[PATCH v4 09/11] coresight: etm4x: Add flag to control single-shot restart

[Yeoreum Yun]

Reviewed-by: Yeoreum Yun <yeoreum.yun at arm.com>

> Add a new argument restart_ss to etm4_enable_hw(). When passed as true,
> it resets the TRCSSCSRn.STATUS bit to 0 to re-enable single-shot
> control.
>
> No functional change. This is a preparation for a subsequent change.
>
> Reviewed-by: Mike Leach <mike.leach at linaro.org>
> Tested-by: James Clark <james.clark at linaro.org>
> Signed-off-by: Leo Yan <leo.yan at arm.com>
> ---
>  drivers/hwtracing/coresight/coresight-etm4x-core.c | 16 +++++++++-------
>  1 file changed, 9 insertions(+), 7 deletions(-)
>
> diff --git a/drivers/hwtracing/coresight/coresight-etm4x-core.c b/drivers/hwtracing/coresight/coresight-etm4x-core.c
> index 15f70268e5b605a6881504c0c60b001251fbbddf..4c6236ad241d1a13515160ca478fae839a891e38 100644
> --- a/drivers/hwtracing/coresight/coresight-etm4x-core.c
> +++ b/drivers/hwtracing/coresight/coresight-etm4x-core.c
> @@ -487,7 +487,7 @@ static int etm4_enable_trace_unit(struct etmv4_drvdata *drvdata)
>  	return 0;
>  }
>
> -static int etm4_enable_hw(struct etmv4_drvdata *drvdata)
> +static int etm4_enable_hw(struct etmv4_drvdata *drvdata, bool restart_ss)
>  {
>  	int i, rc;
>  	struct etmv4_config *config = &drvdata->config;
> @@ -562,9 +562,11 @@ static int etm4_enable_hw(struct etmv4_drvdata *drvdata)
>  		etm4x_relaxed_write32(csa, config->res_ctrl[i], TRCRSCTLRn(i));
>
>  	for (i = 0; i < drvdata->nr_ss_cmp; i++) {
> -		/* always clear status bit on restart if using single-shot */
> -		if (config->ss_ctrl[i] || config->ss_pe_cmp[i])
> -			config->ss_status[i] &= ~TRCSSCSRn_STATUS;
> +		if (restart_ss) {
> +			/* always clear status bit on restart if using single-shot */
> +			if (config->ss_ctrl[i] || config->ss_pe_cmp[i])
> +				config->ss_status[i] &= ~TRCSSCSRn_STATUS;
> +		}
>  		etm4x_relaxed_write32(csa, config->ss_ctrl[i], TRCSSCCRn(i));
>  		etm4x_relaxed_write32(csa, config->ss_status[i], TRCSSCSRn(i));
>  		if (etm4x_sspcicrn_present(drvdata, i))
> @@ -628,7 +630,7 @@ static void etm4_enable_sysfs_smp_call(void *info)
>  		return;
>  	}
>
> -	arg->rc = etm4_enable_hw(arg->drvdata);
> +	arg->rc = etm4_enable_hw(arg->drvdata, true);
>
>  	/* The tracer didn't start */
>  	if (arg->rc)
> @@ -865,7 +867,7 @@ static int etm4_enable_perf(struct coresight_device *csdev,
>  	drvdata->paused = !!READ_ONCE(event->hw.aux_paused);
>
>  	/* And enable it */
> -	ret = etm4_enable_hw(drvdata);
> +	ret = etm4_enable_hw(drvdata, true);
>
>  out:
>  	/* Failed to start tracer; roll back to DISABLED mode */
> @@ -1831,7 +1833,7 @@ static int etm4_starting_cpu(unsigned int cpu)
>  		etm4_os_unlock(etmdrvdata[cpu]);
>
>  	if (coresight_get_mode(etmdrvdata[cpu]->csdev))
> -		etm4_enable_hw(etmdrvdata[cpu]);
> +		etm4_enable_hw(etmdrvdata[cpu], true);
>  	raw_spin_unlock(&etmdrvdata[cpu]->spinlock);
>  	return 0;
>  }
>
> --
> 2.34.1
>

--
Sincerely,
Yeoreum Yun