diff --git a/Documentation/atomic_ops.txt b/Documentation/atomic_ops.txt index f1744161ef0694cef8dab811d25e0efea9c1ea7a..23a1c2402bccf3ec6d8bbf97bba3becfcf149272 100644 --- a/Documentation/atomic_ops.txt +++ b/Documentation/atomic_ops.txt @@ -115,7 +115,7 @@ boolean is return which indicates whether the resulting counter value is negative. It requires explicit memory barrier semantics around the operation. -Finally: +Then: int atomic_cmpxchg(atomic_t *v, int old, int new); @@ -129,6 +129,18 @@ atomic_cmpxchg requires explicit memory barriers around the operation. The semantics for atomic_cmpxchg are the same as those defined for 'cas' below. +Finally: + + int atomic_add_unless(atomic_t *v, int a, int u); + +If the atomic value v is not equal to u, this function adds a to v, and +returns non zero. If v is equal to u then it returns zero. This is done as +an atomic operation. + +atomic_add_unless requires explicit memory barriers around the operation. + +atomic_inc_not_zero, equivalent to atomic_add_unless(v, 1, 0) + If a caller requires memory barrier semantics around an atomic_t operation which does not return a value, a set of interfaces are diff --git a/arch/sparc/lib/atomic32.c b/arch/sparc/lib/atomic32.c index be46f65451846af2eef721a0c1d111082cbeec86..cb3cf0f228221154a2dd5e658b8550733a966866 100644 --- a/arch/sparc/lib/atomic32.c +++ b/arch/sparc/lib/atomic32.c @@ -53,6 +53,21 @@ int atomic_cmpxchg(atomic_t *v, int old, int new) return ret; } +int atomic_add_unless(atomic_t *v, int a, int u) +{ + int ret; + unsigned long flags; + + spin_lock_irqsave(ATOMIC_HASH(v), flags); + ret = v->counter; + if (ret != u) + v->counter += a; + spin_unlock_irqrestore(ATOMIC_HASH(v), flags); + return ret != u; +} + +static inline void atomic_clear_mask(unsigned long mask, unsigned long *addr) +/* Atomic operations are already serializing */ void atomic_set(atomic_t *v, int i) { unsigned long flags; diff --git a/include/asm-alpha/atomic.h b/include/asm-alpha/atomic.h index a6660809a879c99c14b2d935a2fe941ff48bdc96..36505bb4e8cbb8790e4be3d44b067f44e3ede462 100644 --- a/include/asm-alpha/atomic.h +++ b/include/asm-alpha/atomic.h @@ -179,6 +179,16 @@ static __inline__ long atomic64_sub_return(long i, atomic64_t * v) #define atomic_cmpxchg(v, o, n) ((int)cmpxchg(&((v)->counter), (o), (n))) +#define atomic_add_unless(v, a, u) \ +({ \ + int c, old; \ + c = atomic_read(v); \ + while (c != (u) && (old = atomic_cmpxchg((v), c, c + (a))) != c) \ + c = old; \ + 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 atomic64_dec_return(v) atomic64_sub_return(1,(v)) diff --git a/include/asm-arm/atomic.h b/include/asm-arm/atomic.h index 8ab1689ef56a1c3388fd0d25801230fd3b6516e7..75b802719723ad459d719b6f598254fe0dfe02e4 100644 --- a/include/asm-arm/atomic.h +++ b/include/asm-arm/atomic.h @@ -173,6 +173,17 @@ static inline void atomic_clear_mask(unsigned long mask, unsigned long *addr) #endif /* __LINUX_ARM_ARCH__ */ +static inline int atomic_add_unless(atomic_t *v, int a, int u) +{ + int c, old; + + c = atomic_read(v); + while (c != u && (old = atomic_cmpxchg((v), c, c + a)) != c) + c = old; + return c != u; +} +#define atomic_inc_not_zero(v) atomic_add_unless((v), 1, 0) + #define atomic_add(i, v) (void) atomic_add_return(i, v) #define atomic_inc(v) (void) atomic_add_return(1, v) #define atomic_sub(i, v) (void) atomic_sub_return(i, v) diff --git a/include/asm-arm26/atomic.h b/include/asm-arm26/atomic.h index 54b24ead7132520692d54ea45eec9329780b3e12..a47cadc59686237260877f1874b2c18ff0ed9421 100644 --- a/include/asm-arm26/atomic.h +++ b/include/asm-arm26/atomic.h @@ -76,6 +76,21 @@ static inline int atomic_cmpxchg(atomic_t *v, int old, int new) return ret; } +static inline int atomic_add_unless(atomic_t *v, int a, int u) +{ + int ret; + unsigned long flags; + + local_irq_save(flags); + ret = v->counter; + if (ret != u) + v->counter += a; + local_irq_restore(flags); + + return ret != u; +} +#define atomic_inc_not_zero(v) atomic_add_unless((v), 1, 0) + static inline void atomic_clear_mask(unsigned long mask, unsigned long *addr) { unsigned long flags; diff --git a/include/asm-cris/atomic.h b/include/asm-cris/atomic.h index 45891f7de00fc1c58a9bcc48158c75dc2a386746..683b05a57d88068527bea8d99343c2425503318c 100644 --- a/include/asm-cris/atomic.h +++ b/include/asm-cris/atomic.h @@ -136,6 +136,20 @@ static inline int atomic_cmpxchg(atomic_t *v, int old, int new) return ret; } +static inline int atomic_add_unless(atomic_t *v, int a, int u) +{ + int ret; + unsigned long flags; + + cris_atomic_save(v, flags); + ret = v->counter; + if (ret != u) + v->counter += a; + cris_atomic_restore(v, flags); + return ret != u; +} +#define atomic_inc_not_zero(v) atomic_add_unless((v), 1, 0) + /* Atomic operations are already serializing */ #define smp_mb__before_atomic_dec() barrier() #define smp_mb__after_atomic_dec() barrier() diff --git a/include/asm-frv/atomic.h b/include/asm-frv/atomic.h index 55f06a0e949f57046869dc0174ea6fb2d25441a7..f6539ff569c5278abece2c6442cbab205dd80311 100644 --- a/include/asm-frv/atomic.h +++ b/include/asm-frv/atomic.h @@ -416,4 +416,14 @@ extern uint32_t __cmpxchg_32(uint32_t *v, uint32_t test, uint32_t new); #define atomic_cmpxchg(v, old, new) ((int)cmpxchg(&((v)->counter), old, new)) +#define atomic_add_unless(v, a, u) \ +({ \ + int c, old; \ + c = atomic_read(v); \ + while (c != (u) && (old = atomic_cmpxchg((v), c, c + (a))) != c) \ + c = old; \ + c != (u); \ +}) +#define atomic_inc_not_zero(v) atomic_add_unless((v), 1, 0) + #endif /* _ASM_ATOMIC_H */ diff --git a/include/asm-h8300/atomic.h b/include/asm-h8300/atomic.h index d504392594919e3389918ab8210c84eb520bc0e2..f23d86819ea82b83fb75bcce32516b78817524e0 100644 --- a/include/asm-h8300/atomic.h +++ b/include/asm-h8300/atomic.h @@ -95,6 +95,20 @@ static inline int atomic_cmpxchg(atomic_t *v, int old, int new) return ret; } +static inline int atomic_add_unless(atomic_t *v, int a, int u) +{ + int ret; + unsigned long flags; + + local_irq_save(flags); + ret = v->counter; + if (ret != u) + v->counter += a; + local_irq_restore(flags); + return ret != u; +} +#define atomic_inc_not_zero(v) atomic_add_unless((v), 1, 0) + static __inline__ void atomic_clear_mask(unsigned long mask, unsigned long *v) { __asm__ __volatile__("stc ccr,r1l\n\t" diff --git a/include/asm-i386/atomic.h b/include/asm-i386/atomic.h index 5ff698e9d2c2f79738fe5d2de237320138bf7f3c..c68557aa04b2b0ef9246086f6d52b156c72966c0 100644 --- a/include/asm-i386/atomic.h +++ b/include/asm-i386/atomic.h @@ -217,6 +217,25 @@ static __inline__ int atomic_sub_return(int i, atomic_t *v) #define atomic_cmpxchg(v, old, new) ((int)cmpxchg(&((v)->counter), old, 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. + */ +#define atomic_add_unless(v, a, u) \ +({ \ + int c, old; \ + c = atomic_read(v); \ + while (c != (u) && (old = atomic_cmpxchg((v), c, c + (a))) != c) \ + c = old; \ + c != (u); \ +}) +#define atomic_inc_not_zero(v) atomic_add_unless((v), 1, 0) + #define atomic_inc_return(v) (atomic_add_return(1,v)) #define atomic_dec_return(v) (atomic_sub_return(1,v)) diff --git a/include/asm-ia64/atomic.h