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authorDaniel Baumann <daniel.baumann@progress-linux.org>2024-05-18 18:50:12 +0000
committerDaniel Baumann <daniel.baumann@progress-linux.org>2024-05-18 18:50:12 +0000
commit8665bd53f2f2e27e5511d90428cb3f60e6d0ce15 (patch)
tree8d58900dc0ebd4a3011f92c128d2fe45bc7c4bf2 /Documentation/networking
parentAdding debian version 6.7.12-1. (diff)
downloadlinux-8665bd53f2f2e27e5511d90428cb3f60e6d0ce15.tar.xz
linux-8665bd53f2f2e27e5511d90428cb3f60e6d0ce15.zip
Merging upstream version 6.8.9.
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'Documentation/networking')
-rw-r--r--Documentation/networking/bridge.rst334
-rw-r--r--Documentation/networking/device_drivers/ethernet/amazon/ena.rst1
-rw-r--r--Documentation/networking/device_drivers/ethernet/intel/ice.rst141
-rw-r--r--Documentation/networking/device_drivers/ethernet/marvell/octeon_ep.rst5
-rw-r--r--Documentation/networking/device_drivers/wifi/index.rst1
-rw-r--r--Documentation/networking/device_drivers/wifi/ray_cs.rst165
-rw-r--r--Documentation/networking/devlink/devlink-reload.rst13
-rw-r--r--Documentation/networking/devlink/ice.rst9
-rw-r--r--Documentation/networking/ethtool-netlink.rst12
-rw-r--r--Documentation/networking/index.rst3
-rw-r--r--Documentation/networking/net_cachelines/index.rst16
-rw-r--r--Documentation/networking/net_cachelines/inet_connection_sock.rst50
-rw-r--r--Documentation/networking/net_cachelines/inet_sock.rst44
-rw-r--r--Documentation/networking/net_cachelines/net_device.rst178
-rw-r--r--Documentation/networking/net_cachelines/netns_ipv4_sysctl.rst158
-rw-r--r--Documentation/networking/net_cachelines/snmp.rst135
-rw-r--r--Documentation/networking/net_cachelines/tcp_sock.rst157
-rw-r--r--Documentation/networking/netlink_spec/.gitignore1
-rw-r--r--Documentation/networking/netlink_spec/readme.txt4
-rw-r--r--Documentation/networking/packet_mmap.rst14
-rw-r--r--Documentation/networking/page_pool.rst10
-rw-r--r--Documentation/networking/scaling.rst15
-rw-r--r--Documentation/networking/smc-sysctl.rst14
-rw-r--r--Documentation/networking/snmp_counter.rst16
-rw-r--r--Documentation/networking/timestamping.rst3
-rw-r--r--Documentation/networking/xdp-rx-metadata.rst10
-rw-r--r--Documentation/networking/xsk-tx-metadata.rst81
27 files changed, 1390 insertions, 200 deletions
diff --git a/Documentation/networking/bridge.rst b/Documentation/networking/bridge.rst
index c859f3c163..ba14e7b078 100644
--- a/Documentation/networking/bridge.rst
+++ b/Documentation/networking/bridge.rst
@@ -4,18 +4,332 @@
Ethernet Bridging
=================
-In order to use the Ethernet bridging functionality, you'll need the
-userspace tools.
+Introduction
+============
-Documentation for Linux bridging is on:
- https://wiki.linuxfoundation.org/networking/bridge
+The IEEE 802.1Q-2022 (Bridges and Bridged Networks) standard defines the
+operation of bridges in computer networks. A bridge, in the context of this
+standard, is a device that connects two or more network segments and operates
+at the data link layer (Layer 2) of the OSI (Open Systems Interconnection)
+model. The purpose of a bridge is to filter and forward frames between
+different segments based on the destination MAC (Media Access Control) address.
-The bridge-utilities are maintained at:
- git://git.kernel.org/pub/scm/linux/kernel/git/shemminger/bridge-utils.git
+Bridge kAPI
+===========
-Additionally, the iproute2 utilities can be used to configure
-bridge devices.
+Here are some core structures of bridge code. Note that the kAPI is *unstable*,
+and can be changed at any time.
-If you still have questions, don't hesitate to post to the mailing list
-(more info https://lists.linux-foundation.org/mailman/listinfo/bridge).
+.. kernel-doc:: net/bridge/br_private.h
+ :identifiers: net_bridge_vlan
+Bridge uAPI
+===========
+
+Modern Linux bridge uAPI is accessed via Netlink interface. You can find
+below files where the bridge and bridge port netlink attributes are defined.
+
+Bridge netlink attributes
+-------------------------
+
+.. kernel-doc:: include/uapi/linux/if_link.h
+ :doc: Bridge enum definition
+
+Bridge port netlink attributes
+------------------------------
+
+.. kernel-doc:: include/uapi/linux/if_link.h
+ :doc: Bridge port enum definition
+
+Bridge sysfs
+------------
+
+The sysfs interface is deprecated and should not be extended if new
+options are added.
+
+STP
+===
+
+The STP (Spanning Tree Protocol) implementation in the Linux bridge driver
+is a critical feature that helps prevent loops and broadcast storms in
+Ethernet networks by identifying and disabling redundant links. In a Linux
+bridge context, STP is crucial for network stability and availability.
+
+STP is a Layer 2 protocol that operates at the Data Link Layer of the OSI
+model. It was originally developed as IEEE 802.1D and has since evolved into
+multiple versions, including Rapid Spanning Tree Protocol (RSTP) and
+`Multiple Spanning Tree Protocol (MSTP)
+<https://lore.kernel.org/netdev/20220316150857.2442916-1-tobias@waldekranz.com/>`_.
+
+The 802.1D-2004 removed the original Spanning Tree Protocol, instead
+incorporating the Rapid Spanning Tree Protocol (RSTP). By 2014, all the
+functionality defined by IEEE 802.1D has been incorporated into either
+IEEE 802.1Q (Bridges and Bridged Networks) or IEEE 802.1AC (MAC Service
+Definition). 802.1D has been officially withdrawn in 2022.
+
+Bridge Ports and STP States
+---------------------------
+
+In the context of STP, bridge ports can be in one of the following states:
+ * Blocking: The port is disabled for data traffic and only listens for
+ BPDUs (Bridge Protocol Data Units) from other devices to determine the
+ network topology.
+ * Listening: The port begins to participate in the STP process and listens
+ for BPDUs.
+ * Learning: The port continues to listen for BPDUs and begins to learn MAC
+ addresses from incoming frames but does not forward data frames.
+ * Forwarding: The port is fully operational and forwards both BPDUs and
+ data frames.
+ * Disabled: The port is administratively disabled and does not participate
+ in the STP process. The data frames forwarding are also disabled.
+
+Root Bridge and Convergence
+---------------------------
+
+In the context of networking and Ethernet bridging in Linux, the root bridge
+is a designated switch in a bridged network that serves as a reference point
+for the spanning tree algorithm to create a loop-free topology.
+
+Here's how the STP works and root bridge is chosen:
+ 1. Bridge Priority: Each bridge running a spanning tree protocol, has a
+ configurable Bridge Priority value. The lower the value, the higher the
+ priority. By default, the Bridge Priority is set to a standard value
+ (e.g., 32768).
+ 2. Bridge ID: The Bridge ID is composed of two components: Bridge Priority
+ and the MAC address of the bridge. It uniquely identifies each bridge
+ in the network. The Bridge ID is used to compare the priorities of
+ different bridges.
+ 3. Bridge Election: When the network starts, all bridges initially assume
+ that they are the root bridge. They start advertising Bridge Protocol
+ Data Units (BPDU) to their neighbors, containing their Bridge ID and
+ other information.
+ 4. BPDU Comparison: Bridges exchange BPDUs to determine the root bridge.
+ Each bridge examines the received BPDUs, including the Bridge Priority
+ and Bridge ID, to determine if it should adjust its own priorities.
+ The bridge with the lowest Bridge ID will become the root bridge.
+ 5. Root Bridge Announcement: Once the root bridge is determined, it sends
+ BPDUs with information about the root bridge to all other bridges in the
+ network. This information is used by other bridges to calculate the
+ shortest path to the root bridge and, in doing so, create a loop-free
+ topology.
+ 6. Forwarding Ports: After the root bridge is selected and the spanning tree
+ topology is established, each bridge determines which of its ports should
+ be in the forwarding state (used for data traffic) and which should be in
+ the blocking state (used to prevent loops). The root bridge's ports are
+ all in the forwarding state. while other bridges have some ports in the
+ blocking state to avoid loops.
+ 7. Root Ports: After the root bridge is selected and the spanning tree
+ topology is established, each non-root bridge processes incoming
+ BPDUs and determines which of its ports provides the shortest path to the
+ root bridge based on the information in the received BPDUs. This port is
+ designated as the root port. And it is in the Forwarding state, allowing
+ it to actively forward network traffic.
+ 8. Designated ports: A designated port is the port through which the non-root
+ bridge will forward traffic towards the designated segment. Designated ports
+ are placed in the Forwarding state. All other ports on the non-root
+ bridge that are not designated for specific segments are placed in the
+ Blocking state to prevent network loops.
+
+STP ensures network convergence by calculating the shortest path and disabling
+redundant links. When network topology changes occur (e.g., a link failure),
+STP recalculates the network topology to restore connectivity while avoiding loops.
+
+Proper configuration of STP parameters, such as the bridge priority, can
+influence network performance, path selection and which bridge becomes the
+Root Bridge.
+
+User space STP helper
+---------------------
+
+The user space STP helper *bridge-stp* is a program to control whether to use
+user mode spanning tree. The ``/sbin/bridge-stp <bridge> <start|stop>`` is
+called by the kernel when STP is enabled/disabled on a bridge
+(via ``brctl stp <bridge> <on|off>`` or ``ip link set <bridge> type bridge
+stp_state <0|1>``). The kernel enables user_stp mode if that command returns
+0, or enables kernel_stp mode if that command returns any other value.
+
+VLAN
+====
+
+A LAN (Local Area Network) is a network that covers a small geographic area,
+typically within a single building or a campus. LANs are used to connect
+computers, servers, printers, and other networked devices within a localized
+area. LANs can be wired (using Ethernet cables) or wireless (using Wi-Fi).
+
+A VLAN (Virtual Local Area Network) is a logical segmentation of a physical
+network into multiple isolated broadcast domains. VLANs are used to divide
+a single physical LAN into multiple virtual LANs, allowing different groups of
+devices to communicate as if they were on separate physical networks.
+
+Typically there are two VLAN implementations, IEEE 802.1Q and IEEE 802.1ad
+(also known as QinQ). IEEE 802.1Q is a standard for VLAN tagging in Ethernet
+networks. It allows network administrators to create logical VLANs on a
+physical network and tag Ethernet frames with VLAN information, which is
+called *VLAN-tagged frames*. IEEE 802.1ad, commonly known as QinQ or Double
+VLAN, is an extension of the IEEE 802.1Q standard. QinQ allows for the
+stacking of multiple VLAN tags within a single Ethernet frame. The Linux
+bridge supports both the IEEE 802.1Q and `802.1AD
+<https://lore.kernel.org/netdev/1402401565-15423-1-git-send-email-makita.toshiaki@lab.ntt.co.jp/>`_
+protocol for VLAN tagging.
+
+`VLAN filtering <https://lore.kernel.org/netdev/1360792820-14116-1-git-send-email-vyasevic@redhat.com/>`_
+on a bridge is disabled by default. After enabling VLAN filtering on a bridge,
+it will start forwarding frames to appropriate destinations based on their
+destination MAC address and VLAN tag (both must match).
+
+Multicast
+=========
+
+The Linux bridge driver has multicast support allowing it to process Internet
+Group Management Protocol (IGMP) or Multicast Listener Discovery (MLD)
+messages, and to efficiently forward multicast data packets. The bridge
+driver supports IGMPv2/IGMPv3 and MLDv1/MLDv2.
+
+Multicast snooping
+------------------
+
+Multicast snooping is a networking technology that allows network switches
+to intelligently manage multicast traffic within a local area network (LAN).
+
+The switch maintains a multicast group table, which records the association
+between multicast group addresses and the ports where hosts have joined these
+groups. The group table is dynamically updated based on the IGMP/MLD messages
+received. With the multicast group information gathered through snooping, the
+switch optimizes the forwarding of multicast traffic. Instead of blindly
+broadcasting the multicast traffic to all ports, it sends the multicast
+traffic based on the destination MAC address only to ports which have
+subscribed the respective destination multicast group.
+
+When created, the Linux bridge devices have multicast snooping enabled by
+default. It maintains a Multicast forwarding database (MDB) which keeps track
+of port and group relationships.
