Re: [PATCH net-next v20 4/6] net: ethtool: tsinfo: Enhance tsinfo to support several hwtstamp by net topology

[Simon Horman <horms@kernel.org>]

On Wed, Dec 04, 2024 at 03:44:45PM +0100, Kory Maincent wrote:
> Either the MAC or the PHY can provide hwtstamp, so we should be able to
> read the tsinfo for any hwtstamp provider.
> 
> Enhance 'get' command to retrieve tsinfo of hwtstamp providers within a
> network topology.
> 
> Add support for a specific dump command to retrieve all hwtstamp
> providers within the network topology, with added functionality for
> filtered dump to target a single interface.
> 
> Signed-off-by: Kory Maincent <kory.maincent@bootlin.com>

...

> diff --git a/net/ethtool/ts.h b/net/ethtool/ts.h
> new file mode 100644
> index 000000000000..b7665dd4330d
> --- /dev/null
> +++ b/net/ethtool/ts.h
> @@ -0,0 +1,21 @@
> +/* SPDX-License-Identifier: GPL-2.0-only */
> +
> +#ifndef _NET_ETHTOOL_TS_H
> +#define _NET_ETHTOOL_TS_H
> +
> +#include "netlink.h"
> +
> +static const struct nla_policy
> +ethnl_ts_hwtst_prov_policy[ETHTOOL_A_TS_HWTSTAMP_PROVIDER_MAX + 1] = {
> +	[ETHTOOL_A_TS_HWTSTAMP_PROVIDER_INDEX] =
> +		NLA_POLICY_MIN(NLA_S32, 0),
> +	[ETHTOOL_A_TS_HWTSTAMP_PROVIDER_QUALIFIER] =
> +		NLA_POLICY_MAX(NLA_U32, HWTSTAMP_PROVIDER_QUALIFIER_CNT - 1)
> +};

Hi Kory,

It looks like ethnl_ts_hwtst_prov_policy is only used in tsinfo.c and could
be moved into that file. That would avoid a separate copy for each file
that includes ts.h and the following warning flagged by gcc-14 W=1 builds
with patch 5/6 applied.

  CC      net/ethtool/tsconfig.o
In file included from net/ethtool/tsconfig.c:10:
net/ethtool/ts.h:9:1: warning: 'ethnl_ts_hwtst_prov_policy' defined but not used [-Wunused-const-variable=]
    9 | ethnl_ts_hwtst_prov_policy[ETHTOOL_A_TS_HWTSTAMP_PROVIDER_MAX + 1] = {
      | ^~~~~~~~~~~~~~~~~~~~~~~~~~

> +
> +int ts_parse_hwtst_provider(const struct nlattr *nest,
> +			    struct hwtstamp_provider_desc *hwprov_desc,
> +			    struct netlink_ext_ack *extack,
> +			    bool *mod);
> +
> +#endif /* _NET_ETHTOOL_TS_H */

...