Hi Michael, Thanks for pointing out the issue. My mistake... This patch should indeed make sense only when CONFIG_PHYS_64BIT=y
I could not find corenet32_smp_defconfig, but I guess in your config, CONFIG_PHYS_64BIT=n ? I will update the patch later today On Sun, Dec 22, 2019 at 5:38 PM Michael Ellerman <m...@ellerman.id.au> wrote: > > yingjie_...@126.com writes: > > From: Bai Yingjie <byj....@gmail.com> > > > > CPU like P4080 has 36bit physical address, its DDR physical > > start address can be configured above 4G by LAW registers. > > > > For such systems in which their physical memory start address was > > configured higher than 4G, we need also to write addr_h into the spin > > table of the target secondary CPU, so that addr_h and addr_l together > > represent a 64bit physical address. > > Otherwise the secondary core can not get correct entry to start from. > > > > This should do no harm for normal case where addr_h is all 0. > > > > Signed-off-by: Bai Yingjie <byj....@gmail.com> > > --- > > arch/powerpc/platforms/85xx/smp.c | 8 ++++++++ > > 1 file changed, 8 insertions(+) > > > > diff --git a/arch/powerpc/platforms/85xx/smp.c > > b/arch/powerpc/platforms/85xx/smp.c > > index 8c7ea2486bc0..f12cdd1e80ff 100644 > > --- a/arch/powerpc/platforms/85xx/smp.c > > +++ b/arch/powerpc/platforms/85xx/smp.c > > @@ -252,6 +252,14 @@ static int smp_85xx_start_cpu(int cpu) > > out_be64((u64 *)(&spin_table->addr_h), > > __pa(ppc_function_entry(generic_secondary_smp_init))); > > #else > > + /* > > + * We need also to write addr_h to spin table for systems > > + * in which their physical memory start address was configured > > + * to above 4G, otherwise the secondary core can not get > > + * correct entry to start from. > > + * This does no harm for normal case where addr_h is all 0. > > + */ > > + out_be32(&spin_table->addr_h, __pa(__early_start) >> 32); > > out_be32(&spin_table->addr_l, __pa(__early_start)); > > This breaks the corenet32_smp_defconfig build: > > /linux/arch/powerpc/platforms/85xx/smp.c: In function 'smp_85xx_start_cpu': > /linux/arch/powerpc/platforms/85xx/smp.c:262:52: error: right shift count > >= width of type [-Werror=shift-count-overflow] > 262 | out_be32(&spin_table->addr_h, __pa(__early_start) >> 32); > | ^~ > cc1: all warnings being treated as errors > > cheers
