Linus TorvaldsLinux-2.6.12-rc21da177e21 years agoHistory
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/* * 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 by Ralf Baechle */ /* * As workaround for the ATOMIC_DEC_AND_LOCK / atomic_dec_and_lock mess in * <linux/spinlock.h> we have to include <linux/spinlock.h> outside the * main big wrapper ... */#include <linux/config.h>#include <linux/spinlock.h> #ifndef _ASM_ATOMIC_H#define _ASM_ATOMIC_H #include <asm/cpu-features.h>#include <asm/war.h> extern spinlock_t atomic_lock; typedef struct { volatile int counter; } atomic_t; #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)		((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 (cpu_has_llsc && R10000_LLSC_WAR) {		unsigned long temp; 		__asm__ __volatile__(		"1:	ll	%0, %1		# atomic_add		\n"		"	addu	%0, %2					\n"		"	sc	%0, %1					\n"		"	beqzl	%0, 1b					\n"		: "=&r" (temp), "=m" (v->counter)		: "Ir" (i), "m" (v->counter));	} else if (cpu_has_llsc) {		unsigned long temp; 		__asm__ __volatile__(		"1:	ll	%0, %1		# atomic_add		\n"		"	addu	%0, %2					\n"		"	sc	%0, %1					\n"		"	beqz	%0, 1b					\n"		: "=&r" (temp), "=m" (v->counter)		: "Ir" (i), "m" (v->counter));	} else {		unsigned long flags; 		spin_lock_irqsave(&atomic_lock, flags);		v->counter += i;		spin_unlock_irqrestore(&atomic_lock, 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 (cpu_has_llsc && R10000_LLSC_WAR) {		unsigned long temp; 		__asm__ __volatile__(		"1:	ll	%0, %1		# atomic_sub		\n"		"	subu	%0, %2					\n"		"	sc	%0, %1					\n"		"	beqzl	%0, 1b					\n"		: "=&r" (temp), "=m" (v->counter)		: "Ir" (i), "m" (v->counter));	} else if (cpu_has_llsc) {		unsigned long temp; 		__asm__ __volatile__(		"1:	ll	%0, %1		# atomic_sub		\n"		"	subu	%0, %2					\n"		"	sc	%0, %1					\n"		"	beqz	%0, 1b					\n"		: "=&r" (temp), "=m" (v->counter)		: "Ir" (i), "m" (v->counter));	} else {		unsigned long flags; 		spin_lock_irqsave(&atomic_lock, flags);		v->counter -= i;		spin_unlock_irqrestore(&atomic_lock, flags);	}} /* * Same as above, but return the result value */static __inline__ int atomic_add_return(int i, atomic_t * v){	unsigned long result; 	if (cpu_has_llsc && R10000_LLSC_WAR) {		unsigned long temp; 		__asm__ __volatile__(		"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"		"	sync						\n"		: "=&r" (result), "=&r" (temp), "=m" (v->counter)		: "Ir" (i), "m" (v->counter)		: "memory");	} else if (cpu_has_llsc) {		unsigned long temp; 		__asm__ __volatile__(		"1:	ll	%1, %2		# atomic_add_return	\n"		"	addu	%0, %1, %3				\n"		"	sc	%0, %2					\n"		"	beqz	%0, 1b					\n"		"	addu	%0, %1, %3				\n"		"	sync						\n"		: "=&r" (result), "=&r" (temp), "=m" (v->counter)		: "Ir" (i), "m" (v->counter)		: "memory");	} else {		unsigned long flags; 		spin_lock_irqsave(&atomic_lock, flags);		result = v->counter;		result += i;		v->counter = result;		spin_unlock_irqrestore(&atomic_lock, flags);	} 	return result;} static __inline__ int atomic_sub_return(int i, atomic_t * v){	unsigned long result; 	if (cpu_has_llsc && R10000_LLSC_WAR) {		unsigned long temp; 		__asm__ __volatile__(		"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"		"	sync						\n"		: "=&r" (result), "=&r" (temp), "=m" (v->counter)		: "Ir" (i), "m" (v->counter)		: "memory");	} else if (cpu_has_llsc) {		unsigned long temp; 		__asm__ __volatile__(		"1:	ll	%1, %2		# atomic_sub_return	\n"		"	subu	%0, %1, %3				\n"		"	sc	%0, %2					\n"		"	beqz	%0, 1b					\n"		"	subu	%0, %1, %3				\n"		"	sync						\n"		: "=&r" (result), "=&r" (temp), "=m" (v->counter)		: "Ir" (i), "m" (v->counter)		: "memory");	} else {		unsigned long flags; 		spin_lock_irqsave(&atomic_lock, flags);		result = v->counter;		result -= i;		v->counter = result;		spin_unlock_irqrestore(&atomic_lock, flags);	} 	return result;} /* * atomic_sub_if_positive - add integer to atomic variable * @v: pointer of type atomic_t * * Atomically test @v and decrement if it is greater than 0. * The function returns the old value of @v minus 1. */static __inline__ int atomic_sub_if_positive(int i, atomic_t * v){	unsigned long result; 	if (cpu_has_llsc && R10000_LLSC_WAR) {		