Rework ADSP into a wrapper for apps

8 files changed, 718 insertions, 0 deletions

diff --git a/src/audio_core/adsp/adsp.cpp b/src/audio_core/adsp/adsp.cpp
new file mode 100644
index 000000000..0580990f5
--- /dev/null
+++ b/src/audio_core/adsp/adsp.cpp
@@ -0,0 +1,18 @@
+// SPDX-FileCopyrightText: Copyright 2023 yuzu Emulator Project
+// SPDX-License-Identifier: GPL-2.0-or-later
+
+#include "audio_core/adsp/adsp.h"
+#include "core/core.h"
+
+namespace AudioCore::ADSP {
+
+ADSP::ADSP(Core::System& system, Sink::Sink& sink) {
+    audio_renderer =
+        std::make_unique<AudioRenderer::AudioRenderer>(system, system.ApplicationMemory(), sink);
+}
+
+AudioRenderer::AudioRenderer& ADSP::AudioRenderer() {
+    return *audio_renderer.get();
+}
+
+} // namespace AudioCore::ADSP
diff --git a/src/audio_core/adsp/adsp.h b/src/audio_core/adsp/adsp.h
new file mode 100644
index 000000000..bd5bcc63b
--- /dev/null
+++ b/src/audio_core/adsp/adsp.h
@@ -0,0 +1,50 @@
+// SPDX-FileCopyrightText: Copyright 2023 yuzu Emulator Project
+// SPDX-License-Identifier: GPL-2.0-or-later
+
+#pragma once
+
+#include "audio_core/adsp/apps/audio_renderer/audio_renderer.h"
+#include "common/common_types.h"
+
+namespace Core {
+class System;
+} // namespace Core
+
+namespace AudioCore {
+namespace Sink {
+class Sink;
+}
+
+namespace ADSP {
+
+/**
+ * Represents the ADSP embedded within the audio sysmodule.
+ * This is a 32-bit Linux4Tegra kernel from nVidia, which is launched with the sysmodule on boot.
+ *
+ * The kernel will run the apps you write for it, Nintendo have the following:
+ *
+ * Gmix - Responsible for mixing final audio and sending it out to hardware. This is last place all
+ *        audio samples end up, and we skip it entirely, since we have very different backends and
+ *        mixing is implicitly handled by the OS (but also due to lack of research/simplicity).
+ *
+ * AudioRenderer - Receives command lists generated by the audio render
+ *                 system on the host, processes them, and sends the samples to Gmix.
+ *
+ * OpusDecoder - Contains libopus, and decodes Opus audio packets into raw pcm data.
+ *
+ * Communication between the host and ADSP is done through mailboxes, and mapping of shared memory.
+ */
+class ADSP {
+public:
+    explicit ADSP(Core::System& system, Sink::Sink& sink);
+    ~ADSP() = default;
+
+    AudioRenderer::AudioRenderer& AudioRenderer();
+
+private:
+    /// AudioRenderer app
+    std::unique_ptr<AudioRenderer::AudioRenderer> audio_renderer{};
+};
+
+} // namespace ADSP
+} // namespace AudioCore
diff --git a/src/audio_core/adsp/apps/audio_renderer/audio_renderer.cpp b/src/audio_core/adsp/apps/audio_renderer/audio_renderer.cpp
new file mode 100644
index 000000000..3da342ea3
--- /dev/null
+++ b/src/audio_core/adsp/apps/audio_renderer/audio_renderer.cpp
@@ -0,0 +1,215 @@
+// SPDX-FileCopyrightText: Copyright 2023 yuzu Emulator Project
+// SPDX-License-Identifier: GPL-2.0-or-later
+
+#include <array>
+#include <chrono>
+
+#include "audio_core/adsp/apps/audio_renderer/audio_renderer.h"
+#include "audio_core/audio_core.h"
+#include "audio_core/common/common.h"
+#include "audio_core/sink/sink.h"
+#include "common/logging/log.h"
+#include "common/microprofile.h"
+#include "common/thread.h"
+#include "core/core.h"
+#include "core/core_timing.h"
+
