include/asm-mips/atomic.h - kernel/msm-4.9 - Gitiles

 /*
  * 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 <asm/barrier.h>
 #include <asm/cpu-features.h>
 #include <asm/war.h>
 #include <asm/system.h>

 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__(
 		"	.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 (cpu_has_llsc) {
 		unsigned long temp;

 		__asm__ __volatile__(
 		"	.set	mips3					\n"
 		"1:	ll	%0, %1		# atomic_add		\n"
 		"	addu	%0, %2					\n"
 		"	sc	%0, %1					\n"
 		"	beqz	%0, 2f					\n"
 		"	.subsection 2					\n"
 		"2:	b	1b					\n"
 		"	.previous					\n"
 		"	.set	mips0					\n"
 		: "=&r" (temp), "=m" (v->counter)
 		: "Ir" (i), "m" (v->counter));
 	} 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 (cpu_has_llsc && R10000_LLSC_WAR) {
 		unsigned long 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 (cpu_has_llsc) {
 		unsigned long temp;

 		__asm__ __volatile__(
 		"	.set	mips3					\n"
 		"1:	ll	%0, %1		# atomic_sub		\n"
 		"	subu	%0, %2					\n"
 		"	sc	%0, %1					\n"
 		"	beqz	%0, 2f					\n"
 		"	.subsection 2					\n"
 		"2:	b	1b					\n"
 		"	.previous					\n"
 		"	.set	mips0					\n"
 		: "=&r" (temp), "=m" (v->counter)
 		: "Ir" (i), "m" (v->counter));
 	} 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)
 {
 	unsigned long result;

 	smp_llsc_mb();

 	if (cpu_has_llsc && R10000_LLSC_WAR) {
 		unsigned long 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 (cpu_has_llsc) {
 		unsigned long temp;

 		__asm__ __volatile__(
 		"	.set	mips3					\n"
 		"1:	ll	%1, %2		# atomic_add_return	\n"
 		"	addu	%0, %1, %3				\n"
 		"	sc	%0, %2					\n"
 		"	beqz	%0, 2f					\n"
 		"	addu	%0, %1, %3				\n"
 		"	.subsection 2					\n"
 		"2:	b	1b					\n"
 		"	.previous					\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;
 		v->counter = result;
 		raw_local_irq_restore(flags);
 	}

 	smp_llsc_mb();

 	return result;
 }

 static __inline__ int atomic_sub_return(int i, atomic_t * v)
 {
 	unsigned long result;

 	smp_llsc_mb();

 	if (cpu_has_llsc && R10000_LLSC_WAR) {
 		unsigned long 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");
 	} else if (cpu_has_llsc) {
 		unsigned long temp;

 		__asm__ __volatile__(
 		"	.set	mips3					\n"
 		"1:	ll	%1, %2		# atomic_sub_return	\n"
 		"	subu	%0, %1, %3				\n"
 		"	sc	%0, %2					\n"
 		"	beqz	%0, 2f					\n"
 		"	subu	%0, %1, %3				\n"
 		"	.subsection 2					\n"
 		"2:	b	1b					\n"
 		"	.previous					\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;
 		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)
 {
 	unsigned long result;

 	smp_llsc_mb();

 	if (cpu_has_llsc && R10000_LLSC_WAR) {
 		unsigned long 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 (cpu_has_llsc) {
 		unsigned long 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, 2f					\n"
 		"	 subu	%0, %1, %3				\n"
 		"	.set	reorder					\n"
 		"1:							\n"
 		"	.subsection 2					\n"
 		"2:	b	1b					\n"
 		"	.previous					\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 non-zero if @v was not @u, and zero otherwise.
  */
 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 != (u);
 }
 #define atomic_inc_not_zero(v) atomic_add_unless((v), 1, 0)

 #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

 typedef struct { volatile long 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__(
 		"	.set	mips3					\n"
 		"1:	lld	%0, %1		# atomic64_add		\n"
 		"	addu	%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 (cpu_has_llsc) {
 		unsigned long temp;

