Subject: [PATCH v2 5/7] acpi: gsi: Add acpi_set_irq_model to initialize the GSI layer

From: [email-masked] (Hanjun Guo)
Date: Sat, 25 Jul 2015 14:57:12 +0800

On 07/24/2015 08:27 PM, Marc Zyngier wrote:
> On 24/07/15 11:00, Hanjun Guo wrote:
>> On 07/23/2015 09:05 PM, Marc Zyngier wrote:
>>> In order to start embrassing irqdomains at the GSI level, introduce
>>> a new initializer:
>>>
>>> void acpi_set_irq_model(enum acpi_irq_model_id model,
>>> 			unsigned long domain_token,
>>> 			int (*populate)(struct acpi_gsi_descriptor *,
>>> 					u32, unsigned int));
>>>
>>> where:
>>> - model is the value assigned to acpi_irq_model
>>> - domain_token is the identifier for the irqdomain mapping
>>>     GSI interrupts
>>> - populate is a function provided by the interrupt controller,
>>>     populating a struct acpi_gsi_descriptor based on a GSI and
>>>     the interrupt trigger information
>>>
>>> As nobody calls this code yet, the current code is left in place.
>>>
>>> Signed-off-by: Marc Zyngier <[email-masked]>
>>> ---
>>>    drivers/acpi/gsi.c   | 32 ++++++++++++++++++++++++++++++++
>>>    include/linux/acpi.h |  5 +++++
>>>    2 files changed, 37 insertions(+)
>>>
>>> diff --git a/drivers/acpi/gsi.c b/drivers/acpi/gsi.c
>>> index a745880..e6f4a0c 100644
>>> --- a/drivers/acpi/gsi.c
>>> +++ b/drivers/acpi/gsi.c
>>> @@ -16,6 +16,9 @@ enum acpi_irq_model_id acpi_irq_model;
>>>
>>>    static void *acpi_gsi_domain_token;
>>>
>>> +static int (*acpi_gsi_descriptor_populate)(struct acpi_gsi_descriptor *data,
>>> +					   u32 gsi, unsigned int irq_type);
>>> +
>>>    static unsigned int acpi_gsi_get_irq_type(int trigger, int polarity)
>>>    {
>>>    	switch (polarity) {
>>> @@ -71,10 +74,20 @@ EXPORT_SYMBOL_GPL(acpi_gsi_to_irq);
>>>    int acpi_register_gsi(struct device *dev, u32 gsi, int trigger,
>>>    		      int polarity)
>>>    {
>>> +	int err;
>>>    	unsigned int irq;
>>>    	unsigned int irq_type = acpi_gsi_get_irq_type(trigger, polarity);
>>>    	struct irq_domain *d = irq_find_host(acpi_gsi_domain_token);
>>>
>>> +	if (acpi_gsi_descriptor_populate) {
>>> +		struct acpi_gsi_descriptor data;
>>> +		err = acpi_gsi_descriptor_populate(&data, gsi, irq_type);
>>> +		if (err)
>>> +			return err;
>>> +
>>> +		return irq_create_acpi_mapping(d, &data);
>>> +	}
>>> +
>>>    	irq = irq_create_mapping(d, gsi);
>>>    	if (!irq)
>>>    		return -EINVAL;
>>> @@ -99,3 +112,22 @@ void acpi_unregister_gsi(u32 gsi)
>>>    	irq_dispose_mapping(irq);
>>>    }
>>>    EXPORT_SYMBOL_GPL(acpi_unregister_gsi);
>>> +
>>> +/**
>>> + * acpi_set_irq_model - Setup the GSI irqdomain information
>>> + * @model: the value assigned to acpi_irq_model
>>> + * @domain_token: the irq_domain identifier for mapping and looking up
>>> + *                GSI interrupts
>>> + * @populate: provided by the interrupt controller, populating a
>>> + *            struct acpi_gsi_descriptor based on a GSI and
>>> + *            the interrupt trigger information
>>> + */
>>> +void acpi_set_irq_model(enum acpi_irq_model_id model,
>>> +			unsigned long domain_token,
>>> +			int (*populate)(struct acpi_gsi_descriptor *,
>>> +					u32, unsigned int))
>>> +{
>>> +	acpi_irq_model = model;
>>> +	acpi_gsi_domain_token = (void *)domain_token;
>>
>> This will work perfectly fine with ARM as it has single GICD and
>> one irq domain, I'm not sure x86 is ok with it because x86 has
>> multi ioapics and each ioapic has a irqdomain if I understand
>> correctly, but x86 don't use functions in this file at all for now,
>> I think I'm over worried :)
>
> When (and if) that day comes, we'll have to either contextualize
> acpi_register_gsi to take a domain token, or have a lookup table that
> maps GSI ranges to domain tokens.
>
> Either way, this doesn't invalidate what is being done here.

Agreed,

Reviewed-by: Hanjun Guo <[email-masked]>

Thanks
Hanjun