From: Heiko Carstens <heiko.carstens@de.ibm.com>
Date: Mon, 14 May 2012 10:41:54 +0000 (+0200)
Subject: s390/barrier: make use of fast-bcr facility
X-Git-Url: https://git.stricted.de/?a=commitdiff_plain;h=e5b8d7553f87d939295e9eb0ca699c0030dc5ff1;p=GitHub%2Fexynos8895%2Fandroid_kernel_samsung_universal8895.git

s390/barrier: make use of fast-bcr facility

If the kernel gets compiled for at least z196, make use of
the fast-BCR facility.

Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
---

diff --git a/arch/s390/include/asm/barrier.h b/arch/s390/include/asm/barrier.h
index 6993b20d64fb..10a508802940 100644
--- a/arch/s390/include/asm/barrier.h
+++ b/arch/s390/include/asm/barrier.h
@@ -15,7 +15,12 @@
 
 static inline void mb(void)
 {
+#ifdef CONFIG_HAVE_MARCH_Z196_FEATURES
+	/* Fast-BCR without checkpoint synchronization */
+	asm volatile("bcr 14,0" : : : "memory");
+#else
 	asm volatile("bcr 15,0" : : : "memory");
+#endif
 }
 
 #define rmb()				mb()