Merge pull request #330 from rust-embedded/riscv-interrupts

`riscv`: Use `riscv_pac::CoreInterrupt` in `mie` register

Author: romancardenas

riscv/CHANGELOG.md

@@ -10,6 +10,9 @@ and this project adheres to [Semantic Versioning](http://semver.org/).
 ### Added
 
 - New convenience  `try_new` and `new` associated functions for `Mtvec` and `Stvec`.
+- New methods and functions for enabling core interrupts in the `mie` and `sie` registers
+  using the `riscv_pac::CoreInterrupt` trait.
+- New `riscv::interrupt::{is_interrupt_enabled, disable_interrupt, enable_interrupt}` functions.
 
 ### Changed
 

riscv/src/interrupt/machine.rs

@@ -1,6 +1,6 @@
 use crate::{
     interrupt::Trap,
-    register::{mcause, mepc, mstatus},
+    register::{mcause, mepc, mie, mstatus},
 };
 use riscv_pac::{
     result::{Error, Result},
@@ -96,18 +96,51 @@ unsafe impl ExceptionNumber for Exception {
     }
 }
 
-/// Disables all interrupts in the current hart (machine mode).
+/// Checks if a specific core interrupt source is enabled in the current hart (machine mode).
+#[inline]
+pub fn is_interrupt_enabled<I: CoreInterruptNumber>(interrupt: I) -> bool {
+    mie::read().is_enabled(interrupt)
+}
+
+/// Disables interrupts for a specific core interrupt source in the current hart (machine mode).
+#[inline]
+pub fn disable_interrupt<I: CoreInterruptNumber>(interrupt: I) {
+    mie::disable(interrupt);
+}
+
+/// Enables interrupts for a specific core interrupt source in the current hart (machine mode).
+///
+/// # Note
+///
+/// Interrupts will only be triggered if globally enabled in the hart. To do this, use [`enable`].
+///
+/// # Safety
+///
+/// Enabling interrupts might break critical sections or other synchronization mechanisms.
+/// Ensure that this is called in a safe context where interrupts can be enabled.
+#[inline]
+pub unsafe fn enable_interrupt<I: CoreInterruptNumber>(interrupt: I) {
+    mie::enable(interrupt);
+}
+
+/// Disables interrupts globally in the current hart (machine mode).
 #[inline]
 pub fn disable() {
     // SAFETY: It is safe to disable interrupts
     unsafe { mstatus::clear_mie() }
 }
 
-/// Enables all the interrupts in the current hart (machine mode).
+/// Enables interrupts globally in the current hart (machine mode).
+///
+/// # Note
+///
+/// Only enabled interrupt sources will be triggered.
+/// To enable specific interrupt sources, use [`enable_interrupt`].
 ///
 /// # Safety
 ///
-/// Do not call this function inside a critical section.
+/// Enabling interrupts might break critical sections or other synchronization mechanisms.
+/// Ensure that this is called in a safe context where interrupts can be enabled.
 #[inline]
 pub unsafe fn enable() {
     mstatus::set_mie()

riscv/src/interrupt/supervisor.rs

@@ -1,6 +1,6 @@
 use crate::{
     interrupt::Trap,
-    register::{scause, sepc, sstatus},
+    register::{scause, sepc, sie, sstatus},
 };
 use riscv_pac::{
     result::{Error, Result},
@@ -88,18 +88,52 @@ unsafe impl ExceptionNumber for Exception {
     }
 }
 
-/// Disables all interrupts in the current hart (supervisor mode).
+/// Checks if a specific core interrupt source is enabled in the current hart (supervisor mode).
+#[inline]
+pub fn is_interrupt_enabled<I: CoreInterruptNumber>(interrupt: I) -> bool {
+    sie::read().is_enabled(interrupt)
+}
+
+/// Disables interrupts for a specific core interrupt source in the current hart (supervisor mode).
+#[inline]
+pub fn disable_interrupt<I: CoreInterruptNumber>(interrupt: I) {
+    // SAFETY: it is safe to disable an interrupt source
+    sie::disable(interrupt);
+}
+
+/// Enables interrupts for a specific core interrupt source in the current hart (supervisor mode).
+///
+/// # Note
+///
+/// Interrupts will only be triggered if globally enabled in the hart. To do this, use [`enable`].
+///
+/// # Safety
+///
+/// Enabling interrupts might break critical sections or other synchronization mechanisms.
+/// Ensure that this is called in a safe context where interrupts can be enabled.
+#[inline]
+pub unsafe fn enable_interrupt<I: CoreInterruptNumber>(interrupt: I) {
+    sie::enable(interrupt);
+}
+
+/// Disables interrupts globally in the current hart (supervisor mode).
 #[inline]
 pub fn disable() {
     // SAFETY: It is safe to disable interrupts
     unsafe { sstatus::clear_sie() }
 }
 
