arm64/nexus: limit to INTR_IRQ_INVALID interrupts
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Authored by ehem_freebsd_m5p.com on May 30 2021, 4:48 PM.

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mhorne
manu

Summary

Even INTR_IRQ_INVALID seems like rather a lot of interrupts right now.
I suppose some future device might need that many internally, but right
now even INTR_IRQ_INVALID exceeds all real world devices.

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Repository

rS FreeBSD src repository - subversion

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Buildable 42135
Build 39023: arc lint + arc unit

Event Timeline

ehem_freebsd_m5p.com created this revision.May 30 2021, 4:48 PM

Herald added a reviewer: manu. · View Herald TranscriptMay 30 2021, 4:48 PM

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

ehem_freebsd_m5p.com requested review of this revision.May 30 2021, 4:48 PM

Harbormaster completed remote builds in B39572: Diff 90130.May 30 2021, 4:48 PM

Based on how rm_end = ~0 breaks the resource manager code, using that as the maximum is wrong. I'm unsure of what upper limit should be used, but 2^16 seems reasonable as the maximum interrupt number for the nexus. Perhaps 2^20 to leave a bit more headroom between the maximum allowed by a GICv3 and what some perverse system designer might actually make use of?

Last comment was mine on May 30th. It is now July 17th and no word. Month and a half seems a bit on the long side...

In light of what the intrng code does, might I suggest this as an alternative? Seems a genuine concern.

Harbormaster completed remote builds in B42135: Diff 96852.Oct 14 2021, 5:52 AM

There would be a distinct issue if this limit got hit...

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sys/

arm64/

nexus.c

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arm64/nexus: limit to INTR_IRQ_INVALID interruptsNeeds ReviewPublicActions