GICv3: Introduce power management APIs for Redistributor

Some GICv3 implementations have provision for power management
operations at Redistributor level. This patch introduces and provides
place-holders for Redistributor power management. The default
implementations are empty stubs, but are weakly bound so as to enable
implementation-specific drivers to override them.

Change-Id: I4fec1358693d3603ca5dce242a2f7f0e730516d8
Signed-off-by: Jeenu Viswambharan <jeenu.viswambharan@arm.com>

drivers/arm/gic/v3/gicv3_main.c

@@ -40,6 +40,13 @@
 static const gicv3_driver_data_t *driver_data;
 static unsigned int gicv2_compat;
 
+/*
+ * Redistributor power operations are weakly bound so that they can be
+ * overridden
+ */
+#pragma weak gicv3_rdistif_off
+#pragma weak gicv3_rdistif_on
+
 /*******************************************************************************
  * This function initialises the ARM GICv3 driver in EL3 with provided platform
  * inputs.
@@ -188,6 +195,9 @@ void gicv3_rdistif_init(unsigned int proc_num)
 
 	assert(IS_IN_EL3());
 
+	/* Power on redistributor */
+	gicv3_rdistif_on(proc_num);
+
 	gicr_base = driver_data->rdistif_base_addrs[proc_num];
 
 	/* Set the default attribute of all SGIs and PPIs */
@@ -210,6 +220,19 @@ void gicv3_rdistif_init(unsigned int proc_num)
 	}
 }
 
+/*******************************************************************************
+ * Functions to perform power operations on GIC Redistributor
+ ******************************************************************************/
+void gicv3_rdistif_off(unsigned int proc_num)
+{
+	return;
+}
+
+void gicv3_rdistif_on(unsigned int proc_num)
+{
+	return;
+}
+
 /*******************************************************************************
  * This function enables the GIC CPU interface of the calling CPU using only
  * system register accesses.

include/drivers/arm/gicv3.h

@@ -259,6 +259,8 @@ typedef struct gicv3_driver_data {
 void gicv3_driver_init(const gicv3_driver_data_t *plat_driver_data);
 void gicv3_distif_init(void);
 void gicv3_rdistif_init(unsigned int proc_num);
+void gicv3_rdistif_on(unsigned int proc_num);
+void gicv3_rdistif_off(unsigned int proc_num);
 void gicv3_cpuif_enable(unsigned int proc_num);
 void gicv3_cpuif_disable(unsigned int proc_num);
 unsigned int gicv3_get_pending_interrupt_type(void);