+MICROPROFILE_DEFINE(Audio_Renderer, "Audio", "DSP", MP_RGB(60, 19, 97));
+
+namespace AudioCore::ADSP::AudioRenderer {
+
+AudioRenderer::AudioRenderer(Core::System& system_, Core::Memory::Memory& memory_,
+                             Sink::Sink& sink_)
+    : system{system_}, memory{memory_}, sink{sink_} {}
+
+AudioRenderer::~AudioRenderer() {
+    Stop();
+}
+
+void AudioRenderer::Start() {
+    CreateSinkStreams();
+
+    mailbox.Initialize(AppMailboxId::AudioRenderer);
+
+    main_thread = std::jthread([this](std::stop_token stop_token) { Main(stop_token); });
+
+    mailbox.Send(Direction::DSP, {Message::InitializeOK, {}});
+    if (mailbox.Receive(Direction::Host).msg != Message::InitializeOK) {
+        LOG_ERROR(Service_Audio, "Host Audio Renderer -- Failed to receive shutdown "
+                                 "message response from ADSP!");
+        return;
+    }
+    running = true;
+}
+
+void AudioRenderer::Stop() {
+    if (!running) {
+        return;
+    }
+
+    mailbox.Send(Direction::DSP, {Message::Shutdown, {}});
+    if (mailbox.Receive(Direction::Host).msg != Message::Shutdown) {
+        LOG_ERROR(Service_Audio, "Host Audio Renderer -- Failed to receive shutdown "
+                                 "message response from ADSP!");
+    }
+    main_thread.request_stop();
+    main_thread.join();
+
+    for (auto& stream : streams) {
+        if (stream) {
+            stream->Stop();
+            sink.CloseStream(stream);
+            stream = nullptr;
+        }
+    }
+    running = false;
+}
+
+void AudioRenderer::Signal() {
+    signalled_tick = system.CoreTiming().GetGlobalTimeNs().count();
+    Send(Direction::DSP, {Message::Render, {}});
+}
+
+void AudioRenderer::Wait() {
+    auto received = Receive(Direction::Host);
+    if (received.msg != Message::RenderResponse) {
+        LOG_ERROR(Service_Audio,
+                  "Did not receive the expected render response from the AudioRenderer! Expected "
+                  "{}, got {}",
+                  Message::RenderResponse, received.msg);
+    }
+}
+
+void AudioRenderer::Send(Direction dir, MailboxMessage message) {
+    mailbox.Send(dir, std::move(message));
+}
+
+MailboxMessage AudioRenderer::Receive(Direction dir, bool block) {
+    return mailbox.Receive(dir, block);
+}
+
+void AudioRenderer::SetCommandBuffer(s32 session_id, CommandBuffer& buffer) noexcept {
+    command_buffers[session_id] = buffer;
+}
+
+u32 AudioRenderer::GetRemainCommandCount(s32 session_id) const noexcept {
+    return command_buffers[session_id].remaining_command_count;
+}
+
+void AudioRenderer::ClearRemainCommandCount(s32 session_id) noexcept {
+    command_buffers[session_id].remaining_command_count = 0;
+}
+
+u64 AudioRenderer::GetRenderingStartTick(s32 session_id) const noexcept {
+    return (1000 * command_buffers[session_id].render_time_taken_us) + signalled_tick;
+}
+
+void AudioRenderer::CreateSinkStreams() {
+    u32 channels{sink.GetDeviceChannels()};
+    for (u32 i = 0; i < MaxRendererSessions; i++) {
+        std::string name{fmt::format("ADSP_RenderStream-{}", i)};
+        streams[i] =
+            sink.AcquireSinkStream(system, channels, name, ::AudioCore::Sink::StreamType::Render);
+        streams[i]->SetRingSize(4);
+    }
+}
+
+void AudioRenderer::Main(std::stop_token stop_token) {
+    static constexpr char name[]{"AudioRenderer"};
