Re: [PATCH v6 4/4] gicv2m: acpi: Introducing GICv2m ACPI support

[Marc Zyngier]

On 09/12/15 19:24, Suravee Suthikulpanit wrote:
> This patch introduces gicv2m_acpi_init(), which uses information
> in MADT GIC MSI frames structure to initialize GICv2m driver.
> It also exposes gicv2m_init() function, which simplifies callers
> to a single GICv2m init function.
> 
> Signed-off-by: Suravee Suthikulpanit <Suravee.Suthikulpanit@xxxxxxx>
> Signed-off-by: Hanjun Guo <hanjun.guo@xxxxxxxxxx>
> ---
>  drivers/irqchip/irq-gic-v2m.c   | 114 +++++++++++++++++++++++++++++++++++++++-
>  drivers/irqchip/irq-gic.c       |   6 ++-
>  include/linux/irqchip/arm-gic.h |   3 +-
>  3 files changed, 120 insertions(+), 3 deletions(-)
> 
> diff --git a/drivers/irqchip/irq-gic-v2m.c b/drivers/irqchip/irq-gic-v2m.c
> index 779c390..e01a495 100644
> --- a/drivers/irqchip/irq-gic-v2m.c
> +++ b/drivers/irqchip/irq-gic-v2m.c
> @@ -15,9 +15,11 @@
>  
>  #define pr_fmt(fmt) "GICv2m: " fmt
>  
> +#include <linux/acpi.h>
>  #include <linux/irq.h>
>  #include <linux/irqdomain.h>
>  #include <linux/kernel.h>
> +#include <linux/msi.h>
>  #include <linux/of_address.h>
>  #include <linux/of_pci.h>
>  #include <linux/slab.h>
> @@ -138,6 +140,11 @@ static int gicv2m_irq_gic_domain_alloc(struct irq_domain *domain,
>  		fwspec.param[0] = 0;
>  		fwspec.param[1] = hwirq - 32;
>  		fwspec.param[2] = IRQ_TYPE_EDGE_RISING;
> +	} else if (is_fwnode_irqchip(domain->parent->fwnode)) {
> +		fwspec.fwnode = domain->parent->fwnode;
> +		fwspec.param_count = 2;
> +		fwspec.param[0] = hwirq;
> +		fwspec.param[1] = IRQ_TYPE_EDGE_RISING;
>  	} else {
>  		return -EINVAL;
>  	}
> @@ -255,6 +262,8 @@ static void gicv2m_teardown(void)
>  		kfree(v2m->bm);
>  		iounmap(v2m->base);
>  		of_node_put(to_of_node(v2m->fwnode));
> +		if (is_fwnode_irqchip(v2m->fwnode))
> +			irq_domain_free_fwnode(v2m->fwnode);
>  		kfree(v2m);
>  	}
>  }
> @@ -373,11 +382,16 @@ static struct of_device_id gicv2m_device_id[] = {
>  	{},
>  };
>  
> -int __init gicv2m_of_init(struct device_node *node, struct irq_domain *parent)
> +static int __init gicv2m_of_init(struct fwnode_handle *parent_handle,
> +				 struct irq_domain *parent)
>  {
>  	int ret = 0;
> +	struct device_node *node = to_of_node(parent_handle);
>  	struct device_node *child;
>  
> +	if (!node)
> +		return -EINVAL;
> +

I don't think we need this, see below.

