isearch/comm/atomic_asm8.h
2021-03-19 18:38:34 +08:00

275 lines
6.8 KiB
C

#ifndef __ARCH_I386_ATOMIC8__
#define __ARCH_I386_ATOMIC8__
#include <sys/cdefs.h>
__BEGIN_DECLS
/*
* cmpxchg8b: require Pentium or above
* compare edx:eax with target memory,
* if equal, write ecx:ebx to memory
* if non-equal, keep old value in edx:eax and write back
*/
/*
* Make sure gcc doesn't try to be clever and move things around
* on us. We need to use _exactly_ the address the user gave us,
* not some alias that contains the same information.
*/
typedef struct { volatile long long counter; } atomic8_t;
#define ATOMIC8_INIT(i) { (i) }
/**
* atomic8_read - read atomic variable
* @v: pointer of type atomic8_t
*
* Atomically reads the value of @v.
*/
static __inline__ long long atomic8_read(atomic8_t *v)
{
register long long r;
__asm__ __volatile__(
/* original value for ebx, ecx doesn't matter */
" movl %%ecx, %%edx\n"
" movl %%ebx, %%eax\n"
"lock; cmpxchg8b %1\n"
: "=&A" (r), "+o" (v->counter)
:
: "memory", "cc");
return r;
}
/**
* atomic8_set - set atomic variable
* @v: pointer of type atomic8_t
* @i: required value
*
* Atomically sets the value of @v to @i.
*/
static __inline__ long long atomic8_return_set(atomic8_t *v, long long i)
{
register long long r = v->counter;
#if __pic__ || __PIC__
__asm__ __volatile__(
" pushl %%ebx\n"
" movl %2, %%ebx\n"
"1: repz; nop\n" // aka pause
"lock; cmpxchg8b (%1)\n"
" jnz 1b\n"
" popl %%ebx\n"
: "+A"(r)
: "ir"(v), "ir" ((int)i), "c"((int)((unsigned long long)i>>32))
: "memory", "cc");
#else
__asm__ __volatile__(
"1: repz; nop\n" // aka pause
"lock; cmpxchg8b %1\n"
" jnz 1b\n"
: "+A"(r), "+o" (v->counter)
: "b" ((int)i), "c"((int)((unsigned long long)i>>32))
: "memory", "cc");
#endif
return r;
}
static __inline__ void atomic8_set(atomic8_t *v, long long i)
{
atomic8_return_set(v, i);
}
/**
* atomic8_set - set atomic variable
* @v: pointer of type atomic8_t
* @i: required value
*
* Atomically sets the value of @v to @i.
*/
static __inline__ long long atomic8_clear(atomic8_t *v)
{
return atomic8_return_set(v, 0);
}
/**
* atomic8_add - add integer to atomic variable
* @i: integer value to add
* @v: pointer of type atomic8_t
*
* Atomically adds @i to @v.