+
+IGMPv3/MLDv2 EHT support
+------------------------
+
+The Linux bridge supports IGMPv3/MLDv2 EHT (Explicit Host Tracking), which
+was added by `474ddb37fa3a ("net: bridge: multicast: add EHT allow/block handling")
+<https://lore.kernel.org/netdev/20210120145203.1109140-1-razor@blackwall.org/>`_
+
+The explicit host tracking enables the device to keep track of each
+individual host that is joined to a particular group or channel. The main
+benefit of the explicit host tracking in IGMP is to allow minimal leave
+latencies when a host leaves a multicast group or channel.
+
+The length of time between a host wanting to leave and a device stopping
+traffic forwarding is called the IGMP leave latency. A device configured
+with IGMPv3 or MLDv2 and explicit tracking can immediately stop forwarding
+traffic if the last host to request to receive traffic from the device
+indicates that it no longer wants to receive traffic. The leave latency
+is thus bound only by the packet transmission latencies in the multiaccess
+network and the processing time in the device.
+
+Other multicast features
+------------------------
+
+The Linux bridge also supports `per-VLAN multicast snooping
+<https://lore.kernel.org/netdev/20210719170637.435541-1-razor@blackwall.org/>`_,
+which is disabled by default but can be enabled. And `Multicast Router Discovery
+<https://lore.kernel.org/netdev/20190121062628.2710-1-linus.luessing@c0d3.blue/>`_,
+which help identify the location of multicast routers.
+
+Switchdev
+=========
+
+Linux Bridge Switchdev is a feature in the Linux kernel that extends the
+capabilities of the traditional Linux bridge to work more efficiently with
+hardware switches that support switchdev. With Linux Bridge Switchdev, certain
+networking functions like forwarding, filtering, and learning of Ethernet
+frames can be offloaded to a hardware switch. This offloading reduces the
+burden on the Linux kernel and CPU, leading to improved network performance
+and lower latency.
+
+To use Linux Bridge Switchdev, you need hardware switches that support the
+switchdev interface. This means that the switch hardware needs to have the
+necessary drivers and functionality to work in conjunction with the Linux
+kernel.
+
+Please see the :ref:`switchdev` document for more details.
+
+Netfilter
+=========
+
+The bridge netfilter module is a legacy feature that allows to filter bridged
+packets with iptables and ip6tables. Its use is discouraged. Users should
+consider using nftables for packet filtering.
+
+The older ebtables tool is more feature-limited compared to nftables, but
+just like nftables it doesn't need this module either to function.
+
+The br_netfilter module intercepts packets entering the bridge, performs
+minimal sanity tests on ipv4 and ipv6 packets and then pretends that
+these packets are being routed, not bridged. br_netfilter then calls
+the ip and ipv6 netfilter hooks from the bridge layer, i.e. ip(6)tables
+rulesets will also see these packets.
+
+br_netfilter is also the reason for the iptables *physdev* match:
+This match is the only way to reliably tell routed and bridged packets
+apart in an iptables ruleset.
+
+Note that ebtables and nftables will work fine without the br_netfilter module.
+iptables/ip6tables/arptables do not work for bridged traffic because they
+plug in the routing stack. nftables rules in ip/ip6/inet/arp families won't
+see traffic that is forwarded by a bridge either, but that's very much how it
+should be.
+
+Historically the feature set of ebtables was very limited (it still is),
+this module was added to pretend packets are routed and invoke the ipv4/ipv6
+netfilter hooks from the bridge so users had access to the more feature-rich
+iptables matching capabilities (including conntrack). nftables doesn't have
+this limitation, pretty much all features work regardless of the protocol family.
+
+So, br_netfilter is only needed if users, for some reason, need to use
+ip(6)tables to filter packets forwarded by the bridge, or NAT bridged
+traffic. For pure link layer filtering, this module isn't needed.
+
+Other Features
+==============
+
+The Linux bridge also supports `IEEE 802.11 Proxy ARP
+<https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=958501163ddd6ea22a98f94fa0e7ce6d4734e5c4>`_,
+`Media Redundancy Protocol (MRP)
+<https://lore.kernel.org/netdev/20200426132208.3232-1-horatiu.vultur@microchip.com/>`_,
+`Media Redundancy Protocol (MRP) LC mode
+<https://lore.kernel.org/r/20201124082525.273820-1-horatiu.vultur@microchip.com>`_,
+`IEEE 802.1X port authentication
+<https://lore.kernel.org/netdev/20220218155148.2329797-1-schultz.hans+netdev@gmail.com/>`_,
+and `MAC Authentication Bypass (MAB)
+<https://lore.kernel.org/netdev/20221101193922.2125323-2-idosch@nvidia.com/>`_.
+
+FAQ
+===
+
+What does a bridge do?
+----------------------
+
+A bridge transparently forwards traffic between multiple network interfaces.
+In plain English this means that a bridge connects two or more physical
+Ethernet networks, to form one larger (logical) Ethernet network.
+
+Is it L3 protocol independent?
+------------------------------
+
+Yes. The bridge sees all frames, but it *uses* only L2 headers/information.
+As such, the bridging functionality is protocol independent, and there should
+be no trouble forwarding IPX, NetBEUI, IP, IPv6, etc.
+
+Contact Info
+============
+
+The code is currently maintained by Roopa Prabhu <roopa@nvidia.com> and
+Nikolay Aleksandrov <razor@blackwall.org>. Bridge bugs and enhancements
+are discussed on the linux-netdev mailing list netdev@vger.kernel.org and
+bridge@lists.linux-foundation.org.
+
+The list is open to anyone interested: http://vger.kernel.org/vger-lists.html#netdev
+
+External Links
+==============
+
+The old Documentation for Linux bridging is on:
+https://wiki.linuxfoundation.org/networking/bridge
diff --git a/Documentation/networking/device_drivers/ethernet/amazon/ena.rst b/Documentation/networking/device_drivers/ethernet/amazon/ena.rst
index 5eaa3ab6c7..b842bcb142 100644
--- a/Documentation/networking/device_drivers/ethernet/amazon/ena.rst
+++ b/Documentation/networking/device_drivers/ethernet/amazon/ena.rst
@@ -54,6 +54,7 @@ ena_common_defs.h Common definitions for ena_com layer.
ena_regs_defs.h Definition of ENA PCI memory-mapped (MMIO) registers.
ena_netdev.[ch] Main Linux kernel driver.
ena_ethtool.c ethtool callbacks.
+ena_xdp.[ch] XDP files
ena_pci_id_tbl.h Supported device IDs.
================= ======================================================
diff --git a/Documentation/networking/device_drivers/ethernet/intel/ice.rst b/Documentation/networking/device_drivers/ethernet/intel/ice.rst
index e4d065c55e..5038e54586 100644
--- a/Documentation/networking/device_drivers/ethernet/intel/ice.rst
+++ b/Documentation/networking/device_drivers/ethernet/intel/ice.rst
@@ -895,6 +895,147 @@ driver writes raw bytes by the GNSS object to the receiver through i2c. Please
refer to the hardware GNSS module documentation for configuration details.
+Firmware (FW) logging
+---------------------
+The driver supports FW logging via the debugfs interface on PF 0 only. The FW
+running on the NIC must support FW logging; if the FW doesn't support FW logging
+the 'fwlog' file will not get created in the ice debugfs directory.
+
+Module configuration
+~~~~~~~~~~~~~~~~~~~~
+Firmware logging is configured on a per module basis. Each module can be set to
+a value independent of the other modules (unless the module 'all' is specified).
+The modules will be instantiated under the 'fwlog/modules' directory.
+
+The user can set the log level for a module by writing to the module file like
+this::
+
+ # echo <log_level> > /sys/kernel/debug/ice/0000\:18\:00.0/fwlog/modules/<module>
+
+where
+
+* log_level is a name as described below. Each level includes the
+ messages from the previous/lower level
+
+ * none
+ * error
+ * warning
+ * normal
+ * verbose
+
+* module is a name that represents the module to receive events for. The
+ module names are
+
+ * general
+ * ctrl
+ * link
+ * link_topo
+ * dnl
+ * i2c
+ * sdp
+ * mdio
+ * adminq
+ * hdma
+ * lldp
+ * dcbx
+ * dcb
+ * xlr
+ * nvm
+ * auth
+ * vpd
+ * iosf
+ * parser
+ * sw
+ * scheduler
+ * txq
+ * rsvd
+ * post
+ * watchdog
+ * task_dispatch
+ * mng
+ * synce
+ * health
+ * tsdrv
+ * pfreg
+ * mdlver
+ * all
+
+The name 'all' is special and allows the user to set all of the modules to the
+specified log_level or to read the log_level of all of the modules.
+
+Example usage to configure the modules
+^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+
+To set a single module to 'verbose'::
+
+ # echo verbose > /sys/kernel/debug/ice/0000\:18\:00.0/fwlog/modules/link
+
+To set multiple modules then issue the command multiple times::
+
+ # echo verbose > /sys/kernel/debug/ice/0000\:18\:00.0/fwlog/modules/link
+ # echo warning > /sys/kernel/debug/ice/0000\:18\:00.0/fwlog/modules/ctrl
+ # echo none > /sys/kernel/debug/ice/0000\:18\:00.0/fwlog/modules/dcb
+
+To set all the modules to the same value::
+
+ # echo normal > /sys/kernel/debug/ice/0000\:18\:00.0/fwlog/modules/all
+
+To read the log_level of a specific module (e.g. module 'general')::
+
+ # cat /sys/kernel/debug/ice/0000\:18\:00.0/fwlog/modules/general
+
+To read the log_level of all the modules::
+
+ # cat /sys/kernel/debug/ice/0000\:18\:00.0/fwlog/modules/all
+
+Enabling FW log
+~~~~~~~~~~~~~~~
+Configuring the modules indicates to the FW that the configured modules should
+generate events that the driver is interested in, but it **does not** send the
+events to the driver until the enable message is sent to the FW. To do this
+the user can write a 1 (enable) or 0 (disable) to 'fwlog/enable'. An example
+is::
+
+ # echo 1 > /sys/kernel/debug/ice/0000\:18\:00.0/fwlog/enable
+
+Retrieving FW log data
+~~~~~~~~~~~~~~~~~~~~~~
+The FW log data can be retrieved by reading from 'fwlog/data'. The user can
+write any value to 'fwlog/data' to clear the data. The data can only be cleared
+when FW logging is disabled. The FW log data is a binary file that is sent to
+Intel and used to help debug user issues.
+
+An example to read the data is::
+
+ # cat /sys/kernel/debug/ice/0000\:18\:00.0/fwlog/data > fwlog.bin
+
+An example to clear the data is::
+
+ # echo 0 > /sys/kernel/debug/ice/0000\:18\:00.0/fwlog/data
+
+Changing how often the log events are sent to the driver
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+The driver receives FW log data from the Admin Receive Queue (ARQ). The
+frequency that the FW sends the ARQ events can be configured by writing to
+'fwlog/nr_messages'. The range is 1-128 (1 means push every log message, 128
+means push only when the max AQ command buffer is full). The suggested value is
+10. The user can see what the value is configured to by reading
+'fwlog/nr_messages'. An example to set the value is::
+
+ # echo 50 > /sys/kernel/debug/ice/0000\:18\:00.0/fwlog/nr_messages
+
+Configuring the amount of memory used to store FW log data
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+The driver stores FW log data within the driver. The default size of the memory
+used to store the data is 1MB. Some use cases may require more or less data so
+the user can change the amount of memory that is allocated for FW log data.
+To change the amount of memory then write to 'fwlog/log_size'. The value must be
+one of: 128K, 256K, 512K, 1M, or 2M. FW logging must be disabled to change the
+value. An example of changing the value is::
+
+ # echo 128K > /sys/kernel/debug/ice/0000\:18\:00.0/fwlog/log_size
+
+
Performance Optimization
========================
Driver defaults are meant to fit a wide variety of workloads, but if further
diff --git a/Documentation/networking/device_drivers/ethernet/marvell/octeon_ep.rst b/Documentation/networking/device_drivers/ethernet/marvell/octeon_ep.rst
index cad96c8d1f..c96d262b30 100644
--- a/Documentation/networking/device_drivers/ethernet/marvell/octeon_ep.rst
+++ b/Documentation/networking/device_drivers/ethernet/marvell/octeon_ep.rst
@@ -22,8 +22,13 @@ EndPoint NIC.
