From a4a8bf0152597db9e05bb80cb6b19a3cd2f46ce5 Mon Sep 17 00:00:00 2001
From: pjht <pterpstra@pterpstra.com>
Date: Thu, 28 Nov 2024 14:04:38 -0600
Subject: [PATCH] Keep track of # of clock ticks and bump PIT freq to 1kHz

---
 src/interrupts.rs | 15 +++++++++------
 src/main.rs       |  2 +-
 src/pit.rs        |  5 +++++
 3 files changed, 15 insertions(+), 7 deletions(-)

diff --git a/src/interrupts.rs b/src/interrupts.rs
index f6f5c4f..ea2735b 100644
--- a/src/interrupts.rs
+++ b/src/interrupts.rs
@@ -1,16 +1,12 @@
 use crate::{
-    bootinfo::BOOTINFO,
-    print, println,
-    tasking::{InvalidPid, IpcMessage, SleepReason},
-    virtual_memory::{ASpaceMutex, AddressSpace, PagingError, ACTIVE_SPACE, KERNEL_SPACE},
-    TASKING,
+    bootinfo::BOOTINFO, pit::NUM_INTERRUPTS, print, println, tasking::{InvalidPid, IpcMessage, SleepReason}, virtual_memory::{ASpaceMutex, AddressSpace, PagingError, ACTIVE_SPACE, KERNEL_SPACE}, TASKING
 };
 use alloc::{boxed::Box, vec::Vec};
 use az::WrappingCast;
 use cast::{u64, usize};
 use core::{
     arch::{asm, naked_asm},
-    ptr, slice,
+    ptr, slice, sync::atomic::Ordering,
 };
 use hashbrown::HashMap;
 use pic8259::ChainedPics;
@@ -809,6 +805,13 @@ extern "C" fn syscall_handler() {
         }
         35 => TASKING.unlock_mutex(usize(regs.rcx)),
         36 => TASKING.drop_mutex(usize(regs.rcx)),
+        37 => {
+            // Frequency of clock ticks
+            retval = 1000;
+        }
+        38 => {
+            retval = NUM_INTERRUPTS.load(Ordering::Relaxed);
+        }
         _ => (),
     };
     unsafe { SYSCALL_REGS = regs };
diff --git a/src/main.rs b/src/main.rs
index 0312383..bec0edd 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -129,7 +129,7 @@ pub fn main() {
     Lazy::force(&KERNEL_SPACE);
     Lazy::force(&ACTIVE_SPACE);
     interrupts::init();
-    pit::init(100);
+    pit::init(1000);
     let initrd = unsafe {
         let ramdisk_start = BOOTINFO.ramdisk_addr.into_option().expect("initrd no present");
         let ramdisk_len = BOOTINFO.ramdisk_len;
diff --git a/src/pit.rs b/src/pit.rs
index f9c39fd..e8b57d9 100644
--- a/src/pit.rs
+++ b/src/pit.rs
@@ -1,3 +1,5 @@
+use core::sync::atomic::{AtomicU64, Ordering};
+
 use crate::{
     interrupts::{self, EoiGuard},
     println, TASKING,
@@ -10,6 +12,8 @@ static CMD: Mutex<PortWriteOnly<u8>> = Mutex::new(PortWriteOnly::new(0x43));
 
 const MAX_FREQ: u32 = 1_193_180;
 
+pub static NUM_INTERRUPTS: AtomicU64 = AtomicU64::new(0);
+
 pub fn init(mut freq: u32) {
     assert_ne!(freq, 0);
     #[expect(
@@ -47,6 +51,7 @@ pub fn init(mut freq: u32) {
 }
 
 fn handler(_irq: u8, eoi_guard: EoiGuard) {
+    NUM_INTERRUPTS.fetch_add(1, Ordering::Relaxed);
     drop(eoi_guard);
     if TASKING.ok_to_yield() {
         TASKING.task_yield();