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/PCI/endpoint/pci-endpoint.rst | 231 ++++++++++++++++++++++++++++ 1 file changed, 231 insertions(+) create mode 100644 Documentation/PCI/endpoint/pci-endpoint.rst (limited to 'Documentation/PCI/endpoint/pci-endpoint.rst') diff --git a/Documentation/PCI/endpoint/pci-endpoint.rst b/Documentation/PCI/endpoint/pci-endpoint.rst new file mode 100644 index 000000000..4f5622a65 --- /dev/null +++ b/Documentation/PCI/endpoint/pci-endpoint.rst @@ -0,0 +1,231 @@ +.. SPDX-License-Identifier: GPL-2.0 + +:Author: Kishon Vijay Abraham I + +This document is a guide to use the PCI Endpoint Framework in order to create +endpoint controller driver, endpoint function driver, and using configfs +interface to bind the function driver to the controller driver. + +Introduction +============ + +Linux has a comprehensive PCI subsystem to support PCI controllers that +operates in Root Complex mode. The subsystem has capability to scan PCI bus, +assign memory resources and IRQ resources, load PCI driver (based on +vendor ID, device ID), support other services like hot-plug, power management, +advanced error reporting and virtual channels. + +However the PCI controller IP integrated in some SoCs is capable of operating +either in Root Complex mode or Endpoint mode. PCI Endpoint Framework will +add endpoint mode support in Linux. This will help to run Linux in an +EP system which can have a wide variety of use cases from testing or +validation, co-processor accelerator, etc. + +PCI Endpoint Core +================= + +The PCI Endpoint Core layer comprises 3 components: the Endpoint Controller +library, the Endpoint Function library, and the configfs layer to bind the +endpoint function with the endpoint controller. + +PCI Endpoint Controller(EPC) Library +------------------------------------ + +The EPC library provides APIs to be used by the controller that can operate +in endpoint mode. It also provides APIs to be used by function driver/library +in order to implement a particular endpoint function. + +APIs for the PCI controller Driver +~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ + +This section lists the APIs that the PCI Endpoint core provides to be used +by the PCI controller driver. + +* devm_pci_epc_create()/pci_epc_create() + + The PCI controller driver should implement the following ops: + + * write_header: ops to populate configuration space header + * set_bar: ops to configure the BAR + * clear_bar: ops to reset the BAR + * alloc_addr_space: ops to allocate in PCI controller address space + * free_addr_space: ops to free the allocated address space + * raise_irq: ops to raise a legacy, MSI or MSI-X interrupt + * start: ops to start the PCI link + * stop: ops to stop the PCI link + + The PCI controller driver can then create a new EPC device by invoking + devm_pci_epc_create()/pci_epc_create(). + +* devm_pci_epc_destroy()/pci_epc_destroy() + + The PCI controller driver can destroy the EPC device created by either + devm_pci_epc_create() or pci_epc_create() using devm_pci_epc_destroy() or + pci_epc_destroy(). + +* pci_epc_linkup() + + In order to notify all the function devices that the EPC device to which + they are linked has established a link with the host, the PCI controller + driver should invoke pci_epc_linkup(). + +* pci_epc_mem_init() + + Initialize the pci_epc_mem structure used for allocating EPC addr space. + +* pci_epc_mem_exit() + + Cleanup the pci_epc_mem structure allocated during pci_epc_mem_init(). + + +EPC APIs for the PCI Endpoint Function Driver +~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ + +This section lists the APIs that the PCI Endpoint core provides to be used +by the PCI endpoint function driver. + +* pci_epc_write_header() + + The PCI endpoint function driver should use pci_epc_write_header() to + write the standard configuration header to the endpoint controller. + +* pci_epc_set_bar() + + The PCI endpoint function driver should use pci_epc_set_bar() to configure + the Base Address Register in order for the host to assign PCI addr space. + Register space of the function driver is usually configured + using this API. + +* pci_epc_clear_bar() + + The PCI endpoint function driver should use pci_epc_clear_bar() to reset + the BAR. + +* pci_epc_raise_irq() + + The PCI endpoint function driver should use pci_epc_raise_irq() to raise + Legacy Interrupt, MSI or MSI-X Interrupt. + +* pci_epc_mem_alloc_addr() + + The PCI endpoint function driver should use pci_epc_mem_alloc_addr(), to + allocate memory address from EPC addr space which is required to access + RC's buffer + +* pci_epc_mem_free_addr() + + The PCI endpoint function driver should use pci_epc_mem_free_addr() to + free the memory space allocated using pci_epc_mem_alloc_addr(). + +Other EPC APIs +~~~~~~~~~~~~~~ + +There are other APIs provided by the EPC library. These are used for binding +the EPF device with EPC device. pci-ep-cfs.c can be used as reference for +using these APIs. + +* pci_epc_get() + + Get a reference to the PCI endpoint controller based on the device name of + the controller. + +* pci_epc_put() + + Release the reference to the PCI endpoint controller obtained using + pci_epc_get() + +* pci_epc_add_epf() + + Add a PCI endpoint function to a PCI endpoint controller. A PCIe device + can have up to 8 functions according to the specification. + +* pci_epc_remove_epf() + + Remove the PCI endpoint function from PCI endpoint controller. + +* pci_epc_start() + + The PCI endpoint function driver should invoke pci_epc_start() once it + has configured the endpoint function and wants to start the PCI link. + +* pci_epc_stop() + + The PCI endpoint function driver should invoke pci_epc_stop() to stop + the PCI LINK. + + +PCI Endpoint Function(EPF) Library +---------------------------------- + +The EPF library provides APIs to be used by the function driver and the EPC +library to provide endpoint mode functionality. + +EPF APIs for the PCI Endpoint Function Driver +~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ + +This section lists the APIs that the PCI Endpoint core provides to be used +by the PCI endpoint function driver. + +* pci_epf_register_driver() + + The PCI Endpoint Function driver should implement the following ops: + * bind: ops to perform when a EPC device has been bound to EPF device + * unbind: ops to perform when a binding has been lost between a EPC + device and EPF device + * linkup: ops to perform when the EPC device has established a + connection with a host system + + The PCI Function driver can then register the PCI EPF driver by using + pci_epf_register_driver(). + +* pci_epf_unregister_driver() + + The PCI Function driver can unregister the PCI EPF driver by using + pci_epf_unregister_driver(). + +* pci_epf_alloc_space() + + The PCI Function driver can allocate space for a particular BAR using + pci_epf_alloc_space(). + +* pci_epf_free_space() + + The PCI Function driver can free the allocated space + (using pci_epf_alloc_space) by invoking pci_epf_free_space(). + +APIs for the PCI Endpoint Controller Library +~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ + +This section lists the APIs that the PCI Endpoint core provides to be used +by the PCI endpoint controller library. + +* pci_epf_linkup() + + The PCI endpoint controller library invokes pci_epf_linkup() when the + EPC device has established the connection to the host. + +Other EPF APIs +~~~~~~~~~~~~~~ + +There are other APIs provided by the EPF library. These are used to notify +the function driver when the EPF device is bound to the EPC device. +pci-ep-cfs.c can be used as reference for using these APIs. + +* pci_epf_create() + + Create a new PCI EPF device by passing the name of the PCI EPF device. + This name will be used to bind the EPF device to a EPF driver. + +* pci_epf_destroy() + + Destroy the created PCI EPF device. + +* pci_epf_bind() + + pci_epf_bind() should be invoked when the EPF device has been bound to + a EPC device. + +* pci_epf_unbind() + + pci_epf_unbind() should be invoked when the binding between EPC device + and EPF device is lost. -- cgit v1.2.3