Kernel/Graphics: Move x86-specific support for VGA to Arch/x86 directory

The new VGAIOArbiter class is now responsible to conduct x86-specific
instructions to control VGA hardware from the old ISA ports. This allows
us to ensure the GraphicsManagement code doesn't use x86-specific code,
thus allowing it to be compiled within non-x86 kernel builds.

Kernel/Arch/x86/VGA/IOArbiter.cpp

@@ -0,0 +1,83 @@
+/*
+ * Copyright (c) 2022, Liav A. <liavalb@hotmail.co.il>
+ *
+ * SPDX-License-Identifier: BSD-2-Clause
+ */
+
+#include <AK/Try.h>
+#include <Kernel/Arch/Delay.h>
+#include <Kernel/Arch/x86/CPU.h>
+#include <Kernel/Arch/x86/IO.h>
+#include <Kernel/Arch/x86/VGA/IOArbiter.h>
+
+namespace Kernel {
+
+NonnullOwnPtr<VGAIOArbiter> VGAIOArbiter::must_create(Badge<GraphicsManagement>)
+{
+    return MUST(adopt_nonnull_own_or_enomem(new (nothrow) VGAIOArbiter()));
+}
+
+VGAIOArbiter::~VGAIOArbiter() = default;
+VGAIOArbiter::VGAIOArbiter() = default;
+
+void VGAIOArbiter::disable_vga_emulation_access_permanently(Badge<GraphicsManagement>)
+{
+    SpinlockLocker locker(m_main_vga_lock);
+    disable_vga_text_mode_console_cursor();
+    IO::out8(0x3c4, 1);
+    u8 sr1 = IO::in8(0x3c5);
+    IO::out8(0x3c5, sr1 | 1 << 5);
+    microseconds_delay(1000);
+    m_vga_access_is_disabled = true;
+}
+
+void VGAIOArbiter::enable_vga_text_mode_console_cursor(Badge<GraphicsManagement>)
+{
+    enable_vga_text_mode_console_cursor();
+}
+
+void VGAIOArbiter::enable_vga_text_mode_console_cursor()
+{
+    SpinlockLocker locker(m_main_vga_lock);
+    if (m_vga_access_is_disabled)
+        return;
+    IO::out8(0x3D4, 0xA);
+    IO::out8(0x3D5, 0);
+}
+
+void VGAIOArbiter::disable_vga_text_mode_console_cursor(Badge<GraphicsManagement>)
+{
+    disable_vga_text_mode_console_cursor();
+}
+
+void VGAIOArbiter::disable_vga_text_mode_console_cursor()
+{
+    SpinlockLocker locker(m_main_vga_lock);
+    if (m_vga_access_is_disabled)
+        return;
+    IO::out8(0x3D4, 0xA);
+    IO::out8(0x3D5, 0x20);
+}
+
+void VGAIOArbiter::unblank_screen(Badge<GraphicsManagement>)
+{
+    SpinlockLocker locker(m_main_vga_lock);
+    if (m_vga_access_is_disabled)
+        return;
+    IO::out8(0x3c0, 0x20);
+}
+
+void VGAIOArbiter::set_vga_text_mode_cursor(Badge<GraphicsManagement>, size_t console_width, size_t x, size_t y)
+{
+    SpinlockLocker locker(m_main_vga_lock);
+    if (m_vga_access_is_disabled)
+        return;
+    enable_vga_text_mode_console_cursor();
+    u16 value = y * console_width + x;
+    IO::out8(0x3d4, 0x0e);
+    IO::out8(0x3d5, MSB(value));
+    IO::out8(0x3d4, 0x0f);
+    IO::out8(0x3d5, LSB(value));
+}
+
+}

Kernel/Arch/x86/VGA/IOArbiter.h

@@ -0,0 +1,40 @@
+/*
+ * Copyright (c) 2022, Liav A. <liavalb@hotmail.co.il>
+ *
+ * SPDX-License-Identifier: BSD-2-Clause
+ */
+
+#pragma once
+
+#include <AK/NonnullOwnPtr.h>
+#include <AK/Platform.h>
+#include <AK/Types.h>
+#include <Kernel/Locking/Spinlock.h>
+
+namespace Kernel {
+
+class GraphicsManagement;
+class VGAIOArbiter {
+public:
+    static NonnullOwnPtr<VGAIOArbiter> must_create(Badge<GraphicsManagement>);
+
+    void disable_vga_emulation_access_permanently(Badge<GraphicsManagement>);
+    void enable_vga_text_mode_console_cursor(Badge<GraphicsManagement>);
+    void disable_vga_text_mode_console_cursor(Badge<GraphicsManagement>);
+    void set_vga_text_mode_cursor(Badge<GraphicsManagement>, size_t console_width, size_t x, size_t y);
+
+    void unblank_screen(Badge<GraphicsManagement>);
+
+    ~VGAIOArbiter();
+
+private:
+    VGAIOArbiter();
+
+    void disable_vga_text_mode_console_cursor();
+    void enable_vga_text_mode_console_cursor();
+
+    RecursiveSpinlock m_main_vga_lock { LockRank::None };
+    bool m_vga_access_is_disabled { false };
+};
+
+}

