From 9e6e09a8d747ec90aae215df8471dfe349993487 Mon Sep 17 00:00:00 2001 From: Dummyc0m Date: Sun, 6 Oct 2024 23:23:33 -0700 Subject: executor/spin: introduce an architecture agnostic executor Spin polls the raw executor and never sleeps. It is useful for disabling any power features associated with wfi/wfe-like instructions. When implementing support for the CH32V30x MCU, the wfi instruction had issues interacting with the USB OTG peripheral and appeared to be non-spec-compliant. 1. When sending a USB Data-in packet, the USB peripheral appears to be unable to read the system main memory while in WFI. This manifests in the USB peripheral sending all or partially zeroed DATA packets. Disabling WFI works around this issue. 2. The WFI instruction does not wake up the processor when MIE is disabled. The MCU provides a WFITOWFE bit to emulate the WFE instruction on arm, which, when enabled, ignores the MIE and allows the processor to wake up. This works around the non-compliant WFI implementation. Co-authored-by: Codetector Co-authored-by: Dummyc0m --- embassy-executor/src/arch/spin.rs | 58 +++++++++++++++++++++++++++++++++++++++ 1 file changed, 58 insertions(+) create mode 100644 embassy-executor/src/arch/spin.rs (limited to 'embassy-executor/src/arch') diff --git a/embassy-executor/src/arch/spin.rs b/embassy-executor/src/arch/spin.rs new file mode 100644 index 000000000..340023620 --- /dev/null +++ b/embassy-executor/src/arch/spin.rs @@ -0,0 +1,58 @@ +#[cfg(feature = "executor-interrupt")] +compile_error!("`executor-interrupt` is not supported with `arch-spin`."); + +#[cfg(feature = "executor-thread")] +pub use thread::*; +#[cfg(feature = "executor-thread")] +mod thread { + use core::marker::PhantomData; + + pub use embassy_executor_macros::main_spin as main; + + use crate::{raw, Spawner}; + + #[export_name = "__pender"] + fn __pender(_context: *mut ()) {} + + /// Spin Executor + pub struct Executor { + inner: raw::Executor, + not_send: PhantomData<*mut ()>, + } + + impl Executor { + /// Create a new Executor. + pub fn new() -> Self { + Self { + inner: raw::Executor::new(core::ptr::null_mut()), + not_send: PhantomData, + } + } + + /// Run the executor. + /// + /// The `init` closure is called with a [`Spawner`] that spawns tasks on + /// this executor. Use it to spawn the initial task(s). After `init` returns, + /// the executor starts running the tasks. + /// + /// To spawn more tasks later, you may keep copies of the [`Spawner`] (it is `Copy`), + /// for example by passing it as an argument to the initial tasks. + /// + /// This function requires `&'static mut self`. This means you have to store the + /// Executor instance in a place where it'll live forever and grants you mutable + /// access. There's a few ways to do this: + /// + /// - a [StaticCell](https://docs.rs/static_cell/latest/static_cell/) (safe) + /// - a `static mut` (unsafe) + /// - a local variable in a function you know never returns (like `fn main() -> !`), upgrading its lifetime with `transmute`. (unsafe) + /// + /// This function never returns. + pub fn run(&'static mut self, init: impl FnOnce(Spawner)) -> ! { + init(self.inner.spawner()); + + loop { + unsafe { self.inner.poll() }; + } + } + } +} -- cgit From 8ebe059ecb311ee949f92dde33f2cb8d972b0f7b Mon Sep 17 00:00:00 2001 From: Dániel Buga Date: Tue, 19 Nov 2024 15:59:31 +0100 Subject: Add initialize --- embassy-executor/src/arch/avr.rs | 4 ++++ embassy-executor/src/arch/cortex_m.rs | 6 ++++++ embassy-executor/src/arch/riscv32.rs | 4 ++++ embassy-executor/src/arch/spin.rs | 4 ++++ embassy-executor/src/arch/std.rs | 4 ++++ embassy-executor/src/arch/wasm.rs | 4 ++++ 6 files changed, 26 insertions(+) (limited to 'embassy-executor/src/arch') diff --git a/embassy-executor/src/arch/avr.rs b/embassy-executor/src/arch/avr.rs index 70085d04d..7f9ed4421 100644 --- a/embassy-executor/src/arch/avr.rs +++ b/embassy-executor/src/arch/avr.rs @@ -53,6 +53,10 @@ mod thread { /// /// This function never