Supported Devices
=================
Currently, this driver support following devices:
+ * Network controller: Cavium, Inc. Device b100
* Network controller: Cavium, Inc. Device b200
* Network controller: Cavium, Inc. Device b400
+ * Network controller: Cavium, Inc. Device b900
+ * Network controller: Cavium, Inc. Device ba00
+ * Network controller: Cavium, Inc. Device bc00
+ * Network controller: Cavium, Inc. Device bd00
Interface Control
=================
diff --git a/Documentation/networking/device_drivers/wifi/index.rst b/Documentation/networking/device_drivers/wifi/index.rst
index bf91a87c7a..fb394f5de4 100644
--- a/Documentation/networking/device_drivers/wifi/index.rst
+++ b/Documentation/networking/device_drivers/wifi/index.rst
@@ -10,7 +10,6 @@ Contents:
intel/ipw2100
intel/ipw2200
- ray_cs
.. only:: subproject and html
diff --git a/Documentation/networking/device_drivers/wifi/ray_cs.rst b/Documentation/networking/device_drivers/wifi/ray_cs.rst
deleted file mode 100644
index 9a46d1ae8f..0000000000
--- a/Documentation/networking/device_drivers/wifi/ray_cs.rst
+++ /dev/null
@@ -1,165 +0,0 @@
-.. SPDX-License-Identifier: GPL-2.0
-
-.. include:: <isonum.txt>
-
-=========================
-Raylink wireless LAN card
-=========================
-
-September 21, 1999
-
-Copyright |copy| 1998 Corey Thomas (corey@world.std.com)
-
-This file is the documentation for the Raylink Wireless LAN card driver for
-Linux. The Raylink wireless LAN card is a PCMCIA card which provides IEEE
-802.11 compatible wireless network connectivity at 1 and 2 megabits/second.
-See http://www.raytheon.com/micro/raylink/ for more information on the Raylink
-card. This driver is in early development and does have bugs. See the known
-bugs and limitations at the end of this document for more information.
-This driver also works with WebGear's Aviator 2.4 and Aviator Pro
-wireless LAN cards.
-
-As of kernel 2.3.18, the ray_cs driver is part of the Linux kernel
-source. My web page for the development of ray_cs is at
-http://web.ralinktech.com/ralink/Home/Support/Linux.html
-and I can be emailed at corey@world.std.com
-
-The kernel driver is based on ray_cs-1.62.tgz
-
-The driver at my web page is intended to be used as an add on to
-David Hinds pcmcia package. All the command line parameters are
-available when compiled as a module. When built into the kernel, only
-the essid= string parameter is available via the kernel command line.
-This will change after the method of sorting out parameters for all
-the PCMCIA drivers is agreed upon. If you must have a built in driver
-with nondefault parameters, they can be edited in
-/usr/src/linux/drivers/net/pcmcia/ray_cs.c. Searching for module_param
-will find them all.
-
-Information on card services is available at:
-
- http://pcmcia-cs.sourceforge.net/
-
-
-Card services user programs are still required for PCMCIA devices.
-pcmcia-cs-3.1.1 or greater is required for the kernel version of
-the driver.
-
-Currently, ray_cs is not part of David Hinds card services package,
-so the following magic is required.
-
-At the end of the /etc/pcmcia/config.opts file, add the line:
-source ./ray_cs.opts
-This will make card services read the ray_cs.opts file
-when starting. Create the file /etc/pcmcia/ray_cs.opts containing the
-following::
-
- #### start of /etc/pcmcia/ray_cs.opts ###################
- # Configuration options for Raylink Wireless LAN PCMCIA card
- device "ray_cs"
- class "network" module "misc/ray_cs"
-
- card "RayLink PC Card WLAN Adapter"
- manfid 0x01a6, 0x0000
- bind "ray_cs"
-
- module "misc/ray_cs" opts ""
- #### end of /etc/pcmcia/ray_cs.opts #####################
-
-
-To join an existing network with
-different parameters, contact the network administrator for the
-configuration information, and edit /etc/pcmcia/ray_cs.opts.
-Add the parameters below between the empty quotes.
-
-Parameters for ray_cs driver which may be specified in ray_cs.opts:
-
-=============== =============== =============================================
-bc integer 0 = normal mode (802.11 timing),
- 1 = slow down inter frame timing to allow
- operation with older breezecom access
- points.
-
-beacon_period integer beacon period in Kilo-microseconds,
-
- legal values = must be integer multiple
- of hop dwell
-
- default = 256
-
-country integer 1 = USA (default),
- 2 = Europe,
- 3 = Japan,
- 4 = Korea,
- 5 = Spain,
- 6 = France,
- 7 = Israel,
- 8 = Australia
-
-essid string ESS ID - network name to join
-
- string with maximum length of 32 chars
- default value = "ADHOC_ESSID"
-
-hop_dwell integer hop dwell time in Kilo-microseconds
-
- legal values = 16,32,64,128(default),256
-
-irq_mask integer linux standard 16 bit value 1bit/IRQ
-
- lsb is IRQ 0, bit 1 is IRQ 1 etc.
- Used to restrict choice of IRQ's to use.
- Recommended method for controlling
- interrupts is in /etc/pcmcia/config.opts
-
-net_type integer 0 (default) = adhoc network,
- 1 = infrastructure
-
-phy_addr string string containing new MAC address in
- hex, must start with x eg
- x00008f123456
-
-psm integer 0 = continuously active,
- 1 = power save mode (not useful yet)
-
-pc_debug integer (0-5) larger values for more verbose
- logging. Replaces ray_debug.
-
-ray_debug integer Replaced with pc_debug
-
-ray_mem_speed integer defaults to 500
-
-sniffer integer 0 = not sniffer (default),
- 1 = sniffer which can be used to record all
- network traffic using tcpdump or similar,
- but no normal network use is allowed.
-
-translate integer 0 = no translation (encapsulate frames),
- 1 = translation (RFC1042/802.1)
-=============== =============== =============================================
-
-More on sniffer mode:
-
-tcpdump does not understand 802.11 headers, so it can't
-interpret the contents, but it can record to a file. This is only
-useful for debugging 802.11 lowlevel protocols that are not visible to
-linux. If you want to watch ftp xfers, or do similar things, you
-don't need to use sniffer mode. Also, some packet types are never
-sent up by the card, so you will never see them (ack, rts, cts, probe
-etc.) There is a simple program (showcap) included in the ray_cs
-package which parses the 802.11 headers.
-
-Known Problems and missing features
-
- Does not work with non x86
-
- Does not work with SMP
-
- Support for defragmenting frames is not yet debugged, and in
- fact is known to not work. I have never encountered a net set
- up to fragment, but still, it should be fixed.
-
- The ioctl support is incomplete. The hardware address cannot be set
- using ifconfig yet. If a different hardware address is needed, it may
- be set using the phy_addr parameter in ray_cs.opts. This requires
- a card insertion to take effect.
diff --git a/Documentation/networking/devlink/devlink-reload.rst b/Documentation/networking/devlink/devlink-reload.rst
index 505d22da02..2fb0269b20 100644
--- a/Documentation/networking/devlink/devlink-reload.rst
+++ b/Documentation/networking/devlink/devlink-reload.rst
@@ -22,8 +22,17 @@ By default ``driver_reinit`` action is selected.
* - ``driver-reinit``
- Devlink driver entities re-initialization, including applying
new values to devlink entities which are used during driver
- load such as ``devlink-params`` in configuration mode
- ``driverinit`` or ``devlink-resources``
+ load which are:
+
+ * ``devlink-params`` in configuration mode ``driverinit``
+ * ``devlink-resources``
+
+ Other devlink entities may stay over the re-initialization:
+
+ * ``devlink-health-reporter``
+ * ``devlink-region``
+
+ The rest of the devlink entities have to be removed and readded.
* - ``fw_activate``
- Firmware activate. Activates new firmware if such image is stored and
pending activation. If no limitation specified this action may involve
diff --git a/Documentation/networking/devlink/ice.rst b/Documentation/networking/devlink/ice.rst
index 2f60e34ab9..7f30ebd5de 100644
--- a/Documentation/networking/devlink/ice.rst
+++ b/Documentation/networking/devlink/ice.rst
@@ -38,6 +38,10 @@ The ``ice`` driver reports the following versions
- fixed
- K65390-000
- The Product Board Assembly (PBA) identifier of the board.
+ * - ``cgu.id``
+ - fixed
+ - 36
+ - The Clock Generation Unit (CGU) hardware revision identifier.
* - ``fw.mgmt``
- running
- 2.1.7
@@ -104,6 +108,11 @@ The ``ice`` driver reports the following versions
- running
- 0xee16ced7
- The first 4 bytes of the hash of the netlist module contents.
+ * - ``fw.cgu``
+ - running
+ - 8032.16973825.6021
+ - The version of Clock Generation Unit (CGU). Format:
+ <CGU type>.<configuration version>.<firmware version>.
Flash Update
============
diff --git a/Documentation/networking/ethtool-netlink.rst b/Documentation/networking/ethtool-netlink.rst
index 2540c70952..d583d9abf2 100644
--- a/Documentation/networking/ethtool-netlink.rst
+++ b/Documentation/networking/ethtool-netlink.rst
@@ -223,6 +223,9 @@ Userspace to kernel:
``ETHTOOL_MSG_PSE_SET`` set PSE parameters
``ETHTOOL_MSG_PSE_GET`` get PSE parameters
``ETHTOOL_MSG_RSS_GET`` get RSS settings
+ ``ETHTOOL_MSG_PLCA_GET_CFG`` get PLCA RS parameters
+ ``ETHTOOL_MSG_PLCA_SET_CFG`` set PLCA RS parameters
+ ``ETHTOOL_MSG_PLCA_GET_STATUS`` get PLCA RS status
``ETHTOOL_MSG_MM_GET`` get MAC merge layer state
``ETHTOOL_MSG_MM_SET`` set MAC merge layer parameters
===================================== =================================
@@ -267,6 +270,9 @@ Kernel to userspace:
``ETHTOOL_MSG_MODULE_GET_REPLY`` transceiver module parameters
``ETHTOOL_MSG_PSE_GET_REPLY`` PSE parameters
``ETHTOOL_MSG_RSS_GET_REPLY`` RSS settings
+ ``ETHTOOL_MSG_PLCA_GET_CFG_REPLY`` PLCA RS parameters
+ ``ETHTOOL_MSG_PLCA_GET_STATUS_REPLY`` PLCA RS status
+ ``ETHTOOL_MSG_PLCA_NTF`` PLCA RS parameters
``ETHTOOL_MSG_MM_GET_REPLY`` MAC merge layer status
======================================== =================================
@@ -1768,12 +1774,16 @@ Kernel response contents:
``ETHTOOL_A_RSS_HFUNC`` u32 RSS hash func
``ETHTOOL_A_RSS_INDIR`` binary Indir table bytes
``ETHTOOL_A_RSS_HKEY`` binary Hash key bytes
+ ``ETHTOOL_A_RSS_INPUT_XFRM`` u32 RSS input data transformation
===================================== ====== ==========================
ETHTOOL_A_RSS_HFUNC attribute is bitmap indicating the hash function
being used. Current supported options are toeplitz, xor or crc32.
-ETHTOOL_A_RSS_INDIR attribute returns RSS indrection table where each byte
+ETHTOOL_A_RSS_INDIR attribute returns RSS indirection table where each byte
indicates queue number.
+ETHTOOL_A_RSS_INPUT_XFRM attribute is a bitmap indicating the type of
+transformation applied to the input protocol fields before given to the RSS
+hfunc. Current supported option is symmetric-xor.
