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, 178 insertions, 0 deletions

diff --git a/Documentation/timers/hrtimers.rst b/Documentation/timers/hrtimers.rst
new file mode 100644
index 000000000..7ac448908
--- /dev/null
+++ b/Documentation/timers/hrtimers.rst
@@ -0,0 +1,178 @@
+======================================================
+hrtimers - subsystem for high-resolution kernel timers
+======================================================
+
+This patch introduces a new subsystem for high-resolution kernel timers.
+
+One might ask the question: we already have a timer subsystem
+(kernel/timers.c), why do we need two timer subsystems? After a lot of
+back and forth trying to integrate high-resolution and high-precision
+features into the existing timer framework, and after testing various
+such high-resolution timer implementations in practice, we came to the
+conclusion that the timer wheel code is fundamentally not suitable for
+such an approach. We initially didn't believe this ('there must be a way
+to solve this'), and spent a considerable effort trying to integrate
+things into the timer wheel, but we failed. In hindsight, there are
+several reasons why such integration is hard/impossible:
+
+- the forced handling of low-resolution and high-resolution timers in
+  the same way leads to a lot of compromises, macro magic and #ifdef
+  mess. The timers.c code is very "tightly coded" around jiffies and
+  32-bitness assumptions, and has been honed and micro-optimized for a
+  relatively narrow use case (jiffies in a relatively narrow HZ range)
+  for many years - and thus even small extensions to it easily break
+  the wheel concept, leading to even worse compromises. The timer wheel
+  code is very good and tight code, there's zero problems with it in its
+  current usage - but it is simply not suitable to be extended for
+  high-res timers.
+
+- the unpredictable [O(N)] overhead of cascading leads to delays which
+  necessitate a more complex handling of high resolution timers, which
+  in turn decreases robustness. Such a design still leads to rather large
+  timing inaccuracies. Cascading is a fundamental property of the timer
+  wheel concept, it cannot be 'designed out' without inevitably
+  degrading other portions of the timers.c code in an unacceptable way.
+
+- the implementation of the current posix-timer subsystem on top of
+  the timer wheel has already introduced a quite complex handling of
+  the required readjusting of absolute CLOCK_REALTIME timers at
+  settimeofday or NTP time - further underlying our experience by
+  example: that the timer wheel data structure is too rigid for high-res
+  timers.
+
+- the timer wheel code is most optimal for use cases which can be
+  identified as "timeouts". Such timeouts are usually set up to cover
+  error conditions in various I/O paths, such as networking and block
+  I/O. The vast majority of those timers never expire and are rarely
+  recascaded because the expected correct event arrives in time so they
+  can be removed from the timer wheel before any further processing of
+  them becomes necessary. Thus the users of these timeouts can accept
+  the granularity and precision tradeoffs of the timer wheel, and
+  largely expect the timer subsystem to have near-zero overhead.
+  Accurate timing for them is not a core purpose - in fact most of the
+  timeout values used are ad-hoc. For them it is at most a necessary
+  evil to guarantee the processing of actual timeout completions
+  (because most of the timeouts are deleted before completion), which
+  should thus be as cheap and unintrusive as possible.
+
+The primary users of precision timers are user-space applications that
+utilize nanosleep, posix-timers and itimer interfaces. Also, in-kernel
+users like drivers and subsystems which require precise timed events
+(e.g. multimedia) can benefit from the availability of a separate
+high-resolution timer subsystem as well.
+
+While this subsystem does not offer high-resolution clock sources just
+yet, the hrtimer subsystem can be easily extended with high-resolution
+clock capabilities, and patches for that exist and are maturing quickly.
+The increasing demand for realtime and multimedia applications along
+with other potential users for precise timers gives another reason to
+separate the "timeout" and "precise timer" subsystems.
+
+Another potential benefit is that such a separation allows even more
+special-purpose optimization of the existing timer wheel for the low
+resolution and low precision use cases - once the precision-sensitive
+APIs are separated from the timer wheel and are migrated over to
+hrtimers. E.g. we could decrease the frequency of the timeout subsystem
+from 250 Hz to 100 HZ (or even smaller).
