arm-trusted-firmware/lib/extensions/trf/aarch64/trf.c

37 lines
718 B
C

/*
* 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/trf.h>
static bool trf_supported(void)
{
uint64_t features;
features = read_id_aa64dfr0_el1() >> ID_AA64DFR0_TRACEFILT_SHIFT;
return ((features & ID_AA64DFR0_TRACEFILT_MASK) ==
ID_AA64DFR0_TRACEFILT_SUPPORTED);
}
void trf_enable(void)
{
uint64_t val;
if (trf_supported()) {
/*
* MDCR_EL3.TTRF = b0
* Allow access of trace filter control registers from NS-EL2
* and NS-EL1 when NS-EL2 is implemented but not used
*/
val = read_mdcr_el3();
val &= ~MDCR_TTRF_BIT;
write_mdcr_el3(val);
}
}