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_BARRIER "bcr   14,0\n"
  31
  32 #define __ATOMIC_LOOP(ptr, op_val, op_string, __barrier)                \
  33 ({                                                                      \
  34         int old_val;                                                    \
  35                                                                         \
  36         typecheck(atomic_t *, ptr);                                     \
  37         asm volatile(                                                   \
  38                 __barrier                                               \
  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_BARRIER "\n"
  53
  54 #define __ATOMIC_LOOP(ptr, op_val, op_string, __barrier)                \
  55 ({                                                                      \
  56         int old_val, new_val;                                           \
  57                                                                         \
  58         typecheck(atomic_t *, ptr);                                     \
  59         asm volatile(                                                   \
  60                 "       l       %0,%2\n"                                \
  61                 "0:     lr      %1,%0\n"                                \
  62                 op_string "     %1,%3\n"                                \
  63                 "       cs      %0,%1,%2\n"                             \
  64                 "       jl      0b"                                     \
  65                 : "=&d" (old_val), "=&d" (new_val), "+Q" ((ptr)->counter)\
  66                 : "d" (op_val)                                          \
  67                 : "cc", "memory");                                      \
  68         old_val;                                                        \
  69 })
  70
  71 #endif /* CONFIG_HAVE_MARCH_Z196_FEATURES */
  72
  73 static inline int atomic_read(const atomic_t *v)
  74 {
  75         int c;
  76
  77         asm volatile(
  78                 "       l       %0,%1\n"
  79                 : "=d" (c) : "Q" (v->counter));
  80         return c;
  81 }
  82
  83 static inline void atomic_set(atomic_t *v, int i)
  84 {
  85         asm volatile(
  86                 "       st      %1,%0\n"
  87                 : "=Q" (v->counter) : "d" (i));
  88 }
  89
  90 static inline int atomic_add_return(int i, atomic_t *v)
  91 {
  92         return __ATOMIC_LOOP(v, i, __ATOMIC_ADD, __ATOMIC_BARRIER) + i;
  93 }
  94
  95 static inline void atomic_add(int i, atomic_t *v)
  96 {
  97 #ifdef CONFIG_HAVE_MARCH_Z196_FEATURES
  98         if (__builtin_constant_p(i) && (i > -129) && (i < 128)) {
  99                 asm volatile(
 100                         "asi    %0,%1\n"
 101                         : "+Q" (v->counter)
 102                         : "i" (i)
 103                         : "cc", "memory");
 104                 return;
 105         }
 106 #endif
 107         __ATOMIC_LOOP(v, i, __ATOMIC_ADD, __ATOMIC_NO_BARRIER);
 108 }
 109
 110 #define atomic_add_negative(_i, _v)     (atomic_add_return(_i, _v) < 0)
 111 #define atomic_inc(_v)                  atomic_add(1, _v)
 112 #define atomic_inc_return(_v)           atomic_add_return(1, _v)
 113 #define atomic_inc_and_test(_v)         (atomic_add_return(1, _v) == 0)
 114 #define atomic_sub(_i, _v)              atomic_add(-(int)(_i), _v)
 115 #define atomic_sub_return(_i, _v)       atomic_add_return(-(int)(_i), _v)
 116 #define atomic_sub_and_test(_i, _v)     (atomic_sub_return(_i, _v) == 0)
 117 #define atomic_dec(_v)                  atomic_sub(1, _v)
 118 #define atomic_dec_return(_v)           atomic_sub_return(1, _v)
 119 #define atomic_dec_and_test(_v)         (atomic_sub_return(1, _v) == 0)
 120
 121 static inline void atomic_clear_mask(unsigned int mask, atomic_t *v)
 122 {
