From b01735b448bfdd39bb0b0f8f28db149d8a088e55 Mon Sep 17 00:00:00 2001
From: Jerome Forissier <jerome.forissier@linaro.org>
Date: Fri, 18 Apr 2025 16:09:35 +0200
Subject: uthread: add uthread_mutex

Add struct uthread_mutex and uthread_mutex_lock(),
uthread_mutex_trylock(), uthread_mutex_unlock() to protect shared data
structures from concurrent modifications.

Signed-off-by: Jerome Forissier <jerome.forissier@linaro.org>
---
 lib/uthread.c | 27 +++++++++++++++++++++++++++
 1 file changed, 27 insertions(+)

(limited to 'lib')

diff --git a/lib/uthread.c b/lib/uthread.c
index aa264b1d95f..062fca7d209 100644
--- a/lib/uthread.c
+++ b/lib/uthread.c
@@ -8,6 +8,7 @@
  */
 
 #include <compiler.h>
+#include <linux/errno.h>
 #include <linux/kernel.h>
 #include <linux/list.h>
 #include <malloc.h>
@@ -136,3 +137,29 @@ bool uthread_grp_done(unsigned int grp_id)
 
 	return true;
 }
+
+int uthread_mutex_lock(struct uthread_mutex *mutex)
+{
+	while (mutex->state == UTHREAD_MUTEX_LOCKED)
+		uthread_schedule();
+
+	mutex->state = UTHREAD_MUTEX_LOCKED;
+	return 0;
+}
+
+int uthread_mutex_trylock(struct uthread_mutex *mutex)
+{
+	if (mutex->state == UTHREAD_MUTEX_UNLOCKED) {
+		mutex->state = UTHREAD_MUTEX_LOCKED;
+		return 0;
+	}
+
+	return -EBUSY;
+}
+
+int uthread_mutex_unlock(struct uthread_mutex *mutex)
+{
+	mutex->state = UTHREAD_MUTEX_UNLOCKED;
+
+	return 0;
+}
-- 
cgit v1.2.3