spd: dispatcher for interacting with the Trusty TEE

This patch adds the secure payload dispatcher for interacting
with Google's Trusty TEE. Documentation for Trusty can be found
at https://source.android.com/security/trusty

Original authors:
-----------------
* Arve Hjønnevåg <arve@android.com>
* Michael Ryleev <gmar@google.com>

Signed-off-by: Varun Wadekar <vwadekar@nvidia.com>

5 files changed, 658 insertions, 0 deletions

diff --git a/services/spd/trusty/sm_err.h b/services/spd/trusty/sm_err.h
new file mode 100644
index 00000000..d7cddec2
--- /dev/null
+++ b/services/spd/trusty/sm_err.h
@@ -0,0 +1,46 @@
+/*
+ * Copyright (c) 2016, 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 __LIB_SM_SM_ERR_H
+#define __LIB_SM_SM_ERR_H
+
+/* Errors from the secure monitor */
+#define SM_ERR_UNDEFINED_SMC		0xFFFFFFFF /* Unknown SMC (defined by ARM DEN 0028A(0.9.0) */
+#define SM_ERR_INVALID_PARAMETERS	-2
+#define SM_ERR_INTERRUPTED		-3	/* Got interrupted. Call back with restart SMC */
+#define SM_ERR_UNEXPECTED_RESTART	-4	/* Got an restart SMC when we didn't expect it */
+#define SM_ERR_BUSY			-5	/* Temporarily busy. Call back with original args */
+#define SM_ERR_INTERLEAVED_SMC		-6	/* Got a trusted_service SMC when a restart SMC is required */
+#define SM_ERR_INTERNAL_FAILURE		-7	/* Unknown error */
+#define SM_ERR_NOT_SUPPORTED		-8
+#define SM_ERR_NOT_ALLOWED		-9	/* SMC call not allowed */
+#define SM_ERR_END_OF_INPUT		-10
+
+#endif
diff --git a/services/spd/trusty/smcall.h b/services/spd/trusty/smcall.h
new file mode 100644
index 00000000..7e876c89
--- /dev/null
+++ b/services/spd/trusty/smcall.h
@@ -0,0 +1,97 @@
+/*
+ * Copyright (c) 2016, 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 __LIB_SM_SMCALL_H
+#define __LIB_SM_SMCALL_H
+
+#define SMC_NUM_ENTITIES	64
+#define SMC_NUM_ARGS		4
+#define SMC_NUM_PARAMS		(SMC_NUM_ARGS - 1)
+
+#define SMC_IS_FASTCALL(smc_nr)	((smc_nr) & 0x80000000)
+#define SMC_IS_SMC64(smc_nr)	((smc_nr) & 0x40000000)
+#define SMC_ENTITY(smc_nr)	(((smc_nr) & 0x3F000000) >> 24)
+#define SMC_FUNCTION(smc_nr)	((smc_nr) & 0x0000FFFF)
+
+#define SMC_NR(entity, fn, fastcall, smc64) ((((fastcall) & 0x1) << 31) | \
+					     (((smc64) & 0x1) << 30) | \
+					     (((entity) & 0x3F) << 24) | \
+					     ((fn) & 0xFFFF) \
+					    )
+
+#define SMC_FASTCALL_NR(entity, fn)	SMC_NR((entity), (fn), 1, 0)
+#define SMC_STDCALL_NR(entity, fn)	SMC_NR((entity), (fn), 0, 0)
+#define SMC_FASTCALL64_NR(entity, fn)	SMC_NR((entity), (fn), 1, 1)
+#define SMC_STDCALL64_NR(entity, fn)	SMC_NR((entity), (fn), 0, 1)
