On Wed, 2016-07-27 at 17:32 +1000, Balbir Singh wrote: > From: Balbir Singh <bsinghar...@gmail.com> > > Currently the power management bits are broken w.r.t. relocation. > There are direct branches from system_reset_pSeries to > power7_wakeup_*.
Side track: we should really get rid of the _pSeries suffix for these things :-) > The correct way to do it is to do what > the slb miss handler does, which is jump to a small stub within > the first 64k of the relocated address and then jump to the > actual location. > > The code has been lightly tested (not the kvm bits), I would highly > appreciate a review of the code. I suspect there might be easy > to find bugs :) > > Cc: b...@kernel.crashing.org > Cc: m...@ellerman.id.au > Cc: pau...@samba.org > Cc: npig...@gmail.com > Cc: sva...@linux.vnet.ibm.com > > Signed-off-by: Balbir Singh <bsinghar...@gmail.com> > --- > arch/powerpc/kernel/exceptions-64s.S | 82 ++++++++++++++++++++++-- > ------------ > 1 file changed, 51 insertions(+), 31 deletions(-) > > diff --git a/arch/powerpc/kernel/exceptions-64s.S > b/arch/powerpc/kernel/exceptions-64s.S > index 8bcc1b4..64f9650 100644 > --- a/arch/powerpc/kernel/exceptions-64s.S > +++ b/arch/powerpc/kernel/exceptions-64s.S > @@ -118,39 +118,21 @@ BEGIN_FTR_SECTION > cmpwi cr4,r5,1 > mtspr SPRN_HSPRG0,r13 > > - lbz r0,PACA_THREAD_IDLE_STATE(r13) > - cmpwi cr2,r0,PNV_THREAD_NAP > - bgt cr2,8f /* Either > sleep or Winkle */ > - > - /* Waking up from nap should not cause hypervisor state loss > */ > - bgt cr3,. > - > - /* Waking up from nap */ > - li r0,PNV_THREAD_RUNNING > - stb r0,PACA_THREAD_IDLE_STATE(r13) /* Clear > thread state */ > - > -#ifdef CONFIG_KVM_BOOK3S_HV_POSSIBLE > - li r0,KVM_HWTHREAD_IN_KERNEL > - stb r0,HSTATE_HWTHREAD_STATE(r13) > - /* Order setting hwthread_state vs. testing hwthread_req */ > - sync > - lbz r0,HSTATE_HWTHREAD_REQ(r13) > - cmpwi r0,0 > - beq 1f > - b kvm_start_guest > -1: > +#ifndef CONFIG_RELOCATABLE > + b power7_wakeup_common > +#else > + /* > + * We can't just use a direct branch to power7_wakeup_common > + * because the distance from here to there depends on where > + * the kernel ends up being put. > + */ > + mfctr r11 > + ld r10, PACAKBASE(r13) > + LOAD_HANDLER(r10, power7_wakeup_common) > + mtctr r10 > + bctr > #endif > > - /* Return SRR1 from power7_nap() */ > - mfspr r3,SPRN_SRR1 > - beq cr3,2f > - b power7_wakeup_noloss > -2: b power7_wakeup_loss > - > - /* Fast Sleep wakeup on PowerNV */ > -8: GET_PACA(r13) > - b power7_wakeup_tb_loss > - > 9: > END_FTR_SECTION_IFSET(CPU_FTR_HVMODE | CPU_FTR_ARCH_206) > #endif /* CONFIG_PPC_P7_NAP */ > @@ -1448,6 +1430,44 @@ power4_fixup_nap: > blr > #endif > > + .align 7 > +_GLOBAL(power7_wakeup_common) > +#ifdef CONFIG_RELOCATABLE > + mtctr r11 > +#endif > + lbz r0,PACA_THREAD_IDLE_STATE(r13) > + cmpwi cr2,r0,PNV_THREAD_NAP > + bgt cr2,8f /* Either > sleep or Winkle */ > + > + /* Waking up from nap should not cause hypervisor state loss > */ > + bgt cr3,. > + > + /* Waking up from nap */ > + li r0,PNV_THREAD_RUNNING > + stb r0,PACA_THREAD_IDLE_STATE(r13) /* Clear > thread state */ > + > +#ifdef CONFIG_KVM_BOOK3S_HV_POSSIBLE > + li r0,KVM_HWTHREAD_IN_KERNEL > + stb r0,HSTATE_HWTHREAD_STATE(r13) > + /* Order setting hwthread_state vs. testing hwthread_req */ > + sync > + lbz r0,HSTATE_HWTHREAD_REQ(r13) > + cmpwi r0,0 > + beq 1f > + b kvm_start_guest > +1: > +#endif > + > + /* Return SRR1 from power7_nap() */ > + mfspr r3,SPRN_SRR1 > + beq cr3,2f > + b power7_wakeup_noloss > +2: b power7_wakeup_loss > + > + /* Fast Sleep wakeup on PowerNV */ > +8: GET_PACA(r13) > + b power7_wakeup_tb_loss > + > /* > * Hash table stuff > */ _______________________________________________ Linuxppc-dev mailing list Linuxppc-dev@lists.ozlabs.org https://lists.ozlabs.org/listinfo/linuxppc-dev