 123         __ATOMIC_LOOP(v, ~mask, __ATOMIC_AND, __ATOMIC_NO_BARRIER);
 124 }
 125
 126 static inline void atomic_set_mask(unsigned int mask, atomic_t *v)
 127 {
 128         __ATOMIC_LOOP(v, mask, __ATOMIC_OR, __ATOMIC_NO_BARRIER);
 129 }
 130
 131 #define atomic_xchg(v, new) (xchg(&((v)->counter), new))
 132
 133 static inline int atomic_cmpxchg(atomic_t *v, int old, int new)
 134 {
 135         asm volatile(
 136                 "       cs      %0,%2,%1"
 137                 : "+d" (old), "+Q" (v->counter)
 138                 : "d" (new)
 139                 : "cc", "memory");
 140         return old;
 141 }
 142
 143 static inline int __atomic_add_unless(atomic_t *v, int a, int u)
 144 {
 145         int c, old;
 146         c = atomic_read(v);
 147         for (;;) {
 148                 if (unlikely(c == u))
 149                         break;
 150                 old = atomic_cmpxchg(v, c, c + a);
 151                 if (likely(old == c))
 152                         break;
 153                 c = old;
 154         }
 155         return c;
 156 }
 157
 158
 159 #undef __ATOMIC_LOOP
 160
 161 #define ATOMIC64_INIT(i)  { (i) }
 162
 163 #define __ATOMIC64_NO_BARRIER   "\n"
 164
 165 #ifdef CONFIG_HAVE_MARCH_Z196_FEATURES
 166
 167 #define __ATOMIC64_OR   "laog"
 168 #define __ATOMIC64_AND  "lang"
 169 #define __ATOMIC64_ADD  "laag"
 170 #define __ATOMIC64_BARRIER "bcr 14,0\n"
 171
 172 #define __ATOMIC64_LOOP(ptr, op_val, op_string, __barrier)              \
 173 ({                                                                      \
 174         long long old_val;                                              \
 175                                                                         \
 176         typecheck(atomic64_t *, ptr);                                   \
 177         asm volatile(                                                   \
 178                 __barrier                                               \
 179                 op_string "     %0,%2,%1\n"                             \
 180                 __barrier                                               \
 181                 : "=d" (old_val), "+Q" ((ptr)->counter)                 \
 182                 : "d" (op_val)                                          \
 183                 : "cc", "memory");                                      \
 184         old_val;                                                        \
 185 })
 186
 187 #else /* CONFIG_HAVE_MARCH_Z196_FEATURES */
 188
 189 #define __ATOMIC64_OR   "ogr"
 190 #define __ATOMIC64_AND  "ngr"
 191 #define __ATOMIC64_ADD  "agr"
 192 #define __ATOMIC64_BARRIER "\n"
 193
 194 #define __ATOMIC64_LOOP(ptr, op_val, op_string, __barrier)              \
 195 ({                                                                      \
 196         long long old_val, new_val;                                     \
 197                                                                         \
 198         typecheck(atomic64_t *, ptr);                                   \
 199         asm volatile(                                                   \
 200                 "       lg      %0,%2\n"                                \
 201                 "0:     lgr     %1,%0\n"                                \
 202                 op_string "     %1,%3\n"                                \
 203                 "       csg     %0,%1,%2\n"                             \
 204                 "       jl      0b"                                     \
 205                 : "=&d" (old_val), "=&d" (new_val), "+Q" ((ptr)->counter)\
 206                 : "d" (op_val)                                          \
 207                 : "cc", "memory");                                      \
 208         old_val;                                                        \
 209 })
 210
 211 #endif /* CONFIG_HAVE_MARCH_Z196_FEATURES */
 212
