The Linux Kernel API

The Linux Kernel API

 

http://kernelnewbies.org/documents/kdoc/kernel-api/linuxkernelapi.html

 

The Linux Kernel API

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Table of Contents

1. Driver Basics

Driver Entry and Exit points

module_init — driver initialization entry point

module_exit — driver exit entry point

Atomic and pointer manipulation

atomic_read — read atomic variable

atomic_set — set atomic variable

atomic_add — add integer to atomic variable

atomic_sub — subtract the atomic variable

atomic_sub_and_test — subtract value from variable and test result

atomic_inc — increment atomic variable

atomic_dec — decrement atomic variable

atomic_dec_and_test — decrement and test

atomic_inc_and_test — increment and test

atomic_add_negative — add and test if negative

get_unaligned — get value from possibly mis-aligned location

put_unaligned — put value to a possibly mis-aligned location

Delaying, scheduling, and timer routines

schedule_timeout — sleep until timeout

2. Data Types

Doubly Linked Lists

list_add — add a new entry

list_add_tail — add a new entry

list_del — deletes entry from list.

list_del_init — deletes entry from list and reinitialize it.

list_empty — tests whether a list is empty

list_splice — join two lists

list_entry — get the struct for this entry

list_for_each — iterate over a list

list_for_each_safe — iterate over a list safe against removal of list entry

3. Basic C Library Functions

String Conversions

simple_strtol — convert a string to a signed long

simple_strtoll — convert a string to a signed long long

simple_strtoul — convert a string to an unsigned long

simple_strtoull — convert a string to an unsigned long long

vsnprintf — Format a string and place it in a buffer

snprintf — Format a string and place it in a buffer

vsprintf — Format a string and place it in a buffer

sprintf — Format a string and place it in a buffer

String Manipulation

strcpy — Copy a NUL terminated string

strncpy — Copy a length-limited, NUL-terminated string

strcat — Append one NUL-terminated string to another

strncat — Append a length-limited, NUL-terminated string to another

strcmp — Compare two strings

strncmp — Compare two length-limited strings

strchr — Find the first occurrence of a character in a string

strrchr — Find the last occurrence of a character in a string

strlen — Find the length of a string

strnlen — Find the length of a length-limited string

strpbrk — Find the first occurrence of a set of characters

strtok — Split a string into tokens

memset — Fill a region of memory with the given value

bcopy — Copy one area of memory to another

memcpy — Copy one area of memory to another

memmove — Copy one area of memory to another

memcmp — Compare two areas of memory

memscan — Find a character in an area of memory.

strstr — Find the first substring in a NUL terminated string

memchr — Find a character in an area of memory.

Bit Operations

set_bit — Atomically set a bit in memory

__set_bit — Set a bit in memory

clear_bit — Clears a bit in memory

__change_bit — Toggle a bit in memory

change_bit — Toggle a bit in memory

test_and_set_bit — Set a bit and return its old value

__test_and_set_bit — Set a bit and return its old value

test_and_clear_bit — Clear a bit and return its old value

__test_and_clear_bit — Clear a bit and return its old value

test_and_change_bit — Change a bit and return its new value

test_bit — Determine whether a bit is set

find_first_zero_bit — find the first zero bit in a memory region

find_next_zero_bit — find the first zero bit in a memory region

ffz — find first zero in word.

ffs — find first bit set

hweight32 — returns the hamming weight of a N-bit word

4. Memory Management in Linux

The Slab Cache

kmem_cache_create — Create a cache.

kmem_cache_shrink — Shrink a cache.

kmem_cache_destroy — delete a cache

kmem_cache_alloc — Allocate an object

kmalloc — allocate memory

kmem_cache_free — Deallocate an object

kfree — free previously allocated memory

5. The proc filesystem

sysctl interface

register_sysctl_table — register a sysctl heirarchy

unregister_sysctl_table — unregister a sysctl table heirarchy

proc_dostring — read a string sysctl

proc_dointvec — read a vector of integers

proc_dointvec_minmax — read a vector of integers with min/max values

proc_doulongvec_minmax — read a vector of long integers with min/max values

proc_doulongvec_ms_jiffies_minmax — read a vector of millisecond values with min/max values

