From: German Gomez german.gomez@arm.com
Add a new sysfs interface in /sys/bus/coresight/devices/etm<N>/ts_source indicating the configured timestamp source when the ETM device driver was probed.
The perf tool will use this information to detect if the trace data timestamp matches the kernel time, enabling correlation of CoreSight trace with perf events.
Suggested-by: Suzuki K Poulose suzuki.poulose@arm.com Signed-off-by: German Gomez german.gomez@arm.com Reviewed-by: Leo Yan leo.yan@linaro.org Signed-off-by: James Clark james.clark@arm.com --- arch/arm64/include/asm/sysreg.h | 1 + .../coresight/coresight-etm4x-sysfs.c | 29 +++++++++++++++++++ 2 files changed, 30 insertions(+)
diff --git a/arch/arm64/include/asm/sysreg.h b/arch/arm64/include/asm/sysreg.h index 7c71358d44c4..7a518a011669 100644 --- a/arch/arm64/include/asm/sysreg.h +++ b/arch/arm64/include/asm/sysreg.h @@ -1021,6 +1021,7 @@ #define SYS_MPIDR_SAFE_VAL (BIT(31))
#define TRFCR_ELx_TS_SHIFT 5 +#define TRFCR_ELx_TS_MASK ((0x3UL) << TRFCR_ELx_TS_SHIFT) #define TRFCR_ELx_TS_VIRTUAL ((0x1UL) << TRFCR_ELx_TS_SHIFT) #define TRFCR_ELx_TS_GUEST_PHYSICAL ((0x2UL) << TRFCR_ELx_TS_SHIFT) #define TRFCR_ELx_TS_PHYSICAL ((0x3UL) << TRFCR_ELx_TS_SHIFT) diff --git a/drivers/hwtracing/coresight/coresight-etm4x-sysfs.c b/drivers/hwtracing/coresight/coresight-etm4x-sysfs.c index 6ea8181816fc..9cac848cffaf 100644 --- a/drivers/hwtracing/coresight/coresight-etm4x-sysfs.c +++ b/drivers/hwtracing/coresight/coresight-etm4x-sysfs.c @@ -2306,6 +2306,34 @@ static ssize_t cpu_show(struct device *dev, } static DEVICE_ATTR_RO(cpu);
+static ssize_t ts_source_show(struct device *dev, + struct device_attribute *attr, + char *buf) +{ + int val; + struct etmv4_drvdata *drvdata = dev_get_drvdata(dev->parent); + + if (!drvdata->trfcr) { + val = -1; + goto out; + } + + switch (drvdata->trfcr & TRFCR_ELx_TS_MASK) { + case TRFCR_ELx_TS_VIRTUAL: + case TRFCR_ELx_TS_GUEST_PHYSICAL: + case TRFCR_ELx_TS_PHYSICAL: + val = FIELD_GET(TRFCR_ELx_TS_MASK, drvdata->trfcr); + break; + default: + val = -1; + break; + } + +out: + return sysfs_emit(buf, "%d\n", val); +} +static DEVICE_ATTR_RO(ts_source); + static struct attribute *coresight_etmv4_attrs[] = { &dev_attr_nr_pe_cmp.attr, &dev_attr_nr_addr_cmp.attr, @@ -2360,6 +2388,7 @@ static struct attribute *coresight_etmv4_attrs[] = { &dev_attr_vmid_val.attr, &dev_attr_vmid_masks.attr, &dev_attr_cpu.attr, + &dev_attr_ts_source.attr, NULL, };