1 /* SPDX-License-Identifier: GPL-2.0-only */ 2 /* 3 * Arm v8 Self-Hosted trace support. 4 * 5 * Copyright (C) 2021 ARM Ltd. 6 */ 7 8 #ifndef __CORESIGHT_SELF_HOSTED_TRACE_H 9 #define __CORESIGHT_SELF_HOSTED_TRACE_H 10 11 #include <asm/sysreg.h> 12 13 static inline u64 read_trfcr(void) 14 { 15 return read_sysreg_s(SYS_TRFCR_EL1); 16 } 17 18 static inline void write_trfcr(u64 val) 19 { 20 write_sysreg_s(val, SYS_TRFCR_EL1); 21 isb(); 22 } 23 24 static inline u64 cpu_prohibit_trace(void) 25 { 26 u64 trfcr = read_trfcr(); 27 28 /* Prohibit tracing at EL0 & the kernel EL */ 29 write_trfcr(trfcr & ~(TRFCR_ELx_ExTRE | TRFCR_ELx_E0TRE)); 30 /* Return the original value of the TRFCR */ 31 return trfcr; 32 } 33 #endif /* __CORESIGHT_SELF_HOSTED_TRACE_H */ 34