From mboxrd@z Thu Jan 1 00:00:00 1970 From: Vladimir Oltean Date: Sun, 27 Jun 2021 19:43:36 +0000 Subject: [Intel-wired-lan] [PATCH net-next v4 01/12] ethtool: Add support for configuring frame preemption In-Reply-To: <20210626003314.3159402-2-vinicius.gomes@intel.com> References: <20210626003314.3159402-1-vinicius.gomes@intel.com> <20210626003314.3159402-2-vinicius.gomes@intel.com> Message-ID: <20210627194335.vrhwurg43esnodi3@skbuf> MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: intel-wired-lan@osuosl.org List-ID: On Fri, Jun 25, 2021 at 05:33:03PM -0700, Vinicius Costa Gomes wrote: > Frame preemption (described in IEEE 802.3-2018, Section 99 in > particular) defines the concept of preemptible and express queues. It > allows traffic from express queues to "interrupt" traffic from > preemptible queues, which are "resumed" after the express traffic has > finished transmitting. > > Frame preemption can only be used when both the local device and the > link partner support it. > > Only parameters for enabling/disabling frame preemption and > configuring the minimum fragment size are included here. Expressing > which queues are marked as preemptible is left to mqprio/taprio, as > having that information there should be easier on the user. > > Signed-off-by: Vinicius Costa Gomes > --- > Documentation/networking/ethtool-netlink.rst | 38 +++++ > include/linux/ethtool.h | 22 +++ > include/uapi/linux/ethtool_netlink.h | 17 +++ > net/ethtool/Makefile | 2 +- > net/ethtool/common.c | 25 ++++ > net/ethtool/netlink.c | 19 +++ > net/ethtool/netlink.h | 4 + > net/ethtool/preempt.c | 146 +++++++++++++++++++ > 8 files changed, 272 insertions(+), 1 deletion(-) > create mode 100644 net/ethtool/preempt.c > > diff --git a/Documentation/networking/ethtool-netlink.rst b/Documentation/networking/ethtool-netlink.rst > index 6ea91e41593f..a87f1716944e 100644 > --- a/Documentation/networking/ethtool-netlink.rst > +++ b/Documentation/networking/ethtool-netlink.rst > @@ -1477,6 +1477,44 @@ Low and high bounds are inclusive, for example: > etherStatsPkts512to1023Octets 512 1023 > ============================= ==== ==== I think you need to add some extra documentation bits to the List of message types ===================== and Request translation =================== sections. > > +PREEMPT_GET > +=========== > + > +Get information about frame preemption state. > + > +Request contents: > + > + ==================================== ====== ========================== > + ``ETHTOOL_A_PREEMPT_HEADER`` nested request header > + ==================================== ====== ========================== > + > +Request contents: > + > + ===================================== ====== ========================== > + ``ETHTOOL_A_PREEMPT_HEADER`` nested reply header > + ``ETHTOOL_A_PREEMPT_ENABLED`` u8 frame preemption enabled > + ``ETHTOOL_A_PREEMPT_ADD_FRAG_SIZE`` u32 Min additional frag size > + ===================================== ====== ========================== > + > +``ETHTOOL_A_PREEMPT_ADD_FRAG_SIZE`` configures the minimum non-final > +fragment size that the receiver device supports. > + > +PREEMPT_SET > +=========== > + > +Sets frame preemption parameters. > + > +Request contents: > + > + ===================================== ====== ========================== > + ``ETHTOOL_A_CHANNELS_HEADER`` nested reply header > + ``ETHTOOL_A_PREEMPT_ENABLED`` u8 frame preemption enabled > + ``ETHTOOL_A_PREEMPT_ADD_FRAG_SIZE`` u32 Min additional frag size > + ===================================== ====== ========================== > + > +``ETHTOOL_A_PREEMPT_ADD_FRAG_SIZE`` configures