+    MicroProfileOnThreadCreate(name);
+    Common::SetCurrentThreadName(name);
+    Common::SetCurrentThreadPriority(Common::ThreadPriority::High);
+
+    // TODO: Create buffer map/unmap thread + mailbox
+    // TODO: Create gMix devices, initialize them here
+
+    if (mailbox.Receive(Direction::DSP).msg != Message::InitializeOK) {
+        LOG_ERROR(Service_Audio,
+                  "ADSP Audio Renderer -- Failed to receive initialize message from host!");
+        return;
+    }
+
+    mailbox.Send(Direction::Host, {Message::InitializeOK, {}});
+
+    // 0.12 seconds (2,304,000 / 19,200,000)
+    constexpr u64 max_process_time{2'304'000ULL};
+
+    while (!stop_token.stop_requested()) {
+        auto received{mailbox.Receive(Direction::DSP)};
+        switch (received.msg) {
+        case Message::Shutdown:
+            mailbox.Send(Direction::Host, {Message::Shutdown, {}});
+            return;
+
+        case Message::Render: {
+            if (system.IsShuttingDown()) [[unlikely]] {
+                std::this_thread::sleep_for(std::chrono::milliseconds(5));
+                mailbox.Send(Direction::Host, {Message::RenderResponse, {}});
+                continue;
+            }
+            std::array<bool, MaxRendererSessions> buffers_reset{};
+            std::array<u64, MaxRendererSessions> render_times_taken{};
+            const auto start_time{system.CoreTiming().GetGlobalTimeUs().count()};
+
+            for (u32 index = 0; index < MaxRendererSessions; index++) {
+                auto& command_buffer{command_buffers[index]};
+                auto& command_list_processor{command_list_processors[index]};
+
+                // Check this buffer is valid, as it may not be used.
+                if (command_buffer.buffer != 0) {
+                    // If there are no remaining commands (from the previous list),
+                    // this is a new command list, initialize it.
+                    if (command_buffer.remaining_command_count == 0) {
+                        command_list_processor.Initialize(system, command_buffer.buffer,
+                                                          command_buffer.size, streams[index]);
+                    }
+
+                    if (command_buffer.reset_buffer && !buffers_reset[index]) {
+                        streams[index]->ClearQueue();
+                        buffers_reset[index] = true;
+                    }
+
+                    u64 max_time{max_process_time};
+                    if (index == 1 && command_buffer.applet_resource_user_id ==
+                                          command_buffers[0].applet_resource_user_id) {
+                        max_time = max_process_time - render_times_taken[0];
+                        if (render_times_taken[0] > max_process_time) {
+                            max_time = 0;
+                        }
+                    }
+
+                    max_time = std::min(command_buffer.time_limit, max_time);
+                    command_list_processor.SetProcessTimeMax(max_time);
+
+                    if (index == 0) {
+                        streams[index]->WaitFreeSpace(stop_token);
+                    }
+
+                    // Process the command list
+                    {
+                        MICROPROFILE_SCOPE(Audio_Renderer);
+                        render_times_taken[index] =
