feat(kernel): ipc cap transfer drops Delegate; one owner per irq line, freed when owner dies

crates/domain/src/irq/mod.rs

@@ -1,7 +1,7 @@
 use types::{
     badge::Badge,
     generation::Generation,
-    id::{IrqId, NotificationId},
+    id::{IrqId, NotificationId, ProcessId},
 };
 
 #[cfg(test)]
@@ -17,6 +17,8 @@ pub struct IrqRoute {
     pub notification: NotificationId,
     pub generation: Generation,
     pub badge: Badge,
+    /// The process that set the route, and so owns the line.
+    pub owner: ProcessId,
 }
 
 pub struct IrqRoutingTable {
@@ -53,6 +55,15 @@ impl IrqRoutingTable {
         }
     }
 
+    /// Drops every route `owner` set, when it dies.
+    pub fn clear_owned_by(&mut self, owner: ProcessId) {
+        for slot in self.routes.iter_mut() {
+            if slot.is_some_and(|r| r.owner == owner) {
+                *slot = None;
+            }
+        }
+    }
+
     /// The route for `irq`; `None` for unknown or unrouted lines.
     pub fn route(&self, irq: IrqId) -> Option<IrqRoute> {
         *self.routes.get(irq.raw() as usize)?

crates/domain/src/irq/tests.rs

@@ -8,6 +8,7 @@ fn route(n: u16) -> IrqRoute {
         notification: NotificationId::from_raw(n),
         generation: Generation::initial(),
         badge: Badge::new(1 << n),
+        owner: types::id::ProcessId::from_raw(0),
     }
 }