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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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+============================================
+Linux USB gadget configured through configfs
+============================================
+
+
+25th April 2013
+
+
+
+
+Overview
+========
+
+A USB Linux Gadget is a device which has a UDC (USB Device Controller) and can
+be connected to a USB Host to extend it with additional functions like a serial
+port or a mass storage capability.
+
+A gadget is seen by its host as a set of configurations, each of which contains
+a number of interfaces which, from the gadget's perspective, are known as
+functions, each function representing e.g. a serial connection or a SCSI disk.
+
+Linux provides a number of functions for gadgets to use.
+
+Creating a gadget means deciding what configurations there will be
+and which functions each configuration will provide.
+
+Configfs (please see `Documentation/filesystems/configfs.rst`) lends itself nicely
+for the purpose of telling the kernel about the above mentioned decision.
+This document is about how to do it.
+
+It also describes how configfs integration into gadget is designed.
+
+
+
+
+Requirements
+============
+
+In order for this to work configfs must be available, so CONFIGFS_FS must be
+'y' or 'm' in .config. As of this writing USB_LIBCOMPOSITE selects CONFIGFS_FS.
+
+
+
+
+Usage
+=====
+
+(The original post describing the first function
+made available through configfs can be seen here:
+http://www.spinics.net/lists/linux-usb/msg76388.html)
+
+::
+
+ $ modprobe libcomposite
+ $ mount none $CONFIGFS_HOME -t configfs
+
+where CONFIGFS_HOME is the mount point for configfs
+
+1. Creating the gadgets
+-----------------------
+
+For each gadget to be created its corresponding directory must be created::
+
+ $ mkdir $CONFIGFS_HOME/usb_gadget/<gadget name>
+
+e.g.::
+
+ $ mkdir $CONFIGFS_HOME/usb_gadget/g1
+
+ ...
+ ...
+ ...
+
+ $ cd $CONFIGFS_HOME/usb_gadget/g1
+
+Each gadget needs to have its vendor id <VID> and product id <PID> specified::
+
+ $ echo <VID> > idVendor
+ $ echo <PID> > idProduct
+
+A gadget also needs its serial number, manufacturer and product strings.
+In order to have a place to store them, a strings subdirectory must be created
+for each language, e.g.::
+
+ $ mkdir strings/0x409
+
+Then the strings can be specified::
+
+ $ echo <serial number> > strings/0x409/serialnumber
+ $ echo <manufacturer> > strings/0x409/manufacturer
+ $ echo <product> > strings/0x409/product
+
+2. Creating the configurations
+------------------------------
+
+Each gadget will consist of a number of configurations, their corresponding
+directories must be created:
+
+$ mkdir configs/<name>.<number>
+
+where <name> can be any string which is legal in a filesystem and the
+<number> is the configuration's number, e.g.::
+
+ $ mkdir configs/c.1
+
+ ...
+ ...
+ ...
+
+Each configuration also needs its strings, so a subdirectory must be created
+for each language, e.g.::
+
+ $ mkdir configs/c.1/strings/0x409
+
+Then the configuration string can be specified::
+
+ $ echo <configuration> > configs/c.1/strings/0x409/configuration
+
+Some attributes can also be set for a configuration, e.g.::
+
+ $ echo 120 > configs/c.1/MaxPower
+
+3. Creating the functions
+-------------------------
+
+The gadget will provide some functions, for each function its corresponding
+directory must be created::
+
+ $ mkdir functions/<name>.<instance name>
+
+where <name> corresponds to one of allowed function names and instance name
+is an arbitrary string allowed in a filesystem, e.g.::
+
+ $ mkdir functions/ncm.usb0 # usb_f_ncm.ko gets loaded with request_module()
+
+ ...
+ ...
+ ...
+
+Each function provides its specific set of attributes, with either read-only
+or read-write access. Where applicable they need to be written to as
+appropriate.
+Please refer to Documentation/ABI/testing/configfs-usb-gadget for more information.
+
+4. Associating the functions with their configurations
+------------------------------------------------------
+
+At this moment a number of gadgets is created, each of which has a number of
+configurations specified and a number of functions available. What remains
+is specifying which function is available in which configuration (the same
+function can be used in multiple configurations). This is achieved with
+creating symbolic links::
+
+ $ ln -s functions/<name>.<instance name> configs/<name>.<number>
+
+e.g.::
+
+ $ ln -s functions/ncm.usb0 configs/c.1
+
+ ...
+ ...
+ ...
+
+5. Enabling the gadget
+----------------------
+
+All the above steps serve the purpose of composing the gadget of
+configurations and functions.
+
+An example directory structure might look like this::
+
+ .
+ ./strings
+ ./strings/0x409
+ ./strings/0x409/serialnumber
+ ./strings/0x409/product
+ ./strings/0x409/manufacturer
+ ./configs
+ ./configs/c.1
+ ./configs/c.1/ncm.usb0 -> ../../../../usb_gadget/g1/functions/ncm.usb0
+ ./configs/c.1/strings
+ ./configs/c.1/strings/0x409
+ ./configs/c.1/strings/0x409/configuration
+ ./configs/c.1/bmAttributes
+ ./configs/c.1/MaxPower
+ ./functions
+ ./functions/ncm.usb0
+ ./functions/ncm.usb0/ifname
+ ./functions/ncm.usb0/qmult
+ ./functions/ncm.usb0/host_addr
+ ./functions/ncm.usb0/dev_addr
+ ./UDC
+ ./bcdUSB
+ ./bcdDevice
+ ./idProduct
+ ./idVendor
+ ./bMaxPacketSize0
+ ./bDeviceProtocol
+ ./bDeviceSubClass
+ ./bDeviceClass
+
+
+Such a gadget must be finally enabled so that the USB host can enumerate it.
