diff --git a/sys/arm/arm/pmu_acpi.c b/sys/arm/arm/pmu_acpi.c
new file mode 100644
--- /dev/null
+++ b/sys/arm/arm/pmu_acpi.c
@@ -0,0 +1,170 @@
+/*-
+ * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
+ *
+ * Copyright (c) 2020 Greg V <greg@unrelenting.technology>
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ */
+
+#include <sys/cdefs.h>
+#include <sys/param.h>
+#include <sys/bus.h>
+#include <sys/kernel.h>
+#include <sys/module.h>
+#include <sys/rman.h>
+
+#include <contrib/dev/acpica/include/acpi.h>
+#include <dev/acpica/acpivar.h>
+
+#include <arm/arm/gic_common.h>
+
+#include "acpi_bus_if.h"
+#include "pmu.h"
+
+struct madt_ctx {
+	struct pmu_softc *sc;
+	int i;
+};
+
+static void
+madt_handler(ACPI_SUBTABLE_HEADER *entry, void *arg)
+{
+	ACPI_MADT_GENERIC_INTERRUPT *intr;
+	struct madt_ctx *ctx = arg;
+	struct pmu_softc *sc = ctx->sc;
+	struct acpi_device *ad;
+	struct pcpu *pcpu;
+	rman_res_t irq;
+	int rid = ctx->i;
+	int cpuid = -1;
+	int i;
+
+	if (entry->Type != ACPI_MADT_TYPE_GENERIC_INTERRUPT)
+		return;
+
+	intr = (ACPI_MADT_GENERIC_INTERRUPT *)entry;
+
+	for (i = 0; i < MAXCPU; i++) {
+		pcpu = pcpu_find(i);
+		if (pcpu != NULL && pcpu->pc_mpidr == intr->ArmMpidr) {
+			cpuid = i;
+			break;
+		}
+	}
+
+	if (bootverbose)
+		device_printf(sc->dev, "MADT: cpu %d (mpidr %lu) irq %d %s-triggered\n",
+		    cpuid,
+		    intr->ArmMpidr,
+		    intr->PerformanceInterrupt,
+		    (intr->Flags & ACPI_MADT_PERFORMANCE_IRQ_MODE) ? "edge" : "level");
+
+	/*
+	 * BUS_CONFIG_INTR does nothing on arm64, so we manually register an IRQ
+	 * resource with correct trigger mode instead of doing BUS_SET_RESOURCE.
+	 */
+	irq = (rman_res_t)ACPI_BUS_MAP_INTR(device_get_parent(sc->dev), sc->dev,
+	    intr->PerformanceInterrupt,
+	    (intr->Flags & ACPI_MADT_PERFORMANCE_IRQ_MODE) ?
+	        INTR_TRIGGER_EDGE : INTR_TRIGGER_LEVEL,
+	    INTR_POLARITY_HIGH);
+	ad = device_get_ivars(sc->dev);
+	resource_list_add(&ad->ad_rl, SYS_RES_IRQ,
+	    ctx->i, irq, irq, 1);
+
+	sc->irq[ctx->i].res = bus_alloc_resource_any(sc->dev, SYS_RES_IRQ,
+	    &rid, RF_ACTIVE | RF_SHAREABLE);
+	if (sc->irq[ctx->i].res == NULL)
+		device_printf(sc->dev, "failed to allocate IRQ %d\n", ctx->i);
+
+	/*
+	 * NOTE: AArch64 ACPI systems always use the GIC.
+	 */
+	if (intr->PerformanceInterrupt >= GIC_FIRST_SPI)
+		sc->irq[ctx->i].cpuid = cpuid;
+
+	ctx->i++;
+}
+
+static void
+pmu_acpi_identify(driver_t *driver, device_t parent)
+{
+	device_t dev;
+
+	if (acpi_find_table(ACPI_SIG_MADT) == 0)
+		return;
+
+	dev = BUS_ADD_CHILD(parent, BUS_PASS_INTERRUPT + BUS_PASS_ORDER_LAST,
+	    "pmu", -1);
+
+	if (dev == NULL)
+		device_printf(parent, "pmu: Unable to add pmu child\n");
+}
+
+static int
+pmu_acpi_probe(device_t dev)
+{
+	device_set_desc(dev, "Performance Monitoring Unit");
+	return (BUS_PROBE_NOWILDCARD);
+}
+
+static int
+pmu_acpi_attach(device_t dev)
+{
+	struct pmu_softc *sc;
+	struct madt_ctx ctx;
+	ACPI_TABLE_MADT *madt;
+
+	sc = device_get_softc(dev);
+	sc->dev = dev;
+
+	madt = acpi_map_table(acpi_find_table(ACPI_SIG_MADT), ACPI_SIG_MADT);
+	if (madt == NULL) {
+		device_printf(dev, "Unable to map the MADT table\n");
+		return (ENXIO);
+	}
+
+	ctx.sc = sc;
+	ctx.i = 0;
+	acpi_walk_subtables(madt + 1, (char *)madt + madt->Header.Length,
+	    madt_handler, &ctx);
+
+	acpi_unmap_table(madt);
+	return (pmu_attach(dev));
+}
+
+static device_method_t pmu_acpi_methods[] = {
+	DEVMETHOD(device_identify,		pmu_acpi_identify),
+	DEVMETHOD(device_probe,		pmu_acpi_probe),
+	DEVMETHOD(device_attach,	pmu_acpi_attach),
+	DEVMETHOD_END,
+};
+
+static driver_t pmu_acpi_driver = {
+	"pmu",
+	pmu_acpi_methods,
+	sizeof(struct pmu_softc),
+};
+
+static devclass_t pmu_acpi_devclass;
+
+DRIVER_MODULE(pmu, acpi, pmu_acpi_driver, pmu_acpi_devclass, 0, 0);
diff --git a/sys/conf/files.arm64 b/sys/conf/files.arm64
--- a/sys/conf/files.arm64
+++ b/sys/conf/files.arm64
@@ -85,6 +85,7 @@
 arm/arm/gic_acpi.c		optional	acpi
 arm/arm/gic_fdt.c		optional	fdt
 arm/arm/pmu.c			standard
+arm/arm/pmu_acpi.c		optional	acpi
 arm/arm/pmu_fdt.c		optional	fdt
 arm/broadcom/bcm2835/bcm2835_audio.c		optional sound vchiq fdt \
 	compile-with "${NORMAL_C} -DUSE_VCHIQ_ARM -D__VCCOREVER__=0x04000000 -I$S/contrib/vchiq"