 		__asm__ __volatile__(
 		"	.set	mips3					\n"
 		"1:	lld	%0, %1		# atomic64_add		\n"
 		"	addu	%0, %2					\n"
 		"	scd	%0, %1					\n"
 		"	beqz	%0, 2f					\n"
 		"	.subsection 2					\n"
 		"2:	b	1b					\n"
 		"	.previous					\n"
 		"	.set	mips0					\n"
 		: "=&r" (temp), "=m" (v->counter)
 		: "Ir" (i), "m" (v->counter));
 	} 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 (cpu_has_llsc && R10000_LLSC_WAR) {
 		unsigned long temp;

 		__asm__ __volatile__(
 		"	.set	mips3					\n"
 		"1:	lld	%0, %1		# atomic64_sub		\n"
 		"	subu	%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 (cpu_has_llsc) {
 		unsigned long temp;

 		__asm__ __volatile__(
 		"	.set	mips3					\n"
 		"1:	lld	%0, %1		# atomic64_sub		\n"
 		"	subu	%0, %2					\n"
 		"	scd	%0, %1					\n"
 		"	beqz	%0, 2f					\n"
 		"	.subsection 2					\n"
 		"2:	b	1b					\n"
 		"	.previous					\n"
 		"	.set	mips0					\n"
 		: "=&r" (temp), "=m" (v->counter)
 		: "Ir" (i), "m" (v->counter));
 	} 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__ long atomic64_add_return(long i, atomic64_t * v)
 {
 	unsigned long result;

 	smp_llsc_mb();

 	if (cpu_has_llsc && R10000_LLSC_WAR) {
 		unsigned long temp;

 		__asm__ __volatile__(
 		"	.set	mips3					\n"
 		"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"
 		"	.set	mips0					\n"
 		: "=&r" (result), "=&r" (temp), "=m" (v->counter)
 		: "Ir" (i), "m" (v->counter)
 		: "memory");
 	} else if (cpu_has_llsc) {
 		unsigned long temp;

 		__asm__ __volatile__(
 		"	.set	mips3					\n"
 		"1:	lld	%1, %2		# atomic64_add_return	\n"
 		"	addu	%0, %1, %3				\n"
 		"	scd	%0, %2					\n"
 		"	beqz	%0, 2f					\n"
 		"	addu	%0, %1, %3				\n"
 		"	.subsection 2					\n"
 		"2:	b	1b					\n"
 		"	.previous					\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;
 		v->counter = result;
 		raw_local_irq_restore(flags);
 	}

 	smp_llsc_mb();

 	return result;
 }

 static __inline__ long atomic64_sub_return(long i, atomic64_t * v)
 {
 	unsigned long result;

 	smp_llsc_mb();

 	if (cpu_has_llsc && R10000_LLSC_WAR) {
 		unsigned long temp;

 		__asm__ __volatile__(
 		"	.set	mips3					\n"
 		"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"
 		"	.set	mips0					\n"
 		: "=&r" (result), "=&r" (temp), "=m" (v->counter)
 		: "Ir" (i), "m" (v->counter)
 		: "memory");
 	} else if (cpu_has_llsc) {
 		unsigned long temp;

 		__asm__ __volatile__(
 		"	.set	mips3					\n"
 		"1:	lld	%1, %2		# atomic64_sub_return	\n"
 		"	subu	%0, %1, %3				\n"
 		"	scd	%0, %2					\n"
 		"	beqz	%0, 2f					\n"
 		"	subu	%0, %1, %3				\n"
 		"	.subsection 2					\n"
 		"2:	b	1b					\n"
 		"	.previous					\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;
 		v->counter = result;
 		raw_local_irq_restore(flags);
 	}

 	smp_llsc_mb();

 	return result;
 }

 /*
  * atomic64_sub_if_positive - conditionally subtract integer from atomic variable
  * @i: integer value to subtract
  * @v: pointer of type atomic64_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__ long atomic64_sub_if_positive(long i, atomic64_t * v)
 {
 	unsigned long result;

 	smp_llsc_mb();

 	if (cpu_has_llsc && R10000_LLSC_WAR) {
 		unsigned long temp;

