/* * Atomic operations that C can't guarantee us.  Useful for * resource counting etc.. * * But use these as seldom as possible since they are much more slower * than regular operations. * * This file is subject to the terms and conditions of the GNU General Public * License.  See the file "COPYING" in the main directory of this archive * for more details. * * Copyright (C) 1996, 97, 99, 2000, 03, 04, 06 by Ralf Baechle */#ifndef _ASM_ATOMIC_H#define _ASM_ATOMIC_H #include <linux/irqflags.h>#include <linux/types.h>#include <asm/barrier.h>#include <asm/cpu-features.h>#include <asm/cmpxchg.h>#include <asm/war.h> #define ATOMIC_INIT(i)    { (i) } /* * atomic_read - read atomic variable * @v: pointer of type atomic_t * * Atomically reads the value of @v. */#define atomic_read(v)		(*(volatile int *)&(v)->counter) /* * atomic_set - set atomic variable * @v: pointer of type atomic_t * @i: required value * * Atomically sets the value of @v to @i. */#define atomic_set(v, i)		((v)->counter = (i)) /* * atomic_add - add integer to atomic variable * @i: integer value to add * @v: pointer of type atomic_t * * Atomically adds @i to @v. */static __inline__ void atomic_add(int i, atomic_t * v){	if (kernel_uses_llsc && R10000_LLSC_WAR) {		int temp; 		__asm__ __volatile__(		"	.set	mips3					\n"		"1:	ll	%0, %1		# atomic_add		\n"		"	addu	%0, %2					\n"		"	sc	%0, %1					\n"		"	beqzl	%0, 1b					\n"		"	.set	mips0					\n"		: "=&r" (temp), "=m" (v->counter)		: "Ir" (i), "m" (v->counter));	} else if (kernel_uses_llsc) {		int temp; 		do {			__asm__ __volatile__(			"	.set	mips3				\n"			"	ll	%0, %1		# atomic_add	\n"			"	addu	%0, %2				\n"			"	sc	%0, %1				\n"			"	.set	mips0				\n"			: "=&r" (temp), "=m" (v->counter)			: "Ir" (i), "m" (v->counter));		} while (unlikely(!temp));	} else {		unsigned long flags; 		raw_local_irq_save(flags);		v->counter += i;		raw_local_irq_restore(flags);	}} /* * atomic_sub - subtract the atomic variable * @i: integer value to subtract * @v: pointer of type atomic_t * * Atomically subtracts @i from @v. */static __inline__ void atomic_sub(int i, atomic_t * v){	if (kernel_uses_llsc && R10000_LLSC_WAR) {		int temp; 		__asm__ __volatile__(		"	.set	mips3					\n"		"1:	ll	%0, %1		# atomic_sub		\n"		"	subu	%0, %2					\n"		"	sc	%0, %1					\n"		"	beqzl	%0, 1b					\n"		"	.set	mips0					\n"		: "=&r" (temp), "=m" (v->counter)		: "Ir" (i), "m" (v->counter));	} else if (kernel_uses_llsc) {		int temp; 		do {			__asm__ __volatile__(			"	.set	mips3				\n"			"	ll	%0, %1		# atomic_sub	\n"			"	subu	%0, %2				\n"			"	sc	%0, %1				\n"			"	.set	mips0				\n"			: "=&r" (temp), "=m" (v->counter)			: "Ir" (i), "m" (v->counter));		} while (unlikely(!temp));	} else {		unsigned long flags; 		raw_local_irq_save(flags);		v->counter -= i;		raw_local_irq_restore(flags);	}} /* * Same as above, but return the result value */static __inline__ int atomic_add_return(int i, atomic_t * v){	int result; 	smp_mb__before_llsc(); 	if (kernel_uses_llsc && R10000_LLSC_WAR) {		int temp; 		__asm__ __volatile__(		"	.set	mips3					\n"		"1:	ll	%1, %2		# atomic_add_return	\n"		"	addu	%0, %1, %3				\n"		"	sc	%0, %2					\n"		"	beqzl	%0, 1b					\n"		"	addu	%0, %1, %3				\n"		"	.set	mips0					\n"		: "=&r" (result), "=&r" (temp), "=m" (v->counter)		: "Ir" (i), "m" (v->counter)		: "memory");	} else if (kernel_uses_llsc) {		int temp; 		do {			__asm__ __volatile__(			"	.set	mips3				\n"			"	ll	%1, %2	# atomic_add_return	\n"			"	addu	%0, %1, %3			\n"			"	sc	%0, %2				\n"			"	.set	mips0				\n"			: "=&r" (result), "=&r" (temp), "=m" (v->counter)			: "Ir" (i), "m" (v->counter)			: "memory");		} while (unlikely(!result)); 		