rust: add infiniband mlx4 sample

samples/rust/Kconfig

@@ -163,4 +163,11 @@ config SAMPLE_RUST_SELFTESTS
 
 	  If unsure, say N.
 
+config SAMPLE_RUST_MLX4
+	tristate "infiniband mlx4"
+	help
+	  This option builds the infiniband mlx4 driver cases for Rust.
+
+	  If unsure, say N.
+
 endif # SAMPLES_RUST

samples/rust/Makefile

@@ -15,5 +15,6 @@ obj-$(CONFIG_SAMPLE_RUST_NETFILTER)		+= rust_netfilter.o
 obj-$(CONFIG_SAMPLE_RUST_ECHO_SERVER)		+= rust_echo_server.o
 obj-$(CONFIG_SAMPLE_RUST_FS)			+= rust_fs.o
 obj-$(CONFIG_SAMPLE_RUST_SELFTESTS)		+= rust_selftests.o
+obj-$(CONFIG_SAMPLE_RUST_MLX4)			+= rust_mlx4.o
 
 subdir-$(CONFIG_SAMPLE_RUST_HOSTPROGS)		+= hostprogs

samples/rust/rust_mlx4.rs

@@ -0,0 +1,49 @@
+// SPDX-License-Identifier: GPL-2.0
+
+//! Rust infiniband mls4 device sample.
+
+use kernel::mlx4;
+use kernel::prelude::*;
+
+module! {
+    type: RustMlx4,
+    name: "rust_mlx4",
+    author: "Rust for Linux Contributors",
+    description: "Rust infiniband mlx4 device sample",
+    license: "GPL",
+}
+
+struct RustMlx4Ops;
+
+#[vtable]
+impl mlx4::Mlx4Operation for RustMlx4Ops {
+    fn add() -> Result {
+        Ok(())
+    }
+    fn remove() -> Result {
+        Ok(())
+    }
+    fn event() -> Result {
+        Ok(())
+    }
+}
+
+struct RustMlx4 {
+    _dev: Pin<Box<mlx4::Registration<RustMlx4Ops>>>,
+}
+
+impl kernel::Module for RustMlx4 {
+    fn init(name: &'static CStr, _module: &'static ThisModule) -> Result<Self> {
+        pr_info!("Rust infiniband mlx4 driver sample (init)\n");
+
+        Ok(RustMlx4 {
+            _dev: mlx4::Registration::new_pinned(name)?,
+        })
+    }
+}
+
+impl Drop for RustMlx4 {
+    fn drop(&mut self) {
+        pr_info!("Rust infiniband mlx4 driver sample (exit)\n");
+    }
+}