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, 198 insertions, 0 deletions

diff --git a/Documentation/ia64/mca.rst b/Documentation/ia64/mca.rst
new file mode 100644
index 000000000..08270bba4
--- /dev/null
+++ b/Documentation/ia64/mca.rst
@@ -0,0 +1,198 @@
+=============================================================
+An ad-hoc collection of notes on IA64 MCA and INIT processing
+=============================================================
+
+Feel free to update it with notes about any area that is not clear.
+
+---
+
+MCA/INIT are completely asynchronous.  They can occur at any time, when
+the OS is in any state.  Including when one of the cpus is already
+holding a spinlock.  Trying to get any lock from MCA/INIT state is
+asking for deadlock.  Also the state of structures that are protected
+by locks is indeterminate, including linked lists.
+
+---
+
+The complicated ia64 MCA process.  All of this is mandated by Intel's
+specification for ia64 SAL, error recovery and unwind, it is not as
+if we have a choice here.
+
+* MCA occurs on one cpu, usually due to a double bit memory error.
+  This is the monarch cpu.
+
+* SAL sends an MCA rendezvous interrupt (which is a normal interrupt)
+  to all the other cpus, the slaves.
+
+* Slave cpus that receive the MCA interrupt call down into SAL, they
+  end up spinning disabled while the MCA is being serviced.
+
+* If any slave cpu was already spinning disabled when the MCA occurred
+  then it cannot service the MCA interrupt.  SAL waits ~20 seconds then
+  sends an unmaskable INIT event to the slave cpus that have not
+  already rendezvoused.
+
+* Because MCA/INIT can be delivered at any time, including when the cpu
+  is down in PAL in physical mode, the registers at the time of the
+  event are _completely_ undefined.  In particular the MCA/INIT
+  handlers cannot rely on the thread pointer, PAL physical mode can
+  (and does) modify TP.  It is allowed to do that as long as it resets
+  TP on return.  However MCA/INIT events expose us to these PAL
+  internal TP changes.  Hence curr_task().
+
+* If an MCA/INIT event occurs while the kernel was running (not user
+  space) and the kernel has called PAL then the MCA/INIT handler cannot
+  assume that the kernel stack is in a fit state to be used.  Mainly
+  because PAL may or may not maintain the stack pointer internally.
+  Because the MCA/INIT handlers cannot trust the kernel stack, they
+  have to use their own, per-cpu stacks.  The MCA/INIT stacks are
+  preformatted with just enough task state to let the relevant handlers
+  do their job.
+
+* Unlike most other architectures, the ia64 struct task is embedded in
+  the kernel stack[1].  So switching to a new kernel stack means that
+  we switch to a new task as well.  Because various bits of the kernel
+  assume that current points into the struct task, switching to a new
+  stack also means a new value for current.
+
+* Once all slaves have rendezvoused and are spinning disabled, the
+  monarch is entered.  The monarch now tries to diagnose the problem
+  and decide if it can recover or not.
+
+* Part of the monarch's job is to look at the state of all the other
+  tasks.  The only way to do that on ia64 is to call the unwinder,
+  as mandated by Intel.
+
+* The starting point for the unwind depends on whether a task is
+  running or not.  That is, whether it is on a cpu or is blocked.  The
+  monarch has to determine whether or not a task is on a cpu before it
+  knows how to start unwinding it.  The tasks that received an MCA or
+  INIT event are no longer running, they have been converted to blocked
+  tasks.  But (and its a big but), the cpus that received the MCA
+  rendezvous interrupt are still running on their normal kernel stacks!
+
+* To distinguish between these two cases, the monarch must know which
+  tasks are on a cpu and which are not.  Hence each slave cpu that
+  switches to an MCA/INIT stack, registers its new stack using
+  set_curr_task(), so the monarch can tell that the _original_ task is
+  no longer running on that cpu.  That gives us a decent chance of
+  getting a valid backtrace of the _original_ task.
+
+* MCA/INIT can be nested, to a depth of 2 on any cpu.  In the case of a
+  nested error, we want diagnostics on the MCA/INIT handler that
+  failed, not on the task that was originally running.  Again this
+  requires set_curr_task() so the MCA/INIT handlers can register their
+  own stack as running on that cpu.  Then a recursive error gets a
+  trace of the failing handler's "task".
+
+[1]
+    My (Keith Owens) original design called for ia64 to separate its
+    struct task and the kernel stacks.  Then the MCA/INIT data would be
+    chained stacks like i386 interrupt stacks.  But that required
+    radical surgery on the rest of ia64, plus extra hard wired TLB
+    entries with its associated performance degradation.  David
+    Mosberger vetoed that approach.  Which meant that separate kernel
+    stacks meant separate "tasks" for the MCA/INIT handlers.
