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#ifndef __ARCH_X86_ATOMIC__
#define __ARCH_X86_ATOMIC__
#include <xen/config.h>
#include <asm/system.h>
#define build_read_atomic(name, size, type, reg, barrier) \
static inline type name(const volatile type *addr) \
{ type ret; asm volatile("mov" size " %1,%0":reg (ret) \
:"m" (*(volatile type *)addr) barrier); return ret; }
#define build_write_atomic(name, size, type, reg, barrier) \
static inline void name(volatile type *addr, type val) \
{ asm volatile("mov" size " %1,%0": "=m" (*(volatile type *)addr) \
:reg (val) barrier); }
build_read_atomic(read_u8_atomic, "b", uint8_t, "=q", )
build_read_atomic(read_u16_atomic, "w", uint16_t, "=r", )
build_read_atomic(read_u32_atomic, "l", uint32_t, "=r", )
build_write_atomic(write_u8_atomic, "b", uint8_t, "q", )
build_write_atomic(write_u16_atomic, "w", uint16_t, "r", )
build_write_atomic(write_u32_atomic, "l", uint32_t, "r", )
build_read_atomic(read_u64_atomic, "q", uint64_t, "=r", )
build_write_atomic(write_u64_atomic, "q", uint64_t, "r", )
#undef build_read_atomic
#undef build_write_atomic
void __bad_atomic_size(void);
#define read_atomic(p) ({ \
typeof(*p) __x; \
switch ( sizeof(*p) ) { \
case 1: __x = (typeof(*p))read_u8_atomic((uint8_t *)p); break; \
case 2: __x = (typeof(*p))read_u16_atomic((uint16_t *)p); break; \
case 4: __x = (typeof(*p))read_u32_atomic((uint32_t *)p); break; \
case 8: __x = (typeof(*p))read_u64_atomic((uint64_t *)p); break; \
default: __x = 0; __bad_atomic_size(); break; \
} \
__x; \
})
#define write_atomic(p, x) ({ \
typeof(*p) __x = (x); \
switch ( sizeof(*p) ) { \
case 1: write_u8_atomic((uint8_t *)p, (uint8_t)__x); break; \
case 2: write_u16_atomic((uint16_t *)p, (uint16_t)__x); break; \
case 4: write_u32_atomic((uint32_t *)p, (uint32_t)__x); break; \
case 8: write_u64_atomic((uint64_t *)p, (uint64_t)__x); break; \
default: __bad_atomic_size(); break; \
} \
__x; \
})
/*
* NB. I've pushed the volatile qualifier into the operations. This allows
* fast accessors such as _atomic_read() and _atomic_set() which don't give
* the compiler a fit.
*/
typedef struct { int counter; } atomic_t;
#define ATOMIC_INIT(i) { (i) }
/**
* atomic_read - read atomic variable
* @v: pointer of type atomic_t
*
* Atomically reads the value of @v.
*/
#define _atomic_read(v) ((v).counter)
#define atomic_read(v) read_atomic(&((v)->counter))
/**
* atomic_set - set atomic variable
* @v: pointer of type atomic_t
* @i: required value
*
* Atomically sets the value of @v to @i.
*/
#define _atomic_set(v,i) (((v).counter) = (i))
#define atomic_set(v,i) write_atomic(&((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; addl %1,%0"
: "=m" (*(volatile int *)&v->counter)
: "ir" (i), "m" (*(volatile int *)&v->counter) );
}
/**
* atomic_sub - subtract the 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; subl %1,%0"
: "=m" (*(volatile int *)&v->counter)
: "ir" (i), "m" (*(volatile int *)&v->counter) );
}
/**
* 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; subl %2,%0; sete %1"
: "=m" (*(volatile int *)&v->counter), "=qm" (c)
: "ir" (i), "m" (*(volatile int *)&v->counter) : "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; incl %0"
: "=m" (*(volatile int *)&v->counter)
: "m" (*(volatile int *)&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; decl %0"
: "=m" (*(volatile int *)&v->counter)
: "m" (*(volatile int *)&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; decl %0; sete %1"
: "=m" (*(volatile int *)&v->counter), "=qm" (c)
: "m" (*(volatile int *)&v->counter) : "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; incl %0; sete %1"
: "=m" (*(volatile int *)&v->counter), "=qm" (c)
: "m" (*(volatile int *)&v->counter) : "memory" );
return c != 0;
}
/**
* atomic_add_negative - add and test if negative
* @v: pointer of type atomic_t
* @i: integer value to add
*
* 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; addl %2,%0; sets %1"
: "=m" (*(volatile int *)&v->counter), "=qm" (c)
: "ir" (i), "m" (*(volatile int *)&v->counter) : "memory" );
return c;
}
static inline atomic_t atomic_compareandswap(
atomic_t old, atomic_t new, atomic_t *v)
{
atomic_t rc;
rc.counter = __cmpxchg(&v->counter, old.counter, new.counter, sizeof(int));
return rc;
}
#endif /* __ARCH_X86_ATOMIC__ */
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