Nicholas Piggin <npig...@gmail.com> writes: > On Wed, 22 Aug 2018 22:46:05 +0530 > "Aneesh Kumar K.V" <aneesh.ku...@linux.ibm.com> wrote: > >> The Nest MMU workaround is only needed for RW upgrades. Avoid doing that >> for other pte updates. >> >> We also avoid clearing the pte while marking it invalid. This is because >> other >> page table walk will find this pte none and can result in unexpected >> behaviour >> due to that. Instead we clear _PAGE_PRESENT and set the software pte bit >> _PAGE_INVALID. pte_present is already updated to check for bot the bits. This >> make sure page table walkers will find the pte present and things like >> pte_pfn(pte) returns the right value. >> >> Based on the original patch from Benjamin Herrenschmidt >> <b...@kernel.crashing.org> >> >> Signed-off-by: Aneesh Kumar K.V <aneesh.ku...@linux.ibm.com> >> --- >> arch/powerpc/mm/pgtable-radix.c | 8 +++++--- > > This is powerpc/mm/radix, isn't it? Subject says hash.
I fixed it when applying. > Could we make this fix POWER9 only and use a RSV bit for it > rather than use up a SW bit? Other than that, > > Reviewed-by: Nicholas Piggin <npig...@gmail.com> Thanks. cheers