/* * 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" " .subsection 2 \n" "2: b 1b \n" " .previous \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 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" " .subsection 2 \n" "2: b 1b \n" " .previous \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 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 */