Re: [PATCH v3 6/9] irqchip/gic-v3: Parse and export virtual GIC information

[Graeme Gregory <gg@slimlogic.co.uk>]

On Tue, Mar 08, 2016 at 11:29:30AM +0000, Julien Grall wrote:
> Fill up the recently introduced gic_kvm_info with the virtual GIC
> information.
> 
> Signed-off-by: Julien Grall <julien.grall@arm.com>
> Cc: Thomas Gleixner <tglx@linutronix.de>
> Cc: Jason Cooper <jason@lakedaemon.net>
> Cc: Marc Zyngier <marc.zyngier@arm.com>
> 
> ---
>     Changes in v3:
>         - Add ACPI support
> 
>     Changes in v2:
>         - Use 0 rather than a negative value to know when the maintenance IRQ
>         is not present.
>         - Use resource for vcpu and vctrl
> ---
>  drivers/irqchip/irq-gic-v3.c           | 85 +++++++++++++++++++++++++++++++++-
>  include/linux/irqchip/arm-gic-common.h |  1 +
>  2 files changed, 85 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/irqchip/irq-gic-v3.c b/drivers/irqchip/irq-gic-v3.c
> index 50e87e6..6ae25120 100644
> --- a/drivers/irqchip/irq-gic-v3.c
> +++ b/drivers/irqchip/irq-gic-v3.c
> @@ -28,6 +28,7 @@
>  #include <linux/slab.h>
>  
>  #include <linux/irqchip.h>
> +#include <linux/irqchip/arm-gic-common.h>
>  #include <linux/irqchip/arm-gic-v3.h>
>  
>  #include <asm/cputype.h>
> @@ -56,6 +57,8 @@ struct gic_chip_data {
>  static struct gic_chip_data gic_data __read_mostly;
>  static struct static_key supports_deactivate = STATIC_KEY_INIT_TRUE;
>  
> +static struct gic_kvm_info gic_v3_kvm_info;
> +
>  #define gic_data_rdist()		(this_cpu_ptr(gic_data.rdists.rdist))
>  #define gic_data_rdist_rd_base()	(gic_data_rdist()->rd_base)
>  #define gic_data_rdist_sgi_base()	(gic_data_rdist_rd_base() + SZ_64K)
> @@ -901,6 +904,37 @@ static int __init gic_validate_dist_version(void __iomem *dist_base)
>  	return 0;
>  }
>  
> +static void __init gic_of_setup_kvm_info(struct device_node *node)
> +{
> +	int ret;
> +	struct resource r;
> +	u32 gicv_idx;
> +
> +	gic_v3_kvm_info.type = GIC_V3;
> +
> +	gic_v3_kvm_info.maint_irq = irq_of_parse_and_map(node, 0);
> +
> +	if (of_property_read_u32(node, "#redistributor-regions",
> +				 &gicv_idx))
> +		gicv_idx = 1;
> +
> +	gicv_idx += 3;	/* Also skip GICD, GICC, GICH */
> +	ret = of_address_to_resource(node, gicv_idx, &r);
> +	if (!ret) {
> +		if (!PAGE_ALIGNED(r.start))
> +			pr_warn("GICV physical address 0x%llx not page aligned\n",
> +				(unsigned long long)r.start);
> +		else if (!PAGE_ALIGNED(resource_size(&r)))
> +			pr_warn("GICV size 0x%llx not a multiple of page size 0x%lx\n",
> +				(unsigned long long)resource_size(&r),
> +				PAGE_SIZE);
> +		else
> +			gic_v3_kvm_info.vcpu = r;
> +	}
> +
> +	gic_set_kvm_info(&gic_v3_kvm_info);
> +}
> +
>  static int __init gic_of_init(struct device_node *node, struct device_node *parent)
>  {
>  	void __iomem *dist_base;
> @@ -952,8 +986,10 @@ static int __init gic_of_init(struct device_node *node, struct device_node *pare
>  
>  	err = gic_init_bases(dist_base, rdist_regs, nr_redist_regions,
>  			     redist_stride, &node->fwnode);
> -	if (!err)
> +	if (!err) {
> +		gic_of_setup_kvm_info(node);
>  		return 0;
> +	}
>  
>  out_unmap_rdist:
>  	for (i = 0; i < nr_redist_regions; i++)
> @@ -974,6 +1010,10 @@ static struct
>  	struct redist_region *redist_regs;
>  	u32 nr_redist_regions;
>  	bool single_redist;
> +	u32 maint_irq;
> +	int maint_irq_mode;
> +	phys_addr_t vctrl_base;
> +	phys_addr_t vcpu_base;
>  } acpi_data __initdata;
>  
>  static void __init
> @@ -1020,6 +1060,13 @@ gic_acpi_parse_madt_gicc(struct acpi_subtable_header *header,
>  		return -ENOMEM;
>  
>  	gic_acpi_register_redist(gicc->gicr_base_address, redist_base);
> +
> +	acpi_data.maint_irq = gicc->vgic_interrupt;
> +	acpi_data.maint_irq_mode = (gicc->flags & ACPI_MADT_VGIC_IRQ_MODE) ?
> +				    ACPI_EDGE_SENSITIVE : ACPI_LEVEL_SENSITIVE;
> +	acpi_data.vctrl_base = gicc->gich_base_address;
> +	acpi_data.vcpu_base = gicc->gicv_base_address;
> +
>  	return 0;
>  }

