leroy christophe <christophe.le...@c-s.fr> wrote on 2013/10/15 18:27:00: > > > Le 11/10/2013 17:13, Joakim Tjernlund a écrit : > > "Linuxppc-dev" > > <linuxppc-dev-bounces+joakim.tjernlund=transmode...@lists.ozlabs.org> > > wrote on 2013/10/11 14:56:40: > >> Activating CONFIG_PIN_TLB allows access to the 24 first Mbytes of memory > > at > >> bootup instead of 8. It is needed for "big" kernels for instance when > > activating > >> CONFIG_LOCKDEP_SUPPORT. This needs to be taken into account in init_32 > > too, > >> otherwise memory allocation soon fails after startup. > >> > >> 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/mm/init_32.c 2013-09-02 > > 22:46:10.000000000 +0200 > >> +++ linux-3.11/arch/powerpc/mm/init_32.c 2013-09-09 11:28:54.000000000 > > +0200 > >> @@ -213,7 +213,12 @@ > >> */ > >> BUG_ON(first_memblock_base != 0); > >> > >> +#ifdef CONFIG_PIN_TLB > >> + /* 8xx can only access 24MB at the moment */ > >> + memblock_set_current_limit(min_t(u64, first_memblock_size, > > 0x01800000)); > >> +#else > >> /* 8xx can only access 8MB at the moment */ > >> memblock_set_current_limit(min_t(u64, first_memblock_size, > > 0x00800000)); > >> +#endif > >> } > >> #endif /* CONFIG_8xx */ > > hmm, I think you should always map 24 MB (or less if RAM < 24 MB) and do > > the same > > in head_8xx.S. > > > > Or to keep it simple, just always map at least 16 MB here and in > > head_8xx.S, assuming > > that 16 MB is min RAM for any 8xx system running 3.x kernels. > Yes we could do a more elaborated modification in the future. However it
> also has an impact on the boot loader, so I'm not sure we should make it > the default without thinking twice. > > In the meantime, my patch does take into account the existing situation > where you have 8Mb by default and 24Mb when you activate CONFIG_PIN_TLB. > I see it as a bug fix and I believe we should include it at least in > order to allow including in the stable releases. > > Do you see any issue with this approach ? Not at all, so: Acked-by: Joakim Tjernlund <joakim.tjernl...@transmode.se> _______________________________________________ Linuxppc-dev mailing list Linuxppc-dev@lists.ozlabs.org https://lists.ozlabs.org/listinfo/linuxppc-dev
