linux/rust/kernel/ioctl.rs
Miguel Ojeda bc2e7d5c29 rust: support srctree-relative links
Some of our links use relative paths in order to point to files in the
source tree, e.g.:

    //! C header: [`include/linux/printk.h`](../../../../include/linux/printk.h)
    /// [`struct mutex`]: ../../../../include/linux/mutex.h

These are problematic because they are hard to maintain and do not support
`O=` builds.

Instead, provide support for `srctree`-relative links, e.g.:

    //! C header: [`include/linux/printk.h`](srctree/include/linux/printk.h)
    /// [`struct mutex`]: srctree/include/linux/mutex.h

The links are fixed after `rustdoc` generation to be based on the absolute
path to the source tree.

Essentially, this is the automatic version of Tomonori's fix [1],
suggested by Gary [2].

Suggested-by: Gary Guo <gary@garyguo.net>
Reported-by: FUJITA Tomonori <fujita.tomonori@gmail.com>
Closes: https://lore.kernel.org/r/20231026.204058.2167744626131849993.fujita.tomonori@gmail.com [1]
Fixes: 48fadf4400 ("docs: Move rustdoc output, cross-reference it")
Link: https://lore.kernel.org/rust-for-linux/20231026154525.6d14b495@eugeo/ [2]
Reviewed-by: Martin Rodriguez Reboredo <yakoyoku@gmail.com>
Reviewed-by: Benno Lossin <benno.lossin@proton.me>
Link: https://lore.kernel.org/r/20231215235428.243211-1-ojeda@kernel.org
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2023-12-21 20:54:17 +01:00

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)
#![allow(non_snake_case)]
use crate::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 an 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 an 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
}