1 files changed, 82 insertions, 0 deletions
diff --git a/lib/kobject.cc b/lib/kobject.cc
new file mode 100644
index 0000000..8e8329e
--- /dev/null
+++ b/lib/kobject.cc
@@ -0,0 +1,82 @@
+/* SPDX-License-Identifier: GPL-2.0-or-later */
+/* Copyright (C) 2026 Richard Qin */
+
+/*
+ * kobject — implementation.
+ *
+ * Lives in lib/ (mirroring Linux's lib/kobject.c) because kobject is a
+ * generic primitive, not tied to the driver model.
+ *
+ * Reference: docs/specs/storage_stack.md §4.2
+ */
+
+#include <lume/kobject.h>
+#include <lume/container_of.h>
+#include <lume/klog.h>
+
+void kobject_init(kobject* k, const kobj_type* type)
+{
+    if (k == nullptr) {
+        return;
+    }
+    k->name = nullptr;
+    k->parent = nullptr;
+    k->ktype = type;
+    k->state_in_sysfs = false;
+    k->entry.init();
+    k->children.init();
+    k->lock.init("kobject");
+    kref_init(&k->refcount);
+}
+
+int kobject_add(kobject* k, kobject* parent, const char* name)
+{
+    if (k == nullptr) {
+        return -1;
+    }
+    k->name = name;
+    if (parent != nullptr) {
+        kobject_get(parent);
+        k->parent = parent;
+        LockGuard g(parent->lock);
+        list_add_tail(&k->entry, &parent->children);
+    }
+    return 0;
+}
+
+void kobject_del(kobject* k)
+{
+    if (k == nullptr || k->parent == nullptr) {
+        return;
+    }
+    kobject* parent = k->parent;
+    {
+        LockGuard g(parent->lock);
+        list_del_init(&k->entry);
+    }
+    k->parent = nullptr;
+    kobject_put(parent);
+}
+
+void kobject_get(kobject* k)
+{
+    if (k != nullptr) {
+        kref_get(&k->refcount);
+    }
+}
+
+static void kobject_release(kref* r)
+{
+    kobject* k = container_of(r, kobject, refcount);
+    if (k->ktype != nullptr && k->ktype->release != nullptr) {
+        k->ktype->release(k);
+    }
+}
+
+void kobject_put(kobject* k)
+{
+    if (k == nullptr) {
+        return;
+    }
+    kref_put(&k->refcount, kobject_release);
+}