b/include/asm-ia64/atomic.h index 593d3da9f3c20f6a03e96165fd8395e465497e24..2fbebf85c31d55a1b1ac8b5f7d69a62f5c554860 100644 --- a/include/asm-ia64/atomic.h +++ b/include/asm-ia64/atomic.h @@ -90,6 +90,16 @@ ia64_atomic64_sub (__s64 i, atomic64_t *v) #define atomic_cmpxchg(v, old, new) ((int)cmpxchg(&((v)->counter), old, new)) +#define atomic_add_unless(v, a, u) \ +({ \ + int c, old; \ + c = atomic_read(v); \ + while (c != (u) && (old = atomic_cmpxchg((v), c, c + (a))) != c) \ + c = old; \ + c != (u); \ +}) +#define atomic_inc_not_zero(v) atomic_add_unless((v), 1, 0) + #define atomic_add_return(i,v) \ ({ \ int __ia64_aar_i = (i); \ diff --git a/include/asm-m68k/atomic.h b/include/asm-m68k/atomic.h index b821975a361a1e7af8caba44d56ffb29d8a0083a..e3c962eeabf3d37871d24e87638fcc8005bf3048 100644 --- a/include/asm-m68k/atomic.h +++ b/include/asm-m68k/atomic.h @@ -141,6 +141,16 @@ static inline void atomic_set_mask(unsigned long mask, unsigned long *v) #define atomic_cmpxchg(v, o, n) ((int)cmpxchg(&((v)->counter), (o), (n))) +#define atomic_add_unless(v, a, u) \ +({ \ + int c, old; \ + c = atomic_read(v); \ + while (c != (u) && (old = atomic_cmpxchg((v), c, c + (a))) != c) \ + c = old; \ + c != (u); \ +}) +#define atomic_inc_not_zero(v) atomic_add_unless((v), 1, 0) + /* Atomic operations are already serializing */ #define smp_mb__before_atomic_dec() barrier() #define smp_mb__after_atomic_dec() barrier() diff --git a/include/asm-m68knommu/atomic.h b/include/asm-m68knommu/atomic.h index 2fd33a56b603a2bc63e93c26bbb94801d7b3dd14..3c1cc153c4154c233fc05dc6f0f0b8f7f3b8e9f9 100644 --- a/include/asm-m68knommu/atomic.h +++ b/include/asm-m68knommu/atomic.h @@ -130,6 +130,16 @@ static inline int atomic_sub_return(int i, atomic_t * v) #define atomic_cmpxchg(v, o, n) ((int)cmpxchg(&((v)->counter), (o), (n))) +#define atomic_add_unless(v, a, u) \ +({ \ + int c, old; \ + c = atomic_read(v); \ + while (c != (u) && (old = atomic_cmpxchg((v), c, c + (a))) != c) \ + c = old; \ + 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)) diff --git a/include/asm-mips/atomic.h b/include/asm-mips/atomic.h index 4fba0d003c995b1b8c4ed3313a6b8d715c1b073c..2c87b41e69baa60019143bfed35550fc13fc6e2f 100644 --- a/include/asm-mips/atomic.h +++ b/include/asm-mips/atomic.h @@ -289,6 +289,25 @@ static __inline__ int atomic_sub_if_positive(int i, atomic_t * v) #define atomic_cmpxchg(v, o, n) ((int)cmpxchg(&((v)->counter), (o), (n))) +/** + * 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. + */ +#define atomic_add_unless(v, a, u) \ +({ \ + int c, old; \ + c = atomic_read(v); \ + while (c != (u) && (old = atomic_cmpxchg((v), c, c + (a))) != c) \ + c = old; \ + 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)) diff --git a/include/asm-parisc/atomic.h b/include/asm-parisc/atomic.h index 52c9a45b5f871211bfd4aa7bc28f65be82735ffe..983e9a2b6042858b492d8dbde8b97b9d5f96b701 100644 --- a/include/asm-parisc/atomic.h +++ b/include/asm-parisc/atomic.h @@ -166,6 +166,25 @@ static __inline__ int atomic_read(const atomic_t *v) /* exported interface */ #define atomic_cmpxchg(v, o, n) ((int)cmpxchg(&((v)->counter), (o), (n))) +/** + * 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. + */ +#define atomic_add_unless(v, a, u) \ +({ \ + int c, old; \ + c = atomic_read(v); \ + while (c != (u) && (old = atomic_cmpxchg((v), c, c + (a))) != c) \ + c = old; \ + c != (u); \ +}) +#define atomic_inc_not_zero(v) atomic_add_unless((v), 1, 0) + #define atomic_add(i,v) ((void)(__atomic_add_return( ((int)i),(v)))) #define atomic_sub(i,v) ((void)(__atomic_add_return(-((int)i),(v)))) #define