Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
tjh.dev
kernel
os
linux
1// SPDX-License-Identifier: GPL-2.0
2
3use kernel::prelude::*;
4use kernel::time::{Delta, Instant, Monotonic};
5
6pub(crate) const fn to_lowercase_bytes<const N: usize>(s: &str) -> [u8; N] {
7 let src = s.as_bytes();
8 let mut dst = [0; N];
9 let mut i = 0;
10
11 while i < src.len() && i < N {
12 dst[i] = (src[i] as char).to_ascii_lowercase() as u8;
13 i += 1;
14 }
15
16 dst
17}
18
19pub(crate) const fn const_bytes_to_str(bytes: &[u8]) -> &str {
20 match core::str::from_utf8(bytes) {
21 Ok(string) => string,
22 Err(_) => kernel::build_error!("Bytes are not valid UTF-8."),
23 }
24}
25
26/// Wait until `cond` is true or `timeout` elapsed.
27///
28/// When `cond` evaluates to `Some`, its return value is returned.
29///
30/// `Err(ETIMEDOUT)` is returned if `timeout` has been reached without `cond` evaluating to
31/// `Some`.
32///
33/// TODO[DLAY]: replace with `read_poll_timeout` once it is available.
34/// (https://lore.kernel.org/lkml/20250220070611.214262-8-fujita.tomonori@gmail.com/)
35pub(crate) fn wait_on<R, F: Fn() -> Option<R>>(timeout: Delta, cond: F) -> Result<R> {
36 let start_time = Instant::<Monotonic>::now();
37
38 loop {
39 if let Some(ret) = cond() {
40 return Ok(ret);
41 }
42
43 if start_time.elapsed().as_nanos() > timeout.as_nanos() {
44 return Err(ETIMEDOUT);
45 }
46 }
47}