1 #ifndef _ALPHA_ATOMIC_H 2 #define _ALPHA_ATOMIC_H 3 4 #include <linux/types.h> 5 #include <asm/barrier.h> 6 #include <asm/cmpxchg.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) { (i) } 18 #define ATOMIC64_INIT(i) { (i) } 19 20 #define atomic_read(v) ACCESS_ONCE((v)->counter) 21 #define atomic64_read(v) ACCESS_ONCE((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 #define ATOMIC_OP(op) \ 33 static __inline__ void atomic_##op(int i, atomic_t * v) \ 34 { \ 35 unsigned long temp; \ 36 __asm__ __volatile__( \ 37 "1: ldl_l %0,%1\n" \ 38 " " #op "l %0,%2,%0\n" \ 39 " stl_c %0,%1\n" \ 40 " beq %0,2f\n" \ 41 ".subsection 2\n" \ 42 "2: br 1b\n" \ 43 ".previous" \ 44 :"=&r" (temp), "=m" (v->counter) \ 45 :"Ir" (i), "m" (v->counter)); \ 46 } \ 47 48 #define ATOMIC_OP_RETURN(op) \ 49 static inline int atomic_##op##_return(int i, atomic_t *v) \ 50 { \ 51 long temp, result; \ 52 smp_mb(); \ 53 __asm__ __volatile__( \ 54 "1: ldl_l %0,%1\n" \ 55 " " #op "l %0,%3,%2\n" \ 56 " " #op "l %0,%3,%0\n" \ 57 " stl_c %0,%1\n" \ 58 " beq %0,2f\n" \ 59 ".subsection 2\n" \ 60 "2: br 1b\n" \ 61 ".previous" \ 62 :"=&r" (temp), "=m" (v->counter), "=&r" (result) \ 63 :"Ir" (i), "m" (v->counter) : "memory"); \ 64 smp_mb(); \ 65 return result; \ 66 } 67 68 #define ATOMIC64_OP(op) \ 69 static __inline__ void atomic64_##op(long i, atomic64_t * v) \ 70 { \ 71 unsigned long temp; \ 72 __asm__ __volatile__( \ 73 "1: ldq_l %0,%1\n" \ 74 " " #op "q %0,%2,%0\n" \ 75 " stq_c %0,%1\n" \ 76 " beq %0,2f\n" \ 77 ".subsection 2\n" \ 78 "2: br 1b\n" \ 79 ".previous" \ 80 :"=&r" (temp), "=m" (v->counter) \ 81 :"Ir" (i), "m" (v->counter)); \ 82 } \ 83 84 #define ATOMIC64_OP_RETURN(op) \ 85 static __inline__ long atomic64_##op##_return(long i, atomic64_t * v) \ 86 { \ 87 long temp, result; \ 88 smp_mb(); \ 89 __asm__ __volatile__( \ 90 "1: ldq_l %0,%1\n" \ 91 " " #op "q %0,%3,%2\n" \ 92 " " #op "q %0,%3,%0\n" \ 93 " stq_c %0,%1\n" \ 94 " beq %0,2f\n" \ 95 ".subsection 2\n" \ 96 "2: br 1b\n" \ 97 ".previous" \ 98 :"=&r" (temp), "=m" (v->counter), "=&r" (result) \ 99 :"Ir" (i), "m" (v->counter) : "memory"); \ 100 smp_mb(); \ 101 return result; \ 102 } 103 104 #define ATOMIC_OPS(opg) \ 105 ATOMIC_OP(opg) \ 106 ATOMIC_OP_RETURN(opg) \ 107 ATOMIC64_OP(opg) \ 108 ATOMIC64_OP_RETURN(opg) 109 110 ATOMIC_OPS(add) 111 ATOMIC_OPS(sub) 112 113 #undef ATOMIC_OPS 114 #undef ATOMIC64_OP_RETURN 115 #undef ATOMIC64_OP 116 #undef ATOMIC_OP_RETURN 117 #undef ATOMIC_OP 118 119 #define atomic64_cmpxchg(v, old, new) (cmpxchg(&((v)->counter), old, new)) 120 #define atomic64_xchg(v, new) (xchg(&((v)->counter), new)) 121 122 #define atomic_cmpxchg(v, old, new) (cmpxchg(&((v)->counter), old, new)) 123 #define atomic_xchg(v, new) (xchg(&((v)->counter), new)) 124 125 /** 126 * __atomic_add_unless - add unless the number is a given value 127 * @v: pointer of type atomic_t 128 * @a: the amount to add to v... 129 * @u: ...unless v is equal to u. 130 * 131 * Atomically adds @a to @v, so long as it was not @u. 132 * Returns the old value of @v. 133 */ 134 static __inline__ int __atomic_add_unless(atomic_t *v, int a, int u) 