diff --git a/sys/arm/arm/gic.c b/sys/arm/arm/gic.c
index b1b7aacd63ab..ffce86e62128 100644
--- a/sys/arm/arm/gic.c
+++ b/sys/arm/arm/gic.c
@@ -200,7 +200,7 @@ gic_cpu_mask(struct arm_gic_softc *sc)
 
 #ifdef SMP
 static void
-arm_gic_init_secondary(device_t dev, uint32_t rootnum)
+arm_gic_init_secondary(device_t dev, enum root_type root_type)
 {
 	struct arm_gic_softc *sc = device_get_softc(dev);
 	u_int irq, cpu;
diff --git a/sys/arm/broadcom/bcm2835/bcm2836.c b/sys/arm/broadcom/bcm2835/bcm2836.c
index 7ed9dedaa77e..fd34ff8818ad 100644
--- a/sys/arm/broadcom/bcm2835/bcm2836.c
+++ b/sys/arm/broadcom/bcm2835/bcm2836.c
@@ -538,7 +538,7 @@ bcm_lintc_init_pmu_on_ap(struct bcm_lintc_softc *sc, u_int cpu)
 }
 
 static void
-bcm_lintc_init_secondary(device_t dev, uint32_t rootnum)
+bcm_lintc_init_secondary(device_t dev, enum root_type root_type)
 {
 	u_int cpu;
 	struct bcm_lintc_softc *sc;
diff --git a/sys/arm/include/intr.h b/sys/arm/include/intr.h
index d0d0ff9fc32a..e74be3ac548e 100644
--- a/sys/arm/include/intr.h
+++ b/sys/arm/include/intr.h
@@ -43,6 +43,12 @@
 #include <dev/ofw/openfirm.h>
 #endif
 
+enum root_type {
+	INTR_ROOT_IRQ =	0,
+
+	INTR_ROOT_COUNT	/* MUST BE LAST */
+};
+
 #ifndef NIRQ
 #define	NIRQ		1024	/* XXX - It should be an option. */
 #endif
diff --git a/sys/arm64/arm64/gic_v3.c b/sys/arm64/arm64/gic_v3.c
index 964a129111e2..750f734a7757 100644
--- a/sys/arm64/arm64/gic_v3.c
+++ b/sys/arm64/arm64/gic_v3.c
@@ -1093,7 +1093,7 @@ gic_v3_bind_intr(device_t dev, struct intr_irqsrc *isrc)
 
 #ifdef SMP
 static void
-gic_v3_init_secondary(device_t dev, uint32_t rootnum)
+gic_v3_init_secondary(device_t dev, enum root_type root_type)
 {
 	struct gic_v3_setup_periph_args pargs;
 	device_t child;
@@ -1140,7 +1140,7 @@ gic_v3_init_secondary(device_t dev, uint32_t rootnum)
 
 	for (i = 0; i < sc->gic_nchildren; i++) {
 		child = sc->gic_children[i];
-		PIC_INIT_SECONDARY(child, rootnum);
+		PIC_INIT_SECONDARY(child, root_type);
 	}
 }
 
diff --git a/sys/arm64/arm64/gicv3_its.c b/sys/arm64/arm64/gicv3_its.c
index 5ecd9b8c0e94..31e23fc01224 100644
--- a/sys/arm64/arm64/gicv3_its.c
+++ b/sys/arm64/arm64/gicv3_its.c
@@ -1293,7 +1293,7 @@ gicv3_its_setup_intr(device_t dev, struct intr_irqsrc *isrc,
 
 #ifdef SMP
 static void
-gicv3_its_init_secondary(device_t dev, uint32_t rootnum)
+gicv3_its_init_secondary(device_t dev, enum root_type root_type)
 {
 	struct gicv3_its_softc *sc;
 
diff --git a/sys/arm64/include/intr.h b/sys/arm64/include/intr.h
index 99b4d15ccc1c..008c377b7a16 100644
--- a/sys/arm64/include/intr.h
+++ b/sys/arm64/include/intr.h
@@ -31,6 +31,13 @@
 #include <dev/ofw/openfirm.h>
 #endif
 
+enum root_type {
+	INTR_ROOT_IRQ =	0,
+	INTR_ROOT_FIQ =	1,
+
+	INTR_ROOT_COUNT	/* MUST BE LAST */
+};
+
 #include <sys/intr.h>
 
 #ifndef NIRQ
@@ -48,7 +55,4 @@ arm_irq_memory_barrier(uintptr_t irq)
 #define	ACPI_GPIO_XREF	3
 #endif
 
