1*6e59bcc9SAlice Ryhl // SPDX-License-Identifier: GPL-2.0 2*6e59bcc9SAlice Ryhl 3*6e59bcc9SAlice Ryhl // Copyright (C) 2024 Google LLC. 4*6e59bcc9SAlice Ryhl 5*6e59bcc9SAlice Ryhl //! Logic for static keys. 6*6e59bcc9SAlice Ryhl //! 7*6e59bcc9SAlice Ryhl //! C header: [`include/linux/jump_label.h`](srctree/include/linux/jump_label.h). 8*6e59bcc9SAlice Ryhl 9*6e59bcc9SAlice Ryhl /// Branch based on a static key. 10*6e59bcc9SAlice Ryhl /// 11*6e59bcc9SAlice Ryhl /// Takes three arguments: 12*6e59bcc9SAlice Ryhl /// 13*6e59bcc9SAlice Ryhl /// * `key` - the path to the static variable containing the `static_key`. 14*6e59bcc9SAlice Ryhl /// * `keytyp` - the type of `key`. 15*6e59bcc9SAlice Ryhl /// * `field` - the name of the field of `key` that contains the `static_key`. 16*6e59bcc9SAlice Ryhl /// 17*6e59bcc9SAlice Ryhl /// # Safety 18*6e59bcc9SAlice Ryhl /// 19*6e59bcc9SAlice Ryhl /// The macro must be used with a real static key defined by C. 20*6e59bcc9SAlice Ryhl #[macro_export] 21*6e59bcc9SAlice Ryhl macro_rules! static_branch_unlikely { 22*6e59bcc9SAlice Ryhl ($key:path, $keytyp:ty, $field:ident) => {{ 23*6e59bcc9SAlice Ryhl let _key: *const $keytyp = ::core::ptr::addr_of!($key); 24*6e59bcc9SAlice Ryhl let _key: *const $crate::bindings::static_key_false = ::core::ptr::addr_of!((*_key).$field); 25*6e59bcc9SAlice Ryhl let _key: *const $crate::bindings::static_key = _key.cast(); 26*6e59bcc9SAlice Ryhl 27*6e59bcc9SAlice Ryhl $crate::bindings::static_key_count(_key.cast_mut()) > 0 28*6e59bcc9SAlice Ryhl }}; 29*6e59bcc9SAlice Ryhl } 30*6e59bcc9SAlice Ryhl pub use static_branch_unlikely; 31