From: Will Deacon <will.deacon@arm.com>
Date: Thu, 24 Jan 2013 13:47:38 +0000 (+0100)
Subject: ARM: 7632/1: spinlock: avoid exclusive accesses on unlock() path
X-Git-Tag: v3.9-rc1~143^2^2~15
X-Git-Url: http://git.openpandora.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=20e260b6f4f717c100620122f626a2c06a4cfd72;p=pandora-kernel.git

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>
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