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   1 #ifndef __ARCH_S390_ATOMIC__
   2 #define __ARCH_S390_ATOMIC__
   3
   4 #include <linux/compiler.h>
   5
   6 /*
   7  *  include/asm-s390/atomic.h
   8  *
   9  *  S390 version
  10  *    Copyright (C) 1999-2005 IBM Deutschland Entwicklung GmbH, IBM Corporation
  11  *    Author(s): Martin Schwidefsky (schwidefsky@de.ibm.com),
  12  *               Denis Joseph Barrow,
  13  *               Arnd Bergmann (arndb@de.ibm.com)
  14  *
  15  *  Derived from "include/asm-i386/bitops.h"
  16  *    Copyright (C) 1992, Linus Torvalds
  17  *
  18  */
  19
  20 /*
  21  * Atomic operations that C can't guarantee us.  Useful for
  22  * resource counting etc..
  23  * S390 uses 'Compare And Swap' for atomicity in SMP enviroment
  24  */
  25
  26 typedef struct {
  27         int counter;
  28 } __attribute__ ((aligned (4))) atomic_t;
  29 #define ATOMIC_INIT(i)  { (i) }
  30
  31 #ifdef __KERNEL__
  32
  33 #if __GNUC__ > 3 || (__GNUC__ == 3 && __GNUC_MINOR__ > 2)
  34
  35 #define __CS_LOOP(ptr, op_val, op_string) ({                            \
  36         typeof(ptr->counter) old_val, new_val;                          \
  37         asm volatile(                                                   \
  38                 "       l       %0,%2\n"                                \
  39                 "0:     lr      %1,%0\n"                                \
  40                 op_string "     %1,%3\n"                                \
  41                 "       cs      %0,%1,%2\n"                             \
  42                 "       jl      0b"                                     \
  43                 : "=&d" (old_val), "=&d" (new_val),                     \
  44                   "=Q" (((atomic_t *)(ptr))->counter)                   \
  45                 : "d" (op_val),  "Q" (((atomic_t *)(ptr))->counter)     \
  46                 : "cc", "memory");                                      \
  47         new_val;                                                        \
  48 })
  49
  50 #else /* __GNUC__ */
  51
  52 #define __CS_LOOP(ptr, op_val, op_string) ({                            \
  53         typeof(ptr->counter) old_val, new_val;                          \
  54         asm volatile(                                                   \
  55                 "       l       %0,0(%3)\n"                             \
  56                 "0:     lr      %1,%0\n"                                \
  57                 op_string "     %1,%4\n"                                \
  58                 "       cs      %0,%1,0(%3)\n"                          \
  59                 "       jl      0b"                                     \
  60                 : "=&d" (old_val), "=&d" (new_val),                     \
  61                   "=m" (((atomic_t *)(ptr))->counter)                   \
  62                 : "a" (ptr), "d" (op_val),                              \
  63                   "m" (((atomic_t *)(ptr))->counter)                    \
  64                 : "cc", "memory");                                      \
  65         new_val;                                                        \
  66 })
  67
  68 #endif /* __GNUC__ */
  69
  70 static inline int atomic_read(const atomic_t *v)
  71 {
  72         barrier();
  73         return v->counter;
  74 }
  75
  76 static inline void atomic_set(atomic_t *v, int i)
  77 {
  78         v->counter = i;
  79         barrier();
  80 }
  81
  82 static __inline__ int atomic_add_return(int i, atomic_t * v)
  83 {
  84         return __CS_LOOP(v, i, "ar");
  85 }
  86 #define atomic_add(_i, _v)              atomic_add_return(_i, _v)
  87 #define atomic_add_negative(_i, _v)     (atomic_add_return(_i, _v) < 0)
  88 #define atomic_inc(_v)                  atomic_add_return(1, _v)
  89 #define atomic_inc_return(_v)           atomic_add_return(1, _v)
  90 #define atomic_inc_and_test(_v)         (atomic_add_return(1, _v) == 0)