+                            command_list_processor.Process(index) - start_time;
+                    }
+
+                    const auto end_time{system.CoreTiming().GetGlobalTimeUs().count()};
+
+                    command_buffer.remaining_command_count =
+                        command_list_processor.GetRemainingCommandCount();
+                    command_buffer.render_time_taken_us = end_time - start_time;
+                }
+            }
+
+            mailbox.Send(Direction::Host, {Message::RenderResponse, {}});
+        } break;
+
+        default:
+            LOG_WARNING(Service_Audio,
+                        "ADSP AudioRenderer received an invalid message, msg={:02X}!",
+                        received.msg);
+            break;
+        }
+    }
+}
+
+} // namespace AudioCore::ADSP::AudioRenderer
diff --git a/src/audio_core/adsp/apps/audio_renderer/audio_renderer.h b/src/audio_core/adsp/apps/audio_renderer/audio_renderer.h
new file mode 100644
index 000000000..b225e10fb
--- /dev/null
+++ b/src/audio_core/adsp/apps/audio_renderer/audio_renderer.h
@@ -0,0 +1,115 @@
+// SPDX-FileCopyrightText: Copyright 2023 yuzu Emulator Project
+// SPDX-License-Identifier: GPL-2.0-or-later
+
+#pragma once
+
+#include <array>
+#include <memory>
+#include <thread>
+
+#include "audio_core/adsp/apps/audio_renderer/command_buffer.h"
+#include "audio_core/adsp/apps/audio_renderer/command_list_processor.h"
+#include "audio_core/adsp/mailbox.h"
+#include "common/common_types.h"
+#include "common/polyfill_thread.h"
+#include "common/reader_writer_queue.h"
+#include "common/thread.h"
+
+namespace Core {
+class System;
+namespace Timing {
+struct EventType;
+}
+namespace Memory {
+class Memory;
+}
+class System;
+} // namespace Core
+
+namespace AudioCore {
+namespace Sink {
+class Sink;
+}
+
+namespace ADSP::AudioRenderer {
+
+enum Message : u32 {
+    Invalid = 0x00,
+    MapUnmap_Map = 0x01,
+    MapUnmap_MapResponse = 0x02,
+    MapUnmap_Unmap = 0x03,
+    MapUnmap_UnmapResponse = 0x04,
+    MapUnmap_InvalidateCache = 0x05,
+    MapUnmap_InvalidateCacheResponse = 0x06,
+    MapUnmap_Shutdown = 0x07,
+    MapUnmap_ShutdownResponse = 0x08,
+    InitializeOK = 0x16,
+    RenderResponse = 0x20,
+    Render = 0x2A,
+    Shutdown = 0x34,
+};
+
+/**
+ * The AudioRenderer application running on the ADSP.
+ */
+class AudioRenderer {
+public:
+    explicit AudioRenderer(Core::System& system, Core::Memory::Memory& memory, Sink::Sink& sink);
+    ~AudioRenderer();
+
+    /**
+     * Start the AudioRenderer.
+     *
+     * @param mailbox The mailbox to use for this session.
+     */
+    void Start();
+
+    /**
+     * Stop the AudioRenderer.
+     */
+    void Stop();
+
+    void Signal();
+    void Wait();
+
+    void Send(Direction dir, MailboxMessage message);
+    MailboxMessage Receive(Direction dir, bool block = true);
+
+    void SetCommandBuffer(s32 session_id, CommandBuffer& buffer) noexcept;
+    u32 GetRemainCommandCount(s32 session_id) const noexcept;
+    void ClearRemainCommandCount(s32 session_id) noexcept;
+    u64 GetRenderingStartTick(s32 session_id) const noexcept;
+
+private:
+    /**
+     * Main AudioRenderer thread, responsible for processing the command lists.
+     */
+    void Main(std::stop_token stop_token);
+
+    /**
+     * Creates the streams which will receive the processed samples.
