On 1/17/24 17:28, alison.schofi...@intel.com wrote:
> From: Alison Schofield <alison.schofi...@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.schofi...@intel.com>
Reviewed-by: Dave Jiang <dave.ji...@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
