Improve comment, as suggested by @bz.

Use ARRAY_SIZE() as suggested by @bz.

In D55734#1286250, @bz wrote:

You made me run a grep on Linux; I assume your comments are for 6.11 as I just checked 7 and cannot find any hard coded 21ones anymore.

Explain how the constants are computed on Linux and use the corresponding FreeBSD constants. This should address @bz concerns.

Add a comment to indicate the source of the defined constant in Linux. This addresses @bz concerns.

Here is an example on a computer running Linux 6.18:

In D53440#1275937, @bz wrote:

The drm-kmod part is here; I hope it still applies cleanly otherwise I have a branch https://github.com/freebsd/drm-kmod/pull/398

Use parenthesis as suggested by @emaste.

Fix copyright header to use SPDX comment.

Fix copyright header to use SPDX comment.

Define for several architectures to address @emaste concerns.

Fix duplicate define as reported by @emaste

Refresh patch

Address comment from @emaste

Fix copyright header and restore copyright of @nc

Fix use of memcpy() as reported by @emaste

Wrap lines to address @emaste comment

Address feedback from @emaste and @wulf.

Anyway, someone just committed the same update concurrently. Abandonning this revision.

I see :-) Thanks!

Fix style, as reported by @markj.

Address feedback from @bz.

In D50853#1248923, @christos wrote:

Should this be committed now?