From fe107fbad3c4977a58b20b7ac65a90bec0188950 Mon Sep 17 00:00:00 2001
From: Max Wash <mbswash@gmail.com>
Date: Mon, 23 Feb 2026 18:24:49 +0000
Subject: [PATCH] kernel: locks: add spin lock/unlock function that don't
 change interrupt state

---
 arch/user/hwlock.c                          |  2 +-
 arch/x86_64/hwlock.S                        | 45 +++++++++++++++++++--
 arch/x86_64/include/kernel/machine/hwlock.h |  3 ++
 include/kernel/locks.h                      | 12 ++++--
 4 files changed, 53 insertions(+), 9 deletions(-)

diff --git a/arch/user/hwlock.c b/arch/user/hwlock.c
index 0074865..6c635ff 100644
--- a/arch/user/hwlock.c
+++ b/arch/user/hwlock.c
@@ -1,5 +1,5 @@
-#include <kernel/machine/hwlock.h>
 #include <kernel/compiler.h>
+#include <kernel/machine/hwlock.h>
 
 void ml_hwlock_lock(ml_hwlock_t *lck)
 {
diff --git a/arch/x86_64/hwlock.S b/arch/x86_64/hwlock.S
index b659333..9ee5f86 100644
--- a/arch/x86_64/hwlock.S
+++ b/arch/x86_64/hwlock.S
@@ -11,6 +11,41 @@ ml_hwlock_lock:
 
 	mov $1, %ecx
 
+	mfence
+
+1:	mov $0, %eax
+	lock cmpxchg %ecx, (%rdi)
+	jne 1b
+
+	pop %rbp
+	ret
+
+
+	.global ml_hwlock_unlock
+	.type ml_hwlock_unlock, @function
+
+	/* %rdi = pointer to ml_hwlock_t (int) */
+ml_hwlock_unlock:
+	push %rbp
+	mov %rsp, %rbp
+
+	movl $0, (%rdi)
+	mfence
+
+	pop %rbp
+	ret
+
+
+	.global ml_hwlock_lock_irq
+	.type ml_hwlock_lock_irq, @function
+
+	/* %rdi = pointer to ml_hwlock_t (int) */
+ml_hwlock_lock_irq:
+	push %rbp
+	mov %rsp, %rbp
+
+	mov $1, %ecx
+
 	cli
 	mfence
 
@@ -21,11 +56,12 @@ ml_hwlock_lock:
 	pop %rbp
 	ret
 
-	.global ml_hwlock_unlock
-	.type ml_hwlock_unlock, @function
+
+	.global ml_hwlock_unlock_irq
+	.type ml_hwlock_unlock_irq, @function
 
 	/* %rdi = pointer to ml_hwlock_t (int) */
-ml_hwlock_unlock:
+ml_hwlock_unlock_irq:
 	push %rbp
 	mov %rsp, %rbp
 
@@ -42,7 +78,7 @@ ml_hwlock_unlock:
 
 	/* %rdi = pointer to ml_hwlock_t (int)
 	   %rsi = pointer to quadword to store rflags in */
-ml_hwlock_lock_irqsave:	
+ml_hwlock_lock_irqsave:
 	push %rbp
 	mov %rsp, %rbp
 
@@ -62,6 +98,7 @@ ml_hwlock_lock_irqsave:
 	pop %rbp
 	ret
 
+
 	.global ml_hwlock_unlock_irqrestore
 	.type ml_hwlock_unlock_irqrestore, @function
 
diff --git a/arch/x86_64/include/kernel/machine/hwlock.h b/arch/x86_64/include/kernel/machine/hwlock.h
index 355e82c..4d83654 100644
--- a/arch/x86_64/include/kernel/machine/hwlock.h
+++ b/arch/x86_64/include/kernel/machine/hwlock.h
@@ -12,6 +12,9 @@ typedef int ml_hwlock_t;
 extern void ml_hwlock_lock(ml_hwlock_t *lck);
 extern void ml_hwlock_unlock(ml_hwlock_t *lck);
 
+extern void ml_hwlock_lock_irq(ml_hwlock_t *lck);
+extern void ml_hwlock_unlock_irq(ml_hwlock_t *lck);
+
 extern void ml_hwlock_lock_irqsave(ml_hwlock_t *lck, unsigned long *flags);
 extern void ml_hwlock_unlock_irqrestore(ml_hwlock_t *lck, unsigned long flags);
 
diff --git a/include/kernel/locks.h b/include/kernel/locks.h
index 8ff7098..83feacb 100644
--- a/include/kernel/locks.h
+++ b/include/kernel/locks.h
@@ -10,13 +10,17 @@ extern "C" {
 
 typedef __aligned(8) ml_hwlock_t spin_lock_t;
 
-#define SPIN_LOCK_INIT ML_HWLOCK_INIT
+#define SPIN_LOCK_INIT                ML_HWLOCK_INIT
 
-#define spin_lock(lck) ml_hwlock_lock(lck);
-#define spin_unlock(lck) ml_hwlock_unlock(lck);
+#define spin_lock(lck)                ml_hwlock_lock(lck);
+#define spin_unlock(lck)              ml_hwlock_unlock(lck);
+
+#define spin_lock_irq(lck)            ml_hwlock_lock_irq(lck);
+#define spin_unlock_irq(lck)          ml_hwlock_unlock_irq(lck);
 
 #define spin_lock_irqsave(lck, flags) ml_hwlock_lock_irqsave(lck, flags);
-#define spin_unlock_irqrestore(lck, flags) ml_hwlock_unlock_irqrestore(lck, flags);
+#define spin_unlock_irqrestore(lck, flags)                                     \
+	ml_hwlock_unlock_irqrestore(lck, flags);
 
 #ifdef __cplusplus
 }