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   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  by Hiroyuki Kondo, Hirokazu Takata, and Hitoshi Yamamoto
  10  * Copyright (C) 2004  Hirokazu Takata <takata at linux-m32r.org>
  11  */
  12
  13 #include <linux/config.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 #ifndef CONFIG_SMP
  26 #define prepare_to_switch()  do { } while(0)
  27 #endif  /* not CONFIG_SMP */
  28
  29 #define switch_to(prev, next, last)  do { \
  30         register unsigned long  arg0 __asm__ ("r0") = (unsigned long)prev; \
  31         register unsigned long  arg1 __asm__ ("r1") = (unsigned long)next; \
  32         register unsigned long  *oldsp __asm__ ("r2") = &(prev->thread.sp); \
  33         register unsigned long  *newsp __asm__ ("r3") = &(next->thread.sp); \
  34         register unsigned long  *oldlr __asm__ ("r4") = &(prev->thread.lr); \
  35         register unsigned long  *newlr __asm__ ("r5") = &(next->thread.lr); \
  36         register struct task_struct  *__last __asm__ ("r6"); \
  37         __asm__ __volatile__ ( \
  38                 "st     r8, @-r15                                 \n\t" \
  39                 "st     r9, @-r15                                 \n\t" \
  40                 "st    r10, @-r15                                 \n\t" \
  41                 "st    r11, @-r15                                 \n\t" \
  42                 "st    r12, @-r15                                 \n\t" \
  43                 "st    r13, @-r15                                 \n\t" \
  44                 "st    r14, @-r15                                 \n\t" \
  45                 "seth  r14, #high(1f)                             \n\t" \
  46                 "or3   r14, r14, #low(1f)                         \n\t" \
  47                 "st    r14, @r4    ; store old LR                 \n\t" \
  48                 "st    r15, @r2    ; store old SP                 \n\t" \
  49                 "ld    r15, @r3    ; load new SP                  \n\t" \
  50                 "st     r0, @-r15  ; store 'prev' onto new stack  \n\t" \
  51                 "ld    r14, @r5    ; load new LR                  \n\t" \
  52                 "jmp   r14                                        \n\t" \
  53                 ".fillinsn                                        \n  " \
  54                 "1:                                               \n\t" \
  55                 "ld     r6, @r15+  ; load 'prev' from new stack   \n\t" \
  56                 "ld    r14, @r15+                                 \n\t" \
  57                 "ld    r13, @r15+                                 \n\t" \
  58                 "ld    r12, @r15+                                 \n\t" \
  59                 "ld    r11, @r15+                                 \n\t" \
  60                 "ld    r10, @r15+                                 \n\t" \
  61                 "ld     r9, @r15+                                 \n\t" \
  62                 "ld     r8, @r15+                                 \n\t" \
  63                 : "=&r" (__last) \
  64                 : "r" (arg0), "r" (arg1), "r" (oldsp), "r" (newsp), \
  65                   "r" (oldlr), "r" (newlr) \
  66                 : "memory" \
  67         ); \
  68         last = __last; \
  69 } while(0)
  70
  71 /* Interrupt Control */
  72 #if !defined(CONFIG_CHIP_M32102)
  73 #define local_irq_enable() \
  74         __asm__ __volatile__ ("setpsw #0x40 -> nop": : :"memory")
  75 #define local_irq_disable() \
  76         __asm__ __volatile__ ("clrpsw #0x40 -> nop": : :"memory")
  77 #else   /* CONFIG_CHIP_M32102 */
  78 static inline void local_irq_enable(void)
  79 {
