diff --git a/include/services/sdei.h b/include/services/sdei.h
new file mode 100644
index 0000000..72eb6d7
--- /dev/null
+++ b/include/services/sdei.h
@@ -0,0 +1,178 @@
+/*
+ * Copyright (c) 2017, ARM Limited and Contributors. All rights reserved.
+ *
+ * SPDX-License-Identifier: BSD-3-Clause
+ */
+
+#ifndef __SDEI_H__
+#define __SDEI_H__
+
+#include <spinlock.h>
+#include <utils_def.h>
+
+/* Range 0xC4000020 - 0xC400003F reserved for SDE 64bit smc calls */
+#define SDEI_VERSION				0xC4000020
+#define SDEI_EVENT_REGISTER			0xC4000021
+#define SDEI_EVENT_ENABLE			0xC4000022
+#define SDEI_EVENT_DISABLE			0xC4000023
+#define SDEI_EVENT_CONTEXT			0xC4000024
+#define SDEI_EVENT_COMPLETE			0xC4000025
+#define SDEI_EVENT_COMPLETE_AND_RESUME		0xC4000026
+
+#define SDEI_EVENT_UNREGISTER			0xC4000027
+#define SDEI_EVENT_STATUS			0xC4000028
+#define SDEI_EVENT_GET_INFO			0xC4000029
+#define SDEI_EVENT_ROUTING_SET			0xC400002A
+#define SDEI_PE_MASK				0xC400002B
+#define SDEI_PE_UNMASK				0xC400002C
+
+#define SDEI_INTERRUPT_BIND			0xC400002D
+#define SDEI_INTERRUPT_RELEASE			0xC400002E
+#define SDEI_EVENT_SIGNAL			0xC400002F
+#define SDEI_FEATURES				0xC4000030
+#define SDEI_PRIVATE_RESET			0xC4000031
+#define SDEI_SHARED_RESET			0xC4000032
+
+/* SDEI_EVENT_REGISTER flags */
+#define SDEI_REGF_RM_ANY	0
+#define SDEI_REGF_RM_PE		1
+
+/* SDEI_EVENT_COMPLETE status flags */
+#define SDEI_EV_HANDLED		0
+#define SDEI_EV_FAILED		1
+
+/* SDE event status values in bit position */
+#define SDEI_STATF_REGISTERED		0
+#define SDEI_STATF_ENABLED		1
+#define SDEI_STATF_RUNNING		2
+
+/* Internal: SDEI flag bit positions */
+#define _SDEI_MAPF_DYNAMIC_SHIFT	1
+#define _SDEI_MAPF_BOUND_SHIFT		2
+#define _SDEI_MAPF_SIGNALABLE_SHIFT	3
+#define _SDEI_MAPF_PRIVATE_SHIFT	4
+#define _SDEI_MAPF_CRITICAL_SHIFT	5
+
+/* SDEI event 0 */
+#define SDEI_EVENT_0	0
+
+/* Placeholder interrupt for dynamic mapping */
+#define SDEI_DYN_IRQ	0
+
+/* SDEI flags */
+
+/*
+ * These flags determine whether or not an event can be associated with an
+ * interrupt. Static events are permanently associated with an interrupt, and
+ * can't be changed at runtime.  Association of dynamic events with interrupts
+ * can be changed at run time using the SDEI_INTERRUPT_BIND and
+ * SDEI_INTERRUPT_RELEASE calls.
+ *
+ * SDEI_MAPF_DYNAMIC only indicates run time configurability, where as
+ * SDEI_MAPF_BOUND indicates interrupt association. For example:
+ *
+ *  - Calling SDEI_INTERRUPT_BIND on a dynamic event will have both
+ *    SDEI_MAPF_DYNAMIC and SDEI_MAPF_BOUND set.
+ *
+ *  - Statically-bound events will always have SDEI_MAPF_BOUND set, and neither
+ *    SDEI_INTERRUPT_BIND nor SDEI_INTERRUPT_RELEASE can be called on them.
+ *
+ * See also the is_map_bound() macro.
