From fc00c656c96528112d05cf0edf8631bd5eaea446 Mon Sep 17 00:00:00 2001
From: Kacper <kacper@mail.openlinux.dev>
Date: Sun, 7 Dec 2025 20:10:31 +0100
Subject: Add build system scaffolding and libc headers

---
 lib/libc/include/atomic.h | 23 +++++++++++++++++++++++
 1 file changed, 23 insertions(+)
 create mode 100644 lib/libc/include/atomic.h

(limited to 'lib/libc/include/atomic.h')

diff --git a/lib/libc/include/atomic.h b/lib/libc/include/atomic.h
new file mode 100644
index 00000000..94cd34db
--- /dev/null
+++ b/lib/libc/include/atomic.h
@@ -0,0 +1,23 @@
+#ifndef __LIBC_ATOMIC_H
+#define __LIBC_ATOMIC_H
+
+#include <stdatomic.h>
+
+#define LIBC_LOCK(__lock)   __libc_lock(&__lock)
+#define LIBC_UNLOCK(__lock) atomic_flag_clear(&__lock)
+
+static __inline void __libc_lock(volatile atomic_flag *lock)
+{
+	while (atomic_flag_test_and_set_explicit(lock, memory_order_acquire)) {
+		unsigned int spins = 1;
+		do {
+			for (unsigned int i = 0; i < spins; i++)
+				__asm__ volatile("pause");
+			if (spins < 64)
+				spins *= 2;
+		} while (atomic_flag_test_and_set_explicit(
+			lock, memory_order_relaxed));
+	}
+}
+
+#endif
-- 
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