git.oblomov.eu Git - linux-2.6/blob - arch/s390/include/asm/atomic.h

   1 #ifndef __ARCH_S390_ATOMIC__
   2 #define __ARCH_S390_ATOMIC__
   3
   4 #include <linux/compiler.h>
   5 #include <linux/types.h>
   6
   7 /*
   8  *  include/asm-s390/atomic.h
   9  *
  10  *  S390 version
  11  *    Copyright (C) 1999-2005 IBM Deutschland Entwicklung GmbH, IBM Corporation
  12  *    Author(s): Martin Schwidefsky (schwidefsky@de.ibm.com),
  13  *               Denis Joseph Barrow,
  14  *               Arnd Bergmann (arndb@de.ibm.com)
  15  *
  16  *  Derived from "include/asm-i386/bitops.h"
  17  *    Copyright (C) 1992, Linus Torvalds
  18  *
  19  */
  20
  21 /*
  22  * Atomic operations that C can't guarantee us.  Useful for
  23  * resource counting etc..
  24  * S390 uses 'Compare And Swap' for atomicity in SMP enviroment
  25  */
  26
  27 #define ATOMIC_INIT(i)  { (i) }
  28
  29 #ifdef __KERNEL__
  30
  31 #if __GNUC__ > 3 || (__GNUC__ == 3 && __GNUC_MINOR__ > 2)
  32
  33 #define __CS_LOOP(ptr, op_val, op_string) ({                            \
  34         typeof(ptr->counter) old_val, new_val;                          \
  35         asm volatile(                                                   \
  36                 "       l       %0,%2\n"                                \
  37                 "0:     lr      %1,%0\n"                                \
  38                 op_string "     %1,%3\n"                                \
  39                 "       cs      %0,%1,%2\n"                             \
  40                 "       jl      0b"                                     \
  41                 : "=&d" (old_val), "=&d" (new_val),                     \
  42                   "=Q" (((atomic_t *)(ptr))->counter)                   \
  43                 : "d" (op_val),  "Q" (((atomic_t *)(ptr))->counter)     \
  44                 : "cc", "memory");                                      \
  45         new_val;                                                        \
  46 })
  47
  48 #else /* __GNUC__ */
  49
  50 #define __CS_LOOP(ptr, op_val, op_string) ({                            \
  51         typeof(ptr->counter) old_val, new_val;                          \
  52         asm volatile(                                                   \
  53                 "       l       %0,0(%3)\n"                             \
  54                 "0:     lr      %1,%0\n"                                \
  55                 op_string "     %1,%4\n"                                \
  56                 "       cs      %0,%1,0(%3)\n"                          \
  57                 "       jl      0b"                                     \
  58                 : "=&d" (old_val), "=&d" (new_val),                     \
  59                   "=m" (((atomic_t *)(ptr))->counter)                   \
  60                 : "a" (ptr), "d" (op_val),                              \
  61                   "m" (((atomic_t *)(ptr))->counter)                    \
  62                 : "cc", "memory");                                      \
  63         new_val;                                                        \
  64 })
  65
  66 #endif /* __GNUC__ */
  67
  68 static inline int atomic_read(const atomic_t *v)
  69 {
  70         barrier();
  71         return v->counter;
  72 }
  73
  74 static inline void atomic_set(atomic_t *v, int i)
  75 {
  76         v->counter = i;
  77         barrier();
  78 }
  79
  80 static __inline__ int atomic_add_return(int i, atomic_t * v)
  81 {
  82         return __CS_LOOP(v, i, "ar");
  83 }
  84 #define atomic_add(_i, _v)              atomic_add_return(_i, _v)
  85 #define atomic_add_negative(_i, _v)     (atomic_add_return(_i, _v) < 0)
  86 #define atomic_inc(_v)                  atomic_add_return(1, _v)
  87 #define atomic_inc_return(_v)           atomic_add_return(1, _v)
  88 #define atomic_inc_and_test(_v)         (atomic_add_return(1, _v) == 0)
