Messages in this thread | | | Date | Thu, 18 Dec 2014 08:05:11 +0100 | From | leroy christophe <> | Subject | Re: [v2 PATCH 2/2] powerpc/8xx: use _PAGE_RO instead of _PAGE_RW |
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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 <christophe.leroy@c-s.fr> >> >> --- >> 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
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