feat: add local_irq_save_and_disable and local_irq_restore for mclass target

Author: luodeb

src/arch/arm.rs

@@ -4,6 +4,7 @@ use core::arch::asm;
 const IRQ_DISABLE_BIT: usize = 1 << 7;
 
 #[inline]
+#[cfg(target_feature = "aclass")]
 pub fn local_irq_save_and_disable() -> usize {
     let flags: usize;
     unsafe {
@@ -19,6 +20,7 @@ pub fn local_irq_save_and_disable() -> usize {
 }
 
 #[inline]
+#[cfg(target_feature = "aclass")]
 pub fn local_irq_restore(flags: usize) {
     if flags & IRQ_DISABLE_BIT == 0 {
         // IRQs were enabled before, re-enable them
@@ -27,3 +29,29 @@ pub fn local_irq_restore(flags: usize) {
         }
     }
 }
+
+#[inline]
+#[cfg(target_feature = "mclass")]
+pub fn local_irq_save_and_disable() -> usize {
+    let primask: usize;
+    unsafe {
+        asm!(
+            "mrs {0}, primask",
+            "cpsid i",
+            out(reg) primask,
+            options(nomem, nostack, preserves_flags)
+        );
+    }
+    primask
+}
+
+#[inline]
+#[cfg(target_feature = "mclass")]
+pub fn local_irq_restore(flags: usize) {
+    if flags & 1 == 0 {
+        unsafe {
+            asm!("cpsie i", options(nomem, nostack));
+        }
+    }
+}
+