On Sat, 2008-02-02 at 10:47 +0300, Yuri Tikhonov wrote: > Hello, > > Here is the patch which makes Linux-2.6 swap routines operate correctly on > the ppc-8xx-based machines.
Best is to just remove writeback completely and let the generic code handle it. Ben. > Signed-off-by: Yuri Tikhonov <[EMAIL PROTECTED]> > -- > diff --git a/arch/ppc/kernel/head_8xx.S b/arch/ppc/kernel/head_8xx.S > index eb8d26f..321bda2 100644 > --- a/arch/ppc/kernel/head_8xx.S > +++ b/arch/ppc/kernel/head_8xx.S > @@ -329,8 +329,18 @@ InstructionTLBMiss: > mfspr r11, SPRN_MD_TWC /* ....and get the pte address */ > lwz r10, 0(r11) /* Get the pte */ > > +#ifdef CONFIG_SWAP > + /* do not set the _PAGE_ACCESSED bit of a non-present page */ > + andi. r11, r10, _PAGE_PRESENT > + beq 4f > + ori r10, r10, _PAGE_ACCESSED > + mfspr r11, SPRN_MD_TWC /* get the pte address again */ > + stw r10, 0(r11) > +4: > +#else > ori r10, r10, _PAGE_ACCESSED > stw r10, 0(r11) > +#endif > > /* The Linux PTE won't go exactly into the MMU TLB. > * Software indicator bits 21, 22 and 28 must be clear. > @@ -395,8 +405,17 @@ DataStoreTLBMiss: > DO_8xx_CPU6(0x3b80, r3) > mtspr SPRN_MD_TWC, r11 > > - mfspr r11, SPRN_MD_TWC /* get the pte address again */ > +#ifdef CONFIG_SWAP > + /* do not set the _PAGE_ACCESSED bit of a non-present page */ > + andi. r11, r10, _PAGE_PRESENT > + beq 4f > + ori r10, r10, _PAGE_ACCESSED > +4: > + /* and update pte in table */ > +#else > ori r10, r10, _PAGE_ACCESSED > +#endif > + mfspr r11, SPRN_MD_TWC /* get the pte address again */ > stw r10, 0(r11) > > /* The Linux PTE won't go exactly into the MMU TLB. > @@ -575,7 +594,16 @@ DataTLBError: > > /* Update 'changed', among others. > */ > +#ifdef CONFIG_SWAP > + ori r10, r10, _PAGE_DIRTY|_PAGE_HWWRITE > + /* do not set the _PAGE_ACCESSED bit of a non-present page */ > + andi. r11, r10, _PAGE_PRESENT > + beq 4f > + ori r10, r10, _PAGE_ACCESSED > +4: > +#else > ori r10, r10, _PAGE_DIRTY|_PAGE_ACCESSED|_PAGE_HWWRITE > +#endif > mfspr r11, SPRN_MD_TWC /* Get pte address again */ > stw r10, 0(r11) /* and update pte in table */ > > diff --git a/include/asm-ppc/pgtable.h b/include/asm-ppc/pgtable.h > index c159315..76717ff 100644 > --- a/include/asm-ppc/pgtable.h > +++ b/include/asm-ppc/pgtable.h > @@ -341,14 +341,6 @@ extern unsigned long ioremap_bot, ioremap_base; > #define _PMD_PAGE_MASK 0x000c > #define _PMD_PAGE_8M 0x000c > > -/* > - * The 8xx TLB miss handler allegedly sets _PAGE_ACCESSED in the PTE > - * for an address even if _PAGE_PRESENT is not set, as a performance > - * optimization. This is a bug if you ever want to use swap unless > - * _PAGE_ACCESSED is 2, which it isn't, or unless you have 8xx-specific > - * definitions for __swp_entry etc. below, which would be gross. > - * -- paulus > - */ > #define _PTE_NONE_MASK _PAGE_ACCESSED > > #else /* CONFIG_6xx */ > _______________________________________________ Linuxppc-dev mailing list Linuxppc-dev@ozlabs.org https://ozlabs.org/mailman/listinfo/linuxppc-dev