-#define	INTR_ROOT_FIQ	1
-#define	INTR_ROOT_NUM	2
-
 #endif	/* _MACHINE_INTR_H */
diff --git a/sys/kern/pic_if.m b/sys/kern/pic_if.m
index f78e787594c5..2d938520b106 100644
--- a/sys/kern/pic_if.m
+++ b/sys/kern/pic_if.m
@@ -74,7 +74,7 @@ CODE {
 	}
 
 	static void
-	null_pic_init_secondary(device_t dev, uint32_t rootnum)
+	null_pic_init_secondary(device_t dev, enum root_type root_type)
 	{
 	}
 
@@ -157,7 +157,7 @@ METHOD void pre_ithread {
 
 METHOD void init_secondary {
 	device_t	dev;
-	uint32_t	rootnum;
+	enum root_type	root_type;
 } DEFAULT null_pic_init_secondary;
 
 METHOD void ipi_send {
diff --git a/sys/kern/subr_intr.c b/sys/kern/subr_intr.c
index a6052f28b04c..6b4ebd16675c 100644
--- a/sys/kern/subr_intr.c
+++ b/sys/kern/subr_intr.c
@@ -89,15 +89,6 @@
 
 #define	INTRNAME_LEN	(2*MAXCOMLEN + 1)
 
-/*
- * Archs may define multiple roots with INTR_ROOT_NUM to support different kinds
- * of interrupts (e.g. arm64 FIQs which use a different exception vector than
- * IRQs).
- */
-#if !defined(INTR_ROOT_NUM)
-#define	INTR_ROOT_NUM	1
-#endif
-
 #ifdef DEBUG
 #define debugf(fmt, args...) do { printf("%s(): ", __func__);	\
     printf(fmt,##args); } while (0)
@@ -115,7 +106,7 @@ struct intr_irq_root {
 	void *arg;
 };
 
-static struct intr_irq_root intr_irq_roots[INTR_ROOT_NUM];
+static struct intr_irq_root intr_irq_roots[INTR_ROOT_COUNT];
 
 struct intr_pic_child {
 	SLIST_ENTRY(intr_pic_child)	 pc_next;
@@ -337,16 +328,16 @@ isrc_release_counters(struct intr_irqsrc *isrc)
  *  from the assembler, where CPU interrupt is served.
  */
 void
-intr_irq_handler(struct trapframe *tf, uint32_t rootnum)
+intr_irq_handler(struct trapframe *tf, u_register_t root_type)
 {
 	struct trapframe * oldframe;
 	struct thread * td;
 	struct intr_irq_root *root;
 
-	KASSERT(rootnum < INTR_ROOT_NUM,
-	    ("%s: invalid interrupt root %d", __func__, rootnum));
+	KASSERT((uintmax_t)root_type < INTR_ROOT_COUNT,
+	    ("%s: invalid interrupt root %ju", __func__, (uintmax_t)root_type));
 
-	root = &intr_irq_roots[rootnum];
+	root = &intr_irq_roots[root_type];
 	KASSERT(root->filter != NULL, ("%s: no filter", __func__));
 
 	kasan_mark(tf, sizeof(*tf), sizeof(*tf), 0);
@@ -495,11 +486,11 @@ isrc_free_irq(struct intr_irqsrc *isrc)
 }
 
 device_t
-intr_irq_root_device(uint32_t rootnum)
+intr_irq_root_device(enum root_type root_type)
 {
-	KASSERT(rootnum < INTR_ROOT_NUM,
-	    ("%s: invalid interrupt root %d", __func__, rootnum));
-	return (intr_irq_roots[rootnum].dev);
+	KASSERT((uintmax_t)root_type < INTR_ROOT_COUNT,
+	    ("%s: invalid interrupt root %ju", __func__, (uintmax_t)root_type));
+	return (intr_irq_roots[root_type].dev);
 }
 
