powerpc/mm/slice: Update the function prototype
authorAneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Wed, 22 Mar 2017 03:36:48 +0000 (09:06 +0530)
committerMichael Ellerman <mpe@ellerman.id.au>
Fri, 31 Mar 2017 12:09:54 +0000 (23:09 +1100)
This avoid copying the slice_mask struct as function return value

Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
arch/powerpc/mm/slice.c

index 639c7171d1745c359b5376a7583edc2e88adca0b..d1da357583e34212993e73ae1a7dc39d16ddc464 100644 (file)
@@ -75,19 +75,18 @@ static void slice_print_mask(const char *label, struct slice_mask mask) {}
 
 #endif
 
-static struct slice_mask slice_range_to_mask(unsigned long start,
-                                            unsigned long len)
+static void slice_range_to_mask(unsigned long start, unsigned long len,
+                               struct slice_mask *ret)
 {
        unsigned long end = start + len - 1;
-       struct slice_mask ret;
 
-       ret.low_slices = 0;
-       bitmap_zero(ret.high_slices, SLICE_NUM_HIGH);
+       ret->low_slices = 0;
+       bitmap_zero(ret->high_slices, SLICE_NUM_HIGH);
 
        if (start < SLICE_LOW_TOP) {
                unsigned long mend = min(end, (SLICE_LOW_TOP - 1));
 
-               ret.low_slices = (1u << (GET_LOW_SLICE_INDEX(mend) + 1))
+               ret->low_slices = (1u << (GET_LOW_SLICE_INDEX(mend) + 1))
                        - (1u << GET_LOW_SLICE_INDEX(start));
        }
 
@@ -96,9 +95,8 @@ static struct slice_mask slice_range_to_mask(unsigned long start,
                unsigned long align_end = ALIGN(end, (1UL << SLICE_HIGH_SHIFT));
                unsigned long count = GET_HIGH_SLICE_INDEX(align_end) - start_index;
 
-               bitmap_set(ret.high_slices, start_index, count);
+               bitmap_set(ret->high_slices, start_index, count);
        }
-       return ret;
 }
 
 static int slice_area_is_free(struct mm_struct *mm, unsigned long addr,
@@ -132,53 +130,47 @@ static int slice_high_has_vma(struct mm_struct *mm, unsigned long slice)
        return !slice_area_is_free(mm, start, end - start);
 }
 
-static struct slice_mask slice_mask_for_free(struct mm_struct *mm)
+static void slice_mask_for_free(struct mm_struct *mm, struct slice_mask *ret)
 {
-       struct slice_mask ret;
        unsigned long i;
 
-       ret.low_slices = 0;
-       bitmap_zero(ret.high_slices, SLICE_NUM_HIGH);
+       ret->low_slices = 0;
+       bitmap_zero(ret->high_slices, SLICE_NUM_HIGH);
 
        for (i = 0; i < SLICE_NUM_LOW; i++)
                if (!slice_low_has_vma(mm, i))
-                       ret.low_slices |= 1u << i;
+                       ret->low_slices |= 1u << i;
 
        if (mm->task_size <= SLICE_LOW_TOP)
-               return ret;
+               return;
 
        for (i = 0; i < SLICE_NUM_HIGH; i++)
                if (!slice_high_has_vma(mm, i))
-                       __set_bit(i, ret.high_slices);
-
-       return ret;
+                       __set_bit(i, ret->high_slices);
 }
 
-static struct slice_mask slice_mask_for_size(struct mm_struct *mm, int psize)
+static void slice_mask_for_size(struct mm_struct *mm, int psize, struct slice_mask *ret)
 {
        unsigned char *hpsizes;
        int index, mask_index;
-       struct slice_mask ret;
        unsigned long i;
        u64 lpsizes;
 
