"Gautham R. Shenoy" <e...@linux.vnet.ibm.com> writes: > From: "Gautham R. Shenoy" <e...@linux.vnet.ibm.com> > > On wakeup from a deep-stop used for CPU-Hotplug, we invoke > cur_cpu_spec->cpu_restore() which would set sane default values to > various SPRs including LPCR. > > On POWER9, the cpu_restore_power9() call would would restore LPCR to a > sane value that is set at early boot time, thereby clearing LPCR_UPRT. > > However, LPCR_UPRT is required to be set if we are running in Radix > mode. If this is not set we will end up with a crash when we enable > IR,DR. > > To fix this, after returning from cur_cpu_spec->cpu_restore() in the > idle exit path, set LPCR_UPRT if we are running in Radix mode. > > Cc: Aneesh Kumar K.V <aneesh.ku...@linux.vnet.ibm.com> > Signed-off-by: Gautham R. Shenoy <e...@linux.vnet.ibm.com> > --- > arch/powerpc/kernel/idle_book3s.S | 13 +++++++++++++ > 1 file changed, 13 insertions(+) > > diff --git a/arch/powerpc/kernel/idle_book3s.S > b/arch/powerpc/kernel/idle_book3s.S > index 6a9bd28..39a9b63 100644 > --- a/arch/powerpc/kernel/idle_book3s.S > +++ b/arch/powerpc/kernel/idle_book3s.S > @@ -804,6 +804,19 @@ no_segments: > #endif > mtctr r12 > bctrl > +/* > + * cur_cpu_spec->cpu_restore would restore LPCR to a > + * sane value that is set at early boot time, > + * thereby clearing LPCR_UPRT. > + * LPCR_UPRT is required if we are running in Radix mode. > + * Set it here if that be the case. > + */ > +BEGIN_MMU_FTR_SECTION > + mfspr r3, SPRN_LPCR > + LOAD_REG_IMMEDIATE(r4, LPCR_UPRT) > + or r3, r3, r4 > + mtspr SPRN_LPCR, r3 > +END_MMU_FTR_SECTION_IFSET(MMU_FTR_TYPE_RADIX)
What about LPCR_HR ? > > hypervisor_state_restored: > > -- > 1.9.4 -aneesh
