diff options
Diffstat (limited to 'arch/x86/include/asm/atomic_32.h')
| -rw-r--r-- | arch/x86/include/asm/atomic_32.h | 185 |
1 files changed, 57 insertions, 128 deletions
diff --git a/arch/x86/include/asm/atomic_32.h b/arch/x86/include/asm/atomic_32.h index 2503d4e64c2a..dc5a667ff791 100644 --- a/arch/x86/include/asm/atomic_32.h +++ b/arch/x86/include/asm/atomic_32.h @@ -19,7 +19,10 @@ * * Atomically reads the value of @v. */ -#define atomic_read(v) ((v)->counter) +static inline int atomic_read(const atomic_t *v) +{ + return v->counter; +} /** * atomic_set - set atomic variable @@ -28,7 +31,10 @@ * * Atomically sets the value of @v to @i. */ -#define atomic_set(v, i) (((v)->counter) = (i)) +static inline void atomic_set(atomic_t *v, int i) +{ + v->counter = i; +} /** * atomic_add - add integer to atomic variable @@ -200,8 +206,15 @@ static inline int atomic_sub_return(int i, atomic_t *v) return atomic_add_return(-i, v); } -#define atomic_cmpxchg(v, old, new) (cmpxchg(&((v)->counter), (old), (new))) -#define atomic_xchg(v, new) (xchg(&((v)->counter), (new))) +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 @@ -250,45 +263,12 @@ static inline int atomic_add_unless(atomic_t *v, int a, int u) /* An 64bit atomic type */ typedef struct { - unsigned long long counter; + u64 __aligned(8) counter; } atomic64_t; #define ATOMIC64_INIT(val) { (val) } -/** - * atomic64_read - read atomic64 variable - * @ptr: pointer of type atomic64_t - * - * Atomically reads the value of @v. - * Doesn't imply a read memory barrier. - */ -#define __atomic64_read(ptr) ((ptr)->counter) - -static inline unsigned long long -cmpxchg8b(unsigned long long *ptr, unsigned long long old, unsigned long long new) -{ - asm volatile( - - LOCK_PREFIX "cmpxchg8b (%[ptr])\n" - - : "=A" (old) - - : [ptr] "D" (ptr), - "A" (old), - "b" (ll_low(new)), - "c" (ll_high(new)) - - : "memory"); - - return old; -} - -static inline unsigned long long -atomic64_cmpxchg(atomic64_t *ptr, unsigned long long old_val, - unsigned long long new_val) -{ - return cmpxchg8b(&ptr->counter, old_val, new_val); -} +extern u64 atomic64_cmpxchg(atomic64_t *ptr, u64 old_val, u64 new_val); /** * atomic64_xchg - xchg atomic64 variable @@ -298,18 +278,7 @@ atomic64_cmpxchg(atomic64_t *ptr, unsigned long long old_val, * Atomically xchgs the value of @ptr to @new_val and returns * the old value. */ - -static inline unsigned long long -atomic64_xchg(atomic64_t *ptr, unsigned long long new_val) -{ - unsigned long long old_val; - - do { - old_val = atomic_read(ptr); - } while (atomic64_cmpxchg(ptr, old_val, new_val) != old_val); - - return old_val; -} +extern u64 atomic64_xchg(atomic64_t *ptr, u64 new_val); /** * atomic64_set - set atomic64 variable @@ -318,10 +287,7 @@ atomic64_xchg(atomic64_t *ptr, unsigned long long new_val) * * Atomically sets the value of @ptr to @new_val. */ -static inline void atomic64_set(atomic64_t *ptr, unsigned long long new_val) -{ - atomic64_xchg(ptr, new_val); -} +extern void atomic64_set(atomic64_t *ptr, u64 new_val); /** * atomic64_read - read atomic64 variable @@ -329,17 +295,30 @@ static inline void atomic64_set(atomic64_t *ptr, unsigned long long new_val) * * Atomically reads the value of @ptr and returns it. */ -static inline unsigned long long atomic64_read(atomic64_t *ptr) +static inline u64 atomic64_read(atomic64_t *ptr) { - unsigned long long curr_val; - - do { - curr_val = __atomic64_read(ptr); - } while (atomic64_cmpxchg(ptr, curr_val, curr_val) != curr_val); - - return curr_val; + 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 @@ -347,34 +326,14 @@ static inline unsigned long long atomic64_read(atomic64_t *ptr) * * Atomically adds @delta to @ptr and returns @delta + *@ptr */ -static inline unsigned long long -atomic64_add_return(unsigned long long delta, atomic64_t *ptr) -{ - unsigned long long old_val, new_val; - - do { - old_val = atomic_read(ptr); - new_val = old_val + delta; - - } while (atomic64_cmpxchg(ptr, old_val, new_val) != old_val); - - return new_val; -} - -static inline long atomic64_sub_return(unsigned long long delta, atomic64_t *ptr) -{ - return atomic64_add_return(-delta, ptr); -} +extern u64 atomic64_add_return(u64 delta, atomic64_t *ptr); -static inline long atomic64_inc_return(atomic64_t *ptr) -{ - return atomic64_add_return(1, ptr); -} - -static inline long atomic64_dec_return(atomic64_t *ptr) -{ - return atomic64_sub_return(1, 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 @@ -383,10 +342,7 @@ static inline long atomic64_dec_return(atomic64_t *ptr) * * Atomically adds @delta to @ptr. */ -static inline void atomic64_add(unsigned long long delta, atomic64_t *ptr) -{ - atomic64_add_return(delta, ptr); -} +extern void atomic64_add(u64 delta, atomic64_t *ptr); /** * atomic64_sub - subtract the atomic64 variable @@ -395,10 +351,7 @@ static inline void atomic64_add(unsigned long long delta, atomic64_t *ptr) * * Atomically subtracts @delta from @ptr. */ -static inline void atomic64_sub(unsigned long long delta, atomic64_t *ptr) -{ - atomic64_add(-delta, ptr); -} +extern void atomic64_sub(u64 delta, atomic64_t *ptr); /** * atomic64_sub_and_test - subtract value from variable and test result @@ -409,13 +362,7 @@ static inline void atomic64_sub(unsigned long long delta, atomic64_t *ptr) * true if the result is zero, or false for all * other cases. */ -static inline int -atomic64_sub_and_test(unsigned long long delta, atomic64_t *ptr) -{ - unsigned long long old_val = atomic64_sub_return(delta, ptr); - - return old_val == 0; -} +extern int atomic64_sub_and_test(u64 delta, atomic64_t *ptr); /** * atomic64_inc - increment atomic64 variable @@ -423,10 +370,7 @@ atomic64_sub_and_test(unsigned long long delta, atomic64_t *ptr) * * Atomically increments @ptr by 1. */ -static inline void atomic64_inc(atomic64_t *ptr) -{ - atomic64_add(1, ptr); -} +extern void atomic64_inc(atomic64_t *ptr); /** * atomic64_dec - decrement atomic64 variable @@ -434,10 +378,7 @@ static inline void atomic64_inc(atomic64_t *ptr) * * Atomically decrements @ptr by 1. */ -static inline void atomic64_dec(atomic64_t *ptr) -{ - atomic64_sub(1, ptr); -} +extern void atomic64_dec(atomic64_t *ptr); /** * atomic64_dec_and_test - decrement and test @@ -447,10 +388,7 @@ static inline void atomic64_dec(atomic64_t *ptr) * returns true if the result is 0, or false for all other * cases. */ -static inline int atomic64_dec_and_test(atomic64_t *ptr) -{ - return atomic64_sub_and_test(1, ptr); -} +extern int atomic64_dec_and_test(atomic64_t *ptr); /** * atomic64_inc_and_test - increment and test @@ -460,10 +398,7 @@ static inline int atomic64_dec_and_test(atomic64_t *ptr) * and returns true if the result is zero, or false for all * other cases. */ -static inline int atomic64_inc_and_test(atomic64_t *ptr) -{ - return atomic64_sub_and_test(-1, ptr); -} +extern int atomic64_inc_and_test(atomic64_t *ptr); /** * atomic64_add_negative - add and test if negative @@ -474,13 +409,7 @@ static inline int atomic64_inc_and_test(atomic64_t *ptr) * if the result is negative, or false when * result is greater than or equal to zero. */ -static inline int -atomic64_add_negative(unsigned long long delta, atomic64_t *ptr) -{ - long long old_val = atomic64_add_return(delta, ptr); - - return old_val < 0; -} +extern int atomic64_add_negative(u64 delta, atomic64_t *ptr); #include <asm-generic/atomic-long.h> #endif /* _ASM_X86_ATOMIC_32_H */ |