On 2/29/24 6:31 PM, 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.
>
> Since this is in preparation for adding a cxl_poison private parser
> for 'cxl list --media-errors' support, add those specific required
> types: u8, u32, u64, char*
>
> Signed-off-by: Alison Schofield <alison.schofi...@intel.com>
Reviewed-by: Dave Jiang <dave.ji...@intel.com>
> ---
> cxl/event_trace.c | 75 +++++++++++++++++++++++++++++++++++++++++++++++
> cxl/event_trace.h | 10 ++++++-
> 2 files changed, 84 insertions(+), 1 deletion(-)
>
> diff --git a/cxl/event_trace.c b/cxl/event_trace.c
> index bdad0c19dbd4..6cc9444f3204 100644
> --- a/cxl/event_trace.c
> +++ b/cxl/event_trace.c
> @@ -15,6 +15,81 @@
> #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;
> +}
> +
> +u64 cxl_get_field_u64(struct tep_event *event, struct tep_record *record,
> + const char *name)
> +{
> + struct tep_format_field *f;
> + unsigned char *val;
> + int len;
> +
> + f = __find_field(event, name);
> + if (!f)
> + return ULLONG_MAX;
> +
> + val = tep_get_field_raw(NULL, event, f->name, record, &len, 0);
> + if (!val)
> + return ULLONG_MAX;
> +
> + return *(u64 *)val;
> +}
> +
> +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);
> +}
> +
> +u32 cxl_get_field_u32(struct tep_event *event, struct tep_record *record,
> + const char *name)
> +{
> + char *val;
> +
> + val = cxl_get_field_string(event, record, name);
> + if (!val)
> + return UINT_MAX;
> +
> + return *(u32 *)val;
> +}
> +
> +u8 cxl_get_field_u8(struct tep_event *event, struct tep_record *record,
> + const char *name)
> +{
> + char *val;
> +
> + val = cxl_get_field_string(event, record, name);
> + if (!val)
> + return UCHAR_MAX;
> +
> + return *(u8 *)val;
> +}
> +
> 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..bbdea3b896e0 100644
> --- a/cxl/event_trace.h
> +++ b/cxl/event_trace.h
> @@ -5,6 +5,7 @@
>
> #include <json-c/json.h>
> #include <ccan/list/list.h>
> +#include <ccan/short_types/short_types.h>
>
> struct jlist_node {
> struct json_object *jobj;
> @@ -25,5 +26,12 @@ 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);
> +u8 cxl_get_field_u8(struct tep_event *event, struct tep_record *record,
> + const char *name);
> +u32 cxl_get_field_u32(struct tep_event *event, struct tep_record *record,
> + const char *name);
> +u64 cxl_get_field_u64(struct tep_event *event, struct tep_record *record,
> + const char *name);
> #endif
