1 #ifndef _ARCH_I386_LOCAL_H
2 #define _ARCH_I386_LOCAL_H
4 static inline void local_inc(local_t *l)
11 static inline void local_dec(local_t *l)
15 :"+m" (l->a.counter));
18 static inline void local_add(long i, local_t *l)
26 static inline void local_sub(long i, local_t *l)
35 * local_sub_and_test - subtract value from variable and test result
36 * @i: integer value to subtract
37 * @l: pointer of type local_t
39 * Atomically subtracts @i from @l and returns
40 * true if the result is zero, or false for all
43 static inline int local_sub_and_test(long i, local_t *l)
48 _ASM_SUB "%2,%0; sete %1"
49 :"+m" (l->a.counter), "=qm" (c)
50 :"ir" (i) : "memory");
55 * local_dec_and_test - decrement and test
56 * @l: pointer of type local_t
58 * Atomically decrements @l by 1 and
59 * returns true if the result is 0, or false for all other
62 static inline int local_dec_and_test(local_t *l)
67 _ASM_DEC "%0; sete %1"
68 :"+m" (l->a.counter), "=qm" (c)
74 * local_inc_and_test - increment and test
75 * @l: pointer of type local_t
77 * Atomically increments @l by 1
78 * and returns true if the result is zero, or false for all
81 static inline int local_inc_and_test(local_t *l)
86 _ASM_INC "%0; sete %1"
87 :"+m" (l->a.counter), "=qm" (c)
93 * local_add_negative - add and test if negative
94 * @l: pointer of type local_t
95 * @i: integer value to add
97 * Atomically adds @i to @l and returns true
98 * if the result is negative, or false when
99 * result is greater than or equal to zero.
101 static inline int local_add_negative(long i, local_t *l)
105 __asm__ __volatile__(
106 _ASM_ADD "%2,%0; sets %1"
107 :"+m" (l->a.counter), "=qm" (c)
108 :"ir" (i) : "memory");
113 * local_add_return - add and return
114 * @l: pointer of type local_t
115 * @i: integer value to add
117 * Atomically adds @i to @l and returns @i + @l
119 static inline long local_add_return(long i, local_t *l)
124 if(unlikely(boot_cpu_data.x86 <= 3))
127 /* Modern 486+ processor */
129 __asm__ __volatile__(
131 :"+r" (i), "+m" (l->a.counter)
136 no_xadd: /* Legacy 386 processor */
137 local_irq_save(flags);
139 local_set(l, i + __i);
140 local_irq_restore(flags);
145 static inline long local_sub_return(long i, local_t *l)
147 return local_add_return(-i,l);
150 #define local_inc_return(l) (local_add_return(1,l))
151 #define local_dec_return(l) (local_sub_return(1,l))
153 #define local_cmpxchg(l, o, n) \
154 (cmpxchg_local(&((l)->a.counter), (o), (n)))
155 /* Always has a lock prefix */
156 #define local_xchg(l, n) (xchg(&((l)->a.counter), (n)))
159 * local_add_unless - add unless the number is a given value
160 * @l: pointer of type local_t
161 * @a: the amount to add to l...
162 * @u: ...unless l is equal to u.
164 * Atomically adds @a to @l, so long as it was not @u.
165 * Returns non-zero if @l was not @u, and zero otherwise.
167 #define local_add_unless(l, a, u) \
172 if (unlikely(c == (u))) \
174 old = local_cmpxchg((l), c, c + (a)); \
175 if (likely(old == c)) \
181 #define local_inc_not_zero(l) local_add_unless((l), 1, 0)
183 /* On x86, these are no better than the atomic variants. */
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))
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.
194 /* Need to disable preemption for the cpu local counters otherwise we could
195 still access a variable of a previous CPU in a non atomic way. */
196 #define cpu_local_wrap_v(l) \
202 #define cpu_local_wrap(l) \
203 ({ preempt_disable(); \
205 preempt_enable(); }) \
207 #define cpu_local_read(l) cpu_local_wrap_v(local_read(&__get_cpu_var(l)))
208 #define cpu_local_set(l, i) cpu_local_wrap(local_set(&__get_cpu_var(l), (i)))
209 #define cpu_local_inc(l) cpu_local_wrap(local_inc(&__get_cpu_var(l)))
210 #define cpu_local_dec(l) cpu_local_wrap(local_dec(&__get_cpu_var(l)))
211 #define cpu_local_add(i, l) cpu_local_wrap(local_add((i), &__get_cpu_var(l)))
212 #define cpu_local_sub(i, l) cpu_local_wrap(local_sub((i), &__get_cpu_var(l)))
214 #define __cpu_local_inc(l) cpu_local_inc(l)
215 #define __cpu_local_dec(l) cpu_local_dec(l)
216 #define __cpu_local_add(i, l) cpu_local_add((i), (l))
217 #define __cpu_local_sub(i, l) cpu_local_sub((i), (l))
219 #endif /* _ARCH_I386_LOCAL_H */