Kernel: Remove the AllMiceDevice class

This device was a short-lived solution to allow userspace (WindowServer)
to easily support hotplugging mouse devices with presumably very small
modifications on userspace side.

Now that we have a proper mechanism to propagate hotplug events from the
DeviceMapper program to any program that needs to get such events, we no
longer need this device, so let's remove it.

Kernel/API/MajorNumberAllocation.h

@@ -24,7 +24,6 @@ enum class CharacterDeviceFamily : unsigned {
     Console = 5,
     Mouse = 10,
     FUSE = 11,
-    AllMice = 12,
     GPURender = 28,
     VirtualConsole = 35,
     Keyboard = 85,
@@ -42,7 +41,6 @@ static constexpr CharacterDeviceFamily s_character_device_numbers[] = {
     CharacterDeviceFamily::Console,
     CharacterDeviceFamily::Mouse,
     CharacterDeviceFamily::FUSE,
-    CharacterDeviceFamily::AllMice,
     CharacterDeviceFamily::GPURender,
     CharacterDeviceFamily::VirtualConsole,
     CharacterDeviceFamily::Keyboard,
@@ -85,8 +83,6 @@ ALWAYS_INLINE StringView character_device_family_to_string_view(CharacterDeviceF
         return "mouse"sv;
     case CharacterDeviceFamily::FUSE:
         return "fuse"sv;
-    case CharacterDeviceFamily::AllMice:
-        return "all-mice"sv;
     case CharacterDeviceFamily::GPURender:
         return "gpu-render"sv;
     case CharacterDeviceFamily::VirtualConsole:

Kernel/CMakeLists.txt

@@ -66,7 +66,6 @@ set(KERNEL_SOURCES
     Devices/FUSEDevice.cpp
     Devices/PCISerialDevice.cpp
     Devices/SerialDevice.cpp
-    Devices/HID/AllMiceDevice.cpp
     Devices/HID/KeyboardDevice.cpp
     Devices/HID/Management.cpp
     Devices/HID/MouseDevice.cpp

Kernel/Devices/HID/AllMiceDevice.cpp

@@ -1,58 +0,0 @@
-/*
- * Copyright (c) 2023, Liav A. <liavalb@hotmail.co.il>
- *
- * SPDX-License-Identifier: BSD-2-Clause
- */
-
-#include <Kernel/API/MajorNumberAllocation.h>
-#include <Kernel/Devices/DeviceManagement.h>
-#include <Kernel/Devices/HID/AllMiceDevice.h>
-#include <Kernel/Devices/HID/Management.h>
-
-namespace Kernel {
-
-NonnullRefPtr<AllMiceDevice> AllMiceDevice::must_create()
-{
-    return *MUST(DeviceManagement::try_create_device<AllMiceDevice>());
-}
-
-AllMiceDevice::AllMiceDevice()
-    : CharacterDevice(MajorAllocation::CharacterDeviceFamily::AllMice, 0)
-{
-}
-
-void AllMiceDevice::enqueue_mouse_packet(MousePacket packet)
-{
-    {
-        SpinlockLocker lock(m_queue_lock);
-        m_queue.enqueue(packet);
-    }
-    evaluate_block_conditions();
-}
-
-AllMiceDevice::~AllMiceDevice() = default;
-
-bool AllMiceDevice::can_read(OpenFileDescription const&, u64) const
-{
-    SpinlockLocker lock(m_queue_lock);
-    return !m_queue.is_empty();
-}
-
-ErrorOr<size_t> AllMiceDevice::read(OpenFileDescription&, u64, UserOrKernelBuffer& buffer, size_t size)
-{
-    VERIFY(size > 0);
-    size_t nread = 0;
-    size_t remaining_space_in_buffer = static_cast<size_t>(size) - nread;
-    SpinlockLocker lock(m_queue_lock);
-    while (!m_queue.is_empty() && remaining_space_in_buffer) {
-        auto packet = m_queue.dequeue();
-
-        size_t bytes_read_from_packet = min(remaining_space_in_buffer, sizeof(MousePacket));
-        TRY(buffer.write(&packet, nread, bytes_read_from_packet));
-        nread += bytes_read_from_packet;
-        remaining_space_in_buffer -= bytes_read_from_packet;
-    }
-    return nread;
-}
-
-}

