Kernel/USB: Split SysFS code into its own file

This makes it controller agnostic and allows us to access it from the
USB hub code.

The copyright says "Liav A." because git blame says he wrote this.

Kernel/Bus/USB/SysFSUSB.cpp

@@ -0,0 +1,127 @@
+/*
+ * Copyright (c) 2021, Liav A. <liavalb@hotmail.co.il>
+ *
+ * SPDX-License-Identifier: BSD-2-Clause
+ */
+
+#include <AK/JsonArraySerializer.h>
+#include <AK/JsonObjectSerializer.h>
+#include <Kernel/Bus/USB/SysFSUSB.h>
+#include <Kernel/KBufferBuilder.h>
+
+namespace Kernel::USB {
+
+static SysFSUSBBusDirectory* s_procfs_usb_bus_directory;
+
+SysFSUSBDeviceInformation::SysFSUSBDeviceInformation(USB::Device& device)
+    : SysFSComponent(String::number(device.address()))
+    , m_device(device)
+{
+}
+
+SysFSUSBDeviceInformation::~SysFSUSBDeviceInformation()
+{
+}
+
+KResultOr<size_t> SysFSUSBDeviceInformation::read_bytes(off_t offset, size_t count, UserOrKernelBuffer& buffer, FileDescription*) const
+{
+    KBufferBuilder builder;
+    JsonArraySerializer array { builder };
+
+    auto obj = array.add_object();
+    obj.add("usb_spec_compliance_bcd", m_device->device_descriptor().usb_spec_compliance_bcd);
+    obj.add("device_class", m_device->device_descriptor().device_class);
+    obj.add("device_sub_class", m_device->device_descriptor().device_sub_class);
+    obj.add("device_protocol", m_device->device_descriptor().device_protocol);
+    obj.add("max_packet_size", m_device->device_descriptor().max_packet_size);
+    obj.add("vendor_id", m_device->device_descriptor().vendor_id);
+    obj.add("product_id", m_device->device_descriptor().product_id);
+    obj.add("device_release_bcd", m_device->device_descriptor().device_release_bcd);
+    obj.add("manufacturer_id_descriptor_index", m_device->device_descriptor().manufacturer_id_descriptor_index);
+    obj.add("product_string_descriptor_index", m_device->device_descriptor().product_string_descriptor_index);
+    obj.add("serial_number_descriptor_index", m_device->device_descriptor().serial_number_descriptor_index);
+    obj.add("num_configurations", m_device->device_descriptor().num_configurations);
+    obj.finish();
+    array.finish();
+
+    auto data = builder.build();
+    if (!data)
+        return ENOMEM;
+
+    ssize_t nread = min(static_cast<off_t>(data->size() - offset), static_cast<off_t>(count));
+    if (!buffer.write(data->data() + offset, nread))
+        return EFAULT;
+
+    return nread;
+}
+
+KResult SysFSUSBBusDirectory::traverse_as_directory(unsigned fsid, Function<bool(FileSystem::DirectoryEntryView const&)> callback) const
+{
+    ScopedSpinLock lock(m_lock);
+    // Note: if the parent directory is null, it means something bad happened as this should not happen for the USB directory.
+    VERIFY(m_parent_directory);
+    callback({ ".", { fsid, component_index() }, 0 });
+    callback({ "..", { fsid, m_parent_directory->component_index() }, 0 });
+
+    for (auto& device_node : m_device_nodes) {
+        InodeIdentifier identifier = { fsid, device_node.component_index() };
+        callback({ device_node.name(), identifier, 0 });
+    }
+    return KSuccess;
+}
+
+RefPtr<SysFSComponent> SysFSUSBBusDirectory::lookup(StringView name)
+{
+    ScopedSpinLock lock(m_lock);
+    for (auto& device_node : m_device_nodes) {
+        if (device_node.name() == name) {
+            return device_node;
+        }
+    }
+    return {};
+}
+
+RefPtr<SysFSUSBDeviceInformation> SysFSUSBBusDirectory::device_node_for(USB::Device& device)
+{
+    RefPtr<USB::Device> checked_device = device;
+    for (auto& device_node : m_device_nodes) {
+        if (device_node.device().ptr() == checked_device.ptr())
+            return device_node;
+    }
+    return {};
+}
+
+void SysFSUSBBusDirectory::plug(USB::Device& new_device)
+{
+    ScopedSpinLock lock(m_lock);
+    auto device_node = device_node_for(new_device);
+    VERIFY(!device_node);
+    m_device_nodes.append(SysFSUSBDeviceInformation::create(new_device));
+}
+
+void SysFSUSBBusDirectory::unplug(USB::Device& deleted_device)
+{
+    ScopedSpinLock lock(m_lock);
+    auto device_node = device_node_for(deleted_device);
+    VERIFY(device_node);
+    device_node->m_list_node.remove();
+}
+
+UNMAP_AFTER_INIT SysFSUSBBusDirectory::SysFSUSBBusDirectory(SysFSBusDirectory& buses_directory)
+    : SysFSDirectory("usb"sv, buses_directory)
+{
+}
+
+UNMAP_AFTER_INIT void SysFSUSBBusDirectory::initialize()
+{
+    auto directory = adopt_ref(*new SysFSUSBBusDirectory(SysFSComponentRegistry::the().buses_directory()));
+    SysFSComponentRegistry::the().register_new_bus_directory(directory);
+    s_procfs_usb_bus_directory = directory;
+}
+
+NonnullRefPtr<SysFSUSBDeviceInformation> SysFSUSBDeviceInformation::create(USB::Device& device)
+{
+    return adopt_ref(*new SysFSUSBDeviceInformation(device));
+}
+
+}

