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, 827 insertions, 0 deletions

diff --git a/Documentation/trace/coresight/coresight-etm4x-reference.rst b/Documentation/trace/coresight/coresight-etm4x-reference.rst
new file mode 100644
index 000000000..70e34b8c8
--- /dev/null
+++ b/Documentation/trace/coresight/coresight-etm4x-reference.rst
@@ -0,0 +1,827 @@
+===============================================
+ETMv4 sysfs linux driver programming reference.
+===============================================
+
+    :Author:   Mike Leach <mike.leach@linaro.org>
+    :Date:     October 11th, 2019
+
+Supplement to existing ETMv4 driver documentation.
+
+Sysfs files and directories
+---------------------------
+
+Root: ``/sys/bus/coresight/devices/etm<N>``
+
+
+The following paragraphs explain the association between sysfs files and the
+ETMv4 registers that they effect. Note the register names are given without
+the ‘TRC’ prefix.
+
+----
+
+:File:            ``mode`` (rw)
+:Trace Registers: {CONFIGR + others}
+:Notes:
+    Bit select trace features. See ‘mode’ section below. Bits
+    in this will cause equivalent programming of trace config and
+    other registers to enable the features requested.
+
+:Syntax & eg:
+    ``echo bitfield > mode``
+
+    bitfield up to 32 bits setting trace features.
+
+:Example:
+    ``$> echo 0x012 > mode``
+
+----
+
+:File:            ``reset`` (wo)
+:Trace Registers: All
+:Notes:
+    Reset all programming to trace nothing / no logic programmed.
+
+:Syntax:
+    ``echo 1 > reset``
+
+----
+
+:File:            ``enable_source`` (wo)
+:Trace Registers: PRGCTLR, All hardware regs.
+:Notes:
+    - > 0 : Programs up the hardware with the current values held in the driver
+      and enables trace.
+
+    - = 0 : disable trace hardware.
+
+:Syntax:
+    ``echo 1 > enable_source``
+
+----
+
+:File:            ``cpu`` (ro)
+:Trace Registers: None.
+:Notes:
+    CPU ID that this ETM is attached to.
+
+:Example:
+    ``$> cat cpu``
+
+    ``$> 0``
+
+----
+
+:File:            ``ts_source`` (ro)
+:Trace Registers: None.
+:Notes:
+    When FEAT_TRF is implemented, value of TRFCR_ELx.TS used for trace session. Otherwise -1
+    indicates an unknown time source. Check trcidr0.tssize to see if a global timestamp is
+    available.
+
+:Example:
+    ``$> cat ts_source``
+
+    ``$> 1``
+
+----
+
+:File:            ``addr_idx`` (rw)
+:Trace Registers: None.
+:Notes:
+    Virtual register to index address comparator and range
+    features. Set index for first of the pair in a range.
+
+:Syntax:
+    ``echo idx > addr_idx``
+
+    Where idx < nr_addr_cmp x 2
+
+----
+
+:File:            ``addr_range`` (rw)
+:Trace Registers: ACVR[idx, idx+1], VIIECTLR
+:Notes:
+    Pair of addresses for a range selected by addr_idx. Include
+    / exclude according to the optional parameter, or if omitted
+    uses the current ‘mode’ setting. Select comparator range in
+    control register. Error if index is odd value.
+
+:Depends: ``mode, addr_idx``
+:Syntax:
+   ``echo addr1 addr2 [exclude] > addr_range``
+
+   Where addr1 and addr2 define the range and addr1 < addr2.
+
+   Optional exclude value:-
+
+   - 0 for include
+   - 1 for exclude.
+:Example:
+   ``$> echo 0x0000 0x2000 0 > addr_range``
+
+----
+
+:File:            ``addr_single`` (rw)
+:Trace Registers: ACVR[idx]
+:Notes:
+    Set a single address comparator according to addr_idx. This
+    is used if the address comparator is used as part of event
+    generation logic etc.
