Re: [RFC net-next 2/4] ethtool: extend coalesce setting uAPI with CQE mode
From: Jakub Kicinski <kuba@kernel.org>
Date: 2021-05-27 00:00:38
Also in:
linux-wireless
On Wed, 26 May 2021 17:27:40 +0800 Huazhong Tan wrote:
Currently, there many drivers who support CQE mode configuration, some configure it as a fixed when initialized, some provide an interface to change it by ethtool private flags. In order make it more generic, add 'ETHTOOL_A_COALESCE_USE_CQE_TX' and 'ETHTOOL_A_COALESCE_USE_CQE_RX' attribute and expand struct kernel_ethtool_coalesce with use_cqe_mode_tx and use_cqe_mode_rx, then these parameters can be accessed by ethtool netlink coalesce uAPI. Signed-off-by: Huazhong Tan <redacted>
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diff --git a/Documentation/networking/ethtool-netlink.rst b/Documentation/networking/ethtool-netlink.rst index 25131df..975394e 100644 --- a/Documentation/networking/ethtool-netlink.rst +++ b/Documentation/networking/ethtool-netlink.rst@@ -937,6 +937,8 @@ Kernel response contents: ``ETHTOOL_A_COALESCE_TX_USECS_HIGH`` u32 delay (us), high Tx ``ETHTOOL_A_COALESCE_TX_MAX_FRAMES_HIGH`` u32 max packets, high Tx ``ETHTOOL_A_COALESCE_RATE_SAMPLE_INTERVAL`` u32 rate sampling interval + ``ETHTOOL_A_COALESCE_USE_CQE_TX`` bool Tx CQE mode + ``ETHTOOL_A_COALESCE_USE_CQE_RX`` bool Rx CQE mode =========================================== ====== ======================= Attributes are only included in reply if their value is not zero or the@@ -975,6 +977,8 @@ Request contents: ``ETHTOOL_A_COALESCE_TX_USECS_HIGH`` u32 delay (us), high Tx ``ETHTOOL_A_COALESCE_TX_MAX_FRAMES_HIGH`` u32 max packets, high Tx ``ETHTOOL_A_COALESCE_RATE_SAMPLE_INTERVAL`` u32 rate sampling interval + ``ETHTOOL_A_COALESCE_USE_CQE_TX`` bool Tx CQE mode + ``ETHTOOL_A_COALESCE_USE_CQE_RX`` bool Rx CQE mode =========================================== ====== ======================= Request is rejected if it attributes declared as unsupported by driver (i.e.
You need to thoroughly document the semantics. Can you point us to which drivers/devices implement similar modes of operation (if they exist we need to make sure semantics match)?
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diff --git a/include/linux/ethtool.h b/include/linux/ethtool.h index 1030540..9d0a386 100644 --- a/include/linux/ethtool.h +++ b/include/linux/ethtool.h@@ -179,6 +179,8 @@ __ethtool_get_link_ksettings(struct net_device *dev, struct kernel_ethtool_coalesce { struct ethtool_coalesce base; + __u32 use_cqe_mode_tx; + __u32 use_cqe_mode_rx;
No __ in front, this is not a user space structure. Why not bool or a bitfield?
}; /**
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@@ -216,6 +223,8 @@ const struct nla_policy ethnl_coalesce_set_policy[] = { [ETHTOOL_A_COALESCE_TX_USECS_HIGH] = { .type = NLA_U32 }, [ETHTOOL_A_COALESCE_TX_MAX_FRAMES_HIGH] = { .type = NLA_U32 }, [ETHTOOL_A_COALESCE_RATE_SAMPLE_INTERVAL] = { .type = NLA_U32 }, + [ETHTOOL_A_COALESCE_USE_CQE_MODE_TX] = { .type = NLA_U8 }, + [ETHTOOL_A_COALESCE_USE_CQE_MODE_RX] = { .type = NLA_U8 },
This needs a policy to make sure values are <= 1.