From 8582f0720f73c35784c9f23559ec19b6e2bfb9ad Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?S=C3=B6nke=20Holz?= <sholz8530@gmail.com>
Date: Thu, 18 Jan 2024 17:02:27 +0100
Subject: [PATCH] Kernel/riscv64: Make RISC-V Timer inherit from
 GenericInterruptHandler

IRQHandler is not the correct class to inherit from, as the timer
is not connected to an IRQController.
Each hart has one of these Timers directly connected to it.
---
 Kernel/Arch/riscv64/Timer.cpp | 29 +++++++++++++++++------------
 Kernel/Arch/riscv64/Timer.h   | 11 ++++-------
 2 files changed, 21 insertions(+), 19 deletions(-)

diff --git a/Kernel/Arch/riscv64/Timer.cpp b/Kernel/Arch/riscv64/Timer.cpp
index 84d3b68b56..ac252e472c 100644
--- a/Kernel/Arch/riscv64/Timer.cpp
+++ b/Kernel/Arch/riscv64/Timer.cpp
@@ -19,14 +19,16 @@ Timer::Timer()
     m_frequency = 10'000'000; // in Hz
 
     set_interrupt_interval_usec(m_frequency / OPTIMAL_TICKS_PER_SECOND_RATE);
-    enable_interrupt_mode();
-}
 
-Timer::~Timer() = default;
+    set_compare(microseconds_since_boot() + m_interrupt_interval);
+    RISCV64::CSR::set_bits(RISCV64::CSR::Address::SIE, 1 << interrupt_number());
+}
 
 NonnullLockRefPtr<Timer> Timer::initialize()
 {
-    return adopt_lock_ref(*new Timer);
+    auto timer = adopt_lock_ref(*new Timer);
+    timer->register_interrupt_handler();
+    return timer;
 }
 
 u64 Timer::microseconds_since_boot()
@@ -34,9 +36,9 @@ u64 Timer::microseconds_since_boot()
     return RISCV64::CSR::read(RISCV64::CSR::Address::TIME);
 }
 
-bool Timer::handle_irq(RegisterState const& regs)
+bool Timer::handle_interrupt(RegisterState const& regs)
 {
-    auto result = HardwareTimer::handle_irq(regs);
+    auto result = HardwareTimer::handle_interrupt(regs);
 
     set_compare(microseconds_since_boot() + m_interrupt_interval);
 
@@ -69,12 +71,6 @@ u64 Timer::update_time(u64& seconds_since_boot, u32& ticks_this_second, bool que
     return (delta_ticks * 1000000000ull) / ticks_per_second;
 }
 
-void Timer::enable_interrupt_mode()
-{
-    set_compare(microseconds_since_boot() + m_interrupt_interval);
-    enable_irq();
-}
-
 void Timer::set_interrupt_interval_usec(u32 interrupt_interval)
 {
     m_interrupt_interval = interrupt_interval;
@@ -87,3 +83,12 @@ void Timer::set_compare(u64 compare)
 }
 
 }
+
+namespace Kernel {
+
+bool HardwareTimer<GenericInterruptHandler>::eoi()
+{
+    return true;
+}
+
+}
diff --git a/Kernel/Arch/riscv64/Timer.h b/Kernel/Arch/riscv64/Timer.h
index 3988b833ab..55db7f1a25 100644
--- a/Kernel/Arch/riscv64/Timer.h
+++ b/Kernel/Arch/riscv64/Timer.h
@@ -7,7 +7,7 @@
 #pragma once
 
 #include <AK/Types.h>
-#include <Kernel/Interrupts/IRQHandler.h>
+#include <Kernel/Interrupts/GenericInterruptHandler.h>
 #include <Kernel/Library/NonnullLockRefPtr.h>
 #include <Kernel/Time/HardwareTimer.h>
 
@@ -15,10 +15,8 @@ namespace Kernel::RISCV64 {
 
 struct TimerRegisters;
 
-class Timer final : public HardwareTimer<IRQHandler> {
+class Timer final : public HardwareTimer<GenericInterruptHandler> {
 public:
-    virtual ~Timer();
-
     static NonnullLockRefPtr<Timer> initialize();
 
     virtual HardwareTimerType timer_type() const override { return HardwareTimerType::RISCVTimer; }
@@ -42,15 +40,14 @@ public:
     u64 microseconds_since_boot();
 
     void set_interrupt_interval_usec(u32);
-    void enable_interrupt_mode();
 
 private:
     Timer();
 
     void set_compare(u64 compare);
 
-    //^ IRQHandler
-    virtual bool handle_irq(RegisterState const&) override;
+    //^ GenericInterruptHandler
+    virtual bool handle_interrupt(RegisterState const&) override;
 
     u32 m_interrupt_interval { 0 };