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author | 2023-02-21 18:24:12 -0800 | |
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committer | 2023-02-21 18:24:12 -0800 | |
commit | 5b7c4cabbb65f5c469464da6c5f614cbd7f730f2 (patch) | |
tree | cc5c2d0a898769fd59549594fedb3ee6f84e59a0 /Documentation/trace/intel_th.rst | |
download | linux-5b7c4cabbb65f5c469464da6c5f614cbd7f730f2.tar.gz linux-5b7c4cabbb65f5c469464da6c5f614cbd7f730f2.zip |
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().
...
Diffstat (limited to 'Documentation/trace/intel_th.rst')
-rw-r--r-- | Documentation/trace/intel_th.rst | 150 |
1 files changed, 150 insertions, 0 deletions
diff --git a/Documentation/trace/intel_th.rst b/Documentation/trace/intel_th.rst new file mode 100644 index 000000000..b31818d5f --- /dev/null +++ b/Documentation/trace/intel_th.rst @@ -0,0 +1,150 @@ +.. SPDX-License-Identifier: GPL-2.0 + +======================= +Intel(R) Trace Hub (TH) +======================= + +Overview +-------- + +Intel(R) Trace Hub (TH) is a set of hardware blocks that produce, +switch and output trace data from multiple hardware and software +sources over several types of trace output ports encoded in System +Trace Protocol (MIPI STPv2) and is intended to perform full system +debugging. For more information on the hardware, see Intel(R) Trace +Hub developer's manual [1]. + +It consists of trace sources, trace destinations (outputs) and a +switch (Global Trace Hub, GTH). These devices are placed on a bus of +their own ("intel_th"), where they can be discovered and configured +via sysfs attributes. + +Currently, the following Intel TH subdevices (blocks) are supported: + - Software Trace Hub (STH), trace source, which is a System Trace + Module (STM) device, + - Memory Storage Unit (MSU), trace output, which allows storing + trace hub output in system memory, + - Parallel Trace Interface output (PTI), trace output to an external + debug host via a PTI port, + - Global Trace Hub (GTH), which is a switch and a central component + of Intel(R) Trace Hub architecture. + +Common attributes for output devices are described in +Documentation/ABI/testing/sysfs-bus-intel_th-output-devices, the most +notable of them is "active", which enables or disables trace output +into that particular output device. + +GTH allows directing different STP masters into different output ports +via its "masters" attribute group. More detailed GTH interface +description is at Documentation/ABI/testing/sysfs-bus-intel_th-devices-gth. + +STH registers an stm class device, through which it provides interface +to userspace and kernelspace software trace sources. See +Documentation/trace/stm.rst for more information on that. + +MSU can be configured to collect trace data into a system memory +buffer, which can later on be read from its device nodes via read() or +mmap() interface and directed to a "software sink" driver that will +consume the data and/or relay it further. + +On the whole, Intel(R) Trace Hub does not require any special +userspace software to function; everything can be configured, started +and collected via sysfs attributes, and device nodes. + +[1] https://software.intel.com/sites/default/files/managed/d3/3c/intel-th-developer-manual.pdf + +Bus and Subdevices +------------------ + +For each Intel TH device in the system a bus of its own is +created and assigned an id number that reflects the order in which TH +devices were enumerated. All TH subdevices (devices on intel_th bus) +begin with this id: 0-gth, 0-msc0, 0-msc1, 0-pti, 0-sth, which is +followed by device's name and an optional index. + +Output devices also get a device node in /dev/intel_thN, where N is +the Intel TH device id. For example, MSU's memory buffers, when +allocated, are accessible via /dev/intel_th0/msc{0,1}. + +Quick example +------------- + +# figure out which GTH port is the first memory controller:: + + $ cat /sys/bus/intel_th/devices/0-msc0/port + 0 + +# looks like it's port 0, configure master 33 to send data to port 0:: + + $ echo 0 > /sys/bus/intel_th/devices/0-gth/masters/33 + +# allocate a 2-windowed multiblock buffer on the first memory +# controller, each with 64 pages:: + + $ echo multi > /sys/bus/intel_th/devices/0-msc0/mode + $ echo 64,64 > /sys/bus/intel_th/devices/0-msc0/nr_pages + +# enable wrapping for this controller, too:: + + $ echo 1 > /sys/bus/intel_th/devices/0-msc0/wrap + +# and enable tracing into this port:: + + $ echo 1 > /sys/bus/intel_th/devices/0-msc0/active + +# .. send data to master 33, see stm.txt for more details .. +# .. wait for traces to pile up .. +# .. and stop the trace:: + + $ echo 0 > /sys/bus/intel_th/devices/0-msc0/active + +# and now you can collect the trace from the device node:: + + $ cat /dev/intel_th0/msc0 > my_stp_trace + +Host Debugger Mode +------------------ + +It is possible to configure the Trace Hub and control its trace +capture from a remote debug host, which should be connected via one of +the hardware debugging interfaces, which will then be used to both +control Intel Trace Hub and transfer its trace data to the debug host. + +The driver needs to be told that such an arrangement is taking place +so that it does not touch any capture/port configuration and avoids +conflicting with the debug host's configuration accesses. The only +activity that the driver will perform in this mode is collecting +software traces to the Software Trace Hub (an stm class device). The +user is still responsible for setting up adequate master/channel +mappings that the decoder on the receiving end would recognize. + +In order to enable the host mode, set the 'host_mode' parameter of the +'intel_th' kernel module to 'y'. None of the virtual output devices +will show up on the intel_th bus. Also, trace configuration and +capture controlling attribute groups of the 'gth' device will not be +exposed. The 'sth' device will operate as usual. + +Software Sinks +-------------- + +The Memory Storage Unit (MSU) driver provides an in-kernel API for +drivers to register themselves as software sinks for the trace data. +Such drivers can further export the data via other devices, such as +USB device controllers or network cards. + +The API has two main parts:: + - notifying the software sink that a particular window is full, and + "locking" that window, that is, making it unavailable for the trace + collection; when this happens, the MSU driver will automatically + switch to the next window in the buffer if it is unlocked, or stop + the trace capture if it's not; + - tracking the "locked" state of windows and providing a way for the + software sink driver to notify the MSU driver when a window is + unlocked and can be used again to collect trace data. + +An example sink driver, msu-sink illustrates the implementation of a +software sink. Functionally, it simply unlocks windows as soon as they +are full, keeping the MSU running in a circular buffer mode. Unlike the +"multi" mode, it will fill out all the windows in the buffer as opposed +to just the first one. It can be enabled by writing "sink" to the "mode" +file (assuming msu-sink.ko is loaded). |