result = temp + i;	} else {		unsigned long flags; 		raw_local_irq_save(flags);		result = v->counter;		result += i;		v->counter = result;		raw_local_irq_restore(flags);	} 	smp_llsc_mb(); 	return result;} static __inline__ int atomic_sub_return(int i, atomic_t * v){	int result; 	smp_mb__before_llsc(); 	if (kernel_uses_llsc && R10000_LLSC_WAR) {		int temp; 		__asm__ __volatile__(		"	.set	mips3					\n"		"1:	ll	%1, %2		# atomic_sub_return	\n"		"	subu	%0, %1, %3				\n"		"	sc	%0, %2					\n"		"	beqzl	%0, 1b					\n"		"	subu	%0, %1, %3				\n"		"	.set	mips0					\n"		: "=&r" (result), "=&r" (temp), "=m" (v->counter)		: "Ir" (i), "m" (v->counter)		: "memory"); 		result = temp - i;	} else if (kernel_uses_llsc) {		int temp; 		do {			__asm__ __volatile__(			"	.set	mips3				\n"			"	ll	%1, %2	# atomic_sub_return	\n"			"	subu	%0, %1, %3			\n"			"	sc	%0, %2				\n"			"	.set	mips0				\n"			: "=&r" (result), "=&r" (temp), "=m" (v->counter)			: "Ir" (i), "m" (v->counter)			: "memory");		} while (unlikely(!result)); 		result = temp - i;	} else {		unsigned long flags; 		raw_local_irq_save(flags);		result = v->counter;		result -= i;		v->counter = result;		raw_local_irq_restore(flags);	} 	smp_llsc_mb(); 	return result;} /* * atomic_sub_if_positive - conditionally subtract integer from atomic variable * @i: integer value to subtract * @v: pointer of type atomic_t * * Atomically test @v and subtract @i if @v is greater or equal than @i. * The function returns the old value of @v minus @i. */static __inline__ int atomic_sub_if_positive(int i, atomic_t * v){	int result; 	smp_mb__before_llsc(); 	if (kernel_uses_llsc && R10000_LLSC_WAR) {		int temp; 		__asm__ __volatile__(		"	.set	mips3					\n"		"1:	ll	%1, %2		# atomic_sub_if_positive\n"		"	subu	%0, %1, %3				\n"		"	bltz	%0, 1f					\n"		"	sc	%0, %2					\n"		"	.set	noreorder				\n"		"	beqzl	%0, 1b					\n"		"	 subu	%0, %1, %3				\n"		"	.set	reorder					\n"		"1:							\n"		"	.set	mips0					\n"		: "=&r" (result), "=&r" (temp), "=m" (v->counter)		: "Ir" (i), "m" (v->counter)		: "memory");	} else if (kernel_uses_llsc) {		int temp; 		__asm__ __volatile__(		"	.set	mips3					\n"		"1:	ll	%1, %2		# atomic_sub_if_positive\n"		"	subu	%0, %1, %3				\n"		"	bltz	%0, 1f					\n"		"	sc	%0, %2					\n"		"	.set	noreorder				\n"		"	beqz	%0, 1b					\n"		"	 subu	%0, %1, %3				\n"		"	.set	reorder					\n"		"1:							\n"		"	.set	mips0					\n"		: "=&r" (result), "=&r" (temp), "=m" (v->counter)		: "Ir" (i), "m" (v->counter)		: "memory");	} else {		unsigned long flags; 		raw_local_irq_save(flags);		result = v->counter;		result -= i;		if (result >= 0)			v->counter = result;		raw_local_irq_restore(flags);	} 	smp_llsc_mb(); 	return result;} #define atomic_cmpxchg(v, o, n) (cmpxchg(&((v)->counter), (o), (n)))#define atomic_xchg(v, new) (xchg(&((v)->counter), (new))) /** * __atomic_add_unless - add unless the number is a given value * @v: pointer of type atomic_t * @a: the amount to add to v... * @u: ...unless v is equal to u. * * Atomically adds @a to @v, so long as it was not @u. * Returns the old value of @v. */static __inline__ int __atomic_add_unless(atomic_t *v, int a, int u){	int c, old;	c = atomic_read(v);	for (;;) {		if (unlikely(c == (u)))			break;		old = atomic_cmpxchg((v), c, c + (a));		if (likely(old == c))			break;		c = old;	}	return c;} #define atomic_dec_return(v) atomic_sub_return(1, (v))#define atomic_inc_return(v) atomic_add_return(1, (v)) /* * atomic_sub_and_test - subtract value from variable and test result * @i: integer value to subtract * @v: pointer of type atomic_t * * Atomically subtracts @i from @v and returns * true if the