Merge tag 'net-next-6.3' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-nextgrafted

Pull networking updates from Jakub Kicinski:
 "Core:

   - Add dedicated kmem_cache for typical/small skb->head, avoid having
     to access struct page at kfree time, and improve memory use.

   - Introduce sysctl to set default RPS configuration for new netdevs.

   - Define Netlink protocol specification format which can be used to
     describe messages used by each family and auto-generate parsers.
     Add tools for generating kernel data structures and uAPI headers.

   - Expose all net/core sysctls inside netns.

   - Remove 4s sleep in netpoll if carrier is instantly detected on
     boot.

   - Add configurable limit of MDB entries per port, and port-vlan.

   - Continue populating drop reasons throughout the stack.

   - Retire a handful of legacy Qdiscs and classifiers.

  Protocols:

   - Support IPv4 big TCP (TSO frames larger than 64kB).

   - Add IP_LOCAL_PORT_RANGE socket option, to control local port range
     on socket by socket basis.

   - Track and report in procfs number of MPTCP sockets used.

   - Support mixing IPv4 and IPv6 flows in the in-kernel MPTCP path
     manager.

   - IPv6: don't check net.ipv6.route.max_size and rely on garbage
     collection to free memory (similarly to IPv4).

   - Support Penultimate Segment Pop (PSP) flavor in SRv6 (RFC8986).

   - ICMP: add per-rate limit counters.

   - Add support for user scanning requests in ieee802154.

   - Remove static WEP support.

   - Support minimal Wi-Fi 7 Extremely High Throughput (EHT) rate
     reporting.

   - WiFi 7 EHT channel puncturing support (client & AP).

  BPF:

   - Add a rbtree data structure following the "next-gen data structure"
     precedent set by recently added linked list, that is, by using
     kfunc + kptr instead of adding a new BPF map type.

   - Expose XDP hints via kfuncs with initial support for RX hash and
     timestamp metadata.

   - Add BPF_F_NO_TUNNEL_KEY extension to bpf_skb_set_tunnel_key to
     better support decap on GRE tunnel devices not operating in collect
     metadata.

   - Improve x86 JIT's codegen for PROBE_MEM runtime error checks.

   - Remove the need for trace_printk_lock for bpf_trace_printk and
     bpf_trace_vprintk helpers.

   - Extend libbpf's bpf_tracing.h support for tracing arguments of
     kprobes/uprobes and syscall as a special case.

   - Significantly reduce the search time for module symbols by
     livepatch and BPF.

   - Enable cpumasks to be used as kptrs, which is useful for tracing
     programs tracking which tasks end up running on which CPUs in
     different time intervals.

   - Add support for BPF trampoline on s390x and riscv64.

   - Add capability to export the XDP features supported by the NIC.

   - Add __bpf_kfunc tag for marking kernel functions as kfuncs.

   - Add cgroup.memory=nobpf kernel parameter option to disable BPF
     memory accounting for container environments.

  Netfilter:

   - Remove the CLUSTERIP target. It has been marked as obsolete for
     years, and we still have WARN splats wrt races of the out-of-band
     /proc interface installed by this target.

   - Add 'destroy' commands to nf_tables. They are identical to the
     existing 'delete' commands, but do not return an error if the
     referenced object (set, chain, rule...) did not exist.

  Driver API:

   - Improve cpumask_local_spread() locality to help NICs set the right
     IRQ affinity on AMD platforms.

   - Separate C22 and C45 MDIO bus transactions more clearly.

   - Introduce new DCB table to control DSCP rewrite on egress.

   - Support configuration of Physical Layer Collision Avoidance (PLCA)
     Reconciliation Sublayer (RS) (802.3cg-2019). Modern version of
     shared medium Ethernet.

   - Support for MAC Merge layer (IEEE 802.3-2018 clause 99). Allowing
     preemption of low priority frames by high priority frames.

   - Add support for controlling MACSec offload using netlink SET.

   - Rework devlink instance refcounts to allow registration and
     de-registration under the instance lock. Split the code into
     multiple files, drop some of the unnecessarily granular locks and
     factor out common parts of netlink operation handling.

   - Add TX frame aggregation parameters (for USB drivers).

   - Add a new attr TCA_EXT_WARN_MSG to report TC (offload) warning
     messages with notifications for debug.

   - Allow offloading of UDP NEW connections via act_ct.

   - Add support for per action HW stats in TC.

   - Support hardware miss to TC action (continue processing in SW from
     a specific point in the action chain).

