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//! `ioctl` opcode behavior for Linux platforms.
use super::{Direction, RawOpcode};
use consts::*;
/// Compose an opcode from its component parts.
pub(super) const fn compose_opcode(
dir: Direction,
group: RawOpcode,
num: RawOpcode,
size: RawOpcode,
) -> RawOpcode {
macro_rules! mask_and_shift {
($val:expr, $shift:expr, $mask:expr) => {{
($val & $mask) << $shift
}};
}
let dir = match dir {
Direction::None => NONE,
Direction::Read => READ,
Direction::Write => WRITE,
Direction::ReadWrite => READ | WRITE,
};
mask_and_shift!(group, GROUP_SHIFT, GROUP_MASK)
| mask_and_shift!(num, NUM_SHIFT, NUM_MASK)
| mask_and_shift!(size, SIZE_SHIFT, SIZE_MASK)
| mask_and_shift!(dir, DIR_SHIFT, DIR_MASK)
}
const NUM_BITS: RawOpcode = 8;
const GROUP_BITS: RawOpcode = 8;
const NUM_SHIFT: RawOpcode = 0;
const GROUP_SHIFT: RawOpcode = NUM_SHIFT + NUM_BITS;
const SIZE_SHIFT: RawOpcode = GROUP_SHIFT + GROUP_BITS;
const DIR_SHIFT: RawOpcode = SIZE_SHIFT + SIZE_BITS;
const NUM_MASK: RawOpcode = (1 << NUM_BITS) - 1;
const GROUP_MASK: RawOpcode = (1 << GROUP_BITS) - 1;
const SIZE_MASK: RawOpcode = (1 << SIZE_BITS) - 1;
const DIR_MASK: RawOpcode = (1 << DIR_BITS) - 1;
#[cfg(any(
target_arch = "x86",
target_arch = "arm",
target_arch = "s390x",
target_arch = "x86_64",
target_arch = "aarch64",
target_arch = "riscv32",
target_arch = "riscv64",
target_arch = "loongarch64",
target_arch = "csky"
))]
mod consts {
use super::RawOpcode;
pub(super) const NONE: RawOpcode = 0;
pub(super) const READ: RawOpcode = 2;
pub(super) const WRITE: RawOpcode = 1;
pub(super) const SIZE_BITS: RawOpcode = 14;
pub(super) const DIR_BITS: RawOpcode = 2;
}
#[cfg(any(
target_arch = "mips",
target_arch = "mips32r6",
target_arch = "mips64",
target_arch = "mips64r6",
target_arch = "powerpc",
target_arch = "powerpc64",
target_arch = "sparc",
target_arch = "sparc64"
))]
mod consts {
use super::RawOpcode;
pub(super) const NONE: RawOpcode = 1;
pub(super) const READ: RawOpcode = 2;
pub(super) const WRITE: RawOpcode = 4;
pub(super) const SIZE_BITS: RawOpcode = 13;
pub(super) const DIR_BITS: RawOpcode = 3;
}
#[cfg(not(any(
// These have no ioctl opcodes defined in linux_raw_sys
// so can't use that as a known-good value for this test.
target_arch = "sparc",
target_arch = "sparc64"
)))]
#[test]
fn check_known_opcodes() {
use crate::backend::c::{c_long, c_uint};
use core::mem::size_of;
// _IOR('U', 15, unsigned int)
assert_eq!(
compose_opcode(
Direction::Read,
b'U' as RawOpcode,
15,
size_of::<c_uint>() as RawOpcode
),
linux_raw_sys::ioctl::USBDEVFS_CLAIMINTERFACE as RawOpcode
);
// _IOW('v', 2, long)
assert_eq!(
compose_opcode(
Direction::Write,
b'v' as RawOpcode,
2,
size_of::<c_long>() as RawOpcode
),
linux_raw_sys::ioctl::FS_IOC_SETVERSION as RawOpcode
);
}