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mod atomic {
use super::*;
use portable_atomic::Ordering;
pub trait AtomicOperations {
unsafe fn atomic_or(ptr: *mut Self, val: Self);
unsafe fn atomic_and(ptr: *mut Self, val: Self);
unsafe fn atomic_xor(ptr: *mut Self, val: Self);
}
macro_rules! impl_atomics {
($U:ty, $Atomic:ty) => {
impl AtomicOperations for $U {
unsafe fn atomic_or(ptr: *mut Self, val: Self) {
(*(ptr as *const $Atomic)).or(val, Ordering::SeqCst);
}
unsafe fn atomic_and(ptr: *mut Self, val: Self) {
(*(ptr as *const $Atomic)).and(val, Ordering::SeqCst);
}
unsafe fn atomic_xor(ptr: *mut Self, val: Self) {
(*(ptr as *const $Atomic)).xor(val, Ordering::SeqCst);
}
}
};
}
impl_atomics!(u8, portable_atomic::AtomicU8);
impl_atomics!(u16, portable_atomic::AtomicU16);
// Exclude 16-bit archs from 32-bit atomics
#[cfg(not(target_pointer_width = "16"))]
impl_atomics!(u32, portable_atomic::AtomicU32);
// Enable 64-bit atomics for 64-bit RISCV
#[cfg(any(target_pointer_width = "64", target_has_atomic = "64"))]
impl_atomics!(u64, portable_atomic::AtomicU64);
impl<REG: Readable + Writable> Reg<REG>
where
REG::Ux: AtomicOperations,
{
/// Set high every bit in the register that was set in the write proxy. Leave other bits
/// untouched. The write is done in a single atomic instruction.
///
/// # Safety
///
/// The resultant bit pattern may not be valid for the register.
#[inline(always)]
pub unsafe fn set_bits<F>(&self, f: F)
where
F: FnOnce(&mut W<REG>) -> &mut W<REG>,
{
let bits = f(&mut W {
bits: REG::Ux::ZERO,
_reg: marker::PhantomData,
})
.bits;
REG::Ux::atomic_or(self.register.as_ptr(), bits);
}
/// Clear every bit in the register that was cleared in the write proxy. Leave other bits
/// untouched. The write is done in a single atomic instruction.
///
/// # Safety
///
/// The resultant bit pattern may not be valid for the register.
#[inline(always)]
pub unsafe fn clear_bits<F>(&self, f: F)
where
F: FnOnce(&mut W<REG>) -> &mut W<REG>,
{
let bits = f(&mut W {
bits: !REG::Ux::ZERO,
_reg: marker::PhantomData,
})
.bits;
REG::Ux::atomic_and(self.register.as_ptr(), bits);
}
/// Toggle every bit in the register that was set in the write proxy. Leave other bits
/// untouched. The write is done in a single atomic instruction.
///
/// # Safety
///
/// The resultant bit pattern may not be valid for the register.
#[inline(always)]
pub unsafe fn toggle_bits<F>(&self, f: F)
where
F: FnOnce(&mut W<REG>) -> &mut W<REG>,
{
let bits = f(&mut W {
bits: REG::Ux::ZERO,
_reg: marker::PhantomData,
})
.bits;
REG::Ux::atomic_xor(self.register.as_ptr(), bits);
}
}
}