Introduce ARM platform APIs for GICv3 Redistributor

As with other ARM platform GIC APIs, these directly invoke the GICv3
driver APIs for Redistributor power management.

For the sake of uniform GIC API, empty stubs are placed for those GIC
drivers that lack Redistributor component.

Change-Id: Iad0d760d4dbca790998f7768cda621ff3b15a864
Signed-off-by: Jeenu Viswambharan <jeenu.viswambharan@arm.com>

include/plat/arm/common/plat_arm.h

@@ -194,6 +194,8 @@ void plat_arm_gic_driver_init(void);
 void plat_arm_gic_init(void);
 void plat_arm_gic_cpuif_enable(void);
 void plat_arm_gic_cpuif_disable(void);
+void plat_arm_gic_redistif_on(void);
+void plat_arm_gic_redistif_off(void);
 void plat_arm_gic_pcpu_init(void);
 void plat_arm_security_setup(void);
 void plat_arm_pwrc_setup(void);

plat/arm/common/arm_gicv2.c

@@ -97,3 +97,17 @@ void plat_arm_gic_pcpu_init(void)
 {
 	gicv2_pcpu_distif_init();
 }
+
+/******************************************************************************
+ * Stubs for Redistributor power management. Although GICv2 doesn't have
+ * Redistributor interface, these are provided for the sake of uniform GIC API
+ *****************************************************************************/
+void plat_arm_gic_redistif_on(void)
+{
+	return;
+}
+
+void plat_arm_gic_redistif_off(void)
+{
+	return;
+}

plat/arm/common/arm_gicv3.c

@@ -43,6 +43,8 @@
 #pragma weak plat_arm_gic_cpuif_enable
 #pragma weak plat_arm_gic_cpuif_disable
 #pragma weak plat_arm_gic_pcpu_init
+#pragma weak plat_arm_gic_redistif_on
+#pragma weak plat_arm_gic_redistif_off
 
 /* The GICv3 driver only needs to be initialized in EL3 */
 static uintptr_t rdistif_base_addrs[PLATFORM_CORE_COUNT];
@@ -115,3 +117,16 @@ void plat_arm_gic_pcpu_init(void)
 {
 	gicv3_rdistif_init(plat_my_core_pos());
 }
+
+/******************************************************************************
+ * ARM common helpers to power GIC redistributor interface
+ *****************************************************************************/
+void plat_arm_gic_redistif_on(void)
+{
+	gicv3_rdistif_on(plat_my_core_pos());
+}
+
+void plat_arm_gic_redistif_off(void)
+{
+	gicv3_rdistif_off(plat_my_core_pos());
+}

plat/arm/common/arm_gicv3_legacy.c

@@ -94,3 +94,17 @@ void plat_arm_gic_pcpu_init(void)
 {
 	arm_gic_pcpu_distif_setup();
 }
+
+/******************************************************************************
+ * Stubs for Redistributor power management. Although legacy configuration isn't
+ * supported, these are provided for the sake of uniform GIC API
+ *****************************************************************************/
+void plat_arm_gic_redistif_on(void)
+{
+	return;
+}
+
+void plat_arm_gic_redistif_off(void)
+{
+	return;
+}