Linux generic IRQ handling

Table of Contents

1. Introduction

2. Rationale

3. Known Bugs And Assumptions

4. Abstraction layers

Interrupt control flow

Highlevel Driver API

Highlevel IRQ flow handlers

Default flow implementations

Default flow handler implementations

Quirks and optimizations

Delayed interrupt disable

Chiplevel hardware encapsulation

5. __do_IRQ entry point

6. Locking on SMP

7. Structures

struct irq_data — per irq and irq chip data passed down to chip functions

struct irq_chip — hardware interrupt chip descriptor

struct irq_chip_regs — register offsets for struct irq_gci

struct irq_chip_type — Generic interrupt chip instance for a flow type

struct irq_chip_generic — Generic irq chip data structure

enum irq_gc_flags — Initialization flags for generic irq chips

struct irqaction — per interrupt action descriptor

struct irq_affinity_notify — context for notification of IRQ affinity changes

8. Public Functions Provided

synchronize_irq — wait for pending IRQ handlers (on other CPUs)

irq_set_affinity_notifier — control notification of IRQ affinity changes

disable_irq_nosync — disable an irq without waiting

disable_irq — disable an irq and wait for completion

enable_irq — enable handling of an irq

irq_set_irq_wake — control irq power management wakeup

setup_irq — setup an interrupt

remove_irq — free an interrupt

free_irq — free an interrupt allocated with request_irq

request_threaded_irq — allocate an interrupt line

request_any_context_irq — allocate an interrupt line

irq_set_chip — set the irq chip for an irq

irq_set_irq_type — set the irq trigger type for an irq

irq_set_handler_data — set irq handler data for an irq

irq_set_chip_data — set irq chip data for an irq

handle_simple_irq — Simple and software-decoded IRQs.

handle_level_irq — Level type irq handler

9. Internal Functions Provided

irq_reserve_irqs — mark irqs allocated

irq_get_next_irq — get next allocated irq number

dynamic_irq_cleanup — cleanup a dynamically allocated irq

handle_bad_irq — handle spurious and unhandled irqs

irq_set_msi_desc — set MSI descriptor data for an irq

handle_fasteoi_irq — irq handler for transparent controllers

handle_edge_irq — edge type IRQ handler

handle_edge_eoi_irq — edge eoi type IRQ handler

handle_percpu_irq — Per CPU local irq handler

irq_cpu_online — Invoke all irq_cpu_online functions.

irq_cpu_offline — Invoke all irq_cpu_offline functions.

10. Credits