Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752114Ab3GJFpX (ORCPT ); Wed, 10 Jul 2013 01:45:23 -0400 Received: from mail.windriver.com ([147.11.1.11]:54679 "EHLO mail.windriver.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750891Ab3GJFpW (ORCPT ); Wed, 10 Jul 2013 01:45:22 -0400 Message-ID: <51DCF518.4090105@windriver.com> Date: Wed, 10 Jul 2013 13:46:00 +0800 From: "tiejun.chen" User-Agent: Mozilla/5.0 (X11; Linux i686; rv:17.0) Gecko/20130623 Thunderbird/17.0.7 MIME-Version: 1.0 To: Bhushan Bharat-R65777 CC: "benh@kernel.crashing.org" , Wood Scott-B07421 , "linuxppc-dev@lists.ozlabs.org" , "linux-kernel@vger.kernel.org" Subject: Re: [v3][PATCH 7/8] book3e/kexec/kdump: redefine VIRT_PHYS_OFFSET References: <1373357007-30785-1-git-send-email-tiejun.chen@windriver.com> <1373357007-30785-8-git-send-email-tiejun.chen@windriver.com> <6A3DF150A5B70D4F9B66A25E3F7C888D070AE138@039-SN2MPN1-011.039d.mgd.msft.net> In-Reply-To: <6A3DF150A5B70D4F9B66A25E3F7C888D070AE138@039-SN2MPN1-011.039d.mgd.msft.net> Content-Type: text/plain; charset="UTF-8"; format=flowed Content-Transfer-Encoding: 7bit X-Originating-IP: [128.224.162.214] Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1929 Lines: 48 On 07/10/2013 01:20 PM, Bhushan Bharat-R65777 wrote: > > >> -----Original Message----- >> From: Linuxppc-dev [mailto:linuxppc-dev- >> bounces+bharat.bhushan=freescale.com@lists.ozlabs.org] On Behalf Of Tiejun Chen >> Sent: Tuesday, July 09, 2013 1:33 PM >> To: benh@kernel.crashing.org >> Cc: linuxppc-dev@lists.ozlabs.org; linux-kernel@vger.kernel.org >> Subject: [v3][PATCH 7/8] book3e/kexec/kdump: redefine VIRT_PHYS_OFFSET >> >> Book3e is always aligned 1GB to create TLB so we should >> use (KERNELBASE - MEMORY_START) as VIRT_PHYS_OFFSET to >> get __pa/__va properly while boot kdump. >> >> Signed-off-by: Tiejun Chen >> --- >> arch/powerpc/include/asm/page.h | 2 ++ >> 1 file changed, 2 insertions(+) >> >> diff --git a/arch/powerpc/include/asm/page.h b/arch/powerpc/include/asm/page.h >> index 988c812..5b00081 100644 >> --- a/arch/powerpc/include/asm/page.h >> +++ b/arch/powerpc/include/asm/page.h >> @@ -112,6 +112,8 @@ extern long long virt_phys_offset; >> /* See Description below for VIRT_PHYS_OFFSET */ >> #ifdef CONFIG_RELOCATABLE_PPC32 >> #define VIRT_PHYS_OFFSET virt_phys_offset >> +#elif defined(CONFIG_PPC_BOOK3E_64) >> +#define VIRT_PHYS_OFFSET (KERNELBASE - MEMORY_START) > > Can you please explain this code a bit more. I am not understanding this part:) Nothing is special, we only need to redefine this to make sure __va()/__pa() can work well for BOOk3E-64 in BOOKE case: #ifdef CONFIG_BOOKE #define __va(x) ((void *)(unsigned long)((phys_addr_t)(x) + VIRT_PHYS_OFFSET)) #define __pa(x) ((unsigned long)(x) - VIRT_PHYS_OFFSET) And the arch/powerpc/include/asm/page.h file has more descriptions inline :) Tiejun -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/