  89
  90 static __inline__ int atomic_sub_return(int i, atomic_t * v)
  91 {
  92         return __CS_LOOP(v, i, "sr");
  93 }
  94 #define atomic_sub(_i, _v)              atomic_sub_return(_i, _v)
  95 #define atomic_sub_and_test(_i, _v)     (atomic_sub_return(_i, _v) == 0)
  96 #define atomic_dec(_v)                  atomic_sub_return(1, _v)
  97 #define atomic_dec_return(_v)           atomic_sub_return(1, _v)
  98 #define atomic_dec_and_test(_v)         (atomic_sub_return(1, _v) == 0)
  99
 100 static __inline__ void atomic_clear_mask(unsigned long mask, atomic_t * v)
 101 {
 102                __CS_LOOP(v, ~mask, "nr");
 103 }
 104
 105 static __inline__ void atomic_set_mask(unsigned long mask, atomic_t * v)
 106 {
 107                __CS_LOOP(v, mask, "or");
 108 }
 109
 110 #define atomic_xchg(v, new) (xchg(&((v)->counter), new))
 111
 112 static __inline__ int atomic_cmpxchg(atomic_t *v, int old, int new)
 113 {
 114 #if __GNUC__ > 3 || (__GNUC__ == 3 && __GNUC_MINOR__ > 2)
 115         asm volatile(
 116                 "       cs      %0,%2,%1"
 117                 : "+d" (old), "=Q" (v->counter)
 118                 : "d" (new), "Q" (v->counter)
 119                 : "cc", "memory");
 120 #else /* __GNUC__ */
 121         asm volatile(
 122                 "       cs      %0,%3,0(%2)"
 123                 : "+d" (old), "=m" (v->counter)
 124                 : "a" (v), "d" (new), "m" (v->counter)
 125                 : "cc", "memory");
 126 #endif /* __GNUC__ */
 127         return old;
 128 }
 129
 130 static __inline__ int atomic_add_unless(atomic_t *v, int a, int u)
 131 {
 132         int c, old;
 133         c = atomic_read(v);
 134         for (;;) {
 135                 if (unlikely(c == u))
 136                         break;
 137                 old = atomic_cmpxchg(v, c, c + a);
 138                 if (likely(old == c))
 139                         break;
 140                 c = old;
 141         }
 142         return c != u;
 143 }
 144
 145 #define atomic_inc_not_zero(v) atomic_add_unless((v), 1, 0)
 146
 147 #undef __CS_LOOP
 148
 149 #ifdef __s390x__
 150 #define ATOMIC64_INIT(i)  { (i) }
 151
 152 #if __GNUC__ > 3 || (__GNUC__ == 3 && __GNUC_MINOR__ > 2)
 153
 154 #define __CSG_LOOP(ptr, op_val, op_string) ({                           \
 155         typeof(ptr->counter) old_val, new_val;                          \
 156         asm volatile(                                                   \
 157                 "       lg      %0,%2\n"                                \
 158                 "0:     lgr     %1,%0\n"                                \
 159                 op_string "     %1,%3\n"                                \
 160                 "       csg     %0,%1,%2\n"                             \
 161                 "       jl      0b"                                     \
 162                 : "=&d" (old_val), "=&d" (new_val),                     \
 163                   "=Q" (((atomic_t *)(ptr))->counter)                   \
 164                 : "d" (op_val), "Q" (((atomic_t *)(ptr))->counter)      \
 165                 : "cc", "memory" );                                     \
 166         new_val;                                                        \
 167 })
 168
 169 #else /* __GNUC__ */
 170
 171 #define __CSG_LOOP(ptr, op_val, op_string) ({                           \
 172         typeof(ptr->counter) old_val, new_val;                          \
 173         asm volatile(                                                   \
 174                 "       lg      %0,0(%3)\n"                             \
 175                 "0:     lgr     %1,%0\n"                                \
 176                 op_string "     %1,%4\n"                                \
 177                 "       csg     %0,%1,0(%3)\n"                          \
 178                 "       jl      0b"                                     \
