Dec 4, 2024 · Fundamentals

Understanding Linux Interrupt Number Mapping Mechanism

This article explores the Linux kernel's interrupt management architecture, detailing how hardware interrupt IDs are mapped to software IRQ numbers through the irq_domain structure, GIC controller design, and various mapping strategies such as linear, radix‑tree, and no‑map approaches.

Device TreeIRQ MappingInterrupts

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Understanding Linux Interrupt Number Mapping Mechanism

OPPO Kernel Craftsman

May 20, 2022 · Fundamentals

Linux Kernel Interrupt Mapping: Hardware and Software IRQ Translation Process

The article explains how the Linux kernel translates ARM GIC hardware interrupt numbers into virtual software IRQs by maintaining a global bitmap, initializing the interrupt controller, using irq_domain structures to map and associate hwirq and virq values, and storing relationships in descriptor and revmap trees for efficient lookup.

Device TreeIRQ Mappinggic

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Linux Kernel Interrupt Mapping: Hardware and Software IRQ Translation Process