1 // SPDX-License-Identifier: GPL-2.0 2 3 //! `ioctl()` number definitions. 4 //! 5 //! C header: [`include/asm-generic/ioctl.h`](srctree/include/asm-generic/ioctl.h) 6 7 #![expect(non_snake_case)] 8 9 use crate::build_assert; 10 11 /// Build an ioctl number, analogous to the C macro of the same name. 12 #[inline(always)] 13 const fn _IOC(dir: u32, ty: u32, nr: u32, size: usize) -> u32 { 14 build_assert!(dir <= uapi::_IOC_DIRMASK); 15 build_assert!(ty <= uapi::_IOC_TYPEMASK); 16 build_assert!(nr <= uapi::_IOC_NRMASK); 17 build_assert!(size <= (uapi::_IOC_SIZEMASK as usize)); 18 19 (dir << uapi::_IOC_DIRSHIFT) 20 | (ty << uapi::_IOC_TYPESHIFT) 21 | (nr << uapi::_IOC_NRSHIFT) 22 | ((size as u32) << uapi::_IOC_SIZESHIFT) 23 } 24 25 /// Build an ioctl number for an argumentless ioctl. 26 #[inline(always)] 27 pub const fn _IO(ty: u32, nr: u32) -> u32 { 28 _IOC(uapi::_IOC_NONE, ty, nr, 0) 29 } 30 31 /// Build an ioctl number for a read-only ioctl. 32 #[inline(always)] 33 pub const fn _IOR<T>(ty: u32, nr: u32) -> u32 { 34 _IOC(uapi::_IOC_READ, ty, nr, core::mem::size_of::<T>()) 35 } 36 37 /// Build an ioctl number for a write-only ioctl. 38 #[inline(always)] 39 pub const fn _IOW<T>(ty: u32, nr: u32) -> u32 { 40 _IOC(uapi::_IOC_WRITE, ty, nr, core::mem::size_of::<T>()) 41 } 42 43 /// Build an ioctl number for a read-write ioctl. 44 #[inline(always)] 45 pub const fn _IOWR<T>(ty: u32, nr: u32) -> u32 { 46 _IOC( 47 uapi::_IOC_READ | uapi::_IOC_WRITE, 48 ty, 49 nr, 50 core::mem::size_of::<T>(), 51 ) 52 } 53 54 /// Get the ioctl direction from an ioctl number. 55 pub const fn _IOC_DIR(nr: u32) -> u32 { 56 (nr >> uapi::_IOC_DIRSHIFT) & uapi::_IOC_DIRMASK 57 } 58 59 /// Get the ioctl type from an ioctl number. 60 pub const fn _IOC_TYPE(nr: u32) -> u32 { 61 (nr >> uapi::_IOC_TYPESHIFT) & uapi::_IOC_TYPEMASK 62 } 63 64 /// Get the ioctl number from an ioctl number. 65 pub const fn _IOC_NR(nr: u32) -> u32 { 66 (nr >> uapi::_IOC_NRSHIFT) & uapi::_IOC_NRMASK 67 } 68 69 /// Get the ioctl size from an ioctl number. 70 pub const fn _IOC_SIZE(nr: u32) -> usize { 71 ((nr >> uapi::_IOC_SIZESHIFT) & uapi::_IOC_SIZEMASK) as usize 72 } 73