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#ifndef _ASM_X86_ATOMIC_H |
#define _ASM_X86_ATOMIC_H |
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#include <linux/compiler.h> |
#include <linux/types.h> |
#include <asm/processor.h> |
#include <asm/alternative.h> |
#include <asm/cmpxchg.h> |
#include <asm/rmwcc.h> |
#include <asm/barrier.h> |
|
/* |
* Atomic operations that C can't guarantee us. Useful for |
* resource counting etc.. |
*/ |
|
#define ATOMIC_INIT(i) { (i) } |
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/** |
* 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 ACCESS_ONCE((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) |
{ |
GEN_BINARY_RMWcc(LOCK_PREFIX "subl", v->counter, "er", i, "%0", "e"); |
} |
|
/** |
* 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)); |
} |
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/** |
* 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) |
{ |
GEN_UNARY_RMWcc(LOCK_PREFIX "decl", v->counter, "%0", "e"); |
} |
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/** |
* 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) |
{ |
GEN_UNARY_RMWcc(LOCK_PREFIX "incl", v->counter, "%0", "e"); |
} |
|
/** |
* 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) |
{ |
GEN_BINARY_RMWcc(LOCK_PREFIX "addl", v->counter, "er", i, "%0", "s"); |
} |
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/** |
* 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) |
{ |
return i + xadd(&v->counter, i); |
} |
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/** |
* 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); |
} |
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#define atomic_inc_return(v) (atomic_add_return(1, v)) |
#define atomic_dec_return(v) (atomic_sub_return(1, v)) |
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static inline int atomic_cmpxchg(atomic_t *v, int old, int new) |
{ |
return cmpxchg(&v->counter, old, new); |
} |
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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 the old value of @v. |
*/ |
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; |
} |
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/** |
* 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; |
} |
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/* 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") |
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#define atomic_set_mask(mask, addr) \ |
asm volatile(LOCK_PREFIX "orl %0,%1" \ |
: : "r" ((unsigned)(mask)), "m" (*(addr)) \ |
: "memory") |
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#ifdef CONFIG_X86_32 |
# include <asm/atomic64_32.h> |
#else |
# include <asm/atomic64_64.h> |
#endif |
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#endif /* _ASM_X86_ATOMIC_H */ |