   - Warn if old Wireless Extension user space interface is used with
     modern cfg80211/mac80211 drivers. Do not support Wireless
     Extensions for Wi-Fi 7 devices at all. Everyone should switch to
     using nl80211 interface instead.

   - Improve the CAN bit timing configuration. Use extack to return
     error messages directly to user space, update the SJW handling,
     including the definition of a new default value that will benefit
     CAN-FD controllers, by increasing their oscillator tolerance.

  New hardware / drivers:

   - Ethernet:
      - nVidia BlueField-3 support (control traffic driver)
      - Ethernet support for imx93 SoCs
      - Motorcomm yt8531 gigabit Ethernet PHY
      - onsemi NCN26000 10BASE-T1S PHY (with support for PLCA)
      - Microchip LAN8841 PHY (incl. cable diagnostics and PTP)
      - Amlogic gxl MDIO mux

   - WiFi:
      - RealTek RTL8188EU (rtl8xxxu)
      - Qualcomm Wi-Fi 7 devices (ath12k)

   - CAN:
      - Renesas R-Car V4H

  Drivers:

   - Bluetooth:
      - Set Per Platform Antenna Gain (PPAG) for Intel controllers.

   - Ethernet NICs:
      - Intel (1G, igc):
         - support TSN / Qbv / packet scheduling features of i226 model
      - Intel (100G, ice):
         - use GNSS subsystem instead of TTY
         - multi-buffer XDP support
         - extend support for GPIO pins to E823 devices
      - nVidia/Mellanox:
         - update the shared buffer configuration on PFC commands
         - implement PTP adjphase function for HW offset control
         - TC support for Geneve and GRE with VF tunnel offload
         - more efficient crypto key management method
         - multi-port eswitch support
      - Netronome/Corigine:
         - add DCB IEEE support
         - support IPsec offloading for NFP3800
      - Freescale/NXP (enetc):
         - support XDP_REDIRECT for XDP non-linear buffers
         - improve reconfig, avoid link flap and waiting for idle
         - support MAC Merge layer
      - Other NICs:
         - sfc/ef100: add basic devlink support for ef100
         - ionic: rx_push mode operation (writing descriptors via MMIO)
         - bnxt: use the auxiliary bus abstraction for RDMA
         - r8169: disable ASPM and reset bus in case of tx timeout
         - cpsw: support QSGMII mode for J721e CPSW9G
         - cpts: support pulse-per-second output
         - ngbe: add an mdio bus driver
         - usbnet: optimize usbnet_bh() by avoiding unnecessary queuing
         - r8152: handle devices with FW with NCM support
         - amd-xgbe: support 10Mbps, 2.5GbE speeds and rx-adaptation
         - virtio-net: support multi buffer XDP
         - virtio/vsock: replace virtio_vsock_pkt with sk_buff
         - tsnep: XDP support

   - Ethernet high-speed switches:
      - nVidia/Mellanox (mlxsw):
         - add support for latency TLV (in FW control messages)
      - Microchip (sparx5):
         - separate explicit and implicit traffic forwarding rules, make
           the implicit rules always active
         - add support for egress DSCP rewrite
         - IS0 VCAP support (Ingress Classification)
         - IS2 VCAP filters (protos, L3 addrs, L4 ports, flags, ToS
           etc.)
         - ES2 VCAP support (Egress Access Control)
         - support for Per-Stream Filtering and Policing (802.1Q,
           8.6.5.1)

   - Ethernet embedded switches:
      - Marvell (mv88e6xxx):
         - add MAB (port auth) offload support
         - enable PTP receive for mv88e6390
      - NXP (ocelot):
         - support MAC Merge layer
         - support for the the vsc7512 internal copper phys
      - Microchip:
         - lan9303: convert to PHYLINK
         - lan966x: support TC flower filter statistics
         - lan937x: PTP support for KSZ9563/KSZ8563 and LAN937x
         - lan937x: support Credit Based Shaper configuration
         - ksz9477: support Energy Efficient Ethernet
      - other:
         - qca8k: convert to regmap read/write API, use bulk operations
         - rswitch: Improve TX timestamp accuracy

   - Intel WiFi (iwlwifi):
      - EHT (Wi-Fi 7) rate reporting
      - STEP equalizer support: transfer some STEP (connection to radio
        on platforms with integrated wifi) related parameters from the
        BIOS to the firmware.