+
+In order to enable the gadget it must be bound to a UDC (USB Device
+Controller)::
+
+ $ echo <udc name> > UDC
+
+where <udc name> is one of those found in /sys/class/udc/*
+e.g.::
+
+ $ echo s3c-hsotg > UDC
+
+
+6. Disabling the gadget
+-----------------------
+
+::
+
+ $ echo "" > UDC
+
+7. Cleaning up
+--------------
+
+Remove functions from configurations::
+
+ $ rm configs/<config name>.<number>/<function>
+
+where <config name>.<number> specify the configuration and <function> is
+a symlink to a function being removed from the configuration, e.g.::
+
+ $ rm configs/c.1/ncm.usb0
+
+ ...
+ ...
+ ...
+
+Remove strings directories in configurations:
+
+ $ rmdir configs/<config name>.<number>/strings/<lang>
+
+e.g.::
+
+ $ rmdir configs/c.1/strings/0x409
+
+ ...
+ ...
+ ...
+
+and remove the configurations::
+
+ $ rmdir configs/<config name>.<number>
+
+e.g.::
+
+ rmdir configs/c.1
+
+ ...
+ ...
+ ...
+
+Remove functions (function modules are not unloaded, though):
+
+ $ rmdir functions/<name>.<instance name>
+
+e.g.::
+
+ $ rmdir functions/ncm.usb0
+
+ ...
+ ...
+ ...
+
+Remove strings directories in the gadget::
+
+ $ rmdir strings/<lang>
+
+e.g.::
+
+ $ rmdir strings/0x409
+
+and finally remove the gadget::
+
+ $ cd ..
+ $ rmdir <gadget name>
+
+e.g.::
+
+ $ rmdir g1
+
+
+
+
+Implementation design
+=====================
+
+Below the idea of how configfs works is presented.
+In configfs there are items and groups, both represented as directories.
+The difference between an item and a group is that a group can contain
+other groups. In the picture below only an item is shown.
+Both items and groups can have attributes, which are represented as files.
+The user can create and remove directories, but cannot remove files,
+which can be read-only or read-write, depending on what they represent.
+
+The filesystem part of configfs operates on config_items/groups and
+configfs_attributes which are generic and of the same type for all
+configured elements. However, they are embedded in usage-specific
+larger structures. In the picture below there is a "cs" which contains
+a config_item and an "sa" which contains a configfs_attribute.
+
+The filesystem view would be like this::
+
+ ./
+ ./cs (directory)
+ |
+ +--sa (file)
+ |
+ .
+ .
+ .
+
+Whenever a user reads/writes the "sa" file, a function is called
+which accepts a struct config_item and a struct configfs_attribute.
+In the said function the "cs" and "sa" are retrieved using the well
+known container_of technique and an appropriate sa's function (show or
+store) is called and passed the "cs" and a character buffer. The "show"
+is for displaying the file's contents (copy data from the cs to the
+buffer), while the "store" is for modifying the file's contents (copy data
+from the buffer to the cs), but it is up to the implementer of the
+two functions to decide what they actually do.
+
+::
+
+ typedef struct configured_structure cs;
+ typedef struct specific_attribute sa;
+
+ sa
+ +----------------------------------+
+ cs | (*show)(cs *, buffer); |
+ +-----------------+ | (*store)(cs *, buffer, length); |
+ | | | |
+ | +-------------+ | | +------------------+ |
+ | | struct |-|----|------>|struct | |
+ | | config_item | | | |configfs_attribute| |
+ | +-------------+ | | +------------------+ |
+ | | +----------------------------------+
+ | data to be set | .
+ | | .
+ +-----------------+ .
+
+The file names are decided by the config item/group designer, while
+the directories in general can be named at will. A group can have
+a number of its default sub-groups created automatically.
+
+For more information on configfs please see
+`Documentation/filesystems/configfs.rst`.
+
+The concepts described above translate to USB gadgets like this:
+
+1. A gadget has its config group, which has some attributes (idVendor,
+idProduct etc) and default sub-groups (configs, functions, strings).
+Writing to the attributes causes the information to be stored in
+appropriate locations. In the configs, functions and strings sub-groups
+a user can create their sub-groups to represent configurations, functions,
+and groups of strings in a given language.
+
+2. The user creates configurations and functions, in the configurations
+creates symbolic links to functions. This information is used when the
+gadget's UDC attribute is written to, which means binding the gadget
+to the UDC. The code in drivers/usb/gadget/configfs.c iterates over
+all configurations, and in each configuration it iterates over all
+functions and binds them. This way the whole gadget is bound.
+
+3. The file drivers/usb/gadget/configfs.c contains code for
+
+ - gadget's config_group
+ - gadget's default groups (configs, functions, strings)
+ - associating functions with configurations (symlinks)
+
+4. Each USB function naturally has its own view of what it wants
+configured, so config_groups for particular functions are defined
+in the functions implementation files drivers/usb/gadget/f_*.c.
+
+5. Function's code is written in such a way that it uses
+
+usb_get_function_instance(), which, in turn, calls request_module.
+So, provided that modprobe works, modules for particular functions
+are loaded automatically. Please note that the converse is not true:
+after a gadget is disabled and torn down, the modules remain loaded.