 		__asm__ __volatile__(
 		"	.set	mips3					\n"
 		"1:	lld	%1, %2		# atomic64_sub_if_positive\n"
 		"	dsubu	%0, %1, %3				\n"
 		"	bltz	%0, 1f					\n"
 		"	scd	%0, %2					\n"
 		"	.set	noreorder				\n"
 		"	beqzl	%0, 1b					\n"
 		"	 dsubu	%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 (cpu_has_llsc) {
 		unsigned long temp;

 		__asm__ __volatile__(
 		"	.set	mips3					\n"
 		"1:	lld	%1, %2		# atomic64_sub_if_positive\n"
 		"	dsubu	%0, %1, %3				\n"
 		"	bltz	%0, 1f					\n"
 		"	scd	%0, %2					\n"
 		"	.set	noreorder				\n"
 		"	beqz	%0, 2f					\n"
 		"	 dsubu	%0, %1, %3				\n"
 		"	.set	reorder					\n"
 		"1:							\n"
 		"	.subsection 2					\n"
 		"2:	b	1b					\n"
 		"	.previous					\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 atomic64_cmpxchg(v, o, n) \
 	((__typeof__((v)->counter))cmpxchg(&((v)->counter), (o), (n)))
 #define atomic64_xchg(v, new) (xchg(&((v)->counter), (new)))

 /**
  * atomic64_add_unless - add unless the number is a given value
  * @v: pointer of type atomic64_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 non-zero if @v was not @u, and zero otherwise.
  */
 static __inline__ int atomic64_add_unless(atomic64_t *v, long a, long u)
 {
 	long c, old;
 	c = atomic64_read(v);
 	for (;;) {
 		if (unlikely(c == (u)))
 			break;
 		old = atomic64_cmpxchg((v), c, c + (a));
 		if (likely(old == c))
 			break;
 		c = old;
 	}
 	return c != (u);
 }

 #define atomic64_inc_not_zero(v) atomic64_add_unless((v), 1, 0)

 #define atomic64_dec_return(v) atomic64_sub_return(1,(v))
 #define atomic64_inc_return(v) atomic64_add_return(1,(v))

 /*
  * atomic64_sub_and_test - subtract value from variable and test result
  * @i: integer value to subtract
  * @v: pointer of type atomic64_t
  *
  * Atomically subtracts @i from @v and returns
  * true if the result is zero, or false for all
  * other cases.
  */
 #define atomic64_sub_and_test(i,v) (atomic64_sub_return((i), (v)) == 0)

 /*
  * atomic64_inc_and_test - increment and test
  * @v: pointer of type atomic64_t
  *
  * Atomically increments @v by 1
  * and returns true if the result is zero, or false for all
  * other cases.
  */
 #define atomic64_inc_and_test(v) (atomic64_inc_return(v) == 0)

 /*
  * atomic64_dec_and_test - decrement by 1 and test
  * @v: pointer of type atomic64_t
  *
  * Atomically decrements @v by 1 and
  * returns true if the result is 0, or false for all other
  * cases.
  */
 #define atomic64_dec_and_test(v) (atomic64_sub_return(1, (v)) == 0)

 /*
  * atomic64_dec_if_positive - decrement by 1 if old value positive
  * @v: pointer of type atomic64_t
  */
 #define atomic64_dec_if_positive(v)	atomic64_sub_if_positive(1, v)

 /*
  * atomic64_inc - increment atomic variable
  * @v: pointer of type atomic64_t
  *
  * Atomically increments @v by 1.
  */
 #define atomic64_inc(v) atomic64_add(1,(v))

 /*
  * atomic64_dec - decrement and test
  * @v: pointer of type atomic64_t
  *
  * Atomically decrements @v by 1.
  */
 #define atomic64_dec(v) atomic64_sub(1,(v))

 /*
  * atomic64_add_negative - add and test if negative
  * @v: pointer of type atomic64_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 atomic64_add_negative(i,v) (atomic64_add_return(i, (v)) < 0)

