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@@ -26,13 +26,11 @@
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#ifndef __ASSEMBLER__
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#ifndef PT_EI
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-# define PT_EI __extern_always_inline
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+# define PT_EI __extern_always_inline __attribute__((visibility("hidden")))
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#endif
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-/*
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extern long int testandset (int *spinlock);
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extern int __compare_and_swap (long int *p, long int oldval, long int newval);
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-*/
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/* Get some notion of the current stack. Need not be exactly the top
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of the stack, just something somewhere in the current frame. */
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@@ -85,7 +83,7 @@ __compare_and_swap (long int *p, long int oldval, long int newval)
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#else /* Generic i386 implementation */
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-
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+extern int compare_and_swap_is_available (void);
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/* Spinlock implementation; required. */
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PT_EI long int
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@@ -123,8 +121,8 @@ __compare_and_swap (long int *p, long int oldval, long int newval)
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return ret;
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}
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-
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-PT_EI int
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+#if 00
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+static __always_inline int
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get_eflags (void)
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{
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int res;
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@@ -132,25 +130,28 @@ get_eflags (void)
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return res;
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}
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-
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-PT_EI void
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+static __always_inline void
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set_eflags (int newflags)
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{
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__asm__ __volatile__ ("pushl %0; popfl" : : "r" (newflags) : "cc");
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}
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-
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+#endif
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PT_EI int
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compare_and_swap_is_available (void)
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{
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- int oldflags = get_eflags ();
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int changed;
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+ int oldflags;
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+ /* get EFLAGS */
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+ __asm__ __volatile__ ("pushfl; popl %0" : "=r" (oldflags) : );
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/* Flip AC bit in EFLAGS. */
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- set_eflags (oldflags ^ 0x40000);
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+ __asm__ __volatile__ ("pushl %0; popfl" : : "r" (oldflags ^ 0x40000) : "cc");
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+ /* reread EFLAGS */
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+ __asm__ __volatile__ ("pushfl; popl %0" : "=r" (changed) : );
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/* See if bit changed. */
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- changed = (get_eflags () ^ oldflags) & 0x40000;
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+ changed = (changed ^ oldflags) & 0x40000;
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/* Restore EFLAGS. */
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- set_eflags (oldflags);
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+ __asm__ __volatile__ ("pushl %0; popfl" : : "r" (oldflags) : "cc");
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/* If the AC flag did not change, it's a 386 and it lacks cmpxchg.
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Otherwise, it's a 486 or above and it has cmpxchg. */
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return changed != 0;
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