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, 173 insertions, 0 deletions

diff --git a/Documentation/scheduler/schedutil.rst b/Documentation/scheduler/schedutil.rst
new file mode 100644
index 000000000..32c7d69fc
--- /dev/null
+++ b/Documentation/scheduler/schedutil.rst
@@ -0,0 +1,173 @@
+=========
+Schedutil
+=========
+
+.. note::
+
+   All this assumes a linear relation between frequency and work capacity,
+   we know this is flawed, but it is the best workable approximation.
+
+
+PELT (Per Entity Load Tracking)
+===============================
+
+With PELT we track some metrics across the various scheduler entities, from
+individual tasks to task-group slices to CPU runqueues. As the basis for this
+we use an Exponentially Weighted Moving Average (EWMA), each period (1024us)
+is decayed such that y^32 = 0.5. That is, the most recent 32ms contribute
+half, while the rest of history contribute the other half.
+
+Specifically:
+
+  ewma_sum(u) := u_0 + u_1*y + u_2*y^2 + ...
+
+  ewma(u) = ewma_sum(u) / ewma_sum(1)
+
+Since this is essentially a progression of an infinite geometric series, the
+results are composable, that is ewma(A) + ewma(B) = ewma(A+B). This property
+is key, since it gives the ability to recompose the averages when tasks move
+around.
+
+Note that blocked tasks still contribute to the aggregates (task-group slices
+and CPU runqueues), which reflects their expected contribution when they
+resume running.
+
+Using this we track 2 key metrics: 'running' and 'runnable'. 'Running'
+reflects the time an entity spends on the CPU, while 'runnable' reflects the
+time an entity spends on the runqueue. When there is only a single task these
+two metrics are the same, but once there is contention for the CPU 'running'
+will decrease to reflect the fraction of time each task spends on the CPU
+while 'runnable' will increase to reflect the amount of contention.
+
+For more detail see: kernel/sched/pelt.c
+
+
+Frequency / CPU Invariance
+==========================
+
+Because consuming the CPU for 50% at 1GHz is not the same as consuming the CPU
+for 50% at 2GHz, nor is running 50% on a LITTLE CPU the same as running 50% on
+a big CPU, we allow architectures to scale the time delta with two ratios, one
+Dynamic Voltage and Frequency Scaling (DVFS) ratio and one microarch ratio.
+
+For simple DVFS architectures (where software is in full control) we trivially
+compute the ratio as::
+
+	    f_cur
+  r_dvfs := -----
+            f_max
+
+For more dynamic systems where the hardware is in control of DVFS we use
+hardware counters (Intel APERF/MPERF, ARMv8.4-AMU) to provide us this ratio.
+For Intel specifically, we use::
+
+	   APERF
+  f_cur := ----- * P0
+	   MPERF
+
+	     4C-turbo;	if available and turbo enabled
+  f_max := { 1C-turbo;	if turbo enabled
+	     P0;	otherwise
+
+                    f_cur
+  r_dvfs := min( 1, ----- )
+                    f_max
+
+We pick 4C turbo over 1C turbo to make it slightly more sustainable.
+
+r_cpu is determined as the ratio of highest performance level of the current
+CPU vs the highest performance level of any other CPU in the system.
+
+  r_tot = r_dvfs * r_cpu
+
+The result is that the above 'running' and 'runnable' metrics become invariant
+of DVFS and CPU type. IOW. we can transfer and compare them between CPUs.
+
+For more detail see:
+
+ - kernel/sched/pelt.h:update_rq_clock_pelt()
+ - arch/x86/kernel/smpboot.c:"APERF/MPERF frequency ratio computation."
+ - Documentation/scheduler/sched-capacity.rst:"1. CPU Capacity + 2. Task utilization"
+
+
+UTIL_EST / UTIL_EST_FASTUP
+==========================
+
+Because periodic tasks have their averages decayed while they sleep, even
+though when running their expected utilization will be the same, they suffer a
+(DVFS) ramp-up after they are running again.
+
+To alleviate this (a default enabled option) UTIL_EST drives an Infinite
+Impulse Response (IIR) EWMA with the 'running' value on dequeue -- when it is
+highest. A further default enabled option UTIL_EST_FASTUP modifies the IIR
+filter to instantly increase and only decay on decrease.
+
+A further runqueue wide sum (of runnable tasks) is maintained of:
+
+  util_est := \Sum_t max( t_running, t_util_est_ewma )
+
+For more detail see: kernel/sched/fair.c:util_est_dequeue()
+
+
+UCLAMP
+======
+
+It is possible to set effective u_min and u_max clamps on each CFS or RT task;
+the runqueue keeps an max aggregate of these clamps for all running tasks.
+
+For more detail see: include/uapi/linux/sched/types.h
+
+
+Schedutil / DVFS
+================
+
+Every time the scheduler load tracking is updated (task wakeup, task
+migration, time progression) we call out to schedutil to update the hardware
+DVFS state.
+
+The basis is the CPU runqueue's 'running' metric, which per the above it is
+the frequency invariant utilization estimate of the CPU. From this we compute
+a desired frequency like::
+
+             max( running, util_est );	if UTIL_EST
+  u_cfs := { running;			otherwise
+
+               clamp( u_cfs + u_rt , u_min, u_max );	if UCLAMP_TASK
+  u_clamp := { u_cfs + u_rt;				otherwise
+
+  u := u_clamp + u_irq + u_dl;		[approx. see source for more detail]
+
+  f_des := min( f_max, 1.25 u * f_max )
+
+XXX IO-wait: when the update is due to a task wakeup from IO-completion we
+boost 'u' above.
+
+This frequency is then used to select a P-state/OPP or directly munged into a
+CPPC style request to the hardware.
+
+XXX: deadline tasks (Sporadic Task Model) allows us to calculate a hard f_min
+required to satisfy the workload.
+
+Because these callbacks are directly from the scheduler, the DVFS hardware
+interaction should be 'fast' and non-blocking. Schedutil supports
+rate-limiting DVFS requests for when hardware interaction is slow and
+expensive, this reduces effectiveness.
+
+For more information see: kernel/sched/cpufreq_schedutil.c
+
+
+NOTES
+=====
+
+ - On low-load scenarios, where DVFS is most relevant, the 'running' numbers
+   will closely reflect utilization.
+
+ - In saturated scenarios task movement will cause some transient dips,
+   suppose we have a CPU saturated with 4 tasks, then when we migrate a task
+   to an idle CPU, the old CPU will have a 'running' value of 0.75 while the
+   new CPU will gain 0.25. This is inevitable and time progression will
+   correct this. XXX do we still guarantee f_max due to no idle-time?
+
+ - Much of the above is about avoiding DVFS dips, and independent DVFS domains
+   having to re-learn / ramp-up when load shifts.
+