atomic_inc(v) ((void)(__atomic_add_return( 1,(v)))) diff --git a/include/asm-powerpc/atomic.h b/include/asm-powerpc/atomic.h index 37205faa9d7c7a872f4a711ee3b162ec1858ab6d..ec4b14468959e295dc29ebbd0b212b6899597f70 100644 --- a/include/asm-powerpc/atomic.h +++ b/include/asm-powerpc/atomic.h @@ -166,6 +166,31 @@ static __inline__ int atomic_dec_return(atomic_t *v) #define atomic_cmpxchg(v, o, n) ((int)cmpxchg(&((v)->counter), (o), (n))) +/** + * 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. + */ +#define atomic_add_unless(v, a, 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; \ + } \ + c != (u); \ +}) +#define atomic_inc_not_zero(v) atomic_add_unless((v), 1, 0) + #define atomic_sub_and_test(a, v) (atomic_sub_return((a), (v)) == 0) #define atomic_dec_and_test(v) (atomic_dec_return((v)) == 0) diff --git a/include/asm-s390/atomic.h b/include/asm-s390/atomic.h index 631014d5de9084ba843454ee136f4288703e452d..b3bd4f679f727d2c3bc24293d845e6f6166ff471 100644 --- a/include/asm-s390/atomic.h +++ b/include/asm-s390/atomic.h @@ -200,6 +200,16 @@ atomic_compare_and_swap(int expected_oldval,int new_val,atomic_t *v) #define atomic_cmpxchg(v, o, n) (atomic_compare_and_swap((o), (n), &((v)->counter))) +#define atomic_add_unless(v, a, u) \ +({ \ + int c, old; \ + c = atomic_read(v); \ + while (c != (u) && (old = atomic_cmpxchg((v), c, c + (a))) != c) \ + c = old; \ + c != (u); \ +}) +#define atomic_inc_not_zero(v) atomic_add_unless((v), 1, 0) + #define smp_mb__before_atomic_dec() smp_mb() #define smp_mb__after_atomic_dec() smp_mb() #define smp_mb__before_atomic_inc() smp_mb() diff --git a/include/asm-sh/atomic.h b/include/asm-sh/atomic.h index a148c762d3666567b70528c102c58152cabf0ca2..aabfd334462c178bbba76327a86a48a1efef70ab 100644 --- a/include/asm-sh/atomic.h +++ b/include/asm-sh/atomic.h @@ -101,6 +101,21 @@ static inline int atomic_cmpxchg(atomic_t *v, int old, int new) return ret; } +static inline int atomic_add_unless(atomic_t *v, int a, int u) +{ + int ret; + unsigned long flags; + + local_irq_save(flags); + ret = v->counter; + if (ret != u) + v->counter += a; + local_irq_restore(flags); + + return ret != u; +} +#define atomic_inc_not_zero(v) atomic_add_unless((v), 1, 0) + static __inline__ void atomic_clear_mask(unsigned int mask, atomic_t *v) { unsigned long flags; diff --git a/include/asm-sh64/atomic.h b/include/asm-sh64/atomic.h index 6eeb57b015ce50442cd5b3c17dad2e21d022980f..927a2bc27b3086140bea65c7345f49b2f97bd995 100644 --- a/include/asm-sh64/atomic.h +++ b/include/asm-sh64/atomic.h @@ -113,6 +113,21 @@ static inline int atomic_cmpxchg(atomic_t *v, int old, int new) return ret; } +static inline int atomic_add_unless(atomic_t *v, int a, int u) +{ + int ret; + unsigned long flags; + + local_irq_save(flags); + ret = v->counter; + if (ret != u) + v->counter += a; + local_irq_restore(flags); + + return ret != u; +} +#define atomic_inc_not_zero(v) atomic_add_unless((v), 1, 0) + static __inline__ void atomic_clear_mask(unsigned int mask, atomic_t *v) { unsigned long flags; diff --git a/include/asm-sparc/atomic.h b/include/asm-sparc/atomic.h index 52bdd1a895faaf0df90d57d42ec0140cdb5f45b8..62bec7ad271c496e81a8f2d95d4f4377cb16c952 100644 --- a/include/asm-sparc/atomic.h +++ b/include/asm-sparc/atomic.h @@ -20,6 +20,7 @@ typedef struct { volatile int counter; } atomic_t; extern int __atomic_add_return(int, atomic_t *); extern int atomic_cmpxchg(atomic_t *, int, int); +extern int atomic_add_unless(atomic_t *, int, int); extern void atomic_set(atomic_t *, int); #define