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authorChristian Borntraeger <borntraeger@de.ibm.com>2013-04-23 01:23:02 +0000
committerAlexander Graf <agraf@suse.de>2013-04-26 20:18:24 +0200
commit7f61cbc108dd16df9a53649d53f26143ad506fe1 (patch)
treeaad118b1591884e0d6cdef919a4de8712fc4f197 /pc-bios/s390-ccw/start.S
parentb462fcd57c0949e4dfd457fafa91db17e0e99113 (diff)
downloadqemu-7f61cbc108dd16df9a53649d53f26143ad506fe1.tar.gz
s390-ccw.img: replace while loop with a disabled wait on s390 bios
dont waste cpu power on an error condition. Lets stop the guest with a disabled wait. Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com> Signed-off-by: Alexander Graf <agraf@suse.de>
Diffstat (limited to 'pc-bios/s390-ccw/start.S')
-rw-r--r--pc-bios/s390-ccw/start.S15
1 files changed, 15 insertions, 0 deletions
diff --git a/pc-bios/s390-ccw/start.S b/pc-bios/s390-ccw/start.S
index c2b9a19d34..09deee7fc0 100644
--- a/pc-bios/s390-ccw/start.S
+++ b/pc-bios/s390-ccw/start.S
@@ -3,6 +3,7 @@
* into the pc-bios directory of qemu.
*
* Copyright (c) 2013 Alexander Graf <agraf@suse.de>
+ * Copyright 2013 IBM Corp.
*
* This work is licensed under the terms of the GNU GPL, version 2 or (at
* your option) any later version. See the COPYING file in the top-level
@@ -14,3 +15,17 @@ _start:
larl %r15, stack + 0x8000 /* Set up stack */
j main /* And call C */
+
+/*
+ * void disabled_wait(void)
+ *
+ * stops the current guest cpu.
+ */
+ .globl disabled_wait
+disabled_wait:
+ larl %r1,disabled_wait_psw
+ lpswe 0(%r1)
+
+ .align 8
+disabled_wait_psw:
+ .quad 0x0002000180000000,0x0000000000000000