 179                 : "=&d" (old_val), "=&d" (new_val),                     \
 180                   "=m" (((atomic_t *)(ptr))->counter)                   \
 181                 : "a" (ptr), "d" (op_val),                              \
 182                   "m" (((atomic_t *)(ptr))->counter)                    \
 183                 : "cc", "memory" );                                     \
 184         new_val;                                                        \
 185 })
 186
 187 #endif /* __GNUC__ */
 188
 189 static inline long long atomic64_read(const atomic64_t *v)
 190 {
 191         barrier();
 192         return v->counter;
 193 }
 194
 195 static inline void atomic64_set(atomic64_t *v, long long i)
 196 {
 197         v->counter = i;
 198         barrier();
 199 }
 200
 201 static __inline__ long long atomic64_add_return(long long i, atomic64_t * v)
 202 {
 203         return __CSG_LOOP(v, i, "agr");
 204 }
 205 #define atomic64_add(_i, _v)            atomic64_add_return(_i, _v)
 206 #define atomic64_add_negative(_i, _v)   (atomic64_add_return(_i, _v) < 0)
 207 #define atomic64_inc(_v)                atomic64_add_return(1, _v)
 208 #define atomic64_inc_return(_v)         atomic64_add_return(1, _v)
 209 #define atomic64_inc_and_test(_v)       (atomic64_add_return(1, _v) == 0)
 210
 211 static __inline__ long long atomic64_sub_return(long long i, atomic64_t * v)
 212 {
 213         return __CSG_LOOP(v, i, "sgr");
 214 }
 215 #define atomic64_sub(_i, _v)            atomic64_sub_return(_i, _v)
 216 #define atomic64_sub_and_test(_i, _v)   (atomic64_sub_return(_i, _v) == 0)
 217 #define atomic64_dec(_v)                atomic64_sub_return(1, _v)
 218 #define atomic64_dec_return(_v)         atomic64_sub_return(1, _v)
 219 #define atomic64_dec_and_test(_v)       (atomic64_sub_return(1, _v) == 0)
 220
 221 static __inline__ void atomic64_clear_mask(unsigned long mask, atomic64_t * v)
 222 {
 223                __CSG_LOOP(v, ~mask, "ngr");
 224 }
 225
 226 static __inline__ void atomic64_set_mask(unsigned long mask, atomic64_t * v)
 227 {
 228                __CSG_LOOP(v, mask, "ogr");
 229 }
 230
 231 #define atomic64_xchg(v, new) (xchg(&((v)->counter), new))
 232
 233 static __inline__ long long atomic64_cmpxchg(atomic64_t *v,
 234                                              long long old, long long new)
 235 {
 236 #if __GNUC__ > 3 || (__GNUC__ == 3 && __GNUC_MINOR__ > 2)
 237         asm volatile(
 238                 "       csg     %0,%2,%1"
 239                 : "+d" (old), "=Q" (v->counter)
 240                 : "d" (new), "Q" (v->counter)
 241                 : "cc", "memory");
 242 #else /* __GNUC__ */
 243         asm volatile(
 244                 "       csg     %0,%3,0(%2)"
 245                 : "+d" (old), "=m" (v->counter)
 246                 : "a" (v), "d" (new), "m" (v->counter)
 247                 : "cc", "memory");
 248 #endif /* __GNUC__ */
 249         return old;
 250 }
 251
 252 static __inline__ int atomic64_add_unless(atomic64_t *v,
 253                                           long long a, long long u)
 254 {
 255         long long c, old;
 256         c = atomic64_read(v);
 257         for (;;) {
 258                 if (unlikely(c == u))
 259                         break;
 260                 old = atomic64_cmpxchg(v, c, c + a);
 261                 if (likely(old == c))
 262                         break;
 263                 c = old;
 264         }
 265         return c != u;
 266 }
 267
 268 #define atomic64_inc_not_zero(v) atomic64_add_unless((v), 1, 0)
 269
 270 #undef __CSG_LOOP
 271 #endif
 272
 273 #define smp_mb__before_atomic_dec()     smp_mb()
 274 #define smp_mb__after_atomic_dec()      smp_mb()
 275 #define smp_mb__before_atomic_inc()     smp_mb()
 276 #define smp_mb__after_atomic_inc()      smp_mb()
 277
 278 #include <asm-generic/atomic.h>
 279 #endif /* __KERNEL__ */
 280 #endif /* __ARCH_S390_ATOMIC__  */