Re: [PATCH V6 2/3] ACPI: Add support for ResourceSource/IRQ domain mapping

[agustinv@codeaurora.org]

Hey Hanjun,

On 2016-11-09 21:36, Hanjun Guo wrote:
> Hi Marc, Rafael, Lorenzo,
> 
> Since we agreed to add a probe deferral if we failed to get irq
> resources which mirroring the DT does (patch 1 in this patch set),
> I think the last blocker to make things work both for Agustin and
> me [1] is this patch, which makes the interrupt producer and consumer
> work in ACPI, we have two different solution for one thing, we'd happy
> to work together for one solution, could you give some suggestions
> please?
> 
> [1]: 
> https://mail-archive.com/linux-kernel@vger.kernel.org/msg1257419.html
> 
> Agustin, I have some comments below.
> 
> On 2016/10/29 4:48, Agustin Vega-Frias wrote:
>> This allows irqchip drivers to associate an ACPI DSDT device to
>> an IRQ domain and provides support for using the ResourceSource
>> in Extended IRQ Resources to find the domain and map the IRQs
>> specified on that domain.
>> 
>> Signed-off-by: Agustin Vega-Frias <agustinv@codeaurora.org>
>> ---
>>  drivers/acpi/Makefile    |   1 +
>>  drivers/acpi/irqdomain.c | 119 
>> +++++++++++++++++++++++++++++++++++++++++++++++
> 
> Could we just reuse the gsi.c and not introduce a new
> file, probably we can change the gsi.c to irqdomain.c
> or something similar, then reuse the code in gsi.c.

I was thinking just that after we chatted off-list.
I might revisit and see what I come up with given that we already have
a device argument and we could pass the IRQ source there.

