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 static __inline__ int atomic_inc_and_test(volatile atomic_t * v)
  73 {
  74         return __CS_LOOP(v, 1, "ar") != 0;
  75 }
  76 static __inline__ void atomic_dec(volatile atomic_t * v)
  77 {
  78                __CS_LOOP(v, 1, "sr");
  79 }
  80 static __inline__ int atomic_dec_return(volatile atomic_t * v)
  81 {
  82         return __CS_LOOP(v, 1, "sr");
  83 }
  84 static __inline__ int atomic_dec_and_test(volatile atomic_t * v)
  85 {
  86         return __CS_LOOP(v, 1, "sr") == 0;
  87 }
  88 static __inline__ void atomic_clear_mask(unsigned long mask, atomic_t * v)
  89 {
  90                __CS_LOOP(v, ~mask, "nr");
  91 }
  92 static __inline__ void atomic_set_mask(unsigned long mask, atomic_t * v)
  93 {
  94                __CS_LOOP(v, mask, "or");
  95 }
  96 #undef __CS_LOOP
  97
  98 #ifdef __s390x__
  99 typedef struct {
 100         volatile long long counter;
 101 } __attribute__ ((aligned (8))) atomic64_t;
 102 #define ATOMIC64_INIT(i)  { (i) }
 103
 104 #define __CSG_LOOP(ptr, op_val, op_string) ({                           \
 105         typeof(ptr->counter) old_val, new_val;                          \
 106         __asm__ __volatile__("   lg    %0,0(%3)\n"                      \
 107                              "0: lgr   %1,%0\n"                         \
 108                              op_string "  %1,%4\n"                      \
 109                              "   csg   %0,%1,0(%3)\n"                   \
 110                              "   jl    0b"                              \
 111                              : "=&d" (old_val), "=&d" (new_val),        \
 112                                "=m" (((atomic_t *)(ptr))->counter)      \
 113                              : "a" (ptr), "d" (op_val),                 \
 114                                "m" (((atomic_t *)(ptr))->counter)       \
 115                              : "cc", "memory" );                        \
 116         new_val;                                                        \
 117 })
 118 #define atomic64_read(v)          ((v)->counter)
 119 #define atomic64_set(v,i)         (((v)->counter) = (i))
 120
 121 static __inline__ void atomic64_add(int i, atomic64_t * v)
 122 {
 123                __CSG_LOOP(v, i, "agr");
 124 }
 125 static __inline__ long long atomic64_add_return(int i, atomic64_t * v)
 126 {
 127         return __CSG_LOOP(v, i, "agr");
 128 }
 129 static __inline__ long long atomic64_add_negative(int i, atomic64_t * v)
 130 {
 131         return __CSG_LOOP(v, i, "agr") < 0;
 132 }
 133 static __inline__ void atomic64_sub(int i, atomic64_t * v)
 134 {
 135                __CSG_LOOP(v, i, "sgr");
 136 }
 137 static __inline__ void atomic64_inc(volatile atomic64_t * v)
 138 {
 139                __CSG_LOOP(v, 1, "agr");
 140 }
 141 static __inline__ long long atomic64_inc_return(volatile atomic64_t * v)
 142 {
 143         return __CSG_LOOP(v, 1, "agr");
 144 }
 145 static __inline__ long long atomic64_inc_and_test(volatile atomic64_t * v)
 146 {
 147         return __CSG_LOOP(v, 1, "agr") != 0;
 148 }
 149 static __inline__ void atomic64_dec(volatile atomic64_t * v)
 150 {
 151                __CSG_LOOP(v, 1, "sgr");
 152 }
 153 static __inline__ long long atomic64_dec_return(volatile atomic64_t * v)
 154 {
 155         return __CSG_LOOP(v, 1, "sgr");
 156 }
 157 static __inline__ long long atomic64_dec_and_test(volatile atomic64_t * v)
 158 {
 159         return __CSG_LOOP(v, 1, "sgr") == 0;
 160 }
 161 static __inline__ void atomic64_clear_mask(unsigned long mask, atomic64_t * v)
 162 {
 163                __CSG_LOOP(v, ~mask, "ngr");
 164 }
 165 static __inline__ void atomic64_set_mask(unsigned long mask, atomic64_t * v)
 166 {
 167                __CSG_LOOP(v, mask, "ogr");
 168 }
 169
 170 #undef __CSG_LOOP
 171 #endif
 172
 173 /*
 174   returns 0  if expected_oldval==value in *v ( swap was successful )
 175   returns 1  if unsuccessful.
 176
 177   This is non-portable, use bitops or spinlocks instead!
 178 */
 179 static __inline__ int
 180 atomic_compare_and_swap(int expected_oldval,int new_val,atomic_t *v)
 181 {
 182         int retval;
 183
 184         __asm__ __volatile__(
 185                 "  lr   %0,%3\n"
 186                 "  cs   %0,%4,0(%2)\n"
 187                 "  ipm  %0\n"
 188                 "  srl  %0,28\n"
 189                 "0:"
 190                 : "=&d" (retval), "=m" (v->counter)
 191                 : "a" (v), "d" (expected_oldval) , "d" (new_val),
 192                   "m" (v->counter) : "cc", "memory" );
 193         return retval;
 194 }
 195
 196 #define smp_mb__before_atomic_dec()     smp_mb()
 197 #define smp_mb__after_atomic_dec()      smp_mb()
 198 #define smp_mb__before_atomic_inc()     smp_mb()
 199 #define smp_mb__after_atomic_inc()      smp_mb()
 200
 201 #endif /* __KERNEL__ */
 202 #endif /* __ARCH_S390_ATOMIC__  */