From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752896Ab3LRDuu (ORCPT ); Tue, 17 Dec 2013 22:50:50 -0500 Received: from mail-bn1lp0154.outbound.protection.outlook.com ([207.46.163.154]:50765 "EHLO na01-bn1-obe.outbound.protection.outlook.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752588Ab3LRDut (ORCPT ); Tue, 17 Dec 2013 22:50:49 -0500 Message-ID: <1387338638.3140.43.camel@snotra.buserror.net> Subject: Re: [v3][PATCH 8/8] book3e/kexec/kdump: recover "r4 = 0" to create the initial TLB From: Scott Wood To: Tiejun Chen CC: , , Date: Tue, 17 Dec 2013 21:50:38 -0600 In-Reply-To: <1373357007-30785-9-git-send-email-tiejun.chen@windriver.com> References: <1373357007-30785-1-git-send-email-tiejun.chen@windriver.com> <1373357007-30785-9-git-send-email-tiejun.chen@windriver.com> Content-Type: text/plain; charset="UTF-8" X-Mailer: Evolution 3.6.4-0ubuntu1 MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Originating-IP: [2601:2:5800:3f7:12bf:48ff:fe84:c9a0] X-ClientProxiedBy: BN1PR06CA015.namprd06.prod.outlook.com (10.141.56.35) To DM2PR03MB398.namprd03.prod.outlook.com (10.141.84.140) X-Forefront-PRVS: 0064B3273C X-Forefront-Antispam-Report: SFV:NSPM;SFS:(10009001)(377424004)(24454002)(51704005)(189002)(199002)(81342001)(47446002)(31966008)(81542001)(80022001)(74662001)(74502001)(74876001)(62966002)(33646001)(74706001)(50226001)(50466002)(77156001)(76796001)(79102001)(49866001)(65816001)(47736001)(4396001)(47976001)(81686001)(83322001)(19580405001)(63696002)(47776003)(81816001)(50986001)(23676002)(19580395003)(56816005)(80976001)(85306002)(89996001)(51856001)(76482001)(90146001)(53806001)(42186004)(54316002)(87286001)(87266001)(77096001)(77982001)(76786001)(83072002)(74366001)(56776001)(46102001)(59766001)(87976001)(69226001)(85852003)(88136002)(32563001)(3826001);DIR:OUT;SFP:1101;SCL:1;SRVR:DM2PR03MB398;H:[IPv6:2601:2:5800:3f7:12bf:48ff:fe84:c9a0];CLIP:2601:2:5800:3f7:12bf:48ff:fe84:c9a0;FPR:;RD:InfoNoRecords;MX:1;A:1;LANG:en; X-OriginatorOrg: freescale.com Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, 2013-07-09 at 16:03 +0800, Tiejun Chen wrote: > In commit 96f013f, "powerpc/kexec: Add kexec "hold" support for Book3e > processors", requires that GPR4 survive the "hold" process, for IBM Blue > Gene/Q with with some very strange firmware. But for FSL Book3E, r4 = 1 > to indicate that the initial TLB entry for this core already exists so > we still should set r4 with 0 to create that initial TLB. > > Signed-off-by: Tiejun Chen > --- > arch/powerpc/kernel/head_64.S | 4 ++++ > 1 file changed, 4 insertions(+) > > diff --git a/arch/powerpc/kernel/head_64.S b/arch/powerpc/kernel/head_64.S > index 0b46c9d..d546c5e 100644 > --- a/arch/powerpc/kernel/head_64.S > +++ b/arch/powerpc/kernel/head_64.S > @@ -127,6 +127,10 @@ __secondary_hold: > /* Grab our physical cpu number */ > mr r24,r3 > /* stash r4 for book3e */ > +#ifdef CONFIG_PPC_FSL_BOOK3E > + /* we need to setup initial TLB entry. */ > + li r4,0 > +#endif > mr r25,r4 This breaks being able to build one kernel that supports both FSL book3e and IBM book3e. -Scott