Re: [PATCH v2 05/25] irqchip/gic-v3: Add FW info retrieval support
From: Jonathan Cameron <jonathan.cameron@huawei.com>
Date: 2025-09-16 15:34:18
Also in:
linux-acpi, lkml
On Mon, 15 Sep 2025 09:56:42 +0100 Marc Zyngier [off-list ref] wrote:
Plug the new .get_info() callback into the GICv3 core driver, using some of the existing PPI affinity handling infrastructure. Signed-off-by: Marc Zyngier <maz@kernel.org>
Hi Marc, Yet another trivial comment. It's one of those days it seems :)
quoted hunk ↗ jump to hunk
--- 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..71c278ddd1e39 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_node_to_fwnode(of_find_node_by_phandle(fwspec->param[3]));
of_node_to_fwnode() has a note that says it'll be removed in the merge window. It was enough of an oddity I wondered why it existed. Of course it did say it would be removed in the previous merge window and wasn't... Probably want of_fwnode_handle()
+ 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;