Re: [PATCH v1] irqchip: loongson-liointc: add hierarchy irq support

[Yinbo Zhu <zhuyinbo@loongson.cn>]

在 2022/12/7 19:07, Marc Zyngier 写道:
> On Wed, 07 Dec 2022 10:50:56 +0000,
> Yinbo Zhu <zhuyinbo@loongson.cn> wrote:
>>
>> 在 2022/12/7 16:08, Marc Zyngier 写道:
>>> On Wed, 07 Dec 2022 01:45:55 +0000,
>>> Yinbo Zhu <zhuyinbo@loongson.cn> wrote:
>>>> When the irq of hierarchical interrupt chip was routed to liointc
>>>> that asked liointc driver to support hierarchy irq and this patch
>>>> was to add such support.
>>>>
>>>> In addition, this patch only consider dts, and acpi hierarchy irq
>>>> support will be added later as required.
>>>>
>>>> Signed-off-by: Yinbo Zhu <zhuyinbo@loongson.cn>
>>>> ---
>>>>    drivers/irqchip/irq-loongson-liointc.c | 31 ++++++++++++++++++++++++++
>>>>    1 file changed, 31 insertions(+)
>>>>
>>>> diff --git a/drivers/irqchip/irq-loongson-liointc.c b/drivers/irqchip/irq-loongson-liointc.c
>>>> index 0da8716f8f24..58e43a2cd02e 100644
>>>> --- a/drivers/irqchip/irq-loongson-liointc.c
>>>> +++ b/drivers/irqchip/irq-loongson-liointc.c
>>>> @@ -177,6 +177,32 @@ static const struct irq_domain_ops acpi_irq_gc_ops = {
>>>>    	.xlate	= liointc_domain_xlate,
>>>>    };
>>>>    +#ifdef	CONFIG_IRQ_DOMAIN_HIERARCHY
>>>> +static int liointc_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_twocell(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 of_irq_gc_ops = {
>>>> +	.translate	= irq_domain_translate_twocell,
>>>> +	.alloc		= liointc_domain_alloc,
>>>> +	.free		= irq_domain_free_irqs_top,
>>>> +};
>>>> +#endif
>>>> +
>>>>    static int liointc_init(phys_addr_t addr, unsigned long size, int revision,
>>>>    		struct fwnode_handle *domain_handle, struct device_node *node)
>>>>    {
>>>> @@ -218,8 +244,13 @@ static int liointc_init(phys_addr_t addr, unsigned long size, int revision,
>>>>    		domain = irq_domain_create_linear(domain_handle, LIOINTC_CHIP_IRQ,
>>>>    					&acpi_irq_gc_ops, priv);
>>>>    	else
>>>> +#ifdef	CONFIG_IRQ_DOMAIN_HIERARCHY
>>>> +		domain = irq_domain_create_linear(domain_handle, LIOINTC_CHIP_IRQ,
>>>> +					&of_irq_gc_ops, priv);
>>>> +#else
>>>>    		domain = irq_domain_create_linear(domain_handle, LIOINTC_CHIP_IRQ,
>>>>    					&irq_generic_chip_ops, priv);
>>>> +#endif
>>> Two things:
>>>
>>> - Why do we need three calls to create the same domains depending on
>>>     what firmware is used and kernel configuration?
>> yes, It depend on firmeware and kernel configuration.
> Read again:
>
> why do we need 3 different calls to irq_domain_create_linear when you
> can *indirect* them with a pointer to the correct structure?
It was not considered comprehensively before, one call is enough.
>
>>> - who is going to decide whether to select the
>>>     CONFIG_IRQ_DOMAIN_HIERARCHY option?
>> The latest gpio driver will select  CONFIG_IRQ_DOMAIN_HIERARCHY
> Then why do we need two different behaviours? The same kernel should
> run everywhere.

in fact, A behaviours can handle it, and I will add proper change

in v2.

>
>>> I'd really like to see a statement from the Loongson folks about what
>>> this whole DT stuff is all about. AFAICT, the core ACPICA stuff isn't
>>> even fully merged (i.e. we still rely on arch-specific hacks).
>> The support of dts is mainly for Loongson embedded chips, such as
>> LoongArch Loongson-2 series SoC.  and it use dts to descripte device
>> and don't support acpi.
> That doesn't answer my question. Please have a *consistent* approach
> to your interrupt handling, and work with your ACPI colleagues.

I have a talk with ACPI colleagues that the dts and acpi can keep consistent

approach and I will add it in v2.

>
> 	M.
>