  80         unsigned long tmpreg;
  81         __asm__ __volatile__(
  82                 "mvfc   %0, psw;                \n\t"
  83                 "or3    %0, %0, #0x0040;        \n\t"
  84                 "mvtc   %0, psw;                \n\t"
  85         : "=&r" (tmpreg) : : "cbit", "memory");
  86 }
  87
  88 static inline void local_irq_disable(void)
  89 {
  90         unsigned long tmpreg0, tmpreg1;
  91         __asm__ __volatile__(
  92                 "ld24   %0, #0  ; Use 32-bit insn. \n\t"
  93                 "mvfc   %1, psw ; No interrupt can be accepted here. \n\t"
  94                 "mvtc   %0, psw \n\t"
  95                 "and3   %0, %1, #0xffbf \n\t"
  96                 "mvtc   %0, psw \n\t"
  97         : "=&r" (tmpreg0), "=&r" (tmpreg1) : : "cbit", "memory");
  98 }
  99 #endif  /* CONFIG_CHIP_M32102 */
 100
 101 #define local_save_flags(x) \
 102         __asm__ __volatile__("mvfc %0,psw" : "=r"(x) : /* no input */)
 103
 104 #define local_irq_restore(x) \
 105         __asm__ __volatile__("mvtc %0,psw" : /* no outputs */ \
 106                 : "r" (x) : "cbit", "memory")
 107
 108 #if !defined(CONFIG_CHIP_M32102)
 109 #define local_irq_save(x)                               \
 110         __asm__ __volatile__(                           \
 111                 "mvfc   %0, psw;                \n\t"   \
 112                 "clrpsw #0x40 -> nop;           \n\t"   \
 113                 : "=r" (x) : /* no input */ : "memory")
 114 #else   /* CONFIG_CHIP_M32102 */
 115 #define local_irq_save(x)                               \
 116         ({                                              \
 117                 unsigned long tmpreg;                   \
 118                 __asm__ __volatile__(                   \
 119                         "ld24   %1, #0 \n\t"            \
 120                         "mvfc   %0, psw \n\t"           \
 121                         "mvtc   %1, psw \n\t"           \
 122                         "and3   %1, %0, #0xffbf \n\t"   \
 123                         "mvtc   %1, psw \n\t"           \
 124                         : "=r" (x), "=&r" (tmpreg)      \
 125                         : : "cbit", "memory");          \
 126         })
 127 #endif  /* CONFIG_CHIP_M32102 */
 128
 129 #define irqs_disabled()                                 \
 130         ({                                              \
 131                 unsigned long flags;                    \
 132                 local_save_flags(flags);                \
 133                 !(flags & 0x40);                        \
 134         })
 135
 136 #define nop()   __asm__ __volatile__ ("nop" : : )
 137
 138 #define xchg(ptr,x) \
 139         ((__typeof__(*(ptr)))__xchg((unsigned long)(x),(ptr),sizeof(*(ptr))))
 140
 141 #define tas(ptr)        (xchg((ptr),1))
 142
 143 #ifdef CONFIG_SMP
 144 extern void  __xchg_called_with_bad_pointer(void);
 145 #endif
 146
 147 #ifdef CONFIG_CHIP_M32700_TS1
 148 #define DCACHE_CLEAR(reg0, reg1, addr)                          \
 149         "seth   "reg1", #high(dcache_dummy);            \n\t"   \
 150         "or3    "reg1", "reg1", #low(dcache_dummy);     \n\t"   \
 151         "lock   "reg0", @"reg1";                        \n\t"   \
 152         "add3   "reg0", "addr", #0x1000;                \n\t"   \
 153         "ld     "reg0", @"reg0";                        \n\t"   \
 154         "add3   "reg0", "addr", #0x2000;                \n\t"   \
 155         "ld     "reg0", @"reg0";                        \n\t"   \
 156         "unlock "reg0", @"reg1";                        \n\t"
 157         /* FIXME: This workaround code cannot handle kenrel modules
 158          * correctly under SMP environment.
