GIC: Add API to set interrupt priority

API documentation updated.

Change-Id: Ib700eb1b8ca65503aeed0ac4ce0e7b934df67ff9
Co-authored-by: Yousuf A <yousuf.sait@arm.com>
Signed-off-by: Jeenu Viswambharan <jeenu.viswambharan@arm.com>

docs/platform-interrupt-controller-API.rst

@@ -111,6 +111,21 @@ In case of ARM standard platforms using GIC, the implementation of the API
 writes to GIC *Clear Enable Register* to disable the interrupt, and inserts
 barrier to make memory updates visible afterwards.
 
+Function: void plat_ic_set_interrupt_priority(unsigned int id, unsigned int priority); [optional]
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+::
+
+    Argument : unsigned int
+    Argument : unsigned int
+    Return   : void
+
+This API should set the priority of the interrupt specified by first parameter
+``id`` to the value set by the second parameter ``priority``.
+
+In case of ARM standard platforms using GIC, the implementation of the API
+writes to GIC *Priority Register* set interrupt priority.
+
 ----
 
 *Copyright (c) 2017, ARM Limited and Contributors. All rights reserved.*

drivers/arm/gic/v2/gicv2_main.c

@@ -322,3 +322,16 @@ void gicv2_disable_interrupt(unsigned int id)
 	gicd_set_icenabler(driver_data->gicd_base, id);
 	dsbishst();
 }
+
+/*******************************************************************************
+ * This function sets the interrupt priority as supplied for the given interrupt
+ * id.
+ ******************************************************************************/
+void gicv2_set_interrupt_priority(unsigned int id, unsigned int priority)
+{
+	assert(driver_data);
+	assert(driver_data->gicd_base);
+	assert(id <= MAX_SPI_ID);
+
+	gicd_set_ipriorityr(driver_data->gicd_base, id, priority);
+}

drivers/arm/gic/v3/gicv3_main.c

@@ -869,3 +869,26 @@ void gicv3_disable_interrupt(unsigned int id, unsigned int proc_num)
 
 	dsbishst();
 }
+
+/*******************************************************************************
+ * This function sets the interrupt priority as supplied for the given interrupt
+ * id.
+ ******************************************************************************/
+void gicv3_set_interrupt_priority(unsigned int id, unsigned int proc_num,
+		unsigned int priority)
+{
+	uintptr_t gicr_base;
+
+	assert(gicv3_driver_data);
+	assert(gicv3_driver_data->gicd_base);
+	assert(proc_num < gicv3_driver_data->rdistif_num);
+	assert(gicv3_driver_data->rdistif_base_addrs);
+	assert(id <= MAX_SPI_ID);
+
+	if (id < MIN_SPI_ID) {
+		gicr_base = gicv3_driver_data->rdistif_base_addrs[proc_num];
+		gicr_set_ipriorityr(gicr_base, id, priority);
+	} else {
+		gicd_set_ipriorityr(gicv3_driver_data->gicd_base, id, priority);
+	}
+}

include/drivers/arm/gicv2.h

@@ -150,6 +150,7 @@ void gicv2_set_pe_target_mask(unsigned int proc_num);
 unsigned int gicv2_get_interrupt_active(unsigned int id);
 void gicv2_enable_interrupt(unsigned int id);
 void gicv2_disable_interrupt(unsigned int id);
+void gicv2_set_interrupt_priority(unsigned int id, unsigned int priority);
 
 #endif /* __ASSEMBLY__ */
 #endif /* __GICV2_H__ */

include/drivers/arm/gicv3.h

@@ -353,6 +353,8 @@ unsigned int gicv3_get_running_priority(void);
 unsigned int gicv3_get_interrupt_active(unsigned int id, unsigned int proc_num);
 void gicv3_enable_interrupt(unsigned int id, unsigned int proc_num);
 void gicv3_disable_interrupt(unsigned int id, unsigned int proc_num);
+void gicv3_set_interrupt_priority(unsigned int id, unsigned int proc_num,
+		unsigned int priority);
 
 #endif /* __ASSEMBLY__ */
 #endif /* __GICV3_H__ */

include/plat/common/platform.h

@@ -79,6 +79,7 @@ int plat_ic_is_sgi(unsigned int id);
 unsigned int plat_ic_get_interrupt_active(unsigned int id);
 void plat_ic_disable_interrupt(unsigned int id);
 void plat_ic_enable_interrupt(unsigned int id);
+void plat_ic_set_interrupt_priority(unsigned int id, unsigned int priority);
 
 /*******************************************************************************
  * Optional common functions (may be overridden)

plat/common/plat_gicv2.c

@@ -27,6 +27,7 @@
 #pragma weak plat_ic_get_interrupt_active
 #pragma weak plat_ic_enable_interrupt
 #pragma weak plat_ic_disable_interrupt
+#pragma weak plat_ic_set_interrupt_priority
 
 /*
  * This function returns the highest priority pending interrupt at
@@ -165,3 +166,8 @@ void plat_ic_disable_interrupt(unsigned int id)
 {
 	gicv2_disable_interrupt(id);
 }
+
+void plat_ic_set_interrupt_priority(unsigned int id, unsigned int priority)
+{
+	gicv2_set_interrupt_priority(id, priority);
+}

plat/common/plat_gicv3.c

@@ -33,6 +33,7 @@
 #pragma weak plat_ic_get_interrupt_active
 #pragma weak plat_ic_enable_interrupt
 #pragma weak plat_ic_disable_interrupt
+#pragma weak plat_ic_set_interrupt_priority
 
 CASSERT((INTR_TYPE_S_EL1 == INTR_GROUP1S) &&
 	(INTR_TYPE_NS == INTR_GROUP1NS) &&
@@ -198,6 +199,11 @@ void plat_ic_disable_interrupt(unsigned int id)
 {
 	gicv3_disable_interrupt(id, plat_my_core_pos());
 }
+
+void plat_ic_set_interrupt_priority(unsigned int id, unsigned int priority)
+{
+	gicv3_set_interrupt_priority(id, plat_my_core_pos(), priority);
+}
 #endif
 #ifdef IMAGE_BL32