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

Hanjun Guo
2015-07-25T06:57:24Z

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 <marc.zyngier@arm.com>
>>> ---
>>> 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 <hanjun.guo@linaro.org>

Thanks
Hanjun