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serenity/Kernel/Arch/x86_64/PCI/Initializer.cpp
2022-12-28 11:53:41 +01:00

93 lines
2.9 KiB
C++

/*
* Copyright (c) 2020, Liav A. <liavalb@hotmail.co.il>
*
* SPDX-License-Identifier: BSD-2-Clause
*/
#include <Kernel/Arch/x86_64/IO.h>
#include <Kernel/Bus/PCI/API.h>
#include <Kernel/Bus/PCI/Access.h>
#include <Kernel/Bus/PCI/Initializer.h>
#include <Kernel/CommandLine.h>
#include <Kernel/FileSystem/SysFS/Subsystems/Bus/PCI/BusDirectory.h>
#include <Kernel/Firmware/ACPI/Parser.h>
#include <Kernel/Panic.h>
#include <Kernel/Sections.h>
namespace Kernel::PCI {
READONLY_AFTER_INIT bool g_pci_access_io_probe_failed;
READONLY_AFTER_INIT bool g_pci_access_is_disabled_from_commandline;
static bool test_pci_io();
UNMAP_AFTER_INIT static PCIAccessLevel detect_optimal_access_type()
{
auto boot_determined = kernel_command_line().pci_access_level();
if (!ACPI::is_enabled() || !ACPI::Parser::the()->find_table("MCFG"sv).has_value())
return PCIAccessLevel::IOAddressing;
if (boot_determined != PCIAccessLevel::IOAddressing)
return boot_determined;
if (!g_pci_access_io_probe_failed)
return PCIAccessLevel::IOAddressing;
PANIC("No PCI bus access method detected!");
}
UNMAP_AFTER_INIT void initialize()
{
g_pci_access_is_disabled_from_commandline = kernel_command_line().is_pci_disabled();
Optional<PhysicalAddress> possible_mcfg;
// FIXME: There are other arch-specific methods to find the memory range
// for accessing the PCI configuration space.
// For example, the QEMU microvm machine type might expose an FDT so we could
// parse it to find a PCI host bridge.
if (ACPI::is_enabled()) {
possible_mcfg = ACPI::Parser::the()->find_table("MCFG"sv);
g_pci_access_io_probe_failed = (!test_pci_io()) && (!possible_mcfg.has_value());
} else {
g_pci_access_io_probe_failed = !test_pci_io();
}
if (g_pci_access_is_disabled_from_commandline || g_pci_access_io_probe_failed)
return;
switch (detect_optimal_access_type()) {
case PCIAccessLevel::MemoryAddressing: {
VERIFY(possible_mcfg.has_value());
auto success = Access::initialize_for_multiple_pci_domains(possible_mcfg.value());
VERIFY(success);
break;
}
case PCIAccessLevel::IOAddressing: {
auto success = Access::initialize_for_one_pci_domain();
VERIFY(success);
break;
}
default:
VERIFY_NOT_REACHED();
}
PCIBusSysFSDirectory::initialize();
MUST(PCI::enumerate([&](DeviceIdentifier const& device_identifier) {
dmesgln("{} {}", device_identifier.address(), device_identifier.hardware_id());
}));
}
UNMAP_AFTER_INIT bool test_pci_io()
{
dmesgln("Testing PCI via manual probing...");
u32 tmp = 0x80000000;
IO::out32(PCI::address_port, tmp);
tmp = IO::in32(PCI::address_port);
if (tmp == 0x80000000) {
dmesgln("PCI IO supported");
return true;
}
dmesgln("PCI IO not supported");
return false;
}
}