ARM: 7632/1: spinlock: avoid exclusive accesses on unlock() path
authorWill Deacon <will.deacon@arm.com>
Thu, 24 Jan 2013 13:47:38 +0000 (14:47 +0100)
committerRussell King <rmk+kernel@arm.linux.org.uk>
Mon, 28 Jan 2013 14:13:05 +0000 (14:13 +0000)
commit20e260b6f4f717c100620122f626a2c06a4cfd72
treeb2f0c8c70f86ae41f742604b4eb6c08d75109595
parent0a301110b7bd33ef10164c184fe2c1d8c4c3ab6b
ARM: 7632/1: spinlock: avoid exclusive accesses on unlock() path

When unlocking a spinlock, all we need to do is increment the owner
field of the lock. Since only one CPU can be performing an unlock()
operation for a given lock, this doesn't need to be exclusive.

This patch simplifies arch_spin_unlock to use non-exclusive accesses
when updating the owner field of the lock.

Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
arch/arm/include/asm/spinlock.h