the minimum non-final > +fragment size that the receiver device supports. > + > Request translation > =================== > > diff --git a/include/linux/ethtool.h b/include/linux/ethtool.h > index 29dbb603bc91..7e449be8f335 100644 > --- a/include/linux/ethtool.h > +++ b/include/linux/ethtool.h > @@ -409,6 +409,19 @@ struct ethtool_module_eeprom { > u8 *data; > }; > > +/** > + * struct ethtool_fp - Frame Preemption information > + * > + * @enabled: Enable frame preemption. > + * @add_frag_size: Minimum size for additional (non-final) fragments > + * in bytes, for the value defined in the IEEE 802.3-2018 standard see > + * ethtool_frag_size_to_mult(). > + */ > +struct ethtool_fp { > + u8 enabled; > + u32 add_frag_size; Strange that the verify_disable bit is not in here? I haven't looked at further patches in detail but I saw in the commit message that you added support for it, maybe it needs to be squashed with this? Can we make "enabled" a bool? > +}; > + > /** > * struct ethtool_ops - optional netdev operations > * @cap_link_lanes_supported: indicates if the driver supports lanes > @@ -561,6 +574,8 @@ struct ethtool_module_eeprom { > * not report statistics. > * @get_fecparam: Get the network device Forward Error Correction parameters. > * @set_fecparam: Set the network device Forward Error Correction parameters. > + * @get_preempt: Get the network device Frame Preemption parameters. > + * @set_preempt: Set the network device Frame Preemption parameters. > * @get_ethtool_phy_stats: Return extended statistics about the PHY device. > * This is only useful if the device maintains PHY statistics and > * cannot use the standard PHY library helpers. > @@ -675,6 +690,10 @@ struct ethtool_ops { > struct ethtool_fecparam *); > int (*set_fecparam)(struct net_device *, > struct ethtool_fecparam *); > + int (*get_preempt)(struct net_device *, > + struct ethtool_fp *); > + int (*set_preempt)(struct net_device *, struct ethtool_fp *, > + struct netlink_ext_ack *); > void (*get_ethtool_phy_stats)(struct net_device *, > struct ethtool_stats *, u64 *); > int (*get_phy_tunable)(struct net_device *, > @@ -766,4 +785,7 @@ ethtool_params_from_link_mode(struct ethtool_link_ksettings *link_ksettings, > * next string. > */ > extern __printf(2, 3) void ethtool_sprintf(u8 **data, const char *fmt, ...); > + > +u8 ethtool_frag_size_to_mult(u32 frag_size); > + > #endif /* _LINUX_ETHTOOL_H */ > diff --git a/include/uapi/linux/ethtool_netlink.h b/include/uapi/linux/ethtool_netlink.h > index c7135c9c37a5..4600aba1c693 100644 > --- a/include/uapi/linux/ethtool_netlink.h > +++ b/include/uapi/linux/ethtool_netlink.h > @@ -44,6 +44,8 @@ enum { > ETHTOOL_MSG_TUNNEL_INFO_GET, > ETHTOOL_MSG_FEC_GET, > ETHTOOL_MSG_FEC_SET, > + ETHTOOL_MSG_PREEMPT_GET, > + ETHTOOL_MSG_PREEMPT_SET, > ETHTOOL_MSG_MODULE_EEPROM_GET, > ETHTOOL_MSG_STATS_GET, > > @@ -86,6 +88,8 @@ enum { > ETHTOOL_MSG_TUNNEL_INFO_GET_REPLY, > ETHTOOL_MSG_FEC_GET_REPLY, > ETHTOOL_MSG_FEC_NTF, > + ETHTOOL_MSG_PREEMPT_GET_REPLY, > + ETHTOOL_MSG_PREEMPT_NTF, > ETHTOOL_MSG_MODULE_EEPROM_GET_REPLY, > ETHTOOL_MSG_STATS_GET_REPLY, Correct me if I'm wrong, but enums in uapi should always be added at the end, otherwise you break value with user space binaries which use ETHTOOL_MSG_MODULE_EEPROM_GET and are compiled against old kernel headers. > > @@ -664,6 +668,19 @@ enum { > ETHTOOL_A_FEC_STAT_MAX = (__ETHTOOL_A_FEC_STAT_CNT - 1) > }; > > +/* FRAME PREEMPTION */ > + > +enum { > + ETHTOOL_A_PREEMPT_UNSPEC, > + ETHTOOL_A_PREEMPT_HEADER, /* nest - _A_HEADER_* */ > + ETHTOOL_A_PREEMPT_ENABLED, /* u8 */ > + ETHTOOL_A_PREEMPT_ADD_FRAG_SIZE, /* u32 */ > + > + /* add new constants above here */ > + __ETHTOOL_A_PREEMPT_CNT, > + ETHTOOL_A_PREEMPT_MAX = (__ETHTOOL_A_PREEMPT_CNT - 1) > +}; > + > /* MODULE EEPROM */ > > enum { > diff --git a/net/ethtool/Makefile b/net/ethtool/Makefile > index 723c9a8a8cdf..4b84b2d34c7a 100644 > --- a/net/ethtool/Makefile > +++ b/net/ethtool/Makefile > @@ -7,4 +7,4 @@ obj-$(CONFIG_ETHTOOL_NETLINK) += ethtool_nl.o > ethtool_nl-y := netlink.o bitset.o strset.o linkinfo.o linkmodes.o \ > linkstate.o debug.o wol.o features.o privflags.o rings.o \ > channels.o coalesce.o pause.o eee.o tsinfo.o cabletest.o \ > - tunnels.o fec.o eeprom.o stats.o > + tunnels.o fec.o preempt.o eeprom.o stats.o > diff --git a/net/ethtool/common.c b/net/ethtool/common.c > index f9dcbad84788..68d123dd500b 100644 > --- a/net/ethtool/common.c > +++ b/net/ethtool/common.c > @@ -579,3 +579,28 @@ ethtool_params_from_link_mode(struct ethtool_link_ksettings *link_ksettings, > link_ksettings->base.duplex = link_info->duplex; > } > EXPORT_SYMBOL_GPL(ethtool_params_from_link_mode); > + > +/** > + * ethtool_frag_size_to_mult() - Convert from a Frame Preemption > + * Additional Fragment size in bytes to a multiplier. > + * @frag_size: minimum non-final fragment size in bytes. > + * > + * The multiplier is defined as: > + * "A 2-bit integer value used to indicate the minimum size of > + * non-final fragments supported by the receiver on the given port > + * associated with the local System. This value is expressed in units > + * of 64 octets of additional fragment length." > + * Equivalent to `30.14.1.7 aMACMergeAddFragSize` from the IEEE 802.3-2018 > + * standard. > + * > + * Return: the multiplier is a number in the [0, 2] interval. > + */ > +u8 ethtool_frag_size_to_mult(u32 frag_size) > +{ > + u8 mult = (frag_size / 64) - 1; > + > + mult = clamp_t(u8, mult, 0, 3); > + > + return mult; I think it would look better as "return clamp_t(u8, mult, 0, 3);" > +} > +EXPORT_SYMBOL_GPL(ethtool_frag_size_to_mult); > diff --git a/net/ethtool/netlink.c b/net/ethtool/netlink.c > index a7346346114f..f4e07b740790 100644 > --- a/net/ethtool/netlink.c > +++ b/net/ethtool/netlink.c > @@ -246,6 +246,7 @@ ethnl_default_requests[__ETHTOOL_MSG_USER_CNT] = { > [ETHTOOL_MSG_EEE_GET] = ðnl_eee_request_ops, > [ETHTOOL_MSG_FEC_GET] = ðnl_fec_request_ops, > [ETHTOOL_MSG_TSINFO_GET] = ðnl_tsinfo_request_ops, > + [ETHTOOL_MSG_PREEMPT_GET] = ðnl_preempt_request_ops, > [ETHTOOL_MSG_MODULE_EEPROM_GET] = ðnl_module_eeprom_request_ops, > [ETHTOOL_MSG_STATS_GET] = ðnl_stats_request_ops, > }; > @@ -561,6 +562,7 @@ ethnl_default_notify_ops[ETHTOOL_MSG_KERNEL_MAX + 1] = { > [ETHTOOL_MSG_PAUSE_NTF] = ðnl_pause_request_ops, > [ETHTOOL_MSG_EEE_NTF] = ðnl_eee_request_ops, > [ETHTOOL_MSG_FEC_NTF] = ðnl_fec_request_ops, > + [ETHTOOL_MSG_PREEMPT_NTF] = ðnl_preempt_request_ops, > }; > > /* default notification handler */ > @@ -654,6 +656,7 @@ static const ethnl_notify_handler_t ethnl_notify_handlers[] = { > [ETHTOOL_MSG_PAUSE_NTF] = ethnl_default_notify, > [ETHTOOL_MSG_EEE_NTF] = ethnl_default_notify, > [ETHTOOL_MSG_FEC_NTF] = ethnl_default_notify, > + [ETHTOOL_MSG_PREEMPT_NTF] = ethnl_default_notify, > }; > > void ethtool_notify(struct net_device *dev, unsigned int cmd, const void *data) > @@ -958,6 +961,22 @@ static const struct genl_ops ethtool_genl_ops[] = { > .policy = ethnl_stats_get_policy, > .maxattr = ARRAY_SIZE(ethnl_stats_get_policy) - 1, > }, > + { > + .cmd = ETHTOOL_MSG_PREEMPT_GET, > + .doit = ethnl_default_doit, > + .start = ethnl_default_start, > + .dumpit = ethnl_default_dumpit, > + .done = ethnl_default_done, > + .policy = ethnl_preempt_get_policy, > + .maxattr = ARRAY_SIZE(ethnl_preempt_get_policy) - 1, > + }, > + { > + .cmd = ETHTOOL_MSG_PREEMPT_SET, > + .flags = GENL_UNS_ADMIN_PERM, > + .doit = ethnl_set_preempt, > + .policy = ethnl_preempt_set_policy, > + .maxattr = ARRAY_SIZE(ethnl_preempt_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 3e25a47fd482..cc90a463a81c 100644 > --- a/net/ethtool/netlink.h > +++ b/net/ethtool/netlink.h > @@ -345,6 +345,7 @@ extern const struct ethnl_request_ops ethnl_pause_request_ops; > extern const struct ethnl_request_ops ethnl_eee_request_ops; > extern const struct ethnl_request_ops ethnl_tsinfo_request_ops; > extern const struct ethnl_request_ops ethnl_fec_request_ops; > +extern const struct ethnl_request_ops ethnl_preempt_request_ops; > extern const struct ethnl_request_ops ethnl_module_eeprom_request_ops; > extern const struct ethnl_request_ops ethnl_stats_request_ops; > > @@ -381,6 +382,8 @@ extern const struct nla_policy ethnl_tunnel_info_get_policy[ETHTOOL_A_TUNNEL_INF > extern const struct nla_policy ethnl_fec_get_policy[ETHTOOL_A_FEC_HEADER + 1]; > extern const struct nla_policy ethnl_fec_set_policy[ETHTOOL_A_FEC_AUTO + 1]; > extern const struct nla_policy ethnl_module_eeprom_get_policy[ETHTOOL_A_MODULE_EEPROM_I2C_ADDRESS + 1]; > +extern const struct nla_policy ethnl_preempt_get_policy[ETHTOOL_A_PREEMPT_HEADER + 1]; > +extern const struct nla_policy ethnl_preempt_set_policy[ETHTOOL_A_PREEMPT_ADD_FRAG_SIZE + 1]; > extern const struct nla_policy ethnl_stats_get_policy[ETHTOOL_A_STATS_GROUPS + 1]; > > int ethnl_set_linkinfo(struct sk_buff *skb, struct genl_info *info); > @@ -400,6 +403,7 @@ int ethnl_tunnel_info_doit(struct sk_buff *skb, struct genl_info *info); > int ethnl_tunnel_info_start(struct netlink_callback *cb); > int ethnl_tunnel_info_dumpit(struct sk_buff *skb, struct netlink_callback *cb); > int ethnl_set_fec(struct sk_buff *skb, struct genl_info *info); > +int ethnl_set_preempt(struct sk_buff *skb, struct genl_info *info); > > extern const char stats_std_names[__ETHTOOL_STATS_CNT][ETH_GSTRING_LEN]; > extern const char stats_eth_phy_names[__ETHTOOL_A_STATS_ETH_PHY_CNT][ETH_GSTRING_LEN]; > diff --git a/net/ethtool/preempt.c b/net/ethtool/preempt.c > new file mode 100644 > index 000000000000..4f96d3c2b1d5 > --- /dev/null > +++ b/net/ethtool/preempt.c > @@ -0,0 +1,146 @@ > +// SPDX-License-Identifier: GPL-2.0-only > + > +#include "netlink.h" > +#include "common.h" > + > +struct preempt_req_info { > + struct ethnl_req_info base; > +}; > + > +struct preempt_reply_data { > + struct ethnl_reply_data base; > + struct ethtool_fp fp; > +}; > + > +#define PREEMPT_REPDATA(__reply_base) \ > + container_of(__reply_base, struct preempt_reply_data, base) > + > +const struct nla_policy > +ethnl_preempt_get_policy[] = { > + [ETHTOOL_A_PREEMPT_HEADER] = NLA_POLICY_NESTED(ethnl_header_policy), > +}; > + > +static int preempt_prepare_data(const struct ethnl_req_info *req_base, > + struct ethnl_reply_data *reply_base, > + struct genl_info *info) > +{ > + struct preempt_reply_data *data = PREEMPT_REPDATA(reply_base); > + struct net_device *dev = reply_base->dev; > + int ret; > + > + if (!dev->ethtool_ops->get_preempt) > + return -EOPNOTSUPP; > + > + ret = ethnl_ops_begin(dev); > + if (ret < 0) > + return ret; > + > + ret = dev->ethtool_ops->get_preempt(dev, &data->fp); > + ethnl_ops_complete(dev); > + > + return ret; > +} > + > +static int preempt_reply_size(const struct ethnl_req_info *req_base, > + const