From 80a60f6ef19a0d4d06a55065f69fa3dbbbac8bcc Mon Sep 17 00:00:00 2001
From: Heiko Carstens <heiko.carstens@de.ibm.com>
Date: Mon, 20 Jun 2016 14:04:17 +0200
Subject: [PATCH] s390/smp: use basic blocks for sigp inline assemblies

Use only simple inline assemblies which consist of a single basic
block if the register asm construct is being used.

Otherwise gcc would generate broken code if the compiler option
--sanitize-coverage=trace-pc would be used.

Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
---
 arch/s390/include/asm/sigp.h | 17 ++++++++++++++---
 arch/s390/kernel/smp.c       |  8 +-------
 2 files changed, 15 insertions(+), 10 deletions(-)

diff --git a/arch/s390/include/asm/sigp.h b/arch/s390/include/asm/sigp.h
index 1c8f33fca356..72df5f2de6b0 100644
--- a/arch/s390/include/asm/sigp.h
+++ b/arch/s390/include/asm/sigp.h
@@ -37,8 +37,8 @@
 
 #ifndef __ASSEMBLY__
 
-static inline int __pcpu_sigp(u16 addr, u8 order, unsigned long parm,
-			      u32 *status)
+static inline int ____pcpu_sigp(u16 addr, u8 order, unsigned long parm,
+				u32 *status)
 {
 	register unsigned long reg1 asm ("1") = parm;
 	int cc;
@@ -48,8 +48,19 @@ static inline int __pcpu_sigp(u16 addr, u8 order, unsigned long parm,
 		"	ipm	%0\n"
 		"	srl	%0,28\n"
 		: "=d" (cc), "+d" (reg1) : "d" (addr), "a" (order) : "cc");
+	*status = reg1;
+	return cc;
+}
+
+static inline int __pcpu_sigp(u16 addr, u8 order, unsigned long parm,
+			      u32 *status)
+{
+	u32 _status;
+	int cc;
+
+	cc = ____pcpu_sigp(addr, order, parm, &_status);
 	if (status && cc == 1)
-		*status = reg1;
+		*status = _status;
 	return cc;
 }
 
diff --git a/arch/s390/kernel/smp.c b/arch/s390/kernel/smp.c
index 830537432493..5c8f7caf9f31 100644
--- a/arch/s390/kernel/smp.c
+++ b/arch/s390/kernel/smp.c
@@ -318,17 +318,11 @@ static void pcpu_delegate(struct pcpu *pcpu, void (*func)(void *),
  */
 static int pcpu_set_smt(unsigned int mtid)
 {
-	register unsigned long reg1 asm ("1") = (unsigned long) mtid;
 	int cc;
 
 	if (smp_cpu_mtid == mtid)
 		return 0;
-	asm volatile(
-		"	sigp	%1,0,%2	# sigp set multi-threading\n"
-		"	ipm	%0\n"
-		"	srl	%0,28\n"
-		: "=d" (cc) : "d" (reg1), "K" (SIGP_SET_MULTI_THREADING)
-		: "cc");
+	cc = __pcpu_sigp(0, SIGP_SET_MULTI_THREADING, mtid, NULL);
 	if (cc == 0) {
 		smp_cpu_mtid = mtid;
 		smp_cpu_mt_shift = 0;