 #endif /* CONFIG_64BIT */

 /*
  * atomic*_return operations are serializing but not the non-*_return
  * versions.
  */
 #define smp_mb__before_atomic_dec()	smp_llsc_mb()
 #define smp_mb__after_atomic_dec()	smp_llsc_mb()
 #define smp_mb__before_atomic_inc()	smp_llsc_mb()
 #define smp_mb__after_atomic_inc()	smp_llsc_mb()

 #include <asm-generic/atomic.h>

 #endif /* _ASM_ATOMIC_H */
	/*
	* 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 <asm/barrier.h>
	#include <asm/cpu-features.h>
	#include <asm/war.h>
	#include <asm/system.h>

	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__(
	" .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 (cpu_has_llsc) {
	unsigned long temp;

	__asm__ __volatile__(
	" .set mips3 \n"
	"1: ll %0, %1 # atomic_add \n"
	" addu %0, %2 \n"
	" sc %0, %1 \n"
	" beqz %0, 2f \n"
	" .subsection 2 \n"
	"2: b 1b \n"
	" .previous \n"
	" .set mips0 \n"
	: "=&r" (temp), "=m" (v->counter)
	: "Ir" (i), "m" (v->counter));
	} 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 (cpu_has_llsc && R10000_LLSC_WAR) {
	unsigned long 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 (cpu_has_llsc) {
	unsigned long temp;

	__asm__ __volatile__(
	" .set mips3 \n"
	"1: ll %0, %1 # atomic_sub \n"
	" subu %0, %2 \n"
	" sc %0, %1 \n"
	" beqz %0, 2f \n"
	" .subsection 2 \n"
	"2: b 1b \n"
	" .previous \n"
	" .set mips0 \n"
	: "=&r" (temp), "=m" (v->counter)
	: "Ir" (i), "m" (v->counter));
	} 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)
	{
	unsigned long result;

	smp_llsc_mb();

	if (cpu_has_llsc && R10000_LLSC_WAR) {
	unsigned long 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 (cpu_has_llsc) {
	unsigned long temp;

	__asm__ __volatile__(
	" .set mips3 \n"
	"1: ll %1, %2 # atomic_add_return \n"
	" addu %0, %1, %3 \n"
	" sc %0, %2 \n"
	" beqz %0, 2f \n"
	" addu %0, %1, %3 \n"
	" .subsection 2 \n"
	"2: b 1b \n"
	" .previous \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;
	v->counter = result;
	raw_local_irq_restore(flags);
	}

	smp_llsc_mb();

	return result;
	}

	static __inline__ int atomic_sub_return(int i, atomic_t * v)
	{
	unsigned long result;

	smp_llsc_mb();

	if (cpu_has_llsc && R10000_LLSC_WAR) {
	unsigned long 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");
	} else if (cpu_has_llsc) {
	unsigned long temp;

	__asm__ __volatile__(
	" .set mips3 \n"
	"1: ll %1, %2 # atomic_sub_return \n"
	" subu %0, %1, %3 \n"
	" sc %0, %2 \n"
	" beqz %0, 2f \n"
	" subu %0, %1, %3 \n"
	" .subsection 2 \n"
	"2: b 1b \n"
	" .previous \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;
	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)
	{
	unsigned long result;

	smp_llsc_mb();

	if (cpu_has_llsc && R10000_LLSC_WAR) {
	unsigned long 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 (cpu_has_llsc) {
	unsigned long 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, 2f \n"
	" subu %0, %1, %3 \n"
	" .set reorder \n"
	"1: \n"
	" .subsection 2 \n"
	"2: b 1b \n"
	" .previous \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 non-zero if @v was not @u, and zero otherwise.
	*/
	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 != (u);
	}
	#define atomic_inc_not_zero(v) atomic_add_unless((v), 1, 0)

	#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

	typedef struct { volatile long 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__(
	" .set mips3 \n"
	"1: lld %0, %1 # atomic64_add \n"
	" addu %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 (cpu_has_llsc) {
	unsigned long temp;

