[PATCH v2 1/2] powerpc/powernv: Get L1D flush requirements from device-tree

[Russell Currey]

On Tue, 2022-04-05 at 02:49 +0000, Joel Stanley wrote:

> I booted both patches in this series on a power10 powernv machine,
> applied on top of v5.18-rc1:
> 
> $ dmesg |grep -i flush
> [    0.000000] rfi-flush: fallback displacement flush available
> [    0.000000] rfi-flush: patched 12 locations (no flush)
> [    0.000000] count-cache-flush: flush disabled.
> [    0.000000] link-stack-flush: flush disabled.

In this case you'd be looking for stf-barrier, uaccess-flush and entry-
flush so this doesn't tell us anything.  This must have been from a
no_spectrev2 boot with count cache and link stack flushes disabled.

> 
> $ grep . /sys/devices/system/cpu/vulnerabilities/*
> /sys/devices/system/cpu/vulnerabilities/itlb_multihit:Not affected
> /sys/devices/system/cpu/vulnerabilities/l1tf:Not affected
> /sys/devices/system/cpu/vulnerabilities/mds:Not affected
> /sys/devices/system/cpu/vulnerabilities/meltdown:Not affected
> /sys/devices/system/cpu/vulnerabilities/spec_store_bypass:Not
> affected
> /sys/devices/system/cpu/vulnerabilities/spectre_v1:Mitigation: __user
> pointer sanitization, ori31 speculation barrier enabled
> /sys/devices/system/cpu/vulnerabilities/spectre_v2:Mitigation:
> Software count cache flush (hardware accelerated), Software link
> stack
> flush
> /sys/devices/system/cpu/vulnerabilities/srbds:Not affected
> /sys/devices/system/cpu/vulnerabilities/tsx_async_abort:Not affected
> 
> Does that match what we expect?

This is as expected for P10, though clearly from a different boot to
the above :)

- Russell

> 
> Cheers,
> 
> Joel