linux-yocto/rust
FUJITA Tomonori 1b7bbd5975 rust: time: Avoid 64-bit integer division on 32-bit architectures
Avoid 64-bit integer division that 32-bit architectures don't
implement generally. This uses ktime_to_us() and ktime_to_ms()
instead.

The time abstraction needs i64 / u32 division so C's div_s64() can be
used but ktime_to_us() and ktime_to_ms() provide a simpler solution
for this time abstraction problem on 32-bit architectures.

32-bit ARM is the only 32-bit architecture currently supported by
Rust. Using the cfg attribute, only 32-bit architectures will call
ktime_to_us() and ktime_to_ms(), while the other 64-bit architectures
will continue to use the current code as-is to avoid the overhead.

One downside of calling the C's functions is that the as_micros/millis
methods can no longer be const fn. We stick with the simpler approach
unless there's a compelling need for a const fn.

Suggested-by: Arnd Bergmann <arnd@arndb.de>
Suggested-by: Boqun Feng <boqun.feng@gmail.com>
Signed-off-by: FUJITA Tomonori <fujita.tomonori@gmail.com>
Reviewed-by: Andreas Hindborg <a.hindborg@kernel.org>
Link: https://lore.kernel.org/r/20250502004524.230553-1-fujita.tomonori@gmail.com
Signed-off-by: Andreas Hindborg <a.hindborg@kernel.org>
2025-06-16 15:01:15 +02:00
..
bindings Rust changes for v6.16 2025-06-04 21:18:37 -07:00
helpers rust: time: Avoid 64-bit integer division on 32-bit architectures 2025-06-16 15:01:15 +02:00
kernel rust: time: Avoid 64-bit integer division on 32-bit architectures 2025-06-16 15:01:15 +02:00
macros Rust changes for v6.16 2025-06-04 21:18:37 -07:00
pin-init pin-init changes for v6.16 2025-05-18 20:42:49 +02:00
uapi drm for 6.16-rc1 2025-05-28 09:46:39 -07:00
.gitignore
.kunitconfig rust: add kunitconfig 2025-03-19 23:22:21 +01:00
bindgen_parameters rust: map __kernel_size_t and friends also to usize/isize 2024-11-10 23:58:00 +01:00
build_error.rs
compiler_builtins.rs ARM: 9441/1: rust: Enable Rust support for ARMv7 2025-03-26 13:31:16 +00:00
exports.c rust: exports: improve grammar in commentary 2024-10-21 17:35:33 +02:00
ffi.rs rust: use absolute paths in macros referencing core and kernel 2025-05-23 00:12:14 +02:00
Makefile Rust changes for v6.16 2025-06-04 21:18:37 -07:00