powerpc/mm/slice: Remove intermediate bitmap copy
authorChristophe Leroy <christophe.leroy@c-s.fr>
Thu, 22 Feb 2018 14:27:20 +0000 (15:27 +0100)
committerMichael Ellerman <mpe@ellerman.id.au>
Mon, 5 Mar 2018 22:21:22 +0000 (09:21 +1100)
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>
arch/powerpc/mm/slice.c

index 23ec2c5e3b782412f8b10717cee352e56cc31217..98b53d48968f15e38d541da30a871b04cd464eff 100644 (file)
@@ -388,21 +388,17 @@ static unsigned long slice_find_area(struct mm_struct *mm, unsigned long len,
 
 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