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/s390/driver-model.rst | 328 ++++++++++++++++++++++++++++++++++++ 1 file changed, 328 insertions(+) create mode 100644 Documentation/s390/driver-model.rst (limited to 'Documentation/s390/driver-model.rst') diff --git a/Documentation/s390/driver-model.rst b/Documentation/s390/driver-model.rst new file mode 100644 index 000000000..ad4bc2dbe --- /dev/null +++ b/Documentation/s390/driver-model.rst @@ -0,0 +1,328 @@ +============================= +S/390 driver model interfaces +============================= + +1. CCW devices +-------------- + +All devices which can be addressed by means of ccws are called 'CCW devices' - +even if they aren't actually driven by ccws. + +All ccw devices are accessed via a subchannel, this is reflected in the +structures under devices/:: + + devices/ + - system/ + - css0/ + - 0.0.0000/0.0.0815/ + - 0.0.0001/0.0.4711/ + - 0.0.0002/ + - 0.1.0000/0.1.1234/ + ... + - defunct/ + +In this example, device 0815 is accessed via subchannel 0 in subchannel set 0, +device 4711 via subchannel 1 in subchannel set 0, and subchannel 2 is a non-I/O +subchannel. Device 1234 is accessed via subchannel 0 in subchannel set 1. + +The subchannel named 'defunct' does not represent any real subchannel on the +system; it is a pseudo subchannel where disconnected ccw devices are moved to +if they are displaced by another ccw device becoming operational on their +former subchannel. The ccw devices will be moved again to a proper subchannel +if they become operational again on that subchannel. + +You should address a ccw device via its bus id (e.g. 0.0.4711); the device can +be found under bus/ccw/devices/. + +All ccw devices export some data via sysfs. + +cutype: + The control unit type / model. + +devtype: + The device type / model, if applicable. + +availability: + Can be 'good' or 'boxed'; 'no path' or 'no device' for + disconnected devices. + +online: + An interface to set the device online and offline. + In the special case of the device being disconnected (see the + notify function under 1.2), piping 0 to online will forcibly delete + the device. + +The device drivers can add entries to export per-device data and interfaces. + +There is also some data exported on a per-subchannel basis (see under +bus/css/devices/): + +chpids: + Via which chpids the device is connected. + +pimpampom: + The path installed, path available and path operational masks. + +There also might be additional data, for example for block devices. + + +1.1 Bringing up a ccw device +---------------------------- + +This is done in several steps. + +a. Each driver can provide one or more parameter interfaces where parameters can + be specified. These interfaces are also in the driver's responsibility. +b. After a. has been performed, if necessary, the device is finally brought up + via the 'online' interface. + + +1.2 Writing a driver for ccw devices +------------------------------------ + +The basic struct ccw_device and struct ccw_driver data structures can be found +under include/asm/ccwdev.h:: + + struct ccw_device { + spinlock_t *ccwlock; + struct ccw_device_private *private; + struct ccw_device_id id; + + struct ccw_driver *drv; + struct device dev; + int online; + + void (*handler) (struct ccw_device *dev, unsigned long intparm, + struct irb *irb); + }; + + struct ccw_driver { + struct module *owner; + struct ccw_device_id *ids; + int (*probe) (struct ccw_device *); + int (*remove) (struct ccw_device *); + int (*set_online) (struct ccw_device *); + int (*set_offline) (struct ccw_device *); + int (*notify) (struct ccw_device *, int); + struct device_driver driver; + char *name; + }; + +The 'private' field contains data needed for internal i/o operation only, and +is not available to the device driver. + +Each driver should declare in a MODULE_DEVICE_TABLE into which CU types/models +and/or device types/models it is interested. This information can later be found +in the struct ccw_device_id fields:: + + struct ccw_device_id { + __u16 match_flags; + + __u16 cu_type; + __u16 dev_type; + __u8 cu_model; + __u8 dev_model; + + unsigned long driver_info; + }; + +The functions in ccw_driver should be used in the following way: + +probe: + This function is called by the device layer for each device the driver + is interested in. The driver should only allocate private structures + to put in dev->driver_data and create attributes (if needed). Also, + the interrupt handler (see below) should be set here. + +:: + + int (*probe) (struct ccw_device *cdev); + +Parameters: + cdev + - the device to be probed. + + +remove: + This function is called by the device layer upon removal of the driver, + the device or the module. The driver should perform cleanups here. + +:: + + int (*remove) (struct ccw_device *cdev); + +Parameters: + cdev + - the device to be removed. + + +set_online: + This function is called by the common I/O layer when the device is + activated via the 'online' attribute. The driver should finally + setup and activate the device here. + +:: + + int (*set_online) (struct ccw_device *); + +Parameters: + cdev + - the device to be activated. The common layer has + verified that the device is not already online. + + +set_offline: This function is called by the common I/O layer when the