diff options
Diffstat (limited to 'src')
| -rw-r--r-- | src/critical_section.rs | 35 | ||||
| -rw-r--r-- | src/lib.rs | 24 | ||||
| -rw-r--r-- | src/macros.rs | 7 |
3 files changed, 40 insertions, 26 deletions
diff --git a/src/critical_section.rs b/src/critical_section.rs index 688058d..e3d57d1 100644 --- a/src/critical_section.rs +++ b/src/critical_section.rs @@ -1,27 +1,22 @@ -#[cfg(all(cortex_m, feature = "critical-section-single-core"))] -mod single_core_critical_section { - use critical_section::{set_impl, Impl, RawRestoreState}; +use critical_section::{set_impl, Impl, RawRestoreState}; - use crate::interrupt; - use crate::register::primask; +use crate::interrupt; +use crate::register::primask; - struct SingleCoreCriticalSection; - set_impl!(SingleCoreCriticalSection); +struct SingleCoreCriticalSection; +set_impl!(SingleCoreCriticalSection); - unsafe impl Impl for SingleCoreCriticalSection { - unsafe fn acquire() -> RawRestoreState { - let was_active = primask::read().is_active(); - interrupt::disable(); - was_active - } +unsafe impl Impl for SingleCoreCriticalSection { + unsafe fn acquire() -> RawRestoreState { + let was_active = primask::read().is_active(); + interrupt::disable(); + was_active + } - unsafe fn release(was_active: RawRestoreState) { - // Only re-enable interrupts if they were enabled before the critical section. - if was_active { - interrupt::enable() - } + unsafe fn release(was_active: RawRestoreState) { + // Only re-enable interrupts if they were enabled before the critical section. + if was_active { + interrupt::enable() } } } - -pub use critical_section::with; @@ -9,6 +9,16 @@ //! //! # Optional features //! +//! ## `critical-section-single-core` +//! +//! This feature enables a [`critical-section`](https://github.com/rust-embedded/critical-section) +//! implementation suitable for single-core targets, based on disabling interrupts globally. +//! +//! It is **unsound** to enable it on multi-core targets or for code running in unprivileged mode, +//! and may cause functional problems in systems where some interrupts must be not be disabled +//! or critical sections are managed as part of an RTOS. In these cases, you should use +//! a target-specific implementation instead, typically provided by a HAL or RTOS crate. +//! //! ## `cm7-r0p1` //! //! This feature enables workarounds for errata found on Cortex-M7 chips with revision r0p1. Some @@ -49,10 +59,6 @@ mod macros; pub mod asm; #[cfg(armv8m)] pub mod cmse; -// This is only public so the `singleton` macro does not require depending on -// the `critical-section` crate separately. -#[doc(hidden)] -pub mod critical_section; pub mod delay; pub mod interrupt; #[cfg(all(not(armv6m), not(armv8m_base)))] @@ -61,3 +67,13 @@ pub mod peripheral; pub mod register; pub use crate::peripheral::Peripherals; + +#[cfg(all(cortex_m, feature = "critical-section-single-core"))] +mod critical_section; + +/// Used to reexport items for use in macros. Do not use directly. +/// Not covered by semver guarantees. +#[doc(hidden)] +pub mod _export { + pub use critical_section; +} diff --git a/src/macros.rs b/src/macros.rs index 21bf78b..2cf4f89 100644 --- a/src/macros.rs +++ b/src/macros.rs @@ -31,7 +31,10 @@ macro_rules! iprintln { /// at most once in the whole lifetime of the program. /// /// # Notes -/// This macro is unsound on multi core systems. +/// +/// This macro requires a `critical-section` implementation to be set. For most single core systems, +/// you can enable the `critical-section-single-core` feature for this crate. For other systems, you +/// have to provide one from elsewhere, typically your chip's HAL crate. /// /// For debuggability, you can set an explicit name for a singleton. This name only shows up the /// the debugger and is not referencable from other code. See example below. @@ -62,7 +65,7 @@ macro_rules! iprintln { #[macro_export] macro_rules! singleton { ($name:ident: $ty:ty = $expr:expr) => { - $crate::critical_section::with(|_| { + $crate::_export::critical_section::with(|_| { // this is a tuple of a MaybeUninit and a bool because using an Option here is // problematic: Due to niche-optimization, an Option could end up producing a non-zero // initializer value which would move the entire static from `.bss` into `.data`... |