Re: [PATCH v5 13/13] mm: Remove device private pages from the physical address space

[kernel test robot <lkp@intel.com>]

Hi Jordan,

kernel test robot noticed the following build warnings:

[auto build test WARNING on 344db0fba38920be64a429c64a8ca0531572896c]

url:    https://github.com/intel-lab-lkp/linux/commits/Jordan-Niethe/mm-migrate_device-Introduce-migrate_pfn_from_page-helper/20260130-191416
base:   344db0fba38920be64a429c64a8ca0531572896c
patch link:    https://lore.kernel.org/r/20260130111050.53670-14-jniethe%40nvidia.com
patch subject: [PATCH v5 13/13] mm: Remove device private pages from the physical address space
config: loongarch-allmodconfig (https://download.01.org/0day-ci/archive/20260201/202602012037.jpAjBFBa-lkp@intel.com/config)
compiler: clang version 19.1.7 (https://github.com/llvm/llvm-project cd708029e0b2869e80abe31ddb175f7c35361f90)
reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20260201/202602012037.jpAjBFBa-lkp@intel.com/reproduce)

If you fix the issue in a separate patch/commit (i.e. not just a new version of
the same patch/commit), kindly add following tags
| Reported-by: kernel test robot <lkp@intel.com>
| Closes: https://lore.kernel.org/oe-kbuild-all/202602012037.jpAjBFBa-lkp@intel.com/

All warnings (new ones prefixed by >>):

>> drivers/gpu/drm/amd/amdgpu/../amdkfd/kfd_migrate.c:1071:7: warning: variable 'ret' is used uninitialized whenever 'if' condition is false [-Wsometimes-uninitialized]
    1071 |                 if (IS_ERR(r))
         |                     ^~~~~~~~~
   drivers/gpu/drm/amd/amdgpu/../amdkfd/kfd_migrate.c:1075:6: note: uninitialized use occurs here
    1075 |         if (ret) {
         |             ^~~
   drivers/gpu/drm/amd/amdgpu/../amdkfd/kfd_migrate.c:1071:3: note: remove the 'if' if its condition is always true
    1071 |                 if (IS_ERR(r))
         |                 ^~~~~~~~~~~~~~
    1072 |                         ret = PTR_ERR(r);
   drivers/gpu/drm/amd/amdgpu/../amdkfd/kfd_migrate.c:1035:9: note: initialize the variable 'ret' to silence this warning
    1035 |         int ret;
         |                ^
         |                 = 0
   1 warning generated.


vim +1071 drivers/gpu/drm/amd/amdgpu/../amdkfd/kfd_migrate.c

  1028	
  1029	int kgd2kfd_init_zone_device(struct amdgpu_device *adev)
  1030	{
  1031		struct amdgpu_kfd_dev *kfddev = &adev->kfd;
  1032		struct dev_pagemap *pgmap;
  1033		unsigned long size;
  1034		void *r;
  1035		int ret;
  1036	
  1037		/* Page migration works on gfx9 or newer */
  1038		if (amdgpu_ip_version(adev, GC_HWIP, 0) < IP_VERSION(9, 0, 1))
  1039			return -EINVAL;
  1040	
  1041		if (adev->apu_prefer_gtt)
  1042			return 0;
  1043	
  1044		pgmap = &kfddev->pgmap;
  1045		memset(pgmap, 0, sizeof(*pgmap));
  1046	
  1047		/* TODO: register all vram to HMM for now.
  1048		 * should remove reserved size
  1049		 */
  1050		size = ALIGN(adev->gmc.real_vram_size, 2ULL << 20);
  1051		if (adev->gmc.xgmi.connected_to_cpu) {
  1052			pgmap->range.start = adev->gmc.aper_base;
  1053			pgmap->range.end = adev->gmc.aper_base + adev->gmc.aper_size - 1;
  1054			pgmap->type = MEMORY_DEVICE_COHERENT;
  1055		} else {
  1056			pgmap->nr_pages = size / PAGE_SIZE;
  1057			pgmap->type = MEMORY_DEVICE_PRIVATE;
  1058		}
  1059	
  1060		pgmap->nr_range = 1;
  1061		pgmap->ops = &svm_migrate_pgmap_ops;
  1062		pgmap->owner = SVM_ADEV_PGMAP_OWNER(adev);
  1063		pgmap->flags = 0;
  1064		/* Device manager releases device-specific resources, memory region and
  1065		 * pgmap when driver disconnects from device.
  1066		 */
  1067		if (pgmap->type == MEMORY_DEVICE_PRIVATE) {
  1068			ret = devm_memremap_device_private_pagemap(adev->dev, pgmap);
  1069		} else {
  1070			r = devm_memremap_pages(adev->dev, pgmap);
> 1071			if (IS_ERR(r))

-- 
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https://github.com/intel/lkp-tests/wiki