 213 static inline long long atomic64_read(const atomic64_t *v)
 214 {
 215         long long c;
 216
 217         asm volatile(
 218                 "       lg      %0,%1\n"
 219                 : "=d" (c) : "Q" (v->counter));
 220         return c;
 221 }
 222
 223 static inline void atomic64_set(atomic64_t *v, long long i)
 224 {
 225         asm volatile(
 226                 "       stg     %1,%0\n"
 227                 : "=Q" (v->counter) : "d" (i));
 228 }
 229
 230 static inline long long atomic64_add_return(long long i, atomic64_t *v)
 231 {
 232         return __ATOMIC64_LOOP(v, i, __ATOMIC64_ADD, __ATOMIC64_BARRIER) + i;
 233 }
 234
 235 static inline void atomic64_add(long long i, atomic64_t *v)
 236 {
 237 #ifdef CONFIG_HAVE_MARCH_Z196_FEATURES
 238         if (__builtin_constant_p(i) && (i > -129) && (i < 128)) {
 239                 asm volatile(
 240                         "agsi   %0,%1\n"
 241                         : "+Q" (v->counter)
 242                         : "i" (i)
 243                         : "cc", "memory");
 244                 return;
 245         }
 246 #endif
 247         __ATOMIC64_LOOP(v, i, __ATOMIC64_ADD, __ATOMIC64_NO_BARRIER);
 248 }
 249
 250 static inline void atomic64_clear_mask(unsigned long mask, atomic64_t *v)
 251 {
 252         __ATOMIC64_LOOP(v, ~mask, __ATOMIC64_AND, __ATOMIC64_NO_BARRIER);
 253 }
 254
 255 static inline void atomic64_set_mask(unsigned long mask, atomic64_t *v)
 256 {
 257         __ATOMIC64_LOOP(v, mask, __ATOMIC64_OR, __ATOMIC64_NO_BARRIER);
 258 }
 259
 260 #define atomic64_xchg(v, new) (xchg(&((v)->counter), new))
 261
 262 static inline long long atomic64_cmpxchg(atomic64_t *v,
 263                                              long long old, long long new)
 264 {
 265         asm volatile(
 266                 "       csg     %0,%2,%1"
 267                 : "+d" (old), "+Q" (v->counter)
 268                 : "d" (new)
 269                 : "cc", "memory");
 270         return old;
 271 }
 272
 273 #undef __ATOMIC64_LOOP
 274
 275 static inline int atomic64_add_unless(atomic64_t *v, long long i, long long u)
 276 {
 277         long long c, old;
 278
 279         c = atomic64_read(v);
 280         for (;;) {
 281                 if (unlikely(c == u))
 282                         break;
 283                 old = atomic64_cmpxchg(v, c, c + i);
 284                 if (likely(old == c))
 285                         break;
 286                 c = old;
 287         }
 288         return c != u;
 289 }
 290
 291 static inline long long atomic64_dec_if_positive(atomic64_t *v)
 292 {
 293         long long c, old, dec;
 294
 295         c = atomic64_read(v);
 296         for (;;) {
 297                 dec = c - 1;
 298                 if (unlikely(dec < 0))
 299                         break;
 300                 old = atomic64_cmpxchg((v), c, dec);
 301                 if (likely(old == c))
 302                         break;
 303                 c = old;
 304         }
 305         return dec;
 306 }
 307
 308 #define atomic64_add_negative(_i, _v)   (atomic64_add_return(_i, _v) < 0)
 309 #define atomic64_inc(_v)                atomic64_add(1, _v)
 310 #define atomic64_inc_return(_v)         atomic64_add_return(1, _v)
 311 #define atomic64_inc_and_test(_v)       (atomic64_add_return(1, _v) == 0)
 312 #define atomic64_sub_return(_i, _v)     atomic64_add_return(-(long long)(_i), _v)
 313 #define atomic64_sub(_i, _v)            atomic64_add(-(long long)(_i), _v)
 314 #define atomic64_sub_and_test(_i, _v)   (atomic64_sub_return(_i, _v) == 0)
 315 #define atomic64_dec(_v)                atomic64_sub(1, _v)
 316 #define atomic64_dec_return(_v)         atomic64_sub_return(1, _v)
 317 #define atomic64_dec_and_test(_v)       (atomic64_sub_return(1, _v) == 0)
 318 #define atomic64_inc_not_zero(v)        atomic64_add_unless((v), 1, 0)
 319
 320 #endif /* __ARCH_S390_ATOMIC__  */