+     */
+    void CreateSinkStreams();
+
+    /// Core system
+    Core::System& system;
+    /// Memory
+    Core::Memory::Memory& memory;
+    /// The output sink the AudioRenderer will use
+    Sink::Sink& sink;
+    /// The active mailbox
+    Mailbox mailbox;
+    /// Main thread
+    std::jthread main_thread{};
+    /// The current state
+    std::atomic<bool> running{};
+    std::array<CommandBuffer, MaxRendererSessions> command_buffers{};
+    /// The command lists to process
+    std::array<CommandListProcessor, MaxRendererSessions> command_list_processors{};
+    /// The streams which will receive the processed samples
+    std::array<Sink::SinkStream*, MaxRendererSessions> streams{};
+    u64 signalled_tick{0};
+};
+
+} // namespace ADSP::AudioRenderer
+} // namespace AudioCore
diff --git a/src/audio_core/adsp/apps/audio_renderer/command_buffer.h b/src/audio_core/adsp/apps/audio_renderer/command_buffer.h
new file mode 100644
index 000000000..3fd1b09dc
--- /dev/null
+++ b/src/audio_core/adsp/apps/audio_renderer/command_buffer.h
@@ -0,0 +1,23 @@
+// SPDX-FileCopyrightText: Copyright 2023 yuzu Emulator Project
+// SPDX-License-Identifier: GPL-2.0-or-later
+
+#pragma once
+
+#include "audio_core/common/common.h"
+#include "common/common_types.h"
+
+namespace AudioCore::ADSP::AudioRenderer {
+
+struct CommandBuffer {
+    // Set by the host
+    CpuAddr buffer{};
+    u64 size{};
+    u64 time_limit{};
+    u64 applet_resource_user_id{};
+    bool reset_buffer{};
+    // Set by the DSP
+    u32 remaining_command_count{};
+    u64 render_time_taken_us{};
+};
+
+} // namespace AudioCore::ADSP::AudioRenderer
diff --git a/src/audio_core/adsp/apps/audio_renderer/command_list_processor.cpp b/src/audio_core/adsp/apps/audio_renderer/command_list_processor.cpp
new file mode 100644
index 000000000..acbc9100c
--- /dev/null
+++ b/src/audio_core/adsp/apps/audio_renderer/command_list_processor.cpp
@@ -0,0 +1,108 @@
+// SPDX-FileCopyrightText: Copyright 2023 yuzu Emulator Project
+// SPDX-License-Identifier: GPL-2.0-or-later
+
+#include <string>
+
+#include "audio_core/adsp/apps/audio_renderer/command_list_processor.h"
+#include "audio_core/renderer/command/command_list_header.h"
+#include "audio_core/renderer/command/commands.h"
+#include "common/settings.h"
+#include "core/core.h"
+#include "core/core_timing.h"
+#include "core/memory.h"
+
+namespace AudioCore::ADSP::AudioRenderer {
+
+void CommandListProcessor::Initialize(Core::System& system_, CpuAddr buffer, u64 size,
+                                      Sink::SinkStream* stream_) {
+    system = &system_;
+    memory = &system->ApplicationMemory();
+    stream = stream_;
+    header = reinterpret_cast<Renderer::CommandListHeader*>(buffer);
+    commands = reinterpret_cast<u8*>(buffer + sizeof(Renderer::CommandListHeader));
+    commands_buffer_size = size;
+    command_count = header->command_count;
+    sample_count = header->sample_count;
+    target_sample_rate = header->sample_rate;
+    mix_buffers = header->samples_buffer;
+    buffer_count = header->buffer_count;
+    processed_command_count = 0;
+}
+
+void CommandListProcessor::SetProcessTimeMax(const u64 time) {
+    max_process_time = time;
+}
+
+u32 CommandListProcessor::GetRemainingCommandCount() const {
+    return command_count - processed_command_count;
+}
+
+void CommandListProcessor::SetBuffer(const CpuAddr buffer, const u64 size) {
+    commands = reinterpret_cast<u8*>(buffer + sizeof(Renderer::CommandListHeader));
+    commands_buffer_size = size;
+}
+
+Sink::SinkStream* CommandListProcessor::GetOutputSinkStream() const {
+    return stream;
+}
+
+u64 CommandListProcessor::Process(u32 session_id) {
+    const auto start_time_{system->CoreTiming().GetGlobalTimeUs().count()};