proc_dointvec_jiffies — read a vector of integers as seconds

6. The Linux VFS

The Directory Cache

d_invalidate — invalidate a dentry

d_find_alias — grab a hashed alias of inode

prune_dcache — shrink the dcache

shrink_dcache_sb — shrink dcache for a superblock

have_submounts — check for mounts over a dentry

shrink_dcache_parent — prune dcache

d_alloc — allocate a dcache entry

d_instantiate — fill in inode information for a dentry

d_alloc_root — allocate root dentry

d_lookup — search for a dentry

d_validate — verify dentry provided from insecure source

d_delete — delete a dentry

d_rehash — add an entry back to the hash

d_move — move a dentry

__d_path — return the path of a dentry

is_subdir — is new dentry a subdirectory of old_dentry

find_inode_number — check for dentry with name

d_drop — drop a dentry

d_add — add dentry to hash queues

dget — get a reference to a dentry

d_unhashed — is dentry hashed

Inode Handling

__mark_inode_dirty — internal function

write_inode_now — write an inode to disk

clear_inode — clear an inode

invalidate_inodes — discard the inodes on a device

get_empty_inode — obtain an inode

iunique — get a unique inode number

insert_inode_hash — hash an inode

remove_inode_hash — remove an inode from the hash

iput — put an inode

bmap — find a block number in a file

update_atime — update the access time

make_bad_inode — mark an inode bad due to an I/O error

is_bad_inode — is an inode errored

Registration and Superblocks

register_filesystem — register a new filesystem

unregister_filesystem — unregister a file system

get_super — get the superblock of a device

File Locks

posix_lock_file —

__get_lease — revoke all outstanding leases on file

lease_get_mtime —

posix_block_lock — blocks waiting for a file lock

posix_unblock_lock — stop waiting for a file lock

lock_may_read — checks that the region is free of locks

lock_may_write — checks that the region is free of locks

fcntl_getlease — Enquire what lease is currently active

fcntl_setlease — sets a lease on an open file

sys_flock — flock system call.

get_locks_status — reports lock usage in /proc/locks

7. Linux Networking

Socket Buffer Functions

skb_queue_empty — check if a queue is empty

skb_get — reference buffer

kfree_skb — free an sk_buff

skb_cloned — is the buffer a clone

skb_shared — is the buffer shared

skb_share_check — check if buffer is shared and if so clone it

skb_unshare — make a copy of a shared buffer

skb_peek —

skb_peek_tail —

skb_queue_len — get queue length

__skb_queue_head — queue a buffer at the list head

skb_queue_head — queue a buffer at the list head

__skb_queue_tail — queue a buffer at the list tail

skb_queue_tail — queue a buffer at the list tail

__skb_dequeue — remove from the head of the queue

skb_dequeue — remove from the head of the queue

skb_insert — insert a buffer

skb_append — append a buffer

skb_unlink — remove a buffer from a list

__skb_dequeue_tail — remove from the tail of the queue

skb_dequeue_tail — remove from the head of the queue

skb_put — add data to a buffer

skb_push — add data to the start of a buffer

skb_pull — remove data from the start of a buffer

skb_headroom — bytes at buffer head

skb_tailroom — bytes at buffer end

skb_reserve — adjust headroom

skb_trim — remove end from a buffer

skb_orphan — orphan a buffer

skb_queue_purge — empty a list

__skb_queue_purge — empty a list

__dev_alloc_skb — allocate an skbuff for sending

dev_alloc_skb — allocate an skbuff for sending

skb_cow — copy header of skb when it is required

skb_over_panic — private function

skb_under_panic — private function

alloc_skb — allocate a network buffer

__kfree_skb — private function

skb_clone — duplicate an sk_buff

skb_copy — create private copy of an sk_buff

pskb_copy — create copy of an sk_buff with private head.

pskb_expand_head — reallocate header of sk_buff

skb_copy_expand — copy and expand sk_buff

__pskb_pull_tail — advance tail of skb header

Socket Filter

sk_run_filter — run a filter on a socket

sk_chk_filter — verify socket filter code

8. Network device support

Driver Support

init_etherdev — Register ethernet device

alloc_etherdev — Allocates and sets up an ethernet device

init_fddidev — Register FDDI device

alloc_fddidev — Register FDDI device

init_hippi_dev — Register HIPPI device

alloc_hippi_dev — Register HIPPI device

init_trdev — Register token ring device

alloc_trdev — Register token ring device

init_fcdev — Register fibre channel device

alloc_fcdev — Register fibre channel device

dev_add_pack — add packet handler

dev_remove_pack — remove packet handler

__dev_get_by_name — find a device by its name

dev_get_by_name — find a device by its name

dev_get — test if a device exists

__dev_get_by_index — find a device by its ifindex

dev_get_by_index — find a device by its ifindex

dev_alloc_name — allocate a name for a device

dev_alloc — allocate a network device and name

netdev_state_change — device changes state

dev_load — load a network module

dev_open — prepare an interface for use.

dev_close — shutdown an interface.

