Re: [linux-next:master 2778/3213] arch/x86/mm/init_64.c:1583:6: error: implicit declaration of function 'vmemmap_use_new_sub_pmd'

[Souptick Joarder <jrdr.linux@gmail.com>]

On Wed, Mar 10, 2021 at 1:02 PM kernel test robot <lkp@intel.com> wrote:
>
> tree:   https://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git master
> head:   b01d57bfdc41c8f635b08b8a5af8a31217d46936
> commit: 3c583493688a0a1276f6a8c0bbc5ece84e77f086 [2778/3213] x86/vmemmap: handle unpopulated sub-pmd ranges
> config: x86_64-randconfig-s022-20210309 (attached as .config)
> compiler: gcc-9 (Debian 9.3.0-22) 9.3.0
> reproduce:
>         # apt-get install sparse
>         # sparse version: v0.6.3-262-g5e674421-dirty
>         # https://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git/commit/?id=3c583493688a0a1276f6a8c0bbc5ece84e77f086
>         git remote add linux-next https://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git
>         git fetch --no-tags linux-next master
>         git checkout 3c583493688a0a1276f6a8c0bbc5ece84e77f086
>         # save the attached .config to linux build tree
>         make W=1 C=1 CF='-fdiagnostic-prefix -D__CHECK_ENDIAN__' ARCH=x86_64
>
> If you fix the issue, kindly add following tag as appropriate
> Reported-by: kernel test robot <lkp@intel.com>
>
> All errors (new ones prefixed by >>):
>
>    arch/x86/mm/init_64.c: In function 'vmemmap_populate_hugepages':
> >> arch/x86/mm/init_64.c:1583:6: error: implicit declaration of function 'vmemmap_use_new_sub_pmd' [-Werror=implicit-function-declaration]
>     1583 |      vmemmap_use_new_sub_pmd(addr, next);
>          |      ^~~~~~~~~~~~~~~~~~~~~~~
> >> arch/x86/mm/init_64.c:1589:4: error: implicit declaration of function 'vmemmap_use_sub_pmd' [-Werror=implicit-function-declaration]
>     1589 |    vmemmap_use_sub_pmd(addr, next);
>          |    ^~~~~~~~~~~~~~~~~~~
>    cc1: some warnings being treated as errors
>

But both the functions are defined in arch/x86/mm/init_64.c.

> vim +/vmemmap_use_new_sub_pmd +1583 arch/x86/mm/init_64.c
>
>   1530
>   1531  static int __meminit vmemmap_populate_hugepages(unsigned long start,
>   1532                  unsigned long end, int node, struct vmem_altmap *altmap)
>   1533  {
>   1534          unsigned long addr;
>   1535          unsigned long next;
>   1536          pgd_t *pgd;
>   1537          p4d_t *p4d;
>   1538          pud_t *pud;
>   1539          pmd_t *pmd;
>   1540
>   1541          for (addr = start; addr < end; addr = next) {
>   1542                  next = pmd_addr_end(addr, end);
>   1543
>   1544                  pgd = vmemmap_pgd_populate(addr, node);
>   1545                  if (!pgd)
>   1546                          return -ENOMEM;
>   1547
>   1548                  p4d = vmemmap_p4d_populate(pgd, addr, node);
>   1549                  if (!p4d)
>   1550                          return -ENOMEM;
>   1551
>   1552                  pud = vmemmap_pud_populate(p4d, addr, node);
>   1553                  if (!pud)
>   1554                          return -ENOMEM;
>   1555
>   1556                  pmd = pmd_offset(pud, addr);
>   1557                  if (pmd_none(*pmd)) {
>   1558                          void *p;
>   1559
>   1560                          p = vmemmap_alloc_block_buf(PMD_SIZE, node, altmap);
>   1561                          if (p) {
>   1562                                  pte_t entry;
>   1563
>   1564                                  entry = pfn_pte(__pa(p) >> PAGE_SHIFT,
>   1565                                                  PAGE_KERNEL_LARGE);
>   1566                                  set_pmd(pmd, __pmd(pte_val(entry)));
>   1567
>   1568                                  /* check to see if we have contiguous blocks */
>   1569                                  if (p_end != p || node_start != node) {
>   1570                                          if (p_start)
>   1571                                                  pr_debug(" [%lx-%lx] PMD -> [%p-%p] on node %d\n",
>   1572                                                         addr_start, addr_end-1, p_start, p_end-1, node_start);
>   1573                                          addr_start = addr;
>   1574                                          node_start = node;
>   1575                                          p_start = p;
>   1576                                  }
>   1577
>   1578                                  addr_end = addr + PMD_SIZE;
>   1579                                  p_end = p + PMD_SIZE;
>   1580
>   1581                                  if (!IS_ALIGNED(addr, PMD_SIZE) ||
>   1582                                      !IS_ALIGNED(next, PMD_SIZE))
> > 1583                                          vmemmap_use_new_sub_pmd(addr, next);
>   1584                                  continue;
>   1585                          } else if (altmap)
>   1586                                  return -ENOMEM; /* no fallback */
>   1587                  } else if (pmd_large(*pmd)) {
>   1588                          vmemmap_verify((pte_t *)pmd, node, addr, next);
> > 1589                          vmemmap_use_sub_pmd(addr, next);
>   1590                          continue;
>   1591                  }
>   1592                  if (vmemmap_populate_basepages(addr, next, node, NULL))
>   1593                          return -ENOMEM;
>   1594          }
>   1595          return 0;
>   1596  }
>   1597
>
> ---
> 0-DAY CI Kernel Test Service, Intel Corporation
> https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org