  91
  92 static __inline__ int atomic_sub_return(int i, atomic_t * v)
  93 {
  94         return __CS_LOOP(v, i, "sr");
  95 }
  96 #define atomic_sub(_i, _v)              atomic_sub_return(_i, _v)
  97 #define atomic_sub_and_test(_i, _v)     (atomic_sub_return(_i, _v) == 0)
  98 #define atomic_dec(_v)                  atomic_sub_return(1, _v)
  99 #define atomic_dec_return(_v)           atomic_sub_return(1, _v)
 100 #define atomic_dec_and_test(_v)         (atomic_sub_return(1, _v) == 0)
 101
 102 static __inline__ void atomic_clear_mask(unsigned long mask, atomic_t * v)
 103 {
 104                __CS_LOOP(v, ~mask, "nr");
 105 }
 106
 107 static __inline__ void atomic_set_mask(unsigned long mask, atomic_t * v)
 108 {
 109                __CS_LOOP(v, mask, "or");
 110 }
 111
 112 #define atomic_xchg(v, new) (xchg(&((v)->counter), new))
 113
 114 static __inline__ int atomic_cmpxchg(atomic_t *v, int old, int new)
 115 {
 116 #if __GNUC__ > 3 || (__GNUC__ == 3 && __GNUC_MINOR__ > 2)
 117         asm volatile(
 118                 "       cs      %0,%2,%1"
 119                 : "+d" (old), "=Q" (v->counter)
 120                 : "d" (new), "Q" (v->counter)
 121                 : "cc", "memory");
 122 #else /* __GNUC__ */
 123         asm volatile(
 124                 "       cs      %0,%3,0(%2)"
 125                 : "+d" (old), "=m" (v->counter)
 126                 : "a" (v), "d" (new), "m" (v->counter)
 127                 : "cc", "memory");
 128 #endif /* __GNUC__ */
 129         return old;
 130 }
 131
 132 static __inline__ int atomic_add_unless(atomic_t *v, int a, int u)
 133 {
 134         int c, old;
 135         c = atomic_read(v);
 136         for (;;) {
 137                 if (unlikely(c == u))
 138                         break;
 139                 old = atomic_cmpxchg(v, c, c + a);
 140                 if (likely(old == c))
 141                         break;
 142                 c = old;
 143         }
 144         return c != u;
 145 }
 146
 147 #define atomic_inc_not_zero(v) atomic_add_unless((v), 1, 0)
 148
 149 #undef __CS_LOOP
 150
 151 #ifdef __s390x__
 152 typedef struct {
 153         long long counter;
 154 } __attribute__ ((aligned (8))) atomic64_t;
 155 #define ATOMIC64_INIT(i)  { (i) }
 156
 157 #if __GNUC__ > 3 || (__GNUC__ == 3 && __GNUC_MINOR__ > 2)
 158
 159 #define __CSG_LOOP(ptr, op_val, op_string) ({                           \
 160         typeof(ptr->counter) old_val, new_val;                          \
 161         asm volatile(                                                   \
 162                 "       lg      %0,%2\n"                                \
 163                 "0:     lgr     %1,%0\n"                                \
 164                 op_string "     %1,%3\n"                                \
 165                 "       csg     %0,%1,%2\n"                             \
 166                 "       jl      0b"                                     \
 167                 : "=&d" (old_val), "=&d" (new_val),                     \
 168                   "=Q" (((atomic_t *)(ptr))->counter)                   \
 169                 : "d" (op_val), "Q" (((atomic_t *)(ptr))->counter)      \
 170                 : "cc", "memory" );                                     \
 171         new_val;                                                        \
 172 })
 173
 174 #else /* __GNUC__ */
 175
 176 #define __CSG_LOOP(ptr, op_val, op_string) ({                           \
 177         typeof(ptr->counter) old_val, new_val;                          \
 178         asm volatile(                                                   \
 179                 "       lg      %0,0(%3)\n"                             \
 180                 "0:     lgr     %1,%0\n"                                \
 181                 op_string "     %1,%4\n"                                \
 182                 "       csg     %0,%1,0(%3)\n"                          \
