Commit 7179ba52 authored Jan 15, 2014 by Michael Ellerman Committed by Benjamin Herrenschmidt Jan 28, 2014

powerpc: Implement arch_spin_is_locked() using arch_spin_value_unlocked()



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>

parent 3405d230

arch/powerpc/include/asm/spinlock.h

+5 −2

Original line number	Diff line number	Diff line
		@@ -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.