/*
* 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 <string.h>
#include <tsp.h>
#include <uuid.h>
#include "tspd_private.h"
/*******************************************************************************
* Address of the entrypoint vector table in the Secure Payload. It is
* initialised once on the primary core after a cold boot.
******************************************************************************/
tsp_vectors_t *tsp_vectors;
/*******************************************************************************
* Array to keep track of per-cpu Secure Payload state
******************************************************************************/
tsp_context_t tspd_sp_context[TSPD_CORE_COUNT];
/* TSP UID */
DEFINE_SVC_UUID(tsp_uuid,
0x5b3056a0, 0x3291, 0x427b, 0x98, 0x11,
0x71, 0x68, 0xca, 0x50, 0xf3, 0xfa);
int32_t tspd_init(void);
/*
* This helper function handles Secure EL1 preemption. The preemption could be
* due Non Secure interrupts or EL3 interrupts. In both the cases we context
* switch to the normal world and in case of EL3 interrupts, it will again be
* routed to EL3 which will get handled at the exception vectors.
*/
uint64_t tspd_handle_sp_preemption(void *handle)
{
cpu_context_t *ns_cpu_context;
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);
/*
* To allow Secure EL1 interrupt handler to re-enter TSP while TSP
* is preempted, the secure system register context which will get
* overwritten must be additionally saved. This is currently done
* by the TSPD S-EL1 interrupt handler.
*/
/*
* Restore non-secure state.
*/
cm_el1_sysregs_context_restore(NON_SECURE);
cm_set_next_eret_context(NON_SECURE);
/*
* The TSP was preempted during execution of a Yielding SMC Call.
* Return back to the normal world with SMC_PREEMPTED as error
* code in x0.
*/
SMC_RET1(ns_cpu_context, SMC_PREEMPTED);
}
/*******************************************************************************
* This function is the handler registered for S-EL1 interrupts by the TSPD. It
* validates the interrupt and upon success arranges entry into the TSP at
* 'tsp_sel1_intr_entry()' for handling the interrupt.
******************************************************************************/
static uint64_t tspd_sel1_interrupt_handler(uint32_t id,
uint32_t flags,
void *handle,
void *cookie)
{
uint32_t linear_id;
tsp_context_t *tsp_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 TSP */
cm_el1_sysregs_context_save(NON_SECURE);
/* Get a reference to this cpu's TSP context */
linear_id = plat_my_core_pos();
tsp_ctx = &tspd_sp_context[linear_id];
assert(&tsp_ctx->cpu_ctx == cm_get_context(SECURE));
/*
* Determine if the TSP was previously preempted. Its last known
* context has to be preserved in this case.
* The TSP should return control to the TSPD after handling this
* S-EL1 interrupt. Preserve essential EL3 context to allow entry into
* the TSP at the S-EL1 interrupt entry point using the 'cpu_context'
* structure. There is no need to save the secure system register
* context since the TSP is supposed to preserve it during S-EL1
* interrupt handling.
*/
if (get_yield_smc_active_flag(tsp_ctx->state)) {
tsp_ctx->saved_spsr_el3 = SMC_GET_EL3(&tsp_ctx->cpu_ctx,
CTX_SPSR_EL3);
tsp_ctx->saved_elr_el3 = SMC_GET_EL3(&tsp_ctx->cpu_ctx,
CTX_ELR_EL3);
#if TSP_NS_INTR_ASYNC_PREEMPT
/*Need to save the previously interrupted secure context */
memcpy(&tsp_ctx->sp_ctx, &tsp_ctx->cpu_ctx, TSPD_SP_CTX_SIZE);
#endif
}
cm_el1_sysregs_context_restore(SECURE);
cm_set_elr_spsr_el3(SECURE, (uint64_t) &tsp_vectors->sel1_intr_entry,
SPSR_64(MODE_EL1, MODE_SP_ELX, DISABLE_ALL_EXCEPTIONS));
cm_set_next_eret_context(SECURE);
/*
* Tell the TSP that it has to handle a S-EL1 interrupt 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_RET2(&tsp_ctx->cpu_ctx, TSP_HANDLE_SEL1_INTR_AND_RETURN, read_elr_el3());
}
#if TSP_NS_INTR_ASYNC_PREEMPT
/*******************************************************************************
* This function is the handler registered for Non secure interrupts by the
* TSPD. It validates the interrupt and upon success arranges entry into the
* normal world for handling the interrupt.
