Kernel: Unify BIOS and ACPI components in the SysFS firmware directory

Both should reside in the SysFS firmware directory which is normally
located in /sys/firmware.
Also, apply some OOM-safety patterns when creating the BIOS and ACPI
directories.

Kernel/CMakeLists.txt

@@ -127,6 +127,7 @@ set(KERNEL_SOURCES
     Firmware/ACPI/MultiProcessorParser.cpp
     Firmware/ACPI/Parser.cpp
     Firmware/BIOS.cpp
+    Firmware/SysFSFirmware.cpp
     FutexQueue.cpp
     Interrupts/APIC.cpp
     Interrupts/GenericInterruptHandler.cpp

Kernel/Firmware/ACPI/Parser.cpp

@@ -7,6 +7,7 @@
 
 #include <AK/Format.h>
 #include <AK/StringView.h>
+#include <AK/Try.h>
 #include <Kernel/Arch/x86/InterruptDisabler.h>
 #include <Kernel/Bus/PCI/API.h>
 #include <Kernel/Debug.h>
@@ -63,14 +64,14 @@ UNMAP_AFTER_INIT ACPISysFSComponent::ACPISysFSComponent(String name, PhysicalAdd
 {
 }
 
-UNMAP_AFTER_INIT void ACPISysFSDirectory::initialize()
+UNMAP_AFTER_INIT KResultOr<NonnullRefPtr<ACPISysFSDirectory>> ACPISysFSDirectory::try_create(FirmwareSysFSDirectory& firmware_directory)
 {
-    auto acpi_directory = adopt_ref(*new (nothrow) ACPISysFSDirectory());
+    auto acpi_directory = TRY(adopt_nonnull_ref_or_enomem(new (nothrow) ACPISysFSDirectory(firmware_directory)));
-    SysFSComponentRegistry::the().register_new_component(acpi_directory);
+    return acpi_directory;
 }
 
-UNMAP_AFTER_INIT ACPISysFSDirectory::ACPISysFSDirectory()
+UNMAP_AFTER_INIT ACPISysFSDirectory::ACPISysFSDirectory(FirmwareSysFSDirectory& firmware_directory)
-    : SysFSDirectory("acpi", SysFSComponentRegistry::the().root_directory())
+    : SysFSDirectory("acpi", firmware_directory)
 {
     NonnullRefPtrVector<SysFSComponent> components;
     size_t ssdt_count = 0;

Kernel/Firmware/ACPI/Parser.h

@@ -6,11 +6,13 @@
 
 #pragma once
 
+#include <AK/RefPtr.h>
 #include <AK/Types.h>
 #include <Kernel/CommandLine.h>
 #include <Kernel/FileSystem/SysFSComponent.h>
 #include <Kernel/Firmware/ACPI/Definitions.h>
 #include <Kernel/Firmware/ACPI/Initialize.h>
+#include <Kernel/Firmware/SysFSFirmware.h>
 #include <Kernel/Interrupts/IRQHandler.h>
 #include <Kernel/Memory/Region.h>
 #include <Kernel/PhysicalAddress.h>
@@ -20,10 +22,10 @@ namespace Kernel::ACPI {
 
 class ACPISysFSDirectory : public SysFSDirectory {
 public:
-    static void initialize();
+    static KResultOr<NonnullRefPtr<ACPISysFSDirectory>> try_create(FirmwareSysFSDirectory& firmware_directory);
 
 private:
-    ACPISysFSDirectory();
+    explicit ACPISysFSDirectory(FirmwareSysFSDirectory& firmware_directory);
 };
 
 class ACPISysFSComponent : public SysFSComponent {

Kernel/Firmware/BIOS.cpp

@@ -90,11 +90,11 @@ UNMAP_AFTER_INIT void BIOSSysFSDirectory::set_dmi_32_bit_entry_initialization_va
     m_smbios_structure_table_length = smbios_entry.ptr()->legacy_structure.smboios_table_length;
 }
 
-UNMAP_AFTER_INIT void BIOSSysFSDirectory::initialize()
+UNMAP_AFTER_INIT KResultOr<NonnullRefPtr<BIOSSysFSDirectory>> BIOSSysFSDirectory::try_create(FirmwareSysFSDirectory& firmware_directory)
 {
-    auto bios_directory = adopt_ref(*new (nothrow) BIOSSysFSDirectory());
+    auto bios_directory = TRY(adopt_nonnull_ref_or_enomem(new (nothrow) BIOSSysFSDirectory(firmware_directory)));
-    SysFSComponentRegistry::the().register_new_component(bios_directory);
     bios_directory->create_components();
+    return bios_directory;
 }
 
 void BIOSSysFSDirectory::create_components()
@@ -126,8 +126,8 @@ UNMAP_AFTER_INIT void BIOSSysFSDirectory::initialize_dmi_exposer()
     dbgln("BIOSSysFSDirectory: Data table @ {}", m_smbios_structure_table);
 }
 
