[PATCH net-next v4 5/7] net: ethtool: Add new power limit get and set features

Kory Maincent
2024-06-25T12:34:04Z

This patch expands the status information provided by ethtool for PSE c33
with available power limit and available power limit ranges. It also adds
a call to pse_ethtool_set_pw_limit() to configure the PSE control power
limit.

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

Change in v3:
- Add ethtool netlink documentation.

Change in v4:
- Update documentation
- Add support for c33 pse power limit ranges.
---
Documentation/networking/ethtool-netlink.rst | 64 ++++++++++++++------
include/linux/ethtool.h | 5 ++
include/uapi/linux/ethtool_netlink.h | 8 +++
net/ethtool/pse-pd.c | 89 +++++++++++++++++++++++++---
4 files changed, 141 insertions(+), 25 deletions(-)

diff --git a/Documentation/networking/ethtool-netlink.rst b/Documentation/networking/ethtool-netlink.rst
index 7dbf2ef3ac0e..5cba6ef39927 100644
--- a/Documentation/networking/ethtool-netlink.rst
+++ b/Documentation/networking/ethtool-netlink.rst
@@ -1720,24 +1720,28 @@ Request contents:

Kernel response contents:

- ====================================== ====== =============================
- ``ETHTOOL_A_PSE_HEADER`` nested reply header
- ``ETHTOOL_A_PODL_PSE_ADMIN_STATE`` u32 Operational state of the PoDL
- PSE functions
- ``ETHTOOL_A_PODL_PSE_PW_D_STATUS`` u32 power detection status of the
- PoDL PSE.
- ``ETHTOOL_A_C33_PSE_ADMIN_STATE`` u32 Operational state of the PoE
- PSE functions.
- ``ETHTOOL_A_C33_PSE_PW_D_STATUS`` u32 power detection status of the
- PoE PSE.
- ``ETHTOOL_A_C33_PSE_PW_CLASS`` u32 power class of the PoE PSE.
- ``ETHTOOL_A_C33_PSE_ACTUAL_PW`` u32 actual power drawn on the
- PoE PSE.
- ``ETHTOOL_A_C33_PSE_EXT_STATE`` u32 power extended state of the
- PoE PSE.
- ``ETHTOOL_A_C33_PSE_EXT_SUBSTATE`` u32 power extended substatus of
- the PoE PSE.
- ====================================== ====== =============================
+ ========================================== ====== =============================
+ ``ETHTOOL_A_PSE_HEADER`` nested reply header
+ ``ETHTOOL_A_PODL_PSE_ADMIN_STATE`` u32 Operational state of the PoDL
+ PSE functions
+ ``ETHTOOL_A_PODL_PSE_PW_D_STATUS`` u32 power detection status of the
+ PoDL PSE.
+ ``ETHTOOL_A_C33_PSE_ADMIN_STATE`` u32 Operational state of the PoE
+ PSE functions.
+ ``ETHTOOL_A_C33_PSE_PW_D_STATUS`` u32 power detection status of the
+ PoE PSE.
+ ``ETHTOOL_A_C33_PSE_PW_CLASS`` u32 power class of the PoE PSE.
+ ``ETHTOOL_A_C33_PSE_ACTUAL_PW`` u32 actual power drawn on the
+ PoE PSE.
+ ``ETHTOOL_A_C33_PSE_EXT_STATE`` u32 power extended state of the
+ PoE PSE.
+ ``ETHTOOL_A_C33_PSE_EXT_SUBSTATE`` u32 power extended substatus of
+ the PoE PSE.
+ ``ETHTOOL_A_C33_PSE_AVAIL_PW_LIMIT`` u32 currently configured power
+ limit of the PoE PSE.
+ ``ETHTOOL_A_C33_PSE_PW_LIMIT_RANGES`` nested Supported power limit
+ configuration ranges.
+ ========================================== ====== =============================

When set, the optional ``ETHTOOL_A_PODL_PSE_ADMIN_STATE`` attribute identifies
the operational state of the PoDL PSE functions. The operational state of the
@@ -1799,6 +1803,16 @@ Possible values are:
ethtool_c33_pse_ext_substate_power_not_available
ethtool_c33_pse_ext_substate_short_detected

+When set, the optional ``ETHTOOL_A_C33_PSE_AVAIL_PW_LIMIT`` attribute
+identifies the C33 PSE power limit in mW.
+
+When set the optional ``ETHTOOL_A_C33_PSE_PW_LIMIT_RANGES`` nested attribute
+identifies the C33 PSE power limit ranges through
+``ETHTOOL_A_C33_PSE_PWR_VAL_LIMIT_RANGE_MIN`` and
+``ETHTOOL_A_C33_PSE_PWR_VAL_LIMIT_RANGE_MAX``.
+If the controller works with fixed classes, the min and max values will be
+equal.
+
PSE_SET
=======

