Re: [RFC PATCH v3 4/9] coresight: etm-perf: update to handle configuration selection

Hi Mathieu,

On Fri, 20 Nov 2020 at 18:52, Mathieu Poirier mathieu.poirier@linaro.org wrote:

On Fri, Oct 30, 2020 at 05:56:50PM +0000, Mike Leach wrote:

...

Loaded coresight configurations are registered in the cs_etm\cs_config sub directory. This extends the etm-perf code to handle these registrations, and the cs_syscfg driver to perform the registration on load.

Signed-off-by: Mike Leach mike.leach@linaro.org

.../hwtracing/coresight/coresight-config.h | 5 +- .../hwtracing/coresight/coresight-etm-perf.c | 164 +++++++++++++++--- .../hwtracing/coresight/coresight-etm-perf.h | 8 + .../hwtracing/coresight/coresight-syscfg.c | 23 ++- 4 files changed, 172 insertions(+), 28 deletions(-)

diff --git a/drivers/hwtracing/coresight/coresight-config.h b/drivers/hwtracing/coresight/coresight-config.h index a3d374ebb70f..372f29a59688 100644 --- a/drivers/hwtracing/coresight/coresight-config.h +++ b/drivers/hwtracing/coresight/coresight-config.h @@ -154,7 +154,8 @@ struct cscfg_config_feat_ref {

• @nr_presets: Number of sets of presets supplied by this configuration.
• @nr_total_params: Sum of all parameters declared by used features
• @presets: Array of preset values.

• • @id_ea: Extended attribute for perf configid value
• • @event_ea: Extended attribute for perf event value
  */

struct cscfg_config_desc { const char *name; @@ -165,6 +166,8 @@ struct cscfg_config_desc { int nr_presets; int nr_total_params; const u64 *presets; /* nr_presets * nr_total_params */

• struct dev_ext_attribute *id_ea;
  

• struct dev_ext_attribute *event_ea;
  

};

/** diff --git a/drivers/hwtracing/coresight/coresight-etm-perf.c b/drivers/hwtracing/coresight/coresight-etm-perf.c index a608081bd446..8a87984195ed 100644 --- a/drivers/hwtracing/coresight/coresight-etm-perf.c +++ b/drivers/hwtracing/coresight/coresight-etm-perf.c @@ -20,6 +20,8 @@

#include "coresight-etm-perf.h" #include "coresight-priv.h" +#include "coresight-config.h"

Alphabetical order

OK

...

+#include "coresight-syscfg.h"

static struct pmu etm_pmu; static bool etm_perf_up; @@ -34,6 +36,11 @@ PMU_FORMAT_ATTR(timestamp, "config:" __stringify(ETM_OPT_TS)); PMU_FORMAT_ATTR(retstack, "config:" __stringify(ETM_OPT_RETSTK)); /* Sink ID - same for all ETMs */ PMU_FORMAT_ATTR(sinkid, "config2:0-31"); +/* preset - if sink ID is used as a configuration selector */ +PMU_FORMAT_ATTR(preset, "config:0-3");

Please move this before sinkid to keep the "config" together. I also looked at bit 0-3 of the ETMCR on ETMv3.x and I don't think we'll be using those bits any time soon.

Agreed.

...

+/* config ID - set if a system configuration is selected */ +PMU_FORMAT_ATTR(configid, "config2:32-63");

static struct attribute *etm_config_formats_attr[] = { &format_attr_cycacc.attr, @@ -41,6 +48,8 @@ static struct attribute *etm_config_formats_attr[] = { &format_attr_timestamp.attr, &format_attr_retstack.attr, &format_attr_sinkid.attr,

• &format_attr_preset.attr,
  

• &format_attr_configid.attr,
  NULL,
  

};

@@ -58,9 +67,29 @@ static const struct attribute_group etm_pmu_sinks_group = { .attrs = etm_config_sinks_attr, };

+static struct attribute *etm_config_cscfg_attr[] = {

• NULL,
  

+};

+static const struct attribute_group etm_pmu_cscfg_group = {

• .name   = "configurations",
  

• .attrs  = etm_config_cscfg_attr,
  

+};

+static struct attribute *etm_config_events_attr[] = {

• NULL,
  

+};

