apex: add a driver for the Google Apex Edge TPU

[seuros]

Summary

The Apex is the accelerator on Coral PCI Express and M.2 modules,
appearing as 1ac1:089a
Google's Linux driver left staging in 5.16 and the out of tree
repository was archived; no BSD has had one.

Tested on: amd64, Coral M.2 Accelerator, running MobileNet v1
with the TensorFlow Lite 2.16 and LiteRT runtimes

[seuros]

The USB variant is more common than the PCIE/M2 in the wild, but i did not want to port it without testing it on hardware.

I will check with some frigate or home-assistant friends if they have they can undust the coral .

PS: the linux driver has a bug that will never be fixed (the repo is archived) which pushed people in stopped the coral usage. this port address it.

[seuros]

fix docs

[adrian]

in general good; just update your email address!

sys/dev/apex/apex.c

60

Maybe create a #define for how big this can get instead of '3' and use that for bounds checking the array?

[ziaee]

looks cool; please also relnotes: yes for any new driver

share/man/man4/apex.4

14–27

can also add tunables and sysctls if you want, see share/examples/mdoc/example.4

44

see share/man/man5/style.mdoc.5

[seuros]

refactor/doc/split driver

[seuros]

rebase on main

[seuros]

rebase

[ziaee]

Accepted provided feedback is addressed, thanks for tagging me and waiting for me.

share/man/man4/apex.4

8

Am I correct in understanding that this only works on amd64 for now? If so, please specify in the manpage. There is an optional architectural specifier here where you can do that.

44

This is not done, and it is specified in the style guide I linked.

72

This is not a sentence so is not traditionally capitalized/punctuated, see intro(5)

[ziaee]

wait omg please dont forget Relnotes: yes

[seuros]

relnotes

[seuros]

rebase