Kernel/Bus/USB/SysFSUSB.h

@@ -0,0 +1,52 @@
+/*
+ * Copyright (c) 2021, Liav A. <liavalb@hotmail.co.il>
+ *
+ * SPDX-License-Identifier: BSD-2-Clause
+ */
+
+#pragma once
+
+#include <Kernel/Bus/USB/USBDevice.h>
+#include <Kernel/FileSystem/SysFS.h>
+
+namespace Kernel::USB {
+
+class SysFSUSBDeviceInformation : public SysFSComponent {
+    friend class SysFSUSBBusDirectory;
+
+public:
+    virtual ~SysFSUSBDeviceInformation() override;
+
+    static NonnullRefPtr<SysFSUSBDeviceInformation> create(USB::Device&);
+
+    RefPtr<USB::Device> device() const { return m_device; }
+
+protected:
+    explicit SysFSUSBDeviceInformation(USB::Device& device);
+
+    virtual KResultOr<size_t> read_bytes(off_t offset, size_t count, UserOrKernelBuffer& buffer, FileDescription*) const override;
+
+    IntrusiveListNode<SysFSUSBDeviceInformation, RefPtr<SysFSUSBDeviceInformation>> m_list_node;
+
+    NonnullRefPtr<USB::Device> m_device;
+};
+
+class SysFSUSBBusDirectory final : public SysFSDirectory {
+public:
+    static void initialize();
+    void plug(USB::Device&);
+    void unplug(USB::Device&);
+
+    virtual KResult traverse_as_directory(unsigned, Function<bool(FileSystem::DirectoryEntryView const&)>) const override;
+    virtual RefPtr<SysFSComponent> lookup(StringView name) override;
+
+private:
+    explicit SysFSUSBBusDirectory(SysFSBusDirectory&);
+
+    RefPtr<SysFSUSBDeviceInformation> device_node_for(USB::Device& device);
+
+    IntrusiveList<SysFSUSBDeviceInformation, RefPtr<SysFSUSBDeviceInformation>, &SysFSUSBDeviceInformation::m_list_node> m_device_nodes;
+    mutable SpinLock<u8> m_lock;
+};
+
+}

Kernel/Bus/USB/UHCIController.cpp

@@ -5,15 +5,11 @@
  * SPDX-License-Identifier: BSD-2-Clause
  */
 
-#include <AK/JsonArraySerializer.h>
-#include <AK/JsonObjectSerializer.h>
 #include <AK/Platform.h>
 #include <Kernel/Bus/USB/UHCIController.h>
 #include <Kernel/Bus/USB/USBRequest.h>
 #include <Kernel/CommandLine.h>
 #include <Kernel/Debug.h>
-#include <Kernel/FileSystem/SysFS.h>
-#include <Kernel/KBufferBuilder.h>
 #include <Kernel/Memory/AnonymousVMObject.h>
 #include <Kernel/Memory/MemoryManager.h>
 #include <Kernel/Process.h>
@@ -68,148 +64,6 @@ static constexpr u16 UCHI_PORTSC_NON_WRITE_CLEAR_BIT_MASK = 0x1FF5; // This is u
 static constexpr u8 UHCI_NUMBER_OF_ISOCHRONOUS_TDS = 128;
 static constexpr u16 UHCI_NUMBER_OF_FRAMES = 1024;
 