Kernel/CMakeLists.txt

@@ -344,6 +344,8 @@ if ("${SERENITY_ARCH}" STREQUAL "i686" OR "${SERENITY_ARCH}" STREQUAL "x86_64")
         Arch/x86/PCI/Controller/HostBridge.cpp
         Arch/x86/PCI/IDELegacyModeController.cpp
         Arch/x86/PCI/Initializer.cpp
+
+        Arch/x86/VGA/IOArbiter.cpp
     )
 
     set(KERNEL_SOURCES

Kernel/Graphics/GraphicsManagement.cpp

@@ -6,7 +6,6 @@
 
 #include <AK/Singleton.h>
 #include <Kernel/Arch/Delay.h>
-#include <Kernel/Arch/x86/IO.h>
 #if ARCH(I386) || ARCH(X86_64)
 #    include <Kernel/Arch/x86/Hypervisor/BochsDisplayConnector.h>
 #endif
@@ -45,44 +44,38 @@ UNMAP_AFTER_INIT GraphicsManagement::GraphicsManagement()
 
 void GraphicsManagement::disable_vga_emulation_access_permanently()
 {
-    SpinlockLocker locker(m_main_vga_lock);
+#if ARCH(I386) || ARCH(X86_64)
-    disable_vga_text_mode_console_cursor();
+    if (!m_vga_arbiter)
-    IO::out8(0x3c4, 1);
+        return;
-    u8 sr1 = IO::in8(0x3c5);
+    m_vga_arbiter->disable_vga_emulation_access_permanently({});
-    IO::out8(0x3c5, sr1 | 1 << 5);
+#endif
-    microseconds_delay(1000);
-    m_vga_access_is_disabled = true;
 }
 
 void GraphicsManagement::enable_vga_text_mode_console_cursor()
 {
-    SpinlockLocker locker(m_main_vga_lock);
+#if ARCH(I386) || ARCH(X86_64)
-    if (m_vga_access_is_disabled)
+    if (!m_vga_arbiter)
         return;
-    IO::out8(0x3D4, 0xA);
+    m_vga_arbiter->enable_vga_text_mode_console_cursor({});
-    IO::out8(0x3D5, 0);
+#endif
 }
 
 void GraphicsManagement::disable_vga_text_mode_console_cursor()
 {
-    SpinlockLocker locker(m_main_vga_lock);
+#if ARCH(I386) || ARCH(X86_64)
-    if (m_vga_access_is_disabled)
+    if (!m_vga_arbiter)
         return;
-    IO::out8(0x3D4, 0xA);
+    m_vga_arbiter->disable_vga_text_mode_console_cursor({});
-    IO::out8(0x3D5, 0x20);
+#endif
 }
 
-void GraphicsManagement::set_vga_text_mode_cursor(size_t console_width, size_t x, size_t y)
+void GraphicsManagement::set_vga_text_mode_cursor([[maybe_unused]] size_t console_width, [[maybe_unused]] size_t x, [[maybe_unused]] size_t y)
 {
-    SpinlockLocker locker(m_main_vga_lock);
+#if ARCH(I386) || ARCH(X86_64)
-    if (m_vga_access_is_disabled)
+    if (!m_vga_arbiter)
         return;
-    enable_vga_text_mode_console_cursor();
+    m_vga_arbiter->set_vga_text_mode_cursor({}, console_width, x, y);
-    u16 value = y * console_width + x;
+#endif
-    IO::out8(0x3d4, 0x0e);
-    IO::out8(0x3d5, MSB(value));
-    IO::out8(0x3d4, 0x0f);
-    IO::out8(0x3d5, LSB(value));
 }
 
 void GraphicsManagement::deactivate_graphical_mode()
@@ -202,6 +195,9 @@ UNMAP_AFTER_INIT bool GraphicsManagement::initialize()
             }
         }
     });
+#if ARCH(I386) || ARCH(X86_64)
+    m_vga_arbiter = VGAIOArbiter::must_create({});
+#endif
 
     auto graphics_subsystem_mode = kernel_command_line().graphics_subsystem_mode();
     if (graphics_subsystem_mode == CommandLine::GraphicsSubsystemMode::Disabled) {
@@ -221,8 +217,7 @@ UNMAP_AFTER_INIT bool GraphicsManagement::initialize()
             MUST(vga_isa_bochs_display_connector->set_safe_mode_setting());
             m_platform_board_specific_display_connector = vga_isa_bochs_display_connector;
             dmesgln("Graphics: Invoking manual blanking with VGA ISA ports");
-            SpinlockLocker locker(m_main_vga_lock);
+            m_vga_arbiter->unblank_screen({});
-            IO::out8(0x3c0, 0x20);
             return true;
         }
 #endif

Kernel/Graphics/GraphicsManagement.h

@@ -7,7 +7,11 @@
 #pragma once
 
 #include <AK/NonnullOwnPtr.h>
+#include <AK/Platform.h>
 #include <AK/Types.h>
+#if ARCH(I386) || ARCH(X86_64)
+#    include <Kernel/Arch/x86/VGA/IOArbiter.h>
+#endif
 #include <Kernel/Bus/PCI/Definitions.h>
 #include <Kernel/Graphics/Console/Console.h>
 #include <Kernel/Graphics/DisplayConnector.h>
@@ -61,9 +65,9 @@ private:
     unsigned m_current_minor_number { 0 };
 
     SpinlockProtected<IntrusiveList<&DisplayConnector::m_list_node>> m_display_connector_nodes { LockRank::None };
-
+#if ARCH(I386) || ARCH(X86_64)
-    RecursiveSpinlock m_main_vga_lock { LockRank::None };
+    OwnPtr<VGAIOArbiter> m_vga_arbiter;
-    bool m_vga_access_is_disabled { false };
+#endif
 };
 
 }