include/asm-m32r/spinlock.h

   1 #ifndef _ASM_M32R_SPINLOCK_H
   2 #define _ASM_M32R_SPINLOCK_H
   3
   4 /*
   5  *  linux/include/asm-m32r/spinlock.h
   6  *
   7  *  M32R version:
   8  *    Copyright (C) 2001, 2002  Hitoshi Yamamoto
   9  *    Copyright (C) 2004  Hirokazu Takata <takata at linux-m32r.org>
  10  */
  11
  12 #include <linux/config.h>       /* CONFIG_DEBUG_SPINLOCK, CONFIG_SMP */
  13 #include <linux/compiler.h>
  14 #include <asm/atomic.h>
  15 #include <asm/page.h>
  16
  17 extern int printk(const char * fmt, ...)
  18         __attribute__ ((format (printf, 1, 2)));
  19
  20 #define RW_LOCK_BIAS             0x01000000
  21 #define RW_LOCK_BIAS_STR        "0x01000000"
  22
  23 /*
  24  * Your basic SMP spinlocks, allowing only a single CPU anywhere
  25  */
  26
  27 typedef struct {
  28         volatile int slock;
  29 #ifdef CONFIG_DEBUG_SPINLOCK
  30         unsigned magic;
  31 #endif
  32 #ifdef CONFIG_PREEMPT
  33         unsigned int break_lock;
  34 #endif
  35 } spinlock_t;
  36
  37 #define SPINLOCK_MAGIC  0xdead4ead
  38
  39 #ifdef CONFIG_DEBUG_SPINLOCK
  40 #define SPINLOCK_MAGIC_INIT     , SPINLOCK_MAGIC
  41 #else
  42 #define SPINLOCK_MAGIC_INIT     /* */
  43 #endif
  44
  45 #define SPIN_LOCK_UNLOCKED (spinlock_t) { 1 SPINLOCK_MAGIC_INIT }
  46
  47 #define spin_lock_init(x)       do { *(x) = SPIN_LOCK_UNLOCKED; } while(0)
  48
  49 /*
  50  * Simple spin lock operations.  There are two variants, one clears IRQ's
  51  * on the local processor, one does not.
  52  *
  53  * We make no fairness assumptions. They have a cost.
  54  */
  55
  56 #define spin_is_locked(x)       (*(volatile int *)(&(x)->slock) <= 0)
  57 #define spin_unlock_wait(x)     do { barrier(); } while(spin_is_locked(x))
  58 #define _raw_spin_lock_flags(lock, flags) _raw_spin_lock(lock)
  59
  60 /**
  61  * _raw_spin_trylock - Try spin lock and return a result
  62  * @lock: Pointer to the lock variable
  63  *
  64  * _raw_spin_trylock() tries to get the lock and returns a result.
  65  * On the m32r, the result value is 1 (= Success) or 0 (= Failure).
  66  */
  67 static inline int _raw_spin_trylock(spinlock_t *lock)
  68 {
  69         int oldval;
  70         unsigned long tmp1, tmp2;
  71
  72         /*
  73          * lock->slock :  =1 : unlock
  74          *             : <=0 : lock
  75          * {
  76          *   oldval = lock->slock; <--+ need atomic operation
  77          *   lock->slock = 0;      <--+
  78          * }
  79          */
  80         __asm__ __volatile__ (
  81                 "# spin_trylock                 \n\t"
  82                 "ldi    %1, #0;                 \n\t"
  83                 "mvfc   %2, psw;                \n\t"
  84                 "clrpsw #0x40 -> nop;           \n\t"
  85                 DCACHE_CLEAR("%0", "r6", "%3")
  86                 "lock   %0, @%3;                \n\t"
  87                 "unlock %1, @%3;                \n\t"
  88                 "mvtc   %2, psw;                \n\t"
  89                 : "=&r" (oldval), "=&r" (tmp1), "=&r" (tmp2)
  90                 : "r" (&lock->slock)
  91                 : "memory"
  92 #ifdef CONFIG_CHIP_M32700_TS1
  93                 , "r6"
  94 #endif  /* CONFIG_CHIP_M32700_TS1 */
  95         );
  96
  97         return (oldval > 0);
  98 }
  99
 100 static inline void _raw_spin_lock(spinlock_t *lock)
 101 {
 102         unsigned long tmp0, tmp1;
 103
 104 #ifdef CONFIG_DEBUG_SPINLOCK
 105         if (unlikely(lock->magic != SPINLOCK_MAGIC)) {