+
+hrtimer subsystem implementation details
+----------------------------------------
+
+the basic design considerations were:
+
+- simplicity
+
+- data structure not bound to jiffies or any other granularity. All the
+  kernel logic works at 64-bit nanoseconds resolution - no compromises.
+
+- simplification of existing, timing related kernel code
+
+another basic requirement was the immediate enqueueing and ordering of
+timers at activation time. After looking at several possible solutions
+such as radix trees and hashes, we chose the red black tree as the basic
+data structure. Rbtrees are available as a library in the kernel and are
+used in various performance-critical areas of e.g. memory management and
+file systems. The rbtree is solely used for time sorted ordering, while
+a separate list is used to give the expiry code fast access to the
+queued timers, without having to walk the rbtree.
+
+(This separate list is also useful for later when we'll introduce
+high-resolution clocks, where we need separate pending and expired
+queues while keeping the time-order intact.)
+
+Time-ordered enqueueing is not purely for the purposes of
+high-resolution clocks though, it also simplifies the handling of
+absolute timers based on a low-resolution CLOCK_REALTIME. The existing
+implementation needed to keep an extra list of all armed absolute
+CLOCK_REALTIME timers along with complex locking. In case of
+settimeofday and NTP, all the timers (!) had to be dequeued, the
+time-changing code had to fix them up one by one, and all of them had to
+be enqueued again. The time-ordered enqueueing and the storage of the
+expiry time in absolute time units removes all this complex and poorly
+scaling code from the posix-timer implementation - the clock can simply
+be set without having to touch the rbtree. This also makes the handling
+of posix-timers simpler in general.
+
+The locking and per-CPU behavior of hrtimers was mostly taken from the
+existing timer wheel code, as it is mature and well suited. Sharing code
+was not really a win, due to the different data structures. Also, the
+hrtimer functions now have clearer behavior and clearer names - such as
+hrtimer_try_to_cancel() and hrtimer_cancel() [which are roughly
+equivalent to timer_delete() and timer_delete_sync()] - so there's no direct
+1:1 mapping between them on the algorithmic level, and thus no real
+potential for code sharing either.
+
+Basic data types: every time value, absolute or relative, is in a
+special nanosecond-resolution type: ktime_t. The kernel-internal
+representation of ktime_t values and operations is implemented via
+macros and inline functions, and can be switched between a "hybrid
+union" type and a plain "scalar" 64bit nanoseconds representation (at
+compile time). The hybrid union type optimizes time conversions on 32bit
+CPUs. This build-time-selectable ktime_t storage format was implemented
+to avoid the performance impact of 64-bit multiplications and divisions
+on 32bit CPUs. Such operations are frequently necessary to convert
+between the storage formats provided by kernel and userspace interfaces
+and the internal time format. (See include/linux/ktime.h for further
+details.)
+
+hrtimers - rounding of timer values
+-----------------------------------
+
+the hrtimer code will round timer events to lower-resolution clocks
+because it has to. Otherwise it will do no artificial rounding at all.
+
+one question is, what resolution value should be returned to the user by
+the clock_getres() interface. This will return whatever real resolution
+a given clock has - be it low-res, high-res, or artificially-low-res.
+
+hrtimers - testing and verification
+-----------------------------------
+
+We used the high-resolution clock subsystem ontop of hrtimers to verify
+the hrtimer implementation details in praxis, and we also ran the posix
+timer tests in order to ensure specification compliance. We also ran
+tests on low-resolution clocks.
+
+The hrtimer patch converts the following kernel functionality to use
+hrtimers:
+
+ - nanosleep
+ - itimers
+ - posix-timers
+
+The conversion of nanosleep and posix-timers enabled the unification of
+nanosleep and clock_nanosleep.
+
+The code was successfully compiled for the following platforms:
+
+ i386, x86_64, ARM, PPC, PPC64, IA64
+
+The code was run-tested on the following platforms:
+
+ i386(UP/SMP), x86_64(UP/SMP), ARM, PPC
+
+hrtimers were also integrated into the -rt tree, along with a
+hrtimers-based high-resolution clock implementation, so the hrtimers
+code got a healthy amount of testing and use in practice.
+
+	Thomas Gleixner, Ingo Molnar