include/asm-powerpc/atomic.h

   1 #ifndef _ASM_POWERPC_ATOMIC_H_
   2 #define _ASM_POWERPC_ATOMIC_H_
   3
   4 /*
   5  * PowerPC atomic operations
   6  */
   7
   8 typedef struct { volatile int counter; } atomic_t;
   9
  10 #ifdef __KERNEL__
  11 #include <linux/compiler.h>
  12 #include <asm/synch.h>
  13 #include <asm/asm-compat.h>
  14
  15 #define ATOMIC_INIT(i)          { (i) }
  16
  17 #define atomic_read(v)          ((v)->counter)
  18 #define atomic_set(v,i)         (((v)->counter) = (i))
  19
  20 static __inline__ void atomic_add(int a, atomic_t *v)
  21 {
  22         int t;
  23
  24         __asm__ __volatile__(
  25 "1:     lwarx   %0,0,%3         # atomic_add\n\
  26         add     %0,%2,%0\n"
  27         PPC405_ERR77(0,%3)
  28 "       stwcx.  %0,0,%3 \n\
  29         bne-    1b"
  30         : "=&r" (t), "+m" (v->counter)
  31         : "r" (a), "r" (&v->counter)
  32         : "cc");
  33 }
  34
  35 static __inline__ int atomic_add_return(int a, atomic_t *v)
  36 {
  37         int t;
  38
  39         __asm__ __volatile__(
  40         LWSYNC_ON_SMP
  41 "1:     lwarx   %0,0,%2         # atomic_add_return\n\
  42         add     %0,%1,%0\n"
  43         PPC405_ERR77(0,%2)
  44 "       stwcx.  %0,0,%2 \n\
  45         bne-    1b"
  46         ISYNC_ON_SMP
  47         : "=&r" (t)
  48         : "r" (a), "r" (&v->counter)
  49         : "cc", "memory");
  50
  51         return t;
  52 }
  53
  54 #define atomic_add_negative(a, v)       (atomic_add_return((a), (v)) < 0)
  55
  56 static __inline__ void atomic_sub(int a, atomic_t *v)
  57 {
  58         int t;
  59
  60         __asm__ __volatile__(
  61 "1:     lwarx   %0,0,%3         # atomic_sub\n\
  62         subf    %0,%2,%0\n"
  63         PPC405_ERR77(0,%3)
  64 "       stwcx.  %0,0,%3 \n\
  65         bne-    1b"
  66         : "=&r" (t), "+m" (v->counter)
  67         : "r" (a), "r" (&v->counter)
  68         : "cc");
  69 }
  70
  71 static __inline__ int atomic_sub_return(int a, atomic_t *v)
  72 {
  73         int t;
  74
  75         __asm__ __volatile__(
  76         LWSYNC_ON_SMP
  77 "1:     lwarx   %0,0,%2         # atomic_sub_return\n\
  78         subf    %0,%1,%0\n"
  79         PPC405_ERR77(0,%2)
  80 "       stwcx.  %0,0,%2 \n\
  81         bne-    1b"
  82         ISYNC_ON_SMP
  83         : "=&r" (t)
  84         : "r" (a), "r" (&v->counter)
  85         : "cc", "memory");
  86
  87         return t;
  88 }
  89
  90 static __inline__ void atomic_inc(atomic_t *v)
  91 {
  92         int t;
  93
  94         __asm__ __volatile__(
  95 "1:     lwarx   %0,0,%2         # atomic_inc\n\
  96         addic   %0,%0,1\n"
  97         PPC405_ERR77(0,%2)
  98 "       stwcx.  %0,0,%2 \n\
  99         bne-    1b"
 100         : "=&r" (t), "+m" (v->counter)
 101         : "r" (&v->counter)
 102         : "cc");
 103 }
 104
 105 static __inline__ int atomic_inc_return(atomic_t *v)
 106 {
 107         int t;
 108
 109         __asm__ __volatile__(
 110         LWSYNC_ON_SMP
 111 "1:     lwarx   %0,0,%1         # atomic_inc_return\n\
 112         addic   %0,%0,1\n"
 113         PPC405_ERR77(0,%1)
 114 "       stwcx.  %0,0,%1 \n\
 115         bne-    1b"
 116         ISYNC_ON_SMP
 117         : "=&r" (t)
 118         : "r" (&v->counter)
 119         : "cc", "memory");
 120
 121         return t;
 122 }
 123
 124 /*
 125  * atomic_inc_and_test - increment and test
 126  * @v: pointer of type atomic_t
 127  *
 128  * Atomically increments @v by 1
 129  * and returns true if the result is zero, or false for all
 130  * other cases.
