Differential D35234

Support LSE atomics in the arm64 casue* functions
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Authored by andrew on May 17 2022, 1:56 PM.

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Reviewers

markj
kib
manu

Group Reviewers

Commits

rG20d21e435145: Support LSE atomics in the arm64 casue* functions
rG88ac318759f2: Support LSE atomics in the arm64 casue* functions

Summary

As with atomic(9) use the ARMv8.1 Large System Extension atomic
instructions to implement the userspace compare and swap functions.

Diff Detail

Repository

rS FreeBSD src repository - subversion

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No Test Coverage

Build Status

Buildable 45607
Build 42495: arc lint + arc unit

Event Timeline

andrew created this revision.May 17 2022, 1:56 PM

Herald added a reviewer: manu. · View Herald TranscriptMay 17 2022, 1:56 PM

Herald added subscribers: emaste, imp. · View Herald Transcript

andrew requested review of this revision.May 17 2022, 1:56 PM

Harbormaster completed remote builds in B45607: Diff 106108.May 17 2022, 1:56 PM

andrew added a reviewer: arm64.May 17 2022, 2:01 PM

I believe that the patch itself if fine.

But I noted a thing with casueword(32) and its use in kern_umtx.c. It seems that kern_umtx.c assumes that the function has sequential-constistent fence semantic. Note that both lock acquire and release just return success if casueword32 succeeded, in do_lock_normal() and do_unlock_normal(). The full fence semantic is provided on x86, but I suspect all ll/sc arches are affected.

This revision is now accepted and ready to land.May 17 2022, 11:47 PM

Closed by commit rG88ac318759f2: Support LSE atomics in the arm64 casue* functions (authored by andrew). · Explain WhyMay 19 2022, 10:33 AM

This revision was automatically updated to reflect the committed changes.

andrew added a commit: rG88ac318759f2: Support LSE atomics in the arm64 casue* functions.

andrew added a commit: rG20d21e435145: Support LSE atomics in the arm64 casue* functions.Jun 7 2022, 2:24 PM

Revision Contents
Changeset List

Path

Size

sys/

arm64/

arm64/

52 lines

support_ifunc.c

58 lines

conf/

1 line

Diff 106108

sys/arm64/arm64/support.S

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sys/arm64/arm64/support_ifunc.c

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sys/conf/files.arm64

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