+
+:Depends: ``addr_idx``
+:Syntax:
+   ``echo addr1 > addr_single``
+
+----
+
+:File:           ``addr_start`` (rw)
+:Trace Registers: ACVR[idx], VISSCTLR
+:Notes:
+    Set a trace start address comparator according to addr_idx.
+    Select comparator in control register.
+
+:Depends: ``addr_idx``
+:Syntax:
+    ``echo addr1 > addr_start``
+
+----
+
+:File:            ``addr_stop`` (rw)
+:Trace Registers: ACVR[idx], VISSCTLR
+:Notes:
+    Set a trace stop address comparator according to addr_idx.
+    Select comparator in control register.
+
+:Depends: ``addr_idx``
+:Syntax:
+    ``echo addr1 > addr_stop``
+
+----
+
+:File:            ``addr_context`` (rw)
+:Trace Registers: ACATR[idx,{6:4}]
+:Notes:
+    Link context ID comparator to address comparator addr_idx
+
+:Depends: ``addr_idx``
+:Syntax:
+    ``echo ctxt_idx > addr_context``
+
+    Where ctxt_idx is the index of the linked context id / vmid
+    comparator.
+
+----
+
+:File:            ``addr_ctxtype`` (rw)
+:Trace Registers: ACATR[idx,{3:2}]
+:Notes:
+    Input value string. Set type for linked context ID comparator
+
+:Depends: ``addr_idx``
+:Syntax:
+    ``echo type > addr_ctxtype``
+
+    Type one of {all, vmid, ctxid, none}
+:Example:
+    ``$> echo ctxid > addr_ctxtype``
+
+----
+
+:File:            ``addr_exlevel_s_ns`` (rw)
+:Trace Registers: ACATR[idx,{14:8}]
+:Notes:
+    Set the ELx secure and non-secure matching bits for the
+    selected address comparator
+
+:Depends: ``addr_idx``
+:Syntax:
+    ``echo val > addr_exlevel_s_ns``
+
+    val is a 7 bit value for exception levels to exclude. Input
+    value shifted to correct bits in register.
+:Example:
+    ``$> echo 0x4F > addr_exlevel_s_ns``
+
+----
+
+:File:            ``addr_instdatatype`` (rw)
+:Trace Registers: ACATR[idx,{1:0}]
+:Notes:
+    Set the comparator address type for matching. Driver only
+    supports setting instruction address type.
+
+:Depends: ``addr_idx``
+
+----
+
+:File:            ``addr_cmp_view`` (ro)
+:Trace Registers: ACVR[idx, idx+1], ACATR[idx], VIIECTLR
+:Notes:
+    Read the currently selected address comparator. If part of
+    address range then display both addresses.
+
+:Depends: ``addr_idx``
+:Syntax:
+    ``cat addr_cmp_view``
+:Example:
+    ``$> cat addr_cmp_view``
+
+   ``addr_cmp[0] range 0x0 0xffffffffffffffff include ctrl(0x4b00)``
+
+----
+
+:File:            ``nr_addr_cmp`` (ro)
+:Trace Registers: From IDR4
+:Notes:
+    Number of address comparator pairs
+
+----
+
+:File:            ``sshot_idx`` (rw)
+:Trace Registers: None
+:Notes:
+    Select single shot register set.
+
+----
+
+:File:            ``sshot_ctrl`` (rw)
+:Trace Registers: SSCCR[idx]
+:Notes:
+    Access a single shot comparator control register.
+
+:Depends: ``sshot_idx``
+:Syntax:
+    ``echo val > sshot_ctrl``
+
+    Writes val into the selected control register.
+
+----
+
+:File:            ``sshot_status`` (ro)
+:Trace Registers: SSCSR[idx]
+:Notes:
+    Read a single shot comparator status register
+
+:Depends: ``sshot_idx``
+:Syntax:
+    ``cat sshot_status``
+
+    Read status.