 131  */
 132 #define atomic_inc_and_test(v) (atomic_inc_return(v) == 0)
 133
 134 static __inline__ void atomic_dec(atomic_t *v)
 135 {
 136         int t;
 137
 138         __asm__ __volatile__(
 139 "1:     lwarx   %0,0,%2         # atomic_dec\n\
 140         addic   %0,%0,-1\n"
 141         PPC405_ERR77(0,%2)\
 142 "       stwcx.  %0,0,%2\n\
 143         bne-    1b"
 144         : "=&r" (t), "+m" (v->counter)
 145         : "r" (&v->counter)
 146         : "cc");
 147 }
 148
 149 static __inline__ int atomic_dec_return(atomic_t *v)
 150 {
 151         int t;
 152
 153         __asm__ __volatile__(
 154         LWSYNC_ON_SMP
 155 "1:     lwarx   %0,0,%1         # atomic_dec_return\n\
 156         addic   %0,%0,-1\n"
 157         PPC405_ERR77(0,%1)
 158 "       stwcx.  %0,0,%1\n\
 159         bne-    1b"
 160         ISYNC_ON_SMP
 161         : "=&r" (t)
 162         : "r" (&v->counter)
 163         : "cc", "memory");
 164
 165         return t;
 166 }
 167
 168 #define atomic_cmpxchg(v, o, n) ((int)cmpxchg(&((v)->counter), (o), (n)))
 169 #define atomic_xchg(v, new) (xchg(&((v)->counter), new))
 170
 171 /**
 172  * atomic_add_unless - add unless the number is a given value
 173  * @v: pointer of type atomic_t
 174  * @a: the amount to add to v...
 175  * @u: ...unless v is equal to u.
 176  *
 177  * Atomically adds @a to @v, so long as it was not @u.
 178  * Returns non-zero if @v was not @u, and zero otherwise.
 179  */
 180 static __inline__ int atomic_add_unless(atomic_t *v, int a, int u)
 181 {
 182         int t;
 183
 184         __asm__ __volatile__ (
 185         LWSYNC_ON_SMP
 186 "1:     lwarx   %0,0,%1         # atomic_add_unless\n\
 187         cmpw    0,%0,%3 \n\
 188         beq-    2f \n\
 189         add     %0,%2,%0 \n"
 190         PPC405_ERR77(0,%2)
 191 "       stwcx.  %0,0,%1 \n\
 192         bne-    1b \n"
 193         ISYNC_ON_SMP
 194 "       subf    %0,%2,%0 \n\
 195 2:"
 196         : "=&r" (t)
 197         : "r" (&v->counter), "r" (a), "r" (u)
 198         : "cc", "memory");
 199
 200         return t != u;
 201 }
 202
 203 #define atomic_inc_not_zero(v) atomic_add_unless((v), 1, 0)
 204
 205 #define atomic_sub_and_test(a, v)       (atomic_sub_return((a), (v)) == 0)
 206 #define atomic_dec_and_test(v)          (atomic_dec_return((v)) == 0)
 207
 208 /*
 209  * Atomically test *v and decrement if it is greater than 0.
 210  * The function returns the old value of *v minus 1, even if
 211  * the atomic variable, v, was not decremented.
 212  */
 213 static __inline__ int atomic_dec_if_positive(atomic_t *v)
 214 {
 215         int t;
 216
 217         __asm__ __volatile__(
 218         LWSYNC_ON_SMP
 219 "1:     lwarx   %0,0,%1         # atomic_dec_if_positive\n\
 220         cmpwi   %0,1\n\
 221         addi    %0,%0,-1\n\
 222         blt-    2f\n"
 223         PPC405_ERR77(0,%1)
 224 "       stwcx.  %0,0,%1\n\
 225         bne-    1b"
 226         ISYNC_ON_SMP
 227         "\n\
 228 2:"     : "=&b" (t)
 229         : "r" (&v->counter)
 230         : "cc", "memory");
 231
 232         return t;
 233 }
 234
 235 #define smp_mb__before_atomic_dec()     smp_mb()
 236 #define smp_mb__after_atomic_dec()      smp_mb()
 237 #define smp_mb__before_atomic_inc()     smp_mb()
 238 #define smp_mb__after_atomic_inc()      smp_mb()
 239
 240 #ifdef __powerpc64__
 241
 242 typedef struct { volatile long counter; } atomic64_t;
 243
 244 #define ATOMIC64_INIT(i)        { (i) }
 245
 246 #define atomic64_read(v)        ((v)->counter)
 247 #define atomic64_set(v,i)       (((v)->counter) = (i))
 248
 249 static __inline__ void atomic64_add(long a, atomic64_t *v)
 250 {
 251         long t;
 252
 253         __asm__ __volatile__(
 254 "1:     ldarx   %0,0,%3         # atomic64_add\n\
 255         add     %0,%2,%0\n\
 256         stdcx.  %0,0,%3 \n\
 257         bne-    1b"
 258         : "=&r" (t), "+m" (v->counter)
 259         : "r" (a), "r" (&v->counter)
 260         : "cc");
 261 }
 262
 263 static __inline__ long atomic64_add_return(long a, atomic64_t *v)
 264 {
 265         long t;
 266
 267         __asm__ __volatile__(
 268         LWSYNC_ON_SMP
 269 "1:     ldarx   %0,0,%2         # atomic64_add_return\n\
