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From: Michael Ellerman <patch-notifications@ellerman.id.au>
To: Jordan Niethe <jniethe5@gmail.com>, linuxppc-dev@lists.ozlabs.org
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Subject: Re: [PATCH v3 1/2] powerpc/64s: Fix pte update for kernel memory on
 radix
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On Mon, 8 Feb 2021 14:29:56 +1100, Jordan Niethe wrote:
> When adding a pte a ptesync is needed to order the update of the pte
> with subsequent accesses otherwise a spurious fault may be raised.
> 
> radix__set_pte_at() does not do this for performance gains. For
> non-kernel memory this is not an issue as any faults of this kind are
> corrected by the page fault handler.  For kernel memory these faults are
> not handled.  The current solution is that there is a ptesync in
> flush_cache_vmap() which should be called when mapping from the vmalloc
> region.
> 
> [...]

Applied to powerpc/next.

[1/2] powerpc/64s: Fix pte update for kernel memory on radix
      https://git.kernel.org/powerpc/c/b8b2f37cf632434456182e9002d63cbc4cccc50c
[2/2] selftests/powerpc: Test for spurious kernel memory faults on radix
      https://git.kernel.org/powerpc/c/29e3ea8cbd2958cf237b84652ec236803f2c6202

cheers