+:Example:
+    ``$> cat sshot_status``
+
+    ``0x1``
+
+----
+
+:File:            ``sshot_pe_ctrl`` (rw)
+:Trace Registers: SSPCICR[idx]
+:Notes:
+    Access a single shot PE comparator input control register.
+
+:Depends: ``sshot_idx``
+:Syntax:
+    ``echo val > sshot_pe_ctrl``
+
+    Writes val into the selected control register.
+
+----
+
+:File:            ``ns_exlevel_vinst`` (rw)
+:Trace Registers: VICTLR{23:20}
+:Notes:
+    Program non-secure exception level filters. Set / clear NS
+    exception filter bits. Setting ‘1’ excludes trace from the
+    exception level.
+
+:Syntax:
+    ``echo bitfield > ns_exlevel_viinst``
+
+    Where bitfield contains bits to set clear for EL0 to EL2
+:Example:
+    ``%> echo 0x4 > ns_exlevel_viinst``
+
+    Excludes EL2 NS trace.
+
+----
+
+:File:            ``vinst_pe_cmp_start_stop`` (rw)
+:Trace Registers: VIPCSSCTLR
+:Notes:
+    Access PE start stop comparator input control registers
+
+----
+
+:File:            ``bb_ctrl`` (rw)
+:Trace Registers: BBCTLR
+:Notes:
+    Define ranges that Branch Broadcast will operate in.
+    Default (0x0) is all addresses.
+
+:Depends: BB enabled.
+
+----
+
+:File:            ``cyc_threshold`` (rw)
+:Trace Registers: CCCTLR
+:Notes:
+    Set the threshold for which cycle counts will be emitted.
+    Error if attempt to set below minimum defined in IDR3, masked
+    to width of valid bits.
+
+:Depends: CC enabled.
+
+----
+
+:File:            ``syncfreq`` (rw)
+:Trace Registers: SYNCPR
+:Notes:
+    Set trace synchronisation period. Power of 2 value, 0 (off)
+    or 8-20. Driver defaults to 12 (every 4096 bytes).
+
+----
+
+:File:            ``cntr_idx`` (rw)
+:Trace Registers: none
+:Notes:
+    Select the counter to access
+
+:Syntax:
+    ``echo idx > cntr_idx``
+
+    Where idx < nr_cntr
+
+----
+
+:File:            ``cntr_ctrl`` (rw)
+:Trace Registers: CNTCTLR[idx]
+:Notes:
+    Set counter control value.
+
+:Depends: ``cntr_idx``
+:Syntax:
+    ``echo val > cntr_ctrl``
+
+    Where val is per ETMv4 spec.
+
+----
+
+:File:            ``cntrldvr`` (rw)
+:Trace Registers: CNTRLDVR[idx]
+:Notes:
+    Set counter reload value.
+
+:Depends: ``cntr_idx``
+:Syntax:
+    ``echo val > cntrldvr``
+
+    Where val is per ETMv4 spec.
+
+----
+
+:File:            ``nr_cntr`` (ro)
+:Trace Registers: From IDR5
+
+:Notes:
+    Number of counters implemented.
+
+----
+
+:File:            ``ctxid_idx`` (rw)
+:Trace Registers: None
+:Notes:
+    Select the context ID comparator to access
+
+:Syntax:
+    ``echo idx > ctxid_idx``
+
+    Where idx < numcidc
+
+----
+
+:File:            ``ctxid_pid`` (rw)
+:Trace Registers: CIDCVR[idx]
+:Notes:
+   Set the context ID comparator value
+
+:Depends: ``ctxid_idx``
+
+----
+
+:File: ``ctxid_masks`` (rw)
+:Trace Registers: CIDCCTLR0, CIDCCTLR1, CIDCVR<0-7>
+:Notes:
+    Pair of values to set the byte masks for 1-8 context ID
+    comparators. Automatically clears masked bytes to 0 in CID
+    value registers.
