linux.git/rust/kernel/sync/lock.rs, branch v6.6.132

rust: lock: Add intra-doc links to the Backend trait

2023-08-07T09:33:33+00:00

Add missing intra-doc links to the Backend trait to make navigating the
documentation easier.

Suggested-by: Benno Lossin 
Link: https://lore.kernel.org/rust-for-linux/94625fe6-b87a-a8f0-5b2a-a8152d5f7436@proton.me/
Link: https://github.com/Rust-for-Linux/linux/issues/1001
Signed-off-by: Ben Gooding 
Link: https://lore.kernel.org/r/20230509202314.8248-1-ben.gooding.dev@gmail.com
Signed-off-by: Miguel Ojeda

rust: sync: introduce `CondVar`

2023-04-21T23:46:45+00:00

This is the traditional condition variable or monitor synchronisation
primitive. It is implemented with C's `wait_queue_head_t`.

It allows users to release a lock and go to sleep while guaranteeing
that notifications won't be missed. This is achieved by enqueuing a wait
entry before releasing the lock.

Cc: Peter Zijlstra 
Cc: Ingo Molnar 
Cc: Will Deacon 
Cc: Waiman Long 
Reviewed-by: Martin Rodriguez Reboredo 
Signed-off-by: Wedson Almeida Filho 
Reviewed-by: Alice Ryhl 
Link: https://lore.kernel.org/r/20230411054543.21278-12-wedsonaf@gmail.com
Signed-off-by: Miguel Ojeda

rust: lock: add `Guard::do_unlocked`

2023-04-21T23:46:30+00:00

It releases the lock, executes some function provided by the caller,
then reacquires the lock. This is preparation for the implementation of
condvars, which will sleep after between unlocking and relocking.

We need an explicit `relock` method for primitives like `SpinLock` that
have an irqsave variant: we use the guard state to determine if the lock
was originally acquired with the regular `lock` function or
`lock_irqsave`.

Reviewed-by: Martin Rodriguez Reboredo 
Signed-off-by: Wedson Almeida Filho 
Link: https://lore.kernel.org/rust-for-linux/20230412121431.41627-1-wedsonaf@gmail.com/
[ Removed the irqsave bits as discussed. ]
Signed-off-by: Miguel Ojeda

rust: sync: introduce `LockedBy`

2023-04-21T22:20:00+00:00

This allows us to have data protected by a lock despite not being
wrapped by it. Access is granted by providing evidence that the lock is
held by the caller.

Reviewed-by: Martin Rodriguez Reboredo 
Signed-off-by: Wedson Almeida Filho 
Reviewed-by: Benno Lossin 
Link: https://lore.kernel.org/r/20230411054543.21278-13-wedsonaf@gmail.com
Signed-off-by: Miguel Ojeda

rust: lock: introduce `SpinLock`

2023-04-21T22:20:00+00:00

This is the `spinlock_t` lock backend and allows Rust code to use the
kernel spinlock idiomatically.

Cc: Peter Zijlstra 
Cc: Ingo Molnar 
Cc: Will Deacon 
Cc: Waiman Long 
Reviewed-by: Martin Rodriguez Reboredo 
Signed-off-by: Wedson Almeida Filho 
Link: https://lore.kernel.org/r/20230419174426.132207-1-wedsonaf@gmail.com
Signed-off-by: Miguel Ojeda

rust: lock: introduce `Mutex`

2023-04-21T22:20:00+00:00

This is the `struct mutex` lock backend and allows Rust code to use the
kernel mutex idiomatically.

Cc: Peter Zijlstra 
Cc: Ingo Molnar 
Cc: Will Deacon 
Cc: Waiman Long 
Reviewed-by: Martin Rodriguez Reboredo 
Signed-off-by: Wedson Almeida Filho 
Link: https://lore.kernel.org/r/20230411054543.21278-3-wedsonaf@gmail.com
Signed-off-by: Miguel Ojeda

rust: sync: introduce `Lock` and `Guard`

2023-04-21T22:19:42+00:00

They are generic Rust implementations of a lock and a lock guard that
contain code that is common to all locks. Different backends will be
introduced in subsequent commits.

Reviewed-by: Martin Rodriguez Reboredo 
Suggested-by: Gary Guo 
Signed-off-by: Wedson Almeida Filho 
Link: https://lore.kernel.org/r/20230411054543.21278-2-wedsonaf@gmail.com
[ Fixed typo. ]
Signed-off-by: Miguel Ojeda