Placing this here means that it will not collect the info in the case
where there is a Generic Interrupt Redistributor structure in the MADT.

I guess collecting this info should not be a side effect of happening to
pass GICC for redistributor base. Which unfortuneately probably means we
do need to parse the GICCs specifically for this information.

Graeme

>  
> @@ -1111,6 +1158,40 @@ static bool __init acpi_validate_gic_table(struct acpi_subtable_header *header,
>  }
>  
>  #define ACPI_GICV3_DIST_MEM_SIZE (SZ_64K)
> +#define ACPI_GICV2_VCTRL_MEM_SIZE	(SZ_4K)
> +#define ACPI_GICV2_VCPU_MEM_SIZE	(SZ_8K)
> +
> +static void __init gic_acpi_setup_kvm_info(void)
> +{
> +	int irq;
> +
> +	gic_v3_kvm_info.type = GIC_V3;
> +
> +	irq = acpi_register_gsi(NULL, acpi_data.maint_irq,
> +				acpi_data.maint_irq_mode,
> +				ACPI_ACTIVE_HIGH);
> +	if (irq > 0)
> +		gic_v3_kvm_info.maint_irq = irq;
> +
> +	if (acpi_data.vctrl_base) {
> +		struct resource *vctrl = &gic_v3_kvm_info.vctrl;
> +
> +		vctrl->flags = IORESOURCE_MEM;
> +		vctrl->start = acpi_data.vctrl_base;
> +		vctrl->end = vctrl->start + ACPI_GICV2_VCTRL_MEM_SIZE - 1;
> +	}
> +
> +	if (acpi_data.vcpu_base) {
> +		struct resource *vcpu = &gic_v3_kvm_info.vcpu;
> +
> +		vcpu->flags = IORESOURCE_MEM;
> +		vcpu->start = acpi_data.vcpu_base;
> +		vcpu->end = vcpu->start + ACPI_GICV2_VCPU_MEM_SIZE - 1;
> +	}
> +
> +	gic_set_kvm_info(&gic_v3_kvm_info);
> +}
> +
>  
>  static int __init
>  gic_acpi_init(struct acpi_subtable_header *header, const unsigned long end)
> @@ -1159,6 +1240,8 @@ gic_acpi_init(struct acpi_subtable_header *header, const unsigned long end)
>  		goto out_fwhandle_free;
>  
>  	acpi_set_irq_model(ACPI_IRQ_MODEL_GIC, domain_handle);
> +	gic_acpi_setup_kvm_info();
> +
>  	return 0;
>  
>  out_fwhandle_free:
> diff --git a/include/linux/irqchip/arm-gic-common.h b/include/linux/irqchip/arm-gic-common.h
> index f7723b9..15d68c6 100644
> --- a/include/linux/irqchip/arm-gic-common.h
> +++ b/include/linux/irqchip/arm-gic-common.h
> @@ -15,6 +15,7 @@
>  
>  enum gic_type {
>  	GIC_V2,
> +	GIC_V3,
>  };
>  
>  struct gic_kvm_info {
> -- 
> 1.9.1
> 
> 
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