diff options
Diffstat (limited to 'rust/kernel')
| -rw-r--r-- | rust/kernel/jump_label.rs | 30 | ||||
| -rw-r--r-- | rust/kernel/lib.rs | 1 |
2 files changed, 31 insertions, 0 deletions
diff --git a/rust/kernel/jump_label.rs b/rust/kernel/jump_label.rs new file mode 100644 index 000000000000..4b7655b2a022 --- /dev/null +++ b/rust/kernel/jump_label.rs @@ -0,0 +1,30 @@ +// SPDX-License-Identifier: GPL-2.0 + +// Copyright (C) 2024 Google LLC. + +//! Logic for static keys. +//! +//! C header: [`include/linux/jump_label.h`](srctree/include/linux/jump_label.h). + +/// Branch based on a static key. +/// +/// Takes three arguments: +/// +/// * `key` - the path to the static variable containing the `static_key`. +/// * `keytyp` - the type of `key`. +/// * `field` - the name of the field of `key` that contains the `static_key`. +/// +/// # Safety +/// +/// The macro must be used with a real static key defined by C. +#[macro_export] +macro_rules! static_branch_unlikely { + ($key:path, $keytyp:ty, $field:ident) => {{ + let _key: *const $keytyp = ::core::ptr::addr_of!($key); + let _key: *const $crate::bindings::static_key_false = ::core::ptr::addr_of!((*_key).$field); + let _key: *const $crate::bindings::static_key = _key.cast(); + + $crate::bindings::static_key_count(_key.cast_mut()) > 0 + }}; +} +pub use static_branch_unlikely; diff --git a/rust/kernel/lib.rs b/rust/kernel/lib.rs index b5f4b3ce6b48..708ff817ccc3 100644 --- a/rust/kernel/lib.rs +++ b/rust/kernel/lib.rs @@ -36,6 +36,7 @@ pub mod error; pub mod firmware; pub mod init; pub mod ioctl; +pub mod jump_label; #[cfg(CONFIG_KUNIT)] pub mod kunit; pub mod list; |