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authorChristophe Leroy <christophe.leroy@c-s.fr>2016-09-19 12:58:54 +0200
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2016-10-31 05:02:14 -0600
commit56b47c0b7968f71ad971fc3f600bc5f1dc8d8ee8 (patch)
tree29743d937cd27c3edfd46b4827226a2474a5f7e5
parentc80b599ab5d40c6aea170fd670b4802758623e54 (diff)
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powerpc: Fix usage of _PAGE_RO in hugepage
commit 6b8cb66a6a7cc182b47da6a0a1d4e5da324c0695 upstream. 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> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
-rw-r--r--arch/powerpc/include/asm/book3s/64/pgtable.h2
-rw-r--r--arch/powerpc/mm/hugetlbpage.c7
2 files changed, 9 insertions, 0 deletions
diff --git a/arch/powerpc/include/asm/book3s/64/pgtable.h b/arch/powerpc/include/asm/book3s/64/pgtable.h
index 263bf39ced40..9bd84ba06ec4 100644
--- a/arch/powerpc/include/asm/book3s/64/pgtable.h
+++ b/arch/powerpc/include/asm/book3s/64/pgtable.h
@@ -6,6 +6,8 @@
*/
#define _PAGE_BIT_SWAP_TYPE 0
+#define _PAGE_RO 0
+
#define _PAGE_EXEC 0x00001 /* execute permission */
#define _PAGE_WRITE 0x00002 /* write access allowed */
#define _PAGE_READ 0x00004 /* read access allowed */
diff --git a/arch/powerpc/mm/hugetlbpage.c b/arch/powerpc/mm/hugetlbpage.c
index 7372ee13eb1e..a5d3ecdabc44 100644
--- a/arch/powerpc/mm/hugetlbpage.c
+++ b/arch/powerpc/mm/hugetlbpage.c
@@ -1019,8 +1019,15 @@ int gup_hugepte(pte_t *ptep, unsigned long sz, unsigned long addr,
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;