kernel/arch/s390/include/asm/atomic.h

   1 /*
   2  * Copyright IBM Corp. 1999, 2009
   3  * Author(s): Martin Schwidefsky <schwidefsky@de.ibm.com>,
   4  *            Denis Joseph Barrow,
   5  *            Arnd Bergmann <arndb@de.ibm.com>,
   6  *
   7  * Atomic operations that C can't guarantee us.
   8  * Useful for resource counting etc.
   9  * s390 uses 'Compare And Swap' for atomicity in SMP environment.
  10  *
  11  */
  12
  13 #ifndef __ARCH_S390_ATOMIC__
  14 #define __ARCH_S390_ATOMIC__
  15
  16 #include <linux/compiler.h>
  17 #include <linux/types.h>
  18 #include <asm/barrier.h>
  19 #include <asm/cmpxchg.h>
  20
  21 #define ATOMIC_INIT(i)  { (i) }
  22
  23 #define __ATOMIC_NO_BARRIER     "\n"
  24
  25 #ifdef CONFIG_HAVE_MARCH_Z196_FEATURES
  26
  27 #define __ATOMIC_OR     "lao"
  28 #define __ATOMIC_AND    "lan"
  29 #define __ATOMIC_ADD    "laa"
  30 #define __ATOMIC_XOR    "lax"
  31 #define __ATOMIC_BARRIER "bcr   14,0\n"
  32
  33 #define __ATOMIC_LOOP(ptr, op_val, op_string, __barrier)                \
  34 ({                                                                      \
  35         int old_val;                                                    \
  36                                                                         \
  37         typecheck(atomic_t *, ptr);                                     \
  38         asm volatile(                                                   \
  39                 op_string "     %0,%2,%1\n"                             \
  40                 __barrier                                               \
  41                 : "=d" (old_val), "+Q" ((ptr)->counter)                 \
  42                 : "d" (op_val)                                          \
  43                 : "cc", "memory");                                      \
  44         old_val;                                                        \
  45 })
  46
  47 #else /* CONFIG_HAVE_MARCH_Z196_FEATURES */
  48
  49 #define __ATOMIC_OR     "or"
  50 #define __ATOMIC_AND    "nr"
  51 #define __ATOMIC_ADD    "ar"
  52 #define __ATOMIC_XOR    "xr"
  53 #define __ATOMIC_BARRIER "\n"
  54
  55 #define __ATOMIC_LOOP(ptr, op_val, op_string, __barrier)                \
  56 ({                                                                      \
  57         int old_val, new_val;                                           \
  58                                                                         \
  59         typecheck(atomic_t *, ptr);                                     \
  60         asm volatile(                                                   \
  61                 "       l       %0,%2\n"                                \
  62                 "0:     lr      %1,%0\n"                                \
  63                 op_string "     %1,%3\n"                                \
  64                 "       cs      %0,%1,%2\n"                             \
  65                 "       jl      0b"                                     \
  66                 : "=&d" (old_val), "=&d" (new_val), "+Q" ((ptr)->counter)\
  67                 : "d" (op_val)                                          \
  68                 : "cc", "memory");                                      \
  69         old_val;                                                        \
  70 })
  71
  72 #endif /* CONFIG_HAVE_MARCH_Z196_FEATURES */
  73
  74 static inline int atomic_read(const atomic_t *v)
  75 {
  76         int c;
  77
  78         asm volatile(
  79                 "       l       %0,%1\n"
  80                 : "=d" (c) : "Q" (v->counter));
  81         return c;
  82 }
  83
  84 static inline void atomic_set(atomic_t *v, int i)
  85 {
  86         asm volatile(
  87                 "       st      %1,%0\n"
  88                 : "=Q" (v->counter) : "d" (i));
  89 }
  90
  91 static inline int atomic_add_return(int i, atomic_t *v)
  92 {
  93         return __ATOMIC_LOOP(v, i, __ATOMIC_ADD, __ATOMIC_BARRIER) + i;
  94 }
  95
  96 static inline void atomic_add(int i, atomic_t *v)
  97 {
  98 #ifdef CONFIG_HAVE_MARCH_Z196_FEATURES
  99         if (__builtin_constant_p(i) && (i > -129) && (i < 128)) {
 100                 asm volatile(
 101                         "asi    %0,%1\n"
 102                         : "+Q" (v->counter)
 103                         : "i" (i)
 104                         : "cc", "memory");
 105                 return;
 106         }
