include/asm-m32r/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 <asm/assembler.h>
  14
  15 #ifdef __KERNEL__
  16
  17 /*
  18  * switch_to(prev, next) should switch from task `prev' to `next'
  19  * `prev' will never be the same as `next'.
  20  *
  21  * `next' and `prev' should be struct task_struct, but it isn't always defined
  22  */
  23
  24 #define switch_to(prev, next, last)  do { \
  25         __asm__ __volatile__ ( \
  26                 "       seth    lr, #high(1f)                           \n" \
  27                 "       or3     lr, lr, #low(1f)                        \n" \
  28                 "       st      lr, @%4  ; store old LR                 \n" \
  29                 "       ld      lr, @%5  ; load new LR                  \n" \
  30                 "       st      sp, @%2  ; store old SP                 \n" \
  31                 "       ld      sp, @%3  ; load new SP                  \n" \
  32                 "       push    %1  ; store `prev' on new stack         \n" \
  33                 "       jmp     lr                                      \n" \
  34                 "       .fillinsn                                       \n" \
  35                 "1:                                                     \n" \
  36                 "       pop     %0  ; restore `__last' from new stack   \n" \
  37                 : "=r" (last) \
  38                 : "0" (prev), \
  39                   "r" (&(prev->thread.sp)), "r" (&(next->thread.sp)), \
  40                   "r" (&(prev->thread.lr)), "r" (&(next->thread.lr)) \
  41                 : "memory", "lr" \
  42         ); \
  43 } while(0)
  44
  45 /*
  46  * On SMP systems, when the scheduler does migration-cost autodetection,
  47  * it needs a way to flush as much of the CPU's caches as possible.
  48  *
  49  * TODO: fill this in!
  50  */
  51 static inline void sched_cacheflush(void)
  52 {
  53 }
  54
  55 /* Interrupt Control */
  56 #if !defined(CONFIG_CHIP_M32102) && !defined(CONFIG_CHIP_M32104)
  57 #define local_irq_enable() \
  58         __asm__ __volatile__ ("setpsw #0x40 -> nop": : :"memory")
  59 #define local_irq_disable() \
  60         __asm__ __volatile__ ("clrpsw #0x40 -> nop": : :"memory")
  61 #else   /* CONFIG_CHIP_M32102 || CONFIG_CHIP_M32104 */
  62 static inline void local_irq_enable(void)
  63 {
  64         unsigned long tmpreg;
  65         __asm__ __volatile__(
  66                 "mvfc   %0, psw;                \n\t"
  67                 "or3    %0, %0, #0x0040;        \n\t"
  68                 "mvtc   %0, psw;                \n\t"
  69         : "=&r" (tmpreg) : : "cbit", "memory");
  70 }
  71
  72 static inline void local_irq_disable(void)
  73 {
  74         unsigned long tmpreg0, tmpreg1;
  75         __asm__ __volatile__(
  76                 "ld24   %0, #0  ; Use 32-bit insn. \n\t"
  77                 "mvfc   %1, psw ; No interrupt can be accepted here. \n\t"
  78                 "mvtc   %0, psw \n\t"
  79                 "and3   %0, %1, #0xffbf \n\t"
  80                 "mvtc   %0, psw \n\t"
  81         : "=&r" (tmpreg0), "=&r" (tmpreg1) : : "cbit", "memory");
  82 }
  83 #endif  /* CONFIG_CHIP_M32102 || CONFIG_CHIP_M32104 */
  84
  85 #define local_save_flags(x) \
  86         __asm__ __volatile__("mvfc %0,psw" : "=r"(x) : /* no input */)
  87
  88 #define local_irq_restore(x) \
  89         __asm__ __volatile__("mvtc %0,psw" : /* no outputs */ \
  90                 : "r" (x) : "cbit", "memory")
  91
  92 #if !(defined(CONFIG_CHIP_M32102) || defined(CONFIG_CHIP_M32104))
  93 #define local_irq_save(x)                               \
  94         __asm__ __volatile__(                           \
  95                 "mvfc   %0, psw;                \n\t"   \
  96                 "clrpsw #0x40 -> nop;           \n\t"   \
  97                 : "=r" (x) : /* no input */ : "memory")
  98 #else   /* CONFIG_CHIP_M32102 || CONFIG_CHIP_M32104 */
  99 #define local_irq_save(x)                               \
 100         ({                                              \
 101                 unsigned long tmpreg;                   \
 102                 __asm__ __volatile__(                   \
 103                         "ld24   %1, #0 \n\t"            \
 104                         "mvfc   %0, psw \n\t"           \
 105                         "mvtc   %1, psw \n\t"           \
 106                         "and3   %1, %0, #0xffbf \n\t"   \
