[PATCH net-next v6 15/16] net ethtool: net: Let the active time stamping layer be selectable

From: Kory Maincent
Date: Thu Oct 19 2023 - 10:30:39 EST

Now that the current timestamp is saved in a variable lets add the
ETHTOOL_MSG_TS_SET ethtool netlink socket to make it selectable.

Signed-off-by: Kory Maincent <kory.maincent@xxxxxxxxxxx>
---

Changes in v2:
- Move selected_timestamping_layer introduction in this patch.
- Replace strmcmp by sysfs_streq.
- Use the PHY timestamp only if available.

Changes in v3:
- Add a devicetree binding to select the preferred timestamp
- Replace the way to select timestamp through ethtool instead of sysfs
You can test it with the ethtool source on branch feature_ptp of:
https://github.com/kmaincent/ethtool

Changes in v4:
- Change the API to select MAC default time stamping instead of the PHY.
- Add a whitelist to no break the old timestamp PHY default preferences
for current PHY.
- Replace the ethtool ioctl by netlink.
- Add a netdev notifier to allow network device to create trap on PTP
packets. Not tested as it need to change the lan966x driver that
implement packet traps. I will do after the hwtstamp management change
to NDOs.

Changes in v5:
- Remove the netdev notifier added in v4.
- Extract the default timestamp API change in another patch.

Changes in v6:
- Update the error message.
- Put ndo_hwtstamp_set check first as it is most likely what most drivers
currently do not support.
- Follow timestamping layer naming update.
- Update the timestamp layer check.
- Update timestamp set between MAC and software.
---
Documentation/networking/ethtool-netlink.rst | 17 +++++
include/uapi/linux/ethtool_netlink.h | 1 +
net/ethtool/netlink.c | 8 +++
net/ethtool/netlink.h | 1 +
net/ethtool/ts.c | 99 ++++++++++++++++++++++++++++
5 files changed, 126 insertions(+)

diff --git a/Documentation/networking/ethtool-netlink.rst b/Documentation/networking/ethtool-netlink.rst
index b8d00676ed82..530c1775e5f4 100644
--- a/Documentation/networking/ethtool-netlink.rst
+++ b/Documentation/networking/ethtool-netlink.rst
@@ -227,6 +227,7 @@ Userspace to kernel:
``ETHTOOL_MSG_MM_SET`` set MAC merge layer parameters
``ETHTOOL_MSG_TS_GET`` get current timestamping
``ETHTOOL_MSG_TS_LIST_GET`` list available timestampings
+ ``ETHTOOL_MSG_TS_SET`` set current timestamping
===================================== =================================

Kernel to userspace:
@@ -2038,6 +2039,21 @@ Kernel response contents:

This command lists all the possible timestamp layer available.

+TS_SET
+======
+
+Modify the selected timestamping.
+
+Request contents:
+
+ ======================= ====== ===================
+ ``ETHTOOL_A_TS_HEADER`` nested reply header
+ ``ETHTOOL_A_TS_LAYER`` u32 timestamping
+ ======================= ====== ===================
+
+This command set the timestamping with one that should be listed by the
+TSLIST_GET command.
+
Request translation
===================

@@ -2146,4 +2162,5 @@ are netlink only.
n/a ``ETHTOOL_MSG_MM_SET``
n/a ``ETHTOOL_MSG_TS_GET``
n/a ``ETHTOOL_MSG_TS_LIST_GET``
+ n/a ``ETHTOOL_MSG_TS_SET``
=================================== =====================================
diff --git a/include/uapi/linux/ethtool_netlink.h b/include/uapi/linux/ethtool_netlink.h
index 62b885d44d06..df6c4fcc62c1 100644
--- a/include/uapi/linux/ethtool_netlink.h
+++ b/include/uapi/linux/ethtool_netlink.h
@@ -59,6 +59,7 @@ enum {
ETHTOOL_MSG_MM_SET,
ETHTOOL_MSG_TS_GET,
ETHTOOL_MSG_TS_LIST_GET,
+ ETHTOOL_MSG_TS_SET,

/* add new constants above here */
__ETHTOOL_MSG_USER_CNT,
diff --git a/net/ethtool/netlink.c b/net/ethtool/netlink.c
index 842c9db1531f..8322bf71f80d 100644
--- a/net/ethtool/netlink.c
+++ b/net/ethtool/netlink.c
@@ -308,6 +308,7 @@ ethnl_default_requests[__ETHTOOL_MSG_USER_CNT] = {
[ETHTOOL_MSG_MM_SET] = &ethnl_mm_request_ops,
[ETHTOOL_MSG_TS_GET] = &ethnl_ts_request_ops,
[ETHTOOL_MSG_TS_LIST_GET] = &ethnl_ts_list_request_ops,
+ [ETHTOOL_MSG_TS_SET] = &ethnl_ts_request_ops,
};

static struct ethnl_dump_ctx *ethnl_dump_context(struct netlink_callback *cb)
@@ -1148,6 +1149,13 @@ static const struct genl_ops ethtool_genl_ops[] = {
.policy = ethnl_ts_get_policy,
.maxattr = ARRAY_SIZE(ethnl_ts_get_policy) - 1,
},
+ {
+ .cmd = ETHTOOL_MSG_TS_SET,
+ .flags = GENL_UNS_ADMIN_PERM,
+ .doit = ethnl_default_set_doit,
+ .policy = ethnl_ts_set_policy,
+ .maxattr = ARRAY_SIZE(ethnl_ts_set_policy) - 1,
+ },
};

