Hi Ivan,

Thank you for the patch! Yet something to improve:

[auto build test ERROR on net-next/master]

url:    https://github.com/0day-ci/linux/commits/Ivan-Khoronzhuk/xdp-xdp_umem-fix-umem-pages-mapping-for-32bits-systems/20190627-135949
config: i386-randconfig-x073-201925 (attached as .config)
compiler: gcc-7 (Debian 7.4.0-9) 7.4.0
reproduce:
        # save the attached .config to linux build tree
        make ARCH=i386 

If you fix the issue, kindly add following tag
Reported-by: kbuild test robot <lkp@intel.com>

All errors (new ones prefixed by >>):

   net//xdp/xdp_umem.c: In function 'xdp_umem_unmap_pages':
   net//xdp/xdp_umem.c:177:3: error: implicit declaration of function 'kunmap'; did you mean 'vunmap'? [-Werror=implicit-function-declaration]
      kunmap(umem->pgs[i]);
      ^~~~~~
      vunmap
   net//xdp/xdp_umem.c: In function 'xdp_umem_reg':
>> net//xdp/xdp_umem.c:384:25: error: implicit declaration of function 'kmap'; did you mean 'vmap'? [-Werror=implicit-function-declaration]
      umem->pages[i].addr = kmap(umem->pgs[i]);
                            ^~~~
                            vmap
   net//xdp/xdp_umem.c:384:23: warning: assignment makes pointer from integer without a cast [-Wint-conversion]
      umem->pages[i].addr = kmap(umem->pgs[i]);
                          ^
   cc1: some warnings being treated as errors

vim +384 net//xdp/xdp_umem.c

   311	
   312	static int xdp_umem_reg(struct xdp_umem *umem, struct xdp_umem_reg *mr)
   313	{
   314		u32 chunk_size = mr->chunk_size, headroom = mr->headroom;
   315		unsigned int chunks, chunks_per_page;
   316		u64 addr = mr->addr, size = mr->len;
   317		int size_chk, err, i;
   318	
   319		if (chunk_size < XDP_UMEM_MIN_CHUNK_SIZE || chunk_size > PAGE_SIZE) {
   320			/* Strictly speaking we could support this, if:
   321			 * - huge pages, or*
   322			 * - using an IOMMU, or
   323			 * - making sure the memory area is consecutive
   324			 * but for now, we simply say "computer says no".
   325			 */
   326			return -EINVAL;
   327		}
   328	
   329		if (!is_power_of_2(chunk_size))
   330			return -EINVAL;
   331	
   332		if (!PAGE_ALIGNED(addr)) {
   333			/* Memory area has to be page size aligned. For
   334			 * simplicity, this might change.
   335			 */
   336			return -EINVAL;
   337		}
   338	
   339		if ((addr + size) < addr)
   340			return -EINVAL;
   341	
   342		chunks = (unsigned int)div_u64(size, chunk_size);
   343		if (chunks == 0)
   344			return -EINVAL;
   345	
   346		chunks_per_page = PAGE_SIZE / chunk_size;
   347		if (chunks < chunks_per_page || chunks % chunks_per_page)
   348			return -EINVAL;
   349	
   350		headroom = ALIGN(headroom, 64);
   351	
   352		size_chk = chunk_size - headroom - XDP_PACKET_HEADROOM;
   353		if (size_chk < 0)
   354			return -EINVAL;
   355	
   356		umem->address = (unsigned long)addr;
   357		umem->chunk_mask = ~((u64)chunk_size - 1);
   358		umem->size = size;
   359		umem->headroom = headroom;
   360		umem->chunk_size_nohr = chunk_size - headroom;
   361		umem->npgs = size / PAGE_SIZE;
   362		umem->pgs = NULL;
   363		umem->user = NULL;
   364		INIT_LIST_HEAD(&umem->xsk_list);
   365		spin_lock_init(&umem->xsk_list_lock);
   366	
   367		refcount_set(&umem->users, 1);
   368	
   369		err = xdp_umem_account_pages(umem);
   370		if (err)
   371			return err;
   372	
   373		err = xdp_umem_pin_pages(umem);
   374		if (err)
   375			goto out_account;
   376	
   377		umem->pages = kcalloc(umem->npgs, sizeof(*umem->pages), GFP_KERNEL);
   378		if (!umem->pages) {
   379			err = -ENOMEM;
   380			goto out_account;
   381		}
   382	
   383		for (i = 0; i < umem->npgs; i++)
 > 384			umem->pages[i].addr = kmap(umem->pgs[i]);
   385	
   386		return 0;
   387	
   388	out_account:
   389		xdp_umem_unaccount_pages(umem);
   390		return err;
   391	}
   392	

---
0-DAY kernel test infrastructure                Open Source Technology Center
https://lists.01.org/pipermail/kbuild-all                   Intel Corporation