 106                 printk("pc: %p\n", __builtin_return_address(0));
 107                 BUG();
 108         }
 109 #endif
 110         /*
 111          * lock->slock :  =1 : unlock
 112          *             : <=0 : lock
 113          *
 114          * for ( ; ; ) {
 115          *   lock->slock -= 1;  <-- need atomic operation
 116          *   if (lock->slock == 0) break;
 117          *   for ( ; lock->slock <= 0 ; );
 118          * }
 119          */
 120         __asm__ __volatile__ (
 121                 "# spin_lock                    \n\t"
 122                 ".fillinsn                      \n"
 123                 "1:                             \n\t"
 124                 "mvfc   %1, psw;                \n\t"
 125                 "clrpsw #0x40 -> nop;           \n\t"
 126                 DCACHE_CLEAR("%0", "r6", "%2")
 127                 "lock   %0, @%2;                \n\t"
 128                 "addi   %0, #-1;                \n\t"
 129                 "unlock %0, @%2;                \n\t"
 130                 "mvtc   %1, psw;                \n\t"
 131                 "bltz   %0, 2f;                 \n\t"
 132                 LOCK_SECTION_START(".balign 4 \n\t")
 133                 ".fillinsn                      \n"
 134                 "2:                             \n\t"
 135                 "ld     %0, @%2;                \n\t"
 136                 "bgtz   %0, 1b;                 \n\t"
 137                 "bra    2b;                     \n\t"
 138                 LOCK_SECTION_END
 139                 : "=&r" (tmp0), "=&r" (tmp1)
 140                 : "r" (&lock->slock)
 141                 : "memory"
 142 #ifdef CONFIG_CHIP_M32700_TS1
 143                 , "r6"
 144 #endif  /* CONFIG_CHIP_M32700_TS1 */
 145         );
 146 }
 147
 148 static inline void _raw_spin_unlock(spinlock_t *lock)
 149 {
 150 #ifdef CONFIG_DEBUG_SPINLOCK
 151         BUG_ON(lock->magic != SPINLOCK_MAGIC);
 152         BUG_ON(!spin_is_locked(lock));
 153 #endif
 154         mb();
 155         lock->slock = 1;
 156 }
 157
 158 /*
 159  * Read-write spinlocks, allowing multiple readers
 160  * but only one writer.
 161  *
 162  * NOTE! it is quite common to have readers in interrupts
 163  * but no interrupt writers. For those circumstances we
 164  * can "mix" irq-safe locks - any writer needs to get a
 165  * irq-safe write-lock, but readers can get non-irqsafe
 166  * read-locks.
 167  */
 168 typedef struct {
 169         volatile int lock;
 170 #ifdef CONFIG_DEBUG_SPINLOCK
 171         unsigned magic;
 172 #endif
 173 #ifdef CONFIG_PREEMPT
 174         unsigned int break_lock;
 175 #endif
 176 } rwlock_t;
 177
 178 #define RWLOCK_MAGIC    0xdeaf1eed
 179
 180 #ifdef CONFIG_DEBUG_SPINLOCK
 181 #define RWLOCK_MAGIC_INIT       , RWLOCK_MAGIC
 182 #else
 183 #define RWLOCK_MAGIC_INIT       /* */
 184 #endif
 185
 186 #define RW_LOCK_UNLOCKED (rwlock_t) { RW_LOCK_BIAS RWLOCK_MAGIC_INIT }
 187
 188 #define rwlock_init(x)  do { *(x) = RW_LOCK_UNLOCKED; } while(0)
 189
 190 /**
 191  * read_can_lock - would read_trylock() succeed?
 192  * @lock: the rwlock in question.
 193  */
 194 #define read_can_lock(x) ((int)(x)->lock > 0)
 195
 196 /**
 197  * write_can_lock - would write_trylock() succeed?
 198  * @lock: the rwlock in question.
 199  */
 200 #define write_can_lock(x) ((x)->lock == RW_LOCK_BIAS)
 201
 202 /*
 203  * On x86, we implement read-write locks as a 32-bit counter
 204  * with the high bit (sign) being the "contended" bit.
