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Diffstat (limited to 'arch/x86/include/asm/atomic64_32.h')
-rw-r--r-- | arch/x86/include/asm/atomic64_32.h | 160 |
1 files changed, 160 insertions, 0 deletions
diff --git a/arch/x86/include/asm/atomic64_32.h b/arch/x86/include/asm/atomic64_32.h new file mode 100644 index 00000000000..03027bf28de --- /dev/null +++ b/arch/x86/include/asm/atomic64_32.h @@ -0,0 +1,160 @@ +#ifndef _ASM_X86_ATOMIC64_32_H +#define _ASM_X86_ATOMIC64_32_H + +#include <linux/compiler.h> +#include <linux/types.h> +#include <asm/processor.h> +//#include <asm/cmpxchg.h> + +/* An 64bit atomic type */ + +typedef struct { + u64 __aligned(8) counter; +} atomic64_t; + +#define ATOMIC64_INIT(val) { (val) } + +extern u64 atomic64_cmpxchg(atomic64_t *ptr, u64 old_val, u64 new_val); + +/** + * atomic64_xchg - xchg atomic64 variable + * @ptr: pointer to type atomic64_t + * @new_val: value to assign + * + * Atomically xchgs the value of @ptr to @new_val and returns + * the old value. + */ +extern u64 atomic64_xchg(atomic64_t *ptr, u64 new_val); + +/** + * atomic64_set - set atomic64 variable + * @ptr: pointer to type atomic64_t + * @new_val: value to assign + * + * Atomically sets the value of @ptr to @new_val. + */ +extern void atomic64_set(atomic64_t *ptr, u64 new_val); + +/** + * atomic64_read - read atomic64 variable + * @ptr: pointer to type atomic64_t + * + * Atomically reads the value of @ptr and returns it. + */ +static inline u64 atomic64_read(atomic64_t *ptr) +{ + u64 res; + + /* + * Note, we inline this atomic64_t primitive because + * it only clobbers EAX/EDX and leaves the others + * untouched. We also (somewhat subtly) rely on the + * fact that cmpxchg8b returns the current 64-bit value + * of the memory location we are touching: + */ + asm volatile( + "mov %%ebx, %%eax\n\t" + "mov %%ecx, %%edx\n\t" + LOCK_PREFIX "cmpxchg8b %1\n" + : "=&A" (res) + : "m" (*ptr) + ); + + return res; +} + +extern u64 atomic64_read(atomic64_t *ptr); + +/** + * atomic64_add_return - add and return + * @delta: integer value to add + * @ptr: pointer to type atomic64_t + * + * Atomically adds @delta to @ptr and returns @delta + *@ptr + */ +extern u64 atomic64_add_return(u64 delta, atomic64_t *ptr); + +/* + * Other variants with different arithmetic operators: + */ +extern u64 atomic64_sub_return(u64 delta, atomic64_t *ptr); +extern u64 atomic64_inc_return(atomic64_t *ptr); +extern u64 atomic64_dec_return(atomic64_t *ptr); + +/** + * atomic64_add - add integer to atomic64 variable + * @delta: integer value to add + * @ptr: pointer to type atomic64_t + * + * Atomically adds @delta to @ptr. + */ +extern void atomic64_add(u64 delta, atomic64_t *ptr); + +/** + * atomic64_sub - subtract the atomic64 variable + * @delta: integer value to subtract + * @ptr: pointer to type atomic64_t + * + * Atomically subtracts @delta from @ptr. + */ +extern void atomic64_sub(u64 delta, atomic64_t *ptr); + +/** + * atomic64_sub_and_test - subtract value from variable and test result + * @delta: integer value to subtract + * @ptr: pointer to type atomic64_t + * + * Atomically subtracts @delta from @ptr and returns + * true if the result is zero, or false for all + * other cases. + */ +extern int atomic64_sub_and_test(u64 delta, atomic64_t *ptr); + +/** + * atomic64_inc - increment atomic64 variable + * @ptr: pointer to type atomic64_t + * + * Atomically increments @ptr by 1. + */ +extern void atomic64_inc(atomic64_t *ptr); + +/** + * atomic64_dec - decrement atomic64 variable + * @ptr: pointer to type atomic64_t + * + * Atomically decrements @ptr by 1. + */ +extern void atomic64_dec(atomic64_t *ptr); + +/** + * atomic64_dec_and_test - decrement and test + * @ptr: pointer to type atomic64_t + * + * Atomically decrements @ptr by 1 and + * returns true if the result is 0, or false for all other + * cases. + */ +extern int atomic64_dec_and_test(atomic64_t *ptr); + +/** + * atomic64_inc_and_test - increment and test + * @ptr: pointer to type atomic64_t + * + * Atomically increments @ptr by 1 + * and returns true if the result is zero, or false for all + * other cases. + */ +extern int atomic64_inc_and_test(atomic64_t *ptr); + +/** + * atomic64_add_negative - add and test if negative + * @delta: integer value to add + * @ptr: pointer to type atomic64_t + * + * Atomically adds @delta to @ptr and returns true + * if the result is negative, or false when + * result is greater than or equal to zero. + */ +extern int atomic64_add_negative(u64 delta, atomic64_t *ptr); + +#endif /* _ASM_X86_ATOMIC64_32_H */ |