linux/arch/s390/include/asm/atomic.h
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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
  26typedef 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
  70static inline int atomic_read(const atomic_t *v)
  71{
  72        barrier();
  73        return v->counter;
  74}
  75
  76static inline void atomic_set(atomic_t *v, int i)
  77{
  78        v->counter = i;
  79        barrier();
  80}
  81
  82static __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
  92static __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
 102static __inline__ void atomic_clear_mask(unsigned long mask, atomic_t * v)
 103{
 104               __CS_LOOP(v, ~mask, "nr");
 105}
 106
 107static __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
 114static __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
 132static __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__
 152typedef 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
 194static inline long long atomic64_read(const atomic64_t *v)
 195{
 196        barrier();
 197        return v->counter;
 198}
 199
 200static inline void atomic64_set(atomic64_t *v, long long i)
 201{
 202        v->counter = i;
 203        barrier();
 204}
 205
 206static __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
 216static __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
 226static __inline__ void atomic64_clear_mask(unsigned long mask, atomic64_t * v)
 227{
 228               __CSG_LOOP(v, ~mask, "ngr");
 229}
 230
 231static __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
 238static __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
 257static __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__  */
 286
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