Re: [PATCH V4 5/7] irqchip, gicv3, its: Probe ITS in the ACPI way.

From: Marc Zyngier
Date: Thu Apr 14 2016 - 05:01:17 EST


On 04/04/16 09:52, Tomasz Nowicki wrote:
> ITS is prepared for being initialized different than DT,
> therefore we can initialize it in ACPI way. We collect register base
> address from MADT table and pass mandatory info to firmware-agnostic
> ITS init call.
>
> Note that we are using here IORT lib to register ITS domain which
> then can be found and used to build another PCI MSI domain
> in hierarchical stack domain.
>
> Signed-off-by: Tomasz Nowicki <tn@xxxxxxxxxxxx>
> ---
> drivers/irqchip/irq-gic-v3-its.c | 61 ++++++++++++++++++++++++++++++++++++++++
> 1 file changed, 61 insertions(+)
>
> diff --git a/drivers/irqchip/irq-gic-v3-its.c b/drivers/irqchip/irq-gic-v3-its.c
> index 2dcc7b4..a277c9b 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>
> @@ -1277,6 +1280,11 @@ 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;
> }
> @@ -1617,6 +1625,57 @@ its_of_probe(struct device_node *node, struct irq_domain *parent)
> return 0;
> }
>
> +#ifdef CONFIG_ACPI
> +
> +#define ACPI_GICV3_ITS_MEM_SIZE (2 * SZ_64K)
> +
> +static struct irq_domain *its_parent __initdata;

Given that there is only one of those, maybe it is worth making it
common to DT and ACPI, and drop the parameter from its_probe_one.

> +
> +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 GICv3 ITS domain token\n");
> + return -ENOMEM;
> + }
> +
> + err = iort_register_domain_token(its_entry->translation_id, domain_handle);
> + if (err) {
> + irq_domain_free_fwnode(domain_handle);
> + goto out;
> + }
> +
> + err = its_probe_one(its_entry->base_address, ACPI_GICV3_ITS_MEM_SIZE,
> + its_parent, domain_handle);

struct resource.

> + if (err) {
> + iort_deregister_domain_token(its_entry->translation_id);
> + irq_domain_free_fwnode(domain_handle);
> + }
> +out:
> + return err;
> +}
> +
> +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
> +
> int __init its_init(struct fwnode_handle *handle, struct rdists *rdists,
> struct irq_domain *parent_domain)
> {
> @@ -1625,6 +1684,8 @@ int __init its_init(struct fwnode_handle *handle, struct rdists *rdists,
> of_node = to_of_node(handle);
> if (of_node)
> its_of_probe(of_node, parent_domain);
> + else
> + its_acpi_probe(parent_domain);
>
> 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...