ladybird/Kernel/PCI.cpp
Andreas Kling 731fc5a7c8 Kernel: Much improved BochsVGA (BXVGA) support.
Instead of cowboy-calling the VESA BIOS in the bootloader, find the emulator
VGA adapter by scanning the PCI bus. Then set up the desired video mode by
sending device commands.
2019-02-06 10:17:26 +01:00

121 lines
4.5 KiB
C++

#include <Kernel/PCI.h>
#include <Kernel/IO.h>
#define PCI_VENDOR_ID 0x00 // word
#define PCI_DEVICE_ID 0x02 // word
#define PCI_COMMAND 0x04 // word
#define PCI_STATUS 0x06 // word
#define PCI_REVISION_ID 0x08 // byte
#define PCI_PROG_IF 0x09 // byte
#define PCI_SUBCLASS 0x0a // byte
#define PCI_CLASS 0x0b // byte
#define PCI_CACHE_LINE_SIZE 0x0c // byte
#define PCI_LATENCY_TIMER 0x0d // byte
#define PCI_HEADER_TYPE 0x0e // byte
#define PCI_BIST 0x0f // byte
#define PCI_BAR0 0x10 // dword
#define PCI_BAR1 0x14 // dword
#define PCI_BAR2 0x18 // dword
#define PCI_BAR3 0x1C // dword
#define PCI_BAR4 0x20 // dword
#define PCI_BAR5 0x24 // dword
#define PCI_INTERRUPT_LINE 0x3C // byte
#define PCI_SECONDARY_BUS 0x19 // byte
#define PCI_HEADER_TYPE_DEVICE 0
#define PCI_HEADER_TYPE_BRIDGE 1
#define PCI_TYPE_BRIDGE 0x0604
#define PCI_ADDRESS_PORT 0xCF8
#define PCI_VALUE_PORT 0xCFC
#define PCI_NONE 0xFFFF
namespace PCI {
template<typename T>
T read_field(Address address, dword field)
{
IO::out32(PCI_ADDRESS_PORT, address.io_address_for_field(field));
if constexpr (sizeof(T) == 4)
return IO::in32(PCI_VALUE_PORT);
if constexpr (sizeof(T) == 2)
return IO::in16(PCI_VALUE_PORT + (field & 2));
if constexpr (sizeof(T) == 1)
return IO::in8(PCI_VALUE_PORT + (field & 3));
}
template<typename T>
void write_field(Address address, dword field, T value)
{
IO::out32(PCI_ADDRESS_PORT, address.io_address_for_field(field));
if constexpr (sizeof(T) == 4)
IO::out32(PCI_VALUE_PORT, value);
if constexpr (sizeof(T) == 2)
IO::out16(PCI_VALUE_PORT + (field & 2), value);
if constexpr (sizeof(T) == 1)
IO::out8(PCI_VALUE_PORT + (field & 3), value);
}
word read_type(Address address)
{
return (read_field<byte>(address, PCI_CLASS) << 8u) | read_field<byte>(address, PCI_SUBCLASS);
}
void enumerate_bus(int type, byte bus, Function<void(Address, ID)>&);
void enumerate_functions(int type, byte bus, byte slot, byte function, Function<void(Address, ID)>& callback)
{
Address address(bus, slot, function);
if (type == -1 || type == read_type(address))
callback(address, { read_field<word>(address, PCI_VENDOR_ID), read_field<word>(address, PCI_DEVICE_ID) });
if (read_type(address) == PCI_TYPE_BRIDGE) {
byte secondary_bus = read_field<byte>(address, PCI_SECONDARY_BUS);
kprintf("PCI: Found secondary bus: %u\n", secondary_bus);
ASSERT(secondary_bus != bus);
enumerate_bus(type, secondary_bus, callback);
}
}
void enumerate_slot(int type, byte bus, byte slot, Function<void(Address, ID)>& callback)
{
Address address(bus, slot, 0);
if (read_field<word>(address, PCI_VENDOR_ID) == PCI_NONE)
return;
enumerate_functions(type, bus, slot, 0, callback);
if (!(read_field<byte>(address, PCI_HEADER_TYPE) & 0x80))
return;
for (byte function = 1; function < 8; ++function) {
Address address(bus, slot, function);
if (read_field<word>(address, PCI_VENDOR_ID) != PCI_NONE)
enumerate_functions(type, bus, slot, function, callback);
}
}
void enumerate_bus(int type, byte bus, Function<void(Address, ID)>& callback)
{
for (byte slot = 0; slot < 32; ++slot)
enumerate_slot(type, bus, slot, callback);
}
dword get_BAR0(Address address) { return read_field<dword>(address, PCI_BAR0); }
dword get_BAR1(Address address) { return read_field<dword>(address, PCI_BAR1); }
dword get_BAR2(Address address) { return read_field<dword>(address, PCI_BAR2); }
dword get_BAR3(Address address) { return read_field<dword>(address, PCI_BAR3); }
dword get_BAR4(Address address) { return read_field<dword>(address, PCI_BAR4); }
dword get_BAR5(Address address) { return read_field<dword>(address, PCI_BAR5); }
void enumerate_all(Function<void(Address, ID)> callback)
{
// Single PCI host controller.
if ((read_field<byte>(Address(), PCI_HEADER_TYPE) & 0x80) == 0) {
enumerate_bus(-1, 0, callback);
return;
}
// Multiple PCI host controllers.
for (byte function = 0; function < 8; ++function) {
if (read_field<word>(Address(0, 0, function), PCI_VENDOR_ID) == PCI_NONE)
break;
enumerate_bus(-1, function, callback);
}
}
}