diff --git a/rust/kernel/workqueue.rs b/rust/kernel/workqueue.rs index 19e5c50127af..6dbc5b9b3da9 100644 --- a/rust/kernel/workqueue.rs +++ b/rust/kernel/workqueue.rs @@ -107,3 +107,74 @@ pub unsafe trait RawWorkItem { where F: FnOnce(*mut bindings::work_struct) -> bool; } + +/// Returns the system work queue (`system_wq`). +/// +/// It is the one used by `schedule[_delayed]_work[_on]()`. Multi-CPU multi-threaded. There are +/// users which expect relatively short queue flush time. +/// +/// Callers shouldn't queue work items which can run for too long. +pub fn system() -> &'static Queue { + // SAFETY: `system_wq` is a C global, always available. + unsafe { Queue::from_raw(bindings::system_wq) } +} + +/// Returns the system high-priority work queue (`system_highpri_wq`). +/// +/// It is similar to the one returned by [`system`] but for work items which require higher +/// scheduling priority. +pub fn system_highpri() -> &'static Queue { + // SAFETY: `system_highpri_wq` is a C global, always available. + unsafe { Queue::from_raw(bindings::system_highpri_wq) } +} + +/// Returns the system work queue for potentially long-running work items (`system_long_wq`). +/// +/// It is similar to the one returned by [`system`] but may host long running work items. Queue +/// flushing might take relatively long. +pub fn system_long() -> &'static Queue { + // SAFETY: `system_long_wq` is a C global, always available. + unsafe { Queue::from_raw(bindings::system_long_wq) } +} + +/// Returns the system unbound work queue (`system_unbound_wq`). +/// +/// Workers are not bound to any specific CPU, not concurrency managed, and all queued work items +/// are executed immediately as long as `max_active` limit is not reached and resources are +/// available. +pub fn system_unbound() -> &'static Queue { + // SAFETY: `system_unbound_wq` is a C global, always available. + unsafe { Queue::from_raw(bindings::system_unbound_wq) } +} + +/// Returns the system freezable work queue (`system_freezable_wq`). +/// +/// It is equivalent to the one returned by [`system`] except that it's freezable. +/// +/// A freezable workqueue participates in the freeze phase of the system suspend operations. Work +/// items on the workqueue are drained and no new work item starts execution until thawed. +pub fn system_freezable() -> &'static Queue { + // SAFETY: `system_freezable_wq` is a C global, always available. + unsafe { Queue::from_raw(bindings::system_freezable_wq) } +} + +/// Returns the system power-efficient work queue (`system_power_efficient_wq`). +/// +/// It is inclined towards saving power and is converted to "unbound" variants if the +/// `workqueue.power_efficient` kernel parameter is specified; otherwise, it is similar to the one +/// returned by [`system`]. +pub fn system_power_efficient() -> &'static Queue { + // SAFETY: `system_power_efficient_wq` is a C global, always available. + unsafe { Queue::from_raw(bindings::system_power_efficient_wq) } +} + +/// Returns the system freezable power-efficient work queue (`system_freezable_power_efficient_wq`). +/// +/// It is similar to the one returned by [`system_power_efficient`] except that is freezable. +/// +/// A freezable workqueue participates in the freeze phase of the system suspend operations. Work +/// items on the workqueue are drained and no new work item starts execution until thawed. +pub fn system_freezable_power_efficient() -> &'static Queue { + // SAFETY: `system_freezable_power_efficient_wq` is a C global, always available. + unsafe { Queue::from_raw(bindings::system_freezable_power_efficient_wq) } +}