register_netdevice_notifier — register a network notifier block

unregister_netdevice_notifier — unregister a network notifier block

dev_queue_xmit — transmit a buffer

netif_rx — post buffer to the network code

net_call_rx_atomic —

register_gifconf — register a SIOCGIF handler

netdev_set_master — set up master/slave pair

dev_set_promiscuity — update promiscuity count on a device

dev_set_allmulti — update allmulti count on a device

dev_ioctl — network device ioctl

dev_new_index — allocate an ifindex

netdev_finish_unregister — complete unregistration

unregister_netdevice — remove device from the kernel

8390 Based Network Cards

ei_open — Open/initialize the board.

ei_close — shut down network device

ei_tx_timeout — handle transmit time out condition

ei_interrupt — handle the interrupts from an 8390

ethdev_init — init rest of 8390 device struct

NS8390_init — initialize 8390 hardware

Synchronous PPP

sppp_input — receive and process a WAN PPP frame

sppp_close — close down a synchronous PPP or Cisco HDLC link

sppp_open — open a synchronous PPP or Cisco HDLC link

sppp_reopen — notify of physical link loss

sppp_change_mtu — Change the link MTU

sppp_do_ioctl — Ioctl handler for ppp/hdlc

sppp_attach — attach synchronous PPP/HDLC to a device

sppp_detach — release PPP resources from a device

9. Module Support

Module Loading

request_module — try to load a kernel module

call_usermodehelper — start a usermode application

Inter Module support

inter_module_register — register a new set of inter module data.

inter_module_unregister — unregister a set of inter module data.

inter_module_get — return arbitrary userdata from another module.

inter_module_get_request — im get with automatic request_module.

inter_module_put — release use of data from another module.

10. Hardware Interfaces

Interrupt Handling

disable_irq_nosync — disable an irq without waiting

disable_irq — disable an irq and wait for completion

enable_irq — enable handling of an irq

probe_irq_mask — scan a bitmap of interrupt lines

MTRR Handling

mtrr_add — Add a memory type region

mtrr_del — delete a memory type region

PCI Support Library

pci_find_slot — locate PCI device from a given PCI slot

pci_find_subsys — begin or continue searching for a PCI device by vendor/subvendor/device/subdevice id

pci_find_device — begin or continue searching for a PCI device by vendor/device id

pci_find_class — begin or continue searching for a PCI device by class

pci_find_capability — query for devices' capabilities

pci_find_parent_resource — return resource region of parent bus of given region

pci_set_power_state — Set the power state of a PCI device

pci_save_state — save the PCI configuration space of a device before suspending

pci_restore_state — Restore the saved state of a PCI device

pci_enable_device — Initialize device before it's used by a driver.

pci_disable_device — Disable PCI device after use

pci_enable_wake — enable device to generate PME# when suspended

pci_release_regions — Release reserved PCI I/O and memory resources

pci_request_regions — Reserved PCI I/O and memory resources

pci_match_device — Tell if a PCI device structure has a matching PCI device id structure

pci_register_driver — register a new pci driver

pci_unregister_driver — unregister a pci driver

pci_insert_device — insert a hotplug device

pci_remove_device — remove a hotplug device

pci_dev_driver — get the pci_driver of a device

pci_set_master — enables bus-mastering for device dev

pci_setup_device — fill in class and map information of a device

pci_pool_create — Creates a pool of pci consistent memory blocks, for dma.

pci_pool_destroy — destroys a pool of pci memory blocks.

pci_pool_alloc — get a block of consistent memory

pci_pool_free — put block back into pci pool

MCA Architecture

MCA Device Functions

MCA Bus DMA

11. The Device File System

devfs_register — Register a device entry.

devfs_unregister — Unregister a device entry.

devfs_mk_symlink —

devfs_mk_dir — Create a directory in the devfs namespace.

devfs_find_handle — Find the handle of a devfs entry.

devfs_get_flags — Get the flags for a devfs entry.

devfs_get_maj_min — Get the major and minor numbers for a devfs entry.

devfs_get_handle_from_inode — Get the devfs handle for a VFS inode.

devfs_generate_path — Generate a pathname for an entry, relative to the devfs root.

devfs_get_ops — Get the device operations for a devfs entry.

devfs_set_file_size — Set the file size for a devfs regular file.

devfs_get_info — Get the info pointer written to private_data of de upon open.

devfs_set_info — Set the info pointer written to private_data upon open.

devfs_get_parent — Get the parent device entry.

devfs_get_first_child — Get the first leaf node in a directory.

devfs_get_next_sibling — Get the next sibling leaf node. for a device entry.

devfs_auto_unregister — Configure a devfs entry to be automatically unregistered.

devfs_get_unregister_slave — Get the slave entry which will be automatically unregistered.

devfs_get_name — Get the name for a device entry in its parent directory.

devfs_register_chrdev — Optionally register a conventional character driver.

devfs_register_blkdev — Optionally register a conventional block driver.

devfs_unregister_chrdev — Optionally unregister a conventional character driver.

devfs_unregister_blkdev — Optionally unregister a conventional block driver.

