Re: [PATCH V10 1/8] irqchip: add C-SKY SMP interrupt controller

[Guo Ren]

Hi Marc,

On Mon, Oct 08, 2018 at 05:35:19PM +0100, Marc Zyngier wrote:
> Hi Guo,
> 
> On 04/10/18 18:22, Guo Ren wrote:
> >  - Irq-csky-mpintc is C-SKY smp system interrupt controller and it
> >    could support 16 soft irqs, 16 private irqs, and 992 max common
> >    irqs.
> >
> >Changelog:
> >  - pass checkpatch.pl
> >  - Move IPI_IRQ into the driver
> >  - Remove irq_set_default_host() and use set_ipi_irq_mapping()

 [...]

> >+#ifdef CONFIG_SMP
> >+static void csky_mpintc_send_ipi(const unsigned long *mask)
> >+{
> 
> Why isn't this a cpumask? It should be this driver's job to convert the
> cpumask to an interrupt-controller specific representation, and not the SMP
> code's.
Ok, use cpumask. 

 [...]

> >+#ifdef CONFIG_SMP
> >+	set_send_ipi(&csky_mpintc_send_ipi);
> >+
> >+	set_ipi_irq_mapping(&csky_mpintc_ipi_irq_mapping);
> 
> Since you seem to be inventing a new set_send_ipi callback, why don't you
> define it as:
> 
> void set_send_ipi(void (*func)(const struct cpumask *),
> 		  unsigned int ipi_irq);
> after having created the mapping for the IPI interrupt? It would avoid this
> rather pointless mapping callback.

I'll define it to:

void set_send_ipi(void (*func)(const struct cpumask *));

IPI_IRQ only use software-irq-15 in mpintc driver, so arch needn't care
about irq-num.

	/*
	 * INTCL_SIGR[3:0] INTID
	 * INTCL_SIGR[8:15] CPUMASK
	 */
	writel_relaxed((*mask) << 8 | IPI_IRQ, reg_base + INTCL_SIGR);

We direct put IPI_IRQ to the hw-reg for the target core.

Best Regards
 Guo Ren