Re: [PATCH V3 08/10] irqchip, gicv3, its: Probe ITS in the ACPI way.

[Marc Zyngier <marc.zyngier@arm.com>]

On 19/01/16 13:11, Tomasz Nowicki wrote:
> Since we prepared ITS for being initialized different that via DT,
> it is now possible to parse MADT and pass mandatory info to
> firmware-agnostic ITS init call.
> 
> Note that we are using here IORT lib to keep track of allocated
> domain handler which will be used to build PCI MSI domain on top
> in the later patches.
> 
> Signed-off-by: Tomasz Nowicki <tn@semihalf.com>
> Signed-off-by: Hanjun Guo <hanjun.guo@linaro.org>
> ---
>  drivers/irqchip/irq-gic-v3-its.c | 57 +++++++++++++++++++++++++++++++++++++++-
>  1 file changed, 56 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/irqchip/irq-gic-v3-its.c b/drivers/irqchip/irq-gic-v3-its.c
> index fecb7a6..42f378a 100644
> --- a/drivers/irqchip/irq-gic-v3-its.c
> +++ b/drivers/irqchip/irq-gic-v3-its.c
> @@ -15,10 +15,13 @@
>   * along with this program.  If not, see <http://www.gnu.org/licenses/>.
>   */
>  
> +#include <linux/acpi.h>
>  #include <linux/bitmap.h>
>  #include <linux/cpu.h>
>  #include <linux/delay.h>
>  #include <linux/interrupt.h>
> +#include <linux/irqdomain.h>
> +#include <linux/iort.h>
>  #include <linux/log2.h>
>  #include <linux/mm.h>
>  #include <linux/msi.h>
> @@ -1272,6 +1275,11 @@ static int its_irq_gic_domain_alloc(struct irq_domain *domain,
>  		fwspec.param[0] = GIC_IRQ_TYPE_LPI;
>  		fwspec.param[1] = hwirq;
>  		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;
>  	}
> @@ -1594,6 +1602,52 @@ int its_cpu_init(void)
>  	return 0;
>  }
>  
> +#ifdef CONFIG_ACPI
> +
> +#define ACPI_GICV3_ITS_MEM_SIZE (2 * SZ_64K)
> +
> +static struct irq_domain *its_parent __initdata;
> +
> +static int __init
> +gic_acpi_parse_madt_its(struct acpi_subtable_header *header,
> +			const unsigned long end)
> +{
> +	struct acpi_madt_generic_translator *its_entry;
> +	struct fwnode_handle *domain_handle;
> +	int err;
> +
> +	its_entry = (struct acpi_madt_generic_translator *)header;
> +	domain_handle = irq_domain_alloc_fwnode((void *)its_entry->base_address);
> +	if (!domain_handle) {
> +		pr_err("Unable to allocate GICv2m domain token\n");

-ECOPYPASTE.

> +		return -ENOMEM;
> +	}
> +
> +	/* ITS works as msi controller in ACPI case */
> +	err = its_probe_one(its_entry->base_address, ACPI_GICV3_ITS_MEM_SIZE,
> +			    its_parent, true, domain_handle);
> +	if (err) {
> +		irq_domain_free_fwnode(domain_handle);
> +		return err;
> +	}
> +	iort_register_domain_token(its_entry->translation_id, domain_handle);

And what if this fails?

> +	return 0;
> +}
> +
> +void __init its_acpi_probe(struct irq_domain *parent_domain)
> +{
> +	int count;
> +
> +	its_parent = parent_domain;
> +	count = acpi_table_parse_madt(ACPI_MADT_TYPE_GENERIC_TRANSLATOR,
> +				      gic_acpi_parse_madt_its, 0);
> +	if (count <= 0)
> +		pr_info("No valid GIC ITS entries exist\n");
> +}
> +#else
> +static inline void __init its_acpi_probe(struct irq_domain *parent_domain) { }
> +#endif
> +
>  static struct of_device_id its_device_id[] = {
>  	{	.compatible	= "arm,gic-v3-its",	},
>  	{},
> @@ -1610,7 +1664,8 @@ int __init its_init(struct fwnode_handle *handle, struct rdists *rdists,
>  		     np = of_find_matching_node(np, its_device_id)) {
>  			its_of_probe(np, parent_domain);
>  		}
> -	}
> +	} else
> +		its_acpi_probe(parent_domain);

Missing braces.

>  
>  	if (list_empty(&its_nodes)) {
>  		pr_warn("ITS: No ITS available, not enabling LPIs\n");
> 

Thanks,

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