Re: [PATCH v4 04/10] coresight: etm-perf: update to handle configuration selection

On 1/28/21 5:09 PM, 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 | 13 +- 4 files changed, 166 insertions(+), 24 deletions(-)

diff --git a/drivers/hwtracing/coresight/coresight-config.h b/drivers/hwtracing/coresight/coresight-config.h index 9d66e0071f38..98380b496046 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..e270bb1e0f7d 100644 --- a/drivers/hwtracing/coresight/coresight-etm-perf.c +++ b/drivers/hwtracing/coresight/coresight-etm-perf.c @@ -18,8 +18,10 @@ #include <linux/types.h> #include <linux/workqueue.h> +#include "coresight-config.h" #include "coresight-etm-perf.h" #include "coresight-priv.h" +#include "coresight-syscfg.h" static struct pmu etm_pmu; static bool etm_perf_up; @@ -32,8 +34,13 @@ PMU_FORMAT_ATTR(cycacc, "config:" __stringify(ETM_OPT_CYCACC)); PMU_FORMAT_ATTR(contextid, "config:" __stringify(ETM_OPT_CTXTID)); PMU_FORMAT_ATTR(timestamp, "config:" __stringify(ETM_OPT_TS)); PMU_FORMAT_ATTR(retstack, "config:" __stringify(ETM_OPT_RETSTK)); +/* preset - if sink ID is used as a configuration selector */ +PMU_FORMAT_ATTR(preset, "config:0-3"); /* Sink ID - same for all ETMs */ PMU_FORMAT_ATTR(sinkid, "config2:0-31"); +/* 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)
  

Couple of nits:

This could be:

struct dev_ext_attribute * etm_perf_add_to_group_hashed(struct device *dev, const char *group, const char *name) { }

This could return the ea on success avoiding the **ext_attr as argument. Also the name of the function indicates what it does.

{

• 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)

void etm_perf_del_from_group(group, ea)

+/* 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));

+}

"configid=0x%lx", (unsigned long)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;
  

Could we drop this string and use the "hash" instead ?

• 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)

etm_perf_add_cscfg() ?

+{

• 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)

etm_perf_del_cscfg() ?

Suzuki