[PATCH 4.16 208/272] powerpc/mm/slice: Remove intermediate bitmap copy

Greg Kroah-Hartman
2018-05-28T11:15:09Z

From: Christophe Leroy <christophe.leroy@c-s.fr>

commit 326691ad4f179e6edc7eb1271e618dd673e4736d upstream.

bitmap_or() and bitmap_andnot() can work properly with dst identical
to src1 or src2. There is no need of an intermediate result bitmap
that is copied back to dst in a second step.

Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Reviewed-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Reviewed-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
arch/powerpc/mm/slice.c | 12 ++++--------
1 file changed, 4 insertions(+), 8 deletions(-)

--- a/arch/powerpc/mm/slice.c
+++ b/arch/powerpc/mm/slice.c
@@ -388,21 +388,17 @@ static unsigned long slice_find_area(str

static inline void slice_or_mask(struct slice_mask *dst, struct slice_mask *src)
{
- DECLARE_BITMAP(result, SLICE_NUM_HIGH);
-
dst->low_slices |= src->low_slices;
- bitmap_or(result, dst->high_slices, src->high_slices, SLICE_NUM_HIGH);
- bitmap_copy(dst->high_slices, result, SLICE_NUM_HIGH);
+ bitmap_or(dst->high_slices, dst->high_slices, src->high_slices,
+ SLICE_NUM_HIGH);
}

static inline void slice_andnot_mask(struct slice_mask *dst, struct slice_mask *src)
{
- DECLARE_BITMAP(result, SLICE_NUM_HIGH);
-
dst->low_slices &= ~src->low_slices;

- bitmap_andnot(result, dst->high_slices, src->high_slices, SLICE_NUM_HIGH);
- bitmap_copy(dst->high_slices, result, SLICE_NUM_HIGH);
+ bitmap_andnot(dst->high_slices, dst->high_slices, src->high_slices,
+ SLICE_NUM_HIGH);
}

#ifdef CONFIG_PPC_64K_PAGES