/*
* Copyright (c) 2013-2017, ARM Limited and Contributors. All rights reserved.
*
* SPDX-License-Identifier: BSD-3-Clause
*/
/*******************************************************************************
* This is the Secure Payload Dispatcher (SPD). The dispatcher is meant to be a
* plug-in component to the Secure Monitor, registered as a runtime service. The
* SPD is expected to be a functional extension of the Secure Payload (SP) that
* executes in Secure EL1. The Secure Monitor will delegate all SMCs targeting
* the Trusted OS/Applications range to the dispatcher. The SPD will either
* handle the request locally or delegate it to the Secure Payload. It is also
* responsible for initialising and maintaining communication with the SP.
******************************************************************************/
#include <arch_helpers.h>
#include <assert.h>
#include <bl31.h>
#include <bl_common.h>
#include <context_mgmt.h>
#include <debug.h>
#include <errno.h>
#include <platform.h>
#include <runtime_svc.h>
#include <stddef.h>
#include <uuid.h>
#include "opteed_private.h"
#include "teesmc_opteed.h"
#include "teesmc_opteed_macros.h"
/*******************************************************************************
* Address of the entrypoint vector table in OPTEE. It is
* initialised once on the primary core after a cold boot.
******************************************************************************/
optee_vectors_t *optee_vectors;
/*******************************************************************************
* Array to keep track of per-cpu OPTEE state
******************************************************************************/
optee_context_t opteed_sp_context[OPTEED_CORE_COUNT];
uint32_t opteed_rw;
static int32_t opteed_init(void);
/*******************************************************************************
* This function is the handler registered for S-EL1 interrupts by the
* OPTEED. It validates the interrupt and upon success arranges entry into
* the OPTEE at 'optee_fiq_entry()' for handling the interrupt.
******************************************************************************/
static uint64_t opteed_sel1_interrupt_handler(uint32_t id,
uint32_t flags,
void *handle,
void *cookie)
{
uint32_t linear_id;
optee_context_t *optee_ctx;
/* Check the security state when the exception was generated */
assert(get_interrupt_src_ss(flags) == NON_SECURE);
/* Sanity check the pointer to this cpu's context */
assert(handle == cm_get_context(NON_SECURE));
/* Save the non-secure context before entering the OPTEE */
cm_el1_sysregs_context_save(NON_SECURE);
/* Get a reference to this cpu's OPTEE context */
linear_id = plat_my_core_pos();
optee_ctx = &opteed_sp_context[linear_id];
assert(&optee_ctx->cpu_ctx == cm_get_context(SECURE));
cm_set_elr_el3(SECURE, (uint64_t)&optee_vectors->fiq_entry);
cm_el1_sysregs_context_restore(SECURE);
cm_set_next_eret_context(SECURE);
/*
* Tell the OPTEE that it has to handle an FIQ (synchronously).
* Also the instruction in normal world where the interrupt was
* generated is passed for debugging purposes. It is safe to
* retrieve this address from ELR_EL3 as the secure context will
* not take effect until el3_exit().
*/
SMC_RET1(&optee_ctx->cpu_ctx, read_elr_el3());
}
/*******************************************************************************
* OPTEE Dispatcher setup. The OPTEED finds out the OPTEE entrypoint and type
* (aarch32/aarch64) if not already known and initialises the context for entry
* into OPTEE for its initialization.
******************************************************************************/
int32_t opteed_setup(void)
{
entry_point_info_t *optee_ep_info;
uint32_t linear_id;
uint64_t opteed_pageable_part;
uint64_t opteed_mem_limit;
uint64_t dt_addr;
linear_id = plat_my_core_pos();
/*
* Get information about the Secure Payload (BL32) image. Its
* absence is a critical failure. TODO: Add support to
* conditionally include the SPD service
*/
optee_ep_info = bl31_plat_get_next_image_ep_info(SECURE);
if (!optee_ep_info) {
WARN("No OPTEE provided by BL2 boot loader, Booting device"
" without OPTEE initialization. SMC`s destined for OPTEE"
" will return SMC_UNK\n");
return 1;
}
/*
* If there's no valid entry point for SP, we return a non-zero value
* signalling failure initializing the service. We bail out without
* registering any handlers
*/
if (!optee_ep_info->pc)
return 1;
opteed_rw = optee_ep_info->args.arg0;
opteed_pageable_part = optee_ep_info->args.arg1;
opteed_mem_limit = optee_ep_info->args.arg2;
dt_addr = optee_ep_info->args.arg3;
opteed_init_optee_ep_state(optee_ep_info,
opteed_rw,
optee_ep_info->pc,
opteed_pageable_part,
opteed_mem_limit,
dt_addr,
&opteed_sp_context[linear_id]);
/*
* All OPTEED initialization done. Now register our init function with
* BL31 for deferred invocation
*/
bl31_register_bl32_init(&opteed_init);
return 0;
}
/*******************************************************************************
* This function passes control to the OPTEE image (BL32) for the first time
* on the primary cpu after a cold boot. It assumes that a valid secure
* context has already been created by opteed_setup() which can be directly
* used. It also assumes that a valid non-secure context has been
* initialised by PSCI so it does not need to save and restore any
* non-secure state. This function performs a synchronous entry into
* OPTEE. OPTEE passes control back to this routine through a SMC.