******************************************************************************/
static uint64_t tspd_ns_interrupt_handler(uint32_t id,
uint32_t flags,
void *handle,
void *cookie)
{
/* Check the security state when the exception was generated */
assert(get_interrupt_src_ss(flags) == SECURE);
/*
* Disable the routing of NS interrupts from secure world to EL3 while
* interrupted on this core.
*/
disable_intr_rm_local(INTR_TYPE_NS, SECURE);
return tspd_handle_sp_preemption(handle);
}
#endif
/*******************************************************************************
* Secure Payload Dispatcher setup. The SPD finds out the SP entrypoint and type
* (aarch32/aarch64) if not already known and initialises the context for entry
* into the SP for its initialisation.
******************************************************************************/
int32_t tspd_setup(void)
{
entry_point_info_t *tsp_ep_info;
uint32_t linear_id;
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
*/
tsp_ep_info = bl31_plat_get_next_image_ep_info(SECURE);
if (!tsp_ep_info) {
WARN("No TSP provided by BL2 boot loader, Booting device"
" without TSP initialization. SMC`s destined for TSP"
" 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 (!tsp_ep_info->pc)
return 1;
/*
* We could inspect the SP image and determine its execution
* state i.e whether AArch32 or AArch64. Assuming it's AArch64
* for the time being.
*/
tspd_init_tsp_ep_state(tsp_ep_info,
TSP_AARCH64,
tsp_ep_info->pc,
&tspd_sp_context[linear_id]);
#if TSP_INIT_ASYNC
bl31_set_next_image_type(SECURE);
#else
/*
* All TSPD initialization done. Now register our init function with
* BL31 for deferred invocation
*/
bl31_register_bl32_init(&tspd_init);
#endif
return 0;
}
/*******************************************************************************
* This function passes control to the Secure Payload 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 tspd_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 the Secure payload. The SP passes control
* back to this routine through a SMC.
******************************************************************************/
int32_t tspd_init(void)
{
uint32_t linear_id = plat_my_core_pos();
tsp_context_t *tsp_ctx = &tspd_sp_context[linear_id];
entry_point_info_t *tsp_entry_point;
uint64_t rc;
/*
* Get information about the Secure Payload (BL32) image. Its
* absence is a critical failure.
*/
tsp_entry_point = bl31_plat_get_next_image_ep_info(SECURE);
assert(tsp_entry_point);
cm_init_my_context(tsp_entry_point);
/*
* Arrange for an entry into the test secure payload. It will be
* returned via TSP_ENTRY_DONE case
*/
rc = tspd_synchronous_sp_entry(tsp_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 the secure payload needs to do the
* work assigned to it.
******************************************************************************/
uint64_t tspd_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(), ns;
tsp_context_t *tsp_ctx = &tspd_sp_context[linear_id];
uint64_t rc;
#if TSP_INIT_ASYNC
entry_point_info_t *next_image_info;
#endif
/* Determine which security state this SMC originated from */
ns = is_caller_non_secure(flags);
switch (smc_fid) {
/*
* This function ID is used by TSP to indicate that it was
* preempted by a normal world IRQ.
*
*/
case TSP_PREEMPTED:
if (ns)
SMC_RET1(handle, SMC_UNK);
return tspd_handle_sp_preemption(handle);
/*
* This function ID is used only by the TSP to indicate that it has
* finished handling a S-EL1 interrupt or was preempted by a higher
* priority pending EL3 interrupt. Execution should resume
* in the normal world.
*/
case TSP_HANDLED_S_EL1_INTR:
if (ns)
SMC_RET1(handle, SMC_UNK);
assert(handle == cm_get_context(SECURE));
/*
* Restore the relevant EL3 state which saved to service
* this SMC.
*/
if (get_yield_smc_active_flag(tsp_ctx->state)) {
SMC_SET_EL3(&tsp_ctx->cpu_ctx,
CTX_SPSR_EL3,
tsp_ctx->saved_spsr_el3);
SMC_SET_EL3(&tsp_ctx->cpu_ctx,
CTX_ELR_EL3,
tsp_ctx->saved_elr_el3);
#if TSP_NS_INTR_ASYNC_PREEMPT
/*
* Need to restore the previously interrupted
* secure context.
