Introduction ============ This patchset introduces an interface to iterate over doubly circular linked lists used in the kernel (allocated by C kernel code). The main usecase is iterating over the list of blocks provided by the DRM buddy allocator.
The first 2 patches introduce a new rust module called clist. The last 2 patches use the clist in the DRM buddy allocator bindings. Samples have been provided to show the usage. A question may arise: Why not use rust list.rs for this? ========================================================= Rust's list.rs is used to provide safe intrusive lists for Rust-allocated items. In doing so, it takes ownership of the items in the list and the links between list items. However, the usecase for DRM buddy allocator bindings, the C side allocates the items in the list, and also links the list together. Due to this, there is an ownership conflict making list.rs not the best abstraction for this usecase. What we need is a view of the list, not ownership of it. Further, the list links in a bindings usecase may come from C allocated objects, not from the Rust side. Other comments ============== The patches IMO are ahead of RFC-quality, but I am still keeping the RFC tag for initial comments and to get a sense of what everyone thinks. I already presented the idea in Zulip and it seemed it mostly got agreements there. I rebased the patches on linux-next. I can also add MAINTAINER entries in v2, if folks agree this should have its own MAINTAINER record. Joel Fernandes (4): rust: clist: Add abstraction for iterating over C linked lists samples: rust: Add sample demonstrating C linked list iteration rust: drm: Add DRM buddy allocator bindings samples: rust: Add sample demonstrating DRM buddy allocator rust/bindings/bindings_helper.h | 11 + rust/helpers/drm.c | 23 +- rust/helpers/helpers.c | 1 + rust/helpers/list.c | 28 +++ rust/kernel/clist.rs | 296 ++++++++++++++++++++++++++ rust/kernel/drm/buddy.rs | 357 ++++++++++++++++++++++++++++++++ rust/kernel/drm/mod.rs | 1 + rust/kernel/lib.rs | 1 + samples/rust/Kconfig | 25 +++ samples/rust/Makefile | 3 + samples/rust/rust_clist_c.c | 54 +++++ samples/rust/rust_clist_main.rs | 138 ++++++++++++ samples/rust/rust_drm_buddy.rs | 106 ++++++++++ 13 files changed, 1043 insertions(+), 1 deletion(-) create mode 100644 rust/helpers/list.c create mode 100644 rust/kernel/clist.rs create mode 100644 rust/kernel/drm/buddy.rs create mode 100644 samples/rust/rust_clist_c.c create mode 100644 samples/rust/rust_clist_main.rs create mode 100644 samples/rust/rust_drm_buddy.rs base-commit: 131f3d9446a6075192cdd91f197989d98302faa6 -- 2.34.1
