.. SPDX-License-Identifier: GPL-2.0 ===================================================================== Linux kernel driver for Huawei Ethernet Device Driver (hinic3) family ===================================================================== Overview ======== The hinic3 is a network interface card (NIC) for Data Center. It supports a range of link-speed devices (10GE, 25GE, 100GE, etc.). The hinic3 devices can have multiple physical forms: LOM (Lan on Motherboard) NIC, PCIe standard NIC, OCP (Open Compute Project) NIC, etc. The hinic3 driver supports the following features: - IPv4/IPv6 TCP/UDP checksum offload - TSO (TCP Segmentation Offload), LRO (Large Receive Offload) - RSS (Receive Side Scaling) - MSI-X interrupt aggregation configuration and interrupt adaptation. - SR-IOV (Single Root I/O Virtualization). Content ======= - Supported PCI vendor ID/device IDs - Source Code Structure of Hinic3 Driver - Management Interface Supported PCI vendor ID/device IDs ================================== 19e5:0222 - hinic3 PF/PPF 19e5:375F - hinic3 VF Prime Physical Function (PPF) is responsible for the management of the whole NIC card. For example, clock synchronization between the NIC and the host. Any PF may serve as a PPF. The PPF is selected dynamically. Source Code Structure of Hinic3 Driver ====================================== ======================== ================================================ hinic3_pci_id_tbl.h Supported device IDs hinic3_hw_intf.h Interface between HW and driver hinic3_queue_common.[ch] Common structures and methods for NIC queues hinic3_common.[ch] Encapsulation of memory operations in Linux hinic3_csr.h Register definitions in the BAR hinic3_hwif.[ch] Interface for BAR hinic3_eqs.[ch] Interface for AEQs and CEQs hinic3_mbox.[ch] Interface for mailbox hinic3_mgmt.[ch] Management interface based on mailbox and AEQ hinic3_wq.[ch] Work queue data structures and interface hinic3_cmdq.[ch] Command queue is used to post command to HW hinic3_hwdev.[ch] HW structures and methods abstractions hinic3_lld.[ch] Auxiliary driver adaptation layer hinic3_hw_comm.[ch] Interface for common HW operations hinic3_mgmt_interface.h Interface between firmware and driver hinic3_hw_cfg.[ch] Interface for HW configuration hinic3_irq.c Interrupt request hinic3_netdev_ops.c Operations registered to Linux kernel stack hinic3_nic_dev.h NIC structures and methods abstractions hinic3_main.c Main Linux kernel driver hinic3_nic_cfg.[ch] NIC service configuration hinic3_nic_io.[ch] Management plane interface for TX and RX hinic3_rss.[ch] Interface for Receive Side Scaling (RSS) hinic3_rx.[ch] Interface for transmit hinic3_tx.[ch] Interface for receive hinic3_ethtool.c Interface for ethtool operations (ops) hinic3_filter.c Interface for MAC address ======================== ================================================ Management Interface ==================== Asynchronous Event Queue (AEQ) ------------------------------ AEQ receives high priority events from the HW over a descriptor queue. Every descriptor is a fixed size of 64 bytes. AEQ can receive solicited or unsolicited events. Every device, VF or PF, can have up to 4 AEQs. Every AEQ is associated to a dedicated IRQ. AEQ can receive multiple types of events, but in practice the hinic3 driver ignores all events except for 2 mailbox related events. Mailbox ------- Mailbox is a communication mechanism between the hinic3 driver and the HW. Each device has an independent mailbox. Driver can use the mailbox to send requests to management. Driver receives mailbox messages, such as responses to requests, over the AEQ (using event HINIC3_AEQ_FOR_MBOX). Due to the limited size of mailbox data register, mailbox messages are sent segment-by-segment. Every device can use its mailbox to post request to firmware. The mailbox can also be used to post requests and responses between the PF and its VFs. Completion Event Queue (CEQ) ---------------------------- The implementation of CEQ is the same as AEQ. It receives completion events from HW over a fixed size descriptor of 32 bits. Every device can have up to 32 CEQs. Every CEQ has a dedicated IRQ. CEQ only receives solicited events that are responses to requests from the driver. CEQ can receive multiple types of events, but in practice the hinic3 driver ignores all events except for HINIC3_CMDQ that represents completion of previously posted commands on a cmdq. Command Queue (cmdq) -------------------- Every cmdq has a dedicated work queue on which commands are posted. Commands on the work queue are fixed size descriptor of size 64 bytes. Completion of a command will be indicated using ctrl bits in the descriptor that carried the command. Notification of command completions will also be provided via event on CEQ. Every device has 4 command queues that are initialized as a set (called cmdqs), each with its own type. Hinic3 driver only uses type HINIC3_CMDQ_SYNC. Work Queues(WQ) --------------- Work queues are logical arrays of fixed size WQEs. The array may be spread over multiple non-contiguous pages using indirection table. Work queues are used by I/O queues and command queues. Global function ID ------------------ Every function, PF or VF, has a unique ordinal identification within the device. Many management commands (mbox or cmdq) contain this ID so HW can apply the command effect to the right function. PF is allowed to post management commands to a subordinate VF by specifying the VFs ID. A VF must provide its own ID. Anti-spoofing in the HW will cause command from a VF to fail if it contains the wrong ID.