PLCA_GET_CFG
============
diff --git a/Documentation/networking/index.rst b/Documentation/networking/index.rst
index 683eb42309..69f3d6dcd9 100644
--- a/Documentation/networking/index.rst
+++ b/Documentation/networking/index.rst
@@ -55,6 +55,7 @@ Contents:
filter
generic-hdlc
generic_netlink
+ netlink_spec/index
gen_stats
gtp
ila
@@ -74,6 +75,7 @@ Contents:
mptcp-sysctl
multiqueue
napi
+ net_cachelines/index
netconsole
netdev-features
netdevices
@@ -123,6 +125,7 @@ Contents:
xfrm_sync
xfrm_sysctl
xdp-rx-metadata
+ xsk-tx-metadata
.. only:: subproject and html
diff --git a/Documentation/networking/net_cachelines/index.rst b/Documentation/networking/net_cachelines/index.rst
new file mode 100644
index 0000000000..2669e4cda0
--- /dev/null
+++ b/Documentation/networking/net_cachelines/index.rst
@@ -0,0 +1,16 @@
+.. SPDX-License-Identifier: GPL-2.0
+.. Copyright (C) 2023 Google LLC
+
+===================================
+Common Networking Struct Cachelines
+===================================
+
+.. toctree::
+ :maxdepth: 1
+
+ inet_connection_sock
+ inet_sock
+ net_device
+ netns_ipv4_sysctl
+ snmp
+ tcp_sock
diff --git a/Documentation/networking/net_cachelines/inet_connection_sock.rst b/Documentation/networking/net_cachelines/inet_connection_sock.rst
new file mode 100644
index 0000000000..7a911dc956
--- /dev/null
+++ b/Documentation/networking/net_cachelines/inet_connection_sock.rst
@@ -0,0 +1,50 @@
+.. SPDX-License-Identifier: GPL-2.0
+.. Copyright (C) 2023 Google LLC
+
+=====================================================
+inet_connection_sock struct fast path usage breakdown
+=====================================================
+
+Type Name fastpath_tx_access fastpath_rx_access comment
+..struct ..inet_connection_sock
+struct_inet_sock icsk_inet read_mostly read_mostly tcp_init_buffer_space,tcp_init_transfer,tcp_finish_connect,tcp_connect,tcp_send_rcvq,tcp_send_syn_data
+struct_request_sock_queue icsk_accept_queue - -
+struct_inet_bind_bucket icsk_bind_hash read_mostly - tcp_set_state
+struct_inet_bind2_bucket icsk_bind2_hash read_mostly - tcp_set_state,inet_put_port
+unsigned_long icsk_timeout read_mostly - inet_csk_reset_xmit_timer,tcp_connect
+struct_timer_list icsk_retransmit_timer read_mostly - inet_csk_reset_xmit_timer,tcp_connect
+struct_timer_list icsk_delack_timer read_mostly - inet_csk_reset_xmit_timer,tcp_connect
+u32 icsk_rto read_write - tcp_cwnd_validate,tcp_schedule_loss_probe,tcp_connect_init,tcp_connect,tcp_write_xmit,tcp_push_one
+u32 icsk_rto_min - -
+u32 icsk_delack_max - -
+u32 icsk_pmtu_cookie read_write - tcp_sync_mss,tcp_current_mss,tcp_send_syn_data,tcp_connect_init,tcp_connect
+struct_tcp_congestion_ops icsk_ca_ops read_write - tcp_cwnd_validate,tcp_tso_segs,tcp_ca_dst_init,tcp_connect_init,tcp_connect,tcp_write_xmit
+struct_inet_connection_sock_af_ops icsk_af_ops read_mostly - tcp_finish_connect,tcp_send_syn_data,tcp_mtup_init,tcp_mtu_check_reprobe,tcp_mtu_probe,tcp_connect_init,tcp_connect,__tcp_transmit_skb
+struct_tcp_ulp_ops* icsk_ulp_ops - -
+void* icsk_ulp_data - -
+u8:5 icsk_ca_state read_write - tcp_cwnd_application_limited,tcp_set_ca_state,tcp_enter_cwr,tcp_tso_should_defer,tcp_mtu_probe,tcp_schedule_loss_probe,tcp_write_xmit,__tcp_transmit_skb
+u8:1 icsk_ca_initialized read_write - tcp_init_transfer,tcp_init_congestion_control,tcp_init_transfer,tcp_finish_connect,tcp_connect
+u8:1 icsk_ca_setsockopt - -
+u8:1 icsk_ca_dst_locked write_mostly - tcp_ca_dst_init,tcp_connect_init,tcp_connect
+u8 icsk_retransmits write_mostly - tcp_connect_init,tcp_connect
+u8 icsk_pending read_write - inet_csk_reset_xmit_timer,tcp_connect,tcp_check_probe_timer,__tcp_push_pending_frames,tcp_rearm_rto,tcp_event_new_data_sent,tcp_event_new_data_sent
+u8 icsk_backoff write_mostly - tcp_write_queue_purge,tcp_connect_init
+u8 icsk_syn_retries - -
+u8 icsk_probes_out - -
+u16 icsk_ext_hdr_len read_mostly - __tcp_mtu_to_mss,tcp_mtu_to_rss,tcp_mtu_probe,tcp_write_xmit,tcp_mtu_to_mss,
+struct_icsk_ack_u8 pending read_write read_write inet_csk_ack_scheduled,__tcp_cleanup_rbuf,tcp_cleanup_rbuf,inet_csk_clear_xmit_timer,tcp_event_ack-sent,inet_csk_reset_xmit_timer
+struct_icsk_ack_u8 quick read_write write_mostly tcp_dec_quickack_mode,tcp_event_ack_sent,__tcp_transmit_skb,__tcp_select_window,__tcp_cleanup_rbuf
+struct_icsk_ack_u8 pingpong - -
+struct_icsk_ack_u8 retry write_mostly read_write inet_csk_clear_xmit_timer,tcp_rearm_rto,tcp_event_new_data_sent,tcp_write_xmit,__tcp_send_ack,tcp_send_ack,
+struct_icsk_ack_u8 ato read_mostly write_mostly tcp_dec_quickack_mode,tcp_event_ack_sent,__tcp_transmit_skb,__tcp_send_ack,tcp_send_ack
+struct_icsk_ack_unsigned_long timeout read_write read_write inet_csk_reset_xmit_timer,tcp_connect
+struct_icsk_ack_u32 lrcvtime read_write - tcp_finish_connect,tcp_connect,tcp_event_data_sent,__tcp_transmit_skb
+struct_icsk_ack_u16 rcv_mss write_mostly read_mostly __tcp_select_window,__tcp_cleanup_rbuf,tcp_initialize_rcv_mss,tcp_connect_init
+struct_icsk_mtup_int search_high read_write - tcp_mtup_init,tcp_sync_mss,tcp_connect_init,tcp_mtu_check_reprobe,tcp_write_xmit
+struct_icsk_mtup_int search_low read_write - tcp_mtu_probe,tcp_mtu_check_reprobe,tcp_write_xmit,tcp_sync_mss,tcp_connect_init,tcp_mtup_init
+struct_icsk_mtup_u32:31 probe_size read_write - tcp_mtup_init,tcp_connect_init,__tcp_transmit_skb
+struct_icsk_mtup_u32:1 enabled read_write - tcp_mtup_init,tcp_sync_mss,tcp_connect_init,tcp_mtu_probe,tcp_write_xmit
+struct_icsk_mtup_u32 probe_timestamp read_write - tcp_mtup_init,tcp_connect_init,tcp_mtu_check_reprobe,tcp_mtu_probe
+u32 icsk_probes_tstamp - -
+u32 icsk_user_timeout - -
+u64[104/sizeof(u64)] icsk_ca_priv - -
diff --git a/Documentation/networking/net_cachelines/inet_sock.rst b/Documentation/networking/net_cachelines/inet_sock.rst
new file mode 100644
index 0000000000..595d7ef5fc
--- /dev/null
+++ b/Documentation/networking/net_cachelines/inet_sock.rst
@@ -0,0 +1,44 @@
+.. SPDX-License-Identifier: GPL-2.0
+.. Copyright (C) 2023 Google LLC
+
+==========================================
+inet_sock struct fast path usage breakdown
+==========================================
+
+Type Name fastpath_tx_access fastpath_rx_access comment
+..struct ..inet_sock
+struct_sock sk read_mostly read_mostly tcp_init_buffer_space,tcp_init_transfer,tcp_finish_connect,tcp_connect,tcp_send_rcvq,tcp_send_syn_data
+struct_ipv6_pinfo* pinet6 - -
+be16 inet_sport read_mostly - __tcp_transmit_skb
+be32 inet_daddr read_mostly - ip_select_ident_segs
+be32 inet_rcv_saddr - -
+be16 inet_dport read_mostly - __tcp_transmit_skb
+u16 inet_num - -
+be32 inet_saddr - -
+s16 uc_ttl read_mostly - __ip_queue_xmit/ip_select_ttl
+u16 cmsg_flags - -
+struct_ip_options_rcu* inet_opt read_mostly - __ip_queue_xmit
+u16 inet_id read_mostly - ip_select_ident_segs
+u8 tos read_mostly - ip_queue_xmit
+u8 min_ttl - -
+u8 mc_ttl - -
+u8 pmtudisc - -
+u8:1 recverr - -
+u8:1 is_icsk - -
+u8:1 freebind - -
+u8:1 hdrincl - -
+u8:1 mc_loop - -
+u8:1 transparent - -
+u8:1 mc_all - -
+u8:1 nodefrag - -
+u8:1 bind_address_no_port - -
+u8:1 recverr_rfc4884 - -
+u8:1 defer_connect read_mostly - tcp_sendmsg_fastopen
+u8 rcv_tos - -
+u8 convert_csum - -
+int uc_index - -
+int mc_index - -
+be32 mc_addr - -
+struct_ip_mc_socklist* mc_list - -
+struct_inet_cork_full cork read_mostly - __tcp_transmit_skb
+struct local_port_range - -
diff --git a/Documentation/networking/net_cachelines/net_device.rst b/Documentation/networking/net_cachelines/net_device.rst
new file mode 100644
index 0000000000..70c4fb9d4e
--- /dev/null
+++ b/Documentation/networking/net_cachelines/net_device.rst
@@ -0,0 +1,178 @@
+.. SPDX-License-Identifier: GPL-2.0
+.. Copyright (C) 2023 Google LLC
+
+===========================================
+net_device struct fast path usage breakdown
+===========================================
+
+Type Name fastpath_tx_access fastpath_rx_access Comments
+..struct ..net_device
+char name[16] - -
+struct_netdev_name_node* name_node
+struct_dev_ifalias* ifalias
+unsigned_long mem_end
+unsigned_long mem_start
+unsigned_long base_addr
+unsigned_long state read_mostly read_mostly netif_running(dev)
+struct_list_head dev_list
+struct_list_head napi_list
+struct_list_head unreg_list
+struct_list_head close_list
+struct_list_head ptype_all read_mostly - dev_nit_active(tx)
+struct_list_head ptype_specific read_mostly deliver_ptype_list_skb/__netif_receive_skb_core(rx)
+struct adj_list
+unsigned_int flags read_mostly read_mostly __dev_queue_xmit,__dev_xmit_skb,ip6_output,__ip6_finish_output(tx);ip6_rcv_core(rx)
+xdp_features_t xdp_features
+unsigned_long_long priv_flags read_mostly - __dev_queue_xmit(tx)
+struct_net_device_ops* netdev_ops read_mostly - netdev_core_pick_tx,netdev_start_xmit(tx)
+struct_xdp_metadata_ops* xdp_metadata_ops
+int ifindex - read_mostly ip6_rcv_core
+unsigned_short gflags
+unsigned_short hard_header_len read_mostly read_mostly ip6_xmit(tx);gro_list_prepare(rx)
+unsigned_int mtu read_mostly - ip_finish_output2
+unsigned_short needed_headroom read_mostly - LL_RESERVED_SPACE/ip_finish_output2
+unsigned_short needed_tailroom
+netdev_features_t features read_mostly read_mostly HARD_TX_LOCK,netif_skb_features,sk_setup_caps(tx);netif_elide_gro(rx)
+netdev_features_t hw_features
+netdev_features_t wanted_features
+netdev_features_t vlan_features
+netdev_features_t hw_enc_features - - netif_skb_features
+netdev_features_t mpls_features
+netdev_features_t gso_partial_features read_mostly gso_features_check
