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, 155 insertions, 0 deletions

diff --git a/Documentation/arm64/asymmetric-32bit.rst b/Documentation/arm64/asymmetric-32bit.rst
new file mode 100644
index 000000000..64a0b505d
--- /dev/null
+++ b/Documentation/arm64/asymmetric-32bit.rst
@@ -0,0 +1,155 @@
+======================
+Asymmetric 32-bit SoCs
+======================
+
+Author: Will Deacon <will@kernel.org>
+
+This document describes the impact of asymmetric 32-bit SoCs on the
+execution of 32-bit (``AArch32``) applications.
+
+Date: 2021-05-17
+
+Introduction
+============
+
+Some Armv9 SoCs suffer from a big.LITTLE misfeature where only a subset
+of the CPUs are capable of executing 32-bit user applications. On such
+a system, Linux by default treats the asymmetry as a "mismatch" and
+disables support for both the ``PER_LINUX32`` personality and
+``execve(2)`` of 32-bit ELF binaries, with the latter returning
+``-ENOEXEC``. If the mismatch is detected during late onlining of a
+64-bit-only CPU, then the onlining operation fails and the new CPU is
+unavailable for scheduling.
+
+Surprisingly, these SoCs have been produced with the intention of
+running legacy 32-bit binaries. Unsurprisingly, that doesn't work very
+well with the default behaviour of Linux.
+
+It seems inevitable that future SoCs will drop 32-bit support
+altogether, so if you're stuck in the unenviable position of needing to
+run 32-bit code on one of these transitionary platforms then you would
+be wise to consider alternatives such as recompilation, emulation or
+retirement. If neither of those options are practical, then read on.
+
+Enabling kernel support
+=======================
+
+Since the kernel support is not completely transparent to userspace,
+allowing 32-bit tasks to run on an asymmetric 32-bit system requires an
+explicit "opt-in" and can be enabled by passing the
+``allow_mismatched_32bit_el0`` parameter on the kernel command-line.
+
+For the remainder of this document we will refer to an *asymmetric
+system* to mean an asymmetric 32-bit SoC running Linux with this kernel
+command-line option enabled.
+
+Userspace impact
+================
+
+32-bit tasks running on an asymmetric system behave in mostly the same
+way as on a homogeneous system, with a few key differences relating to
+CPU affinity.
+
+sysfs
+-----
+
+The subset of CPUs capable of running 32-bit tasks is described in
+``/sys/devices/system/cpu/aarch32_el0`` and is documented further in
+``Documentation/ABI/testing/sysfs-devices-system-cpu``.
+
+**Note:** CPUs are advertised by this file as they are detected and so
+late-onlining of 32-bit-capable CPUs can result in the file contents
+being modified by the kernel at runtime. Once advertised, CPUs are never
+removed from the file.
+
+``execve(2)``
+-------------
+
+On a homogeneous system, the CPU affinity of a task is preserved across
+``execve(2)``. This is not always possible on an asymmetric system,
+specifically when the new program being executed is 32-bit yet the
+affinity mask contains 64-bit-only CPUs. In this situation, the kernel
+determines the new affinity mask as follows:
+
+  1. If the 32-bit-capable subset of the affinity mask is not empty,
+     then the affinity is restricted to that subset and the old affinity
+     mask is saved. This saved mask is inherited over ``fork(2)`` and
+     preserved across ``execve(2)`` of 32-bit programs.
+
+     **Note:** This step does not apply to ``SCHED_DEADLINE`` tasks.
+     See `SCHED_DEADLINE`_.
+
+  2. Otherwise, the cpuset hierarchy of the task is walked until an
+     ancestor is found containing at least one 32-bit-capable CPU. The
+     affinity of the task is then changed to match the 32-bit-capable
+     subset of the cpuset determined by the walk.
+
+  3. On failure (i.e. out of memory), the affinity is changed to the set
+     of all 32-bit-capable CPUs of which the kernel is aware.
+
+A subsequent ``execve(2)`` of a 64-bit program by the 32-bit task will
+invalidate the affinity mask saved in (1) and attempt to restore the CPU
+affinity of the task using the saved mask if it was previously valid.
+This restoration may fail due to intervening changes to the deadline
+policy or cpuset hierarchy, in which case the ``execve(2)`` continues
+with the affinity unchanged.
+
+Calls to ``sched_setaffinity(2)`` for a 32-bit task will consider only
+the 32-bit-capable CPUs of the requested affinity mask. On success, the
+affinity for the task is updated and any saved mask from a prior
+``execve(2)`` is invalidated.
+
+``SCHED_DEADLINE``
+------------------
+
+Explicit admission of a 32-bit deadline task to the default root domain
+(e.g. by calling ``sched_setattr(2)``) is rejected on an asymmetric
+32-bit system unless admission control is disabled by writing -1 to
+``/proc/sys/kernel/sched_rt_runtime_us``.
+
+``execve(2)`` of a 32-bit program from a 64-bit deadline task will
+return ``-ENOEXEC`` if the root domain for the task contains any
+64-bit-only CPUs and admission control is enabled. Concurrent offlining
+of 32-bit-capable CPUs may still necessitate the procedure described in
+`execve(2)`_, in which case step (1) is skipped and a warning is
+emitted on the console.
+
+**Note:** It is recommended that a set of 32-bit-capable CPUs are placed
+into a separate root domain if ``SCHED_DEADLINE`` is to be used with
+32-bit tasks on an asymmetric system. Failure to do so is likely to
+result in missed deadlines.
+
+Cpusets
+-------
+
+The affinity of a 32-bit task on an asymmetric system may include CPUs
+that are not explicitly allowed by the cpuset to which it is attached.
+This can occur as a result of the following two situations:
+
+  - A 64-bit task attached to a cpuset which allows only 64-bit CPUs
+    executes a 32-bit program.
+
+  - All of the 32-bit-capable CPUs allowed by a cpuset containing a
+    32-bit task are offlined.
+
+In both of these cases, the new affinity is calculated according to step
+(2) of the process described in `execve(2)`_ and the cpuset hierarchy is
+unchanged irrespective of the cgroup version.
+
+CPU hotplug
+-----------
+
+On an asymmetric system, the first detected 32-bit-capable CPU is
+prevented from being offlined by userspace and any such attempt will
+return ``-EPERM``. Note that suspend is still permitted even if the
+primary CPU (i.e. CPU 0) is 64-bit-only.
+
+KVM
+---
+
+Although KVM will not advertise 32-bit EL0 support to any vCPUs on an
+asymmetric system, a broken guest at EL1 could still attempt to execute
+32-bit code at EL0. In this case, an exit from a vCPU thread in 32-bit
+mode will return to host userspace with an ``exit_reason`` of
+``KVM_EXIT_FAIL_ENTRY`` and will remain non-runnable until successfully
+re-initialised by a subsequent ``KVM_ARM_VCPU_INIT`` operation.