[RFC PATCH 02/33] irqchip/gic-v3: Add VLPI/DirectLPI discovery

[Auger Eric]

Hi,

On 17/01/2017 11:20, Marc Zyngier wrote:
> Add helper functions that probe for VLPI and DirectLPI properties.
> 
> Signed-off-by: Marc Zyngier <marc.zyngier at arm.com>
Besides the returned value previous questions,

Reviewed-by: Eric Auger <eric.auger at redhat.com>

Eric


> ---
>  drivers/irqchip/irq-gic-v3.c       | 22 ++++++++++++++++++++++
>  include/linux/irqchip/arm-gic-v3.h |  3 +++
>  2 files changed, 25 insertions(+)
> 
> diff --git a/drivers/irqchip/irq-gic-v3.c b/drivers/irqchip/irq-gic-v3.c
> index 5cadec0..8a6de91 100644
> --- a/drivers/irqchip/irq-gic-v3.c
> +++ b/drivers/irqchip/irq-gic-v3.c
> @@ -514,6 +514,24 @@ static int gic_populate_rdist(void)
>  	return -ENODEV;
>  }
>  
> +static int __gic_update_vlpi_properties(struct redist_region *region,
> +					void __iomem *ptr)
> +{
> +	u64 typer = gic_read_typer(ptr + GICR_TYPER);
> +	gic_data.rdists.has_vlpis &= !!(typer & GICR_TYPER_VLPIS);
> +	gic_data.rdists.has_direct_lpi &= !!(typer & GICR_TYPER_DirectLPIS);
> +
> +	return 1;
> +}
> +
> +static void gic_update_vlpi_properties(void)
> +{
> +	gic_scan_rdist_properties(__gic_update_vlpi_properties);
> +	pr_info("%sVLPI support, %sdirect LPI support\n",
> +		!gic_data.rdists.has_vlpis ? "no " : "",
> +		!gic_data.rdists.has_direct_lpi ? "no " : "");
> +}
> +
>  static void gic_cpu_sys_reg_init(void)
>  {
>  	/*
> @@ -975,6 +993,8 @@ static int __init gic_init_bases(void __iomem *dist_base,
>  	gic_data.domain = irq_domain_create_tree(handle, &gic_irq_domain_ops,
>  						 &gic_data);
>  	gic_data.rdists.rdist = alloc_percpu(typeof(*gic_data.rdists.rdist));
> +	gic_data.rdists.has_vlpis = true;
> +	gic_data.rdists.has_direct_lpi = true;
>  
>  	if (WARN_ON(!gic_data.domain) || WARN_ON(!gic_data.rdists.rdist)) {
>  		err = -ENOMEM;
> @@ -983,6 +1003,8 @@ static int __init gic_init_bases(void __iomem *dist_base,
>  
>  	set_handle_irq(gic_handle_irq);
>  
> +	gic_update_vlpi_properties();
> +
>  	if (IS_ENABLED(CONFIG_ARM_GIC_V3_ITS) && gic_dist_supports_lpis())
>  		its_init(handle, &gic_data.rdists, gic_data.domain);
>  
> diff --git a/include/linux/irqchip/arm-gic-v3.h b/include/linux/irqchip/arm-gic-v3.h
> index e808f8a..b162bfa 100644
> --- a/include/linux/irqchip/arm-gic-v3.h
> +++ b/include/linux/irqchip/arm-gic-v3.h
> @@ -200,6 +200,7 @@
>  
>  #define GICR_TYPER_PLPIS		(1U << 0)
>  #define GICR_TYPER_VLPIS		(1U << 1)
> +#define GICR_TYPER_DirectLPIS		(1U << 3)
>  #define GICR_TYPER_LAST			(1U << 4)
>  
>  #define GIC_V3_REDIST_SIZE		0x20000
> @@ -427,6 +428,8 @@ struct rdists {
>  	struct page		*prop_page;
>  	int			id_bits;
>  	u64			flags;
> +	bool			has_vlpis;
> +	bool			has_direct_lpi;
>  };
>  
>  struct irq_domain;
>