Small workaround for a rare, but annoying, erratum

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Merge tag 'please-pull-ia64-erratum' of git://git.kernel.org/pub/scm/linux/kernel/git/aegl/linux

Pull itanium erratum fix from Tony Luck:
 "Small workaround for a rare, but annoying, erratum #237"

* tag 'please-pull-ia64-erratum' of git://git.kernel.org/pub/scm/linux/kernel/git/aegl/linux:
  [IA64] Change default PSR.ac from '1' to '0' (Fix erratum #237)

arch/ia64/kernel/head.S

@@ -259,7 +259,7 @@ start_ap:
 	 * Switch into virtual mode:
 	 */
 	movl r16=(IA64_PSR_IT|IA64_PSR_IC|IA64_PSR_DT|IA64_PSR_RT|IA64_PSR_DFH|IA64_PSR_BN \
-		  |IA64_PSR_DI|IA64_PSR_AC)
+		  |IA64_PSR_DI)
 	;;
 	mov cr.ipsr=r16
 	movl r17=1f

arch/ia64/kernel/ivt.S

@@ -58,7 +58,7 @@
 #include <asm/unistd.h>
 #include <asm/errno.h>
 
-#if 1
+#if 0
 # define PSR_DEFAULT_BITS	psr.ac
 #else
 # define PSR_DEFAULT_BITS	0

arch/ia64/kvm/vmm_ivt.S

@@ -64,7 +64,7 @@
 #include "kvm_minstate.h"
 #include "vti.h"
 
-#if 1
+#if 0
 # define PSR_DEFAULT_BITS   psr.ac
 #else
 # define PSR_DEFAULT_BITS   0