/*
 * Copyright (c) 2017, ARM Limited and Contributors. All rights reserved.
 *
 * SPDX-License-Identifier: BSD-3-Clause
 */

#include <amu.h>
#include <arch.h>
#include <arch_helpers.h>
#include <debug.h>

void amu_enable(int el2_unused)
{
	uint64_t features;

	features = read_id_pfr0() >> ID_PFR0_AMU_SHIFT;
	if ((features & ID_PFR0_AMU_MASK) != 1) {
		WARN("Cannot enable AMU - not supported\n");
		return;
	}

	if (el2_unused) {
		uint64_t v;

		/*
		 * Non-secure access from EL0 or EL1 to the Activity Monitor
		 * registers do not trap to EL2.
		 */
		v = read_hcptr();
		v &= ~TAM_BIT;
		write_hcptr(v);
	}

	/* Enable group 0 counters */
	write_amcntenset0(AMU_GROUP0_COUNTERS_MASK);
}