   - Qualcomm 802.11ax WiFi (ath11k):
      - IPQ5018 support
      - Fine Timing Measurement (FTM) responder role support
      - channel 177 support

   - MediaTek WiFi (mt76):
      - per-PHY LED support
      - mt7996: EHT (Wi-Fi 7) support
      - Wireless Ethernet Dispatch (WED) reset support
      - switch to using page pool allocator

   - RealTek WiFi (rtw89):
      - support new version of Bluetooth co-existance

   - Mobile:
      - rmnet: support TX aggregation"

* tag 'net-next-6.3' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next: (1872 commits)
  page_pool: add a comment explaining the fragment counter usage
  net: ethtool: fix __ethtool_dev_mm_supported() implementation
  ethtool: pse-pd: Fix double word in comments
  xsk: add linux/vmalloc.h to xsk.c
  sefltests: netdevsim: wait for devlink instance after netns removal
  selftest: fib_tests: Always cleanup before exit
  net/mlx5e: Align IPsec ASO result memory to be as required by hardware
  net/mlx5e: TC, Set CT miss to the specific ct action instance
  net/mlx5e: Rename CHAIN_TO_REG to MAPPED_OBJ_TO_REG
  net/mlx5: Refactor tc miss handling to a single function
  net/mlx5: Kconfig: Make tc offload depend on tc skb extension
  net/sched: flower: Support hardware miss to tc action
  net/sched: flower: Move filter handle initialization earlier
  net/sched: cls_api: Support hardware miss to tc action
  net/sched: Rename user cookie and act cookie
  sfc: fix builds without CONFIG_RTC_LIB
  sfc: clean up some inconsistent indentings
  net/mlx4_en: Introduce flexible array to silence overflow warning
  net: lan966x: Fix possible deadlock inside PTP
  net/ulp: Remove redundant ->clone() test in inet_clone_ulp().
  ...

