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/* SPDX-License-Identifier: GPL-2.0 */
#ifndef _ASM_X86_ATOMIC_H
#define _ASM_X86_ATOMIC_H
#include <linux/compiler.h>
#include <linux/types.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..
*/
/**
* arch_atomic_read - read atomic variable
* @v: pointer of type atomic_t
*
* Atomically reads the value of @v.
*/
static __always_inline int arch_atomic_read(const atomic_t *v)
{
/*
* Note for KASAN: we deliberately don't use READ_ONCE_NOCHECK() here,
* it's non-inlined function that increases binary size and stack usage.
*/
return __READ_ONCE((v)->counter);
}
/**
* arch_atomic_set - set atomic variable
* @v: pointer of type atomic_t
* @i: required value
*
* Atomically sets the value of @v to @i.
*/
static __always_inline void arch_atomic_set(atomic_t *v, int i)
{
__WRITE_ONCE(v->counter, i);
}
/**
* arch_atomic_add - add integer to atomic variable
* @i: integer value to add
* @v: pointer of type atomic_t
*
* Atomically adds @i to @v.
*/
static __always_inline void arch_atomic_add(int i, atomic_t *v)
{
asm volatile(LOCK_PREFIX "addl %1,%0"
: "+m" (v->counter)
: "ir" (i) : "memory");
}
/**
* arch_atomic_sub - subtract integer from atomic variable
* @i: integer value to subtract
* @v: pointer of type atomic_t
*
* Atomically subtracts @i from @v.
*/
static __always_inline void arch_atomic_sub(int i, atomic_t *v)
{
asm volatile(LOCK_PREFIX "subl %1,%0"
: "+m" (v->counter)
: "ir" (i) : "memory");
}
/**
* arch_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 __always_inline bool arch_atomic_sub_and_test(int i, atomic_t *v)
{
return GEN_BINARY_RMWcc(LOCK_PREFIX "subl", v->counter, e, "er", i);
}
#define arch_atomic_sub_and_test arch_atomic_sub_and_test
/**
* arch_atomic_inc - increment atomic variable
* @v: pointer of type atomic_t
*
* Atomically increments @v by 1.
*/
static __always_inline void arch_atomic_inc(atomic_t *v)
{
asm volatile(LOCK_PREFIX "incl %0"
: "+m" (v->counter) :: "memory");
}
#define arch_atomic_inc arch_atomic_inc
/**
* arch_atomic_dec - decrement atomic variable
* @v: pointer of type atomic_t
*
* Atomically decrements @v by 1.
*/
static __always_inline void arch_atomic_dec(atomic_t *v)
{
asm volatile(LOCK_PREFIX "decl %0"
: "+m" (v->counter) :: "memory");
}
#define arch_atomic_dec arch_atomic_dec
/**
* arch_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 __always_inline bool arch_atomic_dec_and_test(atomic_t *v)
{
return GEN_UNARY_RMWcc(LOCK_PREFIX "decl", v->counter, e);
}
#define arch_atomic_dec_and_test arch_atomic_dec_and_test
/**
* arch_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 __always_inline bool arch_atomic_inc_and_test(atomic_t *v)
{
return GEN_UNARY_RMWcc(LOCK_PREFIX "incl", v->counter, e);
}
#define arch_atomic_inc_and_test arch_atomic_inc_and_test
/**
* arch_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 __always_inline bool arch_atomic_add_negative(int i, atomic_t *v)
{
return GEN_BINARY_RMWcc(LOCK_PREFIX "addl", v->counter, s, "er", i);
}
#define arch_atomic_add_negative arch_atomic_add_negative
/**
* arch_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 __always_inline int arch_atomic_add_return(int i, atomic_t *v)
{
return i + xadd(&v->counter, i);
}
#define arch_atomic_add_return arch_atomic_add_return
/**
* arch_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 __always_inline int arch_atomic_sub_return(int i, atomic_t *v)
{
return arch_atomic_add_return(-i, v);
}
#define arch_atomic_sub_return arch_atomic_sub_return
static __always_inline int arch_atomic_fetch_add(int i, atomic_t *v)
{
return xadd(&v->counter, i);
}
#define arch_atomic_fetch_add arch_atomic_fetch_add
static __always_inline int arch_atomic_fetch_sub(int i, atomic_t *v)
{
return xadd(&v->counter, -i);
}
#define arch_atomic_fetch_sub arch_atomic_fetch_sub
static __always_inline int arch_atomic_cmpxchg(atomic_t *v, int old, int new)
{
return arch_cmpxchg(&v->counter, old, new);
}
#define arch_atomic_cmpxchg arch_atomic_cmpxchg
static __always_inline bool arch_atomic_try_cmpxchg(atomic_t *v, int *old, int new)
{
return arch_try_cmpxchg(&v->counter, old, new);
}
#define arch_atomic_try_cmpxchg arch_atomic_try_cmpxchg
static __always_inline int arch_atomic_xchg(atomic_t *v, int new)
{
return arch_xchg(&v->counter, new);
}
#define arch_atomic_xchg arch_atomic_xchg
static __always_inline void arch_atomic_and(int i, atomic_t *v)
{
asm volatile(LOCK_PREFIX "andl %1,%0"
: "+m" (v->counter)
: "ir" (i)
: "memory");
}
static __always_inline int arch_atomic_fetch_and(int i, atomic_t *v)
{
int val = arch_atomic_read(v);
do { } while (!arch_atomic_try_cmpxchg(v, &val, val & i));
return val;
}
#define arch_atomic_fetch_and arch_atomic_fetch_and
static __always_inline void arch_atomic_or(int i, atomic_t *v)
{
asm volatile(LOCK_PREFIX "orl %1,%0"
: "+m" (v->counter)
: "ir" (i)
: "memory");
}
static __always_inline int arch_atomic_fetch_or(int i, atomic_t *v)
{
int val = arch_atomic_read(v);
do { } while (!arch_atomic_try_cmpxchg(v, &val, val | i));
return val;
}
#define arch_atomic_fetch_or arch_atomic_fetch_or
static __always_inline void arch_atomic_xor(int i, atomic_t *v)
{
asm volatile(LOCK_PREFIX "xorl %1,%0"
: "+m" (v->counter)
: "ir" (i)
: "memory");
}
static __always_inline int arch_atomic_fetch_xor(int i, atomic_t *v)
{
int val = arch_atomic_read(v);
do { } while (!arch_atomic_try_cmpxchg(v, &val, val ^ i));
return val;
}
#define arch_atomic_fetch_xor arch_atomic_fetch_xor
#ifdef CONFIG_X86_32
# include <asm/atomic64_32.h>
#else
# include <asm/atomic64_64.h>
#endif
#endif /* _ASM_X86_ATOMIC_H */
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