include/asm-s390/atomic.h

   1 #ifndef __ARCH_S390_ATOMIC__
   2 #define __ARCH_S390_ATOMIC__
   3
   4 /*
   5  *  include/asm-s390/atomic.h
   6  *
   7  *  S390 version
   8  *    Copyright (C) 1999-2003 IBM Deutschland Entwicklung GmbH, IBM Corporation
   9  *    Author(s): Martin Schwidefsky (schwidefsky@de.ibm.com),
  10  *               Denis Joseph Barrow,
  11  *               Arnd Bergmann (arndb@de.ibm.com)
  12  *
  13  *  Derived from "include/asm-i386/bitops.h"
  14  *    Copyright (C) 1992, Linus Torvalds
  15  *
  16  */
  17
  18 /*
  19  * Atomic operations that C can't guarantee us.  Useful for
  20  * resource counting etc..
  21  * S390 uses 'Compare And Swap' for atomicity in SMP enviroment
  22  */
  23
  24 typedef struct {
  25         volatile int counter;
  26 } __attribute__ ((aligned (4))) atomic_t;
  27 #define ATOMIC_INIT(i)  { (i) }
  28
  29 #ifdef __KERNEL__
  30
  31 #define __CS_LOOP(ptr, op_val, op_string) ({                            \
  32         typeof(ptr->counter) old_val, new_val;                          \
  33         __asm__ __volatile__("   l     %0,0(%3)\n"                      \
  34                              "0: lr    %1,%0\n"                         \
  35                              op_string "  %1,%4\n"                      \
  36                              "   cs    %0,%1,0(%3)\n"                   \
  37                              "   jl    0b"                              \
  38                              : "=&d" (old_val), "=&d" (new_val),        \
  39                                "=m" (((atomic_t *)(ptr))->counter)      \
  40                              : "a" (ptr), "d" (op_val),                 \
  41                                "m" (((atomic_t *)(ptr))->counter)       \
  42                              : "cc", "memory" );                        \
  43         new_val;                                                        \
  44 })
  45 #define atomic_read(v)          ((v)->counter)
  46 #define atomic_set(v,i)         (((v)->counter) = (i))
  47
  48 static __inline__ void atomic_add(int i, atomic_t * v)
  49 {
  50                __CS_LOOP(v, i, "ar");
  51 }
  52 static __inline__ int atomic_add_return(int i, atomic_t * v)
  53 {
  54         return __CS_LOOP(v, i, "ar");
  55 }
  56 static __inline__ int atomic_add_negative(int i, atomic_t * v)
  57 {
  58         return __CS_LOOP(v, i, "ar") < 0;
  59 }
  60 static __inline__ void atomic_sub(int i, atomic_t * v)
  61 {
  62                __CS_LOOP(v, i, "sr");
  63 }
  64 static __inline__ void atomic_inc(volatile atomic_t * v)
  65 {
  66                __CS_LOOP(v, 1, "ar");
  67 }
  68 static __inline__ int atomic_inc_return(volatile atomic_t * v)
  69 {
  70         return __CS_LOOP(v, 1, "ar");
  71 }
  72
  73 static __inline__ int atomic_inc_and_test(volatile atomic_t * v)
  74 {
  75         return __CS_LOOP(v, 1, "ar") == 0;
  76 }
  77 static __inline__ void atomic_dec(volatile atomic_t * v)
  78 {
  79                __CS_LOOP(v, 1, "sr");
  80 }
  81 static __inline__ int atomic_dec_return(volatile atomic_t * v)
  82 {
  83         return __CS_LOOP(v, 1, "sr");
  84 }
  85 static __inline__ int atomic_dec_and_test(volatile atomic_t * v)
  86 {
  87         return __CS_LOOP(v, 1, "sr") == 0;
  88 }
  89 static __inline__ void atomic_clear_mask(unsigned long mask, atomic_t * v)
  90 {
  91                __CS_LOOP(v, ~mask, "nr");
  92 }
  93 static __inline__ void atomic_set_mask(unsigned long mask, atomic_t * v)
  94 {
  95                __CS_LOOP(v, mask, "or");
  96 }
  97 #undef __CS_LOOP
  98
  99 #ifdef __s390x__
 100 typedef struct {
 101         volatile long long counter;
 102 } __attribute__ ((aligned (8))) atomic64_t;
 103 #define ATOMIC64_INIT(i)  { (i) }
 104
 105 #define __CSG_LOOP(ptr, op_val, op_string) ({                           \