@@ -1810,6 +1824,8 @@ Request contents:
``ETHTOOL_A_PSE_HEADER`` nested request header
``ETHTOOL_A_PODL_PSE_ADMIN_CONTROL`` u32 Control PoDL PSE Admin state
``ETHTOOL_A_C33_PSE_ADMIN_CONTROL`` u32 Control PSE Admin state
+ ``ETHTOOL_A_C33_PSE_AVAIL_PWR_LIMIT`` u32 Control PoE PSE available
+ power limit
====================================== ====== =============================

When set, the optional ``ETHTOOL_A_PODL_PSE_ADMIN_CONTROL`` attribute is used
@@ -1820,6 +1836,18 @@ to control PoDL PSE Admin functions. This option is implementing
The same goes for ``ETHTOOL_A_C33_PSE_ADMIN_CONTROL`` implementing
``IEEE 802.3-2022`` 30.9.1.2.1 acPSEAdminControl.

+When set, the optional ``ETHTOOL_A_C33_PSE_AVAIL_PWR_LIMIT`` attribute is
+used to control the available power value limit for C33 PSE in milliwatts.
+This attribute corresponds to the `pse_available_power` variable described in
+``IEEE 802.3-2022`` 33.2.4.4 Variables and `pse_avail_pwr` in 145.2.5.4
+Variables, which are described in power classes.
+
+It was decided to use milliwatts for this interface to unify it with other
+power monitoring interfaces, which also use milliwatts, and to align with
+various existing products that document power consumption in watts rather than
+classes. If power limit configuration based on classes is needed, the
+conversion can be done in user space, for example by ethtool.
+
RSS_GET
=======

diff --git a/include/linux/ethtool.h b/include/linux/ethtool.h
index 3c96aa8765d9..d8a73a35e1cc 100644
--- a/include/linux/ethtool.h
+++ b/include/linux/ethtool.h
@@ -1170,4 +1170,9 @@ struct ethtool_c33_pse_ext_state_info {
u32 __c33_pse_ext_substate;
};
};
+
+struct ethtool_c33_pse_pw_limit_range {
+ u32 min;
+ u32 max;
+};
#endif /* _LINUX_ETHTOOL_H */
diff --git a/include/uapi/linux/ethtool_netlink.h b/include/uapi/linux/ethtool_netlink.h
index 398a0aa8daad..b35be6c78d4b 100644
--- a/include/uapi/linux/ethtool_netlink.h
+++ b/include/uapi/linux/ethtool_netlink.h
@@ -906,6 +906,12 @@ enum {
};

/* Power Sourcing Equipment */
+enum {
+ ETHTOOL_A_C33_PSE_PW_LIMIT_UNSPEC,
+ ETHTOOL_A_C33_PSE_PW_LIMIT_MIN, /* u32 */
+ ETHTOOL_A_C33_PSE_PW_LIMIT_MAX, /* u32 */
+};
+
enum {
ETHTOOL_A_PSE_UNSPEC,
ETHTOOL_A_PSE_HEADER, /* nest - _A_HEADER_* */
@@ -919,6 +925,8 @@ enum {
ETHTOOL_A_C33_PSE_ACTUAL_PW, /* u32 */
ETHTOOL_A_C33_PSE_EXT_STATE, /* u32 */
ETHTOOL_A_C33_PSE_EXT_SUBSTATE, /* u32 */
+ ETHTOOL_A_C33_PSE_AVAIL_PW_LIMIT, /* u32 */
+ ETHTOOL_A_C33_PSE_PW_LIMIT_RANGES, /* nest - _C33_PSE_PW_LIMIT_* */

/* add new constants above here */
__ETHTOOL_A_PSE_CNT,
diff --git a/net/ethtool/pse-pd.c b/net/ethtool/pse-pd.c
index d2a1c14d789f..ba46c9c8b12d 100644
--- a/net/ethtool/pse-pd.c
+++ b/net/ethtool/pse-pd.c
@@ -96,9 +96,46 @@ static int pse_reply_size(const struct ethnl_req_info *req_base,
/* _C33_PSE_EXT_SUBSTATE */
len += nla_total_size(sizeof(u32));
}
+ if (st->c33_avail_pw_limit > 0)
+ /* _C33_AVAIL_PSE_PW_LIMIT */
+ len += nla_total_size(sizeof(u32));
+ if (st->c33_pw_limit_nb_ranges > 0)
+ /* _C33_PSE_PW_LIMIT_RANGES */
+ len += st->c33_pw_limit_nb_ranges *
+ (nla_total_size(0) +
+ nla_total_size(sizeof(u32)) * 2);
+
return len;
}