atomic_read(v) ((v)->counter) @@ -49,6 +50,8 @@ extern void atomic_set(atomic_t *, int); #define atomic_dec_and_test(v) (atomic_dec_return(v) == 0) #define atomic_sub_and_test(i, v) (atomic_sub_return(i, v) == 0) +#define atomic_inc_not_zero(v) atomic_add_unless((v), 1, 0) + /* This is the old 24-bit implementation. It's still used internally * by some sparc-specific code, notably the semaphore implementation. */ diff --git a/include/asm-sparc64/atomic.h b/include/asm-sparc64/atomic.h index 3a0b4383bbaca3147e97712dd896366b09c8ed0f..8198c3d0d0074368b0d9fbba5d72969b403c4884 100644 --- a/include/asm-sparc64/atomic.h +++ b/include/asm-sparc64/atomic.h @@ -72,6 +72,16 @@ extern int atomic64_sub_ret(int, atomic64_t *); #define atomic_cmpxchg(v, o, n) ((int)cmpxchg(&((v)->counter), (o), (n))) +#define atomic_add_unless(v, a, u) \ +({ \ + int c, old; \ + c = atomic_read(v); \ + while (c != (u) && (old = atomic_cmpxchg((v), c, c + (a))) != c) \ + c = old; \ + c != (u); \ +}) +#define atomic_inc_not_zero(v) atomic_add_unless((v), 1, 0) + /* Atomic operations are already serializing */ #ifdef CONFIG_SMP #define smp_mb__before_atomic_dec() membar_storeload_loadload(); diff --git a/include/asm-v850/atomic.h b/include/asm-v850/atomic.h index e497166ca42b0946c5b5aa406c936ed8c3ab4acf..bede3172ce7f7e999e202fde6b04d31a6e281478 100644 --- a/include/asm-v850/atomic.h +++ b/include/asm-v850/atomic.h @@ -104,6 +104,22 @@ static inline int atomic_cmpxchg(atomic_t *v, int old, int new) return ret; } +static inline int atomic_add_unless(atomic_t *v, int a, int u) +{ + int ret; + unsigned long flags; + + local_irq_save(flags); + ret = v->counter; + if (ret != u) + v->counter += a; + local_irq_restore(flags); + + return ret != u; +} + +#define atomic_inc_not_zero(v) atomic_add_unless((v), 1, 0) + /* Atomic operations are already serializing on ARM */ #define smp_mb__before_atomic_dec() barrier() #define smp_mb__after_atomic_dec() barrier() diff --git a/include/asm-x86_64/atomic.h b/include/asm-x86_64/atomic.h index 75c8a1e96737adb4acc3ada66ce0acce8bb476d0..0866ef67f198d8380a8241727ea21f0a16a19ec1 100644 --- a/include/asm-x86_64/atomic.h +++ b/include/asm-x86_64/atomic.h @@ -362,6 +362,25 @@ static __inline__ int atomic_sub_return(int i, atomic_t *v) #define atomic_cmpxchg(v, old, new) ((int)cmpxchg(&((v)->counter), old, 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. + */ +#define atomic_add_unless(v, a, u) \ +({ \ + int c, old; \ + c = atomic_read(v); \ + while (c != (u) && (old = atomic_cmpxchg((v), c, c + (a))) != c) \ + c = old; \ + c != (u); \ +}) +#define atomic_inc_not_zero(v) atomic_add_unless((v), 1, 0) + #define atomic_inc_return(v) (atomic_add_return(1,v)) #define atomic_dec_return(v) (atomic_sub_return(1,v)) diff --git a/include/asm-xtensa/atomic.h b/include/asm-xtensa/atomic.h index cd40c5e75160302e3e75d3af55febf513a3c04e2..3670cc7695dad79d3326323e8c974abf417851f6 100644 --- a/include/asm-xtensa/atomic.h +++ b/include/asm-xtensa/atomic.h @@ -225,6 +225,25 @@ static inline int atomic_sub_return(int i, atomic_t * v) #define atomic_cmpxchg(v, o, n) ((int)cmpxchg(&((v)->counter), (o), (n))) +/** + * 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. + */ +#define atomic_add_unless(v, a, u) \ +({ \ + int c, old; \ + c = atomic_read(v); \ + while (c != (u) && (old = atomic_cmpxchg((v), c, c + (a))) != c) \ + c = old; \ + c != (u); \ +}) +#define atomic_inc_not_zero(v) atomic_add_unless((v), 1, 0) + static inline void atomic_clear_mask(unsigned int mask, atomic_t *v) { unsigned int all_f = -1;