 106         typeof(ptr->counter) old_val, new_val;                          \
 107         __asm__ __volatile__("   lg    %0,0(%3)\n"                      \
 108                              "0: lgr   %1,%0\n"                         \
 109                              op_string "  %1,%4\n"                      \
 110                              "   csg   %0,%1,0(%3)\n"                   \
 111                              "   jl    0b"                              \
 112                              : "=&d" (old_val), "=&d" (new_val),        \
 113                                "=m" (((atomic_t *)(ptr))->counter)      \
 114                              : "a" (ptr), "d" (op_val),                 \
 115                                "m" (((atomic_t *)(ptr))->counter)       \
 116                              : "cc", "memory" );                        \
 117         new_val;                                                        \
 118 })
 119 #define atomic64_read(v)          ((v)->counter)
 120 #define atomic64_set(v,i)         (((v)->counter) = (i))
 121
 122 static __inline__ void atomic64_add(int i, atomic64_t * v)
 123 {
 124                __CSG_LOOP(v, i, "agr");
 125 }
 126 static __inline__ long long atomic64_add_return(int i, atomic64_t * v)
 127 {
 128         return __CSG_LOOP(v, i, "agr");
 129 }
 130 static __inline__ long long atomic64_add_negative(int i, atomic64_t * v)
 131 {
 132         return __CSG_LOOP(v, i, "agr") < 0;
 133 }
 134 static __inline__ void atomic64_sub(int i, atomic64_t * v)
 135 {
 136                __CSG_LOOP(v, i, "sgr");
 137 }
 138 static __inline__ void atomic64_inc(volatile atomic64_t * v)
 139 {
 140                __CSG_LOOP(v, 1, "agr");
 141 }
 142 static __inline__ long long atomic64_inc_return(volatile atomic64_t * v)
 143 {
 144         return __CSG_LOOP(v, 1, "agr");
 145 }
 146 static __inline__ long long atomic64_inc_and_test(volatile atomic64_t * v)
 147 {
 148         return __CSG_LOOP(v, 1, "agr") == 0;
 149 }
 150 static __inline__ void atomic64_dec(volatile atomic64_t * v)
 151 {
 152                __CSG_LOOP(v, 1, "sgr");
 153 }
 154 static __inline__ long long atomic64_dec_return(volatile atomic64_t * v)
 155 {
 156         return __CSG_LOOP(v, 1, "sgr");
 157 }
 158 static __inline__ long long atomic64_dec_and_test(volatile atomic64_t * v)
 159 {
 160         return __CSG_LOOP(v, 1, "sgr") == 0;
 161 }
 162 static __inline__ void atomic64_clear_mask(unsigned long mask, atomic64_t * v)
 163 {
 164                __CSG_LOOP(v, ~mask, "ngr");
 165 }
 166 static __inline__ void atomic64_set_mask(unsigned long mask, atomic64_t * v)
 167 {
 168                __CSG_LOOP(v, mask, "ogr");
 169 }
 170
 171 #undef __CSG_LOOP
 172 #endif
 173
 174 /*
 175   returns 0  if expected_oldval==value in *v ( swap was successful )
 176   returns 1  if unsuccessful.
 177
 178   This is non-portable, use bitops or spinlocks instead!
 179 */
 180 static __inline__ int
 181 atomic_compare_and_swap(int expected_oldval,int new_val,atomic_t *v)
 182 {
 183         int retval;
 184
 185         __asm__ __volatile__(
 186                 "  lr   %0,%3\n"
 187                 "  cs   %0,%4,0(%2)\n"
 188                 "  ipm  %0\n"
 189                 "  srl  %0,28\n"
 190                 "0:"
 191                 : "=&d" (retval), "=m" (v->counter)
 192                 : "a" (v), "d" (expected_oldval) , "d" (new_val),
 193                   "m" (v->counter) : "cc", "memory" );
 194         return retval;
 195 }
 196
 197 #define smp_mb__before_atomic_dec()     smp_mb()
 198 #define smp_mb__after_atomic_dec()      smp_mb()
 199 #define smp_mb__before_atomic_inc()     smp_mb()
 200 #define smp_mb__after_atomic_inc()      smp_mb()
 201
 202 #endif /* __KERNEL__ */
 203 #endif /* __ARCH_S390_ATOMIC__  */