+
+:Syntax:
+    ``echo m3m2m1m0 [m7m6m5m4] > ctxid_masks``
+
+    32 bit values made up of mask bytes, where mN represents a
+    byte mask value for Context ID comparator N.
+
+    Second value not required on systems that have fewer than 4
+    context ID comparators
+
+----
+
+:File:            ``numcidc`` (ro)
+:Trace Registers: From IDR4
+:Notes:
+    Number of Context ID comparators
+
+----
+
+:File:            ``vmid_idx`` (rw)
+:Trace Registers: None
+:Notes:
+    Select the VM ID comparator to access.
+
+:Syntax:
+    ``echo idx > vmid_idx``
+
+    Where idx <  numvmidc
+
+----
+
+:File:            ``vmid_val`` (rw)
+:Trace Registers: VMIDCVR[idx]
+:Notes:
+    Set the VM ID comparator value
+
+:Depends: ``vmid_idx``
+
+----
+
+:File:            ``vmid_masks`` (rw)
+:Trace Registers: VMIDCCTLR0, VMIDCCTLR1, VMIDCVR<0-7>
+:Notes:
+    Pair of values to set the byte masks for 1-8 VM ID comparators.
+    Automatically clears masked bytes to 0 in VMID value registers.
+
+:Syntax:
+    ``echo m3m2m1m0 [m7m6m5m4] > vmid_masks``
+
+    Where mN represents a byte mask value for VMID comparator N.
+    Second value not required on systems that have fewer than 4
+    VMID comparators.
+
+----
+
+:File:            ``numvmidc`` (ro)
+:Trace Registers: From IDR4
+:Notes:
+    Number of VMID comparators
+
+----
+
+:File:            ``res_idx`` (rw)
+:Trace Registers: None.
+:Notes:
+    Select the resource selector control to access. Must be 2 or
+    higher as selectors 0 and 1 are hardwired.
+
+:Syntax:
+    ``echo idx > res_idx``
+
+    Where 2 <= idx < nr_resource x 2
+
+----
+
+:File:            ``res_ctrl`` (rw)
+:Trace Registers: RSCTLR[idx]
+:Notes:
+    Set resource selector control value. Value per ETMv4 spec.
+
+:Depends: ``res_idx``
+:Syntax:
+    ``echo val > res_cntr``
+
+    Where val is per ETMv4 spec.
+
+----
+
+:File:            ``nr_resource`` (ro)
+:Trace Registers: From IDR4
+:Notes:
+    Number of resource selector pairs
+
+----
+
+:File:            ``event`` (rw)
+:Trace Registers: EVENTCTRL0R
+:Notes:
+    Set up to 4 implemented event fields.
+
+:Syntax:
+    ``echo ev3ev2ev1ev0 > event``
+
+    Where evN is an 8 bit event field. Up to 4 event fields make up the
+    32-bit input value. Number of valid fields is implementation dependent,
+    defined in IDR0.
+
+----
+
+:File: ``event_instren`` (rw)
+:Trace Registers: EVENTCTRL1R
+:Notes:
+    Choose events which insert event packets into trace stream.
+
+:Depends: EVENTCTRL0R
+:Syntax:
+    ``echo bitfield > event_instren``
+
+    Where bitfield is up to 4 bits according to number of event fields.
+
+----
+
+:File:            ``event_ts`` (rw)
+:Trace Registers: TSCTLR
+:Notes:
+    Set the event that will generate timestamp requests.
+
+:Depends: ``TS activated``
+:Syntax:
+    ``echo evfield > event_ts``
+
+    Where evfield is an 8 bit event selector.
+
+----
+
+:File:            ``seq_idx`` (rw)
+:Trace Registers: None
+:Notes:
+    Sequencer event register select - 0 to 2
+
+----
+
+:File:            ``seq_state`` (rw)
+:Trace Registers: SEQSTR
+:Notes:
+    Sequencer current state - 0 to 3.