 270         add     %0,%1,%0\n\
 271         stdcx.  %0,0,%2 \n\
 272         bne-    1b"
 273         ISYNC_ON_SMP
 274         : "=&r" (t)
 275         : "r" (a), "r" (&v->counter)
 276         : "cc", "memory");
 277
 278         return t;
 279 }
 280
 281 #define atomic64_add_negative(a, v)     (atomic64_add_return((a), (v)) < 0)
 282
 283 static __inline__ void atomic64_sub(long a, atomic64_t *v)
 284 {
 285         long t;
 286
 287         __asm__ __volatile__(
 288 "1:     ldarx   %0,0,%3         # atomic64_sub\n\
 289         subf    %0,%2,%0\n\
 290         stdcx.  %0,0,%3 \n\
 291         bne-    1b"
 292         : "=&r" (t), "+m" (v->counter)
 293         : "r" (a), "r" (&v->counter)
 294         : "cc");
 295 }
 296
 297 static __inline__ long atomic64_sub_return(long a, atomic64_t *v)
 298 {
 299         long t;
 300
 301         __asm__ __volatile__(
 302         LWSYNC_ON_SMP
 303 "1:     ldarx   %0,0,%2         # atomic64_sub_return\n\
 304         subf    %0,%1,%0\n\
 305         stdcx.  %0,0,%2 \n\
 306         bne-    1b"
 307         ISYNC_ON_SMP
 308         : "=&r" (t)
 309         : "r" (a), "r" (&v->counter)
 310         : "cc", "memory");
 311
 312         return t;
 313 }
 314
 315 static __inline__ void atomic64_inc(atomic64_t *v)
 316 {
 317         long t;
 318
 319         __asm__ __volatile__(
 320 "1:     ldarx   %0,0,%2         # atomic64_inc\n\
 321         addic   %0,%0,1\n\
 322         stdcx.  %0,0,%2 \n\
 323         bne-    1b"
 324         : "=&r" (t), "+m" (v->counter)
 325         : "r" (&v->counter)
 326         : "cc");
 327 }
 328
 329 static __inline__ long atomic64_inc_return(atomic64_t *v)
 330 {
 331         long t;
 332
 333         __asm__ __volatile__(
 334         LWSYNC_ON_SMP
 335 "1:     ldarx   %0,0,%1         # atomic64_inc_return\n\
 336         addic   %0,%0,1\n\
 337         stdcx.  %0,0,%1 \n\
 338         bne-    1b"
 339         ISYNC_ON_SMP
 340         : "=&r" (t)
 341         : "r" (&v->counter)
 342         : "cc", "memory");
 343
 344         return t;
 345 }
 346
 347 /*
 348  * atomic64_inc_and_test - increment and test
 349  * @v: pointer of type atomic64_t
 350  *
 351  * Atomically increments @v by 1
 352  * and returns true if the result is zero, or false for all
 353  * other cases.
 354  */
 355 #define atomic64_inc_and_test(v) (atomic64_inc_return(v) == 0)
 356
 357 static __inline__ void atomic64_dec(atomic64_t *v)
 358 {
 359         long t;
 360
 361         __asm__ __volatile__(
 362 "1:     ldarx   %0,0,%2         # atomic64_dec\n\
 363         addic   %0,%0,-1\n\
 364         stdcx.  %0,0,%2\n\
 365         bne-    1b"
 366         : "=&r" (t), "+m" (v->counter)
 367         : "r" (&v->counter)
 368         : "cc");
 369 }
 370
 371 static __inline__ long atomic64_dec_return(atomic64_t *v)
 372 {
 373         long t;
 374
 375         __asm__ __volatile__(
 376         LWSYNC_ON_SMP
 377 "1:     ldarx   %0,0,%1         # atomic64_dec_return\n\
 378         addic   %0,%0,-1\n\
 379         stdcx.  %0,0,%1\n\
 380         bne-    1b"
 381         ISYNC_ON_SMP
 382         : "=&r" (t)
 383         : "r" (&v->counter)
 384         : "cc", "memory");
 385
 386         return t;
 387 }
 388
 389 #define atomic64_sub_and_test(a, v)     (atomic64_sub_return((a), (v)) == 0)
 390 #define atomic64_dec_and_test(v)        (atomic64_dec_return((v)) == 0)
 391
 392 /*
 393  * Atomically test *v and decrement if it is greater than 0.
 394  * The function returns the old value of *v minus 1.
 395  */
 396 static __inline__ long atomic64_dec_if_positive(atomic64_t *v)
 397 {
 398         long t;
 399
 400         __asm__ __volatile__(
 401         LWSYNC_ON_SMP
 402 "1:     ldarx   %0,0,%1         # atomic64_dec_if_positive\n\
 403         addic.  %0,%0,-1\n\
 404         blt-    2f\n\
 405         stdcx.  %0,0,%1\n\
 406         bne-    1b"
 407         ISYNC_ON_SMP
 408         "\n\
 409 2:"     : "=&r" (t)
 410         : "r" (&v->counter)
 411         : "cc", "memory");
 412
 413         return t;
 414 }
 415
 416 #endif /* __powerpc64__ */
 417
 418 #include <asm-generic/atomic.h>
 419 #endif /* __KERNEL__ */
 420 #endif /* _ASM_POWERPC_ATOMIC_H_ */