Messages in this thread |  | | Date | Tue, 28 Apr 2026 00:52:50 +0100 | | Subject | Re: [PATCH 06/24] rust: pci: implement Sync for Device<Bound> | | From | "Gary Guo" <> |
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On Mon Apr 27, 2026 at 11:11 PM BST, Danilo Krummrich wrote: > Implement Sync for Device<Bound> in addition to Device<Normal>. The > underlying struct pci_dev is the same; Bound is a zero-sized type-state > marker that does not affect thread safety. > > This is needed for pci::Bar to hold &'a Device<Bound> (required for > Bar::into_devres()) while remaining Send. > > Signed-off-by: Danilo Krummrich <dakr@kernel.org> > --- > rust/kernel/pci.rs | 4 ++++ > 1 file changed, 4 insertions(+) > > diff --git a/rust/kernel/pci.rs b/rust/kernel/pci.rs > index fe5148f41d8b..6f82f2e6c74f 100644 > --- a/rust/kernel/pci.rs > +++ b/rust/kernel/pci.rs > @@ -526,3 +526,7 @@ unsafe impl Send for Device {} > // SAFETY: `Device` can be shared among threads because all methods of `Device` > // (i.e. `Device<Normal>) are thread safe. > unsafe impl Sync for Device {} > + > +// SAFETY: Same as `Device<Normal>` -- the underlying `struct pci_dev` is the same; > +// `Bound` is a zero-sized type-state marker that does not affect thread safety. > +unsafe impl Sync for Device<device::Bound> {}
Given that you're now implementing for two ctx marker types, it might worth changing the existing one to spell out the `Normal` explicitly (also saves you from having to spell it out in the comment).
It might also make sense to write a comment to say that why it's not the case for `Device<Core>`.
Best, Gary
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