Kernel: Move all Graphics-related code into Devices/GPU directory

Like the HID, Audio and Storage subsystem, the Graphics subsystem (which
handles GPUs technically) exposes unix device files (typically in /dev).
To ensure consistency across the repository, move all related files to a
new directory under Kernel/Devices called "GPU".

Also remove the redundant "GPU" word from the VirtIO driver directory,
and the word "Graphics" from GraphicsManagement.{h,cpp} filenames.

Kernel/Devices/GPU/VirtIO/GraphicsAdapter.h

@@ -0,0 +1,125 @@
+/*
+ * Copyright (c) 2021, Sahan Fernando <sahan.h.fernando@gmail.com>
+ *
+ * SPDX-License-Identifier: BSD-2-Clause
+ */
+
+#pragma once
+
+#include <AK/BinaryBufferWriter.h>
+#include <AK/DistinctNumeric.h>
+#include <Kernel/Bus/VirtIO/Device.h>
+#include <Kernel/Bus/VirtIO/Queue.h>
+#include <Kernel/Devices/GPU/GenericGraphicsAdapter.h>
+#include <Kernel/Devices/GPU/VirtIO/Protocol.h>
+
+namespace Kernel {
+
+#define VIRTIO_GPU_F_VIRGL (1 << 0)
+#define VIRTIO_GPU_F_EDID (1 << 1)
+
+#define VIRTIO_GPU_FLAG_FENCE (1 << 0)
+
+#define CONTROLQ 0
+#define CURSORQ 1
+
+#define MAX_VIRTIOGPU_RESOLUTION_WIDTH 3840
+#define MAX_VIRTIOGPU_RESOLUTION_HEIGHT 2160
+
+#define VIRTIO_GPU_EVENT_DISPLAY (1 << 0)
+
+class VirtIODisplayConnector;
+class VirtIOGPU3DDevice;
+class VirtIOGraphicsAdapter final
+    : public GenericGraphicsAdapter
+    , public VirtIO::Device {
+    friend class VirtIODisplayConnector;
+    friend class VirtIOGPU3DDevice;
+
+public:
+    static ErrorOr<bool> probe(PCI::DeviceIdentifier const&);
+    static ErrorOr<NonnullLockRefPtr<GenericGraphicsAdapter>> create(PCI::DeviceIdentifier const&);
+
+    virtual ErrorOr<void> initialize_virtio_resources() override;
+
+    virtual StringView device_name() const override { return "VirtIOGraphicsAdapter"sv; }
+
+    ErrorOr<void> mode_set_resolution(Badge<VirtIODisplayConnector>, VirtIODisplayConnector&, size_t width, size_t height);
+    void set_dirty_displayed_rect(Badge<VirtIODisplayConnector>, VirtIODisplayConnector&, Graphics::VirtIOGPU::Protocol::Rect const& dirty_rect, bool main_buffer);
+    ErrorOr<void> flush_displayed_image(Badge<VirtIODisplayConnector>, VirtIODisplayConnector&, Graphics::VirtIOGPU::Protocol::Rect const& dirty_rect, bool main_buffer);
+    ErrorOr<void> transfer_framebuffer_data_to_host(Badge<VirtIODisplayConnector>, VirtIODisplayConnector&, Graphics::VirtIOGPU::Protocol::Rect const& rect, bool main_buffer);
+
+private:
+    ErrorOr<void> attach_physical_range_to_framebuffer(VirtIODisplayConnector& connector, bool main_buffer, size_t framebuffer_offset, size_t framebuffer_size);
+
+    ErrorOr<void> initialize_3d_device();
+
+    ErrorOr<void> flush_dirty_rectangle(Graphics::VirtIOGPU::ScanoutID, Graphics::VirtIOGPU::ResourceID, Graphics::VirtIOGPU::Protocol::Rect const& dirty_rect);
+    struct Scanout {
+        struct PhysicalBuffer {
+            size_t framebuffer_offset { 0 };
+            Graphics::VirtIOGPU::Protocol::Rect dirty_rect {};
+            Graphics::VirtIOGPU::ResourceID resource_id { 0 };
+        };
+
+        LockRefPtr<VirtIODisplayConnector> display_connector;
+        PhysicalBuffer main_buffer;
+        PhysicalBuffer back_buffer;
+    };
+
+    VirtIOGraphicsAdapter(PCI::DeviceIdentifier const&, Bitmap&& active_context_ids, NonnullOwnPtr<Memory::Region> scratch_space_region);