 107                         "mvtc   %1, psw \n\t"           \
 108                         : "=r" (x), "=&r" (tmpreg)      \
 109                         : : "cbit", "memory");          \
 110         })
 111 #endif  /* CONFIG_CHIP_M32102 || CONFIG_CHIP_M32104 */
 112
 113 #define irqs_disabled()                                 \
 114         ({                                              \
 115                 unsigned long flags;                    \
 116                 local_save_flags(flags);                \
 117                 !(flags & 0x40);                        \
 118         })
 119
 120 #define nop()   __asm__ __volatile__ ("nop" : : )
 121
 122 #define xchg(ptr,x) \
 123         ((__typeof__(*(ptr)))__xchg((unsigned long)(x),(ptr),sizeof(*(ptr))))
 124
 125 #define tas(ptr)        (xchg((ptr),1))
 126
 127 #ifdef CONFIG_SMP
 128 extern void  __xchg_called_with_bad_pointer(void);
 129 #endif
 130
 131 #ifdef CONFIG_CHIP_M32700_TS1
 132 #define DCACHE_CLEAR(reg0, reg1, addr)                          \
 133         "seth   "reg1", #high(dcache_dummy);            \n\t"   \
 134         "or3    "reg1", "reg1", #low(dcache_dummy);     \n\t"   \
 135         "lock   "reg0", @"reg1";                        \n\t"   \
 136         "add3   "reg0", "addr", #0x1000;                \n\t"   \
 137         "ld     "reg0", @"reg0";                        \n\t"   \
 138         "add3   "reg0", "addr", #0x2000;                \n\t"   \
 139         "ld     "reg0", @"reg0";                        \n\t"   \
 140         "unlock "reg0", @"reg1";                        \n\t"
 141         /* FIXME: This workaround code cannot handle kenrel modules
 142          * correctly under SMP environment.
 143          */
 144 #else   /* CONFIG_CHIP_M32700_TS1 */
 145 #define DCACHE_CLEAR(reg0, reg1, addr)
 146 #endif  /* CONFIG_CHIP_M32700_TS1 */
 147
 148 static inline unsigned long
 149 __xchg(unsigned long x, volatile void * ptr, int size)
 150 {
 151         unsigned long flags;
 152         unsigned long tmp = 0;
 153
 154         local_irq_save(flags);
 155
 156         switch (size) {
 157 #ifndef CONFIG_SMP
 158         case 1:
 159                 __asm__ __volatile__ (
 160                         "ldb    %0, @%2 \n\t"
 161                         "stb    %1, @%2 \n\t"
 162                         : "=&r" (tmp) : "r" (x), "r" (ptr) : "memory");
 163                 break;
 164         case 2:
 165                 __asm__ __volatile__ (
 166                         "ldh    %0, @%2 \n\t"
 167                         "sth    %1, @%2 \n\t"
 168                         : "=&r" (tmp) : "r" (x), "r" (ptr) : "memory");
 169                 break;
 170         case 4:
 171                 __asm__ __volatile__ (
 172                         "ld     %0, @%2 \n\t"
 173                         "st     %1, @%2 \n\t"
 174                         : "=&r" (tmp) : "r" (x), "r" (ptr) : "memory");
 175                 break;
 176 #else  /* CONFIG_SMP */
 177         case 4:
 178                 __asm__ __volatile__ (
 179                         DCACHE_CLEAR("%0", "r4", "%2")
 180                         "lock   %0, @%2;        \n\t"
 181                         "unlock %1, @%2;        \n\t"
 182                         : "=&r" (tmp) : "r" (x), "r" (ptr)
 183                         : "memory"
 184 #ifdef CONFIG_CHIP_M32700_TS1
 185                         , "r4"
 186 #endif  /* CONFIG_CHIP_M32700_TS1 */
 187                 );
 188                 break;
 189         default:
 190                 __xchg_called_with_bad_pointer();
 191 #endif  /* CONFIG_SMP */
 192         }
 193
 194         local_irq_restore(flags);
 195
 196         return (tmp);
 197 }
 198
 199 #define __HAVE_ARCH_CMPXCHG     1
 200
 201 static inline unsigned long
 202 __cmpxchg_u32(volatile unsigned int *p, unsigned int old, unsigned int new)
 203 {
 204         unsigned long flags;
 205         unsigned int retval;
 206
 207         local_irq_save(flags);
 208         __asm__ __volatile__ (
 209                         DCACHE_CLEAR("%0", "r4", "%1")
 210                         M32R_LOCK" %0, @%1;     \n"
 211                 "       bne     %0, %2, 1f;     \n"
 212                         M32R_UNLOCK" %3, @%1;   \n"
 213                 "       bra     2f;             \n"
 214                 "       .fillinsn               \n"
 215                 "1:"
