X-Git-Url: https://git.openpandora.org/cgi-bin/gitweb.cgi?a=blobdiff_plain;f=arch%2Fx86%2Finclude%2Fasm%2Fatomic.h;h=706c69492c14ac4ab867457a1b52dace6f79c4b4;hb=77933c354c6c0e4b6abcb417518e84b8fd9b7ae4;hp=4e1b8873c47438dbbd646eebef82b9c6005259ed;hpb=ecc96e79202ed7225f7a2e2b7cb5a9e09fc74aa6;p=pandora-kernel.git diff --git a/arch/x86/include/asm/atomic.h b/arch/x86/include/asm/atomic.h index 4e1b8873c474..952a826ac4e5 100644 --- a/arch/x86/include/asm/atomic.h +++ b/arch/x86/include/asm/atomic.h @@ -1,5 +1,323 @@ +#ifndef _ASM_X86_ATOMIC_H +#define _ASM_X86_ATOMIC_H + +#include +#include +#include +#include +#include + +/* + * Atomic operations that C can't guarantee us. Useful for + * resource counting etc.. + */ + +#define ATOMIC_INIT(i) { (i) } + +/** + * atomic_read - read atomic variable + * @v: pointer of type atomic_t + * + * Atomically reads the value of @v. + */ +static inline int atomic_read(const atomic_t *v) +{ + return (*(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. + */ +static inline void atomic_set(atomic_t *v, int 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) +{ + asm volatile(LOCK_PREFIX "addl %1,%0" + : "+m" (v->counter) + : "ir" (i)); +} + +/** + * atomic_sub - subtract integer from 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) +{ + asm volatile(LOCK_PREFIX "subl %1,%0" + : "+m" (v->counter) + : "ir" (i)); +} + +/** + * 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. + */ +static inline int atomic_sub_and_test(int i, atomic_t *v) +{ + unsigned char c; + + asm volatile(LOCK_PREFIX "subl %2,%0; sete %1" + : "+m" (v->counter), "=qm" (c) + : "ir" (i) : "memory"); + return c; +} + +/** + * atomic_inc - increment atomic variable + * @v: pointer of type atomic_t + * + * Atomically increments @v by 1. + */ +static inline void atomic_inc(atomic_t *v) +{ + asm volatile(LOCK_PREFIX "incl %0" + : "+m" (v->counter)); +} + +/** + * atomic_dec - decrement atomic variable + * @v: pointer of type atomic_t + * + * Atomically decrements @v by 1. + */ +static inline void atomic_dec(atomic_t *v) +{ + asm volatile(LOCK_PREFIX "decl %0" + : "+m" (v->counter)); +} + +/** + * atomic_dec_and_test - decrement 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. + */ +static inline int atomic_dec_and_test(atomic_t *v) +{ + unsigned char c; + + asm volatile(LOCK_PREFIX "decl %0; sete %1" + : "+m" (v->counter), "=qm" (c) + : : "memory"); + return c != 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. + */ +static inline int atomic_inc_and_test(atomic_t *v) +{ + unsigned char c; + + asm volatile(LOCK_PREFIX "incl %0; sete %1" + : "+m" (v->counter), "=qm" (c) + : : "memory"); + return c != 0; +} + +/** + * atomic_add_negative - add and test if negative + * @i: integer value to add + * @v: pointer of type atomic_t + * + * Atomically adds @i to @v and returns true + * if the result is negative, or false when + * result is greater than or equal to zero. + */ +static inline int atomic_add_negative(int i, atomic_t *v) +{ + unsigned char c; + + asm volatile(LOCK_PREFIX "addl %2,%0; sets %1" + : "+m" (v->counter), "=qm" (c) + : "ir" (i) : "memory"); + return c; +} + +/** + * atomic_add_return - add integer and return + * @i: integer value to add + * @v: pointer of type atomic_t + * + * Atomically adds @i to @v and returns @i + @v + */ +static inline int atomic_add_return(int i, atomic_t *v) +{ + int __i; +#ifdef CONFIG_M386 + unsigned long flags; + if (unlikely(boot_cpu_data.x86 <= 3)) + goto no_xadd; +#endif + /* Modern 486+ processor */ + __i = i; + asm volatile(LOCK_PREFIX "xaddl %0, %1" + : "+r" (i), "+m" (v->counter) + : : "memory"); + return i + __i; + +#ifdef CONFIG_M386 +no_xadd: /* Legacy 386 processor */ + raw_local_irq_save(flags); + __i = atomic_read(v); + atomic_set(v, i + __i); + raw_local_irq_restore(flags); + return i + __i; +#endif +} + +/** + * atomic_sub_return - subtract integer and return + * @v: pointer of type atomic_t + * @i: integer value to subtract + * + * Atomically subtracts @i from @v and returns @v - @i + */ +static inline int atomic_sub_return(int i, atomic_t *v) +{ + return atomic_add_return(-i, v); +} + +#define atomic_inc_return(v) (atomic_add_return(1, v)) +#define atomic_dec_return(v) (atomic_sub_return(1, v)) + +static inline int atomic_cmpxchg(atomic_t *v, int old, int new) +{ + return cmpxchg(&v->counter, old, new); +} + +static inline int atomic_xchg(atomic_t *v, int new) +{ + return xchg(&v->counter, new); +} + +/** + * atomic_add_unless - add unless the number is already 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 @v was not already @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) + +/* + * atomic_dec_if_positive - decrement by 1 if old value positive + * @v: pointer of type atomic_t + * + * The function returns the old value of *v minus 1, even if + * the atomic variable, v, was not decremented. + */ +static inline int atomic_dec_if_positive(atomic_t *v) +{ + int c, old, dec; + c = atomic_read(v); + for (;;) { + dec = c - 1; + if (unlikely(dec < 0)) + break; + old = atomic_cmpxchg((v), c, dec); + if (likely(old == c)) + break; + c = old; + } + return dec; +} + +/** + * atomic_inc_short - increment of a short integer + * @v: pointer to type int + * + * Atomically adds 1 to @v + * Returns the new value of @u + */ +static inline short int atomic_inc_short(short int *v) +{ + asm(LOCK_PREFIX "addw $1, %0" : "+m" (*v)); + return *v; +} + +#ifdef CONFIG_X86_64 +/** + * atomic_or_long - OR of two long integers + * @v1: pointer to type unsigned long + * @v2: pointer to type unsigned long + * + * Atomically ORs @v1 and @v2 + * Returns the result of the OR + */ +static inline void atomic_or_long(unsigned long *v1, unsigned long v2) +{ + asm(LOCK_PREFIX "orq %1, %0" : "+m" (*v1) : "r" (v2)); +} +#endif + +/* These are x86-specific, used by some header files */ +#define atomic_clear_mask(mask, addr) \ + asm volatile(LOCK_PREFIX "andl %0,%1" \ + : : "r" (~(mask)), "m" (*(addr)) : "memory") + +#define atomic_set_mask(mask, addr) \ + asm volatile(LOCK_PREFIX "orl %0,%1" \ + : : "r" ((unsigned)(mask)), "m" (*(addr)) \ + : "memory") + +/* Atomic operations are already serializing on x86 */ +#define smp_mb__before_atomic_dec() barrier() +#define smp_mb__after_atomic_dec() barrier() +#define smp_mb__before_atomic_inc() barrier() +#define smp_mb__after_atomic_inc() barrier() + #ifdef CONFIG_X86_32 -# include "atomic_32.h" +# include "atomic64_32.h" #else -# include "atomic_64.h" +# include "atomic64_64.h" #endif + +#include +#endif /* _ASM_X86_ATOMIC_H */