x86/spinlock: Replace ACCESS_ONCE with READ_ONCE
authorChristian Borntraeger <borntraeger@de.ibm.com>
Mon, 24 Nov 2014 09:53:46 +0000 (10:53 +0100)
committerChristian Borntraeger <borntraeger@de.ibm.com>
Thu, 18 Dec 2014 08:54:38 +0000 (09:54 +0100)
commit4f9d1382e6f80dcfa891b2c02d5a35c53be485f1
treed4d95efc68ca6661661e08fe78b1ff3538baa5de
parente37c698270633327245beb0fbd8699db8a4b65b4
x86/spinlock: Replace ACCESS_ONCE with READ_ONCE

ACCESS_ONCE does not work reliably on non-scalar types. For
example gcc 4.6 and 4.7 might remove the volatile tag for such
accesses during the SRA (scalar replacement of aggregates) step
(https://gcc.gnu.org/bugzilla/show_bug.cgi?id=58145)

Change the spinlock code to replace ACCESS_ONCE with READ_ONCE.

Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
Acked-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
arch/x86/include/asm/spinlock.h