163 lines
3.8 KiB
C
163 lines
3.8 KiB
C
/* SPDX-License-Identifier: GPL-2.0 */
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#ifndef _ASM_X86_LOCAL_H
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#define _ASM_X86_LOCAL_H
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#include <linux/percpu.h>
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#include <linux/atomic.h>
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#include <asm/asm.h>
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typedef struct {
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atomic_long_t a;
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} local_t;
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#define LOCAL_INIT(i) { ATOMIC_LONG_INIT(i) }
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#define local_read(l) atomic_long_read(&(l)->a)
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#define local_set(l, i) atomic_long_set(&(l)->a, (i))
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static inline void local_inc(local_t *l)
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{
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asm volatile(_ASM_INC "%0"
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: "+m" (l->a.counter));
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}
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static inline void local_dec(local_t *l)
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{
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asm volatile(_ASM_DEC "%0"
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: "+m" (l->a.counter));
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}
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static inline void local_add(long i, local_t *l)
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{
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asm volatile(_ASM_ADD "%1,%0"
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: "+m" (l->a.counter)
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: "ir" (i));
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}
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static inline void local_sub(long i, local_t *l)
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{
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asm volatile(_ASM_SUB "%1,%0"
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: "+m" (l->a.counter)
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: "ir" (i));
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}
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/**
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* local_sub_and_test - subtract value from variable and test result
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* @i: integer value to subtract
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* @l: pointer to type local_t
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*
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* Atomically subtracts @i from @l and returns
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* true if the result is zero, or false for all
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* other cases.
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*/
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static inline bool local_sub_and_test(long i, local_t *l)
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{
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return GEN_BINARY_RMWcc(_ASM_SUB, l->a.counter, e, "er", i);
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}
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/**
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* local_dec_and_test - decrement and test
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* @l: pointer to type local_t
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*
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* Atomically decrements @l by 1 and
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* returns true if the result is 0, or false for all other
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* cases.
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*/
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static inline bool local_dec_and_test(local_t *l)
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{
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return GEN_UNARY_RMWcc(_ASM_DEC, l->a.counter, e);
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}
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/**
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* local_inc_and_test - increment and test
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* @l: pointer to type local_t
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*
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* Atomically increments @l by 1
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* and returns true if the result is zero, or false for all
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* other cases.
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*/
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static inline bool local_inc_and_test(local_t *l)
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{
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return GEN_UNARY_RMWcc(_ASM_INC, l->a.counter, e);
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}
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/**
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* local_add_negative - add and test if negative
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* @i: integer value to add
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* @l: pointer to type local_t
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*
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* Atomically adds @i to @l and returns true
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* if the result is negative, or false when
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* result is greater than or equal to zero.
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*/
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static inline bool local_add_negative(long i, local_t *l)
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{
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return GEN_BINARY_RMWcc(_ASM_ADD, l->a.counter, s, "er", i);
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}
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/**
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* local_add_return - add and return
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* @i: integer value to add
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* @l: pointer to type local_t
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*
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* Atomically adds @i to @l and returns @i + @l
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*/
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static inline long local_add_return(long i, local_t *l)
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{
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long __i = i;
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asm volatile(_ASM_XADD "%0, %1;"
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: "+r" (i), "+m" (l->a.counter)
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: : "memory");
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return i + __i;
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}
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static inline long local_sub_return(long i, local_t *l)
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{
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return local_add_return(-i, l);
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}
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#define local_inc_return(l) (local_add_return(1, l))
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#define local_dec_return(l) (local_sub_return(1, l))
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#define local_cmpxchg(l, o, n) \
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(cmpxchg_local(&((l)->a.counter), (o), (n)))
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/* Always has a lock prefix */
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#define local_xchg(l, n) (xchg(&((l)->a.counter), (n)))
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/**
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* local_add_unless - add unless the number is a given value
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* @l: pointer of type local_t
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* @a: the amount to add to l...
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* @u: ...unless l is equal to u.
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*
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* Atomically adds @a to @l, so long as it was not @u.
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* Returns non-zero if @l was not @u, and zero otherwise.
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*/
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#define local_add_unless(l, a, u) \
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({ \
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long c, old; \
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c = local_read((l)); \
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for (;;) { \
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if (unlikely(c == (u))) \
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break; \
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old = local_cmpxchg((l), c, c + (a)); \
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if (likely(old == c)) \
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break; \
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c = old; \
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} \
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c != (u); \
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})
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#define local_inc_not_zero(l) local_add_unless((l), 1, 0)
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/* On x86_32, these are no better than the atomic variants.
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* On x86-64 these are better than the atomic variants on SMP kernels
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* because they dont use a lock prefix.
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*/
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#define __local_inc(l) local_inc(l)
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#define __local_dec(l) local_dec(l)
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#define __local_add(i, l) local_add((i), (l))
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#define __local_sub(i, l) local_sub((i), (l))
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#endif /* _ASM_X86_LOCAL_H */
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