Hi Liu,

url:    https://github.com/0day-ci/linux/commits/Liu-Yi-L/iommu-vt-d-Misc-fixes-on-scalable-mode/20201229-113203
base:    5c8fe583cce542aa0b84adc939ce85293de36e5e
config: i386-randconfig-m021-20201229 (attached as .config)
compiler: gcc-9 (Debian 9.3.0-15) 9.3.0

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

New smatch warnings:
drivers/iommu/intel/iommu.c:1471 domain_update_iotlb() error: we previously assumed 'info' could be null (see line 1472)

Old smatch warnings:
drivers/iommu/intel/iommu.c:920 device_to_iommu() error: we previously assumed 'pdev' could be null (see line 893)
drivers/iommu/intel/iommu.c:3764 intel_iommu_add() warn: should '(1 << sp)' be a 64 bit type?

vim +/info +1471 drivers/iommu/intel/iommu.c

0824c5920b16fe1 drivers/iommu/intel-iommu.c Omer Peleg 2016-04-20  1464  static void domain_update_iotlb(struct dmar_domain *domain)
0824c5920b16fe1 drivers/iommu/intel-iommu.c Omer Peleg 2016-04-20  1465  {
0824c5920b16fe1 drivers/iommu/intel-iommu.c Omer Peleg 2016-04-20  1466  	struct device_domain_info *info;
0824c5920b16fe1 drivers/iommu/intel-iommu.c Omer Peleg 2016-04-20  1467  	bool has_iotlb_device = false;
0824c5920b16fe1 drivers/iommu/intel-iommu.c Omer Peleg 2016-04-20  1468  
0824c5920b16fe1 drivers/iommu/intel-iommu.c Omer Peleg 2016-04-20  1469  	assert_spin_locked(&device_domain_lock);
0824c5920b16fe1 drivers/iommu/intel-iommu.c Omer Peleg 2016-04-20  1470  
1aaf68f8927fb5c drivers/iommu/intel/iommu.c Liu Yi L   2020-12-29 @1471  	list_for_each_entry(info, &domain->devices, link)
1aaf68f8927fb5c drivers/iommu/intel/iommu.c Liu Yi L   2020-12-29 @1472  		if (info && info->ats_enabled) {
                                                                                            ^^^^
"info" is the list iterator so it can't ever be NULL.  Just delete the
NULL check.

1aaf68f8927fb5c drivers/iommu/intel/iommu.c Liu Yi L   2020-12-29  1473  			has_iotlb_device = true;
1aaf68f8927fb5c drivers/iommu/intel/iommu.c Liu Yi L   2020-12-29  1474  			break;
1aaf68f8927fb5c drivers/iommu/intel/iommu.c Liu Yi L   2020-12-29  1475  		}
0824c5920b16fe1 drivers/iommu/intel-iommu.c Omer Peleg 2016-04-20  1476  
1aaf68f8927fb5c drivers/iommu/intel/iommu.c Liu Yi L   2020-12-29  1477  	if (!has_iotlb_device) {
1aaf68f8927fb5c drivers/iommu/intel/iommu.c Liu Yi L   2020-12-29  1478  		struct subdev_domain_info *sinfo;
0824c5920b16fe1 drivers/iommu/intel-iommu.c Omer Peleg 2016-04-20  1479  
1aaf68f8927fb5c drivers/iommu/intel/iommu.c Liu Yi L   2020-12-29  1480  		list_for_each_entry(sinfo, &domain->subdevices, link_domain) {
1aaf68f8927fb5c drivers/iommu/intel/iommu.c Liu Yi L   2020-12-29  1481  			info = get_domain_info(sinfo->pdev);
1aaf68f8927fb5c drivers/iommu/intel/iommu.c Liu Yi L   2020-12-29  1482  			if (info && info->ats_enabled) {
0824c5920b16fe1 drivers/iommu/intel-iommu.c Omer Peleg 2016-04-20  1483  				has_iotlb_device = true;
0824c5920b16fe1 drivers/iommu/intel-iommu.c Omer Peleg 2016-04-20  1484  				break;
0824c5920b16fe1 drivers/iommu/intel-iommu.c Omer Peleg 2016-04-20  1485  			}
0824c5920b16fe1 drivers/iommu/intel-iommu.c Omer Peleg 2016-04-20  1486  		}
1aaf68f8927fb5c drivers/iommu/intel/iommu.c Liu Yi L   2020-12-29  1487  	}
0824c5920b16fe1 drivers/iommu/intel-iommu.c Omer Peleg 2016-04-20  1488  
0824c5920b16fe1 drivers/iommu/intel-iommu.c Omer Peleg 2016-04-20  1489  	domain->has_iotlb_device = has_iotlb_device;
0824c5920b16fe1 drivers/iommu/intel-iommu.c Omer Peleg 2016-04-20  1490  }

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