Thanks

> 
> Thanks
> Hanjun
> 
>>  drivers/acpi/resource.c  |  21 +++++----
>>  include/linux/acpi.h     |  25 ++++++++++
>>  4 files changed, 157 insertions(+), 9 deletions(-)
>>  create mode 100644 drivers/acpi/irqdomain.c
>> 
>> diff --git a/drivers/acpi/Makefile b/drivers/acpi/Makefile
>> index 9ed0878..880401b 100644
>> --- a/drivers/acpi/Makefile
>> +++ b/drivers/acpi/Makefile
>> @@ -57,6 +57,7 @@ acpi-$(CONFIG_ACPI_PROCFS_POWER) += cm_sbs.o
>>  acpi-y				+= acpi_lpat.o
>>  acpi-$(CONFIG_ACPI_GENERIC_GSI) += gsi.o
>>  acpi-$(CONFIG_ACPI_WATCHDOG)	+= acpi_watchdog.o
>> +acpi-$(CONFIG_IRQ_DOMAIN)	+= irqdomain.o
>> 
>>  # These are (potentially) separate modules
>> 
>> diff --git a/drivers/acpi/irqdomain.c b/drivers/acpi/irqdomain.c
>> new file mode 100644
>> index 0000000..11d3658
>> --- /dev/null
>> +++ b/drivers/acpi/irqdomain.c
>> @@ -0,0 +1,119 @@
>> +/*
>> + * ACPI ResourceSource/IRQ domain mapping support
>> + *
>> + * Copyright (c) 2016, The Linux Foundation. All rights reserved.
>> + *
>> + * This program is free software; you can redistribute it and/or 
>> modify
>> + * it under the terms of the GNU General Public License version 2 and
>> + * only version 2 as published by the Free Software Foundation.
>> + *
>> + * This program is distributed in the hope that it will be useful,
>> + * but WITHOUT ANY WARRANTY; without even the implied warranty of
>> + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
>> + * GNU General Public License for more details.
>> + */
>> +#include <linux/acpi.h>
>> +#include <linux/irq.h>
>> +#include <linux/irqdomain.h>
>> +
>> +/**
>> + * acpi_irq_domain_register_irq() - Register the mapping for an IRQ 
>> produced
>> + *                                  by the given acpi_resource_source 
>> to a
>> + *                                  Linux IRQ number
>> + * @source: IRQ source
>> + * @hwirq: Hardware IRQ number
>> + * @trigger: trigger type of the IRQ number to be mapped
>> + * @polarity: polarity of the IRQ to be mapped
>> + *
>> + * Returns: a valid linux IRQ number on success
>> + *          -ENODEV if the given acpi_resource_source cannot be found
>> + *          -EPROBE_DEFER if the IRQ domain has not been registered
>> + *          -EINVAL for all other errors
>> + */
>> +int acpi_irq_domain_register_irq(const struct acpi_resource_source 
>> *source,
>> +				 u32 hwirq, int trigger, int polarity)
>> +{
>> +	struct irq_fwspec fwspec;
>> +	struct acpi_device *device;
>> +	acpi_handle handle;
>> +	acpi_status status;
>> +	int ret;
>> +
>> +	/* An empty acpi_resource_source means it is a GSI */
>> +	if (!source->string_length)
>> +		return acpi_register_gsi(NULL, hwirq, trigger, polarity);
>> +
>> +	status = acpi_get_handle(NULL, source->string_ptr, &handle);
>> +	if (ACPI_FAILURE(status))
>> +		return -ENODEV;
>> +
>> +	device = acpi_bus_get_acpi_device(handle);
>> +	if (!device)
>> +		return -ENODEV;
>> +
>> +	if (irq_find_matching_fwnode(&device->fwnode, DOMAIN_BUS_ANY) == 
>> NULL) {
>> +		ret = -EPROBE_DEFER;
>> +		goto out_put_device;
>> +	}
>> +
>> +	fwspec.fwnode = &device->fwnode;
>> +	fwspec.param[0] = hwirq;
>> +	fwspec.param[1] = acpi_dev_get_irq_type(trigger, polarity);
>> +	fwspec.param_count = 2;
>> +
>> +	ret = irq_create_fwspec_mapping(&fwspec);
>> +
>> +out_put_device:
>> +	acpi_bus_put_acpi_device(device);
>> +
>> +	return ret;
>> +}
>> +EXPORT_SYMBOL_GPL(acpi_irq_domain_register_irq);
>> +
>> +/**
>> + * acpi_irq_domain_unregister_irq() - Delete the mapping for an IRQ 
>> produced
>> + *                                    by the given 
>> acpi_resource_source to a
>> + *                                    Linux IRQ number
>> + * @source: IRQ source
>> + * @hwirq: Hardware IRQ number
>> + *
>> + * Returns: 0 on success
>> + *          -ENODEV if the given acpi_resource_source cannot be found
>> + *          -EINVAL for all other errors
>> + */
>> +int acpi_irq_domain_unregister_irq(const struct acpi_resource_source 
>> *source,
>> +				   u32 hwirq)
>> +{
>> +	struct irq_domain *domain;
>> +	struct acpi_device *device;
>> +	acpi_handle handle;
>> +	acpi_status status;
>> +	int ret = 0;
>> +
>> +	if (!source->string_length) {
>> +		acpi_unregister_gsi(hwirq);
>> +		return 0;
>> +	}
>> +
>> +	status = acpi_get_handle(NULL, source->string_ptr, &handle);
>> +	if (ACPI_FAILURE(status))
>> +		return -ENODEV;
>> +
>> +	device = acpi_bus_get_acpi_device(handle);
>> +	if (!device)
>> +		return -ENODEV;
>> +
>> +	domain = irq_find_matching_fwnode(&device->fwnode, DOMAIN_BUS_ANY);
>> +	if (!domain) {
>> +		ret = -EINVAL;
