Re: [PATCH v2 08/10] coresight: perf: Add helper to retrieve sink configuration

[Suzuki K Poulose]

On 19/07/18 21:07, Mathieu Poirier wrote:
> On Tue, Jul 17, 2018 at 06:11:39PM +0100, Suzuki K Poulose wrote:
> > We can always find the sink configuration for a given perf_output_handle.
> > Add a helper to retrieve the sink configuration for a given
> > perf_output_handle. This will be used to get rid of the set_buffer()
> > call back.
> >
> > Cc: Mathieu Poirier <mathieu.poirier@xxxxxxxxxx>
> > Signed-off-by: Suzuki K Poulose <suzuki.poulose@xxxxxxx>
> > ---
> >   drivers/hwtracing/coresight/coresight-etm-perf.c | 14 -------------
> >   drivers/hwtracing/coresight/coresight-etm-perf.h | 26 ++++++++++++++++++++++++
> >   2 files changed, 26 insertions(+), 14 deletions(-)
> >
> > diff --git a/drivers/hwtracing/coresight/coresight-etm-perf.c b/drivers/hwtracing/coresight/coresight-etm-perf.c
> > index 6a4252b..3cc4a0b 100644
> > --- a/drivers/hwtracing/coresight/coresight-etm-perf.c
> > +++ b/drivers/hwtracing/coresight/coresight-etm-perf.c
> > @@ -23,20 +23,6 @@
> >   static struct pmu etm_pmu;
> >   static bool etm_perf_up;
> >   
> > -/**
> > - * struct etm_event_data - Coresight specifics associated to an event
> > - * @work:		Handle to free allocated memory outside IRQ context.
> > - * @mask:		Hold the CPU(s) this event was set for.
> > - * @snk_config:		The sink configuration.
> > - * @path:		An array of path, each slot for one CPU.
> > - */
> > -struct etm_event_data {
> > -	struct work_struct work;
> > -	cpumask_t mask;
> > -	void *snk_config;
> > -	struct list_head * __percpu *path;
> > -};
> > -
>
> If this is moved to coresight-etm-perf.h, the #include <linux/percpu-defs.h> can
> be removed.

Actually, we do have the PER_CPU variables in the file already, which is why I left
them there.  See the next line.
> >   static DEFINE_PER_CPU(struct perf_output_handle, ctx_handle);
> >   static DEFINE_PER_CPU(struct coresight_device *, csdev_src);
> >   


> > diff --git a/drivers/hwtracing/coresight/coresight-etm-perf.h b/drivers/hwtracing/coresight/coresight-etm-perf.h
> > index 4197df4..da7d933 100644
> > --- a/drivers/hwtracing/coresight/coresight-etm-perf.h
> > +++ b/drivers/hwtracing/coresight/coresight-etm-perf.h
> > @@ -7,6 +7,7 @@
> >   #ifndef _CORESIGHT_ETM_PERF_H
> >   #define _CORESIGHT_ETM_PERF_H
> >   
> > +#include <linux/percpu-defs.h>
> >   #include "coresight-priv.h"
> >   
> >   struct coresight_device;
> > @@ -42,14 +43,39 @@ struct etm_filters {
> >   	bool			ssstatus;
> >   };
> >   
> > +/**
> > + * struct etm_event_data - Coresight specifics associated to an event
> > + * @work:		Handle to free allocated memory outside IRQ context.
> > + * @mask:		Hold the CPU(s) this event was set for.
> > + * @snk_config:		The sink configuration.
> > + * @path:		An array of path, each slot for one CPU.
> > + */
> > +struct etm_event_data {
> > +	struct work_struct work;
> > +	cpumask_t mask;
> > +	void *snk_config;
> > +	struct list_head * __percpu *path;
> > +};
> >   
> >   #ifdef CONFIG_CORESIGHT
> >   int etm_perf_symlink(struct coresight_device *csdev, bool link);
> > +static inline void *etm_perf_sink_config(struct perf_output_handle *handle)
> > +{
> > +	struct etm_event_data *data = perf_get_aux(handle);
> >   
> > +	if (data)
> > +		return data->snk_config;
> > +	return NULL;
> > +}
> >   #else
> >   static inline int etm_perf_symlink(struct coresight_device *csdev, bool link)
> >   { return -EINVAL; }
> >   
> > +static inline void *etm_perf_sink_config(struct perf_output_handle *handle)
> > +{
> > +	return NULL;
> > +}
> > +
>
> I think we can do without those... See my comment in the next patch.

Sure