Kernel/Devices/HID/AllMiceDevice.h

@@ -1,40 +0,0 @@
-/*
- * Copyright (c) 2023, Liav A. <liavalb@hotmail.co.il>
- *
- * SPDX-License-Identifier: BSD-2-Clause
- */
-
-#pragma once
-
-#include <AK/CircularQueue.h>
-#include <AK/Types.h>
-#include <Kernel/API/MousePacket.h>
-#include <Kernel/Devices/CharacterDevice.h>
-#include <Kernel/Security/Random.h>
-
-namespace Kernel {
-
-class AllMiceDevice final : public CharacterDevice {
-    friend class DeviceManagement;
-
-public:
-    static NonnullRefPtr<AllMiceDevice> must_create();
-
-    virtual ~AllMiceDevice() override;
-
-    void enqueue_mouse_packet(MousePacket packet);
-
-private:
-    AllMiceDevice();
-
-    // ^CharacterDevice
-    virtual StringView class_name() const override { return "AllMiceDevice"sv; }
-    virtual ErrorOr<size_t> read(OpenFileDescription&, u64, UserOrKernelBuffer&, size_t) override;
-    virtual bool can_read(OpenFileDescription const&, u64) const override;
-    virtual ErrorOr<size_t> write(OpenFileDescription&, u64, UserOrKernelBuffer const&, size_t) override { return EINVAL; }
-    virtual bool can_write(OpenFileDescription const&, u64) const override { return true; }
-
-    mutable Spinlock<LockRank::None> m_queue_lock {};
-    CircularQueue<MousePacket, 1000> m_queue;
-};
-}

Kernel/Devices/HID/Management.cpp

@@ -79,11 +79,6 @@ static constexpr Keyboard::CharacterMapData DEFAULT_CHARACTER_MAP =
 };
 // clang-format on
 
-void HIDManagement::enqueue_mouse_packet(Badge<MouseDevice>, MousePacket packet)
-{
-    m_all_mice_device->enqueue_mouse_packet(packet);
-}
-
 void HIDManagement::set_client(KeyboardClient* client)
 {
     SpinlockLocker locker(m_client_lock);
@@ -108,7 +103,6 @@ UNMAP_AFTER_INIT HIDManagement::KeymapData::KeymapData()
 }
 
 UNMAP_AFTER_INIT HIDManagement::HIDManagement()
-    : m_all_mice_device(AllMiceDevice::must_create())
 {
 }
 

Kernel/Devices/HID/Management.h

@@ -16,7 +16,6 @@
 #include <AK/Types.h>
 #include <Kernel/API/KeyCode.h>
 #include <Kernel/Bus/SerialIO/Controller.h>
-#include <Kernel/Devices/HID/AllMiceDevice.h>
 #include <Kernel/Devices/HID/Device.h>
 #include <Kernel/Locking/Spinlock.h>
 #include <Kernel/Locking/SpinlockProtected.h>
@@ -33,7 +32,6 @@ class KeyboardClient;
 class HIDManagement {
     friend class KeyboardDevice;
     friend class MouseDevice;
-    friend class AllMiceDevice;
 
 public:
     HIDManagement();
@@ -58,8 +56,6 @@ public:
     void attach_standalone_hid_device(HIDDevice&);
     void detach_standalone_hid_device(HIDDevice&);
 
-    void enqueue_mouse_packet(Badge<MouseDevice>, MousePacket);
-
 private:
     size_t generate_minor_device_number_for_mouse();
     size_t generate_minor_device_number_for_keyboard();
@@ -69,8 +65,6 @@ private:
     size_t m_keyboard_minor_number { 0 };
     KeyboardClient* m_client { nullptr };
 
-    NonnullRefPtr<AllMiceDevice> m_all_mice_device;
-
     SpinlockProtected<IntrusiveList<&SerialIOController::m_list_node>, LockRank::None> m_hid_serial_io_controllers;
     // NOTE: This list is used for standalone devices, like USB HID devices
     // (which are not attached via a SerialIO controller in the sense that

Kernel/Devices/HID/MouseDevice.cpp

@@ -24,7 +24,6 @@ MouseDevice::MouseDevice()
 void MouseDevice::handle_mouse_packet_input_event(MousePacket packet)
 {
     m_entropy_source.add_random_event(packet);
-    HIDManagement::the().enqueue_mouse_packet({}, packet);
     {
         SpinlockLocker lock(m_queue_lock);
         m_queue.enqueue(packet);