[Nouveau] Meaning of the engines in paramaters of nouveau module

[Paul Dufresne]

In https://nouveau.freedesktop.org/KernelModuleParameters.html, there is:
Here is a list of engines:
    DEVICE
    DMAOBJ
    PBSP
    PCE0
    PCE1
    PCE2
    PCRYPT
    PDISP
    PFIFO
    PGRAPH
    PMPEG
    PPM
    PPPP
    PVP
    SW
Also, in debug:
   CLIENT

I have tried to find a description of those.
https://envytools.readthedocs.io/en/latest/
help a bit, but I don't find a precise correlation.

https://nouveau.freedesktop.org/NouveauTerms.html
does not seems to have most of these terms.

I am particularly curious about PCE[0-3].
But also about CLIENT, that seems different and mysterious.

I wonder if it is possible to write:
nouveau.debug=info,PDISP=debug
to have the info debug level as the default, but for PDISP have the debug level

Also, my interest is linked to the state of GPU graph given after a context switch timeout that looks like:
[ 1696.780305] nouveau 0000:01:00.0: fifo: SCHED_ERROR 0a [CTXSW_TIMEOUT]
[ 1696.780361] nouveau 0000:01:00.0: fifo:000000:00[      gr]: 8006e005: busy 1 faulted 0 chsw 1 save 1 load 1 chid 5*-> chid 6 
[ 1696.780422] nouveau 0000:01:00.0: fifo:000000:07[     ce2]: 00050005: busy 0 faulted 0 chsw 0 save 0 load 0 chid 5 -> chid 5 
[ 1696.780476] nouveau 0000:01:00.0: fifo:000004:04[     ce0]: 00000000: busy 0 faulted 0 chsw 0 save 0 load 0 chid 0 -> chid 0 
[ 1696.780529] nouveau 0000:01:00.0: fifo:000001:01[  mspdec]: 00000000: busy 0 faulted 0 chsw 0 save 0 load 0 chid 0 -> chid 0 
[ 1696.780581] nouveau 0000:01:00.0: fifo:000002:02[   msppp]: 00000000: busy 0 faulted 0 chsw 0 save 0 load 0 chid 0 -> chid 0 
[ 1696.780633] nouveau 0000:01:00.0: fifo:000003:03[   msvld]: 00000000: busy 0 faulted 0 chsw 0 save 0 load 0 chid 0 -> chid 0 
[ 1696.780689] nouveau 0000:01:00.0: fifo:000000:00[      gr]: 8006e005: busy 1 faulted 0 chsw 1 save 1 load 1 chid 5*-> chid 6 
[ 1696.780744] nouveau 0000:01:00.0: fifo:000000:00[      gr]: 8006e005: busy 1 faulted 0 chsw 1 save 1 load 1 chid 5*-> chid 6 
[ 1696.780795] nouveau 0000:01:00.0: fifo:000000:00[      gr]: triggering mmu fault on 0x00
[ 1696.780835] nouveau 0000:01:00.0: fifo:000000:07[     ce2]: 00050005: busy 0 faulted 0 chsw 0 save 0 load 0 chid 5 -> chid 5 
[ 1696.780942] nouveau 0000:01:00.0: fifo:000000:00[      gr]: 00000100: mmu fault triggered
[ 1696.780987] nouveau 0000:01:00.0: fifo:000000:00[      gr]: c006e005: busy 1 faulted 1 chsw 1 save 1 load 1 chid 5*-> chid 6 
[ 1696.781040] nouveau 0000:01:00.0: fifo:000000:0005:[Renderer[13701]] rc scheduled

where I suspect ce2, is linked to PCE2.

Is there a documentation that describes those "engines"?