[PATCH v3 05/26] irqchip/gic-v3: Add FW info retrieval support

Marc Zyngier
2025-09-22T08:28:45Z

Plug the new .get_fwspec_info() callback into the GICv3 core driver,
using some of the existing PPI affinity handling infrastructure.

Signed-off-by: Marc Zyngier <maz@kernel.org>
---
drivers/irqchip/irq-gic-v3.c | 53 ++++++++++++++++++++++++++++++++++++
1 file changed, 53 insertions(+)

diff --git a/drivers/irqchip/irq-gic-v3.c b/drivers/irqchip/irq-gic-v3.c
index dbeb85677b08c..23ef0c285f30b 100644
--- a/drivers/irqchip/irq-gic-v3.c
+++ b/drivers/irqchip/irq-gic-v3.c
@@ -69,6 +69,8 @@ struct gic_chip_data {
bool has_rss;
unsigned int ppi_nr;
struct partition_desc **ppi_descs;
+ struct partition_affinity *parts;
+ unsigned int nr_parts;
};

#define T241_CHIPS_MAX 4
@@ -1796,11 +1798,58 @@ static int gic_irq_domain_select(struct irq_domain *d,
return d == partition_get_domain(gic_data.ppi_descs[ppi_idx]);
}

+static int gic_irq_get_fwspec_info(struct irq_fwspec *fwspec, struct irq_fwspec_info *info)
+{
+ const struct cpumask *mask = NULL;
+
+ info->flags = 0;
+ info->affinity = NULL;
+
+ /* ACPI is not capable of describing PPI affinity -- yet */
+ if (!is_of_node(fwspec->fwnode))
+ return 0;
+
+ /* If the specifier provides an affinity, use it */
+ if (fwspec->param_count == 4 && fwspec->param[3]) {
+ struct fwnode_handle *fw;
+
+ switch (fwspec->param[0]) {
+ case 1: /* PPI */
+ case 3: /* EPPI */
+ break;
+ default:
+ return 0;
+ }
+
+ fw = of_fwnode_handle(of_find_node_by_phandle(fwspec->param[3]));
+ if (!fw)
+ return -ENOENT;
+
+ for (int i = 0; i < gic_data.nr_parts; i++) {
+ if (gic_data.parts[i].partition_id == fw) {
+ mask = &gic_data.parts[i].mask;
+ break;
+ }
+ }
+
+ if (!mask)
+ return -ENOENT;
+ } else {
+ mask = cpu_possible_mask;
+ }
+
+ info->affinity = mask;
+ info->flags = IRQ_FWSPEC_INFO_AFFINITY_VALID;
+
+ return 0;
+}
+
static const struct irq_domain_ops gic_irq_domain_ops = {
.translate = gic_irq_domain_translate,
.alloc = gic_irq_domain_alloc,
.free = gic_irq_domain_free,
.select = gic_irq_domain_select,
+ .get_fwspec_info = gic_irq_get_fwspec_info,
};

static int partition_domain_translate(struct irq_domain *d,
@@ -1839,6 +1888,7 @@ static int partition_domain_translate(struct irq_domain *d,
static const struct irq_domain_ops partition_domain_ops = {
.translate = partition_domain_translate,
.select = gic_irq_domain_select,
+ .get_fwspec_info = gic_irq_get_fwspec_info,
};

static bool gic_enable_quirk_msm8996(void *data)
@@ -2231,6 +2281,9 @@ static void __init gic_populate_ppi_partitions(struct device_node *gic_node)
part_idx++;
}

+ gic_data.parts = parts;
+ gic_data.nr_parts = nr_parts;
+
for (i = 0; i < gic_data.ppi_nr; i++) {
unsigned int irq;
struct partition_desc *desc;
--
2.47.3