From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail.windriver.com (mail.windriver.com [147.11.1.11]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (Client CN "mail.windriver.com", Issuer "Intel External Basic Issuing CA 3A" (not verified)) by ozlabs.org (Postfix) with ESMTPS id 465B52C00AF for ; Wed, 10 Jul 2013 15:45:20 +1000 (EST) Message-ID: <51DCF518.4090105@windriver.com> Date: Wed, 10 Jul 2013 13:46:00 +0800 From: "tiejun.chen" MIME-Version: 1.0 To: Bhushan Bharat-R65777 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 Cc: "linuxppc-dev@lists.ozlabs.org" , "linux-kernel@vger.kernel.org" , Wood Scott-B07421 List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , 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