[Intel-wired-lan] [PATCH net-next v4 1/6] net: rtnetlink: add pacing_offload_horizon attribute to net_device
Willem de Bruijn <[email protected]> Thu, 6 Aug 2026 19:25:58 -0400
| Newsgroups | org.osuosl.intel-wired-lan,org.kernel.vger.netdev |
|---|---|
| Message-ID | <[email protected]> |
From: Willem de Bruijn <[email protected]> The 'max_pacing_offload_horizon' field of 'struct net_device' represents the maximum pacing offload horizon supported by the device. Add a new field 'pacing_offload_horizon' to store the active pacing offload horizon. The new attribute is initialized to 0 (disabled) and can be set from userspace via RTM_SETLINK up to dev->max_pacing_offload_horizon. This new default off behavior does not cause regressions, as no driver yet advertises max_pacing_offload_horizon. The equivalent RTM_NEWLINK is absent, as a value may need to be compared to a device maximum, which may be negotiated with the device firmware on init, as is the case for the idpf driver in this series. Make both fields u32, to maintain net_device cacheline layout. This expresses up to 4s of pacing offload, which is sufficient. Update the YNL specification ('rt-link.yaml') to add the 'pacing-offload-horizon' attribute and include it in link-all-attrs. Both fields can be read with python3 tools/net/ynl/pyynl/cli.py \ --spec Documentation/netlink/specs/rt-link.yaml \ --do getlink \ --json '{"ifname": "eth0"}' | grep pacing And the active horizon set with python3 tools/net/ynl/pyynl/cli.py \ --spec Documentation/netlink/specs/rt-link.yaml \ --do setlink \ --json '{"ifname": "eth0", "pacing-offload-horizon": 50000000}' Signed-off-by: Willem de Bruijn <[email protected]> --- Documentation/netlink/specs/rt-link.yaml | 6 ++++++ .../networking/net_cachelines/net_device.rst | 3 ++- include/linux/netdevice.h | 4 +++- include/uapi/linux/if_link.h | 1 + net/core/rtnetlink.c | 21 +++++++++++++++++++ 5 files changed, 33 insertions(+), 2 deletions(-) diff --git a/Documentation/netlink/specs/rt-link.yaml b/Documentation/netlink/specs/rt-link.yaml index 68c26a70bb64..a620135baba3 100644 --- a/Documentation/netlink/specs/rt-link.yaml +++ b/Documentation/netlink/specs/rt-link.yaml @@ -1080,6 +1080,10 @@ attribute-sets: - name: tailroom type: u16 + - + name: pacing-offload-horizon + type: uint + doc: EDT offload horizon setting for the device (in nsec). - name: prop-list-link-attrs subset-of: link-attrs @@ -2548,6 +2552,8 @@ operations: - devlink-port - gso-ipv4-max-size - gro-ipv4-max-size + - max-pacing-offload-horizon + - pacing-offload-horizon dump: request: value: 18 diff --git a/Documentation/networking/net_cachelines/net_device.rst b/Documentation/networking/net_cachelines/net_device.rst index 512f6d6fa3d8..90e257e815b1 100644 --- a/Documentation/networking/net_cachelines/net_device.rst +++ b/Documentation/networking/net_cachelines/net_device.rst @@ -183,7 +183,8 @@ struct devlink_port* devlink_port struct dpll_pin* dpll_pin struct hlist_head page_pools struct dim_irq_moder* irq_moder -u64 max_pacing_offload_horizon +u32 max_pacing_offload_horizon +u32 pacing_offload_horizon struct_napi_config* napi_config unsigned_long gro_flush_timeout u32 napi_defer_hard_irqs diff --git a/include/linux/netdevice.h b/include/linux/netdevice.h index 62cfad7e6b79..93d953caae94 100644 --- a/include/linux/netdevice.h +++ b/include/linux/netdevice.h @@ -2131,6 +2131,7 @@ enum netdev_reg_state { * where the clock is recovered. * * @max_pacing_offload_horizon: max EDT offload horizon in nsec. + * @pacing_offload_horizon: EDT offload horizon setting in nsec. * @napi_config: An array of napi_config structures containing per-NAPI * settings. * @num_napi_configs: number of allocated NAPI config structs, @@ -2553,7 +2554,8 @@ struct net_device { /** @irq_moder: dim parameters used if IS_ENABLED(CONFIG_DIMLIB). */ struct dim_irq_moder *irq_moder; - u64 max_pacing_offload_horizon; + u32 max_pacing_offload_horizon; + u32 pacing_offload_horizon; struct napi_config *napi_config; u32 num_napi_configs; u32 napi_defer_hard_irqs; diff --git a/include/uapi/linux/if_link.h b/include/uapi/linux/if_link.h index 43cecca49f01..7c1d7754a670 100644 --- a/include/uapi/linux/if_link.h +++ b/include/uapi/linux/if_link.h @@ -381,6 +381,7 @@ enum { IFLA_NETNS_IMMUTABLE, IFLA_HEADROOM, IFLA_TAILROOM, + IFLA_PACING_OFFLOAD_HORIZON, __IFLA_MAX }; diff --git a/net/core/rtnetlink.c b/net/core/rtnetlink.c index 31c65a545a10..b8c35f64d49f 100644 --- a/net/core/rtnetlink.c +++ b/net/core/rtnetlink.c @@ -1381,6 +1381,7 @@ static noinline size_t if_nlmsg_size(const struct net_device *dev, + rtnl_devlink_port_size(dev) + rtnl_dpll_pin_size() + nla_total_size(8) /* IFLA_MAX_PACING_OFFLOAD_HORIZON */ + + nla_total_size(8) /* IFLA_PACING_OFFLOAD_HORIZON */ + nla_total_size(2) /* IFLA_HEADROOM */ + nla_total_size(2) /* IFLA_TAILROOM */ + rtnl_dev_parent_size(dev) @@ -2156,6 +2157,8 @@ static int rtnl_fill_ifinfo(struct sk_buff *skb, READ_ONCE(dev->tso_max_segs)) || nla_put_uint(skb, IFLA_MAX_PACING_OFFLOAD_HORIZON, READ_ONCE(dev->max_pacing_offload_horizon)) || + nla_put_uint(skb, IFLA_PACING_OFFLOAD_HORIZON, + READ_ONCE(dev->pacing_offload_horizon)) || #ifdef CONFIG_RPS nla_put_u32(skb, IFLA_NUM_RX_QUEUES, READ_ONCE(dev->num_rx_queues)) || @@ -2324,9 +2327,11 @@ static const struct nla_policy ifla_policy[IFLA_MAX+1] = { [IFLA_ALLMULTI] = { .type = NLA_REJECT }, [IFLA_GSO_IPV4_MAX_SIZE] = NLA_POLICY_MIN(NLA_U32, MAX_TCP_HEADER + 1), [IFLA_GRO_IPV4_MAX_SIZE] = { .type = NLA_U32 }, + [IFLA_MAX_PACING_OFFLOAD_HORIZON] = { .type = NLA_REJECT }, [IFLA_NETNS_IMMUTABLE] = { .type = NLA_REJECT }, [IFLA_HEADROOM] = { .type = NLA_REJECT }, [IFLA_TAILROOM] = { .type = NLA_REJECT }, + [IFLA_PACING_OFFLOAD_HORIZON] = { .type = NLA_UINT }, }; static const struct nla_policy ifla_info_policy[IFLA_INFO_MAX+1] = { @@ -2800,6 +2805,13 @@ static int validate_linkmsg(struct net_device *dev, struct nlattr *tb[], return -EINVAL; } + if (tb[IFLA_PACING_OFFLOAD_HORIZON] && + nla_get_uint(tb[IFLA_PACING_OFFLOAD_HORIZON]) > + dev->max_pacing_offload_horizon) { + NL_SET_ERR_MSG(extack, "too big pacing_offload_horizon"); + return -EINVAL; + } + if (tb[IFLA_AF_SPEC]) { struct nlattr *af; int rem, err; @@ -3317,6 +3329,15 @@ static int do_setlink(const struct sk_buff *skb, struct net_device *dev, } } + if (tb[IFLA_PACING_OFFLOAD_HORIZON]) { + u64 horizon = nla_get_uint(tb[IFLA_PACING_OFFLOAD_HORIZON]); + + if (dev->pacing_offload_horizon ^ horizon) { + WRITE_ONCE(dev->pacing_offload_horizon, horizon); + status |= DO_SETLINK_MODIFIED; + } + } + if (tb[IFLA_OPERSTATE]) set_operstate(dev, nla_get_u8(tb[IFLA_OPERSTATE])); -- 2.55.0.679.g6767b8d81c-goog