net: ethtool: tsconfig: Fix netlink type of hwtstamp flags

Fix the netlink type for hardware timestamp flags, which are represented
as a bitset of flags. Although only one flag is supported currently, the
correct netlink bitset type should be used instead of u32 to keep
consistency with other fields. Address this by adding a new named string
set description for the hwtstamp flag structure.

The code has been introduced in the current release so the uAPI change is
still okay.

Signed-off-by: Kory Maincent <kory.maincent@bootlin.com>
Fixes: 6e9e2ee ("net: ethtool: Add support for tsconfig command to get/set hwtstamp config")
Link: https://patch.msgid.link/20250205110304.375086-1-kory.maincent@bootlin.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

Documentation/netlink/specs/ethtool.yaml

@@ -1524,7 +1524,8 @@ attribute-sets:
         nested-attributes: bitset
       -
         name: hwtstamp-flags
-        type: u32
+        type: nest
+        nested-attributes: bitset
 
 operations:
   enum-model: directional

include/uapi/linux/ethtool.h

@@ -682,6 +682,7 @@ enum ethtool_link_ext_substate_module {
  * @ETH_SS_STATS_ETH_CTRL: names of IEEE 802.3 MAC Control statistics
  * @ETH_SS_STATS_RMON: names of RMON statistics
  * @ETH_SS_STATS_PHY: names of PHY(dev) statistics
+ * @ETH_SS_TS_FLAGS: hardware timestamping flags
  *
  * @ETH_SS_COUNT: number of defined string sets
  */
@@ -708,6 +709,7 @@ enum ethtool_stringset {
 	ETH_SS_STATS_ETH_CTRL,
 	ETH_SS_STATS_RMON,
 	ETH_SS_STATS_PHY,
+	ETH_SS_TS_FLAGS,
 
 	/* add new constants above here */
 	ETH_SS_COUNT

net/ethtool/common.c

@@ -462,6 +462,11 @@ const char ts_rx_filter_names[][ETH_GSTRING_LEN] = {
 };
 static_assert(ARRAY_SIZE(ts_rx_filter_names) == __HWTSTAMP_FILTER_CNT);
 
+const char ts_flags_names[][ETH_GSTRING_LEN] = {
+	[const_ilog2(HWTSTAMP_FLAG_BONDED_PHC_INDEX)] = "bonded-phc-index",
+};
+static_assert(ARRAY_SIZE(ts_flags_names) == __HWTSTAMP_FLAG_CNT);
+
 const char udp_tunnel_type_names[][ETH_GSTRING_LEN] = {
 	[ETHTOOL_UDP_TUNNEL_TYPE_VXLAN]		= "vxlan",
 	[ETHTOOL_UDP_TUNNEL_TYPE_GENEVE]	= "geneve",

net/ethtool/common.h

@@ -13,6 +13,7 @@
 	ETHTOOL_LINK_MODE_ ## speed ## base ## type ## _ ## duplex ## _BIT
 
 #define __SOF_TIMESTAMPING_CNT (const_ilog2(SOF_TIMESTAMPING_LAST) + 1)
+#define __HWTSTAMP_FLAG_CNT (const_ilog2(HWTSTAMP_FLAG_LAST) + 1)
 
 struct link_mode_info {
 	int				speed;
@@ -38,6 +39,7 @@ extern const char wol_mode_names[][ETH_GSTRING_LEN];
 extern const char sof_timestamping_names[][ETH_GSTRING_LEN];
 extern const char ts_tx_type_names[][ETH_GSTRING_LEN];
 extern const char ts_rx_filter_names[][ETH_GSTRING_LEN];
+extern const char ts_flags_names[][ETH_GSTRING_LEN];
 extern const char udp_tunnel_type_names[][ETH_GSTRING_LEN];
 
 int __ethtool_get_link(struct net_device *dev);

net/ethtool/strset.c

@@ -75,6 +75,11 @@ static const struct strset_info info_template[] = {
 		.count		= __HWTSTAMP_FILTER_CNT,
 		.strings	= ts_rx_filter_names,
 	},
+	[ETH_SS_TS_FLAGS] = {
+		.per_dev	= false,
+		.count		= __HWTSTAMP_FLAG_CNT,
+		.strings	= ts_flags_names,
+	},
 	[ETH_SS_UDP_TUNNEL_TYPES] = {
 		.per_dev	= false,
 		.count		= __ETHTOOL_UDP_TUNNEL_TYPE_CNT,

net/ethtool/tsconfig.c

@@ -54,7 +54,7 @@ static int tsconfig_prepare_data(const struct ethnl_req_info *req_base,
 
 	data->hwtst_config.tx_type = BIT(cfg.tx_type);
 	data->hwtst_config.rx_filter = BIT(cfg.rx_filter);
-	data->hwtst_config.flags = BIT(cfg.flags);
+	data->hwtst_config.flags = cfg.flags;
 
 	data->hwprov_desc.index = -1;
 	hwprov = rtnl_dereference(dev->hwprov);
@@ -91,10 +91,16 @@ static int tsconfig_reply_size(const struct ethnl_req_info *req_base,
 
