7 files changed, 57 insertions, 26 deletions

diff --git a/embassy-macros/src/lib.rs b/embassy-macros/src/lib.rs
index c46f114a0..861406393 100644
--- a/embassy-macros/src/lib.rs
+++ b/embassy-macros/src/lib.rs
@@ -117,9 +117,9 @@ pub fn interrupt_declare(item: TokenStream) -> TokenStream {
             fn number(&self) -> u8 {
                 Interrupt::#name as u8
             }
-            unsafe fn __handler(&self) -> &'static ::core::sync::atomic::AtomicPtr<u32> {
+            unsafe fn __handler(&self) -> &'static ::embassy::interrupt::Handler {
                 #[export_name = #name_handler]
-                static HANDLER: ::core::sync::atomic::AtomicPtr<u32> = ::core::sync::atomic::AtomicPtr::new(::core::ptr::null_mut());
+                static HANDLER: ::embassy::interrupt::Handler = ::embassy::interrupt::Handler::new();
                 &HANDLER
             }
         }
@@ -141,13 +141,14 @@ pub fn interrupt_take(item: TokenStream) -> TokenStream {
             pub unsafe extern "C" fn trampoline() {
                 extern "C" {
                     #[link_name = #name_handler]
-                    static HANDLER: ::core::sync::atomic::AtomicPtr<u32>;
+                    static HANDLER: ::embassy::interrupt::Handler;
                 }
 
-                let p = HANDLER.load(::core::sync::atomic::Ordering::Acquire);
-                if !p.is_null() {
-                    let f: fn() = ::core::mem::transmute(p);
-                    f()
+                let func = HANDLER.func.load(::core::sync::atomic::Ordering::Acquire);
+                let ctx = HANDLER.ctx.load(::core::sync::atomic::Ordering::Acquire);
+                if !func.is_null() {
+                    let func: fn(*mut ()) = ::core::mem::transmute(func);
+                    func(ctx)
                 }
             }
 
diff --git a/embassy-nrf/src/gpiote.rs b/embassy-nrf/src/gpiote.rs
index 353f6a94c..65a584c78 100644
--- a/embassy-nrf/src/gpiote.rs
+++ b/embassy-nrf/src/gpiote.rs
@@ -75,7 +75,7 @@ impl Gpiote {
         // Enable interrupts
         gpiote.events_port.write(|w| w);
         gpiote.intenset.write(|w| w.port().set());
-        irq.set_handler(Self::on_irq);
+        irq.set_handler(Self::on_irq, core::ptr::null_mut());
         irq.unpend();
         irq.enable();
 
@@ -296,7 +296,7 @@ impl Gpiote {
         })
     }
 
-    unsafe fn on_irq() {
+    unsafe fn on_irq(_ctx: *mut ()) {
         let s = &(*INSTANCE);
 
         for i in 0..8 {
diff --git a/embassy-nrf/src/qspi.rs b/embassy-nrf/src/qspi.rs
index c9c907cd1..753a5985b 100644
--- a/embassy-nrf/src/qspi.rs
+++ b/embassy-nrf/src/qspi.rs
@@ -146,7 +146,7 @@ impl Qspi {
         SIGNAL.reset();
         qspi.intenset.write(|w| w.ready().set());
 
-        irq.set_handler(irq_handler);
+        irq.set_handler(irq_handler, core::ptr::null_mut());
         irq.unpend();
         irq.enable();
 
@@ -347,7 +347,7 @@ impl Flash for Qspi {
 
 static SIGNAL: Signal<()> = Signal::new();
 
-unsafe fn irq_handler() {
+unsafe fn irq_handler(_ctx: *mut ()) {
     let p = crate::pac::Peripherals::steal().QSPI;
     if p.events_ready.read().events_ready().bit_is_set() {
         p.events_ready.reset();
diff --git a/embassy-nrf/src/rtc.rs b/embassy-nrf/src/rtc.rs
index d65b8d472..fb59faa31 100644
--- a/embassy-nrf/src/rtc.rs
+++ b/embassy-nrf/src/rtc.rs
@@ -105,8 +105,10 @@ impl<T: Instance> RTC<T> {
         while self.rtc.counter.read().bits() != 0 {}
 
         T::set_rtc_instance(self);
-        self.irq
-            .set_handler(|| T::get_rtc_instance().on_interrupt());
+        self.irq.set_handler(
+            |_| T::get_rtc_instance().on_interrupt(),
+            core::ptr::null_mut(),
+        );
         self.irq.unpend();
         self.irq.enable();
     }
diff --git a/embassy-nrf/src/uarte.rs b/embassy-nrf/src/uarte.rs
index 648298b84..8aee11c47 100644
--- a/embassy-nrf/src/uarte.rs
+++ b/embassy-nrf/src/uarte.rs
@@ -119,7 +119,7 @@ where
             .write(|w| w.endtx().set().txstopped().set().endrx().set().rxto().set());
 
