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The Neoverse N2/A710 self hosted trace errata, and updated coresight and spe subsystem

Jeremy Linton requested to merge jlinton/centos-stream-9:coresight_errata into main

Bugzilla: https://bugzilla.redhat.com/show_bug.cgi?id=2055405
Tested: N1SDP (hacked up)

Per the defect:

5.16 merged a number of neoverse/cortexA errata, the one that I think is important for RHEL is one affecting the trace functionality on neoverse N2 cpus.

The upstream patch was merged to 5.16 from this set: https://www.spinics.net/lists/arm-kernel/msg928313.html

and fixes the following errata:

  • TRBE may overwrite trace in FILL mode
    • Arm Neoverse-N2 #2139208
    • Cortex-A710 #211985
  • A TSB instruction may not flush the trace completely when executed in trace prohibited region.
    • Arm Neoverse-N2 #2067961
    • Cortex-A710 #2054223
  • TRBE may write to out-of-range address
    • Arm Neoverse-N2 #2253138
    • Cortex-A710 #2224489

The current errata doc: https://developer.arm.com/documentation/SDEN1982442/0900/?lang=en

This set turned out to be easier to just pull the coresight system forward rather than wedge just the fixes into the existing kernel. Mostly everything was applied cleanly. New with this update, much of the perf subsystem is also updated to handle newer coresight functionality.

There are some further A510 fixes for 5.18 which might be useful if that CPU turns out to be in any machines RHEL is targeting.

(its also possible that there are a couple of conflicts with other sets in flight, in particular, the part numbers patch might have to be dropped from this set).

Signed-off-by: Jeremy Linton jlinton@redhat.com

Edited by Jeremy Linton

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