******************************************************************************/
static int32_t opteed_init(void)
{
uint32_t linear_id = plat_my_core_pos();
optee_context_t *optee_ctx = &opteed_sp_context[linear_id];
entry_point_info_t *optee_entry_point;
uint64_t rc;
/*
* Get information about the OPTEE (BL32) image. Its
* absence is a critical failure.
*/
optee_entry_point = bl31_plat_get_next_image_ep_info(SECURE);
assert(optee_entry_point);
cm_init_my_context(optee_entry_point);
/*
* Arrange for an entry into OPTEE. It will be returned via
* OPTEE_ENTRY_DONE case
*/
rc = opteed_synchronous_sp_entry(optee_ctx);
assert(rc != 0);
return rc;
}
/*******************************************************************************
* This function is responsible for handling all SMCs in the Trusted OS/App
* range from the non-secure state as defined in the SMC Calling Convention
* Document. It is also responsible for communicating with the Secure
* payload to delegate work and return results back to the non-secure
* state. Lastly it will also return any information that OPTEE needs to do
* the work assigned to it.
******************************************************************************/
uint64_t opteed_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)
{
cpu_context_t *ns_cpu_context;
uint32_t linear_id = plat_my_core_pos();
optee_context_t *optee_ctx = &opteed_sp_context[linear_id];
uint64_t rc;
/*
* Determine which security state this SMC originated from
*/
if (is_caller_non_secure(flags)) {
/*
* This is a fresh request from the non-secure client.
* The parameters are in x1 and x2. Figure out which
* registers need to be preserved, save the non-secure
* state and send the request to the secure payload.
*/
assert(handle == cm_get_context(NON_SECURE));
cm_el1_sysregs_context_save(NON_SECURE);
/*
* We are done stashing the non-secure context. Ask the
* OPTEE to do the work now.
*/
/*
* Verify if there is a valid context to use, copy the
* operation type and parameters to the secure context
* and jump to the fast smc entry point in the secure
* payload. Entry into S-EL1 will take place upon exit
* from this function.
*/
assert(&optee_ctx->cpu_ctx == cm_get_context(SECURE));
/* Set appropriate entry for SMC.
* We expect OPTEE to manage the PSTATE.I and PSTATE.F
* flags as appropriate.
*/
if (GET_SMC_TYPE(smc_fid) == SMC_TYPE_FAST) {
cm_set_elr_el3(SECURE, (uint64_t)
&optee_vectors->fast_smc_entry);
} else {
cm_set_elr_el3(SECURE, (uint64_t)
&optee_vectors->yield_smc_entry);
}
cm_el1_sysregs_context_restore(SECURE);
cm_set_next_eret_context(SECURE);
write_ctx_reg(get_gpregs_ctx(&optee_ctx->cpu_ctx),
CTX_GPREG_X4,
read_ctx_reg(get_gpregs_ctx(handle),
CTX_GPREG_X4));
write_ctx_reg(get_gpregs_ctx(&optee_ctx->cpu_ctx),
CTX_GPREG_X5,
read_ctx_reg(get_gpregs_ctx(handle),
CTX_GPREG_X5));
write_ctx_reg(get_gpregs_ctx(&optee_ctx->cpu_ctx),
CTX_GPREG_X6,
read_ctx_reg(get_gpregs_ctx(handle),
CTX_GPREG_X6));
/* Propagate hypervisor client ID */
write_ctx_reg(get_gpregs_ctx(&optee_ctx->cpu_ctx),
CTX_GPREG_X7,
read_ctx_reg(get_gpregs_ctx(handle),
CTX_GPREG_X7));
SMC_RET4(&optee_ctx->cpu_ctx, smc_fid, x1, x2, x3);
}
/*
* Returning from OPTEE
*/
switch (smc_fid) {
/*
* OPTEE has finished initialising itself after a cold boot
*/
case TEESMC_OPTEED_RETURN_ENTRY_DONE:
/*
* Stash the OPTEE entry points information. This is done
* only once on the primary cpu
*/
assert(optee_vectors == NULL);
optee_vectors = (optee_vectors_t *) x1;
if (optee_vectors) {
set_optee_pstate(optee_ctx->state, OPTEE_PSTATE_ON);
/*
* OPTEE has been successfully initialized.
