Kernel: Make major and minor numbers to be DistinctNumerics

This helps avoid confusion in general, and make constructors, methods
and code patterns much more clean and understandable.

Kernel/Devices/BlockDevice.h

@@ -64,7 +64,7 @@ public:
     virtual void start_request(AsyncBlockDeviceRequest&) = 0;
 
 protected:
-    BlockDevice(unsigned major, unsigned minor, size_t block_size = PAGE_SIZE)
+    BlockDevice(MajorNumber major, MinorNumber minor, size_t block_size = PAGE_SIZE)
         : Device(major, minor)
         , m_block_size(block_size)
     {

Kernel/Devices/CharacterDevice.h

@@ -15,7 +15,7 @@ public:
     virtual ~CharacterDevice() override;
 
 protected:
-    CharacterDevice(unsigned major, unsigned minor)
+    CharacterDevice(MajorNumber major, MinorNumber minor)
         : Device(major, minor)
     {
     }

Kernel/Devices/Device.cpp

@@ -114,7 +114,7 @@ RefPtr<SysFSComponent> SysFSCharacterDevicesDirectory::lookup(StringView name)
     });
 }
 
-Device::Device(unsigned major, unsigned minor)
+Device::Device(MajorNumber major, MinorNumber minor)
     : m_major(major)
     , m_minor(minor)
 {

Kernel/Devices/Device.h

@@ -20,6 +20,7 @@
 #include <AK/HashMap.h>
 #include <AK/RefPtr.h>
 #include <Kernel/Devices/AsyncDeviceRequest.h>
+#include <Kernel/FileSystem/DeviceFileTypes.h>
 #include <Kernel/FileSystem/File.h>
 #include <Kernel/FileSystem/SysFS.h>
 #include <Kernel/Locking/Mutex.h>
@@ -37,8 +38,8 @@ protected:
 public:
     virtual ~Device() override;
 
-    unsigned major() const { return m_major; }
-    unsigned minor() const { return m_minor; }
+    MajorNumber major() const { return m_major; }
+    MinorNumber minor() const { return m_minor; }
 
     virtual ErrorOr<NonnullOwnPtr<KString>> pseudo_path(const OpenFileDescription&) const override;
 
@@ -63,13 +64,13 @@ public:
     }
 
 protected:
-    Device(unsigned major, unsigned minor);
+    Device(MajorNumber major, MinorNumber minor);
     void set_uid(UserID uid) { m_uid = uid; }
     void set_gid(GroupID gid) { m_gid = gid; }
 
 private:
-    unsigned m_major { 0 };
-    unsigned m_minor { 0 };
+    MajorNumber m_major { 0 };
+    MinorNumber m_minor { 0 };
     UserID m_uid { 0 };
     GroupID m_gid { 0 };
 

Kernel/Devices/DeviceManagement.cpp

@@ -42,10 +42,10 @@ DeviceManagement& DeviceManagement::the()
     return *s_the;
 }
 
-Device* DeviceManagement::get_device(unsigned major, unsigned minor)
+Device* DeviceManagement::get_device(MajorNumber major, MinorNumber minor)
 {
     return m_devices.with_exclusive([&](auto& map) -> Device* {
-        auto it = map.find(encoded_device(major, minor));
+        auto it = map.find(encoded_device(major.value(), minor.value()));
         if (it == map.end())
             return nullptr;
         return it->value;
@@ -54,7 +54,7 @@ Device* DeviceManagement::get_device(unsigned major, unsigned minor)
 
 void DeviceManagement::before_device_removal(Badge<Device>, Device& device)
 {
-    u32 device_id = encoded_device(device.major(), device.minor());
+    u64 device_id = encoded_device(device.major(), device.minor());
     m_devices.with_exclusive([&](auto& map) -> void {
         VERIFY(map.contains(device_id));
         map.remove(encoded_device(device.major(), device.minor()));
@@ -63,7 +63,7 @@ void DeviceManagement::before_device_removal(Badge<Device>, Device& device)
 
 void DeviceManagement::after_inserting_device(Badge<Device>, Device& device)
 {
-    u32 device_id = encoded_device(device.major(), device.minor());
+    u64 device_id = encoded_device(device.major(), device.minor());
     m_devices.with_exclusive([&](auto& map) -> void {
         if (map.contains(device_id)) {
             dbgln("Already registered {},{}: {}", device.major(), device.minor(), device.class_name());

Kernel/Devices/DeviceManagement.h

@@ -42,7 +42,7 @@ public:
     void before_device_removal(Badge<Device>, Device&);
 
     void for_each(Function<void(Device&)>);
-    Device* get_device(unsigned major, unsigned minor);
+    Device* get_device(MajorNumber major, MinorNumber minor);
 
     NullDevice const& null_device() const;
     NullDevice& null_device();
@@ -63,7 +63,7 @@ private:
     RefPtr<ConsoleDevice> m_console_device;
     // FIXME: Once we have a singleton for managing many sound cards, remove this from here
     NonnullRefPtrVector<CharacterDevice, 1> m_audio_devices;
-    MutexProtected<HashMap<u32, Device*>> m_devices;
+    MutexProtected<HashMap<u64, Device*>> m_devices;
 };
 
 }

Kernel/Devices/HID/HIDDevice.h

@@ -23,7 +23,7 @@ public:
     virtual void enable_interrupts() = 0;
 
 protected:
-    HIDDevice(unsigned major, unsigned minor)
+    HIDDevice(MajorNumber major, MinorNumber minor)
         : CharacterDevice(major, minor)
     {
     }