+
+#define	SMC_ENTITY_ARCH			0	/* ARM Architecture calls */
+#define	SMC_ENTITY_CPU			1	/* CPU Service calls */
+#define	SMC_ENTITY_SIP			2	/* SIP Service calls */
+#define	SMC_ENTITY_OEM			3	/* OEM Service calls */
+#define	SMC_ENTITY_STD			4	/* Standard Service calls */
+#define	SMC_ENTITY_RESERVED		5	/* Reserved for future use */
+#define	SMC_ENTITY_TRUSTED_APP		48	/* Trusted Application calls */
+#define	SMC_ENTITY_TRUSTED_OS		50	/* Trusted OS calls */
+#define SMC_ENTITY_LOGGING              51	/* Used for secure -> nonsecure logging */
+#define	SMC_ENTITY_SECURE_MONITOR	60	/* Trusted OS calls internal to secure monitor */
+
+/* FC = Fast call, SC = Standard call */
+#define SMC_SC_RESTART_LAST	SMC_STDCALL_NR  (SMC_ENTITY_SECURE_MONITOR, 0)
+#define SMC_SC_NOP		SMC_STDCALL_NR  (SMC_ENTITY_SECURE_MONITOR, 1)
+
+/*
+ * Return from secure os to non-secure os with return value in r1
+ */
+#define SMC_SC_NS_RETURN	SMC_STDCALL_NR  (SMC_ENTITY_SECURE_MONITOR, 0)
+
+#define SMC_FC_RESERVED		SMC_FASTCALL_NR (SMC_ENTITY_SECURE_MONITOR, 0)
+#define SMC_FC_FIQ_EXIT		SMC_FASTCALL_NR (SMC_ENTITY_SECURE_MONITOR, 1)
+#define SMC_FC_REQUEST_FIQ	SMC_FASTCALL_NR (SMC_ENTITY_SECURE_MONITOR, 2)
+#define SMC_FC_GET_NEXT_IRQ	SMC_FASTCALL_NR (SMC_ENTITY_SECURE_MONITOR, 3)
+#define SMC_FC_FIQ_ENTER	SMC_FASTCALL_NR (SMC_ENTITY_SECURE_MONITOR, 4)
+
+#define SMC_FC64_SET_FIQ_HANDLER SMC_FASTCALL64_NR(SMC_ENTITY_SECURE_MONITOR, 5)
+#define SMC_FC64_GET_FIQ_REGS	SMC_FASTCALL64_NR (SMC_ENTITY_SECURE_MONITOR, 6)
+
+#define SMC_FC_CPU_SUSPEND	SMC_FASTCALL_NR (SMC_ENTITY_SECURE_MONITOR, 7)
+#define SMC_FC_CPU_RESUME	SMC_FASTCALL_NR (SMC_ENTITY_SECURE_MONITOR, 8)
+
+#define SMC_FC_AARCH_SWITCH	SMC_FASTCALL_NR (SMC_ENTITY_SECURE_MONITOR, 9)
+#define SMC_FC_GET_VERSION_STR	SMC_FASTCALL_NR (SMC_ENTITY_SECURE_MONITOR, 10)
+
+/* Trusted OS entity calls */
+#define SMC_SC_VIRTIO_GET_DESCR	  SMC_STDCALL_NR(SMC_ENTITY_TRUSTED_OS, 20)
+#define SMC_SC_VIRTIO_START	  SMC_STDCALL_NR(SMC_ENTITY_TRUSTED_OS, 21)
+#define SMC_SC_VIRTIO_STOP	  SMC_STDCALL_NR(SMC_ENTITY_TRUSTED_OS, 22)
+
+#define SMC_SC_VDEV_RESET	  SMC_STDCALL_NR(SMC_ENTITY_TRUSTED_OS, 23)
+#define SMC_SC_VDEV_KICK_VQ	  SMC_STDCALL_NR(SMC_ENTITY_TRUSTED_OS, 24)
+
+#endif /* __LIB_SM_SMCALL_H */
diff --git a/services/spd/trusty/trusty.c b/services/spd/trusty/trusty.c
new file mode 100644
index 00000000..4962d44a
--- /dev/null
+++ b/services/spd/trusty/trusty.c
@@ -0,0 +1,400 @@
+/*
+ * Copyright (c) 2016, 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.