*/
memcpy(&tsp_ctx->cpu_ctx, &tsp_ctx->sp_ctx,
TSPD_SP_CTX_SIZE);
#endif
}
/* 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 the TSP 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);
/*
* This function ID is used only by the SP to indicate it has
* finished initialising itself after a cold boot
*/
case TSP_ENTRY_DONE:
if (ns)
SMC_RET1(handle, SMC_UNK);
/*
* Stash the SP entry points information. This is done
* only once on the primary cpu
*/
assert(tsp_vectors == NULL);
tsp_vectors = (tsp_vectors_t *) x1;
if (tsp_vectors) {
set_tsp_pstate(tsp_ctx->state, TSP_PSTATE_ON);
/*
* TSP has been successfully initialized. Register power
* managemnt hooks with PSCI
*/
psci_register_spd_pm_hook(&tspd_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,
tspd_sel1_interrupt_handler,
flags);
if (rc)
panic();
#if TSP_NS_INTR_ASYNC_PREEMPT
/*
* Register an interrupt handler for NS interrupts when
* generated during code executing in secure state are
* routed to EL3.
*/
flags = 0;
set_interrupt_rm_flag(flags, SECURE);
rc = register_interrupt_type_handler(INTR_TYPE_NS,
tspd_ns_interrupt_handler,
flags);
if (rc)
panic();
/*
* Disable the NS interrupt locally.
*/
disable_intr_rm_local(INTR_TYPE_NS, SECURE);
#endif
}
#if TSP_INIT_ASYNC
/* Save the Secure EL1 system register context */
assert(cm_get_context(SECURE) == &tsp_ctx->cpu_ctx);
cm_el1_sysregs_context_save(SECURE);
/* Program EL3 registers to enable entry into the next EL */
next_image_info = bl31_plat_get_next_image_ep_info(NON_SECURE);
assert(next_image_info);
assert(NON_SECURE ==
GET_SECURITY_STATE(next_image_info->h.attr));
cm_init_my_context(next_image_info);
cm_prepare_el3_exit(NON_SECURE);
SMC_RET0(cm_get_context(NON_SECURE));
#else
/*
* SP reports completion. The SPD must have initiated
* the original request through a synchronous entry
* into the SP. Jump back to the original C runtime
* context.
*/
tspd_synchronous_sp_exit(tsp_ctx, x1);
#endif
/*
* This function ID is used only by the SP to indicate it has finished
* aborting a preempted Yielding SMC Call.
*/
case TSP_ABORT_DONE:
/*
* These function IDs are used only by the SP 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 TSP_ON_DONE:
case TSP_RESUME_DONE:
/*
* These function IDs are 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 TSP_OFF_DONE:
case TSP_SUSPEND_DONE:
case TSP_SYSTEM_OFF_DONE:
case TSP_SYSTEM_RESET_DONE:
if (ns)
SMC_RET1(handle, SMC_UNK);
/*
* SP reports completion. The SPD must have initiated the
* original request through a synchronous entry into the SP.
* Jump back to the original C runtime context, and pass x1 as
* return value to the caller
*/
tspd_synchronous_sp_exit(tsp_ctx, x1);
/*
* Request from non-secure client to perform an
* arithmetic operation or response from secure
* payload to an earlier request.
*/
case TSP_FAST_FID(TSP_ADD):
case TSP_FAST_FID(TSP_SUB):
case TSP_FAST_FID(TSP_MUL):
case TSP_FAST_FID(TSP_DIV):
case TSP_YIELD_FID(TSP_ADD):
case TSP_YIELD_FID(TSP_SUB):
case TSP_YIELD_FID(TSP_MUL):
case TSP_YIELD_FID(TSP_DIV):
if (ns) {
/*
* 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));
/* Check if we are already preempted */
if (get_yield_smc_active_flag(tsp_ctx->state))
SMC_RET1(handle, SMC_UNK);
cm_el1_sysregs_context_save(NON_SECURE);
/* Save x1 and x2 for use by TSP_GET_ARGS call below */
store_tsp_args(tsp_ctx, x1, x2);
/*
* We are done stashing the non-secure context. Ask the
* secure payload 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(&tsp_ctx->cpu_ctx == cm_get_context(SECURE));
/* Set appropriate entry for SMC.
* We expect the TSP 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)
&tsp_vectors->fast_smc_entry);
} else {
set_yield_smc_active_flag(tsp_ctx->state);
cm_set_elr_el3(SECURE, (uint64_t)
&tsp_vectors->yield_smc_entry);
#if TSP_NS_INTR_ASYNC_PREEMPT
/*
* Enable the routing of NS interrupts to EL3
* during processing of a Yielding SMC Call on
* this core.
