1da177e4c3
Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
150 lines
3.3 KiB
C
150 lines
3.3 KiB
C
/* $Id: atomic.h,v 1.3 2001/07/25 16:15:19 bjornw Exp $ */
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#ifndef __ASM_CRIS_ATOMIC__
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#define __ASM_CRIS_ATOMIC__
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#include <asm/system.h>
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/*
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* Atomic operations that C can't guarantee us. Useful for
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* resource counting etc..
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*/
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/*
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* Make sure gcc doesn't try to be clever and move things around
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* on us. We need to use _exactly_ the address the user gave us,
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* not some alias that contains the same information.
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*/
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#define __atomic_fool_gcc(x) (*(struct { int a[100]; } *)x)
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typedef struct { int counter; } atomic_t;
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#define ATOMIC_INIT(i) { (i) }
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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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/* These should be written in asm but we do it in C for now. */
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extern __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_save_flags(flags);
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local_irq_disable();
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v->counter += i;
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local_irq_restore(flags);
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}
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extern __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_save_flags(flags);
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local_irq_disable();
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v->counter -= i;
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local_irq_restore(flags);
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}
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extern __inline__ int atomic_add_return(int i, volatile atomic_t *v)
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{
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unsigned long flags;
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int retval;
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local_save_flags(flags);
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local_irq_disable();
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retval = (v->counter += i);
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local_irq_restore(flags);
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return retval;
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}
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#define atomic_add_negative(a, v) (atomic_add_return((a), (v)) < 0)
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extern __inline__ int atomic_sub_return(int i, volatile atomic_t *v)
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{
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unsigned long flags;
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int retval;
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local_save_flags(flags);
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local_irq_disable();
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retval = (v->counter -= i);
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local_irq_restore(flags);
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return retval;
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}
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extern __inline__ int atomic_sub_and_test(int i, volatile atomic_t *v)
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{
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int retval;
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unsigned long flags;
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local_save_flags(flags);
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local_irq_disable();
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retval = (v->counter -= i) == 0;
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local_irq_restore(flags);
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return retval;
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}
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extern __inline__ void atomic_inc(volatile atomic_t *v)
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{
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unsigned long flags;
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local_save_flags(flags);
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local_irq_disable();
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(v->counter)++;
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local_irq_restore(flags);
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}
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extern __inline__ void atomic_dec(volatile atomic_t *v)
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{
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unsigned long flags;
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local_save_flags(flags);
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local_irq_disable();
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(v->counter)--;
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local_irq_restore(flags);
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}
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extern __inline__ int atomic_inc_return(volatile atomic_t *v)
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{
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unsigned long flags;
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int retval;
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local_save_flags(flags);
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local_irq_disable();
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retval = (v->counter)++;
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local_irq_restore(flags);
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return retval;
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}
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extern __inline__ int atomic_dec_return(volatile atomic_t *v)
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{
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unsigned long flags;
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int retval;
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local_save_flags(flags);
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local_irq_disable();
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retval = (v->counter)--;
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local_irq_restore(flags);
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return retval;
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}
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extern __inline__ int atomic_dec_and_test(volatile atomic_t *v)
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{
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int retval;
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unsigned long flags;
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local_save_flags(flags);
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local_irq_disable();
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retval = --(v->counter) == 0;
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local_irq_restore(flags);
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return retval;
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}
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extern __inline__ int atomic_inc_and_test(volatile atomic_t *v)
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{
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int retval;
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unsigned long flags;
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local_save_flags(flags);
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local_irq_disable();
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retval = ++(v->counter) == 0;
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local_irq_restore(flags);
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return retval;
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}
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/* Atomic operations are already serializing */
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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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