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

Marc Zyngier
2015-07-24T12:27:09Z

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.

Thanks,

M.
--
Jazz is not dead. It just smells funny...