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sh: consolidate atomic_cmpxchg()/atomic_add_unless() definitions.

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The LL/SC and IRQ versions were using generic stubs while the GRB version
was just reimplementing what it already had for the standard cmpxchg()
code. As we have optimized cmpxchg() implementations that are decoupled
from the atomic code, simply falling back on the generic wrapper does the
right thing. With this in place the GRB case is unaffected while the
LL/SC case gets to use its optimized cmpxchg().

Signed-off-by: Paul Mundt <lethal@linux-sh.org>
This commit is contained in:
Paul Mundt
2010-01-08 17:02:17 +09:00
parent 56d45b62ce
commit 8c0b8139c8
3 changed files with 28 additions and 116 deletions
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27
arch/sh/include/asm/atomic-llsc.h
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@@ -104,31 +104,4 @@ static inline void atomic_set_mask(unsigned int mask, atomic_t *v)
: "t");
}
#define atomic_cmpxchg(v, o, n) (cmpxchg(&((v)->counter), (o), (n)))
/**
* atomic_add_unless - add unless the number is a given value
* @v: pointer of type atomic_t
* @a: the amount to add to v...
* @u: ...unless v is equal to u.
*
* Atomically adds @a to @v, so long as it was not @u.
* Returns non-zero if @v was not @u, and zero otherwise.
*/
static inline int atomic_add_unless(atomic_t *v, int a, int u)
{
int c, old;
c = atomic_read(v);
for (;;) {
if (unlikely(c == (u)))
break;
old = atomic_cmpxchg((v), c, c + (a));
if (likely(old == c))
break;
c = old;
}
return c != (u);
}
#endif /* __ASM_SH_ATOMIC_LLSC_H */