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

From: [email-masked] (Tomasz Nowicki)
Date: Fri, 12 Feb 2016 11:14:46 +0100

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 <[email-masked]>
>> Signed-off-by: Hanjun Guo <[email-masked]>
>> ---
>>   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