+unsigned_int min_mtu
+unsigned_int max_mtu
+unsigned_short type
+unsigned_char min_header_len
+unsigned_char name_assign_type
+int group
+struct_net_device_stats stats
+struct_net_device_core_stats* core_stats
+atomic_t carrier_up_count
+atomic_t carrier_down_count
+struct_iw_handler_def* wireless_handlers
+struct_iw_public_data* wireless_data
+struct_ethtool_ops* ethtool_ops
+struct_l3mdev_ops* l3mdev_ops
+struct_ndisc_ops* ndisc_ops
+struct_xfrmdev_ops* xfrmdev_ops
+struct_tlsdev_ops* tlsdev_ops
+struct_header_ops* header_ops read_mostly - ip_finish_output2,ip6_finish_output2(tx)
+unsigned_char operstate
+unsigned_char link_mode
+unsigned_char if_port
+unsigned_char dma
+unsigned_char perm_addr[32]
+unsigned_char addr_assign_type
+unsigned_char addr_len
+unsigned_char upper_level
+unsigned_char lower_level
+unsigned_short neigh_priv_len
+unsigned_short padded
+unsigned_short dev_id
+unsigned_short dev_port
+spinlock_t addr_list_lock
+int irq
+struct_netdev_hw_addr_list uc
+struct_netdev_hw_addr_list mc
+struct_netdev_hw_addr_list dev_addrs
+struct_kset* queues_kset
+struct_list_head unlink_list
+unsigned_int promiscuity
+unsigned_int allmulti
+bool uc_promisc
+unsigned_char nested_level
+struct_in_device* ip_ptr read_mostly read_mostly __in_dev_get
+struct_inet6_dev* ip6_ptr read_mostly read_mostly __in6_dev_get
+struct_vlan_info* vlan_info
+struct_dsa_port* dsa_ptr
+struct_tipc_bearer* tipc_ptr
+void* atalk_ptr
+void* ax25_ptr
+struct_wireless_dev* ieee80211_ptr
+struct_wpan_dev* ieee802154_ptr
+struct_mpls_dev* mpls_ptr
+struct_mctp_dev* mctp_ptr
+unsigned_char* dev_addr
+struct_netdev_queue* _rx read_mostly - netdev_get_rx_queue(rx)
+unsigned_int num_rx_queues
+unsigned_int real_num_rx_queues - read_mostly get_rps_cpu
+struct_bpf_prog* xdp_prog - read_mostly netif_elide_gro()
+unsigned_long gro_flush_timeout - read_mostly napi_complete_done
+int napi_defer_hard_irqs - read_mostly napi_complete_done
+unsigned_int gro_max_size - read_mostly skb_gro_receive
+unsigned_int gro_ipv4_max_size - read_mostly skb_gro_receive
+rx_handler_func_t* rx_handler read_mostly - __netif_receive_skb_core
+void* rx_handler_data read_mostly -
+struct_netdev_queue* ingress_queue read_mostly -
+struct_bpf_mprog_entry tcx_ingress - read_mostly sch_handle_ingress
+struct_nf_hook_entries* nf_hooks_ingress
+unsigned_char broadcast[32]
+struct_cpu_rmap* rx_cpu_rmap
+struct_hlist_node index_hlist
+struct_netdev_queue* _tx read_mostly - netdev_get_tx_queue(tx)
+unsigned_int num_tx_queues - -
+unsigned_int real_num_tx_queues read_mostly - skb_tx_hash,netdev_core_pick_tx(tx)
+unsigned_int tx_queue_len
+spinlock_t tx_global_lock
+struct_xdp_dev_bulk_queue__percpu* xdp_bulkq
+struct_xps_dev_maps* xps_maps[2] read_mostly - __netif_set_xps_queue
+struct_bpf_mprog_entry tcx_egress read_mostly - sch_handle_egress
+struct_nf_hook_entries* nf_hooks_egress read_mostly -
+struct_hlist_head qdisc_hash[16]
+struct_timer_list watchdog_timer
+int watchdog_timeo
+u32 proto_down_reason
+struct_list_head todo_list
+int__percpu* pcpu_refcnt
+refcount_t dev_refcnt
+struct_ref_tracker_dir refcnt_tracker
+struct_list_head link_watch_list
+enum:8 reg_state
+bool dismantle
+enum:16 rtnl_link_state
+bool needs_free_netdev
+void*priv_destructor struct_net_device
+struct_netpoll_info* npinfo - read_mostly napi_poll/napi_poll_lock
+possible_net_t nd_net - read_mostly (dev_net)napi_busy_loop,tcp_v(4/6)_rcv,ip(v6)_rcv,ip(6)_input,ip(6)_input_finish
+void* ml_priv
+enum_netdev_ml_priv_type ml_priv_type
+struct_pcpu_lstats__percpu* lstats read_mostly dev_lstats_add()
+struct_pcpu_sw_netstats__percpu* tstats read_mostly dev_sw_netstats_tx_add()
+struct_pcpu_dstats__percpu* dstats
+struct_garp_port* garp_port
+struct_mrp_port* mrp_port
+struct_dm_hw_stat_delta* dm_private
+struct_device dev - -
+struct_attribute_group* sysfs_groups[4]
+struct_attribute_group* sysfs_rx_queue_group
+struct_rtnl_link_ops* rtnl_link_ops
+unsigned_int gso_max_size read_mostly - sk_dst_gso_max_size
+unsigned_int tso_max_size
+u16 gso_max_segs read_mostly - gso_max_segs
+u16 tso_max_segs
+unsigned_int gso_ipv4_max_size read_mostly - sk_dst_gso_max_size
+struct_dcbnl_rtnl_ops* dcbnl_ops
+s16 num_tc read_mostly - skb_tx_hash
+struct_netdev_tc_txq tc_to_txq[16] read_mostly - skb_tx_hash
+u8 prio_tc_map[16]
+unsigned_int fcoe_ddp_xid
+struct_netprio_map* priomap
+struct_phy_device* phydev
+struct_sfp_bus* sfp_bus
+struct_lock_class_key* qdisc_tx_busylock
+bool proto_down
+unsigned:1 wol_enabled
+unsigned:1 threaded - - napi_poll(napi_enable,dev_set_threaded)
+struct_list_head net_notifier_list
+struct_macsec_ops* macsec_ops
+struct_udp_tunnel_nic_info* udp_tunnel_nic_info
+struct_udp_tunnel_nic* udp_tunnel_nic
+unsigned_int xdp_zc_max_segs
+struct_bpf_xdp_entity xdp_state[3]
+u8 dev_addr_shadow[32]
+netdevice_tracker linkwatch_dev_tracker
+netdevice_tracker watchdog_dev_tracker
+netdevice_tracker dev_registered_tracker
+struct_rtnl_hw_stats64* offload_xstats_l3
+struct_devlink_port* devlink_port
+struct_dpll_pin* dpll_pin
diff --git a/Documentation/networking/net_cachelines/netns_ipv4_sysctl.rst b/Documentation/networking/net_cachelines/netns_ipv4_sysctl.rst
new file mode 100644
index 0000000000..9b87089a84
--- /dev/null
+++ b/Documentation/networking/net_cachelines/netns_ipv4_sysctl.rst
@@ -0,0 +1,158 @@
+.. SPDX-License-Identifier: GPL-2.0
+.. Copyright (C) 2023 Google LLC
+
+===========================================
+netns_ipv4 struct fast path usage breakdown
+===========================================
+
+Type Name fastpath_tx_access fastpath_rx_access comment
+..struct ..netns_ipv4
+struct_inet_timewait_death_row tcp_death_row
+struct_udp_table* udp_table
+struct_ctl_table_header* forw_hdr
+struct_ctl_table_header* frags_hdr
+struct_ctl_table_header* ipv4_hdr
+struct_ctl_table_header* route_hdr
+struct_ctl_table_header* xfrm4_hdr
+struct_ipv4_devconf* devconf_all
+struct_ipv4_devconf* devconf_dflt
+struct_ip_ra_chain ra_chain
+struct_mutex ra_mutex
+struct_fib_rules_ops* rules_ops
+struct_fib_table fib_main
+struct_fib_table fib_default
+unsigned_int fib_rules_require_fldissect
+bool fib_has_custom_rules
+bool fib_has_custom_local_routes
+bool fib_offload_disabled
+atomic_t fib_num_tclassid_users
+struct_hlist_head* fib_table_hash
+struct_sock* fibnl
+struct_sock* mc_autojoin_sk
+struct_inet_peer_base* peers
+struct_fqdir* fqdir
+u8 sysctl_icmp_echo_ignore_all
+u8 sysctl_icmp_echo_enable_probe
+u8 sysctl_icmp_echo_ignore_broadcasts
+u8 sysctl_icmp_ignore_bogus_error_responses
+u8 sysctl_icmp_errors_use_inbound_ifaddr
+int sysctl_icmp_ratelimit
+int sysctl_icmp_ratemask
+u32 ip_rt_min_pmtu - -
+int ip_rt_mtu_expires - -
+int ip_rt_min_advmss - -
+struct_local_ports ip_local_ports - -
+u8 sysctl_tcp_ecn - -
+u8 sysctl_tcp_ecn_fallback - -
+u8 sysctl_ip_default_ttl - - ip4_dst_hoplimit/ip_select_ttl
+u8 sysctl_ip_no_pmtu_disc - -
+u8 sysctl_ip_fwd_use_pmtu read_mostly - ip_dst_mtu_maybe_forward/ip_skb_dst_mtu
+u8 sysctl_ip_fwd_update_priority - - ip_forward
+u8 sysctl_ip_nonlocal_bind - -
+u8 sysctl_ip_autobind_reuse - -
+u8 sysctl_ip_dynaddr - -
+u8 sysctl_ip_early_demux - read_mostly ip(6)_rcv_finish_core
+u8 sysctl_raw_l3mdev_accept - -
+u8 sysctl_tcp_early_demux - read_mostly ip(6)_rcv_finish_core
+u8 sysctl_udp_early_demux
+u8 sysctl_nexthop_compat_mode - -
+u8 sysctl_fwmark_reflect - -
+u8 sysctl_tcp_fwmark_accept - -
+u8 sysctl_tcp_l3mdev_accept - -
+u8 sysctl_tcp_mtu_probing - -
+int sysctl_tcp_mtu_probe_floor - -
+int sysctl_tcp_base_mss - -
+int sysctl_tcp_min_snd_mss read_mostly - __tcp_mtu_to_mss(tcp_write_xmit)
+int sysctl_tcp_probe_threshold - - tcp_mtu_probe(tcp_write_xmit)
+u32 sysctl_tcp_probe_interval - - tcp_mtu_check_reprobe(tcp_write_xmit)
+int sysctl_tcp_keepalive_time - -
+int sysctl_tcp_keepalive_intvl - -
+u8 sysctl_tcp_keepalive_probes - -
+u8 sysctl_tcp_syn_retries - -
+u8 sysctl_tcp_synack_retries - -
+u8 sysctl_tcp_syncookies - - generated_on_syn
+u8 sysctl_tcp_migrate_req - - reuseport
+u8 sysctl_tcp_comp_sack_nr - - __tcp_ack_snd_check
+int sysctl_tcp_reordering - read_mostly tcp_may_raise_cwnd/tcp_cong_control
+u8 sysctl_tcp_retries1 - -
+u8 sysctl_tcp_retries2 - -
+u8 sysctl_tcp_orphan_retries - -
+u8 sysctl_tcp_tw_reuse - - timewait_sock_ops
+int sysctl_tcp_fin_timeout - - TCP_LAST_ACK/tcp_rcv_state_process
+unsigned_int sysctl_tcp_notsent_lowat read_mostly - tcp_notsent_lowat/tcp_stream_memory_free
+u8 sysctl_tcp_sack - - tcp_syn_options
+u8 sysctl_tcp_window_scaling - - tcp_syn_options,tcp_parse_options
+u8 sysctl_tcp_timestamps
+u8 sysctl_tcp_early_retrans read_mostly - tcp_schedule_loss_probe(tcp_write_xmit)
+u8 sysctl_tcp_recovery - - tcp_fastretrans_alert
+u8 sysctl_tcp_thin_linear_timeouts - - tcp_retrans_timer(on_thin_streams)
+u8 sysctl_tcp_slow_start_after_idle - - unlikely(tcp_cwnd_validate-network-not-starved)
+u8 sysctl_tcp_retrans_collapse - -
+u8 sysctl_tcp_stdurg - - unlikely(tcp_check_urg)
+u8 sysctl_tcp_rfc1337 - -
+u8 sysctl_tcp_abort_on_overflow - -
+u8 sysctl_tcp_fack - -
+int sysctl_tcp_max_reordering - - tcp_check_sack_reordering
+int sysctl_tcp_adv_win_scale - - tcp_init_buffer_space
+u8 sysctl_tcp_dsack - - partial_packet_or_retrans_in_tcp_data_queue
+u8 sysctl_tcp_app_win - - tcp_win_from_space
+u8 sysctl_tcp_frto - - tcp_enter_loss
+u8 sysctl_tcp_nometrics_save - - TCP_LAST_ACK/tcp_update_metrics
+u8 sysctl_tcp_no_ssthresh_metrics_save - - TCP_LAST_ACK/tcp_(update/init)_metrics
