GIC: Add API to set interrupt routing

SPIs can be routed to either a specific PE, or to any one of all
available PEs.

API documentation updated.

Change-Id: I28675f634568aaf4ea1aa8aa7ebf25b419a963ed
Co-authored-by: Yousuf A <yousuf.sait@arm.com>
Signed-off-by: Jeenu Viswambharan <jeenu.viswambharan@arm.com>

docs/platform-interrupt-controller-API.rst

@@ -217,6 +217,32 @@ In case of ARM standard platforms using GIC, the implementation of the API
 inserts barrier to make memory updates visible before raising SGI, then writes
 to appropriate *SGI Register* in order to raise the EL3 SGI.
 
+Function: void plat_ic_set_spi_routing(unsigned int id, unsigned int routing_mode, u_register_t mpidr); [optional]
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+::
+
+    Argument : unsigned int
+    Argument : unsigned int
+    Argument : u_register_t
+    Return   : void
+
+This API should set the routing mode of Share Peripheral Interrupt (SPI)
+specified by first parameter ``id`` to that specified by the second parameter
+``routing_mode``.
+
+The ``routing_mode`` parameter can be one of:
+
+- ``INTR_ROUTING_MODE_ANY`` means the interrupt can be routed to any PE in the
+  system. The ``mpidr`` parameter is ignored in this case.
+
+- ``INTR_ROUTING_MODE_PE`` means the interrupt is routed to the PE whose MPIDR
+  value is specified by the parameter ``mpidr``.
+
+In case of ARM standard platforms using GIC, the implementation of the API
+writes to the GIC *Target Register* (GICv2) or *Route Register* (GICv3) to set
+the routing.
+
 ----
 
 *Copyright (c) 2017, ARM Limited and Contributors. All rights reserved.*

drivers/arm/gic/v2/gicv2_helpers.c

@@ -1,5 +1,5 @@
 /*
- * 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
  */
@@ -72,15 +72,6 @@ void gicd_write_spendsgir(uintptr_t base, unsigned int id, unsigned int val)
 	mmio_write_32(base + GICD_SPENDSGIR + (n << 2), val);
 }
 
-/*
- * Accessor to write the GIC Distributor ITARGETSR corresponding to the
- * interrupt `id`.
- */
-void gicd_set_itargetsr(uintptr_t base, unsigned int id, unsigned int target)
-{
-	mmio_write_8(base + GICD_ITARGETSR + id, target & GIC_TARGET_CPU_MASK);
-}
-
 /*******************************************************************************
  * Get the current CPU bit mask from GICD_ITARGETSR0
  ******************************************************************************/

drivers/arm/gic/v2/gicv2_main.c

@@ -403,3 +403,38 @@ void gicv2_raise_sgi(int sgi_num, int proc_num)
 	dsbishst();
 	gicd_write_sgir(driver_data->gicd_base, sgir_val);
 }
+
+/*******************************************************************************
+ * This function sets the interrupt routing for the given SPI interrupt id.
+ * The interrupt routing is specified in routing mode. The proc_num parameter is
+ * linear index of the PE to target SPI. When proc_num < 0, the SPI may target
+ * all PEs.
+ ******************************************************************************/
+void gicv2_set_spi_routing(unsigned int id, int proc_num)
+{
+	int target;
+
+	assert(driver_data);
+	assert(driver_data->gicd_base);
+
+	assert(id >= MIN_SPI_ID && id <= MAX_SPI_ID);
+
+	/*
+	 * Target masks array must have been supplied, and the core position
+	 * should be valid.
+	 */
+	assert(driver_data->target_masks);
+	assert(proc_num < GICV2_MAX_TARGET_PE);
+	assert(proc_num < driver_data->target_masks_num);
+
+	if (proc_num < 0) {
+		/* Target all PEs */
+		target = GIC_TARGET_CPU_MASK;
+	} else {
+		/* Don't route interrupt if the mask hasn't been populated */
+		target = driver_data->target_masks[proc_num];
+		assert(target != 0);
+	}
+
+	gicd_set_itargetsr(driver_data->gicd_base, id, target);
+}

