git.armlinux.org.uk/linux.git - Linus' kernel tree

Age	Commit message (Collapse)	Author
2025-05-04	rust: revocable: implement Revocable::access()	Danilo Krummrich
	Implement an unsafe direct accessor for the data stored within the Revocable. This is useful for cases where we can prove that the data stored within the Revocable is not and cannot be revoked for the duration of the lifetime of the returned reference. Reviewed-by: Christian Schrefl <chrisi.schrefl@gmail.com> Reviewed-by: Benno Lossin <benno.lossin@proton.me> Acked-by: Miguel Ojeda <ojeda@kernel.org> Reviewed-by: Alexandre Courbot <acourbot@nvidia.com> Acked-by: Boqun Feng <boqun.feng@gmail.com> Reviewed-by: Joel Fernandes <joelagnelf@nvidia.com> Link: https://lore.kernel.org/r/20250428140137.468709-2-dakr@kernel.org Signed-off-by: Danilo Krummrich <dakr@kernel.org>
2025-04-22	rust/revocable: add try_access_with() convenience method	Alexandre Courbot
	Revocable::try_access() returns a guard through which the wrapped object can be accessed. Code that can sleep is not allowed while the guard is held; thus, it is common for the caller to explicitly drop it before running sleepable code, e.g: let b = bar.try_access()?; let reg = b.readl(...); // Don't forget this or things could go wrong! drop(b); something_that_might_sleep(); let b = bar.try_access()?; let reg2 = b.readl(...); This is arguably error-prone. try_access_with() provides an arguably safer alternative, by taking a closure that is run while the guard is held, and by dropping the guard automatically after the closure completes. This way, code can be organized more clearly around the critical sections and the risk of forgetting to release the guard when needed is considerably reduced: let reg = bar.try_access_with(\|b\| b.readl(...))?; something_that_might_sleep(); let reg2 = bar.try_access_with(\|b\| b.readl(...))?; The closure can return nothing, or any value including a Result which is then wrapped inside the Option returned by try_access_with. Error management is driver-specific, so users are encouraged to create their own macros that map and flatten the returned values to something appropriate for the code they are working on. Suggested-by: Danilo Krummrich <dakr@kernel.org> Reviewed-by: Benno Lossin <benno.lossin@proton.me> Signed-off-by: Alexandre Courbot <acourbot@nvidia.com> Reviewed-by: Joel Fernandes <joelagnelf@nvidia.com> Acked-by: Miguel Ojeda <ojeda@kernel.org> Link: https://lore.kernel.org/r/20250411-try_with-v4-1-f470ac79e2e2@nvidia.com [ Link `None`, `Some`, `Option` in doc-comment. - Danilo ] Signed-off-by: Danilo Krummrich <dakr@kernel.org>
2024-12-20	rust: add `Revocable` type	Wedson Almeida Filho
	Revocable allows access to objects to be safely revoked at run time. This is useful, for example, for resources allocated during device probe; when the device is removed, the driver should stop accessing the device resources even if another state is kept in memory due to existing references (i.e., device context data is ref-counted and has a non-zero refcount after removal of the device). Signed-off-by: Wedson Almeida Filho <wedsonaf@gmail.com> Co-developed-by: Danilo Krummrich <dakr@kernel.org> Signed-off-by: Danilo Krummrich <dakr@kernel.org> Tested-by: Dirk Behme <dirk.behme@de.bosch.com> Link: https://lore.kernel.org/r/20241219170425.12036-7-dakr@kernel.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>