arch/alpha/include/asm/atomic.h

   1 #ifndef _ALPHA_ATOMIC_H
   2 #define _ALPHA_ATOMIC_H
   3
   4 #include <linux/types.h>
   5 #include <asm/barrier.h>
   6 #include <asm/system.h>
   7
   8 /*
   9  * Atomic operations that C can't guarantee us.  Useful for
  10  * resource counting etc...
  11  *
  12  * But use these as seldom as possible since they are much slower
  13  * than regular operations.
  14  */
  15
  16
  17 #define ATOMIC_INIT(i)          ( (atomic_t) { (i) } )
  18 #define ATOMIC64_INIT(i)        ( (atomic64_t) { (i) } )
  19
  20 #define atomic_read(v)          (*(volatile int *)&(v)->counter)
  21 #define atomic64_read(v)        (*(volatile long *)&(v)->counter)
  22
  23 #define atomic_set(v,i)         ((v)->counter = (i))
  24 #define atomic64_set(v,i)       ((v)->counter = (i))
  25
  26 /*
  27  * To get proper branch prediction for the main line, we must branch
  28  * forward to code at the end of this object's .text section, then
  29  * branch back to restart the operation.
  30  */
  31
  32 static __inline__ void atomic_add(int i, atomic_t * v)
  33 {
  34         unsigned long temp;
  35         __asm__ __volatile__(
  36         "1:     ldl_l %0,%1\n"
  37         "       addl %0,%2,%0\n"
  38         "       stl_c %0,%1\n"
  39         "       beq %0,2f\n"
  40         ".subsection 2\n"
  41         "2:     br 1b\n"
  42         ".previous"
  43         :"=&r" (temp), "=m" (v->counter)
  44         :"Ir" (i), "m" (v->counter));
  45 }
  46
  47 static __inline__ void atomic64_add(long i, atomic64_t * v)
  48 {
  49         unsigned long temp;
  50         __asm__ __volatile__(
  51         "1:     ldq_l %0,%1\n"
  52         "       addq %0,%2,%0\n"
  53         "       stq_c %0,%1\n"
  54         "       beq %0,2f\n"
  55         ".subsection 2\n"
  56         "2:     br 1b\n"
  57         ".previous"
  58         :"=&r" (temp), "=m" (v->counter)
  59         :"Ir" (i), "m" (v->counter));
  60 }
  61
  62 static __inline__ void atomic_sub(int i, atomic_t * v)
  63 {
  64         unsigned long temp;
  65         __asm__ __volatile__(
  66         "1:     ldl_l %0,%1\n"
  67         "       subl %0,%2,%0\n"
  68         "       stl_c %0,%1\n"
  69         "       beq %0,2f\n"
  70         ".subsection 2\n"
  71         "2:     br 1b\n"
  72         ".previous"
  73         :"=&r" (temp), "=m" (v->counter)
  74         :"Ir" (i), "m" (v->counter));
  75 }
  76
  77 static __inline__ void atomic64_sub(long i, atomic64_t * v)
  78 {
  79         unsigned long temp;
  80         __asm__ __volatile__(
  81         "1:     ldq_l %0,%1\n"
  82         "       subq %0,%2,%0\n"
  83         "       stq_c %0,%1\n"
  84         "       beq %0,2f\n"
  85         ".subsection 2\n"
  86         "2:     br 1b\n"
  87         ".previous"
  88         :"=&r" (temp), "=m" (v->counter)
  89         :"Ir" (i), "m" (v->counter));
  90 }
  91
  92
  93 /*
  94  * Same as above, but return the result value
  95  */
  96 static inline int atomic_add_return(int i, atomic_t *v)
  97 {
  98         long temp, result;
  99         smp_mb();
 100         __asm__ __volatile__(
 101         "1:     ldl_l %0,%1\n"
 102         "       addl %0,%3,%2\n"
 103         "       addl %0,%3,%0\n"
 104         "       stl_c %0,%1\n"
 105         "       beq %0,2f\n"
 106         ".subsection 2\n"
 107         "2:     br 1b\n"
 108         ".previous"
 109         :"=&r" (temp), "=m" (v->counter), "=&r" (result)
 110         :"Ir" (i), "m" (v->counter) : "memory");
 111         smp_mb();
 112         return result;
 113 }
 114
 115 static __inline__ long atomic64_add_return(long i, atomic64_t * v)
 116 {
 117         long temp, result;
 118         smp_mb();
 119         __asm__ __volatile__(
 120         "1:     ldq_l %0,%1\n"
 121         "       addq %0,%3,%2\n"
 122         "       addq %0,%3,%0\n"
 123         "       stq_c %0,%1\n"
 124         "       beq %0,2f\n"
 125         ".subsection 2\n"
 126         "2:     br 1b\n"
 127         ".previous"
 128         :"=&r" (temp), "=m" (v->counter), "=&r" (result)
 129         :"Ir" (i), "m" (v->counter) : "memory");
 130         smp_mb();
 131         return result;
 132 }
 133
 134 static __inline__ long atomic_sub_return(int i, atomic_t * v)
 135 {
 136         long temp, result;
 137         smp_mb();
 138         __asm__ __volatile__(
