PMM and liballoc port

kernel/sync/.gitignore

@@ -0,0 +1 @@
+*.o

kernel/sync/spin_lock.c

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+#include <libk/std.h>
+#include <sys/spin_lock.h>
+#include <sync/spin_lock.h>
+
+void spin_lock(spin_lock_t *sl) {
+  while (atomic_flag_test_and_set_explicit(sl, memory_order_acquire))
+    spin_lock_relax();
+}
+
+void spin_unlock(spin_lock_t *sl) {
+  atomic_flag_clear_explicit(sl, memory_order_release);
+}

kernel/sync/spin_lock.h

@@ -0,0 +1,13 @@
+#ifndef _KERNEL_SYNC_SPIN_LOCK_H
+#define _KERNEL_SYNC_SPIN_LOCK_H
+
+#include <libk/std.h>
+
+#define SPIN_LOCK_INIT  ATOMIC_FLAG_INIT
+
+typedef atomic_flag spin_lock_t;
+
+void spin_lock(spin_lock_t *sl);
+void spin_unlock(spin_lock_t *sl);
+
+#endif // _KERNEL_SYNC_SPIN_LOCK_H

kernel/sync/src.mk

@@ -0,0 +1,3 @@
+c += sync/spin_lock.c
+
+o += sync/spin_lock.o