+
+    ErrorOr<void> initialize_adapter();
+
+    virtual bool handle_device_config_change() override;
+    virtual void handle_queue_update(u16 queue_index) override;
+    u32 get_pending_events();
+    void clear_pending_events(u32 event_bitmask);
+
+    // 2D framebuffer stuff
+    static ErrorOr<FlatPtr> calculate_framebuffer_size(size_t width, size_t height)
+    {
+        // VirtIO resources can only map on page boundaries!
+        return Memory::page_round_up(sizeof(u32) * width * height);
+    }
+
+    // 3D Command stuff
+    ErrorOr<Graphics::VirtIOGPU::ContextID> create_context();
+    ErrorOr<void> attach_resource_to_context(Graphics::VirtIOGPU::ResourceID resource_id, Graphics::VirtIOGPU::ContextID context_id);
+    ErrorOr<void> submit_command_buffer(Graphics::VirtIOGPU::ContextID, Function<size_t(Bytes)> buffer_writer);
+    Graphics::VirtIOGPU::Protocol::TextureFormat get_framebuffer_format() const { return Graphics::VirtIOGPU::Protocol::TextureFormat::VIRTIO_GPU_FORMAT_B8G8R8X8_UNORM; }
+
+    auto& operation_lock() { return m_operation_lock; }
+    Graphics::VirtIOGPU::ResourceID allocate_resource_id();
+
+    PhysicalAddress start_of_scratch_space() const { return m_scratch_space->physical_page(0)->paddr(); }
+    AK::BinaryBufferWriter create_scratchspace_writer()
+    {
+        return { Bytes(m_scratch_space->vaddr().as_ptr(), m_scratch_space->size()) };
+    }
+    ErrorOr<void> synchronous_virtio_gpu_command(size_t microseconds_timeout, PhysicalAddress buffer_start, size_t request_size, size_t response_size);
+
+    ErrorOr<Graphics::VirtIOGPU::ResourceID> create_2d_resource(Graphics::VirtIOGPU::Protocol::Rect rect);
+    ErrorOr<Graphics::VirtIOGPU::ResourceID> create_3d_resource(Graphics::VirtIOGPU::Protocol::Resource3DSpecification const& resource_3d_specification);
+    ErrorOr<void> delete_resource(Graphics::VirtIOGPU::ResourceID resource_id);
+    ErrorOr<void> ensure_backing_storage(Graphics::VirtIOGPU::ResourceID resource_id, Memory::Region const& region, size_t buffer_offset, size_t buffer_length);
+    ErrorOr<void> detach_backing_storage(Graphics::VirtIOGPU::ResourceID resource_id);
+    ErrorOr<void> set_scanout_resource(Graphics::VirtIOGPU::ScanoutID scanout, Graphics::VirtIOGPU::ResourceID resource_id, Graphics::VirtIOGPU::Protocol::Rect rect);
+    ErrorOr<void> transfer_framebuffer_data_to_host(Graphics::VirtIOGPU::ScanoutID scanout, Graphics::VirtIOGPU::ResourceID resource_id, Graphics::VirtIOGPU::Protocol::Rect const& rect);
+    ErrorOr<void> flush_displayed_image(Graphics::VirtIOGPU::ResourceID resource_id, Graphics::VirtIOGPU::Protocol::Rect const& dirty_rect);
+    ErrorOr<void> query_and_set_edid(u32 scanout_id, VirtIODisplayConnector& display_connector);
+
+    size_t m_num_scanouts { 0 };
+    Scanout m_scanouts[VIRTIO_GPU_MAX_SCANOUTS];
+
+    VirtIO::Configuration const* m_device_configuration { nullptr };
+    // Note: Resource ID 0 is invalid, and we must not allocate 0 as the first resource ID.
+    Atomic<u32> m_resource_id_counter { 1 };
+    SpinlockProtected<Bitmap, LockRank::None> m_active_context_ids {};
+    LockRefPtr<VirtIOGPU3DDevice> m_3d_device;
+    bool m_has_virgl_support { false };
+
+    Spinlock<LockRank::None> m_operation_lock {};
+    NonnullOwnPtr<Memory::Region> m_scratch_space;
+};
+}