Duckstation/src/core/interrupt_controller.cpp
2024-05-24 02:08:14 +10:00

120 lines
3.3 KiB
C++

// SPDX-FileCopyrightText: 2019-2024 Connor McLaughlin <stenzek@gmail.com>
// SPDX-License-Identifier: (GPL-3.0 OR CC-BY-NC-ND-4.0)
#include "interrupt_controller.h"
#include "cpu_core.h"
#include "util/state_wrapper.h"
#include "common/log.h"
Log_SetChannel(InterruptController);
namespace InterruptController {
static constexpr u32 REGISTER_WRITE_MASK = (u32(1) << NUM_IRQS) - 1;
static constexpr u32 DEFAULT_INTERRUPT_MASK = 0;
static void UpdateCPUInterruptRequest();
static u32 s_interrupt_status_register = 0;
static u32 s_interrupt_mask_register = DEFAULT_INTERRUPT_MASK;
static u32 s_interrupt_line_state = 0;
[[maybe_unused]] static constexpr std::array<const char*, static_cast<size_t>(IRQ::MaxCount)> s_irq_names = {
{"VBLANK", "GPU", "CDROM", "DMA", "TMR0", "TMR1", "TMR2", "PAD", "SIO", "SPU", "IRQ10"}};
} // namespace InterruptController
void InterruptController::Reset()
{
s_interrupt_status_register = 0;
s_interrupt_mask_register = DEFAULT_INTERRUPT_MASK;
s_interrupt_line_state = 0;
}
bool InterruptController::DoState(StateWrapper& sw)
{
sw.Do(&s_interrupt_status_register);
sw.Do(&s_interrupt_mask_register);
sw.DoEx(&s_interrupt_line_state, 63, s_interrupt_status_register);
return !sw.HasError();
}
void InterruptController::SetLineState(IRQ irq, bool state)
{
// Interupts are edge-triggered, so only set the flag in the status register on a 0-1 transition.
const u32 bit = (1u << static_cast<u32>(irq));
const u32 prev_state = s_interrupt_line_state;
s_interrupt_line_state = (s_interrupt_line_state & ~bit) | (state ? bit : 0u);
if (s_interrupt_line_state == prev_state)
return;
#ifdef _DEBUG
if (!(prev_state & bit) && state)
DEBUG_LOG("{} IRQ triggered", s_irq_names[static_cast<size_t>(irq)]);
else if ((prev_state & bit) && !state)
DEBUG_LOG("{} IRQ line inactive", s_irq_names[static_cast<size_t>(irq)]);
#endif
s_interrupt_status_register |= (state ? (prev_state ^ s_interrupt_line_state) : 0u) & s_interrupt_line_state;
UpdateCPUInterruptRequest();
}
u32 InterruptController::ReadRegister(u32 offset)
{
switch (offset)
{
case 0x00: // I_STATUS
return s_interrupt_status_register;
case 0x04: // I_MASK
return s_interrupt_mask_register;
[[unlikely]] default:
ERROR_LOG("Invalid read at offset 0x{:08X}", offset);
return UINT32_C(0xFFFFFFFF);
}
}
void InterruptController::WriteRegister(u32 offset, u32 value)
{
switch (offset)
{
case 0x00: // I_STATUS
{
#ifdef _DEBUG
const u32 cleared_bits = (s_interrupt_status_register & ~value);
for (u32 i = 0; i < static_cast<u32>(IRQ::MaxCount); i++)
{
if (cleared_bits & (1u << i))
DEBUG_LOG("{} IRQ cleared", s_irq_names[i]);
}
#endif
s_interrupt_status_register = s_interrupt_status_register & (value & REGISTER_WRITE_MASK);
UpdateCPUInterruptRequest();
}
break;
case 0x04: // I_MASK
{
DEBUG_LOG("Interrupt mask <- 0x{:08X}", value);
s_interrupt_mask_register = value & REGISTER_WRITE_MASK;
UpdateCPUInterruptRequest();
}
break;
default:
[[unlikely]] ERROR_LOG("Invalid write at offset 0x{:08X}", offset);
break;
}
}
ALWAYS_INLINE_RELEASE void InterruptController::UpdateCPUInterruptRequest()
{
const bool state = (s_interrupt_status_register & s_interrupt_mask_register) != 0;
CPU::SetIRQRequest(state);
}