Kernel: Simplify PCI initialization logic

- Get rid of the PCI::Initializer object which was not serving any real
  purpose or holding any data members.
- Move command line parsing from init to PCI::initialize().

Kernel/PCI/Definitions.h

@@ -190,7 +190,6 @@ size_t get_BAR_space_size(Address, u8);
 void enable_bus_mastering(Address);
 void disable_bus_mastering(Address);
 
-class Initializer;
 class Access;
 class MMIOAccess;
 class IOAccess;

Kernel/PCI/Initializer.cpp

@@ -36,36 +36,43 @@
 namespace Kernel {
 namespace PCI {
 
-static Initializer* s_pci_initializer;
+static void initialize_pci_mmio_access(PhysicalAddress mcfg);
+static void initialize_pci_io_access();
+static void test_and_initialize(bool disable_pci_mmio);
+static void detect_devices();
+static bool test_acpi();
+static bool test_pci_io();
+static bool test_pci_mmio();
+static void initialize_pci_mmio_access_after_test();
 
-Initializer& Initializer::the()
+void initialize()
 {
-    if (s_pci_initializer == nullptr) {
-        s_pci_initializer = new Initializer();
+    bool pci_mmio = kernel_command_line().lookup("pci_mmio").value_or("off") == "on";
+    test_and_initialize(!pci_mmio);
 }
-    return *s_pci_initializer;
-}
-void Initializer::initialize_pci_mmio_access(PhysicalAddress mcfg)
+
+void initialize_pci_mmio_access(PhysicalAddress mcfg)
 {
     MMIOAccess::initialize(mcfg);
     detect_devices();
 }
-void Initializer::initialize_pci_io_access()
+
+void initialize_pci_io_access()
 {
     IOAccess::initialize();
     detect_devices();
 }
 
-void Initializer::detect_devices()
+void detect_devices()
 {
     enumerate_all([&](const Address& address, ID id) {
-        klog() << "PCI: device @ " << String::format("%w", address.seg()) << ":" << String::format("%b", address.bus()) << ":" << String::format("%b", address.slot()) << "." << String::format("%d", address.function()) << " [" << String::format("%w", id.vendor_id) << ":" << String::format("%w", id.device_id) << "]";
+        klog() << "PCI: Device @ " << String::format("%w", address.seg()) << ":" << String::format("%b", address.bus()) << ":" << String::format("%b", address.slot()) << "." << String::format("%d", address.function()) << " [" << String::format("%w", id.vendor_id) << ":" << String::format("%w", id.device_id) << "]";
         E1000NetworkAdapter::detect(address);
         RTL8139NetworkAdapter::detect(address);
     });
 }
 
-void Initializer::test_and_initialize(bool disable_pci_mmio)
+void test_and_initialize(bool disable_pci_mmio)
 {
     if (disable_pci_mmio) {
         if (test_pci_io()) {
@@ -96,18 +103,15 @@ void Initializer::test_and_initialize(bool disable_pci_mmio)
         }
     }
 }
-Initializer::Initializer()
-{
-}
-bool Initializer::test_acpi()
+
+bool test_acpi()
 {
     if ((kernel_command_line().contains("noacpi")) || !ACPI::Parser::the().is_operable())
         return false;
-    else
     return true;
 }
 
-bool Initializer::test_pci_io()
+bool test_pci_io()
 {
     klog() << "Testing PCI via manual probing... ";
     u32 tmp = 0x80000000;
@@ -122,28 +126,15 @@ bool Initializer::test_pci_io()
     return false;
 }
 
-bool Initializer::test_pci_mmio()
+bool test_pci_mmio()
 {
     return !ACPI::Parser::the().find_table("MCFG").is_null();
 }
 
-void Initializer::initialize_pci_mmio_access_after_test()
+void initialize_pci_mmio_access_after_test()
 {
     initialize_pci_mmio_access(ACPI::Parser::the().find_table("MCFG"));
 }
 
-void Initializer::dismiss()
-{
-    if (s_pci_initializer == nullptr)
-        return;
-    klog() << "PCI Subsystem Initializer dismissed.";
-    delete s_pci_initializer;
-    s_pci_initializer = nullptr;
-}
-
-Initializer::~Initializer()
-{
-}
-
 }
 }

Kernel/PCI/Initializer.h

@@ -26,28 +26,10 @@
 
 #pragma once
 
-#include <AK/Types.h>
-#include <Kernel/ACPI/Definitions.h>
-#include <Kernel/PCI/Definitions.h>
-
 namespace Kernel {
+namespace PCI {
 
-class PCI::Initializer {
-public:
-    static PCI::Initializer& the();
-    void initialize_pci_mmio_access(PhysicalAddress mcfg);
-    void initialize_pci_io_access();
-    void test_and_initialize(bool disable_pci_mmio);
-    static void dismiss();
-
-private:
-    void detect_devices();
-    ~Initializer();
-    Initializer();
-    bool test_acpi();
-    bool test_pci_io();
-    bool test_pci_mmio();
-    void initialize_pci_mmio_access_after_test();
-};
+void initialize();
 
 }
+}

Kernel/init.cpp

@@ -86,7 +86,6 @@ namespace Kernel {
 [[noreturn]] static void init_stage2();
 static void setup_serial_debug();
 static void setup_acpi();
-static void setup_pci();
 static void setup_interrupts();
 static void setup_time_management();
 
@@ -171,7 +170,7 @@ void init_stage2()
     // Sample test to see if the ACPI parser is working...
     klog() << "ACPI: HPET table @ " << ACPI::Parser::the().find_table("HPET");
 
-    setup_pci();
+    PCI::initialize();
 
     if (kernel_command_line().contains("text_debug")) {
         dbg() << "Text mode enabled";
@@ -389,25 +388,6 @@ void setup_acpi()
     hang();
 }
 
-void setup_pci()
-{
-    if (!kernel_command_line().contains("pci_mmio")) {
-        PCI::Initializer::the().test_and_initialize(false);
-        PCI::Initializer::the().dismiss();
-        return;
-    }
-    auto pci_mmio = kernel_command_line().get("pci_mmio");
-    if (pci_mmio == "on") {
-        PCI::Initializer::the().test_and_initialize(false);
-    } else if (pci_mmio == "off") {
-        PCI::Initializer::the().test_and_initialize(true);
-    } else {
-        klog() << "pci_mmio boot argmuent has an invalid value.";
-        hang();
-    }
-    PCI::Initializer::the().dismiss();
-}
-
 void setup_interrupts()
 {
     InterruptManagement::initialize();