 159          */
 160 #else   /* CONFIG_CHIP_M32700_TS1 */
 161 #define DCACHE_CLEAR(reg0, reg1, addr)
 162 #endif  /* CONFIG_CHIP_M32700_TS1 */
 163
 164 static __inline__ unsigned long __xchg(unsigned long x, volatile void * ptr,
 165         int size)
 166 {
 167         unsigned long flags;
 168         unsigned long tmp = 0;
 169
 170         local_irq_save(flags);
 171
 172         switch (size) {
 173 #ifndef CONFIG_SMP
 174         case 1:
 175                 __asm__ __volatile__ (
 176                         "ldb    %0, @%2 \n\t"
 177                         "stb    %1, @%2 \n\t"
 178                         : "=&r" (tmp) : "r" (x), "r" (ptr) : "memory");
 179                 break;
 180         case 2:
 181                 __asm__ __volatile__ (
 182                         "ldh    %0, @%2 \n\t"
 183                         "sth    %1, @%2 \n\t"
 184                         : "=&r" (tmp) : "r" (x), "r" (ptr) : "memory");
 185                 break;
 186         case 4:
 187                 __asm__ __volatile__ (
 188                         "ld     %0, @%2 \n\t"
 189                         "st     %1, @%2 \n\t"
 190                         : "=&r" (tmp) : "r" (x), "r" (ptr) : "memory");
 191                 break;
 192 #else  /* CONFIG_SMP */
 193         case 4:
 194                 __asm__ __volatile__ (
 195                         DCACHE_CLEAR("%0", "r4", "%2")
 196                         "lock   %0, @%2;        \n\t"
 197                         "unlock %1, @%2;        \n\t"
 198                         : "=&r" (tmp) : "r" (x), "r" (ptr)
 199                         : "memory"
 200 #ifdef CONFIG_CHIP_M32700_TS1
 201                         , "r4"
 202 #endif  /* CONFIG_CHIP_M32700_TS1 */
 203                 );
 204                 break;
 205         default:
 206                 __xchg_called_with_bad_pointer();
 207 #endif  /* CONFIG_SMP */
 208         }
 209
 210         local_irq_restore(flags);
 211
 212         return (tmp);
 213 }
 214
 215 #define __HAVE_ARCH_CMPXCHG     1
 216
 217 static __inline__ unsigned long
 218 __cmpxchg_u32(volatile unsigned int *p, unsigned int old, unsigned int new)
 219 {
 220         unsigned long flags;
 221         unsigned int retval;
 222
 223         local_irq_save(flags);
 224         __asm__ __volatile__ (
 225                         DCACHE_CLEAR("%0", "r4", "%1")
 226                         M32R_LOCK" %0, @%1;     \n"
 227                 "       bne     %0, %2, 1f;     \n"
 228                         M32R_UNLOCK" %3, @%1;   \n"
 229                 "       bra     2f;             \n"
 230                 "       .fillinsn               \n"
 231                 "1:"
 232                         M32R_UNLOCK" %2, @%1;   \n"
 233                 "       .fillinsn               \n"
 234                 "2:"
 235                         : "=&r" (retval)
 236                         : "r" (p), "r" (old), "r" (new)
 237                         : "cbit", "memory"
 238 #ifdef CONFIG_CHIP_M32700_TS1
 239                         , "r4"
 240 #endif  /* CONFIG_CHIP_M32700_TS1 */
 241                 );
 242         local_irq_restore(flags);
 243
 244         return retval;
 245 }
 246
 247 /* This function doesn't exist, so you'll get a linker error
 248    if something tries to do an invalid cmpxchg().  */
 249 extern void __cmpxchg_called_with_bad_pointer(void);
 250
 251 static __inline__ unsigned long
 252 __cmpxchg(volatile void *ptr, unsigned long old, unsigned long new, int size)
 253 {
 254         switch (size) {
 255         case 4:
 256                 return __cmpxchg_u32(ptr, old, new);
 257 #if 0   /* we don't have __cmpxchg_u64 */
 258         case 8:
 259                 return __cmpxchg_u64(ptr, old, new);
 260 #endif /* 0 */
 261         }
 262         __cmpxchg_called_with_bad_pointer();
 263         return old;
 264 }
 265
 266 #define cmpxchg(ptr,o,n)                                                 \
 267   ({                                                                     \
 268      __typeof__(*(ptr)) _o_ = (o);                                       \
 269      __typeof__(*(ptr)) _n_ = (n);                                       \
 270      (__typeof__(*(ptr))) __cmpxchg((ptr), (unsigned long)_o_,           \
 271                                     (unsigned long)_n_, sizeof(*(ptr))); \
 272   })
 273
 274 #endif  /* __KERNEL__ */
 275
 276 /*
 277  * Memory barrier.
