drivers/hwtracing/coresight/coresight-self-hosted-trace.h

   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 */