coresight: etm4x: Fix timestamp bit field handling

Timestamps in the trace data appear as all zeros on recent kernels,
although the feature works correctly on old kernels (e.g., v6.12).

Since commit c382ee674c8b ("arm64/sysreg/tools: Move TRFCR definitions
to sysreg"), the TRFCR_ELx_TS_{VIRTUAL|GUEST_PHYSICAL|PHYSICAL} macros
were updated to remove the bit shift. As a result, the driver no longer
shifts bits when operates the timestamp field.

Fix this by using the FIELD_PREP() and FIELD_GET() helpers.

Reported-by: Tamas Zsoldos <tamas.zsoldos@arm.com>
Fixes: c382ee674c8b ("arm64/sysreg/tools: Move TRFCR definitions to sysreg")
Signed-off-by: Leo Yan <leo.yan@arm.com>
Reviewed-by: James Clark <james.clark@linaro.org>
Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Link: https://lore.kernel.org/r/20250519174945.2245271-2-leo.yan@arm.com

diff --git a/drivers/hwtracing/coresight/coresight-etm4x-core.c b/drivers/hwtracing/coresight/coresight-etm4x-core.c
index 6a5898355a83893973b5aa0b769debae79961673..acb4a58e4bb95df1b12cea9bae8c7085ddc1b2b5 100644 (file)
--- a/drivers/hwtracing/coresight/coresight-etm4x-core.c
+++ b/drivers/hwtracing/coresight/coresight-etm4x-core.c
@@ -1237,7 +1237,7 @@ static void cpu_detect_trace_filtering(struct etmv4_drvdata *drvdata)
         * tracing at the kernel EL and EL0, forcing to use the
         * virtual time as the timestamp.
         */
-       trfcr = (TRFCR_EL1_TS_VIRTUAL |
+       trfcr = (FIELD_PREP(TRFCR_EL1_TS_MASK, TRFCR_EL1_TS_VIRTUAL) |
                 TRFCR_EL1_ExTRE |
                 TRFCR_EL1_E0TRE);
 

diff --git a/drivers/hwtracing/coresight/coresight-etm4x-sysfs.c b/drivers/hwtracing/coresight/coresight-etm4x-sysfs.c
index 49d5fb87a74b613176e172e00d5b355a05b0ac5f..ab251865b893d8f24544b1fe302163025d6382b7 100644 (file)
--- a/drivers/hwtracing/coresight/coresight-etm4x-sysfs.c
+++ b/drivers/hwtracing/coresight/coresight-etm4x-sysfs.c
@@ -2320,11 +2320,11 @@ static ssize_t ts_source_show(struct device *dev,
                goto out;
        }
 
-       switch (drvdata->trfcr & TRFCR_EL1_TS_MASK) {
+       val = FIELD_GET(TRFCR_EL1_TS_MASK, drvdata->trfcr);
+       switch (val) {
        case TRFCR_EL1_TS_VIRTUAL:
        case TRFCR_EL1_TS_GUEST_PHYSICAL:
        case TRFCR_EL1_TS_PHYSICAL:
-               val = FIELD_GET(TRFCR_EL1_TS_MASK, drvdata->trfcr);
                break;
        default:
                val = -1;