+ */
+
+#include <assert.h>
+#include <bl_common.h>
+#include <bl31.h>
+#include <context_mgmt.h>
+#include <debug.h>
+#include <interrupt_mgmt.h>
+#include <platform.h>
+#include <runtime_svc.h>
+#include <string.h>
+
+#include "smcall.h"
+#include "sm_err.h"
+
+struct trusty_stack {
+	uint8_t space[PLATFORM_STACK_SIZE] __aligned(16);
+};
+
+struct trusty_cpu_ctx {
+	cpu_context_t	cpu_ctx;
+	void		*saved_sp;
+	uint32_t	saved_security_state;
+	int		fiq_handler_active;
+	uint64_t	fiq_handler_pc;
+	uint64_t	fiq_handler_cpsr;
+	uint64_t	fiq_handler_sp;
+	uint64_t	fiq_pc;
+	uint64_t	fiq_cpsr;
+	uint64_t	fiq_sp_el1;
+	gp_regs_t	fiq_gpregs;
+	struct trusty_stack	secure_stack;
+};
+
+struct args {
+	uint64_t	r0;
+	uint64_t	r1;
+	uint64_t	r2;
+	uint64_t	r3;
+};
+
+struct trusty_cpu_ctx trusty_cpu_ctx[PLATFORM_CORE_COUNT];
+
+struct args trusty_init_context_stack(void **sp, void *new_stack);
+struct args trusty_context_switch_helper(void **sp, uint64_t r0, uint64_t r1,
+					 uint64_t r2, uint64_t r3);
+
+static struct trusty_cpu_ctx *get_trusty_ctx(void)
+{
+	return &trusty_cpu_ctx[plat_my_core_pos()];
+}
+
+static struct args trusty_context_switch(uint32_t security_state, uint64_t r0,
+					 uint64_t r1, uint64_t r2, uint64_t r3)
+{
+	struct args ret;
+	struct trusty_cpu_ctx *ctx = get_trusty_ctx();
+
+	assert(ctx->saved_security_state != security_state);
+
+	cm_el1_sysregs_context_save(security_state);
+
+	ctx->saved_security_state = security_state;
+	ret = trusty_context_switch_helper(&ctx->saved_sp, r0, r1, r2, r3);
+
+	assert(ctx->saved_security_state == !security_state);
+
+	cm_el1_sysregs_context_restore(security_state);
+	cm_set_next_eret_context(security_state);
+
+	return ret;
+}
+
+static uint64_t trusty_fiq_handler(uint32_t id,
+				   uint32_t flags,
+				   void *handle,
+				   void *cookie)
+{
+	struct args ret;
+	struct trusty_cpu_ctx *ctx = get_trusty_ctx();
+
+	assert(!is_caller_secure(flags));
+
+	ret = trusty_context_switch(NON_SECURE, SMC_FC_FIQ_ENTER, 0, 0, 0);
+	if (ret.r0) {
+		SMC_RET0(handle);
+	}
+
+	if (ctx->fiq_handler_active) {
+		INFO("%s: fiq handler already active\n", __func__);
+		SMC_RET0(handle);
+	}
+
+	ctx->fiq_handler_active = 1;
+	memcpy(&ctx->fiq_gpregs, get_gpregs_ctx(handle), sizeof(ctx->fiq_gpregs));
+	ctx->fiq_pc = SMC_GET_EL3(handle, CTX_ELR_EL3);
+	ctx->fiq_cpsr = SMC_GET_EL3(handle, CTX_SPSR_EL3);
+	ctx->fiq_sp_el1 = read_ctx_reg(get_sysregs_ctx(handle), CTX_SP_EL1);
+
+	write_ctx_reg(get_sysregs_ctx(handle), CTX_SP_EL1, ctx->fiq_handler_sp);
+	cm_set_elr_spsr_el3(NON_SECURE, ctx->fiq_handler_pc, ctx->fiq_handler_cpsr);
+
+	SMC_RET0(handle);
+}
+
+static uint64_t trusty_set_fiq_handler(void *handle, uint64_t cpu,
+			uint64_t handler, uint64_t stack)
+{
