Re: [PATCH RFC] irqchip: gic-v3: Support forced cpu irq affinity setting

[Alim Akhtar]

On 08/08/2017 02:52 PM, Marc Zyngier wrote:
> On 08/08/17 10:04, Alim Akhtar wrote:
> > Skip check for online cpu mask when setting irq affinity of per cpu timer
> > during early startup of not yet online cpu.
> >
> > Signed-off-by: Shaik Ameer Basha <shaik.ameer@xxxxxxxxxxx>
> > Signed-off-by: Aswani Reddy <aswani.reddy@xxxxxxxxxxx>
> > Signed-off-by: Alim Akhtar <alim.akhtar@xxxxxxxxxxx>
> > ---
> >   drivers/irqchip/irq-gic-v3.c | 7 ++++++-
> >   1 file changed, 6 insertions(+), 1 deletion(-)
> >
> > Currently when non boot CPUs comes up and if setting of IRQ affinity gets called
> > before cpu online status gets updated, gic_mpidr_to_affinity() returns
> > undesirable cpu number. Using __force__ flag ignore cpu_online_mask and setup
> > the intended cpu affinity for the irq.
> >
> > The same approch is used in gicv2
> > (commit: ffde1de64012c: irqchip: Gic: Support forced affinity setting)
> >
> > diff --git a/drivers/irqchip/irq-gic-v3.c b/drivers/irqchip/irq-gic-v3.c
> > index dbffb7a..c238c64 100644
> > --- a/drivers/irqchip/irq-gic-v3.c
> > +++ b/drivers/irqchip/irq-gic-v3.c
> > @@ -640,11 +640,16 @@ static void gic_smp_init(void)
> >   static int gic_set_affinity(struct irq_data *d, const struct cpumask *mask_val,
> >   			    bool force)
> >   {
> > -	unsigned int cpu = cpumask_any_and(mask_val, cpu_online_mask);
> > +	unsigned int cpu;
> >   	void __iomem *reg;
> >   	int enabled;
> >   	u64 val;
> >   
> > +	if (!force)
> > +		cpu = cpumask_any_and(mask_val, cpu_online_mask);
> > +	else
> > +		cpu = cpumask_first(mask_val);
> > +
> >   	if (cpu >= nr_cpu_ids)
> >   		return -EINVAL;
> >   
>
> See
>
> https://git.kernel.org/pub/scm/linux/kernel/git/maz/arm-platforms.git/commit/?h=irq/irqchip-4.13&id=65a30f8b300107266f316d550f060ccc186201a3

Thanks Marc for above link. Is this already queued in some tree? I can't 
find this is linux-next.

> 	M.