1 #ifndef _ARCH_I386_LOCAL_H 2 #define _ARCH_I386_LOCAL_H 3 4 #include <linux/percpu.h> 5 #include <asm/system.h> 6 #include <asm/atomic.h> 7 8 typedef struct 9 { 10 atomic_long_t a; 11 } local_t; 12 13 #define LOCAL_INIT(i) { ATOMIC_LONG_INIT(i) } 14 15 #define local_read(l) atomic_long_read(&(l)->a) 16 #define local_set(l,i) atomic_long_set(&(l)->a, (i)) 17 18 static __inline__ void local_inc(local_t *l) 19 { 20 __asm__ __volatile__( 21 "incl %0" 22 :"+m" (l->a.counter)); 23 } 24 25 static __inline__ void local_dec(local_t *l) 26 { 27 __asm__ __volatile__( 28 "decl %0" 29 :"+m" (l->a.counter)); 30 } 31 32 static __inline__ void local_add(long i, local_t *l) 33 { 34 __asm__ __volatile__( 35 "addl %1,%0" 36 :"+m" (l->a.counter) 37 :"ir" (i)); 38 } 39 40 static __inline__ void local_sub(long i, local_t *l) 41 { 42 __asm__ __volatile__( 43 "subl %1,%0" 44 :"+m" (l->a.counter) 45 :"ir" (i)); 46 } 47 48 /** 49 * local_sub_and_test - subtract value from variable and test result 50 * @i: integer value to subtract 51 * @l: pointer of type local_t 52 * 53 * Atomically subtracts @i from @l and returns 54 * true if the result is zero, or false for all 55 * other cases. 56 */ 57 static __inline__ int local_sub_and_test(long i, local_t *l) 58 { 59 unsigned char c; 60 61 __asm__ __volatile__( 62 "subl %2,%0; sete %1" 63 :"+m" (l->a.counter), "=qm" (c) 64 :"ir" (i) : "memory"); 65 return c; 66 } 67 68 /** 69 * local_dec_and_test - decrement and test 70 * @l: pointer of type local_t 71 * 72 * Atomically decrements @l by 1 and 73 * returns true if the result is 0, or false for all other 74 * cases. 75 */ 76 static __inline__ int local_dec_and_test(local_t *l) 77 { 78 unsigned char c; 79 80 __asm__ __volatile__( 81 "decl %0; sete %1" 82 :"+m" (l->a.counter), "=qm" (c) 83 : : "memory"); 84 return c != 0; 85 } 86 87 /** 88 * local_inc_and_test - increment and test 89 * @l: pointer of type local_t 90 * 91 * Atomically increments @l by 1 92 * and returns true if the result is zero, or false for all 93 * other cases. 94 */ 95 static __inline__ int local_inc_and_test(local_t *l) 96 { 97 unsigned char c; 98 99 __asm__ __volatile__( 100 "incl %0; sete %1" 101 :"+m" (l->a.counter), "=qm" (c) 102 : : "memory"); 103 return c != 0; 104 } 105 106 /** 107 * local_add_negative - add and test if negative 108 * @l: pointer of type local_t 109 * @i: integer value to add 110 * 111 * Atomically adds @i to @l and returns true 112 * if the result is negative, or false when 113 * result is greater than or equal to zero. 114 */ 115 static __inline__ int local_add_negative(long i, local_t *l) 116 { 117 unsigned char c; 118 119 __asm__ __volatile__( 120 "addl %2,%0; sets %1" 121 :"+m" (l->a.counter), "=qm" (c) 122 :"ir" (i) : "memory"); 123 return c; 124 } 125 126 /** 127 * local_add_return - add and return 128 * @l: pointer of type local_t 129 * @i: integer value to add 130 * 131 * Atomically adds @i to @l and returns @i + @l 132 */ 133 static __inline__ long local_add_return(long i, local_t *l) 134 { 135 long __i; 136 #ifdef CONFIG_M386 137 unsigned long flags; 138 