Kernel: Move PCI IDE driver code to the Arch/x86 directory

That code heavily relies on x86-specific instructions, and while other
CPU architectures and platforms can have PCI IDE controllers, currently
we don't support those, so this code is a special case which needs to be
in the Arch/x86 directory.
In the future it could be put back to the original place when we make it
more generic and suitable for other platforms.

Kernel/Arch/x86/PCI/IDELegacyModeController.h

@@ -0,0 +1,40 @@
+/*
+ * Copyright (c) 2020-2022, Liav A. <liavalb@hotmail.co.il>
+ *
+ * SPDX-License-Identifier: BSD-2-Clause
+ */
+
+#pragma once
+
+#include <AK/OwnPtr.h>
+#include <AK/Types.h>
+#include <Kernel/Library/LockRefPtr.h>
+#include <Kernel/Storage/ATA/GenericIDE/Controller.h>
+#include <Kernel/Storage/StorageDevice.h>
+
+namespace Kernel {
+
+class AsyncBlockDeviceRequest;
+
+class PCIIDELegacyModeController final : public IDEController
+    , public PCI::Device {
+public:
+    static NonnullLockRefPtr<PCIIDELegacyModeController> initialize(PCI::DeviceIdentifier const&, bool force_pio);
+
+    bool is_bus_master_capable() const;
+    bool is_pci_native_mode_enabled() const;
+
+private:
+    bool is_pci_native_mode_enabled_on_primary_channel() const;
+    bool is_pci_native_mode_enabled_on_secondary_channel() const;
+    PCIIDELegacyModeController(PCI::DeviceIdentifier const&, bool force_pio);
+
+    LockRefPtr<StorageDevice> device_by_channel_and_position(u32 index) const;
+    void initialize(bool force_pio);
+    void detect_disks();
+
+    // FIXME: Find a better way to get the ProgrammingInterface
+    PCI::ProgrammingInterface m_prog_if;
+    PCI::InterruptLine m_interrupt_line;
+};
+}