LinuxKPI: Support lazy BAR allocation
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Authored by jrtc27 on Oct 10 2021, 7:10 PM.

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Reviewers

• hselasky
manu
jhb
mav

Commits

rGfa82e6a10305: LinuxKPI: Support lazy BAR allocation
rG82098c8bb5b3: LinuxKPI: Support lazy BAR allocation

Summary

Linux KPIs like pci_resource_start/len assume that BARs have been
allocated, but FreeBSD lazily allocates BARs if it cannot allocate the
firmware-allocated BARs. Thus using the Linux KPIs must force allocation
of the BARs rather than returning 0 for the start and length, which can
crash drm-kmod drivers that assume the BARs are valid. This is needed
for the AMDGPU driver to be able to attach on SiFive's HiFive Unmatched.

MFC after: 1 week

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Repository

rG FreeBSD src repository

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Tests Not Applicable

Event Timeline

jrtc27 created this revision.Oct 10 2021, 7:10 PM

Herald added subscribers: linuxkpi, emaste, imp. · View Herald TranscriptOct 10 2021, 7:10 PM

jrtc27 requested review of this revision.Oct 10 2021, 7:10 PM

Harbormaster completed remote builds in B42058: Diff 96638.Oct 10 2021, 7:10 PM

jrtc27 edited the summary of this revision. (Show Details)Oct 10 2021, 7:22 PM

• hselasky accepted this revision.Oct 11 2021, 9:27 AM

• hselasky added inline comments.

sys/compat/linuxkpi/common/src/linux_pci.c
678	Maybe put ()'s around "pdev->pdrv != NULL && pdev->pdrv->isdrm".

This revision is now accepted and ready to land.Oct 11 2021, 9:27 AM

You also should bump the __FreeBSD_version in sys/sys/param.h alongside this commit.

• hselasky added inline comments.Oct 11 2021, 9:32 AM

sys/compat/linuxkpi/common/include/linux/pci.h
318	With regards to MFC-ing it would be better to make two different inline functions for getting the "rle". One as-is, and one with reserve_bar always set true. Then you don't change any existing APIs!