 139         "1:     ldl_l %0,%1\n"
 140         "       subl %0,%3,%2\n"
 141         "       subl %0,%3,%0\n"
 142         "       stl_c %0,%1\n"
 143         "       beq %0,2f\n"
 144         ".subsection 2\n"
 145         "2:     br 1b\n"
 146         ".previous"
 147         :"=&r" (temp), "=m" (v->counter), "=&r" (result)
 148         :"Ir" (i), "m" (v->counter) : "memory");
 149         smp_mb();
 150         return result;
 151 }
 152
 153 static __inline__ long atomic64_sub_return(long i, atomic64_t * v)
 154 {
 155         long temp, result;
 156         smp_mb();
 157         __asm__ __volatile__(
 158         "1:     ldq_l %0,%1\n"
 159         "       subq %0,%3,%2\n"
 160         "       subq %0,%3,%0\n"
 161         "       stq_c %0,%1\n"
 162         "       beq %0,2f\n"
 163         ".subsection 2\n"
 164         "2:     br 1b\n"
 165         ".previous"
 166         :"=&r" (temp), "=m" (v->counter), "=&r" (result)
 167         :"Ir" (i), "m" (v->counter) : "memory");
 168         smp_mb();
 169         return result;
 170 }
 171
 172 #define atomic64_cmpxchg(v, old, new) (cmpxchg(&((v)->counter), old, new))
 173 #define atomic64_xchg(v, new) (xchg(&((v)->counter), new))
 174
 175 #define atomic_cmpxchg(v, old, new) (cmpxchg(&((v)->counter), old, new))
 176 #define atomic_xchg(v, new) (xchg(&((v)->counter), new))
 177
 178 /**
 179  * atomic_add_unless - add unless the number is a given value
 180  * @v: pointer of type atomic_t
 181  * @a: the amount to add to v...
 182  * @u: ...unless v is equal to u.
 183  *
 184  * Atomically adds @a to @v, so long as it was not @u.
 185  * Returns non-zero if @v was not @u, and zero otherwise.
 186  */
 187 static __inline__ int atomic_add_unless(atomic_t *v, int a, int u)
 188 {
 189         int c, old;
 190         c = atomic_read(v);
 191         for (;;) {
 192                 if (unlikely(c == (u)))
 193                         break;
 194                 old = atomic_cmpxchg((v), c, c + (a));
 195                 if (likely(old == c))
 196                         break;
 197                 c = old;
 198         }
 199         return c != (u);
 200 }
 201
 202
 203 /**
 204  * atomic64_add_unless - add unless the number is a given value
 205  * @v: pointer of type atomic64_t
 206  * @a: the amount to add to v...
 207  * @u: ...unless v is equal to u.
 208  *
 209  * Atomically adds @a to @v, so long as it was not @u.
 210  * Returns non-zero if @v was not @u, and zero otherwise.
 211  */
 212 static __inline__ int atomic64_add_unless(atomic64_t *v, long a, long u)
 213 {
 214         long c, old;
 215         c = atomic64_read(v);
 216         for (;;) {
 217                 if (unlikely(c == (u)))
 218                         break;
 219                 old = atomic64_cmpxchg((v), c, c + (a));
 220                 if (likely(old == c))
 221                         break;
 222                 c = old;
 223         }
 224         return c != (u);
 225 }
 226
 227 #define atomic64_inc_not_zero(v) atomic64_add_unless((v), 1, 0)
 228
 229 #define atomic_add_negative(a, v) (atomic_add_return((a), (v)) < 0)
 230 #define atomic64_add_negative(a, v) (atomic64_add_return((a), (v)) < 0)
 231
 232 #define atomic_dec_return(v) atomic_sub_return(1,(v))
 233 #define atomic64_dec_return(v) atomic64_sub_return(1,(v))
 234
 235 #define atomic_inc_return(v) atomic_add_return(1,(v))
 236 #define atomic64_inc_return(v) atomic64_add_return(1,(v))
 237
 238 #define atomic_sub_and_test(i,v) (atomic_sub_return((i), (v)) == 0)
 239 #define atomic64_sub_and_test(i,v) (atomic64_sub_return((i), (v)) == 0)
 240
 241 #define atomic_inc_and_test(v) (atomic_add_return(1, (v)) == 0)
 242 #define atomic64_inc_and_test(v) (atomic64_add_return(1, (v)) == 0)
 243
 244 #define atomic_dec_and_test(v) (atomic_sub_return(1, (v)) == 0)
 245 #define atomic64_dec_and_test(v) (atomic64_sub_return(1, (v)) == 0)
 246
 247 #define atomic_inc(v) atomic_add(1,(v))
 248 #define atomic64_inc(v) atomic64_add(1,(v))
 249
 250 #define atomic_dec(v) atomic_sub(1,(v))
 251 #define atomic64_dec(v) atomic64_sub(1,(v))
 252
 253 #define smp_mb__before_atomic_dec()     smp_mb()
 254 #define smp_mb__after_atomic_dec()      smp_mb()
 255 #define smp_mb__before_atomic_inc()     smp_mb()
 256 #define smp_mb__after_atomic_inc()      smp_mb()
 257
 258 #include <asm-generic/atomic-long.h>
 259 #endif /* _ALPHA_ATOMIC_H */