returns. pub fn run(&'static mut self, init: impl FnOnce(Spawner)) -> ! { + unsafe { + self.inner.initialize(); + } + init(self.inner.spawner()); loop { diff --git a/embassy-executor/src/arch/cortex_m.rs b/embassy-executor/src/arch/cortex_m.rs index 5c517e0a2..0c2af88a6 100644 --- a/embassy-executor/src/arch/cortex_m.rs +++ b/embassy-executor/src/arch/cortex_m.rs @@ -98,6 +98,9 @@ mod thread { /// /// This function never returns. pub fn run(&'static mut self, init: impl FnOnce(Spawner)) -> ! { + unsafe { + self.inner.initialize(); + } init(self.inner.spawner()); loop { @@ -207,6 +210,9 @@ mod interrupt { } let executor = unsafe { (&*self.executor.get()).assume_init_ref() }; + unsafe { + executor.initialize(); + } unsafe { NVIC::unmask(irq) } diff --git a/embassy-executor/src/arch/riscv32.rs b/embassy-executor/src/arch/riscv32.rs index 01e63a9fd..715e5f3cf 100644 --- a/embassy-executor/src/arch/riscv32.rs +++ b/embassy-executor/src/arch/riscv32.rs @@ -54,6 +54,10 @@ mod thread { /// /// This function never returns. pub fn run(&'static mut self, init: impl FnOnce(Spawner)) -> ! { + unsafe { + self.inner.initialize(); + } + init(self.inner.spawner()); loop { diff --git a/embassy-executor/src/arch/spin.rs b/embassy-executor/src/arch/spin.rs index 340023620..54c7458b3 100644 --- a/embassy-executor/src/arch/spin.rs +++ b/embassy-executor/src/arch/spin.rs @@ -48,6 +48,10 @@ mod thread { /// /// This function never returns. pub fn run(&'static mut self, init: impl FnOnce(Spawner)) -> ! { + unsafe { + self.inner.initialize(); + } + init(self.inner.spawner()); loop { diff --git a/embassy-executor/src/arch/std.rs b/embassy-executor/src/arch/std.rs index b02b15988..948c7711b 100644 --- a/embassy-executor/src/arch/std.rs +++ b/embassy-executor/src/arch/std.rs @@ -55,6 +55,10 @@ mod thread { /// /// This function never returns. pub fn run(&'static mut self, init: impl FnOnce(Spawner)) -> ! { + unsafe { + self.inner.initialize(); + } + init(self.inner.spawner()); loop { diff --git a/embassy-executor/src/arch/wasm.rs b/embassy-executor/src/arch/wasm.rs index f9d0f935c..35025f11f 100644 --- a/embassy-executor/src/arch/wasm.rs +++ b/embassy-executor/src/arch/wasm.rs @@ -70,6 +70,10 @@ mod thread { /// - a `static mut` (unsafe) /// - a local variable in a function you know never returns (like `fn main() -> !`), upgrading its lifetime with `transmute`. (unsafe) pub fn start(&'static mut self, init: impl FnOnce(Spawner)) { + unsafe { + self.inner.initialize(); + } + unsafe { let executor = &self.inner; let future = Closure::new(move |_| { -- cgit From 5a5495aac43d75610735f2ca80fb6c8e8f31ed71 Mon Sep 17 00:00:00 2001 From: Dániel Buga Date: Tue, 26 Nov 2024 23:54:21 +0100 Subject: Refactor integrated-timers --- embassy-executor/src/arch/avr.rs | 4 ---- embassy-executor/src/arch/cortex_m.rs | 6 ------ embassy-executor/src/arch/riscv32.rs | 4 ---- embassy-executor/src/arch/spin.rs | 4 ---- embassy-executor/src/arch/std.rs | 4 ---- embassy-executor/src/arch/wasm.rs | 4 ---- 6 files changed, 26 deletions(-) (limited to 'embassy-executor/src/arch') diff --git a/embassy-executor/src/arch/avr.rs b/embassy-executor/src/arch/avr.rs index 7f9ed4421..70085d04d 100644 --- a/embassy-executor/src/arch/avr.rs +++ b/embassy-executor/src/arch/avr.rs @@ -53,10 +53,6 @@ mod thread { /// /// This function never returns. pub fn run(&'static mut self, init: impl FnOnce(Spawner)) -> ! { - unsafe { - self.inner.initialize(); - } - init(self.inner.spawner()); loop { diff --git a/embassy-executor/src/arch/cortex_m.rs b/embassy-executor/src/arch/cortex_m.rs index 0c2af88a6..5c517e0a2 100644 --- a/embassy-executor/src/arch/cortex_m.rs +++ b/embassy-executor/src/arch/cortex_m.rs @@ -98,9 +98,6 @@ mod thread { /// /// This function never returns. pub fn run(&'static mut self, init: impl FnOnce(Spawner)) -> ! { - unsafe { - self.inner.initialize(); - } init(self.inner.spawner()); loop { @@ -210,9 +207,6 @@ mod interrupt { } let executor = unsafe { (&*self.executor.get()).assume_init_ref() }; - unsafe { - executor.initialize(); - } unsafe { NVIC::unmask(irq) } diff --git a/embassy-executor/src/arch/riscv32.rs b/embassy-executor/src/arch/riscv32.rs index 715e5f3cf..01e63a9fd 100644 --- a/embassy-executor/src/arch/riscv32.rs +++ b/embassy-executor/src/arch/riscv32.rs @@ -54,10 +54,6 @@ mod thread { /// /// This function never returns. pub fn run(&'static mut self, init: impl FnOnce(Spawner)) -> ! { - unsafe { - self.inner.initialize(); - } - init(self.inner.spawner()); loop { diff --git a/embassy-executor/src/arch/spin.rs b/embassy-executor/src/arch/spin.rs index 54c7458b3..340023620 100644 --- a/embassy-executor/src/arch/spin.rs +++ b/embassy-executor/src/arch/spin.rs @@ -48,10 +48,6 @@ mod thread { /// /// This function never returns. pub fn run(&'static mut self, init: impl FnOnce(Spawner)) -> ! { - unsafe { - self.inner.initialize(); - } - init(self.inner.spawner()); loop { diff --git a/embassy-executor/src/arch/std.rs b/embassy-executor/src/arch/std.rs index 948c7711b..b02b15988 100644 --- a/embassy-executor/src/arch/std.rs +++ b/embassy-executor/src/arch/std.rs @@ -55,10 +55,6 @@ mod thread { /// /// This function never returns. pub fn run(&'static mut self, init: impl FnOnce(Spawner)) -> ! { - unsafe { - self.inner.initialize(); - } - init(self.inner.spawner()); loop { diff --git a/embassy-executor/src/arch/wasm.rs b/embassy-executor/src/arch/wasm.rs index 35025f11f..f9d0f935c 100644 --- a/embassy-executor/src/arch/wasm.rs +++ b/embassy-executor/src/arch/wasm.rs @@ -70,10 +70,6 @@ mod thread { /// - a `static mut` (unsafe) /// - a local variable in a function you know never returns (like `fn main() -> !`), upgrading its lifetime with `transmute`. (unsafe) pub fn start(&'static mut self, init: impl FnOnce(Spawner)) { - unsafe { - self.inner.initialize(); - } - unsafe { let executor = &self.inner; let future = Closure::new(move |_| { -- cgit From b7e1b1ca941b3b92dede55f2a5b65fcad788ce42 Mon Sep 17 00:00:00 2001 From: James Munns Date: Thu, 3 Apr 2025 10:35:00 +0200 Subject: Fix some intra-doc links --- embassy-executor/src/arch/cortex_m.rs | 9 +++++---- 1 file changed, 5 insertions(+), 4 deletions(-) (limited to 'embassy-executor/src/arch') diff --git a/embassy-executor/src/arch/cortex_m.rs b/embassy-executor/src/arch/cortex_m.rs index 5c517e0a2..1c9ddd8a0 100644 --- a/embassy-executor/src/arch/cortex_m.rs +++ b/embassy-executor/src/arch/cortex_m.rs @@ -143,7 +143,7 @@ mod interrupt { /// If this is not the case, you may use an interrupt from any unused peripheral. /// /// It is somewhat more complex to use, it's recommended to use the thread-mode - /// [`Executor`] instead, if it works for your use case. + /// [`Executor`](crate::Executor) instead, if it works for your use case. pub struct InterruptExecutor { started: Mutex>, executor: UnsafeCell>, @@ -179,11 +179,11 @@ mod interrupt { /// The executor keeps running in the background through the interrupt. /// /// This returns a [`SendSpawner`] you can use to spawn tasks on it. A [`SendSpawner`] - /// is returned instead of a [`Spawner`](embassy_executor::Spawner) because the executor effectively runs in a + /// is returned instead of a [`Spawner`](crate::Spawner) because the executor effectively runs in a /// different "thread" (the interrupt), so spawning tasks on it is effectively /// sending them. /// - /// To obtain a [`Spawner`](embassy_executor::Spawner) for this executor, use [`Spawner::for_current_executor()`](embassy_executor::Spawner::for_current_executor()) from + /// To obtain a [`Spawner`](crate::Spawner) for this executor, use [`Spawner::for_current_executor()`](crate::Spawner::for_current_executor()) from /// a task running in it. /// /// # Interrupt requirements @@ -195,6 +195,7 @@ mod interrupt { /// You must set the interrupt priority before calling this method. You MUST NOT /// do it after. /// + /// [`SendSpawner`]: crate::SendSpawner pub fn start(&'static self, irq: impl InterruptNumber) -> crate::SendSpawner { if critical_section::with(|cs| self.started.borrow(cs).replace(true)) { panic!