+	struct trusty_cpu_ctx *ctx;
+
+	if (cpu >= PLATFORM_CORE_COUNT) {
+		ERROR("%s: cpu %ld >= %d\n", __func__, cpu, PLATFORM_CORE_COUNT);
+		return SM_ERR_INVALID_PARAMETERS;
+	}
+
+	ctx = &trusty_cpu_ctx[cpu];
+	ctx->fiq_handler_pc = handler;
+	ctx->fiq_handler_cpsr = SMC_GET_EL3(handle, CTX_SPSR_EL3);
+	ctx->fiq_handler_sp = stack;
+
+	SMC_RET1(handle, 0);
+}
+
+static uint64_t trusty_get_fiq_regs(void *handle)
+{
+	struct trusty_cpu_ctx *ctx = get_trusty_ctx();
+	uint64_t sp_el0 = read_ctx_reg(&ctx->fiq_gpregs, CTX_GPREG_SP_EL0);
+
+	SMC_RET4(handle, ctx->fiq_pc, ctx->fiq_cpsr, sp_el0, ctx->fiq_sp_el1);
+}
+
+static uint64_t trusty_fiq_exit(void *handle, uint64_t x1, uint64_t x2, uint64_t x3)
+{
+	struct args ret;
+	struct trusty_cpu_ctx *ctx = get_trusty_ctx();
+
+	if (!ctx->fiq_handler_active) {
+		NOTICE("%s: fiq handler not active\n", __func__);
+		SMC_RET1(handle, SM_ERR_INVALID_PARAMETERS);
+	}
+
+	ret = trusty_context_switch(NON_SECURE, SMC_FC_FIQ_EXIT, 0, 0, 0);
+	if (ret.r0 != 1) {
+		INFO("%s(%p) SMC_FC_FIQ_EXIT returned unexpected value, %ld\n",
+		       __func__, handle, ret.r0);
+	}
+
+	/*
+	 * Restore register state to state recorded on fiq entry.
+	 *
+	 * x0, sp_el1, pc and cpsr need to be restored because el1 cannot
+	 * restore them.
+	 *
+	 * x1-x4 and x8-x17 need to be restored here because smc_handler64
+	 * corrupts them (el1 code also restored them).
+	 */
+	memcpy(get_gpregs_ctx(handle), &ctx->fiq_gpregs, sizeof(ctx->fiq_gpregs));
+	ctx->fiq_handler_active = 0;
+	write_ctx_reg(get_sysregs_ctx(handle), CTX_SP_EL1, ctx->fiq_sp_el1);
+	cm_set_elr_spsr_el3(NON_SECURE, ctx->fiq_pc, ctx->fiq_cpsr);
+
+	SMC_RET0(handle);
+}
+
+static uint64_t trusty_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)
+{
+	struct args ret;
+
+	if (is_caller_secure(flags)) {
+		if (smc_fid == SMC_SC_NS_RETURN) {
+			ret = trusty_context_switch(SECURE, x1, 0, 0, 0);
+			SMC_RET4(handle, ret.r0, ret.r1, ret.r2, ret.r3);
+		}
+		INFO("%s (0x%x, 0x%lx, 0x%lx, 0x%lx, 0x%lx, %p, %p, 0x%lx) \
+		     cpu %d, unknown smc\n",
+		     __func__, smc_fid, x1, x2, x3, x4, cookie, handle, flags,
+		     plat_my_core_pos());
+		SMC_RET1(handle, SMC_UNK);
+	} else {
+		switch (smc_fid) {
+		case SMC_FC64_SET_FIQ_HANDLER:
+			return trusty_set_fiq_handler(handle, x1, x2, x3);
+		case SMC_FC64_GET_FIQ_REGS:
+			return trusty_get_fiq_regs(handle);
+		case SMC_FC_FIQ_EXIT:
+			return trusty_fiq_exit(handle, x1, x2, x3);
+		default:
+			ret = trusty_context_switch(NON_SECURE, smc_fid, x1,
+				x2, x3);
+			SMC_RET1(handle, ret.r0);
+		}
+	}
+}
+
+static int32_t trusty_init(void)
+{
+	void el3_exit();
+	entry_point_info_t *ep_info;
+	struct trusty_cpu_ctx *ctx = get_trusty_ctx();
+	uint32_t cpu = plat_my_core_pos();
