1 files changed, 111 insertions, 0 deletions
diff --git a/src/asm/barrier.rs b/src/asm/barrier.rs
new file mode 100644
index 0000000..690c32f
--- /dev/null
+++ b/src/asm/barrier.rs
@@ -0,0 +1,111 @@
+// SPDX-License-Identifier: Apache-2.0 OR MIT
+//
+// Copyright (c) 2018-2022 by the author(s)
+//
+// Author(s):
+//   - Andre Richter <andre.o.richter@gmail.com>
+
+//! Barrier functions.
+
+mod sealed {
+    pub trait Dmb {
+        unsafe fn __dmb(&self);
+    }
+
+    pub trait Dsb {
+        unsafe fn __dsb(&self);
+    }
+
+    pub trait Isb {
+        unsafe fn __isb(&self);
+    }
+}
+
+macro_rules! dmb_dsb {
+    ($A:ident) => {
+        impl sealed::Dmb for $A {
+            #[inline(always)]
+            unsafe fn __dmb(&self) {
+                match () {
+                    #[cfg(target_arch = "aarch64")]
+                    () => {
+                        core::arch::asm!(concat!("DMB ", stringify!($A)), options(nostack))
+                    }
+
+                    #[cfg(not(target_arch = "aarch64"))]
+                    () => unimplemented!(),
+                }
+            }
+        }
+        impl sealed::Dsb for $A {
+            #[inline(always)]
+            unsafe fn __dsb(&self) {
+                match () {
+                    #[cfg(target_arch = "aarch64")]
+                    () => {
+                        core::arch::asm!(concat!("DSB ", stringify!($A)), options(nostack))
+                    }
+
+                    #[cfg(not(target_arch = "aarch64"))]
+                    () => unimplemented!(),
+                }
+            }
+        }
+    };
+}
+
+pub struct SY;
+pub struct ISH;
+pub struct ISHST;
+
+dmb_dsb!(ISH);
+dmb_dsb!(ISHST);
+dmb_dsb!(SY);
+
+impl sealed::Isb for SY {
+    #[inline(always)]
+    unsafe fn __isb(&self) {
+        match () {
+            #[cfg(target_arch = "aarch64")]
+            () => {
+                core::arch::asm!("ISB SY", options(nostack))
+            }
+
+            #[cfg(not(target_arch = "aarch64"))]
+            () => unimplemented!(),
+        }
+    }
+}
+
+/// # Safety
+///
+/// In your own hands, this is hardware land!
+#[inline(always)]
+pub unsafe fn dmb<A>(arg: A)
+where
+    A: sealed::Dmb,
+{
+    arg.__dmb()
+}
+
+/// # Safety
+///
+/// In your own hands, this is hardware land!
+#[inline(always)]
+pub unsafe fn dsb<A>(arg: A)
+where
+    A: sealed::Dsb,
+{
+    arg.__dsb()
+}
+
+/// # Safety
+///
+/// In your own hands, this is hardware land!
+#[inline(always)]
+pub unsafe fn isb<A>(arg: A)
+where
+    A: sealed::Isb,
+{
+    arg.__isb()
+}