1 files changed, 268 insertions, 0 deletions

diff --git a/Documentation/process/1.Intro.rst b/Documentation/process/1.Intro.rst
new file mode 100644
index 000000000..c3d0270bb
--- /dev/null
+++ b/Documentation/process/1.Intro.rst
@@ -0,0 +1,268 @@
+.. _development_process_intro:
+
+Introduction
+============
+
+Executive summary
+-----------------
+
+The rest of this section covers the scope of the kernel development process
+and the kinds of frustrations that developers and their employers can
+encounter there.  There are a great many reasons why kernel code should be
+merged into the official ("mainline") kernel, including automatic
+availability to users, community support in many forms, and the ability to
+influence the direction of kernel development.  Code contributed to the
+Linux kernel must be made available under a GPL-compatible license.
+
+:ref:`development_process` introduces the development process, the kernel
+release cycle, and the mechanics of the merge window.  The various phases in
+the patch development, review, and merging cycle are covered.  There is some
+discussion of tools and mailing lists.  Developers wanting to get started
+with kernel development are encouraged to track down and fix bugs as an
+initial exercise.
+
+:ref:`development_early_stage` covers early-stage project planning, with an
+emphasis on involving the development community as soon as possible.
+
+:ref:`development_coding` is about the coding process; several pitfalls which
+have been encountered by other developers are discussed.  Some requirements for
+patches are covered, and there is an introduction to some of the tools
+which can help to ensure that kernel patches are correct.
+
+:ref:`development_posting` talks about the process of posting patches for
+review. To be taken seriously by the development community, patches must be
+properly formatted and described, and they must be sent to the right place.
+Following the advice in this section should help to ensure the best
+possible reception for your work.
+
+:ref:`development_followthrough` covers what happens after posting patches; the
+job is far from done at that point.  Working with reviewers is a crucial part
+of the development process; this section offers a number of tips on how to
+avoid problems at this important stage.  Developers are cautioned against
+assuming that the job is done when a patch is merged into the mainline.
+
+:ref:`development_advancedtopics` introduces a couple of "advanced" topics:
+managing patches with git and reviewing patches posted by others.
+
+:ref:`development_conclusion` concludes the document with pointers to sources
+for more information on kernel development.
+
+What this document is about
+---------------------------
+
+The Linux kernel, at over 8 million lines of code and well over 1000
+contributors to each release, is one of the largest and most active free
+software projects in existence.  Since its humble beginning in 1991, this
+kernel has evolved into a best-of-breed operating system component which
+runs on pocket-sized digital music players, desktop PCs, the largest
+supercomputers in existence, and all types of systems in between.  It is a
+robust, efficient, and scalable solution for almost any situation.
+
+With the growth of Linux has come an increase in the number of developers
+(and companies) wishing to participate in its development.  Hardware
+vendors want to ensure that Linux supports their products well, making
+those products attractive to Linux users.  Embedded systems vendors, who
+use Linux as a component in an integrated product, want Linux to be as
+capable and well-suited to the task at hand as possible.  Distributors and
+other software vendors who base their products on Linux have a clear
+interest in the capabilities, performance, and reliability of the Linux
+kernel.  And end users, too, will often wish to change Linux to make it
+better suit their needs.
+
+One of the most compelling features of Linux is that it is accessible to
+these developers; anybody with the requisite skills can improve Linux and
+influence the direction of its development.  Proprietary products cannot
+offer this kind of openness, which is a characteristic of the free software
+process.  But, if anything, the kernel is even more open than most other
+free software projects.  A typical three-month kernel development cycle can
+involve over 1000 developers working for more than 100 different companies
+(or for no company at all).
+
+Working with the kernel development community is not especially hard.  But,
+that notwithstanding, many potential contributors have experienced
+difficulties when trying to do kernel work.  The kernel community has
+evolved its own distinct ways of operating which allow it to function
+smoothly (and produce a high-quality product) in an environment where
+thousands of lines of code are being changed every day.  So it is not
+surprising that Linux kernel development process differs greatly from
+proprietary development methods.
+
+The kernel's development process may come across as strange and
+intimidating to new developers, but there are good reasons and solid
+experience behind it.  A developer who does not understand the kernel
+community's ways (or, worse, who tries to flout or circumvent them) will
+have a frustrating experience in store.  The development community, while
+being helpful to those who are trying to learn, has little time for those
+who will not listen or who do not care about the development process.
+
+It is hoped that those who read this document will be able to avoid that
+frustrating experience.  There is a lot of material here, but the effort
+involved in reading it will be repaid in short order.  The development
+community is always in need of developers who will help to make the kernel
+better; the following text should help you - or those who work for you -
+join our community.
+
+Credits
+-------
+
+This document was written by Jonathan Corbet, corbet@lwn.net.  It has been
+improved by comments from Johannes Berg, James Berry, Alex Chiang, Roland
+Dreier, Randy Dunlap, Jake Edge, Jiri Kosina, Matt Mackall, Arthur Marsh,
+Amanda McPherson, Andrew Morton, Andrew Price, Tsugikazu Shibata, and
+Jochen Voß.
+
+This work was supported by the Linux Foundation; thanks especially to
+Amanda McPherson, who saw the value of this effort and made it all happen.
+
+The importance of getting code into the mainline
+------------------------------------------------
+
+Some companies and developers occasionally wonder why they should bother
+learning how to work with the kernel community and get their code into the
+mainline kernel (the "mainline" being the kernel maintained by Linus
+Torvalds and used as a base by Linux distributors).  In the short term,
+contributing code can look like an avoidable expense; it seems easier to
+just keep the code separate and support users directly.  The truth of the
+matter is that keeping code separate ("out of tree") is a false economy.
+
+As a way of illustrating the costs of out-of-tree code, here are a few
+relevant aspects of the kernel development process; most of these will be
+discussed in greater detail later in this document.  Consider:
+
+- Code which has been merged into the mainline kernel is available to all
+  Linux users.  It will automatically be present on all distributions which
+  enable it.  There is no need for driver disks, downloads, or the hassles
+  of supporting multiple versions of multiple distributions; it all just
+  works, for the developer and for the user.  Incorporation into the