+    const auto command_base{CpuAddr(commands)};
+
+    if (processed_command_count > 0) {
+        current_processing_time += start_time_ - end_time;
+    } else {
+        start_time = start_time_;
+        current_processing_time = 0;
+    }
+
+    std::string dump{fmt::format("\nSession {}\n", session_id)};
+
+    for (u32 index = 0; index < command_count; index++) {
+        auto& command{*reinterpret_cast<Renderer::ICommand*>(commands)};
+
+        if (command.magic != 0xCAFEBABE) {
+            LOG_ERROR(Service_Audio, "Command has invalid magic! Expected 0xCAFEBABE, got {:08X}",
+                      command.magic);
+            return system->CoreTiming().GetGlobalTimeUs().count() - start_time_;
+        }
+
+        auto current_offset{CpuAddr(commands) - command_base};
+
+        if (current_offset + command.size > commands_buffer_size) {
+            LOG_ERROR(Service_Audio,
+                      "Command exceeded command buffer, buffer size {:08X}, command ends at {:08X}",
+                      commands_buffer_size,
+                      CpuAddr(commands) + command.size - sizeof(Renderer::CommandListHeader));
+            return system->CoreTiming().GetGlobalTimeUs().count() - start_time_;
+        }
+
+        if (Settings::values.dump_audio_commands) {
+            command.Dump(*this, dump);
+        }
+
+        if (!command.Verify(*this)) {
+            break;
+        }
+
+        if (command.enabled) {
+            command.Process(*this);
+        } else {
+            dump += fmt::format("\tDisabled!\n");
+        }
+
+        processed_command_count++;
+        commands += command.size;
+    }
+
+    if (Settings::values.dump_audio_commands && dump != last_dump) {
+        LOG_WARNING(Service_Audio, "{}", dump);
+        last_dump = dump;
+    }
+
+    end_time = system->CoreTiming().GetGlobalTimeUs().count();
+    return end_time - start_time_;
+}
+
+} // namespace AudioCore::ADSP::AudioRenderer
diff --git a/src/audio_core/adsp/apps/audio_renderer/command_list_processor.h b/src/audio_core/adsp/apps/audio_renderer/command_list_processor.h
new file mode 100644
index 000000000..9d6fe1851
--- /dev/null
+++ b/src/audio_core/adsp/apps/audio_renderer/command_list_processor.h
@@ -0,0 +1,120 @@
+// SPDX-FileCopyrightText: Copyright 2023 yuzu Emulator Project
+// SPDX-License-Identifier: GPL-2.0-or-later
+
+#pragma once
+
+#include <span>
+
+#include "audio_core/common/common.h"
+#include "audio_core/renderer/command/command_list_header.h"
+#include "common/common_types.h"
+
+namespace Core {
+namespace Memory {
+class Memory;
+}
+class System;
+} // namespace Core
+
+namespace AudioCore {
+namespace Sink {
+class SinkStream;
+}
+
+namespace Renderer {
+struct CommandListHeader;
+}
+
+namespace ADSP::AudioRenderer {
+
+/**
+ * A processor for command lists given to the AudioRenderer.
+ */
+class CommandListProcessor {
+public:
+    /**
+     * Initialize the processor.
+     *
+     * @param system - The core system.
+     * @param buffer - The command buffer to process.
+     * @param size   - The size of the buffer.
+     * @param stream - The stream to be used for sending the samples.
+     */
+    void Initialize(Core::System& system, CpuAddr buffer, u64 size, Sink::SinkStream* stream);
+
+    /**
+     * Set the maximum processing time for this command list.
+     *
+     * @param time - The maximum process time.
+     */
+    void SetProcessTimeMax(u64 time);
+
+    /**
+     * Get the remaining command count for this list.
+     *
+     * @return The remaining command count.
+     */
+    u32 GetRemainingCommandCount() const;
+
+    /**
+     * Set the command buffer.
+     *
+     * @param buffer - The buffer to use.
+     * @param size   - The size of the buffer.
