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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 #define atomic_read(v)          ((v)->counter)
  71 #define atomic_set(v,i)         (((v)->counter) = (i))
  72
  73 static __inline__ int atomic_add_return(int i, atomic_t * v)
  74 {
  75         return __CS_LOOP(v, i, "ar");
  76 }
  77 #define atomic_add(_i, _v)              atomic_add_return(_i, _v)
  78 #define atomic_add_negative(_i, _v)     (atomic_add_return(_i, _v) < 0)
  79 #define atomic_inc(_v)                  atomic_add_return(1, _v)
  80 #define atomic_inc_return(_v)           atomic_add_return(1, _v)
  81 #define atomic_inc_and_test(_v)         (atomic_add_return(1, _v) == 0)
  82
  83 static __inline__ int atomic_sub_return(int i, atomic_t * v)
  84 {
  85         return __CS_LOOP(v, i, "sr");
  86 }
  87 #define atomic_sub(_i, _v)              atomic_sub_return(_i, _v)
  88 #define atomic_sub_and_test(_i, _v)     (atomic_sub_return(_i, _v) == 0)
  89 #define atomic_dec(_v)                  atomic_sub_return(1, _v)
  90 #define atomic_dec_return(_v)           atomic_sub_return(1, _v)
  91 #define atomic_dec_and_test(_v)         (atomic_sub_return(1, _v) == 0)
  92
  93 static __inline__ void atomic_clear_mask(unsigned long mask, atomic_t * v)
  94 {
  95                __CS_LOOP(v, ~mask, "nr");
  96 }
  97
  98 static __inline__ void atomic_set_mask(unsigned long mask, atomic_t * v)
  99 {
 100                __CS_LOOP(v, mask, "or");
 101 }
 102
 103 #define atomic_xchg(v, new) (xchg(&((v)->counter), new))
 104
 105 static __inline__ int atomic_cmpxchg(atomic_t *v, int old, int new)
 106 {
 107 #if __GNUC__ > 3 || (__GNUC__ == 3 && __GNUC_MINOR__ > 2)
 108         asm volatile(
 109                 "       cs      %0,%2,%1"
 110                 : "+d" (old), "=Q" (v->counter)
 111                 : "d" (new), "Q" (v->counter)
 112                 : "cc", "memory");
 113 #else /* __GNUC__ */
 114         asm volatile(
 115                 "       cs      %0,%3,0(%2)"
 116                 : "+d" (old), "=m" (v->counter)
 117                 : "a" (v), "d" (new), "m" (v->counter)
 118                 : "cc", "memory");
 119 #endif /* __GNUC__ */
 120         return old;
 121 }
 122
 123 static __inline__ int atomic_add_unless(atomic_t *v, int a, int u)
 124 {
 125         int c, old;
 126         c = atomic_read(v);
 127         for (;;) {
 128                 if (unlikely(c == u))
 129                         break;
 130                 old = atomic_cmpxchg(v, c, c + a);
 131                 if (likely(old == c))
 132                         break;
 133                 c = old;
 134         }
 135         return c != u;
 136 }
 137
 138 #define atomic_inc_not_zero(v) atomic_add_unless((v), 1, 0)
 139
 140 #undef __CS_LOOP
 141
 142 #ifdef __s390x__
 143 typedef struct {
 144         long long counter;
 145 } __attribute__ ((aligned (8))) atomic64_t;
 146 #define ATOMIC64_INIT(i)  { (i) }
 147
 148 #if __GNUC__ > 3 || (__GNUC__ == 3 && __GNUC_MINOR__ > 2)
 149
 150 #define __CSG_LOOP(ptr, op_val, op_string) ({                           \
 151         typeof(ptr->counter) old_val, new_val;                          \
 152         asm volatile(                                                   \
 153                 "       lg      %0,%2\n"                                \
 154                 "0:     lgr     %1,%0\n"                                \
 155                 op_string "     %1,%3\n"                                \
 156                 "       csg     %0,%1,%2\n"                             \
 157                 "       jl      0b"                                     \
 158                 : "=&d" (old_val), "=&d" (new_val),                     \
 159                   "=Q" (((atomic_t *)(ptr))->counter)                   \
 160                 : "d" (op_val), "Q" (((atomic_t *)(ptr))->counter)      \
 161                 : "cc", "memory" );                                     \
 162         new_val;                                                        \
 163 })
 164
 165 #else /* __GNUC__ */
 166
 167 #define __CSG_LOOP(ptr, op_val, op_string) ({                           \
 168         typeof(ptr->counter) old_val, new_val;                          \
