From: Danilo Krummrich <dakr@kernel.org>
Date: Wed, 20 Aug 2025 14:53:40 +0000 (+0200)
Subject: rust: page: define trait AsPageIter
X-Git-Url: https://www.infradead.org/git/?a=commitdiff_plain;h=866ec3bab19c33a66ad384bc69dff1cd83d7ed12;p=users%2Fhch%2Fmisc.git

rust: page: define trait AsPageIter

The AsPageIter trait provides a common interface for types that
provide a page iterator, such as VmallocPageIter.

Subsequent patches will leverage this to let VBox and VVec provide a
VmallocPageIter though this trait.

Reviewed-by: Alice Ryhl <aliceryhl@google.com>
Reviewed-by: Alexandre Courbot <acourbot@nvidia.com>
Tested-by: Alexandre Courbot <acourbot@nvidia.com>
Reviewed-by: Daniel Almeida <daniel.almeida@collabora.com>
Link: https://lore.kernel.org/r/20250820145434.94745-5-dakr@kernel.org
Signed-off-by: Danilo Krummrich <dakr@kernel.org>
---

diff --git a/rust/kernel/page.rs b/rust/kernel/page.rs
index 631718a6ad7d..75ef096075cb 100644
--- a/rust/kernel/page.rs
+++ b/rust/kernel/page.rs
@@ -103,6 +103,18 @@ impl<'a> Deref for BorrowedPage<'a> {
     }
 }
 
+/// Trait to be implemented by types which provide an [`Iterator`] implementation of
+/// [`BorrowedPage`] items, such as [`VmallocPageIter`](kernel::alloc::allocator::VmallocPageIter).
+pub trait AsPageIter {
+    /// The [`Iterator`] type, e.g. [`VmallocPageIter`](kernel::alloc::allocator::VmallocPageIter).
+    type Iter<'a>: Iterator<Item = BorrowedPage<'a>>
+    where
+        Self: 'a;
+
+    /// Returns an [`Iterator`] of [`BorrowedPage`] items over all pages owned by `self`.
+    fn page_iter(&mut self) -> Self::Iter<'_>;
+}
+
 /// A pointer to a page that owns the page allocation.
 ///
 /// # Invariants