ladybird/Kernel/Interrupts/SpuriousInterruptHandler.cpp
Liav A 39c1783387 Kernel: Allow to install a real IRQ handler on a spurious one
IRQ 7 and 15 on the PIC architecture are used for spurious interrupts.
IRQ 7 could also be used for LPT connection, and IRQ 15 can be used for
the secondary IDE channel. Therefore, we need to allow to install a
real IRQ handler and check if a real IRQ was asserted. If so, we handle
them in the usual way.

A note on this fix - unregistering or registering a new IRQ handler
after we already registered one in the spurious interrupt handler is
not supported yet.
2020-12-21 00:19:21 +01:00

104 lines
3.6 KiB
C++

/*
* Copyright (c) 2020, Liav A. <liavalb@hotmail.co.il>
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
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*
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#include <Kernel/Interrupts/InterruptManagement.h>
#include <Kernel/Interrupts/SpuriousInterruptHandler.h>
namespace Kernel {
void SpuriousInterruptHandler::initialize(u8 interrupt_number)
{
new SpuriousInterruptHandler(interrupt_number);
}
void SpuriousInterruptHandler::register_handler(GenericInterruptHandler& handler)
{
ASSERT(!m_real_handler);
m_real_handler = &handler;
}
void SpuriousInterruptHandler::unregister_handler(GenericInterruptHandler&)
{
TODO();
}
bool SpuriousInterruptHandler::eoi()
{
// Actually check if IRQ7 or IRQ15 are spurious, and if not, call EOI with the correct interrupt number.
if (m_real_irq) {
m_responsible_irq_controller->eoi(*this);
m_real_irq = false; // return to default state!
return true;
}
m_responsible_irq_controller->spurious_eoi(*this);
return false;
}
SpuriousInterruptHandler::SpuriousInterruptHandler(u8 irq)
: GenericInterruptHandler(irq)
, m_responsible_irq_controller(InterruptManagement::the().get_responsible_irq_controller(irq))
{
}
SpuriousInterruptHandler::~SpuriousInterruptHandler()
{
}
void SpuriousInterruptHandler::handle_interrupt(const RegisterState& state)
{
// Actually check if IRQ7 or IRQ15 are spurious, and if not, call the real handler to handle the IRQ.
if (m_responsible_irq_controller->get_isr() & (1 << 15)) {
m_real_irq = true; // remember that we had a real IRQ, when EOI later!
m_real_handler->increment_invoking_counter();
m_real_handler->handle_interrupt(state);
return;
}
klog() << "Spurious Interrupt, vector " << interrupt_number();
}
void SpuriousInterruptHandler::enable_interrupt_vector()
{
if (m_enabled)
return;
m_enabled = true;
m_responsible_irq_controller->enable(*this);
}
void SpuriousInterruptHandler::disable_interrupt_vector()
{
ASSERT(!m_real_irq); // this flag should not be set when we call this method
if (!m_enabled)
return;
m_enabled = false;
m_responsible_irq_controller->disable(*this);
}
const char* SpuriousInterruptHandler::controller() const
{
if (m_responsible_irq_controller->type() == IRQControllerType::i82093AA)
return "";
return m_responsible_irq_controller->model();
}
}