Add support for routing interrupts to other CPUs in ampintc(4). Most of the

supporting code was already there.  The driver supports establishing multiple
handlers on the same pin.  Make sure that a single pin can only be established
on a specific core by recording the struct cpu_info * of the first establish,
and returning NULL if someone tries to share the pin with a different core.

Since the array of CPU masks, used for enabling/disabling interrupt routing to
specific cores, is only populated during cpu_boot_secondary_processors(), each
core will re-route the interrupts once a core read its mask.  Until then, the
core will not receive interrupts for that pin.

While there, remove a call to ampintc_setipl(), which seems to be a no-op.  It
tries to set the same value that's already set.  Since the function that calls
it is supposed to calculate a pin's mask and do the routing, this doesn't seem
to be the correct place for such a call.  agintc(4) doesn't have it either.

Prompted by dlg@
ok kettenis@

1 files changed, 59 insertions, 35 deletions

diff --git a/sys/arch/arm64/dev/ampintc.c b/sys/arch/arm64/dev/ampintc.c
index a372e0fa96f..eaaa35589f4 100644
--- a/sys/arch/arm64/dev/ampintc.c
+++ b/sys/arch/arm64/dev/ampintc.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: ampintc.c,v 1.17 2020/07/14 15:34:14 patrick Exp $ */
+/* $OpenBSD: ampintc.c,v 1.18 2020/07/14 15:52:20 patrick Exp $ */
 /*
  * Copyright (c) 2007,2009,2011 Dale Rahn <drahn@openbsd.org>
  *
@@ -160,6 +160,7 @@ struct intrhand {
 
 struct intrq {
 	TAILQ_HEAD(, intrhand) iq_list;	/* handler list */
+	struct cpu_info *iq_ci;		/* CPU the IRQ runs on */
 	int iq_irq_max;			/* IRQ to mask while handling */
 	int iq_irq_min;			/* lowest IRQ when shared */
 	int iq_ist;			/* share type */
@@ -174,6 +175,7 @@ void		 ampintc_splx(int);
 int		 ampintc_splraise(int);
 void		 ampintc_setipl(int);
 void		 ampintc_calc_mask(void);
+void		 ampintc_calc_irq(struct ampintc_softc *, int);
 void		*ampintc_intr_establish(int, int, int, struct cpu_info *,
 		    int (*)(void *), void *, char *);
 void		*ampintc_intr_establish_fdt(void *, int *, int,
@@ -453,44 +455,49 @@ ampintc_intr_config(int irqno, int type)
 void
 ampintc_calc_mask(void)
 {
-	struct cpu_info		*ci = curcpu();
-        struct ampintc_softc	*sc = ampintc;
-	struct intrhand		*ih;
+	struct ampintc_softc	*sc = ampintc;
 	int			 irq;
 
-	for (irq = 0; irq < sc->sc_nintr; irq++) {
-		int max = IPL_NONE;
-		int min = IPL_HIGH;
-		TAILQ_FOREACH(ih, &sc->sc_handler[irq].iq_list, ih_list) {
-			if (ih->ih_ipl > max)
-				max = ih->ih_ipl;
-
-			if (ih->ih_ipl < min)
-				min = ih->ih_ipl;
-		}
+	for (irq = 0; irq < sc->sc_nintr; irq++)
+		ampintc_calc_irq(sc, irq);
+}
+
+void
+ampintc_calc_irq(struct ampintc_softc *sc, int irq)
+{
+	struct cpu_info		*ci = sc->sc_handler[irq].iq_ci;
+	struct intrhand		*ih;
+	int			max = IPL_NONE;
+	int			min = IPL_HIGH;
 
-		if (max == IPL_NONE)
-			min = IPL_NONE;
+	TAILQ_FOREACH(ih, &sc->sc_handler[irq].iq_list, ih_list) {
+		if (ih->ih_ipl > max)
+			max = ih->ih_ipl;
 
-		if (sc->sc_handler[irq].iq_irq_max == max &&
-		    sc->sc_handler[irq].iq_irq_min == min)
-			continue;
+		if (ih->ih_ipl < min)
+			min = ih->ih_ipl;
+	}
 
-		sc->sc_handler[irq].iq_irq_max = max;
-		sc->sc_handler[irq].iq_irq_min = min;
-
-		/* Enable interrupts at lower levels, clear -> enable */
-		/* Set interrupt priority/enable */
-		if (min != IPL_NONE) {
-			ampintc_set_priority(irq, min);
-			ampintc_intr_enable(irq);
-			ampintc_route(irq, IRQ_ENABLE, ci);
-		} else {
-			ampintc_intr_disable(irq);
-			ampintc_route(irq, IRQ_DISABLE, ci);
-		}
+	if (max == IPL_NONE)
+		min = IPL_NONE;
+
+	if (sc->sc_handler[irq].iq_irq_max == max &&
+	    sc->sc_handler[irq].iq_irq_min == min)
+		return;
+
+	sc->sc_handler[irq].iq_irq_max = max;
+	sc->sc_handler[irq].iq_irq_min = min;
+
+	/* Enable interrupts at lower levels, clear -> enable */
+	/* Set interrupt priority/enable */
+	if (min != IPL_NONE) {
+		ampintc_set_priority(irq, min);
+		ampintc_intr_enable(irq);
+		ampintc_route(irq, IRQ_ENABLE, ci);
+	} else {
+		ampintc_intr_disable(irq);
+		ampintc_route(irq, IRQ_DISABLE, ci);
 	}
-	ampintc_setipl(ci->ci_cpl);
 }
 
 void
@@ -575,8 +582,8 @@ ampintc_route(int irq, int enable, struct cpu_info *ci)
 void
 ampintc_cpuinit(void)
 {
-	struct ampintc_softc    *sc = ampintc;
-	int			 i;
+	struct ampintc_softc	*sc = ampintc;
+	int			 i, irq;
 
 	/* XXX - this is the only cpu specific call to set this */
 	if (sc->sc_cpu_mask[cpu_number()] == 0) {
@@ -594,6 +601,15 @@ ampintc_cpuinit(void)
 
 	if (sc->sc_cpu_mask[cpu_number()] == 0)
 		panic("could not determine cpu target mask");
+
+	for (irq = 0; irq < sc->sc_nintr; irq++) {
+		if (sc->sc_handler[irq].iq_ci != curcpu())
+			continue;
+		if (sc->sc_handler[irq].iq_irq_min != IPL_NONE)
+			ampintc_route(irq, IRQ_ENABLE, curcpu());
+		else
+			ampintc_route(irq, IRQ_DISABLE, curcpu());
+	}
 }
 
 void
@@ -745,7 +761,15 @@ ampintc_intr_establish(int irqno, int type, int level, struct cpu_info *ci,
 
 	psw = disable_interrupts();
 
+	if (!TAILQ_EMPTY(&sc->sc_handler[irqno].iq_list) &&
+	    sc->sc_handler[irqno].iq_ci != ci) {
+		free(ih, M_DEVBUF, sizeof(*ih));
+		restore_interrupts(psw);
+		return NULL;
+	}
+
 	TAILQ_INSERT_TAIL(&sc->sc_handler[irqno].iq_list, ih, ih_list);
+	sc->sc_handler[irqno].iq_ci = ci;
 
 	if (name != NULL)
 		evcount_attach(&ih->ih_count, name, &ih->ih_irq);