On Wed, 09 Sep 2020 07:58:35 +0100,
Zhen Lei <[email protected]> wrote:
> 
> Add support to use dw-apb-ictl as primary interrupt controller.
> 
> Suggested-by: Marc Zyngier <[email protected]>
> Signed-off-by: Zhen Lei <[email protected]>
> Tested-by: Haoyu Lv <[email protected]>
> ---
>  drivers/irqchip/Kconfig           |  2 +-
>  drivers/irqchip/irq-dw-apb-ictl.c | 76 +++++++++++++++++++++++++++----
>  2 files changed, 69 insertions(+), 9 deletions(-)
> 
> diff --git a/drivers/irqchip/Kconfig b/drivers/irqchip/Kconfig
> index bfc9719dbcdc..7c2d1c8fa551 100644
> --- a/drivers/irqchip/Kconfig
> +++ b/drivers/irqchip/Kconfig
> @@ -148,7 +148,7 @@ config DAVINCI_CP_INTC
>  config DW_APB_ICTL
>       bool
>       select GENERIC_IRQ_CHIP
> -     select IRQ_DOMAIN
> +     select IRQ_DOMAIN_HIERARCHY
>  
>  config FARADAY_FTINTC010
>       bool
> diff --git a/drivers/irqchip/irq-dw-apb-ictl.c 
> b/drivers/irqchip/irq-dw-apb-ictl.c
> index 5458004242e9..3c7bebe1b947 100644
> --- a/drivers/irqchip/irq-dw-apb-ictl.c
> +++ b/drivers/irqchip/irq-dw-apb-ictl.c
> @@ -17,6 +17,7 @@
>  #include <linux/irqchip/chained_irq.h>
>  #include <linux/of_address.h>
>  #include <linux/of_irq.h>
> +#include <linux/interrupt.h>
>  
>  #define APB_INT_ENABLE_L     0x00
>  #define APB_INT_ENABLE_H     0x04
> @@ -26,6 +27,27 @@
>  #define APB_INT_FINALSTATUS_H        0x34
>  #define APB_INT_BASE_OFFSET  0x04
>  
> +/* irq domain of the primary interrupt controller. */
> +static struct irq_domain *dw_apb_ictl_irq_domain;
> +
> +static void __irq_entry dw_apb_ictl_handle_irq(struct pt_regs *regs)
> +{
> +     struct irq_domain *d = dw_apb_ictl_irq_domain;
> +     int n;
> +
> +     for (n = 0; n < d->revmap_size; n += 32) {
> +             struct irq_chip_generic *gc = irq_get_domain_generic_chip(d, n);
> +             u32 stat = readl_relaxed(gc->reg_base + APB_INT_FINALSTATUS_L);
> +
> +             while (stat) {
> +                     u32 hwirq = ffs(stat) - 1;
> +
> +                     handle_domain_irq(d, hwirq, regs);
> +                     stat &= ~BIT(hwirq);
> +             }
> +     }
> +}
> +
>  static void dw_apb_ictl_handle_irq_cascaded(struct irq_desc *desc)
>  {
>       struct irq_domain *d = irq_desc_get_handler_data(desc);
> @@ -50,6 +72,30 @@ static void dw_apb_ictl_handle_irq_cascaded(struct 
> irq_desc *desc)
>       chained_irq_exit(chip, desc);
>  }
>  
> +static int dw_apb_ictl_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 irq_fwspec *fwspec = arg;
> +
> +     ret = irq_domain_translate_onecell(domain, fwspec, &hwirq, &type);
> +     if (ret)
> +             return ret;
> +
> +     for (i = 0; i < nr_irqs; i++)
> +             irq_map_generic_chip(domain, virq + i, hwirq + i);
> +
> +     return 0;
> +}
> +
> +static const struct irq_domain_ops dw_apb_ictl_irq_domain_ops = {
> +     .translate = irq_domain_translate_onecell,
> +     .alloc = dw_apb_ictl_irq_domain_alloc,
> +     .free = irq_domain_free_irqs_top,
> +};
> +
>  #ifdef CONFIG_PM
>  static void dw_apb_ictl_resume(struct irq_data *d)
>  {
> @@ -75,13 +121,20 @@ static int __init dw_apb_ictl_init(struct device_node 
> *np,
>       void __iomem *iobase;
>       int ret, nrirqs, parent_irq, i;
>       u32 reg;
> -     const struct irq_domain_ops *domain_ops = &irq_generic_chip_ops;
> -
> -     /* Map the parent interrupt for the chained handler */
> -     parent_irq = irq_of_parse_and_map(np, 0);
> -     if (parent_irq <= 0) {
> -             pr_err("%pOF: unable to parse irq\n", np);
> -             return -EINVAL;
> +     const struct irq_domain_ops *domain_ops;
> +
> +     if (!parent || (np == parent)) {
> +             /* It's used as the primary interrupt controller */
> +             parent_irq = 0;
> +             domain_ops = &dw_apb_ictl_irq_domain_ops;
> +     } else {
> +             /* Map the parent interrupt for the chained handler */
> +             parent_irq = irq_of_parse_and_map(np, 0);
> +             if (parent_irq <= 0) {
> +                     pr_err("%pOF: unable to parse irq\n", np);
> +                     return -EINVAL;
> +             }
> +             domain_ops = &irq_generic_chip_ops;
>       }
>  
>       ret = of_address_to_resource(np, 0, &r);
> @@ -144,10 +197,17 @@ static int __init dw_apb_ictl_init(struct device_node 
> *np,
>               gc->chip_types[0].chip.irq_mask = irq_gc_mask_set_bit;
>               gc->chip_types[0].chip.irq_unmask = irq_gc_mask_clr_bit;
>               gc->chip_types[0].chip.irq_resume = dw_apb_ictl_resume;
> +             if (!parent_irq)
> +                     gc->chip_types[0].chip.irq_eoi = irq_gc_noop;

Again: what is that for? The level flow doesn't use any EOI callback.

>       }
>  
> -     irq_set_chained_handler_and_data(parent_irq,
> +     if (parent_irq) {
> +             irq_set_chained_handler_and_data(parent_irq,
>                               dw_apb_ictl_handle_irq_cascaded, domain);
> +     } else {
> +             dw_apb_ictl_irq_domain = domain;
> +             set_handle_irq(dw_apb_ictl_handle_irq);

This only exists on architectures that select GENERIC_IRQ_MULTI_HANDLER,
and yet this driver is used on some arc system (AXS10x), which doesn't
have this option selected.

Please make sure this at least builds on all supported architectures.

        M.

-- 
Without deviation from the norm, progress is not possible.

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