GIC: Add API to get interrupt active status

API documentation updated.

Change-Id: I6d61785af0d5330930c709de971a904dc7c3516c
Co-authored-by: Yousuf A <yousuf.sait@arm.com>
Signed-off-by: Jeenu Viswambharan <jeenu.viswambharan@arm.com>

docs/platform-interrupt-controller-API.rst

@@ -66,6 +66,21 @@ as a Software Generated Interrupt. Software Generated Interrupts are raised by
 explicit programming by software, and are typically used in inter-PE
 communication. Secure SGIs are reserved for use by Secure world software.
 
+Function: unsigned int plat_ic_get_interrupt_active(unsigned int id); [optional]
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+::
+
+    Argument : unsigned int
+    Return   : int
+
+This API should return the *active* status of the interrupt ID specified by the
+first parameter, ``id``.
+
+In case of ARM standard platforms using GIC, the implementation of the API reads
+the GIC *Set Active Register* to read and return the active status of the
+interrupt.
+
 ----
 
 *Copyright (c) 2017, ARM Limited and Contributors. All rights reserved.*

drivers/arm/gic/common/gic_common.c

 /*
- * Copyright (c) 2015-2016, ARM Limited and Contributors. All rights reserved.
+ * Copyright (c) 2015-2017, ARM Limited and Contributors. All rights reserved.
  *
  * SPDX-License-Identifier: BSD-3-Clause
  */
@@ -273,6 +273,14 @@ void gicd_set_icpendr(uintptr_t base, unsigned int id)
 	gicd_write_icpendr(base, id, (1 << bit_num));
 }
 
+unsigned int gicd_get_isactiver(uintptr_t base, unsigned int id)
+{
+	unsigned int bit_num = id & ((1 << ISACTIVER_SHIFT) - 1);
+	unsigned int reg_val = gicd_read_isactiver(base, id);
+
+	return (reg_val >> bit_num) & 0x1;
+}
+
 void gicd_set_isactiver(uintptr_t base, unsigned int id)
 {
 	unsigned bit_num = id & ((1 << ISACTIVER_SHIFT) - 1);

drivers/arm/gic/common/gic_common_private.h

 /*
- * Copyright (c) 2016, ARM Limited and Contributors. All rights reserved.
+ * Copyright (c) 2016-2017, ARM Limited and Contributors. All rights reserved.
  *
  * SPDX-License-Identifier: BSD-3-Clause
  */
@@ -73,6 +73,7 @@ void gicd_set_isenabler(uintptr_t base, unsigned int id);
 void gicd_set_icenabler(uintptr_t base, unsigned int id);
 void gicd_set_ispendr(uintptr_t base, unsigned int id);
 void gicd_set_icpendr(uintptr_t base, unsigned int id);
+unsigned int gicd_get_isactiver(uintptr_t base, unsigned int id);
 void gicd_set_isactiver(uintptr_t base, unsigned int id);
 void gicd_set_icactiver(uintptr_t base, unsigned int id);
 void gicd_set_ipriorityr(uintptr_t base, unsigned int id, unsigned int pri);

drivers/arm/gic/v2/gicv2_main.c

@@ -275,3 +275,16 @@ void gicv2_set_pe_target_mask(unsigned int proc_num)
 	driver_data->target_masks[proc_num] =
 		gicv2_get_cpuif_id(driver_data->gicd_base);
 }
+
+/*******************************************************************************
+ * This function returns the active status of the interrupt (either because the
+ * state is active, or active and pending).
+ ******************************************************************************/
+unsigned int gicv2_get_interrupt_active(unsigned int id)
+{
+	assert(driver_data);
+	assert(driver_data->gicd_base);
+	assert(id <= MAX_SPI_ID);
+
+	return gicd_get_isactiver(driver_data->gicd_base, id);
+}

drivers/arm/gic/v3/gicv3_helpers.c

 /*
- * Copyright (c) 2015-2016, ARM Limited and Contributors. All rights reserved.
+ * Copyright (c) 2015-2017, ARM Limited and Contributors. All rights reserved.
  *
  * SPDX-License-Identifier: BSD-3-Clause
  */
@@ -171,6 +171,18 @@ void gicr_set_isenabler0(uintptr_t base, unsigned int id)
 	gicr_write_isenabler0(base, (1 << bit_num));
 }
 
+/*
+ * Accessor to set the bit corresponding to interrupt ID in GIC Re-distributor
+ * ISACTIVER0.
+ */
+unsigned int gicr_get_isactiver0(uintptr_t base, unsigned int id)
+{
+	unsigned bit_num = id & ((1 << ISACTIVER_SHIFT) - 1);
+	unsigned int reg_val = gicr_read_isactiver0(base);
+
+	return (reg_val >> bit_num) & 0x1;
+}
+
 /*
  * Accessor to set the byte corresponding to interrupt ID
  * in GIC Re-distributor IPRIORITYR.

