powerpc: Fix usage of _PAGE_RO in hugepage
On some CPUs like the 8xx, _PAGE_RW hence _PAGE_WRITE is defined
as 0 and _PAGE_RO has to be set when a page is not writable
_PAGE_RO is defined by default in pte-common.h, however BOOK3S/64
doesn't include that file so _PAGE_RO has to be defined explicitly
in book3s/64/pgtable.h
Fixes: a7b9f671f2d14 ("powerpc32: adds handling of _PAGE_RO")
Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Reviewed-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
diff --git a/arch/powerpc/mm/hugetlbpage.c b/arch/powerpc/mm/hugetlbpage.c
index 7372ee1..a5d3ecd 100644
--- a/arch/powerpc/mm/hugetlbpage.c
+++ b/arch/powerpc/mm/hugetlbpage.c
@@ -1019,8 +1019,15 @@
pte = READ_ONCE(*ptep);
mask = _PAGE_PRESENT | _PAGE_READ;
+
+ /*
+ * On some CPUs like the 8xx, _PAGE_RW hence _PAGE_WRITE is defined
+ * as 0 and _PAGE_RO has to be set when a page is not writable
+ */
if (write)
mask |= _PAGE_WRITE;
+ else
+ mask |= _PAGE_RO;
if ((pte_val(pte) & mask) != mask)
return 0;
