[PATCH v5 0/7] BorrowedPage, AsPageIter and VmallocPageIter

[Danilo Krummrich <dakr@kernel.org>]

This patch series implements the BorrowedPage type, the AsPageIter trait and
VmallocPageIter type.

AsPageIter can be implemented by any type that owns pages to allow users to
borrow them through a generic interface.

For instance, this is useful to access and borrow the backing pages of
allocation primitives, such as Box and Vec, backing a scatterlist.

Hence, implement AsPageIter for VBox and VVec.

Additionally, implement Vmalloc::to_page() and ArrayLayout::size(), which are
dependencies of the above.

Changes in v5:
  - Avoid repetition in commit message of "rust: alloc: implement
    VmallocPageIter".
  - Change invariants of VmallocPageIter to:
    - `buf` is a valid and [`page::PAGE_SIZE`] aligned pointer into a
      [`Vmalloc`] allocation.
    - `size` is the number of bytes from `buf` until the end of the [`Vmalloc`]
      allocation `buf` points to.
  - Inline some methods of VmallocPageIter.

Changes in v4:
  - Rename IntoPageIter into AsPageIter.
  - Put lifetime on AsPageIter::Iter instead of AsPageIter itself.
  - Implement size_hint() for VmallocPageIter.
  - Use PhantomData<page::BorrowedPage<'a>> instead of PhantomData<&'a u8>.

Changes in v3:
  - Generalize the previous PageOwner impl of VBox and VVec in VmallocPageIter.
  - Correspondingly, replace PageOwner with IntoPageIter.

Changes in v2:
  - BorrowedPage
    - Add link to Ownable
    - Use borrow_page() in the example
  - Add PageOwner, Vmalloc::to_page(), ArrayLayout, VBox, VVec patches.

Danilo Krummrich (7):
  rust: page: implement BorrowedPage
  rust: alloc: vmalloc: implement Vmalloc::to_page()
  rust: alloc: implement VmallocPageIter
  rust: page: define trait AsPageIter
  rust: alloc: kbox: implement AsPageIter for VBox
  rust: alloc: layout: implement ArrayLayout::size()
  rust: alloc: kvec: implement AsPageIter for VVec

 rust/bindings/bindings_helper.h |   1 +
 rust/kernel/alloc/allocator.rs  | 152 ++++++++++++++++++++++++++++++++
 rust/kernel/alloc/kbox.rs       |  40 ++++++++-
 rust/kernel/alloc/kvec.rs       |  40 ++++++++-
 rust/kernel/alloc/layout.rs     |   5 ++
 rust/kernel/page.rs             |  87 +++++++++++++++++-
 6 files changed, 322 insertions(+), 3 deletions(-)


base-commit: 8f5ae30d69d7543eee0d70083daf4de8fe15d585
-- 
2.50.1