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| author | Mathieu Poirier <mathieu.poirier@linaro.org> | 2016-02-17 17:52:02 -0700 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2016-02-20 14:11:01 -0800 |
| commit | 17534ceb835a1a96eb921a2a80df168723d6570a (patch) | |
| tree | 6cbfd344150ab19190bf415ef4c328ccbf9dcf3d | |
| parent | 0bcbf2e30ff2271b54f54c8697a185f7d86ec6e4 (diff) | |
| download | lwn-17534ceb835a1a96eb921a2a80df168723d6570a.tar.gz lwn-17534ceb835a1a96eb921a2a80df168723d6570a.zip | |
coresight: introducing a global trace ID function
TraceID values have to be unique for all tracers and
consistent between drivers and user space. As such
introducing a central function to be used whenever a
traceID value is required.
The patch also account for data traceIDs, which are usually
I(N) + 1.
Signed-off-by: Mathieu Poirier <mathieu.poirier@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| -rw-r--r-- | drivers/hwtracing/coresight/coresight-etm3x.c | 7 | ||||
| -rw-r--r-- | include/linux/coresight-pmu.h | 12 |
2 files changed, 14 insertions, 5 deletions
diff --git a/drivers/hwtracing/coresight/coresight-etm3x.c b/drivers/hwtracing/coresight/coresight-etm3x.c index 77b37413803f..0ba1a3981373 100644 --- a/drivers/hwtracing/coresight/coresight-etm3x.c +++ b/drivers/hwtracing/coresight/coresight-etm3x.c @@ -27,6 +27,7 @@ #include <linux/cpu.h> #include <linux/of.h> #include <linux/coresight.h> +#include <linux/coresight-pmu.h> #include <linux/amba/bus.h> #include <linux/seq_file.h> #include <linux/uaccess.h> @@ -740,11 +741,7 @@ static void etm_init_arch_data(void *info) static void etm_init_trace_id(struct etm_drvdata *drvdata) { - /* - * A trace ID of value 0 is invalid, so let's start at some - * random value that fits in 7 bits and go from there. - */ - drvdata->traceid = 0x10 + drvdata->cpu; + drvdata->traceid = coresight_get_trace_id(drvdata->cpu); } static int etm_probe(struct amba_device *adev, const struct amba_id *id) diff --git a/include/linux/coresight-pmu.h b/include/linux/coresight-pmu.h index 6c5386b23b10..7d410260661b 100644 --- a/include/linux/coresight-pmu.h +++ b/include/linux/coresight-pmu.h @@ -19,9 +19,21 @@ #define _LINUX_CORESIGHT_PMU_H #define CORESIGHT_ETM_PMU_NAME "cs_etm" +#define CORESIGHT_ETM_PMU_SEED 0x10 /* ETMv3.5/PTM's ETMCR config bit */ #define ETM_OPT_CYCACC 12 #define ETM_OPT_TS 28 +static inline int coresight_get_trace_id(int cpu) +{ + /* + * A trace ID of value 0 is invalid, so let's start at some + * random value that fits in 7 bits and go from there. Since + * the common convention is to have data trace IDs be I(N) + 1, + * set instruction trace IDs as a function of the CPU number. + */ + return (CORESIGHT_ETM_PMU_SEED + (cpu * 2)); +} + #endif |