diff --git a/plat/arm/css/drivers/mhu/css_mhu.c b/plat/arm/css/drivers/mhu/css_mhu.c
index 30492a6..7b33317 100644
--- a/plat/arm/css/drivers/mhu/css_mhu.c
+++ b/plat/arm/css/drivers/mhu/css_mhu.c
@@ -81,7 +81,7 @@
 	arm_lock_release();
 }
 
-void mhu_secure_init(void)
+void __init mhu_secure_init(void)
 {
 	arm_lock_init();
 
@@ -93,7 +93,7 @@
 	assert(mmio_read_32(PLAT_CSS_MHU_BASE + CPU_INTR_S_STAT) == 0);
 }
 
-void plat_arm_pwrc_setup(void)
+void __init plat_arm_pwrc_setup(void)
 {
 	mhu_secure_init();
 }
diff --git a/plat/arm/css/drivers/scp/css_pm_scmi.c b/plat/arm/css/drivers/scp/css_pm_scmi.c
index 258c1c2..d280101 100644
--- a/plat/arm/css/drivers/scp/css_pm_scmi.c
+++ b/plat/arm/css/drivers/scp/css_pm_scmi.c
@@ -328,7 +328,7 @@
 	return 0;
 }
 
-void plat_arm_pwrc_setup(void)
+void __init plat_arm_pwrc_setup(void)
 {
 	channel.info = &plat_css_scmi_plat_info;
 	channel.lock = ARM_LOCK_GET_INSTANCE;
diff --git a/plat/arm/css/sgi/sgi_interconnect.c b/plat/arm/css/sgi/sgi_interconnect.c
index f4e7676..325b5b1 100644
--- a/plat/arm/css/sgi/sgi_interconnect.c
+++ b/plat/arm/css/sgi/sgi_interconnect.c
@@ -17,7 +17,7 @@
 /******************************************************************************
  * Helper function to initialize ARM interconnect driver.
  *****************************************************************************/
-void plat_arm_interconnect_init(void)
+void __init plat_arm_interconnect_init(void)
 {
 }
 
diff --git a/plat/arm/css/sgm/sgm_interconnect.c b/plat/arm/css/sgm/sgm_interconnect.c
index 301ea84..5b45341 100644
--- a/plat/arm/css/sgm/sgm_interconnect.c
+++ b/plat/arm/css/sgm/sgm_interconnect.c
@@ -4,6 +4,8 @@
  * SPDX-License-Identifier: BSD-3-Clause
  */
 
+#include <cdefs.h>
+
 /*
  * As the SGM platform supports FCM (with automatic interconnect
  * enter/exit), we should not do anything in these interface functions.
@@ -13,7 +15,7 @@
 /******************************************************************************
  * Helper function to initialize ARM interconnect driver.
  *****************************************************************************/
-void plat_arm_interconnect_init(void)
+void __init plat_arm_interconnect_init(void)
 {
 }