result is zero, or false for all * other cases. */#define atomic_sub_and_test(i, v) (atomic_sub_return((i), (v)) == 0) /* * atomic_inc_and_test - increment and test * @v: pointer of type atomic_t * * Atomically increments @v by 1 * and returns true if the result is zero, or false for all * other cases. */#define atomic_inc_and_test(v) (atomic_inc_return(v) == 0) /* * atomic_dec_and_test - decrement by 1 and test * @v: pointer of type atomic_t * * Atomically decrements @v by 1 and * returns true if the result is 0, or false for all other * cases. */#define atomic_dec_and_test(v) (atomic_sub_return(1, (v)) == 0) /* * atomic_dec_if_positive - decrement by 1 if old value positive * @v: pointer of type atomic_t */#define atomic_dec_if_positive(v)	atomic_sub_if_positive(1, v) /* * atomic_inc - increment atomic variable * @v: pointer of type atomic_t * * Atomically increments @v by 1. */#define atomic_inc(v) atomic_add(1, (v)) /* * atomic_dec - decrement and test * @v: pointer of type atomic_t * * Atomically decrements @v by 1. */#define atomic_dec(v) atomic_sub(1, (v)) /* * atomic_add_negative - add and test if negative * @v: pointer of type atomic_t * @i: integer value to add * * Atomically adds @i to @v and returns true * if the result is negative, or false when * result is greater than or equal to zero. */#define atomic_add_negative(i, v) (atomic_add_return(i, (v)) < 0) #ifdef CONFIG_64BIT #define ATOMIC64_INIT(i)    { (i) } /* * atomic64_read - read atomic variable * @v: pointer of type atomic64_t * */#define atomic64_read(v)	(*(volatile long *)&(v)->counter) /* * atomic64_set - set atomic variable * @v: pointer of type atomic64_t * @i: required value */#define atomic64_set(v, i)	((v)->counter = (i)) /* * atomic64_add - add integer to atomic variable * @i: integer value to add * @v: pointer of type atomic64_t * * Atomically adds @i to @v. */static __inline__ void atomic64_add(long i, atomic64_t * v){	if (kernel_uses_llsc && R10000_LLSC_WAR) {		long temp; 		__asm__ __volatile__(		"	.set	mips3					\n"		"1:	lld	%0, %1		# atomic64_add		\n"		"	daddu	%0, %2					\n"		"	scd	%0, %1					\n"		"	beqzl	%0, 1b					\n"		"	.set	mips0					\n"		: "=&r" (temp), "=m" (v->counter)		: "Ir" (i), "m" (v->counter));	} else if (kernel_uses_llsc) {		long temp; 		do {			__asm__ __volatile__(			"	.set	mips3				\n"			"	lld	%0, %1		# atomic64_add	\n"			"	daddu	%0, %2				\n"			"	scd	%0, %1				\n"			"	.set	mips0				\n"			: "=&r" (temp), "=m" (v->counter)			: "Ir" (i), "m" (v->counter));		} while (unlikely(!temp));	} else {		unsigned long flags; 		raw_local_irq_save(flags);		v->counter += i;		raw_local_irq_restore(flags);	}} /* * atomic64_sub - subtract the atomic variable * @i: integer value to subtract * @v: pointer of type atomic64_t * * Atomically subtracts @i from @v. */static __inline__ void atomic64_sub(long i, atomic64_t * v){	if (kernel_uses_llsc && R10000_LLSC_WAR) {		long temp; 		__asm__ __volatile__(		"	.set	mips3					\n"		"1:	lld	%0, %1		# atomic64_sub		\n"		"	dsubu	%0, %2					\n"		"	scd	%0, %1					\n"		"	beqzl	%0, 1b					\n"		"	.set	mips0					\n"		: "=&r" (temp), "=m" (v->counter)		: "Ir" (i), "m" (v->counter));	} else if (kernel_uses_llsc) {		long temp; 		do {			__asm__ __volatile__(			"	.set	mips3				\n"			"	lld	%0, %1		# atomic64_sub	\n"			"	dsubu	%0, %2				\n"			"	scd	%0, %1				\n"			"	.set	mips0				\n"			: "=&r" (temp), "=m" (v->counter)			: "Ir" (i), "m" (v->counter));		} while (unlikely(!temp));	} else {		unsigned long flags; 		raw_local_irq_save(flags);		v->counter -= i;		raw_local_irq_restore(flags);	}} /*

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