From 17534ceb835a1a96eb921a2a80df168723d6570a Mon Sep 17 00:00:00 2001 From: Mathieu Poirier Date: Wed, 17 Feb 2016 17:52:02 -0700 Subject: [PATCH] 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 Signed-off-by: Greg Kroah-Hartman --- drivers/hwtracing/coresight/coresight-etm3x.c | 7 ++----- 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 #include #include +#include #include #include #include @@ -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 -- 2.20.1