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744ad97445
This patch enables access to the branch record buffer control registers in non-secure EL2 and EL1 using the new build option ENABLE_BRBE_FOR_NS. It is disabled for all secure world, and cannot be used with ENABLE_RME. This option is disabled by default, however, the FVP platform makefile enables it for FVP builds. Signed-off-by: John Powell <john.powell@arm.com> Change-Id: I576a49d446a8a73286ea6417c16bd0b8de71fca0
35 lines
682 B
C
35 lines
682 B
C
/*
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* Copyright (c) 2022, Arm Limited. All rights reserved.
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*
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* SPDX-License-Identifier: BSD-3-Clause
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*/
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#include <arch.h>
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#include <arch_helpers.h>
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static bool brbe_supported(void)
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{
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uint64_t features;
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features = read_id_aa64dfr0_el1() >> ID_AA64DFR0_BRBE_SHIFT;
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return ((features & ID_AA64DFR0_BRBE_MASK) ==
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ID_AA64DFR0_BRBE_SUPPORTED);
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}
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void brbe_enable(void)
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{
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uint64_t val;
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if (brbe_supported()) {
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/*
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* MDCR_EL3.SBRBE = 0b01
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*
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* Allows BRBE usage in non-secure world and prohibited in
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* secure world.
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*/
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val = read_mdcr_el3();
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val &= ~(MDCR_SBRBE_MASK << MDCR_SBRBE_SHIFT);
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val |= (0x1UL << MDCR_SBRBE_SHIFT);
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write_mdcr_el3(val);
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}
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}
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