Differential D19225

amd64: cleanup pmap_init_pat().
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Authored by kib on Feb 17 2019, 7:41 PM.

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Reviewers

alc
markj

Commits

rS344256: amd64: cleanup pmap_init_pat().

Summary

The pmap_works variable is always true for amd64. Remove it, the branch in the initialization taken when false, and corresponding sysctl.
Remove pat_table[] local array, work on pat_index[] directly.
Collapse whole initialization to not override already assigned values.
Add comment explaining the choice for PAT4 and PAT7.

MFC note: I might leave the sysctl around.

Diff Detail

Repository

rS FreeBSD src repository - subversion

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Unit

Tests Not Applicable

Event Timeline

kib created this revision.Feb 17 2019, 7:41 PM

Herald added a subscriber: imp. · View Herald TranscriptFeb 17 2019, 7:41 PM

Harbormaster completed remote builds in B22546: Diff 54021.Feb 17 2019, 7:41 PM

markj accepted this revision.Feb 17 2019, 8:07 PM

markj added inline comments.

sys/amd64/amd64/pmap.c
1244 ↗	(On Diff #54021)	"a recursive"
1245 ↗	(On Diff #54021)	"a PAT value"
1246 ↗	(On Diff #54021)	I'm confused by the comment. What's special about the recursive map?

This revision is now accepted and ready to land.Feb 17 2019, 8:07 PM

kib marked 2 inline comments as done.Feb 17 2019, 8:30 PM

kib added inline comments.

sys/amd64/amd64/pmap.c
1246 ↗	(On Diff #54021)	For recursive map, pde becomes pte, so PG_PS is interpreted as the PAT bit 3.

markj added inline comments.Feb 17 2019, 11:40 PM

sys/amd64/amd64/pmap.c
1246 ↗	(On Diff #54021)	Oops, I see.

alc accepted this revision.Feb 18 2019, 4:08 AM

Closed by commit rS344256: amd64: cleanup pmap_init_pat(). (authored by kib). · Explain WhyFeb 18 2019, 4:02 PM

This revision was automatically updated to reflect the committed changes.

Revision Contents
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Path

Size

head/

sys/

amd64/

pmap.c

56 lines

Diff 54041

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head/sys/amd64/amd64/pmap.c

amd64: cleanup pmap_init_pat().ClosedPublicActions