Re: [PATCH v2 6/7] irqchip: GIC: Switch ACPI support to stacked domains

[Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>]

On Thu, Jul 23, 2015 at 02:05:12PM +0100, Marc Zyngier wrote:
> Now that the basic ACPI GSI code is irq domain aware, make sure
> that the ACPI support in the GIC doesn't pointlessly deviate from
> the DT path.
> 
> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
> ---
>  drivers/irqchip/irq-gic.c       | 45 ++++++++++++++++++++++++++++++-----------
>  include/linux/irqchip/arm-gic.h |  2 +-
>  2 files changed, 34 insertions(+), 13 deletions(-)

Reviewed-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>

> diff --git a/drivers/irqchip/irq-gic.c b/drivers/irqchip/irq-gic.c
> index b41ccf5..ce531e6 100644
> --- a/drivers/irqchip/irq-gic.c
> +++ b/drivers/irqchip/irq-gic.c
> @@ -813,8 +813,6 @@ static int gic_irq_domain_xlate(struct irq_domain *d,
>  {
>  	unsigned long ret = 0;
>  
> -	if (irq_domain_get_of_node(d) != controller)
> -		return -EINVAL;
>  	if (intsize < 3)
>  		return -EINVAL;
>  
> @@ -887,7 +885,7 @@ void gic_set_irqchip_flags(unsigned long flags)
>  
>  void __init gic_init_bases(unsigned int gic_nr, int irq_start,
>  			   void __iomem *dist_base, void __iomem *cpu_base,
> -			   u32 percpu_offset, struct device_node *node)
> +			   u32 percpu_offset, void *domain_token)
>  {
>  	irq_hw_number_t hwirq_base;
>  	struct gic_chip_data *gic;
> @@ -946,8 +944,8 @@ void __init gic_init_bases(unsigned int gic_nr, int irq_start,
>  		gic_irqs = 1020;
>  	gic->gic_irqs = gic_irqs;
>  
> -	if (node) {		/* DT case */
> -		gic->domain = irq_domain_add_linear(node, gic_irqs,
> +	if (domain_token) {		/* DT/ACPI case */
> +		gic->domain = irq_domain_add_linear(domain_token, gic_irqs,
>  						    &gic_irq_domain_hierarchy_ops,
>  						    gic);
>  	} else {		/* Non-DT case */
> @@ -973,7 +971,7 @@ void __init gic_init_bases(unsigned int gic_nr, int irq_start,
>  			irq_base = irq_start;
>  		}
>  
> -		gic->domain = irq_domain_add_legacy(node, gic_irqs, irq_base,
> +		gic->domain = irq_domain_add_legacy(NULL, gic_irqs, irq_base,
>  					hwirq_base, &gic_irq_domain_ops, gic);
>  	}
>  
> @@ -1086,6 +1084,31 @@ gic_acpi_parse_madt_distributor(struct acpi_subtable_header *header,
>  	return 0;
>  }
>  
> +static int gic_acpi_gsi_desc_populate(struct acpi_gsi_descriptor *data,
> +				      u32 gsi, unsigned int irq_type)
> +{
> +	/*
> +	 * Encode GSI and triggering information the way the GIC likes
> +	 * them.
> +	 */
> +	if (WARN_ON(gsi < 16))
> +		return -EINVAL;
> +
> +	if (gsi >= 32) {
> +		data->param[0] = 0;		/* SPI */
> +		data->param[1] = gsi - 32;
> +		data->param[2] = irq_type;
> +	} else {
> +		data->param[0] = 1; 		/* PPI */
> +		data->param[1] = gsi - 16;
> +		data->param[2] = 0xff << 4 | irq_type;
> +	}
> +
> +	data->param_count = 3;
> +
> +	return 0;
> +}
> +
>  int __init
>  gic_v2_acpi_init(struct acpi_table_header *table)
>  {
> @@ -1132,14 +1155,12 @@ gic_v2_acpi_init(struct acpi_table_header *table)
>  	}
>  
>  	/*
> -	 * Initialize zero GIC instance (no multi-GIC support). Also, set GIC
> -	 * as default IRQ domain to allow for GSI registration and GSI to IRQ
> -	 * number translation (see acpi_register_gsi() and acpi_gsi_to_irq()).
> +	 * Initialize zero GIC instance (no multi-GIC support).
>  	 */
> -	gic_init_bases(0, -1, dist_base, cpu_base, 0, NULL);
> -	irq_set_default_host(gic_data[0].domain);
> +	gic_init_bases(0, -1, dist_base, cpu_base, 0, (void *)ACPI_IRQ_MODEL_GIC);
>  
> -	acpi_irq_model = ACPI_IRQ_MODEL_GIC;
> +	acpi_set_irq_model(ACPI_IRQ_MODEL_GIC, ACPI_IRQ_MODEL_GIC,
> +			   gic_acpi_gsi_desc_populate);
>  	return 0;
>  }
>  #endif
> diff --git a/include/linux/irqchip/arm-gic.h b/include/linux/irqchip/arm-gic.h
> index 9de976b..97799b7 100644
> --- a/include/linux/irqchip/arm-gic.h
> +++ b/include/linux/irqchip/arm-gic.h
> @@ -97,7 +97,7 @@ struct device_node;
>  
>  void gic_set_irqchip_flags(unsigned long flags);
>  void gic_init_bases(unsigned int, int, void __iomem *, void __iomem *,
> -		    u32 offset, struct device_node *);
> +		    u32 offset, void *);
>  void gic_cascade_irq(unsigned int gic_nr, unsigned int irq);
>  void gic_cpu_if_down(void);
>  
> -- 
> 2.1.4
>