static const struct genl_multicast_group ethtool_nl_mcgrps[] = {
diff --git a/net/ethtool/netlink.h b/net/ethtool/netlink.h
index ea8c312db3af..8fedf234b824 100644
--- a/net/ethtool/netlink.h
+++ b/net/ethtool/netlink.h
@@ -444,6 +444,7 @@ extern const struct nla_policy ethnl_plca_get_status_policy[ETHTOOL_A_PLCA_HEADE
extern const struct nla_policy ethnl_mm_get_policy[ETHTOOL_A_MM_HEADER + 1];
extern const struct nla_policy ethnl_mm_set_policy[ETHTOOL_A_MM_MAX + 1];
extern const struct nla_policy ethnl_ts_get_policy[ETHTOOL_A_TS_HEADER + 1];
+extern const struct nla_policy ethnl_ts_set_policy[ETHTOOL_A_TS_MAX + 1];

int ethnl_set_features(struct sk_buff *skb, struct genl_info *info);
int ethnl_act_cable_test(struct sk_buff *skb, struct genl_info *info);
diff --git a/net/ethtool/ts.c b/net/ethtool/ts.c
index bd219512b8de..357265e74e08 100644
--- a/net/ethtool/ts.c
+++ b/net/ethtool/ts.c
@@ -59,6 +59,102 @@ static int ts_fill_reply(struct sk_buff *skb,
return nla_put_u32(skb, ETHTOOL_A_TS_LAYER, data->ts_layer);
}

+/* TS_SET */
+const struct nla_policy ethnl_ts_set_policy[] = {
+ [ETHTOOL_A_TS_HEADER] = NLA_POLICY_NESTED(ethnl_header_policy),
+ [ETHTOOL_A_TS_LAYER] = NLA_POLICY_RANGE(NLA_U32, 0,
+ __TIMESTAMPING_COUNT - 1)
+};
+
+static int ethnl_set_ts_validate(struct ethnl_req_info *req_info,
+ struct genl_info *info)
+{
+ struct nlattr **tb = info->attrs;
+ const struct net_device_ops *ops = req_info->dev->netdev_ops;
+
+ if (!ops->ndo_hwtstamp_set)
+ return -EOPNOTSUPP;
+
+ if (!tb[ETHTOOL_A_TS_LAYER])
+ return 0;
+
+ return 1;
+}
+
+static int ethnl_set_ts(struct ethnl_req_info *req_info, struct genl_info *info)
+{
+ struct net_device *dev = req_info->dev;
+ const struct ethtool_ops *ops = dev->ethtool_ops;
+ struct kernel_hwtstamp_config config = {0};
+ struct nlattr **tb = info->attrs;
+ enum timestamping_layer ts_layer;
+ bool mod = false;
+ int ret;
+
+ ts_layer = dev->ts_layer;
+ ethnl_update_u32(&ts_layer, tb[ETHTOOL_A_TS_LAYER], &mod);
+
+ if (!mod)
+ return 0;
+
+ if (ts_layer == SOFTWARE_TIMESTAMPING) {
+ struct ethtool_ts_info ts_info = {0};
+
+ if (!ops->get_ts_info) {
+ NL_SET_ERR_MSG_ATTR(info->extack,
+ tb[ETHTOOL_A_TS_LAYER],
+ "this net device cannot support timestamping");
+ return -EINVAL;
+ }
+
+ ops->get_ts_info(dev, &ts_info);
+ if ((ts_info.so_timestamping &
+ SOF_TIMESTAMPING_SOFTWARE_MASK) !=
+ SOF_TIMESTAMPING_SOFTWARE_MASK) {
+ NL_SET_ERR_MSG_ATTR(info->extack,
+ tb[ETHTOOL_A_TS_LAYER],
+ "this net device cannot support software timestamping");
+ return -EINVAL;
+ }
+ } else if (ts_layer == MAC_TIMESTAMPING) {
+ struct ethtool_ts_info ts_info = {0};
+
+ if (!ops->get_ts_info) {
+ NL_SET_ERR_MSG_ATTR(info->extack,
+ tb[ETHTOOL_A_TS_LAYER],
+ "this net device cannot support timestamping");
+ return -EINVAL;
+ }
+
+ ops->get_ts_info(dev, &ts_info);
+ if ((ts_info.so_timestamping &
+ SOF_TIMESTAMPING_HARDWARE_MASK) !=
+ SOF_TIMESTAMPING_HARDWARE_MASK) {
+ NL_SET_ERR_MSG_ATTR(info->extack,
+ tb[ETHTOOL_A_TS_LAYER],
+ "this net device cannot support hardware timestamping");
+ return -EINVAL;
+ }
+ } else if (ts_layer == PHY_TIMESTAMPING && !phy_has_tsinfo(dev->phydev)) {
+ NL_SET_ERR_MSG_ATTR(info->extack, tb[ETHTOOL_A_TS_LAYER],
+ "this phy device cannot support timestamping");
+ return -EINVAL;
+ }
+
+ /* Disable time stamping in the current layer. */
+ if (netif_device_present(dev) &&
+ (dev->ts_layer == PHY_TIMESTAMPING ||
+ dev->ts_layer == MAC_TIMESTAMPING)) {
+ ret = dev_set_hwtstamp_phylib(dev, &config, info->extack);
+ if (ret < 0)
+ return ret;
+ }
+
+ dev->ts_layer = ts_layer;
+
+ return 1;
+}
+
const struct ethnl_request_ops ethnl_ts_request_ops = {
.request_cmd = ETHTOOL_MSG_TS_GET,
.reply_cmd = ETHTOOL_MSG_TS_GET_REPLY,
@@ -69,6 +165,9 @@ const struct ethnl_request_ops ethnl_ts_request_ops = {
.prepare_data = ts_prepare_data,
.reply_size = ts_reply_size,
.fill_reply = ts_fill_reply,
+
+ .set_validate = ethnl_set_ts_validate,
+ .set = ethnl_set_ts,
};

/* TS_LIST_GET */

--
2.25.1