Re: [RFC PATCH 09/10] ppc/pnv: Implement POWER10 PC xscom registers for direct controls

[Nicholas Piggin]

On Wed May 29, 2024 at 5:00 PM AEST, Cédric Le Goater wrote:
> On 5/26/24 14:26, Nicholas Piggin wrote:
> > The PC unit in the processor core contains xscom registers that provide
> > low level status and control of the CPU.
> > 
> > This implements "direct controls" sufficient for OPAL (skiboot) firmware
> > use, which is to stop threads and send them non-maskable IPIs in the
> > form of SRESET interrupts.
> > 
> > POWER10 is sufficiently different (particularly QME and special wakeup)
> > from POWER9 that it is not trivial to implement by reusing the code.
> > 
> > Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
> > ---
> >   include/hw/core/cpu.h     |  8 ++++
> >   include/hw/ppc/pnv.h      |  2 +
> >   include/hw/ppc/pnv_core.h |  3 ++
> >   hw/ppc/pnv.c              |  7 +++-
> >   hw/ppc/pnv_core.c         | 88 ++++++++++++++++++++++++++++++++++++---
> >   system/cpus.c             | 10 +++++
> >   6 files changed, 112 insertions(+), 6 deletions(-)
> > 
> > diff --git a/include/hw/core/cpu.h b/include/hw/core/cpu.h
> > index bb398e8237..52a8fc65cb 100644
> > --- a/include/hw/core/cpu.h
> > +++ b/include/hw/core/cpu.h
> > @@ -974,6 +974,14 @@ void cpu_reset_interrupt(CPUState *cpu, int mask);
> >    */
> >   void cpu_exit(CPUState *cpu);
> >   
> > +/**
> > + * cpu_pause:
> > + * @cpu: The CPU to pause.
> > + *
> > + * Resumes CPU, i.e. puts CPU into stopped state.
> > + */
> > +void cpu_pause(CPUState *cpu);
> > +
> >   /**
> >    * cpu_resume:
> >    * @cpu: The CPU to resume.
> > diff --git a/include/hw/ppc/pnv.h b/include/hw/ppc/pnv.h
> > index 93ecb062b4..bec603f1a8 100644
> > --- a/include/hw/ppc/pnv.h
> > +++ b/include/hw/ppc/pnv.h
> > @@ -111,6 +111,8 @@ PnvChip *pnv_chip_add_phb(PnvChip *chip, PnvPHB *phb);
> >   #define PNV_FDT_ADDR          0x01000000
> >   #define PNV_TIMEBASE_FREQ     512000000ULL
> >   
> > +void pnv_cpu_do_nmi(CPUState *cs);
> > +
> >   /*
> >    * BMC helpers
> >    */
> > diff --git a/include/hw/ppc/pnv_core.h b/include/hw/ppc/pnv_core.h
> > index 39f8f33e6c..9599da15ea 100644
> > --- a/include/hw/ppc/pnv_core.h
> > +++ b/include/hw/ppc/pnv_core.h
> > @@ -109,6 +109,9 @@ OBJECT_DECLARE_TYPE(PnvQuad, PnvQuadClass, PNV_QUAD)
> >   struct PnvQuad {
> >       DeviceState parent_obj;
> >   
> > +    bool special_wakeup_done;
> > +    bool special_wakeup[4];
> > +
> >       uint32_t quad_id;
> >       MemoryRegion xscom_regs;
> >       MemoryRegion xscom_qme_regs;
> > diff --git a/hw/ppc/pnv.c b/hw/ppc/pnv.c
> > index 5364c55bbb..765142965f 100644
> > --- a/hw/ppc/pnv.c
> > +++ b/hw/ppc/pnv.c
> > @@ -2700,12 +2700,17 @@ static void pnv_cpu_do_nmi_on_cpu(CPUState *cs, 
> > run_on_cpu_data arg)
> >       }
> >   }
> >   
> > +void pnv_cpu_do_nmi(CPUState *cs)
> > +{
> > +    async_run_on_cpu(cs, pnv_cpu_do_nmi_on_cpu, RUN_ON_CPU_NULL);
> > +}
> > +
> >   static void pnv_nmi(NMIState *n, int cpu_index, Error **errp)
> >   {
> >       CPUState *cs;
> >   
> >       CPU_FOREACH(cs) {
> > -        async_run_on_cpu(cs, pnv_cpu_do_nmi_on_cpu, RUN_ON_CPU_NULL);
> > +        pnv_cpu_do_nmi(cs);
> >       }
> >   }
>
> What about ?
>
> https://lore.kernel.org/qemu-devel/20240424093048.180966-1-clg@redhat.com/

I haven't forgotten it. I just didn't put it in the first PR since
there was quite a lot of pnv patches to do so I thought I will collect
most of them for another PR.

Thanks,
Nick