rust: io: add missing safety requirement in `IoCapable` methods

The current safety comment on `io_read`/`io_write` does not cover the topic
about alignment. Add it so it can be relied on by implementor of
`IoCapable`.

Expand the check performed by `Io` by taking `self.addr()` into
consideration when checking if `offset` is aligned. For the compile-time
`io_addr_assert` check, check using the known minimum alignment of
`Io::Target` and the accessed type.

While at it, fix the alignment check to use `align_of` instead of
`size_of`. The values match for all primitives (including u64, given that
we do not provide u64 accessor on 32-bit platforms), but are not
necessarily true for custom types.

Reviewed-by: Alexandre Courbot <acourbot@nvidia.com>
Signed-off-by: Gary Guo <gary@garyguo.net>
Reviewed-by: Daniel Almeida <daniel.almeida@collabora.com>
Link: https://patch.msgid.link/20260706-io_projection-v6-2-72cd5d055d54@garyguo.net
Signed-off-by: Danilo Krummrich <dakr@kernel.org>

0 files changed, 0 insertions, 0 deletions