         // Register ISR
-        irq.set_handler(Self::on_irq);
+        irq.set_handler(Self::on_irq, core::ptr::null_mut());
         irq.unpend();
         irq.enable();
 
@@ -147,7 +147,7 @@ where
         self.instance.events_rxstarted.read().bits() != 0
     }
 
-    unsafe fn on_irq() {
+    unsafe fn on_irq(_ctx: *mut ()) {
         let uarte = &*pac::UARTE0::ptr();
 
         let mut try_disable = false;
diff --git a/embassy-nrf/src/util/peripheral.rs b/embassy-nrf/src/util/peripheral.rs
index 85de3419e..9b3384e5d 100644
--- a/embassy-nrf/src/util/peripheral.rs
+++ b/embassy-nrf/src/util/peripheral.rs
@@ -55,12 +55,15 @@ impl<P: State> Registration<P> {
         // - therefore it's safe to overwrite it without dropping the previous contents
         unsafe { P::store().write(state) }
 
-        irq.set_handler(|| {
-            // safety:
-            // - If a PeripheralRegistration instance exists, P::storage() is initialized.
-            // - It's OK to get a &mut to it since the irq is disabled.
-            unsafe { P::store().as_mut() }.on_interrupt();
-        });
+        irq.set_handler(
+            |_| {
+                // safety:
+                // - If a PeripheralRegistration instance exists, P::storage() is initialized.
+                // - It's OK to get a &mut to it since the irq is disabled.
+                unsafe { P::store().as_mut() }.on_interrupt();
+            },
+            core::ptr::null_mut(),
+        );
 
         compiler_fence(Ordering::SeqCst);
         irq.enable();
@@ -89,7 +92,7 @@ impl<P: State> Registration<P> {
     pub fn free(self) -> (P::Interrupt, P) {
         let irq = unsafe { ptr::read(&self.irq) };
         irq.disable();
-        irq.set_handler(|| ());
+        irq.remove_handler();
         mem::forget(self);
         let storage = P::store();
         (irq, unsafe { storage.read() })
@@ -99,7 +102,7 @@ impl<P: State> Registration<P> {
 impl<P: State> Drop for Registration<P> {
     fn drop(&mut self) {
         self.irq.disable();
-        self.irq.set_handler(|| ());
+        self.irq.remove_handler();
 
         let storage = P::store();
         unsafe { storage.drop_in_place() };
diff --git a/embassy/src/interrupt.rs b/embassy/src/interrupt.rs
index fee52b326..7690bea0c 100644
--- a/embassy/src/interrupt.rs
+++ b/embassy/src/interrupt.rs
@@ -6,6 +6,22 @@ use cortex_m::peripheral::NVIC;
 pub use embassy_macros::interrupt_declare as declare;
 pub use embassy_macros::interrupt_take as take;
 
+/// Implementation detail, do not use outside embassy crates.
+#[doc(hidden)]
+pub struct Handler {
+    pub func: AtomicPtr<()>,
+    pub ctx: AtomicPtr<()>,
+}
+
+impl Handler {
+    pub const fn new() -> Self {
+        Self {
+            func: AtomicPtr::new(ptr::null_mut()),
+            ctx: AtomicPtr::new(ptr::null_mut()),
+        }
+    }
+}
+
 struct NrWrap(u8);
 unsafe impl cortex_m::interrupt::Nr for NrWrap {
     fn nr(&self) -> u8 {
@@ -16,11 +32,20 @@ unsafe impl cortex_m::interrupt::Nr for NrWrap {
 pub unsafe trait OwnedInterrupt {
     type Priority: From<u8> + Into<u8> + Copy;
     fn number(&self) -> u8;
+
+    /// Implementation detail, do not use outside embassy crates.
     #[doc(hidden)]
-    unsafe fn __handler(&self) -> &'static AtomicPtr<u32>;
+    unsafe fn __handler(&self) -> &'static Handler;
+
+    fn set_handler(&self, func: unsafe fn(*mut ()), ctx: *mut ()) {
+        let handler = unsafe { self.__handler() };
+        handler.func.store(func as *mut (), Ordering::Release);
+        handler.ctx.store(ctx, Ordering::Release);
+    }
 
-    fn set_handler(&self, handler: unsafe fn()) {
-        unsafe { self.__handler() }.store(handler as *mut u32, Ordering::Release);
+    fn remove_handler(&self) {
+        let handler = unsafe { self.__handler() };
+        handler.func.store(ptr::null_mut(), Ordering::Release);
     }
 
     #[inline]