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authorLibravatar Linus Torvalds <torvalds@linux-foundation.org>2023-02-21 18:24:12 -0800
committerLibravatar Linus Torvalds <torvalds@linux-foundation.org>2023-02-21 18:24:12 -0800
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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(). ...
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+.. SPDX-License-Identifier: GPL-2.0 OR GFDL-1.1-no-invariants-or-later
+.. c:namespace:: MC
+
+.. _media-request-api:
+
+Request API
+===========
+
+The Request API has been designed to allow V4L2 to deal with requirements of
+modern devices (stateless codecs, complex camera pipelines, ...) and APIs
+(Android Codec v2). One such requirement is the ability for devices belonging to
+the same pipeline to reconfigure and collaborate closely on a per-frame basis.
+Another is support of stateless codecs, which require controls to be applied
+to specific frames (aka 'per-frame controls') in order to be used efficiently.
+
+While the initial use-case was V4L2, it can be extended to other subsystems
+as well, as long as they use the media controller.
+
+Supporting these features without the Request API is not always possible and if
+it is, it is terribly inefficient: user-space would have to flush all activity
+on the media pipeline, reconfigure it for the next frame, queue the buffers to
+be processed with that configuration, and wait until they are all available for
+dequeuing before considering the next frame. This defeats the purpose of having
+buffer queues since in practice only one buffer would be queued at a time.
+
+The Request API allows a specific configuration of the pipeline (media
+controller topology + configuration for each media entity) to be associated with
+specific buffers. This allows user-space to schedule several tasks ("requests")
+with different configurations in advance, knowing that the configuration will be
+applied when needed to get the expected result. Configuration values at the time
+of request completion are also available for reading.
+
+General Usage
+-------------
+
+The Request API extends the Media Controller API and cooperates with
+subsystem-specific APIs to support request usage. At the Media Controller
+level, requests are allocated from the supporting Media Controller device
+node. Their life cycle is then managed through the request file descriptors in
+an opaque way. Configuration data, buffer handles and processing results
+stored in requests are accessed through subsystem-specific APIs extended for
+request support, such as V4L2 APIs that take an explicit ``request_fd``
+parameter.
+
+Request Allocation
+------------------
+
+User-space allocates requests using :ref:`MEDIA_IOC_REQUEST_ALLOC`
+for the media device node. This returns a file descriptor representing the
+request. Typically, several such requests will be allocated.
+
+Request Preparation
+-------------------
+
+Standard V4L2 ioctls can then receive a request file descriptor to express the
+fact that the ioctl is part of said request, and is not to be applied
+immediately. See :ref:`MEDIA_IOC_REQUEST_ALLOC` for a list of ioctls that
+support this. Configurations set with a ``request_fd`` parameter are stored
+instead of being immediately applied, and buffers queued to a request do not
+enter the regular buffer queue until the request itself is queued.
+
+Request Submission
+------------------
+
+Once the configuration and buffers of the request are specified, it can be
+queued by calling :ref:`MEDIA_REQUEST_IOC_QUEUE` on the request file descriptor.
+A request must contain at least one buffer, otherwise ``ENOENT`` is returned.
+A queued request cannot be modified anymore.
+
+.. caution::
+ For :ref:`memory-to-memory devices <mem2mem>` you can use requests only for
+ output buffers, not for capture buffers. Attempting to add a capture buffer
+ to a request will result in an ``EBADR`` error.
+
+If the request contains configurations for multiple entities, individual drivers
+may synchronize so the requested pipeline's topology is applied before the
+buffers are processed. Media controller drivers do a best effort implementation
+since perfect atomicity may not be possible due to hardware limitations.
+
+.. caution::
+
+ It is not allowed to mix queuing requests with directly queuing buffers:
+ whichever method is used first locks this in place until
+ :ref:`VIDIOC_STREAMOFF <VIDIOC_STREAMON>` is called or the device is
+ :ref:`closed <func-close>`. Attempts to directly queue a buffer when earlier
+ a buffer was queued via a request or vice versa will result in an ``EBUSY``
+ error.
+
+Controls can still be set without a request and are applied immediately,
+regardless of whether a request is in use or not.
+
+.. caution::
+
+ Setting the same control through a request and also directly can lead to
+ undefined behavior!
+
+User-space can :c:func:`poll()` a request file descriptor in
+order to wait until the request completes. A request is considered complete
+once all its associated buffers are available for dequeuing and all the
+associated controls have been updated with the values at the time of completion.
+Note that user-space does not need to wait for the request to complete to
+dequeue its buffers: buffers that are available halfway through a request can
+be dequeued independently of the request's state.
+
+A completed request contains the state of the device after the request was
+executed. User-space can query that state by calling
+:ref:`ioctl VIDIOC_G_EXT_CTRLS <VIDIOC_G_EXT_CTRLS>` with the request file
+descriptor. Calling :ref:`ioctl VIDIOC_G_EXT_CTRLS <VIDIOC_G_EXT_CTRLS>` for a
+request that has been queued but not yet completed will return ``EBUSY``
+since the control values might be changed at any time by the driver while the
+request is in flight.