+u8 sysctl_tcp_moderate_rcvbuf read_mostly read_mostly tcp_tso_should_defer(tx);tcp_rcv_space_adjust(rx)
+u8 sysctl_tcp_tso_win_divisor read_mostly - tcp_tso_should_defer(tcp_write_xmit)
+u8 sysctl_tcp_workaround_signed_windows - - tcp_select_window
+int sysctl_tcp_limit_output_bytes read_mostly - tcp_small_queue_check(tcp_write_xmit)
+int sysctl_tcp_challenge_ack_limit - -
+int sysctl_tcp_min_rtt_wlen read_mostly - tcp_ack_update_rtt
+u8 sysctl_tcp_min_tso_segs - - unlikely(icsk_ca_ops-written)
+u8 sysctl_tcp_tso_rtt_log read_mostly - tcp_tso_autosize
+u8 sysctl_tcp_autocorking read_mostly - tcp_push/tcp_should_autocork
+u8 sysctl_tcp_reflect_tos - - tcp_v(4/6)_send_synack
+int sysctl_tcp_invalid_ratelimit - -
+int sysctl_tcp_pacing_ss_ratio - - default_cong_cont(tcp_update_pacing_rate)
+int sysctl_tcp_pacing_ca_ratio - - default_cong_cont(tcp_update_pacing_rate)
+int sysctl_tcp_wmem[3] read_mostly - tcp_wmem_schedule(sendmsg/sendpage)
+int sysctl_tcp_rmem[3] - read_mostly __tcp_grow_window(tx),tcp_rcv_space_adjust(rx)
+unsigned_int sysctl_tcp_child_ehash_entries
+unsigned_long sysctl_tcp_comp_sack_delay_ns - - __tcp_ack_snd_check
+unsigned_long sysctl_tcp_comp_sack_slack_ns - - __tcp_ack_snd_check
+int sysctl_max_syn_backlog - -
+int sysctl_tcp_fastopen - -
+struct_tcp_congestion_ops tcp_congestion_control - - init_cc
+struct_tcp_fastopen_context tcp_fastopen_ctx - -
+unsigned_int sysctl_tcp_fastopen_blackhole_timeout - -
+atomic_t tfo_active_disable_times - -
+unsigned_long tfo_active_disable_stamp - -
+u32 tcp_challenge_timestamp - -
+u32 tcp_challenge_count - -
+u8 sysctl_tcp_plb_enabled - -
+u8 sysctl_tcp_plb_idle_rehash_rounds - -
+u8 sysctl_tcp_plb_rehash_rounds - -
+u8 sysctl_tcp_plb_suspend_rto_sec - -
+int sysctl_tcp_plb_cong_thresh - -
+int sysctl_udp_wmem_min
+int sysctl_udp_rmem_min
+u8 sysctl_fib_notify_on_flag_change
+u8 sysctl_udp_l3mdev_accept
+u8 sysctl_igmp_llm_reports
+int sysctl_igmp_max_memberships
+int sysctl_igmp_max_msf
+int sysctl_igmp_qrv
+struct_ping_group_range ping_group_range
+atomic_t dev_addr_genid
+unsigned_int sysctl_udp_child_hash_entries
+unsigned_long* sysctl_local_reserved_ports
+int sysctl_ip_prot_sock
+struct_mr_table* mrt
+struct_list_head mr_tables
+struct_fib_rules_ops* mr_rules_ops
+u32 sysctl_fib_multipath_hash_fields
+u8 sysctl_fib_multipath_use_neigh
+u8 sysctl_fib_multipath_hash_policy
+struct_fib_notifier_ops* notifier_ops
+unsigned_int fib_seq
+struct_fib_notifier_ops* ipmr_notifier_ops
+unsigned_int ipmr_seq
+atomic_t rt_genid
+siphash_key_t ip_id_key
diff --git a/Documentation/networking/net_cachelines/snmp.rst b/Documentation/networking/net_cachelines/snmp.rst
new file mode 100644
index 0000000000..6a07153856
--- /dev/null
+++ b/Documentation/networking/net_cachelines/snmp.rst
@@ -0,0 +1,135 @@
+.. SPDX-License-Identifier: GPL-2.0
+.. Copyright (C) 2023 Google LLC
+
+===========================================
+netns_ipv4 enum fast path usage breakdown
+===========================================
+
+Type Name fastpath_tx_access fastpath_rx_access comment
+..enum
+unsigned_long LINUX_MIB_TCPKEEPALIVE write_mostly - tcp_keepalive_timer
+unsigned_long LINUX_MIB_DELAYEDACKS write_mostly - tcp_delack_timer_handler,tcp_delack_timer
+unsigned_long LINUX_MIB_DELAYEDACKLOCKED write_mostly - tcp_delack_timer_handler,tcp_delack_timer
+unsigned_long LINUX_MIB_TCPAUTOCORKING write_mostly - tcp_push,tcp_sendmsg_locked
+unsigned_long LINUX_MIB_TCPFROMZEROWINDOWADV write_mostly - tcp_select_window,tcp_transmit-skb
+unsigned_long LINUX_MIB_TCPTOZEROWINDOWADV write_mostly - tcp_select_window,tcp_transmit-skb
+unsigned_long LINUX_MIB_TCPWANTZEROWINDOWADV write_mostly - tcp_select_window,tcp_transmit-skb
+unsigned_long LINUX_MIB_TCPORIGDATASENT write_mostly - tcp_write_xmit
+unsigned_long LINUX_MIB_TCPHPHITS - write_mostly tcp_rcv_established,tcp_v4_do_rcv,tcp_v6_do_rcv
+unsigned_long LINUX_MIB_TCPRCVCOALESCE - write_mostly tcp_try_coalesce,tcp_queue_rcv,tcp_rcv_established
+unsigned_long LINUX_MIB_TCPPUREACKS - write_mostly tcp_ack,tcp_rcv_established
+unsigned_long LINUX_MIB_TCPHPACKS - write_mostly tcp_ack,tcp_rcv_established
+unsigned_long LINUX_MIB_TCPDELIVERED - write_mostly tcp_newly_delivered,tcp_ack,tcp_rcv_established
+unsigned_long LINUX_MIB_SYNCOOKIESSENT
+unsigned_long LINUX_MIB_SYNCOOKIESRECV
+unsigned_long LINUX_MIB_SYNCOOKIESFAILED
+unsigned_long LINUX_MIB_EMBRYONICRSTS
+unsigned_long LINUX_MIB_PRUNECALLED
+unsigned_long LINUX_MIB_RCVPRUNED
+unsigned_long LINUX_MIB_OFOPRUNED
+unsigned_long LINUX_MIB_OUTOFWINDOWICMPS
+unsigned_long LINUX_MIB_LOCKDROPPEDICMPS
+unsigned_long LINUX_MIB_ARPFILTER
+unsigned_long LINUX_MIB_TIMEWAITED
+unsigned_long LINUX_MIB_TIMEWAITRECYCLED
+unsigned_long LINUX_MIB_TIMEWAITKILLED
+unsigned_long LINUX_MIB_PAWSACTIVEREJECTED
+unsigned_long LINUX_MIB_PAWSESTABREJECTED
+unsigned_long LINUX_MIB_DELAYEDACKLOST
+unsigned_long LINUX_MIB_LISTENOVERFLOWS
+unsigned_long LINUX_MIB_LISTENDROPS
+unsigned_long LINUX_MIB_TCPRENORECOVERY
+unsigned_long LINUX_MIB_TCPSACKRECOVERY
+unsigned_long LINUX_MIB_TCPSACKRENEGING
+unsigned_long LINUX_MIB_TCPSACKREORDER
+unsigned_long LINUX_MIB_TCPRENOREORDER
+unsigned_long LINUX_MIB_TCPTSREORDER
+unsigned_long LINUX_MIB_TCPFULLUNDO
+unsigned_long LINUX_MIB_TCPPARTIALUNDO
+unsigned_long LINUX_MIB_TCPDSACKUNDO
+unsigned_long LINUX_MIB_TCPLOSSUNDO
+unsigned_long LINUX_MIB_TCPLOSTRETRANSMIT
+unsigned_long LINUX_MIB_TCPRENOFAILURES
+unsigned_long LINUX_MIB_TCPSACKFAILURES
+unsigned_long LINUX_MIB_TCPLOSSFAILURES
+unsigned_long LINUX_MIB_TCPFASTRETRANS
+unsigned_long LINUX_MIB_TCPSLOWSTARTRETRANS
+unsigned_long LINUX_MIB_TCPTIMEOUTS
+unsigned_long LINUX_MIB_TCPLOSSPROBES
+unsigned_long LINUX_MIB_TCPLOSSPROBERECOVERY
+unsigned_long LINUX_MIB_TCPRENORECOVERYFAIL
+unsigned_long LINUX_MIB_TCPSACKRECOVERYFAIL
+unsigned_long LINUX_MIB_TCPRCVCOLLAPSED
+unsigned_long LINUX_MIB_TCPDSACKOLDSENT
+unsigned_long LINUX_MIB_TCPDSACKOFOSENT
+unsigned_long LINUX_MIB_TCPDSACKRECV
+unsigned_long LINUX_MIB_TCPDSACKOFORECV
+unsigned_long LINUX_MIB_TCPABORTONDATA
+unsigned_long LINUX_MIB_TCPABORTONCLOSE
+unsigned_long LINUX_MIB_TCPABORTONMEMORY
+unsigned_long LINUX_MIB_TCPABORTONTIMEOUT
+unsigned_long LINUX_MIB_TCPABORTONLINGER
+unsigned_long LINUX_MIB_TCPABORTFAILED
+unsigned_long LINUX_MIB_TCPMEMORYPRESSURES
+unsigned_long LINUX_MIB_TCPMEMORYPRESSURESCHRONO
+unsigned_long LINUX_MIB_TCPSACKDISCARD
+unsigned_long LINUX_MIB_TCPDSACKIGNOREDOLD
+unsigned_long LINUX_MIB_TCPDSACKIGNOREDNOUNDO
+unsigned_long LINUX_MIB_TCPSPURIOUSRTOS
+unsigned_long LINUX_MIB_TCPMD5NOTFOUND
+unsigned_long LINUX_MIB_TCPMD5UNEXPECTED
+unsigned_long LINUX_MIB_TCPMD5FAILURE
+unsigned_long LINUX_MIB_SACKSHIFTED
+unsigned_long LINUX_MIB_SACKMERGED
+unsigned_long LINUX_MIB_SACKSHIFTFALLBACK
+unsigned_long LINUX_MIB_TCPBACKLOGDROP
+unsigned_long LINUX_MIB_PFMEMALLOCDROP
+unsigned_long LINUX_MIB_TCPMINTTLDROP
+unsigned_long LINUX_MIB_TCPDEFERACCEPTDROP
+unsigned_long LINUX_MIB_IPRPFILTER
+unsigned_long LINUX_MIB_TCPTIMEWAITOVERFLOW
+unsigned_long LINUX_MIB_TCPREQQFULLDOCOOKIES
+unsigned_long LINUX_MIB_TCPREQQFULLDROP
+unsigned_long LINUX_MIB_TCPRETRANSFAIL
+unsigned_long LINUX_MIB_TCPBACKLOGCOALESCE
+unsigned_long LINUX_MIB_TCPOFOQUEUE
+unsigned_long LINUX_MIB_TCPOFODROP
+unsigned_long LINUX_MIB_TCPOFOMERGE
+unsigned_long LINUX_MIB_TCPCHALLENGEACK
+unsigned_long LINUX_MIB_TCPSYNCHALLENGE
+unsigned_long LINUX_MIB_TCPFASTOPENACTIVE
+unsigned_long LINUX_MIB_TCPFASTOPENACTIVEFAIL
+unsigned_long LINUX_MIB_TCPFASTOPENPASSIVE
+unsigned_long LINUX_MIB_TCPFASTOPENPASSIVEFAIL
+unsigned_long LINUX_MIB_TCPFASTOPENLISTENOVERFLOW
+unsigned_long LINUX_MIB_TCPFASTOPENCOOKIEREQD
+unsigned_long LINUX_MIB_TCPFASTOPENBLACKHOLE
+unsigned_long LINUX_MIB_TCPSPURIOUS_RTX_HOSTQUEUES
+unsigned_long LINUX_MIB_BUSYPOLLRXPACKETS
+unsigned_long LINUX_MIB_TCPSYNRETRANS
+unsigned_long LINUX_MIB_TCPHYSTARTTRAINDETECT
+unsigned_long LINUX_MIB_TCPHYSTARTTRAINCWND
+unsigned_long LINUX_MIB_TCPHYSTARTDELAYDETECT
+unsigned_long LINUX_MIB_TCPHYSTARTDELAYCWND
+unsigned_long LINUX_MIB_TCPACKSKIPPEDSYNRECV
+unsigned_long LINUX_MIB_TCPACKSKIPPEDPAWS
+unsigned_long LINUX_MIB_TCPACKSKIPPEDSEQ
+unsigned_long LINUX_MIB_TCPACKSKIPPEDFINWAIT2
+unsigned_long LINUX_MIB_TCPACKSKIPPEDTIMEWAIT
+unsigned_long LINUX_MIB_TCPACKSKIPPEDCHALLENGE
+unsigned_long LINUX_MIB_TCPWINPROBE
+unsigned_long LINUX_MIB_TCPMTUPFAIL
+unsigned_long LINUX_MIB_TCPMTUPSUCCESS
+unsigned_long LINUX_MIB_TCPDELIVEREDCE
+unsigned_long LINUX_MIB_TCPACKCOMPRESSED
+unsigned_long LINUX_MIB_TCPZEROWINDOWDROP
+unsigned_long LINUX_MIB_TCPRCVQDROP
+unsigned_long LINUX_MIB_TCPWQUEUETOOBIG
+unsigned_long LINUX_MIB_TCPFASTOPENPASSIVEALTKEY
+unsigned_long LINUX_MIB_TCPTIMEOUTREHASH
+unsigned_long LINUX_MIB_TCPDUPLICATEDATAREHASH
+unsigned_long LINUX_MIB_TCPDSACKRECVSEGS
+unsigned_long LINUX_MIB_TCPDSACKIGNOREDDUBIOUS
+unsigned_long LINUX_MIB_TCPMIGRATEREQSUCCESS
+unsigned_long LINUX_MIB_TCPMIGRATEREQFAILURE
+unsigned_long __LINUX_MIB_MAX
diff --git a/Documentation/networking/net_cachelines/tcp_sock.rst b/Documentation/networking/net_cachelines/tcp_sock.rst
new file mode 100644
index 0000000000..1c154cbd18
--- /dev/null
+++ b/Documentation/networking/net_cachelines/tcp_sock.rst
@@ -0,0 +1,157 @@
+.. SPDX-License-Identifier: GPL-2.0
+.. Copyright (C) 2023 Google LLC
+
+=========================================
+tcp_sock struct fast path usage breakdown
+=========================================
+
+Type Name fastpath_tx_access fastpath_rx_access Comments
+..struct ..tcp_sock