+static const struct attribute_group etm_pmu_events_group = {

• .name   = "events",
  

• .attrs  = etm_config_events_attr,
  

+};

static const struct attribute_group *etm_pmu_attr_groups[] = { &etm_pmu_format_group, &etm_pmu_sinks_group,

• &etm_pmu_cscfg_group,
  

• &etm_pmu_events_group,
  NULL,
  

};

@@ -219,7 +248,7 @@ static void *etm_setup_aux(struct perf_event *event, void **pages, INIT_WORK(&event_data->work, free_event_data);

  /* First get the selected sink from user space. */

• if (event->attr.config2) {
  

• if (event->attr.config2 & GENMASK_ULL(31, 0)) {
          id = (u32)event->attr.config2;
          sink = coresight_get_sink_by_id(id);
  }
  

@@ -537,21 +566,17 @@ static ssize_t etm_perf_sink_name_show(struct device *dev, return scnprintf(buf, PAGE_SIZE, "0x%lx\n", (unsigned long)(ea->var)); }

-int etm_perf_add_symlink_sink(struct coresight_device *csdev) +int etm_perf_add_symlink_group(struct device *dev,

•                        struct dev_ext_attribute **ext_attr,
  

•                        const char *name,
  

•                        const char *group_name)
  

{

• int ret;
  

• struct dev_ext_attribute *ea;
  unsigned long hash;
  

• const char *name;
  

• int ret;
  struct device *pmu_dev = etm_pmu.dev;
  

• struct device *dev = &csdev->dev;
  

• struct dev_ext_attribute *ea;
  
  

• if (csdev->type != CORESIGHT_DEV_TYPE_SINK &&
  

•     csdev->type != CORESIGHT_DEV_TYPE_LINKSINK)
  

•         return -EINVAL;
  

• if (csdev->ea != NULL)
  

•         return -EINVAL;
  

• *ext_attr = NULL;
  
  if (!etm_perf_up)
          return -EPROBE_DEFER;
  

@@ -560,7 +585,6 @@ int etm_perf_add_symlink_sink(struct coresight_device *csdev) if (!ea) return -ENOMEM;

• name = dev_name(dev);
  /* See function coresight_get_sink_by_id() to know where this is used */
  hash = hashlen_hash(hashlen_string(NULL, name));
  
  

@@ -574,31 +598,127 @@ int etm_perf_add_symlink_sink(struct coresight_device *csdev) ea->var = (unsigned long *)hash;

  ret = sysfs_add_file_to_group(&pmu_dev->kobj,

•                               &ea->attr.attr, "sinks");
  

•                               &ea->attr.attr, group_name);
  if (!ret)
  

•         csdev->ea = ea;
  

•         *ext_attr = ea;
  return ret;
  

}

-void etm_perf_del_symlink_sink(struct coresight_device *csdev) +int etm_perf_add_symlink_sink(struct coresight_device *csdev) +{

• const char *name;
  

• struct device *dev = &csdev->dev;
  

• if (csdev->type != CORESIGHT_DEV_TYPE_SINK &&
  

•     csdev->type != CORESIGHT_DEV_TYPE_LINKSINK)
  

•         return -EINVAL;
  

• if (csdev->ea != NULL)
  

•         return -EINVAL;
  

• name = dev_name(dev);
  

• return etm_perf_add_symlink_group(dev, &csdev->ea, name, "sinks");
  

+}

+void etm_perf_del_symlink_group(struct dev_ext_attribute *ea, const char *group_name) { struct device *pmu_dev = etm_pmu.dev;

• struct dev_ext_attribute *ea = csdev->ea;
  
  

• sysfs_remove_file_from_group(&pmu_dev->kobj,
  

•                              &ea->attr.attr, group_name);
  

+}

+void etm_perf_del_symlink_sink(struct coresight_device *csdev) +{ if (csdev->type != CORESIGHT_DEV_TYPE_SINK && csdev->type != CORESIGHT_DEV_TYPE_LINKSINK) return;

• if (!ea)
  

• if (!csdev->ea)
          return;
  
  

• sysfs_remove_file_from_group(&pmu_dev->kobj,
  

•                              &ea->attr.attr, "sinks");
  