 169         asm volatile(                                                   \
 170                 "       lg      %0,0(%3)\n"                             \
 171                 "0:     lgr     %1,%0\n"                                \
 172                 op_string "     %1,%4\n"                                \
 173                 "       csg     %0,%1,0(%3)\n"                          \
 174                 "       jl      0b"                                     \
 175                 : "=&d" (old_val), "=&d" (new_val),                     \
 176                   "=m" (((atomic_t *)(ptr))->counter)                   \
 177                 : "a" (ptr), "d" (op_val),                              \
 178                   "m" (((atomic_t *)(ptr))->counter)                    \
 179                 : "cc", "memory" );                                     \
 180         new_val;                                                        \
 181 })
 182
 183 #endif /* __GNUC__ */
 184
 185 #define atomic64_read(v)          ((v)->counter)
 186 #define atomic64_set(v,i)         (((v)->counter) = (i))
 187
 188 static __inline__ long long atomic64_add_return(long long i, atomic64_t * v)
 189 {
 190         return __CSG_LOOP(v, i, "agr");
 191 }
 192 #define atomic64_add(_i, _v)            atomic64_add_return(_i, _v)
 193 #define atomic64_add_negative(_i, _v)   (atomic64_add_return(_i, _v) < 0)
 194 #define atomic64_inc(_v)                atomic64_add_return(1, _v)
 195 #define atomic64_inc_return(_v)         atomic64_add_return(1, _v)
 196 #define atomic64_inc_and_test(_v)       (atomic64_add_return(1, _v) == 0)
 197
 198 static __inline__ long long atomic64_sub_return(long long i, atomic64_t * v)
 199 {
 200         return __CSG_LOOP(v, i, "sgr");
 201 }
 202 #define atomic64_sub(_i, _v)            atomic64_sub_return(_i, _v)
 203 #define atomic64_sub_and_test(_i, _v)   (atomic64_sub_return(_i, _v) == 0)
 204 #define atomic64_dec(_v)                atomic64_sub_return(1, _v)
 205 #define atomic64_dec_return(_v)         atomic64_sub_return(1, _v)
 206 #define atomic64_dec_and_test(_v)       (atomic64_sub_return(1, _v) == 0)
 207
 208 static __inline__ void atomic64_clear_mask(unsigned long mask, atomic64_t * v)
 209 {
 210                __CSG_LOOP(v, ~mask, "ngr");
 211 }
 212
 213 static __inline__ void atomic64_set_mask(unsigned long mask, atomic64_t * v)
 214 {
 215                __CSG_LOOP(v, mask, "ogr");
 216 }
 217
 218 #define atomic64_xchg(v, new) (xchg(&((v)->counter), new))
 219
 220 static __inline__ long long atomic64_cmpxchg(atomic64_t *v,
 221                                              long long old, long long new)
 222 {
 223 #if __GNUC__ > 3 || (__GNUC__ == 3 && __GNUC_MINOR__ > 2)
 224         asm volatile(
 225                 "       csg     %0,%2,%1"
 226                 : "+d" (old), "=Q" (v->counter)
 227                 : "d" (new), "Q" (v->counter)
 228                 : "cc", "memory");
 229 #else /* __GNUC__ */
 230         asm volatile(
 231                 "       csg     %0,%3,0(%2)"
 232                 : "+d" (old), "=m" (v->counter)
 233                 : "a" (v), "d" (new), "m" (v->counter)
 234                 : "cc", "memory");
 235 #endif /* __GNUC__ */
 236         return old;
 237 }
 238
 239 static __inline__ int atomic64_add_unless(atomic64_t *v,
 240                                           long long a, long long u)
 241 {
 242         long long c, old;
 243         c = atomic64_read(v);
 244         for (;;) {
 245                 if (unlikely(c == u))
 246                         break;
 247                 old = atomic64_cmpxchg(v, c, c + a);
 248                 if (likely(old == c))
 249                         break;
 250                 c = old;
 251         }
 252         return c != u;
 253 }
 254
 255 #define atomic64_inc_not_zero(v) atomic64_add_unless((v), 1, 0)
 256
 257 #undef __CSG_LOOP
 258 #endif
 259
 260 #define smp_mb__before_atomic_dec()     smp_mb()
 261 #define smp_mb__after_atomic_dec()      smp_mb()
 262 #define smp_mb__before_atomic_inc()     smp_mb()
 263 #define smp_mb__after_atomic_inc()      smp_mb()
 264
 265 #include <asm-generic/atomic.h>
 266 #endif /* __KERNEL__ */
 267 #endif /* __ARCH_S390_ATOMIC__  */