if(unlikely(boot_cpu_data.x86 <= 3)) 139 goto no_xadd; 140 #endif 141 /* Modern 486+ processor */ 142 __i = i; 143 __asm__ __volatile__( 144 "xaddl %0, %1;" 145 :"+r" (i), "+m" (l->a.counter) 146 : : "memory"); 147 return i + __i; 148 149 #ifdef CONFIG_M386 150 no_xadd: /* Legacy 386 processor */ 151 local_irq_save(flags); 152 __i = local_read(l); 153 local_set(l, i + __i); 154 local_irq_restore(flags); 155 return i + __i; 156 #endif 157 } 158 159 static __inline__ long local_sub_return(long i, local_t *l) 160 { 161 return local_add_return(-i,l); 162 } 163 164 #define local_inc_return(l) (local_add_return(1,l)) 165 #define local_dec_return(l) (local_sub_return(1,l)) 166 167 #define local_cmpxchg(l, o, n) \ 168 (cmpxchg_local(&((l)->a.counter), (o), (n))) 169 /* Always has a lock prefix */ 170 #define local_xchg(l, n) (xchg(&((l)->a.counter), (n))) 171 172 /** 173 * local_add_unless - add unless the number is a given value 174 * @l: pointer of type local_t 175 * @a: the amount to add to l... 176 * @u: ...unless l is equal to u. 177 * 178 * Atomically adds @a to @l, so long as it was not @u. 179 * Returns non-zero if @l was not @u, and zero otherwise. 180 */ 181 #define local_add_unless(l, a, u) \ 182 ({ \ 183 long c, old; \ 184 c = local_read(l); \ 185 for (;;) { \ 186 if (unlikely(c == (u))) \ 187 break; \ 188 old = local_cmpxchg((l), c, c + (a)); \ 189 if (likely(old == c)) \ 190 break; \ 191 c = old; \ 192 } \ 193 c != (u); \ 194 }) 195 #define local_inc_not_zero(l) local_add_unless((l), 1, 0) 196 197 /* On x86, these are no better than the atomic variants. */ 198 #define __local_inc(l) local_inc(l) 199 #define __local_dec(l) local_dec(l) 200 #define __local_add(i,l) local_add((i),(l)) 201 #define __local_sub(i,l) local_sub((i),(l)) 202 203 /* Use these for per-cpu local_t variables: on some archs they are 204 * much more efficient than these naive implementations. Note they take 205 * a variable, not an address. 206 */ 207 208 /* Need to disable preemption for the cpu local counters otherwise we could 209 still access a variable of a previous CPU in a non atomic way. */ 210 #define cpu_local_wrap_v(l) \ 211 ({ local_t res__; \ 212 preempt_disable(); \ 213 res__ = (l); \ 214 preempt_enable(); \ 215 res__; }) 216 #define cpu_local_wrap(l) \ 217 ({ preempt_disable(); \ 218 l; \ 219 preempt_enable(); }) \ 220 221 #define cpu_local_read(l) cpu_local_wrap_v(local_read(&__get_cpu_var(l))) 222 #define cpu_local_set(l, i) cpu_local_wrap(local_set(&__get_cpu_var(l), (i))) 223 #define cpu_local_inc(l) cpu_local_wrap(local_inc(&__get_cpu_var(l))) 224 #define cpu_local_dec(l) cpu_local_wrap(local_dec(&__get_cpu_var(l))) 225 #define cpu_local_add(i, l) cpu_local_wrap(local_add((i), &__get_cpu_var(l))) 226 #define cpu_local_sub(i, l) cpu_local_wrap(local_sub((i), &__get_cpu_var(l))) 227 228 #define __cpu_local_inc(l) cpu_local_inc(l) 229 #define __cpu_local_dec(l) cpu_local_dec(l) 230 #define __cpu_local_add(i, l) cpu_local_add((i), (l)) 231 #define __cpu_local_sub(i, l) cpu_local_sub((i), (l)) 232 233 #endif /* _ARCH_I386_LOCAL_H */ 234