• etm_perf_del_symlink_group(csdev->ea, "sinks");
  csdev->ea = NULL;
  

}

+/* string to contain the attribute value */ +#define CSCFG_EVENT_STR_SIZE 32

+static ssize_t etm_perf_cscfg_event_show(struct device *dev,

•                                  struct device_attribute *dattr,
  

•                                  char *buf)
  

+{

• struct dev_ext_attribute *ea;
  

• ea = container_of(dattr, struct dev_ext_attribute, attr);
  

• return scnprintf(buf, PAGE_SIZE, "%s\n", (const char *)(ea->var));
  

+}

+static int etm_perf_add_cscfg_event(struct device *dev, struct cscfg_config_desc *cs_cfg) +{

• struct dev_ext_attribute *ea;
  

• unsigned long hash;
  

• int ret;
  

• struct device *pmu_dev = etm_pmu.dev;
  

• ea = devm_kzalloc(dev, sizeof(*ea), GFP_KERNEL);
  

• if (!ea)
  

•         return -ENOMEM;
  

• hash = (unsigned long)cs_cfg->id_ea->var;
  

• sysfs_attr_init(&ea->attr.attr);
  

• ea->attr.attr.name = devm_kstrdup(dev, cs_cfg->name, GFP_KERNEL);
  

• if (!ea->attr.attr.name)
  

•         return -ENOMEM;
  

• /*
  

•  * attribute value is "configid=<hash>".
  

•  * this will be what perf evaluates when the config name is used
  

•  * on the command line.
  

•  */
  

• ea->var = devm_kzalloc(dev, CSCFG_EVENT_STR_SIZE, GFP_KERNEL);
  

• if (!ea->var)
  

•         return -ENOMEM;
  

• scnprintf(ea->var, CSCFG_EVENT_STR_SIZE, "configid=0x%lx", hash);
  

• ea->attr.attr.mode = 0444;
  

• ea->attr.show = etm_perf_cscfg_event_show;
  

• ret = sysfs_add_file_to_group(&pmu_dev->kobj,
  

•                               &ea->attr.attr, "events");
  

• if (!ret)
  

•         cs_cfg->event_ea = ea;
  

• return ret;
  

+}

+int etm_perf_add_symlink_cscfg(struct device *dev, struct cscfg_config_desc *cs_cfg) +{

• int err;
  

• if (cs_cfg->id_ea != NULL)
  

•         return 0;
  

• err = etm_perf_add_symlink_group(dev, &cs_cfg->id_ea,
  

•                                  cs_cfg->name, "configurations");
  

• if (!err)
  

•         err = etm_perf_add_cscfg_event(dev, cs_cfg);
  

• return err;
  

+}

+void etm_perf_del_symlink_cscfg(struct cscfg_config_desc *cs_cfg) +{

• if (!cs_cfg->id_ea)
  

•         return;
  

• etm_perf_del_symlink_group(cs_cfg->id_ea, "configurations");
  

• etm_perf_del_symlink_group(cs_cfg->event_ea, "events");
  

• cs_cfg->id_ea = NULL;
  

• cs_cfg->event_ea = NULL;
  

+}

int __init etm_perf_init(void) { int ret; diff --git a/drivers/hwtracing/coresight/coresight-etm-perf.h b/drivers/hwtracing/coresight/coresight-etm-perf.h index 29d90dfeba31..3646a3837a0b 100644 --- a/drivers/hwtracing/coresight/coresight-etm-perf.h +++ b/drivers/hwtracing/coresight/coresight-etm-perf.h @@ -11,6 +11,7 @@ #include "coresight-priv.h"

struct coresight_device; +struct cscfg_config_desc;

/*

• In both ETMv3 and v4 the maximum number of address comparator implentable

@@ -69,6 +70,9 @@ static inline void *etm_perf_sink_config(struct perf_output_handle *handle) return data->snk_config; return NULL; } +int etm_perf_add_symlink_cscfg(struct device *dev,

•                        struct cscfg_config_desc *cscfg_desc);
  

+void etm_perf_del_symlink_cscfg(struct cscfg_config_desc *cscfg_desc); #else static inline int etm_perf_symlink(struct coresight_device *csdev, bool link) { return -EINVAL; } @@ -79,6 +83,10 @@ static inline void *etm_perf_sink_config(struct perf_output_handle *handle) { return NULL; } +int etm_perf_add_symlink_cscfg(struct device *dev,

