114 lines
2.2 KiB
C
114 lines
2.2 KiB
C
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/*
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* linux/include/asm-arm/atomic.h
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*
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* Copyright (c) 1996 Russell King.
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License version 2 as
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* published by the Free Software Foundation.
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*
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* Changelog:
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* 27-06-1996 RMK Created
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* 13-04-1997 RMK Made functions atomic!
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* 07-12-1997 RMK Upgraded for v2.1.
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* 26-08-1998 PJB Added #ifdef __KERNEL__
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*/
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#ifndef __ASM_ARM_ATOMIC_H
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#define __ASM_ARM_ATOMIC_H
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#include <linux/config.h>
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#ifdef CONFIG_SMP
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#error SMP not supported
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#endif
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typedef struct { volatile int counter; } atomic_t;
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#define ATOMIC_INIT(i) { (i) }
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#ifdef __KERNEL__
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#include <asm/proc/system.h>
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#define atomic_read(v) ((v)->counter)
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#define atomic_set(v,i) (((v)->counter) = (i))
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static inline void atomic_add(int i, volatile atomic_t *v)
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{
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unsigned long flags;
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local_irq_save(flags);
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v->counter += i;
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local_irq_restore(flags);
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}
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static inline void atomic_sub(int i, volatile atomic_t *v)
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{
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unsigned long flags;
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local_irq_save(flags);
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v->counter -= i;
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local_irq_restore(flags);
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}
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static inline void atomic_inc(volatile atomic_t *v)
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{
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unsigned long flags;
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local_irq_save(flags);
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v->counter += 1;
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local_irq_restore(flags);
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}
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static inline void atomic_dec(volatile atomic_t *v)
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{
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unsigned long flags;
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local_irq_save(flags);
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v->counter -= 1;
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local_irq_restore(flags);
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}
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static inline int atomic_dec_and_test(volatile atomic_t *v)
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{
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unsigned long flags;
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int val;
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local_irq_save(flags);
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val = v->counter;
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v->counter = val -= 1;
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local_irq_restore(flags);
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return val == 0;
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}
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static inline int atomic_add_negative(int i, volatile atomic_t *v)
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{
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unsigned long flags;
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int val;
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local_irq_save(flags);
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val = v->counter;
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v->counter = val += i;
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local_irq_restore(flags);
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return val < 0;
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}
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static inline void atomic_clear_mask(unsigned long mask, unsigned long *addr)
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{
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unsigned long flags;
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local_irq_save(flags);
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*addr &= ~mask;
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local_irq_restore(flags);
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}
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/* Atomic operations are already serializing on ARM */
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#define smp_mb__before_atomic_dec() barrier()
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#define smp_mb__after_atomic_dec() barrier()
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#define smp_mb__before_atomic_inc() barrier()
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#define smp_mb__after_atomic_inc() barrier()
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#endif
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#endif
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