From: Jonathan Zhou <redacted>

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 <redacted>
Cc: Will Deacon <will@kernel.org>
Signed-off-by: Jonathan Zhou <redacted>
[ 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;