From d732bdb6c2dd16c9eab8fceab9d9814d11b8de33 Mon Sep 17 00:00:00 2001
From: "Raphael O." <raphael.ob@protonmail.com>
Date: Wed, 17 Jan 2024 20:12:51 +0100
Subject: [PATCH] Add lock_with_ipl macro to easily create a OnDrop type to
 elevate IPL while holding a lock and rename spl to ipl

---
 .../kernel/src/arch/amd64/interrupts/dpc.rs   |  6 ++--
 .../kernel/src/arch/amd64/interrupts/ipl.rs   | 30 ++++++++++++++-----
 .../kernel/src/arch/amd64/interrupts/mod.rs   |  6 ++--
 3 files changed, 29 insertions(+), 13 deletions(-)

diff --git a/xernel/kernel/src/arch/amd64/interrupts/dpc.rs b/xernel/kernel/src/arch/amd64/interrupts/dpc.rs
index 3cbb1449..7a56062d 100644
--- a/xernel/kernel/src/arch/amd64/interrupts/dpc.rs
+++ b/xernel/kernel/src/arch/amd64/interrupts/dpc.rs
@@ -1,7 +1,7 @@
 use alloc::boxed::Box;
 
 use crate::{
-    arch::amd64::interrupts::ipl::{raise_spl, set_ipl, IPL},
+    arch::amd64::interrupts::ipl::{raise_ipl, set_ipl, IPL},
     cpu::{current_cpu, PerCpu},
     sched::scheduler::switch_threads,
 };
@@ -43,10 +43,10 @@ impl<T> Dpc<T> {
 pub fn dpc_interrupt_dispatch() {
     let cpu = current_cpu();
 
-    let ipl = raise_spl(IPL::IPLDPC);
+    let ipl = raise_ipl(IPL::IPLDPC);
 
     while let Some(dpc) = {
-        let old = raise_spl(IPL::IPLHigh);
+        let old = raise_ipl(IPL::IPLHigh);
         let mut lock = cpu.dpc_queue.write();
         let dpc = lock.dequeue();
         set_ipl(old);
diff --git a/xernel/kernel/src/arch/amd64/interrupts/ipl.rs b/xernel/kernel/src/arch/amd64/interrupts/ipl.rs
index 5b47b6d5..85e2ed8c 100644
--- a/xernel/kernel/src/arch/amd64/interrupts/ipl.rs
+++ b/xernel/kernel/src/arch/amd64/interrupts/ipl.rs
@@ -4,6 +4,22 @@ use crate::cpu::current_cpu;
 
 use super::dpc::dpc_interrupt_dispatch;
 
+#[macro_export]
+macro_rules! lock_with_ipl {
+    ($name:ident) => {
+        {
+            let old = raise_ipl(IPL::IPLDPC);
+            OnDrop::new($name.lock(), || { set_ipl(old); })
+        }
+    };
+    ($name:ident, $ipl:expr) => {
+        {
+            let _ = raise_ipl(IPL::IPLDPC);
+            OnDrop::new($name.lock(), || { set_ipl($ipl); })
+        }
+    };
+}
+
 #[derive(Debug, Clone, Copy, PartialEq, PartialOrd)]
 #[repr(u8)]
 pub enum IPL {
@@ -41,7 +57,7 @@ impl From<u8> for IPL {
     }
 }
 
-pub fn get_spl() -> IPL {
+pub fn get_ipl() -> IPL {
     let ipl: u64;
 
     unsafe {
@@ -53,7 +69,7 @@ pub fn get_spl() -> IPL {
 
 pub fn set_ipl(ipl: IPL) -> IPL {
     let requested_ipl = ipl as u64;
-    let old_ipl = get_spl() as u64;
+    let old_ipl = get_ipl() as u64;
 
     unsafe {
         asm!("mov cr8, {}", in(reg) requested_ipl, options(nomem, nostack, preserves_flags));
@@ -66,13 +82,13 @@ pub fn set_ipl(ipl: IPL) -> IPL {
     IPL::from(old_ipl)
 }
 
-pub fn raise_spl(spl: IPL) -> IPL {
-    let old_ipl = get_spl();
+pub fn raise_ipl(ipl: IPL) -> IPL {
+    let old_ipl = get_ipl();
 
-    assert!(old_ipl as u64 <= spl as u64);
+    assert!(old_ipl as u64 <= ipl as u64);
 
-    if old_ipl < spl {
-        set_ipl(spl);
+    if old_ipl < ipl {
+        set_ipl(ipl);
     }
 
     old_ipl
diff --git a/xernel/kernel/src/arch/amd64/interrupts/mod.rs b/xernel/kernel/src/arch/amd64/interrupts/mod.rs
index 94c1f5b5..47f82f94 100644
--- a/xernel/kernel/src/arch/amd64/interrupts/mod.rs
+++ b/xernel/kernel/src/arch/amd64/interrupts/mod.rs
@@ -11,7 +11,7 @@ use core::sync::atomic::{compiler_fence, Ordering};
 use idt::{IRQHandler, IDT_ENTRIES};
 use ipl::IPL;
 
-use self::ipl::{get_spl, raise_spl, set_ipl};
+use self::ipl::{get_ipl, raise_ipl, set_ipl};
 
 use super::apic::apic_spurious_interrupt;
 use libxernel::sync::{Spinlock, SpinlockIRQ};
@@ -33,11 +33,11 @@ pub fn init() {
 extern "sysv64" fn generic_interrupt_handler(isr: usize, ctx: *mut TrapFrame) {
     let mut ipl = IPL::from(isr >> 4);
 
-    if (ipl as u8) < (get_spl() as u8) {
+    if (ipl as u8) < (get_ipl() as u8) {
         panic!("IPL not less or equal");
     }
 
-    ipl = raise_spl(ipl);
+    ipl = raise_ipl(ipl);
 
     let handlers = INTERRUPT_HANDLERS.lock();