135 { 136 int c, new, old; 137 smp_mb(); 138 __asm__ __volatile__( 139 "1: ldl_l %[old],%[mem]\n" 140 " cmpeq %[old],%[u],%[c]\n" 141 " addl %[old],%[a],%[new]\n" 142 " bne %[c],2f\n" 143 " stl_c %[new],%[mem]\n" 144 " beq %[new],3f\n" 145 "2:\n" 146 ".subsection 2\n" 147 "3: br 1b\n" 148 ".previous" 149 : [old] "=&r"(old), [new] "=&r"(new), [c] "=&r"(c) 150 : [mem] "m"(*v), [a] "rI"(a), [u] "rI"((long)u) 151 : "memory"); 152 smp_mb(); 153 return old; 154 } 155 156 157 /** 158 * atomic64_add_unless - add unless the number is a given value 159 * @v: pointer of type atomic64_t 160 * @a: the amount to add to v... 161 * @u: ...unless v is equal to u. 162 * 163 * Atomically adds @a to @v, so long as it was not @u. 164 * Returns true iff @v was not @u. 165 */ 166 static __inline__ int atomic64_add_unless(atomic64_t *v, long a, long u) 167 { 168 long c, tmp; 169 smp_mb(); 170 __asm__ __volatile__( 171 "1: ldq_l %[tmp],%[mem]\n" 172 " cmpeq %[tmp],%[u],%[c]\n" 173 " addq %[tmp],%[a],%[tmp]\n" 174 " bne %[c],2f\n" 175 " stq_c %[tmp],%[mem]\n" 176 " beq %[tmp],3f\n" 177 "2:\n" 178 ".subsection 2\n" 179 "3: br 1b\n" 180 ".previous" 181 : [tmp] "=&r"(tmp), [c] "=&r"(c) 182 : [mem] "m"(*v), [a] "rI"(a), [u] "rI"(u) 183 : "memory"); 184 smp_mb(); 185 return !c; 186 } 187 188 /* 189 * atomic64_dec_if_positive - decrement by 1 if old value positive 190 * @v: pointer of type atomic_t 191 * 192 * The function returns the old value of *v minus 1, even if 193 * the atomic variable, v, was not decremented. 194 */ 195 static inline long atomic64_dec_if_positive(atomic64_t *v) 196 { 197 long old, tmp; 198 smp_mb(); 199 __asm__ __volatile__( 200 "1: ldq_l %[old],%[mem]\n" 201 " subq %[old],1,%[tmp]\n" 202 " ble %[old],2f\n" 203 " stq_c %[tmp],%[mem]\n" 204 " beq %[tmp],3f\n" 205 "2:\n" 206 ".subsection 2\n" 207 "3: br 1b\n" 208 ".previous" 209 : [old] "=&r"(old), [tmp] "=&r"(tmp) 210 : [mem] "m"(*v) 211 : "memory"); 212 smp_mb(); 213 return old - 1; 214 } 215 216 #define atomic64_inc_not_zero(v) atomic64_add_unless((v), 1, 0) 217 218 #define atomic_add_negative(a, v) (atomic_add_return((a), (v)) < 0) 219 #define atomic64_add_negative(a, v) (atomic64_add_return((a), (v)) < 0) 220 221 #define atomic_dec_return(v) atomic_sub_return(1,(v)) 222 #define atomic64_dec_return(v) atomic64_sub_return(1,(v)) 223 224 #define atomic_inc_return(v) atomic_add_return(1,(v)) 225 #define atomic64_inc_return(v) atomic64_add_return(1,(v)) 226 227 #define atomic_sub_and_test(i,v) (atomic_sub_return((i), (v)) == 0) 228 #define atomic64_sub_and_test(i,v) (atomic64_sub_return((i), (v)) == 0) 229 230 #define atomic_inc_and_test(v) (atomic_add_return(1, (v)) == 0) 231 #define atomic64_inc_and_test(v) (atomic64_add_return(1, (v)) == 0) 232 233 #define atomic_dec_and_test(v) (atomic_sub_return(1, (v)) == 0) 234 #define atomic64_dec_and_test(v) (atomic64_sub_return(1, (v)) == 0) 235 236 #define atomic_inc(v) atomic_add(1,(v)) 237 #define atomic64_inc(v) atomic64_add(1,(v)) 238 239 #define atomic_dec(v) atomic_sub(1,(v)) 240 #define atomic64_dec(v) atomic64_sub(1,(v)) 241 242 #endif /* _ALPHA_ATOMIC_H */ 243