On CONFIG_PPC32=y build fails:
drivers/nvdimm/region_devs.c:1034:14: note: in expansion of macro ‘do_div’
  remainder = do_div(per_mapping, mappings);
              ^~~~~~
In file included from ./arch/powerpc/include/generated/asm/div64.h:1:0,
                 from ./include/linux/kernel.h:18,
                 from ./include/asm-generic/bug.h:19,
                 from ./arch/powerpc/include/asm/bug.h:109,
                 from ./include/linux/bug.h:5,
                 from ./include/linux/scatterlist.h:7,
                 from drivers/nvdimm/region_devs.c:5:
./include/asm-generic/div64.h:243:22: error: passing argument 1 of ‘__div64_32’ from incompatible pointer type [-Werror=incompatible-pointer-types]
   __rem = __div64_32(&(n), __base); \
Use div_u64 instead of do_div to fix this.
Fixes: 2522afb86a8c ("libnvdimm/region: Introduce an 'align' attribute")
Signed-off-by: YueHaibing <yuehaibing@huawei.com>
Link: https://lore.kernel.org/r/20200331115024.31628-1-yuehaibing@huawei.com
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
 
         * contribute to the tail capacity in system-physical-address
         * space for the namespace.
         */
-       dpa = val;
-       remainder = do_div(dpa, nd_region->ndr_mappings);
+       dpa = div_u64_rem(val, nd_region->ndr_mappings, &remainder);
        if (!is_power_of_2(dpa) || dpa < PAGE_SIZE
                        || val > region_size(nd_region) || remainder)
                return -EINVAL;
 
 static unsigned long default_align(struct nd_region *nd_region)
 {
-       unsigned long align, per_mapping;
+       unsigned long align;
        int i, mappings;
        u32 remainder;
 
        }
 
        mappings = max_t(u16, 1, nd_region->ndr_mappings);
-       per_mapping = align;
-       remainder = do_div(per_mapping, mappings);
+       div_u64_rem(align, mappings, &remainder);
        if (remainder)
                align *= mappings;