+
+----
+
+:File:            ``seq_event`` (rw)
+:Trace Registers: SEQEVR[idx]
+:Notes:
+    State transition event registers
+
+:Depends: ``seq_idx``
+:Syntax:
+    ``echo evBevF > seq_event``
+
+    Where evBevF is a 16 bit value made up of two event selectors,
+
+    - evB : back
+    - evF : forwards.
+
+----
+
+:File:            ``seq_reset_event`` (rw)
+:Trace Registers: SEQRSTEVR
+:Notes:
+    Sequencer reset event
+
+:Syntax:
+    ``echo evfield > seq_reset_event``
+
+    Where evfield is an 8 bit event selector.
+
+----
+
+:File:            ``nrseqstate`` (ro)
+:Trace Registers: From IDR5
+:Notes:
+    Number of sequencer states (0 or 4)
+
+----
+
+:File:            ``nr_pe_cmp`` (ro)
+:Trace Registers: From IDR4
+:Notes:
+    Number of PE comparator inputs
+
+----
+
+:File:            ``nr_ext_inp`` (ro)
+:Trace Registers: From IDR5
+:Notes:
+    Number of external inputs
+
+----
+
+:File:            ``nr_ss_cmp`` (ro)
+:Trace Registers: From IDR4
+:Notes:
+    Number of Single Shot control registers
+
+----
+
+*Note:* When programming any address comparator the driver will tag the
+comparator with a type used - i.e. RANGE, SINGLE, START, STOP. Once this tag
+is set, then only the values can be changed using the same sysfs file / type
+used to program it.
+
+Thus::
+
+  % echo 0 > addr_idx		; select address comparator 0
+  % echo 0x1000 0x5000 0 > addr_range ; set address range on comparators 0, 1.
+  % echo 0x2000 > addr_start    ; error as comparator 0 is a range comparator
+  % echo 2 > addr_idx		; select address comparator 2
+  % echo 0x2000 > addr_start	; this is OK as comparator 2 is unused.
+  % echo 0x3000 > addr_stop	; error as comparator 2 set as start address.
+  % echo 2 > addr_idx		; select address comparator 3
+  % echo 0x3000 > addr_stop	; this is OK
+
+To remove programming on all the comparators (and all the other hardware) use
+the reset parameter::
+
+  % echo 1 > reset
+
+
+
+The ‘mode’ sysfs parameter.
+---------------------------
+
+This is a bitfield selection parameter that sets the overall trace mode for the
+ETM. The table below describes the bits, using the defines from the driver
+source file, along with a description of the feature these represent. Many
+features are optional and therefore dependent on implementation in the
+hardware.
+
+Bit assignments shown below:-
+
+----
+
+**bit (0):**
+    ETM_MODE_EXCLUDE
+
+**description:**
+    This is the default value for the include / exclude function when
+    setting address ranges. Set 1 for exclude range. When the mode
+    parameter is set this value is applied to the currently indexed
+    address range.
+
+.. _coresight-branch-broadcast:
+
+**bit (4):**
+    ETM_MODE_BB
+
+**description:**
+    Set to enable branch broadcast if supported in hardware [IDR0]. The primary use for this feature
+    is when code is patched dynamically at run time and the full program flow may not be able to be
+    reconstructed using only conditional branches.
+
+    There is currently no support in Perf for supplying modified binaries to the decoder, so this
+    feature is only inteded to be used for debugging purposes or with a 3rd party tool.
+
+    Choosing this option will result in a significant increase in the amount of trace generated -
+    possible danger of overflows, or fewer instructions covered. Note, that this option also
+    overrides any setting of :ref:`ETM_MODE_RETURNSTACK <coresight-return-stack>`, so where a branch
+    broadcast range overlaps a return stack range, return stacks will not be available for that
+    range.
