From a1ae1f399a6dd83dad41e06f9b15b697bc0ed186 Mon Sep 17 00:00:00 2001
From: Alexander Schmidt <alexs@linux.vnet.ibm.com>
Date: Thu, 23 Apr 2015 09:46:05 +0200
Subject: [PATCH] Fix slp_switch assembly for the s390 arch

Use inline assembly to generate the correct return
value.
---
 platform/switch_s390_unix.h | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/platform/switch_s390_unix.h b/platform/switch_s390_unix.h
index 88a42a6a..6641854e 100644
--- a/platform/switch_s390_unix.h
+++ b/platform/switch_s390_unix.h
@@ -36,6 +36,7 @@
 static int
 slp_switch(void)
 {
+    register int ret;
     register long *stackref, stsizediff;
     __asm__ volatile ("" : : : REGS_TO_SAVE);
 #ifdef __s390x__
@@ -68,7 +69,8 @@ slp_switch(void)
         SLP_RESTORE_STATE();
     }
     __asm__ volatile ("" : : : REGS_TO_SAVE);
-    return 0;
+    __asm__ volatile ("lhi %0, 0" : "=r" (ret) : );
+    return ret;
 }
 
 #endif