From patchwork Thu Jan 14 03:14:58 2016 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Mahesh J Salgaonkar X-Patchwork-Id: 567243 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by ozlabs.org (Postfix) with ESMTP id 91E6914029E for ; Thu, 14 Jan 2016 14:16:25 +1100 (AEDT) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752960AbcANDQZ (ORCPT ); Wed, 13 Jan 2016 22:16:25 -0500 Received: from e28smtp06.in.ibm.com ([125.16.236.6]:49275 "EHLO e28smtp06.in.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752890AbcANDQY (ORCPT ); Wed, 13 Jan 2016 22:16:24 -0500 Received: from localhost by e28smtp06.in.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! Violators will be prosecuted for from ; Thu, 14 Jan 2016 08:46:20 +0530 Received: from d28relay02.in.ibm.com (9.184.220.59) by e28smtp06.in.ibm.com (192.168.1.136) with IBM ESMTP SMTP Gateway: Authorized Use Only! Violators will be prosecuted; Thu, 14 Jan 2016 08:46:16 +0530 X-IBM-Helo: d28relay02.in.ibm.com X-IBM-MailFrom: mahesh@linux.vnet.ibm.com X-IBM-RcptTo: kvm-ppc@vger.kernel.org;kvm@vger.kernel.org Received: from d28av04.in.ibm.com (d28av04.in.ibm.com [9.184.220.66]) by d28relay02.in.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id u0E3F0xN59048008; Thu, 14 Jan 2016 08:45:00 +0530 Received: from d28av04.in.ibm.com (localhost [127.0.0.1]) by d28av04.in.ibm.com (8.14.4/8.14.4/NCO v10.0 AVout) with ESMTP id u0E3Ewih032397; Thu, 14 Jan 2016 08:44:59 +0530 Received: from [192.168.0.3] ([9.79.179.157]) by d28av04.in.ibm.com (8.14.4/8.14.4/NCO v10.0 AVin) with ESMTP id u0E3EwJm032374; Thu, 14 Jan 2016 08:44:58 +0530 Subject: [PATCH 1/3] Powernv: Remove the usage of PACAR1 from opal wrappers From: Mahesh J Salgaonkar To: linuxppc-dev , Paul Mackerras , Michael Ellerman Cc: KVM-PPC , KVM Date: Thu, 14 Jan 2016 08:44:58 +0530 Message-ID: <20160114031457.1287.32132.stgit@mars> User-Agent: StGit/0.17.1-dirty MIME-Version: 1.0 X-TM-AS-MML: disable x-cbid: 16011403-0021-0000-0000-00000987BC73 Sender: kvm-ppc-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: kvm-ppc@vger.kernel.org From: Mahesh Salgaonkar OPAL_CALL wrapper code sticks the r1 (stack pointer) into PACAR1 purely for debugging purpose only. The power7_wakeup* functions relies on stack pointer saved in PACAR1. Any opal call made using opal wrapper (directly or in-directly) before we fall through power7_wakeup*, then it ends up replacing r1 in PACAR1(r13) leading to kernel panic. So far we don't see any issues because we have never made any opal calls using OPAL wrapper before power7_wakeup*. But the subsequent HMI patch would need to invoke C calls during cpu wakeup/idle path that in-directly makes opal call using opal wrapper. This patch facilitates the subsequent HMI patch by removing usage of PACAR1 from opal call wrapper. Signed-off-by: Mahesh Salgaonkar Acked-by: Michael Ellerman --- arch/powerpc/platforms/powernv/opal-wrappers.S | 2 -- 1 file changed, 2 deletions(-) -- To unsubscribe from this list: send the line "unsubscribe kvm-ppc" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html diff --git a/arch/powerpc/platforms/powernv/opal-wrappers.S b/arch/powerpc/platforms/powernv/opal-wrappers.S index b7a464f..62fe496 100644 --- a/arch/powerpc/platforms/powernv/opal-wrappers.S +++ b/arch/powerpc/platforms/powernv/opal-wrappers.S @@ -64,7 +64,6 @@ END_FTR_SECTION(0, 1); \ OPAL_BRANCH(opal_tracepoint_entry) \ mfcr r12; \ stw r12,8(r1); \ - std r1,PACAR1(r13); \ li r11,0; \ mfmsr r12; \ ori r11,r11,MSR_EE; \ @@ -127,7 +126,6 @@ opal_tracepoint_entry: mfcr r12 std r11,16(r1) stw r12,8(r1) - std r1,PACAR1(r13) li r11,0 mfmsr r12 ori r11,r11,MSR_EE