 /*
@@ -900,7 +891,7 @@ intr_pic_deregister(device_t dev, intptr_t xref)
  */
 int
 intr_pic_claim_root(device_t dev, intptr_t xref, intr_irq_filter_t *filter,
-    void *arg, uint32_t rootnum)
+    void *arg, enum root_type root_type)
 {
 	struct intr_pic *pic;
 	struct intr_irq_root *root;
@@ -925,9 +916,9 @@ intr_pic_claim_root(device_t dev, intptr_t xref, intr_irq_filter_t *filter,
 	 * Note that we further suppose that there is not threaded interrupt
 	 * routine (handler) on the root. See intr_irq_handler().
 	 */
-	KASSERT(rootnum < INTR_ROOT_NUM,
-	    ("%s: invalid interrupt root %d", __func__, rootnum));
-	root = &intr_irq_roots[rootnum];
+	KASSERT((uintmax_t)root_type < INTR_ROOT_COUNT,
+	    ("%s: invalid interrupt root %ju", __func__, (uintmax_t)root_type));
+	root = &intr_irq_roots[root_type];
 	if (root->dev != NULL) {
 		device_printf(dev, "another root already set\n");
 		return (EBUSY);
@@ -1580,16 +1571,16 @@ void
 intr_pic_init_secondary(void)
 {
 	device_t dev;
-	uint32_t rootnum;
+	enum root_type root_type;
 
 	/*
 	 * QQQ: Only root PICs are aware of other CPUs ???
 	 */
 	//mtx_lock(&isrc_table_lock);
-	for (rootnum = 0; rootnum < INTR_ROOT_NUM; rootnum++) {
-		dev = intr_irq_roots[rootnum].dev;
+	for (root_type = 0; root_type < INTR_ROOT_COUNT; root_type++) {
+		dev = intr_irq_roots[root_type].dev;
 		if (dev != NULL) {
-			PIC_INIT_SECONDARY(dev, rootnum);
+			PIC_INIT_SECONDARY(dev, root_type);
 		}
 	}
 	//mtx_unlock(&isrc_table_lock);
diff --git a/sys/riscv/include/intr.h b/sys/riscv/include/intr.h
index ad811dcbc449..8cbb07c6be24 100644
--- a/sys/riscv/include/intr.h
+++ b/sys/riscv/include/intr.h
@@ -35,6 +35,12 @@
 #ifndef	_MACHINE_INTR_MACHDEP_H_
 #define	_MACHINE_INTR_MACHDEP_H_
 
+enum root_type {
+	INTR_ROOT_IRQ = 0,
+
+	INTR_ROOT_COUNT	/* MUST BE LAST */
+};
+
 #ifndef	NIRQ
 #define	NIRQ			1024
 #endif
diff --git a/sys/riscv/riscv/intc.c b/sys/riscv/riscv/intc.c
index 248175e8bea3..fcfc0c826fb9 100644
--- a/sys/riscv/riscv/intc.c
+++ b/sys/riscv/riscv/intc.c
@@ -241,7 +241,7 @@ intc_setup_intr(device_t dev, struct intr_irqsrc *isrc,
 
 #ifdef SMP
 static void
-intc_init_secondary(device_t dev, uint32_t rootnum)
+intc_init_secondary(device_t dev, enum root_type root_type)
 {
 	struct intc_softc *sc;
 	struct intr_irqsrc *isrc;
diff --git a/sys/sys/intr.h b/sys/sys/intr.h
index c1e440a9fa93..0208844e90c8 100644
--- a/sys/sys/intr.h
+++ b/sys/sys/intr.h
@@ -37,8 +37,6 @@
 
 #define	INTR_IRQ_INVALID	0xFFFFFFFF
 
-#define INTR_ROOT_IRQ	0
-
 enum intr_map_data_type {
 	INTR_MAP_DATA_ACPI = 0,
 	INTR_MAP_DATA_FDT,
@@ -113,12 +111,12 @@ u_int intr_irq_next_cpu(u_int current_cpu, cpuset_t *cpumask);
 struct intr_pic *intr_pic_register(device_t, intptr_t);
 int intr_pic_deregister(device_t, intptr_t);
 int intr_pic_claim_root(device_t, intptr_t, intr_irq_filter_t *, void *,
-    uint32_t);
+    enum root_type);
 int intr_pic_add_handler(device_t, struct intr_pic *,
     intr_child_irq_filter_t *, void *, uintptr_t, uintptr_t);
 bool intr_is_per_cpu(struct resource *);
 
-device_t intr_irq_root_device(uint32_t);
+device_t intr_irq_root_device(enum root_type);
 
 /* Intr interface for BUS. */
 
@@ -166,7 +164,7 @@ void intr_ipi_send(cpuset_t cpus, u_int ipi);
 void intr_ipi_dispatch(u_int ipi);
 #endif
 
-/* Main interrupt handler called from asm on most archs except riscv. */
-void intr_irq_handler(struct trapframe *tf, uint32_t rootnum);
+/* Main interrupt handler called from asm on many archs. */
+void intr_irq_handler(struct trapframe *tf, u_register_t root_type);
 
 #endif	/* _SYS_INTR_H */