Re: [PATCH v8 1/4] irqchip: gic: Support hierarchy irq domain.

[Geert Uytterhoeven]

On Tue, Nov 25, 2014 at 9:04 AM, Yingjoe Chen <yingjoe.chen@xxxxxxxxxxxx> wrote:
> Add support to use gic as a parent for stacked irq domain.
>
> Signed-off-by: Yingjoe Chen <yingjoe.chen@xxxxxxxxxxxx>

This change (which is now in -next as commit 9a1091ef0017c40a) breaks
booting on r8a7740/armadillo-legacy.

It hangs because the timers cannot get their interrupts:

console [tty0] enabled
 sh-tmu.0: ch0: used for clock events
 sh-tmu.0: ch0: used for periodic clock events
 sh-tmu.0: ch0: failed to request irq 230
 sh-tmu.0: ch1: used as clock source
 sh-cmt-48.1: ch0: failed to request irq 90
 sh-cmt-48.1: ch0: registration failed
earlytimer: unable to probe sh-cmt-48 early.
Calibrating delay loop...

> ---
>  drivers/irqchip/Kconfig   |  1 +
>  drivers/irqchip/irq-gic.c | 77 ++++++++++++++++++++++++++++++++---------------
>  2 files changed, 54 insertions(+), 24 deletions(-)
>
> diff --git a/drivers/irqchip/Kconfig b/drivers/irqchip/Kconfig
> index b21f12f..7f34138 100644
> --- a/drivers/irqchip/Kconfig
> +++ b/drivers/irqchip/Kconfig
> @@ -5,6 +5,7 @@ config IRQCHIP
>  config ARM_GIC
>         bool
>         select IRQ_DOMAIN
> +       select IRQ_DOMAIN_HIERARCHY
>         select MULTI_IRQ_HANDLER
>
>  config GIC_NON_BANKED
> diff --git a/drivers/irqchip/irq-gic.c b/drivers/irqchip/irq-gic.c
> index 38493ff..ab6069b 100644
> --- a/drivers/irqchip/irq-gic.c
> +++ b/drivers/irqchip/irq-gic.c
> @@ -788,17 +788,16 @@ static int gic_irq_domain_map(struct irq_domain *d, unsigned int irq,
>  {
>         if (hw < 32) {
>                 irq_set_percpu_devid(irq);
> -               irq_set_chip_and_handler(irq, &gic_chip,
> -                                        handle_percpu_devid_irq);
> +               irq_domain_set_info(d, irq, hw, &gic_chip, d->host_data,
> +                                   handle_percpu_devid_irq, NULL, NULL);
>                 set_irq_flags(irq, IRQF_VALID | IRQF_NOAUTOEN);
>         } else {
> -               irq_set_chip_and_handler(irq, &gic_chip,
> -                                        handle_fasteoi_irq);
> +               irq_domain_set_info(d, irq, hw, &gic_chip, d->host_data,
> +                                   handle_fasteoi_irq, NULL, NULL);
>                 set_irq_flags(irq, IRQF_VALID | IRQF_PROBE);
>
>                 gic_routable_irq_domain_ops->map(d, irq, hw);
>         }
> -       irq_set_chip_data(irq, d->host_data);
>         return 0;
>  }
>
> @@ -858,6 +857,31 @@ static struct notifier_block gic_cpu_notifier = {
>  };
>  #endif
>
> +static int gic_irq_domain_alloc(struct irq_domain *domain, unsigned int virq,
> +                               unsigned int nr_irqs, void *arg)
> +{
> +       int i, ret;
> +       irq_hw_number_t hwirq;
> +       unsigned int type = IRQ_TYPE_NONE;
> +       struct of_phandle_args *irq_data = arg;
> +
> +       ret = gic_irq_domain_xlate(domain, irq_data->np, irq_data->args,
> +                                  irq_data->args_count, &hwirq, &type);
> +       if (ret)
> +               return ret;
> +
> +       for (i = 0; i < nr_irqs; i++)
> +               gic_irq_domain_map(domain, virq + i, hwirq + i);
> +
> +       return 0;
> +}
> +
> +static const struct irq_domain_ops gic_irq_domain_hierarchy_ops = {
> +       .xlate = gic_irq_domain_xlate,
> +       .alloc = gic_irq_domain_alloc,
> +       .free = irq_domain_free_irqs_top,
> +};
> +
>  static const struct irq_domain_ops gic_irq_domain_ops = {
>         .map = gic_irq_domain_map,
>         .unmap = gic_irq_domain_unmap,
> @@ -948,18 +972,6 @@ void __init gic_init_bases(unsigned int gic_nr, int irq_start,
>                 gic_cpu_map[i] = 0xff;
>
>         /*
> -        * For primary GICs, skip over SGIs.
> -        * For secondary GICs, skip over PPIs, too.
> -        */
> -       if (gic_nr == 0 && (irq_start & 31) > 0) {
> -               hwirq_base = 16;
> -               if (irq_start != -1)
> -                       irq_start = (irq_start & ~31) + 16;
> -       } else {
> -               hwirq_base = 32;
> -       }
> -
> -       /*
>          * Find out how many interrupts are supported.
>          * The GIC only supports up to 1020 interrupt sources.
>          */
> @@ -969,10 +981,31 @@ void __init gic_init_bases(unsigned int gic_nr, int irq_start,
>                 gic_irqs = 1020;
>         gic->gic_irqs = gic_irqs;
>
> -       gic_irqs -= hwirq_base; /* calculate # of irqs to allocate */
> +       if (node) {             /* DT case */
> +               const struct irq_domain_ops *ops = &gic_irq_domain_hierarchy_ops;
> +
> +               if (!of_property_read_u32(node, "arm,routable-irqs",
> +                                         &nr_routable_irqs)) {
> +                       ops = &gic_irq_domain_ops;
> +                       gic_irqs = nr_routable_irqs;
> +               }
> +
> +               gic->domain = irq_domain_add_linear(node, gic_irqs, ops, gic);
> +       } else {                /* Non-DT case */
> +               /*
> +                * For primary GICs, skip over SGIs.
> +                * For secondary GICs, skip over PPIs, too.
> +                */
> +               if (gic_nr == 0 && (irq_start & 31) > 0) {
> +                       hwirq_base = 16;
> +                       if (irq_start != -1)
> +                               irq_start = (irq_start & ~31) + 16;
> +               } else {
> +                       hwirq_base = 32;
> +               }
> +
> +               gic_irqs -= hwirq_base; /* calculate # of irqs to allocate */
>
> -       if (of_property_read_u32(node, "arm,routable-irqs",
> -                                &nr_routable_irqs)) {
>                 irq_base = irq_alloc_descs(irq_start, 16, gic_irqs,
>                                            numa_node_id());
>                 if (IS_ERR_VALUE(irq_base)) {
> @@ -983,10 +1016,6 @@ void __init gic_init_bases(unsigned int gic_nr, int irq_start,
>
>                 gic->domain = irq_domain_add_legacy(node, gic_irqs, irq_base,
>                                         hwirq_base, &gic_irq_domain_ops, gic);
> -       } else {
> -               gic->domain = irq_domain_add_linear(node, nr_routable_irqs,
> -                                                   &gic_irq_domain_ops,
> -                                                   gic);
>         }
>
>         if (WARN_ON(!gic->domain))
> --
> 1.8.1.1.dirty

Gr{oetje,eeting}s,

                        Geert

--
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@xxxxxxxxxxxxxx

In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
                                -- Linus Torvalds
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