1 /* 2 * Copyright (c) 2018, ARM Limited and Contributors. All rights reserved. 3 * 4 * SPDX-License-Identifier: BSD-3-Clause 5 */ 6 7 #include <stdbool.h> 8 9 #include <arch.h> 10 #include <arch_helpers.h> 11 #include <lib/extensions/mpam.h> 12 13 bool mpam_supported(void) 14 { 15 uint64_t features = read_id_aa64dfr0_el1() >> ID_AA64PFR0_MPAM_SHIFT; 16 17 return ((features & ID_AA64PFR0_MPAM_MASK) != 0U); 18 } 19 20 void mpam_enable(bool el2_unused) 21 { 22 if (!mpam_supported()) 23 return; 24 25 /* 26 * Enable MPAM, and disable trapping to EL3 when lower ELs access their 27 * own MPAM registers. 28 */ 29 write_mpam3_el3(MPAM3_EL3_MPAMEN_BIT); 30 31 /* 32 * If EL2 is implemented but unused, disable trapping to EL2 when lower 33 * ELs access their own MPAM registers. 34 */ 35 if (el2_unused) { 36 write_mpam2_el2(0); 37 38 if ((read_mpamidr_el1() & MPAMIDR_HAS_HCR_BIT) != 0U) 39 write_mpamhcr_el2(0); 40 } 41 } 42