linux-kernel - Re: [PATCH V9 2/3] ACPI: Add support for ResourceSource/IRQ domain mapping

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Date:   Tue, 17 Jan 2017 20:47:49 +0800
From:   Hanjun Guo <guohanjun@...wei.com>
To:     Agustin Vega-Frias <agustinv@...eaurora.org>,
        <linux-kernel@...r.kernel.org>, <linux-acpi@...r.kernel.org>,
        <linux-arm-kernel@...ts.infradead.org>, <rjw@...ysocki.net>,
        <lenb@...nel.org>, <tglx@...utronix.de>, <jason@...edaemon.net>,
        <marc.zyngier@....com>
CC:     <lorenzo.pieralisi@....com>, <timur@...eaurora.org>,
        <cov@...eaurora.org>, <agross@...eaurora.org>,
        <harba@...eaurora.org>, <jcm@...hat.com>, <msalter@...hat.com>,
        <mlangsdo@...hat.com>, <ahs3@...hat.com>, <astone@...hat.com>,
        <graeme.gregory@...aro.org>, <charles.garcia-tobin@....com>
Subject: Re: [PATCH V9 2/3] ACPI: Add support for ResourceSource/IRQ domain
 mapping

On 2016/12/15 6:10, Agustin Vega-Frias wrote:
> ACPI extended IRQ resources may contain a ResourceSource to specify
> an alternate interrupt controller. Introduce acpi_irq_get and use it
> to implement ResourceSource/IRQ domain mapping.
>
> The new API is similar to of_irq_get and allows re-initialization
> of a platform resource from the ACPI extended IRQ resource, and
> provides proper behavior for probe deferral when the domain is not
> yet present when called.
>
> Signed-off-by: Agustin Vega-Frias <agustinv@...eaurora.org>
> ---
>  drivers/acpi/Makefile         |   2 +-
>  drivers/acpi/{gsi.c => irq.c} | 182 ++++++++++++++++++++++++++++++++++++++++++
>  drivers/base/platform.c       |   9 ++-
>  include/linux/acpi.h          |  10 +++
>  4 files changed, 201 insertions(+), 2 deletions(-)
>  rename drivers/acpi/{gsi.c => irq.c} (32%)
>
[...]
> +/**
> + * acpi_irq_parse_one_cb - Handle the given resource
> + * @ares: resource to handle
> + * @context: context for the walk, contains the lookup index and references
> + *           to the flags and fwspec where the result is returned
> + *
> + * This is called by acpi_walk_resources passing each resource returned by
> + * the _CRS method. We only inspect IRQ resources. Since IRQ resources
> + * might contain multiple interrupts we check if the index is within this
> + * one's interrupt array, otherwise we subtract the current resource IRQ
> + * count from the lookup index to prepare for the next resource.
> + * Once a match is found we call acpi_irq_parse_one_match to populate
> + * the result and end the walk by returning AE_CTRL_TERMINATE.
> + *
> + * Return AE_OK if the walk should continue, AE_CTRL_TERMINATE if a matching
> + * IRQ resource was found.
> + */
> +static acpi_status acpi_irq_parse_one_cb(struct acpi_resource *ares,
> +					 void *context)
> +{
> +	struct acpi_irq_parse_one_ctx *ctx = context;
> +	struct acpi_resource_irq *irq;
> +	struct acpi_resource_extended_irq *eirq;
> +	struct fwnode_handle *fwnode;
> +
> +	switch (ares->type) {
> +	case ACPI_RESOURCE_TYPE_IRQ:
> +		irq = &ares->data.irq;
> +		if (ctx->index >= irq->interrupt_count) {
> +			ctx->index -= irq->interrupt_count;
> +			return AE_OK;
> +		}
> +		fwnode = acpi_gsi_domain_id;
> +		acpi_irq_parse_one_match(fwnode, irq->interrupts[ctx->index],
> +					 irq->triggering, irq->polarity,
> +					 irq->sharable, ctx);
> +		return AE_CTRL_TERMINATE;
> +	case ACPI_RESOURCE_TYPE_EXTENDED_IRQ:
> +		eirq = &ares->data.extended_irq;

If it's an interrupt producer, I think we don't need to map the interrupts in
any irqdomain, and return AE_CTRL_TERMINATE here.

        case ACPI_RESOURCE_TYPE_EXTENDED_IRQ:
                eirq = &ares->data.extended_irq;
+         if (eirq->producer_consumer == ACPI_PRODUCER)
+                 return AE_CTRL_TERMINATE;
                if (ctx->index >= eirq->interrupt_count) {

Thanks
Hanjun