diff options
| -rw-r--r-- | drivers/hwtracing/coresight/coresight-etm4x-core.c | 25 |
1 files changed, 25 insertions, 0 deletions
diff --git a/drivers/hwtracing/coresight/coresight-etm4x-core.c b/drivers/hwtracing/coresight/coresight-etm4x-core.c index c6238e208685..473ab7480a36 100644 --- a/drivers/hwtracing/coresight/coresight-etm4x-core.c +++ b/drivers/hwtracing/coresight/coresight-etm4x-core.c @@ -859,6 +859,30 @@ static bool etm4_init_csdev_access(struct etmv4_drvdata *drvdata, return false; } +static void cpu_enable_tracing(void) +{ + u64 dfr0 = read_sysreg(id_aa64dfr0_el1); + u64 trfcr; + + if (!cpuid_feature_extract_unsigned_field(dfr0, ID_AA64DFR0_TRACE_FILT_SHIFT)) + return; + + /* + * If the CPU supports v8.4 SelfHosted Tracing, enable + * tracing at the kernel EL and EL0, forcing to use the + * virtual time as the timestamp. + */ + trfcr = (TRFCR_ELx_TS_VIRTUAL | + TRFCR_ELx_ExTRE | + TRFCR_ELx_E0TRE); + + /* If we are running at EL2, allow tracing the CONTEXTIDR_EL2. */ + if (is_kernel_in_hyp_mode()) + trfcr |= TRFCR_EL2_CX; + + write_sysreg_s(trfcr, SYS_TRFCR_EL1); +} + static void etm4_init_arch_data(void *info) { u32 etmidr0; @@ -1044,6 +1068,7 @@ static void etm4_init_arch_data(void *info) /* NUMCNTR, bits[30:28] number of counters available for tracing */ drvdata->nr_cntr = BMVAL(etmidr5, 28, 30); etm4_cs_lock(drvdata, csa); + cpu_enable_tracing(); } static inline u32 etm4_get_victlr_access_type(struct etmv4_config *config) |