Right now, ZONE_DEVICE memory is always set PG_reserved. We want to change that.
Rewrite maybe_pte_to_page() to make sure the function produces the same result once we stop setting ZONE_DEVICE pages PG_reserved. Cc: Benjamin Herrenschmidt <b...@kernel.crashing.org> Cc: Paul Mackerras <pau...@samba.org> Cc: Michael Ellerman <m...@ellerman.id.au> Cc: Christophe Leroy <christophe.le...@c-s.fr> Cc: "Aneesh Kumar K.V" <aneesh.ku...@linux.ibm.com> Cc: Allison Randal <alli...@lohutok.net> Cc: Nicholas Piggin <npig...@gmail.com> Cc: Thomas Gleixner <t...@linutronix.de> Signed-off-by: David Hildenbrand <da...@redhat.com> --- arch/powerpc/mm/pgtable.c | 10 ++++++---- 1 file changed, 6 insertions(+), 4 deletions(-) diff --git a/arch/powerpc/mm/pgtable.c b/arch/powerpc/mm/pgtable.c index e3759b69f81b..613c98fa7dc0 100644 --- a/arch/powerpc/mm/pgtable.c +++ b/arch/powerpc/mm/pgtable.c @@ -55,10 +55,12 @@ static struct page *maybe_pte_to_page(pte_t pte) unsigned long pfn = pte_pfn(pte); struct page *page; - if (unlikely(!pfn_valid(pfn))) - return NULL; - page = pfn_to_page(pfn); - if (PageReserved(page)) + /* + * We reject any pages that are not online (not managed by the buddy). + * This includes ZONE_DEVICE pages. + */ + page = pfn_to_online_page(pfn); + if (unlikely(!page || PageReserved(page))) return NULL; return page; } -- 2.21.0