From 5b7c4cabbb65f5c469464da6c5f614cbd7f730f2 Mon Sep 17 00:00:00 2001 From: Linus Torvalds Date: Tue, 21 Feb 2023 18:24:12 -0800 Subject: Merge tag 'net-next-6.3' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next 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(). ... --- Documentation/userspace-api/media/dvb/intro.rst | 183 ++++++++++++++++++++++++ 1 file changed, 183 insertions(+) create mode 100644 Documentation/userspace-api/media/dvb/intro.rst (limited to 'Documentation/userspace-api/media/dvb/intro.rst') diff --git a/Documentation/userspace-api/media/dvb/intro.rst b/Documentation/userspace-api/media/dvb/intro.rst new file mode 100644 index 000000000..6784ae796 --- /dev/null +++ b/Documentation/userspace-api/media/dvb/intro.rst @@ -0,0 +1,183 @@ +.. SPDX-License-Identifier: GFDL-1.1-no-invariants-or-later + +.. _dvb_introdution: + +************ +Introduction +************ + + +.. _requisites: + +What you need to know +===================== + +The reader of this document is required to have some knowledge in the +area of digital video broadcasting (Digital TV) and should be familiar with +part I of the MPEG2 specification ISO/IEC 13818 (aka ITU-T H.222), i.e +you should know what a program/transport stream (PS/TS) is and what is +meant by a packetized elementary stream (PES) or an I-frame. + +Various Digital TV standards documents are available for download at: + +- European standards (DVB): http://www.dvb.org and/or http://www.etsi.org. +- American standards (ATSC): https://www.atsc.org/standards/ +- Japanese standards (ISDB): http://www.dibeg.org/ + +It is also necessary to know how to access Linux devices and how to +use ioctl calls. This also includes the knowledge of C or C++. + + +.. _history: + +History +======= + +The first API for Digital TV cards we used at Convergence in late 1999 was an +extension of the Video4Linux API which was primarily developed for frame +grabber cards. As such it was not really well suited to be used for Digital +TV cards and their new features like recording MPEG streams and filtering +several section and PES data streams at the same time. + +In early 2000, Convergence was approached by Nokia with a proposal for a new +standard Linux Digital TV API. As a commitment to the development of terminals +based on open standards, Nokia and Convergence made it available to all +Linux developers and published it on https://linuxtv.org in September +2000. With the Linux driver for the Siemens/Hauppauge DVB PCI card, +Convergence provided a first implementation of the Linux Digital TV API. +Convergence was the maintainer of the Linux Digital TV API in the early +days. + +Now, the API is maintained by the LinuxTV community (i.e. you, the reader +of this document). The Linux Digital TV API is constantly reviewed and +improved together with the improvements at the subsystem's core at the +Kernel. + + +.. _overview: + +Overview +======== + + +.. _stb_components: + +.. kernel-figure:: dvbstb.svg + :alt: dvbstb.svg + :align: center + + Components of a Digital TV card/STB + +A Digital TV card or set-top-box (STB) usually consists of the +following main hardware components: + +Frontend consisting of tuner and digital TV demodulator + Here the raw signal reaches the digital TV hardware from a satellite dish or + antenna or directly from cable. The frontend down-converts and + demodulates this signal into an MPEG transport stream (TS). In case + of a satellite frontend, this includes a facility for satellite + equipment control (SEC), which allows control of LNB polarization, + multi feed switches or dish rotors. + +Conditional Access (CA) hardware like CI adapters and smartcard slots + The complete TS is passed through the CA hardware. Programs to which + the user has access (controlled by the smart card) are decoded in + real time and re-inserted into the TS. + + .. note:: + + Not every digital TV hardware provides conditional access hardware. + +Demultiplexer which filters the incoming Digital TV MPEG-TS stream + The demultiplexer splits the TS into its components like audio and + video streams. Besides usually several of such audio and video + streams it also contains data streams with information about the + programs offered in this or other streams of the same provider. + +Audio and video decoder + The main targets of the demultiplexer are audio and video + decoders. After decoding, they pass on the uncompressed audio and + video to the computer screen or to a TV set. + + .. note:: + + Modern hardware usually doesn't have a separate decoder hardware, as + such functionality can be provided by the main CPU, by the graphics + adapter of the system or by a signal processing hardware embedded on + a Systems on a Chip (SoC) integrated circuit. + + It may also not be needed for certain usages (e.g. for data-only + uses like "internet over satellite"). + +:ref:`stb_components` shows a crude schematic of the control and data +flow between those components. + + + +.. _dvb_devices: + +Linux Digital TV Devices +======================== + +The Linux Digital TV API lets you control these hardware components through +currently six Unix-style character devices for video, audio, frontend, +demux, CA and IP-over-DVB networking. The video and audio devices +control the MPEG2 decoder hardware, the frontend device the tuner and +the Digital TV demodulator. The demux device gives you control over the PES +and section filters of the hardware. If the hardware does not support +filtering these filters can be implemented in software. Finally, the CA +device controls all the conditional access capabilities of the hardware. +It can depend on the individual security requirements of the platform, +if and how many of the CA functions are made available to the +application through this device. + +All devices can be found in the ``/dev`` tree under ``/dev/dvb``. The +individual devices are called: + +- ``/dev/dvb/adapterN/audioM``, + +- ``/dev/dvb/adapterN/videoM``, + +- ``/dev/dvb/adapterN/frontendM``, + +- ``/dev/dvb/adapterN/netM``, + +- ``/dev/dvb/adapterN/demuxM``, + +- ``/dev/dvb/adapterN/dvrM``, + +- ``/dev/dvb/adapterN/caM``, + +where ``N`` enumerates the Digital TV cards in a system starting from 0, and +``M`` enumerates the devices of each type within each adapter, starting +from 0, too. We will omit the "``/dev/dvb/adapterN/``\ " in the further +discussion of these devices. + +More details about the data structures and function calls of all the +devices are described in the following chapters. + + +.. _include_files: + +API include files +================= + +For each of the Digital TV devices a corresponding include file exists. The +Digital TV API include files should be included in application sources with a +partial path like: + + +.. code-block:: c + + #include + + #include + + #include + + #include + + +To enable applications to support different API version, an additional +include file ``linux/dvb/version.h`` exists, which defines the constant +``DVB_API_VERSION``. This document describes ``DVB_API_VERSION 5.10``. -- cgit v1.2.3