Kernel/PCI: Move IO based HostBridge code to x86 arch-specific directory

The simple PCI::HostBridge class implements access to the PCI
configuration space by using x86 IO instructions. Therefore, it should
be put in the Arch/x86/PCI directory so it can be easily omitted for
non-x86 builds.

2 files changed, 96 insertions, 0 deletions

diff --git a/Kernel/Arch/x86/PCI/Controller/HostBridge.cpp b/Kernel/Arch/x86/PCI/Controller/HostBridge.cpp
new file mode 100644
index 0000000000..81c7e34444
--- /dev/null
+++ b/Kernel/Arch/x86/PCI/Controller/HostBridge.cpp
@@ -0,0 +1,62 @@
+/*
+ * Copyright (c) 2022, Liav A. <liavalb@hotmail.co.il>
+ *
+ * SPDX-License-Identifier: BSD-2-Clause
+ */
+
+#include <Kernel/Arch/x86/IO.h>
+#include <Kernel/Arch/x86/PCI/Controller/HostBridge.h>
+#include <Kernel/Bus/PCI/Access.h>
+#include <Kernel/Sections.h>
+
+namespace Kernel::PCI {
+
+NonnullOwnPtr<HostBridge> HostBridge::must_create_with_io_access()
+{
+    PCI::Domain domain { 0, 0, 0xff };
+    return adopt_own_if_nonnull(new (nothrow) HostBridge(domain)).release_nonnull();
+}
+
+HostBridge::HostBridge(PCI::Domain const& domain)
+    : HostController(domain)
+{
+}
+
+static u32 io_address_for_pci_field(BusNumber bus, DeviceNumber device, FunctionNumber function, u8 field)
+{
+    return 0x80000000u | (bus.value() << 16u) | (device.value() << 11u) | (function.value() << 8u) | (field & 0xfc);
+}
+
+void HostBridge::write8_field(BusNumber bus, DeviceNumber device, FunctionNumber function, u32 field, u8 value)
+{
+    IO::out32(PCI::address_port, io_address_for_pci_field(bus, device, function, field));
+    IO::out8(PCI::value_port + (field & 3), value);
+}
+void HostBridge::write16_field(BusNumber bus, DeviceNumber device, FunctionNumber function, u32 field, u16 value)
+{
+    IO::out32(PCI::address_port, io_address_for_pci_field(bus, device, function, field));
+    IO::out16(PCI::value_port + (field & 2), value);
+}
+void HostBridge::write32_field(BusNumber bus, DeviceNumber device, FunctionNumber function, u32 field, u32 value)
+{
+    IO::out32(PCI::address_port, io_address_for_pci_field(bus, device, function, field));
+    IO::out32(PCI::value_port, value);
+}
+
+u8 HostBridge::read8_field(BusNumber bus, DeviceNumber device, FunctionNumber function, u32 field)
+{
+    IO::out32(PCI::address_port, io_address_for_pci_field(bus, device, function, field));
+    return IO::in8(PCI::value_port + (field & 3));
+}
+u16 HostBridge::read16_field(BusNumber bus, DeviceNumber device, FunctionNumber function, u32 field)
+{
+    IO::out32(PCI::address_port, io_address_for_pci_field(bus, device, function, field));
+    return IO::in16(PCI::value_port + (field & 2));
+}
+u32 HostBridge::read32_field(BusNumber bus, DeviceNumber device, FunctionNumber function, u32 field)
+{
+    IO::out32(PCI::address_port, io_address_for_pci_field(bus, device, function, field));
+    return IO::in32(PCI::value_port);
+}
+
+}
diff --git a/Kernel/Arch/x86/PCI/Controller/HostBridge.h b/Kernel/Arch/x86/PCI/Controller/HostBridge.h
new file mode 100644
index 0000000000..32705ea565
--- /dev/null
+++ b/Kernel/Arch/x86/PCI/Controller/HostBridge.h
@@ -0,0 +1,34 @@
+/*
+ * Copyright (c) 2022, Liav A. <liavalb@hotmail.co.il>
+ *
+ * SPDX-License-Identifier: BSD-2-Clause
+ */
+
+#pragma once
+
+#include <AK/Bitmap.h>
+#include <AK/NonnullOwnPtr.h>
+#include <AK/OwnPtr.h>
+#include <AK/Vector.h>
+#include <Kernel/Bus/PCI/Controller/HostController.h>
+#include <Kernel/Locking/Spinlock.h>
+
+namespace Kernel::PCI {
+
+class HostBridge : public HostController {
+public:
+    static NonnullOwnPtr<HostBridge> must_create_with_io_access();
+
+    virtual void write8_field(BusNumber, DeviceNumber, FunctionNumber, u32 field, u8 value) override;
+    virtual void write16_field(BusNumber, DeviceNumber, FunctionNumber, u32 field, u16 value) override;
+    virtual void write32_field(BusNumber, DeviceNumber, FunctionNumber, u32 field, u32 value) override;
+
+    virtual u8 read8_field(BusNumber, DeviceNumber, FunctionNumber, u32 field) override;
+    virtual u16 read16_field(BusNumber, DeviceNumber, FunctionNumber, u32 field) override;
+    virtual u32 read32_field(BusNumber, DeviceNumber, FunctionNumber, u32 field) override;
+
+private:
+    explicit HostBridge(PCI::Domain const&);
+};
+
+}