+	int reg_width = GET_RW(read_ctx_reg(get_el3state_ctx(&ctx->cpu_ctx),
+			       CTX_SPSR_EL3));
+
+	ep_info = bl31_plat_get_next_image_ep_info(SECURE);
+
+	cm_el1_sysregs_context_save(NON_SECURE);
+
+	cm_set_context(&ctx->cpu_ctx, SECURE);
+	cm_init_my_context(ep_info);
+
+	/*
+	 * Adjust secondary cpu entry point for 32 bit images to the
+	 * end of exeption vectors
+	 */
+	if ((cpu != 0) && (reg_width == MODE_RW_32)) {
+		INFO("trusty: cpu %d, adjust entry point to 0x%lx\n",
+		     cpu, ep_info->pc + (1U << 5));
+		cm_set_elr_el3(SECURE, ep_info->pc + (1U << 5));
+	}
+
+	cm_el1_sysregs_context_restore(SECURE);
+	cm_set_next_eret_context(SECURE);
+
+	ctx->saved_security_state = ~0; /* initial saved state is invalid */
+	trusty_init_context_stack(&ctx->saved_sp, &ctx->secure_stack);
+
+	trusty_context_switch_helper(&ctx->saved_sp, 0, 0, 0, 0);
+
+	cm_el1_sysregs_context_restore(NON_SECURE);
+	cm_set_next_eret_context(NON_SECURE);
+
+	return 0;
+}
+
+static void trusty_cpu_suspend(void)
+{
+	struct args ret;
+	unsigned int linear_id = plat_my_core_pos();
+
+	ret = trusty_context_switch(NON_SECURE, SMC_FC_CPU_SUSPEND, 0, 0, 0);
+	if (ret.r0 != 0) {
+		INFO("%s: cpu %d, SMC_FC_CPU_SUSPEND returned unexpected value, %ld\n",
+		     __func__, linear_id, ret.r0);
+	}
+}
+
+static void trusty_cpu_resume(void)
+{
+	struct args ret;
+	unsigned int linear_id = plat_my_core_pos();
+
+	ret = trusty_context_switch(NON_SECURE, SMC_FC_CPU_RESUME, 0, 0, 0);
+	if (ret.r0 != 0) {
+		INFO("%s: cpu %d, SMC_FC_CPU_RESUME returned unexpected value, %ld\n",
+		     __func__, linear_id, ret.r0);
+	}
+}
+
+static int32_t trusty_cpu_off_handler(uint64_t unused)
+{
+	trusty_cpu_suspend();
+
+	return 0;
+}
+
+static void trusty_cpu_on_finish_handler(uint64_t unused)
+{
+	struct trusty_cpu_ctx *ctx = get_trusty_ctx();
+
+	if (!ctx->saved_sp) {
+		trusty_init();
+	} else {
+		trusty_cpu_resume();
+	}
+}
+
+static void trusty_cpu_suspend_handler(uint64_t unused)
+{
+	trusty_cpu_suspend();
+}
+
+static void trusty_cpu_suspend_finish_handler(uint64_t unused)
+{
+	trusty_cpu_resume();
+}
+
+static const spd_pm_ops_t trusty_pm = {
+	.svc_off = trusty_cpu_off_handler,
+	.svc_suspend = trusty_cpu_suspend_handler,
+	.svc_on_finish = trusty_cpu_on_finish_handler,
+	.svc_suspend_finish = trusty_cpu_suspend_finish_handler,
+};
+
+static int32_t trusty_setup(void)
+{
+	entry_point_info_t *ep_info;
+	uint32_t instr;
+	uint32_t flags;
+	int ret;
+	int aarch32 = 0;
+
+	ep_info = bl31_plat_get_next_image_ep_info(SECURE);
+	if (!ep_info) {
+		INFO("Trusty image missing.\n");
+		return -1;
+	}
+
+	instr = *(uint32_t *)ep_info->pc;
+
+	if (instr >> 24 == 0xea) {
+		INFO("trusty: Found 32 bit image\n");
+		aarch32 = 1;
+	} else if (instr >> 8 == 0xd53810) {
