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.poir...@linaro.org>
Signed-off-by: Suzuki K Poulose <suzuki.poul...@arm.com>
---
  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