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    /*
     * PowerPC atomic operations
     */
    
    #ifndef _ASM_PPC_ATOMIC_H_
    #define _ASM_PPC_ATOMIC_H_
    
    #include <linux/config.h>
    
    #ifdef CONFIG_SMP
    typedef struct { volatile int counter; } atomic_t;
    #else
    typedef struct { int counter; } atomic_t;
    #endif
    
    #define ATOMIC_INIT(i)	{ (i) }
    
    #define atomic_read(v)		((v)->counter)
    #define atomic_set(v,i)		(((v)->counter) = (i))
    
    extern void atomic_clear_mask(unsigned long mask, unsigned long *addr);
    extern void atomic_set_mask(unsigned long mask, unsigned long *addr);
    
    extern __inline__ int atomic_add_return(int a, atomic_t *v)
    {
    	int t;
    
    	__asm__ __volatile__("\n\
    1:	lwarx	%0,0,%3\n\
    	add	%0,%2,%0\n\
    	stwcx.	%0,0,%3\n\
    	bne-	1b"
    	: "=&r" (t), "=m" (*v)
    	: "r" (a), "r" (v), "m" (*v)
    	: "cc");
    
    	return t;
    }
    
    extern __inline__ int atomic_sub_return(int a, atomic_t *v)
    {
    	int t;
    
    	__asm__ __volatile__("\n\
    1:	lwarx	%0,0,%3\n\
    	subf	%0,%2,%0\n\
    	stwcx.	%0,0,%3\n\
    	bne-	1b"
    	: "=&r" (t), "=m" (*v)
    	: "r" (a), "r" (v), "m" (*v)
    	: "cc");
    
    	return t;
    }
    
    extern __inline__ int atomic_inc_return(atomic_t *v)
    {
    	int t;
    
    	__asm__ __volatile__("\n\
    1:	lwarx	%0,0,%2\n\
    	addic	%0,%0,1\n\
    	stwcx.	%0,0,%2\n\
    	bne-	1b"
    	: "=&r" (t), "=m" (*v)
    	: "r" (v), "m" (*v)
    	: "cc");
    
    	return t;
    }
    
    extern __inline__ int atomic_dec_return(atomic_t *v)
    {
    	int t;
    
    	__asm__ __volatile__("\n\
    1:	lwarx	%0,0,%2\n\
    	addic	%0,%0,-1\n\
    	stwcx.	%0,0,%2\n\
    	bne	1b"
    	: "=&r" (t), "=m" (*v)
    	: "r" (v), "m" (*v)
    	: "cc");
    
    	return t;
    }
    
    #define atomic_add(a, v)		((void) atomic_add_return((a), (v)))
    #define atomic_sub(a, v)		((void) atomic_sub_return((a), (v)))
    #define atomic_sub_and_test(a, v)	(atomic_sub_return((a), (v)) == 0)
    #define atomic_inc(v)			((void) atomic_inc_return((v)))
    #define atomic_dec(v)			((void) atomic_dec_return((v)))
    #define atomic_dec_and_test(v)		(atomic_dec_return((v)) == 0)
    
    #endif /* _ASM_PPC_ATOMIC_H_ */