[jgunthorpe:iommufd 2/8] drivers/iommu/iommufd/io_pagetable.c:1212:5: warning: no previous prototype for 'iopt_access_pages'

[jgunthorpe:iommufd 2/8] drivers/iommu/iommufd/io_pagetable.c:1212:5: warning: no previous prototype for 'iopt_access_pages'

[kernel test robot]

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tree:   https://github.com/jgunthorpe/linux iommufd
head:   4d06b5807e799e0293171d872d8c1a40f3b466c5
commit: 60716d1561f09cff04bd92ceb6007cc04d309469 [2/8] iommufd: Data structure to provide IOVA to PFN mapping
config: arc-allyesconfig (attached as .config)
compiler: arceb-elf-gcc (GCC) 11.2.0
reproduce (this is a W=1 build):
        wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross
        chmod +x ~/bin/make.cross
        # https://github.com/jgunthorpe/linux/commit/60716d1561f09cff04bd92ceb6007cc04d309469
        git remote add jgunthorpe https://github.com/jgunthorpe/linux
        git fetch --no-tags jgunthorpe iommufd
        git checkout 60716d1561f09cff04bd92ceb6007cc04d309469
        # save the attached .config to linux build tree
        COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-11.2.0 make.cross ARCH=arc 

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

All warnings (new ones prefixed by >>):

>> drivers/iommu/iommufd/io_pagetable.c:1212:5: warning: no previous prototype for 'iopt_access_pages' [-Wmissing-prototypes]
    1212 | int iopt_access_pages(struct io_pagetable *iopt, unsigned long iova,
         |     ^~~~~~~~~~~~~~~~~
   In file included from include/linux/mm.h:30,
                    from drivers/iommu/iommufd/io_pagetable.c:28:
   drivers/iommu/iommufd/io_pagetable.c: In function 'iopt_access_pages':
>> include/linux/overflow.h:84:22: warning: comparison of distinct pointer types lacks a cast
      84 |         (void) (&__a == &__b);                  \
         |                      ^~
   drivers/iommu/iommufd/io_pagetable.c:1224:13: note: in expansion of macro 'check_mul_overflow'
    1224 |         if (check_mul_overflow(npages, PAGE_SIZE, &length) ||
         |             ^~~~~~~~~~~~~~~~~~
   include/linux/overflow.h:66:22: warning: comparison of distinct pointer types lacks a cast
      66 |         (void) (&__a == &__b);                  \
         |                      ^~
   drivers/iommu/iommufd/io_pagetable.c:1225:13: note: in expansion of macro 'check_add_overflow'
    1225 |             check_add_overflow(iova, length - 1, &iova_end))
         |             ^~~~~~~~~~~~~~~~~~
   drivers/iommu/iommufd/io_pagetable.c: In function 'iopt_unaccess_pages':
>> include/linux/overflow.h:84:22: warning: comparison of distinct pointer types lacks a cast
      84 |         (void) (&__a == &__b);                  \
         |                      ^~
   drivers/iommu/iommufd/io_pagetable.c:1280:13: note: in expansion of macro 'check_mul_overflow'
    1280 |         if (check_mul_overflow(npages, PAGE_SIZE, &length) ||
         |             ^~~~~~~~~~~~~~~~~~
   include/linux/overflow.h:66:22: warning: comparison of distinct pointer types lacks a cast
      66 |         (void) (&__a == &__b);                  \
         |                      ^~
   drivers/iommu/iommufd/io_pagetable.c:1281:13: note: in expansion of macro 'check_add_overflow'
    1281 |             check_add_overflow(iova, length - 1, &iova_end))
         |             ^~~~~~~~~~~~~~~~~~


vim +/iopt_access_pages +1212 drivers/iommu/iommufd/io_pagetable.c

  1200	
  1201	/**
  1202	* iopt_access_pages - Return a list of pages under the iova
  1203	*
  1204	* Reads @npages starting at iova and returns the struct page * pointers. These
  1205	* can be kmap'd by the caller for CPU access.
  1206	*
  1207	* The caller must perform iopt_unaccess_pages() when done to balance this.
  1208	*
  1209	* CHECKME: callers that need a DMA mapping via a sgl should create another
  1210	* interface to build the SGL efficiently)
  1211	*/
> 1212	int iopt_access_pages(struct io_pagetable *iopt, unsigned long iova,
  1213			      size_t npages, struct page **out_pages, bool write)
  1214	{
  1215		unsigned long cur_iova;
  1216		unsigned long iova_end;
  1217		struct iopt_area *area;
  1218		size_t length;
  1219		int rc;
  1220	
  1221		down_read(&iopt->rwsem);
  1222		if (!npages || iova % PAGE_SIZE)
  1223			return -EINVAL;
  1224		if (check_mul_overflow(npages, PAGE_SIZE, &length) ||
  1225		    check_add_overflow(iova, length - 1, &iova_end))
  1226			return -EOVERFLOW;
  1227	
  1228		cur_iova = iova;
  1229		for (area = iopt_area_iter_first(iopt, iova, iova_end); area;
  1230		     area = iopt_area_iter_next(area, iova, iova_end)) {
  1231			unsigned long intr_start = max(iova, iopt_area_iova(area));
  1232			unsigned long intr_end =
  1233				min(iova_end, iopt_area_last_iova(area));
  1234			size_t npages = (intr_end - intr_start + 1) / PAGE_SIZE;
  1235	
  1236			/* Need contiguous areas un the access */
  1237			if (cur_iova != intr_start) {
  1238				rc = -EINVAL;
  1239				goto out_remove;
  1240			}
  1241	
  1242			npages = (intr_end - intr_start + 1) / PAGE_SIZE;
  1243			rc = iopt_pages_add_user(
  1244				area->pages,
  1245				(intr_start - iopt_area_iova(area)) / PAGE_SIZE, npages,
  1246				out_pages + (intr_end - iopt_area_iova(area) + 1) /
  1247						    PAGE_SIZE,
  1248				write);
  1249			if (rc)
  1250				goto out_remove;
  1251			cur_iova += npages * PAGE_SIZE;
  1252			atomic_inc(&area->num_users);
  1253		}
  1254	
  1255		up_read(&iopt->rwsem);
  1256		return 0;
  1257	
  1258	out_remove:
  1259		iopt_unaccess_pages(iopt, iova, (cur_iova - iova) / PAGE_SIZE);
  1260		return rc;
  1261	}
  1262	

---
0-DAY CI Kernel Test Service, Intel Corporation
https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org

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