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Commit 17534ceb authored by Mathieu Poirier's avatar Mathieu Poirier Committed by Greg Kroah-Hartman
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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: default avatarMathieu Poirier <mathieu.poirier@linaro.org>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent 0bcbf2e3

drivers/hwtracing/coresight/coresight-etm3x.c

+2 −5
Original line number Diff line number Diff line
@@ -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)

include/linux/coresight-pmu.h

+12 −0
Original line number Diff line number Diff line
@@ -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