Christophe Leroy <christophe.le...@c-s.fr> writes:
> 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.le...@c-s.fr>
> ---
> This patch was initially part of the v1 serie of patchs for providing
> hugepage support to the 8xx. As suggested by Aneesh, that serie has
> been splited to focus only on hugepage implementation for 8xx.
> This patch is a fix and is independant of 8xx hugepage implementation,
> allthough it is required to have hugepage support working properly on
> the 8xx.
>
> arch/powerpc/include/asm/book3s/64/pgtable.h | 2 ++
> arch/powerpc/mm/hugetlbpage.c | 2 ++
> 2 files changed, 4 insertions(+)
>
> diff --git a/arch/powerpc/include/asm/book3s/64/pgtable.h
> b/arch/powerpc/include/asm/book3s/64/pgtable.h
> index 8ec8be9..9fd77f8 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 7372ee1..8a512b1 100644
> --- a/arch/powerpc/mm/hugetlbpage.c
> +++ b/arch/powerpc/mm/hugetlbpage.c
> @@ -1021,6 +1021,8 @@ int gup_hugepte(pte_t *ptep, unsigned long sz, unsigned
> long addr,
> mask = _PAGE_PRESENT | _PAGE_READ;
> if (write)
> mask |= _PAGE_WRITE;
> + else
> + mask |= _PAGE_RO;
>
> if ((pte_val(pte) & mask) != mask)
> return 0;
> --
Can you add the commit message also as code comment ?. It is confusing
to find that we do mask = _PAGE_READ and then mask |= _PAGE_RO.
Otherwise
Reviewed-by: Aneesh Kumar K.V <aneesh.ku...@linux.vnet.ibm.com>
-aneesh
