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, 223 insertions, 0 deletions

diff --git a/Documentation/process/3.Early-stage.rst b/Documentation/process/3.Early-stage.rst
new file mode 100644
index 000000000..894a92004
--- /dev/null
+++ b/Documentation/process/3.Early-stage.rst
@@ -0,0 +1,223 @@
+.. _development_early_stage:
+
+Early-stage planning
+====================
+
+When contemplating a Linux kernel development project, it can be tempting
+to jump right in and start coding.  As with any significant project,
+though, much of the groundwork for success is best laid before the first
+line of code is written.  Some time spent in early planning and
+communication can save far more time later on.
+
+
+Specifying the problem
+----------------------
+
+Like any engineering project, a successful kernel enhancement starts with a
+clear description of the problem to be solved.  In some cases, this step is
+easy: when a driver is needed for a specific piece of hardware, for
+example.  In others, though, it is tempting to confuse the real problem
+with the proposed solution, and that can lead to difficulties.
+
+Consider an example: some years ago, developers working with Linux audio
+sought a way to run applications without dropouts or other artifacts caused
+by excessive latency in the system.  The solution they arrived at was a
+kernel module intended to hook into the Linux Security Module (LSM)
+framework; this module could be configured to give specific applications
+access to the realtime scheduler.  This module was implemented and sent to
+the linux-kernel mailing list, where it immediately ran into problems.
+
+To the audio developers, this security module was sufficient to solve their
+immediate problem.  To the wider kernel community, though, it was seen as a
+misuse of the LSM framework (which is not intended to confer privileges
+onto processes which they would not otherwise have) and a risk to system
+stability.  Their preferred solutions involved realtime scheduling access
+via the rlimit mechanism for the short term, and ongoing latency reduction
+work in the long term.
+
+The audio community, however, could not see past the particular solution
+they had implemented; they were unwilling to accept alternatives.  The
+resulting disagreement left those developers feeling disillusioned with the
+entire kernel development process; one of them went back to an audio list
+and posted this:
+
+	There are a number of very good Linux kernel developers, but they
+	tend to get outshouted by a large crowd of arrogant fools. Trying
+	to communicate user requirements to these people is a waste of
+	time. They are much too "intelligent" to listen to lesser mortals.
+
+(https://lwn.net/Articles/131776/).
+
+The reality of the situation was different; the kernel developers were far
+more concerned about system stability, long-term maintenance, and finding
+the right solution to the problem than they were with a specific module.
+The moral of the story is to focus on the problem - not a specific solution
+- and to discuss it with the development community before investing in the
+creation of a body of code.
+
+So, when contemplating a kernel development project, one should obtain
+answers to a short set of questions:
+
+ - What, exactly, is the problem which needs to be solved?
+
+ - Who are the users affected by this problem?  Which use cases should the
+   solution address?
+
+ - How does the kernel fall short in addressing that problem now?
+
+Only then does it make sense to start considering possible solutions.
+
+
+Early discussion
+----------------
+
+When planning a kernel development project, it makes great sense to hold
+discussions with the community before launching into implementation.  Early
+communication can save time and trouble in a number of ways:
+
+ - It may well be that the problem is addressed by the kernel in ways which
+   you have not understood.  The Linux kernel is large and has a number of
+   features and capabilities which are not immediately obvious.  Not all
+   kernel capabilities are documented as well as one might like, and it is
+   easy to miss things.  Your author has seen the posting of a complete
+   driver which duplicated an existing driver that the new author had been
+   unaware of.  Code which reinvents existing wheels is not only wasteful;
+   it will also not be accepted into the mainline kernel.
+
+ - There may be elements of the proposed solution which will not be
+   acceptable for mainline merging.  It is better to find out about
+   problems like this before writing the code.
+
+ - It's entirely possible that other developers have thought about the
+   problem; they may have ideas for a better solution, and may be willing
+   to help in the creation of that solution.
+
+Years of experience with the kernel development community have taught a
+clear lesson: kernel code which is designed and developed behind closed
+doors invariably has problems which are only revealed when the code is
+released into the community.  Sometimes these problems are severe,
+requiring months or years of effort before the code can be brought up to
+the kernel community's standards.  Some examples include:
+
+ - The Devicescape network stack was designed and implemented for
+   single-processor systems.  It could not be merged into the mainline
+   until it was made suitable for multiprocessor systems.  Retrofitting
+   locking and such into code is a difficult task; as a result, the merging
+   of this code (now called mac80211) was delayed for over a year.
