| 1 | // SPDX-License-Identifier: GPL-2.0 |
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| 2 | |
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| 3 | //! Synchronisation primitives. |
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| 4 | //! |
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| 5 | //! This module contains the kernel APIs related to synchronisation that have been ported or |
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| 6 | //! wrapped for usage by Rust code in the kernel. |
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| 7 | |
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| 8 | use crate::types::Opaque; |
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| 9 | |
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| 10 | mod arc; |
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| 11 | mod condvar; |
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| 12 | pub mod lock; |
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| 13 | mod locked_by; |
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| 14 | |
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| 15 | pub use arc::{Arc, ArcBorrow, UniqueArc}; |
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| 16 | pub use condvar::{new_condvar, CondVar, CondVarTimeoutResult}; |
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| 17 | pub use lock::mutex::{new_mutex, Mutex}; |
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| 18 | pub use lock::spinlock::{new_spinlock, SpinLock}; |
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| 19 | pub use locked_by::LockedBy; |
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| 20 | |
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| 21 | /// Represents a lockdep class. It's a wrapper around C's `lock_class_key`. |
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| 22 | #[repr(transparent)] |
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| 23 | pub struct LockClassKey(Opaque<bindings::lock_class_key>); |
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| 24 | |
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| 25 | // SAFETY: `bindings::lock_class_key` is designed to be used concurrently from multiple threads and |
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| 26 | // provides its own synchronization. |
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| 27 | unsafe impl Sync for LockClassKey {} |
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| 28 | |
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| 29 | impl LockClassKey { |
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| 30 | /// Creates a new lock class key. |
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| 31 | pub const fn new() -> Self { |
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| 32 | Self(Opaque::uninit()) |
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| 33 | } |
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| 34 | |
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| 35 | pub(crate) fn as_ptr(&self) -> *mut bindings::lock_class_key { |
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| 36 | self.0.get() |
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| 37 | } |
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| 38 | } |
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| 39 | |
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| 40 | /// Defines a new static lock class and returns a pointer to it. |
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| 41 | #[doc(hidden)] |
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| 42 | #[macro_export] |
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| 43 | macro_rules! static_lock_class { |
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| 44 | () => {{ |
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| 45 | static CLASS: $crate::sync::LockClassKey = $crate::sync::LockClassKey::new(); |
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| 46 | &CLASS |
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| 47 | }}; |
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| 48 | } |
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| 49 | |
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| 50 | /// Returns the given string, if one is provided, otherwise generates one based on the source code |
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| 51 | /// location. |
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| 52 | #[doc(hidden)] |
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| 53 | #[macro_export] |
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| 54 | macro_rules! optional_name { |
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| 55 | () => { |
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| 56 | $crate::c_str!(::core::concat!(::core::file!(), ":" , ::core::line!())) |
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| 57 | }; |
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| 58 | ($name:literal) => { |
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| 59 | $crate::c_str!($name) |
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| 60 | }; |
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| 61 | } |
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| 62 | |
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