 	BUILD_BUG_ON(__HWTSTAMP_TX_CNT > 32);
 	BUILD_BUG_ON(__HWTSTAMP_FILTER_CNT > 32);
+	BUILD_BUG_ON(__HWTSTAMP_FLAG_CNT > 32);
 
-	if (data->hwtst_config.flags)
-		/* _TSCONFIG_HWTSTAMP_FLAGS */
-		len += nla_total_size(sizeof(u32));
+	if (data->hwtst_config.flags) {
+		ret = ethnl_bitset32_size(&data->hwtst_config.flags,
+					  NULL, __HWTSTAMP_FLAG_CNT,
+					  ts_flags_names, compact);
+		if (ret < 0)
+			return ret;
+		len += ret;	/* _TSCONFIG_HWTSTAMP_FLAGS */
+	}
 
 	if (data->hwtst_config.tx_type) {
 		ret = ethnl_bitset32_size(&data->hwtst_config.tx_type,
@@ -130,8 +136,10 @@ static int tsconfig_fill_reply(struct sk_buff *skb,
 	int ret;
 
 	if (data->hwtst_config.flags) {
-		ret = nla_put_u32(skb, ETHTOOL_A_TSCONFIG_HWTSTAMP_FLAGS,
-				  data->hwtst_config.flags);
+		ret = ethnl_put_bitset32(skb, ETHTOOL_A_TSCONFIG_HWTSTAMP_FLAGS,
+					 &data->hwtst_config.flags, NULL,
+					 __HWTSTAMP_FLAG_CNT,
+					 ts_flags_names, compact);
 		if (ret < 0)
 			return ret;
 	}
@@ -180,7 +188,7 @@ const struct nla_policy ethnl_tsconfig_set_policy[ETHTOOL_A_TSCONFIG_MAX + 1] =
 	[ETHTOOL_A_TSCONFIG_HEADER] = NLA_POLICY_NESTED(ethnl_header_policy),
 	[ETHTOOL_A_TSCONFIG_HWTSTAMP_PROVIDER] =
 		NLA_POLICY_NESTED(ethnl_ts_hwtst_prov_policy),
-	[ETHTOOL_A_TSCONFIG_HWTSTAMP_FLAGS] = { .type = NLA_U32 },
+	[ETHTOOL_A_TSCONFIG_HWTSTAMP_FLAGS] = { .type = NLA_NESTED },
 	[ETHTOOL_A_TSCONFIG_RX_FILTERS] = { .type = NLA_NESTED },
 	[ETHTOOL_A_TSCONFIG_TX_TYPES] = { .type = NLA_NESTED },
 };
@@ -296,6 +304,7 @@ static int ethnl_set_tsconfig(struct ethnl_req_info *req_base,
 
 	BUILD_BUG_ON(__HWTSTAMP_TX_CNT >= 32);
 	BUILD_BUG_ON(__HWTSTAMP_FILTER_CNT >= 32);
+	BUILD_BUG_ON(__HWTSTAMP_FLAG_CNT > 32);
 
 	if (!netif_device_present(dev))
 		return -ENODEV;
@@ -377,9 +386,13 @@ static int ethnl_set_tsconfig(struct ethnl_req_info *req_base,
 	}
 
 	if (tb[ETHTOOL_A_TSCONFIG_HWTSTAMP_FLAGS]) {
-		ethnl_update_u32(&hwtst_config.flags,
-				 tb[ETHTOOL_A_TSCONFIG_HWTSTAMP_FLAGS],
-				 &config_mod);
+		ret = ethnl_update_bitset32(&hwtst_config.flags,
+					    __HWTSTAMP_FLAG_CNT,
+					    tb[ETHTOOL_A_TSCONFIG_HWTSTAMP_FLAGS],
+					    ts_flags_names, info->extack,
+					    &config_mod);
+		if (ret < 0)
+			goto err_free_hwprov;
 	}
 
 	ret = net_hwtstamp_validate(&hwtst_config);