On Thu, 2013-09-12 at 20:25 +0200, Christophe Leroy wrote: > This is a reorganisation of the setup of the TLB at kernel startup, in order > to handle the CONFIG_PIN_TLB case in accordance with chapter 8.10.3 of MPC866 > and MPC885 reference manuals. > > Signed-off-by: Christophe Leroy <christophe.le...@c-s.fr> > > diff -ur linux-3.11.org/arch/powerpc/kernel/head_8xx.S > linux-3.11/arch/powerpc/kernel/head_8xx.S > --- linux-3.11.org/arch/powerpc/kernel/head_8xx.S 2013-09-02 > 22:46:10.000000000 +0200 > +++ linux-3.11/arch/powerpc/kernel/head_8xx.S 2013-09-09 11:28:54.000000000 > +0200 > @@ -785,27 +785,24 @@ > * these mappings is mapped by page tables. > */ > initial_mmu: > - tlbia /* Invalidate all TLB entries */ > -/* Always pin the first 8 MB ITLB to prevent ITLB > - misses while mucking around with SRR0/SRR1 in asm > -*/ > - lis r8, MI_RSV4I@h > - ori r8, r8, 0x1c00 > - > + lis r8, MI_RESETVAL@h > mtspr SPRN_MI_CTR, r8 /* Set instruction MMU control */ > > -#ifdef CONFIG_PIN_TLB > - lis r10, (MD_RSV4I | MD_RESETVAL)@h > - ori r10, r10, 0x1c00 > - mr r8, r10 > -#else > lis r10, MD_RESETVAL@h > -#endif > #ifndef CONFIG_8xx_COPYBACK > oris r10, r10, MD_WTDEF@h > #endif > mtspr SPRN_MD_CTR, r10 /* Set data TLB control */ > > + tlbia /* Invalidate all TLB entries */
Is this change to make sure we invalidate everything even if the bootloader set RSV4I? > + ori r8, r8, 0x1c00 > + mtspr SPRN_MI_CTR, r8 /* Set instruction MMU control */ > +#ifdef CONFIG_PIN_TLB > + ori r10, r10, 0x1c00 > + mtspr SPRN_MD_CTR, r10 /* Set data TLB control */ > +#endif Still 0x1c00? > /* Now map the lower 8 Meg into the TLBs. For this quick hack, > * we can load the instruction and data TLB registers with the > * same values. > @@ -825,6 +822,12 @@ > mtspr SPRN_MI_AP, r8 > mtspr SPRN_MD_AP, r8 > > + /* Always pin the first 8 MB ITLB to prevent ITLB > + * misses while mucking around with SRR0/SRR1 in asm > + */ > + lis r8, (MI_RSV4I | MI_RESETVAL)@h > + mtspr SPRN_MI_CTR, r8 /* Set instruction MMU control */ Entry 0 is not pinnable. -Scott -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
