[PATCH v2 4/4] coresight: etm4x: Hook panic dump callback for etmv4

[Mathieu Poirier]

On Tue, Nov 21, 2017 at 11:08:44AM +0800, Leo Yan wrote:
> We need to dump etmv4 info as metadata, so the data can be used for
> offline checking for configuration and generate 'perf' compatible
> file.  This commit hooks etmv4 callback for panic dump.
> 
> Signed-off-by: Leo Yan <leo.yan at linaro.org>
> ---
>  drivers/hwtracing/coresight/coresight-etm4x.c | 22 ++++++++++++++++++++++
>  drivers/hwtracing/coresight/coresight-etm4x.h | 15 +++++++++++++++
>  2 files changed, 37 insertions(+)
> 
> diff --git a/drivers/hwtracing/coresight/coresight-etm4x.c b/drivers/hwtracing/coresight/coresight-etm4x.c
> index cf364a5..bf9608b 100644
> --- a/drivers/hwtracing/coresight/coresight-etm4x.c
> +++ b/drivers/hwtracing/coresight/coresight-etm4x.c
> @@ -418,11 +418,33 @@ static void etm4_disable(struct coresight_device *csdev,
>  		local_set(&drvdata->mode, CS_MODE_DISABLED);
>  }
>  
> +static void etm4_panic_cb(void *data)
> +{
> +	struct coresight_device *csdev = (struct coresight_device *)data;
> +	int cpu = smp_processor_id();
> +	struct etmv4_drvdata *drvdata = etmdrvdata[cpu];
> +	struct etmv4_config *config = &drvdata->config;
> +	struct etmv4_metadata *metadata = &drvdata->metadata;
> +
> +	metadata->magic = ETM4_METADATA_MAGIC;
> +	metadata->cpu = cpu;
> +	metadata->trcconfigr = config->cfg;
> +	metadata->trctraceidr = drvdata->trcid;
> +	metadata->trcidr0 = readl_relaxed(drvdata->base + TRCIDR0);
> +	metadata->trcidr1 = readl_relaxed(drvdata->base + TRCIDR1);
> +	metadata->trcidr2 = readl_relaxed(drvdata->base + TRCIDR2);
> +	metadata->trcidr8 = readl_relaxed(drvdata->base + TRCIDR8);

I'm pretty sure this won't work on all architecture.  This tracer may not be
powered when this is called and depending on the power domain the TRCIDRx
registers are in it may lock.

Simply read those at boot time as part of the _probe() function.

> +	metadata->trcauthstatus = readl_relaxed(drvdata->base + TRCAUTHSTATUS);
> +
> +	coresight_dump_update(csdev, (char *)metadata, sizeof(*metadata));
> +}
> +
>  static const struct coresight_ops_source etm4_source_ops = {
>  	.cpu_id		= etm4_cpu_id,
>  	.trace_id	= etm4_trace_id,
>  	.enable		= etm4_enable,
>  	.disable	= etm4_disable,
> +	.panic_cb	= etm4_panic_cb,
>  };
>  
>  static const struct coresight_ops etm4_cs_ops = {
> diff --git a/drivers/hwtracing/coresight/coresight-etm4x.h b/drivers/hwtracing/coresight/coresight-etm4x.h
> index b3b5ea7..08dc8b7 100644
> --- a/drivers/hwtracing/coresight/coresight-etm4x.h
> +++ b/drivers/hwtracing/coresight/coresight-etm4x.h
> @@ -198,6 +198,20 @@
>  #define ETM_EXLEVEL_NS_HYP		BIT(14)
>  #define ETM_EXLEVEL_NS_NA		BIT(15)
>  
> +#define ETM4_METADATA_MAGIC		0x4040404040404040ULL
> +
> +struct etmv4_metadata {
> +	u64 magic;
> +	u64 cpu;
> +	u64 trcconfigr;
> +	u64 trctraceidr;
> +	u64 trcidr0;
> +	u64 trcidr1;
> +	u64 trcidr2;
> +	u64 trcidr8;
> +	u64 trcauthstatus;
> +};
> +
>  /**
>   * struct etmv4_config - configuration information related to an ETMv4
>   * @mode:	Controls various modes supported by this ETM.
> @@ -393,6 +407,7 @@ struct etmv4_drvdata {
>  	bool				atbtrig;
>  	bool				lpoverride;
>  	struct etmv4_config		config;
> +	struct etmv4_metadata		metadata;
>  };
>  
>  /* Address comparator access types */
> -- 
> 2.7.4
>