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-rw-r--r--rust/kernel/ioctl.rs72
1 files changed, 72 insertions, 0 deletions
diff --git a/rust/kernel/ioctl.rs b/rust/kernel/ioctl.rs
new file mode 100644
index 000000000000..c49e1a8d3fd0
--- /dev/null
+++ b/rust/kernel/ioctl.rs
@@ -0,0 +1,72 @@
+// SPDX-License-Identifier: GPL-2.0
+
+//! ioctl() number definitions
+//!
+//! C header: [`include/asm-generic/ioctl.h`](../../../../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
+}