Re: [ndctl PATCH v11 4/7] cxl/event_trace: add helpers to retrieve tep fields by type

[Dan Williams <dan.j.williams@intel.com>]

alison.schofield@ 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. The helpers also return
> the 'type'_MAX of the type when the field is
> 
> Since this is in preparation for adding a cxl_poison private parser
> for 'cxl list --media-errors' support those specific required
> types: u8, u32, u64.
> 
> Signed-off-by: Alison Schofield <alison.schofield@intel.com>
> ---
>  cxl/event_trace.c | 37 +++++++++++++++++++++++++++++++++++++
>  cxl/event_trace.h |  8 +++++++-
>  2 files changed, 44 insertions(+), 1 deletion(-)
> 
> diff --git a/cxl/event_trace.c b/cxl/event_trace.c
> index 640abdab67bf..324edb982888 100644
> --- a/cxl/event_trace.c
> +++ b/cxl/event_trace.c
> @@ -15,6 +15,43 @@
>  #define _GNU_SOURCE
>  #include <string.h>
>  
> +u64 cxl_get_field_u64(struct tep_event *event, struct tep_record *record,
> +		      const char *name)
> +{
> +	unsigned long long val;
> +
> +	if (tep_get_field_val(NULL, event, name, record, &val, 0))
> +		return ULLONG_MAX;
> +
> +	return val;
> +}

Hm, why are these prefixed "cxl_" there is nothing cxl specific in the
internals. Maybe these event trace helpers grow non-CXL users in the
future. Could be "trace_" or "util_" like other generic helpers in the
codebase.