Kernel/Net: Move NE2000 network adapter code to a separate directory

Kernel/Net/NE2000/NetworkAdapter.h

@@ -0,0 +1,70 @@
+/*
+ * Copyright (c) 2021, the SerenityOS developers.
+ *
+ * SPDX-License-Identifier: BSD-2-Clause
+ */
+
+#pragma once
+
+#include <AK/OwnPtr.h>
+#include <Kernel/Arch/x86/IO.h>
+#include <Kernel/Bus/PCI/Access.h>
+#include <Kernel/Bus/PCI/Device.h>
+#include <Kernel/Interrupts/IRQHandler.h>
+#include <Kernel/Net/NetworkAdapter.h>
+#include <Kernel/Random.h>
+
+namespace Kernel {
+
+class NE2000NetworkAdapter final : public NetworkAdapter
+    , public PCI::Device
+    , public IRQHandler {
+public:
+    static RefPtr<NE2000NetworkAdapter> try_to_initialize(PCI::DeviceIdentifier const&);
+
+    virtual ~NE2000NetworkAdapter() override;
+
+    virtual void send_raw(ReadonlyBytes) override;
+    virtual bool link_up() override
+    {
+        // Pure NE2000 doesn't seem to have a link status indicator, so
+        // just assume that it's up.
+        return true;
+    }
+    virtual i32 link_speed() override
+    {
+        // Can only do 10mbit..
+        return 10;
+    }
+    virtual bool link_full_duplex() override { return true; }
+
+    virtual StringView purpose() const override { return class_name(); }
+
+private:
+    NE2000NetworkAdapter(PCI::Address, u8, NonnullOwnPtr<KString>);
+    virtual bool handle_irq(const RegisterState&) override;
+    virtual StringView class_name() const override { return "NE2000NetworkAdapter"sv; }
+
+    int ram_test();
+    void reset();
+
+    void rdma_read(size_t address, Bytes payload);
+    void rdma_write(size_t address, ReadonlyBytes payload);
+
+    void receive();
+
+    void out8(u16 address, u8 data);
+    void out16(u16 address, u16 data);
+    u8 in8(u16 address);
+    u16 in16(u16 address);
+
+    IOAddress m_io_base;
+    int m_ring_read_ptr;
+    u8 m_interrupt_line { 0 };
+
+    MACAddress m_mac_address;
+    EntropySource m_entropy_source;
+
+    WaitQueue m_wait_queue;
+};
+}