From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from ozlabs.org (ozlabs.org [103.22.144.67]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by lists.ozlabs.org (Postfix) with ESMTPS id 3r6qx26Bs7zDq8V for ; Sun, 15 May 2016 14:14:30 +1000 (AEST) Received: from e28smtp06.in.ibm.com (e28smtp06.in.ibm.com [125.16.236.6]) (using TLSv1.2 with cipher CAMELLIA256-SHA (256/256 bits)) (No client certificate requested) by ozlabs.org (Postfix) with ESMTPS id 3r6qx15t0nz9t5c for ; Sun, 15 May 2016 14:14:29 +1000 (AEST) Received: from localhost by e28smtp06.in.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! Violators will be prosecuted for from ; Sun, 15 May 2016 09:44:27 +0530 Received: from d28relay05.in.ibm.com (d28relay05.in.ibm.com [9.184.220.62]) by d28dlp01.in.ibm.com (Postfix) with ESMTP id 6E932E0040 for ; Sun, 15 May 2016 09:47:32 +0530 (IST) Received: from d28av03.in.ibm.com (d28av03.in.ibm.com [9.184.220.65]) by d28relay05.in.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id u4F4ELtf19005776 for ; Sun, 15 May 2016 09:44:21 +0530 Received: from d28av03.in.ibm.com (localhost [127.0.0.1]) by d28av03.in.ibm.com (8.14.4/8.14.4/NCO v10.0 AVout) with ESMTP id u4F4ELv9005577 for ; Sun, 15 May 2016 09:44:22 +0530 Subject: [PATCH v2 1/2] Powernv: Remove the usage of PACAR1 from opal wrappers From: Mahesh J Salgaonkar To: linuxppc-dev , Paul Mackerras , Michael Ellerman Cc: KVM , KVM-PPC Date: Sun, 15 May 2016 09:44:13 +0530 Message-ID: <20160515041413.2280.747.stgit@mars> MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , 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(-) diff --git a/arch/powerpc/platforms/powernv/opal-wrappers.S b/arch/powerpc/platforms/powernv/opal-wrappers.S index e45b88a..df6ad94 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