•                        struct cscfg_config_desc *cscfg_desc)
  

+{ return -EINVAL; } +void etm_perf_del_symlink_cscfg(struct cscfg_config_desc *cscfg_desc) {}

#endif /* CONFIG_CORESIGHT */

diff --git a/drivers/hwtracing/coresight/coresight-syscfg.c b/drivers/hwtracing/coresight/coresight-syscfg.c index 98ee78e3412a..8d52580daf04 100644 --- a/drivers/hwtracing/coresight/coresight-syscfg.c +++ b/drivers/hwtracing/coresight/coresight-syscfg.c @@ -7,6 +7,7 @@ #include <linux/platform_device.h>

#include "coresight-config.h" +#include "coresight-etm-perf.h" #include "coresight-syscfg.h"

/* @@ -85,7 +86,7 @@ static int cscfg_add_csdev_cfg(struct coresight_device *csdev, struct cscfg_config_csdev *dev_cfg = NULL; struct cscfg_config_feat_ref *feat_ref; struct cscfg_feature_csdev *feat;

• int checked;
  

• int checked, err;
  
  /* look at each required feature and see if it matches any feature on the device */
  for (checked = 0; checked < cfg_desc->nr_refs; checked++) {
  

@@ -97,16 +98,22 @@ static int cscfg_add_csdev_cfg(struct coresight_device *csdev, return -EINVAL; if (!dev_cfg) { dev_cfg = cscfg_alloc_csdev_cfg(csdev, cfg_desc->nr_refs);

•                         if (!dev_cfg)
  

•                                 return -ENOMEM;
  

As far as I can tell cscfg_alloc_csdev() can still return NULL and as such the check shouldn't be removed.

...

                          dev_cfg->desc = cfg_desc;

•                         dev_cfg->id_hash = (unsigned long)cfg_desc->id_ea->var;
  

Please add a comment to say that cfg_desc->id_ea->var is initalised in etm_perf_add_symlink_cscfg().

...

                  }
                  dev_cfg->feats[dev_cfg->nr_feat++] = feat;
          }
  }

• /* if matched features, add config to device.*/
  

• if (dev_cfg)
  

• if (dev_cfg) {
  

•         /* add config name to perf event directory if this is valid source */
  

•         if (match_info->match_flags & CS_CFG_MATCH_CLASS_SRC_ALL)
  

To me all configurations should be added and as such there shouldn't be a need for a check here. I'm also puzzled about the comment, especially the "valid source" part. To me a source is an ETM or some device that produce traces but complex configuration also applies to CTIs.

Agreed - I think this was an error due to stopping work on this then restarting. Re-worked to be consistent,

...

•                 err = etm_perf_add_symlink_cscfg(&csdev->dev, cfg_desc);
  

Why is this added here when the same configuration is also added in cscfg_load_config()?

As above - interupt error.

Thanks

Mike

...

•         if (err)
  

•                 return err;
          list_add(&dev_cfg->node, &csdev->syscfg_list);
  

• }
  
  return 0;
  

} @@ -282,8 +289,9 @@ static int cscfg_load_config(struct cscfg_config_desc *cfg_desc) return err;

  list_add(&cfg_desc->item, &cscfg_data.config_list);

• err = etm_perf_add_symlink_cscfg(to_device_cscfg(), cfg_desc);
  

I think this is the right place to do this.

I'm done with this patch - I'll continue on Monday.

Thanks, Mathieu

...

• return 0;
  

• return err;
  

}

/* @@ -532,7 +540,12 @@ int cscfg_create_device(void)

void cscfg_clear_device(void) {

• struct cscfg_config_desc *cfg_desc;
  

• mutex_lock(&cscfg_mutex);
  

• list_for_each_entry(cfg_desc, &cscfg_data.config_list, item) {
  

•         etm_perf_del_symlink_cscfg(cfg_desc);
  

• }
  device_unregister(to_device_cscfg());
  mutex_unlock(&cscfg_mutex);
  

}

2.17.1

-- Mike Leach Principal Engineer, ARM Ltd. Manchester Design Centre. UK