local_lock: Add local_lock

Add local_lock, a nice abstraction over preemption disabling and irq
disabling.

Signed-off-by: Pedro Falcato <pedro.falcato@gmail.com>

kernel/include/onyx/local_lock.h

@@ -0,0 +1,57 @@
+/*
+ * Copyright (c) 2024 Pedro Falcato
+ * This file is part of Onyx, and is released under the terms of the MIT License
+ * check LICENSE at the root directory for more information
+ *
+ * SPDX-License-Identifier: MIT
+ */
+#ifndef _ONYX_LOCAL_LOCK_H
+#define _ONYX_LOCAL_LOCK_H
+
+#include <onyx/lock_annotations.h>
+#include <onyx/preempt.h>
+
+#include <platform/irq.h>
+
+/* Linux-like local_lock implementation as defined in
+ * https://docs.kernel.org/locking/locktypes.html#local-lock
+ */
+struct CAPABILITY("local lock") local_lock
+{
+#ifdef __cplusplus
+    /* We need this dummy[0] to force a zero-sized struct in C++*/
+    int dummy[0];
+#endif
+};
+
+#define local_lock_init(x) ((void) (x))
+
+static inline void local_lock(struct local_lock *ll) ACQUIRE(ll) NO_THREAD_SAFETY_ANALYSIS
+{
+    sched_disable_preempt();
+}
+
+static inline void local_unlock(struct local_lock *ll) RELEASE(ll) NO_THREAD_SAFETY_ANALYSIS
+{
+    sched_enable_preempt();
+}
+
+static inline void local_unlock_nosoftirq(struct local_lock *ll)
+    RELEASE(ll) NO_THREAD_SAFETY_ANALYSIS
+{
+    sched_enable_preempt_no_softirq();
+}
+
+static inline unsigned long local_lock_irqsave(struct local_lock *ll)
+    ACQUIRE(ll) NO_THREAD_SAFETY_ANALYSIS
+{
+    return irq_save_and_disable();
+}
+
+static inline void local_unlock_irqrestore(struct local_lock *ll, unsigned long flags)
+    RELEASE(ll) NO_THREAD_SAFETY_ANALYSIS
+{
+    irq_restore(flags);
+}
+
+#endif