/*
 * Copyright (c) 2020, Liav A. <liavalb@hotmail.co.il>
 *
 * SPDX-License-Identifier: BSD-2-Clause
 */

#pragma once

#include <AK/Types.h>
#include <Kernel/PhysicalAddress.h>
#include <Kernel/VM/Region.h>
#include <Kernel/VirtualAddress.h>

namespace Kernel {
namespace MultiProcessor {

struct [[gnu::packed]] FloatingPointer {
    char sig[4];
    u32 physical_address_ptr;
    u8 length;
    u8 specification_revision;
    u8 checksum;
    u8 feature_info[5];
};

struct [[gnu::packed]] EntryHeader {
    u8 entry_type;
};

struct [[gnu::packed]] ConfigurationTableHeader {
    char sig[4];
    u16 length;
    u8 specification_revision;
    u8 checksum;
    char oem_id[8];
    char product_id[12];
    u32 oem_table_ptr;
    u16 oem_table_size;
    u16 entry_count;
    u32 local_apic_address;
    u16 ext_table_length;
    u8 ext_table_checksum;
    u8 reserved;
    EntryHeader entries[];
};

enum class ConfigurationTableEntryType {
    Processor = 0,
    Bus = 1,
    IOAPIC = 2,
    IO_Interrupt_Assignment = 3,
    Local_Interrupt_Assignment = 4,
    SystemAddressSpaceMapping = 128,
    BusHierarchyDescriptor = 129,
    CompatibilityBusAddressSpaceModifier = 130
};

struct [[gnu::packed]] ExtEntryHeader {
    u8 entry_type;
    u8 entry_length;
};

struct [[gnu::packed]] ProcessorEntry {
    EntryHeader h;
    u8 local_apic_id;
    u8 local_apic_version;
    u8 cpu_flags;
    u32 cpu_signature;
    u32 feature_flags;
    u8 reserved[8];
};

struct [[gnu::packed]] BusEntry {
    EntryHeader h;
    u8 bus_id;
    char bus_type[6];
};

struct [[gnu::packed]] IOAPICEntry {
    EntryHeader h;
    u8 ioapic_id;
    u8 ioapic_version;
    u8 ioapic_flags;
    u32 ioapic_address;
};

enum class InterruptType {
    INT = 0,
    NMI = 1,
    SMI = 2,
    ExtINT = 3,
};

struct [[gnu::packed]] IOInterruptAssignmentEntry {
    EntryHeader h;
    u8 interrupt_type;
    u8 polarity;
    u8 trigger_mode;
    u8 source_bus_id;
    u8 source_bus_irq;
    u8 destination_ioapic_id;
    u8 destination_ioapic_intin_pin;
};

struct [[gnu::packed]] LocalInterruptAssignmentEntry {
    EntryHeader h;
    u8 interrupt_type;
    u8 polarity;
    u8 trigger_mode;
    u8 source_bus_id;
    u8 source_bus_irq;
    u8 destination_lapic_id;
    u8 destination_lapic_lintin_pin;
};

enum class SystemAddressType {
    IO = 0,
    Memory = 1,
    Prefetch = 2,
};

struct [[gnu::packed]] SystemAddressSpaceMappingEntry {
    ExtEntryHeader h;
    u8 bus_id;
    u8 address_type;
    u64 address_base;
    u64 length;
};

struct [[gnu::packed]] BusHierarchyDescriptorEntry {
    ExtEntryHeader h;
    u8 bus_id;
    u8 bus_info;
    u8 parent_bus;
    u8 reserved[3];
};

struct [[gnu::packed]] CompatibilityBusAddressSpaceModifierEntry {
    ExtEntryHeader h;
    u8 bus_id;
    u8 address_modifier;
    u32 predefined_range_list;
};

}

class PCIInterruptOverrideMetadata;

class MultiProcessorParser final {
public:
    static OwnPtr<MultiProcessorParser> autodetect();

    Vector<PCIInterruptOverrideMetadata> get_pci_interrupt_redirections();

private:
    explicit MultiProcessorParser(PhysicalAddress floating_pointer);

    void parse_configuration_table();
    void parse_floating_pointer_data();

    Vector<u8> get_pci_bus_ids() const;

    static Optional<PhysicalAddress> find_floating_pointer();

    PhysicalAddress m_floating_pointer;
    PhysicalAddress m_configuration_table;
    Vector<MultiProcessor::IOInterruptAssignmentEntry> m_io_interrupt_assignment_entries;
    Vector<MultiProcessor::BusEntry> m_bus_entries;
};
}