-UNMAP_AFTER_INIT BIOSSysFSDirectory::BIOSSysFSDirectory()
+UNMAP_AFTER_INIT BIOSSysFSDirectory::BIOSSysFSDirectory(FirmwareSysFSDirectory& firmware_directory)
-    : SysFSDirectory("bios", SysFSComponentRegistry::the().root_directory())
+    : SysFSDirectory("bios", firmware_directory)
 {
     auto entry_32bit = find_dmi_entry32bit_point();
     if (entry_32bit.has_value()) {

Kernel/Firmware/BIOS.h

@@ -7,9 +7,11 @@
 
 #pragma once
 
+#include <AK/RefPtr.h>
 #include <AK/Types.h>
 #include <AK/Vector.h>
 #include <Kernel/FileSystem/SysFS.h>
+#include <Kernel/Firmware/SysFSFirmware.h>
 #include <Kernel/KBuffer.h>
 #include <Kernel/Memory/MappedROM.h>
 #include <Kernel/Memory/Region.h>
@@ -92,12 +94,12 @@ private:
 
 class BIOSSysFSDirectory : public SysFSDirectory {
 public:
-    static void initialize();
+    static KResultOr<NonnullRefPtr<BIOSSysFSDirectory>> try_create(FirmwareSysFSDirectory&);
 
     void create_components();
 
 private:
-    BIOSSysFSDirectory();
+    explicit BIOSSysFSDirectory(FirmwareSysFSDirectory&);
 
     void set_dmi_64_bit_entry_initialization_values();
     void set_dmi_32_bit_entry_initialization_values();

Kernel/Firmware/SysFSFirmware.cpp

@@ -0,0 +1,36 @@
+/*
+ * Copyright (c) 2021, Liav A. <liavalb@hotmail.co.il>
+ *
+ * SPDX-License-Identifier: BSD-2-Clause
+ */
+
+#include <Kernel/Firmware/ACPI/Parser.h>
+#include <Kernel/Firmware/BIOS.h>
+#include <Kernel/Firmware/SysFSFirmware.h>
+#include <Kernel/Sections.h>
+
+namespace Kernel {
+
+UNMAP_AFTER_INIT void FirmwareSysFSDirectory::initialize()
+{
+    auto firmware_directory = adopt_ref_if_nonnull(new (nothrow) FirmwareSysFSDirectory()).release_nonnull();
+    SysFSComponentRegistry::the().register_new_component(firmware_directory);
+    firmware_directory->create_components();
+}
+
+void FirmwareSysFSDirectory::create_components()
+{
+    auto bios_directory_or_error = BIOSSysFSDirectory::try_create(*this);
+    VERIFY(!bios_directory_or_error.is_error());
+    auto acpi_directory_or_error = ACPI::ACPISysFSDirectory::try_create(*this);
+    VERIFY(!acpi_directory_or_error.is_error());
+    m_components.append(bios_directory_or_error.release_value());
+    m_components.append(acpi_directory_or_error.release_value());
+}
+
+UNMAP_AFTER_INIT FirmwareSysFSDirectory::FirmwareSysFSDirectory()
+    : SysFSDirectory("firmware", SysFSComponentRegistry::the().root_directory())
+{
+}
+
+}

Kernel/Firmware/SysFSFirmware.h

@@ -0,0 +1,24 @@
+/*
+ * Copyright (c) 2021, Liav A. <liavalb@hotmail.co.il>
+ *
+ * SPDX-License-Identifier: BSD-2-Clause
+ */
+
+#pragma once
+
+#include <AK/Types.h>
+#include <Kernel/FileSystem/SysFS.h>
+
+namespace Kernel {
+
+class FirmwareSysFSDirectory : public SysFSDirectory {
+public:
+    static void initialize();
+
+    void create_components();
+
+private:
+    FirmwareSysFSDirectory();
+};
+
+}

Kernel/init.cpp

@@ -30,7 +30,7 @@
 #include <Kernel/Firmware/ACPI/Initialize.h>
 #include <Kernel/Firmware/ACPI/MultiProcessorParser.h>
 #include <Kernel/Firmware/ACPI/Parser.h>
-#include <Kernel/Firmware/BIOS.h>
+#include <Kernel/Firmware/SysFSFirmware.h>
 #include <Kernel/Graphics/GraphicsManagement.h>
 #include <Kernel/Heap/SlabAllocator.h>
 #include <Kernel/Heap/kmalloc.h>
@@ -300,9 +300,7 @@ void init_stage2(void*)
     auto boot_profiling = kernel_command_line().is_boot_profiling_enabled();
 
     USB::USBManagement::initialize();
-
+    FirmwareSysFSDirectory::initialize();
-    BIOSSysFSDirectory::initialize();
-    ACPI::ACPISysFSDirectory::initialize();
 
     VirtIO::detect();