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/*
* Copyright (c) 2013-2017, ARM Limited and Contributors. All rights reserved.
*
* SPDX-License-Identifier: BSD-3-Clause
*/
#include <arch_helpers.h>
#include <assert.h>
#include <bl_common.h>
#include <context_mgmt.h>
#include <debug.h>
#include <string.h>
#include <tsp.h>
#include <utils.h>
#include "tspd_private.h"
/*******************************************************************************
* Given a secure payload entrypoint info pointer, entry point PC, register
* width, cpu id & pointer to a context data structure, this function will
* initialize tsp context and entry point info for the secure payload
******************************************************************************/
void tspd_init_tsp_ep_state(struct entry_point_info *tsp_entry_point,
uint32_t rw,
uint64_t pc,
tsp_context_t *tsp_ctx)
{
uint32_t ep_attr;
/* Passing a NULL context is a critical programming error */
assert(tsp_ctx);
assert(tsp_entry_point);
assert(pc);
/*
* We support AArch64 TSP for now.
* TODO: Add support for AArch32 TSP
*/
assert(rw == TSP_AARCH64);
/* Associate this context with the cpu specified */
tsp_ctx->mpidr = read_mpidr_el1();
tsp_ctx->state = 0;
set_tsp_pstate(tsp_ctx->state, TSP_PSTATE_OFF);
clr_yield_smc_active_flag(tsp_ctx->state);
cm_set_context(&tsp_ctx->cpu_ctx, SECURE);
/* initialise an entrypoint to set up the CPU context */
ep_attr = SECURE | EP_ST_ENABLE;
if (read_sctlr_el3() & SCTLR_EE_BIT)
ep_attr |= EP_EE_BIG;
SET_PARAM_HEAD(tsp_entry_point, PARAM_EP, VERSION_1, ep_attr);
tsp_entry_point->pc = pc;
tsp_entry_point->spsr = SPSR_64(MODE_EL1,
MODE_SP_ELX,
DISABLE_ALL_EXCEPTIONS);
zeromem(&tsp_entry_point->args, sizeof(tsp_entry_point->args));
}
/*******************************************************************************
* This function takes an SP context pointer and:
* 1. Applies the S-EL1 system register context from tsp_ctx->cpu_ctx.
* 2. Saves the current C runtime state (callee saved registers) on the stack
* frame and saves a reference to this state.
* 3. Calls el3_exit() so that the EL3 system and general purpose registers
* from the tsp_ctx->cpu_ctx are used to enter the secure payload image.
******************************************************************************/
uint64_t tspd_synchronous_sp_entry(tsp_context_t *tsp_ctx)
{
uint64_t rc;
assert(tsp_ctx != NULL);
assert(tsp_ctx->c_rt_ctx == 0);
/* Apply the Secure EL1 system register context and switch to it */
assert(cm_get_context(SECURE) == &tsp_ctx->cpu_ctx);
cm_el1_sysregs_context_restore(SECURE);
cm_set_next_eret_context(SECURE);
rc = tspd_enter_sp(&tsp_ctx->c_rt_ctx);
#if ENABLE_ASSERTIONS
tsp_ctx->c_rt_ctx = 0;
#endif
return rc;
}
/*******************************************************************************
* This function takes an SP context pointer and:
* 1. Saves the S-EL1 system register context tp tsp_ctx->cpu_ctx.
* 2. Restores the current C runtime state (callee saved registers) from the
* stack frame using the reference to this state saved in tspd_enter_sp().
* 3. It does not need to save any general purpose or EL3 system register state
* as the generic smc entry routine should have saved those.
******************************************************************************/
void tspd_synchronous_sp_exit(tsp_context_t *tsp_ctx, uint64_t ret)
{
assert(tsp_ctx != NULL);
/* Save the Secure EL1 system register context */
assert(cm_get_context(SECURE) == &tsp_ctx->cpu_ctx);
cm_el1_sysregs_context_save(SECURE);
assert(tsp_ctx->c_rt_ctx != 0);
tspd_exit_sp(tsp_ctx->c_rt_ctx, ret);
/* Should never reach here */
assert(0);
}
/*******************************************************************************
* This function takes an SP context pointer and abort any preempted SMC
* request.
* Return 1 if there was a preempted SMC request, 0 otherwise.
******************************************************************************/
int tspd_abort_preempted_smc(tsp_context_t *tsp_ctx)
{
if (!get_yield_smc_active_flag(tsp_ctx->state))
return 0;
/* Abort any preempted SMC request */
clr_yield_smc_active_flag(tsp_ctx->state);
/*
* Arrange for an entry into the test secure payload. It will
* be returned via TSP_ABORT_DONE case in tspd_smc_handler.
*/
cm_set_elr_el3(SECURE,
(uint64_t) &tsp_vectors->abort_yield_smc_entry);
uint64_t rc = tspd_synchronous_sp_entry(tsp_ctx);
if (rc != 0)
panic();
return 1;
}