# interrupt.rs - source
Source of the Rust file `/home/runner/.cargo/git/checkouts/riscv-ab2abd16c438337b/11d43cf/src/interrupt.rs`.
Keywords: rust, rustlang, rust-lang

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    //! Interrupts

    // NOTE: Adapted from cortex-m/src/interrupt.rs
    pub use bare_metal::{CriticalSection, Mutex, Nr};
    use register::mstatus;

    /// Disables all interrupts
    #[inline]
    pub unsafe fn disable() {
        match () {
            #[cfg(riscv)]
            () => mstatus::clear_mie(),
            #[cfg(not(riscv))]
            () => unimplemented!(),
        }
    }

    /// Enables all the interrupts
    ///
    /// # Safety
    ///
    /// - Do not call this function inside an `interrupt::free` critical section
    #[inline]
    pub unsafe fn enable() {
        match () {
            #[cfg(riscv)]
            () => mstatus::set_mie(),
            #[cfg(not(riscv))]
            () => unimplemented!(),
        }
    }

    /// Execute closure `f` in an interrupt-free context.
    ///
    /// This as also known as a "critical section".
    pub fn free<F, R>(f: F) -> R
    where
        F: FnOnce(&CriticalSection) -> R,
    {
        let mstatus = mstatus::read();

        // disable interrupts
        unsafe {
            disable();
        }

        let r = f(unsafe { &CriticalSection::new() });

        // If the interrupts were active before our `disable` call, then re-enable
        // them. Otherwise, keep them disabled
        if mstatus.mie() {
            unsafe {
                enable();
            }
        }

        r
    }