* Register power management hooks with PSCI
*/
psci_register_spd_pm_hook(&opteed_pm);
/*
* Register an interrupt handler for S-EL1 interrupts
* when generated during code executing in the
* non-secure state.
*/
flags = 0;
set_interrupt_rm_flag(flags, NON_SECURE);
rc = register_interrupt_type_handler(INTR_TYPE_S_EL1,
opteed_sel1_interrupt_handler,
flags);
if (rc)
panic();
}
/*
* OPTEE reports completion. The OPTEED must have initiated
* the original request through a synchronous entry into
* OPTEE. Jump back to the original C runtime context.
*/
opteed_synchronous_sp_exit(optee_ctx, x1);
/*
* These function IDs is used only by OP-TEE to indicate it has
* finished:
* 1. turning itself on in response to an earlier psci
* cpu_on request
* 2. resuming itself after an earlier psci cpu_suspend
* request.
*/
case TEESMC_OPTEED_RETURN_ON_DONE:
case TEESMC_OPTEED_RETURN_RESUME_DONE:
/*
* These function IDs is used only by the SP to indicate it has
* finished:
* 1. suspending itself after an earlier psci cpu_suspend
* request.
* 2. turning itself off in response to an earlier psci
* cpu_off request.
*/
case TEESMC_OPTEED_RETURN_OFF_DONE:
case TEESMC_OPTEED_RETURN_SUSPEND_DONE:
case TEESMC_OPTEED_RETURN_SYSTEM_OFF_DONE:
case TEESMC_OPTEED_RETURN_SYSTEM_RESET_DONE:
/*
* OPTEE reports completion. The OPTEED must have initiated the
* original request through a synchronous entry into OPTEE.
* Jump back to the original C runtime context, and pass x1 as
* return value to the caller
*/
opteed_synchronous_sp_exit(optee_ctx, x1);
/*
* OPTEE is returning from a call or being preempted from a call, in
* either case execution should resume in the normal world.
*/
case TEESMC_OPTEED_RETURN_CALL_DONE:
/*
* This is the result from the secure client of an
* earlier request. The results are in x0-x3. Copy it
* into the non-secure context, save the secure state
* and return to the non-secure state.
*/
assert(handle == cm_get_context(SECURE));
cm_el1_sysregs_context_save(SECURE);
/* Get a reference to the non-secure context */
ns_cpu_context = cm_get_context(NON_SECURE);
assert(ns_cpu_context);
/* Restore non-secure state */
cm_el1_sysregs_context_restore(NON_SECURE);
cm_set_next_eret_context(NON_SECURE);
SMC_RET4(ns_cpu_context, x1, x2, x3, x4);
/*
* OPTEE has finished handling a S-EL1 FIQ interrupt. Execution
* should resume in the normal world.
*/
case TEESMC_OPTEED_RETURN_FIQ_DONE:
/* Get a reference to the non-secure context */
ns_cpu_context = cm_get_context(NON_SECURE);
assert(ns_cpu_context);
/*
* Restore non-secure state. There is no need to save the
* secure system register context since OPTEE was supposed
* to preserve it during S-EL1 interrupt handling.
*/
cm_el1_sysregs_context_restore(NON_SECURE);
cm_set_next_eret_context(NON_SECURE);
SMC_RET0((uint64_t) ns_cpu_context);
default:
panic();
}
}
/* Define an OPTEED runtime service descriptor for fast SMC calls */
DECLARE_RT_SVC(
opteed_fast,
OEN_TOS_START,
OEN_TOS_END,
SMC_TYPE_FAST,
opteed_setup,
opteed_smc_handler
);
/* Define an OPTEED runtime service descriptor for yielding SMC calls */
DECLARE_RT_SVC(
opteed_std,
OEN_TOS_START,
OEN_TOS_END,
SMC_TYPE_YIELD,
NULL,
opteed_smc_handler
);