From: Peter Zijlstra <peterz@infradead.org>
Date: Sat, 5 Sep 2015 14:55:05 +0000 (+0200)
Subject: locking/qspinlock/x86: Only emit the test-and-set fallback when building guest support
X-Git-Tag: v4.2.4~236
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=75928be688c2ba28e41566ba1b9d942f906d90f4;p=thirdparty%2Fkernel%2Fstable.git

locking/qspinlock/x86: Only emit the test-and-set fallback when building guest support

commit a6b277857fd2c990bc208ca1958d3f34d26052f7 upstream.

Only emit the test-and-set fallback for Hypervisors lacking
PARAVIRT_SPINLOCKS support when building for guests.

Suggested-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---

diff --git a/arch/x86/include/asm/qspinlock.h b/arch/x86/include/asm/qspinlock.h
index 8dde3bdc4a05c..eaba080760300 100644
--- a/arch/x86/include/asm/qspinlock.h
+++ b/arch/x86/include/asm/qspinlock.h
@@ -39,8 +39,8 @@ static inline void queued_spin_unlock(struct qspinlock *lock)
 }
 #endif
 
+#ifdef CONFIG_PARAVIRT
 #define virt_spin_lock virt_spin_lock
-
 static inline bool virt_spin_lock(struct qspinlock *lock)
 {
 	if (!static_cpu_has(X86_FEATURE_HYPERVISOR))
@@ -59,6 +59,7 @@ static inline bool virt_spin_lock(struct qspinlock *lock)
 
 	return true;
 }
+#endif /* CONFIG_PARAVIRT */
 
 #include <asm-generic/qspinlock.h>