Files
linux-stable-mirror/rust/kernel/ioctl.rs
T
Gary Guo 8d49d90fb9 rust: make build_assert module the home of related macros
Given the macro scoping rules, all macros are rendered twice, in the
module and in the top-level of kernel crate.

Add `#[doc(hidden)]` to the macro definition and `#[doc(inline)]` to the
re-export inside `build_assert` module so the top-level items are hidden.

[ Sadly, because the definition is hidden, `rustdoc` decides to not list
  them as re-exports in the `prelude` page anymore, even if we refer to
  the not-actually-hidden item.

    - Miguel ]

Acked-by: Danilo Krummrich <dakr@kernel.org>
Reviewed-by: Alice Ryhl <aliceryhl@google.com>
Acked-by: Alexandre Courbot <acourbot@nvidia.com>
Acked-by: FUJITA Tomonori <fujita.tomonori@gmail.com>
Acked-by: Boqun Feng <boqun@kernel.org>
Signed-off-by: Gary Guo <gary@garyguo.net>
Link: https://patch.msgid.link/20260609142637.373347-1-gary@kernel.org
[ Kept a single declaration in the prelude, and reworded since they
  already had `no_inline`. Removed other imports from `predefine` since
  we now use the prelude. - Miguel ]
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2026-06-10 09:07:13 +02:00

73 lines
2.0 KiB
Rust

// SPDX-License-Identifier: GPL-2.0
//! `ioctl()` number definitions.
//!
//! C header: [`include/asm-generic/ioctl.h`](srctree/include/asm-generic/ioctl.h)
#![expect(non_snake_case)]
use crate::build_assert::build_assert;
/// Build an ioctl number, analogous to the C macro of the same name.
#[inline(always)]
const fn _IOC(dir: u32, ty: u32, nr: u32, size: usize) -> u32 {
build_assert!(dir <= uapi::_IOC_DIRMASK);
build_assert!(ty <= uapi::_IOC_TYPEMASK);
build_assert!(nr <= uapi::_IOC_NRMASK);
build_assert!(size <= (uapi::_IOC_SIZEMASK as usize));
(dir << uapi::_IOC_DIRSHIFT)
| (ty << uapi::_IOC_TYPESHIFT)
| (nr << uapi::_IOC_NRSHIFT)
| ((size as u32) << uapi::_IOC_SIZESHIFT)
}
/// Build an ioctl number for an argumentless ioctl.
#[inline(always)]
pub const fn _IO(ty: u32, nr: u32) -> u32 {
_IOC(uapi::_IOC_NONE, ty, nr, 0)
}
/// Build an ioctl number for a read-only ioctl.
#[inline(always)]
pub const fn _IOR<T>(ty: u32, nr: u32) -> u32 {
_IOC(uapi::_IOC_READ, ty, nr, core::mem::size_of::<T>())
}
/// Build an ioctl number for a write-only ioctl.
#[inline(always)]
pub const fn _IOW<T>(ty: u32, nr: u32) -> u32 {
_IOC(uapi::_IOC_WRITE, ty, nr, core::mem::size_of::<T>())
}
/// Build an ioctl number for a read-write ioctl.
#[inline(always)]
pub const fn _IOWR<T>(ty: u32, nr: u32) -> u32 {
_IOC(
uapi::_IOC_READ | uapi::_IOC_WRITE,
ty,
nr,
core::mem::size_of::<T>(),
)
}
/// Get the ioctl direction from an ioctl number.
pub const fn _IOC_DIR(nr: u32) -> u32 {
(nr >> uapi::_IOC_DIRSHIFT) & uapi::_IOC_DIRMASK
}
/// Get the ioctl type from an ioctl number.
pub const fn _IOC_TYPE(nr: u32) -> u32 {
(nr >> uapi::_IOC_TYPESHIFT) & uapi::_IOC_TYPEMASK
}
/// Get the ioctl number from an ioctl number.
pub const fn _IOC_NR(nr: u32) -> u32 {
(nr >> uapi::_IOC_NRSHIFT) & uapi::_IOC_NRMASK
}
/// Get the ioctl size from an ioctl number.
pub const fn _IOC_SIZE(nr: u32) -> usize {
((nr >> uapi::_IOC_SIZESHIFT) & uapi::_IOC_SIZEMASK) as usize
}