+
+.. _media-request-life-time:
+
+Recycling and Destruction
+-------------------------
+
+Finally, a completed request can either be discarded or be reused. Calling
+:c:func:`close()` on a request file descriptor will make
+that file descriptor unusable and the request will be freed once it is no
+longer in use by the kernel. That is, if the request is queued and then the
+file descriptor is closed, then it won't be freed until the driver completed
+the request.
+
+The :ref:`MEDIA_REQUEST_IOC_REINIT` will clear a request's state and make it
+available again. No state is retained by this operation: the request is as
+if it had just been allocated.
+
+Example for a Codec Device
+--------------------------
+
+For use-cases such as :ref:`codecs <mem2mem>`, the request API can be used
+to associate specific controls to
+be applied by the driver for the OUTPUT buffer, allowing user-space
+to queue many such buffers in advance. It can also take advantage of requests'
+ability to capture the state of controls when the request completes to read back
+information that may be subject to change.
+
+Put into code, after obtaining a request, user-space can assign controls and one
+OUTPUT buffer to it:
+
+.. code-block:: c
+
+ struct v4l2_buffer buf;
+ struct v4l2_ext_controls ctrls;
+ int req_fd;
+ ...
+ if (ioctl(media_fd, MEDIA_IOC_REQUEST_ALLOC, &req_fd))
+ return errno;
+ ...
+ ctrls.which = V4L2_CTRL_WHICH_REQUEST_VAL;
+ ctrls.request_fd = req_fd;
+ if (ioctl(codec_fd, VIDIOC_S_EXT_CTRLS, &ctrls))
+ return errno;
+ ...
+ buf.type = V4L2_BUF_TYPE_VIDEO_OUTPUT;
+ buf.flags |= V4L2_BUF_FLAG_REQUEST_FD;
+ buf.request_fd = req_fd;
+ if (ioctl(codec_fd, VIDIOC_QBUF, &buf))
+ return errno;
+
+Note that it is not allowed to use the Request API for CAPTURE buffers
+since there are no per-frame settings to report there.
+
+Once the request is fully prepared, it can be queued to the driver:
+
+.. code-block:: c
+
+ if (ioctl(req_fd, MEDIA_REQUEST_IOC_QUEUE))
+ return errno;
+
+User-space can then either wait for the request to complete by calling poll() on
+its file descriptor, or start dequeuing CAPTURE buffers. Most likely, it will
+want to get CAPTURE buffers as soon as possible and this can be done using a
+regular :ref:`VIDIOC_DQBUF <VIDIOC_QBUF>`:
+
+.. code-block:: c
+
+ struct v4l2_buffer buf;
+
+ memset(&buf, 0, sizeof(buf));
+ buf.type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
+ if (ioctl(codec_fd, VIDIOC_DQBUF, &buf))
+ return errno;
+
+Note that this example assumes for simplicity that for every OUTPUT buffer
+there will be one CAPTURE buffer, but this does not have to be the case.
+
+We can then, after ensuring that the request is completed via polling the
+request file descriptor, query control values at the time of its completion via
+a call to :ref:`VIDIOC_G_EXT_CTRLS <VIDIOC_G_EXT_CTRLS>`.
+This is particularly useful for volatile controls for which we want to
+query values as soon as the capture buffer is produced.
+
+.. code-block:: c
+
+ struct pollfd pfd = { .events = POLLPRI, .fd = req_fd };
+ poll(&pfd, 1, -1);
+ ...
+ ctrls.which = V4L2_CTRL_WHICH_REQUEST_VAL;
+ ctrls.request_fd = req_fd;
+ if (ioctl(codec_fd, VIDIOC_G_EXT_CTRLS, &ctrls))
+ return errno;
+
+Once we don't need the request anymore, we can either recycle it for reuse with
+:ref:`MEDIA_REQUEST_IOC_REINIT`...
+
+.. code-block:: c
+
+ if (ioctl(req_fd, MEDIA_REQUEST_IOC_REINIT))
+ return errno;
+
+... or close its file descriptor to completely dispose of it.
+
+.. code-block:: c
+
+ close(req_fd);
+
+Example for a Simple Capture Device
+-----------------------------------
+
+With a simple capture device, requests can be used to specify controls to apply
+for a given CAPTURE buffer.
+
+.. code-block:: c
+
+ struct v4l2_buffer buf;
+ struct v4l2_ext_controls ctrls;
+ int req_fd;
+ ...
+ if (ioctl(media_fd, MEDIA_IOC_REQUEST_ALLOC, &req_fd))
+ return errno;
+ ...
+ ctrls.which = V4L2_CTRL_WHICH_REQUEST_VAL;
+ ctrls.request_fd = req_fd;
+ if (ioctl(camera_fd, VIDIOC_S_EXT_CTRLS, &ctrls))
+ return errno;
+ ...
+ buf.type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
+ buf.flags |= V4L2_BUF_FLAG_REQUEST_FD;
+ buf.request_fd = req_fd;
+ if (ioctl(camera_fd, VIDIOC_QBUF, &buf))
+ return errno;
+
+Once the request is fully prepared, it can be queued to the driver:
+
+.. code-block:: c
+
+ if (ioctl(req_fd, MEDIA_REQUEST_IOC_QUEUE))
+ return errno;
+
+User-space can then dequeue buffers, wait for the request completion, query
+controls and recycle the request as in the M2M example above.