From 2d75a9be32e2510ff32d331c33178c4625a53054 Mon Sep 17 00:00:00 2001
From: Vegard Storheil Eriksen <zyp@jvnv.net>
Date: Sat, 10 Sep 2022 17:10:09 +0200
Subject: riscv: Add critical section.

---
 interrupt/critical_section.h | 37 +++++++++++++++++++++++++++++++++++++
 1 file changed, 37 insertions(+)
 create mode 100644 interrupt/critical_section.h

(limited to 'interrupt/critical_section.h')

diff --git a/interrupt/critical_section.h b/interrupt/critical_section.h
new file mode 100644
index 0000000..aec03a5
--- /dev/null
+++ b/interrupt/critical_section.h
@@ -0,0 +1,37 @@
+#pragma once
+
+#include <cstdint>
+
+#ifdef CORTEX_M
+struct critical_section {
+    uint32_t primask;
+
+    critical_section() {
+        asm volatile("mrs %0, primask" : "=r" (primask));
+
+        asm volatile("cpsid i");
+
+        asm volatile("dmb");
+    }
+
+    ~critical_section() {
+        asm volatile("dmb");
+
+        asm volatile("msr primask, %0" :: "r" (primask));
+    }
+};
+#endif
+
+#ifdef RISCV
+struct critical_section {
+    uint32_t mie;
+
+    critical_section() {
+        asm volatile("csrrw %0, mie, x0" : "=r" (mie));
+    }
+
+    ~critical_section() {
+        asm volatile("csrw mie, %0" :: "r" (mie));
+    }
+};
+#endif
-- 
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