-/// Enables all the interrupts in the current hart (supervisor mode).
+/// Enables interrupts globally in the current hart (supervisor mode).
+///
+/// # Note
+///
+/// Only enabled interrupt sources will be triggered.
+/// To enable specific interrupt sources, use [`enable_interrupt`].
 ///
 /// # Safety
 ///
-/// Do not call this function inside a critical section.
+/// Enabling interrupts might break critical sections or other synchronization mechanisms.
+/// Ensure that this is called in a safe context where interrupts can be enabled.
 #[inline]
 pub unsafe fn enable() {
     sstatus::set_sie()

riscv/src/register/mie.rs

@@ -1,9 +1,12 @@
 //! mie register
 
+use crate::bits::{bf_extract, bf_insert};
+use riscv_pac::CoreInterruptNumber;
+
 read_write_csr! {
     /// `mie` register
     Mie: 0x304,
-    mask: 0xaaa,
+    mask: usize::MAX,
 }
 
 read_write_csr_field! {
@@ -42,6 +45,26 @@ read_write_csr_field! {
     mext: 11,
 }
 
+impl Mie {
+    /// Check if a specific core interrupt source is enabled.
+    #[inline]
+    pub fn is_enabled<I: CoreInterruptNumber>(&self, interrupt: I) -> bool {
+        bf_extract(self.bits, interrupt.number(), 1) != 0
+    }
+
+    /// Enable a specific core interrupt source.
+    #[inline]
+    pub fn enable<I: CoreInterruptNumber>(&mut self, interrupt: I) {
+        self.bits = bf_insert(self.bits, interrupt.number(), 1, 1);
+    }
+
+    /// Disable a specific core interrupt source.
+    #[inline]
+    pub fn disable<I: CoreInterruptNumber>(&mut self, interrupt: I) {
+        self.bits = bf_insert(self.bits, interrupt.number(), 1, 0);
+    }
+}
+
 set!(0x304);
 clear!(0x304);
 
@@ -64,9 +87,28 @@ set_clear_csr!(
     /// Machine External Interrupt Enable
     , set_mext, clear_mext, 1 << 11);
 
+/// Disables a specific core interrupt source.
+#[inline]
+pub fn disable<I: CoreInterruptNumber>(interrupt: I) {
+    // SAFETY: it is safe to disable an interrupt source
+    unsafe { _clear(1 << interrupt.number()) };
+}
+
+/// Enables a specific core interrupt source.
+///
+/// # Safety
+///
+/// Enabling interrupts might break critical sections or other synchronization mechanisms.
+/// Ensure that this is called in a safe context where interrupts can be enabled.
+#[inline]
+pub unsafe fn enable<I: CoreInterruptNumber>(interrupt: I) {
+    unsafe { _set(1 << interrupt.number()) };
+}
+
 #[cfg(test)]
 mod tests {
     use super::*;
+    use crate::interrupt::machine::Interrupt;
 
     #[test]
     fn test_mie() {
@@ -79,4 +121,39 @@ mod tests {
         test_csr_field!(m, sext);
         test_csr_field!(m, mext);
     }
+
+    #[test]
+    fn test_mie_interrupt() {
+        let mut m = Mie::from_bits(0);
+
+        m.enable(Interrupt::SupervisorSoft);
+        assert!(m.is_enabled(Interrupt::SupervisorSoft));
+        m.disable(Interrupt::SupervisorSoft);
+        assert!(!m.is_enabled(Interrupt::SupervisorSoft));
+
+        m.enable(Interrupt::MachineSoft);
+        assert!(m.is_enabled(Interrupt::MachineSoft));
+        m.disable(Interrupt::MachineSoft);
+        assert!(!m.is_enabled(Interrupt::MachineSoft));
+
+        m.enable(Interrupt::SupervisorTimer);
+        assert!(m.is_enabled(Interrupt::SupervisorTimer));
+        m.disable(Interrupt::SupervisorTimer);
+        assert!(!m.is_enabled(Interrupt::SupervisorTimer));
+
+        m.enable(Interrupt::MachineTimer);
+        assert!(m.is_enabled(Interrupt::MachineTimer));
+        m.disable(Interrupt::MachineTimer);
+        assert!(!m.is_enabled(Interrupt::MachineTimer));
+
+        m.enable(Interrupt::SupervisorExternal);
+        assert!(m.is_enabled(Interrupt::SupervisorExternal));
+        m.disable(Interrupt::SupervisorExternal);
+        assert!(!m.is_enabled(Interrupt::SupervisorExternal));
+
+        m.enable(Interrupt::MachineExternal);
+        assert!(m.is_enabled(Interrupt::MachineExternal));
+        m.disable(Interrupt::MachineExternal);
+        assert!(!m.is_enabled(Interrupt::MachineExternal));
+    }
 }