-class SysFSUSBBusDirectory;
-static SysFSUSBBusDirectory* s_procfs_usb_bus_directory;
-
-class SysFSUSBDeviceInformation : public SysFSComponent {
-    friend class SysFSUSBBusDirectory;
-
-public:
-    virtual ~SysFSUSBDeviceInformation() override {};
-
-    static NonnullRefPtr<SysFSUSBDeviceInformation> create(USB::Device&);
-
-    RefPtr<USB::Device> device() const { return m_device; }
-
-protected:
-    explicit SysFSUSBDeviceInformation(USB::Device& device)
-        : SysFSComponent(String::number(device.address()))
-        , m_device(device)
-    {
-    }
-
-    virtual KResultOr<size_t> read_bytes(off_t offset, size_t count, UserOrKernelBuffer& buffer, FileDescription*) const override
-    {
-        KBufferBuilder builder;
-        JsonArraySerializer array { builder };
-
-        auto obj = array.add_object();
-        obj.add("usb_spec_compliance_bcd", m_device->device_descriptor().usb_spec_compliance_bcd);
-        obj.add("device_class", m_device->device_descriptor().device_class);
-        obj.add("device_sub_class", m_device->device_descriptor().device_sub_class);
-        obj.add("device_protocol", m_device->device_descriptor().device_protocol);
-        obj.add("max_packet_size", m_device->device_descriptor().max_packet_size);
-        obj.add("vendor_id", m_device->device_descriptor().vendor_id);
-        obj.add("product_id", m_device->device_descriptor().product_id);
-        obj.add("device_release_bcd", m_device->device_descriptor().device_release_bcd);
-        obj.add("manufacturer_id_descriptor_index", m_device->device_descriptor().manufacturer_id_descriptor_index);
-        obj.add("product_string_descriptor_index", m_device->device_descriptor().product_string_descriptor_index);
-        obj.add("serial_number_descriptor_index", m_device->device_descriptor().serial_number_descriptor_index);
-        obj.add("num_configurations", m_device->device_descriptor().num_configurations);
-        obj.finish();
-        array.finish();
-
-        auto data = builder.build();
-        if (!data)
-            return ENOMEM;
-
-        ssize_t nread = min(static_cast<off_t>(data->size() - offset), static_cast<off_t>(count));
-        if (!buffer.write(data->data() + offset, nread))
-            return EFAULT;
-
-        return nread;
-    }
-    IntrusiveListNode<SysFSUSBDeviceInformation, RefPtr<SysFSUSBDeviceInformation>> m_list_node;
-
-    NonnullRefPtr<USB::Device> m_device;
-};
-
-class SysFSUSBBusDirectory final : public SysFSDirectory {
-public:
-    static void initialize();
-    void plug(USB::Device&);
-    void unplug(USB::Device&);
-
-    virtual KResult traverse_as_directory(unsigned, Function<bool(FileSystem::DirectoryEntryView const&)>) const override;
-    virtual RefPtr<SysFSComponent> lookup(StringView name) override;
-
-private:
-    explicit SysFSUSBBusDirectory(SysFSBusDirectory&);
-
-    RefPtr<SysFSUSBDeviceInformation> device_node_for(USB::Device& device);
-
-    IntrusiveList<SysFSUSBDeviceInformation, RefPtr<SysFSUSBDeviceInformation>, &SysFSUSBDeviceInformation::m_list_node> m_device_nodes;
-    mutable SpinLock<u8> m_lock;
-};
-
-KResult SysFSUSBBusDirectory::traverse_as_directory(unsigned fsid, Function<bool(FileSystem::DirectoryEntryView const&)> callback) const
-{
-    ScopedSpinLock lock(m_lock);
-    // Note: if the parent directory is null, it means something bad happened as this should not happen for the USB directory.
-    VERIFY(m_parent_directory);
-    callback({ ".", { fsid, component_index() }, 0 });
-    callback({ "..", { fsid, m_parent_directory->component_index() }, 0 });
-
-    for (auto& device_node : m_device_nodes) {
-        InodeIdentifier identifier = { fsid, device_node.component_index() };
-        callback({ device_node.name(), identifier, 0 });
-    }
-    return KSuccess;
-}
-RefPtr<SysFSComponent> SysFSUSBBusDirectory::lookup(StringView name)
-{
-    ScopedSpinLock lock(m_lock);
-    for (auto& device_node : m_device_nodes) {
-        if (device_node.name() == name) {
-            return device_node;
-        }
-    }
-    return {};
-}
-
-RefPtr<SysFSUSBDeviceInformation> SysFSUSBBusDirectory::device_node_for(USB::Device& device)
-{
-    RefPtr<USB::Device> checked_device = device;
-    for (auto& device_node : m_device_nodes) {
-        if (device_node.device().ptr() == checked_device.ptr())
-            return device_node;
-    }
-    return {};
-}
-
-void SysFSUSBBusDirectory::plug(USB::Device& new_device)
-{
-    ScopedSpinLock lock(m_lock);
-    auto device_node = device_node_for(new_device);
-    VERIFY(!device_node);
-    m_device_nodes.append(SysFSUSBDeviceInformation::create(new_device));
-}
-
-void SysFSUSBBusDirectory::unplug(USB::Device& deleted_device)
-{
-    ScopedSpinLock lock(m_lock);
-    auto device_node = device_node_for(deleted_device);
-    VERIFY(device_node);
-    device_node->m_list_node.remove();
-}
-
-UNMAP_AFTER_INIT SysFSUSBBusDirectory::SysFSUSBBusDirectory(SysFSBusDirectory& buses_directory)
-    : SysFSDirectory("usb"sv, buses_directory)
-{
-}
-
-UNMAP_AFTER_INIT void SysFSUSBBusDirectory::initialize()
-{
-    auto directory = adopt_ref(*new SysFSUSBBusDirectory(SysFSComponentRegistry::the().buses_directory()));
-    SysFSComponentRegistry::the().register_new_bus_directory(directory);
-    s_procfs_usb_bus_directory = directory;
-}
-
-NonnullRefPtr<SysFSUSBDeviceInformation> SysFSUSBDeviceInformation::create(USB::Device& device)
-{
-    return adopt_ref(*new SysFSUSBDeviceInformation(device));
-}
-
 KResultOr<NonnullRefPtr<UHCIController>> UHCIController::try_to_initialize(PCI::Address address)
 {
     // NOTE: This assumes that address is pointing to a valid UHCI controller.
@@ -226,10 +80,6 @@ KResultOr<NonnullRefPtr<UHCIController>> UHCIController::try_to_initialize(PCI::
 