	__asm__ __volatile__(
	" .set mips3 \n"
	"1: lld %0, %1 # atomic64_add \n"
	" addu %0, %2 \n"
	" scd %0, %1 \n"
	" beqz %0, 2f \n"
	" .subsection 2 \n"
	"2: b 1b \n"
	" .previous \n"
	" .set mips0 \n"
	: "=&r" (temp), "=m" (v->counter)
	: "Ir" (i), "m" (v->counter));
	} 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 (cpu_has_llsc && R10000_LLSC_WAR) {
	unsigned long temp;

	__asm__ __volatile__(
	" .set mips3 \n"
	"1: lld %0, %1 # atomic64_sub \n"
	" subu %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 (cpu_has_llsc) {
	unsigned long temp;

	__asm__ __volatile__(
	" .set mips3 \n"
	"1: lld %0, %1 # atomic64_sub \n"
	" subu %0, %2 \n"
	" scd %0, %1 \n"
	" beqz %0, 2f \n"
	" .subsection 2 \n"
	"2: b 1b \n"
	" .previous \n"
	" .set mips0 \n"
	: "=&r" (temp), "=m" (v->counter)
	: "Ir" (i), "m" (v->counter));
	} 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__ long atomic64_add_return(long i, atomic64_t * v)
	{
	unsigned long result;

	smp_llsc_mb();

	if (cpu_has_llsc && R10000_LLSC_WAR) {
	unsigned long temp;

	__asm__ __volatile__(
	" .set mips3 \n"
	"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"
	" .set mips0 \n"
	: "=&r" (result), "=&r" (temp), "=m" (v->counter)
	: "Ir" (i), "m" (v->counter)
	: "memory");
	} else if (cpu_has_llsc) {
	unsigned long temp;

	__asm__ __volatile__(
	" .set mips3 \n"
	"1: lld %1, %2 # atomic64_add_return \n"
	" addu %0, %1, %3 \n"
	" scd %0, %2 \n"
	" beqz %0, 2f \n"
	" addu %0, %1, %3 \n"
	" .subsection 2 \n"
	"2: b 1b \n"
	" .previous \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;
	v->counter = result;
	raw_local_irq_restore(flags);
	}

	smp_llsc_mb();

	return result;
	}

	static __inline__ long atomic64_sub_return(long i, atomic64_t * v)
	{
	unsigned long result;

	smp_llsc_mb();

	if (cpu_has_llsc && R10000_LLSC_WAR) {
	unsigned long temp;

	__asm__ __volatile__(
	" .set mips3 \n"
	"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"
	" .set mips0 \n"
	: "=&r" (result), "=&r" (temp), "=m" (v->counter)
	: "Ir" (i), "m" (v->counter)
	: "memory");
	} else if (cpu_has_llsc) {
	unsigned long temp;

	__asm__ __volatile__(
	" .set mips3 \n"
	"1: lld %1, %2 # atomic64_sub_return \n"
	" subu %0, %1, %3 \n"
	" scd %0, %2 \n"
	" beqz %0, 2f \n"
	" subu %0, %1, %3 \n"
	" .subsection 2 \n"
	"2: b 1b \n"
	" .previous \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;
	v->counter = result;
	raw_local_irq_restore(flags);
	}

	smp_llsc_mb();

	return result;
	}

	/*
	* atomic64_sub_if_positive - conditionally subtract integer from atomic variable
	* @i: integer value to subtract
	* @v: pointer of type atomic64_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__ long atomic64_sub_if_positive(long i, atomic64_t * v)
	{
	unsigned long result;

	smp_llsc_mb();

	if (cpu_has_llsc && R10000_LLSC_WAR) {
	unsigned long temp;

	__asm__ __volatile__(
	" .set mips3 \n"
	"1: lld %1, %2 # atomic64_sub_if_positive\n"
	" dsubu %0, %1, %3 \n"
	" bltz %0, 1f \n"
	" scd %0, %2 \n"
	" .set noreorder \n"
	" beqzl %0, 1b \n"
	" dsubu %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 (cpu_has_llsc) {
	unsigned long temp;