12. Power Management

pm_register — register a device with power management

pm_unregister — unregister a device with power management

pm_unregister_all — unregister all devices with matching callback

pm_send — send request to a single device

pm_send_all — send request to all managed devices

pm_find — find a device

13. Block Devices

blk_cleanup_queue — release a request_queue_t when it is no longer needed

blk_queue_headactive — indicate whether head of request queue may be active

blk_queue_make_request — define an alternate make_request function for a device

blk_init_queue — prepare a request queue for use with a block device

generic_make_request —

submit_bh —

ll_rw_block — level access to block devices

end_that_request_first — end I/O on one buffer.

14. Miscellaneous Devices

misc_register — register a miscellaneous device

misc_deregister — unregister a miscellaneous device

15. Video4Linux

video_unregister_device — unregister a video4linux device

16. Sound Devices

register_sound_special — register a special sound node

register_sound_mixer — register a mixer device

register_sound_midi — register a midi device

register_sound_dsp — register a DSP device

register_sound_synth — register a synth device

unregister_sound_special — unregister a special sound device

unregister_sound_mixer — unregister a mixer

unregister_sound_midi — unregister a midi device

unregister_sound_dsp — unregister a DSP device

unregister_sound_synth — unregister a synth device

17. USB Devices

usb_register — register a USB driver

usb_scan_devices — scans all unclaimed USB interfaces

usb_deregister — unregister a USB driver

usb_alloc_bus — creates a new USB host controller structure

usb_free_bus — frees the memory used by a bus structure

usb_register_bus — registers the USB host controller with the usb core

usb_deregister_bus — deregisters the USB host controller

usb_match_id — find first usb_device_id matching device or interface

usb_alloc_urb — creates a new urb for a USB driver to use

usb_free_urb — frees the memory used by a urb

usb_control_msg — Builds a control urb, sends it off and waits for completion

usb_bulk_msg — Builds a bulk urb, sends it off and waits for completion

18. 16x50 UART Driver

register_serial — configure a 16x50 serial port at runtime

unregister_serial — deconfigure a 16x50 serial port

19. Z85230 Support Library

z8530_interrupt — Handle an interrupt from a Z8530

z8530_sync_open — Open a Z8530 channel for PIO

z8530_sync_close — Close a PIO Z8530 channel

z8530_sync_dma_open — Open a Z8530 for DMA I/O

z8530_sync_dma_close — Close down DMA I/O

z8530_sync_txdma_open — Open a Z8530 for TX driven DMA

z8530_sync_txdma_close — Close down a TX driven DMA channel

z8530_describe — Uniformly describe a Z8530 port

z8530_init — Initialise a Z8530 device

z8530_shutdown — Shutdown a Z8530 device

z8530_channel_load — Load channel data

z8530_null_rx — Discard a packet

z8530_queue_xmit — Queue a packet

z8530_get_stats — Get network statistics

20. Frame Buffer Library

Frame Buffer Memory

register_framebuffer — registers a frame buffer device

unregister_framebuffer — releases a frame buffer device

Frame Buffer Console

fbcon_redraw_clear — clear area of the screen

fbcon_redraw_bmove — copy area of screen to another area

Frame Buffer Colormap

fb_alloc_cmap — allocate a colormap

fb_copy_cmap — copy a colormap

fb_get_cmap — get a colormap

fb_set_cmap — set the colormap

fb_default_cmap — get default colormap

fb_invert_cmaps — invert all defaults colormaps

Frame Buffer Generic Functions

fbgen_get_fix — get fixed part of display

fbgen_get_var — get user defined part of display

fbgen_set_var — set the user defined part of display

fbgen_get_cmap — get the colormap

fbgen_set_cmap — set the colormap

fbgen_pan_display — pan or wrap the display

fbgen_do_set_var — change the video mode

fbgen_set_disp — set generic display

fbgen_install_cmap — install the current colormap

fbgen_update_var — update user defined part of display

fbgen_switch — switch to a different virtual console.

fbgen_blank — blank the screen

Frame Buffer Video Mode Database

fb_find_mode — finds a valid video mode

__fb_try_mode — test a video mode

Frame Buffer Macintosh Video Mode Database

console_getmode — get current mode

console_setmode — sets current console mode

console_setcmap — sets palette color map for console

console_powermode — sets monitor power mode

mac_vmode_to_var — converts vmode/cmode pair to var structure

mac_var_to_vmode — convert var structure to MacOS vmode/cmode pair

mac_map_monitor_sense — Convert monitor sense to vmode

mac_find_mode — find a video mode

Frame Buffer Fonts

fbcon_find_font — find a font

fbcon_get_default_font — get default font