 278  *
 279  * mb() prevents loads and stores being reordered across this point.
 280  * rmb() prevents loads being reordered across this point.
 281  * wmb() prevents stores being reordered across this point.
 282  */
 283 #define mb()   barrier()
 284 #define rmb()  mb()
 285 #define wmb()  mb()
 286
 287 /**
 288  * read_barrier_depends - Flush all pending reads that subsequents reads
 289  * depend on.
 290  *
 291  * No data-dependent reads from memory-like regions are ever reordered
 292  * over this barrier.  All reads preceding this primitive are guaranteed
 293  * to access memory (but not necessarily other CPUs' caches) before any
 294  * reads following this primitive that depend on the data return by
 295  * any of the preceding reads.  This primitive is much lighter weight than
 296  * rmb() on most CPUs, and is never heavier weight than is
 297  * rmb().
 298  *
 299  * These ordering constraints are respected by both the local CPU
 300  * and the compiler.
 301  *
 302  * Ordering is not guaranteed by anything other than these primitives,
 303  * not even by data dependencies.  See the documentation for
 304  * memory_barrier() for examples and URLs to more information.
 305  *
 306  * For example, the following code would force ordering (the initial
 307  * value of "a" is zero, "b" is one, and "p" is "&a"):
 308  *
 309  * <programlisting>
 310  *      CPU 0                           CPU 1
 311  *
 312  *      b = 2;
 313  *      memory_barrier();
 314  *      p = &b;                         q = p;
 315  *                                      read_barrier_depends();
 316  *                                      d = *q;
 317  * </programlisting>
 318  *
 319  *
 320  * because the read of "*q" depends on the read of "p" and these
 321  * two reads are separated by a read_barrier_depends().  However,
 322  * the following code, with the same initial values for "a" and "b":
 323  *
 324  * <programlisting>
 325  *      CPU 0                           CPU 1
 326  *
 327  *      a = 2;
 328  *      memory_barrier();
 329  *      b = 3;                          y = b;
 330  *                                      read_barrier_depends();
 331  *                                      x = a;
 332  * </programlisting>
 333  *
 334  * does not enforce ordering, since there is no data dependency between
 335  * the read of "a" and the read of "b".  Therefore, on some CPUs, such
 336  * as Alpha, "y" could be set to 3 and "x" to 0.  Use rmb()
 337  * in cases like thiswhere there are no data dependencies.
 338  **/
 339
 340 #define read_barrier_depends()  do { } while (0)
 341
 342 #ifdef CONFIG_SMP
 343 #define smp_mb()        mb()
 344 #define smp_rmb()       rmb()
 345 #define smp_wmb()       wmb()
 346 #define smp_read_barrier_depends()      read_barrier_depends()
 347 #else
 348 #define smp_mb()        barrier()
 349 #define smp_rmb()       barrier()
 350 #define smp_wmb()       barrier()
 351 #define smp_read_barrier_depends()      do { } while (0)
 352 #endif
 353
 354 #define set_mb(var, value) do { xchg(&var, value); } while (0)
 355 #define set_wmb(var, value) do { var = value; wmb(); } while (0)
 356
 357 #define arch_align_stack(x) (x)
 358
 359 #endif  /* _ASM_M32R_SYSTEM_H */