riscv: Add critical section.

1 files changed, 37 insertions, 0 deletions

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