diff --git a/rust/kernel/mm.rs b/rust/kernel/mm.rs
index 3bb2ccd5fda1..60dc66972576 100644
--- a/rust/kernel/mm.rs
+++ b/rust/kernel/mm.rs
@@ -110,48 +110,6 @@ impl Deref for MmWithUser {
     }
 }
 
-/// A wrapper for the kernel's `struct mm_struct`.
-///
-/// This type is identical to `MmWithUser` except that it uses `mmput_async` when dropping a
-/// refcount. This means that the destructor of `ARef<MmWithUserAsync>` is safe to call in atomic
-/// context.
-///
-/// # Invariants
-///
-/// Values of this type are always refcounted using `mmget`. The value of `mm_users` is non-zero.
-#[repr(transparent)]
-pub struct MmWithUserAsync {
-    mm: MmWithUser,
-}
-
-// SAFETY: It is safe to call `mmput_async` on another thread than where `mmget` was called.
-unsafe impl Send for MmWithUserAsync {}
-// SAFETY: All methods on `MmWithUserAsync` can be called in parallel from several threads.
-unsafe impl Sync for MmWithUserAsync {}
-
-// SAFETY: By the type invariants, this type is always refcounted.
-unsafe impl AlwaysRefCounted for MmWithUserAsync {
-    fn inc_ref(&self) {
-        // SAFETY: The pointer is valid since self is a reference.
-        unsafe { bindings::mmget(self.as_raw()) };
-    }
-
-    unsafe fn dec_ref(obj: NonNull<Self>) {
-        // SAFETY: The caller is giving up their refcount.
-        unsafe { bindings::mmput_async(obj.cast().as_ptr()) };
-    }
-}
-
-// Make all `MmWithUser` methods available on `MmWithUserAsync`.
-impl Deref for MmWithUserAsync {
-    type Target = MmWithUser;
-
-    #[inline]
-    fn deref(&self) -> &MmWithUser {
-        &self.mm
-    }
-}
-
 // These methods are safe to call even if `mm_users` is zero.
 impl Mm {
     /// Returns a raw pointer to the inner `mm_struct`.
@@ -203,13 +161,6 @@ impl MmWithUser {
         unsafe { &*ptr.cast() }
     }
 
-    /// Use `mmput_async` when dropping this refcount.
-    #[inline]
-    pub fn into_mmput_async(me: ARef<MmWithUser>) -> ARef<MmWithUserAsync> {
-        // SAFETY: The layouts and invariants are compatible.
-        unsafe { ARef::from_raw(ARef::into_raw(me).cast()) }
-    }
-
     /// Attempt to access a vma using the vma read lock.
     ///
     /// This is an optimistic trylock operation, so it may fail if there is contention. In that