+struct_inet_connection_sock inet_conn
+u16 tcp_header_len read_mostly read_mostly tcp_bound_to_half_wnd,tcp_current_mss(tx);tcp_rcv_established(rx)
+u16 gso_segs read_mostly - tcp_xmit_size_goal
+__be32 pred_flags read_write read_mostly tcp_select_window(tx);tcp_rcv_established(rx)
+u64 bytes_received - read_write tcp_rcv_nxt_update(rx)
+u32 segs_in - read_write tcp_v6_rcv(rx)
+u32 data_segs_in - read_write tcp_v6_rcv(rx)
+u32 rcv_nxt read_mostly read_write tcp_cleanup_rbuf,tcp_send_ack,tcp_inq_hint,tcp_transmit_skb,tcp_receive_window(tx);tcp_v6_do_rcv,tcp_rcv_established,tcp_data_queue,tcp_receive_window,tcp_rcv_nxt_update(write)(rx)
+u32 copied_seq - read_mostly tcp_cleanup_rbuf,tcp_rcv_space_adjust,tcp_inq_hint
+u32 rcv_wup - read_write __tcp_cleanup_rbuf,tcp_receive_window,tcp_receive_established
+u32 snd_nxt read_write read_mostly tcp_rate_check_app_limited,__tcp_transmit_skb,tcp_event_new_data_sent(write)(tx);tcp_rcv_established,tcp_ack,tcp_clean_rtx_queue(rx)
+u32 segs_out read_write - __tcp_transmit_skb
+u32 data_segs_out read_write - __tcp_transmit_skb,tcp_update_skb_after_send
+u64 bytes_sent read_write - __tcp_transmit_skb
+u64 bytes_acked - read_write tcp_snd_una_update/tcp_ack
+u32 dsack_dups
+u32 snd_una read_mostly read_write tcp_wnd_end,tcp_urg_mode,tcp_minshall_check,tcp_cwnd_validate(tx);tcp_ack,tcp_may_update_window,tcp_clean_rtx_queue(write),tcp_ack_tstamp(rx)
+u32 snd_sml read_write - tcp_minshall_check,tcp_minshall_update
+u32 rcv_tstamp - read_mostly tcp_ack
+u32 lsndtime read_write - tcp_slow_start_after_idle_check,tcp_event_data_sent
+u32 last_oow_ack_time
+u32 compressed_ack_rcv_nxt
+u32 tsoffset read_mostly read_mostly tcp_established_options(tx);tcp_fast_parse_options(rx)
+struct_list_head tsq_node - -
+struct_list_head tsorted_sent_queue read_write - tcp_update_skb_after_send
+u32 snd_wl1 - read_mostly tcp_may_update_window
+u32 snd_wnd read_mostly read_mostly tcp_wnd_end,tcp_tso_should_defer(tx);tcp_fast_path_on(rx)
+u32 max_window read_mostly - tcp_bound_to_half_wnd,forced_push
+u32 mss_cache read_mostly read_mostly tcp_rate_check_app_limited,tcp_current_mss,tcp_sync_mss,tcp_sndbuf_expand,tcp_tso_should_defer(tx);tcp_update_pacing_rate,tcp_clean_rtx_queue(rx)
+u32 window_clamp read_mostly read_write tcp_rcv_space_adjust,__tcp_select_window
+u32 rcv_ssthresh read_mostly - __tcp_select_window
+u8 scaling_ratio read_mostly read_mostly tcp_win_from_space
+struct tcp_rack
+u16 advmss - read_mostly tcp_rcv_space_adjust
+u8 compressed_ack
+u8:2 dup_ack_counter
+u8:1 tlp_retrans
+u8:1 tcp_usec_ts read_mostly read_mostly
+u32 chrono_start read_write - tcp_chrono_start/stop(tcp_write_xmit,tcp_cwnd_validate,tcp_send_syn_data)
+u32[3] chrono_stat read_write - tcp_chrono_start/stop(tcp_write_xmit,tcp_cwnd_validate,tcp_send_syn_data)
+u8:2 chrono_type read_write - tcp_chrono_start/stop(tcp_write_xmit,tcp_cwnd_validate,tcp_send_syn_data)
+u8:1 rate_app_limited - read_write tcp_rate_gen
+u8:1 fastopen_connect
+u8:1 fastopen_no_cookie
+u8:1 is_sack_reneg - read_mostly tcp_skb_entail,tcp_ack
+u8:2 fastopen_client_fail
+u8:4 nonagle read_write - tcp_skb_entail,tcp_push_pending_frames
+u8:1 thin_lto
+u8:1 recvmsg_inq
+u8:1 repair read_mostly - tcp_write_xmit
+u8:1 frto
+u8 repair_queue - -
+u8:2 save_syn
+u8:1 syn_data
+u8:1 syn_fastopen
+u8:1 syn_fastopen_exp
+u8:1 syn_fastopen_ch
+u8:1 syn_data_acked
+u8:1 is_cwnd_limited read_mostly - tcp_cwnd_validate,tcp_is_cwnd_limited
+u32 tlp_high_seq - read_mostly tcp_ack
+u32 tcp_tx_delay
+u64 tcp_wstamp_ns read_write - tcp_pacing_check,tcp_tso_should_defer,tcp_update_skb_after_send
+u64 tcp_clock_cache read_write read_write tcp_mstamp_refresh(tcp_write_xmit/tcp_rcv_space_adjust),__tcp_transmit_skb,tcp_tso_should_defer;timer
+u64 tcp_mstamp read_write read_write tcp_mstamp_refresh(tcp_write_xmit/tcp_rcv_space_adjust)(tx);tcp_rcv_space_adjust,tcp_rate_gen,tcp_clean_rtx_queue,tcp_ack_update_rtt/tcp_time_stamp(rx);timer
+u32 srtt_us read_mostly read_write tcp_tso_should_defer(tx);tcp_update_pacing_rate,__tcp_set_rto,tcp_rtt_estimator(rx)
+u32 mdev_us read_write - tcp_rtt_estimator
+u32 mdev_max_us
+u32 rttvar_us - read_mostly __tcp_set_rto
+u32 rtt_seq read_write tcp_rtt_estimator
+struct_minmax rtt_min - read_mostly tcp_min_rtt/tcp_rate_gen,tcp_min_rtttcp_update_rtt_min
+u32 packets_out read_write read_write tcp_packets_in_flight(tx/rx);tcp_slow_start_after_idle_check,tcp_nagle_check,tcp_rate_skb_sent,tcp_event_new_data_sent,tcp_cwnd_validate,tcp_write_xmit(tx);tcp_ack,tcp_clean_rtx_queue,tcp_update_pacing_rate(rx)
+u32 retrans_out - read_mostly tcp_packets_in_flight,tcp_rate_check_app_limited
+u32 max_packets_out - read_write tcp_cwnd_validate
+u32 cwnd_usage_seq - read_write tcp_cwnd_validate
+u16 urg_data - read_mostly tcp_fast_path_check
+u8 ecn_flags read_write - tcp_ecn_send
+u8 keepalive_probes
+u32 reordering read_mostly - tcp_sndbuf_expand
+u32 reord_seen
+u32 snd_up read_write read_mostly tcp_mark_urg,tcp_urg_mode,__tcp_transmit_skb(tx);tcp_clean_rtx_queue(rx)
+struct_tcp_options_received rx_opt read_mostly read_write tcp_established_options(tx);tcp_fast_path_on,tcp_ack_update_window,tcp_is_sack,tcp_data_queue,tcp_rcv_established,tcp_ack_update_rtt(rx)
+u32 snd_ssthresh - read_mostly tcp_update_pacing_rate
+u32 snd_cwnd read_mostly read_mostly tcp_snd_cwnd,tcp_rate_check_app_limited,tcp_tso_should_defer(tx);tcp_update_pacing_rate
+u32 snd_cwnd_cnt
+u32 snd_cwnd_clamp
+u32 snd_cwnd_used
+u32 snd_cwnd_stamp
+u32 prior_cwnd
+u32 prr_delivered
+u32 prr_out read_mostly read_mostly tcp_rate_skb_sent,tcp_newly_delivered(tx);tcp_ack,tcp_rate_gen,tcp_clean_rtx_queue(rx)
+u32 delivered read_mostly read_write tcp_rate_skb_sent, tcp_newly_delivered(tx);tcp_ack, tcp_rate_gen, tcp_clean_rtx_queue (rx)
+u32 delivered_ce read_mostly read_write tcp_rate_skb_sent(tx);tcp_rate_gen(rx)
+u32 lost - read_mostly tcp_ack
+u32 app_limited read_write read_mostly tcp_rate_check_app_limited,tcp_rate_skb_sent(tx);tcp_rate_gen(rx)
+u64 first_tx_mstamp read_write - tcp_rate_skb_sent
+u64 delivered_mstamp read_write - tcp_rate_skb_sent
+u32 rate_delivered - read_mostly tcp_rate_gen
+u32 rate_interval_us - read_mostly rate_delivered,rate_app_limited
+u32 rcv_wnd read_write read_mostly tcp_select_window,tcp_receive_window,tcp_fast_path_check
+u32 write_seq read_write - tcp_rate_check_app_limited,tcp_write_queue_empty,tcp_skb_entail,forced_push,tcp_mark_push
+u32 notsent_lowat read_mostly - tcp_stream_memory_free
+u32 pushed_seq read_write - tcp_mark_push,forced_push
+u32 lost_out read_mostly read_mostly tcp_left_out(tx);tcp_packets_in_flight(tx/rx);tcp_rate_check_app_limited(rx)
+u32 sacked_out read_mostly read_mostly tcp_left_out(tx);tcp_packets_in_flight(tx/rx);tcp_clean_rtx_queue(rx)
+struct_hrtimer pacing_timer
+struct_hrtimer compressed_ack_timer
+struct_sk_buff* lost_skb_hint read_mostly tcp_clean_rtx_queue
+struct_sk_buff* retransmit_skb_hint read_mostly - tcp_clean_rtx_queue
+struct_rb_root out_of_order_queue - read_mostly tcp_data_queue,tcp_fast_path_check
+struct_sk_buff* ooo_last_skb
+struct_tcp_sack_block[1] duplicate_sack
+struct_tcp_sack_block[4] selective_acks
+struct_tcp_sack_block[4] recv_sack_cache
+struct_sk_buff* highest_sack read_write - tcp_event_new_data_sent
+int lost_cnt_hint
+u32 prior_ssthresh
+u32 high_seq
+u32 retrans_stamp
+u32 undo_marker
+int undo_retrans
+u64 bytes_retrans
+u32 total_retrans
+u32 rto_stamp
+u16 total_rto
+u16 total_rto_recoveries
+u32 total_rto_time
+u32 urg_seq - -
+unsigned_int keepalive_time
+unsigned_int keepalive_intvl
+int linger2
+u8 bpf_sock_ops_cb_flags
+u8:1 bpf_chg_cc_inprogress
+u16 timeout_rehash
+u32 rcv_ooopack
+u32 rcv_rtt_last_tsecr
+struct rcv_rtt_est - read_write tcp_rcv_space_adjust,tcp_rcv_established
+struct rcvq_space - read_write tcp_rcv_space_adjust
+struct mtu_probe
+u32 plb_rehash
+u32 mtu_info
+bool is_mptcp
+bool smc_hs_congested
+bool syn_smc
+struct_tcp_sock_af_ops* af_specific
+struct_tcp_md5sig_info* md5sig_info
+struct_tcp_fastopen_request* fastopen_req
+struct_request_sock* fastopen_rsk
+struct_saved_syn* saved_syn \ No newline at end of file
diff --git a/Documentation/networking/netlink_spec/.gitignore b/Documentation/networking/netlink_spec/.gitignore
new file mode 100644
index 0000000000..30d85567b5
--- /dev/null
+++ b/Documentation/networking/netlink_spec/.gitignore
@@ -0,0 +1 @@
+*.rst
diff --git a/Documentation/networking/netlink_spec/readme.txt b/Documentation/networking/netlink_spec/readme.txt
new file mode 100644
index 0000000000..6763f99d21
--- /dev/null
+++ b/Documentation/networking/netlink_spec/readme.txt
@@ -0,0 +1,4 @@
+SPDX-License-Identifier: GPL-2.0
+
+This file is populated during the build of the documentation (htmldocs) by the
+tools/net/ynl/ynl-gen-rst.py script.
diff --git a/Documentation/networking/packet_mmap.rst b/Documentation/networking/packet_mmap.rst
index 30a3be3c48..dca15d15fe 100644
--- a/Documentation/networking/packet_mmap.rst
+++ b/Documentation/networking/packet_mmap.rst
@@ -263,20 +263,20 @@ the name indicates, this function allocates pages of memory, and the second
argument is "order" or a power of two number of pages, that is
(for PAGE_SIZE == 4096) order=0 ==> 4096 bytes, order=1 ==> 8192 bytes,
order=2 ==> 16384 bytes, etc. The maximum size of a
-region allocated by __get_free_pages is determined by the MAX_ORDER macro. More
-precisely the limit can be calculated as::
+region allocated by __get_free_pages is determined by the MAX_PAGE_ORDER macro.
