From f554be42fd0fd8dd14680c67f2db26b3e7de9670 Mon Sep 17 00:00:00 2001
From: Vasily Gorbik <gor@linux.vnet.ibm.com>
Date: Thu, 12 Oct 2017 13:01:47 +0200
Subject: s390/spinlock: use cpu alternatives to enable niai instruction

Enable niai instruction in the spinlock code at run-time for machines
on which facility 49 is available (zEC12 and newer).

Signed-off-by: Vasily Gorbik <gor@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
---
 arch/s390/include/asm/spinlock.h | 5 ++---
 1 file changed, 2 insertions(+), 3 deletions(-)

(limited to 'arch/s390/include/asm')

diff --git a/arch/s390/include/asm/spinlock.h b/arch/s390/include/asm/spinlock.h
index 09e783d..709cb6c 100644
--- a/arch/s390/include/asm/spinlock.h
+++ b/arch/s390/include/asm/spinlock.h
@@ -13,6 +13,7 @@
 #include <asm/atomic_ops.h>
 #include <asm/barrier.h>
 #include <asm/processor.h>
+#include <asm/alternative.h>
 
 #define SPINLOCK_LOCKVAL (S390_lowcore.spinlock_lockval)
 
@@ -86,9 +87,7 @@ static inline void arch_spin_unlock(arch_spinlock_t *lp)
 {
 	typecheck(int, lp->lock);
 	asm volatile(
-#ifdef CONFIG_HAVE_MARCH_ZEC12_FEATURES
-		"	.long	0xb2fa0070\n"	/* NIAI 7 */
-#endif
+		ALTERNATIVE("", ".long 0xb2fa0070", 49)	/* NIAI 7 */
 		"	sth	%1,%0\n"
 		: "=Q" (((unsigned short *) &lp->lock)[1])
 		: "d" (0) : "cc", "memory");
-- 
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