On Fri, 28 Jun 2024 13:23:31 +0000
Alice Ryhl [off-list ref] wrote:

Add just enough support for static key so that we can use it from
tracepoints. Tracepoints rely on `static_key_false` even though it is
deprecated, so we add the same functionality to Rust.

It is not possible to use the existing C implementation of
arch_static_branch because it passes the argument `key` to inline
assembly as an 'i' parameter, so any attempt to add a C helper for this
function will fail to compile because the value of `key` must be known
at compile-time.

Signed-off-by: Alice Ryhl <aliceryhl@google.com>

Reviewed-by: Gary Guo <gary@garyguo.net>

---
 rust/kernel/arch/arm64/jump_label.rs     | 34 ++++++++++++++++++++++++++++
 rust/kernel/arch/loongarch/jump_label.rs | 35 +++++++++++++++++++++++++++++
 rust/kernel/arch/mod.rs                  | 24 ++++++++++++++++++++
 rust/kernel/arch/riscv/jump_label.rs     | 38 ++++++++++++++++++++++++++++++++
 rust/kernel/arch/x86/jump_label.rs       | 35 +++++++++++++++++++++++++++++
 rust/kernel/lib.rs                       |  2 ++
 rust/kernel/static_key.rs                | 32 +++++++++++++++++++++++++++
 scripts/Makefile.build                   |  2 +-
 8 files changed, 201 insertions(+), 1 deletion(-)