drivers/arm/gic/v3/gicv3_main.c

@@ -778,3 +778,30 @@ unsigned int gicv3_get_running_priority(void)
 {
 	return read_icc_rpr_el1();
 }
+
+/*******************************************************************************
+ * This function checks if the interrupt identified by id is active (whether the
+ * state is either active, or active and pending). The proc_num is used if the
+ * interrupt is SGI or PPI and programs the corresponding Redistributor
+ * interface.
+ ******************************************************************************/
+unsigned int gicv3_get_interrupt_active(unsigned int id, unsigned int proc_num)
+{
+	unsigned int value;
+
+	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) {
+		/* For SGIs and PPIs */
+		value = gicr_get_isactiver0(
+				gicv3_driver_data->rdistif_base_addrs[proc_num], id);
+	} else {
+		value = gicd_get_isactiver(gicv3_driver_data->gicd_base, id);
+	}
+
+	return value;
+}

drivers/arm/gic/v3/gicv3_private.h

@@ -67,6 +67,7 @@ void gicr_write_ipriorityr(uintptr_t base, unsigned int id, unsigned int val);
 unsigned int gicd_get_igrpmodr(uintptr_t base, unsigned int id);
 unsigned int gicr_get_igrpmodr0(uintptr_t base, unsigned int id);
 unsigned int gicr_get_igroupr0(uintptr_t base, unsigned int id);
+unsigned int gicr_get_isactiver0(uintptr_t base, unsigned int id);
 void gicd_set_igrpmodr(uintptr_t base, unsigned int id);
 void gicr_set_igrpmodr0(uintptr_t base, unsigned int id);
 void gicr_set_isenabler0(uintptr_t base, unsigned int id);

include/drivers/arm/gicv2.h

@@ -147,6 +147,7 @@ void gicv2_end_of_interrupt(unsigned int id);
 unsigned int gicv2_get_interrupt_group(unsigned int id);
 unsigned int gicv2_get_running_priority(void);
 void gicv2_set_pe_target_mask(unsigned int proc_num);
+unsigned int gicv2_get_interrupt_active(unsigned int id);
 
 #endif /* __ASSEMBLY__ */
 #endif /* __GICV2_H__ */

include/drivers/arm/gicv3.h

@@ -350,6 +350,7 @@ void gicv3_its_save_disable(uintptr_t gits_base, gicv3_its_ctx_t * const its_ctx
 void gicv3_its_restore(uintptr_t gits_base, const gicv3_its_ctx_t * const its_ctx);
 
 unsigned int gicv3_get_running_priority(void);
+unsigned int gicv3_get_interrupt_active(unsigned int id, unsigned int proc_num);
 
 #endif /* __ASSEMBLY__ */
 #endif /* __GICV3_H__ */

include/plat/common/platform.h

@@ -76,6 +76,7 @@ unsigned int plat_ic_get_running_priority(void);
 int plat_ic_is_spi(unsigned int id);
 int plat_ic_is_ppi(unsigned int id);
 int plat_ic_is_sgi(unsigned int id);
+unsigned int plat_ic_get_interrupt_active(unsigned int id);
 
 /*******************************************************************************
  * Optional common functions (may be overridden)

plat/common/plat_gicv2.c

@@ -24,6 +24,7 @@
 #pragma weak plat_ic_is_spi
 #pragma weak plat_ic_is_ppi
 #pragma weak plat_ic_is_sgi
+#pragma weak plat_ic_get_interrupt_active
 
 /*
  * This function returns the highest priority pending interrupt at
@@ -147,3 +148,8 @@ int plat_ic_is_sgi(unsigned int id)
 {
 	return (id >= MIN_SGI_ID) && (id < MIN_PPI_ID);
 }
+
+unsigned int plat_ic_get_interrupt_active(unsigned int id)
+{
+	return gicv2_get_interrupt_active(id);
+}

plat/common/plat_gicv3.c

@@ -30,6 +30,7 @@
 #pragma weak plat_ic_is_spi
 #pragma weak plat_ic_is_ppi
 #pragma weak plat_ic_is_sgi
+#pragma weak plat_ic_get_interrupt_active
 
 CASSERT((INTR_TYPE_S_EL1 == INTR_GROUP1S) &&
 	(INTR_TYPE_NS == INTR_GROUP1NS) &&
@@ -180,6 +181,11 @@ int plat_ic_is_sgi(unsigned int id)
 {
 	return (id >= MIN_SGI_ID) && (id < MIN_PPI_ID);
 }
+
+unsigned int plat_ic_get_interrupt_active(unsigned int id)
+{
+	return gicv3_get_interrupt_active(id, plat_my_core_pos());
+}
 #endif
 #ifdef IMAGE_BL32