From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mailhub1.si.c-s.fr (pegase1.c-s.fr [93.17.236.30]) by lists.ozlabs.org (Postfix) with ESMTP id 81FC11A084F for ; Thu, 18 Dec 2014 18:05:15 +1100 (AEDT) Message-ID: <54927CA7.4000907@c-s.fr> Date: Thu, 18 Dec 2014 08:05:11 +0100 From: leroy christophe MIME-Version: 1.0 To: Scott Wood Subject: Re: [v2 PATCH 2/2] powerpc/8xx: use _PAGE_RO instead of _PAGE_RW References: <20141217091432.072901A5E12@localhost.localdomain> <1418869363.5581.123.camel@freescale.com> In-Reply-To: <1418869363.5581.123.camel@freescale.com> Content-Type: text/plain; charset=UTF-8; format=flowed Cc: linux-kernel@vger.kernel.org, Paul Mackerras , linuxppc-dev@lists.ozlabs.org List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Le 18/12/2014 03:22, Scott Wood a écrit : > On Wed, 2014-12-17 at 10:14 +0100, Christophe Leroy wrote: >> On powerpc 8xx, in TLB entries, 0x400 bit is set to 1 for read-only pages >> and is set to 0 for RW pages. So we should use _PAGE_RO instead of _PAGE_RW >> >> Signed-off-by: Christophe Leroy >> >> --- >> v2 is a complete rework compared to v1 >> >> arch/powerpc/include/asm/pte-8xx.h | 7 +++---- >> arch/powerpc/kernel/head_8xx.S | 3 --- >> 2 files changed, 3 insertions(+), 7 deletions(-) >> >> diff --git a/arch/powerpc/include/asm/pte-8xx.h b/arch/powerpc/include/asm/pte-8xx.h >> index daa4616..4f5583e 100644 >> --- a/arch/powerpc/include/asm/pte-8xx.h >> +++ b/arch/powerpc/include/asm/pte-8xx.h >> @@ -46,7 +46,7 @@ >> * require a TLB exception handler change. It is assumed unused bits >> * are always zero. >> */ >> -#define _PAGE_RW 0x0400 /* lsb PP bits, inverted in HW */ >> +#define _PAGE_RO 0x0400 /* lsb PP bits */ > It looks like pte_update() needs to be updated to match. > >> #define _PAGE_USER 0x0800 /* msb PP bits */ >> /* set when neither _PAGE_USER nor _PAGE_RW are set */ > Also update this comment. > >> #define _PAGE_KNLRO 0x0200 >> @@ -62,9 +62,8 @@ >> #define PTE_ATOMIC_UPDATES 1 >> >> /* We need to add _PAGE_SHARED to kernel pages */ >> -#define _PAGE_KERNEL_RO (_PAGE_SHARED | _PAGE_KNLRO) >> -#define _PAGE_KERNEL_ROX (_PAGE_EXEC | _PAGE_KNLRO) >> -#define _PAGE_KERNEL_RW (_PAGE_DIRTY | _PAGE_RW | _PAGE_HWWRITE) >> +#define _PAGE_KERNEL_RO (_PAGE_SHARED | _PAGE_RO | _PAGE_KNLRO) >> +#define _PAGE_KERNEL_ROX (_PAGE_EXEC | _PAGE_RO | _PAGE_KNLRO) >> >> #endif /* __KERNEL__ */ >> #endif /* _ASM_POWERPC_PTE_8xx_H */ > Where did _PAGE_KERNEL_RW go? > > It is already defined like this in pte-common.h: #ifndef _PAGE_KERNEL_RW #define _PAGE_KERNEL_RW (_PAGE_DIRTY | _PAGE_RW | _PAGE_HWWRITE) #endif Christophe