 183                 "       jl      0b"                                     \
 184                 : "=&d" (old_val), "=&d" (new_val),                     \
 185                   "=m" (((atomic_t *)(ptr))->counter)                   \
 186                 : "a" (ptr), "d" (op_val),                              \
 187                   "m" (((atomic_t *)(ptr))->counter)                    \
 188                 : "cc", "memory" );                                     \
 189         new_val;                                                        \
 190 })
 191
 192 #endif /* __GNUC__ */
 193
 194 static inline long long atomic64_read(const atomic64_t *v)
 195 {
 196         barrier();
 197         return v->counter;
 198 }
 199
 200 static inline void atomic64_set(atomic64_t *v, long long i)
 201 {
 202         v->counter = i;
 203         barrier();
 204 }
 205
 206 static __inline__ long long atomic64_add_return(long long i, atomic64_t * v)
 207 {
 208         return __CSG_LOOP(v, i, "agr");
 209 }
 210 #define atomic64_add(_i, _v)            atomic64_add_return(_i, _v)
 211 #define atomic64_add_negative(_i, _v)   (atomic64_add_return(_i, _v) < 0)
 212 #define atomic64_inc(_v)                atomic64_add_return(1, _v)
 213 #define atomic64_inc_return(_v)         atomic64_add_return(1, _v)
 214 #define atomic64_inc_and_test(_v)       (atomic64_add_return(1, _v) == 0)
 215
 216 static __inline__ long long atomic64_sub_return(long long i, atomic64_t * v)
 217 {
 218         return __CSG_LOOP(v, i, "sgr");
 219 }
 220 #define atomic64_sub(_i, _v)            atomic64_sub_return(_i, _v)
 221 #define atomic64_sub_and_test(_i, _v)   (atomic64_sub_return(_i, _v) == 0)
 222 #define atomic64_dec(_v)                atomic64_sub_return(1, _v)
 223 #define atomic64_dec_return(_v)         atomic64_sub_return(1, _v)
 224 #define atomic64_dec_and_test(_v)       (atomic64_sub_return(1, _v) == 0)
 225
 226 static __inline__ void atomic64_clear_mask(unsigned long mask, atomic64_t * v)
 227 {
 228                __CSG_LOOP(v, ~mask, "ngr");
 229 }
 230
 231 static __inline__ void atomic64_set_mask(unsigned long mask, atomic64_t * v)
 232 {
 233                __CSG_LOOP(v, mask, "ogr");
 234 }
 235
 236 #define atomic64_xchg(v, new) (xchg(&((v)->counter), new))
 237
 238 static __inline__ long long atomic64_cmpxchg(atomic64_t *v,
 239                                              long long old, long long new)
 240 {
 241 #if __GNUC__ > 3 || (__GNUC__ == 3 && __GNUC_MINOR__ > 2)
 242         asm volatile(
 243                 "       csg     %0,%2,%1"
 244                 : "+d" (old), "=Q" (v->counter)
 245                 : "d" (new), "Q" (v->counter)
 246                 : "cc", "memory");
 247 #else /* __GNUC__ */
 248         asm volatile(
 249                 "       csg     %0,%3,0(%2)"
 250                 : "+d" (old), "=m" (v->counter)
 251                 : "a" (v), "d" (new), "m" (v->counter)
 252                 : "cc", "memory");
 253 #endif /* __GNUC__ */
 254         return old;
 255 }
 256
 257 static __inline__ int atomic64_add_unless(atomic64_t *v,
 258                                           long long a, long long u)
 259 {
 260         long long c, old;
 261         c = atomic64_read(v);
 262         for (;;) {
 263                 if (unlikely(c == u))
 264                         break;
 265                 old = atomic64_cmpxchg(v, c, c + a);
 266                 if (likely(old == c))
 267                         break;
 268                 c = old;
 269         }
 270         return c != u;
 271 }
 272
 273 #define atomic64_inc_not_zero(v) atomic64_add_unless((v), 1, 0)
 274
 275 #undef __CSG_LOOP
 276 #endif
 277
 278 #define smp_mb__before_atomic_dec()     smp_mb()
 279 #define smp_mb__after_atomic_dec()      smp_mb()
 280 #define smp_mb__before_atomic_inc()     smp_mb()
 281 #define smp_mb__after_atomic_inc()      smp_mb()
 282
 283 #include <asm-generic/atomic.h>
 284 #endif /* __KERNEL__ */
 285 #endif /* __ARCH_S390_ATOMIC__  */