+More precisely the limit can be calculated as::
- PAGE_SIZE << MAX_ORDER
+ PAGE_SIZE << MAX_PAGE_ORDER
In a i386 architecture PAGE_SIZE is 4096 bytes
- In a 2.4/i386 kernel MAX_ORDER is 10
- In a 2.6/i386 kernel MAX_ORDER is 11
+ In a 2.4/i386 kernel MAX_PAGE_ORDER is 10
+ In a 2.6/i386 kernel MAX_PAGE_ORDER is 11
So get_free_pages can allocate as much as 4MB or 8MB in a 2.4/2.6 kernel
respectively, with an i386 architecture.
User space programs can include /usr/include/sys/user.h and
-/usr/include/linux/mmzone.h to get PAGE_SIZE MAX_ORDER declarations.
+/usr/include/linux/mmzone.h to get PAGE_SIZE MAX_PAGE_ORDER declarations.
The pagesize can also be determined dynamically with the getpagesize (2)
system call.
@@ -324,7 +324,7 @@ Definitions:
(see /proc/slabinfo)
<pointer size> depends on the architecture -- ``sizeof(void *)``
<page size> depends on the architecture -- PAGE_SIZE or getpagesize (2)
-<max-order> is the value defined with MAX_ORDER
+<max-order> is the value defined with MAX_PAGE_ORDER
<frame size> it's an upper bound of frame's capture size (more on this later)
============== ================================================================
diff --git a/Documentation/networking/page_pool.rst b/Documentation/networking/page_pool.rst
index 60993cb56b..9d958128a5 100644
--- a/Documentation/networking/page_pool.rst
+++ b/Documentation/networking/page_pool.rst
@@ -41,6 +41,11 @@ Architecture overview
| Fast cache | | ptr-ring cache |
+-----------------+ +------------------+
+Monitoring
+==========
+Information about page pools on the system can be accessed via the netdev
+genetlink family (see Documentation/netlink/specs/netdev.yaml).
+
API interface
=============
The number of pools created **must** match the number of hardware queues
@@ -107,8 +112,9 @@ page_pool_get_stats() and structures described below are available.
It takes a pointer to a ``struct page_pool`` and a pointer to a struct
page_pool_stats allocated by the caller.
-The API will fill in the provided struct page_pool_stats with
-statistics about the page_pool.
+Older drivers expose page pool statistics via ethtool or debugfs.
+The same statistics are accessible via the netlink netdev family
+in a driver-independent fashion.
.. kernel-doc:: include/net/page_pool/types.h
:identifiers: struct page_pool_recycle_stats
diff --git a/Documentation/networking/scaling.rst b/Documentation/networking/scaling.rst
index 03ae19a689..4eb50bcb9d 100644
--- a/Documentation/networking/scaling.rst
+++ b/Documentation/networking/scaling.rst
@@ -44,6 +44,21 @@ by masking out the low order seven bits of the computed hash for the
packet (usually a Toeplitz hash), taking this number as a key into the
indirection table and reading the corresponding value.
+Some NICs support symmetric RSS hashing where, if the IP (source address,
+destination address) and TCP/UDP (source port, destination port) tuples
+are swapped, the computed hash is the same. This is beneficial in some
+applications that monitor TCP/IP flows (IDS, firewalls, ...etc) and need
+both directions of the flow to land on the same Rx queue (and CPU). The
+"Symmetric-XOR" is a type of RSS algorithms that achieves this hash
+symmetry by XORing the input source and destination fields of the IP
+and/or L4 protocols. This, however, results in reduced input entropy and
+could potentially be exploited. Specifically, the algorithm XORs the input
+as follows::
+
+ # (SRC_IP ^ DST_IP, SRC_IP ^ DST_IP, SRC_PORT ^ DST_PORT, SRC_PORT ^ DST_PORT)
+
+The result is then fed to the underlying RSS algorithm.
+
Some advanced NICs allow steering packets to queues based on
programmable filters. For example, webserver bound TCP port 80 packets
can be directed to their own receive queue. Such “n-tuple” filters can
diff --git a/Documentation/networking/smc-sysctl.rst b/Documentation/networking/smc-sysctl.rst
index 769149d987..a874d007f2 100644
--- a/Documentation/networking/smc-sysctl.rst
+++ b/Documentation/networking/smc-sysctl.rst
@@ -57,3 +57,17 @@ rmem - INTEGER
only allowed 512KiB for SMC-R and 1MiB for SMC-D.
Default: 64KiB
+
+smcr_max_links_per_lgr - INTEGER
+ Controls the max number of links can be added to a SMC-R link group. Notice that
+ the actual number of the links added to a SMC-R link group depends on the number
+ of RDMA devices exist in the system. The acceptable value ranges from 1 to 2. Only
+ for SMC-R v2.1 and later.
+
+ Default: 2
+
+smcr_max_conns_per_lgr - INTEGER
+ Controls the max number of connections can be added to a SMC-R link group. The
+ acceptable value ranges from 16 to 255. Only for SMC-R v2.1 and later.
+
+ Default: 255
diff --git a/Documentation/networking/snmp_counter.rst b/Documentation/networking/snmp_counter.rst
index 2136374744..ff1e6a8ffe 100644
--- a/Documentation/networking/snmp_counter.rst
+++ b/Documentation/networking/snmp_counter.rst
@@ -313,7 +313,7 @@ https://lwn.net/Articles/576263/
* TcpExtTCPOrigDataSent
-This counter is explained by `kernel commit f19c29e3e391`_, I pasted the
+This counter is explained by kernel commit f19c29e3e391, I pasted the
explanation below::
TCPOrigDataSent: number of outgoing packets with original data (excluding
@@ -323,7 +323,7 @@ explanation below::
* TCPSynRetrans
-This counter is explained by `kernel commit f19c29e3e391`_, I pasted the
+This counter is explained by kernel commit f19c29e3e391, I pasted the
explanation below::
TCPSynRetrans: number of SYN and SYN/ACK retransmits to break down
@@ -331,14 +331,12 @@ explanation below::
* TCPFastOpenActiveFail
-This counter is explained by `kernel commit f19c29e3e391`_, I pasted the
+This counter is explained by kernel commit f19c29e3e391, I pasted the
explanation below::
TCPFastOpenActiveFail: Fast Open attempts (SYN/data) failed because
the remote does not accept it or the attempts timed out.
-.. _kernel commit f19c29e3e391: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=f19c29e3e391a66a273e9afebaf01917245148cd
-
* TcpExtListenOverflows and TcpExtListenDrops
When kernel receives a SYN from a client, and if the TCP accept queue
@@ -698,11 +696,9 @@ number of the SACK block. For more details, please refer the comment
of the function tcp_is_sackblock_valid in the kernel source code. A
SACK option could have up to 4 blocks, they are checked
individually. E.g., if 3 blocks of a SACk is invalid, the
-corresponding counter would be updated 3 times. The comment of the
-`Add counters for discarded SACK blocks`_ patch has additional
-explanation:
-
-.. _Add counters for discarded SACK blocks: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=18f02545a9a16c9a89778b91a162ad16d510bb32
+corresponding counter would be updated 3 times. The comment of commit
+18f02545a9a1 ("[TCP] MIB: Add counters for discarded SACK blocks")
+has additional explanation:
* TcpExtTCPSACKDiscard
diff --git a/Documentation/networking/timestamping.rst b/Documentation/networking/timestamping.rst
index f17c01834a..5e93cd71f9 100644
--- a/Documentation/networking/timestamping.rst
+++ b/Documentation/networking/timestamping.rst
@@ -357,7 +357,8 @@ enabling SOF_TIMESTAMPING_OPT_ID and comparing the byte offset at
send time with the value returned for each timestamp. It can prevent
the situation by always flushing the TCP stack in between requests,
for instance by enabling TCP_NODELAY and disabling TCP_CORK and
-autocork.
+autocork. After linux-4.7, a better way to prevent coalescing is
+to use MSG_EOR flag at sendmsg() time.
These precautions ensure that the timestamp is generated only when all
bytes have passed a timestamp point, assuming that the network stack
diff --git a/Documentation/networking/xdp-rx-metadata.rst b/Documentation/networking/xdp-rx-metadata.rst
index 205696780b..a6e0ece18b 100644
--- a/Documentation/networking/xdp-rx-metadata.rst
+++ b/Documentation/networking/xdp-rx-metadata.rst
@@ -1,3 +1,5 @@
+.. SPDX-License-Identifier: GPL-2.0
+
===============
XDP RX Metadata
===============
@@ -18,7 +20,13 @@ Currently, the following kfuncs are supported. In the future, as more
metadata is supported, this set will grow:
.. kernel-doc:: net/core/xdp.c
- :identifiers: bpf_xdp_metadata_rx_timestamp bpf_xdp_metadata_rx_hash
+ :identifiers: bpf_xdp_metadata_rx_timestamp
+
+.. kernel-doc:: net/core/xdp.c
+ :identifiers: bpf_xdp_metadata_rx_hash
+
+.. kernel-doc:: net/core/xdp.c
+ :identifiers: bpf_xdp_metadata_rx_vlan_tag
An XDP program can use these kfuncs to read the metadata into stack
variables for its own consumption. Or, to pass the metadata on to other
diff --git a/Documentation/networking/xsk-tx-metadata.rst b/Documentation/networking/xsk-tx-metadata.rst
new file mode 100644
index 0000000000..bd033fe95c
--- /dev/null
+++ b/Documentation/networking/xsk-tx-metadata.rst
@@ -0,0 +1,81 @@
+.. SPDX-License-Identifier: GPL-2.0
+
+==================
+AF_XDP TX Metadata
+==================
+
+This document describes how to enable offloads when transmitting packets
+via :doc:`af_xdp`. Refer to :doc:`xdp-rx-metadata` on how to access similar
+metadata on the receive side.
+
+General Design
+==============
+
+The headroom for the metadata is reserved via ``tx_metadata_len`` in
+``struct xdp_umem_reg``. The metadata length is therefore the same for
+every socket that shares the same umem. The metadata layout is a fixed UAPI,
+refer to ``union xsk_tx_metadata`` in ``include/uapi/linux/if_xdp.h``.
+Thus, generally, the ``tx_metadata_len`` field above should contain
+``sizeof(union xsk_tx_metadata)``.
+
+The headroom and the metadata itself should be located right before
+``xdp_desc->addr`` in the umem frame. Within a frame, the metadata
+layout is as follows::
+
+ tx_metadata_len
+ / \
+ +-----------------+---------+----------------------------+
+ | xsk_tx_metadata | padding | payload |
+ +-----------------+---------+----------------------------+
+ ^
+ |
+ xdp_desc->addr
+
+An AF_XDP application can request headrooms larger than ``sizeof(struct
+xsk_tx_metadata)``. The kernel will ignore the padding (and will still
+use ``xdp_desc->addr - tx_metadata_len`` to locate
+the ``xsk_tx_metadata``). For the frames that shouldn't carry
+any metadata (i.e., the ones that don't have ``XDP_TX_METADATA`` option),
+the metadata area is ignored by the kernel as well.
+
+The flags field enables the particular offload:
+
+- ``XDP_TXMD_FLAGS_TIMESTAMP``: requests the device to put transmission
+ timestamp into ``tx_timestamp`` field of ``union xsk_tx_metadata``.
+- ``XDP_TXMD_FLAGS_CHECKSUM``: requests the device to calculate L4
+ checksum. ``csum_start`` specifies byte offset of where the checksumming
+ should start and ``csum_offset`` specifies byte offset where the
+ device should store the computed checksum.
+
+Besides the flags above, in order to trigger the offloads, the first
+packet's ``struct xdp_desc`` descriptor should set ``XDP_TX_METADATA``
+bit in the ``options`` field. Also note that in a multi-buffer packet
+only the first chunk should carry the metadata.
+
+Software TX Checksum
+====================
+
+For development and testing purposes its possible to pass
+``XDP_UMEM_TX_SW_CSUM`` flag to ``XDP_UMEM_REG`` UMEM registration call.
+In this case, when running in ``XDK_COPY`` mode, the TX checksum
+is calculated on the CPU. Do not enable this option in production because
+it will negatively affect performance.
+
+Querying Device Capabilities
+============================
+
+Every devices exports its offloads capabilities via netlink netdev family.
+Refer to ``xsk-flags`` features bitmask in
+``Documentation/netlink/specs/netdev.yaml``.
+
+- ``tx-timestamp``: device supports ``XDP_TXMD_FLAGS_TIMESTAMP``
+- ``tx-checksum``: device supports ``XDP_TXMD_FLAGS_CHECKSUM``
+
+See ``tools/net/ynl/samples/netdev.c`` on how to query this information.
+
+Example
+=======
+
+See ``tools/testing/selftests/bpf/xdp_hw_metadata.c`` for an example
+program that handles TX metadata. Also see https://github.com/fomichev/xskgen
+for a more bare-bones example.