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0b76335e8f
The common practice in C drivers is to store pointers into `driver_data` field of device IDs. The Rust code is however currently storing indices into the fields and then carry a side table that maps the index to pointers. It is much simpler to just have `DeviceId` carry the pointer like C code does. However, just doing so naively would cause a "pointers cannot be cast to integers during const eval" error, as kernel_ulong_t does not have provenance while pointers do, and Rust forbids `expose_provenance` during consteval. Work around this limitation by wrapping raw IDs in `MaybeUninit`. `MaybeUninit` is allowed to host arbitrary bytes with or without provenance, so we can just then use `unsafe` to store a pointer with provenance there. This has the same effect as changing the C-side definition to use `void*` instead of `kernel_ulong_t`, but without actually changing the C side. Signed-off-by: Gary Guo <gary@garyguo.net> Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Link: https://patch.msgid.link/20260629-id_info-v2-8-56fccbe9c5ef@garyguo.net Signed-off-by: Danilo Krummrich <dakr@kernel.org>
55 lines
1.7 KiB
55 lines
1.7 KiB