 205  *
 206  * The inline assembly is non-obvious. Think about it.
 207  *
 208  * Changed to use the same technique as rw semaphores.  See
 209  * semaphore.h for details.  -ben
 210  */
 211 /* the spinlock helpers are in arch/i386/kernel/semaphore.c */
 212
 213 static inline void _raw_read_lock(rwlock_t *rw)
 214 {
 215         unsigned long tmp0, tmp1;
 216
 217 #ifdef CONFIG_DEBUG_SPINLOCK
 218         BUG_ON(rw->magic != RWLOCK_MAGIC);
 219 #endif
 220         /*
 221          * rw->lock :  >0 : unlock
 222          *          : <=0 : lock
 223          *
 224          * for ( ; ; ) {
 225          *   rw->lock -= 1;  <-- need atomic operation
 226          *   if (rw->lock >= 0) break;
 227          *   rw->lock += 1;  <-- need atomic operation
 228          *   for ( ; rw->lock <= 0 ; );
 229          * }
 230          */
 231         __asm__ __volatile__ (
 232                 "# read_lock                    \n\t"
 233                 ".fillinsn                      \n"
 234                 "1:                             \n\t"
 235                 "mvfc   %1, psw;                \n\t"
 236                 "clrpsw #0x40 -> nop;           \n\t"
 237                 DCACHE_CLEAR("%0", "r6", "%2")
 238                 "lock   %0, @%2;                \n\t"
 239                 "addi   %0, #-1;                \n\t"
 240                 "unlock %0, @%2;                \n\t"
 241                 "mvtc   %1, psw;                \n\t"
 242                 "bltz   %0, 2f;                 \n\t"
 243                 LOCK_SECTION_START(".balign 4 \n\t")
 244                 ".fillinsn                      \n"
 245                 "2:                             \n\t"
 246                 "clrpsw #0x40 -> nop;           \n\t"
 247                 DCACHE_CLEAR("%0", "r6", "%2")
 248                 "lock   %0, @%2;                \n\t"
 249                 "addi   %0, #1;                 \n\t"
 250                 "unlock %0, @%2;                \n\t"
 251                 "mvtc   %1, psw;                \n\t"
 252                 ".fillinsn                      \n"
 253                 "3:                             \n\t"
 254                 "ld     %0, @%2;                \n\t"
 255                 "bgtz   %0, 1b;                 \n\t"
 256                 "bra    3b;                     \n\t"
 257                 LOCK_SECTION_END
 258                 : "=&r" (tmp0), "=&r" (tmp1)
 259                 : "r" (&rw->lock)
 260                 : "memory"
 261 #ifdef CONFIG_CHIP_M32700_TS1
 262                 , "r6"
 263 #endif  /* CONFIG_CHIP_M32700_TS1 */
 264         );
 265 }
 266
 267 static inline void _raw_write_lock(rwlock_t *rw)
 268 {
 269         unsigned long tmp0, tmp1, tmp2;
 270
 271 #ifdef CONFIG_DEBUG_SPINLOCK
 272         BUG_ON(rw->magic != RWLOCK_MAGIC);
 273 #endif
 274         /*
 275          * rw->lock :  =RW_LOCK_BIAS_STR : unlock
 276          *          : !=RW_LOCK_BIAS_STR : lock
 277          *
 278          * for ( ; ; ) {
 279          *   rw->lock -= RW_LOCK_BIAS_STR;  <-- need atomic operation
 280          *   if (rw->lock == 0) break;
 281          *   rw->lock += RW_LOCK_BIAS_STR;  <-- need atomic operation
 282          *   for ( ; rw->lock != RW_LOCK_BIAS_STR ; ) ;
 283          * }
 284          */
 285         __asm__ __volatile__ (
 286                 "# write_lock                                   \n\t"
 287                 "seth   %1, #high(" RW_LOCK_BIAS_STR ");        \n\t"
 288                 "or3    %1, %1, #low(" RW_LOCK_BIAS_STR ");     \n\t"
 289                 ".fillinsn                                      \n"
 290                 "1:                                             \n\t"
 291                 "mvfc   %2, psw;                                \n\t"
 292                 "clrpsw #0x40 -> nop;                           \n\t"
 293                 DCACHE_CLEAR("%0", "r7", "%3")
 294                 "lock   %0, @%3;                                \n\t"
