drm/ttm/memcg/lru: enable memcg tracking for ttm and amdgpu driver (complete series v3)

[Dave Airlie <airlied@gmail.com>]

Hi all,

This is a 2nd repost with some fixes and cleanups. Original post is below.

https://lore.kernel.org/dri-devel/20250714052243.1149732-1-airlied@gmail.com/ is the 2nd post.
https://lore.kernel.org/dri-devel/20250630045005.1337339-1-airlied@gmail.com/ is the 1st post.

Differences since last posting:
1. Shakeel suggested I squash some export additions - done now
2. Shakeel suggested I use lruvec in the earlier vmstat accounting - done
3. Christian asked for the turn off patch to be more generic - added Kconfig/module option

I would probably squash 16 into other places, but left it alone for now so we can see it.

Christian has an outstanding statement on suspend/resume breakage that I'm waiting for a respone.

I'd like to at least land 01->06 in drm-misc-next soon, to at least reduce the patch load.

Patch order is now:
01->02: add support for global gpu stat counters
03->06: port ttm pools to list_lru for numa awareness
07->13,16: add memcg stats + gpu apis, then port ttm pools to memcg aware list_lru and shrinker
14: enable amdgpu to use new functionality.

Differences since last posting:
1. Added patch 18: add a module option to allow pooled pages to not be stored in the lru per-memcg
   (Requested by Christian Konig)
2. Converged the naming and stats between vmstat and memcg (Suggested by Shakeel Butt)
3. Cleaned up the charge/uncharge code and some other bits.

Dave.

Original cover letter:
tl;dr: start using list_lru/numa/memcg in GPU driver core and amdgpu driver for now.

This is a complete series of patches, some of which have been sent before and reviewed,
but I want to get the complete picture for others, and try to figure out how best to land this.

There are 3 pieces to this:
01->02: add support for global gpu stat counters (previously posted, patch 2 is newer)
03->07: port ttm pools to list_lru for numa awareness
08->14: add memcg stats + gpu apis, then port ttm pools to memcg aware list_lru and shrinker
15->17: enable amdgpu to use new functionality.

The biggest difference in the memcg code from previously is I discovered what
obj cgroups were designed for and I'm reusing the page/objcg intergration that 
already exists, to avoid reinventing that wheel right now.

There are some igt-gpu-tools tests I've written at:
https://gitlab.freedesktop.org/airlied/igt-gpu-tools/-/tree/amdgpu-cgroups?ref_type=heads

One problem is there are a lot of delayed action, that probably means the testing
needs a bit more robustness, but the tests validate all the basic paths.

Regards,
Dave.