 107 #endif
 108         __ATOMIC_LOOP(v, i, __ATOMIC_ADD, __ATOMIC_NO_BARRIER);
 109 }
 110
 111 #define atomic_add_negative(_i, _v)     (atomic_add_return(_i, _v) < 0)
 112 #define atomic_inc(_v)                  atomic_add(1, _v)
 113 #define atomic_inc_return(_v)           atomic_add_return(1, _v)
 114 #define atomic_inc_and_test(_v)         (atomic_add_return(1, _v) == 0)
 115 #define atomic_sub(_i, _v)              atomic_add(-(int)(_i), _v)
 116 #define atomic_sub_return(_i, _v)       atomic_add_return(-(int)(_i), _v)
 117 #define atomic_sub_and_test(_i, _v)     (atomic_sub_return(_i, _v) == 0)
 118 #define atomic_dec(_v)                  atomic_sub(1, _v)
 119 #define atomic_dec_return(_v)           atomic_sub_return(1, _v)
 120 #define atomic_dec_and_test(_v)         (atomic_sub_return(1, _v) == 0)
 121
 122 #define ATOMIC_OP(op, OP)                                               \
 123 static inline void atomic_##op(int i, atomic_t *v)                      \
 124 {                                                                       \
 125         __ATOMIC_LOOP(v, i, __ATOMIC_##OP, __ATOMIC_NO_BARRIER);        \
 126 }
 127
 128 ATOMIC_OP(and, AND)
 129 ATOMIC_OP(or, OR)
 130 ATOMIC_OP(xor, XOR)
 131
 132 #undef ATOMIC_OP
 133
 134 #define atomic_xchg(v, new) (xchg(&((v)->counter), new))
 135
 136 static inline int atomic_cmpxchg(atomic_t *v, int old, int new)
 137 {
 138         asm volatile(
 139                 "       cs      %0,%2,%1"
 140                 : "+d" (old), "+Q" (v->counter)
 141                 : "d" (new)
 142                 : "cc", "memory");
 143         return old;
 144 }
 145
 146 static inline int __atomic_add_unless(atomic_t *v, int a, int u)
 147 {
 148         int c, old;
 149         c = atomic_read(v);
 150         for (;;) {
 151                 if (unlikely(c == u))
 152                         break;
 153                 old = atomic_cmpxchg(v, c, c + a);
 154                 if (likely(old == c))
 155                         break;
 156                 c = old;
 157         }
 158         return c;
 159 }
 160
 161
 162 #undef __ATOMIC_LOOP
 163
 164 #define ATOMIC64_INIT(i)  { (i) }
 165
 166 #define __ATOMIC64_NO_BARRIER   "\n"
 167
 168 #ifdef CONFIG_HAVE_MARCH_Z196_FEATURES
 169
 170 #define __ATOMIC64_OR   "laog"
 171 #define __ATOMIC64_AND  "lang"
 172 #define __ATOMIC64_ADD  "laag"
 173 #define __ATOMIC64_XOR  "laxg"
 174 #define __ATOMIC64_BARRIER "bcr 14,0\n"
 175
 176 #define __ATOMIC64_LOOP(ptr, op_val, op_string, __barrier)              \
 177 ({                                                                      \
 178         long long old_val;                                              \
 179                                                                         \
 180         typecheck(atomic64_t *, ptr);                                   \
 181         asm volatile(                                                   \
 182                 op_string "     %0,%2,%1\n"                             \
 183                 __barrier                                               \
 184                 : "=d" (old_val), "+Q" ((ptr)->counter)                 \
 185                 : "d" (op_val)                                          \
 186                 : "cc", "memory");                                      \
 187         old_val;                                                        \
 188 })
 189
 190 #else /* CONFIG_HAVE_MARCH_Z196_FEATURES */
 191
 192 #define __ATOMIC64_OR   "ogr"
 193 #define __ATOMIC64_AND  "ngr"
 194 #define __ATOMIC64_ADD  "agr"
 195 #define __ATOMIC64_XOR  "xgr"
 196 #define __ATOMIC64_BARRIER "\n"
 197
 198 #define __ATOMIC64_LOOP(ptr, op_val, op_string, __barrier)              \
 199 ({                                                                      \
 200         long long old_val, new_val;                                     \
 201                                                                         \
 202         typecheck(atomic64_t *, ptr);                                   \
 203         asm volatile(                                                   \
 204                 "       lg      %0,%2\n"                                \
 205                 "0:     lgr     %1,%0\n"                                \
 206                 op_string "     %1,%3\n"                                \
 207                 "       csg     %0,%1,%2\n"                             \
