[PATCH v2] irqchip/gic-v3: Print a warning for out-of-range interrupt numbers

Geert Uytterhoeven
2026-03-06T12:13:44Z

gic_irq_domain_translate() does not check if an interrupt number lies
within the valid range of the specified interrupt type. Add these
checks, and print a warning if the interrupt number is out of range.

This can help flagging incorrectly described Extended SPI and PPI
interrupts in DT.

Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
---
This would have prevented the issue fixed by "[PATCH] arm64: dts:
renesas: r8a78000: Fix out-of-range SPI interrupt numbers"[1].

v2:
- Fix off-by-one error in PPI range check.

[1] https://lore.kernel.org/1f9dd274720ea1b66617a5dd84f76c3efc829dc8.1772641415.git.geert+renesas@glider.be/
---
drivers/irqchip/irq-gic-v3.c | 12 ++++++++++++
1 file changed, 12 insertions(+)

diff --git a/drivers/irqchip/irq-gic-v3.c b/drivers/irqchip/irq-gic-v3.c
index 20f13b686ab22faf..9e97505d4b767043 100644
--- a/drivers/irqchip/irq-gic-v3.c
+++ b/drivers/irqchip/irq-gic-v3.c
@@ -1603,15 +1603,27 @@ static int gic_irq_domain_translate(struct irq_domain *d,

switch (fwspec->param[0]) {
case 0: /* SPI */
+ if (fwspec->param[1] > 987)
+ pr_warn_once("SPI %u out of range (use ESPI?)\n",
+ fwspec->param[1]);
*hwirq = fwspec->param[1] + 32;
break;
case 1: /* PPI */
+ if (fwspec->param[1] > 15)
+ pr_warn_once("PPI %u out of range (use EPPI?)\n",
+ fwspec->param[1]);
*hwirq = fwspec->param[1] + 16;
break;
case 2: /* ESPI */
+ if (fwspec->param[1] > 1023)
+ pr_warn_once("ESPI %u out of range\n",
+ fwspec->param[1]);
*hwirq = fwspec->param[1] + ESPI_BASE_INTID;
break;
case 3: /* EPPI */
+ if (fwspec->param[1] > 63)
+ pr_warn_once("EPPI %u out of range\n",
+ fwspec->param[1]);
*hwirq = fwspec->param[1] + EPPI_BASE_INTID;
break;
case GIC_IRQ_TYPE_LPI: /* LPI */
--
2.43.0