PPC64: use hwref instead of cpuid
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Authored by wma on Jan 22 2018, 6:53 AM.

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nwhitehorn
jhibbits
mw
markmi_dsl-only.net

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rS328534: PPC64: use hwref instead of cpuid

Summary

On CHRP and PowerNV, use the interrupt server number in the cpuref and pcpu
hwref field instead of the device-tree phandle and make the CPU IDs reported
to the scheduler dense and with the BSP at 0.

WARNING: tested on PowerNV. Does work only when BSP is CPU[0]. TBD if wokrs on other ppc64 boards.

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rS FreeBSD src repository - subversion

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wma created this revision.Jan 22 2018, 6:53 AM

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wma edited the summary of this revision. (Show Details)Jan 22 2018, 6:54 AM

I like the approach. Why doesn't it work if BSP is non-zero? Doesn't this code arrange for the BSP to always be zero?

It SHOULD work on PowerNV as the code for cpuid swap is there, however I did not run much of testing, so I'd rather consider this as experimental/not-working. The CHRP platform has no such code, so there the BSP must be at CPU0.

This revision was not accepted when it landed; it landed in state Needs Review.Jan 29 2018, 9:15 AM

Closed by commit rS328534: PPC64: use hwref instead of cpuid (authored by wma). · Explain Why

This revision was automatically updated to reflect the committed changes.

There is intrinsically no difference between CHRP and PowerNV. Could you please update CHRP to match, including the BSP 0 code, (copy-and-paste is fine) and test it on your POWER8 system? I don't have access to any POWER8 hardware and the moment and the risk of breaking Power[K]VM is high.