Re: [RFC bpf-next v2 05/11] bpf: Implement devtx timestamp kfunc

From: Stanislav Fomichev <sdf@google.com>
To: "Jesper D. Brouer" <netdev@brouer.com>
Cc: bpf@vger.kernel.org, brouer@redhat.com, ast@kernel.org,
	 daniel@iogearbox.net, andrii@kernel.org, martin.lau@linux.dev,
	 song@kernel.org, yhs@fb.com, john.fastabend@gmail.com,
	kpsingh@kernel.org,  haoluo@google.com, jolsa@kernel.org,
	netdev@vger.kernel.org
Subject: Re: [RFC bpf-next v2 05/11] bpf: Implement devtx timestamp kfunc
Date: Thu, 22 Jun 2023 10:55:14 -0700	[thread overview]
Message-ID: <CAKH8qBthYBKdxGs8idSXwM6VRpv4-sQH+j9N_QD9eXDmrAnmEA@mail.gmail.com> (raw)
In-Reply-To: <00c76c9d-cce8-f3a7-2eda-1c4cc6f36d93@brouer.com>

On Thu, Jun 22, 2023 at 5:07 AM Jesper D. Brouer <netdev@brouer.com> wrote:
>
>
>
> On 21/06/2023 19.02, Stanislav Fomichev wrote:
> > Two kfuncs, one per hook point:
> >
> > 1. at submit time - bpf_devtx_sb_request_timestamp - to request HW
> >     to put TX timestamp into TX completion descriptors
> >
> > 2. at completion time - bpf_devtx_cp_timestamp - to read out
> >     TX timestamp
> >
> [...]
> >
> > diff --git a/include/linux/netdevice.h b/include/linux/netdevice.h
> > index 08fbd4622ccf..2fdb0731eb67 100644
> > --- a/include/linux/netdevice.h
> > +++ b/include/linux/netdevice.h
> [...]
> >   struct xdp_metadata_ops {
> >       int     (*xmo_rx_timestamp)(const struct xdp_md *ctx, u64 *timestamp);
> >       int     (*xmo_rx_hash)(const struct xdp_md *ctx, u32 *hash,
> >                              enum xdp_rss_hash_type *rss_type);
> > +     int     (*xmo_sb_request_timestamp)(const struct devtx_frame *ctx);
> > +     int     (*xmo_cp_timestamp)(const struct devtx_frame *ctx, u64 *timestamp);
> >   };
>
> The "sb" and "cp" abbreviations, what do they stand for?

SuBmit and ComPlete. Should I spell them out? Or any other suitable
abbreviation?