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

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Date:   Wed, 28 Oct 2020 22:09:22 +0000
From:   Suzuki K Poulose <suzuki.poulose@....com>
To:     linux-arm-kernel@...ts.infradead.org
Cc:     mathieu.poirier@...aro.org, mike.leach@...aro.org,
        coresight@...ts.linaro.org, linux-kernel@...r.kernel.org,
        Suzuki K Poulose <suzuki.poulose@....com>
Subject: [PATCH v3 03/26] coresight: etm4x: Update TRCIDR3.NUMPROCS handling to match v4.2

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@...aro.org>
Cc: Mathieu Poirier <mathieu.poirier@...aro.org>
Signed-off-by: Suzuki K Poulose <suzuki.poulose@....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