linux-kernel - drivers/gpu/drm/nouveau/nvkm/subdev/mmu/vmmgm200.c:32:9: sparse: sparse: cast truncates bits from constant value (100000000 becomes 0)

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Message-ID: <202512140713.HUSp33rF-lkp@intel.com>
Date: Sun, 14 Dec 2025 07:34:54 +0800
From: kernel test robot <lkp@...el.com>
To: Arnd Bergmann <arnd@...db.de>
Cc: oe-kbuild-all@...ts.linux.dev, linux-kernel@...r.kernel.org,
	Johannes Berg <johannes.berg@...el.com>
Subject: drivers/gpu/drm/nouveau/nvkm/subdev/mmu/vmmgm200.c:32:9: sparse:
 sparse: cast truncates bits from constant value (100000000 becomes 0)

tree:   https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git master
head:   4a298a43f5e339f48d2dda0665c02b88ee9a4e03
commit: b8c9c3b822fe8e033b9802516f6466099d915488 um: stop using PCI port I/O
date:   7 months ago
config: um-randconfig-r121-20251213 (https://download.01.org/0day-ci/archive/20251214/202512140713.HUSp33rF-lkp@intel.com/config)
compiler: gcc-14 (Debian 14.2.0-19) 14.2.0
reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20251214/202512140713.HUSp33rF-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@...el.com>
| Closes: https://lore.kernel.org/oe-kbuild-all/202512140713.HUSp33rF-lkp@intel.com/

sparse warnings: (new ones prefixed by >>)
>> drivers/gpu/drm/nouveau/nvkm/subdev/mmu/vmmgm200.c:32:9: sparse: sparse: cast truncates bits from constant value (100000000 becomes 0)
   drivers/gpu/drm/nouveau/nvkm/subdev/mmu/vmmgm200.c:57:9: sparse: sparse: cast truncates bits from constant value (800000000 becomes 0)

vim +32 drivers/gpu/drm/nouveau/nvkm/subdev/mmu/vmmgm200.c

5f300fed645597 Ben Skeggs 2017-11-01  26  
e12cf6ad43888c Ben Skeggs 2017-11-01  27  static void
e12cf6ad43888c Ben Skeggs 2017-11-01  28  gm200_vmm_pgt_sparse(struct nvkm_vmm *vmm,
e12cf6ad43888c Ben Skeggs 2017-11-01  29  		     struct nvkm_mmu_pt *pt, u32 ptei, u32 ptes)
e12cf6ad43888c Ben Skeggs 2017-11-01  30  {
e12cf6ad43888c Ben Skeggs 2017-11-01  31  	/* VALID_FALSE + VOL tells the MMU to treat the PTE as sparse. */
e12cf6ad43888c Ben Skeggs 2017-11-01 @32  	VMM_FO064(pt, vmm, ptei * 8, BIT_ULL(32) /* VOL. */, ptes);
e12cf6ad43888c Ben Skeggs 2017-11-01  33  }
e12cf6ad43888c Ben Skeggs 2017-11-01  34  

:::::: The code at line 32 was first introduced by commit
:::::: e12cf6ad43888c152c3b2edb59525587cd98a227 drm/nouveau/mmu/gm200,gm20b: implement new vmm backend

:::::: TO: Ben Skeggs <bskeggs@...hat.com>
:::::: CC: Ben Skeggs <bskeggs@...hat.com>

-- 
0-DAY CI Kernel Test Service
https://github.com/intel/lkp-tests/wiki