From: Jonathan Zhou jonathan.zhouwen@huawei.com
v8.4 tracing extensions added support for trace filtering controlled by TRFCR_ELx. This must be programmed to allow tracing at EL1/EL2 and EL0. The timestamp used is the virtual time. Also enable CONTEXIDR_EL2 tracing if we are running the kernel at EL2.
Cc: Catalin Marinas catalin.marinas@arm.com Cc: Mathieu Poirier mathieu.poirier@linaro.org Cc: Mike Leach mike.leach@linaro.org Cc: Will Deacon will@kernel.org Signed-off-by: Jonathan Zhou jonathan.zhouwen@huawei.com [ Move the trace filtering setup etm_init_arch_data() and clean ups] Signed-off-by: Suzuki K Poulose suzuki.poulose@arm.com --- .../coresight/coresight-etm4x-core.c | 25 +++++++++++++++++++ 1 file changed, 25 insertions(+)
diff --git a/drivers/hwtracing/coresight/coresight-etm4x-core.c b/drivers/hwtracing/coresight/coresight-etm4x-core.c index 1d054d2ab2a0..647685736134 100644 --- a/drivers/hwtracing/coresight/coresight-etm4x-core.c +++ b/drivers/hwtracing/coresight/coresight-etm4x-core.c @@ -760,6 +760,30 @@ 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 (!(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; @@ -943,6 +967,7 @@ 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)