| INTRO(9S) | Data Structures for Drivers | INTRO(9S) |
Intro —
introduction to kernel data structures
Section 9S describes the data structures that are used by the kernel and the various device driver frameworks. The structure manual pages should generally be considered documentation for the structure itself and the companions in sections 9, 9E, and 9F, provide more of the surrounding context.
The structures listed here have varying ABI guarantees. While the majority of structures documented here are part of committed interfaces, that is not true of all of them. Uncommitted structures have no ABI guarantees and may change at any time. They are documented to aid folks working on the system.
The rest of this manual groups documented structures into categories with additional information about what to read for more information.
The structures here are all fundamental to initializing a device driver. See Intro(9E) for more on their use and the examples in _init(9E) for more information. These structures are generally required for every kernel module.
| cb_ops(9S) | dev_ops(9S) |
| modldrv(9S) | modlinkage(9S) |
| modlmisc(9S) | modlstrmod(9S) |
These structures are used as part of the fundamental units of performing I/O for character and block devices and are related to how a driver will implement the corresponding read(9E), write(9E), and strategy(9E) entry points.
| aio_req(9S) | buf(9S) |
| iovec(9S) | uio(9S) |
Message blocks, mblk_t, are the fundamental building block of networking, USB, and STREAMS device drivers. An overview to their design and structure can be found in the Message Block Functions of Intro(9F). The data for a message block is generally found in a corresponding data block structure. The following structures are relevant:
| dblk(9S) | free_rtn(9S) |
| mblk(9S) |
Direct Memory Access is one of the primary things that most device drivers facilitate. See Intro(9F) for more on DMA itself and how these structures fit into those functions.
| ddi_device_acc_attr(9S) | ddi_dma_attr(9S) |
| ddi_dma_cookie(9S) | ddi_dmae_req(9S) |
The following structures are all part of the mac(9E) device driver framework that is used for networking device drivers. See mac(9E) for more information on how they fit in. Networking device drivers use the Message Blocks related data structures for I/O purposes. These structures describe specific parts of interfacing with the MAC framework.
| mac_callbacks(9S) | mac_group_info(9S) |
| mac_intr(9S) | mac_register(9S) |
| mac_ring_info(9S) |
These structures are part of the SCSI/SAS device driver framework and are used in implementing device drivers for host bus adapters (HBAs).
| scsi_address(9S) | scsi_arq_status(9S) |
| scsi_asc_key_strings(9S) | scsi_device(9S) |
| scsi_extended_sense(9S) | scsi_hba_tran(9S) |
| scsi_inquiry(9S) | scsi_pkt(9S) |
| scsi_status(9S) |
Kernel statistics, or kstats, are a means for communicating data to userland through the kstat(4D) driver, libkstat(3LIB) library, and kstat(8) command. Drivers can create their own kstats through the use of kstat_create(9F) and some device driver frameworks create and manage kstats on behalf of drivers. The root kstat structure is discussed in kstat(9S). The other manuals listed discuss the different types of kstats that exist.
| kstat_intr(9S) | kstat_io(9S) |
| kstat_named(9S) | kstat(9S) |
The following structures are all related to the broader device driver interface and serve different parts of it. They cover memory mapping, error handling, interrupts, etc.
| ddi_fm_error(9S) | ddi_idevice_cookie(9S) |
| devmap_callback_ctl(9S) |
These structures include the fundamental structures required for registering a STREAMS based device driver with the kernel as well as the different structures, such as the copyreq(9S), that are used as part of handling specific classes of operations. The queue(9S) is the fundamental building block of STREAMS communication. Like with networking device drivers, STREAMS drivers also leverage the Message Blocks data structures for communication.
| copyreq(9S) | copyresp(9S) |
| fmodsw(9S) | iocblk(9S) |
| linkblk(9S) | module_info(9S) |
| qband(9S) | qinit(9S) |
| queclass(9S) | queue(9S) |
| streamtab(9S) | stroptions(9S) |
Network hooks provide a way for firewalls to participate and manipulate packets as they flow through the system. The following structures are related to the network hooks interfaces.
| hook_nic_event(9S) | hook_pkt_event(9S) |
| hook_t(9S) | net_inject_t(9S) |
| net_instance_t(9S) |
The following structures correspond to subsystems that generally are no longer used (mac(9E) aka GLDv3 has replaced the GLDv2 functions mentioned below) or refer to hardware that is no longer commonly found.
| gld_mac_info(9S) | gld_stats(9S) |
| tuple(9S) |
In addition to the standard manual sections that exist, entries in 9S contain an additional section titled “STRUCTURE MEMBERS”. This enumerates and describes the different members of the structures, their types, their purposes, and any constraints on when they should be used or how they should be interpreted.
| April 28, 2024 | OmniOS |