xref: /rk3399_ARM-atf/lib/extensions/brbe/brbe.c (revision 1298f2f13d6d97dfcac120a2ee68d5eea3797068)
1744ad974Sjohpow01 /*
2744ad974Sjohpow01  * Copyright (c) 2022, Arm Limited. All rights reserved.
3744ad974Sjohpow01  *
4744ad974Sjohpow01  * SPDX-License-Identifier: BSD-3-Clause
5744ad974Sjohpow01  */
6744ad974Sjohpow01 
7744ad974Sjohpow01 #include <arch.h>
8*1298f2f1SJayanth Dodderi Chidanand #include <arch_features.h>
9744ad974Sjohpow01 #include <arch_helpers.h>
10744ad974Sjohpow01 
11744ad974Sjohpow01 void brbe_enable(void)
12744ad974Sjohpow01 {
13744ad974Sjohpow01 	uint64_t val;
14744ad974Sjohpow01 
15*1298f2f1SJayanth Dodderi Chidanand 	if (is_feat_brbe_present()) {
16744ad974Sjohpow01 		/*
17744ad974Sjohpow01 		 * MDCR_EL3.SBRBE = 0b01
18744ad974Sjohpow01 		 *
19744ad974Sjohpow01 		 * Allows BRBE usage in non-secure world and prohibited in
20744ad974Sjohpow01 		 * secure world.
21744ad974Sjohpow01 		 */
22744ad974Sjohpow01 		val = read_mdcr_el3();
23744ad974Sjohpow01 		val &= ~(MDCR_SBRBE_MASK << MDCR_SBRBE_SHIFT);
24744ad974Sjohpow01 		val |= (0x1UL << MDCR_SBRBE_SHIFT);
25744ad974Sjohpow01 		write_mdcr_el3(val);
26744ad974Sjohpow01 	}
27744ad974Sjohpow01 }
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