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, asm_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 " " #asm_op " %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, asm_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 " " #asm_op " %0,%3,%2\n" \ 56 " " #asm_op " %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, asm_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 " " #asm_op " %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, asm_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 " " #asm_op " %0,%3,%2\n" \ 92 " " #asm_op " %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(op) \ 105 ATOMIC_OP(op, op##l) \ 106 ATOMIC_OP_RETURN(op, op##l) \ 107 ATOMIC64_OP(op, op##q) \ 108 ATOMIC64_OP_RETURN(op, op##q) 109 110 ATOMIC_OPS(add) 111 ATOMIC_OPS(sub) 112 113 #define atomic_andnot atomic_andnot 114 #define atomic64_andnot atomic64_andnot 115 116 ATOMIC_OP(and, and) 117 ATOMIC_OP(andnot, bic) 118 ATOMIC_OP(or, bis) 119 ATOMIC_OP(xor, xor) 120 ATOMIC64_OP(and, and) 121 ATOMIC64_OP(andnot, bic) 122 ATOMIC64_OP(or, bis) 123 ATOMIC64_OP(xor, xor) 124 125 #undef ATOMIC_OPS 126 #undef ATOMIC64_OP_RETURN 127 #undef ATOMIC64_OP 128 #undef ATOMIC_OP_RETURN 129 #undef ATOMIC_OP 130 131 #define atomic64_cmpxchg(v, old, new) (cmpxchg(&((v)->counter), old, new)) 132 #define atomic64_xchg(v, new) (xchg(&((v)->counter), new)) 133 134 #define atomic_cmpxchg(v, old, new) (cmpxchg(&((v)->counter), old, new)) 135 #define atomic_xchg(v, new) (xchg(&((v)->counter), new)) 136 137 /** 138 * __atomic_add_unless - add unless the number is a given value 139 * @v: pointer of type atomic_t 140 * @a: the amount to add to v... 141 * @u: ...unless v is equal to u. 142 * 143 * Atomically adds @a to @v, so long as it was not @u. 144 * Returns the old value of @v. 145 */ 146 static __inline__ int __atomic_add_unless(atomic_t *v, int a, int u) 147 { 148 int c, new, old; 149 smp_mb(); 150 __asm__ __volatile__( 151 "1: ldl_l %[old],%[mem]\n" 152 " cmpeq %[old],%[u],%[c]\n" 153 " addl %[old],%[a],%[new]\n" 154 " bne %[c],2f\n" 155 " stl_c %[new],%[mem]\n" 156 " beq %[new],3f\n" 157 "2:\n" 158 ".subsection 2\n" 159 "3: br 1b\n" 160 ".previous" 161 : [old] "=&r"(old), [new] "=&r"(new), [c] "=&r"(c) 162 : [mem] "m"(*v), [a] "rI"(a), [u] "rI"((long)u) 163 : "memory"); 164 smp_mb(); 165 return old; 166 } 167 168 169 /** 170 * atomic64_add_unless - add unless the number is a given value 171 * @v: pointer of type atomic64_t 172 * @a: the amount to add to v... 173 * @u: ...unless v is equal to u. 174 * 175 * Atomically adds @a to @v, so long as it was not @u. 176 * Returns true iff @v was not @u. 177 */ 178 static __inline__ int atomic64_add_unless(atomic64_t *v, long a, long u) 179 { 180 long c, tmp; 181 smp_mb(); 182 __asm__ __volatile__( 183 "1: ldq_l %[tmp],%[mem]\n" 184 " cmpeq %[tmp],%[u],%[c]\n" 185 " addq %[tmp],%[a],%[tmp]\n" 186 " bne %[c],2f\n" 187 " stq_c %[tmp],%[mem]\n" 188 " beq %[tmp],3f\n" 189 "2:\n" 190 ".subsection 2\n" 191 "3: br 1b\n" 192 ".previous" 193 : [tmp] "=&r"(tmp), [c] "=&r"(c) 194 : [mem] "m"(*v), [a] "rI"(a), [u] "rI"(u) 195 : "memory"); 196 smp_mb(); 197 return !c; 198 } 199 200 /* 201 * atomic64_dec_if_positive - decrement by 1 if old value positive 202 * @v: pointer of type atomic_t 203 * 204 * The function returns the old value of *v minus 1, even if 205 * the atomic variable, v, was not decremented. 206 */ 207 static inline long atomic64_dec_if_positive(atomic64_t *v) 208 { 209 long old, tmp; 210 smp_mb(); 211 __asm__ __volatile__( 212 "1: ldq_l %[old],%[mem]\n" 213 " subq %[old],1,%[tmp]\n" 214 " ble %[old],2f\n" 215 " stq_c %[tmp],%[mem]\n" 216 " beq %[tmp],3f\n" 217 "2:\n" 218 ".subsection 2\n" 219 "3: br 1b\n" 220 ".previous" 221 : [old] "=&r"(old), [tmp] "=&r"(tmp) 222 : [mem] "m"(*v) 223 : "memory"); 224 smp_mb(); 225 return old - 1; 226 } 227 228 #define atomic64_inc_not_zero(v) atomic64_add_unless((v), 1, 0) 229 230 #define atomic_add_negative(a, v) (atomic_add_return((a), (v)) < 0) 231 #define atomic64_add_negative(a, v) (atomic64_add_return((a), (v)) < 0) 232 233 #define atomic_dec_return(v) atomic_sub_return(1,(v)) 234 #define atomic64_dec_return(v) atomic64_sub_return(1,(v)) 235 236 #define atomic_inc_return(v) atomic_add_return(1,(v)) 237 #define atomic64_inc_return(v) atomic64_add_return(1,(v)) 238 239 #define atomic_sub_and_test(i,v) (atomic_sub_return((i), (v)) == 0) 240 #define atomic64_sub_and_test(i,v) (atomic64_sub_return((i), (v)) == 0) 241 242 #define atomic_inc_and_test(v) (atomic_add_return(1, (v)) == 0) 243 #define atomic64_inc_and_test(v) (atomic64_add_return(1, (v)) == 0) 244 245 #define atomic_dec_and_test(v) (atomic_sub_return(1, (v)) == 0) 246 #define atomic64_dec_and_test(v) (atomic64_sub_return(1, (v)) == 0) 247 248 #define atomic_inc(v) atomic_add(1,(v)) 249 #define atomic64_inc(v) atomic64_add(1,(v)) 250 251 #define atomic_dec(v) atomic_sub(1,(v)) 252 #define atomic64_dec(v) atomic64_sub(1,(v)) 253 254 #endif /* _ALPHA_ATOMIC_H */ 255