riscv/src/register/sie.rs

@@ -1,9 +1,12 @@
 //! sie register
 
+use crate::bits::{bf_extract, bf_insert};
+use riscv_pac::CoreInterruptNumber;
+
 read_write_csr! {
 /// sie register
     Sie: 0x104,
-    mask: 0x222,
+    mask: usize::MAX,
 }
 
 read_write_csr_field! {
@@ -24,6 +27,26 @@ read_write_csr_field! {
     sext: 9,
 }
 
+impl Sie {
+    /// Check if a specific core interrupt source is enabled.
+    #[inline]
+    pub fn is_enabled<I: CoreInterruptNumber>(&self, interrupt: I) -> bool {
+        bf_extract(self.bits, interrupt.number(), 1) != 0
+    }
+
+    /// Enable a specific core interrupt source.
+    #[inline]
+    pub fn enable<I: CoreInterruptNumber>(&mut self, interrupt: I) {
+        self.bits = bf_insert(self.bits, interrupt.number(), 1, 1);
+    }
+
+    /// Disable a specific core interrupt source.
+    #[inline]
+    pub fn disable<I: CoreInterruptNumber>(&mut self, interrupt: I) {
+        self.bits = bf_insert(self.bits, interrupt.number(), 1, 0);
+    }
+}
+
 set!(0x104);
 clear!(0x104);
 
@@ -37,9 +60,28 @@ set_clear_csr!(
     /// Supervisor External Interrupt Enable
     , set_sext, clear_sext, 1 << 9);
 
+/// Disables a specific core interrupt source.
+#[inline]
+pub fn disable<I: CoreInterruptNumber>(interrupt: I) {
+    // SAFETY: it is safe to disable an interrupt source
+    unsafe { _clear(1 << interrupt.number()) };
+}
+
+/// Enables a specific core interrupt source.
+///
+/// # Safety
+///
+/// Enabling interrupts might break critical sections or other synchronization mechanisms.
+/// Ensure that this is called in a safe context where interrupts can be enabled.
+#[inline]
+pub unsafe fn enable<I: CoreInterruptNumber>(interrupt: I) {
+    unsafe { _set(1 << interrupt.number()) };
+}
+
 #[cfg(test)]
 mod tests {
     use super::*;
+    use crate::interrupt::supervisor::Interrupt;
 
     #[test]
     fn test_sie() {
@@ -49,4 +91,24 @@ mod tests {
         test_csr_field!(sie, stimer);
         test_csr_field!(sie, sext);
     }
+
+    #[test]
+    fn test_sie_interrupt() {
+        let mut s = Sie::from_bits(0);
+
+        s.enable(Interrupt::SupervisorSoft);
+        assert!(s.is_enabled(Interrupt::SupervisorSoft));
+        s.disable(Interrupt::SupervisorSoft);
+        assert!(!s.is_enabled(Interrupt::SupervisorSoft));
+
+        s.enable(Interrupt::SupervisorTimer);
+        assert!(s.is_enabled(Interrupt::SupervisorTimer));
+        s.disable(Interrupt::SupervisorTimer);
+        assert!(!s.is_enabled(Interrupt::SupervisorTimer));
+
+        s.enable(Interrupt::SupervisorExternal);
+        assert!(s.is_enabled(Interrupt::SupervisorExternal));
+        s.disable(Interrupt::SupervisorExternal);
+        assert!(!s.is_enabled(Interrupt::SupervisorExternal));
+    }
 }