244         local_irq_save(flags);
 245         __asm__ __volatile__ (
 246                         DCACHE_CLEAR("%0", "r4", "%1")
 247                         M32R_LOCK" %0, @%1;     \n"
 248                 "       bne     %0, %2, 1f;     \n"
 249                         M32R_UNLOCK" %3, @%1;   \n"
 250                 "       bra     2f;             \n"
 251                 "       .fillinsn               \n"
 252                 "1:"
 253                         M32R_UNLOCK" %0, @%1;   \n"
 254                 "       .fillinsn               \n"
 255                 "2:"
 256                         : "=&r" (retval)
 257                         : "r" (p), "r" (old), "r" (new)
 258                         : "cbit", "memory"
 259 #ifdef CONFIG_CHIP_M32700_TS1
 260                         , "r4"
 261 #endif  /* CONFIG_CHIP_M32700_TS1 */
 262                 );
 263         local_irq_restore(flags);
 264
 265         return retval;
 266 }
 267
 268 static inline unsigned long
 269 __cmpxchg_local_u32(volatile unsigned int *p, unsigned int old,
 270                         unsigned int new)
 271 {
 272         unsigned long flags;
 273         unsigned int retval;
 274
 275         local_irq_save(flags);
 276         __asm__ __volatile__ (
 277                         DCACHE_CLEAR("%0", "r4", "%1")
 278                         "ld %0, @%1;            \n"
 279                 "       bne     %0, %2, 1f;     \n"
 280                         "st %3, @%1;            \n"
 281                 "       bra     2f;             \n"
 282                 "       .fillinsn               \n"
 283                 "1:"
 284                         "st %0, @%1;            \n"
 285                 "       .fillinsn               \n"
 286                 "2:"
 287                         : "=&r" (retval)
 288                         : "r" (p), "r" (old), "r" (new)
 289                         : "cbit", "memory"
 290 #ifdef CONFIG_CHIP_M32700_TS1
 291                         , "r4"
 292 #endif  /* CONFIG_CHIP_M32700_TS1 */
 293                 );
 294         local_irq_restore(flags);
 295
 296         return retval;
 297 }
 298
 299 /* This function doesn't exist, so you'll get a linker error
 300    if something tries to do an invalid cmpxchg().  */
 301 extern void __cmpxchg_called_with_bad_pointer(void);
 302
 303 static inline unsigned long
 304 __cmpxchg(volatile void *ptr, unsigned long old, unsigned long new, int size)
 305 {
 306         switch (size) {
 307         case 4:
 308                 return __cmpxchg_u32(ptr, old, new);
 309 #if 0   /* we don't have __cmpxchg_u64 */
 310         case 8:
 311                 return __cmpxchg_u64(ptr, old, new);
 312 #endif /* 0 */
 313         }
 314         __cmpxchg_called_with_bad_pointer();
 315         return old;
 316 }
 317
 318 #define cmpxchg(ptr, o, n)                                               \
 319         ((__typeof__(*(ptr))) __cmpxchg((ptr), (unsigned long)(o),       \
 320                         (unsigned long)(n), sizeof(*(ptr))))
 321
 322 #include <asm-generic/cmpxchg-local.h>
 323
 324 static inline unsigned long __cmpxchg_local(volatile void *ptr,
 325                                       unsigned long old,
 326                                       unsigned long new, int size)
 327 {
 328         switch (size) {
 329         case 4:
 330                 return __cmpxchg_local_u32(ptr, old, new);
 331         default:
 332                 return __cmpxchg_local_generic(ptr, old, new, size);
 333         }
 334
 335         return old;
 336 }
 337
 338 /*
 339  * cmpxchg_local and cmpxchg64_local are atomic wrt current CPU. Always make
 340  * them available.
 341  */
 342 #define cmpxchg_local(ptr, o, n)                                            \
 343         ((__typeof__(*(ptr)))__cmpxchg_local((ptr), (unsigned long)(o),     \
 344                         (unsigned long)(n), sizeof(*(ptr))))
 345 #define cmpxchg64_local(ptr, o, n) __cmpxchg64_local_generic((ptr), (o), (n))
 346
 347 #endif  /* __KERNEL__ */
 348
 349 /*
 350  * Memory barrier.
 351  *
 352  * mb() prevents loads and stores being reordered across this point.
 353  * rmb() prevents loads being reordered across this point.
 354  * wmb() prevents stores being reordered across this point.
 355  */
 356 #define mb()   barrier()
 357 #define rmb()  mb()
 358 #define wmb()  mb()
 359
 360 /**
 361  * read_barrier_depends - Flush all pending reads that subsequents reads
 362  * depend on.
 363  *
 364  * No data-dependent reads from memory-like regions are ever reordered
 365  * over this barrier.  All reads preceding this primitive are guaranteed
 366  * to access memory (but not necessarily other CPUs' caches) before any
 367  * reads following this primitive that depend on the data return by
 368  * any of the preceding reads.  This primitive is much lighter weight than
 369  * rmb() on most CPUs, and is never heavier weight than is
 370  * rmb().
 371  *
 372  * These ordering constraints are respected by both the local CPU
 373  * and the compiler.
 374  *
 375  * Ordering is not guaranteed by anything other than these primitives,
 376  * not even by data dependencies.  See the documentation for
 377  * memory_barrier() for examples and URLs to more information.
 378  *
 379  * For example, the following code would force ordering (the initial
 380  * value of "a" is zero, "b" is one, and "p" is "&a"):
 381  *
 382  * <programlisting>
 383  *      CPU 0                           CPU 1
 384  *
 385  *      b = 2;
 386  *      memory_barrier();
 387  *      p = &b;                         q = p;
 388  *                                      read_barrier_depends();
 389  *                                      d = *q;
 390  * </programlisting>
 391  *
 392  *
 393  * because the read of "*q" depends on the read of "p" and these
 394  * two reads are separated by a read_barrier_depends().  However,
 395  * the following code, with the same initial values for "a" and "b":
 396  *
 397  * <programlisting>
 398  *      CPU 0                           CPU 1
 399  *
 400  *      a = 2;
 401  *      memory_barrier();
 402  *      b = 3;                          y = b;
 403  *                                      read_barrier_depends();
 404  *                                      x = a;
 405  * </programlisting>
 406  *
 407  * does not enforce ordering, since there is no data dependency between
 408  * the read of "a" and the read of "b".  Therefore, on some CPUs, such
 409  * as Alpha, "y" could be set to 3 and "x" to 0.  Use rmb()
 410  * in cases like this where there are no data dependencies.
 411  **/
 412
 413 #define read_barrier_depends()  do { } while (0)
 414
 415 #ifdef CONFIG_SMP
 416 #define smp_mb()        mb()
 417 #define smp_rmb()       rmb()
 418 #define smp_wmb()       wmb()
 419 #define smp_read_barrier_depends()      read_barrier_depends()
 420 #define set_mb(var, value) do { (void) xchg(&var, value); } while (0)
 421 #else
 422 #define smp_mb()        barrier()
 423 #define smp_rmb()       barrier()
 424 #define smp_wmb()       barrier()
 425 #define smp_read_barrier_depends()      do { } while (0)
 426 #define set_mb(var, value) do { var = value; barrier(); } while (0)
 427 #endif
 428
 429 #define arch_align_stack(x) (x)
 430
 431 #endif /* _ASM_M32R_SYSTEM_H */