1 /* 2 * Copyright (c) 2021, Arm Limited. All rights reserved. 3 * 4 * SPDX-License-Identifier: BSD-3-Clause 5 */ 6 7 #include <arch.h> 8 #include <arch_features.h> 9 #include <arch_helpers.h> 10 #include <lib/extensions/trf.h> 11 12 void trf_enable(void) 13 { 14 uint64_t val; 15 16 /* 17 * MDCR_EL3.TTRF = b0 18 * Allow access of trace filter control registers from NS-EL2 19 * and NS-EL1 when NS-EL2 is implemented but not used 20 */ 21 val = read_mdcr_el3(); 22 val &= ~MDCR_TTRF_BIT; 23 write_mdcr_el3(val); 24 } 25