>> +		goto out_put_device;
>> +	}
>> +
>> +	irq_dispose_mapping(irq_find_mapping(domain, hwirq));
>> +
>> +out_put_device:
>> +	acpi_bus_put_acpi_device(device);
>> +
>> +	return ret;
>> +}
>> +EXPORT_SYMBOL_GPL(acpi_irq_domain_unregister_irq);
>> diff --git a/drivers/acpi/resource.c b/drivers/acpi/resource.c
>> index 4beda15..ccb6f4f 100644
>> --- a/drivers/acpi/resource.c
>> +++ b/drivers/acpi/resource.c
>> @@ -381,14 +381,15 @@ static void acpi_dev_irqresource_disabled(struct 
>> resource *res, u32 gsi)
>>  	res->flags = IORESOURCE_IRQ | IORESOURCE_DISABLED | 
>> IORESOURCE_UNSET;
>>  }
>> 
>> -static void acpi_dev_get_irqresource(struct resource *res, u32 gsi,
>> +static void acpi_dev_get_irqresource(struct resource *res, u32 hwirq,
>> +				     const struct acpi_resource_source *source,
>>  				     u8 triggering, u8 polarity, u8 shareable,
>>  				     bool legacy)
>>  {
>>  	int irq, p, t;
>> 
>> -	if (!valid_IRQ(gsi)) {
>> -		acpi_dev_irqresource_disabled(res, gsi);
>> +	if ((source->string_length == 0) && !valid_IRQ(hwirq)) {
>> +		acpi_dev_irqresource_disabled(res, hwirq);
>>  		return;
>>  	}
>> 
>> @@ -402,25 +403,25 @@ static void acpi_dev_get_irqresource(struct 
>> resource *res, u32 gsi,
>>  	 * using extended IRQ descriptors we take the IRQ configuration
>>  	 * from _CRS directly.
>>  	 */
>> -	if (legacy && !acpi_get_override_irq(gsi, &t, &p)) {
>> +	if (legacy && !acpi_get_override_irq(hwirq, &t, &p)) {
>>  		u8 trig = t ? ACPI_LEVEL_SENSITIVE : ACPI_EDGE_SENSITIVE;
>>  		u8 pol = p ? ACPI_ACTIVE_LOW : ACPI_ACTIVE_HIGH;
>> 
>>  		if (triggering != trig || polarity != pol) {
>> -			pr_warning("ACPI: IRQ %d override to %s, %s\n", gsi,
>> -				   t ? "level" : "edge", p ? "low" : "high");
>> +			pr_warn("ACPI: IRQ %d override to %s, %s\n", hwirq,
>> +				t ? "level" : "edge", p ? "low" : "high");
>>  			triggering = trig;
>>  			polarity = pol;
>>  		}
>>  	}
>> 
>>  	res->flags = acpi_dev_irq_flags(triggering, polarity, shareable);
>> -	irq = acpi_register_gsi(NULL, gsi, triggering, polarity);
>> +	irq = acpi_irq_domain_register_irq(source, hwirq, triggering, 
>> polarity);
>>  	if (irq >= 0) {
>>  		res->start = irq;
>>  		res->end = irq;
>>  	} else {
>> -		acpi_dev_irqresource_disabled(res, gsi);
>> +		acpi_dev_irqresource_disabled(res, hwirq);
>>  	}
>>  }
>> 
>> @@ -446,6 +447,7 @@ static void acpi_dev_get_irqresource(struct 
>> resource *res, u32 gsi,
>>  bool acpi_dev_resource_interrupt(struct acpi_resource *ares, int 
>> index,
>>  				 struct resource *res)
>>  {
>> +	const struct acpi_resource_source dummy = { 0, 0, NULL };
>>  	struct acpi_resource_irq *irq;
>>  	struct acpi_resource_extended_irq *ext_irq;
>> 
>> @@ -460,7 +462,7 @@ bool acpi_dev_resource_interrupt(struct 
>> acpi_resource *ares, int index,
>>  			acpi_dev_irqresource_disabled(res, 0);
>>  			return false;
>>  		}
>> -		acpi_dev_get_irqresource(res, irq->interrupts[index],
>> +		acpi_dev_get_irqresource(res, irq->interrupts[index], &dummy,
>>  					 irq->triggering, irq->polarity,
>>  					 irq->sharable, true);
>>  		break;
>> @@ -471,6 +473,7 @@ bool acpi_dev_resource_interrupt(struct 
>> acpi_resource *ares, int index,
>>  			return false;
>>  		}
>>  		acpi_dev_get_irqresource(res, ext_irq->interrupts[index],
>> +					 &ext_irq->resource_source,
>>  					 ext_irq->triggering, ext_irq->polarity,
>>  					 ext_irq->sharable, false);
>>  		break;
>> diff --git a/include/linux/acpi.h b/include/linux/acpi.h
>> index 40213c4..ce30a12 100644
>> --- a/include/linux/acpi.h
>> +++ b/include/linux/acpi.h
>> @@ -321,6 +321,31 @@ void acpi_set_irq_model(enum acpi_irq_model_id 
>> model,
>>   */
>>  void acpi_unregister_gsi (u32 gsi);
>> 
>> +#ifdef CONFIG_IRQ_DOMAIN
>> +
>> +int acpi_irq_domain_register_irq(const struct acpi_resource_source 
>> *source,
>> +				 u32 hwirq, int trigger, int polarity);
>> +int acpi_irq_domain_unregister_irq(const struct acpi_resource_source 
>> *source,
>> +				   u32 hwirq);
>> +
>> +#else
>> +
>> +static inline int acpi_irq_domain_register_irq(
>> +	const struct acpi_resource_source *source, u32 hwirq, int trigger,
>> +	int polarity)
>> +{
>> +	return acpi_register_gsi(NULL, hwirq, trigger, polarity);
>> +}
>> +
>> +static inline int acpi_irq_domain_unregister_irq(
>> +	const struct acpi_resource_source *source,  u32 hwirq)
>> +{
>> +	acpi_unregister_gsi(hwirq);
>> +	return 0;
>> +}
>> +
>> +#endif /* CONFIG_IRQ_DOMAIN */
>> +
>>  struct pci_dev;
>> 
>>  int acpi_pci_irq_enable (struct pci_dev *dev);
>> 

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