diff --git a/sys/dev/acpica/acpi.c b/sys/dev/acpica/acpi.c
--- a/sys/dev/acpica/acpi.c
+++ b/sys/dev/acpica/acpi.c
@@ -3309,14 +3309,53 @@
 }
 
 enum acpi_sleep_state {
-    ACPI_SS_NONE	= 0,
-    ACPI_SS_GPE_SET	= 1 << 0,
-    ACPI_SS_DEV_SUSPEND	= 1 << 1,
-    ACPI_SS_SPMC_ENTER	= 1 << 2,
-    ACPI_SS_SLP_PREP	= 1 << 3,
-    ACPI_SS_SLEPT	= 1 << 4,
+    ACPI_SS_NONE		= 0,
+    ACPI_SS_GPE_SET		= 1 << 0,
+    ACPI_SS_DEV_SUSPEND		= 1 << 1,
+    ACPI_SS_SPMC_ENTER		= 1 << 2,
+    ACPI_SS_AMDSMU_ENTER	= 1 << 3,
+    ACPI_SS_SLP_PREP		= 1 << 4,
+    ACPI_SS_SLEPT		= 1 << 5,
 };
 
+static int
+acpi_amdsmu_get_device(struct acpi_softc *sc, device_t *dev)
+{
+    devclass_t	amdsmu_dc = devclass_find("amdsmu");
+
+    MPASS(dev != NULL);
+    if (amdsmu_dc == NULL) {
+	device_printf(sc->acpi_dev, "amdsmu device class not found\n");
+	return (ENXIO);
+    }
+    *dev = devclass_get_device(amdsmu_dc, 0);
+    if (*dev == NULL) {
+	device_printf(sc->acpi_dev, "no amdsmu device found\n");
+	return (ENXIO);
+    }
+    return (0);
+}
+
+static int
+acpi_amdsmu_enter(struct acpi_softc *sc)
+{
+    device_t	amdsmu;
+
+    if (acpi_amdsmu_get_device(sc, &amdsmu) != 0)
+	return (ENXIO);
+    return (DEVICE_AMDSMU_ENTER_SLEEP(amdsmu));
+}
+
+static int
+acpi_amdsmu_exit(struct acpi_softc *sc)
+{
+    device_t	amdsmu;
+
+    if (acpi_amdsmu_get_device(sc, &amdsmu) != 0)
+	return (ENXIO);
+    return (DEVICE_AMDSMU_EXIT_SLEEP(amdsmu));
+}
+
 static void
 do_standby(struct acpi_softc *sc, enum acpi_sleep_state *slp_state,
     register_t rflags)
@@ -3517,6 +3556,8 @@
 	else
 	    slp_state |= ACPI_SS_SPMC_ENTER;
     }
+    if (acpi_amdsmu_enter(sc) == 0)
+	slp_state |= ACPI_SS_AMDSMU_ENTER;
 
     if (stype != STYPE_SUSPEND_TO_IDLE) {
 	status = AcpiEnterSleepStatePrep(stype);
@@ -3570,6 +3611,10 @@
 	sc->acpi_stype = STYPE_AWAKE;
 	slp_state &= ~ACPI_SS_GPE_SET;
     }
+    if (slp_state & ACPI_SS_AMDSMU_ENTER) {
+	acpi_amdsmu_exit(sc);
+	slp_state &= ~ACPI_SS_AMDSMU_ENTER;
+    }
     if (slp_state & ACPI_SS_SPMC_ENTER) {
 	MPASS(sc->acpi_spmc_device != NULL);
 	MPASS(sc->acpi_spmc_exit != NULL);
diff --git a/sys/dev/amdsmu/amdsmu.c b/sys/dev/amdsmu/amdsmu.c
--- a/sys/dev/amdsmu/amdsmu.c
+++ b/sys/dev/amdsmu/amdsmu.c
@@ -44,6 +44,7 @@
 
 enum amdsmu_msg {
 	SMU_MSG_GETSMUVERSION		= 0x02,
+	SMU_MSG_SLEEP_HINT		= 0x03,
 	SMU_MSG_LOG_GETDRAM_ADDR_HI	= 0x04,
 	SMU_MSG_LOG_GETDRAM_ADDR_LO	= 0x05,
 	SMU_MSG_LOG_START		= 0x06,
@@ -470,6 +471,29 @@
 	    0, "Total time spent in software DRIPS (SW DRIPS) (us)");
 }
 
+static int
+amdsmu_enter(device_t dev)
+{
+
+	if (amdsmu_cmd(dev, SMU_MSG_SLEEP_HINT, true, NULL) != 0) {
+		device_printf(dev, "failed to hint to SMU to enter sleep");
+		return (-1);
+	}
+	return (0);
+}
+
+static int
+amdsmu_exit(device_t dev)
+{
+
+	if (amdsmu_cmd(dev, SMU_MSG_SLEEP_HINT, false, NULL) != 0) {
+		device_printf(dev, "failed to hint to SMU to exit sleep");
+		return (-1);
+	}
+	amdsmu_dump_metrics(dev);
+	return (0);
+}
+
 static int
 amdsmu_attach(device_t dev)
 {
@@ -550,6 +574,8 @@
 	DEVMETHOD(device_probe,		amdsmu_probe),
 	DEVMETHOD(device_attach,	amdsmu_attach),
 	DEVMETHOD(device_detach,	amdsmu_detach),
+	DEVMETHOD(device_amdsmu_enter_sleep,	amdsmu_enter),
+	DEVMETHOD(device_amdsmu_exit_sleep,	amdsmu_exit),
 	DEVMETHOD_END
 };
 
diff --git a/sys/kern/bus_if.m b/sys/kern/bus_if.m
--- a/sys/kern/bus_if.m
+++ b/sys/kern/bus_if.m
@@ -31,7 +31,7 @@
 
 /**
  * @defgroup BUS bus - KObj methods for drivers of devices with children
- * @brief A set of methods required device drivers that support
+ * @brief A set of methods required for device drivers that support
  * child devices.
  * @{
  */
diff --git a/sys/kern/device_if.m b/sys/kern/device_if.m
--- a/sys/kern/device_if.m
+++ b/sys/kern/device_if.m
@@ -358,3 +358,34 @@
 METHOD void * register {
 	device_t dev;
 } DEFAULT null_register;
+
+/**
+ * @brief Hint to the AMD SMU that we intend to enter sleep.
+ *
+ * Must be called by the ACPI sleep routine during s2idle before actually
+ * idling the CPU but after calling the SPMC entry function, if one was set on
+ * the ACPI softc.
+ *
+ * @param dev		the amdsmu device to hint entry to
+ *
+ * @retval 0		success
+ * @retval ETIMEDOUT	timed out trying to send a message to the SMU
+ */
+METHOD int amdsmu_enter_sleep {
+	device_t dev;
+};
+
+/**
+ * @brief Hint to the AMD SMU that we are exiting sleep.
+ *
+ * Must be called by the ACPI sleep routine during s2idle after waking the CPU
+ * but before calling the SPMC exit function, if one was set on the ACPI softc.
+ *
+ * @param dev		the amdsmu device to hint exit to
+ *
+ * @retval 0		success
+ * @retval ETIMEDOUT	timed out trying to send a message to the SMU
+ */
+METHOD int amdsmu_exit_sleep {
+	device_t dev;
+};