*/
enable_intr_rm_local(INTR_TYPE_NS, SECURE);
#endif
}
cm_el1_sysregs_context_restore(SECURE);
cm_set_next_eret_context(SECURE);
SMC_RET3(&tsp_ctx->cpu_ctx, smc_fid, x1, x2);
} else {
/*
* This is the result from the secure client of an
* earlier request. The results are in x1-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);
if (GET_SMC_TYPE(smc_fid) == SMC_TYPE_YIELD) {
clr_yield_smc_active_flag(tsp_ctx->state);
#if TSP_NS_INTR_ASYNC_PREEMPT
/*
* Disable the routing of NS interrupts to EL3
* after processing of a Yielding SMC Call on
* this core is finished.
*/
disable_intr_rm_local(INTR_TYPE_NS, SECURE);
#endif
}
SMC_RET3(ns_cpu_context, x1, x2, x3);
}
break;
/*
* Request from the non-secure world to abort a preempted Yielding SMC
* Call.
*/
case TSP_FID_ABORT:
/* ABORT should only be invoked by normal world */
if (!ns) {
assert(0);
break;
}
assert(handle == cm_get_context(NON_SECURE));
cm_el1_sysregs_context_save(NON_SECURE);
/* Abort the preempted SMC request */
if (!tspd_abort_preempted_smc(tsp_ctx)) {
/*
* If there was no preempted SMC to abort, return
* SMC_UNK.
*
* Restoring the NON_SECURE context is not necessary as
* the synchronous entry did not take place if the
* return code of tspd_abort_preempted_smc is zero.
*/
cm_set_next_eret_context(NON_SECURE);
break;
}
cm_el1_sysregs_context_restore(NON_SECURE);
cm_set_next_eret_context(NON_SECURE);
SMC_RET1(handle, SMC_OK);
/*
* Request from non secure world to resume the preempted
* Yielding SMC Call.
*/
case TSP_FID_RESUME:
/* RESUME should be invoked only by normal world */
if (!ns) {
assert(0);
break;
}
/*
* This is a resume request from the non-secure client.
* save the non-secure state and send the request to
* the secure payload.
*/
assert(handle == cm_get_context(NON_SECURE));
/* Check if we are already preempted before resume */
if (!get_yield_smc_active_flag(tsp_ctx->state))
SMC_RET1(handle, SMC_UNK);
cm_el1_sysregs_context_save(NON_SECURE);
/*
* We are done stashing the non-secure context. Ask the
* secure payload to do the work now.
*/
#if TSP_NS_INTR_ASYNC_PREEMPT
/*
* Enable the routing of NS interrupts to EL3 during resumption
* of a Yielding SMC Call on this core.
*/
enable_intr_rm_local(INTR_TYPE_NS, SECURE);
#endif
/* We just need to return to the preempted point in
* TSP and the execution will resume as normal.
*/
cm_el1_sysregs_context_restore(SECURE);
cm_set_next_eret_context(SECURE);
SMC_RET0(&tsp_ctx->cpu_ctx);
/*
* This is a request from the secure payload for more arguments
* for an ongoing arithmetic operation requested by the
* non-secure world. Simply return the arguments from the non-
* secure client in the original call.
*/
case TSP_GET_ARGS:
if (ns)
SMC_RET1(handle, SMC_UNK);
get_tsp_args(tsp_ctx, x1, x2);
SMC_RET2(handle, x1, x2);
case TOS_CALL_COUNT:
/*
* Return the number of service function IDs implemented to
* provide service to non-secure
*/
SMC_RET1(handle, TSP_NUM_FID);
case TOS_UID:
/* Return TSP UID to the caller */
SMC_UUID_RET(handle, tsp_uuid);
case TOS_CALL_VERSION:
/* Return the version of current implementation */
SMC_RET2(handle, TSP_VERSION_MAJOR, TSP_VERSION_MINOR);
default:
break;
}
SMC_RET1(handle, SMC_UNK);
}
/* Define a SPD runtime service descriptor for fast SMC calls */
DECLARE_RT_SVC(
tspd_fast,
OEN_TOS_START,
OEN_TOS_END,
SMC_TYPE_FAST,
tspd_setup,
tspd_smc_handler
);
/* Define a SPD runtime service descriptor for Yielding SMC Calls */
DECLARE_RT_SVC(
tspd_std,
OEN_TOS_START,
OEN_TOS_END,
SMC_TYPE_YIELD,
NULL,
tspd_smc_handler
);