intel hwpstate v2

Add support for Intel Speed Shift

Should add an MFC to this...

I think so. I think there are definitely some robustifications needed, but generally it'd be good to know if I need any major overhauls. Also, at this point in the series, it's entirely opt-in, and any regressions should be fixable.

Forgot to add the amd part in the last update

Moved bit definitions to another differential. Took all of kib@ feedback. Will continue to add to this.

Some of this has been moved into D18050

Talked with Kostik offline. Patch should say bit 3 instead of 4 for VM entry. Patch itself is correct.

Can you please identify where the docs say

I asked for clarification and hopefully, I will have some by the end of the day. My understanding is that RDCL_NO still determines whether or not you need to mitigate L1TF type vulnerabilities.

I've tested the latest in github today on Arch Linux and was able to build world and kernel - however at this moment, I haven't been able to test what has been built anywhere.

I have two subsequent ideas which I may or may not get around to:

Small fix for systems which don't have a pm device

The hunks for the idle suspend stuff were some WIP that I hadn't finished. They can be ignored.

commit 5e5bf62ac3ec965fd2809b8c393d7b088b125cab (HEAD)
Author: Ben Widawsky <ben.widawsky@intel.com>
Date: Tue Aug 7 18:40:37 2018 -0700

Addressed kib's comments.

Here is some sample usage from the SPMC driver which will later be up for review:

This was the wrong commit.

Modified .Dd

See Differential Revision: https://reviews.freebsd.org/D12557

Update the revision to hopefully work properly. The patch this time attempts to
separate sharing acpi_ec_probe, and only use acpi_ec_probe for the Device() as
opposed to the fixed ECDT enumerated one.

I think man page does need to be updated as markj said.