diff mbox series

[v6,4/7] cxl/event_trace: add helpers get_field_[string|data]()

Message ID a4e63238ba2137f4a4b69d2c21c67badec15a659.1705534719.git.alison.schofield@intel.com (mailing list archive)
State Superseded
Headers show
Series Support poison list retrieval | expand

Commit Message

Alison Schofield Jan. 18, 2024, 12:28 a.m. UTC 
From: Alison Schofield <alison.schofield@intel.com>

Add helpers to extract the value of an event record field given the
field name. This is useful when the user knows the name and format
of the field and simply needs to get it. Add signed and unsigned
char* versions to support string and u64 data fields.

This is in preparation for adding a private parser of cxl_poison
events.

Signed-off-by: Alison Schofield <alison.schofield@intel.com>
---
 cxl/event_trace.c | 46 ++++++++++++++++++++++++++++++++++++++++++++++
 cxl/event_trace.h |  5 ++++-
 2 files changed, 50 insertions(+), 1 deletion(-)

Comments

Dave Jiang Jan. 19, 2024, 9:18 p.m. UTC | #1 
On 1/17/24 17:28, alison.schofield@intel.com wrote:
> From: Alison Schofield <alison.schofield@intel.com>
> 
> Add helpers to extract the value of an event record field given the
> field name. This is useful when the user knows the name and format
> of the field and simply needs to get it. Add signed and unsigned
> char* versions to support string and u64 data fields.
> 
> This is in preparation for adding a private parser of cxl_poison
> events.
> 
> Signed-off-by: Alison Schofield <alison.schofield@intel.com>
Reviewed-by: Dave Jiang <dave.jiang@intel.com>

> ---
>  cxl/event_trace.c | 46 ++++++++++++++++++++++++++++++++++++++++++++++
>  cxl/event_trace.h |  5 ++++-
>  2 files changed, 50 insertions(+), 1 deletion(-)
> 
> diff --git a/cxl/event_trace.c b/cxl/event_trace.c
> index fbf7a77235ff..8d04d8d34194 100644
> --- a/cxl/event_trace.c
> +++ b/cxl/event_trace.c
> @@ -15,6 +15,52 @@
>  #define _GNU_SOURCE
>  #include <string.h>
>  
> +static struct tep_format_field *__find_field(struct tep_event *event,
> +					     const char *name)
> +{
> +	struct tep_format_field **fields;
> +
> +	fields = tep_event_fields(event);
> +	if (!fields)
> +		return NULL;
> +
> +	for (int i = 0; fields[i]; i++) {
> +		struct tep_format_field *f = fields[i];
> +
> +		if (strcmp(f->name, name) != 0)
> +			continue;
> +
> +		return f;
> +	}
> +	return NULL;
> +}
> +
> +unsigned char *cxl_get_field_data(struct tep_event *event,
> +				  struct tep_record *record, const char *name)
> +{
> +	struct tep_format_field *f;
> +	int len;
> +
> +	f = __find_field(event, name);
> +	if (!f)
> +		return NULL;
> +
> +	return tep_get_field_raw(NULL, event, f->name, record, &len, 0);
> +}
> +
> +char *cxl_get_field_string(struct tep_event *event, struct tep_record *record,
> +			   const char *name)
> +{
> +	struct tep_format_field *f;
> +	int len;
> +
> +	f = __find_field(event, name);
> +	if (!f)
> +		return NULL;
> +
> +	return tep_get_field_raw(NULL, event, f->name, record, &len, 0);
> +}
> +
>  static struct json_object *num_to_json(void *num, int elem_size, unsigned long flags)
>  {
>  	bool sign = flags & TEP_FIELD_IS_SIGNED;
> diff --git a/cxl/event_trace.h b/cxl/event_trace.h
> index ec61962abbc6..6252f583097a 100644
> --- a/cxl/event_trace.h
> +++ b/cxl/event_trace.h
> @@ -25,5 +25,8 @@ int cxl_parse_events(struct tracefs_instance *inst, struct event_ctx *ectx);
>  int cxl_event_tracing_enable(struct tracefs_instance *inst, const char *system,
>  		const char *event);
>  int cxl_event_tracing_disable(struct tracefs_instance *inst);
> -
> +char *cxl_get_field_string(struct tep_event *event, struct tep_record *record,
> +		const char *name);
> +unsigned char *cxl_get_field_data(struct tep_event *event,
> +		struct tep_record *record, const char *name);
>  #endif
diff mbox series

Patch

diff --git a/cxl/event_trace.c b/cxl/event_trace.c
index fbf7a77235ff..8d04d8d34194 100644
--- a/cxl/event_trace.c
+++ b/cxl/event_trace.c
@@ -15,6 +15,52 @@ 
 #define _GNU_SOURCE
 #include <string.h>
 
+static struct tep_format_field *__find_field(struct tep_event *event,
+					     const char *name)
+{
+	struct tep_format_field **fields;
+
+	fields = tep_event_fields(event);
+	if (!fields)
+		return NULL;
+
+	for (int i = 0; fields[i]; i++) {
+		struct tep_format_field *f = fields[i];
+
+		if (strcmp(f->name, name) != 0)
+			continue;
+
+		return f;
+	}
+	return NULL;
+}
+
+unsigned char *cxl_get_field_data(struct tep_event *event,
+				  struct tep_record *record, const char *name)
+{
+	struct tep_format_field *f;
+	int len;
+
+	f = __find_field(event, name);
+	if (!f)
+		return NULL;
+
+	return tep_get_field_raw(NULL, event, f->name, record, &len, 0);
+}
+
+char *cxl_get_field_string(struct tep_event *event, struct tep_record *record,
+			   const char *name)
+{
+	struct tep_format_field *f;
+	int len;
+
+	f = __find_field(event, name);
+	if (!f)
+		return NULL;
+
+	return tep_get_field_raw(NULL, event, f->name, record, &len, 0);
+}
+
 static struct json_object *num_to_json(void *num, int elem_size, unsigned long flags)
 {
 	bool sign = flags & TEP_FIELD_IS_SIGNED;
diff --git a/cxl/event_trace.h b/cxl/event_trace.h
index ec61962abbc6..6252f583097a 100644
--- a/cxl/event_trace.h
+++ b/cxl/event_trace.h
@@ -25,5 +25,8 @@  int cxl_parse_events(struct tracefs_instance *inst, struct event_ctx *ectx);
 int cxl_event_tracing_enable(struct tracefs_instance *inst, const char *system,
 		const char *event);
 int cxl_event_tracing_disable(struct tracefs_instance *inst);
-
+char *cxl_get_field_string(struct tep_event *event, struct tep_record *record,
+		const char *name);
+unsigned char *cxl_get_field_data(struct tep_event *event,
+		struct tep_record *record, const char *name);
 #endif