Re: [PATCH v5 2/5] irqchip/gic-v3: Enable support for SGIs to act as NMIs

From: Sumit Garg
Date: Tue Oct 20 2020 - 03:25:09 EST


On Mon, 19 Oct 2020 at 17:37, Marc Zyngier <maz@xxxxxxxxxx> wrote:
>
> On 2020-10-14 12:12, Sumit Garg wrote:
> > Add support to handle SGIs as regular NMIs. As SGIs or IPIs defaults to
> > a
>
> There is nothing "regular" about NMIs.

Okay, will do s/regular/pseudo/.

> Drop "or IPIs".
> s/defaults/default/
>

Ack.

> > special flow handler: handle_percpu_devid_fasteoi_ipi(), so skip NMI
> > handler update in case of SGIs.
> >
> > Also, enable NMI support prior to gic_smp_init() as allocation of SGIs
> > as IRQs/NMIs happen as part of this routine.
> >
> > Signed-off-by: Sumit Garg <sumit.garg@xxxxxxxxxx>
> > ---
> > drivers/irqchip/irq-gic-v3.c | 13 +++++++++++--
> > 1 file changed, 11 insertions(+), 2 deletions(-)
> >
> > diff --git a/drivers/irqchip/irq-gic-v3.c
> > b/drivers/irqchip/irq-gic-v3.c
> > index 16fecc0..5efc865 100644
> > --- a/drivers/irqchip/irq-gic-v3.c
> > +++ b/drivers/irqchip/irq-gic-v3.c
> > @@ -477,6 +477,11 @@ static int gic_irq_nmi_setup(struct irq_data *d)
> > if (WARN_ON(gic_irq(d) >= 8192))
> > return -EINVAL;
> >
> > + if (get_intid_range(d) == SGI_RANGE) {
> > + gic_irq_set_prio(d, GICD_INT_NMI_PRI);
> > + return 0;
> > + }
> > +
>
> Please follow the existing control flow, or rework it to be organised by
> range.

Okay.

>
> > /* desc lock should already be held */
> > if (gic_irq_in_rdist(d)) {
> > u32 idx = gic_get_ppi_index(d);
> > @@ -514,6 +519,11 @@ static void gic_irq_nmi_teardown(struct irq_data
> > *d)
> > if (WARN_ON(gic_irq(d) >= 8192))
> > return;
> >
> > + if (get_intid_range(d) == SGI_RANGE) {
> > + gic_irq_set_prio(d, GICD_INT_DEF_PRI);
> > + return;
> > + }
>
> Same here.

Okay.

-Sumit

>
> > +
> > /* desc lock should already be held */
> > if (gic_irq_in_rdist(d)) {
> > u32 idx = gic_get_ppi_index(d);
> > @@ -1708,6 +1718,7 @@ static int __init gic_init_bases(void __iomem
> > *dist_base,
> >
> > gic_dist_init();
> > gic_cpu_init();
> > + gic_enable_nmi_support();
> > gic_smp_init();
> > gic_cpu_pm_init();
> >
> > @@ -1719,8 +1730,6 @@ static int __init gic_init_bases(void __iomem
> > *dist_base,
> > gicv2m_init(handle, gic_data.domain);
> > }
> >
> > - gic_enable_nmi_support();
> > -
> > return 0;
> >
> > out_free:
>
> Thanks,
>
> M.
> --
> Jazz is not dead. It just smells funny...