+ */
+#define SDEI_MAPF_DYNAMIC	BIT(_SDEI_MAPF_DYNAMIC_SHIFT)
+#define SDEI_MAPF_BOUND		BIT(_SDEI_MAPF_BOUND_SHIFT)
+
+#define SDEI_MAPF_SIGNALABLE	BIT(_SDEI_MAPF_SIGNALABLE_SHIFT)
+#define SDEI_MAPF_PRIVATE	BIT(_SDEI_MAPF_PRIVATE_SHIFT)
+#define SDEI_MAPF_CRITICAL	BIT(_SDEI_MAPF_CRITICAL_SHIFT)
+
+/* Indices of private and shared mappings */
+#define _SDEI_MAP_IDX_PRIV	0
+#define _SDEI_MAP_IDX_SHRD	1
+#define _SDEI_MAP_IDX_MAX	2
+
+/* The macros below are used to identify SDEI calls from the SMC function ID */
+#define SDEI_FID_MASK		U(0xffe0)
+#define SDEI_FID_VALUE		U(0x20)
+#define is_sdei_fid(_fid) \
+	((((_fid) & SDEI_FID_MASK) == SDEI_FID_VALUE) && \
+	 (((_fid >> FUNCID_CC_SHIFT) & FUNCID_CC_MASK) == SMC_64))
+
+#define SDEI_EVENT_MAP(_event, _intr, _flags) \
+	{ \
+		.ev_num = _event, \
+		.intr = _intr, \
+		.map_flags = _flags \
+	}
+
+#define SDEI_SHARED_EVENT(_event, _intr, _flags) \
+	SDEI_EVENT_MAP(_event, _intr, _flags)
+
+#define SDEI_PRIVATE_EVENT(_event, _intr, _flags) \
+	SDEI_EVENT_MAP(_event, _intr, _flags | SDEI_MAPF_PRIVATE)
+
+#define SDEI_DEFINE_EVENT_0(_intr) \
+	SDEI_PRIVATE_EVENT(SDEI_EVENT_0, _intr, SDEI_MAPF_SIGNALABLE)
+
+/*
+ * Declare shared and private entries for each core. Also declare a global
+ * structure containing private and share entries.
+ *
+ * This macro must be used in the same file as the platform SDEI mappings are
+ * declared. Only then would ARRAY_SIZE() yield a meaningful value.
+ */
+#define REGISTER_SDEI_MAP(_private, _shared) \
+	sdei_entry_t sdei_private_event_table \
+		[PLATFORM_CORE_COUNT * ARRAY_SIZE(_private)]; \
+	sdei_entry_t sdei_shared_event_table[ARRAY_SIZE(_shared)]; \
+	const sdei_mapping_t sdei_global_mappings[] = { \
+		[_SDEI_MAP_IDX_PRIV] = { \
+			.map = _private, \
+			.num_maps = ARRAY_SIZE(_private) \
+		}, \
+		[_SDEI_MAP_IDX_SHRD] = { \
+			.map = _shared, \
+			.num_maps = ARRAY_SIZE(_shared) \
+		}, \
+	}
+
+typedef uint8_t sdei_state_t;
+
+/* Runtime data of SDEI event */
+typedef struct sdei_entry {
+	uint64_t ep;		/* Entry point */
+	uint64_t arg;		/* Entry point argument */
+	uint64_t affinity;	/* Affinity of shared event */
+	unsigned int reg_flags;	/* Registration flags */
+
+	/* Event handler states: registered, enabled, running */
+	sdei_state_t state;
+} sdei_entry_t;
+
+/* Mapping of SDEI events to interrupts, and associated data */
+typedef struct sdei_ev_map {
+	int32_t ev_num;		/* Event number */
+	unsigned int intr;	/* Physical interrupt number for a bound map */
+	unsigned int map_flags;	/* Mapping flags, see SDEI_MAPF_* */
+	unsigned int reg_count;	/* Registration count */
+	spinlock_t lock;	/* Per-event lock */
+} sdei_ev_map_t;
+
+typedef struct sdei_mapping {
+	sdei_ev_map_t *map;
+	size_t num_maps;
+} sdei_mapping_t;
+
+/* Handler to be called to handle SDEI smc calls */
+uint64_t sdei_smc_handler(uint32_t smc_fid,
+		uint64_t x1,
+		uint64_t x2,
+		uint64_t x3,
+		uint64_t x4,
+		void *cookie,
+		void *handle,
+		uint64_t flags);
+
+void sdei_init(void);
+
+#endif /* __SDEI_H__ */