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arm64/pmap: Add support for FEAT_TTL
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Authored by sarah.walker2_arm.com on Sep 28 2026, 11:03 AM.

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Referenced Files

	F177430966: D60090.1794363432.diff
	Tue, Nov 10, 2:17 AM

	F177409557: D60090.1794308798.diff
	Mon, Nov 9, 11:06 AM

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emaste

imp

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andrew
manu
alc
markj
kib

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rGf0b589edc7a7: arm64/pmap: Add support for FEAT_TTL

Summary

FEAT_TTL adds a Translation Table Level field for TLB maintenance intructions,
to indicate the level holding the leaf address for the address being
invalidated. This can reduce the cost of TLB invalidation.

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rG FreeBSD src repository

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Buildable 77851
Build 74734: arc lint + arc unit

Event Timeline

sarah.walker2_arm.com created this revision.Sep 28 2026, 11:03 AM

Herald added a reviewer: andrew. · View Herald TranscriptSep 28 2026, 11:03 AM

Herald added a reviewer: andrew. · View Herald Transcript

Herald added a reviewer: manu. · View Herald Transcript

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

Harbormaster completed remote builds in B77409: Diff 187869.Sep 28 2026, 11:03 AM

sarah.walker2_arm.com requested review of this revision.Sep 28 2026, 11:03 AM

I think these TLBI_TTL_UNKNOWN values can specify the level, but it would be useful for someone else to check

sys/arm64/arm64/pmap.c
3021	`TLBI_TTL_L3`?
3720	`TLBI_TTL_L3`?
4764	`TLBI_TTL_L3`?
6018	`TLBI_TTL_L3`?
6037	`TLBI_TTL_L3`?
6108	`TLBI_TTL_L3`?
8442	`TLBI_TTL_L3`?
8937	`TLBI_TTL_L3`?

andrew added reviewers: alc, markj, kib.Sep 29 2026, 10:01 AM

alc added inline comments.Sep 30 2026, 4:04 PM

sys/arm64/arm64/pmap.c
3021	No, not this one. (This function is misnamed. It's suffix should be _ptp, not _l3.)
8108	TLBI_TTL_L2

Address review comments and rebase

Harbormaster completed remote builds in B77851: Diff 189058.Oct 8 2026, 3:31 PM

andrew accepted this revision.Oct 8 2026, 3:52 PM

This revision is now accepted and ready to land.Oct 8 2026, 3:52 PM

alc added inline comments.Oct 10 2026, 4:02 PM

sys/arm64/arm64/pmap.c
460–473	I didn't see a reason for this change.
464–472	Aren't these backwards? They evaluate to a non-zero value when ttl is UNKNOWN.
2164	The prevailing style is simply `if (pmap_ttl_support)`.

Address review comments

This revision now requires review to proceed.Mon, Oct 12, 10:41 AM

Harbormaster completed remote builds in B78056: Diff 189584.Mon, Oct 12, 10:41 AM

andrew accepted this revision.Thu, Nov 5, 11:25 AM

This revision is now accepted and ready to land.Thu, Nov 5, 11:25 AM

Closed by commit rGf0b589edc7a7: arm64/pmap: Add support for FEAT_TTL. · Explain WhyFri, Nov 6, 3:39 PM

This revision was automatically updated to reflect the committed changes.

andrew added a commit: rGf0b589edc7a7: arm64/pmap: Add support for FEAT_TTL.

alc added inline comments.Sun, Nov 8, 8:01 AM

sys/arm64/arm64/pmap.c
542	There is no need to test `pmap_ttl_support` here. These TTL bits are defined by FEAT_TLBIRANGE, not FEAT_TTL.
2241	Needed below.
2265–2270	The per-page path should pass the TTL hint too.

alc added inline comments.Sun, Nov 8, 8:45 AM

sys/arm64/arm64/pmap.c
2314	If you add `int ttl` here and ...
2321	here too, all of the callers, except `pmap_update_entry()`, can pass TLBI_TTL_L3.

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sys/

arm64/

pmap.c

130 lines

Diff 189058

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arm64/pmap: Add support for FEAT_TTLClosedPublicActions