 KResult UHCIController::initialize()
 {
-    // FIXME: We create the /proc/bus/usb representation here, but it should really be handled
-    // in a more broad singleton than this once we refactor things in USB subsystem.
-    SysFSUSBBusDirectory::initialize();
-
     dmesgln("UHCI: Controller found {} @ {}", PCI::get_id(pci_address()), pci_address());
     dmesgln("UHCI: I/O base {}", m_io_base);
     dmesgln("UHCI: Interrupt line: {}", PCI::get_interrupt_line(pci_address()));

Kernel/Bus/USB/USBManagement.cpp

@@ -6,6 +6,7 @@
 
 #include <AK/Singleton.h>
 #include <Kernel/Bus/PCI/Access.h>
+#include <Kernel/Bus/USB/SysFSUSB.h>
 #include <Kernel/Bus/USB/UHCIController.h>
 #include <Kernel/Bus/USB/USBManagement.h>
 #include <Kernel/CommandLine.h>
@@ -14,6 +15,7 @@
 namespace Kernel::USB {
 
 static Singleton<USBManagement> s_the;
+READONLY_AFTER_INIT bool s_initialized_sys_fs_directory = false;
 
 UNMAP_AFTER_INIT USBManagement::USBManagement()
 {
@@ -64,6 +66,11 @@ bool USBManagement::initialized()
 
 UNMAP_AFTER_INIT void USBManagement::initialize()
 {
+    if (!s_initialized_sys_fs_directory) {
+        USB::SysFSUSBBusDirectory::initialize();
+        s_initialized_sys_fs_directory = true;
+    }
+
     s_the.ensure_instance();
 }
 

Kernel/CMakeLists.txt

@@ -31,6 +31,7 @@ set(KERNEL_SOURCES
     Bus/PCI/MMIOAccess.cpp
     Bus/PCI/Initializer.cpp
     Bus/PCI/WindowedMMIOAccess.cpp
+    Bus/USB/SysFSUSB.cpp
     Bus/USB/UHCIController.cpp
     Bus/USB/UHCIRootHub.cpp
     Bus/USB/USBController.cpp