*/
static __inline__ long long atomic8_add(long long i, atomic8_t *v)
{
register long long r = v->counter;
#if __pic__ || __PIC__
__asm__ __volatile__(
" pushl %%ebx\n"
"1: movl %2, %%ebx\n"
" movl %3, %%ecx\n"
" addl %%eax, %%ebx\n"
" adcl %%edx, %%ecx\n"
"repz; nop\n"
"lock; cmpxchg8b (%1)\n"
" jnz 1b\n"
" popl %%ebx\n"
: "+A" (r)
: "ir"(v), "ir" ((int)i), "ir"((int)((unsigned long long)i>>32))
: "memory", "ecx", "cc");
#else
__asm__ __volatile__(
"1: movl %2, %%ebx\n"
" movl %3, %%ecx\n"
" addl %%eax, %%ebx\n"
" adcl %%edx, %%ecx\n"
"repz; nop\n"
"lock; cmpxchg8b %1\n"
" jnz 1b\n"
: "+A"(r), "+o" (v->counter)
: "g" ((int)i), "g"((int)((unsigned long long)i>>32))
: "memory", "ebx", "ecx", "cc");
#endif
return r;
}
/**
* atomic8_add_return - add and return
* @v: pointer of type atomic8_t
* @i: integer value to add
*
* Atomically adds @i to @v and returns @i + @v
*/
static __inline__ long long atomic8_add_return(long long i, atomic8_t *v)
{
register long long r = v->counter;
#if __pic__ || __PIC__
__asm__ __volatile__(
" pushl %%ebx\n"
"1: movl %2, %%ebx\n"
" movl %3, %%ecx\n"
" addl %%eax, %%ebx\n"
" adcl %%edx, %%ecx\n"
"repz; nop\n"
"lock; cmpxchg8b (%1)\n"
" jnz 1b\n"
" movl %%ebx, %%eax\n"
" movl %%ecx, %%edx\n"
" popl %%ebx\n"
: "+A" (r)
: "ir"(v), "ir" ((int)i), "ir"((int)((unsigned long long)i>>32))
: "memory", "ecx", "cc");
#else
__asm__ __volatile__(
"1: movl %2, %%ebx\n"
" movl %3, %%ecx\n"
" addl %%eax, %%ebx\n"
" adcl %%edx, %%ecx\n"
"repz; nop\n"
"lock; cmpxchg8b %1\n"
" jnz 1b\n"
" movl %%ebx, %%eax\n"
" movl %%ecx, %%edx\n"
: "+A" (r), "+o" (v->counter)
: "g" ((int)i), "g"((int)((unsigned long long)i>>32))
: "memory", "ebx", "ecx", "cc");
#endif
return r;
}
/**
* atomic8_sub - subtract the atomic variable
* @i: integer value to subtract
* @v: pointer of type atomic8_t
*
* Atomically subtracts @i from @v.
*/
static __inline__ long long atomic8_sub(long long i, atomic8_t *v)
{
return atomic8_add(-i, v);
}
/**
* atomic8_sub_and_test - subtract value from variable and test result
* @i: integer value to subtract
* @v: pointer of type atomic8_t
*
* Atomically subtracts @i from @v and returns
* true if the result is zero, or false for all
* other cases.
*/
static __inline__ int atomic8_sub_and_test(long long i, atomic8_t *v)
{
return atomic8_add_return(-i, v)==0;
}
/**
* atomic8_inc - increment atomic variable
* @v: pointer of type atomic8_t
*
* Atomically increments @v by 1.
*/
static __inline__ long long atomic8_inc(atomic8_t *v)
{
return atomic8_add(1, v);
}
/**
* atomic8_dec - decrement atomic variable
* @v: pointer of type atomic8_t
*
* Atomically decrements @v by 1.
*/
static __inline__ long long atomic8_dec(atomic8_t *v)
{
return atomic8_add(-1, v);
}
/**
* atomic8_dec_and_test - decrement and test
* @v: pointer of type atomic8_t
*
* Atomically decrements @v by 1 and
* returns true if the result is 0, or false for all other
* cases.
*/
static __inline__ int atomic8_dec_and_test(atomic8_t *v)
{
return atomic8_add_return(-1, v)==0;
}
/**
* atomic8_inc_and_test - increment and test
* @v: pointer of type atomic8_t
*
* Atomically increments @v by 1
* and returns true if the result is zero, or false for all
* other cases.
*/
static __inline__ int atomic8_inc_and_test(atomic8_t *v)
{
return atomic8_add_return(1, v)==0;
}
/**
* atomic8_add_negative - add and test if negative
* @v: pointer of type atomic8_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 atomic8_add_negative(long long i, atomic8_t *v)
{
return atomic8_add_return(i, v) < 0;
}
static __inline__ long long atomic8_sub_return(long long i, atomic8_t *v)
{
return atomic8_add_return(-i,v);
}
#define atomic8_inc_return(v) (atomic8_add_return(1,v))
#define atomic8_dec_return(v) (atomic8_sub_return(1,v))
__END_DECLS
#endif