#include "arch/PCI.h"
#include "arch/x86_64/IO.h"
#include <luna/Check.h>
#include <luna/Ignore.h>

#define PCI_ADDRESS_PORT 0xCF8
#define PCI_VALUE_PORT 0xCFC

static inline constexpr u32 make_pci_address(const PCI::Device::Address& address, u32 field)
{
    return 0x80000000 | (address.bus << 16) | (address.slot << 11) | (address.function << 8) | ((field)&0xFC);
}

namespace PCI
{
    u8 read8(const Device::Address& address, u32 field)
    {
        IO::outl(PCI_ADDRESS_PORT, make_pci_address(address, field));
        return IO::inb(PCI_VALUE_PORT + (field & 3));
    }

    u16 read16(const Device::Address& address, u32 field)
    {
        IO::outl(PCI_ADDRESS_PORT, make_pci_address(address, field));
        return IO::inw(PCI_VALUE_PORT + (field & 2));
    }

    u32 read32(const Device::Address& address, u32 field)
    {
        IO::outl(PCI_ADDRESS_PORT, make_pci_address(address, field));
        return IO::inl(PCI_VALUE_PORT);
    }

    void write8(const Device::Address& address, u32 field, u8 value)
    {
        u8 offset = (u8)(field & ~0x3);
        union {
            u8 split[4];
            u32 full;
        };
        full = read32(address, offset);
        split[(field & 0x3)] = value;
        write32(address, offset, full);
    }

    void write16(const Device::Address& address, u32 field, u16 value)
    {
        u8 offset = (u8)(field & ~0x3);
        union {
            u8 split[4];
            u32 full;
        };
        full = read32(address, offset);
        split[(field & 0x3)] = (u8)(value >> 8);
        split[(field & 0x3) + 1] = (u8)(value & 0xff);
        write32(address, offset, full);
    }

    void write32(const Device::Address& address, u32 field, u32 value)
    {
        IO::outl(PCI_ADDRESS_PORT, make_pci_address(address, field));
        IO::outl(PCI_VALUE_PORT, value);
    }
}