drivers/arm/gic/v2/gicv2_private.h

@@ -34,6 +34,17 @@ static inline unsigned int gicd_read_pidr2(uintptr_t base)
 /*******************************************************************************
  * GIC Distributor interface accessors for writing entire registers
  ******************************************************************************/
+static inline unsigned int gicd_get_itargetsr(uintptr_t base, unsigned int id)
+{
+	return mmio_read_8(base + GICD_ITARGETSR + id);
+}
+
+static inline void gicd_set_itargetsr(uintptr_t base, unsigned int id,
+		unsigned int target)
+{
+	mmio_write_8(base + GICD_ITARGETSR + id, target & GIC_TARGET_CPU_MASK);
+}
+
 static inline void gicd_write_sgir(uintptr_t base, unsigned int val)
 {
 	mmio_write_32(base + GICD_SGIR, val);

drivers/arm/gic/v3/gicv3_main.c

@@ -999,3 +999,41 @@ void gicv3_raise_secure_g0_sgi(int sgi_num, u_register_t target)
 	write_icc_sgi0r_el1(sgi_val);
 	isb();
 }
+
+/*******************************************************************************
+ * This function sets the interrupt routing for the given SPI interrupt id.
+ * The interrupt routing is specified in routing mode and mpidr.
+ *
+ * The routing mode can be either of:
+ *  - GICV3_IRM_ANY
+ *  - GICV3_IRM_PE
+ *
+ * The mpidr is the affinity of the PE to which the interrupt will be routed,
+ * and is ignored for routing mode GICV3_IRM_ANY.
+ ******************************************************************************/
+void gicv3_set_spi_routing(unsigned int id, unsigned int irm, u_register_t mpidr)
+{
+	unsigned long long aff;
+	uint64_t router;
+
+	assert(gicv3_driver_data);
+	assert(gicv3_driver_data->gicd_base);
+
+	assert((irm == GICV3_IRM_ANY) || (irm == GICV3_IRM_PE));
+	assert(id >= MIN_SPI_ID && id <= MAX_SPI_ID);
+
+	aff = gicd_irouter_val_from_mpidr(mpidr, irm);
+	gicd_write_irouter(gicv3_driver_data->gicd_base, id, aff);
+
+	/*
+	 * In implementations that do not require 1 of N distribution of SPIs,
+	 * IRM might be RAZ/WI. Read back and verify IRM bit.
+	 */
+	if (irm == GICV3_IRM_ANY) {
+		router = gicd_read_irouter(gicv3_driver_data->gicd_base, id);
+		if (!((router >> IROUTER_IRM_SHIFT) & IROUTER_IRM_MASK)) {
+			ERROR("GICv3 implementation doesn't support routing ANY\n");
+			panic();
+		}
+	}
+}

include/bl31/interrupt_mgmt.h

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2014, ARM Limited and Contributors. All rights reserved.
+ * Copyright (c) 2014-2017, ARM Limited and Contributors. All rights reserved.
  *
  * SPDX-License-Identifier: BSD-3-Clause
  */
@@ -17,6 +17,11 @@
 #define INTR_TYPE_NS			U(2)
 #define MAX_INTR_TYPES			U(3)
 #define INTR_TYPE_INVAL			MAX_INTR_TYPES
+
+/* Interrupt routing modes */
+#define INTR_ROUTING_MODE_PE		0
+#define INTR_ROUTING_MODE_ANY		1
+
 /*
  * Constant passed to the interrupt handler in the 'id' field when the
  * framework does not read the gic registers to determine the interrupt id.

include/drivers/arm/gic_common.h

@@ -74,6 +74,7 @@
 #define ISACTIVER_SHIFT		5
 #define ICACTIVER_SHIFT		ISACTIVER_SHIFT
 #define IPRIORITYR_SHIFT	2
+#define ITARGETSR_SHIFT		2
 #define ICFGR_SHIFT		4
 #define NSACR_SHIFT		4
 

include/drivers/arm/gicv2.h

@@ -171,6 +171,7 @@ void gicv2_disable_interrupt(unsigned int id);
 void gicv2_set_interrupt_priority(unsigned int id, unsigned int priority);
 void gicv2_set_interrupt_type(unsigned int id, unsigned int type);
 void gicv2_raise_sgi(int sgi_num, int proc_num);
+void gicv2_set_spi_routing(unsigned int id, int proc_num);
 
