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powerpc: Implement arch_spin_is_locked() using arch_spin_value_unlocked()

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At a glance these are just the inverse of each other. The one subtlety
is that arch_spin_value_unlocked() takes the lock by value, rather than
as a pointer, which is important for the lockref code.

On the other hand arch_spin_is_locked() doesn't really care, so
implement it in terms of arch_spin_value_unlocked().

Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
This commit is contained in:
Michael Ellerman 2014-01-15 18:14:29 +11:00 committed by Benjamin Herrenschmidt
parent 3405d230b3
commit 7179ba5288
1 changed files with 5 additions and 2 deletions
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7
arch/powerpc/include/asm/spinlock.h
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@ -28,8 +28,6 @@
#include <asm/synch.h>
#include <asm/ppc-opcode.h>
#define arch_spin_is_locked(x) ((x)->slock != 0)
#ifdef CONFIG_PPC64
/* use 0x800000yy when locked, where yy == CPU number */
#ifdef __BIG_ENDIAN__
@ -59,6 +57,11 @@ static __always_inline int arch_spin_value_unlocked(arch_spinlock_t lock)
return lock.slock == 0;
}
static inline int arch_spin_is_locked(arch_spinlock_t *lock)
{
return !arch_spin_value_unlocked(*lock);
}
/*
* This returns the old value in the lock, so we succeeded
* in getting the lock if the return value is 0.