-       ret.low_slices = 0;
-       bitmap_zero(ret.high_slices, SLICE_NUM_HIGH);
+       ret->low_slices = 0;
+       bitmap_zero(ret->high_slices, SLICE_NUM_HIGH);
 
        lpsizes = mm->context.low_slices_psize;
        for (i = 0; i < SLICE_NUM_LOW; i++)
                if (((lpsizes >> (i * 4)) & 0xf) == psize)
-                       ret.low_slices |= 1u << i;
+                       ret->low_slices |= 1u << i;
 
        hpsizes = mm->context.high_slices_psize;
        for (i = 0; i < SLICE_NUM_HIGH; i++) {
                mask_index = i & 0x1;
                index = i >> 1;
                if (((hpsizes[index] >> (mask_index * 4)) & 0xf) == psize)
-                       __set_bit(i, ret.high_slices);
+                       __set_bit(i, ret->high_slices);
        }
-
-       return ret;
 }
 
 static int slice_check_fit(struct slice_mask mask, struct slice_mask available)
@@ -460,7 +452,7 @@ unsigned long slice_get_unmapped_area(unsigned long addr, unsigned long len,
        /* First make up a "good" mask of slices that have the right size
         * already
         */
-       good_mask = slice_mask_for_size(mm, psize);
+       slice_mask_for_size(mm, psize, &good_mask);
        slice_print_mask(" good_mask", good_mask);
 
        /*
@@ -485,7 +477,7 @@ unsigned long slice_get_unmapped_area(unsigned long addr, unsigned long len,
 #ifdef CONFIG_PPC_64K_PAGES
        /* If we support combo pages, we can allow 64k pages in 4k slices */
        if (psize == MMU_PAGE_64K) {
-               compat_mask = slice_mask_for_size(mm, MMU_PAGE_4K);
+               slice_mask_for_size(mm, MMU_PAGE_4K, &compat_mask);
                if (fixed)
                        slice_or_mask(&good_mask, &compat_mask);
        }
@@ -494,7 +486,7 @@ unsigned long slice_get_unmapped_area(unsigned long addr, unsigned long len,
        /* First check hint if it's valid or if we have MAP_FIXED */
        if (addr != 0 || fixed) {
                /* Build a mask for the requested range */
-               mask = slice_range_to_mask(addr, len);
+               slice_range_to_mask(addr, len, &mask);
                slice_print_mask(" mask", mask);
 
                /* Check if we fit in the good mask. If we do, we just return,
@@ -521,7 +513,7 @@ unsigned long slice_get_unmapped_area(unsigned long addr, unsigned long len,
        /* We don't fit in the good mask, check what other slices are
         * empty and thus can be converted
         */
-       potential_mask = slice_mask_for_free(mm);
+       slice_mask_for_free(mm, &potential_mask);
        slice_or_mask(&potential_mask, &good_mask);
        slice_print_mask(" potential", potential_mask);
 
@@ -564,7 +556,7 @@ unsigned long slice_get_unmapped_area(unsigned long addr, unsigned long len,
        if (addr == -ENOMEM)
                return -ENOMEM;
 
-       mask = slice_range_to_mask(addr, len);
+       slice_range_to_mask(addr, len, &mask);
        slice_dbg(" found potential area at 0x%lx\n", addr);
        slice_print_mask(" mask", mask);
 
@@ -696,9 +688,11 @@ void slice_set_user_psize(struct mm_struct *mm, unsigned int psize)
 void slice_set_range_psize(struct mm_struct *mm, unsigned long start,
                           unsigned long len, unsigned int psize)
 {
-       struct slice_mask mask = slice_range_to_mask(start, len);
+       struct slice_mask mask;
 
        VM_BUG_ON(radix_enabled());
+
+       slice_range_to_mask(start, len, &mask);
        slice_convert(mm, mask, psize);
 }
 
@@ -731,13 +725,13 @@ int is_hugepage_only_range(struct mm_struct *mm, unsigned long addr,
        if (radix_enabled())
                return 0;
 
-       mask = slice_range_to_mask(addr, len);
-       available = slice_mask_for_size(mm, psize);
+       slice_range_to_mask(addr, len, &mask);
+       slice_mask_for_size(mm, psize, &available);
 #ifdef CONFIG_PPC_64K_PAGES
        /* We need to account for 4k slices too */
        if (psize == MMU_PAGE_64K) {
                struct slice_mask compat_mask;
-               compat_mask = slice_mask_for_size(mm, MMU_PAGE_4K);
+               slice_mask_for_size(mm, MMU_PAGE_4K, &compat_mask);
                slice_or_mask(&available, &compat_mask);
        }
 #endif