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>
This commit is contained in:
Mathieu Poirier 2016-02-17 17:52:02 -07:00 committed by Greg Kroah-Hartman
parent 0bcbf2e30f
commit 17534ceb83
2 changed files with 14 additions and 5 deletions

View File

@ -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)

View File

@ -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