+
+.. _coresight-cycle-accurate:
+
+**bit (5):**
+    ETMv4_MODE_CYCACC
+
+**description:**
+    Set to enable cycle accurate trace if supported [IDR0].
+
+
+**bit (6):**
+    ETMv4_MODE_CTXID
+
+**description:**
+    Set to enable context ID tracing if supported in hardware [IDR2].
+
+
+**bit (7):**
+    ETM_MODE_VMID
+
+**description:**
+    Set to enable virtual machine ID tracing if supported [IDR2].
+
+.. _coresight-timestamp:
+
+**bit (11):**
+    ETMv4_MODE_TIMESTAMP
+
+**description:**
+    Set to enable timestamp generation if supported [IDR0].
+
+.. _coresight-return-stack:
+
+**bit (12):**
+    ETM_MODE_RETURNSTACK
+**description:**
+    Set to enable trace return stack use if supported [IDR0].
+
+
+**bit (13-14):**
+    ETM_MODE_QELEM(val)
+
+**description:**
+    ‘val’ determines level of Q element support enabled if
+    implemented by the ETM [IDR0]
+
+
+**bit (19):**
+    ETM_MODE_ATB_TRIGGER
+
+**description:**
+    Set to enable the ATBTRIGGER bit in the event control register
+    [EVENTCTLR1] if supported [IDR5].
+
+
+**bit (20):**
+    ETM_MODE_LPOVERRIDE
+
+**description:**
+    Set to enable the LPOVERRIDE bit in the event control register
+    [EVENTCTLR1], if supported [IDR5].
+
+
+**bit (21):**
+    ETM_MODE_ISTALL_EN
+
+**description:**
+    Set to enable the ISTALL bit in the stall control register
+    [STALLCTLR]
+
+
+**bit (23):**
+    ETM_MODE_INSTPRIO
+
+**description:**
+	      Set to enable the INSTPRIORITY bit in the stall control register
+	      [STALLCTLR] , if supported [IDR0].
+
+
+**bit (24):**
+    ETM_MODE_NOOVERFLOW
+
+**description:**
+    Set to enable the NOOVERFLOW bit in the stall control register
+    [STALLCTLR], if supported [IDR3].
+
+
+**bit (25):**
+    ETM_MODE_TRACE_RESET
+
+**description:**
+    Set to enable the TRCRESET bit in the viewinst control register
+    [VICTLR] , if supported [IDR3].
+
+
+**bit (26):**
+    ETM_MODE_TRACE_ERR
+
+**description:**
+    Set to enable the TRCCTRL bit in the viewinst control register
+    [VICTLR].
+
+
+**bit (27):**
+    ETM_MODE_VIEWINST_STARTSTOP
+
+**description:**
+    Set the initial state value of the ViewInst start / stop logic
+    in the viewinst control register [VICTLR]
+
+
+**bit (30):**
+    ETM_MODE_EXCL_KERN
+
+**description:**
+    Set default trace setup to exclude kernel mode trace (see note a)
+
+
+**bit (31):**
+    ETM_MODE_EXCL_USER
+
+**description:**
+    Set default trace setup to exclude user space trace (see note a)
+
+----
+
+*Note a)* On startup the ETM is programmed to trace the complete address space
+using address range comparator 0. ‘mode’ bits 30 / 31 modify this setting to
+set EL exclude bits for NS state in either user space (EL0) or kernel space
+(EL1) in the address range comparator. (the default setting excludes all
+secure EL, and NS EL2)
+
+Once the reset parameter has been used, and/or custom programming has been
+implemented - using these bits will result in the EL bits for address
+comparator 0 being set in the same way.
+
+*Note b)* Bits 2-3, 8-10, 15-16, 18, 22, control features that only work with
+data trace. As A-profile data trace is architecturally prohibited in ETMv4,
+these have been omitted here. Possible uses could be where a kernel has
+support for control of R or M profile infrastructure as part of a heterogeneous
+system.
+
+Bits 17, 28-29 are unused.