device is + de-activated via the 'online' attribute. The driver should shut + down the device, but not de-allocate its private data. + +:: + + int (*set_offline) (struct ccw_device *); + +Parameters: + cdev + - the device to be deactivated. The common layer has + verified that the device is online. + + +notify: + This function is called by the common I/O layer for some state changes + of the device. + + Signalled to the driver are: + + * In online state, device detached (CIO_GONE) or last path gone + (CIO_NO_PATH). The driver must return !0 to keep the device; for + return code 0, the device will be deleted as usual (also when no + notify function is registered). If the driver wants to keep the + device, it is moved into disconnected state. + * In disconnected state, device operational again (CIO_OPER). The + common I/O layer performs some sanity checks on device number and + Device / CU to be reasonably sure if it is still the same device. + If not, the old device is removed and a new one registered. By the + return code of the notify function the device driver signals if it + wants the device back: !0 for keeping, 0 to make the device being + removed and re-registered. + +:: + + int (*notify) (struct ccw_device *, int); + +Parameters: + cdev + - the device whose state changed. + + event + - the event that happened. This can be one of CIO_GONE, + CIO_NO_PATH or CIO_OPER. + +The handler field of the struct ccw_device is meant to be set to the interrupt +handler for the device. In order to accommodate drivers which use several +distinct handlers (e.g. multi subchannel devices), this is a member of ccw_device +instead of ccw_driver. +The handler is registered with the common layer during set_online() processing +before the driver is called, and is deregistered during set_offline() after the +driver has been called. Also, after registering / before deregistering, path +grouping resp. disbanding of the path group (if applicable) are performed. + +:: + + void (*handler) (struct ccw_device *dev, unsigned long intparm, struct irb *irb); + +Parameters: dev - the device the handler is called for + intparm - the intparm which allows the device driver to identify + the i/o the interrupt is associated with, or to recognize + the interrupt as unsolicited. + irb - interruption response block which contains the accumulated + status. + +The device driver is called from the common ccw_device layer and can retrieve +information about the interrupt from the irb parameter. + + +1.3 ccwgroup devices +-------------------- + +The ccwgroup mechanism is designed to handle devices consisting of multiple ccw +devices, like lcs or ctc. + +The ccw driver provides a 'group' attribute. Piping bus ids of ccw devices to +this attributes creates a ccwgroup device consisting of these ccw devices (if +possible). This ccwgroup device can be set online or offline just like a normal +ccw device. + +Each ccwgroup device also provides an 'ungroup' attribute to destroy the device +again (only when offline). This is a generic ccwgroup mechanism (the driver does +not need to implement anything beyond normal removal routines). + +A ccw device which is a member of a ccwgroup device carries a pointer to the +ccwgroup device in the driver_data of its device struct. This field must not be +touched by the driver - it should use the ccwgroup device's driver_data for its +private data. + +To implement a ccwgroup driver, please refer to include/asm/ccwgroup.h. Keep in +mind that most drivers will need to implement both a ccwgroup and a ccw +driver. + + +2. Channel paths +----------------- + +Channel paths show up, like subchannels, under the channel subsystem root (css0) +and are called 'chp0.'. They have no driver and do not belong to any bus. +Please note, that unlike /proc/chpids in 2.4, the channel path objects reflect +only the logical state and not the physical state, since we cannot track the +latter consistently due to lacking machine support (we don't need to be aware +of it anyway). + +status + - Can be 'online' or 'offline'. + Piping 'on' or 'off' sets the chpid logically online/offline. + Piping 'on' to an online chpid triggers path reprobing for all devices + the chpid connects to. This can be used to force the kernel to re-use + a channel path the user knows to be online, but the machine hasn't + created a machine check for. + +type + - The physical type of the channel path. + +shared + - Whether the channel path is shared. + +cmg + - The channel measurement group. + +3. System devices +----------------- + +3.1 xpram +--------- + +xpram shows up under devices/system/ as 'xpram'. + +3.2 cpus +-------- + +For each cpu, a directory is created under devices/system/cpu/. Each cpu has an +attribute 'online' which can be 0 or 1. + + +4. Other devices +---------------- + +4.1 Netiucv +----------- + +The netiucv driver creates an attribute 'connection' under +bus/iucv/drivers/netiucv. Piping to this attribute creates a new netiucv +connection to the specified host. + +Netiucv connections show up under devices/iucv/ as "netiucv". The interface +number is assigned sequentially to the connections defined via the 'connection' +attribute. + +user + - shows the connection partner. + +buffer + - maximum buffer size. Pipe to it to change buffer size. -- cgit v1.2.3