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[Kernel] Refactor ACPI into separate modules
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@codyd51
codyd51 committed Jan 4, 2023
1 parent 635d3e3 commit bab95bb
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Showing 3 changed files with 246 additions and 222 deletions.
236 changes: 14 additions & 222 deletions rust_kernel_libs/acpi/src/lib.rs
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Original file line number Diff line number Diff line change
Expand Up @@ -5,225 +5,20 @@
extern crate alloc;
extern crate ffi_bindings;

use crate::structs::{
ApicNonMaskableInterrupt, ExtendedSystemDescriptionHeader, InterruptControllerHeader, IoApic,
IoApicInterruptSourceOverride, MultiApicDescriptionTable, ProcessorLocalApic,
RootSystemDescriptionHeader, SystemDescriptionHeader,
};
use crate::utils::{get_tabs, parse_struct_at_phys_addr, parse_struct_at_virt_addr};
use alloc::string::String;
use alloc::vec;
use alloc::vec::Vec;
use core::mem;
use ffi_bindings::println;

/// PT: Matches the definitions in kernel/util/vmm
const KERNEL_MEMORY_BASE: usize = 0xFFFF800000000000;

/// Converts a physical address to its corresponding remapped address in high memory
fn phys_addr_to_remapped_high_memory_virt_addr(phys_addr: usize) -> usize {
KERNEL_MEMORY_BASE + phys_addr
}

#[repr(packed)]
#[derive(Debug, Copy, Clone)]
/// Ref: https://uefi.org/htmlspecs/ACPI_Spec_6_4_html/05_ACPI_Software_Programming_Model/ACPI_Software_Programming_Model.html#root-system-description-pointer-rsdp-structure
struct RootSystemDescriptionHeader {
signature: [u8; 8],
checksum: u8,
oem_id: [u8; 6],
revision: u8,
rsdt_phys_addr: u32,
table_length: u32,
xsdt_phys_addr: u64,
extended_checksum: u8,
reserved: [u8; 3],
}

// Design note: We need getters for many fields rather than raw field access because many of the
// fields are unaligned, due to the packed structs. If we tried to directly use fields inside
// println!() this would implicitly create a reference, which is undefined for unaligned fields.
// Copying into a local works, though, so getters (that copy the field) get around this quirk.

impl RootSystemDescriptionHeader {
fn signature(&self) -> String {
String::from_utf8_lossy(&self.signature).into_owned()
}

fn oem_id(&self) -> String {
String::from_utf8_lossy(&self.oem_id).into_owned()
}

fn table_length(&self) -> usize {
self.table_length as usize
}

fn rsdt_phys_addr(&self) -> usize {
self.rsdt_phys_addr as usize
}

fn xsdt_phys_addr(&self) -> usize {
self.xsdt_phys_addr as usize
}
}

#[repr(packed)]
#[derive(Debug, Copy, Clone)]
/// Ref: https://uefi.org/htmlspecs/ACPI_Spec_6_4_html/05_ACPI_Software_Programming_Model/ACPI_Software_Programming_Model.html#system-description-table-header
struct SystemDescriptionHeader {
signature: [u8; 4],
length: u32,
revision: u8,
checksum: u8,
oem_id: [u8; 6],
oem_table_id: [u8; 8],
oem_revision: [u8; 4],
creator_id: [u8; 4],
creator_revision: [u8; 4],
}

impl SystemDescriptionHeader {
fn signature(&self) -> String {
String::from_utf8_lossy(&self.signature).into_owned()
}

fn oem_id(&self) -> String {
String::from_utf8_lossy(&self.oem_id).into_owned()
}

fn oem_table_id(&self) -> String {
String::from_utf8_lossy(&self.oem_table_id).into_owned()
}
}

#[repr(packed)]
#[derive(Debug, Copy, Clone)]
/// Ref: https://uefi.org/htmlspecs/ACPI_Spec_6_4_html/05_ACPI_Software_Programming_Model/ACPI_Software_Programming_Model.html#extended-system-description-table-xsdt
struct ExtendedSystemDescriptionHeader {
base: SystemDescriptionHeader,
entries: [u64; 0],
}

#[repr(packed)]
#[derive(Debug, Copy, Clone)]
/// Ref: https://uefi.org/htmlspecs/ACPI_Spec_6_4_html/05_ACPI_Software_Programming_Model/ACPI_Software_Programming_Model.html#multiple-apic-description-table-madt
struct MultiApicDescriptionTable {
base: SystemDescriptionHeader,
local_interrupt_controller_phys_addr: u32,
flags: u32,
interrupt_controller_headers: [InterruptControllerHeader; 0],
}

impl MultiApicDescriptionTable {
fn local_interrupt_controller_phys_addr(&self) -> u32 {
self.local_interrupt_controller_phys_addr
}
}

