arm-trusted-firmware/lib/extensions/brbe/brbe.c

/*
 * Copyright (c) 2022-2023, Arm Limited. All rights reserved.
 *
 * SPDX-License-Identifier: BSD-3-Clause
 */

#include <arch.h>
#include <arch_features.h>
#include <arch_helpers.h>
#include <lib/extensions/brbe.h>

void brbe_init_el3(void)
{
	uint64_t val;

	/*
	 * MDCR_EL3.SBRBE = 0b01
	 *
	 * Allows BRBE usage in non-secure world and prohibited in
	 * secure world.
	 */
	val = read_mdcr_el3();
	val &= ~(MDCR_SBRBE_MASK << MDCR_SBRBE_SHIFT);
	val |= (0x1UL << MDCR_SBRBE_SHIFT);
	write_mdcr_el3(val);
}