unsigned long temp; 		__asm__ __volatile__(		"1:	ll	%1, %2		# atomic_sub_if_positive\n"		"	subu	%0, %1, %3				\n"		"	bltz	%0, 1f					\n"		"	sc	%0, %2					\n"		"	beqzl	%0, 1b					\n"		"	sync						\n"		"1:							\n"		: "=&r" (result), "=&r" (temp), "=m" (v->counter)		: "Ir" (i), "m" (v->counter)		: "memory");	} else if (cpu_has_llsc) {		unsigned long temp; 		__asm__ __volatile__(		"1:	ll	%1, %2		# atomic_sub_if_positive\n"		"	subu	%0, %1, %3				\n"		"	bltz	%0, 1f					\n"		"	sc	%0, %2					\n"		"	beqz	%0, 1b					\n"		"	sync						\n"		"1:							\n"		: "=&r" (result), "=&r" (temp), "=m" (v->counter)		: "Ir" (i), "m" (v->counter)		: "memory");	} else {		unsigned long flags; 		spin_lock_irqsave(&atomic_lock, flags);		result = v->counter;		result -= i;		if (result >= 0)			v->counter = result;		spin_unlock_irqrestore(&atomic_lock, flags);	} 	return result;} #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_MIPS64 typedef struct { volatile __s64 counter; } atomic64_t; #define ATOMIC64_INIT(i)    { (i) } /* * atomic64_read - read atomic variable * @v: pointer of type atomic64_t * */#define atomic64_read(v)	((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 (cpu_has_llsc && R10000_LLSC_WAR) {		unsigned long temp; 		__asm__ __volatile__(		"1:	lld	%0, %1		# atomic64_add		\n"		"	addu	%0, %2					\n"		"	scd	%0, %1					\n"		"	beqzl	%0, 1b					\n"		: "=&r" (temp), "=m" (v->counter)		: "Ir" (i), "m" (v->counter));	} else if (cpu_has_llsc) {		unsigned long temp; 		__asm__ __volatile__(		"1:	lld	%0, %1		# atomic64_add		\n"		"	addu	%0, %2					\n"		"	scd	%0, %1					\n"		"	beqz	%0, 1b					\n"		: "=&r" (temp), "=m" (v->counter)		: "Ir" (i), "m" (v->counter));	} else {		unsigned long flags; 		spin_lock_irqsave(&atomic_lock, flags);		v->counter += i;		spin_unlock_irqrestore(&atomic_lock, 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 (cpu_has_llsc && R10000_LLSC_WAR) {		unsigned long temp; 		__asm__ __volatile__(		"1:	lld	%0, %1		# atomic64_sub		\n"		"	subu	%0, %2					\n"		"	scd	%0, %1					\n"		"	beqzl	%0, 1b					\n"		: "=&r" (temp), "=m" (v->counter)		: "Ir" (i), "m" (v->counter));	} else if (cpu_has_llsc) {		unsigned long temp; 		__asm__ __volatile__(		"1:	lld	%0, %1		# atomic64_sub		\n"		"	subu	%0, %2					\n"		"	scd	%0, %1					\n"		"	beqz	%0, 1b					\n"		: "=&r" (temp), "=m" (v->counter)		: "Ir" (i), "m" (v->counter));	} else {		unsigned long flags; 		spin_lock_irqsave(&atomic_lock, flags);		v->counter -= i;		spin_unlock_irqrestore(&atomic_lock, flags);	}} /* * Same as above, but return the result value */static __inline__ long atomic64_add_return(long i, atomic64_t * v){	unsigned long result; 	if (cpu_has_llsc && R10000_LLSC_WAR) {		unsigned long temp; 		__asm__ __volatile__(		"1:	lld	%1, %2		# atomic64_add_return	\n"		"	addu	%0, %1, %3				\n"		"	scd	%0, %2					\n"		"	beqzl	%0, 1b					\n"		"	addu	%0, %1, %3				\n"		"	sync						\n"		: "=&r" (result), "=&r" (temp), "=m" (v->counter)		: "Ir" (i), "m" (v->counter)		: "memory");	} else if (cpu_has_llsc) {		unsigned long temp; 		__asm__ __volatile__(		"1:	lld	%1, %2		# atomic64_add_return	\n"		"	addu	%0, %1, %3				\n"		"	scd	%0, %2					\n"		"	beqz	%0, 1b					\n"		"	addu	%0, %1, %3				\n"		"	sync						\n"		: "=&r" (result), "=&r" (temp), "=m" (v->counter)		: "Ir" (i), "m" (v->counter)		: "memory");	} else {		unsigned long flags; 		spin_lock_irqsave(&atomic_lock, flags);		result = v->counter;		result += i;		v->counter = result;		spin_unlock_irqrestore(&atomic_lock, flags);	} 	return result;} static __inline__ long atomic64_sub_return(long i, atomic64_t * v){	unsigned long result; 	if (cpu_has_llsc && R10000_LLSC_WAR) {		unsigned long temp; 		__asm__ __volatile__(		"1:	lld	%1, %2		# atomic64_sub_return	\n"		"	subu	%0, %1, %3				\n"		"	scd	%0, %2					\n"		"	beqzl	%0, 1b					\n"		"	subu	%0, %1, %3				\n"		"	sync						\n"		: "=&r" (result), "=&r" (temp), "=m" (v->counter)		: "Ir" (i), "m" (v->counter)		: "memory");	} else if (cpu_has_llsc) {		unsigned long temp; 		__asm__ __volatile__(		"1:	lld	%1, %2		# atomic64_sub_return	\n"

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