Manish V Badarkhe | f356f7e | 2021-06-29 11:44:20 +0100 | [diff] [blame] | 1 | /* |
| 2 | * Copyright (c) 2021, Arm Limited. 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/sys_reg_trace.h> |
| 12 | |
| 13 | static bool sys_reg_trace_supported(void) |
| 14 | { |
| 15 | uint64_t features; |
| 16 | |
| 17 | features = read_id_aa64dfr0_el1() >> ID_AA64DFR0_TRACEVER_SHIFT; |
| 18 | return ((features & ID_AA64DFR0_TRACEVER_MASK) == |
| 19 | ID_AA64DFR0_TRACEVER_SUPPORTED); |
| 20 | } |
| 21 | |
| 22 | void sys_reg_trace_enable(cpu_context_t *ctx) |
| 23 | { |
| 24 | uint64_t val; |
| 25 | |
| 26 | if (sys_reg_trace_supported()) { |
| 27 | /* Retrieve CPTR_EL3 value from the given context 'ctx', |
| 28 | * and update CPTR_EL3.TTA bit to 0. |
| 29 | * This function is called while switching context to NS to |
| 30 | * allow system trace register access to NS-EL2 and NS-EL1 |
| 31 | * when NS-EL2 is implemented but not used. |
| 32 | */ |
| 33 | val = read_ctx_reg(get_el3state_ctx(ctx), CTX_CPTR_EL3); |
| 34 | val &= ~TTA_BIT; |
| 35 | write_ctx_reg(get_el3state_ctx(ctx), CTX_CPTR_EL3, val); |
| 36 | } |
| 37 | } |