1 files changed, 52 insertions, 0 deletions
diff --git a/rust/kernel/seq_file.rs b/rust/kernel/seq_file.rs
new file mode 100644
index 000000000000..6ca29d576d02
--- /dev/null
+++ b/rust/kernel/seq_file.rs
@@ -0,0 +1,52 @@
+// SPDX-License-Identifier: GPL-2.0
+
+//! Seq file bindings.
+//!
+//! C header: [`include/linux/seq_file.h`](srctree/include/linux/seq_file.h)
+
+use crate::{bindings, c_str, types::NotThreadSafe, types::Opaque};
+
+/// A utility for generating the contents of a seq file.
+#[repr(transparent)]
+pub struct SeqFile {
+    inner: Opaque<bindings::seq_file>,
+    _not_send: NotThreadSafe,
+}
+
+impl SeqFile {
+    /// Creates a new [`SeqFile`] from a raw pointer.
+    ///
+    /// # Safety
+    ///
+    /// The caller must ensure that for the duration of 'a the following is satisfied:
+    /// * The pointer points at a valid `struct seq_file`.
+    /// * The `struct seq_file` is not accessed from any other thread.
+    pub unsafe fn from_raw<'a>(ptr: *mut bindings::seq_file) -> &'a SeqFile {
+        // SAFETY: The caller ensures that the reference is valid for 'a. There's no way to trigger
+        // a data race by using the `&SeqFile` since this is the only thread accessing the seq_file.
+        //
+        // CAST: The layout of `struct seq_file` and `SeqFile` is compatible.
+        unsafe { &*ptr.cast() }
+    }
+
+    /// Used by the [`seq_print`] macro.
+    pub fn call_printf(&self, args: core::fmt::Arguments<'_>) {
+        // SAFETY: Passing a void pointer to `Arguments` is valid for `%pA`.
+        unsafe {
+            bindings::seq_printf(
+                self.inner.get(),
+                c_str!("%pA").as_char_ptr(),
+                &args as *const _ as *const core::ffi::c_void,
+            );
+        }
+    }
+}
+
+/// Write to a [`SeqFile`] with the ordinary Rust formatting syntax.
+#[macro_export]
+macro_rules! seq_print {
+    ($m:expr, $($arg:tt)+) => (
+        $m.call_printf(format_args!($($arg)+))
+    );
+}
+pub use seq_print;