From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([208.118.235.92]:36172) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1UUaQ8-0002vu-5B for qemu-devel@nongnu.org; Tue, 23 Apr 2013 06:25:58 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1UUaQ5-0007lM-NI for qemu-devel@nongnu.org; Tue, 23 Apr 2013 06:25:56 -0400 Received: from e06smtp17.uk.ibm.com ([195.75.94.113]:37348) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1UUaQ5-0007kl-EK for qemu-devel@nongnu.org; Tue, 23 Apr 2013 06:25:53 -0400 Received: from /spool/local by e06smtp17.uk.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! Violators will be prosecuted for from ; Tue, 23 Apr 2013 11:23:07 +0100 Received: from b06cxnps4075.portsmouth.uk.ibm.com (d06relay12.portsmouth.uk.ibm.com [9.149.109.197]) by d06dlp03.portsmouth.uk.ibm.com (Postfix) with ESMTP id 0C3FA1B08061 for ; Tue, 23 Apr 2013 11:25:47 +0100 (BST) Received: from d06av03.portsmouth.uk.ibm.com (d06av03.portsmouth.uk.ibm.com [9.149.37.213]) by b06cxnps4075.portsmouth.uk.ibm.com (8.13.8/8.13.8/NCO v10.0) with ESMTP id r3NAPa6Y54198322 for ; Tue, 23 Apr 2013 10:25:36 GMT Received: from d06av03.portsmouth.uk.ibm.com (localhost.localdomain [127.0.0.1]) by d06av03.portsmouth.uk.ibm.com (8.14.4/8.13.1/NCO v10.0 AVout) with ESMTP id r3NAPkwO013504 for ; Tue, 23 Apr 2013 04:25:46 -0600 From: Christian Borntraeger Date: Tue, 23 Apr 2013 12:26:08 +0200 Message-Id: <1366712768-8918-1-git-send-email-borntraeger@de.ibm.com> Subject: [Qemu-devel] [PATCH] replace while loop with a disabled wait on s390 bios List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Alexander Graf Cc: cornelia.huck@de.ibm.com, Christian Borntraeger , qemu-devel@nongnu.org, Dominik Dingel dont waste cpu power on an error condition. Lets stop the guest with a disabled wait. Signed-off-by: Christian Borntraeger --- pc-bios/s390-ccw/main.c | 4 ++-- pc-bios/s390-ccw/s390-ccw.h | 3 +++ pc-bios/s390-ccw/start.S | 15 +++++++++++++++ 3 files changed, 20 insertions(+), 2 deletions(-) diff --git a/pc-bios/s390-ccw/main.c b/pc-bios/s390-ccw/main.c index 0913aac..c00f702 100644 --- a/pc-bios/s390-ccw/main.c +++ b/pc-bios/s390-ccw/main.c @@ -16,7 +16,7 @@ char stack[PAGE_SIZE * 8] __attribute__((__aligned__(PAGE_SIZE))); void virtio_panic(const char *string) { sclp_print(string); - while (1) { } + disabled_wait(); } static void virtio_setup(void) @@ -52,5 +52,5 @@ int main(void) virtio_setup(); if (zipl_load() < 0) sclp_print("Failed to load OS from hard disk\n"); - while (1) { } + disabled_wait(); } diff --git a/pc-bios/s390-ccw/s390-ccw.h b/pc-bios/s390-ccw/s390-ccw.h index a03dbaf..8241b0a 100644 --- a/pc-bios/s390-ccw/s390-ccw.h +++ b/pc-bios/s390-ccw/s390-ccw.h @@ -45,6 +45,9 @@ typedef unsigned long long __u64; #include "cio.h" +/* start.s */ +void disabled_wait(void); + /* main.c */ void virtio_panic(const char *string); diff --git a/pc-bios/s390-ccw/start.S b/pc-bios/s390-ccw/start.S index c2b9a19..09deee7 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 + * 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 -- 1.8.1.4