+		INFO("trusty: Found 64 bit image\n");
+	} else {
+		INFO("trusty: Found unknown image, 0x%x\n", instr);
+	}
+
+	SET_PARAM_HEAD(ep_info, PARAM_EP, VERSION_1, SECURE | EP_ST_ENABLE);
+	if (!aarch32)
+		ep_info->spsr = SPSR_64(MODE_EL1, MODE_SP_ELX,
+					DISABLE_ALL_EXCEPTIONS);
+	else
+		ep_info->spsr = SPSR_MODE32(MODE32_svc, SPSR_T_ARM,
+					    SPSR_E_LITTLE,
+					    DAIF_FIQ_BIT |
+					    DAIF_IRQ_BIT |
+					    DAIF_ABT_BIT);
+
+	bl31_register_bl32_init(trusty_init);
+
+	psci_register_spd_pm_hook(&trusty_pm);
+
+	flags = 0;
+	set_interrupt_rm_flag(flags, NON_SECURE);
+	ret = register_interrupt_type_handler(INTR_TYPE_S_EL1,
+					      trusty_fiq_handler,
+					      flags);
+	if (ret)
+		ERROR("trusty: failed to register fiq handler, ret = %d\n", ret);
+
+	return 0;
+}
+
+/* Define a SPD runtime service descriptor for fast SMC calls */
+DECLARE_RT_SVC(
+	trusty_fast,
+
+	OEN_TOS_START,
+	SMC_ENTITY_SECURE_MONITOR,
+	SMC_TYPE_FAST,
+	trusty_setup,
+	trusty_smc_handler
+);
+
+/* Define a SPD runtime service descriptor for standard SMC calls */
+DECLARE_RT_SVC(
+	trusty_std,
+
+	OEN_TOS_START,
+	SMC_ENTITY_SECURE_MONITOR,
+	SMC_TYPE_STD,
+	NULL,
+	trusty_smc_handler
+);
diff --git a/services/spd/trusty/trusty.mk b/services/spd/trusty/trusty.mk
new file mode 100644
index 00000000..9f535157
--- /dev/null
+++ b/services/spd/trusty/trusty.mk
@@ -0,0 +1,34 @@
+#
+# Copyright (c) 2016, 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.
+#
+
+SPD_INCLUDES		:=
+
+SPD_SOURCES		:=	services/spd/trusty/trusty.c		\
+				services/spd/trusty/trusty_helpers.S
diff --git a/services/spd/trusty/trusty_helpers.S b/services/spd/trusty/trusty_helpers.S
new file mode 100644
index 00000000..9bbb044a
--- /dev/null
+++ b/services/spd/trusty/trusty_helpers.S
@@ -0,0 +1,81 @@
+/*
+ * Copyright (c) 2016, 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.
+ */
+
+#include <asm_macros.S>
+
+.macro push ra, rb, sp=sp
+	stp \ra, \rb, [\sp,#-16]!
+.endm
+
+.macro pop ra, rb, sp=sp
+	ldp \ra, \rb, [\sp], #16
+.endm
+
+	.global trusty_context_switch_helper
+func trusty_context_switch_helper
+	push	x8, xzr
+	push	x19, x20
+	push	x21, x22
+	push	x23, x24
+	push	x25, x26
+	push	x27, x28
+	push	x29, x30
+
+	mov	x9, sp
+	ldr	x10, [x0]
+	mov	sp, x10
+	str	x9, [x0]
+
+	pop	x29, x30
+	pop	x27, x28
+	pop	x25, x26
+	pop	x23, x24
+	pop	x21, x22
+	pop	x19, x20
+	pop	x8, xzr
+	stp	x1, x2, [x8]
+	stp	x3, x4, [x8, #16]
+
+	ret
+endfunc trusty_context_switch_helper
+
+	.global trusty_init_context_stack
+func trusty_init_context_stack
+	push	x8, xzr, x1
+	push	xzr, xzr, x1
+	push	xzr, xzr, x1
+	push	xzr, xzr, x1
+	push	xzr, xzr, x1
+	push	xzr, xzr, x1
+	adr	x9, el3_exit
+	push	xzr, x9, x1
+	str	x1, [x0]
+	ret
+endfunc trusty_init_context_stack