[PATCH v7 21/26] rust: alloc: implement `contains` for `Flags`

Danilo Krummrich
2024-09-11T22:56:52Z

Provide a simple helper function to check whether given flags do
contain one or multiple other flags.

This is used by a subsequent patch implementing the Cmalloc `Allocator`
to check for __GFP_ZERO.

Reviewed-by: Alice Ryhl <aliceryhl@google.com>
Reviewed-by: Benno Lossin <benno.lossin@proton.me>
Signed-off-by: Danilo Krummrich <dakr@kernel.org>
---
rust/kernel/alloc.rs | 7 ++++++-
1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/rust/kernel/alloc.rs b/rust/kernel/alloc.rs
index aabdf80e4f7b..caa0b9dfac87 100644
--- a/rust/kernel/alloc.rs
+++ b/rust/kernel/alloc.rs
@@ -34,7 +34,7 @@
/// They can be combined with the operators `|`, `&`, and `!`.
///
/// Values can be used from the [`flags`] module.
-#[derive(Clone, Copy)]
+#[derive(Clone, Copy, PartialEq)]
pub struct Flags(u32);

impl Flags {
@@ -42,6 +42,11 @@ impl Flags {
pub(crate) fn as_raw(self) -> u32 {
self.0
}
+
+ /// Check whether `flags` is contained in `self`.
+ pub fn contains(self, flags: Flags) -> bool {
+ (self & flags) == flags
+ }
}

impl core::ops::BitOr for Flags {
--
2.46.0