Re: [PATCH v2 1/3] irqchip/sifive-plic: Set default irq affinity in plic_irqdomain_map()

From: Anup Patel
Date: Fri May 22 2020 - 02:44:18 EST


On Fri, May 22, 2020 at 3:36 AM Palmer Dabbelt <palmer@xxxxxxxxxxx> wrote:
>
> On Mon, 18 May 2020 02:14:39 PDT (-0700), Anup Patel wrote:
> > For multiple PLIC instances, each PLIC can only target a subset of
> > CPUs which is represented by "lmask" in the "struct plic_priv".
> >
> > Currently, the default irq affinity for each PLIC interrupt is all
> > online CPUs which is illegal value for default irq affinity when we
> > have multiple PLIC instances. To fix this, we now set "lmask" as the
> > default irq affinity in for each interrupt in plic_irqdomain_map().
> >
> > Fixes: f1ad1133b18f ("irqchip/sifive-plic: Add support for multiple PLICs")
> > Cc: stable@xxxxxxxxxxxxxxx
> > Signed-off-by: Anup Patel <anup.patel@xxxxxxx>
> > ---
> > drivers/irqchip/irq-sifive-plic.c | 3 +++
> > 1 file changed, 3 insertions(+)
> >
> > diff --git a/drivers/irqchip/irq-sifive-plic.c b/drivers/irqchip/irq-sifive-plic.c
> > index 822e074c0600..9f7f8ce88c00 100644
> > --- a/drivers/irqchip/irq-sifive-plic.c
> > +++ b/drivers/irqchip/irq-sifive-plic.c
> > @@ -176,9 +176,12 @@ static struct irq_chip plic_chip = {
> > static int plic_irqdomain_map(struct irq_domain *d, unsigned int irq,
> > irq_hw_number_t hwirq)
> > {
> > + struct plic_priv *priv = d->host_data;
> > +
> > irq_domain_set_info(d, irq, hwirq, &plic_chip, d->host_data,
> > handle_fasteoi_irq, NULL, NULL);
>
> If you're going to re-spin this, d->host_data could be priv here.

The controller's private data is named "host_data" for "struct irq_domain"
in Linux irq subsystem hence the usage.

>
> > irq_set_noprobe(irq);
> > + irq_set_affinity(irq, &priv->lmask);
> > return 0;
> > }
>
> Reviewed-by: Palmer Dabbelt <palmerdabbelt@xxxxxxxxxx>
> Acked-by: Palmer Dabbelt <palmerdabbelt@xxxxxxxxxx>

Thanks,
Anup