+  mainline solves a large number of distribution and support problems.
+
+- While kernel developers strive to maintain a stable interface to user
+  space, the internal kernel API is in constant flux.  The lack of a stable
+  internal interface is a deliberate design decision; it allows fundamental
+  improvements to be made at any time and results in higher-quality code.
+  But one result of that policy is that any out-of-tree code requires
+  constant upkeep if it is to work with new kernels.  Maintaining
+  out-of-tree code requires significant amounts of work just to keep that
+  code working.
+
+  Code which is in the mainline, instead, does not require this work as the
+  result of a simple rule requiring any developer who makes an API change
+  to also fix any code that breaks as the result of that change.  So code
+  which has been merged into the mainline has significantly lower
+  maintenance costs.
+
+- Beyond that, code which is in the kernel will often be improved by other
+  developers.  Surprising results can come from empowering your user
+  community and customers to improve your product.
+
+- Kernel code is subjected to review, both before and after merging into
+  the mainline.  No matter how strong the original developer's skills are,
+  this review process invariably finds ways in which the code can be
+  improved.  Often review finds severe bugs and security problems.  This is
+  especially true for code which has been developed in a closed
+  environment; such code benefits strongly from review by outside
+  developers.  Out-of-tree code is lower-quality code.
+
+- Participation in the development process is your way to influence the
+  direction of kernel development.  Users who complain from the sidelines
+  are heard, but active developers have a stronger voice - and the ability
+  to implement changes which make the kernel work better for their needs.
+
+- When code is maintained separately, the possibility that a third party
+  will contribute a different implementation of a similar feature always
+  exists.  Should that happen, getting your code merged will become much
+  harder - to the point of impossibility.  Then you will be faced with the
+  unpleasant alternatives of either (1) maintaining a nonstandard feature
+  out of tree indefinitely, or (2) abandoning your code and migrating your
+  users over to the in-tree version.
+
+- Contribution of code is the fundamental action which makes the whole
+  process work.  By contributing your code you can add new functionality to
+  the kernel and provide capabilities and examples which are of use to
+  other kernel developers.  If you have developed code for Linux (or are
+  thinking about doing so), you clearly have an interest in the continued
+  success of this platform; contributing code is one of the best ways to
+  help ensure that success.
+
+All of the reasoning above applies to any out-of-tree kernel code,
+including code which is distributed in proprietary, binary-only form.
+There are, however, additional factors which should be taken into account
+before considering any sort of binary-only kernel code distribution.  These
+include:
+
+- The legal issues around the distribution of proprietary kernel modules
+  are cloudy at best; quite a few kernel copyright holders believe that
+  most binary-only modules are derived products of the kernel and that, as
+  a result, their distribution is a violation of the GNU General Public
+  license (about which more will be said below).  Your author is not a
+  lawyer, and nothing in this document can possibly be considered to be
+  legal advice.  The true legal status of closed-source modules can only be
+  determined by the courts.  But the uncertainty which haunts those modules
+  is there regardless.
+
+- Binary modules greatly increase the difficulty of debugging kernel
+  problems, to the point that most kernel developers will not even try.  So
+  the distribution of binary-only modules will make it harder for your
+  users to get support from the community.
+
+- Support is also harder for distributors of binary-only modules, who must
+  provide a version of the module for every distribution and every kernel
+  version they wish to support.  Dozens of builds of a single module can
+  be required to provide reasonably comprehensive coverage, and your users
+  will have to upgrade your module separately every time they upgrade their
+  kernel.
+
+- Everything that was said above about code review applies doubly to
+  closed-source code.  Since this code is not available at all, it cannot
+  have been reviewed by the community and will, beyond doubt, have serious
+  problems.
+
+Makers of embedded systems, in particular, may be tempted to disregard much
+of what has been said in this section in the belief that they are shipping
+a self-contained product which uses a frozen kernel version and requires no
+more development after its release.  This argument misses the value of
+widespread code review and the value of allowing your users to add
+capabilities to your product.  But these products, too, have a limited
+commercial life, after which a new version must be released.  At that
+point, vendors whose code is in the mainline and well maintained will be
+much better positioned to get the new product ready for market quickly.
+
+Licensing
+---------
+
+Code is contributed to the Linux kernel under a number of licenses, but all
+code must be compatible with version 2 of the GNU General Public License
+(GPLv2), which is the license covering the kernel distribution as a whole.
+In practice, that means that all code contributions are covered either by
+GPLv2 (with, optionally, language allowing distribution under later
+versions of the GPL) or the three-clause BSD license.  Any contributions
+which are not covered by a compatible license will not be accepted into the
+kernel.
+
+Copyright assignments are not required (or requested) for code contributed
+to the kernel.  All code merged into the mainline kernel retains its
+original ownership; as a result, the kernel now has thousands of owners.
+
+One implication of this ownership structure is that any attempt to change
+the licensing of the kernel is doomed to almost certain failure.  There are
+few practical scenarios where the agreement of all copyright holders could
+be obtained (or their code removed from the kernel).  So, in particular,
+there is no prospect of a migration to version 3 of the GPL in the
+foreseeable future.
+
+It is imperative that all code contributed to the kernel be legitimately
+free software.  For that reason, code from anonymous (or pseudonymous)
+contributors will not be accepted.  All contributors are required to "sign
+off" on their code, stating that the code can be distributed with the
+kernel under the GPL.  Code which has not been licensed as free software by
+its owner, or which risks creating copyright-related problems for the
+kernel (such as code which derives from reverse-engineering efforts lacking
+proper safeguards) cannot be contributed.
+
+Questions about copyright-related issues are common on Linux development
+mailing lists.  Such questions will normally receive no shortage of
+answers, but one should bear in mind that the people answering those
+questions are not lawyers and cannot provide legal advice.  If you have
+legal questions relating to Linux source code, there is no substitute for
+talking with a lawyer who understands this field.  Relying on answers
+obtained on technical mailing lists is a risky affair.