From b00670ea7764d61c9e18cd56b142c620bc51ee4a Mon Sep 17 00:00:00 2001
From: Mark Poliakov <mark@alnyan.me>
Date: Thu, 31 Aug 2023 19:54:09 +0300
Subject: [PATCH] x86-64: implement ACPI stall function

---
 src/arch/x86_64/acpi.rs |  5 +++++
 src/main.rs             |  1 +
 src/util.rs             | 16 ++++++++++++++++
 3 files changed, 22 insertions(+)
 create mode 100644 src/util.rs

diff --git a/src/arch/x86_64/acpi.rs b/src/arch/x86_64/acpi.rs
index bf92a485..d9a1871f 100644
--- a/src/arch/x86_64/acpi.rs
+++ b/src/arch/x86_64/acpi.rs
@@ -24,6 +24,7 @@ use crate::{
     },
     mem::{heap::GLOBAL_HEAP, ConvertAddress},
     sync::IrqSafeSpinlock,
+    util,
 };
 
 use super::intrinsics;
@@ -198,6 +199,10 @@ impl acpi_system::Handler for AcpiHandlerImpl {
 
         Ok(())
     }
+
+    fn stall(duration: Duration) {
+        util::polling_sleep(duration).ok();
+    }
 }
 
 impl aml::Handler for AcpiHandlerImpl {
diff --git a/src/main.rs b/src/main.rs
index 7de3c63e..63732170 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -46,6 +46,7 @@ pub mod proc;
 pub mod sync;
 pub mod syscall;
 pub mod task;
+pub mod util;
 
 static CPU_INIT_FENCE: SpinFence = SpinFence::new();
 
diff --git a/src/util.rs b/src/util.rs
new file mode 100644
index 00000000..d03dd27f
--- /dev/null
+++ b/src/util.rs
@@ -0,0 +1,16 @@
+use core::time::Duration;
+
+use yggdrasil_abi::error::Error;
+
+use crate::arch::{Architecture, ARCHITECTURE};
+
+pub fn polling_sleep(duration: Duration) -> Result<(), Error> {
+    let timer = ARCHITECTURE.monotonic_timer();
+    let deadline = timer.monotonic_timestamp()? + duration;
+
+    while timer.monotonic_timestamp()? < deadline {
+        core::hint::spin_loop();
+    }
+
+    Ok(())
+}