diff --git a/sys/x86/cpufreq/hwpstate_amd.c b/sys/x86/cpufreq/hwpstate_amd.c
--- a/sys/x86/cpufreq/hwpstate_amd.c
+++ b/sys/x86/cpufreq/hwpstate_amd.c
@@ -161,23 +161,9 @@
 static int	hwpstate_goto_pstate(device_t dev, int pstate_id);
 
 static int	hwpstate_verbose;
-SYSCTL_INT(_debug, OID_AUTO, hwpstate_verbose, CTLFLAG_RWTUN,
-    &hwpstate_verbose, 0, "Debug hwpstate");
-
 static int	hwpstate_verify;
-SYSCTL_INT(_debug, OID_AUTO, hwpstate_verify, CTLFLAG_RWTUN,
-    &hwpstate_verify, 0, "Verify P-state after setting");
-
 static bool	hwpstate_pstate_limit;
-SYSCTL_BOOL(_debug, OID_AUTO, hwpstate_pstate_limit, CTLFLAG_RWTUN,
-    &hwpstate_pstate_limit, 0,
-    "If enabled (1), limit administrative control of P-states to the value in "
-    "CurPstateLimit");
-
 static bool hwpstate_pkg_ctrl_enable = true;
-SYSCTL_BOOL(_machdep, OID_AUTO, hwpstate_pkg_ctrl, CTLFLAG_RDTUN,
-    &hwpstate_pkg_ctrl_enable, 0,
-    "Set 1 (default) to enable package-level control, 0 to disable");
 
 static device_method_t hwpstate_methods[] = {
 	/* Device interface */
@@ -376,7 +362,44 @@
 	sizeof(struct hwpstate_softc),
 };
 
-DRIVER_MODULE(hwpstate, cpu, hwpstate_driver, 0, 0);
+static struct sysctl_ctx_list sysctl_ctx;
+
+static int
+hwpstate_modevent(struct module *mod, int what, void *arg __unused)
+{
+	if (cpu_vendor_id != CPU_VENDOR_AMD &&
+	    cpu_vendor_id != CPU_VENDOR_HYGON)
+		return (0);
+
+	switch (what) {
+	case MOD_LOAD:
+		sysctl_ctx_init(&sysctl_ctx);
+		SYSCTL_ADD_INT(&sysctl_ctx, SYSCTL_CHILDREN(&sysctl___debug),
+		    OID_AUTO, "hwpstate_verify", CTLFLAG_RWTUN,
+		    &hwpstate_verify, 0, "Verify P-state after setting");
+		SYSCTL_ADD_INT(&sysctl_ctx, SYSCTL_CHILDREN(&sysctl___debug),
+		    OID_AUTO, "hwpstate_verbose", CTLFLAG_RWTUN,
+		    &hwpstate_verbose, 0, "Debug hwpstate");
+		SYSCTL_ADD_BOOL(&sysctl_ctx, SYSCTL_CHILDREN(&sysctl___debug),
+		    OID_AUTO, "hwpstate_pstate_limit", CTLFLAG_RWTUN,
+		    &hwpstate_pstate_limit, 0,
+		    "If enabled (1), limit administrative control of P-states to the value in "
+		    "CurPstateLimit");
+		SYSCTL_ADD_BOOL(&sysctl_ctx, SYSCTL_CHILDREN(&sysctl___machdep),
+		    OID_AUTO, "hwpstate_pkg_ctrl", CTLFLAG_RDTUN,
+		    &hwpstate_pkg_ctrl_enable, 0,
+		    "Set 1 (default) to enable package-level control, 0 to disable");
+		break;
+	case MOD_UNLOAD:
+	case MOD_SHUTDOWN:
+		sysctl_ctx_free(&sysctl_ctx);
+		break;
+	}
+
+	return (0);
+}
+
+DRIVER_MODULE(hwpstate, cpu, hwpstate_driver, hwpstate_modevent, 0);
 
 static int
 hwpstate_amd_iscale(int val, int div)
diff --git a/sys/x86/cpufreq/hwpstate_intel.c b/sys/x86/cpufreq/hwpstate_intel.c
--- a/sys/x86/cpufreq/hwpstate_intel.c
+++ b/sys/x86/cpufreq/hwpstate_intel.c
@@ -55,6 +55,8 @@
 
 extern uint64_t	tsc_freq;
 
+static bool	hwpstate_pkg_ctrl_enable = true;
+
 static int	intel_hwpstate_probe(device_t dev);
 static int	intel_hwpstate_attach(device_t dev);
 static int	intel_hwpstate_detach(device_t dev);
@@ -105,13 +107,34 @@
 	sizeof(struct hwp_softc),
 };
 
-DRIVER_MODULE(hwpstate_intel, cpu, hwpstate_intel_driver, NULL, NULL);
-MODULE_VERSION(hwpstate_intel, 1);
+static struct sysctl_ctx_list sysctl_ctx;
 
-static bool hwpstate_pkg_ctrl_enable = true;
-SYSCTL_BOOL(_machdep, OID_AUTO, hwpstate_pkg_ctrl, CTLFLAG_RDTUN,
-    &hwpstate_pkg_ctrl_enable, 0,
-    "Set 1 (default) to enable package-level control, 0 to disable");
+static int
+hwpstate_modevent(struct module *mod, int what, void *arg __unused)
+{
+	if (cpu_vendor_id != CPU_VENDOR_INTEL)
+		return (0);
+
+	switch (what) {
+	case MOD_LOAD:
+		sysctl_ctx_init(&sysctl_ctx);
+		SYSCTL_ADD_BOOL(&sysctl_ctx, SYSCTL_CHILDREN(&sysctl___machdep),
+		    OID_AUTO, "hwpstate_pkg_ctrl", CTLFLAG_RDTUN,
+		    &hwpstate_pkg_ctrl_enable, 0,
+		    "Set 1 (default) to enable package-level control, 0 to disable");
+		break;
+	case MOD_UNLOAD:
+	case MOD_SHUTDOWN:
+		sysctl_ctx_free(&sysctl_ctx);
+		break;
+	}
+
+	return (0);
+}
+
+DRIVER_MODULE(hwpstate_intel, cpu, hwpstate_intel_driver, hwpstate_modevent,
+    NULL);
+MODULE_VERSION(hwpstate_intel, 1);
 
 static int
 intel_hwp_dump_sysctl_handler(SYSCTL_HANDLER_ARGS)