1 files changed, 0 insertions, 120 deletions
diff --git a/na/kernel/sync/spinlock.cc b/na/kernel/sync/spinlock.cc
deleted file mode 100644
index f649fe7..0000000
--- a/na/kernel/sync/spinlock.cc
+++ /dev/null
@@ -1,120 +0,0 @@
-/* SPDX-License-Identifier: GPL-2.0-or-later */
-/* Copyright (C) 2026 Richard Qin */
-
-/*
- * Spinlock Implementation
- *
- * TTAS (Test-and-Test-and-Set) spinlock with:
- *   - Acquire: __ATOMIC_ACQUIRE memory ordering
- *   - Release: __ATOMIC_RELEASE memory ordering
- *   - Automatic interrupt disable/enable via push_intr/pop_intr
- *   - Dead-lock and invalid-release detection via kernel_panic
- *
- * Reference: docs/specs/spinlock.md
- */
-
-#include "spinlock.h"
-#include "cpu_state.h"
-#include <arch/cpu.h>
-#include <lume/klog.h>
-#include <lume/task.h>
-
-// ============================================================
-// Per-CPU sync state (BSS zero-initialized)
-// ============================================================
-namespace sync {
-
-CpuSyncState g_cpu_sync_states[kMaxCpus];
-
-void push_intr() {
-    bool was_on = arch::cpu::intr_enabled();
-    arch::cpu::intr_off();
-
-    auto& state = g_cpu_sync_states[arch::cpu::id()];
-    if (state.lock_depth == 0) {
-        state.intr_was_on = was_on;
-    }
-    state.lock_depth++;
-}
-
-void pop_intr() {
-    auto& state = g_cpu_sync_states[arch::cpu::id()];
-    state.lock_depth--;
-
-    if (state.lock_depth == 0 && state.intr_was_on) {
-        arch::cpu::intr_on();
-    }
-}
-
-}  // namespace sync
-
-// ============================================================
-// Spinlock methods
-// ============================================================
-
-void Spinlock::init(const char* name) {
-    name_ = name;
-    locked_.store(0, __ATOMIC_RELAXED);
-    cpu_id_ = sync::kInvalidCpuId;
-}
-
-void Spinlock::acquire() {
-#ifdef DEBUG
-    // Optional: detect interrupt-state leakage
-    if (arch::cpu::intr_enabled()) {
-        auto& state = sync::g_cpu_sync_states[arch::cpu::id()];
-        if (state.lock_depth > 0) {
-            kernel_panic("spinlock: interrupts enabled while holding lock");
-        }
-    }
-#endif
-
-    // Step 1: disable interrupts, track nesting depth
-    sync::push_intr();
-
-    // Step 2: dead-lock detection (same CPU re-acquiring)
-    if (is_held_by_current_cpu()) {
-        kernel_panic("spinlock: double lock", name_);
-    }
-
-    // Step 3: TTAS spin loop
-    while (true) {
-        // Outer: spin on local cache copy (no bus traffic)
-        while (locked_.load(__ATOMIC_RELAXED))
-            ;
-        // Inner: attempt atomic exchange with acquire semantics
-        if (locked_.exchange(1, __ATOMIC_ACQUIRE) == 0)
-            break;
-    }
-
-    // Step 4: record owner
-    cpu_id_ = arch::cpu::id();
-
-    // Step 5: bump preempt_count — prevents schedule() from preempting
-    TaskControlBlock* curr = current_task();
-    if (curr) curr->preempt_count++;
-}
-
-void Spinlock::release() {
-    // Step 1: verify caller is the holder
-    if (!is_held_by_current_cpu()) {
-        kernel_panic("spinlock: invalid release", name_);
-    }
-
-    // Step 2: clear owner
-    cpu_id_ = sync::kInvalidCpuId;
-
-    // Step 3: release the lock with release semantics
-    locked_.store(0, __ATOMIC_RELEASE);
-
-    // Step 4: drop preempt_count
-    TaskControlBlock* curr = current_task();
-    if (curr) curr->preempt_count--;
-
-    // Step 5: restore interrupt state if this was the last lock
-    sync::pop_intr();
-}
-
-bool Spinlock::is_held_by_current_cpu() const {
-    return cpu_id_ == arch::cpu::id();
-}