diff --git a/services/std_svc/spmd/spmd_private.h b/services/std_svc/spmd/spmd_private.h
new file mode 100644
index 0000000..61b479a
--- /dev/null
+++ b/services/std_svc/spmd/spmd_private.h
@@ -0,0 +1,78 @@
+/*
+ * Copyright (c) 2019-2020, ARM Limited and Contributors. All rights reserved.
+ *
+ * SPDX-License-Identifier: BSD-3-Clause
+ */
+
+#ifndef SPMD_PRIVATE_H
+#define SPMD_PRIVATE_H
+
+#include <context.h>
+
+/*******************************************************************************
+ * Constants that allow assembler code to preserve callee-saved registers of the
+ * C runtime context while performing a security state switch.
+ ******************************************************************************/
+#define SPMD_C_RT_CTX_X19		0x0
+#define SPMD_C_RT_CTX_X20		0x8
+#define SPMD_C_RT_CTX_X21		0x10
+#define SPMD_C_RT_CTX_X22		0x18
+#define SPMD_C_RT_CTX_X23		0x20
+#define SPMD_C_RT_CTX_X24		0x28
+#define SPMD_C_RT_CTX_X25		0x30
+#define SPMD_C_RT_CTX_X26		0x38
+#define SPMD_C_RT_CTX_X27		0x40
+#define SPMD_C_RT_CTX_X28		0x48
+#define SPMD_C_RT_CTX_X29		0x50
+#define SPMD_C_RT_CTX_X30		0x58
+
+#define SPMD_C_RT_CTX_SIZE		0x60
+#define SPMD_C_RT_CTX_ENTRIES		(SPMD_C_RT_CTX_SIZE >> DWORD_SHIFT)
+
+#ifndef __ASSEMBLER__
+#include <services/spci_svc.h>
+#include <stdint.h>
+
+/*
+ * Convert a function no. in a FID to a bit position. All function nos. are
+ * between 0 and 0x1f
+ */
+#define SPCI_FNO_TO_BIT_POS(_fid)	(1 << ((_fid) & U(0x1f)))
+
+typedef enum spmc_state {
+	SPMC_STATE_RESET = 0,
+	SPMC_STATE_IDLE
+} spmc_state_t;
+
+/*
+ * Data structure used by the SPM dispatcher (SPMD) in EL3 to track context of
+ * the SPM core (SPMC) at the next lower EL.
+ */
+typedef struct spmd_spm_core_context {
+	uint64_t c_rt_ctx;
+	cpu_context_t cpu_ctx;
+	spmc_state_t state;
+} spmd_spm_core_context_t;
+
+/*
+ * Data structure used by the SPM dispatcher (SPMD) in EL3 to track sequence of
+ * SPCI calls from lower ELs.
+ *
+ * next_smc_bit_map: Per-cpu bit map of SMCs from each world that are expected
+ *                   next.
+ */
+typedef struct spmd_spci_context {
+	uint32_t next_smc_bit_map[2];
+} spmd_spci_context_t;
+
+/* Functions used to enter/exit a Secure Partition synchronously */
+uint64_t spmd_spm_core_sync_entry(spmd_spm_core_context_t *ctx);
+__dead2 void spmd_spm_core_sync_exit(uint64_t rc);
+
+/* Assembly helpers */
+uint64_t spmd_spm_core_enter(uint64_t *c_rt_ctx);
+void __dead2 spmd_spm_core_exit(uint64_t c_rt_ctx, uint64_t ret);
+
+#endif /* __ASSEMBLER__ */
+
+#endif /* SPMD_PRIVATE_H */