Introduce interrupt registration framework in BL3-1

This patch introduces a framework for registering interrupts routed to
EL3. The interrupt routing model is governed by the SCR_EL3.IRQ and
FIQ bits and the security state an interrupt is generated in. The
framework recognizes three type of interrupts depending upon which
exception level and security state they should be handled in
i.e. Secure EL1 interrupts, Non-secure interrupts and EL3
interrupts. It provides an API and macros that allow a runtime service
to register an handler for a type of interrupt and specify the routing
model. The framework validates the routing model and uses the context
management framework to ensure that it is applied to the SCR_EL3 prior
to entry into the target security state. It saves the handler in
internal data structures. An API is provided to retrieve the handler
when an interrupt of a particular type is asserted. Registration is
expected to be done once by the primary CPU. The same handler and
routing model is used for all CPUs.

Support for EL3 interrupts will be added to the framework in the
future. A makefile flag has been added to allow the FVP port choose
between ARM GIC v2 and v3 support in EL3. The latter version is
currently unsupported.

A framework for handling interrupts in BL3-1 will be introduced in
subsequent patches. The default routing model in the absence of any
handlers expects no interrupts to be routed to EL3.

Change-Id: Idf7c023b34fcd4800a5980f2bef85e4b5c29e649

1 files changed, 128 insertions, 0 deletions

diff --git a/include/bl31/interrupt_mgmt.h b/include/bl31/interrupt_mgmt.h
new file mode 100644
index 0000000..0b24f39
--- /dev/null
+++ b/include/bl31/interrupt_mgmt.h
@@ -0,0 +1,128 @@
+/*
+ * Copyright (c) 2014, ARM Limited and Contributors. All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *
+ * Redistributions of source code must retain the above copyright notice, this
+ * list of conditions and the following disclaimer.
+ *
+ * Redistributions in binary form must reproduce the above copyright notice,
+ * this list of conditions and the following disclaimer in the documentation
+ * and/or other materials provided with the distribution.
+ *
+ * Neither the name of ARM nor the names of its contributors may be used
+ * to endorse or promote products derived from this software without specific
+ * prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+ * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
+ * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+ * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+ * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+ * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+ * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#ifndef __INTERRUPT_MGMT_H__
+#define __INTERRUPT_MGMT_H__
+
+#include <arch.h>
+
+/*******************************************************************************
+ * Constants for the types of interrupts recognised by the IM framework
+ ******************************************************************************/
+#define INTR_TYPE_S_EL1			0
+#define INTR_TYPE_EL3			1
+#define INTR_TYPE_NS			2
+#define MAX_INTR_TYPES			3
+#define INTR_TYPE_INVAL			MAX_INTR_TYPES
+/*
+ * Constant passed to the interrupt handler in the 'id' field when the
+ * framework does not read the gic registers to determine the interrupt id.
+ */
+#define INTR_ID_UNAVAILABLE		0xFFFFFFFF
+
+
+/*******************************************************************************
+ * Mask for _both_ the routing model bits in the 'flags' parameter and
+ * constants to define the valid routing models for each supported interrupt
+ * type
+ ******************************************************************************/
+#define INTR_RM_FLAGS_SHIFT		0x0
+#define INTR_RM_FLAGS_MASK		0x3
+/* Routed to EL3 from NS. Taken to S-EL1 from Secure */
+#define INTR_SEL1_VALID_RM0		0x2
+/* Routed to EL3 from NS and Secure */
+#define INTR_SEL1_VALID_RM1		0x3
+/* Routed to EL1/EL2 from NS and to S-EL1 from Secure */
+#define INTR_NS_VALID_RM0		0x0
+/* Routed to EL1/EL2 from NS and to EL3 from Secure */
+#define INTR_NS_VALID_RM1		0x1
+
+
+/*******************************************************************************
+ * Constants for the _individual_ routing model bits in the 'flags' field for
+ * each interrupt type and mask to validate the 'flags' parameter while
+ * registering an interrupt handler
+ ******************************************************************************/
+#define INTR_TYPE_FLAGS_MASK		0xFFFFFFFC
+
+#define INTR_RM_FROM_SEC_SHIFT		SECURE		/* BIT[0] */
+#define INTR_RM_FROM_NS_SHIFT		NON_SECURE	/* BIT[1] */
+#define INTR_RM_FROM_FLAG_MASK		1
+#define get_interrupt_rm_flag(flag, ss)	(((flag >> INTR_RM_FLAGS_SHIFT) >> ss) \
+					 & INTR_RM_FROM_FLAG_MASK)
+#define set_interrupt_rm_flag(flag, ss)	(flag |= 1 << ss)
+#define clr_interrupt_rm_flag(flag, ss)	(flag &= ~(1 << ss))
+
+
+/*******************************************************************************
+ * Macros to validate the routing model bits in the 'flags' for a type
+ * of interrupt. If the model does not match one of the valid masks
+ * -EINVAL is returned.
+ ******************************************************************************/
+#define validate_sel1_interrupt_rm(x)	(x == INTR_SEL1_VALID_RM0 ? 0 : \
+					 (x == INTR_SEL1_VALID_RM1 ? 0 :\
+					  -EINVAL))
+
+#define validate_ns_interrupt_rm(x)	(x == INTR_NS_VALID_RM0 ? 0 : \
+					 (x == INTR_NS_VALID_RM1 ? 0 :\
+					  -EINVAL))
+
+/*******************************************************************************
+ * Macros to set the 'flags' parameter passed to an interrupt type handler. Only
+ * the flag to indicate the security state when the exception was generated is
+ * supported.
+ ******************************************************************************/
+#define INTR_SRC_SS_FLAG_SHIFT		0		/* BIT[0] */
+#define INTR_SRC_SS_FLAG_MASK		1
+#define set_interrupt_src_ss(flag, val)	(flag |= val << INTR_SRC_SS_FLAG_SHIFT)
+#define clr_interrupt_src_ss(flag)	(flag &= ~(1 << INTR_SRC_SS_FLAG_SHIFT))
+#define get_interrupt_src_ss(flag)	((flag >> INTR_SRC_SS_FLAG_SHIFT) & \
+					 INTR_SRC_SS_FLAG_MASK)
+
+#ifndef __ASSEMBLY__
+
+/* Prototype for defining a handler for an interrupt type */
+typedef uint64_t (*interrupt_type_handler_t)(uint32_t id,
+					     uint32_t flags,
+					     void *handle,
+					     void *cookie);
+
+/*******************************************************************************
+ * Function & variable prototypes
+ ******************************************************************************/
+extern uint32_t get_scr_el3_from_routing_model(uint32_t security_state);
+extern int32_t set_routing_model(uint32_t type, uint32_t flags);
+extern int32_t register_interrupt_type_handler(uint32_t type,
+					       interrupt_type_handler_t handler,
+					       uint32_t flags);
+extern interrupt_type_handler_t get_interrupt_type_handler(uint32_t interrupt_type);
+
+#endif /*__ASSEMBLY__*/
+#endif /* __INTERRUPT_MGMT_H__ */