Re: [PATCH 1/2] irqdomain: support three-cell scheme interrupts

[Alex Elder <elder@riscstar.com>]

On 2/27/25 5:24 AM, Yixun Lan wrote:
> The is a prerequisite patch to support parsing three-cell
> interrupts which encoded as <instance hwirq irqflag>,
> the translate function will always retrieve irq number and
> flag from last two cells.
> 
> Signed-off-by: Yixun Lan <dlan@gentoo.org>
> ---
>   kernel/irq/irqdomain.c | 11 +++++++++--
>   1 file changed, 9 insertions(+), 2 deletions(-)
> 
> diff --git a/kernel/irq/irqdomain.c b/kernel/irq/irqdomain.c
> index ec6d8e72d980f604ded2bfa2143420e0e0095920..cb874ab5e54a4763d601122becd63b6d759e55d2 100644
> --- a/kernel/irq/irqdomain.c
> +++ b/kernel/irq/irqdomain.c
> @@ -1208,10 +1208,17 @@ int irq_domain_translate_twocell(struct irq_domain *d,
>   				 unsigned long *out_hwirq,
>   				 unsigned int *out_type)
>   {

This function is meant for "twocell".  There is also another function
irq_domain_translate_onecell().  Why don't you just create
irq_domain_translate_threecell" instead?

					-Alex


> +	u32 irq, type;
> +
>   	if (WARN_ON(fwspec->param_count < 2))
>   		return -EINVAL;
> -	*out_hwirq = fwspec->param[0];
> -	*out_type = fwspec->param[1] & IRQ_TYPE_SENSE_MASK;
> +
> +	irq = fwspec->param_count - 2;
> +	type = fwspec->param_count - 1;
> +
> +	*out_hwirq = fwspec->param[irq];
> +	*out_type = fwspec->param[type] & IRQ_TYPE_SENSE_MASK;
> +
>   	return 0;
>   }
>   EXPORT_SYMBOL_GPL(irq_domain_translate_twocell);
>