blob: 960d69842a8c3bdf84b6ad7d891e7edc084b04e0 [file] [log] [blame]
/*
* Copyright (c) 2021, Arm Limited. All rights reserved.
*
* SPDX-License-Identifier: BSD-3-Clause
*/
#include <stdbool.h>
#include <arch.h>
#include <arch_helpers.h>
#include <lib/extensions/sys_reg_trace.h>
static bool sys_reg_trace_supported(void)
{
uint64_t features;
features = read_id_aa64dfr0_el1() >> ID_AA64DFR0_TRACEVER_SHIFT;
return ((features & ID_AA64DFR0_TRACEVER_MASK) ==
ID_AA64DFR0_TRACEVER_SUPPORTED);
}
void sys_reg_trace_enable(cpu_context_t *ctx)
{
uint64_t val;
if (sys_reg_trace_supported()) {
/* Retrieve CPTR_EL3 value from the given context 'ctx',
* and update CPTR_EL3.TTA bit to 0.
* This function is called while switching context to NS to
* allow system trace register access to NS-EL2 and NS-EL1
* when NS-EL2 is implemented but not used.
*/
val = read_ctx_reg(get_el3state_ctx(ctx), CTX_CPTR_EL3);
val &= ~TTA_BIT;
write_ctx_reg(get_el3state_ctx(ctx), CTX_CPTR_EL3, val);
}
}