>  	for (child = of_find_matching_node(node, gicv2m_device_id); child;
>  	     child = of_find_matching_node(child, gicv2m_device_id)) {
>  		u32 spi_start = 0, nr_spis = 0;
> @@ -411,3 +425,101 @@ int __init gicv2m_of_init(struct device_node *node, struct irq_domain *parent)
>  		gicv2m_teardown();
>  	return ret;
>  }
> +
> +#ifdef CONFIG_ACPI
> +static int acpi_num_msi;
> +
> +static struct fwnode_handle *gicv2m_get_fwnode(struct device *dev)
> +{
> +	struct v2m_data *data;
> +
> +	if (WARN_ON(acpi_num_msi <= 0))
> +		return NULL;
> +
> +	/* We only return the fwnode of the first MSI frame. */
> +	data = list_first_entry_or_null(&v2m_nodes, struct v2m_data, entry);
> +	if (!data)
> +		return NULL;
> +
> +	return data->fwnode;
> +}
> +
> +static int __init
> +acpi_parse_madt_msi(struct acpi_subtable_header *header,
> +		    const unsigned long end)
> +{
> +	int ret;
> +	struct resource res;
> +	u32 spi_start = 0, nr_spis = 0;
> +	struct acpi_madt_generic_msi_frame *m;
> +	struct fwnode_handle *fwnode;
> +
> +	m = (struct acpi_madt_generic_msi_frame *)header;
> +	if (BAD_MADT_ENTRY(m, end))
> +		return -EINVAL;
> +
> +	res.start = m->base_address;
> +	res.end = m->base_address + SZ_4K;
> +
> +	if (m->flags & ACPI_MADT_OVERRIDE_SPI_VALUES) {
> +		spi_start = m->spi_base;
> +		nr_spis = m->spi_count;
> +
> +		pr_info("ACPI overriding V2M MSI_TYPER (base:%u, num:%u)\n",
> +			spi_start, nr_spis);
> +	}
> +
> +	fwnode = irq_domain_alloc_fwnode((void *)m->base_address);
> +	if (!fwnode) {
> +		pr_err("Unable to allocate GICv2m domain token\n");
> +		return -EINVAL;
> +	}
> +
> +	ret = gicv2m_init_one(fwnode, spi_start, nr_spis, &res);
> +	if (ret)
> +		irq_domain_free_fwnode(fwnode);
> +
> +	return ret;
> +}
> +
> +static int __init gicv2m_acpi_init(struct irq_domain *parent)
> +{
> +	int ret;
> +
> +	if (acpi_num_msi > 0)
> +		return 0;
> +
> +	acpi_num_msi = acpi_table_parse_madt(ACPI_MADT_TYPE_GENERIC_MSI_FRAME,
> +				      acpi_parse_madt_msi, 0);
> +
> +	if (acpi_num_msi <= 0)
> +		goto err_out;
> +
> +	ret = gicv2m_allocate_domains(parent);
> +	if (ret)
> +		goto err_out;
> +
> +	pci_msi_register_fwnode_provider(&gicv2m_get_fwnode);
> +
> +	return 0;
> +
> +err_out:
> +	gicv2m_teardown();
> +	return -EINVAL;
> +}
> +#else /* CONFIG_ACPI */
> +static int __init gicv2m_acpi_init(struct irq_domain *parent)
> +{
> +	return -EINVAL;
> +}
> +#endif /* CONFIG_ACPI */
> +
> +int __init gicv2m_init(struct fwnode_handle *parent_handle,
> +		       struct irq_domain *parent)
> +{
> +	int ret = gicv2m_of_init(parent_handle, parent);
> +
> +	if (ret)
> +		ret = gicv2m_acpi_init(parent);
> +	return ret;

This should really read:

	if (is_of_node(parent_handle))
		return gicv2m_of_init(parent_handle, parent);
	
	return gicv2m_acpi_init(parent);

and you can loose the test for NULL in gicv2m_of_init().

> +}
> diff --git a/drivers/irqchip/irq-gic.c b/drivers/irqchip/irq-gic.c
> index fcd327f..644e8bb 100644
> --- a/drivers/irqchip/irq-gic.c
> +++ b/drivers/irqchip/irq-gic.c
> @@ -1234,7 +1234,7 @@ gic_of_init(struct device_node *node, struct device_node *parent)
>  	}
>  
>  	if (IS_ENABLED(CONFIG_ARM_GIC_V2M))
> -		gicv2m_of_init(node, gic_data[gic_cnt].domain);
> +		gicv2m_init(&node->fwnode, gic_data[gic_cnt].domain);
>  
>  	gic_cnt++;
>  	return 0;
> @@ -1359,6 +1359,10 @@ static int __init gic_v2_acpi_init(struct acpi_subtable_header *header,
>  	__gic_init_bases(0, -1, dist_base, cpu_base, 0, domain_handle);
>  
>  	acpi_set_irq_model(ACPI_IRQ_MODEL_GIC, domain_handle);
> +
> +	if (IS_ENABLED(CONFIG_ARM_GIC_V2M))
> +		gicv2m_init(NULL, gic_data[0].domain);
> +
>  	return 0;
>  }
>  IRQCHIP_ACPI_DECLARE(gic_v2, ACPI_MADT_TYPE_GENERIC_DISTRIBUTOR,
> diff --git a/include/linux/irqchip/arm-gic.h b/include/linux/irqchip/arm-gic.h
> index bae69e5..febc6c3 100644
> --- a/include/linux/irqchip/arm-gic.h
> +++ b/include/linux/irqchip/arm-gic.h
> @@ -106,7 +106,8 @@ int gic_cpu_if_down(unsigned int gic_nr);
>  void gic_init(unsigned int nr, int start,
>  	      void __iomem *dist , void __iomem *cpu);
>  
> -int gicv2m_of_init(struct device_node *node, struct irq_domain *parent);
> +int gicv2m_init(struct fwnode_handle *parent_handle,
> +		struct irq_domain *parent);
>  
>  void gic_send_sgi(unsigned int cpu_id, unsigned int irq);
>  int gic_get_cpu_id(unsigned int cpu);
> 

Apart from the fairly minor issue above:

Reviewed-by: Marc Zyngier <marc.zyngier@xxxxxxx>

	M.
-- 
Jazz is not dead. It just smells funny...
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