 208                 "       jl      0b"                                     \
 209                 : "=&d" (old_val), "=&d" (new_val), "+Q" ((ptr)->counter)\
 210                 : "d" (op_val)                                          \
 211                 : "cc", "memory");                                      \
 212         old_val;                                                        \
 213 })
 214
 215 #endif /* CONFIG_HAVE_MARCH_Z196_FEATURES */
 216
 217 static inline long long atomic64_read(const atomic64_t *v)
 218 {
 219         long long c;
 220
 221         asm volatile(
 222                 "       lg      %0,%1\n"
 223                 : "=d" (c) : "Q" (v->counter));
 224         return c;
 225 }
 226
 227 static inline void atomic64_set(atomic64_t *v, long long i)
 228 {
 229         asm volatile(
 230                 "       stg     %1,%0\n"
 231                 : "=Q" (v->counter) : "d" (i));
 232 }
 233
 234 static inline long long atomic64_add_return(long long i, atomic64_t *v)
 235 {
 236         return __ATOMIC64_LOOP(v, i, __ATOMIC64_ADD, __ATOMIC64_BARRIER) + i;
 237 }
 238
 239 static inline void atomic64_add(long long i, atomic64_t *v)
 240 {
 241 #ifdef CONFIG_HAVE_MARCH_Z196_FEATURES
 242         if (__builtin_constant_p(i) && (i > -129) && (i < 128)) {
 243                 asm volatile(
 244                         "agsi   %0,%1\n"
 245                         : "+Q" (v->counter)
 246                         : "i" (i)
 247                         : "cc", "memory");
 248                 return;
 249         }
 250 #endif
 251         __ATOMIC64_LOOP(v, i, __ATOMIC64_ADD, __ATOMIC64_NO_BARRIER);
 252 }
 253
 254 #define atomic64_xchg(v, new) (xchg(&((v)->counter), new))
 255
 256 static inline long long atomic64_cmpxchg(atomic64_t *v,
 257                                              long long old, long long new)
 258 {
 259         asm volatile(
 260                 "       csg     %0,%2,%1"
 261                 : "+d" (old), "+Q" (v->counter)
 262                 : "d" (new)
 263                 : "cc", "memory");
 264         return old;
 265 }
 266
 267 #define ATOMIC64_OP(op, OP)                                             \
 268 static inline void atomic64_##op(long i, atomic64_t *v)                 \
 269 {                                                                       \
 270         __ATOMIC64_LOOP(v, i, __ATOMIC64_##OP, __ATOMIC64_NO_BARRIER);  \
 271 }
 272
 273 ATOMIC64_OP(and, AND)
 274 ATOMIC64_OP(or, OR)
 275 ATOMIC64_OP(xor, XOR)
 276
 277 #undef ATOMIC64_OP
 278 #undef __ATOMIC64_LOOP
 279
 280 static inline int atomic64_add_unless(atomic64_t *v, long long i, long long u)
 281 {
 282         long long c, old;
 283
 284         c = atomic64_read(v);
 285         for (;;) {
 286                 if (unlikely(c == u))
 287                         break;
 288                 old = atomic64_cmpxchg(v, c, c + i);
 289                 if (likely(old == c))
 290                         break;
 291                 c = old;
 292         }
 293         return c != u;
 294 }
 295
 296 static inline long long atomic64_dec_if_positive(atomic64_t *v)
 297 {
 298         long long c, old, dec;
 299
 300         c = atomic64_read(v);
 301         for (;;) {
 302                 dec = c - 1;
 303                 if (unlikely(dec < 0))
 304                         break;
 305                 old = atomic64_cmpxchg((v), c, dec);
 306                 if (likely(old == c))
 307                         break;
 308                 c = old;
 309         }
 310         return dec;
 311 }
 312
 313 #define atomic64_add_negative(_i, _v)   (atomic64_add_return(_i, _v) < 0)
 314 #define atomic64_inc(_v)                atomic64_add(1, _v)
 315 #define atomic64_inc_return(_v)         atomic64_add_return(1, _v)
 316 #define atomic64_inc_and_test(_v)       (atomic64_add_return(1, _v) == 0)
 317 #define atomic64_sub_return(_i, _v)     atomic64_add_return(-(long long)(_i), _v)
 318 #define atomic64_sub(_i, _v)            atomic64_add(-(long long)(_i), _v)
 319 #define atomic64_sub_and_test(_i, _v)   (atomic64_sub_return(_i, _v) == 0)
 320 #define atomic64_dec(_v)                atomic64_sub(1, _v)
 321 #define atomic64_dec_return(_v)         atomic64_sub_return(1, _v)
 322 #define atomic64_dec_and_test(_v)       (atomic64_sub_return(1, _v) == 0)
 323 #define atomic64_inc_not_zero(v)        atomic64_add_unless((v), 1, 0)
 324
 325 #endif /* __ARCH_S390_ATOMIC__  */