1#ifndef _ARCH_X8664_LOCAL_H 2#define _ARCH_X8664_LOCAL_H 3 4#include <linux/percpu.h> 5#include <asm/atomic.h> 6 7typedef struct 8{ 9 atomic_long_t a; 10} local_t; 11 12#define LOCAL_INIT(i) { ATOMIC_LONG_INIT(i) } 13 14#define local_read(l) atomic_long_read(&(l)->a) 15#define local_set(l,i) atomic_long_set(&(l)->a, (i)) 16 17static inline void local_inc(local_t *l) 18{ 19 __asm__ __volatile__( 20 "incq %0" 21 :"=m" (l->a.counter) 22 :"m" (l->a.counter)); 23} 24 25static inline void local_dec(local_t *l) 26{ 27 __asm__ __volatile__( 28 "decq %0" 29 :"=m" (l->a.counter) 30 :"m" (l->a.counter)); 31} 32 33static inline void local_add(long i, local_t *l) 34{ 35 __asm__ __volatile__( 36 "addq %1,%0" 37 :"=m" (l->a.counter) 38 :"ir" (i), "m" (l->a.counter)); 39} 40 41static inline void local_sub(long i, local_t *l) 42{ 43 __asm__ __volatile__( 44 "subq %1,%0" 45 :"=m" (l->a.counter) 46 :"ir" (i), "m" (l->a.counter)); 47} 48 49/** 50 * local_sub_and_test - subtract value from variable and test result 51 * @i: integer value to subtract 52 * @l: pointer to type local_t 53 * 54 * Atomically subtracts @i from @l and returns 55 * true if the result is zero, or false for all 56 * other cases. 57 */ 58static __inline__ int local_sub_and_test(long i, local_t *l) 59{ 60 unsigned char c; 61 62 __asm__ __volatile__( 63 "subq %2,%0; sete %1" 64 :"=m" (l->a.counter), "=qm" (c) 65 :"ir" (i), "m" (l->a.counter) : "memory"); 66 return c; 67} 68 69/** 70 * local_dec_and_test - decrement and test 71 * @l: pointer to type local_t 72 * 73 * Atomically decrements @l by 1 and 74 * returns true if the result is 0, or false for all other 75 * cases. 76 */ 77static __inline__ int local_dec_and_test(local_t *l) 78{ 79 unsigned char c; 80 81 __asm__ __volatile__( 82 "decq %0; sete %1" 83 :"=m" (l->a.counter), "=qm" (c) 84 :"m" (l->a.counter) : "memory"); 85 return c != 0; 86} 87 88/** 89 * local_inc_and_test - increment and test 90 * @l: pointer to type local_t 91 * 92 * Atomically increments @l by 1 93 * and returns true if the result is zero, or false for all 94 * other cases. 95 */ 96static __inline__ int local_inc_and_test(local_t *l) 97{ 98 unsigned char c; 99 100 __asm__ __volatile__( 101 "incq %0; sete %1" 102 :"=m" (l->a.counter), "=qm" (c) 103 :"m" (l->a.counter) : "memory"); 104 return c != 0; 105} 106 107/** 108 * local_add_negative - add and test if negative 109 * @i: integer value to add 110 * @l: pointer to type local_t 111 * 112 * Atomically adds @i to @l and returns true 113 * if the result is negative, or false when 114 * result is greater than or equal to zero. 115 */ 116static __inline__ int local_add_negative(long i, local_t *l) 117{ 118 unsigned char c; 119 120 __asm__ __volatile__( 121 "addq %2,%0; sets %1" 122 :"=m" (l->a.counter), "=qm" (c) 123 :"ir" (i), "m" (l->a.counter) : "memory"); 124 return c; 125} 126 127/** 128 * local_add_return - add and return 129 * @i: integer value to add 130 * @l: pointer to type local_t 131 * 132 * Atomically adds @i to @l and returns @i + @l 133 */ 134static __inline__ long local_add_return(long i, local_t *l) 135{ 136 long __i = i; 137 __asm__ __volatile__( 138 "xaddq %0, %1;" 139 :"+r" (i), "+m" (l->a.counter) 140 : : "memory"); 141 return i + __i; 142} 143 144static __inline__ long local_sub_return(long i, local_t *l) 145{ 146 return local_add_return(-i,l); 147} 148 149#define local_inc_return(l) (local_add_return(1,l)) 150#define local_dec_return(l) (local_sub_return(1,l)) 151 152#define local_cmpxchg(l, o, n) \ 153 (cmpxchg_local(&((l)->a.counter), (o), (n))) 154/* Always has a lock prefix */ 155#define local_xchg(l, n) (xchg(&((l)->a.counter), (n))) 156 157/** 158 * atomic_up_add_unless - add unless the number is a given value 159 * @l: pointer of type local_t 160 * @a: the amount to add to l... 161 * @u: ...unless l is equal to u. 162 * 163 * Atomically adds @a to @l, so long as it was not @u. 164 * Returns non-zero if @l was not @u, and zero otherwise. 165 */ 166#define local_add_unless(l, a, u) \ 167({ \ 168 long c, old; \ 169 c = local_read(l); \ 170 for (;;) { \ 171 if (unlikely(c == (u))) \ 172 break; \ 173 old = local_cmpxchg((l), c, c + (a)); \ 174 if (likely(old == c)) \ 175 break; \ 176 c = old; \ 177 } \ 178 c != (u); \ 179}) 180#define local_inc_not_zero(l) local_add_unless((l), 1, 0) 181 182/* On x86-64 these are better than the atomic variants on SMP kernels 183 because they dont use a lock prefix. */ 184#define __local_inc(l) local_inc(l) 185#define __local_dec(l) local_dec(l) 186#define __local_add(i,l) local_add((i),(l)) 187#define __local_sub(i,l) local_sub((i),(l)) 188 189/* Use these for per-cpu local_t variables: on some archs they are 190 * much more efficient than these naive implementations. Note they take 191 * a variable, not an address. 192 * 193 * This could be done better if we moved the per cpu data directly 194 * after GS. 195 */ 196 197/* Need to disable preemption for the cpu local counters otherwise we could 198 still access a variable of a previous CPU in a non atomic way. */ 199#define cpu_local_wrap_v(l) \ 200 ({ local_t res__; \ 201 preempt_disable(); \ 202 res__ = (l); \ 203 preempt_enable(); \ 204 res__; }) 205#define cpu_local_wrap(l) \ 206 ({ preempt_disable(); \ 207 l; \ 208 preempt_enable(); }) \ 209 210#define cpu_local_read(l) cpu_local_wrap_v(local_read(&__get_cpu_var(l))) 211#define cpu_local_set(l, i) cpu_local_wrap(local_set(&__get_cpu_var(l), (i))) 212#define cpu_local_inc(l) cpu_local_wrap(local_inc(&__get_cpu_var(l))) 213#define cpu_local_dec(l) cpu_local_wrap(local_dec(&__get_cpu_var(l))) 214#define cpu_local_add(i, l) cpu_local_wrap(local_add((i), &__get_cpu_var(l))) 215#define cpu_local_sub(i, l) cpu_local_wrap(local_sub((i), &__get_cpu_var(l))) 216 217#define __cpu_local_inc(l) cpu_local_inc(l) 218#define __cpu_local_dec(l) cpu_local_dec(l) 219#define __cpu_local_add(i, l) cpu_local_add((i), (l)) 220#define __cpu_local_sub(i, l) cpu_local_sub((i), (l)) 221 222#endif /* _ARCH_X8664_LOCAL_H */ 223