("InterruptExecutor::start() called multiple times on the same executor."); @@ -215,7 +216,7 @@ mod interrupt { /// Get a SendSpawner for this executor /// - /// This returns a [`SendSpawner`] you can use to spawn tasks on this + /// This returns a [`SendSpawner`](crate::SendSpawner) you can use to spawn tasks on this /// executor. /// /// This MUST only be called on an executor that has already been started. -- cgit From 5a07ea5d851768223e2e41342e69d14c1afb2b2b Mon Sep 17 00:00:00 2001 From: Robin Mueller Date: Sun, 9 Mar 2025 20:55:11 +0100 Subject: Add support for Cortex-A/R --- embassy-executor/src/arch/cortex_ar.rs | 84 ++++++++++++++++++++++++++++++++++ 1 file changed, 84 insertions(+) create mode 100644 embassy-executor/src/arch/cortex_ar.rs (limited to 'embassy-executor/src/arch') diff --git a/embassy-executor/src/arch/cortex_ar.rs b/embassy-executor/src/arch/cortex_ar.rs new file mode 100644 index 000000000..f9e2f3f7c --- /dev/null +++ b/embassy-executor/src/arch/cortex_ar.rs @@ -0,0 +1,84 @@ +#[cfg(feature = "executor-interrupt")] +compile_error!("`executor-interrupt` is not supported with `arch-cortex-ar`."); + +#[export_name = "__pender"] +#[cfg(any(feature = "executor-thread", feature = "executor-interrupt"))] +fn __pender(context: *mut ()) { + // `context` is always `usize::MAX` created by `Executor::run`. + let context = context as usize; + + #[cfg(feature = "executor-thread")] + // Try to make Rust optimize the branching away if we only use thread mode. + if !cfg!(feature = "executor-interrupt") || context == THREAD_PENDER { + cortex_ar::asm::sev(); + return; + } +} + +#[cfg(feature = "executor-thread")] +pub use thread::*; +#[cfg(feature = "executor-thread")] +mod thread { + pub(super) const THREAD_PENDER: usize = usize::MAX; + + use core::marker::PhantomData; + + use cortex_ar::asm::wfe; + pub use embassy_executor_macros::main_cortex_ar as main; + + use crate::{raw, Spawner}; + + /// Thread mode executor, using WFE/SEV. + /// + /// This is the simplest and most common kind of executor. It runs on + /// thread mode (at the lowest priority level), and uses the `WFE` ARM instruction + /// to sleep when it has no more work to do. When a task is woken, a `SEV` instruction + /// is executed, to make the `WFE` exit from sleep and poll the task. + /// + /// This executor allows for ultra low power consumption for chips where `WFE` + /// triggers low-power sleep without extra steps. If your chip requires extra steps, + /// you may use [`raw::Executor`] directly to program custom behavior. + pub struct Executor { + inner: raw::Executor, + not_send: PhantomData<*mut ()>, + } + + impl Executor { + /// Create a new Executor. + pub fn new() -> Self { + Self { + inner: raw::Executor::new(THREAD_PENDER as *mut ()), + not_send: PhantomData, + } + } + + /// Run the executor. + /// + /// The `init` closure is called with a [`Spawner`] that spawns tasks on + /// this executor. Use it to spawn the initial task(s). After `init` returns, + /// the executor starts running the tasks. + /// + /// To spawn more tasks later, you may keep copies of the [`Spawner`] (it is `Copy`), + /// for example by passing it as an argument to the initial tasks. + /// + /// This function requires `&'static mut self`. This means you have to store the + /// Executor instance in a place where it'll live forever and grants you mutable + /// access. There's a few ways to do this: + /// + /// - a [StaticCell](https://docs.rs/static_cell/latest/static_cell/) (safe) + /// - a `static mut` (unsafe) + /// - a local variable in a function you know never returns (like `fn main() -> !`), upgrading its lifetime with `transmute`. (unsafe) + /// + /// This function never returns. + pub fn run(&'static mut self, init: impl FnOnce(Spawner)) -> ! { + init(self.inner.spawner()); + + loop { + unsafe { + self.inner.poll(); + } + wfe(); + } + } + } +} -- cgit