From c0dc373a780f4ec63e45a573b9551763abd8cd1a Mon Sep 17 00:00:00 2001
From: Waiman Long <longman@redhat.com>
Date: Tue, 17 Jul 2018 16:16:00 -0400
Subject: [PATCH] locking/pvqspinlock/x86: Use LOCK_PREFIX in __pv_queued_spin_unlock() assembly code
Git-commit: c0dc373a780f4ec63e45a573b9551763abd8cd1a
Patch-mainline: v4.18-rc8
References: bsc#1050549

The LOCK_PREFIX macro should be used in the __raw_callee_save___pv_queued_spin_unlock()
assembly code, so that the lock prefix can be patched out on UP systems.

Signed-off-by: Waiman Long <longman@redhat.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Joe Mario <jmario@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Will Deacon <will.deacon@arm.com>
Link: http://lkml.kernel.org/r/1531858560-21547-1-git-send-email-longman@redhat.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Davidlohr Bueso <dbueso@suse.de> 

---
 arch/x86/include/asm/qspinlock_paravirt.h | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/arch/x86/include/asm/qspinlock_paravirt.h b/arch/x86/include/asm/qspinlock_paravirt.h
index 9ef5ee03d2d7..159622ee0674 100644
--- a/arch/x86/include/asm/qspinlock_paravirt.h
+++ b/arch/x86/include/asm/qspinlock_paravirt.h
@@ -43,7 +43,7 @@ asm    (".pushsection .text;"
 	"push  %rdx;"
 	"mov   $0x1,%eax;"
 	"xor   %edx,%edx;"
-	"lock cmpxchg %dl,(%rdi);"
+	LOCK_PREFIX "cmpxchg %dl,(%rdi);"
 	"cmp   $0x1,%al;"
 	"jne   .slowpath;"
 	"pop   %rdx;"
-- 
2.26.2