+
+---
+
+INIT is less complicated than MCA.  Pressing the nmi button or using
+the equivalent command on the management console sends INIT to all
+cpus.  SAL picks one of the cpus as the monarch and the rest are
+slaves.  All the OS INIT handlers are entered at approximately the same
+time.  The OS monarch prints the state of all tasks and returns, after
+which the slaves return and the system resumes.
+
+At least that is what is supposed to happen.  Alas there are broken
+versions of SAL out there.  Some drive all the cpus as monarchs.  Some
+drive them all as slaves.  Some drive one cpu as monarch, wait for that
+cpu to return from the OS then drive the rest as slaves.  Some versions
+of SAL cannot even cope with returning from the OS, they spin inside
+SAL on resume.  The OS INIT code has workarounds for some of these
+broken SAL symptoms, but some simply cannot be fixed from the OS side.
+
+---
+
+The scheduler hooks used by ia64 (curr_task, set_curr_task) are layer
+violations.  Unfortunately MCA/INIT start off as massive layer
+violations (can occur at _any_ time) and they build from there.
+
+At least ia64 makes an attempt at recovering from hardware errors, but
+it is a difficult problem because of the asynchronous nature of these
+errors.  When processing an unmaskable interrupt we sometimes need
+special code to cope with our inability to take any locks.
+
+---
+
+How is ia64 MCA/INIT different from x86 NMI?
+
+* x86 NMI typically gets delivered to one cpu.  MCA/INIT gets sent to
+  all cpus.
+
+* x86 NMI cannot be nested.  MCA/INIT can be nested, to a depth of 2
+  per cpu.
+
+* x86 has a separate struct task which points to one of multiple kernel
+  stacks.  ia64 has the struct task embedded in the single kernel
+  stack, so switching stack means switching task.
+
+* x86 does not call the BIOS so the NMI handler does not have to worry
+  about any registers having changed.  MCA/INIT can occur while the cpu
+  is in PAL in physical mode, with undefined registers and an undefined
+  kernel stack.
+
+* i386 backtrace is not very sensitive to whether a process is running
+  or not.  ia64 unwind is very, very sensitive to whether a process is
+  running or not.
+
+---
+
+What happens when MCA/INIT is delivered what a cpu is running user
+space code?
+
+The user mode registers are stored in the RSE area of the MCA/INIT on
+entry to the OS and are restored from there on return to SAL, so user
+mode registers are preserved across a recoverable MCA/INIT.  Since the
+OS has no idea what unwind data is available for the user space stack,
+MCA/INIT never tries to backtrace user space.  Which means that the OS
+does not bother making the user space process look like a blocked task,
+i.e. the OS does not copy pt_regs and switch_stack to the user space
+stack.  Also the OS has no idea how big the user space RSE and memory
+stacks are, which makes it too risky to copy the saved state to a user
+mode stack.
+
+---
+
+How do we get a backtrace on the tasks that were running when MCA/INIT
+was delivered?
+
+mca.c:::ia64_mca_modify_original_stack().  That identifies and
+verifies the original kernel stack, copies the dirty registers from
+the MCA/INIT stack's RSE to the original stack's RSE, copies the
+skeleton struct pt_regs and switch_stack to the original stack, fills
+in the skeleton structures from the PAL minstate area and updates the
+original stack's thread.ksp.  That makes the original stack look
+exactly like any other blocked task, i.e. it now appears to be
+sleeping.  To get a backtrace, just start with thread.ksp for the
+original task and unwind like any other sleeping task.
+
+---
+
+How do we identify the tasks that were running when MCA/INIT was
+delivered?
+
+If the previous task has been verified and converted to a blocked
+state, then sos->prev_task on the MCA/INIT stack is updated to point to
+the previous task.  You can look at that field in dumps or debuggers.
+To help distinguish between the handler and the original tasks,
+handlers have _TIF_MCA_INIT set in thread_info.flags.
+
+The sos data is always in the MCA/INIT handler stack, at offset
+MCA_SOS_OFFSET.  You can get that value from mca_asm.h or calculate it
+as KERNEL_STACK_SIZE - sizeof(struct pt_regs) - sizeof(struct
+ia64_sal_os_state), with 16 byte alignment for all structures.
+
+Also the comm field of the MCA/INIT task is modified to include the pid
+of the original task, for humans to use.  For example, a comm field of
+'MCA 12159' means that pid 12159 was running when the MCA was
+delivered.