	__asm__ __volatile__(
	" .set mips3 \n"
	"1: lld %1, %2 # atomic64_sub_if_positive\n"
	" dsubu %0, %1, %3 \n"
	" bltz %0, 1f \n"
	" scd %0, %2 \n"
	" .set noreorder \n"
	" beqz %0, 2f \n"
	" dsubu %0, %1, %3 \n"
	" .set reorder \n"
	"1: \n"
	" .subsection 2 \n"
	"2: b 1b \n"
	" .previous \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 atomic64_cmpxchg(v, o, n) \
	((__typeof__((v)->counter))cmpxchg(&((v)->counter), (o), (n)))
	#define atomic64_xchg(v, new) (xchg(&((v)->counter), (new)))

	/**
	* atomic64_add_unless - add unless the number is a given value
	* @v: pointer of type atomic64_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 non-zero if @v was not @u, and zero otherwise.
	*/
	static __inline__ int atomic64_add_unless(atomic64_t *v, long a, long u)
	{
	long c, old;
	c = atomic64_read(v);
	for (;;) {
	if (unlikely(c == (u)))
	break;
	old = atomic64_cmpxchg((v), c, c + (a));
	if (likely(old == c))
	break;
	c = old;
	}
	return c != (u);
	}

	#define atomic64_inc_not_zero(v) atomic64_add_unless((v), 1, 0)

	#define atomic64_dec_return(v) atomic64_sub_return(1,(v))
	#define atomic64_inc_return(v) atomic64_add_return(1,(v))

	/*
	* atomic64_sub_and_test - subtract value from variable and test result
	* @i: integer value to subtract
	* @v: pointer of type atomic64_t
	*
	* Atomically subtracts @i from @v and returns
	* true if the result is zero, or false for all
	* other cases.
	*/
	#define atomic64_sub_and_test(i,v) (atomic64_sub_return((i), (v)) == 0)

	/*
	* atomic64_inc_and_test - increment and test
	* @v: pointer of type atomic64_t
	*
	* Atomically increments @v by 1
	* and returns true if the result is zero, or false for all
	* other cases.
	*/
	#define atomic64_inc_and_test(v) (atomic64_inc_return(v) == 0)

	/*
	* atomic64_dec_and_test - decrement by 1 and test
	* @v: pointer of type atomic64_t
	*
	* Atomically decrements @v by 1 and
	* returns true if the result is 0, or false for all other
	* cases.
	*/
	#define atomic64_dec_and_test(v) (atomic64_sub_return(1, (v)) == 0)

	/*
	* atomic64_dec_if_positive - decrement by 1 if old value positive
	* @v: pointer of type atomic64_t
	*/
	#define atomic64_dec_if_positive(v) atomic64_sub_if_positive(1, v)

	/*
	* atomic64_inc - increment atomic variable
	* @v: pointer of type atomic64_t
	*
	* Atomically increments @v by 1.
	*/
	#define atomic64_inc(v) atomic64_add(1,(v))

	/*
	* atomic64_dec - decrement and test
	* @v: pointer of type atomic64_t
	*
	* Atomically decrements @v by 1.
	*/
	#define atomic64_dec(v) atomic64_sub(1,(v))

	/*
	* atomic64_add_negative - add and test if negative
	* @v: pointer of type atomic64_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 atomic64_add_negative(i,v) (atomic64_add_return(i, (v)) < 0)

	#endif /* CONFIG_64BIT */

	/*
	* atomic_return operations are serializing but not the non-_return
	* versions.
	*/
	#define smp_mb__before_atomic_dec() smp_llsc_mb()
	#define smp_mb__after_atomic_dec() smp_llsc_mb()
	#define smp_mb__before_atomic_inc() smp_llsc_mb()
	#define smp_mb__after_atomic_inc() smp_llsc_mb()

	#include <asm-generic/atomic.h>

	#endif /* _ASM_ATOMIC_H */