Kernel/Storage: Move all ATA related code to a new subdirectory

Like what happened with the PCI and USB code, this feels like the right
thing to do because we can improve on the ATA capabilities and keep it
distinguished from the rest of the subsystem.

Kernel/Storage/ATA/ATAPIDiscDevice.cpp

@@ -0,0 +1,45 @@
+/*
+ * Copyright (c) 2021, Liav A. <liavalb@hotmail.co.il>
+ *
+ * SPDX-License-Identifier: BSD-2-Clause
+ */
+
+#include <AK/StringView.h>
+#include <Kernel/Devices/DeviceManagement.h>
+#include <Kernel/Sections.h>
+#include <Kernel/Storage/ATA/ATAPIDiscDevice.h>
+#include <Kernel/Storage/ATA/IDEChannel.h>
+#include <Kernel/Storage/ATA/IDEController.h>
+#include <Kernel/Storage/StorageManagement.h>
+
+namespace Kernel {
+
+NonnullRefPtr<ATAPIDiscDevice> ATAPIDiscDevice::create(const ATAController& controller, ATADevice::Address ata_address, u16 capabilities, u64 max_addressable_block)
+{
+    auto minor_device_number = StorageManagement::minor_number();
+
+    // FIXME: We need a way of formatting strings with KString.
+    auto device_name = String::formatted("hd{:c}", 'a' + minor_device_number);
+    auto device_name_kstring = KString::must_create(device_name.view());
+
+    auto disc_device_or_error = DeviceManagement::try_create_device<ATAPIDiscDevice>(controller, ata_address, minor_device_number, capabilities, max_addressable_block, move(device_name_kstring));
+    // FIXME: Find a way to propagate errors
+    VERIFY(!disc_device_or_error.is_error());
+    return disc_device_or_error.release_value();
+}
+
+ATAPIDiscDevice::ATAPIDiscDevice(const ATAController& controller, ATADevice::Address ata_address, unsigned minor_number, u16 capabilities, u64 max_addressable_block, NonnullOwnPtr<KString> early_storage_name)
+    : ATADevice(controller, ata_address, minor_number, capabilities, 0, max_addressable_block, move(early_storage_name))
+{
+}
+
+ATAPIDiscDevice::~ATAPIDiscDevice()
+{
+}
+
+StringView ATAPIDiscDevice::class_name() const
+{
+    return "ATAPIDiscDevice";
+}
+
+}