 #endif /* __ASSEMBLY__ */
 #endif /* __GICV2_H__ */

include/drivers/arm/gicv3.h

@@ -75,6 +75,9 @@
 #define IROUTER_IRM_SHIFT	31
 #define IROUTER_IRM_MASK	0x1
 
+#define GICV3_IRM_PE		0
+#define GICV3_IRM_ANY		1
+
 #define NUM_OF_DIST_REGS	30
 
 /*******************************************************************************
@@ -382,6 +385,8 @@ void gicv3_set_interrupt_priority(unsigned int id, unsigned int proc_num,
 void gicv3_set_interrupt_type(unsigned int id, unsigned int proc_num,
 		unsigned int group);
 void gicv3_raise_secure_g0_sgi(int sgi_num, u_register_t target);
+void gicv3_set_spi_routing(unsigned int id, unsigned int irm,
+		u_register_t mpidr);
 
 #endif /* __ASSEMBLY__ */
 #endif /* __GICV3_H__ */

include/plat/common/platform.h

@@ -83,6 +83,8 @@ int plat_ic_has_interrupt_type(unsigned int type);
 void plat_ic_set_interrupt_type(unsigned int id, unsigned int type);
 void plat_ic_set_interrupt_priority(unsigned int id, unsigned int priority);
 void plat_ic_raise_el3_sgi(int sgi_num, u_register_t target);
+void plat_ic_set_spi_routing(unsigned int id, unsigned int routing_mode,
+		u_register_t mpidr);
 
 /*******************************************************************************
  * Optional common functions (may be overridden)

plat/common/plat_gicv2.c

@@ -31,6 +31,7 @@
 #pragma weak plat_ic_set_interrupt_priority
 #pragma weak plat_ic_set_interrupt_type
 #pragma weak plat_ic_raise_el3_sgi
+#pragma weak plat_ic_set_spi_routing
 
 /*
  * This function returns the highest priority pending interrupt at
@@ -240,3 +241,24 @@ void plat_ic_raise_el3_sgi(int sgi_num, u_register_t target)
 	assert(0);
 #endif
 }
+
+void plat_ic_set_spi_routing(unsigned int id, unsigned int routing_mode,
+		u_register_t mpidr)
+{
+	int proc_num = 0;
+
+	switch (routing_mode) {
+	case INTR_ROUTING_MODE_PE:
+		proc_num = plat_core_pos_by_mpidr(mpidr);
+		assert(proc_num >= 0);
+		break;
+	case INTR_ROUTING_MODE_ANY:
+		/* Bit mask selecting all 8 CPUs as candidates */
+		proc_num = -1;
+		break;
+	default:
+		assert(0);
+	}
+
+	gicv2_set_spi_routing(id, proc_num);
+}

plat/common/plat_gicv3.c

@@ -36,6 +36,7 @@
 #pragma weak plat_ic_set_interrupt_priority
 #pragma weak plat_ic_set_interrupt_type
 #pragma weak plat_ic_raise_el3_sgi
+#pragma weak plat_ic_set_spi_routing
 
 CASSERT((INTR_TYPE_S_EL1 == INTR_GROUP1S) &&
 	(INTR_TYPE_NS == INTR_GROUP1NS) &&
@@ -229,6 +230,26 @@ void plat_ic_raise_el3_sgi(int sgi_num, u_register_t target)
 
 	gicv3_raise_secure_g0_sgi(sgi_num, target);
 }
+
+void plat_ic_set_spi_routing(unsigned int id, unsigned int routing_mode,
+		u_register_t mpidr)
+{
+	unsigned int irm = 0;
+
+	switch (routing_mode) {
+	case INTR_ROUTING_MODE_PE:
+		assert(plat_core_pos_by_mpidr(mpidr) >= 0);
+		irm = GICV3_IRM_PE;
+		break;
+	case INTR_ROUTING_MODE_ANY:
+		irm = GICV3_IRM_ANY;
+		break;
+	default:
+		assert(0);
+	}
+
+	gicv3_set_spi_routing(id, irm, mpidr);
+}
 #endif
 #ifdef IMAGE_BL32