powerpc/mm/slice: Switch to 3-operand slice bitops helpers

This converts the slice_mask bit operation helpers to be the usual
3-operand kind, which allows 2 inputs to set a different output
without an extra copy, which is used in the next patch.

Adds slice_copy_mask, which will be used in the next patch.

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

arch/powerpc/mm/slice.c

@@ -429,25 +429,33 @@ static unsigned long slice_find_area(struct mm_struct *mm, unsigned long len,
 		return slice_find_area_bottomup(mm, len, mask, psize, high_limit);
 }
 
-static inline void slice_or_mask(struct slice_mask *dst,
+static inline void slice_copy_mask(struct slice_mask *dst,
 					const struct slice_mask *src)
 {
-	dst->low_slices |= src->low_slices;
+	dst->low_slices = src->low_slices;
 	if (!SLICE_NUM_HIGH)
 		return;
-	bitmap_or(dst->high_slices, dst->high_slices, src->high_slices,
-		  SLICE_NUM_HIGH);
+	bitmap_copy(dst->high_slices, src->high_slices, SLICE_NUM_HIGH);
 }
 
-static inline void slice_andnot_mask(struct slice_mask *dst,
-					const struct slice_mask *src)
+static inline void slice_or_mask(struct slice_mask *dst,
+					const struct slice_mask *src1,
+					const struct slice_mask *src2)
 {
-	dst->low_slices &= ~src->low_slices;
+	dst->low_slices = src1->low_slices | src2->low_slices;
+	if (!SLICE_NUM_HIGH)
+		return;
+	bitmap_or(dst->high_slices, src1->high_slices, src2->high_slices, SLICE_NUM_HIGH);
+}
 
+static inline void slice_andnot_mask(struct slice_mask *dst,
+					const struct slice_mask *src1,
+					const struct slice_mask *src2)
+{
+	dst->low_slices = src1->low_slices & ~src2->low_slices;
 	if (!SLICE_NUM_HIGH)
 		return;
-	bitmap_andnot(dst->high_slices, dst->high_slices, src->high_slices,
-		      SLICE_NUM_HIGH);
+	bitmap_andnot(dst->high_slices, src1->high_slices, src2->high_slices, SLICE_NUM_HIGH);
 }
 
 #ifdef CONFIG_PPC_64K_PAGES
@@ -562,7 +570,7 @@ unsigned long slice_get_unmapped_area(unsigned long addr, unsigned long len,
 	if (psize == MMU_PAGE_64K) {
 		compat_mask = *slice_mask_for_size(mm, MMU_PAGE_4K);
 		if (fixed)
-			slice_or_mask(&good_mask, &compat_mask);
+			slice_or_mask(&good_mask, &good_mask, &compat_mask);
 	}
 #endif
 
@@ -594,7 +602,7 @@ unsigned long slice_get_unmapped_area(unsigned long addr, unsigned long len,
 	 * empty and thus can be converted
 	 */
 	slice_mask_for_free(mm, &potential_mask, high_limit);
-	slice_or_mask(&potential_mask, &good_mask);
+	slice_or_mask(&potential_mask, &potential_mask, &good_mask);
 	slice_print_mask(" potential", &potential_mask);
 
 	if (addr != 0 || fixed) {
@@ -631,7 +639,7 @@ unsigned long slice_get_unmapped_area(unsigned long addr, unsigned long len,
 #ifdef CONFIG_PPC_64K_PAGES
 	if (addr == -ENOMEM && psize == MMU_PAGE_64K) {
 		/* retry the search with 4k-page slices included */
-		slice_or_mask(&potential_mask, &compat_mask);
+		slice_or_mask(&potential_mask, &potential_mask, &compat_mask);
 		addr = slice_find_area(mm, len, &potential_mask,
 				       psize, topdown, high_limit);
 	}
@@ -645,8 +653,8 @@ unsigned long slice_get_unmapped_area(unsigned long addr, unsigned long len,
 	slice_print_mask(" mask", &mask);
 
  convert:
-	slice_andnot_mask(&mask, &good_mask);
-	slice_andnot_mask(&mask, &compat_mask);
+	slice_andnot_mask(&mask, &mask, &good_mask);
+	slice_andnot_mask(&mask, &mask, &compat_mask);
 	if (mask.low_slices ||
 	    (SLICE_NUM_HIGH &&
 	     !bitmap_empty(mask.high_slices, SLICE_NUM_HIGH))) {
@@ -791,7 +799,7 @@ int is_hugepage_only_range(struct mm_struct *mm, unsigned long addr,
 	if (psize == MMU_PAGE_64K) {
 		struct slice_mask compat_mask;
 		compat_mask = *slice_mask_for_size(mm, MMU_PAGE_4K);
-		slice_or_mask(&available, &compat_mask);
+		slice_or_mask(&available, &available, &compat_mask);
 	}
 #endif