ladybird/Kernel/PCI/Initializer.cpp

/*
 * Copyright (c) 2020, Liav A. <liavalb@hotmail.co.il>
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are met:
 *
 * 1. Redistributions of source code must retain the above copyright notice, this
 *    list of conditions and the following disclaimer.
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 * 2. Redistributions in binary form must reproduce the above copyright notice,
 *    this list of conditions and the following disclaimer in the documentation
 *    and/or other materials provided with the distribution.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
 * DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
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 * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
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#include <Kernel/ACPI/Parser.h>
#include <Kernel/CommandLine.h>
#include <Kernel/IO.h>
#include <Kernel/PCI/IOAccess.h>
#include <Kernel/PCI/Initializer.h>
#include <Kernel/PCI/MMIOAccess.h>
#include <Kernel/Panic.h>

namespace Kernel {
namespace PCI {

static bool test_pci_io();

static Access::Type detect_optimal_access_type(bool mmio_allowed)
{
    if (mmio_allowed && ACPI::is_enabled() && !ACPI::Parser::the()->find_table("MCFG").is_null())
        return Access::Type::MMIO;

    if (test_pci_io())
        return Access::Type::IO;

    PANIC("No PCI bus access method detected!");
}

void initialize()
{
    bool mmio_allowed = kernel_command_line().lookup("pci_mmio").value_or("off") == "on";

    if (detect_optimal_access_type(mmio_allowed) == Access::Type::MMIO)
        MMIOAccess::initialize(ACPI::Parser::the()->find_table("MCFG"));
    else
        IOAccess::initialize();
    PCI::enumerate([&](const Address& address, ID id) {
        klog() << address << " " << id;
    });
}

bool test_pci_io()
{
    klog() << "Testing PCI via manual probing... ";
    u32 tmp = 0x80000000;
    IO::out32(PCI_ADDRESS_PORT, tmp);
    tmp = IO::in32(PCI_ADDRESS_PORT);
    if (tmp == 0x80000000) {
        klog() << "PCI IO Supported!";
        return true;
    }

    klog() << "PCI IO Not Supported!";
    return false;
}

}
}