+static int pse_put_pw_limit_ranges(struct sk_buff *skb,
+ const struct pse_control_status *st)
+{
+ const struct ethtool_c33_pse_pw_limit_range *pw_limit_ranges;
+ int i;
+
+ pw_limit_ranges = st->c33_pw_limit_ranges;
+ for (i = 0; i < st->c33_pw_limit_nb_ranges; i++) {
+ struct nlattr *nest;
+
+ nest = nla_nest_start(skb, ETHTOOL_A_C33_PSE_PW_LIMIT_RANGES);
+ if (!nest)
+ return -EMSGSIZE;
+
+ if (nla_put_u32(skb, ETHTOOL_A_C33_PSE_PW_LIMIT_MIN,
+ pw_limit_ranges->min) ||
+ nla_put_u32(skb, ETHTOOL_A_C33_PSE_PW_LIMIT_MAX,
+ pw_limit_ranges->max)) {
+ nla_nest_cancel(skb, nest);
+ return -EMSGSIZE;
+ }
+ nla_nest_end(skb, nest);
+ pw_limit_ranges++;
+ }
+
+ return 0;
+}
+
static int pse_fill_reply(struct sk_buff *skb,
const struct ethnl_req_info *req_base,
const struct ethnl_reply_data *reply_base)
@@ -147,9 +184,25 @@ static int pse_fill_reply(struct sk_buff *skb,
return -EMSGSIZE;
}

+ if (st->c33_avail_pw_limit > 0 &&
+ nla_put_u32(skb, ETHTOOL_A_C33_PSE_AVAIL_PW_LIMIT,
+ st->c33_avail_pw_limit))
+ return -EMSGSIZE;
+
+ if (st->c33_pw_limit_nb_ranges > 0 &&
+ pse_put_pw_limit_ranges(skb, st))
+ return -EMSGSIZE;
+
return 0;
}

+static void pse_cleanup_data(struct ethnl_reply_data *reply_base)
+{
+ const struct pse_reply_data *data = PSE_REPDATA(reply_base);
+
+ kfree(data->status.c33_pw_limit_ranges);
+}
+
/* PSE_SET */

const struct nla_policy ethnl_pse_set_policy[ETHTOOL_A_PSE_MAX + 1] = {
@@ -160,6 +213,7 @@ const struct nla_policy ethnl_pse_set_policy[ETHTOOL_A_PSE_MAX + 1] = {
[ETHTOOL_A_C33_PSE_ADMIN_CONTROL] =
NLA_POLICY_RANGE(NLA_U32, ETHTOOL_C33_PSE_ADMIN_STATE_DISABLED,
ETHTOOL_C33_PSE_ADMIN_STATE_ENABLED),
+ [ETHTOOL_A_C33_PSE_AVAIL_PW_LIMIT] = { .type = NLA_U32 },
};

static int
@@ -202,19 +256,39 @@ static int
ethnl_set_pse(struct ethnl_req_info *req_info, struct genl_info *info)
{
struct net_device *dev = req_info->dev;
- struct pse_control_config config = {};
struct nlattr **tb = info->attrs;
struct phy_device *phydev;
+ int ret = 0;

phydev = dev->phydev;
+
+ if (tb[ETHTOOL_A_C33_PSE_AVAIL_PW_LIMIT]) {
+ unsigned int pw_limit;
+
+ pw_limit = nla_get_u32(tb[ETHTOOL_A_C33_PSE_AVAIL_PW_LIMIT]);
+ ret = pse_ethtool_set_pw_limit(phydev->psec, info->extack,
+ pw_limit);
+ if (ret)
+ return ret;
+ }
+
/* These values are already validated by the ethnl_pse_set_policy */
- if (pse_has_podl(phydev->psec))
- config.podl_admin_control = nla_get_u32(tb[ETHTOOL_A_PODL_PSE_ADMIN_CONTROL]);
- if (pse_has_c33(phydev->psec))
- config.c33_admin_control = nla_get_u32(tb[ETHTOOL_A_C33_PSE_ADMIN_CONTROL]);
+ if (tb[ETHTOOL_A_PODL_PSE_ADMIN_CONTROL] ||
+ tb[ETHTOOL_A_C33_PSE_ADMIN_CONTROL]) {
+ struct pse_control_config config = {};
+
+ if (pse_has_podl(phydev->psec))
+ config.podl_admin_control = nla_get_u32(tb[ETHTOOL_A_PODL_PSE_ADMIN_CONTROL]);
+ if (pse_has_c33(phydev->psec))
+ config.c33_admin_control = nla_get_u32(tb[ETHTOOL_A_C33_PSE_ADMIN_CONTROL]);
+
+ ret = pse_ethtool_set_config(phydev->psec, info->extack,
+ &config);
+ if (ret)
+ return ret;
+ }

- /* Return errno directly - PSE has no notification */
- return pse_ethtool_set_config(phydev->psec, info->extack, &config);
+ return ret;
}

const struct ethnl_request_ops ethnl_pse_request_ops = {
@@ -227,6 +301,7 @@ const struct ethnl_request_ops ethnl_pse_request_ops = {
.prepare_data = pse_prepare_data,
.reply_size = pse_reply_size,
.fill_reply = pse_fill_reply,
+ .cleanup_data = pse_cleanup_data,

.set_validate = ethnl_set_pse_validate,
.set = ethnl_set_pse,

--
2.34.1