+     */
+    void SetBuffer(CpuAddr buffer, u64 size);
+
+    /**
+     * Get the stream for this command list.
+     *
+     * @return The stream associated with this command list.
+     */
+    Sink::SinkStream* GetOutputSinkStream() const;
+
+    /**
+     * Process the command list.
+     *
+     * @param session_id - Session ID for the commands being processed.
+     *
+     * @return The time taken to process.
+     */
+    u64 Process(u32 session_id);
+
+    /// Core system
+    Core::System* system{};
+    /// Core memory
+    Core::Memory::Memory* memory{};
+    /// Stream for the processed samples
+    Sink::SinkStream* stream{};
+    /// Header info for this command list
+    Renderer::CommandListHeader* header{};
+    /// The command buffer
+    u8* commands{};
+    /// The command buffer size
+    u64 commands_buffer_size{};
+    /// The maximum processing time allotted
+    u64 max_process_time{};
+    /// The number of commands in the buffer
+    u32 command_count{};
+    /// The target sample count for output
+    u32 sample_count{};
+    /// The target sample rate for output
+    u32 target_sample_rate{};
+    /// The mixing buffers used by the commands
+    std::span<s32> mix_buffers{};
+    /// The number of mix buffers
+    u32 buffer_count{};
+    /// The number of processed commands so far
+    u32 processed_command_count{};
+    /// The processing start time of this list
+    u64 start_time{};
+    /// The current processing time for this list
+    u64 current_processing_time{};
+    /// The end processing time for this list
+    u64 end_time{};
+    /// Last command list string generated, used for dumping audio commands to console
+    std::string last_dump{};
+};
+
+} // namespace ADSP::AudioRenderer
+} // namespace AudioCore
diff --git a/src/audio_core/adsp/mailbox.h b/src/audio_core/adsp/mailbox.h
new file mode 100644
index 000000000..c31b73717
--- /dev/null
+++ b/src/audio_core/adsp/mailbox.h
@@ -0,0 +1,69 @@
+// SPDX-FileCopyrightText: Copyright 2023 yuzu Emulator Project
+// SPDX-License-Identifier: GPL-2.0-or-later
+
+#pragma once
+
+#include "common/bounded_threadsafe_queue.h"
+#include "common/common_types.h"
+
+namespace AudioCore::ADSP {
+
+enum class AppMailboxId : u32 {
+    Invalid = 0,
+    AudioRenderer = 50,
+    AudioRendererMemoryMapUnmap = 51,
+};
+
+enum class Direction : u32 {
+    Host,
+    DSP,
+};
+
+struct MailboxMessage {
+    u32 msg;
+    std::span<u8> data;
+};
+
+class Mailbox {
+public:
+    void Initialize(AppMailboxId id_) {
+        Reset();
+        id = id_;
+    }
+
+    AppMailboxId Id() const noexcept {
+        return id;
+    }
+
+    void Send(Direction dir, MailboxMessage&& message) {
+        auto& queue = dir == Direction::Host ? host_queue : adsp_queue;
+        queue.EmplaceWait(std::move(message));
+    }
+
+    MailboxMessage Receive(Direction dir, bool block = true) {
+        auto& queue = dir == Direction::Host ? host_queue : adsp_queue;
+        MailboxMessage t;
+        if (block) {
+            queue.PopWait(t);
+        } else {
+            queue.TryPop(t);
+        }
+        return t;
+    }
+
+    void Reset() {
+        id = AppMailboxId::Invalid;
+        MailboxMessage t;
+        while (host_queue.TryPop(t)) {
+        }
+        while (adsp_queue.TryPop(t)) {
+        }
+    }
+
+private:
+    AppMailboxId id{0};
+    Common::SPSCQueue<MailboxMessage> host_queue;
+    Common::SPSCQueue<MailboxMessage> adsp_queue;
+};
+
+} // namespace AudioCore::ADSP