#ifndef __ASSEMBLER__
#ifndef PT_EI
-# define PT_EI __extern_always_inline
+# define PT_EI __extern_always_inline __attribute__((visibility("hidden")))
#endif
-/*
extern long int testandset (int *spinlock);
extern int __compare_and_swap (long int *p, long int oldval, long int newval);
-*/
/* Get some notion of the current stack. Need not be exactly the top
of the stack, just something somewhere in the current frame. */
#else /* Generic i386 implementation */
-
+extern int compare_and_swap_is_available (void);
/* Spinlock implementation; required. */
PT_EI long int
return ret;
}
-
-PT_EI int
+#if 00
+static __always_inline int
get_eflags (void)
{
int res;
return res;
}
-
-PT_EI void
+static __always_inline void
set_eflags (int newflags)
{
__asm__ __volatile__ ("pushl %0; popfl" : : "r" (newflags) : "cc");
}
-
+#endif
PT_EI int
compare_and_swap_is_available (void)
{
- int oldflags = get_eflags ();
int changed;
+ int oldflags;
+ /* get EFLAGS */
+ __asm__ __volatile__ ("pushfl; popl %0" : "=r" (oldflags) : );
/* Flip AC bit in EFLAGS. */
- set_eflags (oldflags ^ 0x40000);
+ __asm__ __volatile__ ("pushl %0; popfl" : : "r" (oldflags ^ 0x40000) : "cc");
+ /* reread EFLAGS */
+ __asm__ __volatile__ ("pushfl; popl %0" : "=r" (changed) : );
/* See if bit changed. */
- changed = (get_eflags () ^ oldflags) & 0x40000;
+ changed = (changed ^ oldflags) & 0x40000;
/* Restore EFLAGS. */
- set_eflags (oldflags);
+ __asm__ __volatile__ ("pushl %0; popfl" : : "r" (oldflags) : "cc");
/* If the AC flag did not change, it's a 386 and it lacks cmpxchg.
Otherwise, it's a 486 or above and it has cmpxchg. */
return changed != 0;