struct ethnl_reply_data *reply_base) > +{ > + int len = 0; > + > + len += nla_total_size(sizeof(u8)); /* _PREEMPT_ENABLED */ > + len += nla_total_size(sizeof(u32)); /* _PREEMPT_ADD_FRAG_SIZE */ > + > + return len; > +} > + > +static int preempt_fill_reply(struct sk_buff *skb, > + const struct ethnl_req_info *req_base, > + const struct ethnl_reply_data *reply_base) > +{ > + const struct preempt_reply_data *data = PREEMPT_REPDATA(reply_base); > + const struct ethtool_fp *preempt = &data->fp; > + > + if (nla_put_u8(skb, ETHTOOL_A_PREEMPT_ENABLED, preempt->enabled)) > + return -EMSGSIZE; > + > + if (nla_put_u32(skb, ETHTOOL_A_PREEMPT_ADD_FRAG_SIZE, > + preempt->add_frag_size)) > + return -EMSGSIZE; > + > + return 0; > +} > + > +const struct ethnl_request_ops ethnl_preempt_request_ops = { > + .request_cmd = ETHTOOL_MSG_PREEMPT_GET, > + .reply_cmd = ETHTOOL_MSG_PREEMPT_GET_REPLY, > + .hdr_attr = ETHTOOL_A_PREEMPT_HEADER, > + .req_info_size = sizeof(struct preempt_req_info), > + .reply_data_size = sizeof(struct preempt_reply_data), > + > + .prepare_data = preempt_prepare_data, > + .reply_size = preempt_reply_size, > + .fill_reply = preempt_fill_reply, > +}; > + > +const struct nla_policy > +ethnl_preempt_set_policy[ETHTOOL_A_PREEMPT_MAX + 1] = { > + [ETHTOOL_A_PREEMPT_HEADER] = NLA_POLICY_NESTED(ethnl_header_policy), > + [ETHTOOL_A_PREEMPT_ENABLED] = NLA_POLICY_RANGE(NLA_U8, 0, 1), > + [ETHTOOL_A_PREEMPT_ADD_FRAG_SIZE] = { .type = NLA_U32 }, > +}; > + > +int ethnl_set_preempt(struct sk_buff *skb, struct genl_info *info) > +{ > + struct ethnl_req_info req_info = {}; > + struct nlattr **tb = info->attrs; > + struct ethtool_fp preempt = {}; > + struct net_device *dev; > + bool mod = false; > + int ret; > + > + ret = ethnl_parse_header_dev_get(&req_info, > + tb[ETHTOOL_A_PREEMPT_HEADER], > + genl_info_net(info), info->extack, > + true); > + if (ret < 0) > + return ret; > + dev = req_info.dev; > + ret = -EOPNOTSUPP; Some new lines around here please? And maybe it would look a bit cleaner if you could assign "ret = -EOPNOTSUPP" in the "preempt ops not present" if condition body? > + if (!dev->ethtool_ops->get_preempt || > + !dev->ethtool_ops->set_preempt) > + goto out_dev; > + > + rtnl_lock(); > + ret = ethnl_ops_begin(dev); > + if (ret < 0) > + goto out_rtnl; > + > + ret = dev->ethtool_ops->get_preempt(dev, &preempt); I don't know much about the background of ethtool netlink, but why does the .doit of ETHTOOL_MSG_*_SET go through a getter first? Is it because all the netlink attributes from the message are optional, and we need to default to the current state? > + if (ret < 0) { > + GENL_SET_ERR_MSG(info, "failed to retrieve frame preemption settings"); > + goto out_ops; > + } > + > + ethnl_update_u8(&preempt.enabled, > + tb[ETHTOOL_A_PREEMPT_ENABLED], &mod); > + ethnl_update_u32(&preempt.add_frag_size, > + tb[ETHTOOL_A_PREEMPT_ADD_FRAG_SIZE], &mod); > + ret = 0; This reinitialization of ret to zero is interesting. It implies ->get_preempt() is allowed to return > 0 as a success error code. However ->set_preempt() below isn't? (its return value is directly propagated to callers of ethnl_set_preempt(). > + if (!mod) > + goto out_ops; > + > + ret = dev->ethtool_ops->set_preempt(dev, &preempt, info->extack); > + if (ret < 0) { > + GENL_SET_ERR_MSG(info, "frame preemption settings update failed"); > + goto out_ops; > + } > + > + ethtool_notify(dev, ETHTOOL_MSG_PREEMPT_NTF, NULL); > + > +out_ops: > + ethnl_ops_complete(dev); > +out_rtnl: > + rtnl_unlock(); > +out_dev: > + dev_put(dev); > + return ret; > +} > -- > 2.32.0 >