38 lines
951 B
C
38 lines
951 B
C
/*
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* Copyright (c) 2021, 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 <stdbool.h>
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#include <arch.h>
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#include <arch_helpers.h>
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#include <lib/extensions/sys_reg_trace.h>
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static bool sys_reg_trace_supported(void)
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{
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uint64_t features;
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features = read_id_aa64dfr0_el1() >> ID_AA64DFR0_TRACEVER_SHIFT;
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return ((features & ID_AA64DFR0_TRACEVER_MASK) ==
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ID_AA64DFR0_TRACEVER_SUPPORTED);
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}
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void sys_reg_trace_enable(cpu_context_t *ctx)
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{
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uint64_t val;
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if (sys_reg_trace_supported()) {
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/* Retrieve CPTR_EL3 value from the given context 'ctx',
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* and update CPTR_EL3.TTA bit to 0.
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* This function is called while switching context to NS to
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* allow system trace register access to NS-EL2 and NS-EL1
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* when NS-EL2 is implemented but not used.
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*/
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val = read_ctx_reg(get_el3state_ctx(ctx), CTX_CPTR_EL3);
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val &= ~TTA_BIT;
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write_ctx_reg(get_el3state_ctx(ctx), CTX_CPTR_EL3, val);
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}
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}
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