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[xarray] iov_iter_npages(): just use DIV_ROUND_UP()

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Compiler is capable of recognizing division by power of 2 and turning
it into shifts.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
This commit is contained in:
Al Viro 2021-05-03 11:05:29 -04:00
parent 66531c65aa
commit e4f8df8679
1 changed files with 2 additions and 14 deletions
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16
lib/iov_iter.c
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@ -1925,20 +1925,8 @@ int iov_iter_npages(const struct iov_iter *i, int maxpages)
return min(npages, maxpages); return min(npages, maxpages);
} }
if (iov_iter_is_xarray(i)) { if (iov_iter_is_xarray(i)) {
size_t size = i->count; unsigned offset = (i->xarray_start + i->iov_offset) % PAGE_SIZE;
unsigned offset; int npages = DIV_ROUND_UP(offset + i->count, PAGE_SIZE);
int npages;
offset = (i->xarray_start + i->iov_offset) & ~PAGE_MASK;
npages = 1;
if (size > PAGE_SIZE - offset) {
size -= PAGE_SIZE - offset;
npages += size >> PAGE_SHIFT;
size &= ~PAGE_MASK;
if (size)
npages++;
}
return min(npages, maxpages); return min(npages, maxpages);
} }
return 0; return 0;