[PATCH v3 03/26] coresight: etm4x: Update TRCIDR3.NUMPROCS handling to match v4.2

Suzuki K Poulose
2020-10-28T22:10:15Z

Since ETMv4.2, TRCIDR3.NUMPROCS has been extended to a 5bit field
by encoding the top 2 bits[4:3] in TRCIDR3.[13:12], which were RES0.
Fix the driver to compute the field correctly for ETMv4.2+

Cc: Mike Leach <mike.leach@linaro.org>
Cc: Mathieu Poirier <mathieu.poirier@linaro.org>
Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>
---
drivers/hwtracing/coresight/coresight-etm4x-core.c | 9 +++++++--
1 file changed, 7 insertions(+), 2 deletions(-)

diff --git a/drivers/hwtracing/coresight/coresight-etm4x-core.c b/drivers/hwtracing/coresight/coresight-etm4x-core.c
index af0ab2f44865..cbbe755d1d16 100644
--- a/drivers/hwtracing/coresight/coresight-etm4x-core.c
+++ b/drivers/hwtracing/coresight/coresight-etm4x-core.c
@@ -724,8 +724,13 @@ static void etm4_init_arch_data(void *info)
else
drvdata->sysstall = false;

- /* NUMPROC, bits[30:28] the number of PEs available for tracing */
- drvdata->nr_pe = BMVAL(etmidr3, 28, 30);
+ /*
+ * NUMPROC - the number of PEs available for tracing, 5bits
+ * = TRCIDR3.bits[13:12]bits[30:28]
+ * bits[4:3] = TRCIDR3.bits[13:12] (since etm-v4.2, otherwise RES0)
+ * bits[3:0] = TRCIDR3.bits[30:28]
+ */
+ drvdata->nr_pe = (BMVAL(etmidr3, 12, 13) << 3) | BMVAL(etmidr3, 28, 30);

/* NOOVERFLOW, bit[31] is trace overflow prevention supported */
if (BMVAL(etmidr3, 31, 31))
--
2.24.1