arm64: lop off another 24MB of KVA for early device mappings
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Authored by kevans on Nov 23 2023, 6:07 AM.

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andrew
manu
emaste

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arm64

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rGa3ceeef26bc8: arm64: lop off another 24MB of KVA for early device mappings

Summary

This grows the block enough to fit a 4K 32-bit depth framebuffer; some
firmware would present smaller GOP modes to be able to boot with a
smaller framebuffer on these devices, but the Windows Devkit firmware
is simply not that nice. Instead, it offers exactly one GOP mode that
matches the current resolution of the attached display, so with limited
control over resolution on most of my displays it'd be nice if we could
Just Work(TM) at 4K.

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rG FreeBSD src repository

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Event Timeline

kevans created this revision.Nov 23 2023, 6:07 AM

Herald added a reviewer: andrew. · View Herald TranscriptNov 23 2023, 6:07 AM

Herald added a reviewer: andrew. · View Herald Transcript

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kevans requested review of this revision.Nov 23 2023, 6:07 AM

Harbormaster completed remote builds in B54582: Diff 130449.Nov 23 2023, 6:07 AM

Is there any downside of the increase (beyond the tiny increase in time spent in pmap_bootstrap_l3)?

In D42726#974806, @emaste wrote:

Is there any downside of the increase (beyond the tiny increase in time spent in pmap_bootstrap_l3)?

I couldn't find one... it's allocated from the very top of KVA (with kernel growing from the bottom), with 512GB of KVA to work with it seems like we'll have bigger issues to solve if this ends up becoming a problem.

andrew accepted this revision.Nov 23 2023, 3:02 PM

This revision is now accepted and ready to land.Nov 23 2023, 3:02 PM

emaste accepted this revision.Nov 23 2023, 3:43 PM

Closed by commit rGa3ceeef26bc8: arm64: lop off another 24MB of KVA for early device mappings (authored by kevans). · Explain WhyNov 23 2023, 4:24 PM

This revision was automatically updated to reflect the committed changes.

kevans added a commit: rGa3ceeef26bc8: arm64: lop off another 24MB of KVA for early device mappings.