asterinas/kernel/comps/pci/src/arch/x86/mod.rs

69 lines
2.1 KiB
Rust

// SPDX-License-Identifier: MPL-2.0
//! PCI bus access
use ostd::{
arch::device::io_port::{ReadWriteAccess, WriteOnlyAccess},
io::IoPort,
Error,
};
use spin::Once;
use crate::device_info::PciDeviceLocation;
static PCI_ADDRESS_PORT: Once<IoPort<u32, WriteOnlyAccess>> = Once::new();
static PCI_DATA_PORT: Once<IoPort<u32, ReadWriteAccess>> = Once::new();
const BIT32_ALIGN_MASK: u32 = 0xFFFC;
pub(crate) fn write32(location: &PciDeviceLocation, offset: u32, value: u32) -> Result<(), Error> {
PCI_ADDRESS_PORT
.get()
.ok_or(Error::IoError)?
.write(encode_as_port(location) | (offset & BIT32_ALIGN_MASK));
PCI_DATA_PORT
.get()
.ok_or(Error::IoError)?
.write(value.to_le());
Ok(())
}
pub(crate) fn read32(location: &PciDeviceLocation, offset: u32) -> Result<u32, Error> {
PCI_ADDRESS_PORT
.get()
.ok_or(Error::IoError)?
.write(encode_as_port(location) | (offset & BIT32_ALIGN_MASK));
Ok(PCI_DATA_PORT.get().ok_or(Error::IoError)?.read().to_le())
}
/// Encodes the bus, device, and function into a port address for use with the PCI I/O port.
fn encode_as_port(location: &PciDeviceLocation) -> u32 {
// 1 << 31: Configuration enable
(1 << 31)
| ((location.bus as u32) << 16)
| (((location.device as u32) & 0b11111) << 11)
| (((location.function as u32) & 0b111) << 8)
}
pub(crate) fn has_pci_bus() -> bool {
true
}
pub(crate) fn init() {
PCI_ADDRESS_PORT.call_once(|| IoPort::acquire(0xCF8).unwrap());
PCI_DATA_PORT.call_once(|| IoPort::acquire(0xCFC).unwrap());
}
pub(crate) const MSIX_DEFAULT_MSG_ADDR: u32 = 0xFEE0_0000;
pub(crate) fn construct_remappable_msix_address(remapping_index: u32) -> u32 {
// Use remappable format. The bits[4:3] should be always set to 1 according to the manual.
let mut address = MSIX_DEFAULT_MSG_ADDR | 0b1_1000;
// Interrupt index[14:0] is on address[19:5] and interrupt index[15] is on address[2].
address |= (remapping_index & 0x7FFF) << 5;
address |= (remapping_index & 0x8000) >> 13;
address
}