Expose a new public routine intr_event_execute_handlers() which executes

all the non-filter handlers attached to an interrupt event.  This can be
used by device drivers which multiplex their interrupt onto the interrupt
handlers for child devices.

2 files changed, 29 insertions, 6 deletions

diff --git a/sys/kern/kern_intr.c b/sys/kern/kern_intr.c
index 41be569..5bed43d 100644
--- a/sys/kern/kern_intr.c
+++ b/sys/kern/kern_intr.c
@@ -1085,16 +1085,16 @@ priv_ithread_execute_handler(struct proc *p, struct intr_handler *ih)
 }
 #endif
 
-static void
-ithread_execute_handlers(struct proc *p, struct intr_event *ie)
+/*
+ * This is a public function for use by drivers that mux interrupt
+ * handlers for child devices from their interrupt handler.
+ */
+void
+intr_event_execute_handlers(struct proc *p, struct intr_event *ie)
 {
 	struct intr_handler *ih, *ihn;
 
-	/* Interrupt handlers should not sleep. */
-	if (!(ie->ie_flags & IE_SOFT))
-		THREAD_NO_SLEEPING();
 	TAILQ_FOREACH_SAFE(ih, &ie->ie_handlers, ih_next, ihn) {
-
 		/*
 		 * If this handler is marked for death, remove it from
 		 * the list of handlers and wake up the sleeper.
@@ -1135,6 +1135,16 @@ ithread_execute_handlers(struct proc *p, struct intr_event *ie)
 		if (!(ih->ih_flags & IH_MPSAFE))
 			mtx_unlock(&Giant);
 	}
+}
+
+static void
+ithread_execute_handlers(struct proc *p, struct intr_event *ie)
+{
+
+	/* Interrupt handlers should not sleep. */
+	if (!(ie->ie_flags & IE_SOFT))
+		THREAD_NO_SLEEPING();
+	intr_event_execute_handlers(p, ie);
 	if (!(ie->ie_flags & IE_SOFT))
 		THREAD_SLEEPING_OK();
 
diff --git a/sys/sys/interrupt.h b/sys/sys/interrupt.h
index be5d0f4..fed9020 100644
--- a/sys/sys/interrupt.h
+++ b/sys/sys/interrupt.h
@@ -90,6 +90,16 @@ struct intr_handler {
  * The 'assign_cpu' hook is used to bind an interrupt source to a
  * specific CPU.  If the interrupt cannot be bound, this function may
  * return an error.
+ *
+ * Note that device drivers may also use interrupt events to manage
+ * multiplexing interrupt interrupt handler into handlers for child
+ * devices.  In that case, the above hooks are not used.  The device
+ * can create an event for its interrupt resource and register child
+ * event handlers with that event.  It can then use
+ * intr_event_execute_handlers() to execute non-filter handlers.
+ * Currently filter handlers are not supported by this, but that can
+ * be added by splitting out the filter loop from intr_event_handle()
+ * if desired.
  */
 struct intr_event {
 	TAILQ_ENTRY(intr_event) ie_list;
@@ -132,6 +142,8 @@ struct intr_event {
 #define	SWI_TQ		6
 #define	SWI_TQ_GIANT	6
 
+struct proc;
+
 extern struct	intr_event *tty_intr_event;
 extern struct	intr_event *clk_intr_event;
 extern void	*softclock_ih;
@@ -157,6 +169,7 @@ int	intr_event_create(struct intr_event **event, void *source,
 	    int (*assign_cpu)(void *, u_char), const char *fmt, ...)
 	    __printflike(9, 10);
 int	intr_event_destroy(struct intr_event *ie);
+void	intr_event_execute_handlers(struct proc *p, struct intr_event *ie);
 int	intr_event_handle(struct intr_event *ie, struct trapframe *frame);
 int	intr_event_remove_handler(void *cookie);
 int	intr_getaffinity(int irq, void *mask);