 295                 "sub    %0, %1;                                 \n\t"
 296                 "unlock %0, @%3;                                \n\t"
 297                 "mvtc   %2, psw;                                \n\t"
 298                 "bnez   %0, 2f;                                 \n\t"
 299                 LOCK_SECTION_START(".balign 4 \n\t")
 300                 ".fillinsn                                      \n"
 301                 "2:                                             \n\t"
 302                 "clrpsw #0x40 -> nop;                           \n\t"
 303                 DCACHE_CLEAR("%0", "r7", "%3")
 304                 "lock   %0, @%3;                                \n\t"
 305                 "add    %0, %1;                                 \n\t"
 306                 "unlock %0, @%3;                                \n\t"
 307                 "mvtc   %2, psw;                                \n\t"
 308                 ".fillinsn                                      \n"
 309                 "3:                                             \n\t"
 310                 "ld     %0, @%3;                                \n\t"
 311                 "beq    %0, %1, 1b;                             \n\t"
 312                 "bra    3b;                                     \n\t"
 313                 LOCK_SECTION_END
 314                 : "=&r" (tmp0), "=&r" (tmp1), "=&r" (tmp2)
 315                 : "r" (&rw->lock)
 316                 : "memory"
 317 #ifdef CONFIG_CHIP_M32700_TS1
 318                 , "r7"
 319 #endif  /* CONFIG_CHIP_M32700_TS1 */
 320         );
 321 }
 322
 323 static inline void _raw_read_unlock(rwlock_t *rw)
 324 {
 325         unsigned long tmp0, tmp1;
 326
 327         __asm__ __volatile__ (
 328                 "# read_unlock                  \n\t"
 329                 "mvfc   %1, psw;                \n\t"
 330                 "clrpsw #0x40 -> nop;           \n\t"
 331                 DCACHE_CLEAR("%0", "r6", "%2")
 332                 "lock   %0, @%2;                \n\t"
 333                 "addi   %0, #1;                 \n\t"
 334                 "unlock %0, @%2;                \n\t"
 335                 "mvtc   %1, psw;                \n\t"
 336                 : "=&r" (tmp0), "=&r" (tmp1)
 337                 : "r" (&rw->lock)
 338                 : "memory"
 339 #ifdef CONFIG_CHIP_M32700_TS1
 340                 , "r6"
 341 #endif  /* CONFIG_CHIP_M32700_TS1 */
 342         );
 343 }
 344
 345 static inline void _raw_write_unlock(rwlock_t *rw)
 346 {
 347         unsigned long tmp0, tmp1, tmp2;
 348
 349         __asm__ __volatile__ (
 350                 "# write_unlock                                 \n\t"
 351                 "seth   %1, #high(" RW_LOCK_BIAS_STR ");        \n\t"
 352                 "or3    %1, %1, #low(" RW_LOCK_BIAS_STR ");     \n\t"
 353                 "mvfc   %2, psw;                                \n\t"
 354                 "clrpsw #0x40 -> nop;                           \n\t"
 355                 DCACHE_CLEAR("%0", "r7", "%3")
 356                 "lock   %0, @%3;                                \n\t"
 357                 "add    %0, %1;                                 \n\t"
 358                 "unlock %0, @%3;                                \n\t"
 359                 "mvtc   %2, psw;                                \n\t"
 360                 : "=&r" (tmp0), "=&r" (tmp1), "=&r" (tmp2)
 361                 : "r" (&rw->lock)
 362                 : "memory"
 363 #ifdef CONFIG_CHIP_M32700_TS1
 364                 , "r7"
 365 #endif  /* CONFIG_CHIP_M32700_TS1 */
 366         );
 367 }
 368
 369 #define _raw_read_trylock(lock) generic_raw_read_trylock(lock)
 370
 371 static inline int _raw_write_trylock(rwlock_t *lock)
 372 {
 373         atomic_t *count = (atomic_t *)lock;
 374         if (atomic_sub_and_test(RW_LOCK_BIAS, count))
 375                 return 1;
 376         atomic_add(RW_LOCK_BIAS, count);
 377         return 0;
 378 }
 379
 380 #endif  /* _ASM_M32R_SPINLOCK_H */