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

[Tomasz Nowicki]

On 10.02.2016 12:46, Marc Zyngier wrote:
> 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@xxxxxxxxxxxx>
> > Signed-off-by: Hanjun Guo <hanjun.guo@xxxxxxxxxx>
> > ---
> >   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.

Right, I will address all your comments in the next ITS-only series.

Tomasz