#[repr(packed)]
#[derive(Debug, Copy, Clone)]
/// Ref: https://uefi.org/htmlspecs/ACPI_Spec_6_4_html/05_ACPI_Software_Programming_Model/ACPI_Software_Programming_Model.html#multiple-apic-description-table-madt
struct InterruptControllerHeader {
entry_type: u8,
entry_len: u8,
}

#[repr(packed)]
#[derive(Debug, Copy, Clone)]
struct ProcessorLocalApic {
processor_id: u8,
apic_id: u8,
flags: u32,
}

impl ProcessorLocalApic {
fn processor_id(&self) -> u8 {
self.processor_id
}

fn apic_id(&self) -> u8 {
self.apic_id
}

fn flags(&self) -> u32 {
self.flags
}
}

#[repr(packed)]
#[derive(Debug, Copy, Clone)]
struct IoApic {
id: u8,
reserved: u8,
apic_phys_addr: u32,
global_system_interrupt_base: u32,
}

impl IoApic {
fn id(&self) -> u8 {
self.id
}

fn apic_phys_addr(&self) -> u32 {
self.apic_phys_addr
}

fn global_system_interrupt_base(&self) -> u32 {
self.global_system_interrupt_base
}
}

#[repr(packed)]
#[derive(Debug, Copy, Clone)]
struct IoApicInterruptSourceOverride {
bus_source: u8,
irq_source: u8,
global_system_interrupt: u32,
flags: u16,
}

impl IoApicInterruptSourceOverride {
fn bus_source(&self) -> u8 {
self.bus_source
}

fn irq_source(&self) -> u8 {
self.irq_source
}

fn global_system_interrupt(&self) -> u32 {
self.global_system_interrupt
}

fn flags(&self) -> u16 {
self.flags
}
}

#[repr(packed)]
#[derive(Debug, Copy, Clone)]
struct ApicNonMaskableInterrupt {
for_processor_id: u8,
flags: u16,
lint: u8,
}

impl ApicNonMaskableInterrupt {
fn for_processor_id(&self) -> u8 {
self.for_processor_id
}

fn flags(&self) -> u16 {
self.flags
}

fn lint(&self) -> u8 {
self.lint
}
}

pub fn parse_struct_at_virt_addr<T>(virt_addr: usize) -> &'static T {
unsafe { &*(virt_addr as *const T) }
}

pub fn parse_struct_at_phys_addr<T>(phys_addr: usize) -> &'static T {
let virt_addr = phys_addr_to_remapped_high_memory_virt_addr(phys_addr);
parse_struct_at_virt_addr(virt_addr)
}
mod structs;
mod utils;

#[no_mangle]
pub fn acpi_parse_root_system_description(phys_addr: usize) {
Expand All @@ -236,18 +31,14 @@ pub fn acpi_parse_root_system_description(phys_addr: usize) {
let root_header: &RootSystemDescriptionHeader = parse_struct_at_phys_addr(phys_addr);
assert_eq!(root_header.signature(), "RSD PTR ");
// Only ACPI 2.0 is supported, for now
assert_eq!(root_header.revision, 2);
assert_eq!(root_header.revision(), 2);

parse_xstd_at_phys_addr(1, root_header.xsdt_phys_addr());

// Ensure this allocation isn't optimized away by accessing it at the end
hack_to_occupy_some_heap_memory.push(1);
}

fn get_tabs(num: usize) -> String {
"\t".repeat(num)
}

fn dump_system_description(tab_level: usize, desc: &SystemDescriptionHeader) {
let tabs = get_tabs(tab_level);
println!("{tabs}ACPI System Description Header:");
Expand All @@ -264,7 +55,7 @@ fn parse_xstd_at_phys_addr(tab_level: usize, phys_addr: usize) {
println!("{tabs}[{phys_addr:#016x} XSTD]");
assert_eq!(extended_header.signature(), "XSDT");

let length = extended_header.length;
let length = extended_header.length();
let num_entries = (length as usize - mem::size_of::<ExtendedSystemDescriptionHeader>())
/ mem::size_of::<u64>();

Expand Down Expand Up @@ -293,14 +84,15 @@ fn parse_apic_table(tab_level: usize, phys_addr: usize) {
let tabs = get_tabs(tab_level);
let apic_header: &MultiApicDescriptionTable = parse_struct_at_phys_addr(phys_addr);
println!(
"{tabs}[{:#016x} IntController]",
apic_header.local_interrupt_controller_phys_addr()
"{tabs}[{:#016x} IntController Flags {:#08x}]",
apic_header.local_interrupt_controller_phys_addr(),
apic_header.flags(),
);

let mut interrupt_controller_header_ptr =
core::ptr::addr_of!(apic_header.interrupt_controller_headers) as *const u8;
let interrupt_controllers_len =
(apic_header.base.length as usize) - mem::size_of::<MultiApicDescriptionTable>();
(apic_header.base.length() as usize) - mem::size_of::<MultiApicDescriptionTable>();

unsafe {
let end_ptr = interrupt_controller_header_ptr.offset(interrupt_controllers_len as isize);
Expand Down
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