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Feature #13146

Want a driver for AMD SMN user access

Added by Robert Mustacchi 7 months ago. Updated 6 months ago.

Status:
Closed
Priority:
Normal
Category:
driver - device drivers
Start date:
Due date:
% Done:

100%

Estimated time:
Difficulty:
Medium
Tags:
Gerrit CR:

Description

The AMD system management network (SMN) is used for certain parts of the SoC to provide services. Being able to driver arbitrary read requests could be helpful to folks who are trying to develop on this platform specifically. This adds a new driver usmn which is a child of amdzen and a development tool to read this. This driver is not intended to be generally installed and will be in a separate package that contains other future AMD kernel development related drivers. Future work here would include things like certain kinds of error injection.

#1

Updated by Electric Monk 7 months ago

  • Gerrit CR set to 940
#2

Updated by Robert Mustacchi 6 months ago

I've tested this by doing SMN reads from various addresses that have meanings like I expect (such as the temperature ones) and verifying their outputs. I've also manually checked the behavior for reading various registers that the SoC says we don't have permission to (they're restricted to more privileged contexts than the kernel) and those are failing cleanly and don't prevent future use of the interface.

#3

Updated by Electric Monk 6 months ago

  • Status changed from New to Closed
  • % Done changed from 80 to 100

git commit 047043c2181e939608ea2c09257fd2d515e99643

commit  047043c2181e939608ea2c09257fd2d515e99643
Author: Robert Mustacchi <rm@fingolfin.org>
Date:   2020-10-21T21:02:57.000Z

    13144 refactor amdf17nbdf into a nexus
    13145 rewrite amdf17nbdf to use the ksensor framework
    13146 Want a driver for AMD SMN user access
    Reviewed by: Patrick Mooney <pmooney@pfmooney.com>
    Reviewed by: Mike Zeller <mike.zeller@joyent.com>
    Reviewed by: Robert French <robert@robertdfrench.me>
    Approved by: Richard Lowe <richlowe@richlowe.net>

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