 216                         M32R_UNLOCK" %0, @%1;   \n"
 217                 "       .fillinsn               \n"
 218                 "2:"
 219                         : "=&r" (retval)
 220                         : "r" (p), "r" (old), "r" (new)
 221                         : "cbit", "memory"
 222 #ifdef CONFIG_CHIP_M32700_TS1
 223                         , "r4"
 224 #endif  /* CONFIG_CHIP_M32700_TS1 */
 225                 );
 226         local_irq_restore(flags);
 227
 228         return retval;
 229 }
 230
 231 /* This function doesn't exist, so you'll get a linker error
 232    if something tries to do an invalid cmpxchg().  */
 233 extern void __cmpxchg_called_with_bad_pointer(void);
 234
 235 static inline unsigned long
 236 __cmpxchg(volatile void *ptr, unsigned long old, unsigned long new, int size)
 237 {
 238         switch (size) {
 239         case 4:
 240                 return __cmpxchg_u32(ptr, old, new);
 241 #if 0   /* we don't have __cmpxchg_u64 */
 242         case 8:
 243                 return __cmpxchg_u64(ptr, old, new);
 244 #endif /* 0 */
 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 #endif  /* __KERNEL__ */
 259
 260 /*
 261  * Memory barrier.
 262  *
 263  * mb() prevents loads and stores being reordered across this point.
 264  * rmb() prevents loads being reordered across this point.
 265  * wmb() prevents stores being reordered across this point.
 266  */
 267 #define mb()   barrier()
 268 #define rmb()  mb()
 269 #define wmb()  mb()
 270
 271 /**
 272  * read_barrier_depends - Flush all pending reads that subsequents reads
 273  * depend on.
 274  *
 275  * No data-dependent reads from memory-like regions are ever reordered
 276  * over this barrier.  All reads preceding this primitive are guaranteed
 277  * to access memory (but not necessarily other CPUs' caches) before any
 278  * reads following this primitive that depend on the data return by
 279  * any of the preceding reads.  This primitive is much lighter weight than
 280  * rmb() on most CPUs, and is never heavier weight than is
 281  * rmb().
 282  *
 283  * These ordering constraints are respected by both the local CPU
 284  * and the compiler.
 285  *
 286  * Ordering is not guaranteed by anything other than these primitives,
 287  * not even by data dependencies.  See the documentation for
 288  * memory_barrier() for examples and URLs to more information.
 289  *
 290  * For example, the following code would force ordering (the initial
 291  * value of "a" is zero, "b" is one, and "p" is "&a"):
 292  *
 293  * <programlisting>
 294  *      CPU 0                           CPU 1
 295  *
 296  *      b = 2;
 297  *      memory_barrier();
 298  *      p = &b;                         q = p;
 299  *                                      read_barrier_depends();
 300  *                                      d = *q;
 301  * </programlisting>
 302  *
 303  *
 304  * because the read of "*q" depends on the read of "p" and these
 305  * two reads are separated by a read_barrier_depends().  However,
 306  * the following code, with the same initial values for "a" and "b":
 307  *
 308  * <programlisting>
 309  *      CPU 0                           CPU 1
 310  *
 311  *      a = 2;
 312  *      memory_barrier();
 313  *      b = 3;                          y = b;
 314  *                                      read_barrier_depends();
 315  *                                      x = a;
 316  * </programlisting>
 317  *
 318  * does not enforce ordering, since there is no data dependency between
 319  * the read of "a" and the read of "b".  Therefore, on some CPUs, such
 320  * as Alpha, "y" could be set to 3 and "x" to 0.  Use rmb()
 321  * in cases like this where there are no data dependencies.
 322  **/
 323
 324 #define read_barrier_depends()  do { } while (0)
 325
 326 #ifdef CONFIG_SMP
 327 #define smp_mb()        mb()
 328 #define smp_rmb()       rmb()
 329 #define smp_wmb()       wmb()
 330 #define smp_read_barrier_depends()      read_barrier_depends()
 331 #else
 332 #define smp_mb()        barrier()
 333 #define smp_rmb()       barrier()
 334 #define smp_wmb()       barrier()
 335 #define smp_read_barrier_depends()      do { } while (0)
 336 #endif
 337
 338 #define set_mb(var, value) do { xchg(&var, value); } while (0)
 339 #define set_wmb(var, value) do { var = value; wmb(); } while (0)
 340
 341 #define arch_align_stack(x) (x)
 342
 343 #endif  /* _ASM_M32R_SYSTEM_H */