+
+ - The Reiser4 filesystem included a number of capabilities which, in the
+   core kernel developers' opinion, should have been implemented in the
+   virtual filesystem layer instead.  It also included features which could
+   not easily be implemented without exposing the system to user-caused
+   deadlocks.  The late revelation of these problems - and refusal to
+   address some of them - has caused Reiser4 to stay out of the mainline
+   kernel.
+
+ - The AppArmor security module made use of internal virtual filesystem
+   data structures in ways which were considered to be unsafe and
+   unreliable.  This concern (among others) kept AppArmor out of the
+   mainline for years.
+
+In each of these cases, a great deal of pain and extra work could have been
+avoided with some early discussion with the kernel developers.
+
+
+Who do you talk to?
+-------------------
+
+When developers decide to take their plans public, the next question will
+be: where do we start?  The answer is to find the right mailing list(s) and
+the right maintainer.  For mailing lists, the best approach is to look in
+the MAINTAINERS file for a relevant place to post.  If there is a suitable
+subsystem list, posting there is often preferable to posting on
+linux-kernel; you are more likely to reach developers with expertise in the
+relevant subsystem and the environment may be more supportive.
+
+Finding maintainers can be a bit harder.  Again, the MAINTAINERS file is
+the place to start.  That file tends to not always be up to date, though,
+and not all subsystems are represented there.  The person listed in the
+MAINTAINERS file may, in fact, not be the person who is actually acting in
+that role currently.  So, when there is doubt about who to contact, a
+useful trick is to use git (and "git log" in particular) to see who is
+currently active within the subsystem of interest.  Look at who is writing
+patches, and who, if anybody, is attaching Signed-off-by lines to those
+patches.  Those are the people who will be best placed to help with a new
+development project.
+
+The task of finding the right maintainer is sometimes challenging enough
+that the kernel developers have added a script to ease the process:
+
+::
+
+	.../scripts/get_maintainer.pl
+
+This script will return the current maintainer(s) for a given file or
+directory when given the "-f" option.  If passed a patch on the
+command line, it will list the maintainers who should probably receive
+copies of the patch.  This is the preferred way (unlike "-f" option) to get the
+list of people to Cc for your patches.  There are a number of options
+regulating how hard get_maintainer.pl will search for maintainers; please be
+careful about using the more aggressive options as you may end up including
+developers who have no real interest in the code you are modifying.
+
+If all else fails, talking to Andrew Morton can be an effective way to
+track down a maintainer for a specific piece of code.
+
+
+When to post?
+-------------
+
+If possible, posting your plans during the early stages can only be
+helpful.  Describe the problem being solved and any plans that have been
+made on how the implementation will be done.  Any information you can
+provide can help the development community provide useful input on the
+project.
+
+One discouraging thing which can happen at this stage is not a hostile
+reaction, but, instead, little or no reaction at all.  The sad truth of the
+matter is (1) kernel developers tend to be busy, (2) there is no shortage
+of people with grand plans and little code (or even prospect of code) to
+back them up, and (3) nobody is obligated to review or comment on ideas
+posted by others.  Beyond that, high-level designs often hide problems
+which are only revealed when somebody actually tries to implement those
+designs; for that reason, kernel developers would rather see the code.
+
+If a request-for-comments posting yields little in the way of comments, do
+not assume that it means there is no interest in the project.
+Unfortunately, you also cannot assume that there are no problems with your
+idea.  The best thing to do in this situation is to proceed, keeping the
+community informed as you go.
+
+
+Getting official buy-in
+-----------------------
+
+If your work is being done in a corporate environment - as most Linux
+kernel work is - you must, obviously, have permission from suitably
+empowered managers before you can post your company's plans or code to a
+public mailing list.  The posting of code which has not been cleared for
+release under a GPL-compatible license can be especially problematic; the
+sooner that a company's management and legal staff can agree on the posting
+of a kernel development project, the better off everybody involved will be.
+
+Some readers may be thinking at this point that their kernel work is
+intended to support a product which does not yet have an officially
+acknowledged existence.  Revealing their employer's plans on a public
+mailing list may not be a viable option.  In cases like this, it is worth
+considering whether the secrecy is really necessary; there is often no real
+need to keep development plans behind closed doors.
+
+That said, there are also cases where a company legitimately cannot
+disclose its plans early in the development process.  Companies with
+experienced kernel developers may choose to proceed in an open-loop manner
+on the assumption that they will be able to avoid serious integration
+problems later.  For companies without that sort of in-house expertise, the
+best option is often to hire an outside developer to review the plans under
+a non-disclosure agreement.  The Linux Foundation operates an NDA program
+designed to help with this sort of situation; more information can be found
+at:
+
+    https://www.linuxfoundation.org/nda/
+
+This kind of review is often enough to avoid serious problems later on
+without requiring public disclosure of the project.