Ubuntu kernel modules for applications

Question

We can see there are a lot of modules in the Ubuntu OS. How are these modules are being utilized, and by whom? Is there an example that shows some application interfacing one of these modules via ioctl or /dev/something? For example, there is aesni_intel module, and it seems to me that it provides AES functionality using Intel's special instruction set for the AES algorithm. Who is utilizing this feature? Is there any representative case?

Is there any document or reference that explains the details of these modules? Google doesn't give me anything.

root@ubuntu:/dev/dri# lsmod
Module                  Size  Used by
vsock                  52846  0 
acpiphp                23954  0 
coretemp               13355  0 
ghash_clmulni_intel    13259  0 
aesni_intel            55399  0 
aes_x86_64             17255  1 aesni_intel
xts                    12885  1 aesni_intel
lrw                    13257  1 aesni_intel
gf128mul               14951  2 lrw,xts
ablk_helper            13597  1 aesni_intel
cryptd                 20373  3 ghash_clmulni_intel,aesni_intel,ablk_helper
snd_ens1371            25378  2 
snd_ac97_codec        130268  1 snd_ens1371
ac97_bus               12766  1 snd_ac97_codec
gameport               15515  1 snd_ens1371
snd_pcm                97451  2 snd_ac97_codec,snd_ens1371
snd_page_alloc         18710  1 snd_pcm
snd_seq_midi           13324  0 
vmw_balloon            12673  0 
snd_seq_midi_event     14899  1 snd_seq_midi
snd_rawmidi            30180  2 snd_ens1371,snd_seq_midi
microcode              22881  0 
psmouse                95870  0 
serio_raw              13215  0 
snd_seq                61554  2 snd_seq_midi_event,snd_seq_midi
snd_seq_device         14497  3 snd_seq,snd_rawmidi,snd_seq_midi
snd_timer              29425  2 snd_pcm,snd_seq
joydev                 17377  0 
btusb                  22474  0 
snd                    68876  11 snd_ac97_codec,snd_timer,snd_pcm,snd_seq,snd_rawmidi,snd_ens1371,snd_seq_device
soundcore              12680  1 snd
vmwgfx                130610  3 
rfcomm                 42641  12 
bnep                   18036  2 
ttm                    83187  1 vmwgfx
parport_pc             28152  1 
ppdev                  17073  0 
bluetooth             228619  22 bnep,btusb,rfcomm
drm                   286313  4 ttm,vmwgfx
vmci                   87554  1 vsock
i2c_piix4              13266  0 
shpchp                 37032  0 
mac_hid                13205  0 
lp                     17759  0 
parport                46345  3 lp,ppdev,parport_pc
hid_generic            12540  0 
usbhid                 47074  0 
hid                   101002  2 hid_generic,usbhid
mptspi                 22529  2 
e1000                 114507  0 
mptscsih               40289  1 mptspi
mptbase               101888  2 mptspi,mptscsih
floppy                 69449  0 
vmxnet                 26564  0 
vmw_pvscsi             22358  0 
vmxnet3                44609  0 

Answer 1

look for the module's name in /usr/src/linux/Documentation. (For example, documentation on the sound modules is found in /usr/src/linux/Documentation/sound.)

if you do not have the kernel docs installed, have a look here: https://www.kernel.org/doc/Documentation/