// 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;