Use macro section_nr_to_pfn() to switch between section and pfn, instead
of open-coding it.  No semantic changes.
Signed-off-by: Sheng Yong <shengyong1@huawei.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
        struct page *first_page;
        int ret;
 
-       start_pfn = phys_index << PFN_SECTION_SHIFT;
+       start_pfn = section_nr_to_pfn(phys_index);
        first_page = pfn_to_page(start_pfn);
 
        switch (action) {
 
        end_sec = pfn_to_section_nr(phys_start_pfn + nr_pages - 1);
 
        for (i = start_sec; i <= end_sec; i++) {
-               err = __add_section(nid, zone, i << PFN_SECTION_SHIFT);
+               err = __add_section(nid, zone, section_nr_to_pfn(i));
 
                /*
                 * EEXIST is finally dealt with by ioresource collision