Kernel/Interrupts: Return boolean on whether we handled the interrupt

If we are in a shared interrupt handler, the called handlers might
indicate it was not their interrupt, so we should not increment the
call counter of these handlers.

Kernel/Devices/HID/I8042Controller.cpp

@@ -129,25 +129,26 @@ UNMAP_AFTER_INIT void I8042Controller::detect_devices()
         m_mouse_device->enable_interrupts();
 }
 
-void I8042Controller::irq_process_input_buffer(HIDDevice::Type)
+bool I8042Controller::irq_process_input_buffer(HIDDevice::Type)
 {
     VERIFY(Processor::current().in_irq());
 
     u8 status = IO::in8(I8042_STATUS);
     if (!(status & I8042_BUFFER_FULL))
-        return;
+        return false;
     HIDDevice::Type data_for_device = ((status & I8042_WHICH_BUFFER) == I8042_MOUSE_BUFFER) ? HIDDevice::Type::Mouse : HIDDevice::Type::Keyboard;
     u8 byte = IO::in8(I8042_BUFFER);
     if (data_for_device == HIDDevice::Type::Mouse) {
         VERIFY(m_mouse_device);
         static_cast<PS2MouseDevice&>(*m_mouse_device).irq_handle_byte_read(byte);
-        return;
+        return true;
     }
     if (data_for_device == HIDDevice::Type::Keyboard) {
         VERIFY(m_keyboard_device);
         static_cast<PS2KeyboardDevice&>(*m_keyboard_device).irq_handle_byte_read(byte);
-        return;
+        return true;
     }
+    return false;
 }
 
 void I8042Controller::do_drain()

Kernel/Devices/HID/I8042Controller.h

@@ -89,7 +89,7 @@ public:
     void prepare_for_output();
     void prepare_for_input(HIDDevice::Type);
 
-    void irq_process_input_buffer(HIDDevice::Type);
+    bool irq_process_input_buffer(HIDDevice::Type);
 
     RefPtr<MouseDevice> mouse() const;
     RefPtr<KeyboardDevice> keyboard() const;

Kernel/Devices/HID/PS2KeyboardDevice.cpp

@@ -85,11 +85,11 @@ void PS2KeyboardDevice::irq_handle_byte_read(u8 byte)
     }
 }
 
-void PS2KeyboardDevice::handle_irq(const RegisterState&)
+bool PS2KeyboardDevice::handle_irq(const RegisterState&)
 {
     // The controller will read the data and call irq_handle_byte_read
     // for the appropriate device
-    m_i8042_controller->irq_process_input_buffer(HIDDevice::Type::Keyboard);
+    return m_i8042_controller->irq_process_input_buffer(HIDDevice::Type::Keyboard);
 }
 
 UNMAP_AFTER_INIT RefPtr<PS2KeyboardDevice> PS2KeyboardDevice::try_to_initialize(const I8042Controller& ps2_controller)

Kernel/Devices/HID/PS2KeyboardDevice.h

@@ -39,7 +39,7 @@ private:
     explicit PS2KeyboardDevice(const I8042Controller&);
 
     // ^IRQHandler
-    virtual void handle_irq(const RegisterState&) override;
+    virtual bool handle_irq(const RegisterState&) override;
 
     // ^CharacterDevice
     virtual const char* class_name() const override { return "KeyboardDevice"; }

Kernel/Devices/HID/PS2MouseDevice.cpp

@@ -40,11 +40,11 @@ UNMAP_AFTER_INIT PS2MouseDevice::~PS2MouseDevice()
 {
 }
 
-void PS2MouseDevice::handle_irq(const RegisterState&)
+bool PS2MouseDevice::handle_irq(const RegisterState&)
 {
     // The controller will read the data and call irq_handle_byte_read
     // for the appropriate device
-    m_i8042_controller->irq_process_input_buffer(instrument_type());
+    return m_i8042_controller->irq_process_input_buffer(instrument_type());
 }
 
 void PS2MouseDevice::irq_handle_byte_read(u8 byte)

Kernel/Devices/HID/PS2MouseDevice.h

@@ -35,7 +35,7 @@ public:
 protected:
     explicit PS2MouseDevice(const I8042Controller&);
     // ^IRQHandler
-    virtual void handle_irq(const RegisterState&) override;
+    virtual bool handle_irq(const RegisterState&) override;
 
     struct RawPacket {
         union {

Kernel/Devices/SB16.cpp

@@ -205,8 +205,10 @@ void SB16::dma_start(uint32_t length)
     IO::out8(0xd4, (channel % 4));
 }
 
-void SB16::handle_irq(const RegisterState&)
+bool SB16::handle_irq(const RegisterState&)
 {
+    // FIXME: Check if the interrupt was actually for us or not... (shared IRQs)
+
     // Stop sound output ready for the next block.
     dsp_write(0xd5);
 
@@ -215,6 +217,7 @@ void SB16::handle_irq(const RegisterState&)
         IO::in8(DSP_R_ACK); // 16 bit interrupt
 
     m_irq_queue.wake_all();
+    return true;
 }
 
 void SB16::wait_for_irq()

Kernel/Devices/SB16.h

@@ -40,7 +40,7 @@ public:
 
 private:
     // ^IRQHandler
-    virtual void handle_irq(const RegisterState&) override;
+    virtual bool handle_irq(const RegisterState&) override;
 
     // ^CharacterDevice
     virtual const char* class_name() const override { return "SB16"; }

Kernel/Devices/USB/UHCIController.cpp

@@ -586,13 +586,13 @@ void UHCIController::spawn_port_proc()
     });
 }
 
-void UHCIController::handle_irq(const RegisterState&)
+bool UHCIController::handle_irq(const RegisterState&)
 {
     u32 status = read_usbsts();
 
     // Shared IRQ. Not ours!
     if (!status)
-        return;
+        return false;
 
     if constexpr (UHCI_DEBUG) {
         dbgln("UHCI: Interrupt happened!");
@@ -601,6 +601,7 @@ void UHCIController::handle_irq(const RegisterState&)
 
     // Write back USBSTS to clear bits
     write_usbsts(status);
+    return true;
 }
 
 }

Kernel/Devices/USB/UHCIController.h

@@ -60,7 +60,7 @@ private:
     void write_portsc1(u16 value) { m_io_base.offset(0x10).out(value); }
     void write_portsc2(u16 value) { m_io_base.offset(0x12).out(value); }
 
-    virtual void handle_irq(const RegisterState&) override;
+    virtual bool handle_irq(const RegisterState&) override;
 
     void create_structures();
     void setup_schedule();